githaven-fork/docs/content/doc/developers/oauth2-provider.md
Johnny Oskarsson a07e67d9cc
Minimal OpenID Connect implementation (#14139)
This is "minimal" in the sense that only the Authorization Code Flow
from OpenID Connect Core is implemented.  No discovery, no configuration
endpoint, and no user scope management.

OpenID Connect is an extension to the (already implemented) OAuth 2.0
protocol, and essentially an `id_token` JWT is added to the access token
endpoint response when using the Authorization Code Flow.  I also added
support for the "nonce" field since it is required to be used in the
id_token if the client decides to include it in its initial request.

In order to enable this extension an OAuth 2.0 scope containing
"openid" is needed. Other OAuth 2.0 requests should not be impacted by
this change.

This minimal implementation is enough to enable single sign-on (SSO)
for other sites, e.g. by using something like `mod_auth_openidc` to
only allow access to a CI server if a user has logged into Gitea.

Fixes: #1310

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>
2021-01-02 00:33:27 +08:00

3.9 KiB

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2019-04-19:44:00+01:00 OAuth2 provider oauth2-provider 41 false false
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OAuth2 provider

Table of Contents

{{< toc >}}

Gitea supports acting as an OAuth2 provider to allow third party applications to access its resources with the user's consent. This feature is available since release 1.8.0.

Endpoints

Endpoint URL
Authorization Endpoint /login/oauth/authorize
Access Token Endpoint /login/oauth/access_token

Supported OAuth2 Grants

At the moment Gitea only supports the Authorization Code Grant standard with additional support of the following extensions:

To use the Authorization Code Grant as a third party application it is required to register a new application via the "Settings" (/user/settings/applications) section of the settings.

Scopes

Currently Gitea does not support scopes (see #4300) and all third party applications will be granted access to all resources of the user and his/her organizations.

Example

Note: This example does not use PKCE.

  1. Redirect to user to the authorization endpoint in order to get his/her consent for accessing the resources:

    https://[YOUR-GITEA-URL]/login/oauth/authorize?client_id=CLIENT_ID&redirect_uri=REDIRECT_URI& response_type=code&state=STATE
    

    The CLIENT_ID can be obtained by registering an application in the settings. The STATE is a random string that will be send back to your application after the user authorizes. The state parameter is optional but should be used to prevent CSRF attacks.

    Authorization Page

    The user will now be asked to authorize your application. If they authorize it, the user will be redirected to the REDIRECT_URL, for example:

    https://[REDIRECT_URI]?code=RETURNED_CODE&state=STATE
    
  2. Using the provided code from the redirect, you can request a new application and refresh token. The access token endpoints accepts POST requests with application/json and application/x-www-form-urlencoded body, for example:

    POST https://[YOUR-GITEA-URL]/login/oauth/access_token
    
    {
      "client_id": "YOUR_CLIENT_ID",
      "client_secret": "YOUR_CLIENT_SECRET",
      "code": "RETURNED_CODE",
      "grant_type": "authorization_code",
      "redirect_uri": "REDIRECT_URI"
    }
    

    Response:

    {
      "access_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjowLCJleHAiOjE1NTUxNzk5MTIsImlhdCI6MTU1NTE3NjMxMn0.0-iFsAwBtxuckA0sNZ6QpBQmywVPz129u75vOM7wPJecw5wqGyBkmstfJHAjEOqrAf_V5Z-1QYeCh_Cz4RiKug",
      "token_type": "bearer",
      "expires_in": 3600,
      "refresh_token": "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJnbnQiOjIsInR0IjoxLCJjbnQiOjEsImV4cCI6MTU1NzgwNDMxMiwiaWF0IjoxNTU1MTc2MzEyfQ.S_HZQBy4q9r5SEzNGNIoFClT43HPNDbUdHH-GYNYYdkRfft6XptJBkUQscZsGxOW975Yk6RbgtGvq1nkEcklOw"
    }
    

    The CLIENT_SECRET is the unique secret code generated for this application. Please note that the secret will only be visible after you created/registered the application with Gitea and cannot be recovered. If you lose the secret you must regenerate the secret via the application's settings.

    The REDIRECT_URI in the access_token request must match the REDIRECT_URI in the authorize request.

  3. Use the access_token to make API requests to access the user's resources.