mock-oauth2-server

A scriptable/customizable web server for testing HTTP clients using OAuth2/OpenID Connect or applications with a dependency to a running OAuth2 server (i.e. APIs requiring signed JWTs from a known issuer). The server also provides the necessary endpoints for token validation (endpoint for JWKS) and ID Provider metadata discovery ("well-known" endpoints providing server metadata)

mock-oauth2-server is written in Kotlin using the great OkHttp MockWebServer as the underlying server library and can be used in unit/integration tests in both Java and Kotlin or in any language as a standalone server in e.g. docker-compose.

Even though the server aims to be compliant with regards to the supported OAuth2/OpenID Connect specifications, you should never use it for anything else than tests. That being said, when developing OAuth2 clients you should always verify that the expected requests are being made in your tests.

Motivation

The motivation behind this library is to provide a setup such that application developers don't feel the need to disable security in their apps when running tests! If you have any issues with regards to OAuth2 and tokens et. al. and consider to disable "security" when running tests please submit an issue or a PR so that we can all help developers and security to live in harmony once again (if ever..)!

Features

• Multi-issuer/Multi-tenancy support: the server can represent as many different Identity Providers/Token Issuers as you need (with different token issuer names) WITHOUT any setup!
• Implements OAuth2/OpenID Connect grants/flows
  • OpenID Connect Authorization Code Flow
  • OAuth2 Client Credentials Grant
  • OAuth2 JWT Bearer Grant (On-Behalf-Of flow)
  • OAuth2 Token Exchange Grant
  • OAuth2 Refresh Token Grant
  • OAuth2 Resource Owner Password Credentials (Password Grant)
    • usage should be avoided if possible as this grant is considered insecure and removed in its entirety from OAuth 2.1
• Issued JWT tokens are verifiable through standard mechanisms with OpenID Connect Discovery / OAuth2 Authorization Server Metadata
• Unit/Integration test support
  • Start and stop server for each test
  • Sane defaults with minimal setup if you don't need token customization
  • Enqueue expected tokens if you need to customize token claims
  • Enqueue expected responses
  • Verify expected requests made to the server
  • Customizable through exposure of underlying OkHttp MockWebServer
• Standalone support - i.e. run as application in IDE, run inside your app, or as a Docker image (provided)
• OAuth2 Client Debugger - e.g. support for triggering OIDC Auth Code Flow and receiving callback in debugger app, view token response from server (intended for standalone support)

API Documentation

mock-oauth2-server

📦 Install

Gradle Kotlin DSL

Latest version

testImplementation("no.nav.security:mock-oauth2-server:$mockOAuth2ServerVersion")

Maven

Latest version

<dependency>
  <groupId>no.nav.security</groupId>
  <artifactId>mock-oauth2-server</artifactId>
  <version>${mock-oauth2-server.version}</version>
  <scope>test</scope>
</dependency>

Docker

Latest version

docker pull ghcr.io/navikt/mock-oauth2-server:$MOCK_OAUTH2_SERVER_VERSION

⌨️ Usage

Well-Known Configuration

The mock-oauth2-server will supply different configurations depending on the url used against the server, more specifically the first path (or context root) element in your request url will specify the issuerId.

A request to http://localhost:8080/default/.well-known/openid-configuration will yield an issuerId of default with the following configuration:

{
   "issuer":"http://localhost:8080/default",
   "authorization_endpoint":"http://localhost:8080/default/authorize",
   "end_session_endpoint" : "http://localhost:8080/default/endsession",
   "revocation_endpoint" : "http://localhost:8080/default/revoke",
   "token_endpoint":"http://localhost:8080/default/token",
   "userinfo_endpoint":"http://localhost:8080/default/userinfo",
   "jwks_uri":"http://localhost:8080/default/jwks",
   "introspection_endpoint":"http://localhost:8080/default/introspect",
   "response_types_supported":[
      "query",
      "fragment",
      "form_post"
   ],
   "subject_types_supported":[
      "public"
   ],
   "id_token_signing_alg_values_supported":[
     "ES256",
     "ES384",
     "RS256",
     "RS384",
     "RS512",
     "PS256",
     "PS384",
     "PS512"
   ],
  "code_challenge_methods_supported":[
      "plain", 
      "S256" 
  ]
}

The actual issuer value in a JWT will be iss: "http://localhost:8080/default"

To use another issuer with id anotherissuer simply make a request to http://localhost:8080/anotherissuer/.well-known/openid-configuration and the configuration will change accordingly.

Unit tests

Setup test

• Start the server at a random port
• Get url for server metadata/configuration
• Setup your app to use the OAuth2 server metadata and conduct your tests
• Shutdown the server

val server = MockOAuth2Server()
server.start()
// Can be anything you choose - should uniquely identify your issuer if you have several
val issuerId = "default"
// Discovery url to authorization server metadata
val wellKnownUrl = server.wellKnownUrl(issuerId).toString()
// ......
// Setup your app with metadata from wellKnownUrl and do your testing here
// ......
server.shutdown()

Testing an app requiring user login with OpenID Connect Authorization Code Flow

• Setup test like above
• Make your test HTTP client follow redirects
• Your callback (redirect_uri) endpoint should receive the callback request as required and be able to retrieve a token from the token endpoint.

If you need to get a login for a specific user you can use the OAuth2TokenCallback interface to provide your own or set values in the DefaultOAuth2TokenCallback

@Test
fun loginWithIdTokenForSubjectFoo() {
    server.enqueueCallback(
        DefaultOAuth2TokenCallback(
            issuerId = issuerId,
            subject = "foo"
        )
    )
  // Invoke your app here and assert user foo is logged in
}

If you need specific claims in the resulting id_token - e.g. acr or a custom claim you can also use the OAuth2TokenCallback:

@Test
fun loginWithIdTokenForAcrClaimEqualsLevel4() {
    server.enqueueCallback(
        DefaultOAuth2TokenCallback(
            issuerId = issuerId,
            claims = mapOf("acr" to "Level4")
        )
    )
  // Invoke your app here and assert acr=Level4 is present in id_token
}

Testing an API requiring access_token (e.g. a signed JWT)

val token: SignedJWT = oAuth2Server.issueToken(issuerId, "someclientid", DefaultOAuth2TokenCallback())
//use your favourite HTTP client to invoke your API and attach the serialized token
val request = // ....
request.addHeader("Authorization", "Bearer ${token.serialize()}")

More examples

Have a look at some examples in both Java and Kotlin in the src/test directory:

• Kotlin with the ktor framework
• Java with Spring Boot and Spring Security

API

Server URLs

You can retrieve URLs from the server with the correct port and issuerId etc. by invoking one of the fun *Url(issuerId: String): HttpUrl functions/methods:

val server = MockOAuth2Server()
server.start()
val wellKnownUrl = server.wellKnownUrl("yourissuer")
// will result in the following url:
// http://localhost:<a random port>/yourissuer/.well-known/openid-configuration

Standalone server

The standalone server will default to port 8080 and can be started by invoking main() in StandaloneMockOAuth2Server.kt (in kotlin) or StandaloneMockOAuth2ServerKt (in Java)

On Windows, it's easier to run the server in docker while specifying the host as localhost, e.g. docker run -p 8080:8080 -h localhost $IMAGE_NAME

Note If you want to check if the server is up and running you can visit /isalive and see if you get a 200 in return.

Configuration

The standalone server supports the following configuration by ENV variables:

Variable	Description
SERVER_HOSTNAME	Lets the standalone server bind to a specific hostname, by default it binds to 0.0.0.0
SERVER_PORT or PORT	The port that the standalone server will listen to, defaults to 8080. The PORT environment variable may be used to run the Docker image on Heroku as per the documentation here.
JSON_CONFIG_PATH	The absolute path to a json file containing configuration about the OAuth2 part of the server (OAuth2Config). More details on the format below.
JSON_CONFIG	The actual JSON content of OAuth2Config, this ENV var takes precedence over the JSON_CONFIG_PATH var. More details on the format below.
LOG_LEVEL	How verbose the root logging output is, defaults to INFO

JSON_CONFIG

The JSON_CONFIG lets you configure the contents of the OAuth2Config class using JSON.

Example:

{
    "interactiveLogin": true,
    "httpServer": "NettyWrapper",
    "tokenCallbacks": [
        {
            "issuerId": "issuer1",
            "tokenExpiry": 120,
            "requestMappings": [
                {
                    "requestParam": "scope",
                    "match": "scope1",
                    "claims": {
                        "sub": "subByScope",
                        "aud": [
                            "audByScope"
                        ]
                    }
                }
            ]
        },
        {
            "issuerId": "issuer2",
            "requestMappings": [
                {
                    "requestParam": "someparam",
                    "match": "somevalue",
                    "claims": {
                        "sub": "subBySomeParam",
                        "aud": [
                            "audBySomeParam"
                        ]
                    }
                }
            ]
        }
    ]
}

A token provider can support different signing algorithms. Configure your token provider and add this to your config with preferred JWS algorithm:

{
  "tokenProvider" : {
    "keyProvider" : {
      "algorithm" : "ES256"
    }
  }
}

Property	Description
interactiveLogin	true or false, enables login screen when redirecting to server /authorize endpoint
loginPagePath	An optional string refering to a html file that is served as login page. This page needs to contain a form that posts a username and optionally a claims field. See src/test/resource/login.example.html as an example.
staticAssetsPath	The path to a directory containing static resources/assets. Lets you serve your own static resources from the server. Resources are served under the /static URL path. E.g. http://localhost:8080/static/myimage.svg or by reference /static/myimage.svg from the login page.
rotateRefreshToken	true or false, setting to true will generate a new unique refresh token when using the refresh_token grant.
httpServer	A string identifying the httpserver to use. Must match one of the following enum values: MockWebServerWrapper or NettyWrapper
tokenCallbacks	A list of RequestMappingTokenCallback that lets you specify which token claims to return when a token request matches the specified condition.

From the JSON example above:

A token request to http://localhost:8080/issuer1/token with parameter scope equal to scope1 will match the first tokenCallback:

{
    "issuerId": "issuer1",
    "tokenExpiry": 120,
    "requestMappings": [
        {
            "requestParam": "scope",
            "match": "scope1",
            "claims": {
                "sub": "subByScope",
                "aud": [
                    "audByScope"
                ]
            }
        }
    ]
}

and return a token response containing a token with the following claims:

{
  "sub": "subByScope",
  "aud": "audByScope",
  "nbf": 1616416942,
  "iss": "http://localhost:54905/issuer1",
  "exp": 1616417062,
  "iat": 1616416942,
  "jti": "28697333-6f25-4b1f-b2c2-409ce010933a"
}

Use variable clientId to set sub claim for Client Credentials Grant dynamically.

A token request with client credentials where clientId = myClientId and tokenCallback:

{
    "issuerId": "issuer1",
    "tokenExpiry": 120,
    "requestMappings": [
        {
            "requestParam": "scope",
            "match": "scope1",
            "claims": {
                "sub": "${clientId}",
                "aud": [
                    "audByScope"
                ]
            }
        }
    ]
}

will return a token response containing a token with the following claims:

{
  "sub": "myClientId",
  "aud": "audByScope",
  "nbf": 1616416942,
  "iss": "http://localhost:54905/issuer1",
  "exp": 1616417062,
  "iat": 1616416942,
  "jti": "28697333-6f25-4b1f-b2c2-409ce010933a"
}

Docker

Build to local docker daemon

./gradlew -Djib.from.platforms=linux/amd64 jibDockerBuild # or alternatively -Djib.from.platforms=linux/arm64 for ARM64

Run container

docker run -p 8080:8080 $IMAGE_NAME

Docker-Compose

In order to get container-to-container networking to work smoothly alongside browser interaction you must specify a host entry in your hosts file, 127.0.0.1 host.docker.internal and set hostname in the mock-oauth2-server service in your docker-compose.yaml file:

version: '3.7'
services:
  your_app:
    build: .
    ports:
      - 8080:8080
  mock-oauth2-server:
    image: ghcr.io/navikt/mock-oauth2-server:$MOCK_OAUTH2_SERVER_VERSION
    ports:
      - 8080:8080
    hostname: host.docker.internal

Debugger

The debugger is a OAuth2 client implementing the authorization_code flow with a UI for debugging (e.g. request parameters). Point your browser to http://localhost:8080/default/debugger to check it out.

Enabling HTTPS

In order to enable HTTPS you can either provide your own keystore or let the server generate one for you.

Unit tests

You need to supply the server with an SSL config, in order to do that you must specify your chosen server type in OAuth2Config and pass in the SSL config to your server.

Generate keystore:

val ssl = Ssl()
val server = MockOAuth2Server(
    OAuth2Config(httpServer = MockWebServerWrapper(ssl))
)

This will generate a SSL certificate for localhost and can be added to your client's truststore by getting the ssl config: ssl.sslKeystore.keyStore

Bring your own:

val ssl = Ssl(
    SslKeystore(
        keyPassword = "",
        keystoreFile = File("src/test/resources/localhost.p12"),
        keystorePassword = "",
        keystoreType = SslKeystore.KeyStoreType.PKCS12
    )
)
val server = MockOAuth2Server(
    OAuth2Config(httpServer = MockWebServerWrapper(ssl))
)

Docker / Standalone mode - JSON_CONFIG

In order to enable HTTPS for the server in Docker or standalone mode you can either make the server generate the keystore or bring your own.

Generate keystore:

{
  "httpServer" : {
    "type" : "NettyWrapper",
    "ssl" : {}
  }
}

Bring your own:

{
    "httpServer" : {
        "type" : "NettyWrapper",
        "ssl" : {
            "keyPassword" : "",
            "keystoreFile" : "src/test/resources/localhost.p12",
            "keystoreType" : "PKCS12",
            "keystorePassword" : "" 
        }
    }
}

Upgrading the gradle wrapper

Find the newest version of gradle here: https://gradle.org/releases/ Then run this command: ./gradlew wrapper --gradle-version $gradleVersion

Remeber to also update the gradle version in the build.gradle.kts file gradleVersion = "$gradleVersion"

👥 Contact

This project is currently maintained by the organisation @navikt.

If you need to raise an issue or question about this library, please create an issue here and tag it with the appropriate label.

For contact requests within the @navikt org, you can use the Slack channel #pig_sikkerhet

If you need to contact anyone directly, please see contributors.

✏️ Contributing

To get started, please fork the repo and checkout a new branch. You can then build the library with the Gradle wrapper

./gradlew build

See more info in CONTRIBUTING.md

⚖️ License

This library is licensed under the MIT License