1 files changed, 117 insertions, 0 deletions
diff --git a/node_modules/browserify-aes/authCipher.js b/node_modules/browserify-aes/authCipher.js
new file mode 100644
index 0000000..c6e8a76
--- /dev/null
+++ b/node_modules/browserify-aes/authCipher.js
@@ -0,0 +1,117 @@
+var aes = require('./aes')
+var Buffer = require('safe-buffer').Buffer
+var Transform = require('cipher-base')
+var inherits = require('inherits')
+var GHASH = require('./ghash')
+var xor = require('buffer-xor')
+var incr32 = require('./incr32')
+
+function xorTest (a, b) {
+  var out = 0
+  if (a.length !== b.length) out++
+
+  var len = Math.min(a.length, b.length)
+  for (var i = 0; i < len; ++i) {
+    out += (a[i] ^ b[i])
+  }
+
+  return out
+}
+
+function calcIv (self, iv, ck) {
+  if (iv.length === 12) {
+    self._finID = Buffer.concat([iv, Buffer.from([0, 0, 0, 1])])
+    return Buffer.concat([iv, Buffer.from([0, 0, 0, 2])])
+  }
+  var ghash = new GHASH(ck)
+  var len = iv.length
+  var toPad = len % 16
+  ghash.update(iv)
+  if (toPad) {
+    toPad = 16 - toPad
+    ghash.update(Buffer.alloc(toPad, 0))
+  }
+  ghash.update(Buffer.alloc(8, 0))
+  var ivBits = len * 8
+  var tail = Buffer.alloc(8)
+  tail.writeUIntBE(ivBits, 0, 8)
+  ghash.update(tail)
+  self._finID = ghash.state
+  var out = Buffer.from(self._finID)
+  incr32(out)
+  return out
+}
+function StreamCipher (mode, key, iv, decrypt) {
+  Transform.call(this)
+
+  var h = Buffer.alloc(4, 0)
+
+  this._cipher = new aes.AES(key)
+  var ck = this._cipher.encryptBlock(h)
+  this._ghash = new GHASH(ck)
+  iv = calcIv(this, iv, ck)
+
+  this._prev = Buffer.from(iv)
+  this._cache = Buffer.allocUnsafe(0)
+  this._secCache = Buffer.allocUnsafe(0)
+  this._decrypt = decrypt
+  this._alen = 0
+  this._len = 0
+  this._mode = mode
+
+  this._authTag = null
+  this._called = false
+}
+
+inherits(StreamCipher, Transform)
+
+StreamCipher.prototype._update = function (chunk) {
+  if (!this._called && this._alen) {
+    var rump = 16 - (this._alen % 16)
+    if (rump < 16) {
+      rump = Buffer.alloc(rump, 0)
+      this._ghash.update(rump)
+    }
+  }
+
+  this._called = true
+  var out = this._mode.encrypt(this, chunk)
+  if (this._decrypt) {
+    this._ghash.update(chunk)
+  } else {
+    this._ghash.update(out)
+  }
+  this._len += chunk.length
+  return out
+}
+
+StreamCipher.prototype._final = function () {
+  if (this._decrypt && !this._authTag) throw new Error('Unsupported state or unable to authenticate data')
+
+  var tag = xor(this._ghash.final(this._alen * 8, this._len * 8), this._cipher.encryptBlock(this._finID))
+  if (this._decrypt && xorTest(tag, this._authTag)) throw new Error('Unsupported state or unable to authenticate data')
+
+  this._authTag = tag
+  this._cipher.scrub()
+}
+
+StreamCipher.prototype.getAuthTag = function getAuthTag () {
+  if (this._decrypt || !Buffer.isBuffer(this._authTag)) throw new Error('Attempting to get auth tag in unsupported state')
+
+  return this._authTag
+}
+
+StreamCipher.prototype.setAuthTag = function setAuthTag (tag) {
+  if (!this._decrypt) throw new Error('Attempting to set auth tag in unsupported state')
+
+  this._authTag = tag
+}
+
+StreamCipher.prototype.setAAD = function setAAD (buf) {
+  if (this._called) throw new Error('Attempting to set AAD in unsupported state')
+
+  this._ghash.update(buf)
+  this._alen += buf.length
+}
+
+module.exports = StreamCipher