[MD5加密的javascript实现例子

/* MD5 Message-Digest Algorithm - JavaScript
' MODIFICATION HISTORY:
' 1.0 16-Feb-2001 - Phil Fresle (sales@frez.co.uk) - Initial Version (VB/ASP code)
' 1.0 21-Feb-2001 - Enrico Mosanghini (erik504@yahoo.com) - JavaScript porting
*/
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;
}