 = keys;

  // If no encoding was chosen, return key objects instead.
  return {
    publicKey: wrapKey(publicKey, PublicKeyObject),
    privateKey: wrapKey(privateKey, PrivateKeyObject),
  };
}

function parseKeyEncoding(keyType, options = kEmptyObject) {
  const { publicKeyEncoding, privateKeyEncoding } = options;

  let publicFormat, publicType;
  if (publicKeyEncoding == null) {
    publicFormat = publicType = undefined;
  } else if (typeof publicKeyEncoding === 'object') {
    ({
      format: publicFormat,
      type: publicType,
    } = parsePublicKeyEncoding(publicKeyEncoding, keyType,
                               'publicKeyEncoding'));
  } else {
    throw new ERR_INVALID_ARG_VALUE('options.publicKeyEncoding',
                                    publicKeyEncoding);
  }

  let privateFormat, privateType, cipher, passphrase;
  if (privateKeyEncoding == null) {
    privateFormat = privateType = undefined;
  } else if (typeof privateKeyEncoding === 'object') {
    ({
      format: privateFormat,
      type: privateType,
      cipher,
      passphrase,
    } = parsePrivateKeyEncoding(privateKeyEncoding, keyType,
                                'privateKeyEncoding'));
  } else {
    throw new ERR_INVALID_ARG_VALUE('options.privateKeyEncoding',
                                    privateKeyEncoding);
  }

  return [
    publicFormat,
    publicType,
    privateFormat,
    privateType,
    cipher,
    passphrase,
  ];
}

function createJob(mode, type, options) {
  validateString(type, 'type');

  const encoding = new SafeArrayIterator(parseKeyEncoding(type, options));

  if (options !== undefined)
    validateObject(options, 'options');

  switch (type) {
    case 'rsa':
    case 'rsa-pss':
    {
      validateObject(options, 'options');
      const { modulusLength } = options;
      validateUint32(modulusLength, 'options.modulusLength');

      let { publicExponent } = options;
      if (publicExponent == null) {
        publicExponent = 0x10001;
      } else {
        validateUint32(publicExponent, 'options.publicExponent');
      }

      if (type === 'rsa') {
        return new RsaKeyPairGenJob(
          mode,
          kKeyVariantRSA_SSA_PKCS1_v1_5,  // Used also for RSA-OAEP
          modulusLength,
          publicExponent,
          ...encoding);
      }

      const {
        hash, mgf1Hash, hashAlgorithm, mgf1HashAlgorithm, saltLength,
      } = options;

      if (saltLength !== undefined)
        validateInt32(saltLength, 'options.saltLength', 0);
      if (hashAlgorithm !== undefined)
        validateString(hashAlgorithm, 'options.hashAlgorithm');
      if (mgf1HashAlgorithm !== undefined)
        validateString(mgf1HashAlgorithm, 'options.mgf1HashAlgorithm');
      if (hash !== undefined) {
        process.emitWarning(
          '"options.hash" is deprecated, ' +
          'use "options.hashAlgorithm" instead.',
          'DeprecationWarning',
          'DEP0154');
        validateString(hash, 'options.hash');
        if (hashAlgorithm && hash !== hashAlgorithm) {
          throw new ERR_INVALID_ARG_VALUE('options.hash', hash);
        }
      }
      if (mgf1Hash !== undefined) {
        process.emitWarning(
          '"options.mgf1Hash" is deprecated, ' +
          'use "options.mgf1HashAlgorithm" instead.',
          'DeprecationWarning',
          'DEP0154');
        validateString(mgf1Hash, 'options.mgf1Hash');
        if (mgf1HashAlgorithm && mgf1Hash !== mgf1HashAlgorithm) {
          throw new ERR_INVALID_ARG_VALUE('options.mgf1Hash', mgf1Hash);
        }
      }

      return new RsaKeyPairGenJob(
        mode,
        kKeyVariantRSA_PSS,
        modulusLength,
        publicExponent,
        hashAlgorithm || hash,
        mgf1HashAlgorithm || mgf1Hash,
        saltLength,
        ...encoding);
    }
    case 'dsa':
    {
      validateObject(options, 'options');
      const { modulusLength } = options;
      validateUint32(modulusLength, 'options.modulusLength');

      let { divisorLength } = options;
      if (divisorLength == null) {
        divisorLength = -1;
      } else
        validateInt32(divisorLength, 'options.divisorLength', 0);

      return new DsaKeyPairGenJob(
        mode,
        modulusLength,
        divisorLength,
        ...encoding);
    }
    case 'ec':
    {
      validateObject(options, 'options');
      const { namedCurve } = options;
      validateString(namedCurve, 'options.namedCurve');
      let { paramEncoding } = options;
      if (paramEncoding == null || paramEncoding === 'named')
        paramEncoding = OPENSSL_EC_NAMED_CURVE;
      else if (paramEncoding === 'explicit')
        paramEncoding = OPENSSL_EC_EXPLICIT_CURVE;
      else
        throw new ERR_INVALID_ARG_VALUE('options.paramEncoding', paramEncoding);

      return new EcKeyPairGenJob(
        mode,
        namedCurve,
        paramEncoding,
        ...encoding);
    }
    case 'ed25519':
    case 'ed448':
    case 'x25519':
    case 'x448':
    {
      let id;
      switch (type) {
        case 'ed25519':
          id = EVP_PKEY_ED25519;
          break;
        case 'ed448':
          id = EVP_PKEY_ED448;
          break;
        case 'x25519':
          id = EVP_PKEY_X25519;
          break;
        case 'x448':
          id = EVP_PKEY_X448;
          break;
      }
      return new NidKeyPairGenJob(mode, id, ...encoding);
    }
    case 'dh':
    {
      validateObject(options, 'options');
      const { group, primeLength, prime, generator } = options;
      if (group != null) {
        if (prime != null)
          throw new ERR_INCOMPATIBLE_OPTION_PAIR('group', 'prime');
        if (primeLength != null)
          throw new ERR_INCOMPATIBLE_OPTION_PAIR('group', 'primeLength');
        if (generator != null)
          throw new ERR_INCOMPATIBLE_OPTION_PAIR('group', 'generator');

        validateString(group, 'options.group');

        return new DhKeyPairGenJob(mode, group, ...encoding);
      }

      if (prime != null) {
        if (primeLength != null)
          throw new ERR_INCOMPATIBLE_OPTION_PAIR('prime', 'primeLength');

        validateBuffer(prime, 'options.prime');
      } else if (primeLength != null) {
        validateInt32(primeLength, 'options.primeLength', 0);
      } else {
        throw new ERR_MISSING_OPTION(
          'At least one of the group, prime, or primeLength options');
      }

      if (generator != null) {
        validateInt32(generator, 'options.generator', 0);
      }
      return new DhKeyPairGenJob(
        mode,
        prime != null ? prime : primeLength,
        generator == null ? 2 : generator,
        ...encoding);
    }
    default:
      // Fall through
  }
  throw new ERR_INVALID_ARG_VALUE('type', type, 'must be a supported key type');
}

// Symmetric Key Generation

function generateKeyJob(mode, keyType, options) {
  validateString(keyType, 'type');
  validateObject(options, 'options');
  const { length } = options;
  switch (keyType) {
    case 'hmac':
      validateInteger(length, 'options.length', 8, 2 ** 31 - 1);
      break;
    case 'aes':
      validateOneOf(length, 'options.length', kAesKeyLengths);
      break;
    default:
      throw new ERR_INVALID_ARG_VALUE(
        'type',
        keyType,
        'must be a supported key type');
  }

  return new SecretKeyGenJob(mode, length);
}

function handleGenerateKeyError(ret) {
  if (ret === undefined)
    return; // async

  const { 0: err, 1: key } = ret;
  if (err !== undefined)
    throw err;

  return wrapKey(key, SecretKeyObject);
}

function generateKey(type, options, callback) {
  if (typeof options === 'function') {
    callback = options;
    options = undefined;
  }

  validateFunction(callback, 'callback');

  const job = generateKeyJob(kCryptoJobAsync, type, options);

  job.ondone = (error, key) => {
    if (error) return FunctionPrototypeCall(callback, job, error);
    FunctionPrototypeCall(callback, job, null, wrapKey(key, SecretKeyObject));
  };

  handleGenerateKeyError(job.run());
}

function generateKeySync(type, options) {
  return handleGenerateKeyError(
    generateKeyJob(kCryptoJobSync, type, options).run());
}

module.exports = {
  generateKeyPair,
  generateKeyPairSync,
  generateKey,
  generateKeySync,
};
