function omkEnc(plain, key) {
	if (plain)
		return AESEncryptCtr(plain, key, 256);
}

function omkDec(ciph, key) {
	if (ciph)
		return AESDecryptCtr(ciph, key, 256);
}

/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
 * in FIPS PUB 180-1
 * Version 2.1a Copyright Paul Johnston 2000 - 2002.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for details.
 */

/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
var hexcase = 0;  /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad  = ""; /* base-64 pad character. "=" for strict RFC compliance   */
var chrsz   = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
function hex_sha1(s){return binb2hex(core_sha1(str2binb(s),s.length * chrsz));}
function b64_sha1(s){return binb2b64(core_sha1(str2binb(s),s.length * chrsz));}
function str_sha1(s){return binb2str(core_sha1(str2binb(s),s.length * chrsz));}
function hex_hmac_sha1(key, data){ return binb2hex(core_hmac_sha1(key, data));}
function b64_hmac_sha1(key, data){ return binb2b64(core_hmac_sha1(key, data));}
function str_hmac_sha1(key, data){ return binb2str(core_hmac_sha1(key, data));}

/*
 * Perform a simple self-test to see if the VM is working
 */
function sha1_vm_test()
{
  return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";
}

/*
 * Calculate the SHA-1 of an array of big-endian words, and a bit length
 */
function core_sha1(x, len)
{
  /* append padding */
  x[len >> 5] |= 0x80 << (24 - len % 32);
  x[((len + 64 >> 9) << 4) + 15] = len;

  var w = Array(80);
  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;
  var e = -1009589776;

  for(var i = 0; i < x.length; i += 16)
  {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;
    var olde = e;

    for(var j = 0; j < 80; j++)
    {
      if(j < 16) w[j] = x[i + j];
      else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
      var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
                       safe_add(safe_add(e, w[j]), sha1_kt(j)));
      e = d;
      d = c;
      c = rol(b, 30);
      b = a;
      a = t;
    }

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
    e = safe_add(e, olde);
  }
  return Array(a, b, c, d, e);

}

/*
 * Perform the appropriate triplet combination function for the current
 * iteration
 */
function sha1_ft(t, b, c, d)
{
  if(t < 20) return (b & c) | ((~b) & d);
  if(t < 40) return b ^ c ^ d;
  if(t < 60) return (b & c) | (b & d) | (c & d);
  return b ^ c ^ d;
}

/*
 * Determine the appropriate additive constant for the current iteration
 */
function sha1_kt(t)
{
  return (t < 20) ?  1518500249 : (t < 40) ?  1859775393 :
         (t < 60) ? -1894007588 : -899497514;
}

/*
 * Calculate the HMAC-SHA1 of a key and some data
 */
function core_hmac_sha1(key, data)
{
  var bkey = str2binb(key);
  if(bkey.length > 16) bkey = core_sha1(bkey, key.length * chrsz);

  var ipad = Array(16), opad = Array(16);
  for(var i = 0; i < 16; i++)
  {
    ipad[i] = bkey[i] ^ 0x36363636;
    opad[i] = bkey[i] ^ 0x5C5C5C5C;
  }

  var hash = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);
  return core_sha1(opad.concat(hash), 512 + 160);
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_add(x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}

/*
 * Convert an 8-bit or 16-bit string to an array of big-endian words
 * In 8-bit function, characters >255 have their hi-byte silently ignored.
 */
function str2binb(str)
{
  var bin = Array();
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < str.length * chrsz; i += chrsz)
    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (32 - chrsz - i%32);
  return bin;
}

/*
 * Convert an array of big-endian words to a string
 */
function binb2str(bin)
{
  var str = "";
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCode((bin[i>>5] >>> (32 - chrsz - i%32)) & mask);
  return str;
}

/*
 * Convert an array of big-endian words to a hex string.
 */
function binb2hex(binarray)
{
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i++)
  {
    str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +
           hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8  )) & 0xF);
  }
  return str;
}

/*
 * Convert an array of big-endian words to a base-64 string
 */
function binb2b64(binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i += 3)
  {
    var triplet = (((binarray[i   >> 2] >> 8 * (3 -  i   %4)) & 0xFF) << 16)
                | (((binarray[i+1 >> 2] >> 8 * (3 - (i+1)%4)) & 0xFF) << 8 )
                |  ((binarray[i+2 >> 2] >> 8 * (3 - (i+2)%4)) & 0xFF);
    for(var j = 0; j < 4; j++)
    {
      if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
      else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
    }
  }
  return str;
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/*
 * AES Cipher function: use 'key' to encrypt 'input' with Rijndael algorithm
 *
 *   takes   byte-array 'input' (16 bytes)
 *           byte-array 'key' (16/24/32 bytes)
 *           2D byte-array key schedule 'w' (Nr+1 x Nb bytes)
 *   returns byte-array encrypted value (16 bytes)
 */
function Cipher(input, key, w) {    // main Cipher function [§5.1]
  var Nk = key.length/4  // key length (in words)
  var Nr = Nk + 6;       // no of rounds
  var Nb = 4;            // block size (in words): no of columns in state (fixed at 4 for AES)

  var state = [[],[],[],[]];  // initialise 4xNb byte-array 'state' with input
  for (var i=0; i<4*Nb; i++) state[i%4][Math.floor(i/4)] = input[i];

  state = AddRoundKey(state, w, 0, Nb);

  for (var round=1; round<Nr; round++) {
    state = SubBytes(state, Nb);
    state = ShiftRows(state, Nb);
    state = MixColumns(state, Nb);
    state = AddRoundKey(state, w, round, Nb);
  }

  state = SubBytes(state, Nb);
  state = ShiftRows(state, Nb);
  state = AddRoundKey(state, w, Nr, Nb);

  var output = new Array(4*Nb);  // convert to 1-d array before returning
  for (var i=0; i<4*Nb; i++) output[i] = state[i%4][Math.floor(i/4)];
  return output;
}


function SubBytes(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] = Sbox[s[r][c]];
  }
  return s;
}


function ShiftRows(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 fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf 
}


function MixColumns(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;
}


function AddRoundKey(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;
}


function KeyExpansion(key) {  // generate Key Schedule (byte-array Nr+1 x Nb) from Key [§5.2]
  var Nk = key.length/4  // key length (in words)
  var Nr = Nk + 6;       // no of rounds
  var Nb = 4;            // block size: no of columns in state (fixed at 4 for AES)

  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 i=Nk; i<(Nb*(Nr+1)); i++) {
    w[i] = new Array(4);
    for (var t=0; t<4; t++) temp[t] = w[i-1][t];
    if (i % Nk == 0) {
      temp = SubWord(RotWord(temp));
      for (var t=0; t<4; t++) temp[t] ^= Rcon[i/Nk][t];
    } else if (Nk > 6 && i%Nk == 4) {
      temp = SubWord(temp);
    }
    for (var t=0; t<4; t++) w[i][t] = w[i-Nk][t] ^ temp[t];
  }

  return w;
}

function SubWord(w) {    // apply SBox to 4-byte word w
  for (var i=0; i<4; i++) w[i] = Sbox[w[i]];
  return w;
}

function RotWord(w) {    // rotate 4-byte word w left by one byte
  w[4] = w[0];
  for (var i=0; i<4; i++) w[i] = w[i+1];
  return w;
}


// Sbox is pre-computed multiplicative inverse in GF(2^8) used in SubBytes and KeyExpansion [§5.1.1]
var 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]
var 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] ]; 


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

function paswordize(pass, nBits) {
  for (var i = pass.length; i < nBits / 8; i ++)
	pass += "0";
}
/* 
 * Use AES to encrypt 'plaintext' with 'password' using 'nBits' key, in 'Counter' mode of operation
 *                           - see http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
 *   for each block
 *   - outputblock = cipher(counter, key)
 *   - cipherblock = plaintext xor outputblock
 */
function AESEncryptCtr(plaintext, password, nBits) {
  if (!(nBits==128 || nBits==192 || nBits==256)) return '';  // standard allows 128/192/256 bit keys
	
  plaintext = encodeUTF8(plaintext);  // so that text is single-byte characters only
  // for this example script, generate the key by applying Cipher to 1st 16/24/32 chars of password; 
  // for real-world applications, a more secure approach would be to hash the password e.g. with SHA-1
  var nBytes = nBits/8;  // no bytes in key
  var pwBytes = new Array(nBytes);
  for (var i=0; i<nBytes; i++) pwBytes[i] = encodeUTF8(password).charCodeAt(i);
  var pwKeySchedule = KeyExpansion(pwBytes);
  var key = Cipher(pwBytes, pwBytes, pwKeySchedule);

  // initialise counter block (NIST SP800-38A §B.2): millisecond time-stamp for nonce in 1st 8 bytes,
  // block counter in 2nd 8 bytes
  var blockSize = 16;  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
  var counterBlock = new Array(blockSize);  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
  //var nonce = (new Date()).getTime();  // milliseconds since 1-Jan-1970
  var nonce = 666;  // milliseconds since 1-Jan-1970

  // encode nonce in two stages to cater for JavaScript 32-bit limit on bitwise ops
  for (var i=0; i<4; i++) counterBlock[i] = (nonce >>> i*8) & 0xff;
  for (var i=0; i<4; i++) counterBlock[i+4] = (nonce/0x100000000 >>> i*8) & 0xff; 

  // generate key schedule - an expansion of the key into distinct Key Rounds for each round
  var keySchedule = KeyExpansion(key);

  var blockCount = Math.ceil(plaintext.length/blockSize);
  var ciphertext = 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)
    // again done in two stages for 32-bit ops
    for (var c=0; c<4; c++) counterBlock[15-c] = (b >>> c*8) & 0xff;
    for (var c=0; c<4; c++) counterBlock[15-c-4] = (b/0x100000000 >>> c*8)

    var cipherCntr = Cipher(counterBlock, key, keySchedule);  // -- encrypt counter block --
    
    // calculate length of final block:
    var blockLength = b<blockCount-1 ? blockSize : (plaintext.length-1)%blockSize+1;

    var ct = '';
    for (var i=0; i<blockLength; i++) {  // -- xor plaintext with ciphered counter byte-by-byte --
      var plaintextByte = plaintext.charCodeAt(b*blockSize+i);
      var cipherByte = plaintextByte ^ cipherCntr[i];
      ct += String.fromCharCode(cipherByte);
    }
    // ct is now ciphertext for this block

   // ciphertext[b] = escCtrlChars(ct);  // escape troublesome characters in ciphertext
      ciphertext[b] = encodeBase64(ct);  // escape troublesome characters in ciphertext
  }

  // convert the nonce to a string to go on the front of the ciphertext
  var ctrTxt = '';
  for (var i=0; i<8; i++) ctrTxt += String.fromCharCode(counterBlock[i]);
  //ctrTxt = escCtrlChars(ctrTxt);
  ctrTxt = encodeBase64(ctrTxt);
  // use '-' to separate blocks, use Array.join to concatenate arrays of strings for efficiency
  return ctrTxt + '-' + ciphertext.join('-');
}


/* 
 * Use AES to decrypt 'ciphertext' with 'password' using 'nBits' key, in Counter mode of operation
 *
 *   for each block
 *   - outputblock = cipher(counter, key)
 *   - cipherblock = plaintext xor outputblock
 */
function AESDecryptCtr(ciphertext, password, nBits) {
  if (!(nBits==128 || nBits==192 || nBits==256)) return '';  // standard allows 128/192/256 bit keys
  
  var nBytes = nBits/8;  // no bytes in key
  var pwBytes = new Array(nBytes);
  for (var i=0; i<nBytes; i++) pwBytes[i] = encodeUTF8(password).charCodeAt(i);
  var pwKeySchedule = KeyExpansion(pwBytes);
  var key = Cipher(pwBytes, pwBytes, pwKeySchedule);

  var keySchedule = KeyExpansion(key);

  ciphertext = ciphertext.split('-');  // split ciphertext into array of block-length strings 

  // recover nonce from 1st element of ciphertext
  var blockSize = 16;  // block size fixed at 16 bytes / 128 bits (Nb=4) for AES
  var counterBlock = new Array(blockSize);
  //var ctrTxt = unescCtrlChars(ciphertext[0]);
  var ctrTxt = decodeBase64(ciphertext[0]);
  for (var i=0; i<8; i++) counterBlock[i] = ctrTxt.charCodeAt(i);

  var plaintext = new Array(ciphertext.length-1);

  for (var b=1; b<ciphertext.length; 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-1) >>> c*8) & 0xff;
    for (var c=0; c<4; c++) counterBlock[15-c-4] = ((b/0x100000000-1) >>> c*8) & 0xff;

    var cipherCntr = Cipher(counterBlock, key, keySchedule);  // encrypt counter block

    //ciphertext[b] = unescCtrlChars(ciphertext[b]);
    ciphertext[b] = decodeBase64(ciphertext[b]);

    var pt = '';
    for (var i=0; i<ciphertext[b].length; i++) {  // -- xor plaintext with ciphered counter byte-by-byte --
      var ciphertextByte = ciphertext[b].charCodeAt(i);
      var plaintextByte = ciphertextByte ^ cipherCntr[i];
      pt += String.fromCharCode(plaintextByte);
    }
    // pt is now plaintext for this block

    plaintext[b-1] = pt;  // b-1 'cos no initial nonce block in plaintext
  }

  return decodeUTF8(plaintext.join(''));
}

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

function encodeUTF8(str) {  // encode multi-byte string into utf-8 multiple single-byte characters 
  str = str.replace(
      /[\u0080-\u07ff]/g,  // U+0080 - U+07FF = 2-byte chars
      function(c) { 
        var cc = c.charCodeAt(0);
        return String.fromCharCode(0xc0 | cc>>6, 0x80 | cc&0x3f); }
    );
  str = str.replace(
      /[\u0800-\uffff]/g,  // U+0800 - U+FFFF = 3-byte chars
      function(c) { 
        var cc = c.charCodeAt(0); 
        return String.fromCharCode(0xe0 | cc>>12, 0x80 | cc>>6&0x3F, 0x80 | cc&0x3f); }
    );
  return str;
}

function decodeUTF8(str) {  // decode utf-8 encoded string back into multi-byte characters
  str = str.replace(
      /[\u00c0-\u00df][\u0080-\u00bf]/g,                 // 2-byte chars
      function(c) { 
        var cc = (c.charCodeAt(0)&0x1f)<<6 | c.charCodeAt(1)&0x3f;
        return String.fromCharCode(cc); }
    );
  str = str.replace(
      /[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g,  // 3-byte chars
      function(c) { 
        var cc = (c.charCodeAt(0)&0x0f)<<12 | (c.charCodeAt(1)&0x3f<<6) | c.charCodeAt(2)&0x3f; 
        return String.fromCharCode(cc); }
    );
  return str;
}

function escCtrlChars(str) {  // escape control chars which might cause problems handling ciphertext
  return str.replace(/[\0\t\n\v\f\r\xa0!-]/g, function(c) { return '!' + c.charCodeAt(0) + '!'; });
}  // \xa0 to cater for bug in Firefox; include '-' to leave it free for use as a block marker

function unescCtrlChars(str) {  // unescape potentially problematic control characters
  return str.replace(/!\d\d?\d?!/g, function(c) { return String.fromCharCode(c.slice(1,-1)); });
}

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

/*
 * if escCtrlChars()/unescCtrlChars() still gives problems, use encodeBase64()/decodeBase64() instead
 */
var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

function encodeBase64(str) {  // http://tools.ietf.org/html/rfc4648
   var o1, o2, o3, h1, h2, h3, h4, bits, i=0, enc='';
   
   str = encodeUTF8(str);  // encode multi-byte chars into UTF-8 for byte-array

   do {  // pack three octets into four hexets
      o1 = str.charCodeAt(i++);
      o2 = str.charCodeAt(i++);
      o3 = str.charCodeAt(i++);
      
      bits = o1<<16 | o2<<8 | o3;
      
      h1 = bits>>18 & 0x3f;
      h2 = bits>>12 & 0x3f;
      h3 = bits>>6 & 0x3f;
      h4 = bits & 0x3f;
      
      // end of string? index to '=' in b64
      if (isNaN(o3)) h4 = 64;
      if (isNaN(o2)) h3 = 64;
      
      // use hexets to index into b64, and append result to encoded string
      enc += b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
   } while (i < str.length);
   
   return enc;
}

function decodeBase64(str) {
   var o1, o2, o3, h1, h2, h3, h4, bits, i=0, enc='';

   do {  // unpack four hexets into three octets using index points in b64
      h1 = b64.indexOf(str.charAt(i++));
      h2 = b64.indexOf(str.charAt(i++));
      h3 = b64.indexOf(str.charAt(i++));
      h4 = b64.indexOf(str.charAt(i++));
      
      bits = h1<<18 | h2<<12 | h3<<6 | h4;
      
      o1 = bits>>16 & 0xff;
      o2 = bits>>8 & 0xff;
      o3 = bits & 0xff;
      
      if (h3 == 64)      enc += String.fromCharCode(o1);
      else if (h4 == 64) enc += String.fromCharCode(o1, o2);
      else               enc += String.fromCharCode(o1, o2, o3);
   } while (i < str.length);

   return decodeUTF8(enc);  // decode UTF-8 byte-array back to Unicode
}


function byteArrayToHexStr(b) {  // convert byte array to hex string for displaying test vectors
  var s = '';
  for (var i=0; i<b.length; i++) s += b[i].toString(16) + ' ';
  return s;
}

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