feat: preserve oidc params in oauth flow

frontend/src/pages/login-page.tsx

@@ -76,10 +76,14 @@ export const LoginPage = () => {
     isPending: oauthIsPending,
     variables: oauthVariables,
   } = useMutation({
-    mutationFn: (provider: string) =>
+    mutationFn: (provider: string) => {
-      axios.get(
+      const params = isOidc
-        `/api/oauth/url/${provider}${props.redirect_uri ? `?redirect_uri=${encodeURIComponent(props.redirect_uri)}` : ""}`,
+        ? `?${compiledOIDCParams}`
-      ),
+        : props.redirect_uri
+          ? `?redirect_uri=${encodeURIComponent(props.redirect_uri)}`
+          : "";
+      return axios.get(`/api/oauth/url/${provider}${params}`);
+    },
     mutationKey: ["oauth"],
     onSuccess: (data) => {
       toast.info(t("loginOauthSuccessTitle"), {

go.mod

@@ -24,7 +24,7 @@ require (
 	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546
 	golang.org/x/oauth2 v0.36.0
 	gotest.tools/v3 v3.5.2
-	modernc.org/sqlite v1.48.1
+	modernc.org/sqlite v1.48.0
 )
 
 require (

go.sum

@@ -389,8 +389,8 @@ modernc.org/opt v0.1.4 h1:2kNGMRiUjrp4LcaPuLY2PzUfqM/w9N23quVwhKt5Qm8=
 modernc.org/opt v0.1.4/go.mod h1:03fq9lsNfvkYSfxrfUhZCWPk1lm4cq4N+Bh//bEtgns=
 modernc.org/sortutil v1.2.1 h1:+xyoGf15mM3NMlPDnFqrteY07klSFxLElE2PVuWIJ7w=
 modernc.org/sortutil v1.2.1/go.mod h1:7ZI3a3REbai7gzCLcotuw9AC4VZVpYMjDzETGsSMqJE=
-modernc.org/sqlite v1.48.1 h1:S85iToyU6cgeojybE2XJlSbcsvcWkQ6qqNXJHtW5hWA=
+modernc.org/sqlite v1.48.0 h1:ElZyLop3Q2mHYk5IFPPXADejZrlHu7APbpB0sF78bq4=
-modernc.org/sqlite v1.48.1/go.mod h1:hWjRO6Tj/5Ik8ieqxQybiEOUXy0NJFNp2tpvVpKlvig=
+modernc.org/sqlite v1.48.0/go.mod h1:hWjRO6Tj/5Ik8ieqxQybiEOUXy0NJFNp2tpvVpKlvig=
 modernc.org/strutil v1.2.1 h1:UneZBkQA+DX2Rp35KcM69cSsNES9ly8mQWD71HKlOA0=
 modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
 modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=

internal/controller/oauth_controller.go

@@ -62,7 +62,29 @@ func (controller *OAuthController) oauthURLHandler(c *gin.Context) {
 		return
 	}
 
-	sessionId, session, err := controller.auth.NewOAuthSession(req.Provider)
+	var reqParams service.OAuthURLParams
+
+	err = c.BindQuery(&reqParams)
+
+	if err != nil {
+		tlog.App.Error().Err(err).Msg("Failed to bind query parameters")
+		c.JSON(400, gin.H{
+			"status":  400,
+			"message": "Bad Request",
+		})
+		return
+	}
+
+	if !controller.isOidcRequest(reqParams) {
+		isRedirectSafe := utils.IsRedirectSafe(reqParams.RedirectURI, controller.config.CookieDomain)
+
+		if !isRedirectSafe {
+			tlog.App.Warn().Str("redirect_uri", reqParams.RedirectURI).Msg("Unsafe redirect URI detected, ignoring")
+			reqParams.RedirectURI = ""
+		}
+	}
+
+	sessionId, _, err := controller.auth.NewOAuthSession(req.Provider, reqParams)
 
 	if err != nil {
 		tlog.App.Error().Err(err).Msg("Failed to create OAuth session")
@@ -85,20 +107,6 @@ func (controller *OAuthController) oauthURLHandler(c *gin.Context) {
 	}
 
 	c.SetCookie(controller.config.OAuthSessionCookieName, sessionId, int(time.Hour.Seconds()), "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
-	c.SetCookie(controller.config.CSRFCookieName, session.State, int(time.Hour.Seconds()), "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
-
-	redirectURI := c.Query("redirect_uri")
-	isRedirectSafe := utils.IsRedirectSafe(redirectURI, controller.config.CookieDomain)
-
-	if !isRedirectSafe {
-		tlog.App.Warn().Str("redirect_uri", redirectURI).Msg("Unsafe redirect URI detected, ignoring")
-		redirectURI = ""
-	}
-
-	if redirectURI != "" && isRedirectSafe {
-		tlog.App.Debug().Msg("Setting redirect URI cookie")
-		c.SetCookie(controller.config.RedirectCookieName, redirectURI, int(time.Hour.Seconds()), "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
-	}
 
 	c.JSON(200, gin.H{
 		"status":  200,
@@ -129,19 +137,23 @@ func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
 	}
 
 	c.SetCookie(controller.config.OAuthSessionCookieName, "", -1, "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
-	defer controller.auth.EndOAuthSession(sessionIdCookie)
 
-	state := c.Query("state")
+	oauthPendingSession, err := controller.auth.GetOAuthPendingSession(sessionIdCookie)
-	csrfCookie, err := c.Cookie(controller.config.CSRFCookieName)
 
-	if err != nil || state != csrfCookie {
+	if err != nil {
-		tlog.App.Warn().Err(err).Msg("CSRF token mismatch or cookie missing")
+		tlog.App.Error().Err(err).Msg("Failed to get OAuth pending session")
-		c.SetCookie(controller.config.CSRFCookieName, "", -1, "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
 		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
 		return
 	}
 
-	c.SetCookie(controller.config.CSRFCookieName, "", -1, "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
+	defer controller.auth.EndOAuthSession(sessionIdCookie)
+
+	state := c.Query("state")
+	if state != oauthPendingSession.State {
+		tlog.App.Warn().Err(err).Msg("CSRF token mismatch")
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+		return
+	}
 
 	code := c.Query("code")
 	_, err = controller.auth.GetOAuthToken(sessionIdCookie, code)
@@ -198,7 +210,7 @@ func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
 		username = strings.Replace(user.Email, "@", "_", 1)
 	}
 
-	service, err := controller.auth.GetOAuthService(sessionIdCookie)
+	svc, err := controller.auth.GetOAuthService(sessionIdCookie)
 
 	if err != nil {
 		tlog.App.Error().Err(err).Msg("Failed to get OAuth service for session")
@@ -206,8 +218,8 @@ func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
 		return
 	}
 
-	if service.ID() != req.Provider {
+	if svc.ID() != req.Provider {
-		tlog.App.Error().Msgf("OAuth service ID mismatch: expected %s, got %s", service.ID(), req.Provider)
+		tlog.App.Error().Msgf("OAuth service ID mismatch: expected %s, got %s", svc.ID(), req.Provider)
 		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
 		return
 	}
@@ -216,9 +228,9 @@ func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
 		Username:    username,
 		Name:        name,
 		Email:       user.Email,
-		Provider:    service.ID(),
+		Provider:    svc.ID(),
 		OAuthGroups: utils.CoalesceToString(user.Groups),
-		OAuthName:   service.Name(),
+		OAuthName:   svc.Name(),
 		OAuthSub:    user.Sub,
 	}
 
@@ -234,24 +246,39 @@ func (controller *OAuthController) oauthCallbackHandler(c *gin.Context) {
 
 	tlog.AuditLoginSuccess(c, sessionCookie.Username, sessionCookie.Provider)
 
-	redirectURI, err := c.Cookie(controller.config.RedirectCookieName)
+	if controller.isOidcRequest(oauthPendingSession.CallbackParams) {
-
+		tlog.App.Debug().Msg("OIDC request, redirecting to authorize page")
-	if err != nil || !utils.IsRedirectSafe(redirectURI, controller.config.CookieDomain) {
+		queries, err := query.Values(oauthPendingSession.CallbackParams)
-		tlog.App.Debug().Msg("No redirect URI cookie found, redirecting to app root")
+		if err != nil {
-		c.Redirect(http.StatusTemporaryRedirect, controller.config.AppURL)
+			tlog.App.Error().Err(err).Msg("Failed to encode OIDC callback query")
+			c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+			return
+		}
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/authorize?%s", controller.config.AppURL, queries.Encode()))
 		return
 	}
 
-	queries, err := query.Values(config.RedirectQuery{
+	if oauthPendingSession.CallbackParams.RedirectURI != "" {
-		RedirectURI: redirectURI,
+		queries, err := query.Values(config.RedirectQuery{
-	})
+			RedirectURI: oauthPendingSession.CallbackParams.RedirectURI,
+		})
 
-	if err != nil {
+		if err != nil {
-		tlog.App.Error().Err(err).Msg("Failed to encode redirect URI query")
+			tlog.App.Error().Err(err).Msg("Failed to encode redirect URI query")
-		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+			c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/error", controller.config.AppURL))
+			return
+		}
+
+		c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/continue?%s", controller.config.AppURL, queries.Encode()))
 		return
 	}
 
-	c.SetCookie(controller.config.RedirectCookieName, "", -1, "/", fmt.Sprintf(".%s", controller.config.CookieDomain), controller.config.SecureCookie, true)
+	c.Redirect(http.StatusTemporaryRedirect, controller.config.AppURL)
-	c.Redirect(http.StatusTemporaryRedirect, fmt.Sprintf("%s/continue?%s", controller.config.AppURL, queries.Encode()))
+}
+
+func (controller *OAuthController) isOidcRequest(params service.OAuthURLParams) bool {
+	return params.Scope != "" &&
+		params.ResponseType != "" &&
+		params.ClientID != "" &&
+		params.RedirectURI != ""
 }

internal/controller/oidc_controller.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/google/go-querystring/query"
+
 	"github.com/steveiliop56/tinyauth/internal/service"
 	"github.com/steveiliop56/tinyauth/internal/utils"
 	"github.com/steveiliop56/tinyauth/internal/utils/tlog"
@@ -376,22 +377,48 @@ func (controller *OIDCController) Userinfo(c *gin.Context) {
 		return
 	}
 
+	var token string
+
 	authorization := c.GetHeader("Authorization")
+	if authorization != "" {
+		tokenType, bearerToken, ok := strings.Cut(authorization, " ")
+		if !ok {
+			tlog.App.Warn().Msg("OIDC userinfo accessed with malformed authorization header")
+			c.JSON(401, gin.H{
+				"error": "invalid_request",
+			})
+			return
+		}
 
-	tokenType, token, ok := strings.Cut(authorization, " ")
+		if strings.ToLower(tokenType) != "bearer" {
+			tlog.App.Warn().Msg("OIDC userinfo accessed with invalid token type")
+			c.JSON(401, gin.H{
+				"error": "invalid_request",
+			})
+			return
+		}
 
-	if !ok {
+		token = bearerToken
+	} else if c.Request.Method == http.MethodPost {
+		if c.ContentType() != "application/x-www-form-urlencoded" {
+			tlog.App.Warn().Msg("OIDC userinfo POST accessed with invalid content type")
+			c.JSON(400, gin.H{
+				"error": "invalid_request",
+			})
+			return
+		}
+		token = c.PostForm("access_token")
+		if token == "" {
+			tlog.App.Warn().Msg("OIDC userinfo POST accessed without access_token in body")
+			c.JSON(401, gin.H{
+				"error": "invalid_request",
+			})
+			return
+		}
+	} else {
 		tlog.App.Warn().Msg("OIDC userinfo accessed without authorization header")
 		c.JSON(401, gin.H{
-			"error": "invalid_grant",
+			"error": "invalid_request",
-		})
-		return
-	}
-
-	if strings.ToLower(tokenType) != "bearer" {
-		tlog.App.Warn().Msg("OIDC userinfo accessed with invalid token type")
-		c.JSON(401, gin.H{
-			"error": "invalid_grant",
 		})
 		return
 	}

internal/controller/oidc_controller_test.go

@@ -435,6 +435,128 @@ func TestOIDCController(t *testing.T) {
 				assert.False(t, ok, "Did not expect email claim in userinfo response")
 			},
 		},
+		{
+			description: "Ensure userinfo forbids access with no authorization header",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("GET", "/api/oidc/userinfo", nil)
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 401, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_request", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo forbids access with malformed authorization header",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("GET", "/api/oidc/userinfo", nil)
+				req.Header.Set("Authorization", "Bearer")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 401, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_request", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo forbids access with invalid token type",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("GET", "/api/oidc/userinfo", nil)
+				req.Header.Set("Authorization", "Basic some-token")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 401, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_request", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo forbids access with empty bearer token",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("GET", "/api/oidc/userinfo", nil)
+				req.Header.Set("Authorization", "Bearer ")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 401, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_grant", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo POST rejects missing access token in body",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("POST", "/api/oidc/userinfo", strings.NewReader(""))
+				req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 401, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_request", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo POST rejects wrong content type",
+			middlewares: []gin.HandlerFunc{},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				req := httptest.NewRequest("POST", "/api/oidc/userinfo", strings.NewReader(`{"access_token":"some-token"}`))
+				req.Header.Set("Content-Type", "application/json")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 400, recorder.Code)
+
+				var res map[string]any
+				err := json.Unmarshal(recorder.Body.Bytes(), &res)
+				assert.NoError(t, err)
+				assert.Equal(t, "invalid_request", res["error"])
+			},
+		},
+		{
+			description: "Ensure userinfo accepts access token via POST body",
+			middlewares: []gin.HandlerFunc{
+				simpleCtx,
+			},
+			run: func(t *testing.T, router *gin.Engine, recorder *httptest.ResponseRecorder) {
+				tokenTest, found := getTestByDescription("Ensure we can get a token with a valid request")
+				assert.True(t, found, "Token test not found")
+				tokenRecorder := httptest.NewRecorder()
+				tokenTest(t, router, tokenRecorder)
+
+				var tokenRes map[string]any
+				err := json.Unmarshal(tokenRecorder.Body.Bytes(), &tokenRes)
+				assert.NoError(t, err)
+
+				accessToken := tokenRes["access_token"].(string)
+				assert.NotEmpty(t, accessToken)
+
+				body := url.Values{}
+				body.Set("access_token", accessToken)
+				req := httptest.NewRequest("POST", "/api/oidc/userinfo", strings.NewReader(body.Encode()))
+				req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+				router.ServeHTTP(recorder, req)
+				assert.Equal(t, 200, recorder.Code)
+
+				var userInfoRes map[string]any
+				err = json.Unmarshal(recorder.Body.Bytes(), &userInfoRes)
+				assert.NoError(t, err)
+
+				_, ok := userInfoRes["sub"]
+				assert.True(t, ok, "Expected sub claim in userinfo response")
+			},
+		},
 		{
 			description: "Ensure plain PKCE succeeds",
 			middlewares: []gin.HandlerFunc{

internal/service/auth_service.go

@@ -28,12 +28,26 @@ const MaxOAuthPendingSessions = 256
 const OAuthCleanupCount = 16
 const MaxLoginAttemptRecords = 256
 
+// slightly modified version of the AuthorizeRequest from the OIDC service to basically accept all
+// parameters and pass them to the authorize page if needed
+type OAuthURLParams struct {
+	Scope               string `form:"scope" url:"scope"`
+	ResponseType        string `form:"response_type" url:"response_type"`
+	ClientID            string `form:"client_id" url:"client_id"`
+	RedirectURI         string `form:"redirect_uri" url:"redirect_uri"`
+	State               string `form:"state" url:"state"`
+	Nonce               string `form:"nonce" url:"nonce"`
+	CodeChallenge       string `form:"code_challenge" url:"code_challenge"`
+	CodeChallengeMethod string `form:"code_challenge_method" url:"code_challenge_method"`
+}
+
 type OAuthPendingSession struct {
-	State     string
+	State          string
-	Verifier  string
+	Verifier       string
-	Token     *oauth2.Token
+	Token          *oauth2.Token
-	Service   *OAuthServiceImpl
+	Service        *OAuthServiceImpl
-	ExpiresAt time.Time
+	ExpiresAt      time.Time
+	CallbackParams OAuthURLParams
 }
 
 type LdapGroupsCache struct {
@@ -598,7 +612,7 @@ func (auth *AuthService) IsBypassedIP(acls config.AppIP, ip string) bool {
 	return false
 }
 
-func (auth *AuthService) NewOAuthSession(serviceName string) (string, OAuthPendingSession, error) {
+func (auth *AuthService) NewOAuthSession(serviceName string, params OAuthURLParams) (string, OAuthPendingSession, error) {
 	auth.ensureOAuthSessionLimit()
 
 	service, ok := auth.oauthBroker.GetService(serviceName)
@@ -617,10 +631,11 @@ func (auth *AuthService) NewOAuthSession(serviceName string) (string, OAuthPendi
 	verifier := service.NewRandom()
 
 	session := OAuthPendingSession{
-		State:     state,
+		State:          state,
-		Verifier:  verifier,
+		Verifier:       verifier,
-		Service:   &service,
+		Service:        &service,
-		ExpiresAt: time.Now().Add(1 * time.Hour),
+		ExpiresAt:      time.Now().Add(1 * time.Hour),
+		CallbackParams: params,
 	}
 
 	auth.oauthMutex.Lock()
@@ -631,7 +646,7 @@ func (auth *AuthService) NewOAuthSession(serviceName string) (string, OAuthPendi
 }
 
 func (auth *AuthService) GetOAuthURL(sessionId string) (string, error) {
-	session, err := auth.getOAuthPendingSession(sessionId)
+	session, err := auth.GetOAuthPendingSession(sessionId)
 
 	if err != nil {
 		return "", err
@@ -641,7 +656,7 @@ func (auth *AuthService) GetOAuthURL(sessionId string) (string, error) {
 }
 
 func (auth *AuthService) GetOAuthToken(sessionId string, code string) (*oauth2.Token, error) {
-	session, err := auth.getOAuthPendingSession(sessionId)
+	session, err := auth.GetOAuthPendingSession(sessionId)
 
 	if err != nil {
 		return nil, err
@@ -661,7 +676,7 @@ func (auth *AuthService) GetOAuthToken(sessionId string, code string) (*oauth2.T
 }
 
 func (auth *AuthService) GetOAuthUserinfo(sessionId string) (config.Claims, error) {
-	session, err := auth.getOAuthPendingSession(sessionId)
+	session, err := auth.GetOAuthPendingSession(sessionId)
 
 	if err != nil {
 		return config.Claims{}, err
@@ -681,7 +696,7 @@ func (auth *AuthService) GetOAuthUserinfo(sessionId string) (config.Claims, erro
 }
 
 func (auth *AuthService) GetOAuthService(sessionId string) (OAuthServiceImpl, error) {
-	session, err := auth.getOAuthPendingSession(sessionId)
+	session, err := auth.GetOAuthPendingSession(sessionId)
 
 	if err != nil {
 		return nil, err
@@ -715,7 +730,7 @@ func (auth *AuthService) CleanupOAuthSessionsRoutine() {
 	}
 }
 
-func (auth *AuthService) getOAuthPendingSession(sessionId string) (*OAuthPendingSession, error) {
+func (auth *AuthService) GetOAuthPendingSession(sessionId string) (*OAuthPendingSession, error) {
 	auth.ensureOAuthSessionLimit()
 
 	auth.oauthMutex.RLock()