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OAuth 2.0 Authorization Code Grant#

The Authorization Code grant type is used by confidential and public clients to exchange an authorization code for an access token. After the user returns to the client via the redirect URL, the application will get the authorization code from the URL and use it to request an access token.

Sequence Diagram#


sequenceDiagram
title Authorization code flow
autonumber 1

participant Resource owner User 
activate Resource owner User
Client->>Jans AS:Authorization Request
activate Client 
activate Jans AS
Resource owner User ->>Jans AS:User login and consent
Jans AS-->>Client:Authorization code response
deactivate Client
deactivate Jans AS

Client->>Jans AS: Exchange code for Access Token
activate Client
activate Jans AS
Jans AS-->>Client: Access Token with optional Refresh Token
deactivate Client
deactivate Jans AS

loop 
    Client->>Resource Server: Call API with Access Token
    activate Client
    activate Resource Server
    Resource Server-->>Client: Protected Resource
    deactivate Client
    deactivate Resource Server
end


Client->>Resource Server: Call API with expired Access Token
activate Client
activate Resource Server
Resource Server-->>Client: Invalid token error
deactivate Client
deactivate Resource Server


Client->>Jans AS: Resource Token
activate Client
activate Jans AS
Jans AS-->>Client: Access Token with optional Refresh Token
deactivate Client
deactivate Jans AS
deactivate Resource owner User

Testing#

  1. https://github.com/JanssenProject/jans/blob/main/jans-auth-server/client/src/test/java/io/jans/as/client/ws/rs/AuthorizationCodeFlowHttpTest.java

  2. On a browser access https://my.jans.server/jans-auth/restv1/authorize?redirect_uri=https://my-redirect-app:8080&client_id=Put_client_id_here&scope=username+openid&response_type=code Based on the default authentication method set (acr), the user will be presented with credentials for login. The OpenID Provider (Gluu Server) verifies the user’s identity and authenticates the user. In the back channel the following steps take place :

  3. The OpenID Provider (Gluu Server) sends the user back to the application with an authorization code.
  4. The application sends the code to the Token Endpoint to receive an Access Token and ID Token in the response.
  5. The application uses the ID Token to authorize the user. At this point the application/RP can access the UserInfo endpoint for claims.
Last update: 2024-09-27
Created: 2023-01-10