/* xxtea.js
*
* Author:       Ma Bingyao <andot@ujn.edu.cn>
* Copyright:    CoolCode.CN
* Version:      1.4
* LastModified: 2006-07-23
* This library is free.  You can redistribute it and/or modify it.
* http://www.coolcode.cn/?p=128
*/
 
function long2str(v, w) {
    var vl = v.length;
    var sl = v[vl - 1] & 0xffffffff;
    for (var i = 0; i < vl; i++)
    {
        v[i] = String.fromCharCode(v[i] & 0xff,
                                   v[i] >>> 8 & 0xff,
                                   v[i] >>> 16 & 0xff, 
                                   v[i] >>> 24 & 0xff);
    }
    if (w) {
        return v.join('').substring(0, sl);
    }
    else {
        return v.join('');
    }
}
 
function str2long(s, w) {
    var len = s.length;
    var v = [];
    for (var i = 0; i < len; i += 4)
    {
        v[i >> 2] = s.charCodeAt(i)
                  | s.charCodeAt(i + 1) << 8
                  | s.charCodeAt(i + 2) << 16
                  | s.charCodeAt(i + 3) << 24;
    }
    if (w) {
        v[v.length] = len;
    }
    return v;
}
 
function xxtea_encrypt(str, key) {
    if (str == "") {
        return "";
    }
    var v = str2long(str, true);
    var k = str2long(key, false);
    if (k.length < 4)
    {
        k.length = 4;
    }
    var n = v.length - 1;
 
    var z = v[n], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52 / (n + 1)), sum = 0;
    while (0 < q--) {
        sum = sum + delta & 0xffffffff;
        e = sum >>> 2 & 3;
        for (var p = 0; p < n; p++) {
            y = v[p + 1];
            mx = (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
            z = v[p] = v[p] + mx & 0xffffffff;
        }
        y = v[0];
        mx = (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
        z = v[n] = v[n] + mx & 0xffffffff;
    }
 
    return long2str(v, false);
}
 
function xxtea_decrypt(str, key) {
    if (str == "") {
        return "";
    }
    var v = str2long(str, false);
    var k = str2long(key, false);
    if (k.length < 4)
    {
        k.length = 4;
    }
    var n = v.length - 1;
 
    var z = v[n - 1], y = v[0], delta = 0x9E3779B9;
    var mx, e, q = Math.floor(6 + 52 / (n + 1)), sum = q * delta & 0xffffffff;
    while (sum != 0) {
        e = sum >>> 2 & 3;
        for (var p = n; p > 0; p--) {
            z = v[p - 1];
            mx = (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
            y = v[p] = v[p] - mx & 0xffffffff;
        }
        z = v[n];
        mx = (z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4) ^ (sum ^ y) + (k[p & 3 ^ e] ^ z);
        y = v[0] = v[0] - mx & 0xffffffff;
        sum = sum - delta & 0xffffffff;
    }
 
    return long2str(v, true);
}

/* utf.js - UTF-8 <=> UTF-16 convertion
 *
 * Copyright (C) 1999 Masanao Izumo <iz@onicos.co.jp> & 2006 Ma Bingyao <andot@ujn.edu.cn>
 * Version: 1.1
 * LastModified: Feb 17 2006
 * This library is free.  You can redistribute it and/or modify it.
 */

/*
 * Interfaces:
 * utf8 = utf16to8(utf16);
 * utf16 = utf16to8(utf8);
 */

function utf16to8(str) {
    var out, i, len, c;

    out = [];
    len = str.length;
    for(i = 0; i < len; i++) {
	    c = str.charCodeAt(i);
	    if ((c >= 0x0001) && (c <= 0x007F)) {
	        out[i] = str.charAt(i);
	    } else if (c > 0x07FF) {
	        out[i] = String.fromCharCode(0xE0 | ((c >> 12) & 0x0F),
	                                     0x80 | ((c >>  6) & 0x3F),
	                                     0x80 | ((c >>  0) & 0x3F));
	    } else {
	        out[i] = String.fromCharCode(0xC0 | ((c >>  6) & 0x1F),
	                                     0x80 | ((c >>  0) & 0x3F));
	    }
    }
    return out.join('');
}

function utf8to16(str) {
    var out, i, len, c;
    var char2, char3;

    out = [];
    len = str.length;
    i = 0;
    while(i < len) {
	    c = str.charCodeAt(i++);
	    switch(c >> 4)
	    { 
	        case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
	        // 0xxxxxxx
	        out[out.length] = str.charAt(i-1);
	        break;
	        case 12: case 13:
    	    // 110x xxxx   10xx xxxx
	        char2 = str.charCodeAt(i++);
	        out[out.length] = String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
    	    break;
            case 14:
    	    // 1110 xxxx  10xx xxxx  10xx xxxx
	        char2 = str.charCodeAt(i++);
	        char3 = str.charCodeAt(i++);
    	    out[out.length] = String.fromCharCode(((c & 0x0F) << 12) |
	    	    ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));
	        break;
    	}
    }

    return out.join('');
}


// see http://rumkin.com/tools/compression/base64.php

// This code was written by Tyler Akins and has been placed in the
// public domain.  It would be nice if you left this header intact.
// Base64 code from Tyler Akins -- http://rumkin.com

var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

function encode64(input) {
   var output = "";
   var chr1, chr2, chr3;
   var enc1, enc2, enc3, enc4;
   var i = 0;

   do {
      chr1 = input.charCodeAt(i++);
      chr2 = input.charCodeAt(i++);
      chr3 = input.charCodeAt(i++);

      enc1 = chr1 >> 2;
      enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
      enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
      enc4 = chr3 & 63;

      if (isNaN(chr2)) {
         enc3 = enc4 = 64;
      } else if (isNaN(chr3)) {
         enc4 = 64;
      }

      output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + 
         keyStr.charAt(enc3) + keyStr.charAt(enc4);
   } while (i < input.length);
   
   return output;
}

function decode64(input) {
   var output = "";
   var chr1, chr2, chr3;
   var enc1, enc2, enc3, enc4;
   var i = 0;

   // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
   input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

   do {
      enc1 = keyStr.indexOf(input.charAt(i++));
      enc2 = keyStr.indexOf(input.charAt(i++));
      enc3 = keyStr.indexOf(input.charAt(i++));
      enc4 = keyStr.indexOf(input.charAt(i++));

      chr1 = (enc1 << 2) | (enc2 >> 4);
      chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
      chr3 = ((enc3 & 3) << 6) | enc4;

      output = output + String.fromCharCode(chr1);

      if (enc3 != 64) {
         output = output + String.fromCharCode(chr2);
      }
      if (enc4 != 64) {
         output = output + String.fromCharCode(chr3);
      }
   } while (i < input.length);

   return output;
}