Merge branch 'main' into docs/utils-jsdoc

client/src/App.tsx

@@ -34,7 +34,6 @@ import {
   useDraggablePane,
   useDraggableSidebar,
 } from "./lib/hooks/useDraggablePane";
-import { StdErrNotification } from "./lib/notificationTypes";
 
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { Button } from "@/components/ui/button";
@@ -106,9 +105,6 @@ const App = () => {
   >(getInitialTransportType);
   const [logLevel, setLogLevel] = useState<LoggingLevel>("debug");
   const [notifications, setNotifications] = useState<ServerNotification[]>([]);
-  const [stdErrNotifications, setStdErrNotifications] = useState<
-    StdErrNotification[]
-  >([]);
   const [roots, setRoots] = useState<Root[]>([]);
   const [env, setEnv] = useState<Record<string, string>>({});
 
@@ -224,12 +220,6 @@ const App = () => {
     onNotification: (notification) => {
       setNotifications((prev) => [...prev, notification as ServerNotification]);
     },
-    onStdErrNotification: (notification) => {
-      setStdErrNotifications((prev) => [
-        ...prev,
-        notification as StdErrNotification,
-      ]);
-    },
     onPendingRequest: (request, resolve, reject) => {
       setPendingSampleRequests((prev) => [
         ...prev,
@@ -757,10 +747,6 @@ const App = () => {
     setLogLevel(level);
   };
 
-  const clearStdErrNotifications = () => {
-    setStdErrNotifications([]);
-  };
-
   const AuthDebuggerWrapper = () => (
     <TabsContent value="auth">
       <AuthDebugger
@@ -829,11 +815,9 @@ const App = () => {
           setOauthScope={setOauthScope}
           onConnect={connectMcpServer}
           onDisconnect={disconnectMcpServer}
-          stdErrNotifications={stdErrNotifications}
           logLevel={logLevel}
           sendLogLevelRequest={sendLogLevelRequest}
           loggingSupported={!!serverCapabilities?.logging || false}
-          clearStdErrNotifications={clearStdErrNotifications}
         />
         <div
           onMouseDown={handleSidebarDragStart}

client/src/components/AuthDebugger.tsx

@@ -6,6 +6,7 @@ import { AuthDebuggerState, EMPTY_DEBUGGER_STATE } from "../lib/auth-types";
 import { OAuthFlowProgress } from "./OAuthFlowProgress";
 import { OAuthStateMachine } from "../lib/oauth-state-machine";
 import { SESSION_KEYS } from "../lib/constants";
+import { validateRedirectUrl } from "@/utils/urlValidation";
 
 export interface AuthDebuggerProps {
   serverUrl: string;
@@ -163,6 +164,23 @@ const AuthDebugger = ({
           currentState.oauthStep === "authorization_code" &&
           currentState.authorizationUrl
         ) {
+          // Validate the URL before redirecting
+          try {
+            validateRedirectUrl(currentState.authorizationUrl);
+          } catch (error) {
+            updateAuthState({
+              ...currentState,
+              isInitiatingAuth: false,
+              latestError:
+                error instanceof Error ? error : new Error(String(error)),
+              statusMessage: {
+                type: "error",
+                message: `Invalid authorization URL: ${error instanceof Error ? error.message : String(error)}`,
+              },
+            });
+            return;
+          }
+
           // Store the current auth state before redirecting
           sessionStorage.setItem(
             SESSION_KEYS.AUTH_DEBUGGER_STATE,

client/src/components/OAuthDebugCallback.tsx

@@ -46,6 +46,17 @@ const OAuthDebugCallback = ({ onConnect }: OAuthCallbackProps) => {
       if (storedState) {
         try {
           restoredState = JSON.parse(storedState);
+          if (restoredState && typeof restoredState.resource === "string") {
+            restoredState.resource = new URL(restoredState.resource);
+          }
+          if (
+            restoredState &&
+            typeof restoredState.authorizationUrl === "string"
+          ) {
+            restoredState.authorizationUrl = new URL(
+              restoredState.authorizationUrl,
+            );
+          }
           // Clean up the stored state
           sessionStorage.removeItem(SESSION_KEYS.AUTH_DEBUGGER_STATE);
         } catch (e) {

client/src/components/OAuthFlowProgress.tsx

@@ -4,6 +4,8 @@ import { Button } from "./ui/button";
 import { DebugInspectorOAuthClientProvider } from "@/lib/auth";
 import { useEffect, useMemo, useState } from "react";
 import { OAuthClientInformation } from "@modelcontextprotocol/sdk/shared/auth.js";
+import { validateRedirectUrl } from "@/utils/urlValidation";
+import { useToast } from "@/lib/hooks/useToast";
 
 interface OAuthStepProps {
   label: string;
@@ -71,6 +73,7 @@ export const OAuthFlowProgress = ({
   updateAuthState,
   proceedToNextStep,
 }: OAuthFlowProgressProps) => {
+  const { toast } = useToast();
   const provider = useMemo(
     () => new DebugInspectorOAuthClientProvider(serverUrl),
     [serverUrl],
@@ -239,16 +242,32 @@ export const OAuthFlowProgress = ({
                 <p className="text-xs break-all">
                   {authState.authorizationUrl}
                 </p>
-                <a
-                  href={authState.authorizationUrl}
-                  target="_blank"
-                  rel="noopener noreferrer"
+                <button
+                  onClick={() => {
+                    try {
+                      validateRedirectUrl(authState.authorizationUrl!);
+                      window.open(
+                        authState.authorizationUrl!,
+                        "_blank",
+                        "noopener noreferrer",
+                      );
+                    } catch (error) {
+                      toast({
+                        title: "Invalid URL",
+                        description:
+                          error instanceof Error
+                            ? error.message
+                            : "The authorization URL is not valid",
+                        variant: "destructive",
+                      });
+                    }
+                  }}
                   className="flex items-center text-blue-500 hover:text-blue-700"
                   aria-label="Open authorization URL in new tab"
                   title="Open authorization URL"
                 >
                   <ExternalLink className="h-4 w-4" />
-                </a>
+                </button>
               </div>
               <p className="text-xs text-muted-foreground mt-2">
                 Click the link to authorize in your browser. After
@@ -354,7 +373,21 @@ export const OAuthFlowProgress = ({
           authState.authorizationUrl && (
             <Button
               variant="outline"
-              onClick={() => window.open(authState.authorizationUrl!, "_blank")}
+              onClick={() => {
+                try {
+                  validateRedirectUrl(authState.authorizationUrl!);
+                  window.open(authState.authorizationUrl!, "_blank");
+                } catch (error) {
+                  toast({
+                    title: "Invalid URL",
+                    description:
+                      error instanceof Error
+                        ? error.message
+                        : "The authorization URL is not valid",
+                    variant: "destructive",
+                  });
+                }
+              }}
             >
               Open in New Tab
             </Button>

client/src/components/Sidebar.tsx

@@ -24,7 +24,6 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select";
-import { StdErrNotification } from "@/lib/notificationTypes";
 import {
   LoggingLevel,
   LoggingLevelSchema,
@@ -62,8 +61,6 @@ interface SidebarProps {
   setOauthScope: (scope: string) => void;
   onConnect: () => void;
   onDisconnect: () => void;
-  stdErrNotifications: StdErrNotification[];
-  clearStdErrNotifications: () => void;
   logLevel: LoggingLevel;
   sendLogLevelRequest: (level: LoggingLevel) => void;
   loggingSupported: boolean;
@@ -93,8 +90,6 @@ const Sidebar = ({
   setOauthScope,
   onConnect,
   onDisconnect,
-  stdErrNotifications,
-  clearStdErrNotifications,
   logLevel,
   sendLogLevelRequest,
   loggingSupported,
@@ -268,6 +263,7 @@ const Sidebar = ({
                   placeholder="Command"
                   value={command}
                   onChange={(e) => setCommand(e.target.value)}
+                  onBlur={(e) => setCommand(e.target.value.trim())}
                   className="font-mono"
                 />
               </div>
@@ -760,36 +756,6 @@ const Sidebar = ({
                 </Select>
               </div>
             )}
-
-            {stdErrNotifications.length > 0 && (
-              <>
-                <div className="mt-4 border-t border-gray-200 pt-4">
-                  <div className="flex justify-between items-center">
-                    <h3 className="text-sm font-medium">
-                      Error output from MCP server
-                    </h3>
-                    <Button
-                      variant="outline"
-                      size="sm"
-                      onClick={clearStdErrNotifications}
-                      className="h-8 px-2"
-                    >
-                      Clear
-                    </Button>
-                  </div>
-                  <div className="mt-2 max-h-80 overflow-y-auto">
-                    {stdErrNotifications.map((notification, index) => (
-                      <div
-                        key={index}
-                        className="text-sm text-red-500 font-mono py-2 border-b border-gray-200 last:border-b-0"
-                      >
-                        {notification.params.content}
-                      </div>
-                    ))}
-                  </div>
-                </div>
-              </>
-            )}
           </div>
         </div>
       </div>

client/src/lib/auth.ts

@@ -11,6 +11,7 @@ import {
 import { discoverAuthorizationServerMetadata } from "@modelcontextprotocol/sdk/client/auth.js";
 import { SESSION_KEYS, getServerSpecificKey } from "./constants";
 import { generateOAuthState } from "@/utils/oauthUtils";
+import { validateRedirectUrl } from "@/utils/urlValidation";
 
 /**
  * Discovers OAuth scopes from server metadata, with preference for resource metadata scopes
@@ -102,10 +103,15 @@ export const clearClientInformationFromSessionStorage = ({
 };
 
 export class InspectorOAuthClientProvider implements OAuthClientProvider {
-  constructor(protected serverUrl: string) {
+  constructor(
+    protected serverUrl: string,
+    scope?: string,
+  ) {
+    this.scope = scope;
     // Save the server URL to session storage
     sessionStorage.setItem(SESSION_KEYS.SERVER_URL, serverUrl);
   }
+  scope: string | undefined;
 
   get redirectUrl() {
     return window.location.origin + "/oauth/callback";
@@ -119,6 +125,7 @@ export class InspectorOAuthClientProvider implements OAuthClientProvider {
       response_types: ["code"],
       client_name: "MCP Inspector",
       client_uri: "https://github.com/modelcontextprotocol/inspector",
+      scope: this.scope ?? "",
     };
   }
 
@@ -176,12 +183,8 @@ export class InspectorOAuthClientProvider implements OAuthClientProvider {
   }
 
   redirectToAuthorization(authorizationUrl: URL) {
-    if (
-      authorizationUrl.protocol !== "http:" &&
-      authorizationUrl.protocol !== "https:"
-    ) {
-      throw new Error("Authorization URL must be HTTP or HTTPS");
-    }
+    // Validate the URL using the shared utility
+    validateRedirectUrl(authorizationUrl.href);
     window.location.href = authorizationUrl.href;
   }
 

client/src/lib/hooks/useConnection.ts

@@ -36,7 +36,7 @@ import { useEffect, useState } from "react";
 import { useToast } from "@/lib/hooks/useToast";
 import { z } from "zod";
 import { ConnectionStatus } from "../constants";
-import { Notification, StdErrNotificationSchema } from "../notificationTypes";
+import { Notification } from "../notificationTypes";
 import {
   auth,
   discoverOAuthProtectedResourceMetadata,
@@ -92,7 +92,6 @@ export function useConnection({
   oauthScope,
   config,
   onNotification,
-  onStdErrNotification,
   onPendingRequest,
   onElicitationRequest,
   getRoots,
@@ -319,8 +318,6 @@ export function useConnection({
 
   const handleAuthError = async (error: unknown) => {
     if (is401Error(error)) {
-      const serverAuthProvider = new InspectorOAuthClientProvider(sseUrl);
-
       let scope = oauthScope?.trim();
       if (!scope) {
         // Only discover resource metadata when we need to discover scopes
@@ -334,6 +331,10 @@ export function useConnection({
         }
         scope = await discoverScopes(sseUrl, resourceMetadata);
       }
+      const serverAuthProvider = new InspectorOAuthClientProvider(
+        sseUrl,
+        scope,
+      );
 
       const result = await auth(serverAuthProvider, {
         serverUrl: sseUrl,
@@ -503,13 +504,6 @@ export function useConnection({
         };
       }
 
-      if (onStdErrNotification) {
-        client.setNotificationHandler(
-          StdErrNotificationSchema,
-          onStdErrNotification,
-        );
-      }
-
       let capabilities;
       try {
         const transport =

client/src/lib/notificationTypes.ts

@@ -5,18 +5,8 @@ import {
 } from "@modelcontextprotocol/sdk/types.js";
 import { z } from "zod";
 
-export const StdErrNotificationSchema = BaseNotificationSchema.extend({
-  method: z.literal("notifications/stderr"),
-  params: z.object({
-    content: z.string(),
-  }),
-});
-
 export const NotificationSchema = ClientNotificationSchema.or(
-  StdErrNotificationSchema,
-)
-  .or(ServerNotificationSchema)
-  .or(BaseNotificationSchema);
+  ServerNotificationSchema,
+).or(BaseNotificationSchema);
 
-export type StdErrNotification = z.infer<typeof StdErrNotificationSchema>;
 export type Notification = z.infer<typeof NotificationSchema>;

client/src/lib/oauth-state-machine.ts

@@ -177,7 +177,11 @@ export const oauthTransitions: Record<OAuthStep, StateTransition> = {
         authorizationCode: context.state.authorizationCode,
         codeVerifier,
         redirectUri: context.provider.redirectUrl,
-        resource: context.state.resource ?? undefined,
+        resource: context.state.resource
+          ? context.state.resource instanceof URL
+            ? context.state.resource
+            : new URL(context.state.resource)
+          : undefined,
       });
 
       context.provider.saveTokens(tokens);

client/src/utils/__tests__/urlValidation.test.ts

@@ -0,0 +1,135 @@
+import { validateRedirectUrl } from "../urlValidation";
+
+describe("validateRedirectUrl", () => {
+  describe("valid URLs", () => {
+    it("should allow HTTP URLs", () => {
+      expect(() => validateRedirectUrl("http://example.com")).not.toThrow();
+    });
+
+    it("should allow HTTPS URLs", () => {
+      expect(() => validateRedirectUrl("https://example.com")).not.toThrow();
+    });
+
+    it("should allow URLs with ports", () => {
+      expect(() =>
+        validateRedirectUrl("https://example.com:8080"),
+      ).not.toThrow();
+    });
+
+    it("should allow URLs with paths", () => {
+      expect(() =>
+        validateRedirectUrl("https://example.com/path/to/auth"),
+      ).not.toThrow();
+    });
+
+    it("should allow URLs with query parameters", () => {
+      expect(() =>
+        validateRedirectUrl("https://example.com?param=value"),
+      ).not.toThrow();
+    });
+  });
+
+  describe("invalid URLs - XSS vectors", () => {
+    it("should block javascript: protocol", () => {
+      expect(() => validateRedirectUrl("javascript:alert('XSS')")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+
+    it("should block javascript: with encoded characters", () => {
+      expect(() =>
+        validateRedirectUrl("javascript:alert%28%27XSS%27%29"),
+      ).toThrow("Authorization URL must be HTTP or HTTPS");
+    });
+
+    it("should block data: protocol", () => {
+      expect(() =>
+        validateRedirectUrl("data:text/html,<script>alert('XSS')</script>"),
+      ).toThrow("Authorization URL must be HTTP or HTTPS");
+    });
+
+    it("should block vbscript: protocol", () => {
+      expect(() => validateRedirectUrl("vbscript:msgbox")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+
+    it("should block file: protocol", () => {
+      expect(() => validateRedirectUrl("file:///etc/passwd")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+
+    it("should block about: protocol", () => {
+      expect(() => validateRedirectUrl("about:blank")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+
+    it("should block custom protocols", () => {
+      expect(() => validateRedirectUrl("custom://example")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+  });
+
+  describe("edge cases", () => {
+    it("should handle malformed URLs", () => {
+      expect(() => validateRedirectUrl("not a url")).toThrow(
+        "Invalid URL: not a url",
+      );
+    });
+
+    it("should handle empty string", () => {
+      expect(() => validateRedirectUrl("")).toThrow("Invalid URL: ");
+    });
+
+    it("should handle URLs with unicode characters", () => {
+      expect(() => validateRedirectUrl("https://例え.jp")).not.toThrow();
+    });
+
+    it("should handle URLs with case variations", () => {
+      expect(() => validateRedirectUrl("HTTPS://EXAMPLE.COM")).not.toThrow();
+      expect(() => validateRedirectUrl("HtTpS://example.com")).not.toThrow();
+    });
+
+    it("should handle protocol-relative URLs as invalid", () => {
+      expect(() => validateRedirectUrl("//example.com")).toThrow(
+        "Invalid URL: //example.com",
+      );
+    });
+
+    it("should handle URLs with authentication", () => {
+      expect(() =>
+        validateRedirectUrl("https://user:pass@example.com"),
+      ).not.toThrow();
+    });
+  });
+
+  describe("security considerations", () => {
+    it("should not be fooled by whitespace", () => {
+      expect(() => validateRedirectUrl(" javascript:alert('XSS')")).toThrow();
+      expect(() => validateRedirectUrl("javascript:alert('XSS') ")).toThrow();
+    });
+
+    it("should handle null bytes", () => {
+      expect(() =>
+        validateRedirectUrl("java\x00script:alert('XSS')"),
+      ).toThrow();
+    });
+
+    it("should handle tab characters", () => {
+      expect(() => validateRedirectUrl("java\tscript:alert('XSS')")).toThrow();
+    });
+
+    it("should handle newlines", () => {
+      expect(() => validateRedirectUrl("java\nscript:alert('XSS')")).toThrow();
+    });
+
+    it("should handle mixed case protocols", () => {
+      expect(() => validateRedirectUrl("JaVaScRiPt:alert('XSS')")).toThrow(
+        "Authorization URL must be HTTP or HTTPS",
+      );
+    });
+  });
+});

client/src/utils/urlValidation.ts

@@ -0,0 +1,24 @@
+/**
+ * Validates that a URL is safe for redirection.
+ * Only allows HTTP and HTTPS protocols to prevent XSS attacks.
+ *
+ * @param url - The URL string to validate
+ * @throws Error if the URL has an unsafe protocol
+ */
+export function validateRedirectUrl(url: string): void {
+  try {
+    const parsedUrl = new URL(url);
+    if (parsedUrl.protocol !== "http:" && parsedUrl.protocol !== "https:") {
+      throw new Error("Authorization URL must be HTTP or HTTPS");
+    }
+  } catch (error) {
+    if (
+      error instanceof Error &&
+      error.message === "Authorization URL must be HTTP or HTTPS"
+    ) {
+      throw error;
+    }
+    // If URL parsing fails, it's also invalid
+    throw new Error(`Invalid URL: ${url}`);
+  }
+}