forgejo-federation/docs/content/doc/developers/oauth2-provider.md
M Hickford 191a74d622
Record OAuth client type at registration (#21316)
The OAuth spec [defines two types of
client](https://datatracker.ietf.org/doc/html/rfc6749#section-2.1),
confidential and public. Previously Gitea assumed all clients to be
confidential.

> OAuth defines two client types, based on their ability to authenticate
securely with the authorization server (i.e., ability to
>   maintain the confidentiality of their client credentials):
>
>   confidential
> Clients capable of maintaining the confidentiality of their
credentials (e.g., client implemented on a secure server with
> restricted access to the client credentials), or capable of secure
client authentication using other means.
>
>   **public
> Clients incapable of maintaining the confidentiality of their
credentials (e.g., clients executing on the device used by the resource
owner, such as an installed native application or a web browser-based
application), and incapable of secure client authentication via any
other means.**
>
> The client type designation is based on the authorization server's
definition of secure authentication and its acceptable exposure levels
of client credentials. The authorization server SHOULD NOT make
assumptions about the client type.

 https://datatracker.ietf.org/doc/html/rfc8252#section-8.4

> Authorization servers MUST record the client type in the client
registration details in order to identify and process requests
accordingly.

Require PKCE for public clients:
https://datatracker.ietf.org/doc/html/rfc8252#section-8.1

> Authorization servers SHOULD reject authorization requests from native
apps that don't use PKCE by returning an error message

Fixes #21299

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
2022-10-24 15:59:24 +08:00

4.5 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
OpenID Connect Discovery /.well-known/openid-configuration
Authorization Endpoint /login/oauth/authorize
Access Token Endpoint /login/oauth/access_token
OpenID Connect UserInfo /login/oauth/userinfo
JSON Web Key Set /login/oauth/keys

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 their organizations.

Client types

Gitea supports both confidential and public client types, as defined by RFC 6749.

For public clients, a redirect URI of a loopback IP address such as http://127.0.0.1/ allows any port. Avoid using localhost, as recommended by RFC 8252.

Example

Note: This example does not use PKCE.

  1. Redirect to user to the authorization endpoint in order to get their 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.