fork-openpgpjs/src/packet/symmetrically_encrypted.js

106 lines
3.5 KiB
JavaScript

// GPG4Browsers - An OpenPGP implementation in javascript
// Copyright (C) 2011 Recurity Labs GmbH
//
// 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
/**
* @requires config
* @requires crypto
* @requires enums
*/
import config from '../config';
import crypto from '../crypto';
import enums from '../enums';
/**
* Implementation of the Symmetrically Encrypted Data Packet (Tag 9)
*
* {@link https://tools.ietf.org/html/rfc4880#section-5.7|RFC4880 5.7}:
* The Symmetrically Encrypted Data packet contains data encrypted with a
* symmetric-key algorithm. When it has been decrypted, it contains other
* packets (usually a literal data packet or compressed data packet, but in
* theory other Symmetrically Encrypted Data packets or sequences of packets
* that form whole OpenPGP messages).
* @memberof module:packet
* @constructor
*/
function SymmetricallyEncrypted() {
/**
* Packet type
* @type {module:enums.packet}
*/
this.tag = enums.packet.symmetricallyEncrypted;
/**
* Encrypted secret-key data
*/
this.encrypted = null;
/**
* Decrypted packets contained within.
* @type {module:packet.List}
*/
this.packets = null;
/**
* When true, decrypt fails if message is not integrity protected
* @see module:config.ignore_mdc_error
*/
this.ignore_mdc_error = config.ignore_mdc_error;
}
SymmetricallyEncrypted.prototype.read = function (bytes) {
this.encrypted = bytes;
};
SymmetricallyEncrypted.prototype.write = function () {
return this.encrypted;
};
/**
* Decrypt the symmetrically-encrypted packet data
* See {@link https://tools.ietf.org/html/rfc4880#section-9.2|RFC 4880 9.2} for algorithms.
* @param {module:enums.symmetric} sessionKeyAlgorithm Symmetric key algorithm to use
* @param {Uint8Array} key The key of cipher blocksize length to be used
* @returns {Promise<Boolean>}
* @async
*/
SymmetricallyEncrypted.prototype.decrypt = async function (sessionKeyAlgorithm, key) {
const decrypted = crypto.cfb.decrypt(sessionKeyAlgorithm, key, this.encrypted, true);
// If MDC errors are not being ignored, all missing MDC packets in symmetrically encrypted data should throw an error
if (!this.ignore_mdc_error) {
throw new Error('Decryption failed due to missing MDC.');
}
this.packets.read(decrypted);
return true;
};
/**
* Encrypt the symmetrically-encrypted packet data
* See {@link https://tools.ietf.org/html/rfc4880#section-9.2|RFC 4880 9.2} for algorithms.
* @param {module:enums.symmetric} sessionKeyAlgorithm Symmetric key algorithm to use
* @param {Uint8Array} key The key of cipher blocksize length to be used
* @returns {Promise<Boolean>}
* @async
*/
SymmetricallyEncrypted.prototype.encrypt = async function (algo, key) {
const data = this.packets.write();
this.encrypted = crypto.cfb.encrypt(await crypto.getPrefixRandom(algo), algo, data, key, true);
return true;
};
export default SymmetricallyEncrypted;