Files
gitea/services/auth/source/oauth2/providers_openid.go
Zettat123 b1bfca39f1 Add ExternalIDClaim option for OAuth2 OIDC auth source (#37229)
This PR adds an External ID Claim Name configuration field to the OIDC
auth source. When set, Gitea uses the specified JWT claim as the user's
`ExternalID` instead of the default `sub` claim.

This PR fixes the bug when migrating from Azure AD V2 to OIDC. When an
admin migrates the same auth source to OIDC, goth's `openidConnect`
provider defaults to using the `sub` claim as `UserID`. However, Azure
AD's `sub` is a pairwise identifier:

> `sub`: The subject is a pairwise identifier and is unique to an
application ID. If a single user signs into two different apps using two
different client IDs, those apps receive two different values for the
subject claim.


https://learn.microsoft.com/en-us/entra/identity-platform/id-token-claims-reference#payload-claims

As a result, every existing user appears as a new account after
migration.

To fix this issue, Gitea should use `oid` claim for `UserID`.

> `oid`: This ID uniquely identifies the user across applications - two
different applications signing in the same user receives the same value
in the oid claim.

Note: The `oid` claim is not included in Azure AD tokens by default. The
`profile` scope must be added to the Scopes field of the auth source.
2026-04-16 17:30:46 +00:00

69 lines
2.0 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package oauth2
import (
"html/template"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/svg"
"github.com/markbates/goth"
"github.com/markbates/goth/providers/openidConnect"
)
// OpenIDProvider is a GothProvider for OpenID
type OpenIDProvider struct{}
func (o *OpenIDProvider) SupportSSHPublicKey() bool {
return true
}
// Name provides the technical name for this provider
func (o *OpenIDProvider) Name() string {
return "openidConnect"
}
// DisplayName returns the friendly name for this provider
func (o *OpenIDProvider) DisplayName() string {
return "OpenID Connect"
}
// IconHTML returns icon HTML for this provider
func (o *OpenIDProvider) IconHTML(size int) template.HTML {
return svg.RenderHTML("gitea-openid", size)
}
// CreateGothProvider creates a GothProvider from this Provider
func (o *OpenIDProvider) CreateGothProvider(providerName, callbackURL string, source *Source) (goth.Provider, error) {
scopes := setting.OAuth2Client.OpenIDConnectScopes
if len(scopes) == 0 {
scopes = append(scopes, source.Scopes...)
}
provider, err := openidConnect.New(source.ClientID, source.ClientSecret, callbackURL, source.OpenIDConnectAutoDiscoveryURL, scopes...)
if err != nil {
log.Warn("Failed to create OpenID Connect Provider with name '%s' with url '%s': %v", providerName, source.OpenIDConnectAutoDiscoveryURL, err)
return nil, err
}
if source.ExternalIDClaim != "" {
// UserIdClaims is a fallback list; goth returns the first non-empty matching claim.
// A single entry is sufficient because the admin explicitly chooses one claim (e.g. "oid" for Azure AD).
provider.UserIdClaims = []string{source.ExternalIDClaim}
}
return provider, nil
}
// CustomURLSettings returns the custom url settings for this provider
func (o *OpenIDProvider) CustomURLSettings() *CustomURLSettings {
return nil
}
var _ GothProvider = &OpenIDProvider{}
func init() {
RegisterGothProvider(&OpenIDProvider{})
}