ComposioHQ/composio · error · KeyringError

CFDataGetBytePtr returned NULL

Error message

CFDataGetBytePtr returned NULL

What it means

CFDataGetBytePtr returned NULL while extracting bytes from a CFData result (e.g. a secret returned by SecItemCopyMatching). KeyringError kind 'PlatformFailure'.

Source

Thrown at ts/packages/cli-keyring/src/stores/macos-security-ffi.ts:372

  const buf = new Uint8Array(4096);
  const ok = cf.symbols.CFStringGetCString(
    cfString,
    buf,
    BigInt(buf.byteLength),
    kCFStringEncodingUTF8
  );
  if (!ok) return '<unrepresentable>';
  const end = buf.indexOf(0);
  return textDecoder.decode(buf.subarray(0, end === -1 ? buf.byteLength : end));
}

/** Extract raw bytes from a CFData. */
function cfDataToBytes(cfData: bigint): Uint8Array {
  const length = Number(cf.symbols.CFDataGetLength(cfData));
  if (length === 0) return new Uint8Array();
  const bytePtr = cf.symbols.CFDataGetBytePtr(cfData);
  if (bytePtr === 0n) {
    throw new KeyringError({
      kind: 'PlatformFailure',
      cause: new Error('CFDataGetBytePtr returned NULL'),
    });
  }
  // CFData storage is a real heap pointer (never tagged), so the
  // BigInt value fits in JS safe integer range and we can hand it to
  // toArrayBuffer via Number. Copy into JS-owned memory so we don't
  // retain the CFData longer than necessary.
  const view = new Uint8Array(toArrayBuffer(Number(bytePtr) as unknown as never, 0, length));
  return new Uint8Array(view);
}

/** Build a mutable CFDictionary. */
function cfMutableDict(pool: CFPool): bigint {
  const dict = cf.symbols.CFDictionaryCreateMutable(
    0n,
    0n,
    K.kCFTypeDictionaryKeyCallBacks,

View on GitHub (pinned to 64b1b85502)

Solutions

1. Retry once — often transient
2. Delete and re-create the problematic keychain item if consistently reproducible
3. Report with item details to maintainers

catch (e) { if (e instanceof KeyringError && e.kind === 'PlatformFailure' && /CFDataGetBytePtr/.test(String(e.cause))) { return withRetry(fn, 2); } throw e; }

When it happens

Trigger: Reading secret data from the macOS keychain when the CFData reports a non-zero length but yields a NULL byte pointer.

Common situations: Corrupted or unusual keychain items; edge cases in OS-provided data objects; rare platform failures.

Related errors

• PlatformFailure
• dlsym(${name}) failed
• CFStringCreateWithBytes returned NULL
• CFDictionaryCreateMutable returned NULL
• Invalid

AI-assisted analysis of ComposioHQ/composio@64b1b85502 (2026-08-28). Data as JSON: /api/errors/7fdfc2d1ce666e57. Report an issue: GitHub.