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-rw-r--r--node_modules/browserify-aes/decrypter.js124
1 files changed, 124 insertions, 0 deletions
diff --git a/node_modules/browserify-aes/decrypter.js b/node_modules/browserify-aes/decrypter.js
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+++ b/node_modules/browserify-aes/decrypter.js
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+var AuthCipher = require('./authCipher')
+var Buffer = require('safe-buffer').Buffer
+var MODES = require('./modes')
+var StreamCipher = require('./streamCipher')
+var Transform = require('cipher-base')
+var aes = require('./aes')
+var ebtk = require('evp_bytestokey')
+var inherits = require('inherits')
+
+function Decipher (mode, key, iv) {
+ Transform.call(this)
+
+ this._cache = new Splitter()
+ this._last = void 0
+ this._cipher = new aes.AES(key)
+ this._prev = Buffer.from(iv)
+ this._mode = mode
+ this._autopadding = true
+}
+
+inherits(Decipher, Transform)
+
+Decipher.prototype._update = function (data) {
+ this._cache.add(data)
+ var chunk
+ var thing
+ var out = []
+ while ((chunk = this._cache.get(this._autopadding))) {
+ thing = this._mode.decrypt(this, chunk)
+ out.push(thing)
+ }
+ return Buffer.concat(out)
+}
+
+Decipher.prototype._final = function () {
+ var chunk = this._cache.flush()
+ if (this._autopadding) {
+ return unpad(this._mode.decrypt(this, chunk))
+ } else if (chunk) {
+ throw new Error('data not multiple of block length')
+ }
+}
+
+Decipher.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 (autoPadding) {
+ var out
+ if (autoPadding) {
+ if (this.cache.length > 16) {
+ out = this.cache.slice(0, 16)
+ this.cache = this.cache.slice(16)
+ return out
+ }
+ } else {
+ if (this.cache.length >= 16) {
+ out = this.cache.slice(0, 16)
+ this.cache = this.cache.slice(16)
+ return out
+ }
+ }
+
+ return null
+}
+
+Splitter.prototype.flush = function () {
+ if (this.cache.length) return this.cache
+}
+
+function unpad (last) {
+ var padded = last[15]
+ if (padded < 1 || padded > 16) {
+ throw new Error('unable to decrypt data')
+ }
+ var i = -1
+ while (++i < padded) {
+ if (last[(i + (16 - padded))] !== padded) {
+ throw new Error('unable to decrypt data')
+ }
+ }
+ if (padded === 16) return
+
+ return last.slice(0, 16 - padded)
+}
+
+function createDecipheriv (suite, password, iv) {
+ var config = MODES[suite.toLowerCase()]
+ if (!config) throw new TypeError('invalid suite type')
+
+ 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 (typeof password === 'string') password = Buffer.from(password)
+ if (password.length !== config.key / 8) throw new TypeError('invalid key length ' + password.length)
+
+ if (config.type === 'stream') {
+ return new StreamCipher(config.module, password, iv, true)
+ } else if (config.type === 'auth') {
+ return new AuthCipher(config.module, password, iv, true)
+ }
+
+ return new Decipher(config.module, password, iv)
+}
+
+function createDecipher (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 createDecipheriv(suite, keys.key, keys.iv)
+}
+
+exports.createDecipher = createDecipher
+exports.createDecipheriv = createDecipheriv