js md5

来源：http://www.oschina.net/code/snippet_12_8927

/**
*
*  MD5 (Message-Digest Algorithm)
*  http://www.webtoolkit.info/
*
**/
  
var MD5 = function (string) {
  
    function RotateLeft(lValue, iShiftBits) {
        return (lValue<>>(32-iShiftBits));
    }
  
    function AddUnsigned(lX,lY) {
        var lX4,lY4,lX8,lY8,lResult;
        lX8 = (lX & 0x80000000);
        lY8 = (lY & 0x80000000);
        lX4 = (lX & 0x40000000);
        lY4 = (lY & 0x40000000);
        lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF);
        if (lX4 & lY4) {
            return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
        }
        if (lX4 | lY4) {
            if (lResult & 0x40000000) {
                return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
            } else {
                return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
            }
        } else {
            return (lResult ^ lX8 ^ lY8);
        }
    }
  
    function F(x,y,z) { return (x & y) | ((~x) & z); }
    function G(x,y,z) { return (x & z) | (y & (~z)); }
    function H(x,y,z) { return (x ^ y ^ z); }
    function I(x,y,z) { return (y ^ (x | (~z))); }
  
    function FF(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
  
    function GG(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
  
    function HH(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
  
    function II(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
  
    function ConvertToWordArray(string) {
        var lWordCount;
        var lMessageLength = string.length;
        var lNumberOfWords_temp1=lMessageLength + 8;
        var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64;
        var lNumberOfWords = (lNumberOfWords_temp2+1)*16;
        var lWordArray=Array(lNumberOfWords-1);
        var lBytePosition = 0;
        var lByteCount = 0;
        while ( lByteCount < lMessageLength ) {
            lWordCount = (lByteCount-(lByteCount % 4))/4;
            lBytePosition = (lByteCount % 4)*8;
            lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount)<>>29;
        return lWordArray;
    };
  
    function WordToHex(lValue) {
        var WordToHexValue="",WordToHexValue_temp="",lByte,lCount;
        for (lCount = 0;lCount<=3;lCount++) {
            lByte = (lValue>>>(lCount*8)) & 255;
            WordToHexValue_temp = "0" + lByte.toString(16);
            WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2);
        }
        return WordToHexValue;
    };
  
    function Utf8Encode(string) {
        string = string.replace(/\r\n/g,"\n");
        var utftext = "";
  
        for (var n = 0; n < string.length; n++) {
  
            var c = string.charCodeAt(n);
  
            if (c < 128) {
                utftext += String.fromCharCode(c);
            }
            else if((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            }
            else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }
  
        }
  
        return utftext;
    };
  
    var x=Array();
    var k,AA,BB,CC,DD,a,b,c,d;
    var S11=7, S12=12, S13=17, S14=22;
    var S21=5, S22=9 , S23=14, S24=20;
    var S31=4, S32=11, S33=16, S34=23;
    var S41=6, S42=10, S43=15, S44=21;
  
    string = Utf8Encode(string);
  
    x = ConvertToWordArray(string);
  
    a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;
  
    for (k=0;k