v1.11.9: manual redirect handling — re-run URL guard on each hop

apps/server/src/services/__tests__/web_tools.test.ts

@@ -343,3 +343,113 @@ describe('executeWebFetch — size + truncation', () => {
     expect('content' in result && result.truncated).toBe(false);
   });
 });
+
+// ============================================================================
+// v1.11.9: manual redirect handling — re-run URL guard on each hop
+// ============================================================================
+
+// Helper: build a 30x redirect Response. status 302 by default; tests
+// pass other codes (or omit the Location header) when they need to.
+function redirect(loc: string | null, status = 302): Response {
+  const headers: Record<string, string> = {};
+  if (loc !== null) headers['location'] = loc;
+  return new Response('', { status, headers });
+}
+
+describe('executeWebFetch — redirect handling', () => {
+  it('blocks a redirect target that resolves to a private IP (AWS IMDS)', async () => {
+    // Public-IP origin 302s into 169.254.169.254 (link-local). Pre-v1.11.9
+    // `redirect: 'follow'` would silently follow this; the new manual
+    // loop re-runs isPublicUrl on the resolved target and blocks.
+    const fakeFetch = vi
+      .fn<typeof fetch>()
+      .mockResolvedValueOnce(redirect('http://169.254.169.254/latest/meta-data/'));
+    const result = await executeWebFetch(
+      { url: 'https://example.com/redirect' },
+      fakeFetch as unknown as typeof fetch,
+    );
+    expect('error' in result).toBe(true);
+    if ('error' in result) {
+      expect(result.error).toBe('blocked_by_url_guard');
+      // Reason should make it clear this was a REDIRECT hop, not the
+      // initial URL — so logs can distinguish the two failure modes.
+      expect(result.reason).toMatch(/redirect target/);
+    }
+    // Critical: the second fetch (the private target) must NOT happen.
+    expect(fakeFetch).toHaveBeenCalledTimes(1);
+  });
+
+  it('follows a public-to-public redirect and returns the final body', async () => {
+    const fakeFetch = vi
+      .fn<typeof fetch>()
+      .mockResolvedValueOnce(redirect('https://example.org/final'))
+      .mockResolvedValueOnce(mockResponse('ok body', { contentType: 'text/plain' }));
+    const result = await executeWebFetch(
+      { url: 'https://example.com/start' },
+      fakeFetch as unknown as typeof fetch,
+    );
+    expect('content' in result).toBe(true);
+    if ('content' in result) {
+      expect(result.content).toBe('ok body');
+      // Final URL is reported back so the model knows where the body came from.
+      expect(result.url).toBe('https://example.org/final');
+    }
+    expect(fakeFetch).toHaveBeenCalledTimes(2);
+  });
+
+  it('bails after MAX_REDIRECTS hops with a Too many redirects error', async () => {
+    // Chain 6 redirects — one more than the loop allows. Each Location
+    // points at a distinct public host so the URL guard stays happy and
+    // we exercise the redirectCount > MAX_REDIRECTS branch specifically.
+    const fakeFetch = vi
+      .fn<typeof fetch>()
+      .mockResolvedValueOnce(redirect('https://a.example/'))
+      .mockResolvedValueOnce(redirect('https://b.example/'))
+      .mockResolvedValueOnce(redirect('https://c.example/'))
+      .mockResolvedValueOnce(redirect('https://d.example/'))
+      .mockResolvedValueOnce(redirect('https://e.example/'))
+      .mockResolvedValueOnce(redirect('https://f.example/'));
+    const result = await executeWebFetch(
+      { url: 'https://start.example/' },
+      fakeFetch as unknown as typeof fetch,
+    );
+    expect('error' in result).toBe(true);
+    if ('error' in result) {
+      expect(result.error).toBe('too_many_redirects');
+      expect(result.reason).toMatch(/Too many redirects/);
+    }
+  });
+
+  it('errors when a 30x response omits the Location header', async () => {
+    const fakeFetch = vi
+      .fn<typeof fetch>()
+      .mockResolvedValueOnce(redirect(null, 302));
+    const result = await executeWebFetch(
+      { url: 'https://example.com/' },
+      fakeFetch as unknown as typeof fetch,
+    );
+    expect('error' in result).toBe(true);
+    if ('error' in result) {
+      expect(result.error).toBe('redirect_missing_location');
+      expect(result.reason).toMatch(/no Location/);
+    }
+  });
+
+  it('resolves a relative Location against the current URL', async () => {
+    // Server sends `Location: /foo` (relative) on a request to
+    // https://example.com/path. RFC 9110 says resolve against the
+    // request URL, so the next hop is https://example.com/foo. Assert
+    // the second fetch was called with the absolute resolved URL.
+    const fakeFetch = vi
+      .fn<typeof fetch>()
+      .mockResolvedValueOnce(redirect('/foo'))
+      .mockResolvedValueOnce(mockResponse('final', { contentType: 'text/plain' }));
+    const result = await executeWebFetch(
+      { url: 'https://example.com/path' },
+      fakeFetch as unknown as typeof fetch,
+    );
+    expect('content' in result && result.content).toBe('final');
+    expect(fakeFetch).toHaveBeenCalledTimes(2);
+    expect(fakeFetch.mock.calls[1]![0]).toBe('https://example.com/foo');
+  });
+});