pwntools

pwntools is a CTF framework and exploit development library. Written in Python, it is designed for rapid prototyping and development, and intended to make exploit writing as simple as possible.

The primary location for this documentation is at docs.pwntools.com, which uses readthedocs. It comes in three primary flavors:

• Stable
• Beta
• Dev

Getting Started

关于 pwntools

无论你是用pwntools编写exp，还是将它作为一个其它软件工程的一部分，你都可以决定如何使用它。

历史上, pwntools是被用来编写一系列exp的领域特定语言（DSL）。在当前的pwntools版本中，我们只需要简单地用 from pwn import * 短短一行代码就可以使用各种漂亮的作用。

当我们重构pwntools的2.0版本时，我们注意到了两个相反的目标：

• 我们更愿意构造一个“寻常的”python模块结构，来使得使用者更快速地了解和使用pwntools。
• 我们想拥有更多的炫酷效果，尤其是将终端设为raw模式。

为了实现上面两个目标，我们决定开发两个不同的python模块： pwnlib 是一个整洁的python模块，而 pwn 则是我们在CTF中使用和编写exp的模块。

pwn — 为CTF优化的工具箱

就像之前所说的那样，我们希望可以得到各种各样炫酷的结果，这也是这个模块的目的。它可以完成以下事情：

• 可以在子模块中引用所有 pwnlib 顶级模块中的函数。这意味着，如果你使用了 import pwn 或者 from pwn import * ，你就可以使用你所需要的函数去编写exp。
• 调用 pwnlib.term.init() 函数将会使当前终端处于raw模式，同时可以引入一些让其变得与众不同的功能。
• 设置 pwnlib.context.log_level 为info记录状态。
• 试图解析 sys.argv 中的一些值，并且每成功分析一个，就会删除掉一个。

pwnlib — 标准的python模块

这个模块是我们使用“纯净”的python开发的。一般地，我们不想在引用 pwnlib 或是在使用其子模块时出现这样那样的副作用。

大多数情况下，你只会得到你想使用的功能。例如，如果你不使用 import pwnlib.util ，你将没有权使用 pwnlib.util.packing 这个子模块。

尽管pwnlib中有一些特例，例如 pwnlib.shellcraft , 影响这整个模块的简洁，但它们仍可在没有隐性副作用的情况下被使用。

安装

pwntools对ubuntu 12.04和 14.04系统支持地最好，但大多数功能在符合Posix标准的系统上（Debian, Arch, FreeBSD, OSX等等）应该也可以正常使用。

准备

为了能够充分利用 pwntools 的功能，你应该安装下列的系统库。

二进制工具

对国外的系统架构的汇编（比如在Mac OS X上汇编Sparc shellcode），我们需要安装交叉编译版本的binutils，我们尽可能使得这个安装过程流畅一点。

在下列的例子中，使用你的系统架构代替$ARCH(例如arm, mips64, vax等等)。

在一个现代化的8核计算机上编译binutils大约花费60秒。

Ubuntu

对于Ubuntu 12.04到15.10的发行版，你需要添加pwntools的 个人包存档库。

Ubuntu Xenial (16.04) 已经拥有官方的包，不需要做下面的步骤。

$ apt-get install software-properties-common
$ apt-add-repository ppa:pwntools/binutils
$ apt-get update

接着，针对于你的系统架构安装binutils。

$ apt-get install binutils-$ARCH-linux-gnu

Mac OS X

在Mac OS X上安装binutils非常简单，但是需要源码编译安装。然而，既然我们已经有了homebrew，我们就可以使用一条命令来解决。安装 brew 之后, 我们只需要从binutils中获取我们的二进制工具： binutils repo.

$ brew install https://raw.githubusercontent.com/Gallopsled/pwntools-binutils/master/osx/binutils-$ARCH.rb

其他系统

如果你想通过自己的手动编译安装，并且不是上面两个系统之一，编译binutils也非常简单，运行下面的脚本即可。

#!/usr/bin/env bash

V=2.25   # Binutils Version
ARCH=arm # Target architecture

cd /tmp
wget -nc https://ftp.gnu.org/gnu/binutils/binutils-$V.tar.gz
wget -nc https://ftp.gnu.org/gnu/binutils/binutils-$V.tar.gz.sig

gpg --keyserver keys.gnupg.net --recv-keys 4AE55E93
gpg --verify binutils-$V.tar.gz.sig

tar xf binutils-$V.tar.gz

mkdir binutils-build
cd binutils-build

export AR=ar
export AS=as

../binutils-$V/configure \
    --prefix=/usr/local \
    --target=$ARCH-unknown-linux-gnu \
    --disable-static \
    --disable-multilib \
    --disable-werror \
    --disable-nls

MAKE=gmake
hash gmake || MAKE=make

$MAKE -j clean all
sudo $MAKE install

Python 开发环境

一些 pwntools’ 的Python 依赖于本地扩展 (例如, Paramiko 依赖 PyCrypto).

为了编译这些本地扩展, 你必须首先安装Python-dev。

Ubuntu

$ apt-get install python-dev

Mac OS X

无需进行此项操作。

最新发行版

你可以利用 pip 安装pwntools。

$ apt-get update
$ apt-get install python2.7 python-pip python-dev git libssl-dev libffi-dev
$ pip install --upgrade pwntools

开发版

如果你要在本地定制自己的pwntools，你应该这样做：

$ git clone https://github.com/Gallopsled/pwntools
$ pip install --upgrade --editable ./pwntools

开始使用

为了能够让你亲身实践一下pwntools，首先，我们来看几个简单的例子。

当在编写自己的exp时，我们一般会采用下面的方法，这样的话，pwntools就会将会它的所有功能都导入进来。

>>> from pwn import *

显然，这样的话，你将在全局空间里引用pwntools的所有函数。你现在可以用一些简单函数进行汇编，反汇编，pack，unpack等等其他操作。

整个pwntools的使用文档在这里查看： from pwn import *.

连接

如果你想要pwn一个程序的话，你肯定需要和它进行交互，对吧？pwntools使用它的模块 pwnlib.tubes 使这个变得相当简单。

这个模块会建立一个与进程、socket、端口和其他相关的连接。例如，远程操作连接可以通过 pwnlib.tubes.remote 来实现。

>>> conn = remote('ftp.debian.org',21)
>>> conn.recvline() 
'220 ...'
>>> conn.send('USER anonymous\r\n')
>>> conn.recvuntil(' ', drop=True)
'331'
>>> conn.recvline()
'Please specify the password.\r\n'
>>> conn.close()

它也可以很容易地使得一个监听者处于等待状态：

>>> l = listen()
>>> r = remote('localhost', l.lport)
>>> c = l.wait_for_connection()
>>> r.send('hello')
>>> c.recv()
'hello'

此外，我们也可以利用 pwnlib.tubes.process 来简单地和进程进程交互。

>>> sh = process('/bin/sh')
>>> sh.sendline('sleep 3; echo hello world;')
>>> sh.recvline(timeout=1)
''
>>> sh.recvline(timeout=5)
'hello world\n'
>>> sh.close()

当然，你不仅可以利用程序来和进程进行通信，也可以直接与之 交互 ：

>>> sh.interactive() 
$ whoami
user

当你通过ssh方式进行漏洞利用的时候，可以使用 pwnlib.tubes.ssh.

>>> shell = ssh('bandit0', 'bandit.labs.overthewire.org', password='bandit0')
>>> shell['whoami']
'bandit0'
>>> shell.download_file('/etc/motd')
>>> sh = shell.run('sh')
>>> sh.sendline('sleep 3; echo hello world;') 
>>> sh.recvline(timeout=1)
''
>>> sh.recvline(timeout=5)
'hello world\n'
>>> shell.close()

包装整数

在编写exp时，最常见的工作就是在整数之间转换，而且转换后，它们的表现形式就是一个字节序列。通常情况下，我们使用 struct 这个模块。

pwntools通过 pwnlib.util.packing 使之十分简单。这样我们就不需要再记住解包装的代码, 只需要看着说明文档编写代码就行.

>>> import struct
>>> p32(0xdeadbeef) == struct.pack('I', 0xdeadbeef)
True
>>> leet = '37130000'.decode('hex')
>>> u32('abcd') == struct.unpack('I', 'abcd')[0]
True

此外，pack和unpack的操作也支持其它字长，比如8位字长：

>>> u8('A') == 0x41
True

设置目标系统架构及操作系统

我们在操作中特别指定目标机器的系统架构：

>>> asm('nop')
'\x90'
>>> asm('nop', arch='arm')
'\x00\xf0 \xe3'

此外，我们也可以通过一次性地在全局的参数 ``context``中设置，操作系统，字节序，大小端，位宽都可以在那里设定。

>>> context.arch      = 'i386'
>>> context.os        = 'linux'
>>> context.endian    = 'little'
>>> context.word_size = 32

当然，你也可以一次性设置好这些变量：

>>> asm('nop')
'\x90'
>>> context(arch='arm', os='linux', endian='big', word_size=32)
>>> asm('nop')
'\xe3 \xf0\x00'

设置日志记录级别

你可以通过context来控制日志记录的级别：

例如，这样设置：

>>> context.log_level = 'debug'

这样，通过管道发送和接收的数据都会被打印在屏幕上。

汇编和反汇编

有时候，你可能需要从互联网上下载一些shellcode，这时你可以使用 pwnlib.asm 模块。

>>> asm('mov eax, 0').encode('hex')
'b800000000'

如果你按照下面的方式来做，会更加容易：

>>> print disasm('6a0258cd80ebf9'.decode('hex'))
   0:   6a 02                   push   0x2
   2:   58                      pop    eax
   3:   cd 80                   int    0x80
   5:   eb f9                   jmp    0x0

而且，你甚至不需要大部分时间去写shellcode。pwntools提供了 pwnlib.shellcraft ，可以在你编写shellcode的时候提供帮助。

如果说我们想执行 setreuid(getuid(), getuid())，之后复制文件描述符4到 stdin, stdout 以及 stderr, 然后弹出一个shell!，那我们就可以这么做

>>> asm(shellcraft.setreuid() + shellcraft.dupsh(4)).encode('hex') 
'6a3158cd80...'

杂项工具

多亏有了 pwnlib.util.fiddling 这个模块，我们不需要写另外的hexdump。

我们可以通过使用模块 pwnlib.cyclic 在触发的崩溃中寻找偏移量或缓冲区大小。

>>> print cyclic(20)
aaaabaaacaaadaaaeaaa
>>> # Assume EIP = 0x62616166 ('faab' which is pack(0x62616166))  at crash time
>>> print cyclic_find('faab')
120

操纵ELF文件

我们也不需要进行硬编码了，因为我们可以使用 pwnlib.elf 来在运行时查看对应的参数。

>>> e = ELF('/bin/cat')
>>> print hex(e.address) 
0x400000
>>> print hex(e.symbols['write']) 
0x401680
>>> print hex(e.got['write']) 
0x60b070
>>> print hex(e.plt['write']) 
0x401680

你也可以给ELF文件打补丁或是保存。

>>> e = ELF('/bin/cat')
>>> e.read(e.address+1, 3)
'ELF'
>>> e.asm(e.address, 'ret')
>>> e.save('/tmp/quiet-cat')
>>> disasm(file('/tmp/quiet-cat','rb').read(1))
'   0:   c3                      ret'

from pwn import *

The most common way that you’ll see pwntools used is

>>> from pwn import *

Which imports a bazillion things into the global namespace to make your life easier.

This is a quick list of most of the objects and routines imported, in rough order of importance and frequency of use.

• context

  • pwnlib.context.context
  • Responsible for most of the pwntools convenience settings
  • Set context.log_level = ‘debug’ when troubleshooting your exploit
  • Scope-aware, so you can disable logging for a subsection of code via pwnlib.context.ContextType.local

• remote, listen, ssh, process

  • pwnlib.tubes
  • Super convenient wrappers around all of the common functionality for CTF challenges
  • Connect to anything, anywhere, and it works the way you want it to
  • Helpers for common tasks like recvline, recvuntil, clean, etc.
  • Interact directly with the application via .interactive()

• p32 and u32

  • pwnlib.util.packing
  • Useful functions to make sure you never have to remember if '>' means signed or unsigned for struct.pack, and no more ugly [0] index at the end.
  • Set signed and endian in sane manners (also these can be set once on context and not bothered with again)
  • Most common sizes are pre-defined (u8, u64, etc), and pwnlib.util.packing.pack() lets you define your own.

• log

  • pwnlib.log
  • Make your output pretty!

• cyclic and cyclic_func

  • pwnlib.util.cyclic
  • Utilities for generating strings such that you can find the offset of any given substring given only N (usually 4) bytes. This is super useful for straight buffer overflows. Instead of looking at 0x41414141, you could know that 0x61616171 means you control EIP at offset 64 in your buffer.

• asm and disasm

  • pwnlib.asm
  • Quickly turn assembly into some bytes, or vice-versa, without mucking about
  • Supports any architecture for which you have a binutils installed
  • Over 20 different architectures have pre-built binaries at ppa:pwntools/binutils.

• shellcraft

  • pwnlib.shellcraft
  • Library of shellcode ready to go
  • asm(shellcraft.sh()) gives you a shell
  • Templating library for reusability of shellcode fragments

• ELF

  • pwnlib.elf
  • ELF binary manipulation tools, including symbol lookup, virtual memory to file offset helpers, and the ability to modify and save binaries back to disk

• DynELF

  • pwnlib.dynelf
  • Dynamically resolve functions given only a pointer to any loaded module, and a function which can leak data at any address

• ROP

  • pwnlib.rop
  • Automatically generate ROP chains using a DSL to describe what you want to do, rather than raw addresses

• gdb.debug and gdb.attach

  • pwnlib.gdb
  • Launch a binary under GDB and pop up a new terminal to interact with it. Automates setting breakpoints and makes iteration on exploits MUCH faster.
  • Alternately, attach to a running process given a PID, pwnlib.tubes object, or even just a socket that’s connected to it

• args

  • Dictionary contining all-caps command-line arguments for quick access
  • Run via python foo.py REMOTE=1 and args['REMOTE'] == '1'.

  • Can also control logging verbosity and terminal fancyness

    • NOTERM
    • SILENT
    • DEBUG

• randoms, rol, ror, xor, bits

  • pwnlib.util.fiddling
  • Useful utilities for generating random data from a given alphabet, or simplifying math operations that usually require masking off with 0xffffffff or calling ord and chr an ugly number of times

• net

  • pwnlib.util.net
  • Routines for querying about network interfaces

• proc

  • pwnlib.util.proc
  • Routines for querying about processes

• pause

  • It’s the new getch

• safeeval

  • pwnlib.util.safeeval
  • Functions for safely evalutaing python code without nasty side-effects.

These are all pretty self explanatory, but are useful to have in the global namespace.

• hexdump
• read and write
• enhex and unhex
• more
• group
• align and align_down
• urlencode and urldecode
• which
• wget

Additionally, all of the following modules are auto-imported for you. You were going to do it anyway.

• os
• sys
• time
• requests
• re
• random

命令行工具

pwntools附带一些有用的命令行工具，作为内部功能的封装器。

pwn

Pwntools Command-line Interface

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

-h, --help

show this help message and exit

pwn asm

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

line

Lines to assemble. If none are supplied, use stdin

-h, --help

show this help message and exit

-f {raw,hex,string,elf}, --format {raw,hex,string,elf}

Output format (defaults to hex for ttys, otherwise raw)

-o <file>, --output <file>

Output file (defaults to stdout)

-c {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}, --context {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}

The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: [‘16’, ‘32’, ‘64’, ‘android’, ‘cgc’, ‘freebsd’, ‘linux’, ‘windows’, ‘powerpc64’, ‘aarch64’, ‘sparc64’, ‘powerpc’, ‘mips64’, ‘msp430’, ‘thumb’, ‘amd64’, ‘sparc’, ‘alpha’, ‘s390’, ‘i386’, ‘m68k’, ‘mips’, ‘ia64’, ‘cris’, ‘vax’, ‘avr’, ‘arm’, ‘little’, ‘big’, ‘el’, ‘le’, ‘be’, ‘eb’]

-v <avoid>, --avoid <avoid>

Encode the shellcode to avoid the listed bytes (provided as hex; default: 000a)

-n, --newline

Encode the shellcode to avoid newlines

-z, --zero

Encode the shellcode to avoid NULL bytes

-d, --debug

Debug the shellcode with GDB

-e <encoder>, --encoder <encoder>

Specific encoder to use

-i <infile>, --infile <infile>

Specify input file

-r, --run

Run output

pwn checksec

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

elf

Files to check

-h, --help

show this help message and exit

--file <elf>

File to check (for compatibility with checksec.sh)

pwn constgrep

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

regex

The regex matching constant you want to find

constant

The constant to find

-h, --help

show this help message and exit

-e <constant>, --exact <constant>

Do an exact match for a constant instead of searching for a regex

-i, --case-insensitive

Search case insensitive

-m, --mask-mode

Instead of searching for a specific constant value, search for values not containing strictly less bits that the given value.

-c {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}, --context {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}

The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: [‘16’, ‘32’, ‘64’, ‘android’, ‘cgc’, ‘freebsd’, ‘linux’, ‘windows’, ‘powerpc64’, ‘aarch64’, ‘sparc64’, ‘powerpc’, ‘mips64’, ‘msp430’, ‘thumb’, ‘amd64’, ‘sparc’, ‘alpha’, ‘s390’, ‘i386’, ‘m68k’, ‘mips’, ‘ia64’, ‘cris’, ‘vax’, ‘avr’, ‘arm’, ‘little’, ‘big’, ‘el’, ‘le’, ‘be’, ‘eb’]

pwn cyclic

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

count

Number of characters to print

-h, --help

show this help message and exit

-a <alphabet>, --alphabet <alphabet>

The alphabet to use in the cyclic pattern (defaults to all lower case letters)

-n <length>, --length <length>

Size of the unique subsequences (defaults to 4).

-c {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}, --context {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}

The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: [‘16’, ‘32’, ‘64’, ‘android’, ‘cgc’, ‘freebsd’, ‘linux’, ‘windows’, ‘powerpc64’, ‘aarch64’, ‘sparc64’, ‘powerpc’, ‘mips64’, ‘msp430’, ‘thumb’, ‘amd64’, ‘sparc’, ‘alpha’, ‘s390’, ‘i386’, ‘m68k’, ‘mips’, ‘ia64’, ‘cris’, ‘vax’, ‘avr’, ‘arm’, ‘little’, ‘big’, ‘el’, ‘le’, ‘be’, ‘eb’]

-l <lookup_value>, -o <lookup_value>, --offset <lookup_value>, --lookup <lookup_value>

Do a lookup instead printing the alphabet

pwn disasm

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

hex

Hex-string to disasemble. If none are supplied, then it uses stdin in non-hex mode.

-h, --help

show this help message and exit

-c {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}, --context {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}

The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: [‘16’, ‘32’, ‘64’, ‘android’, ‘cgc’, ‘freebsd’, ‘linux’, ‘windows’, ‘powerpc64’, ‘aarch64’, ‘sparc64’, ‘powerpc’, ‘mips64’, ‘msp430’, ‘thumb’, ‘amd64’, ‘sparc’, ‘alpha’, ‘s390’, ‘i386’, ‘m68k’, ‘mips’, ‘ia64’, ‘cris’, ‘vax’, ‘avr’, ‘arm’, ‘little’, ‘big’, ‘el’, ‘le’, ‘be’, ‘eb’]

-a <address>, --address <address>

Base address

--color

Color output

--no-color

Disable color output

pwn elfdiff

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

a

b

-h, --help

show this help message and exit

pwn elfpatch

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

-h, --help

show this help message and exit

pwn errno

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

error

Error message or value

-h, --help

show this help message and exit

pwn hex

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

data

Data to convert into hex

-h, --help

show this help message and exit

pwn phd

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

file

File to hexdump. Reads from stdin if missing.

-h, --help

show this help message and exit

-w <width>, --width <width>

Number of bytes per line.

-l <highlight>, --highlight <highlight>

Byte to highlight.

-s <skip>, --skip <skip>

Skip this many initial bytes.

-c <count>, --count <count>

Only show this many bytes.

-o <offset>, --offset <offset>

Addresses in left hand column starts at this address.

--color {always,never,auto}

Colorize the output. When ‘auto’ output is colorized exactly when stdout is a TTY. Default is ‘auto’.

pwn pwnstrip

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

file

-h, --help

show this help message and exit

-b, --build-id

Strip build ID

-p <function>, --patch <function>

Patch function

-o <output>, --output <output>

pwn scramble

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

-h, --help

show this help message and exit

-f {raw,hex,string,elf}, --format {raw,hex,string,elf}

Output format (defaults to hex for ttys, otherwise raw)

-o <file>, --output <file>

Output file (defaults to stdout)

-c {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}, --context {16,32,64,android,cgc,freebsd,linux,windows,powerpc64,aarch64,sparc64,powerpc,mips64,msp430,thumb,amd64,sparc,alpha,s390,i386,m68k,mips,ia64,cris,vax,avr,arm,little,big,el,le,be,eb}

The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: [‘16’, ‘32’, ‘64’, ‘android’, ‘cgc’, ‘freebsd’, ‘linux’, ‘windows’, ‘powerpc64’, ‘aarch64’, ‘sparc64’, ‘powerpc’, ‘mips64’, ‘msp430’, ‘thumb’, ‘amd64’, ‘sparc’, ‘alpha’, ‘s390’, ‘i386’, ‘m68k’, ‘mips’, ‘ia64’, ‘cris’, ‘vax’, ‘avr’, ‘arm’, ‘little’, ‘big’, ‘el’, ‘le’, ‘be’, ‘eb’]

-p, --alphanumeric

Encode the shellcode with an alphanumeric encoder

-v <avoid>, --avoid <avoid>

Encode the shellcode to avoid the listed bytes

-n, --newline

Encode the shellcode to avoid newlines

-z, --zero

Encode the shellcode to avoid NULL bytes

-d, --debug

Debug the shellcode with GDB

pwn shellcraft

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

shellcode

The shellcode you want

arg

Argument to the chosen shellcode

-h, --help

show this help message and exit

-?, --show

Show shellcode documentation

-o <file>, --out <file>

Output file (default: stdout)

-f {r,raw,s,str,string,c,h,hex,a,asm,assembly,p,i,hexii,e,elf,d,escaped,default}, --format {r,raw,s,str,string,c,h,hex,a,asm,assembly,p,i,hexii,e,elf,d,escaped,default}

Output format (default: hex), choose from {e}lf, {r}aw, {s}tring, {c}-style array, {h}ex string, hex{i}i, {a}ssembly code, {p}reprocssed code, escape{d} hex string

-d, --debug

Debug the shellcode with GDB

-b, --before

Insert a debug trap before the code

-a, --after

Insert a debug trap after the code

-v <avoid>, --avoid <avoid>

Encode the shellcode to avoid the listed bytes

-n, --newline

Encode the shellcode to avoid newlines

-z, --zero

Encode the shellcode to avoid NULL bytes

-r, --run

Run output

--color

Color output

--no-color

Disable color output

--syscalls

List syscalls

--address <address>

Load address

-l, --list

List available shellcodes, optionally provide a filter

pwn unhex

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

hex

Hex bytes to decode

-h, --help

show this help message and exit

pwn update

usage: pwn [-h] {asm,checksec,constgrep,cyclic,disasm,elfdiff,elfpatch,errno,hex,phd,pwnstrip,scramble,shellcraft,unhex,update} ...

-h, --help

show this help message and exit

--install

Install the update automatically.

--pre

Check for pre-releases.

Module Index

Each of the pwntools modules is documented here.

pwnlib.adb — Android Debug Bridge

Provides utilities for interacting with Android devices via the Android Debug Bridge.

Using Android Devices with Pwntools

Pwntools tries to be as easy as possible to use with Android devices.

If you have only one device attached, everything “just works”.

If you have multiple devices, you have a handful of options to select one, or iterate over the devices.

First and most important is the context.device property, which declares the “currently” selected device in any scope. It can be set manually to a serial number, or to a Device instance.

# Take the first available device
context.device = adb.wait_for_device()

# Set a device by serial number
context.device = 'ZX1G22LH8S'

# Set a device by its product name
for device in adb.devices():
    if device.product == 'shamu':
        break
else:
    error("Could not find any shamus!")

Once a device is selected, you can operate on it with any of the functions in the pwnlib.adb module.

# Get a process listing
print adb.process(['ps']).recvall()

# Fetch properties
print adb.properties.ro.build.fingerprint

# Read and write files
print adb.read('/proc/version')
adb.write('/data/local/tmp/foo', 'my data')

class pwnlib.adb.adb.AdbDevice(serial, type, port=None, product='unknown', model='unknown', device='unknown', features=None, **kw)

Encapsulates information about a connected device.

Example

>>> device = adb.wait_for_device()
>>> device.arch
'arm'
>>> device.bits
32
>>> device.os
'android'
>>> device.product
'sdk_phone_armv7'
>>> device.serial
'emulator-5554'

pwnlib.adb.adb.adb(argv, *a, **kw)

Returns the output of an ADB subcommand.

>>> adb.adb(['get-serialno'])
'emulator-5554\n'

pwnlib.adb.adb.boot_time() → int

Returns:Boot time of the device, in Unix time, rounded to the nearest second.

pwnlib.adb.adb.build(*a, **kw)

Returns the Build ID of the device.

pwnlib.adb.adb.compile(source)

Compile a source file or project with the Android NDK.

pwnlib.adb.adb.current_device(any=False)

Returns an AdbDevice instance for the currently-selected device (via context.device).

Example

>>> device = adb.current_device(any=True)
>>> device
AdbDevice(serial='emulator-5554', type='device', port='emulator', product='sdk_phone_armv7', model='sdk phone armv7', device='generic')
>>> device.port
'emulator'

pwnlib.adb.adb.devices(*a, **kw)

Returns a list of Device objects corresponding to the connected devices.

pwnlib.adb.adb.disable_verity(*a, **kw)

Disables dm-verity on the device.

pwnlib.adb.adb.exists(*a, **kw)

Return True if path exists on the target device.

Examples

>>> adb.exists('/')
True
>>> adb.exists('/init')
True
>>> adb.exists('/does/not/exist')
False

pwnlib.adb.adb.fastboot(*a, **kw)

Executes a fastboot command.

Returns:The command output.

pwnlib.adb.adb.find_ndk_project_root(source)

Given a directory path, find the topmost project root.

tl;dr “foo/bar/jni/baz.cpp” ==> “foo/bar”

pwnlib.adb.adb.fingerprint(*a, **kw)

Returns the device build fingerprint.

pwnlib.adb.adb.forward(*a, **kw)

Sets up a port to forward to the device.

pwnlib.adb.adb.getprop(*a, **kw)

Reads a properties from the system property store.

Parameters:name (str) – Optional, read a single property. Returns:If name is not specified, a dict of all properties is returned. Otherwise, a string is returned with the contents of the named property.

pwnlib.adb.adb.install(apk, *arguments)

Install an APK onto the device.

This is a wrapper around ‘pm install’, which backs ‘adb install’.

Parameters:

• apk (str) – Path to the APK to intall (e.g. 'foo.apk')
• arguments – Supplementary arguments to ‘pm install’, e.g. '-l', '-g'.

pwnlib.adb.adb.interactive(*a, **kw)

Spawns an interactive shell.

pwnlib.adb.adb.isdir(*a, **kw)

Return True if path is a on the target device.

Examples

>>> adb.isdir('/')
True
>>> adb.isdir('/init')
False
>>> adb.isdir('/does/not/exist')
False

pwnlib.adb.adb.listdir(*a, **kw)

Returns a list containing the entries in the provided directory.

Note

This uses the SYNC LIST functionality, which runs in the adbd SELinux context. If adbd is running in the su domain (‘adb root’), this behaves as expected.

Otherwise, less files may be returned due to restrictive SELinux policies on adbd.

pwnlib.adb.adb.logcat(*a, **kw)

Reads the system log file.

By default, causes logcat to exit after reading the file.

Parameters:stream (bool) – If True, the contents are streamed rather than read in a one-shot manner. Default is False. Returns:If stream is False, returns a string containing the log data. Otherwise, it returns a pwnlib.tubes.tube.tube connected to the log output.

pwnlib.adb.adb.makedirs(*a, **kw)

Create a directory and all parent directories on the target device.

Note

Silently succeeds if the directory already exists.

Examples

>>> adb.makedirs('/data/local/tmp/this/is/a/directory/heirarchy')
>>> adb.listdir('/data/local/tmp/this/is/a/directory')
['heirarchy']

pwnlib.adb.adb.mkdir(*a, **kw)

Create a directory on the target device.

Note

Silently succeeds if the directory already exists.

Parameters:path (str) – Directory to create.

Examples

>>> adb.mkdir('/')

>>> path = '/data/local/tmp/mkdir_test'
>>> adb.exists(path)
False
>>> adb.mkdir(path)
>>> adb.exists(path)
True

>>> adb.mkdir('/init')
Traceback (most recent call last):
...
PwnlibException: mkdir failed for /init, File exists

pwnlib.adb.adb.packages(*a, **kw)

Returns a list of packages installed on the system

pwnlib.adb.adb.pidof(*a, **kw)

Returns a list of PIDs for the named process.

pwnlib.adb.adb.proc_exe(*a, **kw)

Returns the full path of the executable for the provided PID.

pwnlib.adb.adb.process(*a, **kw)

Execute a process on the device.

See pwnlib.tubes.process.process documentation for more info.

Returns:A pwnlib.tubes.process.process tube.

Examples

>>> adb.root()
>>> print adb.process(['cat','/proc/version']).recvall() 
Linux version ...

pwnlib.adb.adb.product(*a, **kw)

Returns the device product identifier.

pwnlib.adb.adb.pull(*a, **kw)

Download a file from the device.

Parameters:

• remote_path (str) – Path or directory of the file on the device.
• local_path (str) – Path to save the file to. Uses the file’s name by default.

Returns:

The contents of the file.

Example

>>> _=adb.pull('/proc/version', './proc-version')
>>> print read('./proc-version') 
Linux version ...

pwnlib.adb.adb.push(*a, **kw)

Upload a file to the device.

Parameters:

• local_path (str) – Path to the local file to push.
• remote_path (str) – Path or directory to store the file on the device.

Returns:

Remote path of the file.

Example

>>> write('./filename', 'contents')
>>> adb.push('./filename', '/data/local/tmp')
'/data/local/tmp/filename'
>>> adb.read('/data/local/tmp/filename')
'contents'
>>> adb.push('./filename', '/does/not/exist')
Traceback (most recent call last):
...
PwnlibException: Could not stat '/does/not/exist'

pwnlib.adb.adb.read(*a, **kw)

Download a file from the device, and extract its contents.

Parameters:

• path (str) – Path to the file on the device.
• target (str) – Optional, location to store the file. Uses a temporary file by default.
• callback (callable) – See the documentation for adb.protocol.AdbClient.read.

Examples

>>> print adb.read('/proc/version') 
Linux version ...
>>> adb.read('/does/not/exist')
Traceback (most recent call last):
...
PwnlibException: Could not stat '/does/not/exist'

pwnlib.adb.adb.reboot(*a, **kw)

Reboots the device.

pwnlib.adb.adb.reboot_bootloader(*a, **kw)

Reboots the device to the bootloader.

pwnlib.adb.adb.remount(*a, **kw)

Remounts the filesystem as writable.

pwnlib.adb.adb.root(*a, **kw)

Restarts adbd as root.

>>> adb.root()

pwnlib.adb.adb.setprop(*a, **kw)

Writes a property to the system property store.

pwnlib.adb.adb.shell(*a, **kw)

Returns an interactive shell.

pwnlib.adb.adb.uninstall(package, *arguments)

Uninstall an APK from the device.

This is a wrapper around ‘pm uninstall’, which backs ‘adb uninstall’.

Parameters:

• package (str) – Name of the package to uninstall (e.g. 'com.foo.MyPackage')
• arguments – Supplementary arguments to 'pm install', e.g. '-k'.

pwnlib.adb.adb.unlink(*a, **kw)

Unlinks a file or directory on the target device.

Examples

>>> adb.unlink("/does/not/exist")
Traceback (most recent call last):
...
PwnlibException: Could not unlink '/does/not/exist': Does not exist

>>> filename = '/data/local/tmp/unlink-test'
>>> adb.write(filename, 'hello')
>>> adb.exists(filename)
True
>>> adb.unlink(filename)
>>> adb.exists(filename)
False

>>> adb.mkdir(filename)
>>> adb.write(filename + '/contents', 'hello')
>>> adb.unlink(filename)
Traceback (most recent call last):
...
PwnlibException: Cannot delete non-empty directory '/data/local/tmp/unlink-test' without recursive=True

>>> adb.unlink(filename, recursive=True)
>>> adb.exists(filename)
False

pwnlib.adb.adb.unlock_bootloader(*a, **kw)

Unlocks the bootloader of the device.

Note

This requires physical interaction with the device.

pwnlib.adb.adb.unroot(*a, **kw)

Restarts adbd as AID_SHELL.

pwnlib.adb.adb.uptime() → float

Returns:Uptime of the device, in seconds

pwnlib.adb.adb.wait_for_device(*a, **kw)

Waits for a device to be connected.

By default, waits for the currently-selected device (via context.device). To wait for a specific device, set context.device. To wait for any device, clear context.device.

Returns:An AdbDevice instance for the device.

Examples

>>> device = adb.wait_for_device()

pwnlib.adb.adb.which(*a, **kw)

Retrieves the full path to a binary in $PATH on the device

Parameters:

• name (str) – Binary name
• all (bool) – Whether to return all paths, or just the first
• *a – Additional arguments for adb.process()
• **kw – Additional arguments for adb.process()

Returns:

Either a path, or list of paths

Example

>>> adb.which('sh')
'/system/bin/sh'
>>> adb.which('sh', all=True)
['/system/bin/sh']

>>> adb.which('foobar') is None
True
>>> adb.which('foobar', all=True)
[]

pwnlib.adb.adb.write(*a, **kw)

Create a file on the device with the provided contents.

Parameters:

• path (str) – Path to the file on the device
• data (str) – Contents to store in the file

Examples

>>> adb.write('/dev/null', 'data')
>>> adb.write('/data/local/tmp/')

This file exists only for backward compatibility

pwnlib.args — Magic Command-Line Arguments

Pwntools exposes several magic command-line arguments and environment variables when operating in from pwn import * mode.

The arguments extracted from the command-line and removed from sys.argv.

Arguments can be set by appending them to the command-line, or setting them in the environment prefixed by PWNLIB_.

The easiest example is to enable more verbose debugging. Just set DEBUG.

$ PWNLIB_DEBUG=1 python exploit.py
$ python exploit.py DEBUG

These arguments are automatically extracted, regardless of their name, and exposed via pwnlib.args.args, which is exposed as the global variable args. Arguments which pwntools reserves internally are not exposed this way.

$ python -c 'from pwn import *; print args' A=1 B=Hello HOST=1.2.3.4 DEBUG
defaultdict(<type 'str'>, {'A': '1', 'HOST': '1.2.3.4', 'B': 'Hello'})

This is very useful for conditional code, for example determining whether to run an exploit locally or to connect to a remote server. Arguments which are not specified evaluate to an empty string.

if args['REMOTE']:
    io = remote('exploitme.com', 4141)
else:
    io = process('./pwnable')

The full list of supported “magic arguments” and their effects are listed below.

pwnlib.args.DEBUG(x)

Sets the logging verbosity to debug which displays much more information, including logging each byte sent by tubes.

pwnlib.args.LOG_FILE(x)

Sets a log file to be used via context.log_file, e.g. LOG_FILE=./log.txt

pwnlib.args.LOG_LEVEL(x)

Sets the logging verbosity used via context.log_level, e.g. LOG_LEVEL=debug.

pwnlib.args.NOASLR(v)

Disables ASLR via context.aslr

pwnlib.args.NOPTRACE(v)

Disables facilities which require ptrace such as gdb.attach() statements, via context.noptrace.

pwnlib.args.NOTERM(v)

Disables pretty terminal settings and animations.

pwnlib.args.RANDOMIZE(v)

Enables randomization of various pieces via context.randomize

pwnlib.args.SILENT(x)

Sets the logging verbosity to error which silences most output.

pwnlib.args.STDERR(v)

Sends logging to stderr by default, instead of stdout

pwnlib.args.TIMEOUT(v)

Sets a timeout for tube operations (in seconds) via context.timeout, e.g. TIMEOUT=30

pwnlib.args.asbool(s)

Convert a string to its boolean value

pwnlib.args.isident(s)

Helper function to check whether a string is a valid identifier, as passed in on the command-line.

pwnlib.asm — Assembler functions

Utilities for assembling and disassembling code.

Architecture Selection

Architecture, endianness, and word size are selected by using pwnlib.context.

Any parameters which can be specified to context can also be specified as keyword arguments to either asm() or disasm().

Assembly

To assemble code, simply invoke asm() on the code to assemble.

>>> asm('mov eax, 0')
'\xb8\x00\x00\x00\x00'

Additionally, you can use constants as defined in the pwnlib.constants module.

>>> asm('mov eax, SYS_execve')
'\xb8\x0b\x00\x00\x00'

Finally, asm() is used to assemble shellcode provided by pwntools in the shellcraft module.

>>> asm(shellcraft.nop())
'\x90'

Disassembly

To disassemble code, simply invoke disasm() on the bytes to disassemble.

>>> disasm('\xb8\x0b\x00\x00\x00')
'   0:   b8 0b 00 00 00          mov    eax,0xb'

pwnlib.asm.asm(code, vma = 0, extract = True, shared = False, ...) → str

Runs cpp() over a given shellcode and then assembles it into bytes.

To see which architectures or operating systems are supported, look in pwnlib.contex.

Assembling shellcode requires that the GNU assembler is installed for the target architecture. See Installing Binutils for more information.

Parameters:

• shellcode (str) – Assembler code to assemble.
• vma (int) – Virtual memory address of the beginning of assembly
• extract (bool) – Extract the raw assembly bytes from the assembled file. If False, returns the path to an ELF file with the assembly embedded.
• shared (bool) – Create a shared object.
• kwargs (dict) – Any attributes on context can be set, e.g.set arch='arm'.

Examples

>>> asm("mov eax, SYS_select", arch = 'i386', os = 'freebsd')
'\xb8]\x00\x00\x00'
>>> asm("mov eax, SYS_select", arch = 'amd64', os = 'linux')
'\xb8\x17\x00\x00\x00'
>>> asm("mov rax, SYS_select", arch = 'amd64', os = 'linux')
'H\xc7\xc0\x17\x00\x00\x00'
>>> asm("mov r0, #SYS_select", arch = 'arm', os = 'linux', bits=32)
'R\x00\xa0\xe3'

pwnlib.asm.cpp(shellcode, ...) → str

Runs CPP over the given shellcode.

The output will always contain exactly one newline at the end.

Parameters:shellcode (str) – Shellcode to preprocess

Kwargs:

Any arguments/properties that can be set on context

Examples

>>> cpp("mov al, SYS_setresuid", arch = "i386", os = "linux")
'mov al, 164\n'
>>> cpp("weee SYS_setresuid", arch = "arm", os = "linux")
'weee (0+164)\n'
>>> cpp("SYS_setresuid", arch = "thumb", os = "linux")
'(0+164)\n'
>>> cpp("SYS_setresuid", os = "freebsd")
'311\n'

pwnlib.asm.disasm(data, ...) → str

Disassembles a bytestring into human readable assembler.

To see which architectures are supported, look in pwnlib.contex.

To support all these architecture, we bundle the GNU objcopy and objdump with pwntools.

Parameters:

• data (str) – Bytestring to disassemble.
• vma (int) – Passed through to the –adjust-vma argument of objdump
• byte (bool) – Include the hex-printed bytes in the disassembly
• offset (bool) – Include the virtual memory address in the disassembly

Kwargs:

Any arguments/properties that can be set on context

Examples

>>> print disasm('b85d000000'.decode('hex'), arch = 'i386')
   0:   b8 5d 00 00 00          mov    eax,0x5d
>>> print disasm('b85d000000'.decode('hex'), arch = 'i386', byte = 0)
   0:   mov    eax,0x5d
>>> print disasm('b85d000000'.decode('hex'), arch = 'i386', byte = 0, offset = 0)
mov    eax,0x5d
>>> print disasm('b817000000'.decode('hex'), arch = 'amd64')
   0:   b8 17 00 00 00          mov    eax,0x17
>>> print disasm('48c7c017000000'.decode('hex'), arch = 'amd64')
   0:   48 c7 c0 17 00 00 00    mov    rax,0x17
>>> print disasm('04001fe552009000'.decode('hex'), arch = 'arm')
   0:   e51f0004        ldr     r0, [pc, #-4]   ; 0x4
   4:   00900052        addseq  r0, r0, r2, asr r0
>>> print disasm('4ff00500'.decode('hex'), arch = 'thumb', bits=32)
   0:   f04f 0005       mov.w   r0, #5

pwnlib.asm.make_elf(data, vma=None, strip=True, extract=True, shared=False, **kwargs) → str

Builds an ELF file with the specified binary data as its executable code.

Parameters:

• data (str) – Assembled code
• vma (int) – Load address for the ELF file
• strip (bool) – Strip the resulting ELF file. Only matters if extract=False. (Default: True)
• extract (bool) – Extract the assembly from the ELF file. If False, the path of the ELF file is returned. (Default: True)
• shared (bool) – Create a Dynamic Shared Object (DSO, i.e. a .so) which can be loaded via dlopen or LD_PRELOAD.

Examples

This example creates an i386 ELF that just does execve(‘/bin/sh’,...).

>>> context.clear(arch='i386')
>>> bin_sh = '6a68682f2f2f73682f62696e89e331c96a0b5899cd80'.decode('hex')
>>> filename = make_elf(bin_sh, extract=False)
>>> p = process(filename)
>>> p.sendline('echo Hello; exit')
>>> p.recvline()
'Hello\n'

pwnlib.asm.make_elf_from_assembly(assembly, vma=None, extract=None, shared=False, strip=False, **kwargs) → str

Builds an ELF file with the specified assembly as its executable code.

This differs from make_elf() in that all ELF symbols are preserved, such as labels and local variables. Use make_elf() if size matters. Additionally, the default value for extract in make_elf() is different.

Note

This is effectively a wrapper around asm(). with setting extract=False, vma=0x10000000, and marking the resulting file as executable (chmod +x).

Note

ELF files created with arch=thumb will prepend an ARM stub which switches to Thumb mode.

Parameters:

• assembly (str) – Assembly code to build into an ELF
• vma (int) – Load address of the binary (Default: 0x10000000, or 0 if shared=True)
• extract (bool) – Extract the full ELF data from the file. (Default: False)
• shared (bool) – Create a shared library (Default: False)
• kwargs (dict) – Arguments to pass to asm().

Returns:

The path to the assembled ELF (extract=False), or the data of the assembled ELF.

Example

This example shows how to create a shared library, and load it via LD_PRELOAD.

>>> context.clear()
>>> context.arch = 'amd64'
>>> sc = 'push rbp; mov rbp, rsp;'
>>> sc += shellcraft.echo('Hello\n')
>>> sc += 'mov rsp, rbp; pop rbp; ret'
>>> solib = make_elf_from_assembly(sc, shared=1)
>>> subprocess.check_output(['echo', 'World'], env={'LD_PRELOAD': solib})
'Hello\nWorld\n'

The same thing can be done with make_elf(), though the sizes are different. They both

>>> file_a = make_elf(asm('nop'), extract=True)
>>> file_b = make_elf_from_assembly('nop', extract=True)
>>> file_a[:4] == file_b[:4]
True
>>> len(file_a) < 0x200
True
>>> len(file_b) > 0x1000
True

pwnlib.atexception — Callbacks on unhandled exception

Analogous to atexit, this module allows the programmer to register functions to be run if an unhandled exception occurs.

pwnlib.atexception.register(func, *args, **kwargs)

Registers a function to be called when an unhandled exception occurs. The function will be called with positional arguments args and keyword arguments kwargs, i.e. func(*args, **kwargs). The current context is recorded and will be the one used when the handler is run.

E.g. to suppress logging output from an exception-handler one could write:

with context.local(log_level = 'error'):
  atexception.register(handler)

An identifier is returned which can be used to unregister the exception-handler.

This function can be used as a decorator:

@atexception.register
def handler():
  ...

Notice however that this will bind handler to the identifier and not the actual exception-handler. The exception-handler can then be unregistered with:

atexception.unregister(handler)

This function is thread safe.

pwnlib.atexception.unregister(func)

Remove func from the collection of registered functions. If func isn’t registered this is a no-op.

pwnlib.atexit — Replacement for atexit

Replacement for the Python standard library’s atexit.py.

Whereas the standard atexit module only defines atexit.register(), this replacement module also defines unregister().

This module also fixes a the issue that exceptions raised by an exit handler is printed twice when the standard atexit is used.

pwnlib.atexit.register(func, *args, **kwargs)

Registers a function to be called on program termination. The function will be called with positional arguments args and keyword arguments kwargs, i.e. func(*args, **kwargs). The current context is recorded and will be the one used when the handler is run.

E.g. to suppress logging output from an exit-handler one could write:

with context.local(log_level = 'error'):
  atexit.register(handler)

An identifier is returned which can be used to unregister the exit-handler.

This function can be used as a decorator:

@atexit.register
def handler():
  ...

Notice however that this will bind handler to the identifier and not the actual exit-handler. The exit-handler can then be unregistered with:

atexit.unregister(handler)

This function is thread safe.

pwnlib.atexit.unregister(ident)

Remove the exit-handler identified by ident from the list of registered handlers. If ident isn’t registered this is a no-op.

pwnlib.constants — Easy access to header file constants

Module containing constants extracted from header files.

The purpose of this module is to provide quick access to constants from different architectures and operating systems.

The constants are wrapped by a convenience class that allows accessing the name of the constant, while performing all normal mathematical operations on it.

Example

>>> str(constants.freebsd.SYS_stat)
'SYS_stat'
>>> int(constants.freebsd.SYS_stat)
188
>>> hex(constants.freebsd.SYS_stat)
'0xbc'
>>> 0 | constants.linux.i386.SYS_stat
106
>>> 0 + constants.linux.amd64.SYS_stat
4

The submodule freebsd contains all constants for FreeBSD, while the constants for Linux have been split up by architecture.

The variables of the submodules will be “lifted up” by setting the pwnlib.context.arch or pwnlib.context.os in a manner similar to what happens in pwnlib.shellcraft.

Example

>>> with context.local(os = 'freebsd'):
...     print int(constants.SYS_stat)
188
>>> with context.local(os = 'linux', arch = 'i386'):
...     print int(constants.SYS_stat)
106
>>> with context.local(os = 'linux', arch = 'amd64'):
...     print int(constants.SYS_stat)
4

pwnlib.context — Setting runtime variables

pwnlib.context.context = ContextType()

Global ContextType object, used to store commonly-used pwntools settings.

In most cases, the context is used to infer default variables values. For example, asm() can take an arch parameter as a keyword argument.

If it is not supplied, the arch specified by context is used instead.

Consider it a shorthand to passing os= and arch= to every single function call.

class pwnlib.context.ContextType(**kwargs)

Class for specifying information about the target machine. Intended for use as a pseudo-singleton through the global variable context, available via from pwn import * as context.

The context is usually specified at the top of the Python file for clarity.

#!/usr/bin/env python
context.update(arch='i386', os='linux')

Currently supported properties and their defaults are listed below. The defaults are inherited from pwnlib.context.ContextType.defaults.

Additionally, the context is thread-aware when using pwnlib.context.Thread instead of threading.Thread (all internal pwntools threads use the former).

The context is also scope-aware by using the with keyword.

Examples

>>> context.clear()
>>> context.update(os='linux') 
>>> context.os == 'linux'
True
>>> context.arch = 'arm'
>>> vars(context) == {'arch': 'arm', 'bits': 32, 'endian': 'little', 'os': 'linux'}
True
>>> context.endian
'little'
>>> context.bits
32
>>> def nop():
...   print pwnlib.asm.asm('nop').encode('hex')
>>> nop()
00f020e3
>>> with context.local(arch = 'i386'):
...   nop()
90
>>> from pwnlib.context import Thread as PwnThread
>>> from threading      import Thread as NormalThread
>>> with context.local(arch = 'mips'):
...     pwnthread = PwnThread(target=nop)
...     thread    = NormalThread(target=nop)
>>> # Normal thread uses the default value for arch, 'i386'
>>> _=(thread.start(), thread.join())
90
>>> # Pwnthread uses the correct context from creation-time
>>> _=(pwnthread.start(), pwnthread.join())
00000000
>>> nop()
00f020e3

class Thread(*args, **kwargs)

Instantiates a context-aware thread, which inherit its context when it is instantiated. The class can be accessed both on the context module as pwnlib.context.Thread and on the context singleton object inside the context module as pwnlib.context.context.Thread.

Threads created by using the native :class`threading`.Thread` will have a clean (default) context.

Regardless of the mechanism used to create any thread, the context is de-coupled from the parent thread, so changes do not cascade to child or parent.

Saves a copy of the context when instantiated (at __init__) and updates the new thread’s context before passing control to the user code via run or target=.

Examples

>>> context.clear()
>>> context.update(arch='arm')
>>> def p():
...     print context.arch
...     context.arch = 'mips'
...     print context.arch
>>> # Note that a normal Thread starts with a clean context
>>> # (i386 is the default architecture)
>>> t = threading.Thread(target=p)
>>> _=(t.start(), t.join())
i386
mips
>>> # Note that the main Thread's context is unchanged
>>> print context.arch
arm
>>> # Note that a context-aware Thread receives a copy of the context
>>> t = pwnlib.context.Thread(target=p)
>>> _=(t.start(), t.join())
arm
mips
>>> # Again, the main thread is unchanged
>>> print context.arch
arm

Implementation Details:

This class implemented by hooking the private function threading.Thread._Thread_bootstrap(), which is called before passing control to threading.Thread.run().

This could be done by overriding run itself, but we would have to ensure that all uses of the class would only ever use the keyword target= for __init__, or that all subclasses invoke super(Subclass.self).set_up_context() or similar.

ContextType.adb

Returns an argument array for connecting to adb.

Unless $ADB_PATH is set, uses the default adb binary in $PATH.

ContextType.adb_host

Sets the target host which is used for ADB.

This is useful for Android exploitation.

The default value is inherited from ANDROID_ADB_SERVER_HOST, or set to the default ‘localhost’.

ContextType.adb_port

Sets the target port which is used for ADB.

This is useful for Android exploitation.

The default value is inherited from ANDROID_ADB_SERVER_PORT, or set to the default 5037.

ContextType.arch

Target binary architecture.

Allowed values are listed in pwnlib.context.ContextType.architectures.

Side Effects:

If an architecture is specified which also implies additional attributes (e.g. ‘amd64’ implies 64-bit words, ‘powerpc’ implies big-endian), these attributes will be set on the context if a user has not already set a value.

The following properties may be modified.

• bits
• endian

Raises:AttributeError – An invalid architecture was specified

Examples

>>> context.clear()
>>> context.arch == 'i386' # Default architecture
True

>>> context.arch = 'mips'
>>> context.arch == 'mips'
True

>>> context.arch = 'doge' 
Traceback (most recent call last):
 ...
AttributeError: arch must be one of ['aarch64', ..., 'thumb']

>>> context.arch = 'ppc'
>>> context.arch == 'powerpc' # Aliased architecture
True

>>> context.clear()
>>> context.bits == 32 # Default value
True
>>> context.arch = 'amd64'
>>> context.bits == 64 # New value
True

Note that expressly setting bits means that we use that value instead of the default

>>> context.clear()
>>> context.bits = 32
>>> context.arch = 'amd64'
>>> context.bits == 32
True

Setting the architecture can override the defaults for both endian and bits

>>> context.clear()
>>> context.arch = 'powerpc64'
>>> vars(context) == {'arch': 'powerpc64', 'bits': 64, 'endian': 'big'}
True

ContextType.architectures = OrderedDict([('powerpc64', {'bits': 64, 'endian': 'big'}), ('aarch64', {'bits': 64, 'endian': 'little'}), ('sparc64', {'bits': 64, 'endian': 'big'}), ('powerpc', {'bits': 32, 'endian': 'big'}), ('mips64', {'bits': 64, 'endian': 'little'}), ('msp430', {'bits': 16, 'endian': 'little'}), ('thumb', {'bits': 32, 'endian': 'little'}), ('amd64', {'bits': 64, 'endian': 'little'}), ('sparc', {'bits': 32, 'endian': 'big'}), ('alpha', {'bits': 64, 'endian': 'little'}), ('s390', {'bits': 32, 'endian': 'big'}), ('i386', {'bits': 32, 'endian': 'little'}), ('m68k', {'bits': 32, 'endian': 'big'}), ('mips', {'bits': 32, 'endian': 'little'}), ('ia64', {'bits': 64, 'endian': 'big'}), ('cris', {'bits': 32, 'endian': 'little'}), ('vax', {'bits': 32, 'endian': 'little'}), ('avr', {'bits': 8, 'endian': 'little'}), ('arm', {'bits': 32, 'endian': 'little'})])

Keys are valid values for pwnlib.context.ContextType.arch(). Values are defaults which are set when pwnlib.context.ContextType.arch is set

ContextType.aslr

ASLR settings for new processes.

If False, attempt to disable ASLR in all processes which are created via personality (setarch -R) and setrlimit (ulimit -s unlimited).

The setarch changes are lost if a setuid binary is executed.

ContextType.binary

Infer target architecture, bit-with, and endianness from a binary file. Data type is a pwnlib.elf.ELF object.

Examples

>>> context.clear()
>>> context.arch, context.bits
('i386', 32)
>>> context.binary = '/bin/bash'
>>> context.arch, context.bits
('amd64', 64)
>>> context.binary
ELF('/bin/bash')

ContextType.bits

Target machine word size, in bits (i.e. the size of general purpose registers).

The default value is 32, but changes according to arch.

Examples

>>> context.clear()
>>> context.bits == 32
True
>>> context.bits = 64
>>> context.bits == 64
True
>>> context.bits = -1 
Traceback (most recent call last):
...
AttributeError: bits must be > 0 (-1)

ContextType.buffer_size

Internal buffer size to use for pwnlib.tubes.tube.tube objects.

This is not the maximum size of the buffer, but this is the amount of data which is passed to each raw read syscall (or equivalent).

ContextType.bytes

Target machine word size, in bytes (i.e. the size of general purpose registers).

This is a convenience wrapper around bits / 8.

Examples

>>> context.bytes = 1
>>> context.bits == 8
True

>>> context.bytes = 0 
Traceback (most recent call last):
...
AttributeError: bits must be > 0 (0)

ContextType.cache_dir

Directory used for caching data.

Note

May be either a path string, or None.

Example

>>> cache_dir = context.cache_dir
>>> cache_dir is not None
True
>>> os.chmod(cache_dir, 0o000)
>>> context.cache_dir is None
True
>>> os.chmod(cache_dir, 0o755)
>>> cache_dir == context.cache_dir
True

ContextType.clear(*a, **kw)

Clears the contents of the context. All values are set to their defaults.

Parameters:

• a – Arguments passed to update
• kw – Arguments passed to update

Examples

>>> # Default value
>>> context.clear()
>>> context.arch == 'i386'
True
>>> context.arch = 'arm'
>>> context.arch == 'i386'
False
>>> context.clear()
>>> context.arch == 'i386'
True

ContextType.copy() → dict

Returns a copy of the current context as a dictionary.

Examples

>>> context.clear()
>>> context.os   = 'linux'
>>> vars(context) == {'os': 'linux'}
True

ContextType.defaults = {'kernel': None, 'noptrace': False, 'delete_corefiles': False, 'randomize': False, 'binary': None, 'log_level': 20, 'terminal': None, 'bits': 32, 'rename_corefiles': True, 'newline': '\n', 'proxy': None, 'device': None, 'buffer_size': 4096, 'arch': 'i386', 'aslr': True, 'adb_port': 5037, 'signed': False, 'adb_host': 'localhost', 'timeout': pwnlib.timeout.maximum, 'endian': 'little', 'log_file': <pwnlib.context._devnull object>, 'os': 'linux', 'log_console': <open file '<stdout>', mode 'w'>}

Default values for pwnlib.context.ContextType

ContextType.delete_corefiles

Whether pwntools automatically deletes corefiles after exiting. This only affects corefiles accessed via process.corefile.

Default value is False.

ContextType.device

Sets the device being operated on.

ContextType.endian

Endianness of the target machine.

The default value is 'little', but changes according to arch.

Raises:AttributeError – An invalid endianness was provided

Examples

>>> context.clear()
>>> context.endian == 'little'
True

>>> context.endian = 'big'
>>> context.endian
'big'

>>> context.endian = 'be'
>>> context.endian == 'big'
True

>>> context.endian = 'foobar' 
Traceback (most recent call last):
 ...
AttributeError: endian must be one of ['be', 'big', 'eb', 'el', 'le', 'little']

ContextType.endianness

Legacy alias for endian.

Examples

>>> context.endian == context.endianness
True

ContextType.endiannesses = OrderedDict([('little', 'little'), ('big', 'big'), ('el', 'little'), ('le', 'little'), ('be', 'big'), ('eb', 'big')])

Valid values for endian

ContextType.kernel

Target machine’s kernel architecture.

Usually, this is the same as arch, except when running a 32-bit binary on a 64-bit kernel (e.g. i386-on-amd64).

Even then, this doesn’t matter much – only when the the segment registers need to be known

ContextType.local(**kwargs) → context manager

Create a context manager for use with the with statement.

For more information, see the example below or PEP 343.

Parameters:kwargs – Variables to be assigned in the new environment. Returns:ContextType manager for managing the old and new environment.

Examples

>>> context.clear()
>>> context.timeout = 1
>>> context.timeout == 1
True
>>> print context.timeout
1.0
>>> with context.local(timeout = 2):
...     print context.timeout
...     context.timeout = 3
...     print context.timeout
2.0
3.0
>>> print context.timeout
1.0

ContextType.log_console

Sets the default logging console target.

Examples

>>> context.log_level = 'warn'
>>> log.warn("Hello")
[!] Hello
>>> context.log_console=open('/dev/null', 'w')
>>> log.warn("Hello")
>>> context.clear()

ContextType.log_file

Sets the target file for all logging output.

Works in a similar fashion to log_level.

Examples

>>> context.log_file = 'foo.txt' 
>>> log.debug('Hello!') 
>>> with context.local(log_level='ERROR'): 
...     log.info('Hello again!')
>>> with context.local(log_file='bar.txt'):
...     log.debug('Hello from bar!')
>>> log.info('Hello from foo!')
>>> file('foo.txt').readlines()[-3] 
'...:DEBUG:...:Hello!\n'
>>> file('foo.txt').readlines()[-2] 
'...:INFO:...:Hello again!\n'
>>> file('foo.txt').readlines()[-1] 
'...:INFO:...:Hello from foo!\n'
>>> file('bar.txt').readlines()[-1] 
'...:DEBUG:...:Hello from bar!\n'

ContextType.log_level

Sets the verbosity of pwntools logging mechanism.

More specifically it controls the filtering of messages that happens inside the handler for logging to the screen. So if you want e.g. log all messages to a file, then this attribute makes no difference to you.

Valid values are specified by the standard Python logging module.

Default value is set to INFO.

Examples

>>> context.log_level = 'error'
>>> context.log_level == logging.ERROR
True
>>> context.log_level = 10
>>> context.log_level = 'foobar' 
Traceback (most recent call last):
...
AttributeError: log_level must be an integer or one of ['CRITICAL', 'DEBUG', 'ERROR', 'INFO', 'NOTSET', 'WARN', 'WARNING']

ContextType.noptrace

Disable all actions which rely on ptrace.

This is useful for switching between local exploitation with a debugger, and remote exploitation (without a debugger).

This option can be set with the NOPTRACE command-line argument.

ContextType.os

Operating system of the target machine.

The default value is linux.

Allowed values are listed in pwnlib.context.ContextType.oses.

Examples

>>> context.os = 'linux'
>>> context.os = 'foobar' 
Traceback (most recent call last):
...
AttributeError: os must be one of ['android', 'cgc', 'freebsd', 'linux', 'windows']

ContextType.oses = ['android', 'cgc', 'freebsd', 'linux', 'windows']

Valid values for pwnlib.context.ContextType.os()

ContextType.proxy

Default proxy for all socket connections.

Accepts either a string (hostname or IP address) for a SOCKS5 proxy on the default port, or a tuple passed to socks.set_default_proxy, e.g. (socks.SOCKS4, 'localhost', 1234).

>>> context.proxy = 'localhost' 
>>> r=remote('google.com', 80)
Traceback (most recent call last):
...
ProxyConnectionError: Error connecting to SOCKS5 proxy localhost:1080: [Errno 111] Connection refused

>>> context.proxy = None
>>> r=remote('google.com', 80, level='error')

ContextType.quiet

Disables all non-error logging within the enclosed scope, unless the debugging level is set to ‘debug’ or lower.

ContextType.quietfunc(function)

Similar to quiet, but wraps a whole function.

ContextType.randomize

Global flag that lots of things should be randomized.

ContextType.rename_corefiles

Whether pwntools automatically renames corefiles.

This is useful for two things:

• Prevent corefiles from being overwritten, if kernel.core_pattern is something simple like "core".
• Ensure corefiles are generated, if kernel.core_pattern uses apport, which refuses to overwrite any existing files.

This only affects corefiles accessed via process.corefile.

Default value is True.

ContextType.reset_local()

Deprecated. Use clear().

ContextType.sign

Alias for signed

ContextType.signed

Signed-ness for packing operation when it’s not explicitly set.

Can be set to any non-string truthy value, or the specific string values 'signed' or 'unsigned' which are converted into True and False correspondingly.

Examples

>>> context.signed
False
>>> context.signed = 1
>>> context.signed
True
>>> context.signed = 'signed'
>>> context.signed
True
>>> context.signed = 'unsigned'
>>> context.signed
False
>>> context.signed = 'foobar' 
Traceback (most recent call last):
...
AttributeError: signed must be one of ['no', 'signed', 'unsigned', 'yes'] or a non-string truthy value

ContextType.signedness

Alias for signed

ContextType.signednesses = {'yes': True, 'unsigned': False, 'signed': True, 'no': False}

Valid string values for signed

ContextType.silent

Disable all non-error logging within the enclosed scope.

ContextType.terminal

Default terminal used by pwnlib.util.misc.run_in_new_terminal(). Can be a string or an iterable of strings. In the latter case the first entry is the terminal and the rest are default arguments.

ContextType.timeout

Default amount of time to wait for a blocking operation before it times out, specified in seconds.

The default value is to have an infinite timeout.

See pwnlib.timeout.Timeout for additional information on valid values.

ContextType.update(*args, **kwargs)

Convenience function, which is shorthand for setting multiple variables at once.

It is a simple shorthand such that:

context.update(os = 'linux', arch = 'arm', ...)

is equivalent to:

context.os   = 'linux'
context.arch = 'arm'
...

The following syntax is also valid:

context.update({'os': 'linux', 'arch': 'arm'})

Parameters:kwargs – Variables to be assigned in the environment.

Examples

>>> context.clear()
>>> context.update(arch = 'i386', os = 'linux')
>>> context.arch, context.os
('i386', 'linux')

ContextType.verbose

Enable all logging within the enclosed scope.

ContextType.word_size

Alias for bits

class pwnlib.context.Thread(*args, **kwargs)

Instantiates a context-aware thread, which inherit its context when it is instantiated. The class can be accessed both on the context module as pwnlib.context.Thread and on the context singleton object inside the context module as pwnlib.context.context.Thread.

Threads created by using the native :class`threading`.Thread` will have a clean (default) context.

Regardless of the mechanism used to create any thread, the context is de-coupled from the parent thread, so changes do not cascade to child or parent.

Saves a copy of the context when instantiated (at __init__) and updates the new thread’s context before passing control to the user code via run or target=.

Examples

>>> context.clear()
>>> context.update(arch='arm')
>>> def p():
...     print context.arch
...     context.arch = 'mips'
...     print context.arch
>>> # Note that a normal Thread starts with a clean context
>>> # (i386 is the default architecture)
>>> t = threading.Thread(target=p)
>>> _=(t.start(), t.join())
i386
mips
>>> # Note that the main Thread's context is unchanged
>>> print context.arch
arm
>>> # Note that a context-aware Thread receives a copy of the context
>>> t = pwnlib.context.Thread(target=p)
>>> _=(t.start(), t.join())
arm
mips
>>> # Again, the main thread is unchanged
>>> print context.arch
arm

Implementation Details:

This class implemented by hooking the private function threading.Thread._Thread_bootstrap(), which is called before passing control to threading.Thread.run().

This could be done by overriding run itself, but we would have to ensure that all uses of the class would only ever use the keyword target= for __init__, or that all subclasses invoke super(Subclass.self).set_up_context() or similar.

pwnlib.dynelf — 使用leak解析远程函数

这个模块主要用于解析ELF文件中加载的以及动态链接的符号。只要给一个可以泄漏任 何地址内容的函数，我们就可以解析加载的库中的任何地址。

例子

# Assume a process or remote connection
p = process('./pwnme')

# Declare a function that takes a single address, and
# leaks at least one byte at that address.
def leak(address):
    data = p.read(address, 4)
    log.debug("%#x => %s" % (address, (data or '').encode('hex')))
    return data

# For the sake of this example, let's say that we
# have any of these pointers.  One is a pointer into
# the target binary, the other two are pointers into libc
main   = 0xfeedf4ce
libc   = 0xdeadb000
system = 0xdeadbeef

# With our leaker, and a pointer into our target binary,
# we can resolve the address of anything.
#
# We do not actually need to have a copy of the target
# binary for this to work.
d = DynELF(leak, main)
assert d.lookup(None,     'libc') == libc
assert d.lookup('system', 'libc') == system

# However, if we *do* have a copy of the target binary,
# we can speed up some of the steps.
d = DynELF(leak, main, elf=ELF('./pwnme'))
assert d.lookup(None,     'libc') == libc
assert d.lookup('system', 'libc') == system

# Alternately, we can resolve symbols inside another library,
# given a pointer into it.
d = DynELF(leak, libc + 0x1234)
assert d.lookup('system')      == system

DynELF

class pwnlib.dynelf.DynELF(leak,pointer,elf=None)

Dynelf 知道如何借助 pwnlib.memleak.MemLeak. 通过 infoleak 或者 memleak 漏洞解 析远程程序中的符号地址。

应用细节

解析函数：

ELF文件（例如 libc.so ）一般会导出自己声明的符号，以便于其他库使用。这样，就会存在一系列的表格，它们会给出导出符号的名字，地址，以及这些导出符号的 hash 值。通过将hash函数应用在期望符号上(例如 printf )，我们就可以在hash表中找到对应的位置。其相应的索引提供了到string name table( strtab )和symbol address( symtab ) 的寻找的方式。

假设我们有 libc.so 的基地址，解析 printf 的地址的方式就是去定位 symtab, strtab, hashtabe。字符串 "printf" 根据 hash 表的风格( YSV 或者 GNU )被hash，因此我们可以遍历hashtable来找到一个匹配的入口。我们可以通过检查 strtab 来验证一个匹配，然后从 symtab 中获取其在 libc.so 中的偏移。

解析库地址：

如果我们有一个指向动态连接可执行文件的指针，我们可以得到一个内部名叫 link map 的指针结构。这是一个链表，其中包含了每一个被加载的库，以及它的完整路径和基地址。

• 我们可以有两种方法来寻找指向 link map 的指针。两者都参考了 DYNAMIC 数组中的入口。在非RELRO二进制文件中，指针被放在二进制文件的 .got.plt 处。这通过在二进制文件里寻找 DT_PLTGOT 来标记。
• 在所有的二进制文件里，指针可以在 DT_DEBUG 区域中找到。这个区域在stripped 的二进制文件里仍然存在。

为了充分的灵活性，这两种机制都被充分地使用了。

__init__(self, leak, pointer=None, elf=None)()

这是DynELF的一个实例化方法，通过它，如果我们给了 pwnlib.memleak.MemLeak leaker, 以及一个binary文件中的指针，我们可以生成一个可以解析运行库中符号的实例对象。

参数：

• leak (MemLeak) - 泄漏内存的 pwnlib.memleak.MemLeak 的实例。
• pointer (int) - 已经被load的ELF文件中的一个指针。
• elf (str,ELF) - ELF文件对应的路径，或者说一个已经加载的 pwnlib.elf.ELF 。

bases()

解析所有已经被加载的二进制文件的基地址。

返回一个将库路径映射到它的基地址的字典。

static find_base(leak,ptr)()

给定一个 pwnlib.memleak.Memleak 对象，以及一个其二进制文件内部的binary，找到它的基地址。

heap()

通过 __curbrk 来查找当前堆的基地址，这个符号在链接器中已经被导出了，指向当前的brk。

lookup(symb=None,lib=None)-->int()

在lib中找到对应符号的地址。参数如下

• symb (str) - 要查找的名字。
• lib (str) - 用来匹配库文件名的子串。缺省情况下会搜索当前的库，如果设置为 libc , ``libc.so``就会被查找。

返回对应符号的地址，或者None。

stack()

通过 __envrion （这个符号是由libc导出的，指向环境变量部分）来寻找一个指向栈上的变量，

dynamic()

返回指向 .DYNAMIC 的指针。

elfclass(self)()

返回对应的二进制文件的类型。

libc(self)()

得到远程libc.so的build版本，下载对应的文件，并且使用正确的基地址加载 ELF 对象。

返回一个ELF对象，或者什么也不返回。

link_map(self)()

返回指向运行时的link_map对象。

pwnlib.dynelf.gnu_hash(str)-->int

为字符串生成GNU格式的hash值。

pwnlib.dynelf.sysv_hash(str)-->int

为字符串生成SYSV格式的hash值。

pwnlib.encoders — Encoding Shellcode

Encode shellcode to avoid input filtering and impress your friends!

pwnlib.encoders.encoder.alphanumeric(raw_bytes) → str

Encode the shellcode raw_bytes such that it does not contain any bytes except for [A-Za-z0-9].

Accepts the same arguments as encode().

pwnlib.encoders.encoder.encode(raw_bytes, avoid, expr, force) → str

Encode shellcode raw_bytes such that it does not contain any bytes in avoid or expr.

Parameters:

• raw_bytes (str) – Sequence of shellcode bytes to encode.
• avoid (str) – Bytes to avoid
• expr (str) – Regular expression which matches bad characters.
• force (bool) – Force re-encoding of the shellcode, even if it doesn’t contain any bytes in avoid.

pwnlib.encoders.encoder.line(raw_bytes) → str

Encode the shellcode raw_bytes such that it does not contain any NULL bytes or whitespace.

Accepts the same arguments as encode().

pwnlib.encoders.encoder.null(raw_bytes) → str

Encode the shellcode raw_bytes such that it does not contain any NULL bytes.

Accepts the same arguments as encode().

pwnlib.encoders.encoder.printable(raw_bytes) → str

Encode the shellcode raw_bytes such that it only contains non-space printable bytes.

Accepts the same arguments as encode().

pwnlib.encoders.encoder.scramble(raw_bytes) → str

Encodes the input data with a random encoder.

Accepts the same arguments as encode().

class pwnlib.encoders.i386.xor.i386XorEncoder

Generates an XOR decoder for i386.

>>> context.clear(arch='i386')
>>> shellcode = asm(shellcraft.sh())
>>> avoid = '/bin/sh\xcc\xcd\x80'
>>> encoded = pwnlib.encoders.i386.xor.encode(shellcode, avoid)
>>> assert not any(c in encoded for c in avoid)
>>> p = run_shellcode(encoded)
>>> p.sendline('echo hello; exit')
>>> p.recvline()
'hello\n'

pwnlib.elf — Working with ELF binaries

Most exploitable CTF challenges are provided in the Executable and Linkable Format (ELF). Generally, it is very useful to be able to interact with these files to extract data such as function addresses, ROP gadgets, and writable page addresses.

pwnlib.elf.load(*args, **kwargs)

Compatibility wrapper for pwntools v1

class pwnlib.elf.ELF(path)

Encapsulates information about an ELF file.

Example

>>> bash = ELF(which('bash'))
>>> hex(bash.symbols['read'])
0x41dac0
>>> hex(bash.plt['read'])
0x41dac0
>>> u32(bash.read(bash.got['read'], 4))
0x41dac6
>>> print bash.disasm(bash.plt.read, 16)
0:   ff 25 1a 18 2d 00       jmp    QWORD PTR [rip+0x2d181a]        # 0x2d1820
6:   68 59 00 00 00          push   0x59
b:   e9 50 fa ff ff          jmp    0xfffffffffffffa60

address

int – Address of the lowest segment loaded in the ELF.

When updated, the addresses of the following fields are also updated:

• symbols
• got
• plt
• functions

However, the following fields are NOT updated:

• segments
• sections

Example

>>> bash = ELF('/bin/bash')
>>> read = bash.symbols['read']
>>> text = bash.get_section_by_name('.text').header.sh_addr
>>> bash.address += 0x1000
>>> read + 0x1000 == bash.symbols['read']
True
>>> text == bash.get_section_by_name('.text').header.sh_addr
True

asan

bool – Whether the current binary was built with Address Sanitizer (ASAN).

aslr

bool – Whether the current binary is position-independent.

asm(address, assembly)

Assembles the specified instructions and inserts them into the ELF at the specified address.

This modifies the ELF in-pace. The resulting binary can be saved with ELF.save()

bss(offset=0) → int

Returns:Address of the .bss section, plus the specified offset.

buildid

str – GNU Build ID embedded into the binary

canary

bool – Whether the current binary uses stack canaries.

checksec(banner=True)

Prints out information in the binary, similar to checksec.sh.

Parameters:banner (bool) – Whether to print the path to the ELF binary.

data

str – Raw data of the ELF file.

See:

get_data()

debug(argv=[], *a, **kw) → tube

Debug the ELF with gdb.debug().

Parameters:

• argv (list) – List of arguments to the binary
• *args – Extra arguments to gdb.debug()
• **kwargs – Extra arguments to gdb.debug()

Returns:

See gdb.debug()

Return type:

tube

disasm(address, n_bytes) → str

Returns a string of disassembled instructions at the specified virtual memory address

dwarf

DWARF info for the elf

dynamic_by_tag(tag) → tag

Parameters:tag (str) – Named DT_XXX tag (e.g. 'DT_STRTAB'). Returns:elftools.elf.dynamic.DynamicTag

dynamic_string(offset) → bytes

Fetches an enumerated string from the DT_STRTAB table.

Parameters:offset (int) – String index Returns:String from the table as raw bytes. Return type:str

elftype

str – ELF type (EXEC, DYN, etc)

entry

int – Address of the entry point for the ELF

entrypoint

int – Address of the entry point for the ELF

execstack

bool – Whether the current binary uses an executable stack.

executable_segments

list – List of all segments which are executable.

See:

ELF.segments

fit(address, *a, **kw)

Writes fitted data into the specified address.

See: packing.fit()

flat(address, *a, **kw)

Writes a full array of values to the specified address.

See: packing.flat()

fortify

bool – Whether the current binary was built with Fortify Source (-DFORTIFY).

static from_assembly(assembly) → ELF

Given an assembly listing, return a fully loaded ELF object which contains that assembly at its entry point.

Parameters:

• assembly (str) – Assembly language listing
• vma (int) – Address of the entry point and the module’s base address.

Example

>>> e = ELF.from_assembly('nop; foo: int 0x80', vma = 0x400000)
>>> e.symbols['foo'] = 0x400001
>>> e.disasm(e.entry, 1)
'  400000:       90                      nop'
>>> e.disasm(e.symbols['foo'], 2)
'  400001:       cd 80                   int    0x80'

static from_bytes(bytes) → ELF

Given a sequence of bytes, return a fully loaded ELF object which contains those bytes at its entry point.

Parameters:

• bytes (str) – Shellcode byte string
• vma (int) – Desired base address for the ELF.

Example

>>> e = ELF.from_bytes('\x90\xcd\x80', vma=0xc000)
>>> print(e.disasm(e.entry, 3))
    c000:       90                      nop
    c001:       cd 80                   int    0x80

get_data() → bytes

Retrieve the raw data from the ELF file.

>>> bash = ELF(which('bash'))
>>> fd   = open(which('bash'))
>>> bash.get_data() == fd.read()
True

libc

ELF – If this ELF imports any libraries which contain 'libc[.-], and we can determine the appropriate path to it on the local system, returns a new ELF object pertaining to that library.

If not found, the value will be None.

msan

bool – Whether the current binary was built with Memory Sanitizer (MSAN).

non_writable_segments

list – List of all segments which are NOT writeable.

See:

ELF.segments

nx

bool – Whether the current binary uses NX protections.

offset_to_vaddr(offset) → int

Translates the specified offset to a virtual address.

Parameters:offset (int) – Offset to translate Returns:Virtual address which corresponds to the file offset, or None. Return type:int

Examples

This example shows that regardless of changes to the virtual address layout by modifying ELF.address, the offset for any given address doesn’t change.

>>> bash = ELF('/bin/bash')
>>> bash.address == bash.offset_to_vaddr(0)
True
>>> bash.address += 0x123456
>>> bash.address == bash.offset_to_vaddr(0)
True

p16(address, data, *a, **kw)

Writes a 16-bit integer data to the specified address

p32(address, data, *a, **kw)

Writes a 32-bit integer data to the specified address

p64(address, data, *a, **kw)

Writes a 64-bit integer data to the specified address

p8(address, data, *a, **kw)

Writes a 8-bit integer data to the specified address

pack(address, data, *a, **kw)

Writes a packed integer data to the specified address

packed

bool – Whether the current binary is packed with UPX.

pie

bool – Whether the current binary is position-independent.

process(argv=[], *a, **kw) → process

Execute the binary with process. Note that argv is a list of arguments, and should not include argv[0].

Parameters:

• argv (list) – List of arguments to the binary
• *args – Extra arguments to process
• **kwargs – Extra arguments to process

Returns:

process

read(address, count) → bytes

Read data from the specified virtual address

Parameters:

• address (int) – Virtual address to read
• count (int) – Number of bytes to read

Returns:

A str object, or None.

Examples

The simplest example is just to read the ELF header.

>>> bash = ELF(which('bash'))
>>> bash.read(bash.address, 4)
'\x7fELF'

ELF segments do not have to contain all of the data on-disk that gets loaded into memory.

First, let’s create an ELF file has some code in two sections.

>>> assembly = '''
... .section .A,"awx"
... .global A
... A: nop
... .section .B,"awx"
... .global B
... B: int3
... '''
>>> e = ELF.from_assembly(assembly, vma=False)

By default, these come right after eachother in memory.

>>> e.read(e.symbols.A, 2)
'\x90\xcc'
>>> e.symbols.B - e.symbols.A
1

Let’s move the sections so that B is a little bit further away.

>>> objcopy = pwnlib.asm._objcopy()
>>> objcopy += [
...     '--change-section-vma', '.B+5',
...     '--change-section-lma', '.B+5',
...     e.path
... ]
>>> subprocess.check_call(objcopy)
0

Now let’s re-load the ELF, and check again

>>> e = ELF(e.path)
>>> e.symbols.B - e.symbols.A
6
>>> e.read(e.symbols.A, 2)
'\x90\x00'
>>> e.read(e.symbols.A, 7)
'\x90\x00\x00\x00\x00\x00\xcc'
>>> e.read(e.symbols.A, 10)
'\x90\x00\x00\x00\x00\x00\xcc\x00\x00\x00'

Everything is relative to the user-selected base address, so moving things around keeps everything working.

>>> e.address += 0x1000
>>> e.read(e.symbols.A, 10)
'\x90\x00\x00\x00\x00\x00\xcc\x00\x00\x00'

relro

bool – Whether the current binary uses RELRO protections.

rpath

bool – Whether the current binary has an RPATH.

runpath

bool – Whether the current binary has a RUNPATH.

rwx_segments

list – List of all segments which are writeable and executable.

See:

ELF.segments

save(path=None)

Save the ELF to a file

>>> bash = ELF(which('bash'))
>>> bash.save('/tmp/bash_copy')
>>> copy = file('/tmp/bash_copy')
>>> bash = file(which('bash'))
>>> bash.read() == copy.read()
True

search(needle, writable = False) → generator

Search the ELF’s virtual address space for the specified string.

Notes

Does not search empty space between segments, or uninitialized data. This will only return data that actually exists in the ELF file. Searching for a long string of NULL bytes probably won’t work.

Parameters:

• needle (str) – String to search for.
• writable (bool) – Search only writable sections.

Yields:

An iterator for each virtual address that matches.

Examples

An ELF header starts with the bytes \x7fELF, so we sould be able to find it easily.

>>> bash = ELF('/bin/bash')
>>> bash.address + 1 == next(bash.search('ELF'))
True

We can also search for string the binary.

>>> len(list(bash.search('GNU bash'))) > 0
True

section(name) → bytes

Gets data for the named section

Parameters:name (str) – Name of the section Returns:String containing the bytes for that section Return type:str

sections

list – A list of elftools.elf.sections.Section objects for the segments in the ELF.

segments

list – A list of elftools.elf.segments.Segment objects for the segments in the ELF.

start

int – Address of the entry point for the ELF

string(address)

Reads a null-terminated string from the specified address

sym

dotdict – Alias for ELF.symbols

u16(address, *a, **kw)

Unpacks an integer from the specified address.

u32(address, *a, **kw)

Unpacks an integer from the specified address.

u64(address, *a, **kw)

Unpacks an integer from the specified address.

u8(address, *a, **kw)

Unpacks an integer from the specified address.

ubsan

bool – Whether the current binary was built with Undefined Behavior Sanitizer (UBSAN).

unpack(address, *a, **kw)

Unpacks an integer from the specified address.

vaddr_to_offset(address) → int

Translates the specified virtual address to a file offset

Parameters:address (int) – Virtual address to translate Returns:Offset within the ELF file which corresponds to the address, or None. Return type:int

Examples

>>> bash = ELF(which('bash'))
>>> bash.vaddr_to_offset(bash.address)
0
>>> bash.address += 0x123456
>>> bash.vaddr_to_offset(bash.address)
0
>>> bash.vaddr_to_offset(0) is None
True

writable_segments

list – List of all segments which are writeable.

See:

ELF.segments

write(address, data)

Writes data to the specified virtual address

Parameters:

• address (int) – Virtual address to write
• data (str) – Bytes to write

Note

This routine does not check the bounds on the write to ensure that it stays in the same segment.

Examples

>>> bash = ELF(which('bash'))
>>> bash.read(bash.address+1, 3)
'ELF'
>>> bash.write(bash.address, "HELO")
>>> bash.read(bash.address, 4)
'HELO'

class pwnlib.elf.Core(*a, **kw)

Alias for Corefile

pwnlib.exception — Pwnlib exceptions

exception pwnlib.exception.PwnlibException(msg, reason=None, exit_code=None)

Exception thrown by pwnlib.log.error().

Pwnlib functions that encounters unrecoverable errors should call the pwnlib.log.error() function instead of throwing this exception directly.

pwnlib.flag — CTF Flag Management

pwnlib.flag.submit_flag(flag, exploit='unnamed-exploit', target='unknown-target', server='flag-submission-server', port='31337', proto='tcp', team='unknown-team')

Submits a flag to the game server

Parameters:

• flag (str) – The flag to submit.
• exploit (str) – Exploit identifier, optional
• target (str) – Target identifier, optional
• server (str) – Flag server host name, optional
• port (int) – Flag server port, optional
• proto (str) –

Optional arguments are inferred from the environment, or omitted if none is set.

Returns:A string indicating the status of the key submission, or an error code.

Doctest:

>>> l = listen()
>>> _ = submit_flag('flag', server='localhost', port=l.lport)
>>> c = l.wait_for_connection()
>>> c.recvall().split()
['flag', 'unnamed-exploit', 'unknown-target', 'unknown-team']

pwnlib.fmtstr — Format string bug exploitation tools

Provide some tools to exploit format string bug

Examples

>>> program = tempfile.mktemp()
>>> source  = program + ".c"
>>> write(source, '''
... #include <stdio.h>
... #include <stdlib.h>
... #include <unistd.h>
... #include <sys/mman.h>
... #define MEMORY_ADDRESS ((void*)0x11111000)
... #define MEMORY_SIZE 1024
... #define TARGET ((int *) 0x11111110)
... int main(int argc, char const *argv[])
... {
...        char buff[1024];
...        void *ptr = NULL;
...        int *my_var = TARGET;
...        ptr = mmap(MEMORY_ADDRESS, MEMORY_SIZE, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE, 0, 0);
...        if(ptr != MEMORY_ADDRESS)
...        {
...                perror("mmap");
...                return EXIT_FAILURE;
...        }
...        *my_var = 0x41414141;
...        write(1, &my_var, sizeof(int *));
...        scanf("%s", buff);
...        dprintf(2, buff);
...        write(1, my_var, sizeof(int));
...        return 0;
... }''')
>>> cmdline = ["gcc", source, "-Wno-format-security", "-m32", "-o", program]
>>> process(cmdline).wait_for_close()
>>> def exec_fmt(payload):
...     p = process(program)
...     p.sendline(payload)
...     return p.recvall()
...
>>> autofmt = FmtStr(exec_fmt)
>>> offset = autofmt.offset
>>> p = process(program, stderr=PIPE)
>>> addr = unpack(p.recv(4))
>>> payload = fmtstr_payload(offset, {addr: 0x1337babe})
>>> p.sendline(payload)
>>> print hex(unpack(p.recv(4)))
0x1337babe

Example - Payload generation

# we want to do 3 writes
writes = {0x08041337:   0xbfffffff,
          0x08041337+4: 0x1337babe,
          0x08041337+8: 0xdeadbeef}

# the printf() call already writes some bytes
# for example :
# strcat(dest, "blabla :", 256);
# strcat(dest, your_input, 256);
# printf(dest);
# Here, numbwritten parameter must be 8
payload = fmtstr_payload(5, writes, numbwritten=8)

Example - Automated exploitation

# Assume a process that reads a string
# and gives this string as the first argument
# of a printf() call
# It do this indefinitely
p = process('./vulnerable')

# Function called in order to send a payload
def send_payload(payload):
        log.info("payload = %s" % repr(payload))
        p.sendline(payload)
        return p.recv()

# Create a FmtStr object and give to him the function
format_string = FmtStr(execute_fmt=send_payload)
format_string.write(0x0, 0x1337babe) # write 0x1337babe at 0x0
format_string.write(0x1337babe, 0x0) # write 0x0 at 0x1337babe
format_string.execute_writes()

class pwnlib.fmtstr.FmtStr(execute_fmt, offset=None, padlen=0, numbwritten=0)

Provides an automated format string exploitation.

It takes a function which is called every time the automated process want to communicate with the vulnerable process. this function takes a parameter with the payload that you have to send to the vulnerable process and must return the process returns.

If the offset parameter is not given, then try to find the right offset by leaking stack data.

Parameters:

• execute_fmt (function) – function to call for communicate with the vulnerable process
• offset (int) – the first formatter’s offset you control
• padlen (int) – size of the pad you want to add before the payload
• numbwritten (int) – number of already written bytes

execute_writes() → None

Makes payload and send it to the vulnerable process

Returns:None

write(addr, data) → None

In order to tell : I want to write data at addr.

Parameters:

• addr (int) – the address where you want to write
• data (int) – the data that you want to write addr

Returns:

None

Examples

>>> def send_fmt_payload(payload):
...     print repr(payload)
...
>>> f = FmtStr(send_fmt_payload, offset=5)
>>> f.write(0x08040506, 0x1337babe)
>>> f.execute_writes()
'\x06\x05\x04\x08\x07\x05\x04\x08\x08\x05\x04\x08\t\x05\x04\x08%174c%5$hhn%252c%6$hhn%125c%7$hhn%220c%8$hhn'

pwnlib.fmtstr.fmtstr_payload(offset, writes, numbwritten=0, write_size='byte') → str

Makes payload with given parameter. It can generate payload for 32 or 64 bits architectures. The size of the addr is taken from context.bits

Parameters:

• offset (int) – the first formatter’s offset you control
• writes (dict) – dict with addr, value {addr: value, addr2: value2}
• numbwritten (int) – number of byte already written by the printf function
• write_size (str) – must be byte, short or int. Tells if you want to write byte by byte, short by short or int by int (hhn, hn or n)

Returns:

The payload in order to do needed writes

Examples

>>> context.clear(arch = 'amd64')
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='int'))
'\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00%322419374c%1$n%3972547906c%2$n'
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='short'))
'\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00\x00%47774c%1$hn%22649c%2$hn%60617c%3$hn%4$hn'
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='byte'))
'\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00\x00\x07\x00\x00\x00\x00\x00\x00\x00%126c%1$hhn%252c%2$hhn%125c%3$hhn%220c%4$hhn%237c%5$hhn%6$hhn%7$hhn%8$hhn'
>>> context.clear(arch = 'i386')
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='int'))
'\x00\x00\x00\x00%322419386c%1$n'
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='short'))
'\x00\x00\x00\x00\x02\x00\x00\x00%47798c%1$hn%22649c%2$hn'
>>> print repr(fmtstr_payload(1, {0x0: 0x1337babe}, write_size='byte'))
'\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00%174c%1$hhn%252c%2$hhn%125c%3$hhn%220c%4$hhn'

pwnlib.gdb — Working with GDB

attach(target, execute = None, exe = None, arch = None, ssh = None) -> None

在新的终端中启动终端，并将其attach到 target 上。除了 target 是 (host, port) 外，pwnlib.util.proc.pidof() 用来寻找 target 的PID。在那种情况下， target 应该为 一个GDB Server。

如果在本地运行，并且没有提供 exe ，那么我们就尝试分析运行 GDB Server(qemu,gdbserver) 命令的程序，寻找目标二进制文件的路径。注意，如果PID 是一 个已知的(当目标不是GDB Server), exe 将会从 /proc/<pid>/exe 中读取。

如果安装了gdb-multiarch, 我们就使用它，否则就使用gdb。参数如下

• target - 要被attach到的target。
• execute (str or file) - attach 之后，GDB 要运行的脚本。
• exe (str) - 目标二进制程序的路径
• arch (str) - 目标二进制程序的架构，如果 exe 已知的话，GDB 将会进行自动检测（如果支持的话）。

返回值为None。

pwnlib.gdb.debug(args) -> tube

使用给定的命令行启动GDB Server，然后启动GDB，并将其attach到GDB Server上。

参数如下：

• args - 与传给 pwnlib.tubes.process 的参数一致。
• ssh - 用于启动进程的远程ssh会话。这样的话，就会自动启动端口转发，然后gdb就可以在本地运行了。

返回值为连接到目标进程的tube。

pwnlib.gdb.debug_shellcode(*a,**kw)

创建一个ELF文件，并且使用GDB启动它。

参数如下：

• data (str) - 经过汇编的shellcode。
• kwargs (dict) - 传给context的参数(e.g arch=’arm’)。

返回一个管道，这个管道会和stdin/stdout/stderr连接在一起。

pwnlib.gdb.debug_assembly(*a,**kw)

创建一个ELF文件，并且使用GDB启动它。

这和debug_shellcode一样，不仅可以使用所有已经定义在GDB里的符号，而且它还省去了我们对asm的显式调用。

pwnlib.gdb.find_module_addresses(binary,ssh=None,ulimit=False)

通过使用gdb来查找模块。

由于一些服务器会禁止 proc/$pid/map ，所以我们不能够使用这个。这个虽然阻断了GDB中的 info proc ，但是 info sharedlibrary 仍然可以执行。 除此之外， info sharedlibrary 也在FreeBSD上工作，但是，这上面可能没有启动procfs或者说它不可用。

输出的结果就像这个一样:

info proc mapping
process 13961
warning: unable to open /proc file '/proc/13961/maps'

info sharedlibrary
From        To          Syms Read   Shared Object Library
0xf7c820    0xf7ff505f  Yes (*)     /lib/ld-linux.so.2
0xf7fbb650  0xf7fc79f8  Yes         /lib32/libpthread.so.0
0xf7e26f10  0xf7f5b51c  Yes (*)     /lib32/libc.so.6
(*): Shared library is missing debugging information.

注意由 info sharedlibrary 提供的最初始的地址就是 .text 段的地址，并不是镜像基地址。

这个方法自动化了下面的流程：

1. 从远程下载二进制文件。
2. 爬取GDB的信息。
3. 为ELF文件加载每一个库。
4. 修复基地址 vs .text 段地址

参数如下：

• binary (str) - 远程服务器上二进制文件的路径。
• ssh (pwnlib.tubes.tube) - 通过该种方式加载二进制文件的方式，如果什么也不填的话，将会使用 pwnlib.tubes.process.process
• ulimit (bool) - 如果设置为真的话，将会在启动GDB之前执行 ulimit -s unlimited

返回值一个列表，其中每个元素都具有正确的基地址。 :: OB

>>> with context.local(log_level=9999):
...     shell = ssh(host='bandit.labs.overthewire.org',user='bandit0',password='bandit0')
...     bash_libs = gdb.find_module_addresses('/bin/bash', shell)
>>> os.path.basename(bash_libs[0].path)
'libc.so.6'
>>> hex(bash_libs[0].symbols['system'])
'0x7ffff7634660'

pwnlib.log — Logging stuff

Logging module for printing status during an exploit, and internally within pwntools.

Exploit Developers

By using the standard from pwn import *, an object named log will be inserted into the global namespace. You can use this to print out status messages during exploitation.

For example,:

log.info('Hello, world!')

prints:

[*] Hello, world!

Additionally, there are some nifty mechanisms for performing status updates on a running job (e.g. when brute-forcing).:

p = log.progress('Working')
p.status('Reticulating splines')
time.sleep(1)
p.success('Got a shell!')

The verbosity of logging can be most easily controlled by setting log_level on the global context object.:

log.info("No you see me")
context.log_level = 'error'
log.info("Now you don't")

The purpose of this attribute is to control what gets printed to the screen, not what gets emitted. This means that you can put all logging events into a log file, while only wanting to see a small subset of them on your screen.

Pwnlib Developers

A module-specific logger can be imported into the module via:

from pwnlib.log import getLogger
log = getLogger(__name__)

This provides an easy way to filter logging programmatically or via a configuration file for debugging.

When using progress, you should use the with keyword to manage scoping, to ensure the spinner stops if an exception is thrown.

Technical details

Familiarity with the logging module is assumed.

A pwnlib root logger named ‘pwnlib’ is created and a custom handler and formatter is installed for it. The handler determines its logging level from context.log_level.

Ideally context.log_level should only affect which records will be emitted by the handler such that e.g. logging to a file will not be changed by it. But for performance reasons it is not feasible log everything in the normal case. In particular there are tight loops inside pwnlib.tubes.tube, which we would like to be able to debug, but if we are not debugging them, they should not spit out messages (even to a log file). For this reason there are a few places inside pwnlib, that will not even emit a record without context.log_level being set to logging.DEBUG or below.

Log records created by Progress and Logger objects will set 'pwnlib_msgtype' on the extra field to signal which kind of message was generated. This information is used by the formatter to prepend a symbol to the message, e.g. '[+] ' in '[+] got a shell!'

This field is ignored when using the logging module’s standard formatters.

All status updates (which are not dropped due to throttling) on progress loggers result in a log record being created. The extra field then carries a reference to the Progress logger as 'pwnlib_progress'.

If the custom handler determines that term.term_mode is enabled, log records that have a 'pwnlib_progess' in their extra field will not result in a message being emitted but rather an animated progress line (with a spinner!) being created. Note that other handlers will still see a meaningful log record.

The custom handler will only handle log records whith a level of at least context.log_level. Thus if e.g. the level for the 'pwnlib.tubes.ssh' is set to 'DEBUG' no additional output will show up unless context.log_level is also set to 'DEBUG'. Other handlers will however see the extra log records generated by the 'pwnlib.tubes.ssh' logger.

pwnlib.log.install_default_handler()

Instantiates a Handler and Formatter and installs them for the pwnlib root logger. This function is automatically called from when importing pwn.

class pwnlib.log.Progress(logger, msg, status, level, args, kwargs)

Progress logger used to generate log records associated with some running job. Instances can be used as context managers which will automatically declare the running job a success upon exit or a failure upon a thrown exception. After success() or failure() is called the status can no longer be updated.

This class is intended for internal use. Progress loggers should be created using Logger.progress().

status(status, *args, **kwargs)

Logs a status update for the running job.

If the progress logger is animated the status line will be updated in place.

Status updates are throttled at one update per 100ms.

success(status = 'Done', *args, **kwargs)

Logs that the running job succeeded. No further status updates are allowed.

If the Logger is animated, the animation is stopped.

failure(message)

Logs that the running job failed. No further status updates are allowed.

If the Logger is animated, the animation is stopped.

class pwnlib.log.Logger(logger=None)

A class akin to the logging.LoggerAdapter class. All public methods defined on logging.Logger instances are defined on this class.

Also adds some pwnlib flavor:

• progress() (alias waitfor())
• success()
• failure()
• indented()
• info_once()
• warning_once() (alias warn_once())

Adds pwnlib-specific information for coloring, indentation and progress logging via log records extra field.

Loggers instantiated with getLogger() will be of this class.

progress(message, status = '', *args, level = logging.INFO, **kwargs) → Progress

Creates a new progress logger which creates log records with log level level.

Progress status can be updated using Progress.status() and stopped using Progress.success() or Progress.failure().

If term.term_mode is enabled the progress logger will be animated.

The progress manager also functions as a context manager. Using context managers ensures that animations stop even if an exception is raised.

with log.progress('Trying something...') as p:
    for i in range(10):
        p.status("At %i" % i)
        time.sleep(0.5)
    x = 1/0

waitfor(*args, **kwargs)

Alias for progress().

indented(message, *args, level = logging.INFO, **kwargs)

Log a message but don’t put a line prefix on it.

Parameters:level (int) – Alternate log level at which to set the indented message. Defaults to logging.INFO.

success(message, *args, **kwargs)

Logs a success message.

failure(message, *args, **kwargs)

Logs a failure message.

info_once(message, *args, **kwargs)

Logs an info message. The same message is never printed again.

warning_once(message, *args, **kwargs)

Logs a warning message. The same message is never printed again.

warn_once(*args, **kwargs)

Alias for warning_once().

debug(message, *args, **kwargs)

Logs a debug message.

info(message, *args, **kwargs)

Logs an info message.

warning(message, *args, **kwargs)

Logs a warning message.

warn(*args, **kwargs)

Alias for warning().

error(message, *args, **kwargs)

To be called outside an exception handler.

Logs an error message, then raises a PwnlibException.

exception(message, *args, **kwargs)

To be called from an exception handler.

Logs a error message, then re-raises the current exception.

critical(message, *args, **kwargs)

Logs a critical message.

log(level, message, *args, **kwargs)

Logs a message with log level level. The pwnlib formatter will use the default logging formater to format this message.

isEnabledFor(level) → bool

See if the underlying logger is enabled for the specified level.

setLevel(level)

Set the logging level for the underlying logger.

addHandler(handler)

Add the specified handler to the underlying logger.

removeHandler(handler)

Remove the specified handler from the underlying logger.

class pwnlib.log.Handler(stream=None)

A custom handler class. This class will report whatever context.log_level is currently set to as its log level.

If term.term_mode is enabled log records originating from a progress logger will not be emitted but rather an animated progress line will be created.

An instance of this handler is added to the 'pwnlib' logger.

emit(record)

Emit a log record or create/update an animated progress logger depending on whether term.term_mode is enabled.

class pwnlib.log.Formatter(fmt=None, datefmt=None)

Logging formatter which performs custom formatting for log records containing the 'pwnlib_msgtype' attribute. Other records are formatted using the logging modules default formatter.

If 'pwnlib_msgtype' is set, it performs the following actions:

• A prefix looked up in _msgtype_prefixes is prepended to the message.
• The message is prefixed such that it starts on column four.
• If the message spans multiple lines they are split, and all subsequent lines are indented.

This formatter is used by the handler installed on the 'pwnlib' logger.

pwnlib.memleak — Helper class for leaking memory

class pwnlib.memleak.MemLeak(f, search_range=20, reraise=True, relative=False)

MemLeak is a caching and heuristic tool for exploiting memory leaks.

It can be used as a decorator, around functions of the form:

def some_leaker(addr):

... return data_as_string_or_None

It will cache leaked memory (which requires either non-randomized static data or a continouous session). If required, dynamic or known data can be set with the set-functions, but this is usually not required. If a byte cannot be recovered, it will try to leak nearby bytes in the hope that the byte is recovered as a side-effect.

Parameters:

• f (function) – The leaker function.
• search_range (int) – How many bytes to search backwards in case an address does not work.
• reraise (bool) – Whether to reraise call pwnlib.log.warning() in case the leaker function throws an exception.

Example

>>> import pwnlib
>>> binsh = pwnlib.util.misc.read('/bin/sh')
>>> @pwnlib.memleak.MemLeak
... def leaker(addr):
...     print "leaking 0x%x" % addr
...     return binsh[addr:addr+4]
>>> leaker.s(0)[:4]
leaking 0x0
leaking 0x4
'\x7fELF'
>>> leaker[:4]
'\x7fELF'
>>> hex(leaker.d(0))
'0x464c457f'
>>> hex(leaker.clearb(1))
'0x45'
>>> hex(leaker.d(0))
leaking 0x1
'0x464c457f'
>>> @pwnlib.memleak.MemLeak
... def leaker_nonulls(addr):
...     print "leaking 0x%x" % addr
...     if addr & 0xff == 0:
...         return None
...     return binsh[addr:addr+4]
>>> leaker_nonulls.d(0) == None
leaking 0x0
True
>>> leaker_nonulls[0x100:0x104] == binsh[0x100:0x104]
leaking 0x100
leaking 0xff
leaking 0x103
True

>>> memory = {-4+i: c for i,c in enumerate('wxyzABCDE')}
>>> def relative_leak(index):
...     return memory.get(index, None)
>>> leak = pwnlib.memleak.MemLeak(relative_leak, relative = True)
>>> leak[-1:2]
'zAB'

static NoNewlines(function)

Wrapper for leak functions such that addresses which contain newline bytes are not leaked.

This is useful if the address which is used for the leak is provided by e.g. fgets().

static NoNulls(function)

Wrapper for leak functions such that addresses which contain NULL bytes are not leaked.

This is useful if the address which is used for the leak is read in via a string-reading function like scanf("%s") or smilar.

static NoWhitespace(function)

Wrapper for leak functions such that addresses which contain whitespace bytes are not leaked.

This is useful if the address which is used for the leak is read in via e.g. scanf().

static String(function)

Wrapper for leak functions which leak strings, such that a NULL terminator is automaticall added.

This is useful if the data leaked is printed out as a NULL-terminated string, via e.g. printf().

b(addr, ndx = 0) → int

Leak byte at ((uint8_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+2], reraise=False)
>>> l.b(0) == ord('a')
True
>>> l.b(25) == ord('z')
True
>>> l.b(26) is None
True

clearb(addr, ndx = 0) → int

Clears byte at ((uint8_t*)addr)[ndx] from the cache and returns the removed value or None if the address was not completely set.

Examples

>>> l = MemLeak(lambda a: None)
>>> l.cache = {0:'a'}
>>> l.n(0,1) == 'a'
True
>>> l.clearb(0) == unpack('a', 8)
True
>>> l.cache
{}
>>> l.clearb(0) is None
True

cleard(addr, ndx = 0) → int

Clears dword at ((uint32_t*)addr)[ndx] from the cache and returns the removed value or None if the address was not completely set.

Examples

>>> l = MemLeak(lambda a: None)
>>> l.cache = {0:'a', 1: 'b', 2: 'c', 3: 'd'}
>>> l.n(0, 4) == 'abcd'
True
>>> l.cleard(0) == unpack('abcd', 32)
True
>>> l.cache
{}

clearq(addr, ndx = 0) → int

Clears qword at ((uint64_t*)addr)[ndx] from the cache and returns the removed value or None if the address was not completely set.

Examples

>>> c = MemLeak(lambda addr: '')
>>> c.cache = {x:'x' for x in range(0x100, 0x108)}
>>> c.clearq(0x100) == unpack('xxxxxxxx', 64)
True
>>> c.cache == {}
True

clearw(addr, ndx = 0) → int

Clears word at ((uint16_t*)addr)[ndx] from the cache and returns the removed value or None if the address was not completely set.

Examples

>>> l = MemLeak(lambda a: None)
>>> l.cache = {0:'a', 1: 'b'}
>>> l.n(0, 2) == 'ab'
True
>>> l.clearw(0) == unpack('ab', 16)
True
>>> l.cache
{}

d(addr, ndx = 0) → int

Leak dword at ((uint32_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+8], reraise=False)
>>> l.d(0) == unpack('abcd', 32)
True
>>> l.d(22) == unpack('wxyz', 32)
True
>>> l.d(23) is None
True

field(address, obj)

field(address, field) => a structure field.

Leak a field from a structure.

Parameters:

• address (int) – Base address to calculate offsets from
• field (obj) – Instance of a ctypes field

Return Value:

The type of the return value will be dictated by the type of field.

field_compare(address, obj, expected)

field_compare(address, field, expected) ==> bool

Leak a field from a structure, with an expected value. As soon as any mismatch is found, stop leaking the structure.

Parameters:

• address (int) – Base address to calculate offsets from
• field (obj) – Instance of a ctypes field
• expected (int,str) – Expected value

Return Value:

The type of the return value will be dictated by the type of field.

n(addr, ndx = 0) → str

Leak numb bytes at addr.

Returns:A string with the leaked bytes, will return None if any are missing

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+4], reraise=False)
>>> l.n(0,1) == 'a'
True
>>> l.n(0,26) == data
True
>>> len(l.n(0,26)) == 26
True
>>> l.n(0,27) is None
True

p(addr, ndx = 0) → int

Leak a pointer-width value at ((void**) addr)[ndx]

p16(addr, val, ndx=0)

Sets word at ((uint16_t*)addr)[ndx] to val in the cache.

Examples

>>> l = MemLeak(lambda x: '')
>>> l.cache == {}
True
>>> l.setw(33, 0x41)
>>> l.cache == {33: 'A', 34: '\x00'}
True

p32(addr, val, ndx=0)

Sets dword at ((uint32_t*)addr)[ndx] to val in the cache.

Examples

See setw().

p64(addr, val, ndx=0)

Sets qword at ((uint64_t*)addr)[ndx] to val in the cache.

Examples

See setw().

p8(addr, val, ndx=0)

Sets byte at ((uint8_t*)addr)[ndx] to val in the cache.

Examples

>>> l = MemLeak(lambda x: '')
>>> l.cache == {}
True
>>> l.setb(33, 0x41)
>>> l.cache == {33: 'A'}
True

q(addr, ndx = 0) → int

Leak qword at ((uint64_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+16], reraise=False)
>>> l.q(0) == unpack('abcdefgh', 64)
True
>>> l.q(18) == unpack('stuvwxyz', 64)
True
>>> l.q(19) is None
True

raw(addr, numb) → list

Leak numb bytes at addr

s(addr) → str

Leak bytes at addr until failure or a nullbyte is found

Returns:A string, without a NULL terminator. The returned string will be empty if the first byte is a NULL terminator, or if the first byte could not be retrieved.

Examples

>>> data = "Hello\x00World"
>>> l = MemLeak(lambda a: data[a:a+4], reraise=False)
>>> l.s(0) == "Hello"
True
>>> l.s(5) == ""
True
>>> l.s(6) == "World"
True
>>> l.s(999) == ""
True

setb(addr, val, ndx=0)

Sets byte at ((uint8_t*)addr)[ndx] to val in the cache.

Examples

>>> l = MemLeak(lambda x: '')
>>> l.cache == {}
True
>>> l.setb(33, 0x41)
>>> l.cache == {33: 'A'}
True

setd(addr, val, ndx=0)

Sets dword at ((uint32_t*)addr)[ndx] to val in the cache.

Examples

See setw().

setq(addr, val, ndx=0)

Sets qword at ((uint64_t*)addr)[ndx] to val in the cache.

Examples

See setw().

sets(addr, val, null_terminate=True)

Set known string at addr, which will be optionally be null-terminated

Note that this method is a bit dumb about how it handles the data. It will null-terminate the data, but it will not stop at the first null.

Examples

>>> l = MemLeak(lambda x: '')
>>> l.cache == {}
True
>>> l.sets(0, 'H\x00ello')
>>> l.cache == {0: 'H', 1: '\x00', 2: 'e', 3: 'l', 4: 'l', 5: 'o', 6: '\x00'}
True

setw(addr, val, ndx=0)

Sets word at ((uint16_t*)addr)[ndx] to val in the cache.

Examples

>>> l = MemLeak(lambda x: '')
>>> l.cache == {}
True
>>> l.setw(33, 0x41)
>>> l.cache == {33: 'A', 34: '\x00'}
True

struct(address, struct)

struct(address, struct) => structure object Leak an entire structure. :param address: Addess of structure in memory :type address: int :param struct: A ctypes structure to be instantiated with leaked data :type struct: class

Return Value:

An instance of the provided struct class, with the leaked data decoded

Examples

>>> @pwnlib.memleak.MemLeak
... def leaker(addr):
...     return "A"
>>> e = leaker.struct(0, pwnlib.elf.Elf32_Phdr)
>>> hex(e.p_paddr)
'0x41414141'

u16(addr, ndx=0)

w(addr, ndx = 0) -> int

Leak word at ((uint16_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+4], reraise=False)
>>> l.w(0) == unpack('ab', 16)
True
>>> l.w(24) == unpack('yz', 16)
True
>>> l.w(25) is None
True

u32(addr, ndx=0)

d(addr, ndx = 0) -> int

Leak dword at ((uint32_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+8], reraise=False)
>>> l.d(0) == unpack('abcd', 32)
True
>>> l.d(22) == unpack('wxyz', 32)
True
>>> l.d(23) is None
True

u64(addr, ndx=0)

q(addr, ndx = 0) -> int

Leak qword at ((uint64_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+16], reraise=False)
>>> l.q(0) == unpack('abcdefgh', 64)
True
>>> l.q(18) == unpack('stuvwxyz', 64)
True
>>> l.q(19) is None
True

u8(addr, ndx=0)

b(addr, ndx = 0) -> int

Leak byte at ((uint8_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+2], reraise=False)
>>> l.b(0) == ord('a')
True
>>> l.b(25) == ord('z')
True
>>> l.b(26) is None
True

w(addr, ndx = 0) → int

Leak word at ((uint16_t*) addr)[ndx]

Examples

>>> import string
>>> data = string.ascii_lowercase
>>> l = MemLeak(lambda a: data[a:a+4], reraise=False)
>>> l.w(0) == unpack('ab', 16)
True
>>> l.w(24) == unpack('yz', 16)
True
>>> l.w(25) is None
True

pwnlib.replacements — Replacements for various functions

Improved replacements for standard functions

pwnlib.replacements.sleep(n)

Replacement for time.sleep(), which does not return if a signal is received.

Parameters:n (int) – Number of seconds to sleep.

pwnlib.rop — Return Oriented Programming

Submodules

pwnlib.rop.rop — Return Oriented Programming

Return Oriented Programming

Manual ROP

The ROP tool can be used to build stacks pretty trivially. Let’s create a fake binary which has some symbols which might have been useful.

>>> context.clear(arch='i386')
>>> binary = ELF.from_assembly('add esp, 0x10; ret')
>>> binary.symbols = {'read': 0xdeadbeef, 'write': 0xdecafbad, 'exit': 0xfeedface}

Creating a ROP object which looks up symbols in the binary is pretty straightforward.

>>> rop = ROP(binary)

With the ROP object, you can manually add stack frames.

>>> rop.raw(0)
>>> rop.raw(unpack('abcd'))
>>> rop.raw(2)

Inspecting the ROP stack is easy, and laid out in an easy-to-read manner.

>>> print rop.dump()
0x0000:              0x0
0x0004:       0x64636261
0x0008:              0x2

The ROP module is also aware of how to make function calls with standard Linux ABIs.

>>> rop.call('read', [4,5,6])
>>> print rop.dump()
0x0000:              0x0
0x0004:       0x64636261
0x0008:              0x2
0x000c:       0xdeadbeef read(4, 5, 6)
0x0010:           'eaaa' <pad>
0x0014:              0x4 arg0
0x0018:              0x5 arg1
0x001c:              0x6 arg2

You can also use a shorthand to invoke calls. The stack is automatically adjusted for the next frame

>>> rop.write(7,8,9)
>>> rop.exit()
>>> print rop.dump()
0x0000:              0x0
0x0004:       0x64636261
0x0008:              0x2
0x000c:       0xdeadbeef read(4, 5, 6)
0x0010:       0x10000000 <adjust: add esp, 0x10; ret>
0x0014:              0x4 arg0
0x0018:              0x5 arg1
0x001c:              0x6 arg2
0x0020:           'iaaa' <pad>
0x0024:       0xdecafbad write(7, 8, 9)
0x0028:       0x10000000 <adjust: add esp, 0x10; ret>
0x002c:              0x7 arg0
0x0030:              0x8 arg1
0x0034:              0x9 arg2
0x0038:           'oaaa' <pad>
0x003c:       0xfeedface exit()
0x0040:           'qaaa' <pad>

ROP Example

Let’s assume we have a trivial binary that just reads some data onto the stack, and returns.

>>> context.clear(arch='i386')
>>> c = constants
>>> assembly =  'read:'      + shellcraft.read(c.STDIN_FILENO, 'esp', 1024)
>>> assembly += 'ret\n'

Let’s provide some simple gadgets:

>>> assembly += 'add_esp: add esp, 0x10; ret\n'

And perhaps a nice “write” function.

>>> assembly += 'write: enter 0,0\n'
>>> assembly += '    mov ebx, [ebp+4+4]\n'
>>> assembly += '    mov ecx, [ebp+4+8]\n'
>>> assembly += '    mov edx, [ebp+4+12]\n'
>>> assembly += shellcraft.write('ebx', 'ecx', 'edx')
>>> assembly += '    leave\n'
>>> assembly += '    ret\n'
>>> assembly += 'flag: .asciz "The flag"\n'

And a way to exit cleanly.

>>> assembly += 'exit: ' + shellcraft.exit(0)
>>> binary   = ELF.from_assembly(assembly)

Finally, let’s build our ROP stack

>>> rop = ROP(binary)
>>> rop.write(c.STDOUT_FILENO, binary.symbols['flag'], 8)
>>> rop.exit()
>>> print rop.dump()
0x0000:       0x10000012 write(STDOUT_FILENO, 268435494, 8)
0x0004:       0x1000000e <adjust: add esp, 0x10; ret>
0x0008:              0x1 arg0
0x000c:       0x10000026 flag
0x0010:              0x8 arg2
0x0014:           'faaa' <pad>
0x0018:       0x1000002f exit()
0x001c:           'haaa' <pad>

The raw data from the ROP stack is available via str.

>>> raw_rop = str(rop)
>>> print enhex(raw_rop)
120000100e000010010000002600001008000000666161612f00001068616161

Let’s try it out!

>>> p = process(binary.path)
>>> p.send(raw_rop)
>>> print p.recvall(timeout=5)
The flag

ROP + Sigreturn

In some cases, control of the desired register is not available. However, if you have control of the stack, EAX, and can find a int 0x80 gadget, you can use sigreturn.

Even better, this happens automagically.

Our example binary will read some data onto the stack, and not do anything else interesting.

>>> context.clear(arch='i386')
>>> c = constants
>>> assembly =  'read:'      + shellcraft.read(c.STDIN_FILENO, 'esp', 1024)
>>> assembly += 'ret\n'
>>> assembly += 'pop eax; ret\n'
>>> assembly += 'int 0x80\n'
>>> assembly += 'binsh: .asciz "/bin/sh"'
>>> binary    = ELF.from_assembly(assembly)

Let’s create a ROP object and invoke the call.

>>> context.kernel = 'amd64'
>>> rop   = ROP(binary)
>>> binsh = binary.symbols['binsh']
>>> rop.execve(binsh, 0, 0)

That’s all there is to it.

>>> print rop.dump()
0x0000:       0x1000000e pop eax; ret
0x0004:             0x77
0x0008:       0x1000000b int 0x80
0x000c:              0x0 gs
0x0010:              0x0 fs
0x0014:              0x0 es
0x0018:              0x0 ds
0x001c:              0x0 edi
0x0020:              0x0 esi
0x0024:              0x0 ebp
0x0028:              0x0 esp
0x002c:       0x10000012 ebx = binsh
0x0030:              0x0 edx
0x0034:              0x0 ecx
0x0038:              0xb eax
0x003c:              0x0 trapno
0x0040:              0x0 err
0x0044:       0x1000000b int 0x80
0x0048:             0x23 cs
0x004c:              0x0 eflags
0x0050:              0x0 esp_at_signal
0x0054:             0x2b ss
0x0058:              0x0 fpstate

Let’s try it out!

>>> p = process(binary.path)
>>> p.send(str(rop))
>>> time.sleep(1)
>>> p.sendline('echo hello; exit')
>>> p.recvline()
'hello\n'

class pwnlib.rop.rop.ROP(elfs, base=None, **kwargs)

Class which simplifies the generation of ROP-chains.

Example:

elf = ELF('ropasaurusrex')
rop = ROP(elf)
rop.read(0, elf.bss(0x80))
rop.dump()
# ['0x0000:        0x80482fc (read)',
#  '0x0004:       0xdeadbeef',
#  '0x0008:              0x0',
#  '0x000c:        0x80496a8']
str(rop)
# '\xfc\x82\x04\x08\xef\xbe\xad\xde\x00\x00\x00\x00\xa8\x96\x04\x08'

>>> context.clear(arch = "i386", kernel = 'amd64')
>>> assembly = 'int 0x80; ret; add esp, 0x10; ret; pop eax; ret'
>>> e = ELF.from_assembly(assembly)
>>> e.symbols['funcname'] = e.address + 0x1234
>>> r = ROP(e)
>>> r.funcname(1, 2)
>>> r.funcname(3)
>>> r.execve(4, 5, 6)
>>> print r.dump()
0x0000:       0x10001234 funcname(1, 2)
0x0004:       0x10000003 <adjust: add esp, 0x10; ret>
0x0008:              0x1 arg0
0x000c:              0x2 arg1
0x0010:           'eaaa' <pad>
0x0014:           'faaa' <pad>
0x0018:       0x10001234 funcname(3)
0x001c:       0x10000007 <adjust: pop eax; ret>
0x0020:              0x3 arg0
0x0024:       0x10000007 pop eax; ret
0x0028:             0x77
0x002c:       0x10000000 int 0x80
0x0030:              0x0 gs
0x0034:              0x0 fs
0x0038:              0x0 es
0x003c:              0x0 ds
0x0040:              0x0 edi
0x0044:              0x0 esi
0x0048:              0x0 ebp
0x004c:              0x0 esp
0x0050:              0x4 ebx
0x0054:              0x6 edx
0x0058:              0x5 ecx
0x005c:              0xb eax
0x0060:              0x0 trapno
0x0064:              0x0 err
0x0068:       0x10000000 int 0x80
0x006c:             0x23 cs
0x0070:              0x0 eflags
0x0074:              0x0 esp_at_signal
0x0078:             0x2b ss
0x007c:              0x0 fpstate

>>> r = ROP(e, 0x8048000)
>>> r.funcname(1, 2)
>>> r.funcname(3)
>>> r.execve(4, 5, 6)
>>> print r.dump()
0x8048000:       0x10001234 funcname(1, 2)
0x8048004:       0x10000003 <adjust: add esp, 0x10; ret>
0x8048008:              0x1 arg0
0x804800c:              0x2 arg1
0x8048010:           'eaaa' <pad>
0x8048014:           'faaa' <pad>
0x8048018:       0x10001234 funcname(3)
0x804801c:       0x10000007 <adjust: pop eax; ret>
0x8048020:              0x3 arg0
0x8048024:       0x10000007 pop eax; ret
0x8048028:             0x77
0x804802c:       0x10000000 int 0x80
0x8048030:              0x0 gs
0x8048034:              0x0 fs
0x8048038:              0x0 es
0x804803c:              0x0 ds
0x8048040:              0x0 edi
0x8048044:              0x0 esi
0x8048048:              0x0 ebp
0x804804c:        0x8048080 esp
0x8048050:              0x4 ebx
0x8048054:              0x6 edx
0x8048058:              0x5 ecx
0x804805c:              0xb eax
0x8048060:              0x0 trapno
0x8048064:              0x0 err
0x8048068:       0x10000000 int 0x80
0x804806c:             0x23 cs
0x8048070:              0x0 eflags
0x8048074:              0x0 esp_at_signal
0x8048078:             0x2b ss
0x804807c:              0x0 fpstate

base = 0

Stack address where the first byte of the ROP chain lies, if known.

build(base=None, description=None)

Construct the ROP chain into a list of elements which can be passed to flat().

Parameters:

• base (int) – The base address to build the rop-chain from. Defaults to base.
• description (dict) – Optional output argument, which will gets a mapping of address: description for each address on the stack, starting at base.

call(resolvable, arguments=(), abi=None, **kwargs)

Add a call to the ROP chain

Parameters:

• resolvable (str,int) – Value which can be looked up via ‘resolve’, or is already an integer.
• arguments (list) – List of arguments which can be passed to pack(). Alternately, if a base address is set, arbitrarily nested structures of strings or integers can be provided.

chain()

Build the ROP chain

Returns:str containing raw ROP bytes

describe(object)

Return a description for an object in the ROP stack

dump()

Dump the ROP chain in an easy-to-read manner

elfs = []

List of ELF files which are available for mining gadgets

find_gadget(instructions)

Returns a gadget with the exact sequence of instructions specified in the instructions argument.

generatePadding(offset, count)

Generates padding to be inserted into the ROP stack.

migrate(next_base)

Explicitly set $sp, by using a leave; ret gadget

migrated = False

Whether or not the ROP chain directly sets the stack pointer to a value which is not contiguous

raw(value)

Adds a raw integer or string to the ROP chain.

If your architecture requires aligned values, then make sure that any given string is aligned!

Parameters:data (int/str) – The raw value to put onto the rop chain.

resolve(resolvable)

Resolves a symbol to an address

Parameters:resolvable (str,int) – Thing to convert into an address Returns:int containing address of ‘resolvable’, or None

search(move=0, regs=None, order='size')

Search for a gadget which matches the specified criteria.

Parameters:

• move (int) – Minimum number of bytes by which the stack pointer is adjusted.
• regs (list) – Minimum list of registers which are popped off the stack.
• order (str) – Either the string ‘size’ or ‘regs’. Decides how to order multiple gadgets the fulfill the requirements.

The search will try to minimize the number of bytes popped more than requested, the number of registers touched besides the requested and the address.

If order == 'size', then gadgets are compared lexicographically by (total_moves, total_regs, addr), otherwise by (total_regs, total_moves, addr).

Returns:A Gadget object

search_iter(move=None, regs=None)

Iterate through all gadgets which move the stack pointer by at least move bytes, and which allow you to set all registers in regs.

setRegisters(registers)

Returns an OrderedDict of addresses/values which will set the specified register context.

Parameters:registers (dict) – Dictionary of {register name: value} Returns:sequence of gadgets, values, etc.}``. Return type:An OrderedDict of ``{register

unresolve(value)

Inverts ‘resolve’. Given an address, it attempts to find a symbol for it in the loaded ELF files. If none is found, it searches all known gadgets, and returns the disassembly

Parameters:value (int) – Address to look up Returns:String containing the symbol name for the address, disassembly for a gadget (if there’s one at that address), or an empty string.

pwnlib.rop.srop — Sigreturn Oriented Programming

Sigreturn ROP (SROP)

Sigreturn is a syscall used to restore the entire register context from memory pointed at by ESP.

We can leverage this during ROP to gain control of registers for which there are not convenient gadgets. The main caveat is that all registers are set, including ESP and EIP (or their equivalents). This means that in order to continue after using a sigreturn frame, the stack pointer must be set accordingly.

i386 Example:

Let’s just print a message out using SROP.

>>> message = "Hello, World"

First, we’ll create our example binary. It just reads some data onto the stack, and invokes the sigreturn syscall. We also make an int 0x80 gadget available, followed immediately by exit(0).

>>> context.clear(arch='i386')
>>> assembly =  'read:'      + shellcraft.read(constants.STDIN_FILENO, 'esp', 1024)
>>> assembly += 'sigreturn:' + shellcraft.sigreturn()
>>> assembly += 'int3:'      + shellcraft.trap()
>>> assembly += 'syscall: '  + shellcraft.syscall()
>>> assembly += 'exit: '     + 'xor ebx, ebx; mov eax, 1; int 0x80;'
>>> assembly += 'message: '  + ('.asciz "%s"' % message)
>>> binary = ELF.from_assembly(assembly)

Let’s construct our frame to have it invoke a write syscall, and dump the message to stdout.

>>> frame = SigreturnFrame(kernel='amd64')
>>> frame.eax = constants.SYS_write
>>> frame.ebx = constants.STDOUT_FILENO
>>> frame.ecx = binary.symbols['message']
>>> frame.edx = len(message)
>>> frame.esp = 0xdeadbeef
>>> frame.eip = binary.symbols['syscall']

Let’s start the process, send the data, and check the message.

>>> p = process(binary.path)
>>> p.send(str(frame))
>>> p.recvn(len(message)) == message
True
>>> p.wait_for_close()
>>> p.poll() == 0
True

amd64 Example:

>>> context.clear()
>>> context.arch = "amd64"
>>> assembly =  'read:'      + shellcraft.read(constants.STDIN_FILENO, 'rsp', 1024)
>>> assembly += 'sigreturn:' + shellcraft.sigreturn()
>>> assembly += 'int3:'      + shellcraft.trap()
>>> assembly += 'syscall: '  + shellcraft.syscall()
>>> assembly += 'exit: '     + 'xor rdi, rdi; mov rax, 60; syscall;'
>>> assembly += 'message: '  + ('.asciz "%s"' % message)
>>> binary = ELF.from_assembly(assembly)
>>> frame = SigreturnFrame()
>>> frame.rax = constants.SYS_write
>>> frame.rdi = constants.STDOUT_FILENO
>>> frame.rsi = binary.symbols['message']
>>> frame.rdx = len(message)
>>> frame.rsp = 0xdeadbeef
>>> frame.rip = binary.symbols['syscall']
>>> p = process(binary.path)
>>> p.send(str(frame))
>>> p.recvn(len(message)) == message
True
>>> p.wait_for_close()
>>> p.poll() == 0
True

arm Example:

>>> context.clear()
>>> context.arch = "arm"
>>> assembly =  'read:'      + shellcraft.read(constants.STDIN_FILENO, 'sp', 1024)
>>> assembly += 'sigreturn:' + shellcraft.sigreturn()
>>> assembly += 'int3:'      + shellcraft.trap()
>>> assembly += 'syscall: '  + shellcraft.syscall()
>>> assembly += 'exit: '     + 'eor r0, r0; mov r7, 0x1; swi #0;'
>>> assembly += 'message: '  + ('.asciz "%s"' % message)
>>> binary = ELF.from_assembly(assembly)
>>> frame = SigreturnFrame()
>>> frame.r7 = constants.SYS_write
>>> frame.r0 = constants.STDOUT_FILENO
>>> frame.r1 = binary.symbols['message']
>>> frame.r2 = len(message)
>>> frame.sp = 0xdead0000
>>> frame.pc = binary.symbols['syscall']
>>> p = process(binary.path)
>>> p.send(str(frame))
>>> p.recvn(len(message)) == message
True
>>> p.wait_for_close()
>>> p.poll() == 0
True

Mips Example:

>>> context.clear()
>>> context.arch = "mips"
>>> context.endian = "big"
>>> assembly =  'read:'      + shellcraft.read(constants.STDIN_FILENO, '$sp', 1024)
>>> assembly += 'sigreturn:' + shellcraft.sigreturn()
>>> assembly += 'syscall: '  + shellcraft.syscall()
>>> assembly += 'exit: '     + shellcraft.exit(0)
>>> assembly += 'message: '  + ('.asciz "%s"' % message)
>>> binary = ELF.from_assembly(assembly)
>>> frame = SigreturnFrame()
>>> frame.v0 = constants.SYS_write
>>> frame.a0 = constants.STDOUT_FILENO
>>> frame.a1 = binary.symbols['message']
>>> frame.a2 = len(message)
>>> frame.sp = 0xdead0000
>>> frame.pc = binary.symbols['syscall']
>>> p = process(binary.path)
>>> p.send(str(frame))
>>> p.recvn(len(message)) == message
True
>>> p.wait_for_close()
>>> p.poll() == 0
True

Mipsel Example:

>>> context.clear()
>>> context.arch = "mips"
>>> context.endian = "little"
>>> assembly =  'read:'      + shellcraft.read(constants.STDIN_FILENO, '$sp', 1024)
>>> assembly += 'sigreturn:' + shellcraft.sigreturn()
>>> assembly += 'syscall: '  + shellcraft.syscall()
>>> assembly += 'exit: '     + shellcraft.exit(0)
>>> assembly += 'message: '  + ('.asciz "%s"' % message)
>>> binary = ELF.from_assembly(assembly)
>>> frame = SigreturnFrame()
>>> frame.v0 = constants.SYS_write
>>> frame.a0 = constants.STDOUT_FILENO
>>> frame.a1 = binary.symbols['message']
>>> frame.a2 = len(message)
>>> frame.sp = 0xdead0000
>>> frame.pc = binary.symbols['syscall']
>>> p = process(binary.path)
>>> p.send(str(frame))
>>> p.recvn(len(message)) == message
True
>>> p.wait_for_close()
>>> p.poll() == 0
True

class pwnlib.rop.srop.SigreturnFrame(*a, **kw)

Crafts a sigreturn frame with values that are loaded up into registers.

Parameters:arch (str) – The architecture. Currently i386 and amd64 are supported.

Examples

Crafting a SigreturnFrame that calls mprotect on amd64

>>> context.clear(arch='amd64')
>>> s = SigreturnFrame()
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 51, 0, 0, 0, 0, 0, 0, 0]
>>> assert len(s) == 248
>>> s.rax = 0xa
>>> s.rdi = 0x00601000
>>> s.rsi = 0x1000
>>> s.rdx = 0x7
>>> assert len(str(s)) == 248
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6295552, 4096, 0, 0, 7, 10, 0, 0, 0, 0, 51, 0, 0, 0, 0, 0, 0, 0]

Crafting a SigreturnFrame that calls mprotect on i386

>>> context.clear(arch='i386')
>>> s = SigreturnFrame(kernel='i386')
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 115, 0, 0, 123, 0]
>>> assert len(s) == 80
>>> s.eax = 125
>>> s.ebx = 0x00601000
>>> s.ecx = 0x1000
>>> s.edx = 0x7
>>> assert len(str(s)) == 80
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 6295552, 7, 4096, 125, 0, 0, 0, 115, 0, 0, 123, 0]

Crafting a SigreturnFrame that calls mprotect on ARM

>>> s = SigreturnFrame(arch='arm')
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1073741840, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1447448577, 288]
>>> s.r0 = 125
>>> s.r1 = 0x00601000
>>> s.r2 = 0x1000
>>> s.r3 = 0x7
>>> assert len(str(s)) == 240
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 6, 0, 0, 125, 6295552, 4096, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1073741840, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1447448577, 288]

Crafting a SigreturnFrame that calls mprotect on MIPS

>>> context.clear()
>>> context.endian = "big"
>>> s = SigreturnFrame(arch='mips')
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
>>> s.v0 = 0x101d
>>> s.a0 = 0x00601000
>>> s.a1 = 0x1000
>>> s.a2 = 0x7
>>> assert len(str(s)) == 296
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4125, 0, 0, 0, 6295552, 0, 4096, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

Crafting a SigreturnFrame that calls mprotect on MIPSel

>>> context.clear()
>>> context.endian = "little"
>>> s = SigreturnFrame(arch='mips')
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
>>> s.v0 = 0x101d
>>> s.a0 = 0x00601000
>>> s.a1 = 0x1000
>>> s.a2 = 0x7
>>> assert len(str(s)) == 292
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4125, 0, 0, 0, 6295552, 0, 4096, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

Crafting a SigreturnFrame that calls mprotect on Aarch64

>>> context.clear()
>>> context.endian = "little"
>>> s = SigreturnFrame(arch='aarch64')
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1179680769, 528]
>>> s.x8 = 0xe2
>>> s.x0 = 0x4000
>>> s.x1 = 0x1000
>>> s.x2 = 0x7
>>> assert len(str(s)) == 600
>>> unpack_many(str(s))
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16384, 0, 4096, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 226, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1179680769, 528]

set_regvalue(reg, val)

Sets a specific reg to a val

pwnlib.runner — Running Shellcode

pwnlib.runner.run_assembly(*a, **kw)

Given an assembly listing, assemble and execute it.

Returns:A pwnlib.tubes.process.process tube to interact with the process.

Example

>>> p = run_assembly('mov ebx, 3; mov eax, SYS_exit; int 0x80;')
>>> p.wait_for_close()
>>> p.poll()
3

>>> p = run_assembly('mov r0, #12; mov r7, #1; svc #0', arch='arm')
>>> p.wait_for_close()
>>> p.poll()
12

pwnlib.runner.run_shellcode(*a, **kw)

Given assembled machine code bytes, execute them.

Example

>>> bytes = asm('mov ebx, 3; mov eax, SYS_exit; int 0x80;')
>>> p = run_shellcode(bytes)
>>> p.wait_for_close()
>>> p.poll()
3

>>> bytes = asm('mov r0, #12; mov r7, #1; svc #0', arch='arm')
>>> p = run_shellcode(bytes, arch='arm')
>>> p.wait_for_close()
>>> p.poll()
12

pwnlib.runner.run_assembly_exitcode(*a, **kw)

Given an assembly listing, assemble and execute it, and wait for the process to die.

Returns:The exit code of the process.

Example

>>> run_assembly_exitcode('mov ebx, 3; mov eax, SYS_exit; int 0x80;')
3

pwnlib.runner.run_shellcode_exitcode(*a, **kw)

Given assembled machine code bytes, execute them, and wait for the process to die.

Returns:The exit code of the process.

Example

>>> bytes = asm('mov ebx, 3; mov eax, SYS_exit; int 0x80;')
>>> run_shellcode_exitcode(bytes)
3

pwnlib.shellcraft — Shellcode generation

The shellcode module.

This module contains functions for generating shellcode.

It is organized first by architecture and then by operating system.

Submodules

pwnlib.shellcraft.amd64 — Shellcode for AMD64

pwnlib.shellcraft.amd64

Shellcraft module containing generic Intel x86_64 shellcodes.

pwnlib.shellcraft.amd64.crash()

Crash.

Example

>>> run_assembly(shellcraft.crash()).poll(True)
-11

pwnlib.shellcraft.amd64.infloop()

A two-byte infinite loop.

pwnlib.shellcraft.amd64.itoa(v, buffer='rsp', allocate_stack=True)

Converts an integer into its string representation, and pushes it onto the stack.

Parameters:

• v (str, int) – Integer constant or register that contains the value to convert.
• alloca –

Example

>>> sc = shellcraft.amd64.mov('rax', 0xdeadbeef)
>>> sc += shellcraft.amd64.itoa('rax')
>>> sc += shellcraft.amd64.linux.write(1, 'rsp', 32)
>>> run_assembly(sc).recvuntil('\x00')
'3735928559\x00'

pwnlib.shellcraft.amd64.memcpy(dest, src, n)

Copies memory.

Parameters:

• dest – Destination address
• src – Source address
• n – Number of bytes

pwnlib.shellcraft.amd64.mov(dest, src, stack_allowed=True)

Move src into dest without newlines and null bytes.

If the src is a register smaller than the dest, then it will be zero-extended to fit inside the larger register.

If the src is a register larger than the dest, then only some of the bits will be used.

If src is a string that is not a register, then it will locally set context.arch to ‘amd64’ and use pwnlib.constants.eval() to evaluate the string. Note that this means that this shellcode can change behavior depending on the value of context.os.

Example

>>> print shellcraft.amd64.mov('eax','ebx').rstrip()
    mov eax, ebx
>>> print shellcraft.amd64.mov('eax', 0).rstrip()
    xor eax, eax /* 0 */
>>> print shellcraft.amd64.mov('ax', 0).rstrip()
    xor ax, ax /* 0 */
>>> print shellcraft.amd64.mov('rax', 0).rstrip()
    xor eax, eax /* 0 */
>>> print shellcraft.amd64.mov('rdi', 'ax').rstrip()
    movzx edi, ax
>>> print shellcraft.amd64.mov('al', 'ax').rstrip()
    /* moving ax into al, but this is a no-op */
>>> print shellcraft.amd64.mov('ax', 'bl').rstrip()
    movzx ax, bl
>>> print shellcraft.amd64.mov('eax', 1).rstrip()
    push 1
    pop rax
>>> print shellcraft.amd64.mov('rax', 0xc0).rstrip()
    xor eax, eax
    mov al, 0xc0
>>> print shellcraft.amd64.mov('rax', 0xc000).rstrip()
    xor eax, eax
    mov ah, 0xc000 >> 8
>>> print shellcraft.amd64.mov('rax', 0xc0c0).rstrip()
    xor eax, eax
    mov ax, 0xc0c0
>>> print shellcraft.amd64.mov('rdi', 0xff).rstrip()
    mov edi, 0x1010101 /* 255 == 0xff */
    xor edi, 0x10101fe
>>> print shellcraft.amd64.mov('rax', 0xdead00ff).rstrip()
    mov eax, 0x1010101 /* 3735879935 == 0xdead00ff */
    xor eax, 0xdfac01fe
>>> print shellcraft.amd64.mov('rax', 0x11dead00ff).rstrip()
    mov rax, 0x101010101010101 /* 76750323967 == 0x11dead00ff */
    push rax
    mov rax, 0x1010110dfac01fe
    xor [rsp], rax
    pop rax
>>> print shellcraft.amd64.mov('rax', 0xffffffff).rstrip()
    mov eax, 0xffffffff
>>> print shellcraft.amd64.mov('rax', 0x7fffffff).rstrip()
    mov eax, 0x7fffffff
>>> print shellcraft.amd64.mov('rax', 0x80010101).rstrip()
    mov eax, 0x80010101
>>> print shellcraft.amd64.mov('rax', 0x80000000).rstrip()
    mov eax, 0x1010101 /* 2147483648 == 0x80000000 */
    xor eax, 0x81010101
>>> print shellcraft.amd64.mov('rax', 0xffffffffffffffff).rstrip()
    push 0xffffffffffffffff
    pop rax
>>> with context.local(os = 'linux'):
...     print shellcraft.amd64.mov('eax', 'SYS_read').rstrip()
    xor eax, eax /* SYS_read */
>>> with context.local(os = 'freebsd'):
...     print shellcraft.amd64.mov('eax', 'SYS_read').rstrip()
    push SYS_read /* 3 */
    pop rax
>>> with context.local(os = 'linux'):
...     print shellcraft.amd64.mov('eax', 'PROT_READ | PROT_WRITE | PROT_EXEC').rstrip()
    push (PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */
    pop rax

Parameters:

• dest (str) – The destination register.
• src (str) – Either the input register, or an immediate value.
• stack_allowed (bool) – Can the stack be used?

pwnlib.shellcraft.amd64.nop()

A single-byte nop instruction.

pwnlib.shellcraft.amd64.popad()

Pop all of the registers onto the stack which i386 popad does, in the same order.

pwnlib.shellcraft.amd64.push(value)

Pushes a value onto the stack without using null bytes or newline characters.

If src is a string, then we try to evaluate with context.arch = ‘amd64’ using pwnlib.constants.eval() before determining how to push it. Note that this means that this shellcode can change behavior depending on the value of context.os.

Parameters:value (int,str) – The value or register to push

Example

>>> print pwnlib.shellcraft.amd64.push(0).rstrip()
    /* push 0 */
    push 1
    dec byte ptr [rsp]
>>> print pwnlib.shellcraft.amd64.push(1).rstrip()
    /* push 1 */
    push 1
>>> print pwnlib.shellcraft.amd64.push(256).rstrip()
    /* push 256 */
    push 0x1010201 ^ 0x100
    xor dword ptr [rsp], 0x1010201
>>> with context.local(os = 'linux'):
...     print pwnlib.shellcraft.amd64.push('SYS_write').rstrip()
    /* push 'SYS_write' */
    push 1
>>> with context.local(os = 'freebsd'):
...     print pwnlib.shellcraft.amd64.push('SYS_write').rstrip()
    /* push 'SYS_write' */
    push 4

pwnlib.shellcraft.amd64.pushad()

Push all of the registers onto the stack which i386 pushad does, in the same order.

pwnlib.shellcraft.amd64.pushstr(string, append_null=True)

Pushes a string onto the stack without using null bytes or newline characters.

Example

>>> print shellcraft.amd64.pushstr('').rstrip()
    /* push '\x00' */
    push 1
    dec byte ptr [rsp]
>>> print shellcraft.amd64.pushstr('a').rstrip()
    /* push 'a\x00' */
    push 0x61
>>> print shellcraft.amd64.pushstr('aa').rstrip()
    /* push 'aa\x00' */
    push 0x1010101 ^ 0x6161
    xor dword ptr [rsp], 0x1010101
>>> print shellcraft.amd64.pushstr('aaa').rstrip()
    /* push 'aaa\x00' */
    push 0x1010101 ^ 0x616161
    xor dword ptr [rsp], 0x1010101
>>> print shellcraft.amd64.pushstr('aaaa').rstrip()
    /* push 'aaaa\x00' */
    push 0x61616161
>>> print shellcraft.amd64.pushstr('aaa\xc3').rstrip()
    /* push 'aaa\xc3\x00' */
    mov rax, 0x101010101010101
    push rax
    mov rax, 0x101010101010101 ^ 0xc3616161
    xor [rsp], rax
>>> print shellcraft.amd64.pushstr('aaa\xc3', append_null = False).rstrip()
    /* push 'aaa\xc3' */
    push -0x3c9e9e9f
>>> print shellcraft.amd64.pushstr('\xc3').rstrip()
    /* push '\xc3\x00' */
    push 0x1010101 ^ 0xc3
    xor dword ptr [rsp], 0x1010101
>>> print shellcraft.amd64.pushstr('\xc3', append_null = False).rstrip()
    /* push '\xc3' */
    push -0x3d
>>> with context.local():
...    context.arch = 'amd64'
...    print enhex(asm(shellcraft.pushstr("/bin/sh")))
48b801010101010101015048b82e63686f2e72690148310424
>>> with context.local():
...    context.arch = 'amd64'
...    print enhex(asm(shellcraft.pushstr("")))
6a01fe0c24
>>> with context.local():
...    context.arch = 'amd64'
...    print enhex(asm(shellcraft.pushstr("\x00", False)))
6a01fe0c24

Parameters:

• string (str) – The string to push.
• append_null (bool) – Whether to append a single NULL-byte before pushing.

pwnlib.shellcraft.amd64.pushstr_array(reg, array)

Pushes an array/envp-style array of pointers onto the stack.

Parameters:

• reg (str) – Destination register to hold the pointer.
• array (str,list) – Single argument or list of arguments to push. NULL termination is normalized so that each argument ends with exactly one NULL byte.

pwnlib.shellcraft.amd64.ret(return_value=None)

A single-byte RET instruction.

Parameters:return_value – Value to return

pwnlib.shellcraft.amd64.setregs(reg_context, stack_allowed=True)

Sets multiple registers, taking any register dependencies into account (i.e., given eax=1,ebx=eax, set ebx first).

Parameters:

• reg_context (dict) – Desired register context
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.setregs({'rax':1, 'rbx':'rax'}).rstrip()
    mov rbx, rax
    push 1
    pop rax
>>> print shellcraft.setregs({'rax': 'SYS_write', 'rbx':'rax'}).rstrip()
    mov rbx, rax
    push SYS_write /* 1 */
    pop rax
>>> print shellcraft.setregs({'rax':'rbx', 'rbx':'rax', 'rcx':'rbx'}).rstrip()
    mov rcx, rbx
    xchg rax, rbx
>>> print shellcraft.setregs({'rax':1, 'rdx':0}).rstrip()
    push 1
    pop rax
    cdq /* rdx=0 */

pwnlib.shellcraft.amd64.strcpy(dst, src)

Copies a string

Example

>>> sc  = 'jmp get_str\n'
>>> sc += 'pop_str: pop rax\n'
>>> sc += shellcraft.amd64.strcpy('rsp', 'rax')
>>> sc += shellcraft.amd64.linux.write(1, 'rsp', 32)
>>> sc += shellcraft.amd64.linux.exit(0)
>>> sc += 'get_str: call pop_str\n'
>>> sc += '.asciz "Hello, world\\n"'
>>> run_assembly(sc).recvline()
'Hello, world\n'

pwnlib.shellcraft.amd64.strlen(string, reg='rcx')

Calculate the length of the specified string.

Parameters:

• string (str) – Register or address with the string
• reg (str) – Named register to return the value in, rcx is the default.

Example

>>> sc  = 'jmp get_str\n'
>>> sc += 'pop_str: pop rdi\n'
>>> sc += shellcraft.amd64.strlen('rdi', 'rax')
>>> sc += 'push rax;'
>>> sc += shellcraft.amd64.linux.write(1, 'rsp', 8)
>>> sc += shellcraft.amd64.linux.exit(0)
>>> sc += 'get_str: call pop_str\n'
>>> sc += '.asciz "Hello, world\\n"'
>>> run_assembly(sc).unpack() == len('Hello, world\n')
True

pwnlib.shellcraft.amd64.trap()

A trap instruction.

pwnlib.shellcraft.amd64.xor(key, address, count)

XORs data a constant value.

Parameters:

• key (int,str) – XOR key either as a 8-byte integer, If a string, length must be a power of two, and not longer than 8 bytes. Alternately, may be a register.
• address (int) – Address of the data (e.g. 0xdead0000, ‘esp’)
• count (int) – Number of bytes to XOR, or a register containing the number of bytes to XOR.

Example

>>> sc  = shellcraft.read(0, 'rsp', 32)
>>> sc += shellcraft.xor(0xdeadbeef, 'rsp', 32)
>>> sc += shellcraft.write(1, 'rsp', 32)
>>> io = run_assembly(sc)
>>> io.send(cyclic(32))
>>> result = io.recvn(32)
>>> expected = xor(cyclic(32), p32(0xdeadbeef))
>>> result == expected
True

pwnlib.shellcraft.amd64.linux

Shellcraft module containing Intel x86_64 shellcodes for Linux.

pwnlib.shellcraft.amd64.linux.bindsh(port, network)

Listens on a TCP port and spawns a shell for the first to connect. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.amd64.linux.cat(filename, fd=1)

Opens a file and writes its contents to the specified file descriptor.

pwnlib.shellcraft.amd64.linux.connect(host, port, network='ipv4')

Connects to the host on the specified port. Network is either ‘ipv4’ or ‘ipv6’. Leaves the connected socket in rbp.

pwnlib.shellcraft.amd64.linux.connectstager(host, port, network='ipv4')

connect recvsize stager :param host, where to connect to: :param port, which port to connect to: :param network, ipv4 or ipv6? (default: ipv4)

pwnlib.shellcraft.amd64.linux.dup(sock='rbp')

Args: [sock (imm/reg) = rbp] Duplicates sock to stdin, stdout and stderr

pwnlib.shellcraft.amd64.linux.dupsh(sock='rbp')

Args: [sock (imm/reg) = rbp] Duplicates sock to stdin, stdout and stderr and spawns a shell.

pwnlib.shellcraft.amd64.linux.echo(string, sock='1')

Writes a string to a file descriptor

pwnlib.shellcraft.amd64.linux.egghunter(egg, start_address = 0)

Searches memory for the byte sequence ‘egg’.

Return value is the address immediately following the match, stored in RDI.

Parameters:

• egg (str, int) – String of bytes, or word-size integer to search for
• start_address (int) – Where to start the search

pwnlib.shellcraft.amd64.linux.findpeer(port=None)

Args: port (defaults to any port) Finds a socket, which is connected to the specified port. Leaves socket in RDI.

pwnlib.shellcraft.amd64.linux.findpeersh(port=None)

Args: port (defaults to any) Finds an open socket which connects to a specified port, and then opens a dup2 shell on it.

pwnlib.shellcraft.amd64.linux.findpeerstager(port=None)

Findpeer recvsize stager :param port, the port given to findpeer: :type port, the port given to findpeer: defaults to any

pwnlib.shellcraft.amd64.linux.forkbomb()

Performs a forkbomb attack.

pwnlib.shellcraft.amd64.linux.forkexit()

Attempts to fork. If the fork is successful, the parent exits.

pwnlib.shellcraft.amd64.linux.getpid()

Retrieve the current PID

pwnlib.shellcraft.amd64.linux.kill(pid, signal='SIGKILL')

Writes a string to a file descriptor

pwnlib.shellcraft.amd64.linux.killparent()

Kills its parent process until whatever the parent is (probably init) cannot be killed any longer.

pwnlib.shellcraft.amd64.linux.listen(port, network)

Listens on a TCP port, accept a client and leave his socket in RAX. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.amd64.linux.loader(address)

Loads a statically-linked ELF into memory and transfers control.

Parameters:address (int) – Address of the ELF as a register or integer.

pwnlib.shellcraft.amd64.linux.loader_append(data=None)

Loads a statically-linked ELF into memory and transfers control.

Similar to loader.asm but loads an appended ELF.

Parameters:data (str) – If a valid filename, the data is loaded from the named file. Otherwise, this is treated as raw ELF data to append. If None, it is ignored.

Example

>>> gcc = process(['gcc','-m64','-xc','-static','-Wl,-Ttext-segment=0x20000000','-'])
>>> gcc.write('''
... int main() {
...     printf("Hello, %s!\\n", "amd64");
... }
... ''')
>>> gcc.shutdown('send')
>>> gcc.poll(True)
0
>>> sc = shellcraft.loader_append('a.out')

The following doctest is commented out because it doesn’t work on Travis for reasons I cannot diagnose. However, it should work just fine :-)

# >>> run_assembly(sc).recvline() == ‘Hello, amd64!n’ # True

pwnlib.shellcraft.amd64.linux.membot(readsock=0, writesock=1)

Read-write access to a remote process’ memory.

Provide a single pointer-width value to determine the operation to perform:

• 0: Exit the loop
• 1: Read data
• 2: Write data

pwnlib.shellcraft.amd64.linux.migrate_stack(size=1048576, fd=0)

Migrates to a new stack.

pwnlib.shellcraft.amd64.linux.mmap_rwx(size=4096, protection=7, address=None)

Maps some memory

pwnlib.shellcraft.amd64.linux.read(fd=0, buffer='rsp', count=8)

Reads data from the file descriptor into the provided buffer. This is a one-shot and does not fill the request.

pwnlib.shellcraft.amd64.linux.read_upto(fd=0, buffer='rsp', sizereg='rdx')

Reads up to N bytes 8 bytes into the specified register

pwnlib.shellcraft.amd64.linux.readfile(path, dst='rdi')

Args: [path, dst (imm/reg) = rdi ] Opens the specified file path and sends its content to the specified file descriptor.

pwnlib.shellcraft.amd64.linux.readinto(sock=0)

Reads into a buffer of a size and location determined at runtime. When the shellcode is executing, it should send a pointer and pointer-width size to determine the location and size of buffer.

pwnlib.shellcraft.amd64.linux.readloop(sock=0)

Reads into a buffer of a size and location determined at runtime. When the shellcode is executing, it should send a pointer and pointer-width size to determine the location and size of buffer.

pwnlib.shellcraft.amd64.linux.readn(fd, buf, nbytes)

Reads exactly nbytes bytes from file descriptor fd into the buffer buf.

Parameters:

• fd (int) – fd
• buf (void) – buf
• nbytes (size_t) – nbytes

pwnlib.shellcraft.amd64.linux.readptr(fd=0, target_reg='rdx')

Reads 8 bytes into the specified register

pwnlib.shellcraft.amd64.linux.recvsize(sock, reg='rcx')

Recives 4 bytes size field Useful in conjuncion with findpeer and stager :param sock, the socket to read the payload from.: :param reg, the place to put the size: :type reg, the place to put the size: default ecx

Leaves socket in ebx

pwnlib.shellcraft.amd64.linux.setregid(gid='egid')

Args: [gid (imm/reg) = egid] Sets the real and effective group id.

pwnlib.shellcraft.amd64.linux.setreuid(uid='euid')

Args: [uid (imm/reg) = euid] Sets the real and effective user id.

pwnlib.shellcraft.amd64.linux.sh()

Execute a different process.

>>> p = run_assembly(shellcraft.amd64.linux.sh())
>>> p.sendline('echo Hello')
>>> p.recv()
'Hello\n'

pwnlib.shellcraft.amd64.linux.socket(network='ipv4', proto='tcp')

Creates a new socket

pwnlib.shellcraft.amd64.linux.stage(fd=0, length=None)

Migrates shellcode to a new buffer.

Parameters:

• fd (int) – Integer file descriptor to recv data from. Default is stdin (0).
• length (int) – Optional buffer length. If None, the first pointer-width of data received is the length.

Example

>>> p = run_assembly(shellcraft.stage())
>>> sc = asm(shellcraft.echo("Hello\n", constants.STDOUT_FILENO))
>>> p.pack(len(sc))
>>> p.send(sc)
>>> p.recvline()
'Hello\n'

pwnlib.shellcraft.amd64.linux.stager(sock, size, handle_error=False)

Recives a fixed sized payload into a mmaped buffer Useful in conjuncion with findpeer. After running the socket will be left in RDI. :param sock, the socket to read the payload from.: :param size, the size of the payload:

pwnlib.shellcraft.amd64.linux.strace_dos()

Kills strace

pwnlib.shellcraft.amd64.linux.syscall(syscall=None, arg0=None, arg1=None, arg2=None, arg3=None, arg4=None, arg5=None)

Args: [syscall_number, *args]

Does a syscall

Any of the arguments can be expressions to be evaluated by pwnlib.constants.eval().

Example

>>> print pwnlib.shellcraft.amd64.linux.syscall('SYS_execve', 1, 'rsp', 2, 0).rstrip()
    /* call execve(1, 'rsp', 2, 0) */
    xor r10d, r10d /* 0 */
    push SYS_execve /* 0x3b */
    pop rax
    push 1
    pop rdi
    push 2
    pop rdx
    mov rsi, rsp
    syscall
>>> print pwnlib.shellcraft.amd64.linux.syscall('SYS_execve', 2, 1, 0, -1).rstrip()
    /* call execve(2, 1, 0, -1) */
    push -1
    pop r10
    push SYS_execve /* 0x3b */
    pop rax
    push 2
    pop rdi
    push 1
    pop rsi
    cdq /* rdx=0 */
    syscall
>>> print pwnlib.shellcraft.amd64.linux.syscall().rstrip()
    /* call syscall() */
    syscall
>>> print pwnlib.shellcraft.amd64.linux.syscall('rax', 'rdi', 'rsi').rstrip()
    /* call syscall('rax', 'rdi', 'rsi') */
    /* setregs noop */
    syscall
>>> print pwnlib.shellcraft.amd64.linux.syscall('rbp', None, None, 1).rstrip()
    /* call syscall('rbp', ?, ?, 1) */
    mov rax, rbp
    push 1
    pop rdx
    syscall
>>> print pwnlib.shellcraft.amd64.linux.syscall(
...               'SYS_mmap', 0, 0x1000,
...               'PROT_READ | PROT_WRITE | PROT_EXEC',
...               'MAP_PRIVATE | MAP_ANONYMOUS',
...               -1, 0).rstrip()
    /* call mmap(0, 4096, 'PROT_READ | PROT_WRITE | PROT_EXEC', 'MAP_PRIVATE | MAP_ANONYMOUS', -1, 0) */
    push (MAP_PRIVATE | MAP_ANONYMOUS) /* 0x22 */
    pop r10
    push -1
    pop r8
    xor r9d, r9d /* 0 */
    push SYS_mmap /* 9 */
    pop rax
    xor edi, edi /* 0 */
    push (PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */
    pop rdx
    mov esi, 0x1010101 /* 4096 == 0x1000 */
    xor esi, 0x1011101
    syscall
>>> print pwnlib.shellcraft.open('/home/pwn/flag').rstrip()
    /* open(file='/home/pwn/flag', oflag=0, mode=0) */
    /* push '/home/pwn/flag\x00' */
    mov rax, 0x101010101010101
    push rax
    mov rax, 0x101010101010101 ^ 0x67616c662f6e
    xor [rsp], rax
    mov rax, 0x77702f656d6f682f
    push rax
    mov rdi, rsp
    xor edx, edx /* 0 */
    xor esi, esi /* 0 */
    /* call open() */
    push SYS_open /* 2 */
    pop rax
    syscall

pwnlib.shellcraft.amd64.linux.writeloop(readsock=0, writesock=1)

Reads from a buffer of a size and location determined at runtime. When the shellcode is executing, it should send a pointer and pointer-width size to determine the location and size of buffer.

pwnlib.shellcraft.arm — Shellcode for ARM

pwnlib.shellcraft.arm

Shellcraft module containing generic ARM little endian shellcodes.

pwnlib.shellcraft.arm.crash()

Crash.

Example

>>> run_assembly(shellcraft.crash()).poll(True)
-11

pwnlib.shellcraft.arm.infloop()

An infinite loop.

pwnlib.shellcraft.arm.itoa(v, buffer='sp', allocate_stack=True)

Converts an integer into its string representation, and pushes it onto the stack. Uses registers r0-r5.

Parameters:

• v (str, int) – Integer constant or register that contains the value to convert.
• alloca –

Example

>>> sc = shellcraft.arm.mov('r0', 0xdeadbeef)
>>> sc += shellcraft.arm.itoa('r0')
>>> sc += shellcraft.arm.linux.write(1, 'sp', 32)
>>> run_assembly(sc).recvuntil('\x00')
'3735928559\x00'

pwnlib.shellcraft.arm.memcpy(dest, src, n)

Copies memory.

Parameters:

• dest – Destination address
• src – Source address
• n – Number of bytes

pwnlib.shellcraft.arm.mov(dst, src)

Move src into dest.

Support for automatically avoiding newline and null bytes has to be done.

If src is a string that is not a register, then it will locally set context.arch to ‘arm’ and use pwnlib.constants.eval() to evaluate the string. Note that this means that this shellcode can change behavior depending on the value of context.os.

Examples

>>> print shellcraft.arm.mov('r0','r1').rstrip()
    mov  r0, r1
>>> print shellcraft.arm.mov('r0', 5).rstrip()
    mov  r0, #5
>>> print shellcraft.arm.mov('r0', 0x34532).rstrip()
    movw r0, #0x34532 & 0xffff
    movt r0, #0x34532 >> 16
>>> print shellcraft.arm.mov('r0', 0x101).rstrip()
    movw r0, #0x101
>>> print shellcraft.arm.mov('r0', 0xff << 14).rstrip()
    mov  r0, #0x3fc000
>>> print shellcraft.arm.mov('r0', 0xff << 15).rstrip()
    movw r0, #0x7f8000 & 0xffff
    movt r0, #0x7f8000 >> 16
>>> print shellcraft.arm.mov('r0', 0xf00d0000).rstrip()
    eor  r0, r0
    movt r0, #0xf00d0000 >> 16
>>> print shellcraft.arm.mov('r0', 0xffff00ff).rstrip()
    mvn  r0, #(0xffff00ff ^ (-1))
>>> print shellcraft.arm.mov('r0', 0x1fffffff).rstrip()
    mvn  r0, #(0x1fffffff ^ (-1))

Parameters:

• dest (str) – ke destination register.
• src (str) – Either the input register, or an immediate value.

pwnlib.shellcraft.arm.nop()

A nop instruction.

pwnlib.shellcraft.arm.push(word, register='r12')

Pushes a 32-bit integer onto the stack. Uses r12 as a temporary register.

r12 is defined as the inter-procedural scartch register ($ip), so this should not interfere with most usage.

Parameters:

• word (int, str) – The word to push
• tmpreg (str) – Register to use as a temporary register. R7 is used by default.

pwnlib.shellcraft.arm.pushstr(string, append_null=True, register='r7')

Pushes a string onto the stack.

Parameters:

• string (str) – The string to push.
• append_null (bool) – Whether to append a single NULL-byte before pushing.
• register (str) – Temporary register to use. By default, R7 is used.

Examples

>>> print shellcraft.arm.pushstr("Hello!").rstrip()
    /* push 'Hello!\x00A' */
    movw r7, #0x4100216f & 0xffff
    movt r7, #0x4100216f >> 16
    push {r7}
    movw r7, #0x6c6c6548 & 0xffff
    movt r7, #0x6c6c6548 >> 16
    push {r7}

pwnlib.shellcraft.arm.pushstr_array(reg, array)

Pushes an array/envp-style array of pointers onto the stack.

Parameters:

• reg (str) – Destination register to hold the pointer.
• array (str,list) – Single argument or list of arguments to push. NULL termination is normalized so that each argument ends with exactly one NULL byte.

pwnlib.shellcraft.arm.ret(return_value=None)

A single-byte RET instruction.

Parameters:return_value – Value to return

Examples

>>> with context.local(arch='arm'):
...     print enhex(asm(shellcraft.ret()))
...     print enhex(asm(shellcraft.ret(0)))
...     print enhex(asm(shellcraft.ret(0xdeadbeef)))
1eff2fe1
000020e01eff2fe1
ef0e0be3ad0e4de31eff2fe1

pwnlib.shellcraft.arm.setregs(reg_context, stack_allowed=True)

Sets multiple registers, taking any register dependencies into account (i.e., given eax=1,ebx=eax, set ebx first).

Parameters:

• reg_context (dict) – Desired register context
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.setregs({'r0':1, 'r2':'r3'}).rstrip()
    mov  r0, #1
    mov  r2, r3
>>> print shellcraft.setregs({'r0':'r1', 'r1':'r0', 'r2':'r3'}).rstrip()
    mov  r2, r3
    eor  r0, r0, r1 /* xchg r0, r1 */
    eor  r1, r0, r1
    eor  r0, r0, r1

pwnlib.shellcraft.arm.to_thumb(reg=None, avoid=[])

Go from ARM to THUMB mode.

pwnlib.shellcraft.arm.trap()

A trap instruction.

pwnlib.shellcraft.arm.udiv_10(N)

Divides r0 by 10. Result is stored in r0, N and Z flags are updated.

Code is from generated from here:

https://raw.githubusercontent.com/rofirrim/raspberry-pi-assembler/master/chapter15/magic.py

With code:

python magic.py 10 code_for_unsigned

pwnlib.shellcraft.arm.xor(key, address, count)

XORs data a constant value.

Parameters:

• key (int,str) – XOR key either as a 4-byte integer, If a string, length must be a power of two, and not longer than 4 bytes.
• address (int) – Address of the data (e.g. 0xdead0000, ‘rsp’)
• count (int) – Number of bytes to XOR.

Example

>>> sc  = shellcraft.read(0, 'sp', 32)
>>> sc += shellcraft.xor(0xdeadbeef, 'sp', 32)
>>> sc += shellcraft.write(1, 'sp', 32)
>>> io = run_assembly(sc)
>>> io.send(cyclic(32))
>>> result = io.recvn(32)
>>> expected = xor(cyclic(32), p32(0xdeadbeef))
>>> result == expected
True

pwnlib.shellcraft.arm.linux

Shellcraft module containing ARM shellcodes for Linux.

pwnlib.shellcraft.arm.linux.cacheflush()

Invokes the cache-flush operation, without using any NULL or newline bytes.

Effectively is just:

mov r0, #0 mov r1, #-1 mov r2, #0 swi 0x9F0002

How this works:

... However, SWI generates a software interrupt and to the interrupt handler, 0x9F0002 is actually data and as a result will not be read via the instruction cache, so if we modify the argument to SWI in our self-modifyign code, the argument will be read correctly.

pwnlib.shellcraft.arm.linux.cat(filename, fd=1)

Opens a file and writes its contents to the specified file descriptor.

Example

>>> f = tempfile.mktemp()
>>> write(f, 'FLAG\n')
>>> run_assembly(shellcraft.arm.linux.cat(f)).recvline()
'FLAG\n'

pwnlib.shellcraft.arm.linux.connect(host, port, network='ipv4')

Connects to the host on the specified port. Network is either ‘ipv4’ or ‘ipv6’. Leaves the connected socket in R6.

pwnlib.shellcraft.arm.linux.dir(in_fd='r6', size=2048, allocate_stack=True)

Reads to the stack from a directory.

Parameters:

• in_fd (int/str) – File descriptor to be read from.
• size (int) – Buffer size.
• allocate_stack (bool) – allocate ‘size’ bytes on the stack.

You can optioanlly shave a few bytes not allocating the stack space.

The size read is left in eax.

pwnlib.shellcraft.arm.linux.echo(string, sock='1')

Writes a string to a file descriptor

Example

>>> run_assembly(shellcraft.echo('hello\n', 1)).recvline()
'hello\n'

pwnlib.shellcraft.arm.linux.egghunter(egg, start_address = 0, double_check = True)

Searches for an egg, which is either a four byte integer or a four byte string. The egg must appear twice in a row if double_check is True. When the egg has been found the egghunter branches to the address following it. If start_address has been specified search will start on the first address of the page that contains that address.

pwnlib.shellcraft.arm.linux.forkbomb()

Performs a forkbomb attack.

pwnlib.shellcraft.arm.linux.forkexit()

Attempts to fork. If the fork is successful, the parent exits.

pwnlib.shellcraft.arm.linux.killparent()

Kills its parent process until whatever the parent is (probably init) cannot be killed any longer.

pwnlib.shellcraft.arm.linux.open_file(filepath, flags='O_RDONLY', mode=420)

Opens a file. Leaves the file descriptor in r0.

Parameters:

• filepath (str) – The file to open.
• flags (int/str) – The flags to call open with.
• mode (int/str) – The attribute to create the flag. Only matters of flags & O_CREAT is set.

pwnlib.shellcraft.arm.linux.sh()

Execute a different process.

>>> p = run_assembly(shellcraft.arm.linux.sh())
>>> p.sendline('echo Hello')
>>> p.recv()
'Hello\n'

pwnlib.shellcraft.arm.linux.syscall(syscall=None, arg0=None, arg1=None, arg2=None, arg3=None, arg4=None, arg5=None, arg6=None)

Args: [syscall_number, *args]

Does a syscall

Any of the arguments can be expressions to be evaluated by pwnlib.constants.eval().

Example

>>> print shellcraft.arm.linux.syscall(11, 1, 'sp', 2, 0).rstrip()
    /* call syscall(11, 1, 'sp', 2, 0) */
    mov  r0, #1
    mov  r1, sp
    mov  r2, #2
    eor  r3, r3 /* 0 (#0) */
    mov  r7, #0xb
    svc  0
>>> print shellcraft.arm.linux.syscall('SYS_exit', 0).rstrip()
    /* call exit(0) */
    eor  r0, r0 /* 0 (#0) */
    mov  r7, #SYS_exit /* 1 */
    svc  0
>>> print pwnlib.shellcraft.open('/home/pwn/flag').rstrip()
    /* open(file='/home/pwn/flag', oflag=0, mode=0) */
    /* push '/home/pwn/flag\x00A' */
    movw r7, #0x41006761 & 0xffff
    movt r7, #0x41006761 >> 16
    push {r7}
    movw r7, #0x6c662f6e & 0xffff
    movt r7, #0x6c662f6e >> 16
    push {r7}
    movw r7, #0x77702f65 & 0xffff
    movt r7, #0x77702f65 >> 16
    push {r7}
    movw r7, #0x6d6f682f & 0xffff
    movt r7, #0x6d6f682f >> 16
    push {r7}
    mov  r0, sp
    eor  r1, r1 /* 0 (#0) */
    eor  r2, r2 /* 0 (#0) */
    /* call open() */
    mov  r7, #SYS_open /* 5 */
    svc  0

pwnlib.shellcraft.common — Shellcode common to all architecture

Shellcraft module containing shellcode common to all platforms.

pwnlib.shellcraft.common.label(prefix='label')

Returns a new unique label with a given prefix.

Parameters:prefix (str) – The string to prefix the label with

pwnlib.shellcraft.i386 — Shellcode for Intel 80386

pwnlib.shellcraft.i386

Shellcraft module containing generic Intel i386 shellcodes.

pwnlib.shellcraft.i386.breakpoint()

A single-byte breakpoint instruction.

pwnlib.shellcraft.i386.crash()

Crash.

Example

>>> run_assembly(shellcraft.crash()).poll(True)
-11

pwnlib.shellcraft.i386.epilog(nargs=0)

Function epilogue.

Parameters:nargs (int) – Number of arguments to pop off the stack.

pwnlib.shellcraft.i386.function(name, template_function, *registers)

Converts a shellcraft template into a callable function.

Parameters:

• template_sz (callable) – Rendered shellcode template. Any variable Arguments should be supplied as registers.
• name (str) – Name of the function.
• registers (list) – List of registers which should be filled from the stack.

>>> shellcode = ''
>>> shellcode += shellcraft.function('write', shellcraft.i386.linux.write, )

>>> hello = shellcraft.i386.linux.echo("Hello!", 'eax')
>>> hello_fn = shellcraft.i386.function(hello, 'eax').strip()
>>> exit = shellcraft.i386.linux.exit('edi')
>>> exit_fn = shellcraft.i386.function(exit, 'edi').strip()
>>> shellcode = '''
...     push STDOUT_FILENO
...     call hello
...     push 33
...     call exit
... hello:
...     %(hello_fn)s
... exit:
...     %(exit_fn)s
... ''' % (locals())
>>> p = run_assembly(shellcode)
>>> p.recvall()
'Hello!'
>>> p.wait_for_close()
>>> p.poll()
33

Notes

Can only be used on a shellcraft template which takes all of its arguments as registers. For example, the pushstr

pwnlib.shellcraft.i386.getpc(register='ecx')

Retrieves the value of EIP, stores it in the desired register.

Parameters:return_value – Value to return

pwnlib.shellcraft.i386.infloop()

A two-byte infinite loop.

pwnlib.shellcraft.i386.itoa(v, buffer='esp', allocate_stack=True)

Converts an integer into its string representation, and pushes it onto the stack.

Parameters:

• v (str, int) – Integer constant or register that contains the value to convert.
• alloca –

Example

>>> sc = shellcraft.i386.mov('eax', 0xdeadbeef)
>>> sc += shellcraft.i386.itoa('eax')
>>> sc += shellcraft.i386.linux.write(1, 'esp', 32)
>>> run_assembly(sc).recvuntil('\x00')
'3735928559\x00'

pwnlib.shellcraft.i386.memcpy(dest, src, n)

Copies memory.

Parameters:

• dest – Destination address
• src – Source address
• n – Number of bytes

pwnlib.shellcraft.i386.mov(dest, src, stack_allowed=True)

Move src into dest without newlines and null bytes.

If the src is a register smaller than the dest, then it will be zero-extended to fit inside the larger register.

If the src is a register larger than the dest, then only some of the bits will be used.

If src is a string that is not a register, then it will locally set context.arch to ‘i386’ and use pwnlib.constants.eval() to evaluate the string. Note that this means that this shellcode can change behavior depending on the value of context.os.

Parameters:

• dest (str) – The destination register.
• src (str) – Either the input register, or an immediate value.
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.i386.mov('eax','ebx').rstrip()
    mov eax, ebx
>>> print shellcraft.i386.mov('eax', 0).rstrip()
    xor eax, eax
>>> print shellcraft.i386.mov('ax', 0).rstrip()
    xor ax, ax
>>> print shellcraft.i386.mov('ax', 17).rstrip()
    xor ax, ax
    mov al, 0x11
>>> print shellcraft.i386.mov('edi', ord('\n')).rstrip()
    push 9 /* mov edi, '\n' */
    pop edi
    inc edi
>>> print shellcraft.i386.mov('al', 'ax').rstrip()
    /* moving ax into al, but this is a no-op */
>>> print shellcraft.i386.mov('al','ax').rstrip()
    /* moving ax into al, but this is a no-op */
>>> print shellcraft.i386.mov('esp', 'esp').rstrip()
    /* moving esp into esp, but this is a no-op */
>>> print shellcraft.i386.mov('ax', 'bl').rstrip()
    movzx ax, bl
>>> print shellcraft.i386.mov('eax', 1).rstrip()
    push 1
    pop eax
>>> print shellcraft.i386.mov('eax', 1, stack_allowed=False).rstrip()
    xor eax, eax
    mov al, 1
>>> print shellcraft.i386.mov('eax', 0xdead00ff).rstrip()
    mov eax, -0xdead00ff
    neg eax
>>> print shellcraft.i386.mov('eax', 0xc0).rstrip()
    xor eax, eax
    mov al, 0xc0
>>> print shellcraft.i386.mov('edi', 0xc0).rstrip()
    mov edi, -0xc0
    neg edi
>>> print shellcraft.i386.mov('eax', 0xc000).rstrip()
    xor eax, eax
    mov ah, 0xc000 >> 8
>>> print shellcraft.i386.mov('eax', 0xffc000).rstrip()
    mov eax, 0x1010101
    xor eax, 0x1010101 ^ 0xffc000
>>> print shellcraft.i386.mov('edi', 0xc000).rstrip()
    mov edi, (-1) ^ 0xc000
    not edi
>>> print shellcraft.i386.mov('edi', 0xf500).rstrip()
    mov edi, 0x1010101
    xor edi, 0x1010101 ^ 0xf500
>>> print shellcraft.i386.mov('eax', 0xc0c0).rstrip()
    xor eax, eax
    mov ax, 0xc0c0
>>> print shellcraft.i386.mov('eax', 'SYS_execve').rstrip()
    push SYS_execve /* 0xb */
    pop eax
>>> with context.local(os='freebsd'):
...     print shellcraft.i386.mov('eax', 'SYS_execve').rstrip()
    push SYS_execve /* 0x3b */
    pop eax
>>> print shellcraft.i386.mov('eax', 'PROT_READ | PROT_WRITE | PROT_EXEC').rstrip()
    push (PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */
    pop eax

pwnlib.shellcraft.i386.nop()

A single-byte nop instruction.

pwnlib.shellcraft.i386.prolog()

Function prologue.

pwnlib.shellcraft.i386.push(value)

Pushes a value onto the stack without using null bytes or newline characters.

If src is a string, then we try to evaluate with context.arch = ‘i386’ using pwnlib.constants.eval() before determining how to push it. Note that this means that this shellcode can change behavior depending on the value of context.os.

Parameters:value (int,str) – The value or register to push

Example

>>> print pwnlib.shellcraft.i386.push(0).rstrip()
    /* push 0 */
    push 1
    dec byte ptr [esp]
>>> print pwnlib.shellcraft.i386.push(1).rstrip()
    /* push 1 */
    push 1
>>> print pwnlib.shellcraft.i386.push(256).rstrip()
    /* push 0x100 */
    push 0x1010201
    xor dword ptr [esp], 0x1010301
>>> print pwnlib.shellcraft.i386.push('SYS_execve').rstrip()
    /* push SYS_execve (0xb) */
    push 0xb
>>> print pwnlib.shellcraft.i386.push('SYS_sendfile').rstrip()
    /* push SYS_sendfile (0xbb) */
    push 0x1010101
    xor dword ptr [esp], 0x10101ba
>>> with context.local(os = 'freebsd'):
...     print pwnlib.shellcraft.i386.push('SYS_execve').rstrip()
    /* push SYS_execve (0x3b) */
    push 0x3b

pwnlib.shellcraft.i386.pushstr(string, append_null=True)

Pushes a string onto the stack without using null bytes or newline characters.

Example

>>> print shellcraft.i386.pushstr('').rstrip()
    /* push '\x00' */
    push 1
    dec byte ptr [esp]
>>> print shellcraft.i386.pushstr('a').rstrip()
    /* push 'a\x00' */
    push 0x61
>>> print shellcraft.i386.pushstr('aa').rstrip()
    /* push 'aa\x00' */
    push 0x1010101
    xor dword ptr [esp], 0x1016060
>>> print shellcraft.i386.pushstr('aaa').rstrip()
    /* push 'aaa\x00' */
    push 0x1010101
    xor dword ptr [esp], 0x1606060
>>> print shellcraft.i386.pushstr('aaaa').rstrip()
    /* push 'aaaa\x00' */
    push 1
    dec byte ptr [esp]
    push 0x61616161
>>> print shellcraft.i386.pushstr('aaaaa').rstrip()
    /* push 'aaaaa\x00' */
    push 0x61
    push 0x61616161
>>> print shellcraft.i386.pushstr('aaaa', append_null = False).rstrip()
    /* push 'aaaa' */
    push 0x61616161
>>> print shellcraft.i386.pushstr('\xc3').rstrip()
    /* push '\xc3\x00' */
    push 0x1010101
    xor dword ptr [esp], 0x10101c2
>>> print shellcraft.i386.pushstr('\xc3', append_null = False).rstrip()
    /* push '\xc3' */
    push -0x3d
>>> with context.local():
...    context.arch = 'i386'
...    print enhex(asm(shellcraft.pushstr("/bin/sh")))
68010101018134242e726901682f62696e
>>> with context.local():
...    context.arch = 'i386'
...    print enhex(asm(shellcraft.pushstr("")))
6a01fe0c24
>>> with context.local():
...    context.arch = 'i386'
...    print enhex(asm(shellcraft.pushstr("\x00", False)))
6a01fe0c24

Parameters:

• string (str) – The string to push.
• append_null (bool) – Whether to append a single NULL-byte before pushing.

pwnlib.shellcraft.i386.pushstr_array(reg, array)

Pushes an array/envp-style array of pointers onto the stack.

Parameters:

• reg (str) – Destination register to hold the pointer.
• array (str,list) – Single argument or list of arguments to push. NULL termination is normalized so that each argument ends with exactly one NULL byte.

pwnlib.shellcraft.i386.ret(return_value=None)

A single-byte RET instruction.

Parameters:return_value – Value to return

pwnlib.shellcraft.i386.setregs(reg_context, stack_allowed=True)

Sets multiple registers, taking any register dependencies into account (i.e., given eax=1,ebx=eax, set ebx first).

Parameters:

• reg_context (dict) – Desired register context
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.setregs({'eax':1, 'ebx':'eax'}).rstrip()
    mov ebx, eax
    push 1
    pop eax
>>> print shellcraft.setregs({'eax':'ebx', 'ebx':'eax', 'ecx':'ebx'}).rstrip()
    mov ecx, ebx
    xchg eax, ebx

pwnlib.shellcraft.i386.stackarg(index, register)

Loads a stack-based argument into a register.

Assumes that the ‘prolog’ code was used to save EBP.

Parameters:

• index (int) – Zero-based argument index.
• register (str) – Register name.

pwnlib.shellcraft.i386.stackhunter(cookie = 0x7afceb58)

Returns an an egghunter, which searches from esp and upwards for a cookie. However to save bytes, it only looks at a single 4-byte alignment. Use the function stackhunter_helper to generate a suitable cookie prefix for you.

The default cookie has been chosen, because it makes it possible to shave a single byte, but other cookies can be used too.

Example

>>> with context.local():
...    context.arch = 'i386'
...    print enhex(asm(shellcraft.stackhunter()))
3d58ebfc7a75faffe4
>>> with context.local():
...    context.arch = 'i386'
...    print enhex(asm(shellcraft.stackhunter(0xdeadbeef)))
583defbeadde75f8ffe4

pwnlib.shellcraft.i386.strcpy(dst, src)

Copies a string

Example

>>> sc  = 'jmp get_str\n'
>>> sc += 'pop_str: pop eax\n'
>>> sc += shellcraft.i386.strcpy('esp', 'eax')
>>> sc += shellcraft.i386.linux.write(1, 'esp', 32)
>>> sc += shellcraft.i386.linux.exit(0)
>>> sc += 'get_str: call pop_str\n'
>>> sc += '.asciz "Hello, world\\n"'
>>> run_assembly(sc).recvline()
'Hello, world\n'

pwnlib.shellcraft.i386.strlen(string, reg='ecx')

Calculate the length of the specified string.

Parameters:

• string (str) – Register or address with the string
• reg (str) – Named register to return the value in, ecx is the default.

Example

>>> sc  = 'jmp get_str\n'
>>> sc += 'pop_str: pop eax\n'
>>> sc += shellcraft.i386.strlen('eax')
>>> sc += 'push ecx;'
>>> sc += shellcraft.i386.linux.write(1, 'esp', 4)
>>> sc += shellcraft.i386.linux.exit(0)
>>> sc += 'get_str: call pop_str\n'
>>> sc += '.asciz "Hello, world\\n"'
>>> run_assembly(sc).unpack() == len('Hello, world\n')
True

pwnlib.shellcraft.i386.trap()

A trap instruction.

pwnlib.shellcraft.i386.xor(key, address, count)

XORs data a constant value.

Parameters:

• key (int,str) – XOR key either as a 4-byte integer, If a string, length must be a power of two, and not longer than 4 bytes. Alternately, may be a register.
• address (int) – Address of the data (e.g. 0xdead0000, ‘esp’)
• count (int) – Number of bytes to XOR, or a register containing the number of bytes to XOR.

Example

>>> sc  = shellcraft.read(0, 'esp', 32)
>>> sc += shellcraft.xor(0xdeadbeef, 'esp', 32)
>>> sc += shellcraft.write(1, 'esp', 32)
>>> io = run_assembly(sc)
>>> io.send(cyclic(32))
>>> result = io.recvn(32)
>>> expected = xor(cyclic(32), p32(0xdeadbeef))
>>> result == expected
True

pwnlib.shellcraft.i386.linux

Shellcraft module containing Intel i386 shellcodes for Linux.

pwnlib.shellcraft.i386.linux.acceptloop_ipv4(port)

Parameters:port (int) – the listening port

Waits for a connection. Leaves socket in EBP. ipv4 only

pwnlib.shellcraft.i386.linux.cat(filename, fd=1)

Opens a file and writes its contents to the specified file descriptor.

Example

>>> f = tempfile.mktemp()
>>> write(f, 'FLAG')
>>> run_assembly(shellcraft.i386.linux.cat(f)).recvall()
'FLAG'

pwnlib.shellcraft.i386.linux.connect(host, port, network='ipv4')

Connects to the host on the specified port. Leaves the connected socket in edx

Parameters:

• host (str) – Remote IP address or hostname (as a dotted quad / string)
• port (int) – Remote port
• network (str) – Network protocol (ipv4 or ipv6)

Examples

>>> l = listen(timeout=5)
>>> assembly  = shellcraft.i386.linux.connect('localhost', l.lport)
>>> assembly += shellcraft.i386.pushstr('Hello')
>>> assembly += shellcraft.i386.linux.write('edx', 'esp', 5)
>>> p = run_assembly(assembly)
>>> l.wait_for_connection().recv()
'Hello'

>>> l = listen(fam='ipv6', timeout=5)
>>> assembly   = shellcraft.i386.linux.connect('ip6-localhost', l.lport, 'ipv6')
>>> p = run_assembly(assembly)
>>> assert l.wait_for_connection()

pwnlib.shellcraft.i386.linux.connectstager(host, port, network='ipv4')

connect recvsize stager :param host, where to connect to: :param port, which port to connect to: :param network, ipv4 or ipv6? (default: ipv4)

pwnlib.shellcraft.i386.linux.dir(in_fd='ebp', size=2048, allocate_stack=True)

Reads to the stack from a directory.

Parameters:

• in_fd (int/str) – File descriptor to be read from.
• size (int) – Buffer size.
• allocate_stack (bool) – allocate ‘size’ bytes on the stack.

You can optioanlly shave a few bytes not allocating the stack space.

The size read is left in eax.

pwnlib.shellcraft.i386.linux.dupio(sock='ebp')

Args: [sock (imm/reg) = ebp] Duplicates sock to stdin, stdout and stderr

pwnlib.shellcraft.i386.linux.dupsh(sock='ebp')

Args: [sock (imm/reg) = ebp] Duplicates sock to stdin, stdout and stderr and spawns a shell.

pwnlib.shellcraft.i386.linux.echo(string, sock='1')

Writes a string to a file descriptor

Example

>>> run_assembly(shellcraft.echo('hello', 1)).recvall()
'hello'

pwnlib.shellcraft.i386.linux.egghunter(egg, start_address = 0)

Searches memory for the byte sequence ‘egg’.

Return value is the address immediately following the match, stored in RDI.

Parameters:

• egg (str, int) – String of bytes, or word-size integer to search for
• start_address (int) – Where to start the search

pwnlib.shellcraft.i386.linux.findpeer(port=None)

Args: port (defaults to any port) Finds a socket, which is connected to the specified port. Leaves socket in ESI.

pwnlib.shellcraft.i386.linux.findpeersh(port=None)

Args: port (defaults to any) Finds an open socket which connects to a specified port, and then opens a dup2 shell on it.

pwnlib.shellcraft.i386.linux.findpeerstager(port=None)

Findpeer recvsize stager :param port, the port given to findpeer: :type port, the port given to findpeer: defaults to any

pwnlib.shellcraft.i386.linux.forkbomb()

Performs a forkbomb attack.

pwnlib.shellcraft.i386.linux.forkexit()

Attempts to fork. If the fork is successful, the parent exits.

pwnlib.shellcraft.i386.linux.i386_to_amd64()

Returns code to switch from i386 to amd64 mode.

pwnlib.shellcraft.i386.linux.killparent()

Kills its parent process until whatever the parent is (probably init) cannot be killed any longer.

pwnlib.shellcraft.i386.linux.loader(address)

Loads a statically-linked ELF into memory and transfers control.

Parameters:address (int) – Address of the ELF as a register or integer.

pwnlib.shellcraft.i386.linux.loader_append(data=None)

Loads a statically-linked ELF into memory and transfers control.

Similar to loader.asm but loads an appended ELF.

Parameters:data (str) – If a valid filename, the data is loaded from the named file. Otherwise, this is treated as raw ELF data to append. If None, it is ignored.

Example

>>> gcc = process(['gcc','-m32','-xc','-static','-Wl,-Ttext-segment=0x20000000','-'])
>>> gcc.write('''
... int main() {
...     printf("Hello, %s!\\n", "i386");
... }
... ''')
>>> gcc.shutdown('send')
>>> gcc.poll(True)
0
>>> sc = shellcraft.loader_append('a.out')

The following doctest is commented out because it doesn’t work on Travis for reasons I cannot diagnose. However, it should work just fine :-)

# >>> run_assembly(sc).recvline() == ‘Hello, i386!n’ # True

pwnlib.shellcraft.i386.linux.mprotect_all(clear_ebx=True, fix_null=False)

Calls mprotect(page, 4096, PROT_READ | PROT_WRITE | PROT_EXEC) for every page.

It takes around 0.3 seconds on my box, but your milage may vary.

Parameters:

• clear_ebx (bool) – If this is set to False, then the shellcode will assume that ebx has already been zeroed.
• fix_null (bool) – If this is set to True, then the NULL-page will also be mprotected at the cost of slightly larger shellcode

pwnlib.shellcraft.i386.linux.pidmax()

Retrieves the highest numbered PID on the system, according to the sysctl kernel.pid_max.

pwnlib.shellcraft.i386.linux.readfile(path, dst='esi')

Args: [path, dst (imm/reg) = esi ] Opens the specified file path and sends its content to the specified file descriptor.

pwnlib.shellcraft.i386.linux.readn(fd, buf, nbytes)

Reads exactly nbytes bytes from file descriptor fd into the buffer buf.

Parameters:

• fd (int) – fd
• buf (void) – buf
• nbytes (size_t) – nbytes

pwnlib.shellcraft.i386.linux.recvsize(sock, reg='ecx')

Recives 4 bytes size field Useful in conjuncion with findpeer and stager :param sock, the socket to read the payload from.: :param reg, the place to put the size: :type reg, the place to put the size: default ecx

Leaves socket in ebx

pwnlib.shellcraft.i386.linux.setregid(gid='egid')

Args: [gid (imm/reg) = egid] Sets the real and effective group id.

pwnlib.shellcraft.i386.linux.setreuid(uid='euid')

Args: [uid (imm/reg) = euid] Sets the real and effective user id.

pwnlib.shellcraft.i386.linux.sh()

Execute a different process.

>>> p = run_assembly(shellcraft.i386.linux.sh())
>>> p.sendline('echo Hello')
>>> p.recv()
'Hello\n'

pwnlib.shellcraft.i386.linux.socket(network='ipv4', proto='tcp')

Creates a new socket

pwnlib.shellcraft.i386.linux.socketcall(socketcall, socket, sockaddr, sockaddr_len)

Invokes a socket call (e.g. socket, send, recv, shutdown)

pwnlib.shellcraft.i386.linux.stage(fd=0, length=None)

Migrates shellcode to a new buffer.

Parameters:

• fd (int) – Integer file descriptor to recv data from. Default is stdin (0).
• length (int) – Optional buffer length. If None, the first pointer-width of data received is the length.

Example

>>> p = run_assembly(shellcraft.stage())
>>> sc = asm(shellcraft.echo("Hello\n", constants.STDOUT_FILENO))
>>> p.pack(len(sc))
>>> p.send(sc)
>>> p.recvline()
'Hello\n'

pwnlib.shellcraft.i386.linux.stager(sock, size, handle_error=False, tiny=False)

Recives a fixed sized payload into a mmaped buffer Useful in conjuncion with findpeer. :param sock, the socket to read the payload from.: :param size, the size of the payload:

pwnlib.shellcraft.i386.linux.syscall(syscall=None, arg0=None, arg1=None, arg2=None, arg3=None, arg4=None, arg5=None)

Args: [syscall_number, *args]

Does a syscall

Any of the arguments can be expressions to be evaluated by pwnlib.constants.eval().

Example

>>> print pwnlib.shellcraft.i386.linux.syscall('SYS_execve', 1, 'esp', 2, 0).rstrip()
    /* call execve(1, 'esp', 2, 0) */
    push SYS_execve /* 0xb */
    pop eax
    push 1
    pop ebx
    mov ecx, esp
    push 2
    pop edx
    xor esi, esi
    int 0x80
>>> print pwnlib.shellcraft.i386.linux.syscall('SYS_execve', 2, 1, 0, 20).rstrip()
    /* call execve(2, 1, 0, 0x14) */
    push SYS_execve /* 0xb */
    pop eax
    push 2
    pop ebx
    push 1
    pop ecx
    push 0x14
    pop esi
    cdq /* edx=0 */
    int 0x80
>>> print pwnlib.shellcraft.i386.linux.syscall().rstrip()
    /* call syscall() */
    int 0x80
>>> print pwnlib.shellcraft.i386.linux.syscall('eax', 'ebx', 'ecx').rstrip()
    /* call syscall('eax', 'ebx', 'ecx') */
    /* setregs noop */
    int 0x80
>>> print pwnlib.shellcraft.i386.linux.syscall('ebp', None, None, 1).rstrip()
    /* call syscall('ebp', ?, ?, 1) */
    mov eax, ebp
    push 1
    pop edx
    int 0x80
>>> print pwnlib.shellcraft.i386.linux.syscall(
...               'SYS_mmap2', 0, 0x1000,
...               'PROT_READ | PROT_WRITE | PROT_EXEC',
...               'MAP_PRIVATE | MAP_ANONYMOUS',
...               -1, 0).rstrip()
    /* call mmap2(0, 0x1000, 'PROT_READ | PROT_WRITE | PROT_EXEC', 'MAP_PRIVATE | MAP_ANONYMOUS', -1, 0) */
    xor eax, eax
    mov al, 0xc0
    xor ebp, ebp
    xor ebx, ebx
    xor ecx, ecx
    mov ch, 0x1000 >> 8
    push -1
    pop edi
    push (PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */
    pop edx
    push (MAP_PRIVATE | MAP_ANONYMOUS) /* 0x22 */
    pop esi
    int 0x80
>>> print pwnlib.shellcraft.open('/home/pwn/flag').rstrip()
    /* open(file='/home/pwn/flag', oflag=0, mode=0) */
    /* push '/home/pwn/flag\x00' */
    push 0x1010101
    xor dword ptr [esp], 0x1016660
    push 0x6c662f6e
    push 0x77702f65
    push 0x6d6f682f
    mov ebx, esp
    xor ecx, ecx
    xor edx, edx
    /* call open() */
    push SYS_open /* 5 */
    pop eax
    int 0x80

pwnlib.shellcraft.i386.freebsd

Shellcraft module containing Intel i386 shellcodes for FreeBSD.

pwnlib.shellcraft.i386.freebsd.acceptloop_ipv4(port)

Args: port Waits for a connection. Leaves socket in EBP. ipv4 only

pwnlib.shellcraft.i386.freebsd.i386_to_amd64()

Returns code to switch from i386 to amd64 mode.

pwnlib.shellcraft.i386.freebsd.sh()

Execute /bin/sh

pwnlib.shellcraft.mips — Shellcode for MIPS

pwnlib.shellcraft.mips

Shellcraft module containing generic MIPS shellcodes.

pwnlib.shellcraft.mips.mov(dst, src)

Move src into dst without newlines and null bytes.

Register $t8 and $t9 are not guarenteed to be preserved.

If src is a string that is not a register, then it will locally set context.arch to ‘mips’ and use pwnlib.constants.eval() to evaluate the string. Note that this means that this shellcode can change behavior depending on the value of context.os.

Parameters:

• dst (str) – The destination register.
• src (str) – Either the input register, or an immediate value.

Example

>>> print shellcraft.mips.mov('$t0', 0).rstrip()
    slti $t0, $zero, 0xFFFF /* $t0 = 0 */
>>> print shellcraft.mips.mov('$t2', 0).rstrip()
    xor $t2, $t2, $t2  /* $t2 = 0 */
>>> print shellcraft.mips.mov('$t0', 0xcafebabe).rstrip()
    li $t0, 0xcafebabe
>>> print shellcraft.mips.mov('$t2', 0xcafebabe).rstrip()
    li $t9, 0xcafebabe
    add $t2, $t9, $zero
>>> print shellcraft.mips.mov('$s0', 0xca0000be).rstrip()
    li $t9, ~0xca0000be
    not $s0, $t9
>>> print shellcraft.mips.mov('$s0', 0xca0000ff).rstrip()
    li $t9, 0x1010101 ^ 0xca0000ff
    li $s0, 0x1010101
    xor $s0, $t9, $s0
>>> print shellcraft.mips.mov('$t9', 0xca0000be).rstrip()
    li $t9, ~0xca0000be
    not $t9, $t9
>>> print shellcraft.mips.mov('$t2', 0xca0000be).rstrip()
    li $t9, ~0xca0000be
    not $t9, $t9
    add $t2, $t9, $0 /* mov $t2, $t9 */
>>> print shellcraft.mips.mov('$t2', 0xca0000ff).rstrip()
    li $t8, 0x1010101 ^ 0xca0000ff
    li $t9, 0x1010101
    xor $t9, $t8, $t9
    add $t2, $t9, $0 /* mov $t2, $t9 */
>>> print shellcraft.mips.mov('$a0', '$t2').rstrip()
    add $a0, $t2, $0 /* mov $a0, $t2 */
>>> print shellcraft.mips.mov('$a0', '$t8').rstrip()
    sw $t8, -4($sp) /* mov $a0, $t8 */
    lw $a0, -4($sp)

pwnlib.shellcraft.mips.nop()

MIPS nop instruction.

pwnlib.shellcraft.mips.push(value)

Pushes a value onto the stack.

pwnlib.shellcraft.mips.pushstr(string, append_null=True)

Pushes a string onto the stack without using null bytes or newline characters.

Example

>>> print shellcraft.mips.pushstr('').rstrip()
    /* push '\x00' */
    sw $zero, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('a').rstrip()
    /* push 'a\x00' */
    li $t9, ~0x61
    not $t1, $t9
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('aa').rstrip()
    /* push 'aa\x00' */
    ori $t1, $zero, 24929
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('aaa').rstrip()
    /* push 'aaa\x00' */
    li $t9, ~0x616161
    not $t1, $t9
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('aaaa').rstrip()
    /* push 'aaaa\x00' */
    li $t1, 0x61616161
    sw $t1, -8($sp)
    sw $zero, -4($sp)
    addiu $sp, $sp, -8
>>> print shellcraft.mips.pushstr('aaaaa').rstrip()
    /* push 'aaaaa\x00' */
    li $t1, 0x61616161
    sw $t1, -8($sp)
    li $t9, ~0x61
    not $t1, $t9
    sw $t1, -4($sp)
    addiu $sp, $sp, -8
>>> print shellcraft.mips.pushstr('aaaa', append_null = False).rstrip()
    /* push 'aaaa' */
    li $t1, 0x61616161
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('\xc3').rstrip()
    /* push '\xc3\x00' */
    li $t9, ~0xc3
    not $t1, $t9
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print shellcraft.mips.pushstr('\xc3', append_null = False).rstrip()
    /* push '\xc3' */
    li $t9, ~0xc3
    not $t1, $t9
    sw $t1, -4($sp)
    addiu $sp, $sp, -4
>>> print enhex(asm(shellcraft.mips.pushstr("/bin/sh")))
696e093c2f622935f8ffa9af97ff193cd08c393727482003fcffa9aff8ffbd27
>>> print enhex(asm(shellcraft.mips.pushstr("")))
fcffa0affcffbd27
>>> print enhex(asm(shellcraft.mips.pushstr("\x00", False)))
fcffa0affcffbd27

Parameters:

• string (str) – The string to push.
• append_null (bool) – Whether to append a single NULL-byte before pushing.

pwnlib.shellcraft.mips.pushstr_array(reg, array)

Pushes an array/envp-style array of pointers onto the stack.

Parameters:

• reg (str) – Destination register to hold the pointer.
• array (str,list) – Single argument or list of arguments to push. NULL termination is normalized so that each argument ends with exactly one NULL byte.

pwnlib.shellcraft.mips.setregs(reg_context, stack_allowed=True)

Sets multiple registers, taking any register dependencies into account (i.e., given eax=1,ebx=eax, set ebx first).

Parameters:

• reg_context (dict) – Desired register context
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.setregs({'$t0':1, '$a3':'0'}).rstrip()
    slti $a3, $zero, 0xFFFF /* $a3 = 0 */
    li $t9, ~1
    not $t0, $t9
>>> print shellcraft.setregs({'$a0':'$a1', '$a1':'$a0', '$a2':'$a1'}).rstrip()
    sw $a1, -4($sp) /* mov $a2, $a1 */
    lw $a2, -4($sp)
    xor $a1, $a1, $a0 /* xchg $a1, $a0 */
    xor $a0, $a1, $a0
    xor $a1, $a1, $a0

pwnlib.shellcraft.mips.trap()

A trap instruction.

pwnlib.shellcraft.mips.linux

Shellcraft module containing MIPS shellcodes for Linux.

pwnlib.shellcraft.mips.linux.bindsh(port, network)

Listens on a TCP port and spawns a shell for the first to connect. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.mips.linux.cat(filename, fd=1)

Opens a file and writes its contents to the specified file descriptor.

Example

>>> f = tempfile.mktemp()
>>> write(f, 'FLAG')
>>> asm  = shellcraft.mips.linux.cat(f)
>>> asm += shellcraft.mips.linux.exit(0)
>>> run_assembly(asm).recvall()
'FLAG'

pwnlib.shellcraft.mips.linux.connect(host, port, network='ipv4')

Connects to the host on the specified port. Network is either ‘ipv4’ or ‘ipv6’. Leaves the connected socket in $s0.

pwnlib.shellcraft.mips.linux.dupsh(sock='$s0')

Args: [sock (imm/reg) = s0 ] Duplicates sock to stdin, stdout and stderr and spawns a shell.

pwnlib.shellcraft.mips.linux.echo(string, sock=1)

Writes a string to a file descriptor

pwnlib.shellcraft.mips.linux.findpeer(port)

Finds a connected socket. If port is specified it is checked against the peer port. Resulting socket is left in $s0.

pwnlib.shellcraft.mips.linux.findpeersh(port)

Finds a connected socket. If port is specified it is checked against the peer port. A dup2 shell is spawned on it.

pwnlib.shellcraft.mips.linux.forkbomb()

Performs a forkbomb attack.

pwnlib.shellcraft.mips.linux.forkexit()

Attempts to fork. If the fork is successful, the parent exits.

pwnlib.shellcraft.mips.linux.killparent()

Kills its parent process until whatever the parent is (probably init) cannot be killed any longer.

pwnlib.shellcraft.mips.linux.listen(port, network)

Listens on a TCP port, accept a client and leave his socket in $s0. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.mips.linux.readfile(path, dst='$s0')

Args: [path, dst (imm/reg) = $s0 ] Opens the specified file path and sends its content to the specified file descriptor.

pwnlib.shellcraft.mips.linux.sh()

Execute /bin/sh

pwnlib.shellcraft.mips.linux.stager(sock, size)

Read ‘size’ bytes from ‘sock’ and place them in an executable buffer and jump to it. The socket will be left in $s0.

pwnlib.shellcraft.mips.linux.syscall(syscall=None, arg0=None, arg1=None, arg2=None, arg3=None, arg4=None, arg5=None)

Args: [syscall_number, *args]

Does a syscall

Any of the arguments can be expressions to be evaluated by pwnlib.constants.eval().

Example

>>> print pwnlib.shellcraft.mips.linux.syscall('SYS_execve', 1, '$sp', 2, 0).rstrip()
    /* call execve(1, '$sp', 2, 0) */
    li $t9, ~1
    not $a0, $t9
    add $a1, $sp, $0 /* mov $a1, $sp */
    li $t9, ~2
    not $a2, $t9
    slti $a3, $zero, 0xFFFF /* $a3 = 0 */
    ori $v0, $zero, SYS_execve
    syscall 0x40404
>>> print pwnlib.shellcraft.mips.linux.syscall('SYS_execve', 2, 1, 0, 20).rstrip()
    /* call execve(2, 1, 0, 0x14) */
    li $t9, ~2
    not $a0, $t9
    li $t9, ~1
    not $a1, $t9
    slti $a2, $zero, 0xFFFF /* $a2 = 0 */
    li $t9, ~0x14
    not $a3, $t9
    ori $v0, $zero, SYS_execve
    syscall 0x40404
>>> print pwnlib.shellcraft.mips.linux.syscall().rstrip()
    /* call syscall() */
    syscall 0x40404
>>> print pwnlib.shellcraft.mips.linux.syscall('$v0', '$a0', '$a1').rstrip()
    /* call syscall('$v0', '$a0', '$a1') */
    /* setregs noop */
    syscall 0x40404
>>> print pwnlib.shellcraft.mips.linux.syscall('$a3', None, None, 1).rstrip()
    /* call syscall('$a3', ?, ?, 1) */
    li $t9, ~1
    not $a2, $t9
    sw $a3, -4($sp) /* mov $v0, $a3 */
    lw $v0, -4($sp)
    syscall 0x40404
>>> print pwnlib.shellcraft.mips.linux.syscall(
...               'SYS_mmap2', 0, 0x1000,
...               'PROT_READ | PROT_WRITE | PROT_EXEC',
...               'MAP_PRIVATE | MAP_ANONYMOUS',
...               -1, 0).rstrip()
    /* call mmap2(0, 0x1000, 'PROT_READ | PROT_WRITE | PROT_EXEC', 'MAP_PRIVATE | MAP_ANONYMOUS', -1, 0) */
    slti $a0, $zero, 0xFFFF /* $a0 = 0 */
    li $t9, ~0x1000
    not $a1, $t9
    li $t9, ~(PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */
    not $a2, $t9
    ori $a3, $zero, (MAP_PRIVATE | MAP_ANONYMOUS)
    ori $v0, $zero, SYS_mmap2
    syscall 0x40404
>>> print pwnlib.shellcraft.open('/home/pwn/flag').rstrip()
    /* open(file='/home/pwn/flag', oflag=0, mode=0) */
    /* push '/home/pwn/flag\x00' */
    li $t1, 0x6d6f682f
    sw $t1, -16($sp)
    li $t1, 0x77702f65
    sw $t1, -12($sp)
    li $t1, 0x6c662f6e
    sw $t1, -8($sp)
    ori $t1, $zero, 26465
    sw $t1, -4($sp)
    addiu $sp, $sp, -16
    add $a0, $sp, $0 /* mov $a0, $sp */
    slti $a1, $zero, 0xFFFF /* $a1 = 0 */
    slti $a2, $zero, 0xFFFF /* $a2 = 0 */
    /* call open() */
    ori $v0, $zero, SYS_open
    syscall 0x40404

pwnlib.regsort — Register sorting

Topographical sort

pwnlib.regsort.check_cycle(reg, assignments)

Walk down the assignment list of a register, return the path walked if it is encountered again.

Returns:The list of register involved in the cycle. If there is no cycle, this is an empty list.

Example

>>> check_cycle('a', {'a': 1})
[]
>>> check_cycle('a', {'a': 'a'})
['a']
>>> check_cycle('a', {'a': 'b', 'b': 'a'})
['a', 'b']
>>> check_cycle('a', {'a': 'b', 'b': 'c', 'c': 'b', 'd': 'a'})
[]
>>> check_cycle('a', {'a': 'b', 'b': 'c', 'c': 'd', 'd': 'a'})
['a', 'b', 'c', 'd']

pwnlib.regsort.extract_dependencies(reg, assignments)

Return a list of all registers which directly depend on the specified register.

Example

>>> extract_dependencies('a', {'a': 1})
[]
>>> extract_dependencies('a', {'a': 'b', 'b': 1})
[]
>>> extract_dependencies('a', {'a': 1, 'b': 'a'})
['b']
>>> extract_dependencies('a', {'a': 1, 'b': 'a', 'c': 'a'})
['b', 'c']

pwnlib.regsort.regsort(in_out, all_regs, tmp=None, xchg=True, randomize=None)

Sorts register dependencies.

Given a dictionary of registers to desired register contents, return the optimal order in which to set the registers to those contents.

The implementation assumes that it is possible to move from any register to any other register.

If a dependency cycle is encountered, one of the following will occur:

• If xchg is True, it is assumed that dependency cyles can be broken by swapping the contents of two register (a la the xchg instruction on i386).
• If xchg is not set, but not all destination registers in in_out are involved in a cycle, one of the registers outside the cycle will be used as a temporary register, and then overwritten with its final value.
• If xchg is not set, and all registers are involved in a dependency cycle, the named register temporary is used as a temporary register.
• If the dependency cycle cannot be resolved as described above, an exception is raised.

Parameters:

• in_out (dict) – Dictionary of desired register states. Keys are registers, values are either registers or any other value.
• all_regs (list) – List of all possible registers. Used to determine which values in in_out are registers, versus regular values.
• tmp (obj, str) – Named register (or other sentinel value) to use as a temporary register. If tmp is a named register and appears as a source value in in_out, dependencies are handled appropriately. tmp cannot be a destination register in in_out. If bool(tmp)==True, this mode is enabled.
• xchg (obj) – Indicates the existence of an instruction which can swap the contents of two registers without use of a third register. If bool(xchg)==False, this mode is disabled.
• random (bool) – Randomize as much as possible about the order or registers.

Returns:

A list of tuples of (src, dest).

Each register may appear more than once, if a register is used as a temporary register, and later overwritten with its final value.

If xchg is True and it is used to break a dependency cycle, then reg_name will be None and value will be a tuple of the instructions to swap.

Example

>>> R = ['a', 'b', 'c', 'd', 'x', 'y', 'z']

If order doesn’t matter for any subsequence, alphabetic order is used.

>>> regsort({'a': 1, 'b': 2}, R)
[('mov', 'a', 1), ('mov', 'b', 2)]
>>> regsort({'a': 'b', 'b': 'a'}, R)
[('xchg', 'a', 'b')]
>>> regsort({'a': 'b', 'b': 'a'}, R, tmp='X') 
[('mov', 'X', 'a'),
 ('mov', 'a', 'b'),
 ('mov', 'b', 'X')]
>>> regsort({'a': 1, 'b': 'a'}, R) 
[('mov', 'b', 'a'),
 ('mov', 'a', 1)]
>>> regsort({'a': 'b', 'b': 'a', 'c': 3}, R) 
[('mov', 'c', 3),
 ('xchg', 'a', 'b')]
>>> regsort({'a': 'b', 'b': 'a', 'c': 'b'}, R) 
[('mov', 'c', 'b'),
 ('xchg', 'a', 'b')]
>>> regsort({'a':'b', 'b':'a', 'x':'b'}, R, tmp='y', xchg=False) 
[('mov', 'x', 'b'),
 ('mov', 'y', 'a'),
 ('mov', 'a', 'b'),
 ('mov', 'b', 'y')]
>>> regsort({'a':'b', 'b':'a', 'x':'b'}, R, tmp='x', xchg=False) 
Traceback (most recent call last):
...
PwnlibException: Cannot break dependency cycles ...
>>> regsort({'a':'b','b':'c','c':'a','x':'1','y':'z','z':'c'}, R) 
[('mov', 'x', '1'),
 ('mov', 'y', 'z'),
 ('mov', 'z', 'c'),
 ('xchg', 'a', 'b'),
 ('xchg', 'b', 'c')]
>>> regsort({'a':'b','b':'c','c':'a','x':'1','y':'z','z':'c'}, R, tmp='x') 
[('mov', 'y', 'z'),
 ('mov', 'z', 'c'),
 ('mov', 'x', 'a'),
 ('mov', 'a', 'b'),
 ('mov', 'b', 'c'),
 ('mov', 'c', 'x'),
 ('mov', 'x', '1')]
>>> regsort({'a':'b','b':'c','c':'a','x':'1','y':'z','z':'c'}, R, xchg=0) 
[('mov', 'y', 'z'),
 ('mov', 'z', 'c'),
 ('mov', 'x', 'a'),
 ('mov', 'a', 'b'),
 ('mov', 'b', 'c'),
 ('mov', 'c', 'x'),
 ('mov', 'x', '1')]
 >>> regsort({'a': 'b', 'b': 'c'}, ['a','b','c'], xchg=0)
 [('mov', 'a', 'b'), ('mov', 'b', 'c')]

pwnlib.regsort.resolve_order(reg, deps)

Resolve the order of all dependencies starting at a given register.

Example

>>> want = {'a': 1, 'b': 'c', 'c': 'd', 'd': 7, 'x': 'd'}
>>> deps = {'a': [], 'b': [], 'c': ['b'], 'd': ['c', 'x'], 'x': []}
>>> resolve_order('a', deps)
['a']
>>> resolve_order('b', deps)
['b']
>>> resolve_order('c', deps)
['b', 'c']
>>> resolve_order('d', deps)
['b', 'c', 'x', 'd']

pwnlib.shellcraft.thumb — Shellcode for Thumb Mode

pwnlib.shellcraft.thumb

Shellcraft module containing generic thumb little endian shellcodes.

pwnlib.shellcraft.thumb.crash()

Crash.

Example

>>> run_assembly(shellcraft.crash()).poll(True) < 0
True

pwnlib.shellcraft.thumb.infloop()

An infinite loop.

pwnlib.shellcraft.thumb.itoa(v, buffer='sp', allocate_stack=True)

Converts an integer into its string representation, and pushes it onto the stack. Uses registers r0-r5.

Parameters:

• v (str, int) – Integer constant or register that contains the value to convert.
• alloca –

Example

>>> sc = shellcraft.thumb.mov('r0', 0xdeadbeef)
>>> sc += shellcraft.thumb.itoa('r0')
>>> sc += shellcraft.thumb.linux.write(1, 'sp', 32)
>>> run_assembly(sc).recvuntil('\x00')
'3735928559\x00'

pwnlib.shellcraft.thumb.memcpy(dest, src, n)

Copies memory.

Parameters:

• dest – Destination address
• src – Source address
• n – Number of bytes

pwnlib.shellcraft.thumb.mov(dst, src)

Returns THUMB code for moving the specified source value into the specified destination register.

If src is a string that is not a register, then it will locally set context.arch to ‘thumb’ and use pwnlib.constants.eval() to evaluate the string. Note that this means that this shellcode can change behavior depending on the value of context.os.

Example

>>> print shellcraft.thumb.mov('r1','r2').rstrip()
    mov r1, r2
>>> print shellcraft.thumb.mov('r1', 0).rstrip()
    eor r1, r1
>>> print shellcraft.thumb.mov('r1', 10).rstrip()
    mov r1, #0xa + 1
    sub r1, r1, 1
>>> print shellcraft.thumb.mov('r1', 17).rstrip()
    mov r1, #0x11
>>> print shellcraft.thumb.mov('r1', 'r1').rstrip()
    /* moving r1 into r1, but this is a no-op */
>>> print shellcraft.thumb.mov('r1', 512).rstrip()
    mov r1, #0x200
>>> print shellcraft.thumb.mov('r1', 0x10000001).rstrip()
    mov r1, #(0x10000001 >> 28)
    lsl r1, #28
    add r1, #(0x10000001 & 0xff)
>>> print shellcraft.thumb.mov('r1', 0xdead0000).rstrip()
    mov r1, #(0xdead0000 >> 25)
    lsl r1, #(25 - 16)
    add r1, #((0xdead0000 >> 16) & 0xff)
    lsl r1, #16
>>> print shellcraft.thumb.mov('r1', 0xdead00ff).rstrip()
    ldr r1, value_...
    b value_..._after
value_...: .word 0xdead00ff
value_..._after:
>>> with context.local(os = 'linux'):
...     print shellcraft.thumb.mov('r1', 'SYS_execve').rstrip()
    mov r1, #SYS_execve /* 0xb */
>>> with context.local(os = 'freebsd'):
...     print shellcraft.thumb.mov('r1', 'SYS_execve').rstrip()
    mov r1, #SYS_execve /* 0x3b */
>>> with context.local(os = 'linux'):
...     print shellcraft.thumb.mov('r1', 'PROT_READ | PROT_WRITE | PROT_EXEC').rstrip()
    mov r1, #(PROT_READ | PROT_WRITE | PROT_EXEC) /* 7 */

pwnlib.shellcraft.thumb.nop()

A nop instruction.

pwnlib.shellcraft.thumb.popad()

Pop all of the registers onto the stack which i386 popad does, in the same order.

pwnlib.shellcraft.thumb.push(value)

Pushes a value onto the stack without using null bytes or newline characters.

If src is a string, then we try to evaluate with context.arch = ‘thumb’ using pwnlib.constants.eval() before determining how to push it. Note that this means that this shellcode can change behavior depending on the value of context.os.

Parameters:value (int,str) – The value or register to push

Example

>>> print pwnlib.shellcraft.thumb.push('r0').rstrip()
    push {r0}
>>> print pwnlib.shellcraft.thumb.push(0).rstrip()
    /* push 0 */
    eor r7, r7
    push {r7}
>>> print pwnlib.shellcraft.thumb.push(1).rstrip()
    /* push 1 */
    mov r7, #1
    push {r7}
>>> print pwnlib.shellcraft.thumb.push(256).rstrip()
    /* push 256 */
    mov r7, #0x100
    push {r7}
>>> print pwnlib.shellcraft.thumb.push('SYS_execve').rstrip()
    /* push 'SYS_execve' */
    mov r7, #0xb
    push {r7}
>>> with context.local(os = 'freebsd'):
...     print pwnlib.shellcraft.thumb.push('SYS_execve').rstrip()
    /* push 'SYS_execve' */
    mov r7, #0x3b
    push {r7}

pwnlib.shellcraft.thumb.pushad()

Push all of the registers onto the stack which i386 pushad does, in the same order.

pwnlib.shellcraft.thumb.pushstr(string, append_null=True, register='r7')

Pushes a string onto the stack without using null bytes or newline characters.

Parameters:

• string (str) – The string to push.
• append_null (bool) – Whether to append a single NULL-byte before pushing.

Examples:

Note that this doctest has two possibilities for the first result, depending on your version of binutils.

>>> enhex(asm(shellcraft.pushstr('Hello\nWorld!', True))) in [
... '87ea070780b4dff8047001e0726c642180b4dff8047001e06f0a576f80b4dff8047001e048656c6c80b4',
... '87ea070780b4dff8067000f002b8726c642180b4dff8047000f002b86f0a576f80b4014f00f002b848656c6c80b4']
True
>>> print shellcraft.pushstr('abc').rstrip() 
    /* push 'abc\x00' */
    ldr r7, value_...
    b value_..._after
value_...: .word 0xff636261
value_..._after:
    lsl r7, #8
    lsr r7, #8
    push {r7}
>>> print enhex(asm(shellcraft.pushstr('\x00', False)))
87ea070780b4

pwnlib.shellcraft.thumb.pushstr_array(reg, array)

Pushes an array/envp-style array of pointers onto the stack.

Parameters:

• reg (str) – Destination register to hold the pointer.
• array (str,list) – Single argument or list of arguments to push. NULL termination is normalized so that each argument ends with exactly one NULL byte.

pwnlib.shellcraft.thumb.ret(return_value=None)

A single-byte RET instruction.

Parameters:return_value – Value to return

pwnlib.shellcraft.thumb.setregs(reg_context, stack_allowed=True)

Sets multiple registers, taking any register dependencies into account (i.e., given eax=1,ebx=eax, set ebx first).

Parameters:

• reg_context (dict) – Desired register context
• stack_allowed (bool) – Can the stack be used?

Example

>>> print shellcraft.setregs({'r0':1, 'r2':'r3'}).rstrip()
    mov r0, #1
    mov r2, r3
>>> print shellcraft.setregs({'r0':'r1', 'r1':'r0', 'r2':'r3'}).rstrip()
    mov r2, r3
    eor r0, r0, r1 /* xchg r0, r1 */
    eor r1, r0, r1
    eor r0, r0, r1

pwnlib.shellcraft.thumb.to_arm(reg=None, avoid=[])

Go from THUMB to ARM mode.

pwnlib.shellcraft.thumb.trap()

A trap instruction.

pwnlib.shellcraft.thumb.udiv_10(N)

Divides r0 by 10. Result is stored in r0, N and Z flags are updated.

Code is from generated from here:

https://raw.githubusercontent.com/rofirrim/raspberry-pi-assembler/master/chapter15/magic.py

With code:

python magic.py 10 code_for_unsigned

pwnlib.shellcraft.thumb.linux

Shellcraft module containing THUMB shellcodes for Linux.

pwnlib.shellcraft.thumb.linux.bindsh(port, network)

Listens on a TCP port and spawns a shell for the first to connect. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.thumb.linux.cat(filename, fd=1)

Opens a file and writes its contents to the specified file descriptor.

Example

>>> f = tempfile.mktemp()
>>> write(f, 'FLAG\n')
>>> run_assembly(shellcraft.arm.to_thumb()+shellcraft.thumb.linux.cat(f)).recvline()
'FLAG\n'

pwnlib.shellcraft.thumb.linux.connect(host, port, network='ipv4')

Connects to the host on the specified port. Network is either ‘ipv4’ or ‘ipv6’. Leaves the connected socket in R6.

pwnlib.shellcraft.thumb.linux.connectstager(host, port, network='ipv4')

connect recvsize stager :param host, where to connect to: :param port, which port to connect to: :param network, ipv4 or ipv6? (default: ipv4)

pwnlib.shellcraft.thumb.linux.dup(sock='r6')

Args: [sock (imm/reg) = r6] Duplicates sock to stdin, stdout and stderr

pwnlib.shellcraft.thumb.linux.dupsh(sock='r6')

Args: [sock (imm/reg) = ebp] Duplicates sock to stdin, stdout and stderr and spawns a shell.

pwnlib.shellcraft.thumb.linux.echo(string, sock='1')

Writes a string to a file descriptor

Example

>>> run_assembly(shellcraft.echo('hello\n', 1)).recvline()
'hello\n'

pwnlib.shellcraft.thumb.linux.findpeer(port)

Finds a connected socket. If port is specified it is checked against the peer port. Resulting socket is left in r6.

pwnlib.shellcraft.thumb.linux.findpeersh(port)

Finds a connected socket. If port is specified it is checked against the peer port. A dup2 shell is spawned on it.

pwnlib.shellcraft.thumb.linux.findpeerstager(port=None)

Findpeer recvsize stager :param port, the port given to findpeer: :type port, the port given to findpeer: defaults to any

pwnlib.shellcraft.thumb.linux.forkbomb()

Performs a forkbomb attack.

pwnlib.shellcraft.thumb.linux.forkexit()

Attempts to fork. If the fork is successful, the parent exits.

pwnlib.shellcraft.thumb.linux.killparent()

Kills its parent process until whatever the parent is (probably init) cannot be killed any longer.

pwnlib.shellcraft.thumb.linux.listen(port, network)

Listens on a TCP port, accept a client and leave his socket in r6. Port is the TCP port to listen on, network is either ‘ipv4’ or ‘ipv6’.

pwnlib.shellcraft.thumb.linux.loader(address)

Loads a statically-linked ELF into memory and transfers control.

Parameters:address (int) – Address of the ELF as a register or integer.

pwnlib.shellcraft.thumb.linux.loader_append(data=None)

Loads a statically-linked ELF into memory and transfers control.

Similar to loader.asm but loads an appended ELF.

Parameters:data (str) – If a valid filename, the data is loaded from the named file. Otherwise, this is treated as raw ELF data to append. If None, it is ignored.

Example:

The following doctest is commented out because it doesn’t work on Travis for reasons I cannot diagnose. However, it should work just fine :-)

# >>> gcc = process([‘arm-linux-gnueabihf-gcc’,’-xc’,’-static’,’-Wl,-Ttext-segment=0x20000000’,’-‘]) # >>> gcc.write(‘’’ # ... int main() { # ... printf(“Hello, %s!\n”, “world”); # ... } # ... ‘’‘) # >>> gcc.shutdown(‘send’) # >>> gcc.poll(True) # 0 # >>> sc = shellcraft.loader_append(‘a.out’) # >>> run_assembly(sc).recvline() # ‘Hello, world!n’

pwnlib.shellcraft.thumb.linux.readfile(path, dst='r6')

Args: [path, dst (imm/reg) = r6 ] Opens the specified file path and sends its content to the specified file descriptor. Leaves the destination file descriptor in r6 and the input file descriptor in r5.

pwnlib.shellcraft.thumb.linux.readn(fd, buf, nbytes)

Reads exactly nbytes bytes from file descriptor fd into the buffer buf.

Parameters:

• fd (int) – fd
• buf (void) – buf
• nbytes (size_t) – nbytes

pwnlib.shellcraft.thumb.linux.recvsize(sock, reg='r1')

Recives 4 bytes size field Useful in conjuncion with findpeer and stager :param sock, the socket to read the payload from.: :param reg, the place to put the size: :type reg, the place to put the size: default ecx

Leaves socket in ebx

pwnlib.shellcraft.thumb.linux.sh()

Execute a different process.

>>> p = run_assembly(shellcraft.thumb.linux.sh())
>>> p.sendline('echo Hello')
>>> p.recv()
'Hello\n'

pwnlib.shellcraft.thumb.linux.stage(fd=0, length=None)

Migrates shellcode to a new buffer.

Parameters:

• fd (int) – Integer file descriptor to recv data from. Default is stdin (0).
• length (int) – Optional buffer length. If None, the first pointer-width of data received is the length.

Example

>>> p = run_assembly(shellcraft.stage())
>>> sc = asm(shellcraft.echo("Hello\n", constants.STDOUT_FILENO))
>>> p.pack(len(sc))
>>> p.send(sc)
>>> p.recvline()
'Hello\n'

pwnlib.shellcraft.thumb.linux.stager(sock, size)

Read ‘size’ bytes from ‘sock’ and place them in an executable buffer and jump to it. The socket will be left in r6.

pwnlib.shellcraft.thumb.linux.syscall(syscall=None, arg0=None, arg1=None, arg2=None, arg3=None, arg4=None, arg5=None, arg6=None)

Args: [syscall_number, *args]

Does a syscall

Any of the arguments can be expressions to be evaluated by pwnlib.constants.eval().

Example

>>> print shellcraft.thumb.linux.syscall(11, 1, 'sp', 2, 0).rstrip()
    /* call syscall(11, 1, 'sp', 2, 0) */
    mov r0, #1
    mov r1, sp
    mov r2, #2
    eor r3, r3
    mov r7, #0xb
    svc 0x41
>>> print shellcraft.thumb.linux.syscall('SYS_exit', 0).rstrip()
    /* call exit(0) */
    eor r0, r0
    mov r7, #SYS_exit /* 1 */
    svc 0x41
>>> print pwnlib.shellcraft.open('/home/pwn/flag').rstrip() 
    /* open(file='/home/pwn/flag', oflag=0, mode=0) */
    /* push '/home/pwn/flag\x00' */
    mov r7, #(0x6761 >> 8)
    lsl r7, #8
    add r7, #(0x6761 & 0xff)
    push {r7}
    ldr r7, value_...
    b value_..._after
value_...: .word 0x6c662f6e
value_..._after:
    push {r7}
    ldr r7, value_...
    b value_..._after
value_...: .word 0x77702f65
value_..._after:
    push {r7}
    ldr r7, value_...
    b value_..._after
value_...: .word 0x6d6f682f
value_..._after:
    push {r7}
    mov r0, sp
    eor r1, r1
    eor r2, r2
    /* call open() */
    mov r7, #SYS_open /* 5 */
    svc 0x41

pwnlib.term — Terminal handling

pwnlib.term.can_init()

This function returns True iff stderr is a TTY and we are not inside a REPL. Iff this function returns True, a call to init() will let pwnlib manage the terminal.

pwnlib.term.init()

Calling this function will take over the terminal (iff can_init() returns True) until the current python interpreter is closed.

It is on our TODO, to create a function to “give back” the terminal without closing the interpreter.

pwnlib.term.term_mode = False

This is True exactly when we have taken over the terminal using init().

pwnlib.timeout — Timeout handling

Timeout encapsulation, complete with countdowns and scope managers.

class pwnlib.timeout.Timeout(timeout=pwnlib.timeout.Timeout.default)

Implements a basic class which has a timeout, and support for scoped timeout countdowns.

Valid timeout values are:

• Timeout.default use the global default value (context.default)
• Timeout.forever or None never time out
• Any positive float, indicates timeouts in seconds

Example

>>> context.timeout = 30
>>> t = Timeout()
>>> t.timeout == 30
True
>>> t = Timeout(5)
>>> t.timeout == 5
True
>>> i = 0
>>> with t.countdown():
...     print (4 <= t.timeout and t.timeout <= 5)
...
True
>>> with t.countdown(0.5):
...     while t.timeout:
...         print round(t.timeout,1)
...         time.sleep(0.1)
0.5
0.4
0.3
0.2
0.1
>>> print t.timeout
5.0
>>> with t.local(0.5):
...     for i in range(5):
...         print round(t.timeout,1)
...         time.sleep(0.1)
0.5
0.5
0.5
0.5
0.5
>>> print t.timeout
5.0

countdown(timeout=pwnlib.timeout.Timeout.default)

Scoped timeout setter. Sets the timeout within the scope, and restores it when leaving the scope.

When accessing timeout within the scope, it will be calculated against the time when the scope was entered, in a countdown fashion.

If None is specified for timeout, then the current timeout is used is made. This allows None to be specified as a default argument with less complexity.

default = pwnlib.timeout.Timeout.default

Value indicating that the timeout should not be changed

forever = None

Value indicating that a timeout should not ever occur

local(timeout)

Scoped timeout setter. Sets the timeout within the scope, and restores it when leaving the scope.

maximum = pwnlib.timeout.maximum

Maximum value for a timeout. Used to get around platform issues with very large timeouts.

OSX does not permit setting socket timeouts to 2**22. Assume that if we receive a timeout of 2**21 or greater, that the value is effectively infinite.

timeout

Timeout for obj operations. By default, uses context.timeout.

timeout_change()

Callback for subclasses to hook a timeout change.

pwnlib.tubes — Talking to the World!

The pwnlib is not a big truck! It’s a series of tubes!

This is our library for talking to sockets, processes, ssh connections etc. Our goal is to be able to use the same API for e.g. remote TCP servers, local TTY-programs and programs run over over SSH.

It is organized such that the majority of the functionality is implemented in pwnlib.tubes.tube. The remaining classes should only implement just enough for the class to work and possibly code pertaining only to that specific kind of tube.

Types of Tubes

pwnlib.tubes.process — Processes

class pwnlib.tubes.process.process(argv=None, shell=False, executable=None, cwd=None, env=None, stdin=-1, stdout=<pwnlib.tubes.process.PTY object>, stderr=-2, close_fds=True, preexec_fn=<function <lambda>>, raw=True, aslr=None, setuid=None, where='local', display=None, alarm=None, *args, **kwargs)

Bases: pwnlib.tubes.tube.tube

Spawns a new process, and wraps it with a tube for communication.

Parameters:

• argv (list) – List of arguments to pass to the spawned process.
• shell (bool) – Set to True to interpret argv as a string to pass to the shell for interpretation instead of as argv.
• executable (str) – Path to the binary to execute. If None, uses argv[0]. Cannot be used with shell.
• cwd (str) – Working directory. Uses the current working directory by default.
• env (dict) – Environment variables. By default, inherits from Python’s environment.
• stdin (int) – File object or file descriptor number to use for stdin. By default, a pipe is used. A pty can be used instead by setting this to PTY. This will cause programs to behave in an interactive manner (e.g.., python will show a >>> prompt). If the application reads from /dev/tty directly, use a pty.
• stdout (int) – File object or file descriptor number to use for stdout. By default, a pty is used so that any stdout buffering by libc routines is disabled. May also be PIPE to use a normal pipe.
• stderr (int) – File object or file descriptor number to use for stderr. By default, STDOUT is used. May also be PIPE to use a separate pipe, although the pwnlib.tubes.tube.tube wrapper will not be able to read this data.
• close_fds (bool) – Close all open file descriptors except stdin, stdout, stderr. By default, True is used.
• preexec_fn (callable) – Callable to invoke immediately before calling execve.
• raw (bool) – Set the created pty to raw mode (i.e. disable echo and control characters). True by default. If no pty is created, this has no effect.
• aslr (bool) –

  If set to False, disable ASLR via personality (setarch -R) and setrlimit (ulimit -s unlimited).

  This disables ASLR for the target process. However, the setarch changes are lost if a setuid binary is executed.

  The default value is inherited from context.aslr. See setuid below for additional options and information.

• setuid (bool) –

  Used to control setuid status of the target binary, and the corresponding actions taken.

  By default, this value is None, so no assumptions are made.

  If True, treat the target binary as setuid. This modifies the mechanisms used to disable ASLR on the process if aslr=False. This is useful for debugging locally, when the exploit is a setuid binary.

  If False, prevent setuid bits from taking effect on the target binary. This is only supported on Linux, with kernels v3.5 or greater.

• where (str) – Where the process is running, used for logging purposes.
• display (list) – List of arguments to display, instead of the main executable name.
• alarm (int) – Set a SIGALRM alarm timeout on the process.

proc

subprocess

Examples

>>> p = process('python2')
>>> p.sendline("print 'Hello world'")
>>> p.sendline("print 'Wow, such data'");
>>> '' == p.recv(timeout=0.01)
True
>>> p.shutdown('send')
>>> p.proc.stdin.closed
True
>>> p.connected('send')
False
>>> p.recvline()
'Hello world\n'
>>> p.recvuntil(',')
'Wow,'
>>> p.recvregex('.*data')
' such data'
>>> p.recv()
'\n'
>>> p.recv() 
Traceback (most recent call last):
...
EOFError

>>> p = process('cat')
>>> d = open('/dev/urandom').read(4096)
>>> p.recv(timeout=0.1)
''
>>> p.write(d)
>>> p.recvrepeat(0.1) == d
True
>>> p.recv(timeout=0.1)
''
>>> p.shutdown('send')
>>> p.wait_for_close()
>>> p.poll()
0

>>> p = process('cat /dev/zero | head -c8', shell=True, stderr=open('/dev/null', 'w+'))
>>> p.recv()
'\x00\x00\x00\x00\x00\x00\x00\x00'

>>> p = process(['python','-c','import os; print os.read(2,1024)'],
...             preexec_fn = lambda: os.dup2(0,2))
>>> p.sendline('hello')
>>> p.recvline()
'hello\n'

>>> stack_smashing = ['python','-c','open("/dev/tty","wb").write("stack smashing detected")']
>>> process(stack_smashing).recvall()
'stack smashing detected'

>>> process(stack_smashing, stdout=PIPE).recvall()
''

>>> getpass = ['python','-c','import getpass; print getpass.getpass("XXX")']
>>> p = process(getpass, stdin=PTY)
>>> p.recv()
'XXX'
>>> p.sendline('hunter2')
>>> p.recvall()
'\nhunter2\n'

>>> process('echo hello 1>&2', shell=True).recvall()
'hello\n'

>>> process('echo hello 1>&2', shell=True, stderr=PIPE).recvall()
''

>>> a = process(['cat', '/proc/self/maps']).recvall()
>>> b = process(['cat', '/proc/self/maps'], aslr=False).recvall()
>>> with context.local(aslr=False):
...    c = process(['cat', '/proc/self/maps']).recvall()
>>> a == b
False
>>> b == c
True

>>> process(['sh','-c','ulimit -s'], aslr=0).recvline()
'unlimited\n'

>>> io = process(['sh','-c','sleep 10; exit 7'], alarm=2)
>>> io.poll(block=True) == -signal.SIGALRM
True

>>> binary = ELF.from_assembly('nop', arch='mips')
>>> p = process(binary.path)

alarm = None

Alarm timeout of the process

argv = None

Arguments passed on argv

aslr = None

Whether ASLR should be left on

communicate(stdin = None) → str

Calls subprocess.Popen.communicate() method on the process.

corefile

Returns a corefile for the process.

If the process is alive, attempts to create a coredump with GDB.

If the process is dead, attempts to locate the coredump created by the kernel.

cwd

Directory that the process is working in.

Example

>>> p = process('sh')
>>> p.sendline('cd /tmp; echo AAA')
>>> _ = p.recvuntil('AAA')
>>> p.cwd == '/tmp'
True
>>> p.sendline('cd /proc; echo BBB;')
>>> _ = p.recvuntil('BBB')
>>> p.cwd
'/proc'

elf

Returns an ELF file for the executable that launched the process.

env = None

Environment passed on envp

executable = None

Full path to the executable

kill()

Kills the process.

leak(address, count=1)

Leaks memory within the process at the specified address.

Parameters:

• address (int) – Address to leak memory at
• count (int) – Number of bytes to leak at that address.

Example

>>> e = ELF('/bin/sh')
>>> p = process(e.path)

In order to make sure there’s not a race condition against the process getting set up...

>>> p.sendline('echo hello')
>>> p.recvuntil('hello')
'hello'

Now we can leak some data!

>>> p.leak(e.address, 4)
'\x7fELF'

libc

Returns an ELF for the libc for the current process. If possible, it is adjusted to the correct address automatically.

libs() → dict

Return a dictionary mapping the path of each shared library loaded by the process to the address it is loaded at in the process’ address space.

If /proc/$PID/maps for the process cannot be accessed, the output of ldd alone is used. This may give inaccurate results if ASLR is enabled.

poll(block = False) → int

Parameters:block (bool) – Wait for the process to exit

Poll the exit code of the process. Will return None, if the process has not yet finished and the exit code otherwise.

proc = None

subprocess.Popen object

program

Alias for executable, for backward compatibility.

Example

>>> p = process('true')
>>> p.executable == '/bin/true'
True
>>> p.executable == p.program
True

pty = None

Which file descriptor is the controlling TTY

raw = None

Whether the controlling TTY is set to raw mode

pwnlib.tubes.serialtube — Serial Ports

class pwnlib.tubes.serialtube.serialtube(port=None, baudrate=115200, convert_newlines=True, bytesize=8, parity='N', stopbits=1, xonxoff=False, rtscts=False, dsrdtr=False, *a, **kw)

pwnlib.tubes.sock — Sockets

class pwnlib.tubes.sock.sock

Bases: pwnlib.tubes.tube.tube

Methods available exclusively to sockets.

class pwnlib.tubes.remote.remote(host, port, fam='any', typ='tcp', ssl=False, sock=None, *args, **kwargs)

Bases: pwnlib.tubes.sock.sock

Creates a TCP or UDP-connection to a remote host. It supports both IPv4 and IPv6.

The returned object supports all the methods from pwnlib.tubes.sock and pwnlib.tubes.tube.

Parameters:

• host (str) – The host to connect to.
• port (int) – The port to connect to.
• fam – The string “any”, “ipv4” or “ipv6” or an integer to pass to socket.getaddrinfo().
• typ – The string “tcp” or “udp” or an integer to pass to socket.getaddrinfo().
• timeout – A positive number, None or the string “default”.
• ssl (bool) – Wrap the socket with SSL
• sock (socket) – Socket to inherit, rather than connecting

Examples

>>> r = remote('google.com', 443, ssl=True)
>>> r.send('GET /\r\n\r\n')
>>> r.recvn(4)
'HTTP'
>>> r = remote('127.0.0.1', 1)
Traceback (most recent call last):
...
PwnlibException: Could not connect to 127.0.0.1 on port 1
>>> import socket
>>> s = socket.socket()
>>> s.connect(('google.com', 80))
>>> s.send('GET /' + '\r\n'*2)
9
>>> r = remote.fromsocket(s)
>>> r.recvn(4)
'HTTP'

classmethod fromsocket(socket)

Helper method to wrap a standard python socket.socket with the tube APIs.

Parameters:socket – Instance of socket.socket Returns:Instance of pwnlib.tubes.remote.remote.

class pwnlib.tubes.listen.listen(port=0, bindaddr='0.0.0.0', fam='any', typ='tcp', *args, **kwargs)

Bases: pwnlib.tubes.sock.sock

Creates an TCP or UDP-socket to receive data on. It supports both IPv4 and IPv6.

The returned object supports all the methods from pwnlib.tubes.sock and pwnlib.tubes.tube.

Parameters:

• port (int) – The port to connect to.
• bindaddr (str) – The address to bind to.
• fam – The string “any”, “ipv4” or “ipv6” or an integer to pass to socket.getaddrinfo().
• typ – The string “tcp” or “udp” or an integer to pass to socket.getaddrinfo().

wait_for_connection()

Blocks until a connection has been established.

pwnlib.tubes.ssh — SSH

class pwnlib.tubes.ssh.ssh(user, host, port=22, password=None, key=None, keyfile=None, proxy_command=None, proxy_sock=None, level=None, cache=True, ssh_agent=False, *a, **kw)

arch

str – CPU Architecture of the remote machine.

aslr

bool – Whether ASLR is enabled on the system.

Example

>>> s = ssh("esoteric3", "wargame.w3challs.com", 20202, "esoteric3")
>>> s.aslr
True

aslr_ulimit

bool – Whether the entropy of 32-bit processes can be reduced with ulimit.

bits

str – Pointer size of the remote machine.

cache = True

Enable caching of SSH downloads (bool)

checksec()

Prints a helpful message about the remote system.

Parameters:banner (bool) – Whether to print the path to the ELF binary.

client = None

Paramiko SSHClient which backs this object

close()

Close the connection.

connect_remote(host, port, timeout = Timeout.default) → ssh_connecter

Connects to a host through an SSH connection. This is equivalent to using the -L flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_connecter object.

Examples

>>> from pwn import *
>>> l = listen()
>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> a = s.connect_remote(s.host, l.lport)
>>> b = l.wait_for_connection()
>>> a.sendline('Hello')
>>> print repr(b.recvline())
'Hello\n'

connected()

Returns True if we are connected.

Example

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> s.connected()
True
>>> s.close()
>>> s.connected()
False

cwd = None

Working directory (str)

distro

tuple – Linux distribution name and release.

download(file_or_directory, local=None)

Download a file or directory from the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.
• local (str) – Local path to store the data. By default, uses the current directory.

download_data(remote)

Downloads a file from the remote server and returns it as a string.

Parameters:remote (str) – The remote filename to download.

Examples

>>> with file('/tmp/bar','w+') as f:
...     f.write('Hello, world')
>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass',
...         cache=False)
>>> s.download_data('/tmp/bar')
'Hello, world'
>>> s._sftp = None
>>> s._tried_sftp = True
>>> s.download_data('/tmp/bar')
'Hello, world'

download_dir(remote=None, local=None)

Recursively downloads a directory from the remote server

Parameters:

• local – Local directory
• remote – Remote directory

download_file(remote, local=None)

Downloads a file from the remote server.

The file is cached in /tmp/pwntools-ssh-cache using a hash of the file, so calling the function twice has little overhead.

Parameters:

• remote (str) – The remote filename to download
• local (str) – The local filename to save it to. Default is to infer it from the remote filename.

get(file_or_directory, local=None)

download(file_or_directory, local=None)

Download a file or directory from the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.
• local (str) – Local path to store the data. By default, uses the current directory.

getenv(variable, **kwargs)

Retrieve the address of an environment variable on the remote system.

Note

The exact address will differ based on what other environment variables are set, as well as argv[0]. In order to ensure that the path is exactly the same, it is recommended to invoke the process with argv=[].

host = None

Remote host name (str)

interactive(shell=None)

Create an interactive session.

This is a simple wrapper for creating a new pwnlib.tubes.ssh.ssh_channel object and calling pwnlib.tubes.ssh.ssh_channel.interactive() on it.

libs(remote, directory=None)

Downloads the libraries referred to by a file.

This is done by running ldd on the remote server, parsing the output and downloading the relevant files.

The directory argument specified where to download the files. This defaults to ‘./$HOSTNAME’ where $HOSTNAME is the hostname of the remote server.

listen(port=0, bind_address='', timeout=pwnlib.timeout.Timeout.default)

listen_remote(port = 0, bind_address = ‘’, timeout = Timeout.default) -> ssh_connecter

Listens remotely through an SSH connection. This is equivalent to using the -R flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_listener object.

Examples

>>> from pwn import *
>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> l = s.listen_remote()
>>> a = remote(s.host, l.port)
>>> b = l.wait_for_connection()
>>> a.sendline('Hello')
>>> print repr(b.recvline())
'Hello\n'

listen_remote(port = 0, bind_address = '', timeout = Timeout.default) → ssh_connecter

Listens remotely through an SSH connection. This is equivalent to using the -R flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_listener object.

Examples

>>> from pwn import *
>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> l = s.listen_remote()
>>> a = remote(s.host, l.port)
>>> b = l.wait_for_connection()
>>> a.sendline('Hello')
>>> print repr(b.recvline())
'Hello\n'

os

str – Operating System of the remote machine.

pid = None

PID of the remote sshd process servicing this connection.

port = None

Remote port (int)

process(argv=None, executable=None, tty=True, cwd=None, env=None, timeout=pwnlib.timeout.Timeout.default, run=True, stdin=0, stdout=1, stderr=2, preexec_fn=None, preexec_args=[], raw=True, aslr=None, setuid=None, shell=False)

Executes a process on the remote server, in the same fashion as pwnlib.tubes.process.process.

To achieve this, a Python script is created to call os.execve with the appropriate arguments.

As an added bonus, the ssh_channel object returned has a pid property for the process pid.

Parameters:

• argv (list) – List of arguments to pass into the process
• executable (str) – Path to the executable to run. If None, argv[0] is used.
• tty (bool) – Request a tty from the server. This usually fixes buffering problems by causing libc to write data immediately rather than buffering it. However, this disables interpretation of control codes (e.g. Ctrl+C) and breaks .shutdown.
• cwd (str) – Working directory. If None, uses the working directory specified on cwd or set via set_working_directory().
• env (dict) – Environment variables to set in the child. If None, inherits the default environment.
• timeout (int) – Timeout to set on the tube created to interact with the process.
• run (bool) – Set to True to run the program (default). If False, returns the path to an executable Python script on the remote server which, when executed, will do it.
• stdin (int, str) – If an integer, replace stdin with the numbered file descriptor. If a string, a open a file with the specified path and replace stdin with its file descriptor. May also be one of sys.stdin, sys.stdout, sys.stderr. If None, the file descriptor is closed.
• stdout (int, str) – See stdin.
• stderr (int, str) – See stdin.
• preexec_fn (callable) – Function which is executed on the remote side before execve(). This MUST be a self-contained function – it must perform all of its own imports, and cannot refer to variables outside its scope.
• preexec_args (object) – Argument passed to preexec_fn. This MUST only consist of native Python objects.
• raw (bool) – If True, disable TTY control code interpretation.
• aslr (bool) – See pwnlib.tubes.process.process for more information.
• setuid (bool) – See pwnlib.tubes.process.process for more information.
• shell (bool) – Pass the command-line arguments to the shell.

Returns:

A new SSH channel, or a path to a script if run=False.

Notes

Requires Python on the remote server.

Examples

>>> s = ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> sh = s.process('/bin/sh', env={'PS1':''})
>>> sh.sendline('echo Hello; exit')
>>> sh.recvall()
'Hello\n'
>>> s.process(['/bin/echo', '\xff']).recvall()
'\xff\n'
>>> s.process(['readlink', '/proc/self/exe']).recvall()
'/bin/readlink\n'
>>> s.process(['LOLOLOL', '/proc/self/exe'], executable='readlink').recvall()
'/bin/readlink\n'
>>> s.process(['LOLOLOL\x00', '/proc/self/cmdline'], executable='cat').recvall()
'LOLOLOL\x00/proc/self/cmdline\x00'
>>> sh = s.process(executable='/bin/sh')
>>> sh.pid in pidof('sh') 
True
>>> s.process(['pwd'], cwd='/tmp').recvall()
'/tmp\n'
>>> p = s.process(['python','-c','import os; print os.read(2, 1024)'], stderr=0)
>>> p.send('hello')
>>> p.recv()
'hello\n'
>>> s.process(['/bin/echo', 'hello']).recvall()
'hello\n'
>>> s.process(['/bin/echo', 'hello'], stdout='/dev/null').recvall()
''
>>> s.process(['/usr/bin/env'], env={}).recvall()
''
>>> s.process('/usr/bin/env', env={'A':'B'}).recvall()
'A=B\n'

>>> s.process('false', preexec_fn=1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn must be a function

>>> s.process('false', preexec_fn=lambda: 1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn cannot be a lambda

>>> def uses_globals():
...     foo = bar
>>> print s.process('false', preexec_fn=uses_globals).recvall().strip() 
Traceback (most recent call last):
...
NameError: global name 'bar' is not defined

>>> s.process('echo hello', shell=True).recvall()
'hello\n'

put(file_or_directory, remote=None)

upload(file_or_directory, remote=None)

Upload a file or directory to the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.
• remote (str) – Local path to store the data. By default, uses the working directory.

read(path)

Wrapper around download_data to match pwnlib.util.misc.read()

remote(host, port, timeout=pwnlib.timeout.Timeout.default)

connect_remote(host, port, timeout = Timeout.default) -> ssh_connecter

Connects to a host through an SSH connection. This is equivalent to using the -L flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_connecter object.

Examples

>>> from pwn import *
>>> l = listen()
>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> a = s.connect_remote(s.host, l.lport)
>>> b = l.wait_for_connection()
>>> a.sendline('Hello')
>>> print repr(b.recvline())
'Hello\n'

run(process, tty=True, wd=None, env=None, timeout=None, raw=True)

Backward compatibility. Use system()

run_to_end(process, tty = False, timeout = Timeout.default, env = None) → str

Run a command on the remote server and return a tuple with (data, exit_status). If tty is True, then the command is run inside a TTY on the remote server.

Examples

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> print s.run_to_end('echo Hello; exit 17')
('Hello\n', 17)

set_working_directory(wd=None, symlink=False)

Sets the working directory in which future commands will be run (via ssh.run) and to which files will be uploaded/downloaded from if no path is provided

Note

This uses mktemp -d under the covers, sets permissions on the directory to 0700. This means that setuid binaries will not be able to access files created in this directory.

In order to work around this, we also chmod +x the directory.

Parameters:

• wd (string) – Working directory. Default is to auto-generate a directory based on the result of running ‘mktemp -d’ on the remote machine.
• symlink (bool,str) –

  Create symlinks in the new directory.

  The default value, False, implies that no symlinks should be created.

  A string value is treated as a path that should be symlinked. It is passed directly to the shell on the remote end for expansion, so wildcards work.

  Any other value is treated as a boolean, where True indicates that all files in the “old” working directory should be symlinked.

Examples

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> cwd = s.set_working_directory()
>>> s.ls()
''
>>> s.pwd() == cwd
True

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> homedir = s.pwd()
>>> _=s.touch('foo')

>>> _=s.set_working_directory()
>>> assert s.ls() == ''

>>> _=s.set_working_directory(homedir)
>>> assert 'foo' in s.ls().split()

>>> _=s.set_working_directory(symlink=True)
>>> assert 'foo' in s.ls().split()
>>> assert homedir != s.pwd()

>>> symlink=os.path.join(homedir,'*')
>>> _=s.set_working_directory(symlink=symlink)
>>> assert 'foo' in s.ls().split()
>>> assert homedir != s.pwd()

sftp

Paramiko SFTPClient object which is used for file transfers. Set to None to disable sftp.

shell(shell = None, tty = True, timeout = Timeout.default) → ssh_channel

Open a new channel with a shell inside.

Parameters:

• shell (str) – Path to the shell program to run. If None, uses the default shell for the logged in user.
• tty (bool) – If True, then a TTY is requested on the remote server.

Returns:

Return a pwnlib.tubes.ssh.ssh_channel object.

Examples

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> sh = s.shell('/bin/sh')
>>> sh.sendline('echo Hello; exit')
>>> print 'Hello' in sh.recvall()
True

system(process, tty = True, wd = None, env = None, timeout = Timeout.default, raw = True) → ssh_channel

Open a new channel with a specific process inside. If tty is True, then a TTY is requested on the remote server.

If raw is True, terminal control codes are ignored and input is not echoed back.

Return a pwnlib.tubes.ssh.ssh_channel object.

Examples

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> py = s.run('python -i')
>>> _ = py.recvuntil('>>> ')
>>> py.sendline('print 2+2')
>>> py.sendline('exit')
>>> print repr(py.recvline())
'4\n'

unlink(file)

Delete the file on the remote host

Parameters:file (str) – Path to the file

upload(file_or_directory, remote=None)

Upload a file or directory to the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.
• remote (str) – Local path to store the data. By default, uses the working directory.

upload_data(data, remote)

Uploads some data into a file on the remote server.

Parameters:

• data (str) – The data to upload.
• remote (str) – The filename to upload it to.

Example

>>> s =  ssh(host='example.pwnme',
...         user='travis',
...         password='demopass')
>>> s.upload_data('Hello, world', '/tmp/upload_foo')
>>> print file('/tmp/upload_foo').read()
Hello, world
>>> s._sftp = False
>>> s._tried_sftp = True
>>> s.upload_data('Hello, world', '/tmp/upload_bar')
>>> print file('/tmp/upload_bar').read()
Hello, world

upload_dir(local, remote=None)

Recursively uploads a directory onto the remote server

Parameters:

• local – Local directory
• remote – Remote directory

upload_file(filename, remote=None)

Uploads a file to the remote server. Returns the remote filename.

Arguments: filename(str): The local filename to download remote(str): The remote filename to save it to. Default is to infer it from the local filename.

version

tuple – Kernel version of the remote machine.

which(program) → str

Minor modification to just directly invoking which on the remote system which adds the current working directory to the end of $PATH.

write(path, data)

Wrapper around upload_data to match pwnlib.util.misc.write()

class pwnlib.tubes.ssh.ssh_channel

Bases: pwnlib.tubes.sock.sock

interactive(prompt = pwnlib.term.text.bold_red('$') + ' ')

If not in TTY-mode, this does exactly the same as meth:pwnlib.tubes.tube.tube.interactive, otherwise it does mostly the same.

An SSH connection in TTY-mode will typically supply its own prompt, thus the prompt argument is ignored in this case. We also have a few SSH-specific hacks that will ideally be removed once the pwnlib.term is more mature.

kill()

Kills the process.

poll() → int

Poll the exit code of the process. Will return None, if the process has not yet finished and the exit code otherwise.

class pwnlib.tubes.ssh.ssh_connecter

Bases: pwnlib.tubes.sock.sock

class pwnlib.tubes.ssh.ssh_listener

Bases: pwnlib.tubes.sock.sock

pwnlib.tubes.tube — Common Functionality

class pwnlib.tubes.tube.tube

Container of all the tube functions common to sockets, TTYs and SSH connetions.

can_recv(timeout = 0) → bool

Returns True, if there is data available within timeout seconds.

Examples

>>> import time
>>> t = tube()
>>> t.can_recv_raw = lambda *a: False
>>> t.can_recv()
False
>>> _=t.unrecv('data')
>>> t.can_recv()
True
>>> _=t.recv()
>>> t.can_recv()
False

clean(timeout = 0.05)

Removes all the buffered data from a tube by calling pwnlib.tubes.tube.tube.recv() with a low timeout until it fails.

If timeout is zero, only cached data will be cleared.

Note: If timeout is set to zero, the underlying network is not actually polled; only the internal buffer is cleared.

Returns:All data received

Examples

>>> t = tube()
>>> t.unrecv('clean me up')
>>> t.clean(0)
'clean me up'
>>> len(t.buffer)
0

clean_and_log(timeout = 0.05)

Works exactly as pwnlib.tubes.tube.tube.clean(), but logs received data with pwnlib.self.info().

Returns:All data received

Examples

>>> def recv(n, data=['', 'hooray_data']):
...     while data: return data.pop()
>>> t = tube()
>>> t.recv_raw      = recv
>>> t.connected_raw = lambda d: True
>>> t.fileno        = lambda: 1234
>>> with context.local(log_level='info'):
...     data = t.clean_and_log() 
[DEBUG] Received 0xb bytes:
    'hooray_data'
>>> data
'hooray_data'
>>> context.clear()

close()

Closes the tube.

connect_both(other)

Connects the both ends of this tube object with another tube object.

connect_input(other)

Connects the input of this tube to the output of another tube object.

Examples

>>> def p(x): print x
>>> def recvone(n, data=['data']):
...     while data: return data.pop()
...     raise EOFError
>>> a = tube()
>>> b = tube()
>>> a.recv_raw = recvone
>>> b.send_raw = p
>>> a.connected_raw = lambda d: True
>>> b.connected_raw = lambda d: True
>>> a.shutdown      = lambda d: True
>>> b.shutdown      = lambda d: True
>>> import time
>>> _=(b.connect_input(a), time.sleep(0.1))
data

connect_output(other)

Connects the output of this tube to the input of another tube object.

Examples

>>> def p(x): print x
>>> def recvone(n, data=['data']):
...     while data: return data.pop()
...     raise EOFError
>>> a = tube()
>>> b = tube()
>>> a.recv_raw = recvone
>>> b.send_raw = p
>>> a.connected_raw = lambda d: True
>>> b.connected_raw = lambda d: True
>>> a.shutdown      = lambda d: True
>>> b.shutdown      = lambda d: True
>>> _=(a.connect_output(b), time.sleep(0.1))
data

connected(direction = 'any') → bool

Returns True if the tube is connected in the specified direction.

Parameters:direction (str) – Can be the string ‘any’, ‘in’, ‘read’, ‘recv’, ‘out’, ‘write’, ‘send’.

Doctest:

>>> def p(x): print x
>>> t = tube()
>>> t.connected_raw = p
>>> _=map(t.connected, ('any', 'in', 'read', 'recv', 'out', 'write', 'send'))
any
recv
recv
recv
send
send
send
>>> t.connected('bad_value') 
Traceback (most recent call last):
...
KeyError: "direction must be in ['any', 'in', 'out', 'read', 'recv', 'send', 'write']"

connected_raw(direction)

connected(direction = ‘any’) -> bool

Should not be called directly. Returns True iff the tube is connected in the given direction.

fileno() → int

Returns the file number used for reading.

interactive(prompt = pwnlib.term.text.bold_red('$') + ' ')

Does simultaneous reading and writing to the tube. In principle this just connects the tube to standard in and standard out, but in practice this is much more usable, since we are using pwnlib.term to print a floating prompt.

Thus it only works in while in pwnlib.term.term_mode.

newline = '\n'

Delimiter to use for sendline(), recvline(), and related functions.

recv(numb = 4096, timeout = default) → str

Receives up to numb bytes of data from the tube, and returns as soon as any quantity of data is available.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Raises:exceptions.EOFError – The connection is closed Returns:A string containing bytes received from the socket, or '' if a timeout occurred while waiting.

Examples

>>> t = tube()
>>> # Fake a data source
>>> t.recv_raw = lambda n: 'Hello, world'
>>> t.recv() == 'Hello, world'
True
>>> t.unrecv('Woohoo')
>>> t.recv() == 'Woohoo'
True
>>> with context.local(log_level='debug'):
...    _ = t.recv() 
[...] Received 0xc bytes:
    'Hello, world'

recvall() → str

Receives data until EOF is reached.

recvline(keepends = True) → str

Receive a single line from the tube.

A “line” is any sequence of bytes terminated by the byte sequence set in newline, which defaults to '\n'.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:

• keepends (bool) – Keep the line ending (True).
• timeout (int) – Timeout

Returns:

All bytes received over the tube until the first newline '\n' is received. Optionally retains the ending.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: 'Foo\nBar\r\nBaz\n'
>>> t.recvline()
'Foo\n'
>>> t.recvline()
'Bar\r\n'
>>> t.recvline(keepends = False)
'Baz'
>>> t.newline = '\r\n'
>>> t.recvline(keepends = False)
'Foo\nBar'

recvline_contains(items, keepends=False, timeout=pwnlib.timeout.Timeout.default)

Receive lines until one line is found which contains at least one of items.

Parameters:

• items (str,tuple) – List of strings to search for, or a single string.
• keepends (bool) – Return lines with newlines if True
• timeout (int) – Timeout, in seconds

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: "Hello\nWorld\nXylophone\n"
>>> t.recvline_contains('r')
'World'
>>> f = lambda n: "cat dog bird\napple pear orange\nbicycle car train\n"
>>> t = tube()
>>> t.recv_raw = f
>>> t.recvline_contains('pear')
'apple pear orange'
>>> t = tube()
>>> t.recv_raw = f
>>> t.recvline_contains(('car', 'train'))
'bicycle car train'

recvline_endswith(delims, keepends = False, timeout = default) → str

Keep receiving lines until one is found that starts with one of delims. Returns the last line received.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

See recvline_startswith() for more details.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: 'Foo\nBar\nBaz\nKaboodle\n'
>>> t.recvline_endswith('r')
'Bar'
>>> t.recvline_endswith(tuple('abcde'), True)
'Kaboodle\n'
>>> t.recvline_endswith('oodle')
'Kaboodle'

recvline_pred(pred, keepends = False) → str

Receive data until pred(line) returns a truthy value. Drop all other data.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:pred (callable) – Function to call. Returns the line for which this function returns True.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: "Foo\nBar\nBaz\n"
>>> t.recvline_pred(lambda line: line == "Bar\n")
'Bar'
>>> t.recvline_pred(lambda line: line == "Bar\n", keepends=True)
'Bar\n'
>>> t.recvline_pred(lambda line: line == 'Nope!', timeout=0.1)
''

recvline_regex(regex, exact=False, keepends=False, timeout=pwnlib.timeout.Timeout.default)

recvregex(regex, exact = False, keepends = False, timeout = default) -> str

Wrapper around recvline_pred(), which will return when a regex matches a line.

By default re.RegexObject.search() is used, but if exact is set to True, then re.RegexObject.match() will be used instead.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

recvline_startswith(delims, keepends = False, timeout = default) → str

Keep receiving lines until one is found that starts with one of delims. Returns the last line received.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:

• delims (str,tuple) – List of strings to search for, or string of single characters
• keepends (bool) – Return lines with newlines if True
• timeout (int) – Timeout, in seconds

Returns:

The first line received which starts with a delimiter in delims.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: "Hello\nWorld\nXylophone\n"
>>> t.recvline_startswith(tuple('WXYZ'))
'World'
>>> t.recvline_startswith(tuple('WXYZ'), True)
'Xylophone\n'
>>> t.recvline_startswith('Wo')
'World'

recvlines(numlines, keepends = False, timeout = default) → str list

Receive up to numlines lines.

A “line” is any sequence of bytes terminated by the byte sequence set by newline, which defaults to '\n'.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:

• numlines (int) – Maximum number of lines to receive
• keepends (bool) – Keep newlines at the end of each line (False).
• timeout (int) – Maximum timeout

Raises:

exceptions.EOFError – The connection closed before the request could be satisfied

Returns:

A string containing bytes received from the socket, or '' if a timeout occurred while waiting.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: '\n'
>>> t.recvlines(3)
['', '', '']
>>> t.recv_raw = lambda n: 'Foo\nBar\nBaz\n'
>>> t.recvlines(3)
['Foo', 'Bar', 'Baz']
>>> t.recvlines(3, True)
['Foo\n', 'Bar\n', 'Baz\n']

recvn(numb, timeout = default) → str

Receives exactly n bytes.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Raises:exceptions.EOFError – The connection closed before the request could be satisfied Returns:A string containing bytes received from the socket, or '' if a timeout occurred while waiting.

Examples

>>> t = tube()
>>> data = 'hello world'
>>> t.recv_raw = lambda *a: data
>>> t.recvn(len(data)) == data
True
>>> t.recvn(len(data)+1) == data + data[0]
True
>>> t.recv_raw = lambda *a: None
>>> # The remaining data is buffered
>>> t.recv() == data[1:]
True
>>> t.recv_raw = lambda *a: time.sleep(0.01) or 'a'
>>> t.recvn(10, timeout=0.05)
''
>>> t.recvn(10, timeout=0.06) 
'aaaaaa...'

recvpred(pred, timeout = default) → str

Receives one byte at a time from the tube, until pred(bytes) evaluates to True.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:

• pred (callable) – Function to call, with the currently-accumulated data.
• timeout (int) – Timeout for the operation

Raises:

exceptions.EOFError – The connection is closed

Returns:

A string containing bytes received from the socket, or '' if a timeout occurred while waiting.

recvregex(regex, exact = False, timeout = default) → str

Wrapper around recvpred(), which will return when a regex matches the string in the buffer.

By default re.RegexObject.search() is used, but if exact is set to True, then re.RegexObject.match() will be used instead.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

recvrepeat()

Receives data until a timeout or EOF is reached.

Examples

>>> data = [
... 'd',
... '', # simulate timeout
... 'c',
... 'b',
... 'a',
... ]
>>> def delayrecv(n, data=data):
...     return data.pop()
>>> t = tube()
>>> t.recv_raw = delayrecv
>>> t.recvrepeat(0.2)
'abc'
>>> t.recv()
'd'

recvuntil(delims, timeout = default) → str

Receive data until one of delims is encountered.

If the request is not satisfied before timeout seconds pass, all data is buffered and an empty string ('') is returned.

Parameters:

• delims (str,tuple) – String of delimiters characters, or list of delimiter strings.
• drop (bool) – Drop the ending. If True it is removed from the end of the return value.

Raises:

exceptions.EOFError – The connection closed before the request could be satisfied

Returns:

A string containing bytes received from the socket, or '' if a timeout occurred while waiting.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: "Hello World!"
>>> t.recvuntil(' ')
'Hello '
>>> _=t.clean(0)
>>> # Matches on 'o' in 'Hello'
>>> t.recvuntil(tuple(' Wor'))
'Hello'
>>> _=t.clean(0)
>>> # Matches expressly full string
>>> t.recvuntil(' Wor')
'Hello Wor'
>>> _=t.clean(0)
>>> # Matches on full string, drops match
>>> t.recvuntil(' Wor', drop=True)
'Hello'

>>> # Try with regex special characters
>>> t = tube()
>>> t.recv_raw = lambda n: "Hello|World"
>>> t.recvuntil('|', drop=True)
'Hello'

send(data)

Sends data.

If log level DEBUG is enabled, also prints out the data received.

If it is not possible to send anymore because of a closed connection, it raises exceptions.EOFError

Examples

>>> def p(x): print repr(x)
>>> t = tube()
>>> t.send_raw = p
>>> t.send('hello')
'hello'

sendafter(delim, data, timeout = default) → str

A combination of recvuntil(delim, timeout) and send(data).

sendline(data)

Shorthand for t.send(data + t.newline).

Examples

>>> def p(x): print repr(x)
>>> t = tube()
>>> t.send_raw = p
>>> t.sendline('hello')
'hello\n'
>>> t.newline = '\r\n'
>>> t.sendline('hello')
'hello\r\n'

sendlineafter(delim, data, timeout = default) → str

A combination of recvuntil(delim, timeout) and sendline(data).

sendlinethen(delim, data, timeout = default) → str

A combination of sendline(data) and recvuntil(delim, timeout).

sendthen(delim, data, timeout = default) → str

A combination of send(data) and recvuntil(delim, timeout).

settimeout(timeout)

Set the timeout for receiving operations. If the string “default” is given, then context.timeout will be used. If None is given, then there will be no timeout.

Examples

>>> t = tube()
>>> t.settimeout_raw = lambda t: None
>>> t.settimeout(3)
>>> t.timeout == 3
True

shutdown(direction = "send")

Closes the tube for futher reading or writing depending on direction.

Parameters:direction (str) – Which direction to close; “in”, “read” or “recv” closes the tube in the ingoing direction, “out”, “write” or “send” closes it in the outgoing direction. Returns:None

Examples

>>> def p(x): print x
>>> t = tube()
>>> t.shutdown_raw = p
>>> _=map(t.shutdown, ('in', 'read', 'recv', 'out', 'write', 'send'))
recv
recv
recv
send
send
send
>>> t.shutdown('bad_value') 
Traceback (most recent call last):
...
KeyError: "direction must be in ['in', 'out', 'read', 'recv', 'send', 'write']"

shutdown_raw(direction)

Should not be called directly. Closes the tube for further reading or writing.

spawn_process(*args, **kwargs)

Spawns a new process having this tube as stdin, stdout and stderr.

Takes the same arguments as subprocess.Popen.

stream()

Receive data until the tube exits, and print it to stdout.

Similar to interactive(), except that no input is sent.

Similar to print tube.recvall() except that data is printed as it is received, rather than after all data is received.

Parameters:line_mode (bool) – Whether to receive line-by-line or raw data. Returns:All data printed.

timeout_change()

Informs the raw layer of the tube that the timeout has changed.

Should not be called directly.

Inherited from Timeout.

unrecv(data)

Puts the specified data back at the beginning of the receive buffer.

Examples

>>> t = tube()
>>> t.recv_raw = lambda n: 'hello'
>>> t.recv()
'hello'
>>> t.recv()
'hello'
>>> t.unrecv('world')
>>> t.recv()
'world'
>>> t.recv()
'hello'

wait()

Waits until the tube is closed.

wait_for_close()

Waits until the tube is closed.

pwnlib.ui — Functions for user interaction

pwnlib.ui.more(text)

Shows text like the command line tool more.

It not in term_mode, just prints the data to the screen.

Parameters:text (str) – The text to show. Returns:None

pwnlib.ui.options(prompt, opts, default=None)

Presents the user with a prompt (typically in the form of a question) and a number of options.

Parameters:

• prompt (str) – The prompt to show
• opts (list) – The options to show to the user
• default – The default option to choose

Returns:

The users choice in the form of an integer.

pwnlib.ui.pause(n=None)

Waits for either user input or a specific number of seconds.

pwnlib.ui.yesno(prompt, default=None)

Presents the user with prompt (typically in the form of question) which the user must answer yes or no.

Parameters:

• prompt (str) – The prompt to show
• default – The default option; True means “yes”

Returns:

True if the answer was “yes”, False if “no”

pwnlib.update — Updating Pwntools

# Pwntools Update

In order to ensure that Pwntools users always have the latest and greatest version, Pwntools automatically checks for updates.

Since this update check takes a moment, it is only performed once every week. It can be permanently disabled via:

$ echo never > ~/.pwntools-cache/update

pwnlib.update.available_on_pypi(prerelease=False)

Return True if an update is available on PyPI.

>>> available_on_pypi() 
<Version('...')>
>>> available_on_pypi(prerelease=False).is_prerelease
False

pwnlib.update.cache_file()

Returns the path of the file used to cache update data, and ensures that it exists.

pwnlib.update.last_check()

Return the date of the last check

pwnlib.update.perform_check(prerelease=False)

Perform the update check, and report to the user.

Parameters:prerelease (bool) – Whether or not to include pre-release versions. Returns:A list of arguments to the update command.

>>> from packaging.version import Version
>>> pwnlib.update.current_version = Version("999.0.0")
>>> print perform_check()
None
>>> pwnlib.update.current_version = Version("0.0.0")
>>> perform_check() 
['pip', 'install', '-U', ...]

>>> def bail(*a): raise Exception()
>>> pypi   = pwnlib.update.available_on_pypi

>>> perform_check(prerelease=False)
['pip', 'install', '-U', 'pwntools']
>>> perform_check(prerelease=True)  
['pip', 'install', '-U', 'pwntools...']

pwnlib.update.should_check()

Return True if we should check for an update

pwnlib.useragents — A database of useragent strings

Database of >22,000 user agent strings

pwnlib.useragents.getall() → str set

Get all the user agents that we know about.

Parameters:None – Returns:A set of user agent strings.

Examples

>>> 'libcurl-agent/1.0' in getall()
True
>>> 'wget' in getall()
True

pwnlib.useragents.random() → str

Get a random user agent string.

Parameters:None – Returns:A random user agent string selected from getall().

>>> import random as randommod
>>> randommod.seed(1)
>>> random()
'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FunWebProducts; FunWebProducts-MyTotalSearch; iebar)'

pwnlib.util.crc — Calculating CRC-sums

Module for calculating CRC-sums.

Contains all crc implementations know on the interwebz. For most implementations it contains only the core crc algorithm and not e.g. padding schemes.

It is horribly slow, as implements a naive algorithm working direclty on bit polynomials. This class is exposed as BitPolynom.

The current algorithm is super-linear and takes about 4 seconds to calculate the crc32-sum of 'A'*40000.

An obvious optimization would be to actually generate some lookup-tables.

class pwnlib.util.crc.BitPolynom(n)

Class for representing GF(2)[X], i.e. the field of polynomials over GF(2).

In practice the polynomials are represented as numbers such that x**n corresponds to 1 << n. In this representation calculations are easy: Just do everything as normal, but forget about everything the carries.

Addition becomes xor and multiplication becomes carry-less multiplication.

Examples

>>> p1 = BitPolynom("x**3 + x + 1")
>>> p1
BitPolynom('x**3 + x + 1')
>>> int(p1)
11
>>> p1 == BitPolynom(11)
True
>>> p2 = BitPolynom("x**2 + x + 1")
>>> p1 + p2
BitPolynom('x**3 + x**2')
>>> p1 * p2
BitPolynom('x**5 + x**4 + 1')
>>> p1 / p2
BitPolynom('x + 1')
>>> p1 % p2
BitPolynom('x')
>>> d, r = divmod(p1, p2)
>>> d * p2 + r == p1
True
>>> BitPolynom(-1)
Traceback (most recent call last):
    ...
ValueError: Polynomials cannot be negative: -1
>>> BitPolynom('y')
Traceback (most recent call last):
    ...
ValueError: Not a valid polynomial: y

degree()

Returns the degree of the polynomial.

Examples

>>> BitPolynom(0).degree()
0
>>> BitPolynom(1).degree()
0
>>> BitPolynom(2).degree()
1
>>> BitPolynom(7).degree()
2
>>> BitPolynom((1 << 10) - 1).degree()
9
>>> BitPolynom(1 << 10).degree()
10

pwnlib.util.crc.generic_crc(data, polynom, width, init, refin, refout, xorout)

A generic CRC-sum function.

This is suitable to use with: http://reveng.sourceforge.net/crc-catalogue/all.htm

The “check” value in the document is the CRC-sum of the string “123456789”.

Parameters:

• data (str) – The data to calculate the CRC-sum of. This should either be a string or a list of bits.
• polynom (int) – The polynomial to use.
• init (int) – If the CRC-sum was calculated in hardware, then this would b the initial value of the checksum register.
• refin (bool) – Should the input bytes be reflected?
• refout (bool) – Should the checksum be reflected?
• xorout (int) – The value to xor the checksum with before outputting

pwnlib.util.crc.cksum(data) → int

Calculates the same checksum as returned by the UNIX-tool cksum.

Parameters:data (str) – The data to checksum.

Example

>>> print cksum('123456789')
930766865

pwnlib.util.crc.find_crc_function(data, checksum)

Finds all known CRC functions that hashes a piece of data into a specific checksum. It does this by trying all known CRC functions one after the other.

Parameters:data (str) – Data for which the checksum is known.

Example

>>> find_crc_function('test', 46197)
[<function crc_crc_16_dnp at ...>]

pwnlib.util.crc.arc(data) → int

Calculates the arc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.16

Parameters:data (str) – The data to checksum.

Example

>>> print arc('123456789')
47933

pwnlib.util.crc.crc_10(data) → int

Calculates the crc_10 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x233
• width = 10
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.10

Parameters:data (str) – The data to checksum.

Example

>>> print crc_10('123456789')
409

pwnlib.util.crc.crc_10_cdma2000(data) → int

Calculates the crc_10_cdma2000 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3d9
• width = 10
• init = 0x3ff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-10-cdma2000

Parameters:data (str) – The data to checksum.

Example

>>> print crc_10_cdma2000('123456789')
563

pwnlib.util.crc.crc_11(data) → int

Calculates the crc_11 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x385
• width = 11
• init = 0x1a
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.11

Parameters:data (str) – The data to checksum.

Example

>>> print crc_11('123456789')
1443

pwnlib.util.crc.crc_12_3gpp(data) → int

Calculates the crc_12_3gpp checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x80f
• width = 12
• init = 0x0
• refin = False
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.12

Parameters:data (str) – The data to checksum.

Example

>>> print crc_12_3gpp('123456789')
3503

pwnlib.util.crc.crc_12_cdma2000(data) → int

Calculates the crc_12_cdma2000 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xf13
• width = 12
• init = 0xfff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-12-cdma2000

Parameters:data (str) – The data to checksum.

Example

>>> print crc_12_cdma2000('123456789')
3405

pwnlib.util.crc.crc_12_dect(data) → int

Calculates the crc_12_dect checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x80f
• width = 12
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-12-dect

Parameters:data (str) – The data to checksum.

Example

>>> print crc_12_dect('123456789')
3931

pwnlib.util.crc.crc_13_bbc(data) → int

Calculates the crc_13_bbc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1cf5
• width = 13
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.13

Parameters:data (str) – The data to checksum.

Example

>>> print crc_13_bbc('123456789')
1274

pwnlib.util.crc.crc_14_darc(data) → int

Calculates the crc_14_darc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x805
• width = 14
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.14

Parameters:data (str) – The data to checksum.

Example

>>> print crc_14_darc('123456789')
2093

pwnlib.util.crc.crc_15(data) → int

Calculates the crc_15 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4599
• width = 15
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.15

Parameters:data (str) – The data to checksum.

Example

>>> print crc_15('123456789')
1438

pwnlib.util.crc.crc_15_mpt1327(data) → int

Calculates the crc_15_mpt1327 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x6815
• width = 15
• init = 0x0
• refin = False
• refout = False
• xorout = 0x1

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-15-mpt1327

Parameters:data (str) – The data to checksum.

Example

>>> print crc_15_mpt1327('123456789')
9574

pwnlib.util.crc.crc_16_aug_ccitt(data) → int

Calculates the crc_16_aug_ccitt checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0x1d0f
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-aug-ccitt

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_aug_ccitt('123456789')
58828

pwnlib.util.crc.crc_16_buypass(data) → int

Calculates the crc_16_buypass checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-buypass

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_buypass('123456789')
65256

pwnlib.util.crc.crc_16_ccitt_false(data) → int

Calculates the crc_16_ccitt_false checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xffff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-ccitt-false

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_ccitt_false('123456789')
10673

pwnlib.util.crc.crc_16_cdma2000(data) → int

Calculates the crc_16_cdma2000 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xc867
• width = 16
• init = 0xffff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-cdma2000

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_cdma2000('123456789')
19462

pwnlib.util.crc.crc_16_dds_110(data) → int

Calculates the crc_16_dds_110 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0x800d
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-dds-110

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_dds_110('123456789')
40655

pwnlib.util.crc.crc_16_dect_r(data) → int

Calculates the crc_16_dect_r checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x589
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x1

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-dect-r

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_dect_r('123456789')
126

pwnlib.util.crc.crc_16_dect_x(data) → int

Calculates the crc_16_dect_x checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x589
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-dect-x

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_dect_x('123456789')
127

pwnlib.util.crc.crc_16_dnp(data) → int

Calculates the crc_16_dnp checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3d65
• width = 16
• init = 0x0
• refin = True
• refout = True
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-dnp

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_dnp('123456789')
60034

pwnlib.util.crc.crc_16_en_13757(data) → int

Calculates the crc_16_en_13757 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3d65
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-en-13757

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_en_13757('123456789')
49847

pwnlib.util.crc.crc_16_genibus(data) → int

Calculates the crc_16_genibus checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xffff
• refin = False
• refout = False
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-genibus

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_genibus('123456789')
54862

pwnlib.util.crc.crc_16_maxim(data) → int

Calculates the crc_16_maxim checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0x0
• refin = True
• refout = True
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-maxim

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_maxim('123456789')
17602

pwnlib.util.crc.crc_16_mcrf4xx(data) → int

Calculates the crc_16_mcrf4xx checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xffff
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-mcrf4xx

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_mcrf4xx('123456789')
28561

pwnlib.util.crc.crc_16_riello(data) → int

Calculates the crc_16_riello checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xb2aa
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-riello

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_riello('123456789')
25552

pwnlib.util.crc.crc_16_t10_dif(data) → int

Calculates the crc_16_t10_dif checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8bb7
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-t10-dif

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_t10_dif('123456789')
53467

pwnlib.util.crc.crc_16_teledisk(data) → int

Calculates the crc_16_teledisk checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xa097
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-teledisk

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_teledisk('123456789')
4019

pwnlib.util.crc.crc_16_tms37157(data) → int

Calculates the crc_16_tms37157 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0x89ec
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-tms37157

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_tms37157('123456789')
9905

pwnlib.util.crc.crc_16_usb(data) → int

Calculates the crc_16_usb checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0xffff
• refin = True
• refout = True
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-16-usb

Parameters:data (str) – The data to checksum.

Example

>>> print crc_16_usb('123456789')
46280

pwnlib.util.crc.crc_24(data) → int

Calculates the crc_24 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x864cfb
• width = 24
• init = 0xb704ce
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.24

Parameters:data (str) – The data to checksum.

Example

>>> print crc_24('123456789')
2215682

pwnlib.util.crc.crc_24_flexray_a(data) → int

Calculates the crc_24_flexray_a checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x5d6dcb
• width = 24
• init = 0xfedcba
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-24-flexray-a

Parameters:data (str) – The data to checksum.

Example

>>> print crc_24_flexray_a('123456789')
7961021

pwnlib.util.crc.crc_24_flexray_b(data) → int

Calculates the crc_24_flexray_b checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x5d6dcb
• width = 24
• init = 0xabcdef
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-24-flexray-b

Parameters:data (str) – The data to checksum.

Example

>>> print crc_24_flexray_b('123456789')
2040760

pwnlib.util.crc.crc_31_philips(data) → int

Calculates the crc_31_philips checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 31
• init = 0x7fffffff
• refin = False
• refout = False
• xorout = 0x7fffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.31

Parameters:data (str) – The data to checksum.

Example

>>> print crc_31_philips('123456789')
216654956

pwnlib.util.crc.crc_32(data) → int

Calculates the crc_32 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 32
• init = 0xffffffff
• refin = True
• refout = True
• xorout = 0xffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.32

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32('123456789')
3421780262

pwnlib.util.crc.crc_32_bzip2(data) → int

Calculates the crc_32_bzip2 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 32
• init = 0xffffffff
• refin = False
• refout = False
• xorout = 0xffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32-bzip2

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32_bzip2('123456789')
4236843288

pwnlib.util.crc.crc_32_mpeg_2(data) → int

Calculates the crc_32_mpeg_2 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 32
• init = 0xffffffff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32-mpeg-2

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32_mpeg_2('123456789')
58124007

pwnlib.util.crc.crc_32_posix(data) → int

Calculates the crc_32_posix checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 32
• init = 0x0
• refin = False
• refout = False
• xorout = 0xffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32-posix

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32_posix('123456789')
1985902208

pwnlib.util.crc.crc_32c(data) → int

Calculates the crc_32c checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1edc6f41
• width = 32
• init = 0xffffffff
• refin = True
• refout = True
• xorout = 0xffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32c

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32c('123456789')
3808858755

pwnlib.util.crc.crc_32d(data) → int

Calculates the crc_32d checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xa833982b
• width = 32
• init = 0xffffffff
• refin = True
• refout = True
• xorout = 0xffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32d

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32d('123456789')
2268157302

pwnlib.util.crc.crc_32q(data) → int

Calculates the crc_32q checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x814141ab
• width = 32
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-32q

Parameters:data (str) – The data to checksum.

Example

>>> print crc_32q('123456789')
806403967

pwnlib.util.crc.crc_3_rohc(data) → int

Calculates the crc_3_rohc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3
• width = 3
• init = 0x7
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.3

Parameters:data (str) – The data to checksum.

Example

>>> print crc_3_rohc('123456789')
6

pwnlib.util.crc.crc_40_gsm(data) → int

Calculates the crc_40_gsm checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4820009
• width = 40
• init = 0x0
• refin = False
• refout = False
• xorout = 0xffffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.40

Parameters:data (str) – The data to checksum.

Example

>>> print crc_40_gsm('123456789')
910907393606

pwnlib.util.crc.crc_4_itu(data) → int

Calculates the crc_4_itu checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3
• width = 4
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.4

Parameters:data (str) – The data to checksum.

Example

>>> print crc_4_itu('123456789')
7

pwnlib.util.crc.crc_5_epc(data) → int

Calculates the crc_5_epc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x9
• width = 5
• init = 0x9
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.5

Parameters:data (str) – The data to checksum.

Example

>>> print crc_5_epc('123456789')
0

pwnlib.util.crc.crc_5_itu(data) → int

Calculates the crc_5_itu checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x15
• width = 5
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-5-itu

Parameters:data (str) – The data to checksum.

Example

>>> print crc_5_itu('123456789')
7

pwnlib.util.crc.crc_5_usb(data) → int

Calculates the crc_5_usb checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x5
• width = 5
• init = 0x1f
• refin = True
• refout = True
• xorout = 0x1f

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-5-usb

Parameters:data (str) – The data to checksum.

Example

>>> print crc_5_usb('123456789')
25

pwnlib.util.crc.crc_64(data) → int

Calculates the crc_64 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x42f0e1eba9ea3693
• width = 64
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.64

Parameters:data (str) – The data to checksum.

Example

>>> print crc_64('123456789')
7800480153909949255

pwnlib.util.crc.crc_64_we(data) → int

Calculates the crc_64_we checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x42f0e1eba9ea3693
• width = 64
• init = 0xffffffffffffffff
• refin = False
• refout = False
• xorout = 0xffffffffffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-64-we

Parameters:data (str) – The data to checksum.

Example

>>> print crc_64_we('123456789')
7128171145767219210

pwnlib.util.crc.crc_64_xz(data) → int

Calculates the crc_64_xz checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x42f0e1eba9ea3693
• width = 64
• init = 0xffffffffffffffff
• refin = True
• refout = True
• xorout = 0xffffffffffffffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-64-xz

Parameters:data (str) – The data to checksum.

Example

>>> print crc_64_xz('123456789')
11051210869376104954

pwnlib.util.crc.crc_6_cdma2000_a(data) → int

Calculates the crc_6_cdma2000_a checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x27
• width = 6
• init = 0x3f
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.6

Parameters:data (str) – The data to checksum.

Example

>>> print crc_6_cdma2000_a('123456789')
13

pwnlib.util.crc.crc_6_cdma2000_b(data) → int

Calculates the crc_6_cdma2000_b checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x7
• width = 6
• init = 0x3f
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-6-cdma2000-b

Parameters:data (str) – The data to checksum.

Example

>>> print crc_6_cdma2000_b('123456789')
59

pwnlib.util.crc.crc_6_darc(data) → int

Calculates the crc_6_darc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x19
• width = 6
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-6-darc

Parameters:data (str) – The data to checksum.

Example

>>> print crc_6_darc('123456789')
38

pwnlib.util.crc.crc_6_itu(data) → int

Calculates the crc_6_itu checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x3
• width = 6
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-6-itu

Parameters:data (str) – The data to checksum.

Example

>>> print crc_6_itu('123456789')
6

pwnlib.util.crc.crc_7(data) → int

Calculates the crc_7 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x9
• width = 7
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.7

Parameters:data (str) – The data to checksum.

Example

>>> print crc_7('123456789')
117

pwnlib.util.crc.crc_7_rohc(data) → int

Calculates the crc_7_rohc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4f
• width = 7
• init = 0x7f
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-7-rohc

Parameters:data (str) – The data to checksum.

Example

>>> print crc_7_rohc('123456789')
83

pwnlib.util.crc.crc_8(data) → int

Calculates the crc_8 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x7
• width = 8
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.8

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8('123456789')
244

pwnlib.util.crc.crc_82_darc(data) → int

Calculates the crc_82_darc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x308c0111011401440411
• width = 82
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat-bits.82

Parameters:data (str) – The data to checksum.

Example

>>> print crc_82_darc('123456789')
749237524598872659187218

pwnlib.util.crc.crc_8_cdma2000(data) → int

Calculates the crc_8_cdma2000 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x9b
• width = 8
• init = 0xff
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-cdma2000

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_cdma2000('123456789')
218

pwnlib.util.crc.crc_8_darc(data) → int

Calculates the crc_8_darc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x39
• width = 8
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-darc

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_darc('123456789')
21

pwnlib.util.crc.crc_8_dvb_s2(data) → int

Calculates the crc_8_dvb_s2 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xd5
• width = 8
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-dvb-s2

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_dvb_s2('123456789')
188

pwnlib.util.crc.crc_8_ebu(data) → int

Calculates the crc_8_ebu checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1d
• width = 8
• init = 0xff
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-ebu

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_ebu('123456789')
151

pwnlib.util.crc.crc_8_i_code(data) → int

Calculates the crc_8_i_code checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1d
• width = 8
• init = 0xfd
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-i-code

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_i_code('123456789')
126

pwnlib.util.crc.crc_8_itu(data) → int

Calculates the crc_8_itu checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x7
• width = 8
• init = 0x0
• refin = False
• refout = False
• xorout = 0x55

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-itu

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_itu('123456789')
161

pwnlib.util.crc.crc_8_maxim(data) → int

Calculates the crc_8_maxim checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x31
• width = 8
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-maxim

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_maxim('123456789')
161

pwnlib.util.crc.crc_8_rohc(data) → int

Calculates the crc_8_rohc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x7
• width = 8
• init = 0xff
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-rohc

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_rohc('123456789')
208

pwnlib.util.crc.crc_8_wcdma(data) → int

Calculates the crc_8_wcdma checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x9b
• width = 8
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-8-wdcma

Parameters:data (str) – The data to checksum.

Example

>>> print crc_8_wcdma('123456789')
37

pwnlib.util.crc.crc_a(data) → int

Calculates the crc_a checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xc6c6
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.crc-a

Parameters:data (str) – The data to checksum.

Example

>>> print crc_a('123456789')
48901

pwnlib.util.crc.jamcrc(data) → int

Calculates the jamcrc checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x4c11db7
• width = 32
• init = 0xffffffff
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.jamcrc

Parameters:data (str) – The data to checksum.

Example

>>> print jamcrc('123456789')
873187033

pwnlib.util.crc.kermit(data) → int

Calculates the kermit checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0x0
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.kermit

Parameters:data (str) – The data to checksum.

Example

>>> print kermit('123456789')
8585

pwnlib.util.crc.modbus(data) → int

Calculates the modbus checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x8005
• width = 16
• init = 0xffff
• refin = True
• refout = True
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.modbus

Parameters:data (str) – The data to checksum.

Example

>>> print modbus('123456789')
19255

pwnlib.util.crc.x_25(data) → int

Calculates the x_25 checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0xffff
• refin = True
• refout = True
• xorout = 0xffff

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.x-25

Parameters:data (str) – The data to checksum.

Example

>>> print x_25('123456789')
36974

pwnlib.util.crc.xfer(data) → int

Calculates the xfer checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0xaf
• width = 32
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.xfer

Parameters:data (str) – The data to checksum.

Example

>>> print xfer('123456789')
3171672888

pwnlib.util.crc.xmodem(data) → int

Calculates the xmodem checksum.

This is simply the generic_crc() with these frozen arguments:

• polynom = 0x1021
• width = 16
• init = 0x0
• refin = False
• refout = False
• xorout = 0x0

See also: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.xmodem

Parameters:data (str) – The data to checksum.

Example

>>> print xmodem('123456789')
12739

pwnlib.util.cyclic — Generation of unique sequences

pwnlib.util.cyclic.cyclic(length = None, alphabet = string.ascii_lowercase, n = 4) → list/str

A simple wrapper over de_bruijn(). This function returns at most length elements.

If the given alphabet is a string, a string is returned from this function. Otherwise a list is returned.

Parameters:

• length – The desired length of the list or None if the entire sequence is desired.
• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

Example

>>> cyclic(alphabet = "ABC", n = 3)
'AAABAACABBABCACBACCBBBCBCCC'
>>> cyclic(20)
'aaaabaaacaaadaaaeaaa'
>>> alphabet, n = range(30), 3
>>> len(alphabet)**n, len(cyclic(alphabet = alphabet, n = n))
(27000, 27000)

pwnlib.util.cyclic.cyclic_find(subseq, alphabet = string.ascii_lowercase, n = None) → int

Calculates the position of a substring into a De Bruijn sequence.

Parameters:

• subseq – The subsequence to look for. This can be a string, a list or an integer. If an integer is provided it will be packed as a little endian integer.
• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

Examples

>>> cyclic_find(cyclic(1000)[514:518])
514
>>> cyclic_find(0x61616162)
4

pwnlib.util.cyclic.cyclic_metasploit(length = None, sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → str

A simple wrapper over metasploit_pattern(). This function returns a string of length length.

Parameters:

• length – The desired length of the string or None if the entire sequence is desired.
• sets – List of strings to generate the sequence over.

Example

>>> cyclic_metasploit(32)
'Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab'
>>> cyclic_metasploit(sets = ["AB","ab","12"])
'Aa1Aa2Ab1Ab2Ba1Ba2Bb1Bb2'
>>> cyclic_metasploit()[1337:1341]
'5Bs6'
>>> len(cyclic_metasploit())
20280

pwnlib.util.cyclic.cyclic_metasploit_find(subseq, sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → int

Calculates the position of a substring into a Metasploit Pattern sequence.

Parameters:

• subseq – The subsequence to look for. This can be a string or an integer. If an integer is provided it will be packed as a little endian integer.
• sets – List of strings to generate the sequence over.

Examples

>>> cyclic_metasploit_find(cyclic_metasploit(1000)[514:518])
514
>>> cyclic_metasploit_find(0x61413161)
4

pwnlib.util.cyclic.de_bruijn(alphabet = string.ascii_lowercase, n = 4) → generator

Generator for a sequence of unique substrings of length n. This is implemented using a De Bruijn Sequence over the given alphabet.

The returned generator will yield up to len(alphabet)**n elements.

Parameters:

• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

pwnlib.util.cyclic.metasploit_pattern(sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → generator

Generator for a sequence of characters as per Metasploit Framework’s Rex::Text.pattern_create (aka pattern_create.rb).

The returned generator will yield up to len(sets) * reduce(lambda x,y: x*y, map(len, sets)) elements.

Parameters:sets – List of strings to generate the sequence over.

pwnlib.util.fiddling — Utilities bit fiddling

pwnlib.util.fiddling.b64d(s) → str

Base64 decodes a string

Example

>>> b64d('dGVzdA==')
'test'

pwnlib.util.fiddling.b64e(s) → str

Base64 encodes a string

Example

>>> b64e("test")
'dGVzdA=='

pwnlib.util.fiddling.bits(s, endian = 'big', zero = 0, one = 1) → list

Converts the argument a list of bits.

Parameters:

• s – A string or number to be converted into bits.
• endian (str) – The binary endian, default ‘big’.
• zero – The representing a 0-bit.
• one – The representing a 1-bit.

Returns:

A list consisting of the values specified in zero and one.

Examples

>>> bits(511, zero = "+", one = "-")
['+', '+', '+', '+', '+', '+', '+', '-', '-', '-', '-', '-', '-', '-', '-', '-']
>>> sum(bits("test"))
17
>>> bits(0)
[0, 0, 0, 0, 0, 0, 0, 0]

pwnlib.util.fiddling.bits_str(s, endian = 'big', zero = '0', one = '1') → str

A wrapper around bits(), which converts the output into a string.

Examples

>>> bits_str(511)
'0000000111111111'
>>> bits_str("bits_str", endian = "little")
'0100011010010110001011101100111011111010110011100010111001001110'

pwnlib.util.fiddling.bitswap(s) → str

Reverses the bits in every byte of a given string.

Example

>>> bitswap("1234")
'\x8cL\xcc,'

pwnlib.util.fiddling.bitswap_int(n) → int

Reverses the bits of a numbers and returns the result as a new number.

Parameters:

• n (int) – The number to swap.
• width (int) – The width of the integer

Examples

>>> hex(bitswap_int(0x1234, 8))
'0x2c'
>>> hex(bitswap_int(0x1234, 16))
'0x2c48'
>>> hex(bitswap_int(0x1234, 24))
'0x2c4800'
>>> hex(bitswap_int(0x1234, 25))
'0x589000'

pwnlib.util.fiddling.bnot(value, width=None)

Returns the binary inverse of ‘value’.

pwnlib.util.fiddling.enhex(x) → str

Hex-encodes a string.

Example

>>> enhex("test")
'74657374'

pwnlib.util.fiddling.hexdump(s, width=16, skip=True, hexii=False, begin=0, style=None, highlight=None, cyclic=False)

hexdump(s, width = 16, skip = True, hexii = False, begin = 0,

style = None, highlight = None, cyclic = False) -> str generator

Return a hexdump-dump of a string.

Parameters:

• s (str) – The data to hexdump.
• width (int) – The number of characters per line
• skip (bool) – Set to True, if repeated lines should be replaced by a “*”
• hexii (bool) – Set to True, if a hexii-dump should be returned instead of a hexdump.
• begin (int) – Offset of the first byte to print in the left column
• style (dict) – Color scheme to use.
• highlight (iterable) – Byte values to highlight.
• cyclic (bool) – Attempt to skip consecutive, unmodified cyclic lines

Returns:

A hexdump-dump in the form of a string.

Examples

>>> print hexdump("abc")
00000000  61 62 63                                            │abc│
00000003

>>> print hexdump('A'*32)
00000000  41 41 41 41  41 41 41 41  41 41 41 41  41 41 41 41  │AAAA│AAAA│AAAA│AAAA│
*
00000020

>>> print hexdump('A'*32, width=8)
00000000  41 41 41 41  41 41 41 41   │AAAA│AAAA│
*
00000020

>>> print hexdump(cyclic(32), width=8, begin=0xdead0000, hexii=True)
dead0000  .a  .a  .a  .a   .b  .a  .a  .a  │
dead0008  .c  .a  .a  .a   .d  .a  .a  .a  │
dead0010  .e  .a  .a  .a   .f  .a  .a  .a  │
dead0018  .g  .a  .a  .a   .h  .a  .a  .a  │
dead0020

>>> print hexdump(list(map(chr, range(256))))
00000000  00 01 02 03  04 05 06 07  08 09 0a 0b  0c 0d 0e 0f  │····│····│····│····│
00000010  10 11 12 13  14 15 16 17  18 19 1a 1b  1c 1d 1e 1f  │····│····│····│····│
00000020  20 21 22 23  24 25 26 27  28 29 2a 2b  2c 2d 2e 2f  │ !"#│$%&'│()*+│,-./│
00000030  30 31 32 33  34 35 36 37  38 39 3a 3b  3c 3d 3e 3f  │0123│4567│89:;│<=>?│
00000040  40 41 42 43  44 45 46 47  48 49 4a 4b  4c 4d 4e 4f  │@ABC│DEFG│HIJK│LMNO│
00000050  50 51 52 53  54 55 56 57  58 59 5a 5b  5c 5d 5e 5f  │PQRS│TUVW│XYZ[│\]^_│
00000060  60 61 62 63  64 65 66 67  68 69 6a 6b  6c 6d 6e 6f  │`abc│defg│hijk│lmno│
00000070  70 71 72 73  74 75 76 77  78 79 7a 7b  7c 7d 7e 7f  │pqrs│tuvw│xyz{│|}~·│
00000080  80 81 82 83  84 85 86 87  88 89 8a 8b  8c 8d 8e 8f  │····│····│····│····│
00000090  90 91 92 93  94 95 96 97  98 99 9a 9b  9c 9d 9e 9f  │····│····│····│····│
000000a0  a0 a1 a2 a3  a4 a5 a6 a7  a8 a9 aa ab  ac ad ae af  │····│····│····│····│
000000b0  b0 b1 b2 b3  b4 b5 b6 b7  b8 b9 ba bb  bc bd be bf  │····│····│····│····│
000000c0  c0 c1 c2 c3  c4 c5 c6 c7  c8 c9 ca cb  cc cd ce cf  │····│····│····│····│
000000d0  d0 d1 d2 d3  d4 d5 d6 d7  d8 d9 da db  dc dd de df  │····│····│····│····│
000000e0  e0 e1 e2 e3  e4 e5 e6 e7  e8 e9 ea eb  ec ed ee ef  │····│····│····│····│
000000f0  f0 f1 f2 f3  f4 f5 f6 f7  f8 f9 fa fb  fc fd fe ff  │····│····│····│····│
00000100

>>> print hexdump(list(map(chr, range(256))), hexii=True)
00000000      01  02  03   04  05  06  07   08  09  0a  0b   0c  0d  0e  0f  │
00000010  10  11  12  13   14  15  16  17   18  19  1a  1b   1c  1d  1e  1f  │
00000020  20  .!  ."  .#   .$  .%  .&  .'   .(  .)  .*  .+   .,  .-  ..  ./  │
00000030  .0  .1  .2  .3   .4  .5  .6  .7   .8  .9  .:  .;   .<  .=  .>  .?  │
00000040  .@  .A  .B  .C   .D  .E  .F  .G   .H  .I  .J  .K   .L  .M  .N  .O  │
00000050  .P  .Q  .R  .S   .T  .U  .V  .W   .X  .Y  .Z  .[   .\  .]  .^  ._  │
00000060  .`  .a  .b  .c   .d  .e  .f  .g   .h  .i  .j  .k   .l  .m  .n  .o  │
00000070  .p  .q  .r  .s   .t  .u  .v  .w   .x  .y  .z  .{   .|  .}  .~  7f  │
00000080  80  81  82  83   84  85  86  87   88  89  8a  8b   8c  8d  8e  8f  │
00000090  90  91  92  93   94  95  96  97   98  99  9a  9b   9c  9d  9e  9f  │
000000a0  a0  a1  a2  a3   a4  a5  a6  a7   a8  a9  aa  ab   ac  ad  ae  af  │
000000b0  b0  b1  b2  b3   b4  b5  b6  b7   b8  b9  ba  bb   bc  bd  be  bf  │
000000c0  c0  c1  c2  c3   c4  c5  c6  c7   c8  c9  ca  cb   cc  cd  ce  cf  │
000000d0  d0  d1  d2  d3   d4  d5  d6  d7   d8  d9  da  db   dc  dd  de  df  │
000000e0  e0  e1  e2  e3   e4  e5  e6  e7   e8  e9  ea  eb   ec  ed  ee  ef  │
000000f0  f0  f1  f2  f3   f4  f5  f6  f7   f8  f9  fa  fb   fc  fd  fe  ##  │
00000100

>>> print hexdump('X' * 64)
00000000  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
*
00000040

>>> print hexdump('X' * 64, skip=False)
00000000  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
00000010  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
00000020  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
00000030  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
00000040

>>> print hexdump(fit({0x10: 'X'*0x20, 0x50-1: '\xff'*20}, length=0xc0) + '\x00'*32)
00000000  61 61 61 61  62 61 61 61  63 61 61 61  64 61 61 61  │aaaa│baaa│caaa│daaa│
00000010  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
*
00000030  6d 61 61 61  6e 61 61 61  6f 61 61 61  70 61 61 61  │maaa│naaa│oaaa│paaa│
00000040  71 61 61 61  72 61 61 61  73 61 61 61  74 61 61 ff  │qaaa│raaa│saaa│taa·│
00000050  ff ff ff ff  ff ff ff ff  ff ff ff ff  ff ff ff ff  │····│····│····│····│
00000060  ff ff ff 61  7a 61 61 62  62 61 61 62  63 61 61 62  │···a│zaab│baab│caab│
00000070  64 61 61 62  65 61 61 62  66 61 61 62  67 61 61 62  │daab│eaab│faab│gaab│
00000080  68 61 61 62  69 61 61 62  6a 61 61 62  6b 61 61 62  │haab│iaab│jaab│kaab│
00000090  6c 61 61 62  6d 61 61 62  6e 61 61 62  6f 61 61 62  │laab│maab│naab│oaab│
000000a0  70 61 61 62  71 61 61 62  72 61 61 62  73 61 61 62  │paab│qaab│raab│saab│
000000b0  74 61 61 62  75 61 61 62  76 61 61 62  77 61 61 62  │taab│uaab│vaab│waab│
000000c0  00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00  │····│····│····│····│
*
000000e0

>>> print hexdump(fit({0x10: 'X'*0x20, 0x50-1: '\xff'*20}, length=0xc0) + '\x00'*32, cyclic=1)
00000000  61 61 61 61  62 61 61 61  63 61 61 61  64 61 61 61  │aaaa│baaa│caaa│daaa│
00000010  58 58 58 58  58 58 58 58  58 58 58 58  58 58 58 58  │XXXX│XXXX│XXXX│XXXX│
*
00000030  6d 61 61 61  6e 61 61 61  6f 61 61 61  70 61 61 61  │maaa│naaa│oaaa│paaa│
00000040  71 61 61 61  72 61 61 61  73 61 61 61  74 61 61 ff  │qaaa│raaa│saaa│taa·│
00000050  ff ff ff ff  ff ff ff ff  ff ff ff ff  ff ff ff ff  │····│····│····│····│
00000060  ff ff ff 61  7a 61 61 62  62 61 61 62  63 61 61 62  │···a│zaab│baab│caab│
00000070  64 61 61 62  65 61 61 62  66 61 61 62  67 61 61 62  │daab│eaab│faab│gaab│
*
000000c0  00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00  │····│····│····│····│
*
000000e0

>>> print hexdump(fit({0x10: 'X'*0x20, 0x50-1: '\xff'*20}, length=0xc0) + '\x00'*32, cyclic=1, hexii=1)
00000000  .a  .a  .a  .a   .b  .a  .a  .a   .c  .a  .a  .a   .d  .a  .a  .a  │
00000010  .X  .X  .X  .X   .X  .X  .X  .X   .X  .X  .X  .X   .X  .X  .X  .X  │
*
00000030  .m  .a  .a  .a   .n  .a  .a  .a   .o  .a  .a  .a   .p  .a  .a  .a  │
00000040  .q  .a  .a  .a   .r  .a  .a  .a   .s  .a  .a  .a   .t  .a  .a  ##  │
00000050  ##  ##  ##  ##   ##  ##  ##  ##   ##  ##  ##  ##   ##  ##  ##  ##  │
00000060  ##  ##  ##  .a   .z  .a  .a  .b   .b  .a  .a  .b   .c  .a  .a  .b  │
00000070  .d  .a  .a  .b   .e  .a  .a  .b   .f  .a  .a  .b   .g  .a  .a  .b  │
*
000000c0                                                                     │
*
000000e0

>>> print hexdump('A'*16, width=9)
00000000  41 41 41 41  41 41 41 41  41  │AAAA│AAAA│A│
00000009  41 41 41 41  41 41 41         │AAAA│AAA│
00000010
>>> print hexdump('A'*16, width=10)
00000000  41 41 41 41  41 41 41 41  41 41  │AAAA│AAAA│AA│
0000000a  41 41 41 41  41 41               │AAAA│AA│
00000010
>>> print hexdump('A'*16, width=11)
00000000  41 41 41 41  41 41 41 41  41 41 41  │AAAA│AAAA│AAA│
0000000b  41 41 41 41  41                     │AAAA│A│
00000010
>>> print hexdump('A'*16, width=12)
00000000  41 41 41 41  41 41 41 41  41 41 41 41  │AAAA│AAAA│AAAA│
0000000c  41 41 41 41                            │AAAA││
00000010
>>> print hexdump('A'*16, width=13)
00000000  41 41 41 41  41 41 41 41  41 41 41 41  41  │AAAA│AAAA│AAAA│A│
0000000d  41 41 41                                   │AAA│
00000010
>>> print hexdump('A'*16, width=14)
00000000  41 41 41 41  41 41 41 41  41 41 41 41  41 41  │AAAA│AAAA│AAAA│AA│
0000000e  41 41                                         │AA│
00000010
>>> print hexdump('A'*16, width=15)
00000000  41 41 41 41  41 41 41 41  41 41 41 41  41 41 41  │AAAA│AAAA│AAAA│AAA│
0000000f  41                                               │A│
00000010

pwnlib.util.fiddling.hexdump_iter(fd, width=16, skip=True, hexii=False, begin=0, style=None, highlight=None, cyclic=False)

hexdump_iter(s, width = 16, skip = True, hexii = False, begin = 0,

style = None, highlight = None, cyclic = False) -> str generator

Return a hexdump-dump of a string as a generator of lines. Unless you have massive amounts of data you probably want to use hexdump().

Parameters:

• fd (file) – File object to dump. Use StringIO.StringIO() or hexdump() to dump a string.
• width (int) – The number of characters per line
• skip (bool) – Set to True, if repeated lines should be replaced by a “*”
• hexii (bool) – Set to True, if a hexii-dump should be returned instead of a hexdump.
• begin (int) – Offset of the first byte to print in the left column
• style (dict) – Color scheme to use.
• highlight (iterable) – Byte values to highlight.
• cyclic (bool) – Attempt to skip consecutive, unmodified cyclic lines

Returns:

A generator producing the hexdump-dump one line at a time.

Example

>>> tmp = tempfile.NamedTemporaryFile()
>>> tmp.write('XXXXHELLO, WORLD')
>>> tmp.flush()
>>> tmp.seek(4)
>>> print '\n'.join(hexdump_iter(tmp))
00000000  48 45 4c 4c  4f 2c 20 57  4f 52 4c 44               │HELL│O, W│ORLD││
0000000c

>>> t = tube()
>>> t.unrecv('I know kung fu')
>>> print '\n'.join(hexdump_iter(t))
00000000  49 20 6b 6e  6f 77 20 6b  75 6e 67 20  66 75        │I kn│ow k│ung │fu│
0000000e

pwnlib.util.fiddling.hexii(s, width = 16, skip = True) → str

Return a HEXII-dump of a string.

Parameters:

• s (str) – The string to dump
• width (int) – The number of characters per line
• skip (bool) – Should repeated lines be replaced by a “*”

Returns:

A HEXII-dump in the form of a string.

pwnlib.util.fiddling.isprint(c) → bool

Return True if a character is printable

pwnlib.util.fiddling.naf(int) → int generator

Returns a generator for the non-adjacent form (NAF[1]) of a number, n. If naf(n) generates z_0, z_1, ..., then n == z_0 + z_1 * 2 + z_2 * 2**2, ....

[1] https://en.wikipedia.org/wiki/Non-adjacent_form

Example

>>> n = 45
>>> m = 0
>>> x = 1
>>> for z in naf(n):
...     m += x * z
...     x *= 2
>>> n == m
True

pwnlib.util.fiddling.negate(value, width=None)

Returns the two’s complement of ‘value’.

pwnlib.util.fiddling.randoms(count, alphabet = string.lowercase) → str

Returns a random string of a given length using only the specified alphabet.

Parameters:

• count (int) – The length of the desired string.
• alphabet – The alphabet of allowed characters. Defaults to all lowercase characters.

Returns:

A random string.

Example

>>> randoms(10) 
'evafjilupm'

pwnlib.util.fiddling.rol(n, k, word_size=None)

Returns a rotation by k of n.

When n is a number, then means ((n << k) | (n >> (word_size - k))) truncated to word_size bits.

When n is a list, tuple or string, this is n[k % len(n):] + n[:k % len(n)].

Parameters:

• n – The value to rotate.
• k (int) – The rotation amount. Can be a positive or negative number.
• word_size (int) – If n is a number, then this is the assumed bitsize of n. Defaults to pwnlib.context.word_size if None .

Example

>>> rol('abcdefg', 2)
'cdefgab'
>>> rol('abcdefg', -2)
'fgabcde'
>>> hex(rol(0x86, 3, 8))
'0x34'
>>> hex(rol(0x86, -3, 8))
'0xd0'

pwnlib.util.fiddling.ror(n, k, word_size=None)

A simple wrapper around rol(), which negates the values of k.

pwnlib.util.fiddling.unbits(s, endian = 'big') → str

Converts an iterable of bits into a string.

Parameters:

• s – Iterable of bits
• endian (str) – The string “little” or “big”, which specifies the bits endianness.

Returns:

A string of the decoded bits.

Example

>>> unbits([1])
'\x80'
>>> unbits([1], endian = 'little')
'\x01'
>>> unbits(bits('hello'), endian = 'little')
'\x16\xa666\xf6'

pwnlib.util.fiddling.unhex(s) → str

Hex-decodes a string.

Example

>>> unhex("74657374")
'test'
>>> unhex("F\n")
'\x0f'

pwnlib.util.fiddling.urldecode(s, ignore_invalid = False) → str

URL-decodes a string.

Example

>>> urldecode("test%20%41")
'test A'
>>> urldecode("%qq")
Traceback (most recent call last):
...
ValueError: Invalid input to urldecode
>>> urldecode("%qq", ignore_invalid = True)
'%qq'

pwnlib.util.fiddling.urlencode(s) → str

URL-encodes a string.

Example

>>> urlencode("test")
'%74%65%73%74'

pwnlib.util.fiddling.xor(*args, cut = 'max') → str

Flattens its arguments using pwnlib.util.packing.flat() and then xors them together. If the end of a string is reached, it wraps around in the string.

Parameters:

• args – The arguments to be xor’ed together.
• cut – How long a string should be returned. Can be either ‘min’/’max’/’left’/’right’ or a number.

Returns:

The string of the arguments xor’ed together.

Example

>>> xor('lol', 'hello', 42)
'. ***'

pwnlib.util.fiddling.xor_key(data, size=None, avoid='x00n') -> None or (int, str)

Finds a size-width value that can be XORed with a string to produce data, while neither the XOR value or XOR string contain any bytes in avoid.

Parameters:

• data (str) – The desired string.
• avoid – The list of disallowed characters. Defaults to nulls and newlines.
• size (int) – Size of the desired output value, default is word size.

Returns:

A tuple containing two strings; the XOR key and the XOR string. If no such pair exists, None is returned.

Example

>>> xor_key("Hello, world")
('\x01\x01\x01\x01', 'Idmmn-!vnsme')

pwnlib.util.fiddling.xor_pair(data, avoid = 'x00n') -> None or (str, str)

Finds two strings that will xor into a given string, while only using a given alphabet.

Parameters:

• data (str) – The desired string.
• avoid – The list of disallowed characters. Defaults to nulls and newlines.

Returns:

Two strings which will xor to the given string. If no such two strings exist, then None is returned.

Example

>>> xor_pair("test")
('\x01\x01\x01\x01', 'udru')

pwnlib.util.hashes — Hashing functions

Functions for computing various hashes of files and strings.

pwnlib.util.hashes.md5file(x)

Calculates the md5 sum of a file

pwnlib.util.hashes.md5filehex(x)

Calculates the md5 sum of a file; returns hex-encoded

pwnlib.util.hashes.md5sum(x)

Calculates the md5 sum of a string

pwnlib.util.hashes.md5sumhex(x)

Calculates the md5 sum of a string; returns hex-encoded

pwnlib.util.hashes.sha1file(x)

Calculates the sha1 sum of a file

pwnlib.util.hashes.sha1filehex(x)

Calculates the sha1 sum of a file; returns hex-encoded

pwnlib.util.hashes.sha1sum(x)

Calculates the sha1 sum of a string

pwnlib.util.hashes.sha1sumhex(x)

Calculates the sha1 sum of a string; returns hex-encoded

pwnlib.util.hashes.sha224file(x)

Calculates the sha224 sum of a file

pwnlib.util.hashes.sha224filehex(x)

Calculates the sha224 sum of a file; returns hex-encoded

pwnlib.util.hashes.sha224sum(x)

Calculates the sha224 sum of a string

pwnlib.util.hashes.sha224sumhex(x)

Calculates the sha224 sum of a string; returns hex-encoded

pwnlib.util.hashes.sha256file(x)

Calculates the sha256 sum of a file

pwnlib.util.hashes.sha256filehex(x)

Calculates the sha256 sum of a file; returns hex-encoded

pwnlib.util.hashes.sha256sum(x)

Calculates the sha256 sum of a string

pwnlib.util.hashes.sha256sumhex(x)

Calculates the sha256 sum of a string; returns hex-encoded

pwnlib.util.hashes.sha384file(x)

Calculates the sha384 sum of a file

pwnlib.util.hashes.sha384filehex(x)

Calculates the sha384 sum of a file; returns hex-encoded

pwnlib.util.hashes.sha384sum(x)

Calculates the sha384 sum of a string

pwnlib.util.hashes.sha384sumhex(x)

Calculates the sha384 sum of a string; returns hex-encoded

pwnlib.util.hashes.sha512file(x)

Calculates the sha512 sum of a file

pwnlib.util.hashes.sha512filehex(x)

Calculates the sha512 sum of a file; returns hex-encoded

pwnlib.util.hashes.sha512sum(x)

Calculates the sha512 sum of a string

pwnlib.util.hashes.sha512sumhex(x)

Calculates the sha512 sum of a string; returns hex-encoded

pwnlib.util.iters — Extension of standard module itertools

This module includes and extends the standard module itertools.

pwnlib.util.iters.bruteforce(func, alphabet, length, method = 'upto', start = None)

Bruteforce func to return True. func should take a string input and return a bool(). func will be called with strings from alphabet until it returns True or the search space has been exhausted.

The argument start can be used to split the search space, which is useful if multiple CPU cores are available.

Parameters:

• func (function) – The function to bruteforce.
• alphabet – The alphabet to draw symbols from.
• length – Longest string to try.
• method – If ‘upto’ try strings of length 1 .. length, if ‘fixed’ only try strings of length length and if ‘downfrom’ try strings of length length .. 1.
• start – a tuple (i, N) which splits the search space up into N pieces and starts at piece i (1..N). None is equivalent to (1, 1).

Returns:

A string s such that func(s) returns True or None if the search space was exhausted.

Example

>>> bruteforce(lambda x: x == 'hello', string.lowercase, length = 10)
'hello'
>>> bruteforce(lambda x: x == 'hello', 'hllo', 5) is None
True

pwnlib.util.iters.mbruteforce(func, alphabet, length, method = 'upto', start = None, threads = None)

Same functionality as bruteforce(), but multithreaded.

Parameters:

• alphabet, length, method, start (func,) – same as for bruteforce()
• threads – Amount of threads to spawn, default is the amount of cores.

pwnlib.util.iters.chained(func)

A decorator chaining the results of func. Useful for generators.

Parameters:func (function) – The function being decorated. Returns:A generator function whoose elements are the concatenation of the return values from func(*args, **kwargs).

Example

>>> @chained
... def g():
...     for x in count():
...         yield (x, -x)
>>> take(6, g())
[0, 0, 1, -1, 2, -2]

pwnlib.util.iters.consume(n, iterator)

Advance the iterator n steps ahead. If n is :const:`None, consume everything.

Parameters:

• n (int) – Number of elements to consume.
• iterator (iterator) – An iterator.

Returns:

None.

Examples

>>> i = count()
>>> consume(5, i)
>>> i.next()
5
>>> i = iter([1, 2, 3, 4, 5])
>>> consume(2, i)
>>> list(i)
[3, 4, 5]

pwnlib.util.iters.cyclen(n, iterable) → iterator

Repeats the elements of iterable n times.

Parameters:

• n (int) – The number of times to repeat iterable.
• iterable – An iterable.

Returns:

An iterator whoose elements are the elements of iterator repeated n times.

Examples

>>> take(4, cyclen(2, [1, 2]))
[1, 2, 1, 2]
>>> list(cyclen(10, []))
[]

pwnlib.util.iters.dotproduct(x, y) → int

Computes the dot product of x and y.

Parameters:

• x (iterable) – An iterable.
• x – An iterable.

Returns:

x[0] * y[0] + x[1] * y[1] + ....

Return type:

The dot product of x and y, i.e.

Example

>>> dotproduct([1, 2, 3], [4, 5, 6])
... # 1 * 4 + 2 * 5 + 3 * 6 == 32
32

pwnlib.util.iters.flatten(xss) → iterator

Flattens one level of nesting; when xss is an iterable of iterables, returns an iterator whoose elements is the concatenation of the elements of xss.

Parameters:xss – An iterable of iterables. Returns:An iterator whoose elements are the concatenation of the iterables in xss.

Examples

>>> list(flatten([[1, 2], [3, 4]]))
[1, 2, 3, 4]
>>> take(6, flatten([[43, 42], [41, 40], count()]))
[43, 42, 41, 40, 0, 1]

pwnlib.util.iters.group(n, iterable, fill_value = None) → iterator

Similar to pwnlib.util.lists.group(), but returns an iterator and uses itertools fast build-in functions.

Parameters:

• n (int) – The group size.
• iterable – An iterable.
• fill_value – The value to fill into the remaining slots of the last group if the n does not divide the number of elements in iterable.

Returns:

An iterator whoose elements are n-tuples of the elements of iterable.

Examples

>>> list(group(2, range(5)))
[(0, 1), (2, 3), (4, None)]
>>> take(3, group(2, count()))
[(0, 1), (2, 3), (4, 5)]
>>> [''.join(x) for x in group(3, 'ABCDEFG', 'x')]
['ABC', 'DEF', 'Gxx']

pwnlib.util.iters.iter_except(func, exception)

Calls func repeatedly until an exception is raised. Works like the build-in iter() but uses an exception instead of a sentinel to signal the end.

Parameters:

• func – The function to call.
• exception (exception) – The exception that signals the end. Other exceptions will not be caught.

Returns:

An iterator whoose elements are the results of calling func() until an exception matching exception is raised.

Examples

>>> s = {1, 2, 3}
>>> i = iter_except(s.pop, KeyError)
>>> i.next()
1
>>> i.next()
2
>>> i.next()
3
>>> i.next()
Traceback (most recent call last):
    ...
StopIteration

pwnlib.util.iters.lexicographic(alphabet) → iterator

The words with symbols in alphabet, in lexicographic order (determined by the order of alphabet).

Parameters:alphabet – The alphabet to draw symbols from. Returns:An iterator of the words with symbols in alphabet, in lexicographic order.

Example

>>> take(8, imap(lambda x: ''.join(x), lexicographic('01')))
['', '0', '1', '00', '01', '10', '11', '000']

pwnlib.util.iters.lookahead(n, iterable) → object

Inspects the upcoming element at index n without advancing the iterator. Raises IndexError if iterable has too few elements.

Parameters:

• n (int) – Index of the element to return.
• iterable – An iterable.

Returns:

The element in iterable at index n.

Examples

>>> i = count()
>>> lookahead(4, i)
4
>>> i.next()
0
>>> i = count()
>>> nth(4, i)
4
>>> i.next()
5
>>> lookahead(4, i)
10

pwnlib.util.iters.nth(n, iterable, default = None) → object

Returns the element at index n in iterable. If iterable is a iterator it will be advanced.

Parameters:

• n (int) – Index of the element to return.
• iterable – An iterable.
• default (objext) – A default value.

Returns:

The element at index n in iterable or default if iterable has too few elements.

Examples

>>> nth(2, [0, 1, 2, 3])
2
>>> nth(2, [0, 1], 42)
42
>>> i = count()
>>> nth(42, i)
42
>>> nth(42, i)
85

pwnlib.util.iters.pad(iterable, value = None) → iterator

Pad an iterable with value, i.e. returns an iterator whoose elements are first the elements of iterable then value indefinitely.

Parameters:

• iterable – An iterable.
• value – The value to pad with.

Returns:

An iterator whoose elements are first the elements of iterable then value indefinitely.

Examples

>>> take(3, pad([1, 2]))
[1, 2, None]
>>> i = pad(iter([1, 2, 3]), 42)
>>> take(2, i)
[1, 2]
>>> take(2, i)
[3, 42]
>>> take(2, i)
[42, 42]

pwnlib.util.iters.pairwise(iterable) → iterator

Parameters:iterable – An iterable. Returns:An iterator whoose elements are pairs of neighbouring elements of iterable.

Examples

>>> list(pairwise([1, 2, 3, 4]))
[(1, 2), (2, 3), (3, 4)]
>>> i = starmap(operator.add, pairwise(count()))
>>> take(5, i)
[1, 3, 5, 7, 9]

pwnlib.util.iters.powerset(iterable, include_empty = True) → iterator

The powerset of an iterable.

Parameters:

• iterable – An iterable.
• include_empty (bool) – Whether to include the empty set.

Returns:

The powerset of iterable as an interator of tuples.

Examples

>>> list(powerset(range(3)))
[(), (0,), (1,), (2,), (0, 1), (0, 2), (1, 2), (0, 1, 2)]
>>> list(powerset(range(2), include_empty = False))
[(0,), (1,), (0, 1)]

pwnlib.util.iters.quantify(iterable, pred = bool) → int

Count how many times the predicate pred is True.

Parameters:

• iterable – An iterable.
• pred – A function that given an element from iterable returns either True or False.

Returns:

The number of elements in iterable for which pred returns True.

Examples

>>> quantify([1, 2, 3, 4], lambda x: x % 2 == 0)
2
>>> quantify(['1', 'two', '3', '42'], str.isdigit)
3

pwnlib.util.iters.random_combination(iterable, r) → tuple

Parameters:

• iterable – An iterable.
• r (int) – Size of the combination.

Returns:

A random element from itertools.combinations(iterable, r = r).

Examples

>>> random_combination(range(2), 2)
(0, 1)
>>> random_combination(range(10), r = 2) in combinations(range(10), r = 2)
True

pwnlib.util.iters.random_combination_with_replacement(iterable, r)

random_combination(iterable, r) -> tuple

Parameters:

• iterable – An iterable.
• r (int) – Size of the combination.

Returns:

A random element from itertools.combinations_with_replacement(iterable, r = r).

Examples

>>> cs = {(0, 0), (0, 1), (1, 1)}
>>> random_combination_with_replacement(range(2), 2) in cs
True
>>> i = combinations_with_replacement(range(10), r = 2)
>>> random_combination_with_replacement(range(10), r = 2) in i
True

pwnlib.util.iters.random_permutation(iterable, r=None)

random_product(iterable, r = None) -> tuple

Parameters:

• iterable – An iterable.
• r (int) – Size of the permutation. If None select all elements in iterable.

Returns:

A random element from itertools.permutations(iterable, r = r).

Examples

>>> random_permutation(range(2)) in {(0, 1), (1, 0)}
True
>>> random_permutation(range(10), r = 2) in permutations(range(10), r = 2)
True

pwnlib.util.iters.random_product(*args, repeat = 1) → tuple

Parameters:

• args – One or more iterables
• repeat (int) – Number of times to repeat args.

Returns:

A random element from itertools.product(*args, repeat = repeat).

Examples

>>> args = (range(2), range(2))
>>> random_product(*args) in {(0, 0), (0, 1), (1, 0), (1, 1)}
True
>>> args = (range(3), range(3), range(3))
>>> random_product(*args, repeat = 2) in product(*args, repeat = 2)
True

pwnlib.util.iters.repeat_func(func, *args, **kwargs) → iterator

Repeatedly calls func with positional arguments args and keyword arguments kwargs. If no keyword arguments is given the resulting iterator will be computed using only functions from itertools which are very fast.

Parameters:

• func (function) – The function to call.
• args – Positional arguments.
• kwargs – Keyword arguments.

Returns:

An iterator whoose elements are the results of calling func(*args, **kwargs) repeatedly.

Examples

>>> def f(x):
...     x[0] += 1
...     return x[0]
>>> i = repeat_func(f, [0])
>>> take(2, i)
[1, 2]
>>> take(2, i)
[3, 4]
>>> def f(**kwargs):
...     return kwargs.get('x', 43)
>>> i = repeat_func(f, x = 42)
>>> take(2, i)
[42, 42]
>>> i = repeat_func(f, 42)
>>> take(2, i)
Traceback (most recent call last):
    ...
TypeError: f() takes exactly 0 arguments (1 given)

pwnlib.util.iters.roundrobin(*iterables)

Take elements from iterables in a round-robin fashion.

Parameters:*iterables – One or more iterables. Returns:An iterator whoose elements are taken from iterables in a round-robin fashion.

Examples

>>> ''.join(roundrobin('ABC', 'D', 'EF'))
'ADEBFC'
>>> ''.join(take(10, roundrobin('ABC', 'DE', repeat('x'))))
'ADxBExCxxx'

pwnlib.util.iters.tabulate(func, start = 0) → iterator

Parameters:

• func (function) – The function to tabulate over.
• start (int) – Number to start on.

Returns:

An iterator with the elements func(start), func(start + 1), ....

Examples

>>> take(2, tabulate(str))
['0', '1']
>>> take(5, tabulate(lambda x: x**2, start = 1))
[1, 4, 9, 16, 25]

pwnlib.util.iters.take(n, iterable) → list

Returns first n elements of iterable. If iterable is a iterator it will be advanced.

Parameters:

• n (int) – Number of elements to take.
• iterable – An iterable.

Returns:

A list of the first n elements of iterable. If there are fewer than n elements in iterable they will all be returned.

Examples

>>> take(2, range(10))
[0, 1]
>>> i = count()
>>> take(2, i)
[0, 1]
>>> take(2, i)
[2, 3]
>>> take(9001, [1, 2, 3])
[1, 2, 3]

pwnlib.util.iters.unique_everseen(iterable, key = None) → iterator

Get unique elements, preserving order. Remember all elements ever seen. If key is not None then for each element elm in iterable the element that will be rememberes is key(elm). Otherwise elm is remembered.

Parameters:

• iterable – An iterable.
• key – A function to map over each element in iterable before remembering it. Setting to None is equivalent to the identity function.

Returns:

An iterator of the unique elements in iterable.

Examples

>>> ''.join(unique_everseen('AAAABBBCCDAABBB'))
'ABCD'
>>> ''.join(unique_everseen('ABBCcAD', str.lower))
'ABCD'

pwnlib.util.iters.unique_justseen(iterable, key=None)

unique_everseen(iterable, key = None) -> iterator

Get unique elements, preserving order. Remember only the elements just seen. If key is not None then for each element elm in iterable the element that will be rememberes is key(elm). Otherwise elm is remembered.

Parameters:

• iterable – An iterable.
• key – A function to map over each element in iterable before remembering it. Setting to None is equivalent to the identity function.

Returns:

An iterator of the unique elements in iterable.

Examples

>>> ''.join(unique_justseen('AAAABBBCCDAABBB'))
'ABCDAB'
>>> ''.join(unique_justseen('ABBCcAD', str.lower))
'ABCAD'

pwnlib.util.iters.unique_window(iterable, window, key=None)

unique_everseen(iterable, window, key = None) -> iterator

Get unique elements, preserving order. Remember only the last window elements seen. If key is not None then for each element elm in iterable the element that will be rememberes is key(elm). Otherwise elm is remembered.

Parameters:

• iterable – An iterable.
• window (int) – The number of elements to remember.
• key – A function to map over each element in iterable before remembering it. Setting to None is equivalent to the identity function.

Returns:

An iterator of the unique elements in iterable.

Examples

>>> ''.join(unique_window('AAAABBBCCDAABBB', 6))
'ABCDA'
>>> ''.join(unique_window('ABBCcAD', 5, str.lower))
'ABCD'
>>> ''.join(unique_window('ABBCcAD', 4, str.lower))
'ABCAD'

pwnlib.util.iters.chain()

Alias for itertools.chain().

pwnlib.util.iters.combinations()

Alias for itertools.combinations()

pwnlib.util.iters.combinations_with_replacement()

Alias for itertools.combinations_with_replacement()

pwnlib.util.iters.compress()

Alias for itertools.compress()

pwnlib.util.iters.count()

Alias for itertools.count()

pwnlib.util.iters.cycle()

Alias for itertools.cycle()

pwnlib.util.iters.dropwhile()

Alias for itertools.dropwhile()

pwnlib.util.iters.groupby()

Alias for itertools.groupby()

pwnlib.util.iters.ifilter()

Alias for itertools.ifilter()

pwnlib.util.iters.ifilterfalse()

Alias for itertools.ifilterfalse()

pwnlib.util.iters.imap()

Alias for itertools.imap()

pwnlib.util.iters.islice()

Alias for itertools.islice()

pwnlib.util.iters.izip()

Alias for itertools.izip()

pwnlib.util.iters.izip_longest()

Alias for itertools.izip_longest()

pwnlib.util.iters.permutations()

Alias for itertools.permutations()

pwnlib.util.iters.product()

Alias for itertools.product()

pwnlib.util.iters.repeat()

Alias for itertools.repeat()

pwnlib.util.iters.starmap()

Alias for itertools.starmap()

pwnlib.util.iters.takewhile()

Alias for itertools.takewhile()

pwnlib.util.iters.tee()

Alias for itertools.tee()

pwnlib.util.lists — Operations on lists

pwnlib.util.lists.concat(l) → list

Concats a list of lists into a list.

Example

>>> concat([[1, 2], [3]])
[1, 2, 3]

pwnlib.util.lists.concat_all(*args) → list

Concats all the arguments together.

Example

>>> concat_all(0, [1, (2, 3)], [([[4, 5, 6]])])
[0, 1, 2, 3, 4, 5, 6]

pwnlib.util.lists.findall(l, e) → l

Generate all indices of needle in haystack, using the Knuth-Morris-Pratt algorithm.

Example

>>> foo = findall([1,2,3,4,4,3,4,2,1], 4)
>>> foo.next()
3
>>> foo.next()
4
>>> foo.next()
6

pwnlib.util.lists.group(n, lst, underfull_action = 'ignore', fill_value = None) → list

Split sequence into subsequences of given size. If the values cannot be evenly distributed among into groups, then the last group will either be returned as is, thrown out or padded with the value specified in fill_value.

Parameters:

• n (int) – The size of resulting groups
• lst – The list, tuple or string to group
• underfull_action (str) – The action to take in case of an underfull group at the end. Possible values are ‘ignore’, ‘drop’ or ‘fill’.
• fill_value – The value to fill into an underfull remaining group.

Returns:

A list containing the grouped values.

Example

>>> group(3, "ABCDEFG")
['ABC', 'DEF', 'G']
>>> group(3, 'ABCDEFG', 'drop')
['ABC', 'DEF']
>>> group(3, 'ABCDEFG', 'fill', 'Z')
['ABC', 'DEF', 'GZZ']
>>> group(3, list('ABCDEFG'), 'fill')
[['A', 'B', 'C'], ['D', 'E', 'F'], ['G', None, None]]

pwnlib.util.lists.ordlist(s) → list

Turns a string into a list of the corresponding ascii values.

Example

>>> ordlist("hello")
[104, 101, 108, 108, 111]

pwnlib.util.lists.partition(lst, f, save_keys = False) → list

Partitions an iterable into sublists using a function to specify which group they belong to.

It works by calling f on every element and saving the results into an collections.OrderedDict.

Parameters:

• lst – The iterable to partition
• f (function) – The function to use as the partitioner.
• save_keys (bool) – Set this to True, if you want the OrderedDict returned instead of just the values

Example

>>> partition([1,2,3,4,5], lambda x: x&1)
[[1, 3, 5], [2, 4]]

pwnlib.util.lists.unordlist(cs) → str

Takes a list of ascii values and returns the corresponding string.

Example

>>> unordlist([104, 101, 108, 108, 111])
'hello'

pwnlib.util.misc — We could not fit it any other place

pwnlib.util.misc.align(alignment, x) → int

Rounds x up to nearest multiple of the alignment.

Example

>>> [align(5, n) for n in range(15)]
[0, 5, 5, 5, 5, 5, 10, 10, 10, 10, 10, 15, 15, 15, 15]

pwnlib.util.misc.align_down(alignment, x) → int

Rounds x down to nearest multiple of the alignment.

Example

>>> [align_down(5, n) for n in range(15)]
[0, 0, 0, 0, 0, 5, 5, 5, 5, 5, 10, 10, 10, 10, 10]

pwnlib.util.misc.binary_ip(host) → str

Resolve host and return IP as four byte string.

Example

>>> binary_ip("127.0.0.1")
'\x7f\x00\x00\x01'

pwnlib.util.misc.dealarm_shell(tube)

Given a tube which is a shell, dealarm it.

pwnlib.util.misc.mkdir_p(path)

Emulates the behavior of mkdir -p.

pwnlib.util.misc.parse_ldd_output(output)

Parses the output from a run of ‘ldd’ on a binary. Returns a dictionary of {path: address} for each library required by the specified binary.

Parameters:output (str) – The output to parse

Example

>>> sorted(parse_ldd_output('''
...     linux-vdso.so.1 =>  (0x00007fffbf5fe000)
...     libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007fe28117f000)
...     libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fe280f7b000)
...     libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe280bb4000)
...     /lib64/ld-linux-x86-64.so.2 (0x00007fe2813dd000)
... ''').keys())
['/lib/x86_64-linux-gnu/libc.so.6', '/lib/x86_64-linux-gnu/libdl.so.2', '/lib/x86_64-linux-gnu/libtinfo.so.5', '/lib64/ld-linux-x86-64.so.2']

pwnlib.util.misc.read(path, count=-1, skip=0) → str

Open file, return content.

Examples

>>> read('/proc/self/exe')[:4]
'\x7fELF'

pwnlib.util.misc.register_sizes(regs, in_sizes)

Create dictionaries over register sizes and relations

Given a list of lists of overlapping register names (e.g. [‘eax’,’ax’,’al’,’ah’]) and a list of input sizes, it returns the following:

• all_regs : list of all valid registers
• sizes[reg] : the size of reg in bits
• bigger[reg] : list of overlapping registers bigger than reg
• smaller[reg]: list of overlapping registers smaller than reg

Used in i386/AMD64 shellcode, e.g. the mov-shellcode.

Example

>>> regs = [['eax', 'ax', 'al', 'ah'],['ebx', 'bx', 'bl', 'bh'],
... ['ecx', 'cx', 'cl', 'ch'],
... ['edx', 'dx', 'dl', 'dh'],
... ['edi', 'di'],
... ['esi', 'si'],
... ['ebp', 'bp'],
... ['esp', 'sp'],
... ]
>>> all_regs, sizes, bigger, smaller = register_sizes(regs, [32, 16, 8, 8])
>>> all_regs
['eax', 'ax', 'al', 'ah', 'ebx', 'bx', 'bl', 'bh', 'ecx', 'cx', 'cl', 'ch', 'edx', 'dx', 'dl', 'dh', 'edi', 'di', 'esi', 'si', 'ebp', 'bp', 'esp', 'sp']
>>> sizes
{'ch': 8, 'cl': 8, 'ah': 8, 'edi': 32, 'al': 8, 'cx': 16, 'ebp': 32, 'ax': 16, 'edx': 32, 'ebx': 32, 'esp': 32, 'esi': 32, 'dl': 8, 'dh': 8, 'di': 16, 'bl': 8, 'bh': 8, 'eax': 32, 'bp': 16, 'dx': 16, 'bx': 16, 'ecx': 32, 'sp': 16, 'si': 16}
>>> bigger
{'ch': ['ecx', 'cx', 'ch'], 'cl': ['ecx', 'cx', 'cl'], 'ah': ['eax', 'ax', 'ah'], 'edi': ['edi'], 'al': ['eax', 'ax', 'al'], 'cx': ['ecx', 'cx'], 'ebp': ['ebp'], 'ax': ['eax', 'ax'], 'edx': ['edx'], 'ebx': ['ebx'], 'esp': ['esp'], 'esi': ['esi'], 'dl': ['edx', 'dx', 'dl'], 'dh': ['edx', 'dx', 'dh'], 'di': ['edi', 'di'], 'bl': ['ebx', 'bx', 'bl'], 'bh': ['ebx', 'bx', 'bh'], 'eax': ['eax'], 'bp': ['ebp', 'bp'], 'dx': ['edx', 'dx'], 'bx': ['ebx', 'bx'], 'ecx': ['ecx'], 'sp': ['esp', 'sp'], 'si': ['esi', 'si']}
>>> smaller
{'ch': [], 'cl': [], 'ah': [], 'edi': ['di'], 'al': [], 'cx': ['cl', 'ch'], 'ebp': ['bp'], 'ax': ['al', 'ah'], 'edx': ['dx', 'dl', 'dh'], 'ebx': ['bx', 'bl', 'bh'], 'esp': ['sp'], 'esi': ['si'], 'dl': [], 'dh': [], 'di': [], 'bl': [], 'bh': [], 'eax': ['ax', 'al', 'ah'], 'bp': [], 'dx': ['dl', 'dh'], 'bx': ['bl', 'bh'], 'ecx': ['cx', 'cl', 'ch'], 'sp': [], 'si': []}

pwnlib.util.misc.run_in_new_terminal(command, terminal = None) → None

Run a command in a new terminal.

When terminal is not set:

• If context.terminal is set it will be used. If it is an iterable then context.terminal[1:] are default arguments.
• If a pwntools-terminal command exists in $PATH, it is used
• If $TERM_PROGRAM is set, that is used.
• If X11 is detected (by the presence of the $DISPLAY environment variable), x-terminal-emulator is used.
• If tmux is detected (by the presence of the $TMUX environment variable), a new pane will be opened.

Parameters:

• command (str) – The command to run.
• terminal (str) – Which terminal to use.
• args (list) – Arguments to pass to the terminal

Note

The command is opened with /dev/null for stdin, stdout, stderr.

Returns:PID of the new terminal process

pwnlib.util.misc.size(n, abbrev = 'B', si = False) → str

Convert the length of a bytestream to human readable form.

Parameters:

• n (int,iterable) – The length to convert to human readable form, or an object which can have len() called on it.
• abbrev (str) – String appended to the size, defaults to 'B'.

Example

>>> size(451)
'451B'
>>> size(1000)
'1000B'
>>> size(1024)
'1.00KB'
>>> size(1024, ' bytes')
'1.00K bytes'
>>> size(1024, si = True)
'1.02KB'
>>> [size(1024 ** n) for n in range(7)]
['1B', '1.00KB', '1.00MB', '1.00GB', '1.00TB', '1.00PB', '1024.00PB']
>>> size([])
'0B'
>>> size([1,2,3])
'3B'

pwnlib.util.misc.which(name, flags = os.X_OK, all = False) → str or str set

Works as the system command which; searches $PATH for name and returns a full path if found.

If all is True the set of all found locations is returned, else the first occurence or None is returned.

Parameters:

• name (str) – The file to search for.
• all (bool) – Whether to return all locations where name was found.

Returns:

If all is True the set of all locations where name was found, else the first location or None if not found.

Example

>>> which('sh')
'/bin/sh'

pwnlib.util.misc.write(path, data='', create_dir=False, mode='w')

Create new file or truncate existing to zero length and write data.

pwnlib.util.net — Networking interfaces

pwnlib.util.net.getifaddrs() → dict list

A wrapper for libc’s getifaddrs.

Parameters:None – Returns:list of dictionaries each representing a struct ifaddrs. The dictionaries have the fields name, flags, family, addr and netmask. Refer to getifaddrs(3) for details. The fields addr and netmask are themselves dictionaries. Their structure depend on family. If family is not socket.AF_INET or socket.AF_INET6 they will be empty.

pwnlib.util.net.interfaces(all = False) → dict

Parameters:

• all (bool) – Whether to include interfaces with not associated address.
• Default – False.

Returns:

A dictionary mapping each of the hosts interfaces to a list of it’s addresses. Each entry in the list is a tuple (family, addr), and family is either socket.AF_INET or socket.AF_INET6.

pwnlib.util.net.interfaces4(all = False) → dict

As interfaces() but only includes IPv4 addresses and the lists in the dictionary only contains the addresses not the family.

Parameters:

• all (bool) – Whether to include interfaces with not associated address.
• Default – False.

Returns:

A dictionary mapping each of the hosts interfaces to a list of it’s IPv4 addresses.

pwnlib.util.net.interfaces6(all = False) → dict

As interfaces() but only includes IPv6 addresses and the lists in the dictionary only contains the addresses not the family.

Parameters:

• all (bool) – Whether to include interfaces with not associated address.
• Default – False.

Returns:

A dictionary mapping each of the hosts interfaces to a list of it’s IPv6 addresses.

pwnlib.util.net.sockaddr(host, port, network = 'ipv4') -> (data, length, family)

Creates a sockaddr_in or sockaddr_in6 memory buffer for use in shellcode.

Parameters:

• host (str) – Either an IP address or a hostname to be looked up.
• port (int) – TCP/UDP port.
• network (str) – Either ‘ipv4’ or ‘ipv6’.

Returns:

A tuple containing the sockaddr buffer, length, and the address family.

pwnlib.util.packing — Packing and unpacking of strings

Module for packing and unpacking integers.

Simplifies access to the standard struct.pack and struct.unpack functions, and also adds support for packing/unpacking arbitrary-width integers.

The packers are all context-aware for endian and signed arguments, though they can be overridden in the parameters.

Examples

>>> p8(0)
'\x00'
>>> p32(0xdeadbeef)
'\xef\xbe\xad\xde'
>>> p32(0xdeadbeef, endian='big')
'\xde\xad\xbe\xef'
>>> with context.local(endian='big'): p32(0xdeadbeef)
'\xde\xad\xbe\xef'

Make a frozen packer, which does not change with context.

>>> p=make_packer('all')
>>> p(0xff)
'\xff'
>>> p(0x1ff)
'\xff\x01'
>>> with context.local(endian='big'): print repr(p(0x1ff))
'\xff\x01'

pwnlib.util.packing.dd(dst, src, count = 0, skip = 0, seek = 0, truncate = False) → dst

Inspired by the command line tool dd, this function copies count byte values from offset seek in src to offset skip in dst. If count is 0, all of src[seek:] is copied.

If dst is a mutable type it will be updated. Otherwise a new instance of the same type will be created. In either case the result is returned.

src can be an iterable of characters or integers, a unicode string or a file object. If it is an iterable of integers, each integer must be in the range [0;255]. If it is a unicode string, its UTF-8 encoding will be used.

The seek offset of file objects will be preserved.

Parameters:

• dst – Supported types are :class:file, :class:list, :class:tuple, :class:str, :class:bytearray and :class:unicode.
• src – An iterable of byte values (characters or integers), a unicode string or a file object.
• count (int) – How many bytes to copy. If count is 0 or larger than len(src[seek:]), all bytes until the end of src are copied.
• skip (int) – Offset in dst to copy to.
• seek (int) – Offset in src to copy from.
• truncate (bool) – If :const:True, dst is truncated at the last copied byte.

Returns:

A modified version of dst. If dst is a mutable type it will be modified in-place.

Examples: >>> dd(tuple(‘Hello!’), ‘?’, skip = 5) (‘H’, ‘e’, ‘l’, ‘l’, ‘o’, ‘?’) >>> dd(list(‘Hello!’), (63,), skip = 5) [‘H’, ‘e’, ‘l’, ‘l’, ‘o’, ‘?’] >>> write(‘/tmp/foo’, ‘A’ * 10) ... dd(file(‘/tmp/foo’), file(‘/dev/zero’), skip = 3, count = 4) ... read(‘/tmp/foo’) ‘AAAAAA’ >>> write(‘/tmp/foo’, ‘A’ * 10) ... dd(file(‘/tmp/foo’), file(‘/dev/zero’), skip = 3, count = 4, truncate = True) ... read(‘/tmp/foo’) ‘AAA’

pwnlib.util.packing.fit(pieces, filler = de_bruijn(), length = None, preprocessor = None) → str

Generates a string from a dictionary mapping offsets to data to place at that offset.

For each key-value pair in pieces, the key is either an offset or a byte sequence. In the latter case, the offset will be the lowest index at which the sequence occurs in filler. See examples below.

Each piece of data is passed to flat() along with the keyword arguments word_size, endianness and sign.

Space between pieces of data is filled out using the iterable filler. The n‘th byte in the output will be byte at index n % len(iterable) byte in filler if it has finite length or the byte at index n otherwise.

If length is given, the output will padded with bytes from filler to be this size. If the output is longer than length, a ValueError exception is raised.

If entries in pieces overlap, a ValueError exception is raised.

Parameters:

• pieces – Offsets and values to output.
• length – The length of the output.
• filler – Iterable to use for padding.
• preprocessor (function) – Gets called on every element to optionally transform the element before flattening. If None is returned, then the original value is used.
• word_size (int) – Word size of the converted integer.
• endianness (str) – Endianness of the converted integer (“little”/”big”).
• sign (str) – Signedness of the converted integer (False/True)

Examples

>>> fit({12: 0x41414141,
...      24: 'Hello',
...     })
'aaaabaaacaaaAAAAeaaafaaaHello'
>>> fit({'caaa': ''})
'aaaabaaa'
>>> fit({12: 'XXXX'}, filler = 'AB', length = 20)
'ABABABABABABXXXXABAB'
>>> fit({ 8: [0x41414141, 0x42424242],
...      20: 'CCCC'})
'aaaabaaaAAAABBBBeaaaCCCC'
>>> fit({ 0x61616162: 'X'})
'aaaaX'

pwnlib.util.packing.flat(*args, preprocessor = None, word_size = None, endianness = None, sign = None)

Flattens the arguments into a string.

This function takes an arbitrary number of arbitrarily nested lists and tuples. It will then find every string and number inside those and flatten them out. Strings are inserted directly while numbers are packed using the pack() function.

The three kwargs word_size, endianness and sign will default to using values in pwnlib.context if not specified as an argument.

Parameters:

• args – Values to flatten
• preprocessor (function) – Gets called on every element to optionally transform the element before flattening. If None is returned, then the original value is uded.
• word_size (int) – Word size of the converted integer.
• endianness (str) – Endianness of the converted integer (“little”/”big”).
• sign (str) – Signedness of the converted integer (False/True)

Examples

>>> flat(1, "test", [[["AB"]*2]*3], endianness = 'little', word_size = 16, sign = False)
'\x01\x00testABABABABABAB'
>>> flat([1, [2, 3]], preprocessor = lambda x: str(x+1))
'234'

pwnlib.util.packing.make_packer(word_size = None, endianness = None, sign = None) → number → str

Creates a packer by “freezing” the given arguments.

Semantically calling make_packer(w, e, s)(data) is equivalent to calling pack(data, w, e, s). If word_size is one of 8, 16, 32 or 64, it is however faster to call this function, since it will then use a specialized version.

Parameters:

• word_size (int) – The word size to be baked into the returned packer or the string all.
• endianness (str) – The endianness to be baked into the returned packer. (“little”/”big”)
• sign (str) – The signness to be baked into the returned packer. (“unsigned”/”signed”)
• kwargs – Additional context flags, for setting by alias (e.g. endian= rather than index)

Returns:

A function, which takes a single argument in the form of a number and returns a string of that number in a packed form.

Examples

>>> p = make_packer(32, endian='little', sign='unsigned')
>>> p
<function _p32lu at 0x...>
>>> p(42)
'*\x00\x00\x00'
>>> p(-1)
Traceback (most recent call last):
    ...
error: integer out of range for 'I' format code
>>> make_packer(33, endian='little', sign='unsigned')
<function <lambda> at 0x...>

pwnlib.util.packing.make_unpacker(word_size = None, endianness = None, sign = None, **kwargs) → str → number

Creates a unpacker by “freezing” the given arguments.

Semantically calling make_unpacker(w, e, s)(data) is equivalent to calling unpack(data, w, e, s). If word_size is one of 8, 16, 32 or 64, it is however faster to call this function, since it will then use a specialized version.

Parameters:

• word_size (int) – The word size to be baked into the returned packer.
• endianness (str) – The endianness to be baked into the returned packer. (“little”/”big”)
• sign (str) – The signness to be baked into the returned packer. (“unsigned”/”signed”)
• kwargs – Additional context flags, for setting by alias (e.g. endian= rather than index)

Returns:

A function, which takes a single argument in the form of a string and returns a number of that string in an unpacked form.

Examples

>>> u = make_unpacker(32, endian='little', sign='unsigned')
>>> u
<function _u32lu at 0x...>
>>> hex(u('/bin'))
'0x6e69622f'
>>> u('abcde')
Traceback (most recent call last):
    ...
error: unpack requires a string argument of length 4
>>> make_unpacker(33, endian='little', sign='unsigned')
<function <lambda> at 0x...>

pwnlib.util.packing.p16(number, sign, endian, ...) → str

Packs an 16-bit integer

Parameters:

• number (int) – Number to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The packed number as a string

pwnlib.util.packing.p32(number, sign, endian, ...) → str

Packs an 32-bit integer

Parameters:

• number (int) – Number to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The packed number as a string

pwnlib.util.packing.p64(number, sign, endian, ...) → str

Packs an 64-bit integer

Parameters:

• number (int) – Number to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The packed number as a string

pwnlib.util.packing.p8(number, sign, endian, ...) → str

Packs an 8-bit integer

Parameters:

• number (int) – Number to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The packed number as a string

pwnlib.util.packing.pack(number, word_size = None, endianness = None, sign = None, **kwargs) → str

Packs arbitrary-sized integer.

Word-size, endianness and signedness is done according to context.

word_size can be any positive number or the string “all”. Choosing the string “all” will output a string long enough to contain all the significant bits and thus be decodable by unpack().

word_size can be any positive number. The output will contain word_size/8 rounded up number of bytes. If word_size is not a multiple of 8, it will be padded with zeroes up to a byte boundary.

Parameters:

• number (int) – Number to convert
• word_size (int) – Word size of the converted integer or the string ‘all’.
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (False/True)
• kwargs – Anything that can be passed to context.local

Returns:

The packed number as a string.

Examples

>>> pack(0x414243, 24, 'big', True)
'ABC'
>>> pack(0x414243, 24, 'little', True)
'CBA'
>>> pack(0x814243, 24, 'big', False)
'\x81BC'
>>> pack(0x814243, 24, 'big', True)
Traceback (most recent call last):
   ...
ValueError: pack(): number does not fit within word_size
>>> pack(0x814243, 25, 'big', True)
'\x00\x81BC'
>>> pack(-1, 'all', 'little', True)
'\xff'
>>> pack(-256, 'all', 'big', True)
'\xff\x00'
>>> pack(0x0102030405, 'all', 'little', True)
'\x05\x04\x03\x02\x01'
>>> pack(-1)
'\xff\xff\xff\xff'
>>> pack(0x80000000, 'all', 'big', True)
'\x00\x80\x00\x00\x00'

pwnlib.util.packing.routine(*a, **kw)

u32(number, sign, endian, ...) -> int

Unpacks an 32-bit integer

Parameters:

• data (str) – String to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The unpacked number

pwnlib.util.packing.u16(number, sign, endian, ...) → int

Unpacks an 16-bit integer

Parameters:

• data (str) – String to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The unpacked number

pwnlib.util.packing.u32(number, sign, endian, ...) → int

Unpacks an 32-bit integer

Parameters:

• data (str) – String to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The unpacked number

pwnlib.util.packing.u64(number, sign, endian, ...) → int

Unpacks an 64-bit integer

Parameters:

• data (str) – String to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The unpacked number

pwnlib.util.packing.u8(number, sign, endian, ...) → int

Unpacks an 8-bit integer

Parameters:

• data (str) – String to convert
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (“unsigned”/”signed”)
• kwargs (dict) – Arguments passed to context.local(), such as endian or signed.

Returns:

The unpacked number

pwnlib.util.packing.unpack(data, word_size = None, endianness = None, sign = None, **kwargs) → int

Packs arbitrary-sized integer.

Word-size, endianness and signedness is done according to context.

word_size can be any positive number or the string “all”. Choosing the string “all” is equivalent to len(data)*8.

If word_size is not a multiple of 8, then the bits used for padding are discarded.

Parameters:

• number (int) – String to convert
• word_size (int) – Word size of the converted integer or the string “all”.
• endianness (str) – Endianness of the converted integer (“little”/”big”)
• sign (str) – Signedness of the converted integer (False/True)
• kwargs – Anything that can be passed to context.local

Returns:

The unpacked number.

Examples

>>> hex(unpack('\xaa\x55', 16, endian='little', sign=False))
'0x55aa'
>>> hex(unpack('\xaa\x55', 16, endian='big', sign=False))
'0xaa55'
>>> hex(unpack('\xaa\x55', 16, endian='big', sign=True))
'-0x55ab'
>>> hex(unpack('\xaa\x55', 15, endian='big', sign=True))
'0x2a55'
>>> hex(unpack('\xff\x02\x03', 'all', endian='little', sign=True))
'0x302ff'
>>> hex(unpack('\xff\x02\x03', 'all', endian='big', sign=True))
'-0xfdfd'

pwnlib.util.packing.unpack_many(*a, **kw)

unpack(data, word_size = None, endianness = None, sign = None) -> int list

Splits data into groups of word_size//8 bytes and calls unpack() on each group. Returns a list of the results.

word_size must be a multiple of 8 or the string “all”. In the latter case a singleton list will always be returned.

Args

number (int): String to convert word_size (int): Word size of the converted integers or the string “all”. endianness (str): Endianness of the converted integer (“little”/”big”) sign (str): Signedness of the converted integer (False/True) kwargs: Anything that can be passed to context.local

Returns:The unpacked numbers.

Examples

>>> map(hex, unpack_many('\xaa\x55\xcc\x33', 16, endian='little', sign=False))
['0x55aa', '0x33cc']
>>> map(hex, unpack_many('\xaa\x55\xcc\x33', 16, endian='big', sign=False))
['0xaa55', '0xcc33']
>>> map(hex, unpack_many('\xaa\x55\xcc\x33', 16, endian='big', sign=True))
['-0x55ab', '-0x33cd']
>>> map(hex, unpack_many('\xff\x02\x03', 'all', endian='little', sign=True))
['0x302ff']
>>> map(hex, unpack_many('\xff\x02\x03', 'all', endian='big', sign=True))
['-0xfdfd']

pwnlib.util.proc — Working with /proc/

pwnlib.util.proc.ancestors(pid) → int list

Parameters:pid (int) – PID of the process. Returns:List of PIDs of whose parent process is pid or an ancestor of pid.

pwnlib.util.proc.children(ppid) → int list

Parameters:pid (int) – PID of the process. Returns:List of PIDs of whose parent process is pid.

pwnlib.util.proc.cmdline(pid) → str list

Parameters:pid (int) – PID of the process. Returns:A list of the fields in /proc/<pid>/cmdline.

pwnlib.util.proc.cwd(pid) → str

Parameters:pid (int) – PID of the process. Returns:The path of the process’s current working directory. I.e. what /proc/<pid>/cwd points to.

pwnlib.util.proc.descendants(pid) → dict

Parameters:pid (int) – PID of the process. Returns:Dictionary mapping the PID of each child of pid to it’s descendants.

pwnlib.util.proc.exe(pid) → str

Parameters:pid (int) – PID of the process. Returns:The path of the binary of the process. I.e. what /proc/<pid>/exe points to.

pwnlib.util.proc.name(pid) → str

Parameters:pid (int) – PID of the process. Returns:Name of process as listed in /proc/<pid>/status.

Example

>>> pid = pidof('init')[0]
>>> name(pid) == 'init'
True

pwnlib.util.proc.parent(pid) → int

Parameters:pid (int) – PID of the process. Returns:Parent PID as listed in /proc/<pid>/status under PPid, or 0 if there is not parent.

pwnlib.util.proc.pid_by_name(name) → int list

Parameters:name (str) – Name of program. Returns:List of PIDs matching name sorted by lifetime, youngest to oldest.

Example

>>> os.getpid() in pid_by_name(name(os.getpid()))
True

pwnlib.util.proc.pidof(target) → int list

Get PID(s) of target. The returned PID(s) depends on the type of target:

• str: PIDs of all processes with a name matching target.
• pwnlib.tubes.process.process: singleton list of the PID of target.
• pwnlib.tubes.sock.sock: singleton list of the PID at the remote end of target if it is running on the host. Otherwise an empty list.

Parameters:target (object) – The target whose PID(s) to find. Returns:A list of found PIDs.

pwnlib.util.proc.starttime(pid) → float

Parameters:pid (int) – PID of the process. Returns:The time (in seconds) the process started after system boot

pwnlib.util.proc.stat(pid) → str list

Parameters:pid (int) – PID of the process. Returns:A list of the values in /proc/<pid>/stat, with the exception that ( and ) has been removed from around the process name.

pwnlib.util.proc.state(pid) → str

Parameters:pid (int) – PID of the process. Returns:State of the process as listed in /proc/<pid>/status. See proc(5) for details.

Example

>>> state(os.getpid())
'R (running)'

pwnlib.util.proc.status(pid) → dict

Get the status of a process.

Parameters:pid (int) – PID of the process. Returns:The contents of /proc/<pid>/status as a dictionary.

pwnlib.util.proc.tracer(pid) → int

Parameters:pid (int) – PID of the process. Returns:PID of the process tracing pid, or None if no pid is not being traced.

Example

>>> tracer(os.getpid()) is None
True

pwnlib.util.proc.wait_for_debugger(pid) → None

Sleeps until the process with PID pid is being traced.

Parameters:pid (int) – PID of the process. Returns:None

pwnlib.util.safeeval — Safe evaluation of python code

pwnlib.util.safeeval.const(expression) → value

Safe Python constant evaluation

Evaluates a string that contains an expression describing a Python constant. Strings that are not valid Python expressions or that contain other code besides the constant raise ValueError.

Examples

>>> const("10")
10
>>> const("[1,2, (3,4), {'foo':'bar'}]")
[1, 2, (3, 4), {'foo': 'bar'}]
>>> const("[1]+[2]")
Traceback (most recent call last):
...
ValueError: opcode BINARY_ADD not allowed

pwnlib.util.safeeval.expr(expression) → value

Safe Python expression evaluation

Evaluates a string that contains an expression that only uses Python constants. This can be used to e.g. evaluate a numerical expression from an untrusted source.

Examples

>>> expr("1+2")
3
>>> expr("[1,2]*2")
[1, 2, 1, 2]
>>> expr("__import__('sys').modules")
Traceback (most recent call last):
...
ValueError: opcode LOAD_NAME not allowed

pwnlib.util.safeeval.test_expr(expr, allowed_codes) → codeobj

Test that the expression contains only the listed opcodes. If the expression is valid and contains only allowed codes, return the compiled code object. Otherwise raise a ValueError

pwnlib.util.safeeval.values(expression, dict) → value

Safe Python expression evaluation

Evaluates a string that contains an expression that only uses Python constants and values from a supplied dictionary. This can be used to e.g. evaluate e.g. an argument to a syscall.

Note: This is potentially unsafe if e.g. the __add__ method has side

effects.

Examples

>>> values("A + 4", {'A': 6})
10
>>> class Foo:
...    def __add__(self, other):
...        print "Firing the missiles"
>>> values("A + 1", {'A': Foo()})
Firing the missiles
>>> values("A.x", {'A': Foo()})
Traceback (most recent call last):
...
ValueError: opcode LOAD_ATTR not allowed

pwnlib.util.sh_string — Shell Expansion is Hard

Routines here are for getting any NULL-terminated sequence of bytes evaluated intact by any shell. This includes all variants of quotes, whitespace, and non-printable characters.

Supported Shells

The following shells have been evaluated:

• Ubuntu (dash/sh)
• MacOS (GNU Bash)
• Zsh
• FreeBSD (sh)
• OpenBSD (sh)
• NetBSD (sh)

Debian Almquist shell (Dash)

Ubuntu 14.04 and 16.04 use the Dash shell, and /bin/sh is actually just a symlink to /bin/dash. The feature set supported when invoked as “sh” instead of “dash” is different, and we focus exclusively on the “/bin/sh” implementation.

From the Ubuntu Man Pages, every character except for single-quote can be wrapped in single-quotes, and a backslash can be used to escape unquoted single-quotes.

Quoting
  Quoting is used to remove the special meaning of certain characters or
  words to the shell, such as operators, whitespace, or keywords.  There
  are three types of quoting: matched single quotes, matched double quotes,
  and backslash.

Backslash
  A backslash preserves the literal meaning of the following character,
  with the exception of ⟨newline⟩.  A backslash preceding a ⟨newline⟩ is
  treated as a line continuation.

Single Quotes
  Enclosing characters in single quotes preserves the literal meaning of
  all the characters (except single quotes, making it impossible to put
  single-quotes in a single-quoted string).

Double Quotes
  Enclosing characters within double quotes preserves the literal meaning
  of all characters except dollarsign ($), backquote (`), and backslash
  (\).  The backslash inside double quotes is historically weird, and
  serves to quote only the following characters:
        $ ` " \ <newline>.
  Otherwise it remains literal.

GNU Bash

The Bash shell is default on many systems, though it is not generally the default system-wide shell (i.e., the system syscall does not generally invoke it).

That said, its prevalence suggests that it also be addressed.

From the GNU Bash Manual, every character except for single-quote can be wrapped in single-quotes, and a backslash can be used to escape unquoted single-quotes.

3.1.2.1 Escape Character

A non-quoted backslash ‘\’ is the Bash escape character. It preserves the
literal value of the next character that follows, with the exception of
newline. If a ``\newline`` pair appears, and the backslash itself is not
quoted, the ``\newline`` is treated as a line continuation (that is, it
is removed from the input stream and effectively ignored).

3.1.2.2 Single Quotes

Enclosing characters in single quotes (‘'’) preserves the literal value of
each character within the quotes. A single quote may not occur between single
uotes, even when preceded by a backslash.

3.1.2.3 Double Quotes

Enclosing characters in double quotes (‘"’) preserves the literal value of a
ll characters within the quotes, with the exception of ‘$’, ‘`’, ‘\’, and,
when history expansion is enabled, ‘!’. The characters ‘$’ and ‘`’ retain their
pecial meaning within double quotes (see Shell Expansions). The backslash retains
its special meaning only when followed by one of the following characters:
‘$’, ‘`’, ‘"’, ‘\’, or newline. Within double quotes, backslashes that are
followed by one of these characters are removed. Backslashes preceding
characters without a special meaning are left unmodified. A double quote may
be quoted within double quotes by preceding it with a backslash. If enabled,
history expansion will be performed unless an ‘!’ appearing in double quotes
is escaped using a backslash. The backslash preceding the ‘!’ is not removed.

The special parameters ‘*’ and ‘@’ have special meaning when in double quotes
see Shell Parameter Expansion).

Z Shell

The Z shell is also a relatively common user shell, even though it’s not generally the default system-wide shell.

From the Z Shell Manual, every character except for single-quote can be wrapped in single-quotes, and a backslash can be used to escape unquoted single-quotes.

A character may be quoted (that is, made to stand for itself) by preceding
it with a ‘\’. ‘\’ followed by a newline is ignored.

A string enclosed between ‘$'’ and ‘'’ is processed the same way as the
string arguments of the print builtin, and the resulting string is considered
o be entirely quoted. A literal ‘'’ character can be included in the string
by using the ‘\'’ escape.

All characters enclosed between a pair of single quotes ('') that is not
preceded by a ‘$’ are quoted. A single quote cannot appear within single
quotes unless the option RC_QUOTES is set, in which case a pair of single
quotes are turned into a single quote. For example,

print ''''
outputs nothing apart from a newline if RC_QUOTES is not set, but one single
quote if it is set.

Inside double quotes (""), parameter and command substitution occur, and
‘\’ quotes the characters ‘\’, ‘`’, ‘"’, and ‘$’.

FreeBSD Shell

Compatibility with the FreeBSD shell is included for completeness.

From the FreeBSD man pages, every character except for single-quote can be wrapped in single-quotes, and a backslash can be used to escape unquoted single-quotes.

Quoting is used to remove the special meaning of certain characters or
words to the shell, such as operators, whitespace, keywords, or alias
names.

There are four types of quoting: matched single quotes, dollar-single
quotes, matched double quotes, and backslash.

Single Quotes
    Enclosing characters in single quotes preserves the literal mean-
    ing of all the characters (except single quotes, making it impos-
    sible to put single-quotes in a single-quoted string).

Dollar-Single Quotes
    Enclosing characters between $' and ' preserves the literal mean-
    ing of all characters except backslashes and single quotes.  A
    backslash introduces a C-style escape sequence:

    ...

Double Quotes
    Enclosing characters within double quotes preserves the literal
    meaning of all characters except dollar sign (`$'), backquote
    (``'), and backslash (`\').  The backslash inside double quotes
    is historically weird.  It remains literal unless it precedes the
    following characters, which it serves to quote:

      $     `     "     \     \n

Backslash
    A backslash preserves the literal meaning of the following char-
    acter, with the exception of the newline character (`\n').  A
    backslash preceding a newline is treated as a line continuation.

OpenBSD Shell

From the OpenBSD Man Pages, every character except for single-quote can be wrapped in single-quotes, and a backslash can be used to escape unquoted single-quotes.

A backslash (\) can be used to quote any character except a newline.
If a newline follows a backslash the shell removes them both, effectively
making the following line part of the current one.

A group of characters can be enclosed within single quotes (') to quote
every character within the quotes.

A group of characters can be enclosed within double quotes (") to quote
every character within the quotes except a backquote (`) or a dollar
sign ($), both of which retain their special meaning. A backslash (\)
within double quotes retains its special meaning, but only when followed
by a backquote, dollar sign, double quote, or another backslash.
An at sign (@) within double quotes has a special meaning
(see SPECIAL PARAMETERS, below).

NetBSD Shell

The NetBSD shell’s documentation is identical to the Dash documentation.

Android Shells

Android has gone through some number of shells.

• Mksh, a Korn shell, was used with Toolbox releases (5.0 and prior)
• Toybox, also derived from the Almquist Shell (6.0 and newer)

Notably, the Toolbox implementation is not POSIX compliant as it lacks a “printf” builtin (e.g. Android 5.0 emulator images).

Toybox Shell

Android 6.0 (and possibly other versions) use a shell based on toybox.

While it does not include a printf builtin, toybox itself includes a POSIX-compliant printf binary.

The Ash shells should be feature-compatible with dash.

BusyBox Shell

BusyBox’s Wikipedia page claims to use an ash-compliant shell, and should therefore be compatible with dash.

pwnlib.util.sh_string.sh_command_with(f, arg0, ..., argN) → command

Returns a command create by evaluating f(new_arg0, ..., new_argN) whenever f is a function and f % (new_arg0, ..., new_argN) otherwise.

If the arguments are purely alphanumeric, then they are simply passed to function. If they are simple to escape, they will be escaped and passed to the function.

If the arguments contain trailing newlines, then it is hard to use them directly because of a limitation in the posix shell. In this case the output from f is prepended with a bit of code to create the variables.

Examples

>>> sh_command_with(lambda: "echo hello")
'echo hello'
>>> sh_command_with(lambda x: "echo " + x, "hello")
'echo hello'
>>> sh_command_with(lambda x: "/bin/echo " + x, "\\x01")
"/bin/echo '\\x01'"
>>> sh_command_with(lambda x: "/bin/echo " + x, "\\x01\\n")
"/bin/echo '\\x01\\n'"
>>> sh_command_with("/bin/echo %s", "\\x01\\n")
"/bin/echo '\\x01\\n'"

pwnlib.util.sh_string.sh_prepare(variables, export=False)

Outputs a posix compliant shell command that will put the data specified by the dictionary into the environment.

It is assumed that the keys in the dictionary are valid variable names that does not need any escaping.

Parameters:

• variables (dict) – The variables to set.
• export (bool) – Should the variables be exported or only stored in the shell environment?
• output (str) – A valid posix shell command that will set the given variables.

It is assumed that var is a valid name for a variable in the shell.

Examples

>>> sh_prepare({'X': 'foobar'})
'X=foobar'
>>> r = sh_prepare({'X': 'foobar', 'Y': 'cookies'})
>>> r == 'X=foobar;Y=cookies' or r == 'Y=cookies;X=foobar'
True
>>> sh_prepare({'X': 'foo bar'})
"X='foo bar'"
>>> sh_prepare({'X': "foo'bar"})
"X='foo'\\''bar'"
>>> sh_prepare({'X': "foo\\\\bar"})
"X='foo\\\\bar'"
>>> sh_prepare({'X': "foo\\\\'bar"})
"X='foo\\\\'\\''bar'"
>>> sh_prepare({'X': "foo\\x01'bar"})
"X='foo\\x01'\\''bar'"
>>> sh_prepare({'X': "foo\\x01'bar"}, export = True)
"export X='foo\\x01'\\''bar'"
>>> sh_prepare({'X': "foo\\x01'bar\\n"})
"X='foo\\x01'\\''bar\\n'"
>>> sh_prepare({'X': "foo\\x01'bar\\n"})
"X='foo\\x01'\\''bar\\n'"
>>> sh_prepare({'X': "foo\\x01'bar\\n"}, export = True)
"export X='foo\\x01'\\''bar\\n'"

pwnlib.util.sh_string.sh_string(s)

Outputs a string in a format that will be understood by /bin/sh.

If the string does not contain any bad characters, it will simply be returned, possibly with quotes. If it contains bad characters, it will be escaped in a way which is compatible with most known systems.

Warning

This does not play along well with the shell’s built-in “echo”. It works exactly as expected to set environment variables and arguments, unless it’s the shell-builtin echo.

Argument:

s(str): String to escape.

Examples

>>> sh_string('foobar')
'foobar'
>>> sh_string('foo bar')
"'foo bar'"
>>> sh_string("foo'bar")
"'foo'\\''bar'"
>>> sh_string("foo\\\\bar")
"'foo\\\\bar'"
>>> sh_string("foo\\\\'bar")
"'foo\\\\'\\''bar'"
>>> sh_string("foo\\x01'bar")
"'foo\\x01'\\''bar'"

pwnlib.util.sh_string.test(original)

Tests the output provided by a shell interpreting a string

>>> test('foobar')
>>> test('foo bar')
>>> test('foo bar\n')
>>> test("foo'bar")
>>> test("foo\\\\bar")
>>> test("foo\\\\'bar")
>>> test("foo\\x01'bar")
>>> test('\n')
>>> test('\xff')
>>> test(os.urandom(16 * 1024).replace('\x00', ''))

pwnlib.util.web — Utilities for working with the WWW

pwnlib.util.web.wget(url, save=None, timeout=5) → str

Downloads a file via HTTP/HTTPS.

Parameters:

• url (str) – URL to download
• save (str or bool) – Name to save as. Any truthy value will auto-generate a name based on the URL.
• timeout (int) – Timeout, in seconds

Example

>>> url    = 'https://httpbin.org/robots.txt'
>>> result = wget(url, timeout=60)
>>> result
'User-agent: *\nDisallow: /deny\n'
>>> result2 = wget(url, True, timeout=60)
>>> result == file('robots.txt').read()
True

pwnlib.testexample — Example Test Module

Module-level documentation would go here, along with a general description of the functionality. You can also add module-level doctests.

You can see what the documentation for this module will look like here: https://docs.pwntools.com/en/stable/testexample.html

The tests for this module are run when the documentation is automatically-generated by Sphinx. This particular module is invoked by an “automodule” directive, which imports everything in the module, or everything listed in __all__ in the module.

The doctests are automatically picked up by the >>> symbol, like from the Python prompt. For more on doctests, see the Python documentation.

All of the syntax in this file is ReStructuredText. You can find a nice cheat sheet here.

Here’s an example of a module-level doctest:

>>> add(3, add(2, add(1, 0)))
6

If doctests are wrong / broken, you can disable them temporarily.

>>> add(2, 2) 
5

Some things in Python are non-deterministic, like dict or set ordering. There are a lot of ways to work around this, but the accepted way of doing this is to test for equality.

>>> a = {a:a+1 for a in range(3)}
>>> a == {0:1, 1:2, 2:3}
True

In order to use other modules, they need to be imported from the RST which documents the module.

>>> os.path.basename('foo/bar')
'bar'

pwnlib.testexample.add(a, b) → int

Adds the numbers a and b.

Parameters:

• a (int) – First number to add
• b (int) – Second number to add

Returns:

The sum of a and b.

Examples

>>> add(1,2)
3
>>> add(-1, 33)
32

Indices and tables

• Index
• Module Index
• Search Page