117 lines
4.6 KiB
JavaScript
117 lines
4.6 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
|
|
|
|
/**
|
|
* @fileoverview This module wraps native AES-GCM en/decryption for both
|
|
* the WebCrypto api as well as node.js' crypto api.
|
|
*/
|
|
|
|
'use strict';
|
|
|
|
import util from '../util.js';
|
|
import config from '../config';
|
|
import asmCrypto from 'asmcrypto-lite';
|
|
const webCrypto = typeof window !== 'undefined' && window.crypto && window.crypto.subtle; // no GCM support in IE11, Safari 9
|
|
const nodeCrypto = util.getNodeCrypto();
|
|
const Buffer = util.getNodeBuffer();
|
|
|
|
export const ivLength = 12; // size of the IV in bytes
|
|
const TAG_LEN = 16; // size of the tag in bytes
|
|
const ALGO = 'AES-GCM';
|
|
|
|
/**
|
|
* Encrypt plaintext input.
|
|
* @param {String} cipher The symmetric cipher algorithm to use e.g. 'aes128'
|
|
* @param {Uint8Array} plaintext The cleartext input to be encrypted
|
|
* @param {Uint8Array} key The encryption key
|
|
* @param {Uint8Array} iv The initialization vector (12 bytes)
|
|
* @return {Promise<Uint8Array>} The ciphertext output
|
|
*/
|
|
export function encrypt(cipher, plaintext, key, iv) {
|
|
if (cipher.substr(0,3) !== 'aes') {
|
|
return Promise.reject(new Error('GCM mode supports only AES cipher'));
|
|
}
|
|
|
|
if (webCrypto && config.useNative && key.length !== 24) { // WebCrypto (no 192 bit support) see: https://www.chromium.org/blink/webcrypto#TOC-AES-support
|
|
return webEncrypt(plaintext, key, iv);
|
|
} else if (nodeCrypto && config.useNative) { // Node crypto library
|
|
return nodeEncrypt(plaintext, key, iv) ;
|
|
} else { // asm.js fallback
|
|
return Promise.resolve(asmCrypto.AES_GCM.encrypt(plaintext, key, iv));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Decrypt ciphertext input.
|
|
* @param {String} cipher The symmetric cipher algorithm to use e.g. 'aes128'
|
|
* @param {Uint8Array} ciphertext The ciphertext input to be decrypted
|
|
* @param {Uint8Array} key The encryption key
|
|
* @param {Uint8Array} iv The initialization vector (12 bytes)
|
|
* @return {Promise<Uint8Array>} The plaintext output
|
|
*/
|
|
export function decrypt(cipher, ciphertext, key, iv) {
|
|
if (cipher.substr(0,3) !== 'aes') {
|
|
return Promise.reject(new Error('GCM mode supports only AES cipher'));
|
|
}
|
|
|
|
if (webCrypto && config.useNative && key.length !== 24) { // WebCrypto (no 192 bit support) see: https://www.chromium.org/blink/webcrypto#TOC-AES-support
|
|
return webDecrypt(ciphertext, key, iv);
|
|
} else if (nodeCrypto && config.useNative) { // Node crypto library
|
|
return nodeDecrypt(ciphertext, key, iv);
|
|
} else { // asm.js fallback
|
|
return Promise.resolve(asmCrypto.AES_GCM.decrypt(ciphertext, key, iv));
|
|
}
|
|
}
|
|
|
|
|
|
//////////////////////////
|
|
// //
|
|
// Helper functions //
|
|
// //
|
|
//////////////////////////
|
|
|
|
|
|
function webEncrypt(pt, key, iv) {
|
|
return webCrypto.importKey('raw', key, { name: ALGO }, false, ['encrypt'])
|
|
.then(keyObj => webCrypto.encrypt({ name: ALGO, iv }, keyObj, pt))
|
|
.then(ct => new Uint8Array(ct));
|
|
}
|
|
|
|
function webDecrypt(ct, key, iv) {
|
|
return webCrypto.importKey('raw', key, { name: ALGO }, false, ['decrypt'])
|
|
.then(keyObj => webCrypto.decrypt({ name: ALGO, iv }, keyObj, ct))
|
|
.then(pt => new Uint8Array(pt));
|
|
}
|
|
|
|
function nodeEncrypt(pt, key, iv) {
|
|
pt = new Buffer(pt);
|
|
key = new Buffer(key);
|
|
iv = new Buffer(iv);
|
|
const en = new nodeCrypto.createCipheriv('aes-' + (key.length * 8) + '-gcm', key, iv);
|
|
const ct = Buffer.concat([en.update(pt), en.final(), en.getAuthTag()]); // append auth tag to ciphertext
|
|
return Promise.resolve(new Uint8Array(ct));
|
|
}
|
|
|
|
function nodeDecrypt(ct, key, iv) {
|
|
ct = new Buffer(ct);
|
|
key = new Buffer(key);
|
|
iv = new Buffer(iv);
|
|
const de = new nodeCrypto.createDecipheriv('aes-' + (key.length * 8) + '-gcm', key, iv);
|
|
de.setAuthTag(ct.slice(ct.length - TAG_LEN, ct.length)); // read auth tag at end of ciphertext
|
|
const pt = Buffer.concat([de.update(ct.slice(0, ct.length - TAG_LEN)), de.final()]);
|
|
return Promise.resolve(new Uint8Array(pt));
|
|
} |