public final class CheckHandshake {
  /** Rejects otherwise-trusted certificates. */
  private static final Interceptor CHECK_HANDSHAKE_INTERCEPTOR = new Interceptor() {
    final Set<String> denylist = Collections.singleton(
        "sha256/afwiKY3RxoMmLkuRW1l7QsPZTJPwDS2pdDROQjXw8ig=");

    @Override public Response intercept(Chain chain) throws IOException {
      for (Certificate certificate : chain.connection().handshake().peerCertificates()) {

  }

  /** Returns a hash function implementing the SHA-256 algorithm (256 hash bits). */
  public static HashFunction sha256() {
    return Sha256Holder.SHA_256;
  }

  private static class Sha256Holder {
    static final HashFunction SHA_256 =
        new MessageDigestHashFunction("SHA-256", "Hashing.sha256()");
  }

  /**
   * Returns a hash function implementing the SHA-384 algorithm (384 hash bits).
   *

    String APP_CIPHER_ALGORISM = "app.cipher.algorism";

    /** The key of the configuration. e.g. ___change__me___ */
    String APP_CIPHER_KEY = "app.cipher.key";

    /** The key of the configuration. e.g. sha256 */
    String APP_DIGEST_ALGORISM = "app.digest.algorism";

    /** The key of the configuration. e.g. .*password|.*key|.*token|.*secret */
    String APP_ENCRYPT_PROPERTY_PATTERN = "app.encrypt.property.pattern";