黑色海岸线论坛 - Powered by Discuz! Board

<html>
<head>
<script language="JavaScript">
/*
* A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined in FIPS PUB 180-1
* By lizq
* 2006-11-11
*/
/*
* Configurable variables.
*/
var hexcase = 0; /**//* hex output format. 0 - lowercase; 1 - uppercase */
var chrsz = 8; /**//* bits per input character. 8 - ASCII; 16 - Unicode */
/**//*
* The main function to calculate message digest
*/
function hex_sha1(s)
{
return binb2hex(core_sha1(AlignSHA1(s)));
}
/**//*
* Perform a simple self-test to see if the VM is working
*/
function sha1_vm_test()
{
return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";
}
/**//*
* Calculate the SHA-1 of an array of big-endian words, and a bit length
*/
function core_sha1(blockArray)
{
var x = blockArray; //append padding
var w = Array(80);
var a = 1732584193;
var b = -271733879;
var c = -1732584194;
var d = 271733878;
var e = -1009589776;
for(var i = 0; i < x.length; i += 16) //每次处理512位 16*32
{
var olda = a;
var oldb = b;
var oldc = c;
var oldd = d;
var olde = e;
for(var j = 0; j < 80; j++) //对每个512位进行80步操作
{
if(j < 16) w[j] = x[i + j];
else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
safe_add(safe_add(e, w[j]), sha1_kt(j)));
e = d;
d = c;
c = rol(b, 30);
b = a;
a = t;
}
a = safe_add(a, olda);
b = safe_add(b, oldb);
c = safe_add(c, oldc);
d = safe_add(d, oldd);
e = safe_add(e, olde);
}
return new Array(a, b, c, d, e);
}
/**//*
* Perform the appropriate triplet combination function for the current iteration
* 返回对应F函数的值
*/
function sha1_ft(t, b, c, d)
{
if(t < 20) return (b & c) | ((~b) & d);
if(t < 40) return b ^ c ^ d;
if(t < 60) return (b & c) | (b & d) | (c & d);
return b ^ c ^ d; //t<80
}
/**//*
* Determine the appropriate additive constant for the current iteration
* 返回对应的Kt值
*/
function sha1_kt(t)
{
return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 :
(t < 60) ? -1894007588 : -899497514;
}
/**//*
* Add integers, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters.
* 将32位数拆成高16位和低16位分别进行相加，从而实现 MOD 2^32 的加法
*/
function safe_add(x, y)
{
var lsw = (x & 0xFFFF) + (y & 0xFFFF);
var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}
/**//*
* Bitwise rotate a 32-bit number to the left.
* 32位二进制数循环左移
*/
function rol(num, cnt)
{
return (num << cnt) | (num >>> (32 - cnt));
}
/**//*
* The standard SHA1 needs the input string to fit into a block
* This function align the input string to meet the requirement
*/
function AlignSHA1(str){
var nblk=((str.length+8)>>6)+1, blks=new Array(nblk*16);
for(var i=0;i<nblk*16;i++)blks=0;
for(i=0;i<str.length;i++)
blks[i>>2]|=str.charCodeAt(i)<<(24-(i&3)*8);
blks[i>>2]|=0x80<<(24-(i&3)*8);
blks[nblk*16-1]=str.length*8;
return blks;
}
/**//*
* Convert an array of big-endian words to a hex string.
*/
function binb2hex(binarray)
{
var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
var str = "";
for(var i = 0; i < binarray.length * 4; i++)
{
str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +
hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8 )) & 0xF);
}
return str;
}
/**//*
* calculate MessageDigest accord to source message that inputted
*/
function calcDigest()
{
var digestM = hex_sha1(document.SHAForm.SourceMessage.value);
document.SHAForm.MessageDigest.value = digestM;
}
</script>
<title>SHA-1算法JavaScript实现</title>
</head>
<body>
<center>
<BR/>
<BR/>
<H2>SHA-1算法JavaScript实现</H2>
<BR/>
<form name="SHAForm">
　源消息：<input type="text" name="SourceMessage" size=40><BR>
消息摘要：<input type="text" name="MessageDigest" size=40>
<P>
<input type="button" value="计算消息摘要" onclick="calcDigest()">
</form>
</body>
</html>

复制代码