JavaScript实现的MD5算法完整实例

/**
*
* MD5 (Message-Digest Algorithm)
* http://www.webtoolkit.info/
*
**/
var MD5 = function (string) {
 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(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)<<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;
 };
 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<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);
 }
 var temp = WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);
 return temp.toLowerCase();
}