tApply(LazyTransform, this, [options]);
}

ObjectSetPrototypeOf(Hash.prototype, LazyTransform.prototype);
ObjectSetPrototypeOf(Hash, LazyTransform);

Hash.prototype.copy = function copy(options) {
  const state = this[kState];
  if (state[kFinalized])
    throw new ERR_CRYPTO_HASH_FINALIZED();

  return new Hash(this[kHandle], options);
};

Hash.prototype._transform = function _transform(chunk, encoding, callback) {
  this[kHandle].update(chunk, encoding);
  callback();
};

Hash.prototype._flush = function _flush(callback) {
  this.push(this[kHandle].digest());
  callback();
};

Hash.prototype.update = function update(data, encoding) {
  encoding = encoding || getDefaultEncoding();

  const state = this[kState];
  if (state[kFinalized])
    throw new ERR_CRYPTO_HASH_FINALIZED();

  if (typeof data === 'string') {
    validateEncoding(data, encoding);
  } else if (!isArrayBufferView(data)) {
    throw new ERR_INVALID_ARG_TYPE(
      'data', ['string', 'Buffer', 'TypedArray', 'DataView'], data);
  }

  if (!this[kHandle].update(data, encoding))
    throw new ERR_CRYPTO_HASH_UPDATE_FAILED();
  return this;
};


Hash.prototype.digest = function digest(outputEncoding) {
  const state = this[kState];
  if (state[kFinalized])
    throw new ERR_CRYPTO_HASH_FINALIZED();
  outputEncoding = outputEncoding || getDefaultEncoding();

  // Explicit conversion for backward compatibility.
  const ret = this[kHandle].digest(`${outputEncoding}`);
  state[kFinalized] = true;
  return ret;
};

function Hmac(hmac, key, options) {
  if (!(this instanceof Hmac))
    return new Hmac(hmac, key, options);
  validateString(hmac, 'hmac');
  const encoding = getStringOption(options, 'encoding');
  key = prepareSecretKey(key, encoding);
  this[kHandle] = new _Hmac();
  this[kHandle].init(hmac, key);
  this[kState] = {
    [kFinalized]: false
  };
  ReflectApply(LazyTransform, this, [options]);
}

ObjectSetPrototypeOf(Hmac.prototype, LazyTransform.prototype);
ObjectSetPrototypeOf(Hmac, LazyTransform);

Hmac.prototype.update = Hash.prototype.update;

Hmac.prototype.digest = function digest(outputEncoding) {
  const state = this[kState];
  outputEncoding = outputEncoding || getDefaultEncoding();

  if (state[kFinalized]) {
    const buf = Buffer.from('');
    return outputEncoding === 'buffer' ? buf : buf.toString(outputEncoding);
  }

  // Explicit conversion for backward compatibility.
  const ret = this[kHandle].digest(`${outputEncoding}`);
  state[kFinalized] = true;
  return ret;
};

Hmac.prototype._flush = Hash.prototype._flush;
Hmac.prototype._transform = Hash.prototype._transform;

// Implementation for WebCrypto subtle.digest()

async function asyncDigest(algorithm, data) {
  algorithm = normalizeAlgorithm(algorithm);
  data = getArrayBufferOrView(data, 'data');
  validateMaxBufferLength(data, 'data');

  if (algorithm.length !== undefined)
    validateUint32(algorithm.length, 'algorithm.length');

  return jobPromise(new HashJob(
    kCryptoJobAsync,
    normalizeHashName(algorithm.name),
    data,
    algorithm.length));
}

module.exports = {
  Hash,
  Hmac,
  asyncDigest,
};
