aes.js

// based on the aes implimentation in triple sec
// https://github.com/keybase/triplesec

// which is in turn based on the one from crypto-js
// https://code.google.com/p/crypto-js/

var uint_max = Math.pow(2, 32)
function fixup_uint32 (x) {
  var ret, x_pos
  ret = x > uint_max || x < 0 ? (x_pos = Math.abs(x) % uint_max, x < 0 ? uint_max - x_pos : x_pos) : x
  return ret
}
function scrub_vec (v) {
  for (var i = 0; i < v.length; v++) {
    v[i] = 0
  }
  return false
}

function Global () {
  this.SBOX = []
  this.INV_SBOX = []
  this.SUB_MIX = [[], [], [], []]
  this.INV_SUB_MIX = [[], [], [], []]
  this.init()
  this.RCON = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36]
}

Global.prototype.init = function () {
  var d, i, sx, t, x, x2, x4, x8, xi, _i
  d = (function () {
    var _i, _results
    _results = []
    for (i = _i = 0; _i < 256; i = ++_i) {
      if (i < 128) {
        _results.push(i << 1)
      } else {
        _results.push((i << 1) ^ 0x11b)
      }
    }
    return _results
  })()
  x = 0
  xi = 0
  for (i = _i = 0; _i < 256; i = ++_i) {
    sx = xi ^ (xi << 1) ^ (xi << 2) ^ (xi << 3) ^ (xi << 4)
    sx = (sx >>> 8) ^ (sx & 0xff) ^ 0x63
    this.SBOX[x] = sx
    this.INV_SBOX[sx] = x
    x2 = d[x]
    x4 = d[x2]
    x8 = d[x4]
    t = (d[sx] * 0x101) ^ (sx * 0x1010100)
    this.SUB_MIX[0][x] = (t << 24) | (t >>> 8)
    this.SUB_MIX[1][x] = (t << 16) | (t >>> 16)
    this.SUB_MIX[2][x] = (t << 8) | (t >>> 24)
    this.SUB_MIX[3][x] = t
    t = (x8 * 0x1010101) ^ (x4 * 0x10001) ^ (x2 * 0x101) ^ (x * 0x1010100)
    this.INV_SUB_MIX[0][sx] = (t << 24) | (t >>> 8)
    this.INV_SUB_MIX[1][sx] = (t << 16) | (t >>> 16)
    this.INV_SUB_MIX[2][sx] = (t << 8) | (t >>> 24)
    this.INV_SUB_MIX[3][sx] = t
    if (x === 0) {
      x = xi = 1
    } else {
      x = x2 ^ d[d[d[x8 ^ x2]]]
      xi ^= d[d[xi]]
    }
  }
  return true
}

var G = new Global()

AES.blockSize = 4 * 4

AES.prototype.blockSize = AES.blockSize

AES.keySize = 256 / 8

AES.prototype.keySize = AES.keySize

function bufferToArray (buf) {
  var len = buf.length / 4
  var out = new Array(len)
  var i = -1
  while (++i < len) {
    out[i] = buf.readUInt32BE(i * 4)
  }
  return out
}
function AES (key) {
  this._key = bufferToArray(key)
  this._doReset()
}

AES.prototype._doReset = function () {
  var invKsRow, keySize, keyWords, ksRow, ksRows, t
  keyWords = this._key
  keySize = keyWords.length
  this._nRounds = keySize + 6
  ksRows = (this._nRounds + 1) * 4
  this._keySchedule = []
  for (ksRow = 0; ksRow < ksRows; ksRow++) {
    this._keySchedule[ksRow] = ksRow < keySize ? keyWords[ksRow] : (t = this._keySchedule[ksRow - 1], (ksRow % keySize) === 0 ? (t = (t << 8) | (t >>> 24), t = (G.SBOX[t >>> 24] << 24) | (G.SBOX[(t >>> 16) & 0xff] << 16) | (G.SBOX[(t >>> 8) & 0xff] << 8) | G.SBOX[t & 0xff], t ^= G.RCON[(ksRow / keySize) | 0] << 24) : keySize > 6 && ksRow % keySize === 4 ? t = (G.SBOX[t >>> 24] << 24) | (G.SBOX[(t >>> 16) & 0xff] << 16) | (G.SBOX[(t >>> 8) & 0xff] << 8) | G.SBOX[t & 0xff] : void 0, this._keySchedule[ksRow - keySize] ^ t)
  }
  this._invKeySchedule = []
  for (invKsRow = 0; invKsRow < ksRows; invKsRow++) {
    ksRow = ksRows - invKsRow
    t = this._keySchedule[ksRow - (invKsRow % 4 ? 0 : 4)]
    this._invKeySchedule[invKsRow] = invKsRow < 4 || ksRow <= 4 ? t : G.INV_SUB_MIX[0][G.SBOX[t >>> 24]] ^ G.INV_SUB_MIX[1][G.SBOX[(t >>> 16) & 0xff]] ^ G.INV_SUB_MIX[2][G.SBOX[(t >>> 8) & 0xff]] ^ G.INV_SUB_MIX[3][G.SBOX[t & 0xff]]
  }
  return true
}

AES.prototype.encryptBlock = function (M) {
  M = bufferToArray(new Buffer(M))
  var out = this._doCryptBlock(M, this._keySchedule, G.SUB_MIX, G.SBOX)
  var buf = new Buffer(16)
  buf.writeUInt32BE(out[0], 0)
  buf.writeUInt32BE(out[1], 4)
  buf.writeUInt32BE(out[2], 8)
  buf.writeUInt32BE(out[3], 12)
  return buf
}

AES.prototype.decryptBlock = function (M) {
  M = bufferToArray(new Buffer(M))
  var temp = [M[3], M[1]]
  M[1] = temp[0]
  M[3] = temp[1]
  var out = this._doCryptBlock(M, this._invKeySchedule, G.INV_SUB_MIX, G.INV_SBOX)
  var buf = new Buffer(16)
  buf.writeUInt32BE(out[0], 0)
  buf.writeUInt32BE(out[3], 4)
  buf.writeUInt32BE(out[2], 8)
  buf.writeUInt32BE(out[1], 12)
  return buf
}

AES.prototype.scrub = function () {
  scrub_vec(this._keySchedule)
  scrub_vec(this._invKeySchedule)
  scrub_vec(this._key)
}

AES.prototype._doCryptBlock = function (M, keySchedule, SUB_MIX, SBOX) {
  var ksRow, s0, s1, s2, s3, t0, t1, t2, t3

  s0 = M[0] ^ keySchedule[0]
  s1 = M[1] ^ keySchedule[1]
  s2 = M[2] ^ keySchedule[2]
  s3 = M[3] ^ keySchedule[3]
  ksRow = 4
  for (var round = 1; round < this._nRounds; round++) {
    t0 = SUB_MIX[0][s0 >>> 24] ^ SUB_MIX[1][(s1 >>> 16) & 0xff] ^ SUB_MIX[2][(s2 >>> 8) & 0xff] ^ SUB_MIX[3][s3 & 0xff] ^ keySchedule[ksRow++]
    t1 = SUB_MIX[0][s1 >>> 24] ^ SUB_MIX[1][(s2 >>> 16) & 0xff] ^ SUB_MIX[2][(s3 >>> 8) & 0xff] ^ SUB_MIX[3][s0 & 0xff] ^ keySchedule[ksRow++]
    t2 = SUB_MIX[0][s2 >>> 24] ^ SUB_MIX[1][(s3 >>> 16) & 0xff] ^ SUB_MIX[2][(s0 >>> 8) & 0xff] ^ SUB_MIX[3][s1 & 0xff] ^ keySchedule[ksRow++]
    t3 = SUB_MIX[0][s3 >>> 24] ^ SUB_MIX[1][(s0 >>> 16) & 0xff] ^ SUB_MIX[2][(s1 >>> 8) & 0xff] ^ SUB_MIX[3][s2 & 0xff] ^ keySchedule[ksRow++]
    s0 = t0
    s1 = t1
    s2 = t2
    s3 = t3
  }
  t0 = ((SBOX[s0 >>> 24] << 24) | (SBOX[(s1 >>> 16) & 0xff] << 16) | (SBOX[(s2 >>> 8) & 0xff] << 8) | SBOX[s3 & 0xff]) ^ keySchedule[ksRow++]
  t1 = ((SBOX[s1 >>> 24] << 24) | (SBOX[(s2 >>> 16) & 0xff] << 16) | (SBOX[(s3 >>> 8) & 0xff] << 8) | SBOX[s0 & 0xff]) ^ keySchedule[ksRow++]
  t2 = ((SBOX[s2 >>> 24] << 24) | (SBOX[(s3 >>> 16) & 0xff] << 16) | (SBOX[(s0 >>> 8) & 0xff] << 8) | SBOX[s1 & 0xff]) ^ keySchedule[ksRow++]
  t3 = ((SBOX[s3 >>> 24] << 24) | (SBOX[(s0 >>> 16) & 0xff] << 16) | (SBOX[(s1 >>> 8) & 0xff] << 8) | SBOX[s2 & 0xff]) ^ keySchedule[ksRow++]
  return [
    fixup_uint32(t0),
    fixup_uint32(t1),
    fixup_uint32(t2),
    fixup_uint32(t3)
  ]
}

exports.AES = AES