Refactor OpenIDConnect to support SSH/FullName sync (#34978)

* Fix #26585
* Fix #28327
* Fix #34932

services/auth/source/oauth2/providers.go

@@ -27,6 +27,7 @@ type Provider interface {
 	DisplayName() string
 	IconHTML(size int) template.HTML
 	CustomURLSettings() *CustomURLSettings
+	SupportSSHPublicKey() bool
 }
 
 // GothProviderCreator provides a function to create a goth.Provider

services/auth/source/oauth2/providers_base.go

@@ -14,6 +14,13 @@ import (
 type BaseProvider struct {
 	name        string
 	displayName string
+
+	// TODO: maybe some providers also support SSH public keys, then they can set this to true
+	supportSSHPublicKey bool
+}
+
+func (b *BaseProvider) SupportSSHPublicKey() bool {
+	return b.supportSSHPublicKey
 }
 
 // Name provides the technical name for this provider

services/auth/source/oauth2/providers_openid.go

@@ -17,6 +17,10 @@ import (
 // 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"

services/auth/source/oauth2/source.go

@@ -27,6 +27,9 @@ type Source struct {
 	GroupTeamMap        string
 	GroupTeamMapRemoval bool
 	RestrictedGroup     string
+
+	SSHPublicKeyClaimName string
+	FullNameClaimName     string
 }
 
 // FromDB fills up an OAuth2Config from serialized format.