pdf.js/crypto.js

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- /
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */

'use strict';

var ARCFourCipher = (function() {
  function constructor(key) {
    this.a = 0;
    this.b = 0;
    var s = new Uint8Array(256);
    var i, j = 0, tmp, keyLength = key.length;
    for (i = 0; i < 256; ++i)
      s[i] = i;
    for (i = 0; i < 256; ++i) {
      tmp = s[i];
      j = (j + tmp + key[i % keyLength]) & 0xFF;
      s[i] = s[j];
      s[j] = tmp;
    }
    this.s = s;
  }

  constructor.prototype = {
    encryptBlock: function(data) {
      var i, n = data.length, tmp, tmp2;
      var a = this.a, b = this.b, s = this.s;
      var output = new Uint8Array(n);
      for (i = 0; i < n; ++i) {
        var tmp;
        a = (a + 1) & 0xFF;
        tmp = s[a];
        b = (b + tmp) & 0xFF;
        tmp2 = s[b];
        s[a] = tmp2;
        s[b] = tmp;
        output[i] = data[i] ^ s[(tmp + tmp2) & 0xFF];
      }
      this.a = a;
      this.b = b;
      return output;
    }
  };
  constructor.prototype.decryptBlock = constructor.prototype.encryptBlock;

  return constructor;
})();

var md5 = (function() {
  var r = new Uint8Array([
    7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
    5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
    4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
    6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]);

  var k = new Int32Array([
    -680876936, -389564586, 606105819, -1044525330, -176418897, 1200080426,
    -1473231341, -45705983, 1770035416, -1958414417, -42063, -1990404162,
    1804603682, -40341101, -1502002290, 1236535329, -165796510, -1069501632,
    643717713, -373897302, -701558691, 38016083, -660478335, -405537848,
    568446438, -1019803690, -187363961, 1163531501, -1444681467, -51403784,
    1735328473, -1926607734, -378558, -2022574463, 1839030562, -35309556,
    -1530992060, 1272893353, -155497632, -1094730640, 681279174, -358537222,
    -722521979, 76029189, -640364487, -421815835, 530742520, -995338651,
    -198630844, 1126891415, -1416354905, -57434055, 1700485571, -1894986606,
    -1051523, -2054922799, 1873313359, -30611744, -1560198380, 1309151649,
    -145523070, -1120210379, 718787259, -343485551]);

  function hash(data, offset, length) {
    var h0 = 1732584193, h1 = -271733879, h2 = -1732584194, h3 = 271733878;
    // pre-processing
    var paddedLength = (length + 72) & ~63; // data + 9 extra bytes
    var padded = new Uint8Array(paddedLength);
    var i, j, n;
    for (i = 0; i < length; ++i)
      padded[i] = data[offset++];
    padded[i++] = 0x80;
    n = paddedLength - 8;
    for (; i < n; ++i)
      padded[i] = 0;
    padded[i++] = (length << 3) & 0xFF;
    padded[i++] = (length >> 5) & 0xFF;
    padded[i++] = (length >> 13) & 0xFF;
    padded[i++] = (length >> 21) & 0xFF;
    padded[i++] = (length >>> 29) & 0xFF;
    padded[i++] = 0;
    padded[i++] = 0;
    padded[i++] = 0;
    // chunking
    // TODO ArrayBuffer ?
    var w = new Int32Array(16);
    for (i = 0; i < paddedLength;) {
      for (j = 0; j < 16; ++j, i += 4) {
        w[j] = (padded[i] | (padded[i + 1] << 8) |
                (padded[i + 2] << 16) | (padded[i + 3] << 24));
      }
      var a = h0, b = h1, c = h2, d = h3, f, g;
      for (j = 0; j < 64; ++j) {
        if (j < 16) {
          f = (b & c) | ((~b) & d);
          g = j;
        } else if (j < 32) {
          f = (d & b) | ((~d) & c);
          g = (5 * j + 1) & 15;
        } else if (j < 48) {
          f = b ^ c ^ d;
          g = (3 * j + 5) & 15;
        } else {
          f = c ^ (b | (~d));
          g = (7 * j) & 15;
        }
        var tmp = d, rotateArg = (a + f + k[j] + w[g]) | 0, rotate = r[j];
        d = c;
        c = b;
        b = (b + ((rotateArg << rotate) | (rotateArg >>> (32 - rotate)))) | 0;
        a = tmp;
      }
      h0 = (h0 + a) | 0;
      h1 = (h1 + b) | 0;
      h2 = (h2 + c) | 0;
      h3 = (h3 + d) | 0;
    }
    return new Uint8Array([
        h0 & 0xFF, (h0 >> 8) & 0xFF, (h0 >> 16) & 0xFF, (h0 >>> 24) & 0xFF,
        h1 & 0xFF, (h1 >> 8) & 0xFF, (h1 >> 16) & 0xFF, (h1 >>> 24) & 0xFF,
        h2 & 0xFF, (h2 >> 8) & 0xFF, (h2 >> 16) & 0xFF, (h2 >>> 24) & 0xFF,
        h3 & 0xFF, (h3 >> 8) & 0xFF, (h3 >> 16) & 0xFF, (h3 >>> 24) & 0xFF
    ]);
  }
  return hash;
})();

var NullCipher = (function() {
  function constructor() {
  }

  constructor.prototype = {
    decryptBlock: function(data) {
      return data;
    }
  };

  return constructor;
})();

var AES128Cipher = (function() {
  var rcon = new Uint8Array([
    0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
    0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
    0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
    0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
    0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
    0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
    0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
    0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
    0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
    0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
    0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
    0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
    0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
    0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
    0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
    0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d]);

  var s = new Uint8Array([
    0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
    0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
    0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
    0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
    0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
    0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
    0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
    0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
    0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
    0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
    0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
    0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
    0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
    0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
    0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
    0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16]);

  var inv_s = new Uint8Array([
    0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
    0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
    0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
    0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
    0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
    0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
    0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
    0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
    0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
    0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
    0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
    0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
    0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
    0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
    0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
    0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D]);

  var mix = new Uint32Array([
    0x0, 0xe090d0b, 0x1c121a16, 0x121b171d, 0x3824342c, 0x362d3927, 0x24362e3a,
    0x2a3f2331, 0x70486858, 0x7e416553, 0x6c5a724e, 0x62537f45, 0x486c5c74,
    0x4665517f, 0x547e4662, 0x5a774b69, 0xe090d0b0, 0xee99ddbb, 0xfc82caa6,
    0xf28bc7ad, 0xd8b4e49c, 0xd6bde997, 0xc4a6fe8a, 0xcaaff381, 0x90d8b8e8,
    0x9ed1b5e3, 0x8ccaa2fe, 0x82c3aff5, 0xa8fc8cc4, 0xa6f581cf, 0xb4ee96d2,
    0xbae79bd9, 0xdb3bbb7b, 0xd532b670, 0xc729a16d, 0xc920ac66, 0xe31f8f57,
    0xed16825c, 0xff0d9541, 0xf104984a, 0xab73d323, 0xa57ade28, 0xb761c935,
    0xb968c43e, 0x9357e70f, 0x9d5eea04, 0x8f45fd19, 0x814cf012, 0x3bab6bcb,
    0x35a266c0, 0x27b971dd, 0x29b07cd6, 0x38f5fe7, 0xd8652ec, 0x1f9d45f1,
    0x119448fa, 0x4be30393, 0x45ea0e98, 0x57f11985, 0x59f8148e, 0x73c737bf,
    0x7dce3ab4, 0x6fd52da9, 0x61dc20a2, 0xad766df6, 0xa37f60fd, 0xb16477e0,
    0xbf6d7aeb, 0x955259da, 0x9b5b54d1, 0x894043cc, 0x87494ec7, 0xdd3e05ae,
    0xd33708a5, 0xc12c1fb8, 0xcf2512b3, 0xe51a3182, 0xeb133c89, 0xf9082b94,
    0xf701269f, 0x4de6bd46, 0x43efb04d, 0x51f4a750, 0x5ffdaa5b, 0x75c2896a,
    0x7bcb8461, 0x69d0937c, 0x67d99e77, 0x3daed51e, 0x33a7d815, 0x21bccf08,
    0x2fb5c203, 0x58ae132, 0xb83ec39, 0x1998fb24, 0x1791f62f, 0x764dd68d,
    0x7844db86, 0x6a5fcc9b, 0x6456c190, 0x4e69e2a1, 0x4060efaa, 0x527bf8b7,
    0x5c72f5bc, 0x605bed5, 0x80cb3de, 0x1a17a4c3, 0x141ea9c8, 0x3e218af9,
    0x302887f2, 0x223390ef, 0x2c3a9de4, 0x96dd063d, 0x98d40b36, 0x8acf1c2b,
    0x84c61120, 0xaef93211, 0xa0f03f1a, 0xb2eb2807, 0xbce2250c, 0xe6956e65,
    0xe89c636e, 0xfa877473, 0xf48e7978, 0xdeb15a49, 0xd0b85742, 0xc2a3405f,
    0xccaa4d54, 0x41ecdaf7, 0x4fe5d7fc, 0x5dfec0e1, 0x53f7cdea, 0x79c8eedb,
    0x77c1e3d0, 0x65daf4cd, 0x6bd3f9c6, 0x31a4b2af, 0x3fadbfa4, 0x2db6a8b9,
    0x23bfa5b2, 0x9808683, 0x7898b88, 0x15929c95, 0x1b9b919e, 0xa17c0a47,
    0xaf75074c, 0xbd6e1051, 0xb3671d5a, 0x99583e6b, 0x97513360, 0x854a247d,
    0x8b432976, 0xd134621f, 0xdf3d6f14, 0xcd267809, 0xc32f7502, 0xe9105633,
    0xe7195b38, 0xf5024c25, 0xfb0b412e, 0x9ad7618c, 0x94de6c87, 0x86c57b9a,
    0x88cc7691, 0xa2f355a0, 0xacfa58ab, 0xbee14fb6, 0xb0e842bd, 0xea9f09d4,
    0xe49604df, 0xf68d13c2, 0xf8841ec9, 0xd2bb3df8, 0xdcb230f3, 0xcea927ee,
    0xc0a02ae5, 0x7a47b13c, 0x744ebc37, 0x6655ab2a, 0x685ca621, 0x42638510,
    0x4c6a881b, 0x5e719f06, 0x5078920d, 0xa0fd964, 0x406d46f, 0x161dc372,
    0x1814ce79, 0x322bed48, 0x3c22e043, 0x2e39f75e, 0x2030fa55, 0xec9ab701,
    0xe293ba0a, 0xf088ad17, 0xfe81a01c, 0xd4be832d, 0xdab78e26, 0xc8ac993b,
    0xc6a59430, 0x9cd2df59, 0x92dbd252, 0x80c0c54f, 0x8ec9c844, 0xa4f6eb75,
    0xaaffe67e, 0xb8e4f163, 0xb6edfc68, 0xc0a67b1, 0x2036aba, 0x10187da7,
    0x1e1170ac, 0x342e539d, 0x3a275e96, 0x283c498b, 0x26354480, 0x7c420fe9,
    0x724b02e2, 0x605015ff, 0x6e5918f4, 0x44663bc5, 0x4a6f36ce, 0x587421d3,
    0x567d2cd8, 0x37a10c7a, 0x39a80171, 0x2bb3166c, 0x25ba1b67, 0xf853856,
    0x18c355d, 0x13972240, 0x1d9e2f4b, 0x47e96422, 0x49e06929, 0x5bfb7e34,
    0x55f2733f, 0x7fcd500e, 0x71c45d05, 0x63df4a18, 0x6dd64713, 0xd731dcca,
    0xd938d1c1, 0xcb23c6dc, 0xc52acbd7, 0xef15e8e6, 0xe11ce5ed, 0xf307f2f0,
    0xfd0efffb, 0xa779b492, 0xa970b999, 0xbb6bae84, 0xb562a38f, 0x9f5d80be,
    0x91548db5, 0x834f9aa8, 0x8d4697a3]);

  function expandKey128(cipherKey) {
    var b = 176, result = new Uint8Array(b);
    result.set(cipherKey);
    for (var j = 16, i = 1; j < b; ++i) {
      // RotWord
      var t1 = result[j - 3], t2 = result[j - 2], t3 = result[j - 1], t4 = result[j - 4];
      // SubWord
      t1 = s[t1]; t2 = s[t2]; t3 = s[t3]; t4 = s[t4];
      // Rcon
      t1 = t1 ^ rcon[i];
      for (var n = 0; n < 4; ++n) {
        result[j] = (t1 ^= result[j - 16]); j++;
        result[j] = (t2 ^= result[j - 16]); j++;
        result[j] = (t3 ^= result[j - 16]); j++;
        result[j] = (t4 ^= result[j - 16]); j++;
      }
    }
    return result;
  }

  function decrypt128(input, key) {
    var state = new Uint8Array(16);
    state.set(input);
    var i, j, k;
    var t, u, v;
    // AddRoundKey
    for (j = 0, k = 160; j < 16; ++j, ++k)
      state[j] ^= key[k];
    for (i = 9; i >= 1; --i) {
      // InvShiftRows
      t = state[13]; state[13] = state[9]; state[9] = state[5]; state[5] = state[1]; state[1] = t;
      t = state[14]; u = state[10]; state[14] = state[6]; state[10] = state[2]; state[6] = t; state[2] = u;
      t = state[15]; u = state[11]; v = state[7]; state[15] = state[3]; state[11] = t; state[7] = u; state[3] = v;
      // InvSubBytes
      for (j = 0; j < 16; ++j)
        state[j] = inv_s[state[j]];
      // AddRoundKey
      for (j = 0, k = i * 16; j < 16; ++j, ++k)
        state[j] ^= key[k];
      // InvMixColumns
      for (j = 0; j < 16; j += 4) {
        var s0 = mix[state[j]], s1 = mix[state[j + 1]], s2 = mix[state[j + 2]], s3 = mix[state[j + 3]];
        t = s0 ^ (s1 >>> 8) ^ (s1 << 24) ^ (s2 >>> 16) ^ (s2 << 16) ^ (s3 >>> 24) ^ (s3 << 8);
        state[j] = (t >>> 24) & 0xFF;
        state[j + 1] = (t >> 16) & 0xFF;
        state[j + 2] = (t >> 8) & 0xFF;
        state[j + 3] = t & 0xFF;
      }
    }
    // InvShiftRows
    t = state[13]; state[13] = state[9]; state[9] = state[5]; state[5] = state[1]; state[1] = t;
    t = state[14]; u = state[10]; state[14] = state[6]; state[10] = state[2]; state[6] = t; state[2] = u;
    t = state[15]; u = state[11]; v = state[7]; state[15] = state[3]; state[11] = t; state[7] = u; state[3] = v;
    // InvSubBytes
    for (j = 0; j < 16; ++j)
      state[j] = inv_s[state[j]];
    // AddRoundKey
    for (j = 0; j < 16; ++j)
      state[j] ^= key[j];
    return state;
  }

  function constructor(key) {
    this.key = expandKey128(key);
    this.buffer = new Uint8Array(16);
    this.bufferPosition = 0;
  }

  function decryptBlock2(data) {
    var i, j, sourceLength = data.length;
    var buffer = this.buffer, bufferLength = this.bufferPosition, iv = this.iv;
    var result = [];
    for (i = 0; i < sourceLength; ++i) {
      buffer[bufferLength] = data[i];
      ++bufferLength;
      if (bufferLength < 16)
        continue;
      // buffer is full, decrypting
      var plain = decrypt128(buffer, this.key);
      // xor-ing the IV vector to get plain text
      for (j = 0; j < 16; ++j)
        plain[j] ^= iv[j];
      iv = buffer;
      result.push(plain);
      buffer = new Uint8Array(16);
      bufferLength = 0;
    }
    // saving incomplete buffer
    this.buffer = buffer;
    this.bufferLength = bufferLength;
    this.iv = iv;
    if (result.length == 0)
      return new Uint8Array([]);
    if (result.length == 1)
      return result[0];
    // combining plain text blocks into one
    var output = new Uint8Array(16 * result.length);
    for (i = 0, j = 0; i < result.length; ++i, j += 16)
      output.set(result[i], j);
    return output;
  }

  constructor.prototype = {
    decryptBlock: function(data) {
      var i, sourceLength = data.length;
      var buffer = this.buffer, bufferLength = this.bufferPosition;
      // waiting for IV values -- they are at the start of the stream
      for (i = 0; bufferLength < 16 && i < sourceLength; ++i, ++bufferLength)
        buffer[bufferLength] = data[i];
      if (bufferLength < 16) {
        // need more data
        this.bufferLength = bufferLength;
        return new Uint8Array([]);
      }
      this.iv = buffer;
      this.buffer = new Uint8Array(16);
      this.bufferLength = 0;
      // starting decryption
      this.decryptBlock = decryptBlock2;
      return this.decryptBlock(data.subarray(16));
    }
  };

  return constructor;
})();

var CipherTransform = (function() {
  function constructor(stringCipherConstructor, streamCipherConstructor) {
    this.stringCipherConstructor = stringCipherConstructor;
    this.streamCipherConstructor = streamCipherConstructor;
  }
  constructor.prototype = {
    createStream: function(stream) {
      var cipher = new this.streamCipherConstructor();
      return new DecryptStream(stream, function(data) {
        return cipher.decryptBlock(data);
      });
    },
    decryptString: function(s) {
      var cipher = new this.stringCipherConstructor();
      var data = stringToBytes(s);
      data = cipher.decryptBlock(data);
      return bytesToString(data);
    }
  };
  return constructor;
})();

var CipherTransformFactory = (function() {
  function prepareKeyData(fileId, password, ownerPassword, userPassword,
                          flags, revision, keyLength, encryptMetadata) {
    var defaultPasswordBytes = new Uint8Array([
      0x28, 0xBF, 0x4E, 0x5E, 0x4E, 0x75, 0x8A, 0x41,
      0x64, 0x00, 0x4E, 0x56, 0xFF, 0xFA, 0x01, 0x08,
      0x2E, 0x2E, 0x00, 0xB6, 0xD0, 0x68, 0x3E, 0x80,
      0x2F, 0x0C, 0xA9, 0xFE, 0x64, 0x53, 0x69, 0x7A]);
    var hashData = new Uint8Array(100), i = 0, j, n;
    if (password) {
      n = Math.min(32, password.length);
      for (; i < n; ++i)
        hashData[i] = password[i];
    }
    j = 0;
    while (i < 32) {
      hashData[i++] = defaultPasswordBytes[j++];
    }
    // as now the padded password in the hashData[0..i]
    for (j = 0, n = ownerPassword.length; j < n; ++j)
      hashData[i++] = ownerPassword[j];
    hashData[i++] = flags & 0xFF;
    hashData[i++] = (flags >> 8) & 0xFF;
    hashData[i++] = (flags >> 16) & 0xFF;
    hashData[i++] = (flags >>> 24) & 0xFF;
    for (j = 0, n = fileId.length; j < n; ++j)
      hashData[i++] = fileId[j];
    if (revision >= 4 && !encryptMetadata) {
      hashData[i++] = 0xFF;
      hashData[i++] = 0xFF;
      hashData[i++] = 0xFF;
      hashData[i++] = 0xFF;
    }
    var hash = md5(hashData, 0, i);
    var keyLengthInBytes = keyLength >> 3;
    if (revision >= 3) {
      for (j = 0; j < 50; ++j) {
         hash = md5(hash, 0, keyLengthInBytes);
      }
    }
    var encryptionKey = hash.subarray(0, keyLengthInBytes);
    var cipher, checkData;

    if (revision >= 3) {
      // padded password in hashData, we can use this array for user
      // password check
      i = 32;
      for (j = 0, n = fileId.length; j < n; ++j)
        hashData[i++] = fileId[j];
      cipher = new ARCFourCipher(encryptionKey);
      var checkData = cipher.encryptBlock(md5(hashData, 0, i));
      n = encryptionKey.length;
      var derrivedKey = new Uint8Array(n), k;
      for (j = 1; j <= 19; ++j) {
        for (k = 0; k < n; ++k)
          derrivedKey[k] = encryptionKey[k] ^ j;
        cipher = new ARCFourCipher(derrivedKey);
        checkData = cipher.encryptBlock(checkData);
      }
    } else {
      cipher = new ARCFourCipher(encryptionKey);
      checkData = cipher.encryptBlock(hashData.subarray(0, 32));
    }
    for (j = 0, n = checkData.length; j < n; ++j) {
      if (userPassword[j] != checkData[j])
        error('incorrect password');
    }
    return encryptionKey;
  }

  var identityName = new Name('Identity');

  function constructor(dict, fileId, password) {
    var filter = dict.get('Filter');
    if (!IsName(filter) || filter.name != 'Standard')
      error('unknown encryption method');
    this.dict = dict;
    var algorithm = dict.get('V');
    if (!IsInt(algorithm) ||
      (algorithm != 1 && algorithm != 2 && algorithm != 4))
      error('unsupported encryption algorithm');
    this.algorithm = algorithm;
    var keyLength = dict.get('Length') || 40;
    if (!IsInt(keyLength) ||
      keyLength < 40 || (keyLength % 8) != 0)
      error('invalid key length');
    // prepare keys
    var ownerPassword = stringToBytes(dict.get('O'));
    var userPassword = stringToBytes(dict.get('U'));
    var flags = dict.get('P');
    var revision = dict.get('R');
    var encryptMetadata = dict.get('EncryptMetadata') !== false; // makes true as default value
    var fileIdBytes = stringToBytes(fileId);
    var passwordBytes;
    if (password)
      passwordBytes = stringToBytes(password);

    this.encryptionKey = prepareKeyData(fileIdBytes, passwordBytes,
                                        ownerPassword, userPassword,
                                        flags, revision, keyLength, encryptMetadata);
    if (algorithm == 4) {
      this.cf = dict.get('CF');
      this.stmf = dict.get('StmF') || identityName;
      this.strf = dict.get('StrF') || identityName;
      this.eff = dict.get('EFF') || this.strf;
    }
  }

  function buildObjectKey(num, gen, encryptionKey, isAes) {
    var key = new Uint8Array(encryptionKey.length + 9), i, n;
    for (i = 0, n = encryptionKey.length; i < n; ++i)
      key[i] = encryptionKey[i];
    key[i++] = num & 0xFF;
    key[i++] = (num >> 8) & 0xFF;
    key[i++] = (num >> 16) & 0xFF;
    key[i++] = gen & 0xFF;
    key[i++] = (gen >> 8) & 0xFF;
    if (isAes) {
      key[i++] = 0x73;
      key[i++] = 0x41;
      key[i++] = 0x6C;
      key[i++] = 0x54;
    }
    var hash = md5(key, 0, i);
    return hash.subarray(0, Math.min(key.length, 16));
  }

  function buildCipherConstructor(cf, name, num, gen, key) {
    var cryptFilter = cf.get(name.name);
    var cfm;
    if (cryptFilter != null)
      cfm = cryptFilter.get('CFM');
    if (!cfm || cfm.name == 'None') {
      return function() {
        return new NullCipher();
      };
    }
    if ('V2' == cfm.name) {
      return function() {
        return new ARCFourCipher(
          buildObjectKey(num, gen, key, false));
      };
    }
    if ('AESV2' == cfm.name) {
      return function() {
        return new AES128Cipher(
          buildObjectKey(num, gen, key, true));
      };
    }
  }

  constructor.prototype = {
    createCipherTransform: function(num, gen) {
      if (this.algorithm == 4) {
        return new CipherTransform(
          buildCipherConstructor(this.cf, this.stmf, num, gen, this.encryptionKey),
          buildCipherConstructor(this.cf, this.strf, num, gen, this.encryptionKey));
      }
      // algorithms 1 and 2
      var key = buildObjectKey(num, gen, this.encryptionKey, false);
      var cipherConstructor = function() {
        return new ARCFourCipher(key);
      };
      return new CipherTransform(cipherConstructor, cipherConstructor);
    }
  };

  return constructor;
})();