////////////////////////////////////////////////////////////////////////////////////
//
//		CODIFICACIÓN HEXADECIMAL Y BASE 64
//
//		Hexadecimal:
//		codigo = encode16(texto)
//		texto  = decode16(codigo)
//
//		Base 64:
//		codigo = encode64(texto)
//		texto  = decode64(codigo)
//
////////////////////////////////////////////////////////////////////////////////////

var digitos16 = "0123456789abcdef";

function encode16(str) {
	var len = str.length;
	var ret = "";
	var i;
	for (i=0; i<len; i++) {
		ret += digitos16.charAt((str.charCodeAt(i) >> 4) & 0xF);
		ret += digitos16.charAt(str.charCodeAt(i) & 0xF);
	}
	return ret;
}

function decode16(str) {
	var i;
	var ret = "";
	var len = str.length;
	if (len & 1) {
		len++;
		str += "0";
	}
	for (i=0; i<len; i+=2) {
		var x;
		x = digitos16.indexOf(str.charAt(i).toLowerCase());
		x = (x << 4) | digitos16.indexOf(str.charAt(i + 1).toLowerCase());
		ret += String.fromCharCode(x);
	}
	return ret;
}

var digitos64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

function encode64(buffer) {
	var len = buffer.length * 8;
	var ret = "";
	var i;
	buffer += String.fromCharCode(0);
	for (i = 0; i < len; i += 6) {
		var j = i >> 3;
		var x = (buffer.charCodeAt(j) << 8) | buffer.charCodeAt(j + 1);
		ret += digitos64.charAt(((x << (i & 7)) >> 10) & 0x3F);
	}
	return ret;
}

function decode64(buffer) {
	var len = buffer.length * 6
	var ret = "";
	var i;
	len -= len % 8;
	for (i = 0; i < len; i += 8) {
		var j = Math.floor(i / 6);
		var x = (digitos64.indexOf(buffer.charAt(j)) << 6) | digitos64.indexOf(buffer.charAt(j + 1));
		ret += String.fromCharCode(((x << (i % 6)) >> 4) & 0xFF);
	}
	return ret;
}



////////////////////////////////////////////////////////////////////////////////////
//
//		Encriptación RC4
//
//		texto_encriptado = rc4(clave, texto);
//
////////////////////////////////////////////////////////////////////////////////////

function rc4(clave, str) {
	var i, j, t;
	var k = Array(256);
	var s = Array(256);
	var ret = "";
	for (i = 0; i < 256; i++)
		s[i] = i;
	var len = clave.length;
	for (c = 0; c < len; c++) {
		k[c] = clave.charCodeAt(c);
	}
	j = 0;
	for (i = 0; i < 256; i++) {
		j = (j + s[i] + k[i % len]) & 0xFF;
		t=s[i];
		s[i] = s[j];
		s[j] = t;
	}
	len = str.length;
	i = j = 0;
	for (c = 0; c < len; c++) {
		i = (i + 1) & 0xFF;
		j = (j + s[i]) & 0xFF;
		t=s[i];
		s[i] = s[j];
		s[j] = t;
		t = (t + s[i]) & 0xFF;
		ret += String.fromCharCode(str.charCodeAt(c) ^ s[t]);
	}
	return ret;
}


////////////////////////////////////////////////////////////////////////////////////
//
//		Checksum MD5
//
//		x = md5(str);
//
////////////////////////////////////////////////////////////////////////////////////

/*
 * 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))
}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function cmn(q, a, b, x, s, t)
{
  return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
}
function ff(a, b, c, d, x, s, t)
{
  return cmn((b & c) | ((~b) & d), a, b, x, s, t)
}
function gg(a, b, c, d, x, s, t)
{
  return cmn((b & d) | (c & (~d)), a, b, x, s, t)
}
function hh(a, b, c, d, x, s, t)
{
  return cmn(b ^ c ^ d, a, b, x, s, t)
}
function ii(a, b, c, d, x, s, t)
{
  return cmn(c ^ (b | (~d)), a, b, x, s, t)
}

/*
 * Calculate the MD5 of an array of little-endian words, producing an array
 * of little-endian words.
 */
function coreMD5(x)
{
  var a =  1732584193
  var b = -271733879
  var c = -1732584194
  var d =  271733878

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

    a = ff(a, b, c, d, x[i+ 0], 7 , -680876936)
    d = ff(d, a, b, c, x[i+ 1], 12, -389564586)
    c = ff(c, d, a, b, x[i+ 2], 17,  606105819)
    b = ff(b, c, d, a, x[i+ 3], 22, -1044525330)
    a = ff(a, b, c, d, x[i+ 4], 7 , -176418897)
    d = ff(d, a, b, c, x[i+ 5], 12,  1200080426)
    c = ff(c, d, a, b, x[i+ 6], 17, -1473231341)
    b = ff(b, c, d, a, x[i+ 7], 22, -45705983)
    a = ff(a, b, c, d, x[i+ 8], 7 ,  1770035416)
    d = ff(d, a, b, c, x[i+ 9], 12, -1958414417)
    c = ff(c, d, a, b, x[i+10], 17, -42063)
    b = ff(b, c, d, a, x[i+11], 22, -1990404162)
    a = ff(a, b, c, d, x[i+12], 7 ,  1804603682)
    d = ff(d, a, b, c, x[i+13], 12, -40341101)
    c = ff(c, d, a, b, x[i+14], 17, -1502002290)
    b = ff(b, c, d, a, x[i+15], 22,  1236535329)

    a = gg(a, b, c, d, x[i+ 1], 5 , -165796510)
    d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632)
    c = gg(c, d, a, b, x[i+11], 14,  643717713)
    b = gg(b, c, d, a, x[i+ 0], 20, -373897302)
    a = gg(a, b, c, d, x[i+ 5], 5 , -701558691)
    d = gg(d, a, b, c, x[i+10], 9 ,  38016083)
    c = gg(c, d, a, b, x[i+15], 14, -660478335)
    b = gg(b, c, d, a, x[i+ 4], 20, -405537848)
    a = gg(a, b, c, d, x[i+ 9], 5 ,  568446438)
    d = gg(d, a, b, c, x[i+14], 9 , -1019803690)
    c = gg(c, d, a, b, x[i+ 3], 14, -187363961)
    b = gg(b, c, d, a, x[i+ 8], 20,  1163531501)
    a = gg(a, b, c, d, x[i+13], 5 , -1444681467)
    d = gg(d, a, b, c, x[i+ 2], 9 , -51403784)
    c = gg(c, d, a, b, x[i+ 7], 14,  1735328473)
    b = gg(b, c, d, a, x[i+12], 20, -1926607734)

    a = hh(a, b, c, d, x[i+ 5], 4 , -378558)
    d = hh(d, a, b, c, x[i+ 8], 11, -2022574463)
    c = hh(c, d, a, b, x[i+11], 16,  1839030562)
    b = hh(b, c, d, a, x[i+14], 23, -35309556)
    a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060)
    d = hh(d, a, b, c, x[i+ 4], 11,  1272893353)
    c = hh(c, d, a, b, x[i+ 7], 16, -155497632)
    b = hh(b, c, d, a, x[i+10], 23, -1094730640)
    a = hh(a, b, c, d, x[i+13], 4 ,  681279174)
    d = hh(d, a, b, c, x[i+ 0], 11, -358537222)
    c = hh(c, d, a, b, x[i+ 3], 16, -722521979)
    b = hh(b, c, d, a, x[i+ 6], 23,  76029189)
    a = hh(a, b, c, d, x[i+ 9], 4 , -640364487)
    d = hh(d, a, b, c, x[i+12], 11, -421815835)
    c = hh(c, d, a, b, x[i+15], 16,  530742520)
    b = hh(b, c, d, a, x[i+ 2], 23, -995338651)

    a = ii(a, b, c, d, x[i+ 0], 6 , -198630844)
    d = ii(d, a, b, c, x[i+ 7], 10,  1126891415)
    c = ii(c, d, a, b, x[i+14], 15, -1416354905)
    b = ii(b, c, d, a, x[i+ 5], 21, -57434055)
    a = ii(a, b, c, d, x[i+12], 6 ,  1700485571)
    d = ii(d, a, b, c, x[i+ 3], 10, -1894986606)
    c = ii(c, d, a, b, x[i+10], 15, -1051523)
    b = ii(b, c, d, a, x[i+ 1], 21, -2054922799)
    a = ii(a, b, c, d, x[i+ 8], 6 ,  1873313359)
    d = ii(d, a, b, c, x[i+15], 10, -30611744)
    c = ii(c, d, a, b, x[i+ 6], 15, -1560198380)
    b = ii(b, c, d, a, x[i+13], 21,  1309151649)
    a = ii(a, b, c, d, x[i+ 4], 6 , -145523070)
    d = ii(d, a, b, c, x[i+11], 10, -1120210379)
    c = ii(c, d, a, b, x[i+ 2], 15,  718787259)
    b = ii(b, c, d, a, x[i+ 9], 21, -343485551)

    a = safe_add(a, olda)
    b = safe_add(b, oldb)
    c = safe_add(c, oldc)
    d = safe_add(d, oldd)
  }
  return [a, b, c, d]
}

/*
 * Convert an 8-bit character string to a sequence of 16-word blocks, stored
 * as an array, and append appropriate padding for MD4/5 calculation.
 * If any of the characters are >255, the high byte is silently ignored.
 */
function str2binl(str)
{
  var nblk = ((str.length + 8) >> 6) + 1 // number of 16-word blocks
  var blks = new Array(nblk * 16)
  for(var i = 0; i < nblk * 16; i++) blks[i] = 0
  for(var i = 0; i < str.length; i++)
    blks[i>>2] |= (str.charCodeAt(i) & 0xFF) << ((i%4) * 8)
  blks[i>>2] |= 0x80 << ((i%4) * 8)
  blks[nblk*16-2] = str.length * 8
  return blks
}


///////////////////////////////////////////////////////////
function md5(str) {
	var x = coreMD5(str2binl(str));
	var ret = "";
	var i;
	for (i=0; i<4; i++) {
		ret += String.fromCharCode(x[i] & 0xFF);
		ret += String.fromCharCode((x[i] >> 8) & 0xFF);
		ret += String.fromCharCode((x[i] >> 16) & 0xFF);
		ret += String.fromCharCode((x[i] >> 24) & 0xFF);
	}
	return ret;
}