forgejo/docs/content/development/oauth2-provider.en-us.md

date	title	slug	sidebar_position	toc	draft	aliases	menu
2023-06-01T08:40:00+08:00	OAuth2 provider	oauth2-provider	41	false	false	/en-us/oauth2-provider	sidebar parent name sidebar_position identifier development OAuth2 Provider 41 oauth2-provider

OAuth2 provider

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:

• Proof Key for Code Exchange (PKCE)
• OpenID Connect (OIDC)

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. To test or debug you can use the web-tool https://oauthdebugger.com/.

Scopes

Gitea supports scoped access tokens, which allow users the ability to restrict tokens to operate only on selected url routes. Scopes are grouped by high-level API routes, and further refined to the following:

• read: GET routes
• write: POST, PUT, PATCH, and DELETE routes (in addition to GET)

Gitea token scopes are as follows:

Name	Description
(no scope)	Not supported. A scope is required even for public repositories.
activitypub	activitypub API routes: ActivityPub related operations.
read:activitypub	Grants read access for ActivityPub operations.
write:activitypub	Grants read/write/delete access for ActivityPub operations.
admin	/admin/* API routes: Site-wide administrative operations (hidden for non-admin accounts).
read:admin	Grants read access for admin operations, such as getting cron jobs or registered user emails.
write:admin	Grants read/write/delete access for admin operations, such as running cron jobs or updating user accounts.
issue	issues/*, labels/*, milestones/* API routes: Issue-related operations.
read:issue	Grants read access for issues operations, such as getting issue comments, issue attachments, and milestones.
write:issue	Grants read/write/delete access for issues operations, such as posting or editing an issue comment or attachment, and updating milestones.
misc	Reserved for future usage.
read:misc	Reserved for future usage.
write:misc	Reserved for future usage.
notification	notification/* API routes: user notification operations.
read:notification	Grants read access to user notifications, such as which notifications users are subscribed to and read new notifications.
write:notification	Grants read/write/delete access to user notifications, such as marking notifications as read.
organization	orgs/* and teams/* API routes: Organization and team management operations.
read:organization	Grants read access to org and team status, such as listing all orgs a user has visibility to, teams, and team members.
write:organization	Grants read/write/delete access to org and team status, such as creating and updating teams and updating org settings.
package	/packages/* API routes: Packages operations
read:package	Grants read access to package operations, such as reading and downloading available packages.
write:package	Grants read/write/delete access to package operations. Currently the same as read:package.
repository	/repos/* API routes except /repos/issues/*: Repository file, pull-request, and release operations.
read:repository	Grants read access to repository operations, such as getting repository files, releases, collaborators.
write:repository	Grants read/write/delete access to repository operations, such as getting updating repository files, creating pull requests, updating collaborators.
user	/user/* and /users/* API routes: User-related operations.
read:user	Grants read access to user operations, such as getting user repo subscriptions and user settings.
write:user	Grants read/write/delete access to user operations, such as updating user repo subscriptions, followed users, and user settings.

Pre-configured Applications

Gitea creates OAuth applications for the following services by default on startup, as we assume that these are universally useful.

Application	Description	Client ID
git-credential-oauth	Git credential helper	a4792ccc-144e-407e-86c9-5e7d8d9c3269
Git Credential Manager	Git credential helper	e90ee53c-94e2-48ac-9358-a874fb9e0662
tea	tea	d57cb8c4-630c-4168-8324-ec79935e18d4

To prevent unexpected behavior, they are being displayed as locked in the UI and their creation can instead be controlled by the DEFAULT_APPLICATIONS parameter in app.ini.

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.

Examples

Confidential client

Note: This example does not use PKCE.

1. Redirect the 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 sent back to your application after the user authorizes. The state parameter is optional, but should be used to prevent CSRF attacks.

   

   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 endpoint 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.

Public client (PKCE)

PKCE (Proof Key for Code Exchange) is an extension to the OAuth flow which allows for a secure credential exchange without the requirement to provide a client secret.

Note: Please ensure you have registered your OAuth application as a public client.

To achieve this, you have to provide a code_verifier for every authorization request. A code_verifier has to be a random string with a minimum length of 43 characters and a maximum length of 128 characters. It can contain alphanumeric characters as well as the characters -, ., _ and ~.

Using this code_verifier string, a new one called code_challenge is created by using one of two methods:

• If you have the required functionality on your client, set code_challenge to be a URL-safe base64-encoded string of the SHA256 hash of code_verifier. In that case, your code_challenge_method becomes S256.
• If you are unable to do so, you can provide your code_verifier as a plain string to code_challenge. Then you have to set your code_challenge_method as plain.

After you have generated this values, you can continue with your request.

1. Redirect the 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&code_challenge_method=CODE_CHALLENGE_METHOD&code_challenge=CODE_CHALLENGE&state=STATE
   

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

   

   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 endpoint 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",
     "code": "RETURNED_CODE",
     "grant_type": "authorization_code",
     "redirect_uri": "REDIRECT_URI",
     "code_verifier": "CODE_VERIFIER",
   }
   

   Response:

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

   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.