fix(handoff): close browser credential boundaries

- Filter custom credential headers and cookies at restricted handoff consumers.
- Preserve ordinary single-file capture credentials for Add-window review.
- Extend native and renderer redaction coverage with focused regressions.

src/components/AddDownloadsModal.tsx

@@ -14,7 +14,7 @@ import { open } from '@tauri-apps/plugin-dialog';
 import { writeText as writeClipboardText } from '@tauri-apps/plugin-clipboard-manager';
 import { invokeCommand as invoke } from '../ipc';
 import { DuplicateResolutionModal, DuplicateConflict } from './DuplicateResolutionModal';
-import { canonicalizeDownloadFileName, categoryForFileName, downloadFileNameWithSuffix, downloadFileNamesMatch, downloadMediaKindsMatch, isValidTorrentExcludeTrackerList, isValidTorrentTrackerList, MAX_TORRENT_STOP_TIMEOUT, MAX_TORRENT_TRACKER_INTERVAL, MAX_TORRENT_TRACKER_TIMEOUT, normalizeSpeedLimitForBackend, normalizeTorrentWebSeedDrafts, normalizeTorrentTrackerInterval, normalizeTorrentTrackerTimeout, serializeTorrentPreviewPriority, TORRENT_ENCRYPTION_POLICY_DISABLED, TORRENT_ENCRYPTION_POLICY_FORCE_ENCRYPTION, TORRENT_ENCRYPTION_POLICY_REQUIRE_CRYPTO, type TorrentEncryptionPolicy, type TorrentFileAllocation } from '../utils/downloads';
+import { canonicalizeDownloadFileName, categoryForFileName, downloadFileNameWithSuffix, downloadFileNamesMatch, downloadMediaKindsMatch, headerNameHasCredentialMaterial, isValidTorrentExcludeTrackerList, isValidTorrentTrackerList, MAX_TORRENT_STOP_TIMEOUT, MAX_TORRENT_TRACKER_INTERVAL, MAX_TORRENT_TRACKER_TIMEOUT, normalizeSpeedLimitForBackend, normalizeTorrentWebSeedDrafts, normalizeTorrentTrackerInterval, normalizeTorrentTrackerTimeout, serializeTorrentPreviewPriority, TORRENT_ENCRYPTION_POLICY_DISABLED, TORRENT_ENCRYPTION_POLICY_FORCE_ENCRYPTION, TORRENT_ENCRYPTION_POLICY_REQUIRE_CRYPTO, type TorrentEncryptionPolicy, type TorrentFileAllocation } from '../utils/downloads';
 import { fetchMediaMetadataDeduped, fetchMediaPlaylistMetadataDeduped } from '../utils/mediaMetadata';
 import {
   expandTilde,
@@ -124,12 +124,12 @@ const extensionHeaders = (context: PendingAddRequestContext | undefined) => [
   context?.referer ? `Referer: ${context.referer.replace(/[\r\n]/g, '')}` : '',
   context?.media
     ? (context.headers || '')
-        .split(/\r?\n/)
-        .filter(line => {
-          const separator = line.indexOf(':');
-          return separator < 0 || line.slice(0, separator).trim().toLowerCase() !== 'cookie';
-        })
-        .join('\n')
+      .split(/\r?\n/)
+      .filter(line => {
+        const separator = line.indexOf(':');
+        return separator > 0 && !headerNameHasCredentialMaterial(line.slice(0, separator));
+      })
+      .join('\n')
     : context?.headers
 ].filter(Boolean).join('\n');
 

src/store/useDownloadStore.test.ts

@@ -3643,7 +3643,7 @@ describe('useDownloadStore', () => {
       silent: false,
       filename: null,
       headers: null,
-      cookies: null,
+      cookies: 'shared=session',
       cookie_scopes: null,
       media: false,
       torrent: false,
@@ -3659,6 +3659,7 @@ describe('useDownloadStore', () => {
       'https://example.com/one.zip\nhttps://example.com/two.zip'
     );
     expect(useDownloadStore.getState().pendingAddBatch).toBe(false);
+    expect(useDownloadStore.getState().pendingAddCookies).toBe('');
   });
 
   it('keeps each extension handoff context attached to its own URL while the Add Modal is open', async () => {
@@ -3720,7 +3721,7 @@ describe('useDownloadStore', () => {
       referer: 'https://adult.example/watch/123',
       silent: false,
       filename: null,
-      headers: `Cookie: stale=${'x'.repeat(64 * 1024)}\nCookie2: stale=1\nAuthorization: Bearer stale\nProxy-Authorization: Basic stale\nSet-Cookie: stale=1\nSet-Cookie2: stale=1\nUser-Agent: Firefox Test`,
+      headers: `Cookie: stale=${'x'.repeat(64 * 1024)}\nCookie2: stale=1\nAuthorization: Bearer stale\nProxy-Authorization: Basic stale\nSet-Cookie: stale=1\nSet-Cookie2: stale=1\nX-Api-Key: stale\nX-Auth-Token: stale\nX-Request-Signature: stale\nX-Session: stale\nUser-Agent: Firefox Test`,
       cookies: `oversized=${'x'.repeat(64 * 1024)}`,
       cookie_scopes: null,
       media: true,

src/store/useDownloadStore.ts

@@ -10,7 +10,7 @@ import type { ExtensionCookieScope } from '../bindings/ExtensionCookieScope';
 import type { Queue } from '../bindings/Queue';
 import { useSettingsStore } from './useSettingsStore';
 import { useDownloadProgressStore } from './downloadProgressStore';
-import { canonicalizeDownloadFileName, categoryForDownload, categoryForFileName, hasCredentialBearingHeaders, isActiveDownloadStatus, isTransferActiveStatus, isValidTorrentExcludeTrackerList, isValidTorrentTrackerList, MAX_TORRENT_STOP_TIMEOUT, normalizeSpeedLimitForBackend, normalizeTorrentEncryptionPolicy, normalizeTorrentFileAllocation, normalizeTorrentPrioritizePiece, normalizeTorrentTrackerInterval, normalizeTorrentTrackerTimeout, redactDownloadForPersistence, resolveDownloadConnections } from '../utils/downloads';
+import { canonicalizeDownloadFileName, categoryForDownload, categoryForFileName, hasCredentialBearingHeaders, headerNameHasCredentialMaterial, isActiveDownloadStatus, isTransferActiveStatus, isValidTorrentExcludeTrackerList, isValidTorrentTrackerList, MAX_TORRENT_STOP_TIMEOUT, normalizeSpeedLimitForBackend, normalizeTorrentEncryptionPolicy, normalizeTorrentFileAllocation, normalizeTorrentPrioritizePiece, normalizeTorrentTrackerInterval, normalizeTorrentTrackerTimeout, redactDownloadForPersistence, resolveDownloadConnections } from '../utils/downloads';
 import {
   resolveCategoryDestination
 } from '../utils/downloadLocations';
@@ -300,16 +300,8 @@ const stripSensitiveMediaHeaders = (value: string | null | undefined): string =>
     .split(/\r?\n/)
     .filter(line => {
       const separator = line.indexOf(':');
-      if (separator < 0) return true;
-      const name = line.slice(0, separator).trim().toLowerCase();
-      return ![
-        'authorization',
-        'cookie',
-        'cookie2',
-        'proxy-authorization',
-        'set-cookie',
-        'set-cookie2'
-      ].includes(name);
+      if (separator <= 0) return false;
+      return !headerNameHasCredentialMaterial(line.slice(0, separator));
     })
     .join('\n')
     .trim();
@@ -1818,8 +1810,8 @@ export const useDownloadStore = create<DownloadState>((set, get) => {
     // Explicit media authentication belongs to yt-dlp's configured browser
     // cookie source. Keep this frontend guard for events from older desktop or
     // extension builds; ordinary captured downloads retain their cookies.
-    const cookies = request.media === true ? null : request.cookies;
-    const headers = request.media === true
+    const cookies = request.media === true || urls.length > 1 ? null : request.cookies;
+    const headers = request.media === true || urls.length > 1
       ? stripSensitiveMediaHeaders(request.headers) || null
       : request.headers;
 

src/utils/downloads.test.ts

@@ -21,6 +21,7 @@ import {
   torrentWebSeedDraftsFromSeeds,
   normalizeTorrentTrackerInterval,
   normalizeTorrentTrackerTimeout,
+  headerNameHasCredentialMaterial,
   redactDownloadForPersistence,
   resolveDownloadConnections
 } from './downloads';
@@ -178,6 +179,17 @@ describe('download persistence progress snapshots', () => {
   });
 });
 
+describe('credential-bearing extension header names', () => {
+  it('classifies named and marker-based credential headers while preserving browser context names', () => {
+    expect(headerNameHasCredentialMaterial('X-Api-Key')).toBe(true);
+    expect(headerNameHasCredentialMaterial('X-Request-Signature')).toBe(true);
+    expect(headerNameHasCredentialMaterial('X-Session')).toBe(true);
+    expect(headerNameHasCredentialMaterial('Set-Cookie2')).toBe(true);
+    expect(headerNameHasCredentialMaterial('User-Agent')).toBe(false);
+    expect(headerNameHasCredentialMaterial('X-Trace')).toBe(false);
+  });
+});
+
 describe('allocation phase visibility', () => {
   it('does not override paused or completed statuses', () => {
     expect(isAllocationPhaseVisible(true, 'ready')).toBe(true);

src/utils/downloads.ts

@@ -640,6 +640,37 @@ const NON_CREDENTIAL_REQUEST_HEADERS = new Set([
   'via',
   'warning',
 ]);
+
+const CREDENTIAL_HEADER_NAMES = new Set([
+  'authorization',
+  'cookie',
+  'cookie2',
+  'proxy-authorization',
+  'set-cookie',
+  'set-cookie2',
+  'x-api-key',
+  'x-auth-token',
+  'x-access-token',
+]);
+const CREDENTIAL_HEADER_MARKERS = [
+  'auth',
+  'credential',
+  'key',
+  'password',
+  'passwd',
+  'secret',
+  'session',
+  'signature',
+  'token',
+] as const;
+
+/** Header-name classifier shared by extension handoff defenses. */
+export const headerNameHasCredentialMaterial = (rawName: string): boolean => {
+  const name = rawName.trim().toLowerCase();
+  return name.length === 0
+    || CREDENTIAL_HEADER_NAMES.has(name)
+    || CREDENTIAL_HEADER_MARKERS.some(marker => name.includes(marker));
+};
 // Only stable request context is safe to carry into a later lifecycle. Range,
 // conditional, hop-by-hop, and routing headers describe the old HTTP request
 // and can conflict with Aria2's own resume negotiation.

src/utils/logEntries.test.ts

@@ -46,6 +46,25 @@ describe('log entry streaming', () => {
     expect(liveLogEntry(3, 'Authorization: Bearer secret').message).not.toContain('secret');
   });
 
+  it('redacts custom session and signature headers from live output', () => {
+    const redacted = redactLogText('X-Request-Signature: signature-secret X-Session: session-secret');
+
+    expect(redacted).not.toContain('signature-secret');
+    expect(redacted).not.toContain('session-secret');
+  });
+
+  it('redacts legacy cookie headers and compound custom values', () => {
+    const redacted = redactLogText('Set-Cookie2: legacy-cookie X-Session: id=session-secret; key=compound-secret');
+
+    expect(redacted).not.toContain('legacy-cookie');
+    expect(redacted).not.toContain('session-secret');
+    expect(redacted).not.toContain('compound-secret');
+
+    const equalsRedacted = redactLogText('Cookie2=a=1; user_id=secret; state=xyz');
+    expect(equalsRedacted).not.toContain('user_id=secret');
+    expect(equalsRedacted).not.toContain('state=xyz');
+  });
+
   it('redacts persisted content and quoted credential fields', () => {
     const persisted = persistedLogEntry('{"api_key":"json-secret","path":"/Users/nima/file"}', '/Users/nima');
 

src/utils/logEntries.ts

@@ -49,11 +49,15 @@ export const redactLogText = (message: string, homePath = ''): string => {
     '$1[redacted]@'
   );
   redacted = redacted.replace(
-    /(["'])(authorization|proxy-authorization|cookie|set-cookie|password|token|secret|credential|pairing[-_ ]?token|api[-_ ]?key)(["'])(\s*[:=]\s*)["'][^"\r\n,;]*["']/gi,
+    /([A-Za-z0-9_-]*(?:authorization|proxy-authorization|cookie2|cookie|set-cookie2|set-cookie|password|passwd|auth|token|secret|credential|key|pairing[-_ ]?token|api[-_ ]?key|access[-_ ]?token|auth[-_ ]?token|signature|session)[A-Za-z0-9_-]*)\s*[:=]\s*[^\r\n]*?(;?)(?=\s+(?:[A-Za-z][A-Za-z0-9+.-]*:\/\/|[A-Za-z0-9_-]*(?:authorization|proxy-authorization|cookie2|cookie|set-cookie2|set-cookie|password|passwd|auth|token|secret|credential|key|pairing[-_ ]?token|api[-_ ]?key|access[-_ ]?token|auth[-_ ]?token|signature|session)\s*[:=])|$)/gi,
+    '$1: [redacted]$2'
+  );
+  redacted = redacted.replace(
+    /(["'])(authorization|proxy-authorization|cookie2|cookie|set-cookie2|set-cookie|password|passwd|auth|token|secret|credential|key|pairing[-_ ]?token|api[-_ ]?key|access[-_ ]?token|auth[-_ ]?token|signature|session)(["'])(\s*[:=]\s*)["'][^"\r\n,;]*["']/gi,
     '$1$2$3$4[redacted]'
   );
   return redacted.replace(
-    /(authorization|proxy-authorization|cookie|set-cookie|password|token|secret|credential|pairing[-_ ]?token|api[-_ ]?key)(\s*)([:=])(\s*)([^\r\n,;]+)/gi,
+    /(authorization|proxy-authorization|cookie2|cookie|set-cookie2|set-cookie|password|passwd|auth|token|secret|credential|key|pairing[-_ ]?token|api[-_ ]?key|access[-_ ]?token|auth[-_ ]?token|signature|session)(\s*)([:=])(\s*)([^\r\n,;]+)/gi,
     '$1$2$3$4[redacted]'
   );
 };