initial commit

tests/integration/oauth2_client_secret_not_leaked_test.go

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2026 Fluxer Contributors
+ *
+ * This file is part of Fluxer.
+ *
+ * Fluxer is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Fluxer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package integration
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+// TestOAuth2ClientSecretNotLeaked verifies that client_secret is only shown once
+// during application creation and never exposed in subsequent GET requests.
+// Secrets should remain write-only and must be stored securely by the application owner.
+func TestOAuth2ClientSecretNotLeaked(t *testing.T) {
+	client := newTestClient(t)
+	appOwner := createTestAccount(t, client)
+
+	redirectURI := "https://example.com/callback"
+	appID, _, _, clientSecret := createOAuth2Application(t, client, appOwner,
+		fmt.Sprintf("Secret Test App %d", time.Now().UnixNano()),
+		[]string{redirectURI},
+		[]string{"identify"},
+	)
+
+	if clientSecret == "" {
+		t.Fatalf("client_secret should be returned on application creation")
+	}
+
+	t.Run("GET application does not expose client_secret", func(t *testing.T) {
+		app := getOAuth2Application(t, client, appOwner.Token, appID)
+
+		if app.ID != appID {
+			t.Fatalf("expected application ID %s, got %s", appID, app.ID)
+		}
+
+		if app.ClientSecret != "" {
+			t.Fatalf("GET application exposed the client_secret - security leak")
+		}
+	})
+
+	t.Run("LIST applications does not expose client_secret", func(t *testing.T) {
+		apps := listOAuth2Applications(t, client, appOwner.Token)
+
+		var foundApp *oauth2ApplicationResponse
+		for i := range apps {
+			if apps[i].ID == appID {
+				foundApp = &apps[i]
+				break
+			}
+		}
+
+		if foundApp == nil {
+			t.Fatalf("created application not found in list")
+			return
+		}
+
+		if foundApp.ClientSecret != "" {
+			t.Fatalf("LIST applications exposed the client_secret - security leak")
+		}
+	})
+
+	t.Run("UPDATE application does not expose client_secret", func(t *testing.T) {
+		updates := map[string]any{
+			"name": fmt.Sprintf("Updated App %d", time.Now().UnixNano()),
+		}
+		updatedApp := updateOAuth2Application(t, client, appOwner.Token, appID, updates)
+
+		if updatedApp.ID != appID {
+			t.Fatalf("expected application ID %s, got %s", appID, updatedApp.ID)
+		}
+
+		if updatedApp.ClientSecret != "" {
+			t.Fatalf("UPDATE application exposed the client_secret - security leak")
+		}
+	})
+
+	t.Run("client_secret still works for authentication", func(t *testing.T) {
+		endUser := createTestAccount(t, client)
+
+		authCode, _ := authorizeOAuth2(t, client, endUser.Token, appID, redirectURI, []string{"identify"}, "", "", "")
+
+		token := exchangeOAuth2AuthorizationCode(t, client, appID, clientSecret, authCode, redirectURI, "")
+
+		if token.AccessToken == "" {
+			t.Fatalf("original client_secret should still work for token exchange")
+		}
+	})
+}