102 lines
1.9 KiB
JavaScript
102 lines
1.9 KiB
JavaScript
|
/*!
|
||
|
|
* random-bytes
|
||
|
|
* Copyright(c) 2016 Douglas Christopher Wilson
|
||
|
|
* MIT Licensed
|
||
|
|
*/
|
||
|
|
|
||
|
|
'use strict'
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Module dependencies.
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
|
||
|
|
var crypto = require('crypto')
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Module variables.
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
|
||
|
|
var generateAttempts = crypto.randomBytes === crypto.pseudoRandomBytes ? 1 : 3
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Module exports.
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
|
||
|
|
module.exports = randomBytes
|
||
|
|
module.exports.sync = randomBytesSync
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Generates strong pseudo-random bytes.
|
||
|
|
*
|
||
|
|
* @param {number} size
|
||
|
|
* @param {function} [callback]
|
||
|
|
* @return {Promise}
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
|
||
|
|
function randomBytes(size, callback) {
|
||
|
|
// validate callback is a function, if provided
|
||
|
|
if (callback !== undefined && typeof callback !== 'function') {
|
||
|
|
throw new TypeError('argument callback must be a function')
|
||
|
|
}
|
||
|
|
|
||
|
|
// require the callback without promises
|
||
|
|
if (!callback && !global.Promise) {
|
||
|
|
throw new TypeError('argument callback is required')
|
||
|
|
}
|
||
|
|
|
||
|
|
if (callback) {
|
||
|
|
// classic callback style
|
||
|
|
return generateRandomBytes(size, generateAttempts, callback)
|
||
|
|
}
|
||
|
|
|
||
|
|
return new Promise(function executor(resolve, reject) {
|
||
|
|
generateRandomBytes(size, generateAttempts, function onRandomBytes(err, str) {
|
||
|
|
if (err) return reject(err)
|
||
|
|
resolve(str)
|
||
|
|
})
|
||
|
|
})
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Generates strong pseudo-random bytes sync.
|
||
|
|
*
|
||
|
|
* @param {number} size
|
||
|
|
* @return {Buffer}
|
||
|
|
* @public
|
||
|
|
*/
|
||
|
|
|
||
|
|
function randomBytesSync(size) {
|
||
|
|
var err = null
|
||
|
|
|
||
|
|
for (var i = 0; i < generateAttempts; i++) {
|
||
|
|
try {
|
||
|
|
return crypto.randomBytes(size)
|
||
|
|
} catch (e) {
|
||
|
|
err = e
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
throw err
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Generates strong pseudo-random bytes.
|
||
|
|
*
|
||
|
|
* @param {number} size
|
||
|
|
* @param {number} attempts
|
||
|
|
* @param {function} callback
|
||
|
|
* @private
|
||
|
|
*/
|
||
|
|
|
||
|
|
function generateRandomBytes(size, attempts, callback) {
|
||
|
|
crypto.randomBytes(size, function onRandomBytes(err, buf) {
|
||
|
|
if (!err) return callback(null, buf)
|
||
|
|
if (!--attempts) return callback(err)
|
||
|
|
setTimeout(generateRandomBytes.bind(null, size, attempts, callback), 10)
|
||
|
|
})
|
||
|
|
}
|