throw new CIFSException("Preauth integrity context is invalid for session: " + sessionId);
        }

        byte[] actualHash = context.getCurrentHash();
        boolean isValid = MessageDigest.isEqual(actualHash, expectedHash);

        if (isValid) {
            log.debug("Preauth integrity validation passed for session {}", sessionId);
        } else {

            System.arraycopy(mac.doFinal(), 0, cmp, 0, SIGNATURE_LENGTH);

            // Use constant-time comparison to prevent timing attacks
            if (!MessageDigest.isEqual(sig, cmp)) {
                return false; // Signature verification failed
            }
            return true; // Signature verification succeeded
        } finally {
            this.signingLock.unlock();

        }

        final byte[] verify = new byte[8];
        System.arraycopy(mic, 4, verify, 0, 8);
        if (!MessageDigest.isEqual(trunc, verify)) {
            if (log.isDebugEnabled()) {
                log.debug(String.format("Seq = %d ver = %d encrypted = %s", seq, ver, encrypted));

  }

  /**
   * Returns {@code true} if this fluent iterable contains any object for which {@code
   * equals(target)} is true.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.anyMatch(Predicate.isEqual(target))}.
   */
  public final boolean contains(@Nullable Object target) {
    return Iterables.contains(getDelegate(), target);
  }

  /**

   *
   * <p><b>Java 8+ users:</b> In most cases, the {@code Stream} equivalent of this method is {@code
   * stream.filter(element::equals).count()}. If {@code element} might be null, use {@code
   * stream.filter(Predicate.isEqual(element)).count()} instead.
   *
   * @see java.util.Collections#frequency(Collection, Object) Collections.frequency(Collection,
   *     Object)
   */

   *
   * <p><b>Java 8+ users:</b> In most cases, the {@code Stream} equivalent of this method is {@code
   * stream.filter(element::equals).count()}. If {@code element} might be null, use {@code
   * stream.filter(Predicate.isEqual(element)).count()} instead.
   *
   * @see java.util.Collections#frequency(Collection, Object) Collections.frequency(Collection,
   *     Object)
   */