GoScrobble/web/node_modules/browserify-aes/encrypter.js

115 lines
2.8 KiB
JavaScript

var MODES = require('./modes')
var AuthCipher = require('./authCipher')
var Buffer = require('safe-buffer').Buffer
var StreamCipher = require('./streamCipher')
var Transform = require('cipher-base')
var aes = require('./aes')
var ebtk = require('evp_bytestokey')
var inherits = require('inherits')
function Cipher (mode, key, iv) {
Transform.call(this)
this._cache = new Splitter()
this._cipher = new aes.AES(key)
this._prev = Buffer.from(iv)
this._mode = mode
this._autopadding = true
}
inherits(Cipher, Transform)
Cipher.prototype._update = function (data) {
this._cache.add(data)
var chunk
var thing
var out = []
while ((chunk = this._cache.get())) {
thing = this._mode.encrypt(this, chunk)
out.push(thing)
}
return Buffer.concat(out)
}
var PADDING = Buffer.alloc(16, 0x10)
Cipher.prototype._final = function () {
var chunk = this._cache.flush()
if (this._autopadding) {
chunk = this._mode.encrypt(this, chunk)
this._cipher.scrub()
return chunk
}
if (!chunk.equals(PADDING)) {
this._cipher.scrub()
throw new Error('data not multiple of block length')
}
}
Cipher.prototype.setAutoPadding = function (setTo) {
this._autopadding = !!setTo
return this
}
function Splitter () {
this.cache = Buffer.allocUnsafe(0)
}
Splitter.prototype.add = function (data) {
this.cache = Buffer.concat([this.cache, data])
}
Splitter.prototype.get = function () {
if (this.cache.length > 15) {
var out = this.cache.slice(0, 16)
this.cache = this.cache.slice(16)
return out
}
return null
}
Splitter.prototype.flush = function () {
var len = 16 - this.cache.length
var padBuff = Buffer.allocUnsafe(len)
var i = -1
while (++i < len) {
padBuff.writeUInt8(len, i)
}
return Buffer.concat([this.cache, padBuff])
}
function createCipheriv (suite, password, iv) {
var config = MODES[suite.toLowerCase()]
if (!config) throw new TypeError('invalid suite type')
if (typeof password === 'string') password = Buffer.from(password)
if (password.length !== config.key / 8) throw new TypeError('invalid key length ' + password.length)
if (typeof iv === 'string') iv = Buffer.from(iv)
if (config.mode !== 'GCM' && iv.length !== config.iv) throw new TypeError('invalid iv length ' + iv.length)
if (config.type === 'stream') {
return new StreamCipher(config.module, password, iv)
} else if (config.type === 'auth') {
return new AuthCipher(config.module, password, iv)
}
return new Cipher(config.module, password, iv)
}
function createCipher (suite, password) {
var config = MODES[suite.toLowerCase()]
if (!config) throw new TypeError('invalid suite type')
var keys = ebtk(password, false, config.key, config.iv)
return createCipheriv(suite, keys.key, keys.iv)
}
exports.createCipheriv = createCipheriv
exports.createCipher = createCipher