| 123456789101112131415161718192021222324252627 | var aes = require('./aes')var Buffer = require('safe-buffer').Buffervar Transform = require('cipher-base')var inherits = require('inherits')function StreamCipher (mode, key, iv, decrypt) {  Transform.call(this)  this._cipher = new aes.AES(key)  this._prev = Buffer.from(iv)  this._cache = Buffer.allocUnsafe(0)  this._secCache = Buffer.allocUnsafe(0)  this._decrypt = decrypt  this._mode = mode}inherits(StreamCipher, Transform)StreamCipher.prototype._update = function (chunk) {  return this._mode.encrypt(this, chunk, this._decrypt)}StreamCipher.prototype._final = function () {  this._cipher.scrub()}module.exports = StreamCipher
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