Welcome to IdentityServer4 (ASP.NET Core 2.x)

_images/logo.png

IdentityServer4 is an OpenID Connect and OAuth 2.0 framework for ASP.NET Core.

It enables the following features in your applications:

Authentication as a Service
Centralized login logic and workflow for all of your applications (web, native, mobile, services). IdentityServer is an officially certified implementation of OpenID Connect.
Single Sign-on / Sign-out
Single sign-on (and out) over multiple application types.
Access Control for APIs
Issue access tokens for APIs for various types of clients, e.g. server to server, web applications, SPAs and native/mobile apps.
Federation Gateway
Support for external identity providers like Azure Active Directory, Google, Facebook etc. This shields your applications from the details of how to connect to these external providers.
Focus on Customization
The most important part - many aspects of IdentityServer can be customized to fit your needs. Since IdentityServer is a framework and not a boxed product or a SaaS, you can write code to adapt the system the way it makes sense for your scenarios.
Mature Open Source
IdentityServer uses the permissive Apache 2 license that allows building commercial products on top of it. It is also part of the .NET Foundation which provides governance and legal backing.
Free and Commercial Support
If you need help building or running your identity platform, let us know. There are several ways we can help you out.

The Big Picture

Most modern applications look more or less like this:

_images/appArch.png

The most common interactions are:

  • Browsers communicate with web applications
  • Web applications communicate with web APIs (sometimes on their own, sometimes on behalf of a user)
  • Browser-based applications communicate with web APIs
  • Native applications communicate with web APIs
  • Server-based applications communicate with web APIs
  • Web APIs communicate with web APIs (sometimes on their own, sometimes on behalf of a user)

Typically each and every layer (front-end, middle-tier and back-end) has to protect resources and implement authentication and/or authorization – often against the same user store.

Outsourcing these fundamental security functions to a security token service prevents duplicating that functionality across those applications and endpoints.

Restructuring the application to support a security token service leads to the following architecture and protocols:

_images/protocols.png

Such a design divides security concerns into two parts:

Authentication

Authentication is needed when an application needs to know the identity of the current user. Typically these applications manage data on behalf of that user and need to make sure that this user can only access the data for which he is allowed. The most common example for that is (classic) web applications – but native and JS-based applications also have a need for authentication.

The most common authentication protocols are SAML2p, WS-Federation and OpenID Connect – SAML2p being the most popular and the most widely deployed.

OpenID Connect is the newest of the three, but is considered to be the future because it has the most potential for modern applications. It was built for mobile application scenarios right from the start and is designed to be API friendly.

API Access

Applications have two fundamental ways with which they communicate with APIs – using the application identity, or delegating the user’s identity. Sometimes both methods need to be combined.

OAuth2 is a protocol that allows applications to request access tokens from a security token service and use them to communicate with APIs. This delegation reduces complexity in both the client applications as well as the APIs since authentication and authorization can be centralized.

OpenID Connect and OAuth 2.0 – better together

OpenID Connect and OAuth 2.0 are very similar – in fact OpenID Connect is an extension on top of OAuth 2.0. The two fundamental security concerns, authentication and API access, are combined into a single protocol - often with a single round trip to the security token service.

We believe that the combination of OpenID Connect and OAuth 2.0 is the best approach to secure modern applications for the foreseeable future. IdentityServer4 is an implementation of these two protocols and is highly optimized to solve the typical security problems of today’s mobile, native and web applications.

How IdentityServer4 can help

IdentityServer is middleware that adds the spec compliant OpenID Connect and OAuth 2.0 endpoints to an arbitrary ASP.NET Core application.

Typically, you build (or re-use) an application that contains a login and logout page (and maybe consent - depending on your needs), and the IdentityServer middleware adds the necessary protocol heads to it, so that client applications can talk to it using those standard protocols.

_images/middleware.png

The hosting application can be as complex as you want, but we typically recommend to keep the attack surface as small as possible by including authentication related UI only.

Terminology

The specs, documentation and object model use a certain terminology that you should be aware of.

_images/terminology.png

IdentityServer

IdentityServer is an OpenID Connect provider - it implements the OpenID Connect and OAuth 2.0 protocols.

Different literature uses different terms for the same role - you probably also find security token service, identity provider, authorization server, IP-STS and more.

But they are in a nutshell all the same: a piece of software that issues security tokens to clients.

IdentityServer has a number of jobs and features - including:

  • protect your resources
  • authenticate users using a local account store or via an external identity provider
  • provide session management and single sign-on
  • manage and authenticate clients
  • issue identity and access tokens to clients
  • validate tokens

User

A user is a human that is using a registered client to access resources.

Client

A client is a piece of software that requests tokens from IdentityServer - either for authenticating a user (requesting an identity token) or for accessing a resource (requesting an access token). A client must be first registered with IdentityServer before it can request tokens.

Examples for clients are web applications, native mobile or desktop applications, SPAs, server processes etc.

Resources

Resources are something you want to protect with IdentityServer - either identity data of your users, or APIs.

Every resource has a unique name - and clients use this name to specify to which resources they want to get access to.

Identity data Identity information (aka claims) about a user, e.g. name or email address.

APIs APIs resources represent functionality a client wants to invoke - typically modelled as Web APIs, but not necessarily.

Identity Token

An identity token represents the outcome of an authentication process. It contains at a bare minimum an identifier for the user (called the sub aka subject claim) and information about how and when the user authenticated. It can contain additional identity data.

Access Token

An access token allows access to an API resource. Clients request access tokens and forward them to the API. Access tokens contain information about the client and the user (if present). APIs use that information to authorize access to their data.

Supported Specifications

IdentityServer implements the following specifications:

OpenID Connect

  • OpenID Connect Core 1.0 (spec)
  • OpenID Connect Discovery 1.0 (spec)
  • OpenID Connect Session Management 1.0 - draft 28 (spec)
  • OpenID Connect Front-Channel Logout 1.0 - draft 02 (spec)
  • OpenID Connect Back-Channel Logout 1.0 - draft 04 (spec)

OAuth 2.0

  • OAuth 2.0 (RFC 6749)
  • OAuth 2.0 Bearer Token Usage (RFC 6750)
  • OAuth 2.0 Multiple Response Types (spec)
  • OAuth 2.0 Form Post Response Mode (spec)
  • OAuth 2.0 Token Revocation (RFC 7009)
  • OAuth 2.0 Token Introspection (RFC 7662)
  • Proof Key for Code Exchange (RFC 7636)
  • JSON Web Tokens for Client Authentication (RFC 7523)
  • OAuth 2.0 Device Authorization Grant (RFC 8628)
  • OAuth 2.0 Mutual TLS Client Authentication and Certificate-Bound Access Tokens (draft)

Packaging and Builds

IdentityServer consists of a number of nuget packages.

IdentityServer4

nuget | github

Contains the core IdentityServer object model, services and middleware. Only contains support for in-memory configuration and user stores - but you can plug-in support for other stores via the configuration. This is what the other repos and packages are about.

Quickstart UI

github

Contains a simple starter UI including login, logout and consent pages.

Access token validation handler

nuget | github

ASP.NET Core authentication handler for validating tokens in APIs. The handler allows supporting both JWT and reference tokens in the same API.

ASP.NET Core Identity

nuget | github

ASP.NET Core Identity integration package for IdentityServer. This package provides a simple configuration API to use the ASP.NET Identity management library for your IdentityServer users.

EntityFramework Core

nuget | github

EntityFramework Core storage implementation for IdentityServer. This package provides an EntityFramework implementation for the configuration and operational stores in IdentityServer.

Dev builds

In addition we publish dev/interim builds to MyGet. Add the following feed to your Visual Studio if you want to give them a try:

https://www.myget.org/F/identity/

Support and Consulting Options

We have several free and commercial support and consulting options for IdentityServer.

Free support

Free support is community-based and uses public forums

StackOverflow

There’s an ever growing community of people using IdentityServer that monitor questions on StackOverflow. If time permits, we also try to answer as many questions as possible

You can subscribe to all IdentityServer4 related questions using this feed:

https://stackoverflow.com/questions/tagged/?tagnames=identityserver4&sort=newest

Please use the IdentityServer4 tag when asking new questions

Gitter

You can chat with other IdentityServer4 users in our Gitter chat room:

https://gitter.im/IdentityServer/IdentityServer4

Reporting a bug

If you think you have found a bug or unexpected behavior, please open an issue on the Github issue tracker. We try to get back to you ASAP. Please understand that we also have day jobs, and might be too busy to reply immediately.

Also check the contribution guidelines before posting.

Commercial support

We are doing consulting, mentoring and custom software development around identity & access control architecture in general, and IdentityServer in particular. Please get in touch with us to discuss possible options.

Training

We are regularly doing workshops around identity & access control for modern applications. Check the agenda and upcoming public dates here. We can also perform the training privately at your company. Contact us to request the training on-site.

Admin UI, WS-Federation and SAML2p IdP support

There are a couple of commercial add-on products available from our partners, check https://www.identityserver.com/products/.

Demo Server and Tests

You can try IdentityServer4 with your favourite client library. We have a test instance at demo.identityserver.io. On the main page you can find instructions on how to configure your client and how to call an API.

Furthermore we have a repo that exercises a variety of IdentityServer and Web API combinations (IdentityServer 3 and 4, ASP.NET Core and Katana). We use this test harness to make sure all permutations work. You can test it yourself by cloning this repo.

Contributing

We are very open to community contributions, but there are a couple of guidelines you should follow so we can handle this without too much effort.

How to contribute?

The easiest way to contribute is to open an issue and start a discussion. Then we can decide if and how a feature or a change could be implemented. If you should submit a pull request with code changes, start with a description, only make the minimal changes to start with and provide tests that cover those changes.

Also read this first: Being a good open source citizen

General feedback and discussions?

Please start a discussion on the core repo issue tracker.

Bugs and feature requests?

Please log a new issue in the appropriate GitHub repo:

Contributing code and content

You will need to sign a Contributor License Agreement before you can contribute any code or content. This is an automated process that will start after you opened a pull request.

Contribution projects

We very much appreciate if you start a contribution project (e.g. support for Database X or Configuration Store Y). Tell us about it so we can tweet and link it in our docs.

We generally don’t want to take ownership of those contribution libraries, we are already really busy supporting the core projects.

Naming conventions

As of October 2017, the IdentityServer4.* nuget namespace is reserved for our packages. Please use the following naming conventions:

YourProjectName.IdentityServer4

or

IdentityServer4.Contrib.YourProjectName

Overview

The quickstarts provide step by step instructions for various common IdentityServer scenarios. They start with the absolute basics and become more complex - it is recommended you do them in order.

  • adding IdentityServer to an ASP.NET Core application
  • configuring IdentityServer
  • issuing tokens for various clients
  • securing web applications and APIs
  • adding support for EntityFramework based configuration
  • adding support for ASP.NET Identity
  • adding AdminUI community edition to manage users and configuration

Every quickstart has a reference solution - you can find the code in the samples folder.

Preparation

The first thing you should do is install our templates:

dotnet new -i IdentityServer4.Templates::2.7.0

They will be used as a starting point for the various tutorials.

OK - let’s get started!

Protecting an API using Client Credentials

The following Identity Server 4 quickstart provides step by step instructions for various common IdentityServer scenarios. These start with the absolute basics and become more complex as they progress. We recommend that you follow them in sequence. To see the full list, please go to IdentityServer4 Quickstarts Overview

This is quickstart number one it presents the most basic scenario for protecting APIs using IdentityServer 4. In this quickstart you define an API and a Client with which to access it. The client will request an access token from the Identity Server by providing a ClientCredentials which acts as a secret known to both the client and identity server and it will use the token to gain access to the API.

Source Code

As with all of these quickstarts you can find the source code for it in the IdentityServer4 repository. The project for this quickstart is Quickstart #1: Securing an API using Client Credentials

Preparation

In order to make following these quickstarts easier for you the team has created some custom templates for dotnet new.

To install the custom templates open a console window and type the following command:

dotnet new -i IdentityServer4.Templates::2.6.1

They will be used as a starting point for the various tutorials.

Setting up the ASP.NET Core application

First create a directory for the application - then use our template to create an ASP.NET Core application that includes a basic IdentityServer setup, e.g.:

md quickstart
cd quickstart

md src
cd src

dotnet new is4empty -n IdentityServer

This will create the following files:

  • IdentityServer.csproj - the project file and a Properties\launchSettings.json file
  • Program.cs and Startup.cs - the main application entry point
  • Config.cs - IdentityServer resources and clients configuration file

You can now use your favorite text editor to edit or view the files. If you want to have Visual Studio support, you can add a solution file like this:

cd ..
dotnet new sln -n Quickstart

and let it add your IdentityServer project (keep this command in mind as we will create other projects below):

dotnet sln add .\src\IdentityServer\IdentityServer.csproj

Note

The protocol used in this Template is http and the port is set to 5000 when running on Kestrel or a random one on IISExpress. You can change that in the Properties\launchSettings.json file. However, all of the quickstart instructions will assume you use the default port on Kestrel as well as the http protocol, which is sufficient for local development. You should not run identity server http in a production enviroment http should only be used for testing.

Defining an API Resource

An API is a resource in your system that you want to protect. Resource definitions can be loaded in many ways, the template you used to create the project above shows how to use a “code as configuration” approach.

Open the project that we just created above in your favorite editor. Find the Config.cs file you can find a method called GetApis, define the API as follows:

public static IEnumerable<ApiResource> GetApis()
{
    return new List<ApiResource>
    {
        new ApiResource("api1", "My API")
    };
}

Note

If you will be using this in production it is important to give your API a logical name. Developers will be using this to connect to your api though your Identity server. It should describe your api in simple terms to both developers and users.

A good example would be:

new ApiResource("afcpayroll", "Acme Fireworks Co. payroll")

A bad example would be:

new ApiResource("testapi", "My first api")

Defining the client

The next step is to define a client application that we will use to access our new API.

For this scenario, the client will not have an interactive user, and will authenticate using the so called client secret with IdentityServer.

Once again open the Config.cs file and add the following code to it:

public static IEnumerable<Client> GetClients()
{
    return new List<Client>
    {
        new Client
        {
            ClientId = "client",

            // no interactive user, use the clientid/secret for authentication
            AllowedGrantTypes = GrantTypes.ClientCredentials,

            // secret for authentication
            ClientSecrets =
            {
                new Secret("secret".Sha256())
            },

            // scopes that client has access to
            AllowedScopes = { "api1" }
        }
    };
}

You can think of the ClientId and the ClientSecret as the login and password for your application itself. It identifies your application to the identity server so that it knows which application is trying to connect to it.

Configuring IdentityServer

Loading the resource and client definitions happens in Startup.cs - the template already does this for you:

public void ConfigureServices(IServiceCollection services)
{
    var builder = services.AddIdentityServer()
        .AddInMemoryIdentityResources(Config.GetIdentityResources())
        .AddInMemoryApiResources(Config.GetApis())
        .AddInMemoryClients(Config.GetClients());

    // omitted for brevity
}

That’s it your identity server should now be configured. If you run the server and navigate the browser to http://localhost:5000/.well-known/openid-configuration, you should see the so-called discovery document. The discovery document is a standard endpoint in identity servers. The discovery document will be used by your clients and APIs to download the necessary configuration data.

_images/1_discovery.png

At first startup, IdentityServer will create a developer signing key for you, it’s a file called tempkey.rsa. You don’t have to check that file into your source control, it will be re-created if it is not present.

Adding an API

Next, add an API to your solution.

You can either use the ASP.NET Core Web API (or empty) template from Visual Studio or use the .NET CLI to create the API project as we do here. Run from within the src folder the following command:

dotnet new web -n Api

Then add it to the solution by running the following commands:

cd ..
dotnet sln add .\src\Api\Api.csproj

Configure the API application to run on http://localhost:5001 only. You can do this by editing the launchSettings.json file inside the Properties folder. Change the application URL setting to be:

"applicationUrl": "http://localhost:5001"

The controller

Add a new folder Controllers and a new controller IdentityController (note: if you are using Visual Studio select API controller empty>`_ to your API project:

[Route("identity")]
[Authorize]
public class IdentityController : ControllerBase
{
    [HttpGet]
    public IActionResult Get()
    {
        return new JsonResult(from c in User.Claims select new { c.Type, c.Value });
    }
}

This controller will be used later to test the authorization requirement, as well as visualize the claims identity through the eyes of the API.

Configuration

The last step is to add the authentication services to DI (dependency injection) and the authentication middleware to the pipeline. These will:

  • validate the incoming token to make sure it is coming from a trusted issuer
  • validate that the token is valid to be used with this api (aka audience)

Update Startup to look like this:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvcCore()
            .AddAuthorization()
            .AddJsonFormatters();

        services.AddAuthentication("Bearer")
            .AddJwtBearer("Bearer", options =>
            {
                options.Authority = "http://localhost:5000";
                options.RequireHttpsMetadata = false;

                options.Audience = "api1";
            });
    }

    public void Configure(IApplicationBuilder app)
    {
        app.UseAuthentication();

        app.UseMvc();
    }
}

AddAuthentication adds the authentication services to DI and configures "Bearer" as the default scheme. UseAuthentication adds the authentication middleware to the pipeline so authentication will be performed automatically on every call into the host.

Navigating to the controller http://localhost:5001/identity on a browser should return a 401 status code. This means your API requires a credential and is now protected by IdentityServer.

Creating the client

The last step is to write a client that requests an access token, and then uses this token to access the API. For that, add a console project to your solution, remember to create it in the src:

dotnet new console -n Client

Then as before, add it to your solution using:

cd ..
dotnet sln add .\src\Client\Client.csproj

Open up Program.cs and copy the content from here to it..

The client program invokes the Main method asynchronously in order to run asynchronous http calls. This feature is possible since C# 7.1 and will be available once you edit Client.csproj to add the following line as a PropertyGroup:

<LangVersion>latest</LangVersion>

The token endpoint at IdentityServer implements the OAuth 2.0 protocol, and you could use raw HTTP to access it. However, we have a client library called IdentityModel, that encapsulates the protocol interaction in an easy to use API.

Add the IdentityModel NuGet package to your client. This can be done either via Visual Studio’s Nuget Package manager or though the package manager Console with the following command:

Install-Package IdentityModel

or by using the CLI:

dotnet add package IdentityModel

IdentityModel includes a client library to use with the discovery endpoint. This way you only need to know the base-address of IdentityServer - the actual endpoint addresses can be read from the metadata:

// discover endpoints from metadata
var client = new HttpClient();
var disco = await client.GetDiscoveryDocumentAsync("http://localhost:5000");
if (disco.IsError)
{
    Console.WriteLine(disco.Error);
    return;
}

Next you can use the information from the discovery document to request a token to IdentityServer to access api1:

// request token
var tokenResponse = await client.RequestClientCredentialsTokenAsync(new ClientCredentialsTokenRequest
{
    Address = disco.TokenEndpoint,

    ClientId = "client",
    ClientSecret = "secret",
    Scope = "api1"
});

if (tokenResponse.IsError)
{
    Console.WriteLine(tokenResponse.Error);
    return;
}

Console.WriteLine(tokenResponse.Json);

Note

Copy and paste the access token from the console to jwt.io to inspect the raw token.

Calling the API

To send the access token to the API you typically use the HTTP Authorization header. This is done using the SetBearerToken extension method:

// call api
var client = new HttpClient();
client.SetBearerToken(tokenResponse.AccessToken);

var response = await client.GetAsync("http://localhost:5001/identity");
if (!response.IsSuccessStatusCode)
{
    Console.WriteLine(response.StatusCode);
}
else
{
    var content = await response.Content.ReadAsStringAsync();
    Console.WriteLine(JArray.Parse(content));
}

The output should look like this:

_images/1_client_screenshot.png

Note

By default an access token will contain claims about the scope, lifetime (nbf and exp), the client ID (client_id) and the issuer name (iss).

Further experiments

This walkthrough focused on the success path so far

  • client was able to request token
  • client could use the token to access the API

You can now try to provoke errors to learn how the system behaves, e.g.

  • try to connect to IdentityServer when it is not running (unavailable)
  • try to use an invalid client id or secret to request the token
  • try to ask for an invalid scope during the token request
  • try to call the API when it is not running (unavailable)
  • don’t send the token to the API
  • configure the API to require a different scope than the one in the token

Protecting an API using Passwords

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

The OAuth 2.0 resource owner password grant allows a client to send username and password to the token service and get an access token back that represents that user.

The spec generally recommends against using the resource owner password grant besides legacy applications that cannot host a browser. Generally speaking you are typically far better off using one of the interactive OpenID Connect flows when you want to authenticate a user and request access tokens.

Nevertheless, this grant type allows us to introduce the concept of users to our quickstart IdentityServer, and that’s why we show it.

Adding users

Just like there are in-memory stores for resources (aka scopes) and clients, there is also one for users.

Note

Check the ASP.NET Identity based quickstarts for more information on how to properly store and manage user accounts.

The class TestUser represents a test user and its claims. Let’s create a couple of users by adding the following code to our config class:

First add the following using statement to the Config.cs file:

using IdentityServer4.Test;

public static List<TestUser> GetUsers()
{
    return new List<TestUser>
    {
        new TestUser
        {
            SubjectId = "1",
            Username = "alice",
            Password = "password"
        },
        new TestUser
        {
            SubjectId = "2",
            Username = "bob",
            Password = "password"
        }
    };
}

Then register the test users with IdentityServer:

public void ConfigureServices(IServiceCollection services)
{
    // configure identity server with in-memory stores, keys, clients and scopes
    services.AddIdentityServer()
        .AddInMemoryApiResources(Config.GetApiResources())
        .AddInMemoryClients(Config.GetClients())
        .AddTestUsers(Config.GetUsers());
}

The AddTestUsers extension method does a couple of things under the hood

  • adds support for the resource owner password grant
  • adds support to user related services typically used by a login UI (we’ll use that in the next quickstart)
  • adds support for a profile service based on the test users (you’ll learn more about that in the next quickstart)

Adding a client for the resource owner password grant

You could simply add support for the grant type to our existing client by changing the AllowedGrantTypes property. If you need your client to be able to use both grant types that is absolutely supported.

We are creating a separate client for the resource owner use case, add the following to your clients configuration:

public static IEnumerable<Client> GetClients()
{
    return new List<Client>
    {
        // other clients omitted...

        // resource owner password grant client
        new Client
        {
            ClientId = "ro.client",
            AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,

            ClientSecrets =
            {
                new Secret("secret".Sha256())
            },
            AllowedScopes = { "api1" }
        }
    };
}

Requesting a token using the password grant

Add a new console client to your solution.

The new client looks very similar to what we did for the client credentials grant. The main difference is now that the client would collect the user’s password somehow, and send it to the token service during the token request.

Again IdentityModel can help out here:

// request token
var tokenResponse = await client.RequestPasswordTokenAsync(new PasswordTokenRequest
{
    Address = disco.TokenEndpoint,
    ClientId = "ro.client",
    ClientSecret = "secret",

    UserName = "alice",
    Password = "password",
    Scope = "api1"
});

if (tokenResponse.IsError)
{
    Console.WriteLine(tokenResponse.Error);
    return;
}

Console.WriteLine(tokenResponse.Json);

When you send the token to the identity API endpoint, you will notice one small but important difference compared to the client credentials grant. The access token will now contain a sub claim which uniquely identifies the user. This “sub” claim can be seen by examining the content variable after the call to the API and also will be displayed on the screen by the console application.

The presence (or absence) of the sub claim lets the API distinguish between calls on behalf of clients and calls on behalf of users.

Adding User Authentication with OpenID Connect

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

In this quickstart we want to add support for interactive user authentication via the OpenID Connect protocol to our IdentityServer.

Once that is in place, we will create an MVC application that will use IdentityServer for authentication.

Adding the UI

All the protocol support needed for OpenID Connect is already built into IdentityServer. You need to provide the necessary UI parts for login, logout, consent and error.

While the look & feel as well as the exact workflows will probably always differ in every IdentityServer implementation, we provide an MVC-based sample UI that you can use as a starting point.

This UI can be found in the Quickstart UI repo. You can clone or download this repo and drop the controllers, views, models and CSS into your IdentityServer web application.

Alternatively you can use the .NET CLI (run from within the src/IdentityServer folder):

dotnet new is4ui

Once you have added the MVC UI, you will also need to enable MVC, both in the DI system and in the pipeline. When you look at Startup.cs you will find comments in the ConfigureServices and Configure method that tell you how to enable MVC.

Run the IdentityServer application, you should now see a home page.

Spend some time inspecting the controllers and models, the better you understand them, the easier it will be to make future modifications. Most of the code lives in the “Quickstart” folder using a “feature folder” style. If this style doesn’t suit you, feel free to organize the code in any way you want.

Creating an MVC client

Next you will add an MVC application to your solution. Use the ASP.NET Core “Web Application” (i.e. MVC) template for that. Don’t configure the “Authentication” settings in the wizard – you will do this manually in this quickstart. Once you’ve created the project, configure the application to run on port 5002.

To add support for OpenID Connect authentication to the MVC application, add the following to ConfigureServices in Startup:

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc();

    JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();

    services.AddAuthentication(options =>
        {
            options.DefaultScheme = "Cookies";
            options.DefaultChallengeScheme = "oidc";
        })
        .AddCookie("Cookies")
        .AddOpenIdConnect("oidc", options =>
        {
            options.Authority = "http://localhost:5000";
            options.RequireHttpsMetadata = false;

            options.ClientId = "mvc";
            options.SaveTokens = true;
        });
}

AddAuthentication adds the authentication services to DI. We are using a cookie to locally sign-in the user (via "Cookies" as the DefaultScheme), and we set the DefaultChallengeScheme to "oidc" because when we need the user to login, we will be using the OpenID Connect protocol.

We then use AddCookie to add the handler that can process cookies.

Finally, AddOpenIdConnect is used to configure the handler that perform the OpenID Connect protocol. The Authority indicates that we are trusting IdentityServer. We then identify this client via the ClientId. SaveTokens is used to persist the tokens from IdentityServer in the cookie (as they will be needed later).

As well, we’ve turned off the JWT claim type mapping to allow well-known claims (e.g. ‘sub’ and ‘idp’) to flow through unmolested:

JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();

And then to ensure the authentication services execute on each request, add UseAuthentication to Configure in Startup:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }

    app.UseAuthentication();

    app.UseStaticFiles();
    app.UseMvcWithDefaultRoute();
}

The authentication middleware should be added before the MVC in the pipeline.

The last step is to trigger the authentication handshake. For that go to the home controller and add the [Authorize] on one of the actions. Also modify the home view to display the claims of the user as well as the cookie properties:

@using Microsoft.AspNetCore.Authentication

<h2>Claims</h2>

<dl>
    @foreach (var claim in User.Claims)
    {
        <dt>@claim.Type</dt>
        <dd>@claim.Value</dd>
    }
</dl>

<h2>Properties</h2>

<dl>
    @foreach (var prop in (await Context.AuthenticateAsync()).Properties.Items)
    {
        <dt>@prop.Key</dt>
        <dd>@prop.Value</dd>
    }
</dl>

If you now navigate to that controller using the browser, a redirect attempt will be made to IdentityServer - this will result in an error because the MVC client is not registered yet.

Adding support for OpenID Connect Identity Scopes

Similar to OAuth 2.0, OpenID Connect also uses the scopes concept. Again, scopes represent something you want to protect and that clients want to access. In contrast to OAuth, scopes in OIDC don’t represent APIs, but identity data like user id, name or email address.

Add support for the standard openid (subject id) and profile (first name, last name etc..) scopes by ammending the GetIdentityResources method in Config.cs:

public static IEnumerable<IdentityResource> GetIdentityResources()
{
    return new List<IdentityResource>
    {
        new IdentityResources.OpenId(),
        new IdentityResources.Profile(),
    };
}

Note

All standard scopes and their corresponding claims can be found in the OpenID Connect specification

Adding a client for OpenID Connect implicit flow

The last step is to add a new configuration entry for the MVC client to IdentityServer.

OpenID Connect-based clients are very similar to the OAuth 2.0 clients we added so far. But since the flows in OIDC are always interactive, we need to add some redirect URLs to our configuration.

Add the following to your clients configuration:

public static IEnumerable<Client> GetClients()
{
    return new List<Client>
    {
        // other clients omitted...

        // OpenID Connect implicit flow client (MVC)
        new Client
        {
            ClientId = "mvc",
            ClientName = "MVC Client",
            AllowedGrantTypes = GrantTypes.Implicit,

            // where to redirect to after login
            RedirectUris = { "http://localhost:5002/signin-oidc" },

            // where to redirect to after logout
            PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },

            AllowedScopes = new List<string>
            {
                IdentityServerConstants.StandardScopes.OpenId,
                IdentityServerConstants.StandardScopes.Profile
            }
        }
    };
}

Testing the client

Now finally everything should be in place for the new MVC client.

Trigger the authentication handshake by navigating to the protected controller action. You should see a redirect to the login page at IdentityServer.

_images/3_login.png

After successful login, the user is presented with the consent screen. Here the user can decide if he wants to release his identity information to the client application.

Note

Consent can be turned off on a per client basis using the RequireConsent property on the client configuration.

_images/3_consent.png

After that, IdentityServer will redirect back to the MVC client, where the OpenID Connect authentication handler processes the response and signs-in the user locally by setting a cookie. Finally the MVC view will show the contents of the cookie.

_images/3_claims.png

As you can see, the cookie has two parts, the claims of the user, and some metadata. This metadata also contains the original token that was issued by IdentityServer. Feel free to copy this token to jwt.io to inspect its content.

Adding sign-out

The very last step is to add sign-out to the MVC client.

With an authentication service like IdentityServer, it is not enough to clear the local application cookies. In addition you also need to make a roundtrip to IdentityServer to clear the central single sign-on session.

The exact protocol steps are implemented inside the OpenID Connect handler, simply add the following code to some controller to trigger the sign-out:

public IActionResult Logout()
{
    return SignOut("Cookies", "oidc");
}

This will clear the local cookie and then redirect to IdentityServer. IdentityServer will clear its cookies and then give the user a link to return back to the MVC application.

Further experiments

As mentioned above, the OpenID Connect handler asks for the profile scope by default. This scope also includes claims like name or website.

Let’s add these claims to the user, so IdentityServer can put them into the identity token:

public static List<TestUser> GetUsers()
{
    return new List<TestUser>
    {
        new TestUser
        {
            SubjectId = "1",
            Username = "alice",
            Password = "password",

            Claims = new []
            {
                new Claim("name", "Alice"),
                new Claim("website", "https://alice.com")
            }
        },
        new TestUser
        {
            SubjectId = "2",
            Username = "bob",
            Password = "password",

            Claims = new []
            {
                new Claim("name", "Bob"),
                new Claim("website", "https://bob.com")
            }
        }
    };
}

Next time you authenticate, your claims page will now show the additional claims.

Feel free to add more claims - and also more scopes. The Scope property on the OpenID Connect middleware is where you configure which scopes will be sent to IdentityServer during authentication.

It is also noteworthy, that the retrieval of claims for tokens is an extensibility point - IProfileService. Since we are using AddTestUsers, the TestUserProfileService is used by default. You can inspect the source code here to see how it works.

Adding Support for External Authentication

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

Next we will add support for external authentication. This is really easy, because all you really need is an ASP.NET Core compatible authentication handler.

ASP.NET Core itself ships with support for Google, Facebook, Twitter, Microsoft Account and OpenID Connect. In addition you can find implementations for many other authentication providers here.

Adding Google support

To be able to use Google for authentication, you first need to register with them. This is done at their developer console. Create a new project, enable the Google+ API and configure the callback address of your local IdentityServer by adding the /signin-google path to your base-address (e.g. http://localhost:5000/signin-google).

The developer console will show you a client ID and secret issued by Google - you will need that in the next step.

Add the Google authentication handler to the DI of the IdentityServer host. This is done by adding this snippet to ConfigureServices in Startup:

services.AddAuthentication()
    .AddGoogle("Google", options =>
    {
        options.SignInScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme;

        options.ClientId = "<insert here>";
        options.ClientSecret = "<insert here>";
    });

By default, IdentityServer configures a cookie handler specifically for the results of external authentication (with the scheme based on the constant IdentityServerConstants.ExternalCookieAuthenticationScheme). The configuration for the Google handler is then using that cookie handler.

Now run the MVC client and try to authenticate - you will see a Google button on the login page:

_images/4_login_page.png

After authentication with the MVC client, you can see that the claims are now being sourced from Google data.

Further experiments

You can add an additional external provider. We have a cloud-hosted demo version of IdentityServer4 which you can integrate using OpenID Connect.

Add the OpenId Connect handler to DI:

services.AddAuthentication()
    .AddGoogle("Google", options =>
    {
        options.SignInScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme;

        options.ClientId = "<insert here>";
        options.ClientSecret = "<insert here>";
    })
    .AddOpenIdConnect("oidc", "OpenID Connect", options =>
    {
        options.SignInScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme;
        options.SignOutScheme = IdentityServerConstants.SignoutScheme;
        options.SaveTokens = true;

        options.Authority = "https://demo.identityserver.io/";
        options.ClientId = "implicit";

        options.TokenValidationParameters = new TokenValidationParameters
        {
            NameClaimType = "name",
            RoleClaimType = "role"
        };
    });

And now a user should be able to use the cloud-hosted demo identity provider.

Note

The quickstart UI auto-provisions external users. As an external user logs in for the first time, a new local user is created, and all the external claims are copied over and associated with the new user. The way you deal with such a situation is completely up to you though. Maybe you want to show some sort of registration UI first. The source code for the default quickstart can be found here. The controller where auto-provisioning is executed can be found here.

Switching to Hybrid Flow and adding API Access back

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

In the previous quickstarts we explored both API access and user authentication. Now we want to bring the two parts together.

The beauty of the OpenID Connect & OAuth 2.0 combination is, that you can achieve both with a single protocol and a single exchange with the token service.

In the previous quickstart we used the OpenID Connect implicit flow. In the implicit flow all tokens are transmitted via the browser, which is totally fine for the identity token. Now we also want to request an access token.

Access tokens are a bit more sensitive than identity tokens, and we don’t want to expose them to the “outside” world if not needed. OpenID Connect includes a flow called “Hybrid Flow” which gives us the best of both worlds, the identity token is transmitted via the browser channel, so the client can validate it before doing any more work. And if validation is successful, the client opens a back-channel to the token service to retrieve the access token.

Modifying the client configuration

There are not many modifications necessary. First we want to allow the client to use the hybrid flow, in addition we also want the client to allow doing server to server API calls which are not in the context of a user (this is very similar to our client credentials quickstart). This is expressed using the AllowedGrantTypes property.

Next we need to add a client secret. This will be used to retrieve the access token on the back channel.

And finally, we also give the client access to the offline_access scope - this allows requesting refresh tokens for long lived API access:

new Client
{
    ClientId = "mvc",
    ClientName = "MVC Client",
    AllowedGrantTypes = GrantTypes.Hybrid,

    ClientSecrets =
    {
        new Secret("secret".Sha256())
    },

    RedirectUris           = { "http://localhost:5002/signin-oidc" },
    PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        "api1"
    },
    AllowOfflineAccess = true
};

Modifying the MVC client

The modifications at the MVC client are also minimal - the ASP.NET Core OpenID Connect handler has built-in support for the hybrid flow, so we only need to change some configuration values.

We configure the ClientSecret to match the secret at IdentityServer. Add the offline_access and api1 scopes, and set the ResponseType to code id_token (which basically means “use hybrid flow”). To keep the website claim in our mvc client identity we need to explicitly map the claim using ClaimActions.

.AddOpenIdConnect("oidc", options =>
{
    options.SignInScheme = "Cookies";

    options.Authority = "http://localhost:5000";
    options.RequireHttpsMetadata = false;

    options.ClientId = "mvc";
    options.ClientSecret = "secret";
    options.ResponseType = "code id_token";

    options.SaveTokens = true;
    options.GetClaimsFromUserInfoEndpoint = true;

    options.Scope.Add("api1");
    options.Scope.Add("offline_access");
    options.ClaimActions.MapJsonKey("website", "website");
});

When you run the MVC client, there will be no big differences, besides that the consent screen now asks you for the additional API and offline access scope.

Using the access token

The OpenID Connect handler saves the tokens (identity, access and refresh in our case) automatically for you. That’s what the SaveTokens setting does.

The cookie inspection view iterates over those values and shows them on the screen.

Technically the tokens are stored inside the properties section of the cookie. The easiest way to access them is by using extension methods from the Microsoft.AspNetCore.Authentication namespace.

For example:

var accessToken = await HttpContext.GetTokenAsync("access_token")
var refreshToken = await HttpContext.GetTokenAsync("refresh_token");

For accessing the API using the access token, all you need to do is retrieve the token, and set it on your HttpClient:

public async Task<IActionResult> CallApi()
{
    var accessToken = await HttpContext.GetTokenAsync("access_token");

    var client = new HttpClient();
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
    var content = await client.GetStringAsync("http://localhost:5001/identity");

    ViewBag.Json = JArray.Parse(content).ToString();
    return View("json");
}

Create a view called json.cshtml that outputs the json like this:

<pre>@ViewBag.Json</pre>

Make sure the API is running, start the MVC client and call /home/CallApi after authentication.

Adding a JavaScript client

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

This quickstart will show how to build a browser-based JavaScript client application (sometimes referred to as a “SPA”).

The user will login to IdentityServer, invoke the web API with an access token issued by IdentityServer, and logout of IdentityServer. All of this will be driven from the JavaScript running in the browser.

New Project for the JavaScript client

Create a new project for the JavaScript application. It can simply be an empty web project, an empty ASP.NET Core application, or something else like a Node.js application. This quickstart will use an ASP.NET Core application.

Create a new “Empty” ASP.NET Core web application in the ~/src directory. You can use Visual Studio or do this from the command line:

md JavaScriptClient
cd JavaScriptClient
dotnet new web

Modify hosting

Modify the JavaScriptClient project to run on port 5003.

Add the static file middleware

Given that this project is designed to run client-side, all we need ASP.NET Core to do is to serve up the static HTML and JavaScript files that will make up our application. The static file middleware is designed to do this.

Register the static file middleware in Startup.cs in the Configure method (and at the same time remove everything else):

public void Configure(IApplicationBuilder app)
{
    app.UseDefaultFiles();
    app.UseStaticFiles();
}

This middleware will now serve up static files from the application’s ~/wwwroot folder. This is where we will put our HTML and JavaScript files. If that folder does not exist in your project, create it now.

Reference oidc-client

In one of the previous quickstarts in the ASP.NET Core MVC-based client project we used a library to handle the OpenID Connect protocol. In this quickstart in the JavaScriptClient project we need a similar library, except one that works in JavaScript and is designed to run in the browser. The oidc-client library is one such library. It is available via NPM, Bower, as well as a direct download from github.

NPM

If you want to use NPM to download oidc-client, then run these commands from your JavaScriptClient project directory:

npm i oidc-client
copy node_modules\oidc-client\dist\* wwwroot

This downloads the latest oidc-client package locally, and then copies the relevant JavaScript files into ~/wwwroot so they can be served up by your application.

Manual download

If you want to simply download the oidc-client JavaScript files manually, browse to the GitHub repository and download the JavaScript files. Once downloaded, copy them into ~/wwwroot so they can be served up by your application.

Add your HTML and JavaScript files

Next is to add your HTML and JavaScript files to ~/wwwroot. We will have two HTML files and one application-specific JavaScript file (in addition to the oidc-client.js library). In ~/wwwroot, add a HTML file named index.html and callback.html, and add a JavaScript file called app.js.

index.html

This will be the main page in our application. It will simply contain the HTML for the buttons for the user to login, logout, and call the web API. It will also contain the <script> tags to include our two JavaScript files. It will also contain a <pre> used for showing messages to the user.

It should look like this:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
    <button id="login">Login</button>
    <button id="api">Call API</button>
    <button id="logout">Logout</button>

    <pre id="results"></pre>

    <script src="oidc-client.js"></script>
    <script src="app.js"></script>
</body>
</html>

app.js

This will contain the main code for our application. The first thing is to add a helper function to log messages to the <pre>:

function log() {
    document.getElementById('results').innerText = '';

    Array.prototype.forEach.call(arguments, function (msg) {
        if (msg instanceof Error) {
            msg = "Error: " + msg.message;
        }
        else if (typeof msg !== 'string') {
            msg = JSON.stringify(msg, null, 2);
        }
        document.getElementById('results').innerHTML += msg + '\r\n';
    });
}

Next, add code to register click event handlers to the three buttons:

document.getElementById("login").addEventListener("click", login, false);
document.getElementById("api").addEventListener("click", api, false);
document.getElementById("logout").addEventListener("click", logout, false);

Next, we can use the UserManager class from the oidc-client library to manage the OpenID Connect protocol. It requires similar configuration that was necessary in the MVC Client (albeit with different values). Add this code to configure and instantiate the UserManager:

var config = {
    authority: "http://localhost:5000",
    client_id: "js",
    redirect_uri: "http://localhost:5003/callback.html",
    response_type: "code",
    scope:"openid profile api1",
    post_logout_redirect_uri : "http://localhost:5003/index.html",
};
var mgr = new Oidc.UserManager(config);

Next, the UserManager provides a getUser API to know if the user is logged into the JavaScript application. It uses a JavaScript Promise to return the results asynchronously. The returned User object has a profile property which contains the claims for the user. Add this code to detect if the user is logged into the JavaScript application:

mgr.getUser().then(function (user) {
    if (user) {
        log("User logged in", user.profile);
    }
    else {
        log("User not logged in");
    }
});

Next, we want to implement the login, api, and logout functions. The UserManager provides a signinRedirect to log the user in, and a signoutRedirect to log the user out. The User object that we obtained in the above code also has an access_token property which can be used to authenticate to a web API. The access_token will be passed to the web API via the Authorization header with the Bearer scheme. Add this code to implement those three functions in our application:

function login() {
    mgr.signinRedirect();
}

function api() {
    mgr.getUser().then(function (user) {
        var url = "http://localhost:5001/identity";

        var xhr = new XMLHttpRequest();
        xhr.open("GET", url);
        xhr.onload = function () {
            log(xhr.status, JSON.parse(xhr.responseText));
        }
        xhr.setRequestHeader("Authorization", "Bearer " + user.access_token);
        xhr.send();
    });
}

function logout() {
    mgr.signoutRedirect();
}

Note

See the client credentials quickstart for information on how to create the api used in the code above.

callback.html

This HTML file is the designated redirect_uri page once the user has logged into IdentityServer. It will complete the OpenID Connect protocol sign-in handshake with IdentityServer. The code for this is all provided by the UserManager class we used earlier. Once the sign-in is complete, we can then redirect the user back to the main index.html page. Add this code to complete the signin process:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
    <script src="oidc-client.js"></script>
    <script>
        new Oidc.UserManager({response_mode:"query"}).signinRedirectCallback().then(function() {
            window.location = "index.html";
        }).catch(function(e) {
            console.error(e);
        });
    </script>
</body>
</html>

Add a client registration to IdentityServer for the JavaScript client

Now that the client application is ready to go, we need to define a configuration entry in IdentityServer for this new JavaScript client. In the IdentityServer project locate the client configuration (in Config.cs). Add a new Client to the list for our new JavaScript application. It should have the configuration listed below:

// JavaScript Client
new Client
{
    ClientId = "js",
    ClientName = "JavaScript Client",
    AllowedGrantTypes = GrantTypes.Code,
    RequirePkce = true,
    RequireClientSecret = false,

    RedirectUris =           { "http://localhost:5003/callback.html" },
    PostLogoutRedirectUris = { "http://localhost:5003/index.html" },
    AllowedCorsOrigins =     { "http://localhost:5003" },

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        "api1"
    }
}

Allowing Ajax calls to the Web API with CORS

One last bit of configuration that is necessary is to configure CORS in the web API project. This will allow Ajax calls to be made from http://localhost:5003 to http://localhost:5001.

Configure CORS

Add the CORS services to the dependency injection system in ConfigureServices in Startup.cs:

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvcCore()
        .AddAuthorization()
        .AddJsonFormatters();

    services.AddAuthentication("Bearer")
        .AddIdentityServerAuthentication(options =>
        {
            options.Authority = "http://localhost:5000";
            options.RequireHttpsMetadata = false;

            options.ApiName = "api1";
        });

    services.AddCors(options =>
    {
        // this defines a CORS policy called "default"
        options.AddPolicy("default", policy =>
        {
            policy.WithOrigins("http://localhost:5003")
                .AllowAnyHeader()
                .AllowAnyMethod();
        });
    });
}

Add the CORS middleware to the pipeline in Configure:

public void Configure(IApplicationBuilder app)
{
    app.UseCors("default");

    app.UseAuthentication();

    app.UseMvc();
}

Run the JavaScript application

Now you should be able to run the JavaScript client application:

_images/6_not_logged_in.png

Click the “Login” button to sign the user in. Once the user is returned back to the JavaScript application, you should see their profile information:

_images/6_logged_in.png

And click the “API” button to invoke the web API:

_images/6_api_results.png

And finally click “Logout” to sign the user out.

_images/6_signed_out.png

You now have the start of a JavaScript client application that uses IdentityServer for sign-in, sign-out, and authenticating calls to web APIs.

Using EntityFramework Core for configuration and operational data

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

IdentityServer is designed for extensibility, and one of the extensibility points is the storage mechanism used for data that IdentityServer needs. This quickstart shows how to configure IdentityServer to use EntityFramework Core (EF) as the storage mechanism for this data (rather than using the in-memory implementations we had been using up until now).

Note

In addition to manually configuring EF support, there is also an IdentityServer template to create a new project with EF support. Use dotnet new is4ef to create it. See here for more information.

IdentityServer4.EntityFramework

There are two types of data that we are moving to the database:

  • Configuration Data
  • Operational Data

The configuration data is the configuration information about resources and clients. The operational data is information that IdentityServer produces as it’s being used such as tokens, codes, and consents. These stores are modeled with interfaces, and we provide an EF implementation of these interfaces in the IdentityServer4.EntityFramework.Storage Nuget package.

The extension methods to register our EF implementation are contained in the IdentityServer4.EntityFramework Nuget package (which references IdentityServer4.EntityFramework.Storage). Add a reference to the IdentityServer4.EntityFramework Nuget package from you IdentityServer project now:

cd quickstart/src/IdentityServer
dotnet add package IdentityServer4.EntityFramework

Using SqlServer

Given EF’s flexibility, you can then use any EF-supported database. For this quickstart we will use the LocalDb version of SQLServer that comes with Visual Studio.

Database Schema Changes and Using EF Migrations

The IdentityServer4.EntityFramework.Storage package contains entity classes that map from IdentityServer’s models. As IdentityServer’s models change, so will the entity classes in IdentityServer4.EntityFramework.Storage. As you use IdentityServer4.EntityFramework.Storage and upgrade over time, you are responsible for your own database schema and changes necessary to that schema as the entity classes change. One approach for managing those changes is to use EF migrations, and this quickstart will show how that can be done. If migrations are not your preference, then you can manage the schema changes in any way you see fit.

Note

The latest SQL scripts for SqlServer are maintained for the entities in IdentityServer4.EntityFramework.Storage. They are located here.

Configuring the stores

The next step is to replace the current calls to AddInMemoryClients, AddInMemoryIdentityResources, and AddInMemoryApiResources in the ConfigureServices method in Startup.cs. We will replace them with this code:

const string connectionString = @"Data Source=(LocalDb)\MSSQLLocalDB;database=IdentityServer4.Quickstart.EntityFramework-2.0.0;trusted_connection=yes;";
var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;

// configure identity server with in-memory stores, keys, clients and scopes
services.AddIdentityServer()
    .AddTestUsers(Config.GetUsers())
    // this adds the config data from DB (clients, resources)
    .AddConfigurationStore(options =>
    {
        options.ConfigureDbContext = b =>
            b.UseSqlServer(connectionString,
                sql => sql.MigrationsAssembly(migrationsAssembly));
    })
    // this adds the operational data from DB (codes, tokens, consents)
    .AddOperationalStore(options =>
    {
        options.ConfigureDbContext = b =>
            b.UseSqlServer(connectionString,
                sql => sql.MigrationsAssembly(migrationsAssembly));

        // this enables automatic token cleanup. this is optional.
        options.EnableTokenCleanup = true;
    });

You might need these namespaces added to the file:

using Microsoft.EntityFrameworkCore;
using System.Reflection;

The above code is hard-coding a connection string, which you should feel free to change if you wish.

AddConfigurationStore and AddOperationalStore register the EF-backed store implementations.

Inside the calls to add the stores, the assignments to the ConfigureDbContext property registers delegates to configure the database provider on the DbContextOptionsBuilder. In this case we call UseSqlServer to register SQLServer. As you can also tell, this is where the connection string is used.

Finally, given that EF migrations will be used (as least for this quickstart) the call to MigrationsAssembly is used to inform EF the host project that will contain the migrations code (which is necessary since it is a different than the assembly that contains the DbContext classes).

We’ll add the migrations next.

Adding migrations

To create the migrations, open a command prompt in the IdentityServer project directory. In the command prompt run these two commands:

dotnet ef migrations add InitialIdentityServerPersistedGrantDbMigration -c PersistedGrantDbContext -o Data/Migrations/IdentityServer/PersistedGrantDb
dotnet ef migrations add InitialIdentityServerConfigurationDbMigration -c ConfigurationDbContext -o Data/Migrations/IdentityServer/ConfigurationDb

You should now see a ~/Data/Migrations/IdentityServer folder in the project. This contains the code for the newly created migrations.

Initialize the database

Now that we have the migrations, we can write code to create the database from the migrations. We will also seed the database with the in-memory configuration data that we defined in the previous quickstarts.

Note

The approach used in this quickstart is used to simply make it easy to get IdentityServer up and running. You should devise your own database creation and maintenance strategy that is appropriate for your architecture.

In Startup.cs add this method to help initialize the database:

private void InitializeDatabase(IApplicationBuilder app)
{
    using (var serviceScope = app.ApplicationServices.GetService<IServiceScopeFactory>().CreateScope())
    {
        serviceScope.ServiceProvider.GetRequiredService<PersistedGrantDbContext>().Database.Migrate();

        var context = serviceScope.ServiceProvider.GetRequiredService<ConfigurationDbContext>();
        context.Database.Migrate();
        if (!context.Clients.Any())
        {
            foreach (var client in Config.GetClients())
            {
                context.Clients.Add(client.ToEntity());
            }
            context.SaveChanges();
        }

        if (!context.IdentityResources.Any())
        {
            foreach (var resource in Config.GetIdentityResources())
            {
                context.IdentityResources.Add(resource.ToEntity());
            }
            context.SaveChanges();
        }

        if (!context.ApiResources.Any())
        {
            foreach (var resource in Config.GetApis())
            {
                context.ApiResources.Add(resource.ToEntity());
            }
            context.SaveChanges();
        }
    }
}

The above code might require these namespaces to be added to your file:

using System.Linq;
using IdentityServer4.EntityFramework.DbContexts;
using IdentityServer4.EntityFramework.Mappers;

And then we can invoke this from the Configure method:

public void Configure(IApplicationBuilder app)
{
    // this will do the initial DB population
    InitializeDatabase(app);

    // the rest of the code that was already here
    // ...
}

Now if you run the IdentityServer project, the database should be created and seeded with the quickstart configuration data. You should be able to use SQL Server Management Studio or Visual Studio to connect and inspect the data.

_images/7_database.png

Note

The above InitializeDatabase helper API is convenient to seed the database, but this approach is not ideal to leave in to execute each time the applicaion runs. Once your database is populated, consider removing the call to the API.

Run the client applications

You should now be able to run any of the existing client applications and sign-in, get tokens, and call the API – all based upon the database configuration.

Note

The code as it stands in this section still relies upon Config.cs and its fictitious users Alice and Bob. If your user list is short and static, an adjusted version of Config.cs may suffice, however you may wish to manage a larger and more fluid user list dynamically within a database. ASP.NET Identity is one option to consider, and a sample implementation of this solution is listed among the quickstarts in the next section.

Using ASP.NET Core Identity

Note

For any pre-requisites (like e.g. templates) have a look at the overview first.

IdentityServer is designed for flexibility and part of that is allowing you to use any database you want for your users and their data (including passwords). If you are starting with a new user database, then ASP.NET Identity is one option you could choose. This quickstart shows how to use ASP.NET Identity with IdentityServer.

The approach this quickstart takes to using ASP.NET Identity is to create a new project for the IdentityServer host. This new project will replace the prior IdentityServer project we built up in the previous quickstarts. The reason for this new project is due to the differences in UI assets when using ASP.NET Identity (mainly around the differences in login and logout). All the other projects in this solution (for the clients and the API) will remain the same.

Note

This quickstart assumes you are familiar with how ASP.NET Identity works. If you are not, it is recommended that you first learn about it.

New Project for ASP.NET Identity

The first step is to add a new project for ASP.NET Identity to your solution. We provide a template that contains the minimal UI assets needed to ASP.NET Identity with IdentityServer. You will eventually delete the old project for IdentityServer, but there are some items that you will need to migrate over.

Start by creating a new IdentityServer project that will use ASP.NET Identity:

cd quickstart/src
dotnet new is4aspid -n IdentityServerAspNetIdentity

When prompted to “seed” the user database, choose “Y” for “yes”. This populates the user database with our “alice” and “bob” users. Their passwords are “Pass123$”.

Note

The template uses Sqlite as the database for the users, and EF migrations are pre-created in the template. If you wish to use a different database provider, you will need to change the provider used in the code and re-create the EF migrations.

Inspect the new project

Open the new project in the editor of your choice, and inspect the generated code. Be sure to look at:

IdentityServerAspNetIdentity.csproj

Notice the reference to IdentityServer4.AspNetIdentity. This NuGet package contains the ASP.NET Identity integration components for IdentityServer.

Startup.cs

In ConfigureServices notice the necessary AddDbContext<ApplicationDbContext> and AddIdentity<ApplicationUser, IdentityRole> calls are done to configure ASP.NET Identity.

Also notice that much of the same IdentityServer configuration you did in the previous quickstarts is already done. The template uses the in-memory style for clients and resources, and those are sourced from Config.cs.

Finally, notice the addition of the new call to AddAspNetIdentity<ApplicationUser>. AddAspNetIdentity adds the integration layer to allow IdentityServer to access the user data for the ASP.NET Identity user database. This is needed when IdentityServer must add claims for the users into tokens.

Note that AddIdentity<ApplicationUser, IdentityRole> must be invoked before AddIdentityServer.

Config.cs

Config.cs contains the hard-coded in-memory clients and resource definitions. To keep the same clients and API working as the prior quickstarts, we need to copy over the configuration data from the old IdentityServer project into this one. Do that now, and afterwards Config.cs should look like this:

public static class Config
{
    public static IEnumerable<IdentityResource> GetIdentityResources()
    {
        return new List<IdentityResource>
        {
            new IdentityResources.OpenId(),
            new IdentityResources.Profile(),
        };
    }

    public static IEnumerable<ApiResource> GetApis()
    {
        return new List<ApiResource>
        {
            new ApiResource("api1", "My API")
        };
    }

    public static IEnumerable<Client> GetClients()
    {
        return new List<Client>
        {
            new Client
            {
                ClientId = "client",

                // no interactive user, use the clientid/secret for authentication
                AllowedGrantTypes = GrantTypes.ClientCredentials,

                // secret for authentication
                ClientSecrets =
                {
                    new Secret("secret".Sha256())
                },

                // scopes that client has access to
                AllowedScopes = { "api1" }
            },
            // resource owner password grant client
            new Client
            {
                ClientId = "ro.client",
                AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,

                ClientSecrets =
                {
                    new Secret("secret".Sha256())
                },
                AllowedScopes = { "api1" }
            },
            // OpenID Connect hybrid flow client (MVC)
            new Client
            {
                ClientId = "mvc",
                ClientName = "MVC Client",
                AllowedGrantTypes = GrantTypes.Hybrid,

                ClientSecrets =
                {
                    new Secret("secret".Sha256())
                },

                RedirectUris           = { "http://localhost:5002/signin-oidc" },
                PostLogoutRedirectUris = { "http://localhost:5002/signout-callback-oidc" },

                AllowedScopes =
                {
                    IdentityServerConstants.StandardScopes.OpenId,
                    IdentityServerConstants.StandardScopes.Profile,
                    "api1"
                },

                AllowOfflineAccess = true
            },
            // JavaScript Client
            new Client
            {
                ClientId = "js",
                ClientName = "JavaScript Client",
                AllowedGrantTypes = GrantTypes.Code,
                RequirePkce = true,
                RequireClientSecret = false,

                RedirectUris =           { "http://localhost:5003/callback.html" },
                PostLogoutRedirectUris = { "http://localhost:5003/index.html" },
                AllowedCorsOrigins =     { "http://localhost:5003" },

                AllowedScopes =
                {
                    IdentityServerConstants.StandardScopes.OpenId,
                    IdentityServerConstants.StandardScopes.Profile,
                    "api1"
                }
            }
        };
    }
}

At this point, you no longer need the old IdentityServer project.

Program.cs and SeedData.cs

Program.cs’s Main is a little different than most ASP.NET Core projects. Notice how this looks for a command line argument called /seed which is used as a flag to seed the users in the ASP.NET Identity database.

Look at the SeedData class’ code to see how the database is created and the first users are created.

AccountController

The last code to inspect in this template is the AccountController. This contains a slightly different login and logout code than the prior quickstart and templates. Notice the use of the SignInManager<ApplicationUser> and UserManager<ApplicationUser> from ASP.NET Identity to validate credentials and manage the authentication session.

Much of the rest of the code is the same from the prior quickstarts and templates.

Logging in with the MVC client

At this point, you should be albe to run all of the existing clients and samples. One exception is the ResourceOwnerClient – the password will need to be updated to Pass123$ from password.

Launch the MVC client application, and you should be able to click the “Secure” link to get logged in.

_images/8_mvc_client.png

You should be redirected to the ASP.NET Identity login page. Login with your newly created user:

_images/8_login.png

After login you see the normal consent page. After consent you will be redirected back to the MVC client application where your user’s claims should be listed.

_images/8_claims.png

You should also be able to click “Call API using application identity” to invoke the API on behalf of the user:

_images/8_api_claims.png

And now you’re using users from ASP.NET Identity in IdentityServer.

What’s Missing?

Much of the rest of the code in this template is similar to the other quickstart and templates we provide. The one thing you will notice that is missing from this template is UI code for user registration, password reset, and the other things you might expect from the Visual Studio ASP.NET Identity template.

Given the variety of requirements and different approaches to using ASP.NET Identity, our template deliberately does not provide those features. You are expected to know how ASP.NET Identity works sufficiently well to add those features to your project. Alternatively, you can create a new project based on the Visual Studio ASP.NET Identity template and add the IdentityServer features you have learned about in these quickstarts to that project.

Community quickstarts & samples

These samples are not maintained by the IdentityServer organization. The IdentityServer organization happily links to community samples, but can’t make any guarantees about the samples. Please contact the authors directly.

IdentityServer4 EF and ASP.NET Identity

This sample combines the EF and ASP.NET Identity quickstarts.

Co-hosting IdentityServer4 and a Web API

This sample shows how to host an API in the same host as the IdentityServer that is protecting the API.

https://github.com/brockallen/IdentityServerAndApi

IdentityServer4 samples for MongoDB

  • IdentityServer4-mongo: Similar to Quickstart EntityFramework configuration but using MongoDB for the configuration data.
  • IdentityServer4-mongo-AspIdentity: More elaborated sample based on uses ASP.NET Identity for identity management that uses using MongoDB for the configuration data

https://github.com/souzartn/IdentityServer4.Samples.Mongo

Exchanging external tokens from Facebook, Google and Twitter

  • Shows how to exchange an external authentication token to an identity server acesss token using an extension grant

https://github.com/waqaskhan540/IdentityServerExternalAuth

ASP.NET Core MVC RazorPages template for IdentityServer4 Quickstart UI

Razor Pages based QuickStart sample by Martin Fletcher.

.NET Core and ASP.NET Core “Platform” scenario

  • Shows an interaction of trusted “internal” applications and “external” applications with .NET Core 2.0 and ASP.NET Core 2.0 applications

https://github.com/BenjaminAbt/Samples.AspNetCore-IdentityServer4

Securing a Node API with tokens from IdentityServer4 using JWKS

  • Shows how to secure a Node (Express) API using the JWKS endpoint and RS256 algorithm from IdentityServer4.
  • Provides an alternative to the NodeJsApi sample from IdentityServer samples using higher quality - production ready modules.

https://github.com/lyphtec/idsvr4-node-jwks

Startup

IdentityServer is a combination of middleware and services. All configuration is done in your startup class.

Configuring services

You add the IdentityServer services to the DI system by calling:

public void ConfigureServices(IServiceCollection services)
{
    var builder = services.AddIdentityServer();
}

Optionally you can pass in options into this call. See here for details on options.

This will return you a builder object that in turn has a number of convenience methods to wire up additional services.

Key material

  • AddSigningCredential
    Adds a signing key service that provides the specified key material to the various token creation/validation services. You can pass in either an X509Certificate2, a SigningCredential or a reference to a certificate from the certificate store.
  • AddDeveloperSigningCredential
    Creates temporary key material at startup time. This is for dev only scenarios when you don’t have a certificate to use. The generated key will be persisted to the file system so it stays stable between server restarts (can be disabled by passing false). This addresses issues when the client/api metadata caches get out of sync during development.
  • AddValidationKey
    Adds a key for validating tokens. They will be used by the internal token validator and will show up in the discovery document. You can pass in either an X509Certificate2, a SigningCredential or a reference to a certificate from the certificate store. This is useful for key roll-over scenarios.

In-Memory configuration stores

The various “in-memory” configuration APIs allow for configuring IdentityServer from an in-memory list of configuration objects. These “in-memory” collections can be hard-coded in the hosting application, or could be loaded dynamically from a configuration file or a database. By design, though, these collections are only created when the hosting application is starting up.

Use of these configuration APIs are designed for use when prototyping, developing, and/or testing where it is not necessary to dynamically consult database at runtime for the configuration data. This style of configuration might also be appropriate for production scenarios if the configuration rarely changes, or it is not inconvenient to require restarting the application if the value must be changed.

  • AddInMemoryClients
    Registers IClientStore and ICorsPolicyService implementations based on the in-memory collection of Client configuration objects.
  • AddInMemoryIdentityResources
    Registers IResourceStore implementation based on the in-memory collection of IdentityResource configuration objects.
  • AddInMemoryApiResources
    Registers IResourceStore implementation based on the in-memory collection of ApiResource configuration objects.

Test stores

The TestUser class models a user, their credentials, and claims in IdentityServer. Use of TestUser is similar to the use of the “in-memory” stores in that it is intended for when prototyping, developing, and/or testing. The use of TestUser is not recommended in production.

  • AddTestUsers
    Registers TestUserStore based on a collection of TestUser objects. TestUserStore is used by the default quickstart UI. Also registers implementations of IProfileService and IResourceOwnerPasswordValidator.

Additional services

  • AddExtensionGrantValidator
    Adds IExtensionGrantValidator implementation for use with extension grants.
  • AddSecretParser
    Adds ISecretParser implementation for parsing client or API resource credentials.
  • AddSecretValidator
    Adds ISecretValidator implementation for validating client or API resource credentials against a credential store.
  • AddResourceOwnerValidator
    Adds IResourceOwnerPasswordValidator implementation for validating user credentials for the resource owner password credentials grant type.
  • AddProfileService
    Adds IProfileService implementation for connecting to your custom user profile store. The DefaultProfileService class provides the default implementation which relies upon the authentication cookie as the only source of claims for issuing in tokens.
  • AddAuthorizeInteractionResponseGenerator
    Adds IAuthorizeInteractionResponseGenerator implementation to customize logic at authorization endpoint for when a user must be shown a UI for error, login, consent, or any other custom page. The AuthorizeInteractionResponseGenerator class provides a default implementation, so consider deriving from this existing class if you need to augment the existing behavior.
  • AddCustomAuthorizeRequestValidator
    Adds ICustomAuthorizeRequestValidator implementation to customize request parameter validation at the authorization endpoint.
  • AddCustomTokenRequestValidator
    Adds ICustomTokenRequestValidator implementation to customize request parameter validation at the token endpoint.
  • AddRedirectUriValidator
    Adds IRedirectUriValidator implementation to customize redirect URI validation.
  • AddAppAuthRedirectUriValidator
    Adds a an “AppAuth” (OAuth 2.0 for Native Apps) compliant redirect URI validator (does strict validation but also allows http://127.0.0.1 with random port).
  • AddJwtBearerClientAuthentication
    Adds support for client authentication using JWT bearer assertions.
  • AddMutualTlsSecretValidators
    Adds the X509 secret validators for mutual TLS.

Caching

Client and resource configuration data is used frequently by IdentityServer. If this data is being loaded from a database or other external store, then it might be expensive to frequently re-load the same data.

  • AddInMemoryCaching
    To use any of the caches described below, an implementation of ICache<T> must be registered in DI. This API registers a default in-memory implementation of ICache<T> that’s based on ASP.NET Core’s MemoryCache.
  • AddClientStoreCache
    Registers a IClientStore decorator implementation which will maintain an in-memory cache of Client configuration objects. The cache duration is configurable on the Caching configuration options on the IdentityServerOptions.
  • AddResourceStoreCache
    Registers a IResourceStore decorator implementation which will maintain an in-memory cache of IdentityResource and ApiResource configuration objects. The cache duration is configurable on the Caching configuration options on the IdentityServerOptions.
  • AddCorsPolicyCache
    Registers a ICorsPolicyService decorator implementation which will maintain an in-memory cache of the results of the CORS policy service evaluation. The cache duration is configurable on the Caching configuration options on the IdentityServerOptions.

Further customization of the cache is possible:

The default caching relies upon the ICache<T> implementation. If you wish to customize the caching behavior for the specific configuration objects, you can replace this implementation in the dependency injection system.

The default implementation of the ICache<T> itself relies upon the IMemoryCache interface (and MemoryCache implementation) provided by .NET. If you wish to customize the in-memory caching behavior, you can replace the IMemoryCache implementation in the dependency injection system.

Configuring the pipeline

You need to add IdentityServer to the pipeline by calling:

public void Configure(IApplicationBuilder app)
{
    app.UseIdentityServer();
}

Note

UseIdentityServer includes a call to UseAuthentication, so it’s not necessary to have both.

There is no additional configuration for the middleware.

Be aware that order matters in the pipeline. For example, you will want to add IdentitySever before the UI framework that implements the login screen.

Defining Resources

The first thing you will typically define in your system are the resources that you want to protect. That could be identity information of your users, like profile data or email addresses, or access to APIs.

Note

You can define resources using a C# object model - or load them from a data store. An implementation of IResourceStore deals with these low-level details. For this document we are using the in-memory implementation.

Defining identity resources

Identity resources are data like user ID, name, or email address of a user. An identity resource has a unique name, and you can assign arbitrary claim types to it. These claims will then be included in the identity token for the user. The client will use the scope parameter to request access to an identity resource.

The OpenID Connect specification specifies a couple of standard identity resources. The minimum requirement is, that you provide support for emitting a unique ID for your users - also called the subject id. This is done by exposing the standard identity resource called openid:

public static IEnumerable<IdentityResource> GetIdentityResources()
{
    return new List<IdentityResource>
    {
        new IdentityResources.OpenId()
    };
}

The IdentityResources class supports all scopes defined in the specification (openid, email, profile, telephone, and address). If you want to support them all, you can add them to your list of supported identity resources:

public static IEnumerable<IdentityResource> GetIdentityResources()
{
    return new List<IdentityResource>
    {
        new IdentityResources.OpenId(),
        new IdentityResources.Email(),
        new IdentityResources.Profile(),
        new IdentityResources.Phone(),
        new IdentityResources.Address()
    };
}

Defining custom identity resources

You can also define custom identity resources. Create a new IdentityResource class, give it a name and optionally a display name and description and define which user claims should be included in the identity token when this resource gets requested:

public static IEnumerable<IdentityResource> GetIdentityResources()
{
    var customProfile = new IdentityResource(
        name: "custom.profile",
        displayName: "Custom profile",
        claimTypes: new[] { "name", "email", "status" });

    return new List<IdentityResource>
    {
        new IdentityResources.OpenId(),
        new IdentityResources.Profile(),
        customProfile
    };
}

See the reference section for more information on identity resource settings.

Defining API resources

To allow clients to request access tokens for APIs, you need to define API resources, e.g.:

To get access tokens for APIs, you also need to register them as a scope. This time the scope type is of type Resource:

public static IEnumerable<ApiResource> GetApis()
{
    return new[]
    {
        // simple API with a single scope (in this case the scope name is the same as the api name)
        new ApiResource("api1", "Some API 1"),

        // expanded version if more control is needed
        new ApiResource
        {
            Name = "api2",

            // secret for using introspection endpoint
            ApiSecrets =
            {
                new Secret("secret".Sha256())
            },

            // include the following using claims in access token (in addition to subject id)
            UserClaims = { JwtClaimTypes.Name, JwtClaimTypes.Email },

            // this API defines two scopes
            Scopes =
            {
                new Scope()
                {
                    Name = "api2.full_access",
                    DisplayName = "Full access to API 2",
                },
                new Scope
                {
                    Name = "api2.read_only",
                    DisplayName = "Read only access to API 2"
                }
            }
        }
    };
}

See the reference section for more information on API resource settings.

Note

The user claims defined by resources are loaded by the IProfileService extensibility point.

Defining Clients

Clients represent applications that can request tokens from your identityserver.

The details vary, but you typically define the following common settings for a client:

  • a unique client ID
  • a secret if needed
  • the allowed interactions with the token service (called a grant type)
  • a network location where identity and/or access token gets sent to (called a redirect URI)
  • a list of scopes (aka resources) the client is allowed to access

Note

At runtime, clients are retrieved via an implementation of the IClientStore. This allows loading them from arbitrary data sources like config files or databases. For this document we will use the in-memory version of the client store. You can wire up the in-memory store in ConfigureServices via the AddInMemoryClients extensions method.

Defining a client for server to server communication

In this scenario no interactive user is present - a service (aka client) wants to communicate with an API (aka scope):

public class Clients
{
    public static IEnumerable<Client> Get()
    {
        return new List<Client>
        {
            new Client
            {
                ClientId = "service.client",
                ClientSecrets = { new Secret("secret".Sha256()) },

                AllowedGrantTypes = GrantTypes.ClientCredentials,
                AllowedScopes = { "api1", "api2.read_only" }
            }
        };
    }
}

Defining browser-based JavaScript client (e.g. SPA) for user authentication and delegated access and API

This client uses the so called implicit flow to request an identity and access token from JavaScript:

var jsClient = new Client
{
    ClientId = "js",
    ClientName = "JavaScript Client",
    ClientUri = "http://identityserver.io",

    AllowedGrantTypes = GrantTypes.Implicit,
    AllowAccessTokensViaBrowser = true,

    RedirectUris =           { "http://localhost:7017/index.html" },
    PostLogoutRedirectUris = { "http://localhost:7017/index.html" },
    AllowedCorsOrigins =     { "http://localhost:7017" },

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        IdentityServerConstants.StandardScopes.Email,

        "api1", "api2.read_only"
    }
};

Defining a server-side web application (e.g. MVC) for use authentication and delegated API access

Interactive server side (or native desktop/mobile) applications use the hybrid flow. This flow gives you the best security because the access tokens are transmitted via back-channel calls only (and gives you access to refresh tokens):

var mvcClient = new Client
{
    ClientId = "mvc",
    ClientName = "MVC Client",
    ClientUri = "http://identityserver.io",

    AllowedGrantTypes = GrantTypes.Hybrid,
    AllowOfflineAccess = true,
    ClientSecrets = { new Secret("secret".Sha256()) },

    RedirectUris =           { "http://localhost:21402/signin-oidc" },
    PostLogoutRedirectUris = { "http://localhost:21402/" },
    FrontChannelLogoutUri =  "http://localhost:21402/signout-oidc",

    AllowedScopes =
    {
        IdentityServerConstants.StandardScopes.OpenId,
        IdentityServerConstants.StandardScopes.Profile,
        IdentityServerConstants.StandardScopes.Email,

        "api1", "api2.read_only"
    },
};

Defining clients in appsettings.json

The AddInMemoryClients extensions method also supports adding clients from the ASP.NET Core configuration file. This allows you to define static clients directly from the appsettings.json file:

"IdentityServer": {
  "IssuerUri": "urn:sso.company.com",
  "Clients": [
    {
      "Enabled": true,
      "ClientId": "local-dev",
      "ClientName": "Local Development",
      "ClientSecrets": [ { "Value": "<Insert Sha256 hash of the secret encoded as Base64 string>" } ],
      "AllowedGrantTypes": [ "implicit" ],
      "AllowedScopes": [ "openid", "profile" ],
      "RedirectUris": [ "https://localhost:5001/signin-oidc" ],
      "RequireConsent": false
    }
  ]
}

Then pass the configuration section to the AddInMemoryClients method:

AddInMemoryClients(configuration.GetSection("IdentityServer:Clients"))

Sign-in

In order for IdentityServer to issue tokens on behalf of a user, that user must sign-in to IdentityServer.

Login User Interface and Identity Management System

IdentityServer does not provide any user-interface or user database for user authentication. These are things you are expected to provide or develop yourself.

If you need a starting point for a basic UI (login, logout, consent and manage grants), you can use our quickstart UI.

The quickstart UI authenticates users against an in-memory database. You would replace those bits with access to your real user store. We have samples that use ASP.NET Identity.

Login Workflow

When IdentityServer receives a request at the authorization endpoint and the user is not authenticated, the user will be redirected to the configured login page. You must inform IdentityServer of the path to your login page via the UserInteraction settings on the options (the default is /account/login). A returnUrl parameter will be passed informing your login page where the user should be redirected once login is complete.

_images/signin_flow.png

Note

Beware open-redirect attacks via the returnUrl parameter. You should validate that the returnUrl refers to well-known location. See the interaction service for APIs to validate the returnUrl parameter.

Login Context

On your login page you might require information about the context of the request in order to customize the login experience (such as client, prompt parameter, IdP hint, or something else). This is made available via the GetAuthorizationContextAsync API on the interaction service.

Sign-in with External Identity Providers

ASP.NET Core has a flexible way to deal with external authentication. This involves a couple of steps.

Note

If you are using ASP.NET Identity, many of the underlying technical details are hidden from you. It is recommended that you also read the Microsoft docs and do the ASP.NET Identity quickstart.

Adding authentication handlers for external providers

The protocol implementation that is needed to talk to an external provider is encapsulated in an authentication handler. Some providers use proprietary protocols (e.g. social providers like Facebook) and some use standard protocols, e.g. OpenID Connect, WS-Federation or SAML2p.

See this quickstart for step-by-step instructions for adding external authentication and configuring it.

The role of cookies

One option on an external authentication handlers is called SignInScheme, e.g.:

services.AddAuthentication()
    .AddGoogle("Google", options =>
    {
        options.SignInScheme = "scheme of cookie handler to use";

        options.ClientId = "...";
        options.ClientSecret = "...";
    })

The signin scheme specifies the name of the cookie handler that will temporarily store the outcome of the external authentication, e.g. the claims that got sent by the external provider. This is necessary, since there are typically a couple of redirects involved until you are done with the external authentication process.

Given that this is such a common practise, IdentityServer registers a cookie handler specifically for this external provider workflow. The scheme is represented via the IdentityServerConstants.ExternalCookieAuthenticationScheme constant. If you were to use our external cookie handler, then for the SignInScheme above you’d assign the value to be the IdentityServerConstants.ExternalCookieAuthenticationScheme constant:

services.AddAuthentication()
    .AddGoogle("Google", options =>
    {
        options.SignInScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme;

        options.ClientId = "...";
        options.ClientSecret = "...";
    })

You can also register your own custom cookie handler instead, like this:

services.AddAuthentication()
    .AddCookie("YourCustomScheme")
    .AddGoogle("Google", options =>
    {
        options.SignInScheme = "YourCustomScheme";

        options.ClientId = "...";
        options.ClientSecret = "...";
    })

Note

For specialized scenarios, you can also short-circuit the external cookie mechanism and forward the external user directly to the main cookie handler. This typically involves handling events on the external handler to make sure you do the correct claims transformation from the external identity source.

Triggering the authentication handler

You invoke an external authentication handler via the ChallengeAsync extension method on the HttpContext (or using the MVC ChallengeResult).

You typically want to pass in some options to the challenge operation, e.g. the path to your callback page and the name of the provider for bookkeeping, e.g.:

var callbackUrl = Url.Action("ExternalLoginCallback");

var props = new AuthenticationProperties
{
    RedirectUri = callbackUrl,
    Items =
    {
        { "scheme", provider },
        { "returnUrl", returnUrl }
    }
};

return Challenge(provider, props);

Handling the callback and signing in the user

On the callback page your typical tasks are:

  • inspect the identity returned by the external provider.
  • make a decision how you want to deal with that user. This might be different based on the fact if this is a new user or a returning user.
  • new users might need additional steps and UI before they are allowed in.
  • probably create a new internal user account that is linked to the external provider.
  • store the external claims that you want to keep.
  • delete the temporary cookie
  • sign-in the user

Inspecting the external identity:

// read external identity from the temporary cookie
var result = await HttpContext.AuthenticateAsync(IdentityServerConstants.ExternalCookieAuthenticationScheme);
if (result?.Succeeded != true)
{
    throw new Exception("External authentication error");
}

// retrieve claims of the external user
var externalUser = result.Principal;
if (externalUser == null)
{
    throw new Exception("External authentication error");
}

// retrieve claims of the external user
var claims = externalUser.Claims.ToList();

// try to determine the unique id of the external user - the most common claim type for that are the sub claim and the NameIdentifier
// depending on the external provider, some other claim type might be used
var userIdClaim = claims.FirstOrDefault(x => x.Type == JwtClaimTypes.Subject);
if (userIdClaim == null)
{
    userIdClaim = claims.FirstOrDefault(x => x.Type == ClaimTypes.NameIdentifier);
}
if (userIdClaim == null)
{
    throw new Exception("Unknown userid");
}

var externalUserId = userIdClaim.Value;
var externalProvider = userIdClaim.Issuer;

// use externalProvider and externalUserId to find your user, or provision a new user

Clean-up and sign-in:

// issue authentication cookie for user
await HttpContext.SignInAsync(user.SubjectId, user.Username, provider, props, additionalClaims.ToArray());

// delete temporary cookie used during external authentication
await HttpContext.SignOutAsync(IdentityServerConstants.ExternalCookieAuthenticationScheme);

// validate return URL and redirect back to authorization endpoint or a local page
if (_interaction.IsValidReturnUrl(returnUrl) || Url.IsLocalUrl(returnUrl))
{
    return Redirect(returnUrl);
}

return Redirect("~/");

State, URL length, and ISecureDataFormat

When redirecting to an external provider for sign-in, frequently state from the client application must be round-tripped. This means that state is captured prior to leaving the client and preserved until the user has returned to the client application. Many protocols, including OpenID Connect, allow passing some sort of state as a parameter as part of the request, and the identity provider will return that state on the response. The OpenID Connect authentication handler provided by ASP.NET Core utilizes this feature of the protocol, and that is how it implements the returnUrl feature mentioned above.

The problem with storing state in a request parameter is that the request URL can get too large (over the common limit of 2000 characters). The OpenID Connect authentication handler does provide an extensibility point to store the state in your server, rather than in the request URL. You can implement this yourself by implementing ISecureDataFormat<AuthenticationProperties> and configuring it on the OpenIdConnectOptions.

Fortunately, IdentityServer provides an implementation of this for you, backed by the IDistributedCache implementation registered in the DI container (e.g. the standard MemoryDistributedCache). To use the IdentityServer provided secure data format implementation, simply call the AddOidcStateDataFormatterCache extension method on the IServiceCollection when configuring DI. If no parameters are passed, then all OpenID Connect handlers configured will use the IdentityServer provided secure data format implementation:

public void ConfigureServices(IServiceCollection services)
{
    // configures the OpenIdConnect handlers to persist the state parameter into the server-side IDistributedCache.
    services.AddOidcStateDataFormatterCache();

    services.AddAuthentication()
        .AddOpenIdConnect("demoidsrv", "IdentityServer", options =>
        {
            // ...
        })
        .AddOpenIdConnect("aad", "Azure AD", options =>
        {
            // ...
        })
        .AddOpenIdConnect("adfs", "ADFS", options =>
        {
            // ...
        });
}

If only particular schemes are to be configured, then pass those schemes as parameters:

public void ConfigureServices(IServiceCollection services)
{
    // configures the OpenIdConnect handlers to persist the state parameter into the server-side IDistributedCache.
    services.AddOidcStateDataFormatterCache("aad", "demoidsrv");

    services.AddAuthentication()
        .AddOpenIdConnect("demoidsrv", "IdentityServer", options =>
        {
            // ...
        })
        .AddOpenIdConnect("aad", "Azure AD", options =>
        {
            // ...
        })
        .AddOpenIdConnect("adfs", "ADFS", options =>
        {
            // ...
        });
}

Windows Authentication

On supported platforms, you can use IdentityServer to authenticate users using Windows authentication (e.g. against Active Directory). Currently Windows authentication is available when you host IdentityServer using:

  • Kestrel on Windows using IIS and the IIS integration package
  • HTTP.sys server on Windows

In both cases, Windows authentication is triggered by using the ChallengeAsync API on the HttpContext using the scheme "Windows". The account controller in our quickstart UI implements the necessary logic.

Using Kestrel

When using Kestrel, you must run “behind” IIS and use the IIS integration:

var host = new WebHostBuilder()
    .UseKestrel()
    .UseUrls("http://localhost:5000")
    .UseContentRoot(Directory.GetCurrentDirectory())
    .UseIISIntegration()
    .UseStartup<Startup>()
    .Build();

Kestrel is automatically configured when using the WebHost.CreateDefaultBuilder approach for setting up the WebHostBuilder.

Also the virtual directory in IIS (or IIS Express) must have Windows and anonymous authentication enabled.

The IIS integration layer will configure a Windows authentication handler into DI that can be invoked via the authentication service. Typically in IdentityServer it is advisable to disable this automatic behavior. This is done in ConfigureServices:

services.Configure<IISOptions>(iis =>
{
    iis.AuthenticationDisplayName = "Windows";
    iis.AutomaticAuthentication = false;
});

Note

By default, the display name is empty, and the Windows authentication button will not show up in the quickstart UI. You need to set a display name if you rely on automatic discovery of external providers.

Sign-out

Signing out of IdentityServer is as simple as removing the authentication cookie, but for doing a complete federated sign-out, we must consider signing the user out of the client applications (and maybe even up-stream identity providers) as well.

Notifying clients that the user has signed-out

As part of the signout process you will want to ensure client applications are informed that the user has signed out. IdentityServer supports the front-channel specification for server-side clients (e.g. MVC), the back-channel specification for server-side clients (e.g. MVC), and the session management specification for browser-based JavaScript clients (e.g. SPA, React, Angular, etc.).

Front-channel server-side clients

To signout the user from the server-side client applications via the front-channel spec, the “logged out” page in IdentityServer must render an <iframe> to notify the clients that the user has signed out. Clients that wish to be notified must have the FrontChannelLogoutUri configuration value set. IdentityServer tracks which clients the user has signed into, and provides an API called GetLogoutContextAsync on the IIdentityServerInteractionService (details). This API returns a LogoutRequest object with a SignOutIFrameUrl property that your logged out page must render into an <iframe>.

Back-channel server-side clients

To signout the user from the server-side client applications via the back-channel spec, the SignOutIFrameUrl endpoint in IdentityServer will automatically trigger server-to-server invocation passing a signed sign-out request to the client. This means that even if there are no front-channel clients, the “logged out” page in IdentityServer must still render an <iframe> to the SignOutIFrameUrl as described above. Clients that wish to be notified must have the BackChannelLogoutUri configuration value set.

Browser-based JavaScript clients

Given how the session management specification is designed, there is nothing special in IdentityServer that you need to do to notify these clients that the user has signed out. The clients, though, must perform monitoring on the check_session_iframe, and this is implemented by the oidc-client JavaScript library.

Sign-out initiated by a client application

If sign-out was initiated by a client application, then the client first redirected the user to the end session endpoint. Processing at the end session endpoint might require some temporary state to be maintained (e.g. the client’s post logout redirect uri) across the redirect to the logout page. This state might be of use to the logout page, and the identifier for the state is passed via a logoutId parameter to the logout page.

The GetLogoutContextAsync API on the interaction service can be used to load the state. Of interest on the ShowSignoutPrompt is the ShowSignoutPrompt which indicates if the request for sign-out has been authenticated, and therefore it’s safe to not prompt the user for sign-out.

By default this state is managed as a protected data structure passed via the logoutId value. If you wish to use some other persistence between the end session endpoint and the logout page, then you can implement IMessageStore<LogoutMessage> and register the implementation in DI.

Sign-out of External Identity Providers

When a user is signing-out of IdentityServer, and they have used an external identity provider to sign-in then it is likely that they should be redirected to also sign-out of the external provider. Not all external providers support sign-out, as it depends on the protocol and features they support.

To detect that a user must be redirected to an external identity provider for sign-out is typically done by using a idp claim issued into the cookie at IdentityServer. The value set into this claim is the AuthenticationScheme of the corresponding authentication middleware. At sign-out time this claim is consulted to know if an external sign-out is required.

Redirecting the user to an external identity provider is problematic due to the cleanup and state management already required by the normal sign-out workflow. The only way to then complete the normal sign-out and cleanup process at IdentityServer is to then request from the external identity provider that after its logout that the user be redirected back to IdentityServer. Not all external providers support post-logout redirects, as it depends on the protocol and features they support.

The workflow at sign-out is then to revoke IdentityServer’s authentication cookie, and then redirect to the external provider requesting a post-logout redirect. The post-logout redirect should maintain the necessary sign-out state described here (i.e. the logoutId parameter value). To redirect back to IdentityServer after the external provider sign-out, the RedirectUri should be used on the AuthenticationProperties when using ASP.NET Core’s SignOutAsync API, for example:

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Logout(LogoutInputModel model)
{
    // build a model so the logged out page knows what to display
    var vm = await _account.BuildLoggedOutViewModelAsync(model.LogoutId);

    var user = HttpContext.User;
    if (user?.Identity.IsAuthenticated == true)
    {
        // delete local authentication cookie
        await HttpContext.SignOutAsync();

        // raise the logout event
        await _events.RaiseAsync(new UserLogoutSuccessEvent(user.GetSubjectId(), user.GetName()));
    }

    // check if we need to trigger sign-out at an upstream identity provider
    if (vm.TriggerExternalSignout)
    {
        // build a return URL so the upstream provider will redirect back
        // to us after the user has logged out. this allows us to then
        // complete our single sign-out processing.
        string url = Url.Action("Logout", new { logoutId = vm.LogoutId });

        // this triggers a redirect to the external provider for sign-out
        return SignOut(new AuthenticationProperties { RedirectUri = url }, vm.ExternalAuthenticationScheme);
    }

    return View("LoggedOut", vm);
}

Once the user is signed-out of the external provider and then redirected back, the normal sign-out processing at IdentityServer should execute which involves processing the logoutId and doing all necessary cleanup.

Federated Sign-out

Federated sign-out is the situation where a user has used an external identity provider to log into IdentityServer, and then the user logs out of that external identity provider via a workflow unknown to IdentityServer. When the user signs out, it will be useful for IdentityServer to be notified so that it can sign the user out of IdentityServer and all of the applications that use IdentityServer.

Not all external identity providers support federated sign-out, but those that do will provide a mechanism to notify clients that the user has signed out. This notification usually comes in the form of a request in an <iframe> from the external identity provider’s “logged out” page. IdentityServer must then notify all of its clients (as discussed here), also typically in the form of a request in an <iframe> from within the external identity provider’s <iframe>.

What makes federated sign-out a special case (when compared to a normal sign-out) is that the federated sign-out request is not to the normal sign-out endpoint in IdentityServer. In fact, each external IdentityProvider will have a different endpoint into your IdentityServer host. This is due to that fact that each external identity provider might use a different protocol, and each middleware listens on different endpoints.

The net effect of all of these factors is that there is no “logged out” page being rendered as we would on the normal sign-out workflow, which means we are missing the sign-out notifications to IdentityServer’s clients. We must add code for each of these federated sign-out endpoints to render the necessary notifications to achieve federated sign-out.

Fortunately IdentityServer already contains this code. When requests come into IdentityServer and invoke the handlers for external authentication providers, IdentityServer detects if these are federated signout requests and if they are it will automatically render the same <iframe> as described here for signout. In short, federated signout is automatically supported.

Federation Gateway

A common architecture is the so-called federation gateway. In this approach IdentityServer acts as a gateway to one or more external identity providers.

_images/federation_gateway.png

This architecture has the following advantages

  • your applications only need to know about the one token service (the gateway) and are shielded from all the details about connecting to the external provider(s). This also means that you can add or change those external providers without needing to update your applications.
  • you control the gateway (as opposed to some external service provider) - this means you can make any changes to it and can protect your applications from changes those external providers might do to their own services.
  • most external providers only support a fixed set of claims and claim types - having a gateway in the middle allows post-processing the response from the providers to transform/add/amend domain specific identity information.
  • some providers don’t support access tokens (e.g. social providers) - since the gateway knows about your APIs, it can issue access tokens based on the external identities.
  • some providers charge by the number of applications you connect to them. The gateway acts as a single application to the external provider. Internally you can connect as many applications as you want.
  • some providers use proprietary protocols or made proprietary modifications to standard protocols - with a gateway there is only one place you need to deal with that.
  • forcing every authentication (internal or external) through one single place gives you tremendous flexibility with regards to identity mapping, providing a stable identity to all your applications and dealing with new requirements

In other words - owning your federation gateway gives you a lot of control over your identity infrastructure. And since the identity of your users is one of your most important assets, we recommend taking control over the gateway.

Implementation

Our quick start UI utilizes some of the below features. Also check out the external authentication quickstart and the docs about external providers.

  • You can add support for external identity providers by adding authentication handlers to your IdentityServer application.
  • You can programmatically query those external providers by calling IAuthenticationSchemeProvider. This allows to dynamically render your login page based on the registered external providers.
  • Our client configuration model allows restricting the available providers on a per client basis (use the IdentityProviderRestrictions property).
  • You can also use the EnableLocalLogin property on the client to tell your UI whether the username/password input should be rendered.
  • Our quickstart UI funnels all external authentication calls through a single callback (see ExternalLoginCallback on the AccountController class). This allows for a single point for post-processing.

Protecting APIs

IdentityServer issues access tokens in the JWT (JSON Web Token) format by default.

Every relevant platform today has support for validating JWT tokens, a good list of JWT libraries can be found here. Popular libraries are e.g.:

Protecting a ASP.NET Core-based API is only a matter of configuring the JWT bearer authentication handler in DI, and adding the authentication middleware to the pipeline:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();

        services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(options =>
            {
                // base-address of your identityserver
                options.Authority = "https://demo.identityserver.io";

                // name of the API resource
                options.Audience = "api1";
            });
    }

    public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
    {
        app.UseAuthentication();
        app.UseMvc();
    }
}

The IdentityServer authentication handler

Our authentication handler serves the same purpose as the above handler (in fact it uses the Microsoft JWT library internally), but adds a couple of additional features:

  • support for both JWTs and reference tokens
  • extensible caching for reference tokens
  • unified configuration model
  • scope validation

For the simplest case, our handler configuration looks very similar to the above snippet:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();

        services.AddAuthentication(IdentityServerAuthenticationDefaults.AuthenticationScheme)
            .AddIdentityServerAuthentication(options =>
            {
                // base-address of your identityserver
                options.Authority = "https://demo.identityserver.io";

                // name of the API resource
                options.ApiName = "api1";
            });
    }

    public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
    {
        app.UseAuthentication();
        app.UseMvc();
    }
}

You can get the package from nuget or github.

Supporting reference tokens

If the incoming token is not a JWT, our middleware will contact the introspection endpoint found in the discovery document to validate the token. Since the introspection endpoint requires authentication, you need to supply the configured API secret, e.g.:

.AddIdentityServerAuthentication(options =>
{
    // base-address of your identityserver
    options.Authority = "https://demo.identityserver.io";

    // name of the API resource
    options.ApiName = "api1";
    options.ApiSecret = "secret";
})

Typically, you don’t want to do a roundtrip to the introspection endpoint for each incoming request. The middleware has a built-in cache that you can enable like this:

.AddIdentityServerAuthentication(options =>
{
    // base-address of your identityserver
    options.Authority = "https://demo.identityserver.io";

    // name of the API resource
    options.ApiName = "api1";
    options.ApiSecret = "secret";

    options.EnableCaching = true;
    options.CacheDuration = TimeSpan.FromMinutes(10); // that's the default
})

The handler will use whatever IDistributedCache implementation is registered in the DI container (e.g. the standard MemoryDistributedCache).

Validating scopes

The ApiName property checks if the token has a matching audience (or short aud) claim.

In IdentityServer you can also sub-divide APIs into multiple scopes. If you need that granularity you can use the ASP.NET Core authorization policy system to check for scopes.

Creating a global policy:

services
    .AddMvcCore(options =>
    {
        // require scope1 or scope2
        var policy = ScopePolicy.Create("scope1", "scope2");
        options.Filters.Add(new AuthorizeFilter(policy));
    })
    .AddJsonFormatters()
    .AddAuthorization();

Composing a scope policy:

services.AddAuthorization(options =>
{
    options.AddPolicy("myPolicy", builder =>
    {
        // require scope1
        builder.RequireScope("scope1");
        // and require scope2 or scope3
        builder.RequireScope("scope2", "scope3");
    });
});

Deployment

Your identity server is just a standard ASP.NET Core application including the IdentityServer middleware. Read the official Microsoft documentation on publishing and deployment first (and especially the section about load balancers and proxies).

Typical architecture

Typically you will design your IdentityServer deployment for high availability:

_images/deployment.png

IdentityServer itself is stateless and does not require server affinity - but there is data that needs to be shared between the instances.

Configuration data

This typically includes:

  • resources
  • clients
  • startup configuration, e.g. key material, external provider settings etc…

The way you store that data depends on your environment. In situations where configuration data rarely changes we recommend using the in-memory stores and code or configuration files.

In highly dynamic environments (e.g. Saas) we recommend using a database or configuration service to load configuration dynamically.

IdentityServer supports code configuration and configuration files (see here) out of the box. For databases we provide support for Entity Framework Core based databases.

You can also build your own configuration stores by implementing IResourceStore and IClientStore.

Key material

Another important piece of startup configuration is your key material, see here for more details on key material and cryptography.

Operational data

For certain operations, IdentityServer needs a persistence store to keep state, this includes:

  • issuing authorization codes
  • issuing reference and refresh tokens
  • storing consent

You can either use a traditional database for storing operational data, or use a cache with persistence features like Redis. The EF Core implementation mentioned above has also support for operational data.

You can also implement support for your own custom storage mechanism by implementing IPersistedGrantStore - by default IdentityServer injects an in-memory version.

ASP.NET Core data protection

ASP.NET Core itself needs shared key material for protecting sensitive data like cookies, state strings etc. See the official docs here.

You can either re-use one of the above persistence store or use something simple like a shared file if possible.

Logging

IdentityServer uses the standard logging facilities provided by ASP.NET Core. The Microsoft documentation has a good intro and a description of the built-in logging providers.

We are roughly following the Microsoft guidelines for usage of log levels:

  • Trace For information that is valuable only to a developer troubleshooting an issue. These messages may contain sensitive application data like tokens and should not be enabled in a production environment.
  • Debug For following the internal flow and understanding why certain decisions are made. Has short-term usefulness during development and debugging.
  • Information For tracking the general flow of the application. These logs typically have some long-term value.
  • Warning For abnormal or unexpected events in the application flow. These may include errors or other conditions that do not cause the application to stop, but which may need to be investigated.
  • Error For errors and exceptions that cannot be handled. Examples: failed validation of a protocol request.
  • Critical For failures that require immediate attention. Examples: missing store implementation, invalid key material…

Setup for Serilog

We personally like Serilog a lot. Give it a try.

ASP.NET Core 2.0+

For the following configuration you need the Serilog.AspNetCore and Serilog.Sinks.Console packages:

public class Program
{
    public static void Main(string[] args)
    {
        Console.Title = "IdentityServer4";

        Log.Logger = new LoggerConfiguration()
            .MinimumLevel.Debug()
            .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
            .MinimumLevel.Override("System", LogEventLevel.Warning)
            .MinimumLevel.Override("Microsoft.AspNetCore.Authentication", LogEventLevel.Information)
            .Enrich.FromLogContext()
            .WriteTo.Console(outputTemplate: "[{Timestamp:HH:mm:ss} {Level}] {SourceContext}{NewLine}{Message:lj}{NewLine}{Exception}{NewLine}", theme: AnsiConsoleTheme.Literate)
            .CreateLogger();

        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .UseSerilog()
                .Build();
    }
}

.NET Core 1.0, 1.1

For the following configuration you need the Serilog.Extensions.Logging and Serilog.Sinks.Console packages:

public class Program
{
    public static void Main(string[] args)
    {
        Console.Title = "IdentityServer4";

        Log.Logger = new LoggerConfiguration()
            .MinimumLevel.Debug()
            .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
            .MinimumLevel.Override("System", LogEventLevel.Warning)
            .MinimumLevel.Override("Microsoft.AspNetCore.Authentication", LogEventLevel.Information)
            .Enrich.FromLogContext()
            .WriteTo.Console(outputTemplate: "[{Timestamp:HH:mm:ss} {Level}] {SourceContext}{NewLine}{Message:lj}{NewLine}{Exception}{NewLine}", theme: AnsiConsoleTheme.Literate)
            .CreateLogger();

        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .ConfigureLogging(builder =>
                {
                    builder.ClearProviders();
                    builder.AddSerilog();
                })
                .Build();
    }
}

Events

While logging is more low level “printf” style - events represent higher level information about certain operations in IdentityServer. Events are structured data and include event IDs, success/failure information, categories and details. This makes it easy to query and analyze them and extract useful information that can be used for further processing.

Events work great with event stores like ELK, Seq or Splunk.

Emitting events

Events are not turned on by default - but can be globally configured in the ConfigureServices method, e.g.:

services.AddIdentityServer(options =>
{
    options.Events.RaiseSuccessEvents = true;
    options.Events.RaiseFailureEvents = true;
    options.Events.RaiseErrorEvents = true;
});

To emit an event use the IEventService from the DI container and call the RaiseAsync method, e.g.:

public async Task<IActionResult> Login(LoginInputModel model)
{
    if (_users.ValidateCredentials(model.Username, model.Password))
    {
        // issue authentication cookie with subject ID and username
        var user = _users.FindByUsername(model.Username);
        await _events.RaiseAsync(new UserLoginSuccessEvent(user.Username, user.SubjectId, user.Username));
    }
    else
    {
        await _events.RaiseAsync(new UserLoginFailureEvent(model.Username, "invalid credentials"));
    }
}

Custom sinks

Our default event sink will simply serialize the event class to JSON and forward it to the ASP.NET Core logging system. If you want to connect to a custom event store, implement the IEventSink interface and register it with DI.

The following example uses Seq to emit events:

 public class SeqEventSink : IEventSink
{
    private readonly Logger _log;

    public SeqEventSink()
    {
        _log = new LoggerConfiguration()
            .WriteTo.Seq("http://localhost:5341")
            .CreateLogger();
    }

    public Task PersistAsync(Event evt)
    {
        if (evt.EventType == EventTypes.Success ||
            evt.EventType == EventTypes.Information)
        {
            _log.Information("{Name} ({Id}), Details: {@details}",
                evt.Name,
                evt.Id,
                evt);
        }
        else
        {
            _log.Error("{Name} ({Id}), Details: {@details}",
                evt.Name,
                evt.Id,
                evt);
        }

        return Task.CompletedTask;
    }
}

Add the Serilog.Sinks.Seq package to your host to make the above code work.

Built-in events

The following events are defined in IdentityServer:

ApiAuthenticationFailureEvent & ApiAuthenticationSuccessEvent
Gets raised for successful/failed API authentication at the introspection endpoint.
ClientAuthenticationSuccessEvent & ClientAuthenticationFailureEvent
Gets raised for successful/failed client authentication at the token endpoint.
TokenIssuedSuccessEvent & TokenIssuedFailureEvent
Gets raised for successful/failed attempts to request identity tokens, access tokens, refresh tokens and authorization codes.
TokenIntrospectionSuccessEvent & TokenIntrospectionFailureEvent
Gets raised for successful token introspection requests.
TokenRevokedSuccessEvent
Gets raised for successful token revocation requests.
UserLoginSuccessEvent & UserLoginFailureEvent
Gets raised by the quickstart UI for successful/failed user logins.
UserLogoutSuccessEvent
Gets raised for successful logout requests.
ConsentGrantedEvent & ConsentDeniedEvent
Gets raised in the consent UI.
UnhandledExceptionEvent
Gets raised for unhandled exceptions.
DeviceAuthorizationFailureEvent & DeviceAuthorizationSuccessEvent
Gets raised for successful/failed device authorization requests.

Custom events

You can create your own events and emit them via our infrastructure.

You need to derive from our base Event class which injects contextual information like activity ID, timestamp, etc. Your derived class can then add arbitrary data fields specific to the event context:

public class UserLoginFailureEvent : Event
{
    public UserLoginFailureEvent(string username, string error)
        : base(EventCategories.Authentication,
                "User Login Failure",
                EventTypes.Failure,
                EventIds.UserLoginFailure,
                error)
    {
        Username = username;
    }

    public string Username { get; set; }
}

Cryptography, Keys and HTTPS

IdentityServer relies on a couple of crypto mechanisms to do its job.

Token signing and validation

IdentityServer needs an asymmetric key pair to sign and validate JWTs. This keypair can be a certificate/private key combination or raw RSA keys. In any case it must support RSA with SHA256.

Loading of signing key and the corresponding validation part is done by implementations of ISigningCredentialStore and IValidationKeysStore. If you want to customize the loading of the keys, you can implement those interfaces and register them with DI.

The DI builder extensions has a couple of convenience methods to set signing and validation keys - see here.

Signing key rollover

While you can only use one signing key at a time, you can publish more than one validation key to the discovery document. This is useful for key rollover.

A rollover typically works like this:

  1. you request/create new key material
  2. you publish the new validation key in addition to the current one. You can use the AddValidationKeys builder extension method for that.
  3. all clients and APIs now have a chance to learn about the new key the next time they update their local copy of the discovery document
  4. after a certain amount of time (e.g. 24h) all clients and APIs should now accept both the old and the new key material
  5. keep the old key material around for as long as you like, maybe you have long-lived tokens that need validation
  6. retire the old key material when it is not used anymore
  7. all clients and APIs will “forget” the old key next time they update their local copy of the discovery document

This requires that clients and APIs use the discovery document, and also have a feature to periodically refresh their configuration.

Data protection

Cookie authentication in ASP.NET Core (or anti-forgery in MVC) use the ASP.NET Core data protection feature. Depending on your deployment scenario, this might require additional configuration. See the Microsoft docs for more information.

HTTPS

We don’t enforce the use of HTTPS, but for production it is mandatory for every interaction with IdentityServer.

Grant Types

Grant types are a way to specify how a client wants to interact with IdentityServer. The OpenID Connect and OAuth 2 specs define the following grant types:

  • Implicit
  • Authorization code
  • Hybrid
  • Client credentials
  • Resource owner password
  • Device flow
  • Refresh tokens
  • Extension grants

You can specify which grant type a client can use via the AllowedGrantTypes property on the Client configuration.

A client can be configured to use more than a single grant type (e.g. Hybrid for user centric operations and client credentials for server to server communication). The GrantTypes class can be used to pick from typical grant type combinations:

Client.AllowedGrantTypes = GrantTypes.HybridAndClientCredentials;

You can also specify the grant types list manually:

Client.AllowedGrantTypes =
{
    GrantType.Hybrid,
    GrantType.ClientCredentials,
    "my_custom_grant_type"
};

If you want to transmit access tokens via the browser channel, you also need to allow that explicitly on the client configuration:

Client.AllowAccessTokensViaBrowser = true;

Note

For security reasons, not all grant type combinations are allowed. See below for more details.

For the remainder, the grant types are briefly described, and when you would use them. It is also recommended, that in addition you read the corresponding specs to get a better understanding of the differences.

Client credentials

This is the simplest grant type and is used for server to server communication - tokens are always requested on behalf of a client, not a user.

With this grant type you send a token request to the token endpoint, and get an access token back that represents the client. The client typically has to authenticate with the token endpoint using its client ID and secret.

See the Client Credentials Quick Start for a sample how to use it.

Resource owner password

The resource owner password grant type allows to request tokens on behalf of a user by sending the user’s name and password to the token endpoint. This is so called “non-interactive” authentication and is generally not recommended.

There might be reasons for certain legacy or first-party integration scenarios, where this grant type is useful, but the general recommendation is to use an interactive flow like implicit or hybrid for user authentication instead.

See the Resource Owner Password Quick Start for a sample how to use it. You also need to provide code for the username/password validation which can be supplied by implementing the IResourceOwnerPasswordValidator interface. You can find more information about this interface here.

Implicit

The implicit grant type is optimized for browser-based applications. Either for user authentication-only (both server-side and JavaScript applications), or authentication and access token requests (JavaScript applications).

In the implicit flow, all tokens are transmitted via the browser, and advanced features like refresh tokens are thus not allowed.

This quickstart shows authentication for server-side web apps, and this shows JavaScript.

Note

For JavaScript-based applications, Implicit is not recommended anymore. Use Authorization Code with PKCE instead.

Authorization code

Authorization code flow was originally specified by OAuth 2, and provides a way to retrieve tokens on a back-channel as opposed to the browser front-channel. It also support client authentication.

While this grant type is supported on its own, it is generally recommended you combine that with identity tokens which turns it into the so called hybrid flow. Hybrid flow gives you important extra features like signed protocol responses.

Hybrid

Hybrid flow is a combination of the implicit and authorization code flow - it uses combinations of multiple grant types, most typically code id_token.

In hybrid flow the identity token is transmitted via the browser channel and contains the signed protocol response along with signatures for other artifacts like the authorization code. This mitigates a number of attacks that apply to the browser channel. After successful validation of the response, the back-channel is used to retrieve the access and refresh token.

This is the recommended flow for native applications that want to retrieve access tokens (and possibly refresh tokens as well) and is used for server-side web applications and native desktop/mobile applications.

See this quickstart for more information about using hybrid flow with MVC.

Device flow

Device flow is designed for browserless and input constrained devices, where the device is unable to securely capture user credentials. This flow outsources user authentication and consent to an external device (e.g. a smart phone).

This flow is typically used by IoT devices and can request both identity and API resources.

Refresh tokens

Refresh tokens allow gaining long lived access to APIs.

You typically want to keep the lifetime of access tokens as short as possible, but at the same time don’t want to bother the user over and over again with doing a front-channel roundtrips to IdentityServer for requesting new ones.

Refresh tokens allow requesting new access tokens without user interaction. Every time the client refreshes a token it needs to make an (authenticated) back-channel call to IdentityServer. This allows checking if the refresh token is still valid, or has been revoked in the meantime.

Refresh tokens are supported in hybrid, authorization code, device flow and resource owner password flows. To request a refresh token, the client needs to include the offline_access scope in the token request (and must be authorized to request for that scope).

Extension grants

Extension grants allow extending the token endpoint with new grant types. See this for more details.

Incompatible grant types

Some grant type combinations are forbidden:

  • Mixing implicit and authorization code or hybrid would allow a downgrade attack from the more secure code based flow to implicit.
  • Same concern exists for allowing both authorization code and hybrid

Secrets

In certain situations, clients need to authenticate with identityserver, e.g.

  • confidential applications (aka clients) requesting tokens at the token endpoint
  • APIs validating reference tokens at the introspection endpoint

For that purpose you can assign a list of secrets to a client or an API resource.

Secret parsing and validation is an extensibility point in identityserver, out of the box it supports shared secrets as well as transmitting the shared secret via a basic authentication header or the POST body.

Creating a shared secret

The following code sets up a hashed shared secret:

var secret = new Secret("secret".Sha256());

This secret can now be assigned to either a Client or an ApiResource. Notice that both do not only support a single secret, but multiple. This is useful for secret rollover and rotation:

var client = new Client
{
    ClientId = "client",
    ClientSecrets = new List<Secret> { secret },

    AllowedGrantTypes = GrantTypes.ClientCredentials,
    AllowedScopes = new List<string>
    {
        "api1", "api2"
    }
};

In fact you can also assign a description and an expiration date to a secret. The description will be used for logging, and the expiration date for enforcing a secret lifetime:

var secret = new Secret(
    "secret".Sha256(),
    "2016 secret",
    new DateTime(2016, 12, 31));

Authentication using a shared secret

You can either send the client id/secret combination as part of the POST body:

POST /connect/token

client_id=client1&
client_secret=secret&
...

..or as a basic authentication header:

POST /connect/token

Authorization: Basic xxxxx

...

You can manually create a basic authentication header using the following C# code:

var credentials = string.Format("{0}:{1}", clientId, clientSecret);
var headerValue = Convert.ToBase64String(Encoding.UTF8.GetBytes(credentials));

var client = new HttpClient();
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", headerValue);

The IdentityModel library has helper classes called TokenClient and IntrospectionClient that encapsulate both authentication and protocol messages.

Beyond shared secrets

There are other techniques to authenticate clients, e.g. based on public/private key cryptography. IdentityServer includes support for private key JWT client secrets (see RFC 7523).

Secret extensibility typically consists of three things:

  • a secret definition
  • a secret parser that knows how to extract the secret from the incoming request
  • a secret validator that knows how to validate the parsed secret based on the definition

Secret parsers and validators are implementations of the ISecretParser and ISecretValidator interfaces. To make them available to IdentityServer, you need to register them with the DI container, e.g.:

builder.AddSecretParser<JwtBearerClientAssertionSecretParser>()
builder.AddSecretValidator<PrivateKeyJwtSecretValidator>()

Our default private key JWT secret validator expects the full (leaf) certificate as base64 on the secret definition. This certificate will then be used to validate the signature on the self-signed JWT, e.g.:

var client = new Client
{
    ClientId = "client.jwt",
    ClientSecrets =
    {
        new Secret
        {
            Type = IdentityServerConstants.SecretTypes.X509CertificateBase64,
            Value = "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"
        }
    },

    AllowedGrantTypes = GrantTypes.ClientCredentials,
    AllowedScopes = { "api1", "api2" }
};

You could implement your own secret validator (or extend ours) to implement e.g. chain trust validation instead.

Extension Grants

OAuth 2.0 defines standard grant types for the token endpoint, such as password, authorization_code and refresh_token. Extension grants are a way to add support for non-standard token issuance scenarios like token translation, delegation, or custom credentials.

You can add support for additional grant types by implementing the IExtensionGrantValidator interface:

public interface IExtensionGrantValidator
{
    /// <summary>
    /// Handles the custom grant request.
    /// </summary>
    /// <param name="request">The validation context.</param>
    Task ValidateAsync(ExtensionGrantValidationContext context);

    /// <summary>
    /// Returns the grant type this validator can deal with
    /// </summary>
    /// <value>
    /// The type of the grant.
    /// </value>
    string GrantType { get; }
}

The ExtensionGrantValidationContext object gives you access to:

  • the incoming token request - both the well-known validated values, as well as any custom values (via the Raw collection)
  • the result - either error or success
  • custom response parameters

To register the extension grant, add it to DI:

builder.AddExtensionGrantValidator<MyExtensionsGrantValidator>();

Example: Simple delegation using an extension grant

Imagine the following scenario - a front end client calls a middle tier API using a token acquired via an interactive flow (e.g. hybrid flow). This middle tier API (API 1) now wants to call a back end API (API 2) on behalf of the interactive user:

_images/delegation.png

In other words, the middle tier API (API 1) needs an access token containing the user’s identity, but with the scope of the back end API (API 2).

Note

You might have heard of the term poor man’s delegation where the access token from the front end is simply forwarded to the back end. This has some shortcomings, e.g. API 2 must now accept the API 1 scope which would allow the user to call API 2 directly. Also - you might want to add some delegation specific claims into the token, e.g. the fact that the call path is via API 1.

Implementing the extension grant

The front end would send the token to API 1, and now this token needs to be exchanged at IdentityServer with a new token for API 2.

On the wire the call to token service for the exchange could look like this:

POST /connect/token

grant_type=delegation&
scope=api2&
token=...&
client_id=api1.client
client_secret=secret

It’s the job of the extension grant validator to handle that request by validating the incoming token, and returning a result that represents the new token:

public class DelegationGrantValidator : IExtensionGrantValidator
{
    private readonly ITokenValidator _validator;

    public DelegationGrantValidator(ITokenValidator validator)
    {
        _validator = validator;
    }

    public string GrantType => "delegation";

    public async Task ValidateAsync(ExtensionGrantValidationContext context)
    {
        var userToken = context.Request.Raw.Get("token");

        if (string.IsNullOrEmpty(userToken))
        {
            context.Result = new GrantValidationResult(TokenRequestErrors.InvalidGrant);
            return;
        }

        var result = await _validator.ValidateAccessTokenAsync(userToken);
        if (result.IsError)
        {
            context.Result = new GrantValidationResult(TokenRequestErrors.InvalidGrant);
            return;
        }

        // get user's identity
        var sub = result.Claims.FirstOrDefault(c => c.Type == "sub").Value;

        context.Result = new GrantValidationResult(sub, GrantType);
        return;
    }
}

Don’t forget to register the validator with DI.

Registering the delegation client

You need a client registration in IdentityServer that allows a client to use this new extension grant, e.g.:

var client = new client
{
    ClientId = "api1.client",
    ClientSecrets = new List<Secret>
    {
        new Secret("secret".Sha256())
    },

    AllowedGrantTypes = { "delegation" },

    AllowedScopes = new List<string>
    {
        "api2"
    }
}

Calling the token endpoint

In API 1 you can now construct the HTTP payload yourself, or use the IdentityModel helper library:

public async Task<TokenResponse> DelegateAsync(string userToken)
{
    var payload = new
    {
        token = userToken
    };

    // create token client
    var client = new TokenClient(disco.TokenEndpoint, "api1.client", "secret");

    // send custom grant to token endpoint, return response
    return await client.RequestCustomGrantAsync("delegation", "api2", payload);
}

The TokenResponse.AccessToken will now contain the delegation access token.

Resource Owner Password Validation

If you want to use the OAuth 2.0 resource owner password credential grant (aka password), you need to implement and register the IResourceOwnerPasswordValidator interface:

public interface IResourceOwnerPasswordValidator
{
    /// <summary>
    /// Validates the resource owner password credential
    /// </summary>
    /// <param name="context">The context.</param>
    Task ValidateAsync(ResourceOwnerPasswordValidationContext context);
}

On the context you will find already parsed protocol parameters like UserName and Password, but also the raw request if you want to look at other input data.

Your job is then to implement the password validation and set the Result on the context accordingly. See the GrantValidationResult documentation.

Refresh Tokens

Since access tokens have finite lifetimes, refresh tokens allow requesting new access tokens without user interaction.

Refresh tokens are supported for the following flows: authorization code, hybrid and resource owner password credential flow. The clients needs to be explicitly authorized to request refresh tokens by setting AllowOfflineAccess to true.

Additional client settings

AbsoluteRefreshTokenLifetime
Maximum lifetime of a refresh token in seconds. Defaults to 2592000 seconds / 30 days. Zero allows refresh tokens that, when used with RefreshTokenExpiration = Sliding only expire after the SlidingRefreshTokenLifetime is passed.
SlidingRefreshTokenLifetime
Sliding lifetime of a refresh token in seconds. Defaults to 1296000 seconds / 15 days
RefreshTokenUsage

ReUse the refresh token handle will stay the same when refreshing tokens

OneTime the refresh token handle will be updated when refreshing tokens

RefreshTokenExpiration

Absolute the refresh token will expire on a fixed point in time (specified by the AbsoluteRefreshTokenLifetime)

Sliding when refreshing the token, the lifetime of the refresh token will be renewed (by the amount specified in SlidingRefreshTokenLifetime). The lifetime will not exceed AbsoluteRefreshTokenLifetime.

UpdateAccessTokenClaimsOnRefresh
Gets or sets a value indicating whether the access token (and its claims) should be updated on a refresh token request.

Reference Tokens

Access tokens can come in two flavours - self-contained or reference.

A JWT token would be a self-contained access token - it’s a protected data structure with claims and an expiration. Once an API has learned about the key material, it can validate self-contained tokens without needing to communicate with the issuer. This makes JWTs hard to revoke. They will stay valid until they expire.

When using reference tokens - IdentityServer will store the contents of the token in a data store and will only issue a unique identifier for this token back to the client. The API receiving this reference must then open a back-channel communication to IdentityServer to validate the token.

_images/reference_tokens.png

You can switch the token type of a client using the following setting:

client.AccessTokenType = AccessTokenType.Reference;

IdentityServer provides an implementation of the OAuth 2.0 introspection specification which allows APIs to dereference the tokens. You can either use our dedicated introspection handler or use the identity server authentication handler which can validate both JWTs and reference tokens.

The introspection endpoint requires authentication - since the client of an introspection endpoint is an API, you configure the secret on the ApiResource:

var api = new ApiResource("api1")
{
    ApiSecrets = { new Secret("secret".Sha256()) }
}

See here for more information on how to configure the IdentityServer authentication middleware for APIs.

Mutual TLS

Mutual TLS support in IdentityServer allows for two features:

  • Client authentication to endpoints within IdentityServer using a X.509 client certificate
  • Use of sender-constrained access tokens from a client to APIs using a X.509 client certificate certificate

Note

See this spec for more information

Client authentication

Clients can use a X.509 client certificate as an authentication mechanism to endpoints in IdentityServer.

Validating the X.509 client certificate in IdentityServer

It’s the hosting layer’s responsibility to do the actual validation of the client certificate, and then IdentityServer uses (and trusts) this result as part of the client authentication and validation at the application level. This means to use this feature within IdentityServer you must first configure your web server (IIS, Kestrel, etc.) to accept and validate client certificates.

Consult your web server documentation to learn how to do this.

Note

mkcert is a nice utility for creating certificates for development purposes.

Endpoints in IdentityServer for mutual TLS

Given that mutual TLS is performed at the TLS channel, it tends to be more convenient to configure distinct endpoints where mutual TLS is expected and/or required. This allows the existing endpoints in IdentityServer to operate normally without mutual TLS. In IdentityServer, the mutual TLS endpoints are expected to be located beneath the path ~/connect/mtls. This means your web server can be configured to require mutual TLS for all requests at and below that path.

As such, IdentityServer’s discovery document reflects those paths:

_images/mtls_endpoints.png

Mutual TLS configuration in IdentityServer

IdentityServer requires additional configuration to utilize the result of the mutual TLS authentication.

First, there must be an authentication handler configured in the hosting application that will surface the result of the client certificate authentication in the web server. There will be one built into ASP.NET Core 3.0, but prior to that the idunno.Authentication.Certificate handler is recommended. For example:

services.AddAuthentication()
    .AddCertificate("x509", options =>
    {
        options.RevocationMode = System.Security.Cryptography.X509Certificates.X509RevocationMode.NoCheck;

        options.Events = new CertificateAuthenticationEvents
        {
            OnValidateCertificate = context =>
            {
                context.Principal = Principal.CreateFromCertificate(context.ClientCertificate, includeAllClaims:true);
                context.Success();

                return Task.CompletedTask;
            }
        };
    });

Next, in the IdentityServer options, enable mutual TLS and configure the scheme of the authentication handler registered in the previous step.

For example:

var builder = services.AddIdentityServer(options =>
{
    options.MutualTls.Enabled = true;
    options.MutualTls.ClientCertificateAuthenticationScheme = "x509";
});

Next, on the IdentityServer builder add the services to DI which will allow for validating the client certificate by calling AddMutualTlsSecretValidators:

builder.AddMutualTlsSecretValidators();

Finally, for the client configuration add to the ClientSecrets collection a secret type of either SecretTypes.X509CertificateName if you wish to authenticate the client from the certificate distinguished name or SecretTypes.X509CertificateThumbprint if you wish to authenticate the client by certificate thumbprint. For example:

new Client
{
    ClientId = "mtls",
    AllowedGrantTypes = GrantTypes.ClientCredentials,
    AllowedScopes = { "api1" }
    ClientSecrets = {
        new Secret(@"CN=mtls.test, OU=ROO\ballen@roo, O=mkcert development certificate", "mtls.test")
        {
            Type = SecretTypes.X509CertificateName
        },
        // or:
        //new Secret("bca0d040847f843c5ee0fa6eb494837470155868", "mtls.test")
        //{
        //    Type = SecretTypes.X509CertificateThumbprint
        //},
    },
}

Using a client certificate to authenticate to IdentityServer

When writing a client to connect to IdentityServer, the HttpClientHandler class provides a convenient mechanism to use a client certificate by adding to the ClientCertificates collection. The HttpClientHandler can then be used as the message handler in HttpClient. And then HTTP calls (including using the various IdentityModel extension methods) with the HttpClient will perform client certificate authentication at the TLS channel. For example:

static async Task<TokenResponse> RequestTokenAsync()
{
    var handler = new HttpClientHandler();
    var cert = X509.CurrentUser.My.Thumbprint.Find("bca0d040847f843c5ee0fa6eb494837470155868").Single();
    handler.ClientCertificates.Add(cert);

    var client = new HttpClient(handler);

    var disco = await client.GetDiscoveryDocumentAsync(Constants.Authority);
    if (disco.IsError) throw new Exception(disco.Error);

    var response = await client.RequestClientCredentialsTokenAsync(new ClientCredentialsTokenRequest
    {
        Address = disco
                        .TryGetValue(OidcConstants.Discovery.MtlsEndpointAliases)
                        .Value<string>(OidcConstants.Discovery.TokenEndpoint)
                        .ToString(),

        ClientId = "mtls",
        Scope = "api1"
    });

    if (response.IsError) throw new Exception(response.Error);
    return response;
}

Sender-constrained access tokens

Clients can use a X.509 client certificate as a mechanism for sender-constrained access tokens when authenticating to APIs. The use of these sender-constrained access tokens requires the client to use the same X.509 client certificate to authenticate to the API as the one used for IdentityServer.

Confirmation claim

When a client obtains an access token and has authenticated with mutual TLS, IdentityServer issues a confirmation claim (or cnf) in the access token. This value is a hash of the thumbprint of the client certificate used to authenticate with IdentityServer.

This value can be seen in this screen shot of a decoded access token:

_images/mtls_access_token_with_cnf.png

The API will then use this value to ensure the client certificate being used at the API matches the confirmation value in the access token.

Validating and accepting a client certificate in APIs

As mentioned above for client authentication in IdentityServer, in the API the web server is expected to perform the client certificate validation at the TLS layer.

Aditionally, the API hosting application will need a mechanism to accept the client certificate in order to obtain the thumbprint to perform the confirmation claim validation. Below is an example how an API in ASP.NET Core might be configured for both access tokens and client certificates:

services.AddAuthentication("token")
    .AddIdentityServerAuthentication("token", options =>
    {
        options.Authority = Constants.Authority;
        options.RequireHttpsMetadata = false;

        options.ApiName = "api1";
        options.ApiSecret = "secret";
    })
    .AddCertificate("x509", options =>
    {
        options.RevocationMode = System.Security.Cryptography.X509Certificates.X509RevocationMode.NoCheck;

        options.Events = new CertificateAuthenticationEvents
        {
            OnValidateCertificate = context =>
            {
                context.Principal = Principal.CreateFromCertificate(context.ClientCertificate, includeAllClaims: true);
                context.Success();

                return Task.CompletedTask;
            }
        };
    });

Finally, a mechanism is needed that runs after the authentication middleware to authenticate the client certificate and compare the thumbprint to the cnf from the access token.

Below is an example implemented in middleware:

app.UseAuthentication();

app.Use(async (ctx, next) =>
{
    if (ctx.User.Identity.IsAuthenticated)
    {
        var cnfJson = ctx.User.FindFirst("cnf")?.Value;
        if (!String.IsNullOrWhiteSpace(cnfJson))
        {
            var certResult = await ctx.AuthenticateAsync("x509");
            if (!certResult.Succeeded)
            {
                await ctx.ChallengeAsync("x509");
                return;
            }

            var cert = ctx.Connection.ClientCertificate;
            if (cert == null)
            {
                await ctx.ChallengeAsync("x509");
                return;
            }

            var thumbprint = cert.Thumbprint;

            var cnf = JObject.Parse(cnfJson);
            var sha256 = cnf.Value<string>("x5t#S256");

            if (String.IsNullOrWhiteSpace(sha256) ||
                !thumbprint.Equals(sha256, StringComparison.OrdinalIgnoreCase))
            {
                await ctx.ChallengeAsync("token");
                return;
            }
        }
    }

    await next();
});

app.UseMvc();

Once the above middlware succeeds, then the caller has been authenticated with a sender-constrained access token.

Introspection and the confirmation claim

When the access token is a JWT, then the confirmation claim is contained in the token as a claim. When using reference tokens, the claims that the access token represents must be obtained via introspection. The introspection endpoint in IdentityServer will return a cnf claim for reference tokens obtained via mutual TLS.

Authorize Request Objects

Instead of providing all parameters for an authorize request as individual query string parameters, you can package them up in signed JWTs. You can either transmit them by value or by reference to the authorize endpoint - see the spec for more details.

IdentityServer requires the request JWTs to be signed. We support X509 certificates, symmetric and RSA keys. For symmetric and RSA you need to add a JWK secret to the corresponding client, e.g.:

private readonly string _symmetricJwk = @"{ 'kty': 'oct', 'use': 'sig', 'kid': '1', 'k': 'nYA-IFt8xTsdBHe9hunvizcp3Dt7f6qGqudq18kZHNtvqEGjJ9Ud-9x3kbQ-LYfLHS3xM2MpFQFg1JzT_0U_F8DI40oby4TvBDGszP664UgA8_5GjB7Flnrlsap1NlitvNpgQX3lpyTvC2zVuQ-UVsXbBDAaSBUSlnw7SE4LM8Ye2WYZrdCCXL8yAX9vIR7vf77yvNTEcBCI6y4JlvZaqMB4YKVSfygs8XqGGCHjLpE5bvI-A4ESbAUX26cVFvCeDg9pR6HK7BmwPMlO96krgtKZcXEJtUELYPys6-rbwAIdmxJxKxpgRpt0FRv_9fm6YPwG7QivYBX-vRwaodL1TA', 'alg': 'HS256'}";

var client = new Client
{
    ClientId = "foo",

    ClientSecrets =
    {
        new Secret
        {
            Type = IdentityServerConstants.SecretTypes.JsonWebKey,
            Value = _symmetricJwk
        }
    }
}

Note

Microsoft.IdentityModel.Tokens.JsonWebKeyConverter has various helpers to convert keys to JWKs

Because of a bug in Microsoft’s JWT library, X509 certificates cannot be formatted as JWKs right now. You can use the base64 representation instead:

ClientSecrets =
{
    new Secret
    {
        Type = IdentityServerConstants.SecretTypes.X509CertificateBase64,
        Value = Convert.ToBase64String(cert.Export(X509ContentType.Cert))
    }
}

Passing request JWTs by reference

If the request_uri parameter is used, IdentityServer will make an outgoing HTTP call to fetch the JWT from the specified URL.

You can customize the HTTP client used for this outgoing connection, e.g. to add caching or retry logic (e.g. via the Polly library):

builder.AddJwtRequestUriHttpClient(client =>
{
    client.Timeout = TimeSpan.FromSeconds(30);
})
    .AddTransientHttpErrorPolicy(policy => policy.WaitAndRetryAsync(new[]
    {
        TimeSpan.FromSeconds(1),
        TimeSpan.FromSeconds(2),
        TimeSpan.FromSeconds(3)
    }));

Note

Request URI processing is disabled by default. Enable on the IdentityServer Options under Endpoints.

Accessing the request object data

You can access the validated data from the request object in two ways

  • wherever you have access to the ValidatedAuthorizeRequest, the RequestObjectValues dictionary holds the values
  • in the UI code you can call IIdentityServerInteractionService.GetAuthorizationContextAsync, the resulting AuthorizationRequest object contains the RequestObjectValues dictionary as well

Custom Token Request Validation and Issuance

You can run custom code as part of the token issuance pipeline at the token endpoint. This allows e.g. for

  • adding additional validation logic
  • changing certain parameters (e.g. token lifetime) dynamically

For this purpose, implement (and register) the ICustomTokenRequestValidator interface:

/// <summary>
/// Allows inserting custom validation logic into token requests
/// </summary>
public interface ICustomTokenRequestValidator
{
    /// <summary>
    /// Custom validation logic for a token request.
    /// </summary>
    /// <param name="context">The context.</param>
    /// <returns>
    /// The validation result
    /// </returns>
    Task ValidateAsync(CustomTokenRequestValidationContext context);
}

The context object gives you access to:

  • adding custom response parameters
  • return an error and error description
  • modifying the request parameters, e.g. access token lifetime and type, client claims, and the confirmation method

You can register your implementation of the validator using the AddCustomTokenRequestValidator extension method on the configuration builder.

CORS

Many endpoints in IdentityServer will be accessed via Ajax calls from JavaScript-based clients. Given that IdentityServer will most likely be hosted on a different origin than these clients, this implies that Cross-Origin Resource Sharing (CORS) will need to be configured.

Client-based CORS Configuration

One approach to configuring CORS is to use the AllowedCorsOrigins collection on the client configuration. Simply add the origin of the client to the collection and the default configuration in IdentityServer will consult these values to allow cross-origin calls from the origins.

Note

Be sure to use an origin (not a URL) when configuring CORS. For example: https://foo:123/ is a URL, whereas https://foo:123 is an origin.

This default CORS implementation will be in use if you are using either the “in-memory” or EF-based client configuration that we provide. If you define your own IClientStore, then you will need to implement your own custom CORS policy service (see below).

Custom Cors Policy Service

IdentityServer allows the hosting application to implement the ICorsPolicyService to completely control the CORS policy.

The single method to implement is: Task<bool> IsOriginAllowedAsync(string origin). Return true if the origin is allowed, false otherwise.

Once implemented, simply register the implementation in DI and IdentityServer will then use your custom implementation.

DefaultCorsPolicyService

If you simply wish to hard-code a set of allowed origins, then there is a pre-built ICorsPolicyService implementation you can use called DefaultCorsPolicyService. This would be configured as a singleton in DI, and hard-coded with its AllowedOrigins collection, or setting the flag AllowAll to true to allow all origins. For example, in ConfigureServices:

var cors = new DefaultCorsPolicyService(_loggerFactory.CreateLogger<DefaultCorsPolicyService>())
{
    AllowedOrigins = { "https://foo", "https://bar" }
};
services.AddSingleton<ICorsPolicyService>(cors);

Note

Use AllowAll with caution.

Mixing IdentityServer’s CORS policy with ASP.NET Core’s CORS policies

IdentityServer uses the CORS middleware from ASP.NET Core to provide its CORS implementation. It is possible that your application that hosts IdentityServer might also require CORS for its own custom endpoints. In general, both should work together in the same application.

Your code should use the documented CORS features from ASP.NET Core without regard to IdentityServer. This means you should define policies and register the middleware as normal. If your application defines policies in ConfigureServices, then those should continue to work in the same places you are using them (either where you configure the CORS middleware or where you use the MVC EnableCors attributes in your controller code). If instead you define an inline policy in the use of the CORS middleware (via the policy builder callback), then that too should continue to work normally.

The one scenario where there might be a conflict between your use of the ASP.NET Core CORS services and IdentityServer is if you decide to create a custom ICorsPolicyProvider. Given the design of the ASP.NET Core’s CORS services and middleware, IdentityServer implements its own custom ICorsPolicyProvider and registers it in the DI system. Fortunately, the IdentityServer implementation is designed to use the decorator pattern to wrap any existing ICorsPolicyProvider that is already registered in DI. What this means is that you can also implement the ICorsPolicyProvider, but it simply needs to be registered prior to IdentityServer in DI (e.g. in ConfigureServices).

Discovery

The discovery document can be found at https://baseaddress/.well-known/openid-configuration. It contains information about the endpoints, key material and features of your IdentityServer.

By default all information is included in the discovery document, but by using configuration options, you can hide individual sections, e.g.:

services.AddIdentityServer(options =>
{
    options.Discovery.ShowIdentityScopes = false;
    options.Discovery.ShowApiScopes = false;
    options.Discovery.ShowClaims = false;
    options.Discovery.ShowExtensionGrantTypes = false;
});

Extending discovery

You can add custom entries to the discovery document, e.g:

services.AddIdentityServer(options =>
{
    options.Discovery.CustomEntries.Add("my_setting", "foo");
    options.Discovery.CustomEntries.Add("my_complex_setting",
        new
        {
            foo = "foo",
            bar = "bar"
        });
});

When you add a custom value that starts with ~/ it will be expanded to an absolute path below the IdentityServer base address, e.g.:

options.Discovery.CustomEntries.Add("my_custom_endpoint", "~/custom");

If you want to take full control over the rendering of the discovery (and jwks) document, you can implement the IDiscoveryResponseGenerator interface (or derive from our default implementation).

Adding more API Endpoints

It’s a common scenario to add additional API endpoints to the application hosting IdentityServer. These endpoints are typically protected by IdentityServer itself.

For simple scenarios, we give you some helpers. See the advanced section to understand more of the internal plumbing.

Note

You could achieve the same by using either our IdentityServerAuthentication handler or Microsoft’s JwtBearer handler. But this is not recommended since it requires more configuration and creates dependencies on external libraries that might lead to conflicts in future updates.

Start by registering your API as an ApiResource, e.g.:

public static IEnumerable<ApiResource> Apis = new List<ApiResource>
{
    // local API
    new ApiResource(IdentityServerConstants.LocalApi.ScopeName),
};

..and give your clients access to this API, e.g.:

new Client
{
    // rest omitted
    AllowedScopes = { IdentityServerConstants.LocalApi.ScopeName },
}

Note

The value of IdentityServerConstants.LocalApi.ScopeName is IdentityServerApi.

To enable token validation for local APIs, add the following to your IdentityServer startup:

services.AddLocalApiAuthentication();

To protect an API controller, decorate it with an Authorize attribute using the LocalApi.PolicyName policy:

[Route("localApi")]
[Authorize(LocalApi.PolicyName)]
public class LocalApiController : ControllerBase
{
    public IActionResult Get()
    {
        // omitted
    }
}

Authorized clients can then request a token for the IdentityServerApi scope and use it to call the API.

Discovery

You can also add your endpoints to the discovery document if you want, e.g like this:

services.AddIdentityServer(options =>
{
    options.Discovery.CustomEntries.Add("local_api", "~/localapi");
})

Advanced

Under the covers, the AddLocalApiAuthentication helper does a couple of things:

  • adds an authentication handler that validates incoming tokens using IdentityServer’s built-in token validation engine (the name of this handlier is IdentityServerAccessToken or IdentityServerConstants.LocalApi.AuthenticationScheme
  • configures the authentication handler to require a scope claim inside the access token of value IdentityServerApi
  • sets up an authorization policy that checks for a scope claim of value IdentityServerApi

This covers the most common scenarios. You can customize this behavior in the following ways:

  • Add the authentication handler yourself by calling services.AddAuthentication().AddLocalApi(...)
    • this way you can specify the required scope name yourself, or (by specifying no scope at all) accept any token from the current IdentityServer instance
  • Do your own scope validation/authorization in your controllers using custom policies or code, e.g.:

    services.AddAuthorization(options =>
    {
        options.AddPolicy(IdentityServerConstants.LocalApi.PolicyName, policy =>
        {
            policy.AddAuthenticationSchemes(IdentityServerConstants.LocalApi.AuthenticationScheme);
            policy.RequireAuthenticatedUser();
            // custom requirements
        });
    });
    

Claims Transformation

You can provide a callback to transform the claims of the incoming token after validation. Either use the helper method, e.g.:

services.AddLocalApiAuthentication(principal =>
{
    principal.Identities.First().AddClaim(new Claim("additional_claim", "additional_value"));

    return Task.FromResult(principal);
});

…or implement the event on the options if you add the authentication handler manually.

Adding new Protocols

IdentityServer4 allows adding support for other protocols besides the built-in support for OpenID Connect and OAuth 2.0.

You can add those additional protocol endpoints either as middleware or using e.g. MVC controllers. In both cases you have access to the ASP.NET Core DI system which allows re-using our internal services like access to client definitions or key material.

A sample for adding WS-Federation support can be found here.

Typical authentication workflow

An authentication request typically works like this:

  • authentication request arrives at protocol endpoint
  • protocol endpoint does input validation
  • redirection to login page with a return URL set back to protocol endpoint (if user is anonymous)
    • access to current request details via the IIdentityServerInteractionService
    • authentication of user (either locally or via external authentication middleware)
    • signing in the user
    • redirect back to protocol endpoint
  • creation of protocol response (token creation and redirect back to client)

Useful IdentityServer services

To achieve the above workflow, some interaction points with IdentityServer are needed.

Access to configuration and redirecting to the login page

You can get access to the IdentityServer configuration by injecting the IdentityServerOptions class into your code. This, e.g. has the configured path to the login page:

var returnUrl = Url.Action("Index");
returnUrl = returnUrl.AddQueryString(Request.QueryString.Value);

var loginUrl = _options.UserInteraction.LoginUrl;
var url = loginUrl.AddQueryString(_options.UserInteraction.LoginReturnUrlParameter, returnUrl);

return Redirect(url);

Interaction between the login page and current protocol request

The IIdentityServerInteractionService supports turning a protocol return URL into a parsed and validated context object:

var context = await _interaction.GetAuthorizationContextAsync(returnUrl);

By default the interaction service only understands OpenID Connect protocol messages. To extend support, you can write your own IReturnUrlParser:

public interface IReturnUrlParser
{
    bool IsValidReturnUrl(string returnUrl);
    Task<AuthorizationRequest> ParseAsync(string returnUrl);
}

..and then register the parser in DI:

builder.Services.AddTransient<IReturnUrlParser, WsFederationReturnUrlParser>();

This allows the login page to get to information like the client configuration and other protocol parameters.

Access to configuration and key material for creating the protocol response

By injecting the IKeyMaterialService into your code, you get access to the configured signing credential and validation keys:

var credential = await _keys.GetSigningCredentialsAsync();
var key = credential.Key as Microsoft.IdentityModel.Tokens.X509SecurityKey;

var descriptor = new SecurityTokenDescriptor
{
    AppliesToAddress = result.Client.ClientId,
    Lifetime = new Lifetime(DateTime.UtcNow, DateTime.UtcNow.AddSeconds(result.Client.IdentityTokenLifetime)),
    ReplyToAddress = result.Client.RedirectUris.First(),
    SigningCredentials = new X509SigningCredentials(key.Certificate, result.RelyingParty.SignatureAlgorithm, result.RelyingParty.DigestAlgorithm),
    Subject = outgoingSubject,
    TokenIssuerName = _contextAccessor.HttpContext.GetIdentityServerIssuerUri(),
    TokenType = result.RelyingParty.TokenType
};

Tools

The IdentityServerTools class is a collection of useful internal tools that you might need when writing extensibility code for IdentityServer. To use it, inject it into your code, e.g. a controller:

public MyController(IdentityServerTools tools)
{
    _tools = tools;
}

The IssueJwtAsync method allows creating JWT tokens using the IdentityServer token creation engine. The IssueClientJwtAsync is an easier version of that for creating tokens for server-to-server communication (e.g. when you have to call an IdentityServer protected API from your code):

public async Task<IActionResult> MyAction()
{
    var token = await _tools.IssueClientJwtAsync(
        clientId: "client_id",
        lifetime: 3600,
        audiences: new[] { "backend.api" });

    // more code
}

Discovery Endpoint

The discovery endpoint can be used to retrieve metadata about your IdentityServer - it returns information like the issuer name, key material, supported scopes etc. See the spec for more details.

The discovery endpoint is available via /.well-known/openid-configuration relative to the base address, e.g.:

https://demo.identityserver.io/.well-known/openid-configuration

Note

You can use the IdentityModel client library to programmatically access the discovery endpoint from .NET code. For more information check the IdentityModel docs.

Authorize Endpoint

The authorize endpoint can be used to request tokens or authorization codes via the browser. This process typically involves authentication of the end-user and optionally consent.

Note

IdentityServer supports a subset of the OpenID Connect and OAuth 2.0 authorize request parameters. For a full list, see here.

client_id
identifier of the client (required).
request
instead of providing all parameters as individual query string parameters, you can provide a subset or all of them as a JWT
request_uri
URL of a pre-packaged JWT containing request parameters
scope
one or more registered scopes (required)
redirect_uri
must exactly match one of the allowed redirect URIs for that client (required)
response_type

id_token requests an identity token (only identity scopes are allowed)

token requests an access token (only resource scopes are allowed)

id_token token requests an identity token and an access token

code requests an authorization code

code id_token requests an authorization code and identity token

code id_token token requests an authorization code, identity token and access token

response_mode
form_post sends the token response as a form post instead of a fragment encoded redirect (optional)
state
identityserver will echo back the state value on the token response, this is for round tripping state between client and provider, correlating request and response and CSRF/replay protection. (recommended)
nonce

identityserver will echo back the nonce value in the identity token, this is for replay protection)

Required for identity tokens via implicit grant.

prompt

none no UI will be shown during the request. If this is not possible (e.g. because the user has to sign in or consent) an error is returned

login the login UI will be shown, even if the user is already signed-in and has a valid session

code_challenge
sends the code challenge for PKCE
code_challenge_method
plain indicates that the challenge is using plain text (not recommended) S256 indicates the challenge is hashed with SHA256
login_hint
can be used to pre-fill the username field on the login page
ui_locales
gives a hint about the desired display language of the login UI
max_age
if the user’s logon session exceeds the max age (in seconds), the login UI will be shown
acr_values

allows passing in additional authentication related information - identityserver special cases the following proprietary acr_values:

idp:name_of_idp bypasses the login/home realm screen and forwards the user directly to the selected identity provider (if allowed per client configuration)

tenant:name_of_tenant can be used to pass a tenant name to the login UI

Example

GET /connect/authorize?
    client_id=client1&
    scope=openid email api1&
    response_type=id_token token&
    redirect_uri=https://myapp/callback&
    state=abc&
    nonce=xyz

(URL encoding removed, and line breaks added for readability)

Note

You can use the IdentityModel client library to programmatically create authorize requests .NET code. For more information check the IdentityModel docs.

Token Endpoint

The token endpoint can be used to programmatically request tokens. It supports the password, authorization_code, client_credentials, refresh_token and urn:ietf:params:oauth:grant-type:device_code grant types. Furthermore the token endpoint can be extended to support extension grant types.

Note

IdentityServer supports a subset of the OpenID Connect and OAuth 2.0 token request parameters. For a full list, see here.

client_id
client identifier (required)
client_secret
client secret either in the post body, or as a basic authentication header. Optional.
grant_type
authorization_code, client_credentials, password, refresh_token, urn:ietf:params:oauth:grant-type:device_code or custom
scope
one or more registered scopes. If not specified, a token for all explicitly allowed scopes will be issued.
redirect_uri
required for the authorization_code grant type
code
the authorization code (required for authorization_code grant type)
code_verifier
PKCE proof key
username
resource owner username (required for password grant type)
password
resource owner password (required for password grant type)
acr_values

allows passing in additional authentication related information for the password grant type - identityserver special cases the following proprietary acr_values:

idp:name_of_idp bypasses the login/home realm screen and forwards the user directly to the selected identity provider (if allowed per client configuration)

tenant:name_of_tenant can be used to pass a tenant name to the token endpoint

refresh_token
the refresh token (required for refresh_token grant type)
device_code
the device code (required for urn:ietf:params:oauth:grant-type:device_code grant type)

Example

POST /connect/token

    client_id=client1&
    client_secret=secret&
    grant_type=authorization_code&
    code=hdh922&
    redirect_uri=https://myapp.com/callback

(Form-encoding removed and line breaks added for readability)

Note

You can use the IdentityModel client library to programmatically access the token endpoint from .NET code. For more information check the IdentityModel docs.

UserInfo Endpoint

The UserInfo endpoint can be used to retrieve identity information about a user (see spec).

The caller needs to send a valid access token representing the user. Depending on the granted scopes, the UserInfo endpoint will return the mapped claims (at least the openid scope is required).

Example

GET /connect/userinfo
Authorization: Bearer <access_token>
HTTP/1.1 200 OK
Content-Type: application/json

{
    "sub": "248289761001",
    "name": "Bob Smith",
    "given_name": "Bob",
    "family_name": "Smith",
    "role": [
        "user",
        "admin"
    ]
}

Note

You can use the IdentityModel client library to programmatically access the userinfo endpoint from .NET code. For more information check the IdentityModel docs.

Device Authorization Endpoint

The device authorization endpoint can be used to request device and user codes. This endpoint is used to start the device flow authorization process.

Note

The URL for the end session endpoint is available via the discovery endpoint.

client_id
client identifier (required)
client_secret
client secret either in the post body, or as a basic authentication header. Optional.
scope
one or more registered scopes. If not specified, a token for all explicitly allowed scopes will be issued.

Example

POST /connect/deviceauthorization

    client_id=client1&
    client_secret=secret&
    scope=openid api1

(Form-encoding removed and line breaks added for readability)

Note

You can use the IdentityModel client library to programmatically access the device authorization endpoint from .NET code. For more information check the IdentityModel docs.

Introspection Endpoint

The introspection endpoint is an implementation of RFC 7662.

It can be used to validate reference tokens (or JWTs if the consumer does not have support for appropriate JWT or cryptographic libraries). The introspection endpoint requires authentication - since the client of an introspection endpoint is an API, you configure the secret on the ApiResource.

Example

POST /connect/introspect
Authorization: Basic xxxyyy

token=<token>

A successful response will return a status code of 200 and either an active or inactive token:

{
    "active": true,
    "sub": "123"
}

Unknown or expired tokens will be marked as inactive:

{
    "active": false,
}

An invalid request will return a 400, an unauthorized request 401.

Note

You can use the IdentityModel client library to programmatically access the introspection endpoint from .NET code. For more information check the IdentityModel docs.

Revocation Endpoint

This endpoint allows revoking access tokens (reference tokens only) and refresh token. It implements the token revocation specification (RFC 7009).

token
the token to revoke (required)
token_type_hint
either access_token or refresh_token (optional)

Example

POST /connect/revocation HTTP/1.1
Host: server.example.com
Content-Type: application/x-www-form-urlencoded
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW

token=45ghiukldjahdnhzdauz&token_type_hint=refresh_token

Note

You can use the IdentityModel client library to programmatically access the revocation endpoint from .NET code. For more information check the IdentityModel docs.

End Session Endpoint

The end session endpoint can be used to trigger single sign-out (see spec).

To use the end session endpoint a client application will redirect the user’s browser to the end session URL. All applications that the user has logged into via the browser during the user’s session can participate in the sign-out.

Note

The URL for the end session endpoint is available via the discovery endpoint.

Parameters

id_token_hint

When the user is redirected to the endpoint, they will be prompted if they really want to sign-out. This prompt can be bypassed by a client sending the original id_token received from authentication. This is passed as a query string parameter called id_token_hint.

post_logout_redirect_uri

If a valid id_token_hint is passed, then the client may also send a post_logout_redirect_uri parameter. This can be used to allow the user to redirect back to the client after sign-out. The value must match one of the client’s pre-configured PostLogoutRedirectUris (client docs).

state

If a valid post_logout_redirect_uri is passed, then the client may also send a state parameter. This will be returned back to the client as a query string parameter after the user redirects back to the client. This is typically used by clients to round-trip state across the redirect.

Example

GET /connect/endsession?id_token_hint=eyJhbGciOiJSUzI1NiIsImtpZCI6IjdlOGFkZmMzMjU1OTEyNzI0ZDY4NWZmYmIwOThjNDEyIiwidHlwIjoiSldUIn0.eyJuYmYiOjE0OTE3NjUzMjEsImV4cCI6MTQ5MTc2NTYyMSwiaXNzIjoiaHR0cDovL2xvY2FsaG9zdDo1MDAwIiwiYXVkIjoianNfb2lkYyIsIm5vbmNlIjoiYTQwNGFjN2NjYWEwNGFmNzkzNmJjYTkyNTJkYTRhODUiLCJpYXQiOjE0OTE3NjUzMjEsInNpZCI6IjI2YTYzNWVmOTQ2ZjRiZGU3ZWUzMzQ2ZjFmMWY1NTZjIiwic3ViIjoiODg0MjExMTMiLCJhdXRoX3RpbWUiOjE0OTE3NjUzMTksImlkcCI6ImxvY2FsIiwiYW1yIjpbInB3ZCJdfQ.STzOWoeVYMtZdRAeRT95cMYEmClixWkmGwVH2Yyiks9BETotbSZiSfgE5kRh72kghN78N3-RgCTUmM2edB3bZx4H5ut3wWsBnZtQ2JLfhTwJAjaLE9Ykt68ovNJySbm8hjZhHzPWKh55jzshivQvTX0GdtlbcDoEA1oNONxHkpDIcr3pRoGi6YveEAFsGOeSQwzT76aId-rAALhFPkyKnVc-uB8IHtGNSyRWLFhwVqAdS3fRNO7iIs5hYRxeFSU7a5ZuUqZ6RRi-bcDhI-djKO5uAwiyhfpbpYcaY_TxXWoCmq8N8uAw9zqFsQUwcXymfOAi2UF3eFZt02hBu-shKA&post_logout_redirect_uri=http%3A%2F%2Flocalhost%3A7017%2Findex.html

Note

You can use the IdentityModel client library to programmatically create end_session requests .NET code. For more information check the IdentityModel docs.

Identity Resource

This class models an identity resource.

Enabled
Indicates if this resource is enabled and can be requested. Defaults to true.
Name
The unique name of the identity resource. This is the value a client will use for the scope parameter in the authorize request.
DisplayName
This value will be used e.g. on the consent screen.
Description
This value will be used e.g. on the consent screen.
Required
Specifies whether the user can de-select the scope on the consent screen (if the consent screen wants to implement such a feature). Defaults to false.
Emphasize
Specifies whether the consent screen will emphasize this scope (if the consent screen wants to implement such a feature). Use this setting for sensitive or important scopes. Defaults to false.
ShowInDiscoveryDocument
Specifies whether this scope is shown in the discovery document. Defaults to true.
UserClaims
List of associated user claim types that should be included in the identity token.

API Resource

This class model an API resource.

Enabled
Indicates if this resource is enabled and can be requested. Defaults to true.
Name
The unique name of the API. This value is used for authentication with introspection and will be added to the audience of the outgoing access token.
DisplayName
This value can be used e.g. on the consent screen.
Description
This value can be used e.g. on the consent screen.
ApiSecrets
The API secret is used for the introspection endpoint. The API can authenticate with introspection using the API name and secret.
UserClaims
List of associated user claim types that should be included in the access token.
Scopes
An API must have at least one scope. Each scope can have different settings.

Scopes

In the simple case an API has exactly one scope. But there are cases where you might want to sub-divide the functionality of an API, and give different clients access to different parts.

Name
The unique name of the scope. This is the value a client will use for the scope parameter in the authorize/token request.
DisplayName
This value can be used e.g. on the consent screen.
Description
This value can be used e.g. on the consent screen.
Required
Specifies whether the user can de-select the scope on the consent screen (if the consent screen wants to implement such a feature). Defaults to false.
Emphasize
Specifies whether the consent screen will emphasize this scope (if the consent screen wants to implement such a feature). Use this setting for sensitive or important scopes. Defaults to false.
ShowInDiscoveryDocument
Specifies whether this scope is shown in the discovery document. Defaults to true.
UserClaims
List of associated user claim types that should be included in the access token. The claims specified here will be added to the list of claims specified for the API.

Convenience Constructor Behavior

Just a note about the constructors provided for the ApiResource class.

For full control over the data in the ApiResource, use the default constructor with no parameters. You would use this approach if you wanted to configure multiple scopes per API. For example:

new ApiResource
{
    Name = "api2",

    Scopes =
    {
        new Scope()
        {
            Name = "api2.full_access",
            DisplayName = "Full access to API 2"
        },
        new Scope
        {
            Name = "api2.read_only",
            DisplayName = "Read only access to API 2"
        }
    }
}

For simpler scenarios where you only require one scope per API, then several convenience constructors which accept a name are provided. For example:

new ApiResource("api1", "Some API 1")

Using the convenience constructor is equivalent to this:

new ApiResource
{
    Name = "api1",
    DisplayName = "Some API 1",

    Scopes =
    {
        new Scope()
        {
            Name = "api1",
            DisplayName = "Some API 1"
        }
    }
}

Defining API resources in appsettings.json

The AddInMemoryApiResource extensions method also supports adding clients from the ASP.NET Core configuration file. This allows you to define static clients directly from the appsettings.json file:

"IdentityServer": {
  "IssuerUri": "urn:sso.company.com",
  "ApiResources": [
    {
      "Name": "api1",
      "DisplayName": "My API",

      "Scopes": [
        {
          "Name": "api1",
          "DisplayName": "My API"
        }
      ]
    }
  ]
}

Then pass the configuration section to the AddInMemoryApiResource method:

AddInMemoryApiResources(configuration.GetSection("IdentityServer:ApiResources"))

Client

The Client class models an OpenID Connect or OAuth 2.0 client - e.g. a native application, a web application or a JS-based application.

Basics

Enabled
Specifies if client is enabled. Defaults to true.
ClientId
Unique ID of the client
ClientSecrets
List of client secrets - credentials to access the token endpoint.
RequireClientSecret
Specifies whether this client needs a secret to request tokens from the token endpoint (defaults to true)
AllowedGrantTypes
Specifies the grant types the client is allowed to use. Use the GrantTypes class for common combinations.
RequirePkce
Specifies whether clients using an authorization code based grant type must send a proof key
AllowPlainTextPkce
Specifies whether clients using PKCE can use a plain text code challenge (not recommended - and default to false)
RedirectUris
Specifies the allowed URIs to return tokens or authorization codes to
AllowedScopes
By default a client has no access to any resources - specify the allowed resources by adding the corresponding scopes names
AllowOfflineAccess
Specifies whether this client can request refresh tokens (be requesting the offline_access scope)
AllowAccessTokensViaBrowser
Specifies whether this client is allowed to receive access tokens via the browser. This is useful to harden flows that allow multiple response types (e.g. by disallowing a hybrid flow client that is supposed to use code id_token to add the token response type and thus leaking the token to the browser.
Properties
Dictionary to hold any custom client-specific values as needed.

Authentication/Logout

PostLogoutRedirectUris
Specifies allowed URIs to redirect to after logout. See the OIDC Connect Session Management spec for more details.
FrontChannelLogoutUri
Specifies logout URI at client for HTTP based front-channel logout. See the OIDC Front-Channel spec for more details.
FrontChannelLogoutSessionRequired
Specifies if the user’s session id should be sent to the FrontChannelLogoutUri. Defaults to true.
BackChannelLogoutUri
Specifies logout URI at client for HTTP based back-channel logout. See the OIDC Back-Channel spec for more details.
BackChannelLogoutSessionRequired
Specifies if the user’s session id should be sent in the request to the BackChannelLogoutUri. Defaults to true.
EnableLocalLogin
Specifies if this client can use local accounts, or external IdPs only. Defaults to true.
IdentityProviderRestrictions
Specifies which external IdPs can be used with this client (if list is empty all IdPs are allowed). Defaults to empty.
UserSsoLifetime added in 2.3
The maximum duration (in seconds) since the last time the user authenticated. Defaults to null. You can adjust the lifetime of a session token to control when and how often a user is required to reenter credentials instead of being silently authenticated, when using a web application.

Token

IdentityTokenLifetime
Lifetime to identity token in seconds (defaults to 300 seconds / 5 minutes)
AccessTokenLifetime
Lifetime of access token in seconds (defaults to 3600 seconds / 1 hour)
AuthorizationCodeLifetime
Lifetime of authorization code in seconds (defaults to 300 seconds / 5 minutes)
AbsoluteRefreshTokenLifetime
Maximum lifetime of a refresh token in seconds. Defaults to 2592000 seconds / 30 days
SlidingRefreshTokenLifetime
Sliding lifetime of a refresh token in seconds. Defaults to 1296000 seconds / 15 days
RefreshTokenUsage

ReUse the refresh token handle will stay the same when refreshing tokens

OneTime the refresh token handle will be updated when refreshing tokens. This is the default.

RefreshTokenExpiration

Absolute the refresh token will expire on a fixed point in time (specified by the AbsoluteRefreshTokenLifetime)

Sliding when refreshing the token, the lifetime of the refresh token will be renewed (by the amount specified in SlidingRefreshTokenLifetime). The lifetime will not exceed AbsoluteRefreshTokenLifetime.

UpdateAccessTokenClaimsOnRefresh
Gets or sets a value indicating whether the access token (and its claims) should be updated on a refresh token request.
AccessTokenType
Specifies whether the access token is a reference token or a self contained JWT token (defaults to Jwt).
IncludeJwtId
Specifies whether JWT access tokens should have an embedded unique ID (via the jti claim).
AllowedCorsOrigins
If specified, will be used by the default CORS policy service implementations (In-Memory and EF) to build a CORS policy for JavaScript clients.
Claims
Allows settings claims for the client (will be included in the access token).
AlwaysSendClientClaims
If set, the client claims will be sent for every flow. If not, only for client credentials flow (default is false)
AlwaysIncludeUserClaimsInIdToken
When requesting both an id token and access token, should the user claims always be added to the id token instead of requring the client to use the userinfo endpoint. Default is false.
ClientClaimsPrefix
If set, the prefix client claim types will be prefixed with. Defaults to client_. The intent is to make sure they don’t accidentally collide with user claims.
PairWiseSubjectSalt
Salt value used in pair-wise subjectId generation for users of this client.

Device flow

UserCodeType
Specifies the type of user code to use for the client. Otherwise falls back to default.
DeviceCodeLifetime
Lifetime to device code in seconds (defaults to 300 seconds / 5 minutes)

GrantValidationResult

The GrantValidationResult class models the outcome of grant validation for extensions grants and resource owner password grants.

The most common usage is to either new it up using an identity (success case):

context.Result = new GrantValidationResult(
    subject: "818727",
    authenticationMethod: "custom",
    claims: optionalClaims);

…or using an error and description (failure case):

context.Result = new GrantValidationResult(
    TokenRequestErrors.InvalidGrant,
    "invalid custom credential");

In both case you can pass additional custom values that will be included in the token response.

Profile Service

Often IdentityServer requires identity information about users when creating tokens or when handling requests to the userinfo or introspection endpoints. By default, IdentityServer only has the claims in the authentication cookie to draw upon for this identity data.

It is impractical to put all of the possible claims needed for users into the cookie, so IdentityServer defines an extensibility point for allowing claims to be dynamically loaded as needed for a user. This extensibility point is the IProfileService and it is common for a developer to implement this interface to access a custom database or API that contains the identity data for users.

IProfileService APIs

GetProfileDataAsync
The API that is expected to load claims for a user. It is passed an instance of ProfileDataRequestContext.
IsActiveAsync
The API that is expected to indicate if a user is currently allowed to obtain tokens. It is passed an instance of IsActiveContext.

ProfileDataRequestContext

Models the request for user claims and is the vehicle to return those claims. It contains these properties:

Subject
The ClaimsPrincipal modeling the user.
Client
The Client for which the claims are being requested.
RequestedClaimTypes
The collection of claim types being requested.
Caller
An identifier for the context in which the claims are being requested (e.g. an identity token, an access token, or the user info endpoint). The constant IdentityServerConstants.ProfileDataCallers contains the different constant values.
IssuedClaims
The list of Claim s that will be returned. This is expected to be populated by the custom IProfileService implementation.
AddRequestedClaims
Extension method on the ProfileDataRequestContext to populate the IssuedClaims, but first filters the claims based on RequestedClaimTypes.

Requested scopes and claims mapping

The scopes requested by the client control what user claims are returned in the tokens to the client. The GetProfileDataAsync method is responsible for dynamically obtaining those claims based on the RequestedClaimTypes collection on the ProfileDataRequestContext.

The RequestedClaimTypes collection is populated based on the user claims defined on the resources that model the scopes. If the scopes requested are an identity resources, then the claims in the RequestedClaimTypes will be populated based on the user claim types defined in the IdentityResource. If the scopes requested are an API resources, then the claims in the RequestedClaimTypes will be populated based on the user claim types defined in the ApiResource and/or the Scope.

IsActiveContext

Models the request to determine is the user is currently allowed to obtain tokens. It contains these properties:

Subject
The ClaimsPrincipal modeling the user.
Client
The Client for which the claims are being requested.
Caller
An identifier for the context in which the claims are being requested (e.g. an identity token, an access token, or the user info endpoint). The constant IdentityServerConstants.ProfileDataCallers contains the different constant values.
IsActive
The flag indicating if the user is allowed to obtain tokens. This is expected to be assigned by the custom IProfileService implementation.

IdentityServer Interaction Service

The IIdentityServerInteractionService interface is intended to provide services to be used by the user interface to communicate with IdentityServer, mainly pertaining to user interaction. It is available from the dependency injection system and would normally be injected as a constructor parameter into your MVC controllers for the user interface of IdentityServer.

IIdentityServerInteractionService APIs

GetAuthorizationContextAsync
Returns the AuthorizationRequest based on the returnUrl passed to the login or consent pages.
IsValidReturnUrl
Indicates if the returnUrl is a valid URL for redirect after login or consent.
GetErrorContextAsync
Returns the ErrorMessage based on the errorId passed to the error page.
GetLogoutContextAsync
Returns the LogoutRequest based on the logoutId passed to the logout page.
CreateLogoutContextAsync
Used to create a logoutId if there is not one presently. This creates a cookie capturing all the current state needed for signout and the logoutId identifies that cookie. This is typically used when there is no current logoutId and the logout page must capture the current user’s state needed for sign-out prior to redirecting to an external identity provider for signout. The newly created logoutId would need to be round-tripped to the external identity provider at signout time, and then used on the signout callback page in the same way it would be on the normal logout page.
GrantConsentAsync
Accepts a ConsentResponse to inform IdentityServer of the user’s consent to a particular AuthorizationRequest.
GetAllUserConsentsAsync
Returns a collection of Consent for the user.
RevokeUserConsentAsync
Revokes all of a user’s consents and grants for a client.
RevokeTokensForCurrentSessionAsync
Revokes all of a user’s consents and grants for clients the user has signed into during their current session.

AuthorizationRequest

ClientId
The client identifier that initiated the request.
RedirectUri
The URI to redirect the user to after successful authorization.
DisplayMode
The display mode passed from the authorization request.
UiLocales
The UI locales passed from the authorization request.
IdP
The external identity provider requested. This is used to bypass home realm discovery (HRD). This is provided via the “idp:” prefix to the acr_values parameter on the authorize request.
Tenant
The tenant requested. This is provided via the “tenant:” prefix to the acr_values parameter on the authorize request.
LoginHint
The expected username the user will use to login. This is requested from the client via the login_hint parameter on the authorize request.
PromptMode
The prompt mode requested from the authorization request.
AcrValues
The acr values passed from the authorization request.
ScopesRequested
The scopes requested from the authorization request.
Parameters
The entire parameter collection passed to the authorization request.

ErrorMessage

DisplayMode
The display mode passed from the authorization request.
UiLocales
The UI locales passed from the authorization request.
Error
The error code.
RequestId
The per-request identifier. This can be used to display to the end user and can be used in diagnostics.

LogoutRequest

ClientId
The client identifier that initiated the request.
PostLogoutRedirectUri
The URL to redirect the user to after they have logged out.
SessionId
The user’s current session id.
SignOutIFrameUrl
The URL to render in an <iframe> on the logged out page to enable single sign-out.
Parameters
The entire parameter collection passed to the end session endpoint.
ShowSignoutPrompt
Indicates if the user should be prompted for signout based upon the parameters passed to the end session endpoint.

ConsentResponse

ScopesConsented
The collection of scopes the user consented to.
RememberConsent
Flag indicating if the user’s consent is to be persisted.

Device Flow Interaction Service

The IDeviceFlowInteractionService interface is intended to provide services to be used by the user interface to communicate with IdentityServer during device flow authorization. It is available from the dependency injection system and would normally be injected as a constructor parameter into your MVC controllers for the user interface of IdentityServer.

IDeviceFlowInteractionService APIs

GetAuthorizationContextAsync
Returns the DeviceFlowAuthorizationRequest based on the userCode passed to the login or consent pages.
DeviceFlowInteractionResult
Completes device authorization for the given userCode.

DeviceFlowAuthorizationRequest

ClientId
The client identifier that initiated the request.
ScopesRequested
The scopes requested from the authorization request.

DeviceFlowInteractionResult

IsError
Specifies if the authorization request errored.
ErrorDescription
Error description upon failure.

IdentityServer Options

  • IssuerUri
    Set the issuer name that will appear in the discovery document and the issued JWT tokens. It is recommended to not set this property, which infers the issuer name from the host name that is used by the clients.
  • PublicOrigin
    The origin of this server instance, e.g. https://myorigin.com. If not set, the origin name is inferred from the request.

Endpoints

Allows enabling/disabling individual endpoints, e.g. token, authorize, userinfo etc.

By default all endpoints are enabled, but you can lock down your server by disabling endpoint that you don’t need.

  • EnableJwtRequestUri
    JWT request_uri processing is enabled on the authorize endpoint. Defaults to false.

Discovery

Allows enabling/disabling various sections of the discovery document, e.g. endpoints, scopes, claims, grant types etc.

The CustomEntries dictionary allows adding custom elements to the discovery document.

Authentication

  • CookieAuthenticationScheme
    Sets the cookie authenitcation scheme confgured by the host used for interactive users. If not set, the scheme will inferred from the host’s default authentication scheme. This setting is typically used when AddPolicyScheme is used in the host as the default scheme.
  • CookieLifetime
    The authentication cookie lifetime (only effective if the IdentityServer-provided cookie handler is used).
  • CookieSlidingExpiration
    Specified if the cookie should be sliding or not (only effective if the IdentityServer-provided cookie handler is used).
  • RequireAuthenticatedUserForSignOutMessage
    Indicates if user must be authenticated to accept parameters to end session endpoint. Defaults to false.
  • CheckSessionCookieName
    The name of the cookie used for the check session endpoint.
  • RequireCspFrameSrcForSignout
    If set, will require frame-src CSP headers being emitting on the end session callback endpoint which renders iframes to clients for front-channel signout notification. Defaults to true.

Events

Allows configuring if and which events should be submitted to a registered event sink. See here for more information on events.

InputLengthRestrictions

Allows setting length restrictions on various protocol parameters like client id, scope, redirect URI etc.

UserInteraction

  • LoginUrl, LogoutUrl, ConsentUrl, ErrorUrl, DeviceVerificationUrl
    Sets the URLs for the login, logout, consent, error and device verification pages.
  • LoginReturnUrlParameter
    Sets the name of the return URL parameter passed to the login page. Defaults to returnUrl.
  • LogoutIdParameter
    Sets the name of the logout message id parameter passed to the logout page. Defaults to logoutId.
  • ConsentReturnUrlParameter
    Sets the name of the return URL parameter passed to the consent page. Defaults to returnUrl.
  • ErrorIdParameter
    Sets the name of the error message id parameter passed to the error page. Defaults to errorId.
  • CustomRedirectReturnUrlParameter
    Sets the name of the return URL parameter passed to a custom redirect from the authorization endpoint. Defaults to returnUrl.
  • DeviceVerificationUserCodeParameter
    Sets the name of the user code parameter passed to the device verification page. Defaults to userCode.
  • CookieMessageThreshold
    Certain interactions between IdentityServer and some UI pages require a cookie to pass state and context (any of the pages above that have a configurable “message id” parameter). Since browsers have limits on the number of cookies and their size, this setting is used to prevent too many cookies being created. The value sets the maximum number of message cookies of any type that will be created. The oldest message cookies will be purged once the limit has been reached. This effectively indicates how many tabs can be opened by a user when using IdentityServer.

Caching

These setting only apply if the respective caching has been enabled in the services configuration in startup.

  • ClientStoreExpiration
    Cache duration of client configuration loaded from the client store.
  • ResourceStoreExpiration
    Cache duration of identity and API resource configuration loaded from the resource store.

CORS

IdentityServer supports CORS for some of its endpoints. The underlying CORS implementation is provided from ASP.NET Core, and as such it is automatically registered in the dependency injection system.

  • CorsPolicyName
    Name of the CORS policy that will be evaluated for CORS requests into IdentityServer (defaults to "IdentityServer4"). The policy provider that handles this is implemented in terms of the ICorsPolicyService registered in the dependency injection system. If you wish to customize the set of CORS origins allowed to connect, then it is recommended that you provide a custom implementation of ICorsPolicyService.
  • CorsPaths
    The endpoints within IdentityServer where CORS is supported. Defaults to the discovery, user info, token, and revocation endpoints.
  • PreflightCacheDuration
    Nullable<TimeSpan> indicating the value to be used in the preflight Access-Control-Max-Age response header. Defaults to null indicating no caching header is set on the response.

CSP (Content Security Policy)

IdentityServer emits CSP headers for some responses, where appropriate.

  • Level
    The level of CSP to use. CSP Level 2 is used by default, but if older browsers must be supported then this be changed to CspLevel.One to accomodate them.
  • AddDeprecatedHeader
    Indicates if the older X-Content-Security-Policy CSP header should also be emitted (in addition to the standards-based header value). Defaults to true.

Device Flow

  • DefaultUserCodeType
    The user code type to use, unless set at the client level. Defaults to Numeric, a 9-digit code.
  • Interval
    Defines the minimum allowed polling interval on the token endpoint. Defaults to 5.

Mutual TLS

  • Enabled
    Specifies if MTLS support should be enabled. Defaults to false.
  • ClientCertificateAuthenticationScheme
    Specifies the name of the authentication handler for X.509 client certificates. Defaults to "Certificate".

Entity Framework Support

An EntityFramework-based implementation is provided for the configuration and operational data extensibility points in IdentityServer. The use of EntityFramework allows any EF-supported database to be used with this library.

The repo for this library is located here and the NuGet package is here.

The features provided by this library are broken down into two main areas: configuration store and operational store support. These two different areas can be used independently or together, based upon the needs of the hosting application.

Configuration Store support for Clients, Resources, and CORS settings

If client, identity resource, API resource, or CORS data is desired to be loaded from a EF-supported database (rather than use in-memory configuration), then the configuration store can be used. This support provides implementations of the IClientStore, IResourceStore, and the ICorsPolicyService extensibility points. These implementations use a DbContext-derived class called ConfigurationDbContext to model the tables in the database.

To use the configuration store support, use the AddConfigurationStore extension method after the call to AddIdentityServer:

public IServiceProvider ConfigureServices(IServiceCollection services)
{
    const string connectionString = @"Data Source=(LocalDb)\MSSQLLocalDB;database=IdentityServer4.EntityFramework-2.0.0;trusted_connection=yes;";
    var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;

    services.AddIdentityServer()
        // this adds the config data from DB (clients, resources, CORS)
        .AddConfigurationStore(options =>
        {
            options.ConfigureDbContext = builder =>
                builder.UseSqlServer(connectionString,
                    sql => sql.MigrationsAssembly(migrationsAssembly));
        });
}

To configure the configuration store, use the ConfigurationStoreOptions options object passed to the configuration callback.

ConfigurationStoreOptions

This options class contains properties to control the configuration store and ConfigurationDbContext.

ConfigureDbContext
Delegate of type Action<DbContextOptionsBuilder> used as a callback to configure the underlying ConfigurationDbContext. The delegate can configure the ConfigurationDbContext in the same way if EF were being used directly with AddDbContext, which allows any EF-supported database to be used.
DefaultSchema

Allows setting the default database schema name for all the tables in the ConfigurationDbContext

options.DefaultSchema = "myConfigurationSchema";

If you need to change the schema for the Migration History Table, you can chain another action to the UseSqlServer:

options.ConfigureDbContext = b =>
    b.UseSqlServer(connectionString,
        sql => sql.MigrationsAssembly(migrationsAssembly).MigrationsHistoryTable("MyConfigurationMigrationTable", "myConfigurationSchema"));

Operational Store support for authorization grants, consents, and tokens (refresh and reference)

If authorization grants, consents, and tokens (refresh and reference) are desired to be loaded from a EF-supported database (rather than the default in-memory database), then the operational store can be used. This support provides implementations of the IPersistedGrantStore extensibility point. The implementation uses a DbContext-derived class called PersistedGrantDbContext to model the table in the database.

To use the operational store support, use the AddOperationalStore extension method after the call to AddIdentityServer:

public IServiceProvider ConfigureServices(IServiceCollection services)
{
    const string connectionString = @"Data Source=(LocalDb)\MSSQLLocalDB;database=IdentityServer4.EntityFramework-2.0.0;trusted_connection=yes;";
    var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;

    services.AddIdentityServer()
        // this adds the operational data from DB (codes, tokens, consents)
        .AddOperationalStore(options =>
        {
            options.ConfigureDbContext = builder =>
                builder.UseSqlServer(connectionString,
                    sql => sql.MigrationsAssembly(migrationsAssembly));

            // this enables automatic token cleanup. this is optional.
            options.EnableTokenCleanup = true;
            options.TokenCleanupInterval = 30; // interval in seconds
        });
}

To configure the operational store, use the OperationalStoreOptions options object passed to the configuration callback.

OperationalStoreOptions

This options class contains properties to control the operational store and PersistedGrantDbContext.

ConfigureDbContext
Delegate of type Action<DbContextOptionsBuilder> used as a callback to configure the underlying PersistedGrantDbContext. The delegate can configure the PersistedGrantDbContext in the same way if EF were being used directly with AddDbContext, which allows any EF-supported database to be used.
DefaultSchema
Allows setting the default database schema name for all the tables in the PersistedGrantDbContext.
EnableTokenCleanup
Indicates whether stale entries will be automatically cleaned up from the database. The default is false.
TokenCleanupInterval
The token cleanup interval (in seconds). The default is 3600 (1 hour).

Database creation and schema changes across different versions of IdentityServer

It is very likely that across different versions of IdentityServer (and the EF support) that the database schema will change to accommodate new and changing features.

We do not provide any support for creating your database or migrating your data from one version to another. You are expected to manage the database creation, schema changes, and data migration in any way your organization sees fit.

Using EF migrations is one possible approach to this. If you do wish to use migrations, then see the EF quickstart for samples on how to get started, or consult the Microsoft documentation on EF migrations.

We also publish sample SQL scripts for the current version of the database schema.

ASP.NET Identity Support

An ASP.NET Identity-based implementation is provided for managing the identity database for users of IdentityServer. This implementation implements the extensibility points in IdentityServer needed to load identity data for your users to emit claims into tokens.

The repo for this support is located here and the NuGet package is here.

To use this library, configure ASP.NET Identity normally. Then use the AddAspNetIdentity extension method after the call to AddIdentityServer:

public void ConfigureServices(IServiceCollection services)
{
    services.AddIdentity<ApplicationUser, IdentityRole>()
        .AddEntityFrameworkStores<ApplicationDbContext>()
        .AddDefaultTokenProviders();

    services.AddIdentityServer()
        .AddAspNetIdentity<ApplicationUser>();
}

AddAspNetIdentity requires as a generic parameter the class that models your user for ASP.NET Identity (and the same one passed to AddIdentity to configure ASP.NET Identity). This configures IdentityServer to use the ASP.NET Identity implementations of IUserClaimsPrincipalFactory, IResourceOwnerPasswordValidator, and IProfileService. It also configures some of ASP.NET Identity’s options for use with IdentityServer (such as claim types to use and authentication cookie settings).

Training

Here are some online, remote and classroom training options to learn more about ASP.NET Core identity & IdentityServer4.

Identity & Access Control for modern Applications (using ASP.NET Core 2 and IdentityServer4)

That’s our own three day flagship course (including extensive hands-on labs) that we deliver as part of conferences, on-sites and remote.

The agenda and dates for public training can be found here, contact us for private workshops.

Blog posts

Videos