fork-openpgpjs/src/key/factory.js

// OpenPGP.js - An OpenPGP implementation in javascript
// Copyright (C) 2015-2016 Decentral
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3.0 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

import {
  PacketList,
  UserIDPacket,
  SignaturePacket,
  PublicKeyPacket,
  PublicSubkeyPacket,
  SecretKeyPacket,
  SecretSubkeyPacket,
  UserAttributePacket
} from '../packet';
import PrivateKey from './private_key';
import PublicKey from './public_key';
import * as helper from './helper';
import enums from '../enums';
import util from '../util';
import defaultConfig from '../config';
import { unarmor } from '../encoding/armor';

// A Key can contain the following packets
const allowedKeyPackets = /*#__PURE__*/ util.constructAllowedPackets([
  PublicKeyPacket,
  PublicSubkeyPacket,
  SecretKeyPacket,
  SecretSubkeyPacket,
  UserIDPacket,
  UserAttributePacket,
  SignaturePacket
]);

/**
 * Creates a PublicKey or PrivateKey depending on the packetlist in input
 * @param {PacketList} - packets to parse
 * @return {Key} parsed key
 * @throws if no key packet was found
 */
function createKey(packetlist) {
  for (const packet of packetlist) {
    switch (packet.constructor.tag) {
      case enums.packet.secretKey:
        return new PrivateKey(packetlist);
      case enums.packet.publicKey:
        return new PublicKey(packetlist);
    }
  }
  throw new Error('No key packet found');
}


/**
 * Generates a new OpenPGP key. Supports RSA and ECC keys.
 * By default, primary and subkeys will be of same type.
 * @param {ecc|rsa} options.type                  The primary key algorithm type: ECC or RSA
 * @param {String}  options.curve                 Elliptic curve for ECC keys
 * @param {Integer} options.rsaBits               Number of bits for RSA keys
 * @param {Array<String|Object>} options.userIDs  User IDs as strings or objects: 'Jo Doe <info@jo.com>' or { name:'Jo Doe', email:'info@jo.com' }
 * @param {String}  options.passphrase            Passphrase used to encrypt the resulting private key
 * @param {Number}  options.keyExpirationTime     (optional) Number of seconds from the key creation time after which the key expires
 * @param {Date}    options.date                  Creation date of the key and the key signatures
 * @param {Object} config - Full configuration
 * @param {Array<Object>} options.subkeys         (optional) options for each subkey, default to main key options. e.g. [{sign: true, passphrase: '123'}]
 *                                                  sign parameter defaults to false, and indicates whether the subkey should sign rather than encrypt
 * @param {Array<Uint8Array>|null} [randomSeed] - Optional: use Uint8Arrays (one for each subkey) as source of entropy for ecc key generation. Must be long enough to not run out of random bytes. Will be mutated to discard the bytes as they are read.
 * @returns {Promise<{{ key: PrivateKey, revocationCertificate: String }}>}
 * @async
 * @static
 * @private
 */
export async function generate(options, config, randomSeed = null) {
  options.sign = true; // primary key is always a signing key
  options = helper.sanitizeKeyOptions(options);
  let getRandomSeed = (index) => {
    if (randomSeed == null) {
      return null;
    } else if (index >= randomSeed.length) {
      throw new Error('randomSeed does not have a seed for each key/subkey (need at least ' + index + ')');
    } else {
      var s = randomSeed[index];
      randomSeed[index] = null;
      if (s instanceof Uint8Array && s.length == 32) {
        return s;
      } else {
        throw new Error('randomSeed element ' + index + ' does not contain a Unit8Array(32)');
      }
    }
  };
  options.subkeys = options.subkeys.map((subkey, index) => helper.sanitizeKeyOptions(options.subkeys[index], options));
  let promises = [helper.generateSecretKey(options, config, getRandomSeed(0))];
  promises = promises.concat(options.subkeys.map((options, subkeyIndex) => helper.generateSecretSubkey(options, config, getRandomSeed(1 + subkeyIndex))));
  const packets = await Promise.all(promises);

  const key = await wrapKeyObject(packets[0], packets.slice(1), options, config);
  const revocationCertificate = await key.getRevocationCertificate(options.date, config);
  key.revocationSignatures = [];
  return { key, revocationCertificate };
}

/**
 * Reformats and signs an OpenPGP key with a given User ID. Currently only supports RSA keys.
 * @param {PrivateKey} options.privateKey         The private key to reformat
 * @param {Array<String|Object>} options.userIDs  User IDs as strings or objects: 'Jo Doe <info@jo.com>' or { name:'Jo Doe', email:'info@jo.com' }
 * @param {String} options.passphrase             Passphrase used to encrypt the resulting private key
 * @param {Number} options.keyExpirationTime      Number of seconds from the key creation time after which the key expires
 * @param {Date}   options.date                   Override the creation date of the key signatures
 * @param {Array<Object>} options.subkeys         (optional) options for each subkey, default to main key options. e.g. [{sign: true, passphrase: '123'}]
 * @param {Object} config - Full configuration
 *
 * @returns {Promise<{{ key: PrivateKey, revocationCertificate: String }}>}
 * @async
 * @static
 * @private
 */
export async function reformat(options, config) {
  options = sanitize(options);
  const { privateKey } = options;

  if (!privateKey.isPrivate()) {
    throw new Error('Cannot reformat a public key');
  }

  if (privateKey.keyPacket.isDummy()) {
    throw new Error('Cannot reformat a gnu-dummy primary key');
  }

  const isDecrypted = privateKey.getKeys().every(({ keyPacket }) => keyPacket.isDecrypted());
  if (!isDecrypted) {
    throw new Error('Key is not decrypted');
  }

  const secretKeyPacket = privateKey.keyPacket;

  if (!options.subkeys) {
    options.subkeys = await Promise.all(privateKey.subkeys.map(async subkey => {
      const secretSubkeyPacket = subkey.keyPacket;
      const dataToVerify = { key: secretKeyPacket, bind: secretSubkeyPacket };
      const bindingSignature = await (
        helper.getLatestValidSignature(subkey.bindingSignatures, secretKeyPacket, enums.signature.subkeyBinding, dataToVerify, null, config)
      ).catch(() => ({}));
      return {
        sign: bindingSignature.keyFlags && (bindingSignature.keyFlags[0] & enums.keyFlags.signData)
      };
    }));
  }

  const secretSubkeyPackets = privateKey.subkeys.map(subkey => subkey.keyPacket);
  if (options.subkeys.length !== secretSubkeyPackets.length) {
    throw new Error('Number of subkey options does not match number of subkeys');
  }

  options.subkeys = options.subkeys.map(subkeyOptions => sanitize(subkeyOptions, options));

  const key = await wrapKeyObject(secretKeyPacket, secretSubkeyPackets, options, config);
  const revocationCertificate = await key.getRevocationCertificate(options.date, config);
  key.revocationSignatures = [];
  return { key, revocationCertificate };

  function sanitize(options, subkeyDefaults = {}) {
    options.keyExpirationTime = options.keyExpirationTime || subkeyDefaults.keyExpirationTime;
    options.passphrase = util.isString(options.passphrase) ? options.passphrase : subkeyDefaults.passphrase;
    options.date = options.date || subkeyDefaults.date;

    return options;
  }
}

/**
 * Construct PrivateKey object from the given key packets, add certification signatures and set passphrase protection
 * The new key includes a revocation certificate that must be removed before returning the key, otherwise the key is considered revoked.
 * @param {SecretKeyPacket} secretKeyPacket
 * @param {SecretSubkeyPacket} secretSubkeyPackets
 * @param {Object} options
 * @param {Object} config - Full configuration
 * @returns {PrivateKey}
 */
async function wrapKeyObject(secretKeyPacket, secretSubkeyPackets, options, config) {
  // set passphrase protection
  if (options.passphrase) {
    await secretKeyPacket.encrypt(options.passphrase, config);
  }

  await Promise.all(secretSubkeyPackets.map(async function(secretSubkeyPacket, index) {
    const subkeyPassphrase = options.subkeys[index].passphrase;
    if (subkeyPassphrase) {
      await secretSubkeyPacket.encrypt(subkeyPassphrase, config);
    }
  }));

  const packetlist = new PacketList();
  packetlist.push(secretKeyPacket);

  await Promise.all(options.userIDs.map(async function(userID, index) {
    function createPreferredAlgos(algos, preferredAlgo) {
      return [preferredAlgo, ...algos.filter(algo => algo !== preferredAlgo)];
    }

    const userIDPacket = UserIDPacket.fromObject(userID);
    const dataToSign = {};
    dataToSign.userID = userIDPacket;
    dataToSign.key = secretKeyPacket;

    const signatureProperties = {};
    signatureProperties.signatureType = enums.signature.certGeneric;
    signatureProperties.keyFlags = [enums.keyFlags.certifyKeys | enums.keyFlags.signData];
    signatureProperties.preferredSymmetricAlgorithms = createPreferredAlgos([
      // prefer aes256, aes128, then aes192 (no WebCrypto support: https://www.chromium.org/blink/webcrypto#TOC-AES-support)
      enums.symmetric.aes256,
      enums.symmetric.aes128,
      enums.symmetric.aes192
    ], config.preferredSymmetricAlgorithm);
    if (config.aeadProtect) {
      signatureProperties.preferredAEADAlgorithms = createPreferredAlgos([
        enums.aead.eax,
        enums.aead.ocb
      ], config.preferredAEADAlgorithm);
    }
    signatureProperties.preferredHashAlgorithms = createPreferredAlgos([
      // prefer fast asm.js implementations (SHA-256)
      enums.hash.sha256,
      enums.hash.sha512
    ], config.preferredHashAlgorithm);
    signatureProperties.preferredCompressionAlgorithms = createPreferredAlgos([
      enums.compression.zlib,
      enums.compression.zip,
      enums.compression.uncompressed
    ], config.preferredCompressionAlgorithm);
    if (index === 0) {
      signatureProperties.isPrimaryUserID = true;
    }
    // integrity protection always enabled
    signatureProperties.features = [0];
    signatureProperties.features[0] |= enums.features.modificationDetection;
    if (config.aeadProtect) {
      signatureProperties.features[0] |= enums.features.aead;
    }
    if (config.v5Keys) {
      signatureProperties.features[0] |= enums.features.v5Keys;
    }
    if (options.keyExpirationTime > 0) {
      signatureProperties.keyExpirationTime = options.keyExpirationTime;
      signatureProperties.keyNeverExpires = false;
    }

    const signaturePacket = await helper.createSignaturePacket(dataToSign, null, secretKeyPacket, signatureProperties, options.date, undefined, undefined, undefined, config);

    return { userIDPacket, signaturePacket };
  })).then(list => {
    list.forEach(({ userIDPacket, signaturePacket }) => {
      packetlist.push(userIDPacket);
      packetlist.push(signaturePacket);
    });
  });

  await Promise.all(secretSubkeyPackets.map(async function(secretSubkeyPacket, index) {
    const subkeyOptions = options.subkeys[index];
    const subkeySignaturePacket = await helper.createBindingSignature(secretSubkeyPacket, secretKeyPacket, subkeyOptions, config);
    return { secretSubkeyPacket, subkeySignaturePacket };
  })).then(packets => {
    packets.forEach(({ secretSubkeyPacket, subkeySignaturePacket }) => {
      packetlist.push(secretSubkeyPacket);
      packetlist.push(subkeySignaturePacket);
    });
  });

  // Add revocation signature packet for creating a revocation certificate.
  // This packet should be removed before returning the key.
  const dataToSign = { key: secretKeyPacket };
  packetlist.push(await helper.createSignaturePacket(dataToSign, null, secretKeyPacket, {
    signatureType: enums.signature.keyRevocation,
    reasonForRevocationFlag: enums.reasonForRevocation.noReason,
    reasonForRevocationString: ''
  }, options.date, undefined, undefined, undefined, config));

  if (options.passphrase) {
    secretKeyPacket.clearPrivateParams();
  }

  await Promise.all(secretSubkeyPackets.map(async function(secretSubkeyPacket, index) {
    const subkeyPassphrase = options.subkeys[index].passphrase;
    if (subkeyPassphrase) {
      secretSubkeyPacket.clearPrivateParams();
    }
  }));

  return new PrivateKey(packetlist);
}

/**
 * Reads an (optionally armored) OpenPGP key and returns a key object
 * @param {Object} options
 * @param {String} [options.armoredKey] - Armored key to be parsed
 * @param {Uint8Array} [options.binaryKey] - Binary key to be parsed
 * @param {Object} [options.config] - Custom configuration settings to overwrite those in [config]{@link module:config}
 * @returns {Promise<Key>} Key object.
 * @async
 * @static
 */
export async function readKey({ armoredKey, binaryKey, config, ...rest }) {
  config = { ...defaultConfig, ...config };
  if (!armoredKey && !binaryKey) {
    throw new Error('readKey: must pass options object containing `armoredKey` or `binaryKey`');
  }
  if (armoredKey && !util.isString(armoredKey)) {
    throw new Error('readKey: options.armoredKey must be a string');
  }
  if (binaryKey && !util.isUint8Array(binaryKey)) {
    throw new Error('readKey: options.binaryKey must be a Uint8Array');
  }
  const unknownOptions = Object.keys(rest); if (unknownOptions.length > 0) throw new Error(`Unknown option: ${unknownOptions.join(', ')}`);

  let input;
  if (armoredKey) {
    const { type, data } = await unarmor(armoredKey, config);
    if (!(type === enums.armor.publicKey || type === enums.armor.privateKey)) {
      throw new Error('Armored text not of type key');
    }
    input = data;
  } else {
    input = binaryKey;
  }
  const packetlist = await PacketList.fromBinary(input, allowedKeyPackets, config);
  return createKey(packetlist);
}

/**
 * Reads an (optionally armored) OpenPGP private key and returns a PrivateKey object
 * @param {Object} options
 * @param {String} [options.armoredKey] - Armored key to be parsed
 * @param {Uint8Array} [options.binaryKey] - Binary key to be parsed
 * @param {Object} [options.config] - Custom configuration settings to overwrite those in [config]{@link module:config}
 * @returns {Promise<PrivateKey>} Key object.
 * @async
 * @static
 */
export async function readPrivateKey({ armoredKey, binaryKey, config, ...rest }) {
  config = { ...defaultConfig, ...config };
  if (!armoredKey && !binaryKey) {
    throw new Error('readPrivateKey: must pass options object containing `armoredKey` or `binaryKey`');
  }
  if (armoredKey && !util.isString(armoredKey)) {
    throw new Error('readPrivateKey: options.armoredKey must be a string');
  }
  if (binaryKey && !util.isUint8Array(binaryKey)) {
    throw new Error('readPrivateKey: options.binaryKey must be a Uint8Array');
  }
  const unknownOptions = Object.keys(rest); if (unknownOptions.length > 0) throw new Error(`Unknown option: ${unknownOptions.join(', ')}`);

  let input;
  if (armoredKey) {
    const { type, data } = await unarmor(armoredKey, config);
    if (!(type === enums.armor.privateKey)) {
      throw new Error('Armored text not of type private key');
    }
    input = data;
  } else {
    input = binaryKey;
  }
  const packetlist = await PacketList.fromBinary(input, allowedKeyPackets, config);
  return new PrivateKey(packetlist);
}

/**
 * Reads an (optionally armored) OpenPGP key block and returns a list of key objects
 * @param {Object} options
 * @param {String} [options.armoredKeys] - Armored keys to be parsed
 * @param {Uint8Array} [options.binaryKeys] - Binary keys to be parsed
 * @param {Object} [options.config] - Custom configuration settings to overwrite those in [config]{@link module:config}
 * @returns {Promise<Array<Key>>} Key objects.
 * @async
 * @static
 */
export async function readKeys({ armoredKeys, binaryKeys, config, ...rest }) {
  config = { ...defaultConfig, ...config };
  let input = armoredKeys || binaryKeys;
  if (!input) {
    throw new Error('readKeys: must pass options object containing `armoredKeys` or `binaryKeys`');
  }
  if (armoredKeys && !util.isString(armoredKeys)) {
    throw new Error('readKeys: options.armoredKeys must be a string');
  }
  if (binaryKeys && !util.isUint8Array(binaryKeys)) {
    throw new Error('readKeys: options.binaryKeys must be a Uint8Array');
  }
  const unknownOptions = Object.keys(rest); if (unknownOptions.length > 0) throw new Error(`Unknown option: ${unknownOptions.join(', ')}`);

  if (armoredKeys) {
    const { type, data } = await unarmor(armoredKeys, config);
    if (type !== enums.armor.publicKey && type !== enums.armor.privateKey) {
      throw new Error('Armored text not of type key');
    }
    input = data;
  }
  const keys = [];
  const packetlist = await PacketList.fromBinary(input, allowedKeyPackets, config);
  const keyIndex = packetlist.indexOfTag(enums.packet.publicKey, enums.packet.secretKey);
  if (keyIndex.length === 0) {
    throw new Error('No key packet found');
  }
  for (let i = 0; i < keyIndex.length; i++) {
    const oneKeyList = packetlist.slice(keyIndex[i], keyIndex[i + 1]);
    const newKey = createKey(oneKeyList);
    keys.push(newKey);
  }
  return keys;
}

/**
 * Reads an (optionally armored) OpenPGP private key block and returns a list of PrivateKey objects
 * @param {Object} options
 * @param {String} [options.armoredKeys] - Armored keys to be parsed
 * @param {Uint8Array} [options.binaryKeys] - Binary keys to be parsed
 * @param {Object} [options.config] - Custom configuration settings to overwrite those in [config]{@link module:config}
 * @returns {Promise<Array<PrivateKey>>} Key objects.
 * @async
 * @static
 */
export async function readPrivateKeys({ armoredKeys, binaryKeys, config }) {
  config = { ...defaultConfig, ...config };
  let input = armoredKeys || binaryKeys;
  if (!input) {
    throw new Error('readPrivateKeys: must pass options object containing `armoredKeys` or `binaryKeys`');
  }
  if (armoredKeys && !util.isString(armoredKeys)) {
    throw new Error('readPrivateKeys: options.armoredKeys must be a string');
  }
  if (binaryKeys && !util.isUint8Array(binaryKeys)) {
    throw new Error('readPrivateKeys: options.binaryKeys must be a Uint8Array');
  }
  if (armoredKeys) {
    const { type, data } = await unarmor(armoredKeys, config);
    if (type !== enums.armor.privateKey) {
      throw new Error('Armored text not of type private key');
    }
    input = data;
  }
  const keys = [];
  const packetlist = await PacketList.fromBinary(input, allowedKeyPackets, config);
  const keyIndex = packetlist.indexOfTag(enums.packet.secretKey);
  if (keyIndex.length === 0) {
    throw new Error('No secret key packet found');
  }
  for (let i = 0; i < keyIndex.length; i++) {
    const oneKeyList = packetlist.slice(keyIndex[i], keyIndex[i + 1]);
    const newKey = new PrivateKey(oneKeyList);
    keys.push(newKey);
  }
  return keys;
}