"use strict";

/**
 * @author Wuner
 * @date 2020/9/15 16:19
 * @description
 */

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/*  AES implementation in JavaScript (c) Chris Veness 2005-2012                                   */

/*   - see http://csrc.nist.gov/publications/PubsFIPS.html#197                                    */

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
var Aes = {}; // Aes namespace

/**
 * AES Cipher function: encrypt 'input' state with Rijndael algorithm
 *   applies Nr rounds (10/12/14) using key schedule w for 'add round key' stage
 *
 * @param {Number[]} input 16-byte (128-bit) input state array
 * @param {Number[][]} w   Key schedule as 2D byte-array (Nr+1 x Nb bytes)
 * @returns {Number[]}     Encrypted output state array
 */

Aes.cipher = function (input, w) {
  // main Cipher function [§5.1]
  var Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)

  var Nr = w.length / Nb - 1; // no of rounds: 10/12/14 for 128/192/256-bit keys

  var state = [[], [], [], []]; // initialise 4xNb byte-array 'state' with input [§3.4]

  for (var i = 0; i < 4 * Nb; i++) {
    state[i % 4][Math.floor(i / 4)] = input[i];
  }

  state = Aes.addRoundKey(state, w, 0, Nb);

  for (var round = 1; round < Nr; round++) {
    state = Aes.subBytes(state, Nb);
    state = Aes.shiftRows(state, Nb);
    state = Aes.mixColumns(state, Nb);
    state = Aes.addRoundKey(state, w, round, Nb);
  }

  state = Aes.subBytes(state, Nb);
  state = Aes.shiftRows(state, Nb);
  state = Aes.addRoundKey(state, w, Nr, Nb);
  var output = new Array(4 * Nb); // convert state to 1-d array before returning [§3.4]

  for (var _i = 0; _i < 4 * Nb; _i++) {
    output[_i] = state[_i % 4][Math.floor(_i / 4)];
  }

  return output;
};
/**
 * Perform Key Expansion to generate a Key Schedule
 *
 * @param {Number[]} key Key as 16/24/32-byte array
 * @returns {Number[][]} Expanded key schedule as 2D byte-array (Nr+1 x Nb bytes)
 */


Aes.keyExpansion = function (key) {
  // generate Key Schedule (byte-array Nr+1 x Nb) from Key [§5.2]
  var Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES)

  var Nk = key.length / 4; // key length (in words): 4/6/8 for 128/192/256-bit keys

  var Nr = Nk + 6; // no of rounds: 10/12/14 for 128/192/256-bit keys

  var w = new Array(Nb * (Nr + 1));
  var temp = new Array(4);

  for (var i = 0; i < Nk; i++) {
    var r = [key[4 * i], key[4 * i + 1], key[4 * i + 2], key[4 * i + 3]];
    w[i] = r;
  }

  for (var _i2 = Nk; _i2 < Nb * (Nr + 1); _i2++) {
    w[_i2] = new Array(4);

    for (var t = 0; t < 4; t++) {
      temp[t] = w[_i2 - 1][t];
    }

    if (_i2 % Nk == 0) {
      temp = Aes.subWord(Aes.rotWord(temp));

      for (var _t = 0; _t < 4; _t++) {
        temp[_t] ^= Aes.rCon[_i2 / Nk][_t];
      }
    } else if (Nk > 6 && _i2 % Nk == 4) {
      temp = Aes.subWord(temp);
    }

    for (var _t2 = 0; _t2 < 4; _t2++) {
      w[_i2][_t2] = w[_i2 - Nk][_t2] ^ temp[_t2];
    }
  }

  return w;
};
/*
 * ---- remaining routines are private, not called externally ----
 */


Aes.subBytes = function (s, Nb) {
  // apply SBox to state S [§5.1.1]
  for (var r = 0; r < 4; r++) {
    for (var c = 0; c < Nb; c++) {
      s[r][c] = Aes.sBox[s[r][c]];
    }
  }

  return s;
};

Aes.shiftRows = function (s, Nb) {
  // shift row r of state S left by r bytes [§5.1.2]
  var t = new Array(4);

  for (var r = 1; r < 4; r++) {
    for (var c = 0; c < 4; c++) {
      t[c] = s[r][(c + r) % Nb];
    } // shift into temp copy


    for (var _c = 0; _c < 4; _c++) {
      s[r][_c] = t[_c];
    } // and copy back

  } // note that this will work for Nb=4,5,6, but not 7,8 (always 4 for AES):


  return s; // see asmaes.sourceforge.net/rijndael/rijndaelImplementation.pdf
};

Aes.mixColumns = function (s, Nb) {
  // combine bytes of each col of state S [§5.1.3]
  for (var c = 0; c < 4; c++) {
    var a = new Array(4); // 'a' is a copy of the current column from 's'

    var b = new Array(4); // 'b' is a•{02} in GF(2^8)

    for (var i = 0; i < 4; i++) {
      a[i] = s[i][c];
      b[i] = s[i][c] & 0x80 ? s[i][c] << 1 ^ 0x011b : s[i][c] << 1;
    } // a[n] ^ b[n] is a•{03} in GF(2^8)


    s[0][c] = b[0] ^ a[1] ^ b[1] ^ a[2] ^ a[3]; // 2*a0 + 3*a1 + a2 + a3

    s[1][c] = a[0] ^ b[1] ^ a[2] ^ b[2] ^ a[3]; // a0 * 2*a1 + 3*a2 + a3

    s[2][c] = a[0] ^ a[1] ^ b[2] ^ a[3] ^ b[3]; // a0 + a1 + 2*a2 + 3*a3

    s[3][c] = a[0] ^ b[0] ^ a[1] ^ a[2] ^ b[3]; // 3*a0 + a1 + a2 + 2*a3
  }

  return s;
};

Aes.addRoundKey = function (state, w, rnd, Nb) {
  // xor Round Key into state S [§5.1.4]
  for (var r = 0; r < 4; r++) {
    for (var c = 0; c < Nb; c++) {
      state[r][c] ^= w[rnd * 4 + c][r];
    }
  }

  return state;
};

Aes.subWord = function (w) {
  // apply SBox to 4-byte word w
  for (var i = 0; i < 4; i++) {
    w[i] = Aes.sBox[w[i]];
  }

  return w;
};

Aes.rotWord = function (w) {
  // rotate 4-byte word w left by one byte
  var tmp = w[0];

  for (var i = 0; i < 3; i++) {
    w[i] = w[i + 1];
  }

  w[3] = tmp;
  return w;
}; // sBox is pre-computed multiplicative inverse in GF(2^8) used in subBytes and keyExpansion [§5.1.1]


Aes.sBox = [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]; // rCon is Round Constant used for the Key Expansion [1st col is 2^(r-1) in GF(2^8)] [§5.2]

Aes.rCon = [[0x00, 0x00, 0x00, 0x00], [0x01, 0x00, 0x00, 0x00], [0x02, 0x00, 0x00, 0x00], [0x04, 0x00, 0x00, 0x00], [0x08, 0x00, 0x00, 0x00], [0x10, 0x00, 0x00, 0x00], [0x20, 0x00, 0x00, 0x00], [0x40, 0x00, 0x00, 0x00], [0x80, 0x00, 0x00, 0x00], [0x1b, 0x00, 0x00, 0x00], [0x36, 0x00, 0x00, 0x00]];
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/*  AES Counter-mode implementation in JavaScript (c) Chris Veness 2005-2012                      */

/*   - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf                       */

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

Aes.Ctr = {}; // Aes.Ctr namespace: a subclass or extension of Aes

/**
 * Encrypt a text using AES encryption in Counter mode of operation
 *
 * Unicode multi-byte character safe
 *
 * @param {String} plaintext Source text to be encrypted
 * @param {String} password  The password to use to generate a key
 * @param {Number} nBits     Number of bits to be used in the key (128, 192, or 256)
 * @returns {string}         Encrypted text
 */

Aes.Ctr.encrypt = function (plaintext, password, nBits) {
  var blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES

  if (!(nBits == 128 || nBits == 192 || nBits == 256)) return ''; // standard allows 128/192/256 bit keys

  plaintext = Utf8.encode(plaintext);
  password = Utf8.encode(password); //let t = new Date();  // timer
  // use AES itself to encrypt password to get cipher key (using plain password as source for key
  // expansion) - gives us well encrypted key (though hashed key might be preferred for prod'n use)

  var nBytes = nBits / 8; // no bytes in key (16/24/32)

  var pwBytes = new Array(nBytes);

  for (var i = 0; i < nBytes; i++) {
    // use 1st 16/24/32 chars of password for key
    pwBytes[i] = isNaN(password.charCodeAt(i)) ? 0 : password.charCodeAt(i);
  }

  var key = Aes.cipher(pwBytes, Aes.keyExpansion(pwBytes)); // gives us 16-byte key

  key = key.concat(key.slice(0, nBytes - 16)); // expand key to 16/24/32 bytes long
  // initialise 1st 8 bytes of counter block with nonce (NIST SP800-38A §B.2): [0-1] = millisec,
  // [2-3] = random, [4-7] = seconds, together giving full sub-millisec uniqueness up to Feb 2106

  var counterBlock = new Array(blockSize);
  var nonce = new Date().getTime(); // timestamp: milliseconds since 1-Jan-1970

  var nonceMs = nonce % 1000;
  var nonceSec = Math.floor(nonce / 1000);
  var nonceRnd = Math.floor(Math.random() * 0xffff);

  for (var _i3 = 0; _i3 < 2; _i3++) {
    counterBlock[_i3] = nonceMs >>> _i3 * 8 & 0xff;
  }

  for (var _i4 = 0; _i4 < 2; _i4++) {
    counterBlock[_i4 + 2] = nonceRnd >>> _i4 * 8 & 0xff;
  }

  for (var _i5 = 0; _i5 < 4; _i5++) {
    counterBlock[_i5 + 4] = nonceSec >>> _i5 * 8 & 0xff;
  } // and convert it to a string to go on the front of the ciphertext


  var ctrTxt = '';

  for (var _i6 = 0; _i6 < 8; _i6++) {
    ctrTxt += String.fromCharCode(counterBlock[_i6]);
  } // generate key schedule - an expansion of the key into distinct Key Rounds for each round


  var keySchedule = Aes.keyExpansion(key);
  var blockCount = Math.ceil(plaintext.length / blockSize);
  var ciphertxt = new Array(blockCount); // ciphertext as array of strings

  for (var b = 0; b < blockCount; b++) {
    // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
    // done in two stages for 32-bit ops: using two words allows us to go past 2^32 blocks (68GB)
    for (var c = 0; c < 4; c++) {
      counterBlock[15 - c] = b >>> c * 8 & 0xff;
    }

    for (var _c2 = 0; _c2 < 4; _c2++) {
      counterBlock[15 - _c2 - 4] = b / 0x100000000 >>> _c2 * 8;
    }

    var cipherCntr = Aes.cipher(counterBlock, keySchedule); // -- encrypt counter block --
    // block size is reduced on final block

    var blockLength = b < blockCount - 1 ? blockSize : (plaintext.length - 1) % blockSize + 1;
    var cipherChar = new Array(blockLength);

    for (var _i7 = 0; _i7 < blockLength; _i7++) {
      // -- xor plaintext with ciphered counter char-by-char --
      cipherChar[_i7] = cipherCntr[_i7] ^ plaintext.charCodeAt(b * blockSize + _i7);
      cipherChar[_i7] = String.fromCharCode(cipherChar[_i7]);
    }

    ciphertxt[b] = cipherChar.join('');
  } // Array.join is more efficient than repeated string concatenation in IE


  var ciphertext = ctrTxt + ciphertxt.join('');
  ciphertext = Base64.encode(ciphertext); // encode in base64
  //alert((new Date()) - t);

  return ciphertext;
};
/**
 * Decrypt a text encrypted by AES in counter mode of operation
 *
 * @param {String} ciphertext Source text to be encrypted
 * @param {String} password   The password to use to generate a key
 * @param {Number} nBits      Number of bits to be used in the key (128, 192, or 256)
 * @returns {String}          Decrypted text
 */


Aes.Ctr.decrypt = function (ciphertext, password, nBits) {
  var blockSize = 16; // block size fixed at 16 bytes / 128 bits (Nb=4) for AES

  if (!(nBits == 128 || nBits == 192 || nBits == 256)) return ''; // standard allows 128/192/256 bit keys

  ciphertext = Base64.decode(ciphertext);
  password = Utf8.encode(password); //let t = new Date();  // timer
  // use AES to encrypt password (mirroring encrypt routine)

  var nBytes = nBits / 8; // no bytes in key

  var pwBytes = new Array(nBytes);

  for (var i = 0; i < nBytes; i++) {
    pwBytes[i] = isNaN(password.charCodeAt(i)) ? 0 : password.charCodeAt(i);
  }

  var key = Aes.cipher(pwBytes, Aes.keyExpansion(pwBytes));
  key = key.concat(key.slice(0, nBytes - 16)); // expand key to 16/24/32 bytes long
  // recover nonce from 1st 8 bytes of ciphertext

  var counterBlock = new Array(8);
  ctrTxt = ciphertext.slice(0, 8);

  for (var _i8 = 0; _i8 < 8; _i8++) {
    counterBlock[_i8] = ctrTxt.charCodeAt(_i8);
  } // generate key schedule


  var keySchedule = Aes.keyExpansion(key); // separate ciphertext into blocks (skipping past initial 8 bytes)

  var nBlocks = Math.ceil((ciphertext.length - 8) / blockSize);
  var ct = new Array(nBlocks);

  for (var b = 0; b < nBlocks; b++) {
    ct[b] = ciphertext.slice(8 + b * blockSize, 8 + b * blockSize + blockSize);
  }

  ciphertext = ct; // ciphertext is now array of block-length strings
  // plaintext will get generated block-by-block into array of block-length strings

  var plaintxt = new Array(ciphertext.length);

  for (var _b = 0; _b < nBlocks; _b++) {
    // set counter (block #) in last 8 bytes of counter block (leaving nonce in 1st 8 bytes)
    for (var c = 0; c < 4; c++) {
      counterBlock[15 - c] = _b >>> c * 8 & 0xff;
    }

    for (var _c3 = 0; _c3 < 4; _c3++) {
      counterBlock[15 - _c3 - 4] = (_b + 1) / 0x100000000 - 1 >>> _c3 * 8 & 0xff;
    }

    var cipherCntr = Aes.cipher(counterBlock, keySchedule); // encrypt counter block

    var plaintxtByte = new Array(ciphertext[_b].length);

    for (var _i9 = 0; _i9 < ciphertext[_b].length; _i9++) {
      // -- xor plaintxt with ciphered counter byte-by-byte --
      plaintxtByte[_i9] = cipherCntr[_i9] ^ ciphertext[_b].charCodeAt(_i9);
      plaintxtByte[_i9] = String.fromCharCode(plaintxtByte[_i9]);
    }

    plaintxt[_b] = plaintxtByte.join('');
  } // join array of blocks into single plaintext string


  var plaintext = plaintxt.join('');
  plaintext = Utf8.decode(plaintext); // decode from UTF8 back to Unicode multi-byte chars
  //alert((new Date()) - t);

  return plaintext;
};
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/*  Base64 class: Base 64 encoding / decoding (c) Chris Veness 2002-2012                          */

/*    note: depends on Utf8 class                                                                 */

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */


var Base64 = {}; // Base64 namespace

Base64.code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
/**
 * Encode string into Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
 * (instance method extending String object). As per RFC 4648, no newlines are added.
 *
 * @param {String} str The string to be encoded as base-64
 * @param {Boolean} [utf8encode=false] Flag to indicate whether str is Unicode string to be encoded
 *   to UTF8 before conversion to base64; otherwise string is assumed to be 8-bit characters
 * @returns {String} Base64-encoded string
 */

Base64.encode = function (str, utf8encode) {
  // http://tools.ietf.org/html/rfc4648
  utf8encode = typeof utf8encode == 'undefined' ? false : utf8encode;
  var o1,
      o2,
      o3,
      bits,
      h1,
      h2,
      h3,
      h4,
      e = [],
      pad = '',
      c,
      plain,
      coded;
  var b64 = Base64.code;
  plain = utf8encode ? str.encodeUTF8() : str;
  c = plain.length % 3; // pad string to length of multiple of 3

  if (c > 0) {
    while (c++ < 3) {
      pad += '=';
      plain += '\0';
    }
  } // note: doing padding here saves us doing special-case packing for trailing 1 or 2 chars


  for (c = 0; c < plain.length; c += 3) {
    // pack three octets into four hexets
    o1 = plain.charCodeAt(c);
    o2 = plain.charCodeAt(c + 1);
    o3 = plain.charCodeAt(c + 2);
    bits = o1 << 16 | o2 << 8 | o3;
    h1 = bits >> 18 & 0x3f;
    h2 = bits >> 12 & 0x3f;
    h3 = bits >> 6 & 0x3f;
    h4 = bits & 0x3f; // use hextets to index into code string

    e[c / 3] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
  }

  coded = e.join(''); // join() is far faster than repeated string concatenation in IE
  // replace 'A's from padded nulls with '='s

  coded = coded.slice(0, coded.length - pad.length) + pad;
  return coded;
};
/**
 * Decode string from Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
 * (instance method extending String object). As per RFC 4648, newlines are not catered for.
 *
 * @param {String} str The string to be decoded from base-64
 * @param {Boolean} [utf8decode=false] Flag to indicate whether str is Unicode string to be decoded
 *   from UTF8 after conversion from base64
 * @returns {String} decoded string
 */


Base64.decode = function (str, utf8decode) {
  utf8decode = typeof utf8decode == 'undefined' ? false : utf8decode;
  var o1,
      o2,
      o3,
      h1,
      h2,
      h3,
      h4,
      bits,
      d = [],
      plain,
      coded;
  var b64 = Base64.code;
  coded = utf8decode ? str.decodeUTF8() : str;

  for (var c = 0; c < coded.length; c += 4) {
    // unpack four hexets into three octets
    h1 = b64.indexOf(coded.charAt(c));
    h2 = b64.indexOf(coded.charAt(c + 1));
    h3 = b64.indexOf(coded.charAt(c + 2));
    h4 = b64.indexOf(coded.charAt(c + 3));
    bits = h1 << 18 | h2 << 12 | h3 << 6 | h4;
    o1 = bits >>> 16 & 0xff;
    o2 = bits >>> 8 & 0xff;
    o3 = bits & 0xff;
    d[c / 4] = String.fromCharCode(o1, o2, o3); // check for padding

    if (h4 == 0x40) d[c / 4] = String.fromCharCode(o1, o2);
    if (h3 == 0x40) d[c / 4] = String.fromCharCode(o1);
  }

  plain = d.join(''); // join() is far faster than repeated string concatenation in IE

  return utf8decode ? plain.decodeUTF8() : plain;
};
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/*  Utf8 class: encode / decode between multi-byte Unicode characters and UTF-8 multiple          */

/*              single-byte character encoding (c) Chris Veness 2002-2012                         */

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */


var Utf8 = {}; // Utf8 namespace

/**
 * Encode multi-byte Unicode string into utf-8 multiple single-byte characters
 * (BMP / basic multilingual plane only)
 *
 * Chars in range U+0080 - U+07FF are encoded in 2 chars, U+0800 - U+FFFF in 3 chars
 *
 * @param {String} strUni Unicode string to be encoded as UTF-8
 * @returns {String} encoded string
 */

Utf8.encode = function (strUni) {
  // use regular expressions & String.replace callback function for better efficiency
  // than procedural approaches
  var strUtf = strUni.replace(/[\u0080-\u07ff]/g, // U+0080 - U+07FF => 2 bytes 110yyyyy, 10zzzzzz
  function (c) {
    var cc = c.charCodeAt(0);
    return String.fromCharCode(0xc0 | cc >> 6, 0x80 | cc & 0x3f);
  });
  strUtf = strUtf.replace(/[\u0800-\uffff]/g, // U+0800 - U+FFFF => 3 bytes 1110xxxx, 10yyyyyy, 10zzzzzz
  function (c) {
    var cc = c.charCodeAt(0);
    return String.fromCharCode(0xe0 | cc >> 12, 0x80 | cc >> 6 & 0x3F, 0x80 | cc & 0x3f);
  });
  return strUtf;
};
/**
 * Decode utf-8 encoded string back into multi-byte Unicode characters
 *
 * @param {String} strUtf UTF-8 string to be decoded back to Unicode
 * @returns {String} decoded string
 */


Utf8.decode = function (strUtf) {
  // note: decode 3-byte chars first as decoded 2-byte strings could appear to be 3-byte char!
  var strUni = strUtf.replace(/[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g, // 3-byte chars
  function (c) {
    // (note parentheses for precence)
    var cc = (c.charCodeAt(0) & 0x0f) << 12 | (c.charCodeAt(1) & 0x3f) << 6 | c.charCodeAt(2) & 0x3f;
    return String.fromCharCode(cc);
  });
  strUni = strUni.replace(/[\u00c0-\u00df][\u0080-\u00bf]/g, // 2-byte chars
  function (c) {
    // (note parentheses for precence)
    var cc = (c.charCodeAt(0) & 0x1f) << 6 | c.charCodeAt(1) & 0x3f;
    return String.fromCharCode(cc);
  });
  return strUni;
};

module.exports = Aes;