javascript版MD5加密实现

内容来自:http://www.dev26.com/bbs/topic/501

function MD5(sMessage)
{

    function RotateLeft(lValue, iShiftBits) {
        return (lValue<<iShiftBits) | (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(sMessage) {

        var lWordCount;

        var lMessageLength = sMessage.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] | (sMessage.charCodeAt(lByteCount)<<lBytePosition));

            lByteCount++;

        }

        lWordCount = (lByteCount-(lByteCount % 4))/4;

        lBytePosition = (lByteCount % 4)*8;

        lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition);

        lWordArray[lNumberOfWords-2] = lMessageLength<<3;

        lWordArray[lNumberOfWords-1] = lMessageLength>>>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;

    }

    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;

    // Steps 1 and 2.  Append padding bits and length and convert to words

    x = ConvertToWordArray(sMessage);

    // Step 3.  Initialise

    a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;

    // Step 4.  Process the message in 16-word blocks

    for (k=0;k<x.length;k+=16) {

        AA=a; BB=b; CC=c; DD=d;

        a=FF(a,b,c,d,x[k+0], S11,0xD76AA478);

        d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756);

        c=FF(c,d,a,b,x[k+2], S13,0x242070DB);

        b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE);

        a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF);

        d=FF(d,a,b,c,x[k+5], S12,0x4787C62A);

        c=FF(c,d,a,b,x[k+6], S13,0xA8304613);

        b=FF(b,c,d,a,x[k+7], S14,0xFD469501);

        a=FF(a,b,c,d,x[k+8], S11,0x698098D8);

        d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF);

        c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1);

        b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE);

        a=FF(a,b,c,d,x[k+12],S11,0x6B901122);

        d=FF(d,a,b,c,x[k+13],S12,0xFD987193);

        c=FF(c,d,a,b,x[k+14],S13,0xA679438E);

        b=FF(b,c,d,a,x[k+15],S14,0x49B40821);

        a=GG(a,b,c,d,x[k+1], S21,0xF61E2562);

        d=GG(d,a,b,c,x[k+6], S22,0xC040B340);

        c=GG(c,d,a,b,x[k+11],S23,0x265E5A51);

        b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA);

        a=GG(a,b,c,d,x[k+5], S21,0xD62F105D);

        d=GG(d,a,b,c,x[k+10],S22,0x2441453);

        c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681);

        b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8);

        a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6);

        d=GG(d,a,b,c,x[k+14],S22,0xC33707D6);

        c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87);

        b=GG(b,c,d,a,x[k+8], S24,0x455A14ED);

        a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905);

        d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8);

        c=GG(c,d,a,b,x[k+7], S23,0x676F02D9);

        b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A);

        a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942);

        d=HH(d,a,b,c,x[k+8], S32,0x8771F681);

        c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122);

        b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C);

        a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44);

        d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9);

        c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60);

        b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70);

        a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6);

        d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA);

        c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085);

        b=HH(b,c,d,a,x[k+6], S34,0x4881D05);

        a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039);

        d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5);

        c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8);

        b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665);

        a=II(a,b,c,d,x[k+0], S41,0xF4292244);

        d=II(d,a,b,c,x[k+7], S42,0x432AFF97);

        c=II(c,d,a,b,x[k+14],S43,0xAB9423A7);

        b=II(b,c,d,a,x[k+5], S44,0xFC93A039);

        a=II(a,b,c,d,x[k+12],S41,0x655B59C3);

        d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92);

        c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D);

        b=II(b,c,d,a,x[k+1], S44,0x85845DD1);

        a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F);

        d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0);

        c=II(c,d,a,b,x[k+6], S43,0xA3014314);

        b=II(b,c,d,a,x[k+13],S44,0x4E0811A1);

        a=II(a,b,c,d,x[k+4], S41,0xF7537E82);

        d=II(d,a,b,c,x[k+11],S42,0xBD3AF235);

        c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB);

        b=II(b,c,d,a,x[k+9], S44,0xEB86D391);

        a=AddUnsigned(a,AA); b=AddUnsigned(b,BB); c=AddUnsigned(c,CC); d=AddUnsigned(d,DD);

    }

    // Step 5.  Output the 128 bit digest
    var temp= WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);

    //转换大写返回
    return temp.toUpperCase();
}