Add authCodeOptions to openidConnect Provider (#580)

* feat: add authURLParams to BeginAuth

* test: add test case for openidConnect authCodeOptions

* style: whitespace

Author: JensHeise

providers/openidConnect/openidConnect.go

@@ -51,13 +51,14 @@ const (
 
 // Provider is the implementation of `goth.Provider` for accessing OpenID Connect provider
 type Provider struct {
-	ClientKey    string
-	Secret       string
-	CallbackURL  string
-	HTTPClient   *http.Client
-	OpenIDConfig *OpenIDConfig
-	config       *oauth2.Config
-	providerName string
+	ClientKey       string
+	Secret          string
+	CallbackURL     string
+	HTTPClient      *http.Client
+	OpenIDConfig    *OpenIDConfig
+	config          *oauth2.Config
+	authCodeOptions []oauth2.AuthCodeOption
+	providerName    string
 
 	UserIdClaims    []string
 	NameClaims      []string
@@ -186,6 +187,14 @@ func (p *Provider) SetName(name string) {
 	p.providerName = name
 }
 
+// SetAuthCodeOptions sets additional parameters for the authentication URL.
+// It takes a map of string key-value pairs and appends them to the provider's authCodeOptions.
+func (p *Provider) SetAuthCodeOptions(params map[string]string) {
+	for k, v := range params {
+		p.authCodeOptions = append(p.authCodeOptions, oauth2.SetAuthURLParam(k, v))
+	}
+}
+
 func (p *Provider) Client() *http.Client {
 	return goth.HTTPClientWithFallBack(p.HTTPClient)
 }
@@ -195,7 +204,7 @@ func (p *Provider) Debug(debug bool) {}
 
 // BeginAuth asks the OpenID Connect provider for an authentication end-point.
 func (p *Provider) BeginAuth(state string) (goth.Session, error) {
-	url := p.config.AuthCodeURL(state)
+	url := p.config.AuthCodeURL(state, p.authCodeOptions...)
 	session := &Session{
 		AuthURL: url,
 	}

providers/openidConnect/openidConnect_test.go

@@ -78,6 +78,24 @@ func Test_BeginAuth(t *testing.T) {
 	a.Contains(s.AuthURL, "scope=openid")
 }
 
+func Test_BeginAuth_AuthCodeOptions(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+
+	provider := openidConnectProvider()
+	provider.SetAuthCodeOptions(map[string]string{"domain_hint": "test_domain.com", "prompt": "none"})
+	session, err := provider.BeginAuth("test_state")
+	s := session.(*Session)
+	a.NoError(err)
+	a.Contains(s.AuthURL, "https://accounts.google.com/o/oauth2/v2/auth")
+	a.Contains(s.AuthURL, fmt.Sprintf("client_id=%s", os.Getenv("OPENID_CONNECT_KEY")))
+	a.Contains(s.AuthURL, "state=test_state")
+	a.Contains(s.AuthURL, "redirect_uri=http%3A%2F%2Flocalhost%2Ffoo")
+	a.Contains(s.AuthURL, "scope=openid")
+	a.Contains(s.AuthURL, "domain_hint=test_domain.com")
+	a.Contains(s.AuthURL, "prompt=none")
+}
+
 func Test_Implements_Provider(t *testing.T) {
 	t.Parallel()
 	a := assert.New(t)