非常流行的JS的md加密办法
var hexcase = ; /* hex output format. - lowercase; - uppercase */
var bpad = ""; /* base- pad character. "=" for strict RFC compliance */
var chrsz = ; /* bits per input character. - ASCII; - Unicode */
/*
* These are the functions you'll usually want to call
* They take string arguments and return either hex or base- encoded strings
*/
function hex_md(s){ return binlhex(core_md(strbinl(s),s.length * chrsz));}
function b_md(s){ return binlb(core_md(strbinl(s),s.length * chrsz));}
function hex_hmac_md(key,data) { return binlhex(core_hmac_md(key,data)); }
function b_hmac_md(key,data) { return binlb(core_hmac_md(key,data)); }
/* Backwards compatibility - same as hex_md() */
function calcMD(s){ return binlhex(core_md(strbinl(s),s.length * chrsz));}
/*
* Perform a simple self-test to see if the VM is working
*/
function md_vm_test()
{
return hex_md("abc") == "cdfbdfdef";
}
/*
* Calculate the MD of an array of little-endian words,and a bit length
*/
function core_md(x,len)
{
/* append padding */
x[len >> ] |= x << ((len) % );
x[(((len + ) >>> ) << ) + ] = len;
var a = ;
var b = -;
var c = -;
var d = ;
for(var i = ; i < x.length; i += )
{
var olda = a;
var oldb = b;
var oldc = c;
var oldd = d;
a = md_ff(a,b,c,d,x[i+ ],-);
d = md_ff(d,a,-);
c = md_ff(c,);
b = md_ff(b,-);
a = md_ff(a,);
c = md_ff(c,-);
b = md_ff(b,);
d = md_ff(d,x[i+],);
a = md_gg(a,-);
d = md_gg(d,-);
c = md_gg(c,);
b = md_gg(b,-);
a = md_gg(a,);
c = md_gg(c,-);
b = md_gg(b,);
d = md_gg(d,-);
a = md_hh(a,-);
d = md_hh(d,-);
c = md_hh(c,);
b = md_hh(b,);
c = md_hh(c,-);
b = md_hh(b,);
d = md_hh(d,);
a = md_hh(a,-);
a = md_ii(a,-);
d = md_ii(d,);
c = md_ii(c,-);
b = md_ii(b,);
d = md_ii(d,-);
c = md_ii(c,);
a = md_ii(a,);
b = md_ii(b,-);
a = safe_add(a,olda);
b = safe_add(b,oldb);
c = safe_add(c,oldc);
d = safe_add(d,oldd);
}
return Array(a,d);
}
/*
* These functions implement the four basic operations the algorithm uses.
*/
function md_cmn(q,x,s,t)
{
return safe_add(bit_rol(safe_add(safe_add(a,q),safe_add(x,t)),s),b);
}
function md_ff(a,t)
{
return md_cmn((b & c) | ((~b) & d),t);
}
function md_gg(a,t)
{
return md_cmn((b & d) | (c & (~d)),t);
}
function md_hh(a,t)
{
return md_cmn(b ^ c ^ d,t);
}
function md_ii(a,t)
{
return md_cmn(c ^ (b | (~d)),t);
}
/*
* Calculate the HMAC-MD,of a key and some data
*/
function core_hmac_md(key,data)
{
var bkey = strbinl(key);
if(bkey.length > ) bkey = core_md(bkey,key.length * chrsz);
var ipad = Array(),opad = Array();
for(var i = ; i < ; i++)
{
ipad[i] = bkey[i] ^ x;
opad[i] = bkey[i] ^ xCCCC;
}
var hash = core_md(ipad.concat(strbinl(data)),+ data.length * chrsz);
return core_md(opad.concat(hash),+ );
}
/*
* Add integers,wrapping at ^. This uses -bit operations internally
* to work around bugs in some JS interpreters.
*/
function safe_add(x,y)
{
var lsw = (x & xFFFF) + (y & xFFFF);
var msw = (x >> ) + (y >> ) + (lsw >> );
return (msw << ) | (lsw & xFFFF);
}
/*
* Bitwise rotate a -bit number to the left.
*/
function bit_rol(num,cnt)
{
return (num << cnt) | (num >>> ( - cnt));
}
/*
* Convert a string to an array of little-endian words
* If chrsz is ASCII,characters > have their hi-byte silently ignored.
*/
function strbinl(str)
{
var bin = Array();
var mask = ( << chrsz) - ;
for(var i = ; i < str.length * chrsz; i += chrsz)
bin[i>>] |= (str.charCodeAt(i / chrsz) & mask) << (i%);
return bin;
}
/*
* Convert an array of little-endian words to a hex string.
*/
function binlhex(binarray)
{
var hex_tab = hexcase ? "ABCDEF" : "abcdef";
var str = "";
for(var i = ; i < binarray.length * ; i++)
{
str += hex_tab.charAt((binarray[i>>] >> ((i%)*+)) & xF) +
hex_tab.charAt((binarray[i>>] >> ((i%)* )) & xF);
}
return str;
}
/*
* Convert an array of little-endian words to a base- string
*/
function binlb(binarray)
{
var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/";
var str = "";
for(var i = ; i < binarray.length * ; i += )
{
var triplet = (((binarray[i >> ] >> * ( i %)) & xFF) << )
| (((binarray[i+ >> ] >> * ((i+)%)) & xFF) << )
| ((binarray[i+ >> ] >> * ((i+)%)) & xFF);
for(var j = ; j < ; j++)
{
if(i * + j * > binarray.length * ) str += bpad;
else str += tab.charAt((triplet >> *(-j)) & xF);
}
}
return str;
}
