fcoin/lib/crypto/backend-browser.js
2016-11-18 23:05:04 -08:00

74 lines
1.6 KiB
JavaScript

/*!
* backend-browser.js - browser crypto backend for bcoin
* Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
* https://github.com/bcoin-org/bcoin
*/
/* jshint worker: true */
'use strict';
var assert = require('assert');
var hashjs = require('hash.js');
var aes = require('./aes');
var backend = exports;
var crypto, global;
if (typeof window !== 'undefined')
global = window;
else if (typeof self !== 'undefined')
global = self;
if (global)
crypto = global.crypto || global.msCrypto;
backend.hash = function hash(alg, data) {
return new Buffer(hashjs[alg]().update(data).digest());
};
backend.hmac = function hmac(alg, data, salt) {
var hash = hashjs[alg];
var hmac;
assert(hash != null, 'Unknown algorithm.');
hmac = hashjs.hmac(hash, salt);
return new Buffer(hmac.update(data).digest());
};
backend.pbkdf2 = null;
backend.pbkdf2Async = null;
backend.encipher = function encipher(data, key, iv) {
return aes.cbc.encrypt(data, key, iv);
};
backend.decipher = function decipher(data, key, iv) {
try {
return aes.cbc.decrypt(data, key, iv);
} catch (e) {
throw new Error('Bad key for decryption.');
}
};
backend.randomBytes = function randomBytes(n) {
var data = new Uint8Array(n);
crypto.getRandomValues(data);
return new Buffer(data.buffer);
};
if (!crypto || !crypto.getRandomValues) {
// Out of luck here. Use bad randomness for now.
backend.randomBytes = function randomBytes(n) {
var data = new Buffer(n);
var i;
for (i = 0; i < data.length; i++)
data[i] = Math.floor(Math.random() * 256);
return data;
};
}