fork-openpgpjs/src/packet/sym_encrypted_aead_protected.js
2018-03-05 12:18:04 -08:00

87 lines
3.3 KiB
JavaScript

// OpenPGP.js - An OpenPGP implementation in javascript
// Copyright (C) 2016 Tankred Hase
//
// 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
/**
* Implementation of the Symmetrically Encrypted Authenticated Encryption with Additional Data (AEAD) Protected Data Packet
* {@link https://tools.ietf.org/html/draft-ford-openpgp-format-00#section-2.1}: AEAD Protected Data Packet
*/
import util from '../util.js';
import crypto from '../crypto';
import enums from '../enums.js';
const VERSION = 1; // A one-octet version number of the data packet.
const IV_LEN = crypto.gcm.ivLength; // currently only AES-GCM is supported
/**
* @constructor
*/
export default function SymEncryptedAEADProtected() {
this.tag = enums.packet.symEncryptedAEADProtected;
this.version = VERSION;
this.iv = null;
this.encrypted = null;
this.packets = null;
}
/**
* Parse an encrypted payload of bytes in the order: version, IV, ciphertext (see specification)
*/
SymEncryptedAEADProtected.prototype.read = function (bytes) {
let offset = 0;
if (bytes[offset] !== VERSION) { // The only currently defined value is 1.
throw new Error('Invalid packet version.');
}
offset++;
this.iv = bytes.subarray(offset, IV_LEN + offset);
offset += IV_LEN;
this.encrypted = bytes.subarray(offset, bytes.length);
};
/**
* Write the encrypted payload of bytes in the order: version, IV, ciphertext (see specification)
* @return {Uint8Array} The encrypted payload
*/
SymEncryptedAEADProtected.prototype.write = function () {
return util.concatUint8Array([new Uint8Array([this.version]), this.iv, this.encrypted]);
};
/**
* Decrypt the encrypted payload.
* @param {String} sessionKeyAlgorithm The session key's cipher algorithm e.g. 'aes128'
* @param {Uint8Array} key The session key used to encrypt the payload
* @return {Promise<undefined>} Nothing is returned
*/
SymEncryptedAEADProtected.prototype.decrypt = function (sessionKeyAlgorithm, key) {
return crypto.gcm.decrypt(sessionKeyAlgorithm, this.encrypted, key, this.iv).then(decrypted => {
this.packets.read(decrypted);
});
};
/**
* Encrypt the packet list payload.
* @param {String} sessionKeyAlgorithm The session key's cipher algorithm e.g. 'aes128'
* @param {Uint8Array} key The session key used to encrypt the payload
* @return {Promise<undefined>} Nothing is returned
*/
SymEncryptedAEADProtected.prototype.encrypt = function (sessionKeyAlgorithm, key) {
this.iv = crypto.random.getRandomBytes(IV_LEN); // generate new random IV
return crypto.gcm.encrypt(sessionKeyAlgorithm, this.packets.write(), key, this.iv).then(encrypted => {
this.encrypted = encrypted;
});
};