JavascriptMD4_基础知识
2020-11-27
来源：星星旅游
/*
* A JavaScript implementation of the RSA Data Security, Inc. MD4 Message
* Digest Algorithm, as defined in RFC 1320.
* Version 2.1 Copyright (C) Jerrad Pierce, Paul Johnston 1999 - 2002.
* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
* Distributed under the BSD License
* See http://pajhome.org.uk/crypt/md5 for more info.
*/
/*
* Configurable variables. You may need to tweak these to be compatible with
* the server-side, but the defaults work in most cases.
*/
var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */
var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance */
var chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */
/*
* These are the functions you'll usually want to call
*/
function hex_md4(s){ return binl2hex(core_md4(str2binl(s), s.length * chrsz));}
function b64_md4(s){ return binl2b64(core_md4(str2binl(s), s.length * chrsz));}
function str_md4(s){ return binl2str(core_md4(str2binl(s), s.length * chrsz));}
function hex_hmac_md4(key, data) { return binl2hex(core_hmac_md4(key, data)); }
function b64_hmac_md4(key, data) { return binl2b64(core_hmac_md4(key, data)); }
function str_hmac_md4(key, data) { return binl2str(core_hmac_md4(key, data)); }
/*
* Perform a simple self-test to see if the VM is working
*/
function md4_vm_test()
{
return hex_md4("abc") == "a448017aaf21d8525fc10ae87aa6729d";
}
/*
* Calculate the MD4 of an array of little-endian words, and a bit length
*/
function core_md4(x, len)
{
/* append padding */
x[len >> 5] |= 0x80 << (len % 32);
x[(((len + 64) >>> 9) << 4) + 14] = len;
var a = 1732584193;
var b = -271733879;
var c = -1732584194;
var d = 271733878;
for(var i = 0; i < x.length; i += 16)
{
var olda = a;
var oldb = b;
var oldc = c;
var oldd = d;
a = md4_ff(a, b, c, d, x[i+ 0], 3 );
d = md4_ff(d, a, b, c, x[i+ 1], 7 );
c = md4_ff(c, d, a, b, x[i+ 2], 11);
b = md4_ff(b, c, d, a, x[i+ 3], 19);
a = md4_ff(a, b, c, d, x[i+ 4], 3 );
d = md4_ff(d, a, b, c, x[i+ 5], 7 );
c = md4_ff(c, d, a, b, x[i+ 6], 11);
b = md4_ff(b, c, d, a, x[i+ 7], 19);
a = md4_ff(a, b, c, d, x[i+ 8], 3 );
d = md4_ff(d, a, b, c, x[i+ 9], 7 );
c = md4_ff(c, d, a, b, x[i+10], 11);
b = md4_ff(b, c, d, a, x[i+11], 19);
a = md4_ff(a, b, c, d, x[i+12], 3 );
d = md4_ff(d, a, b, c, x[i+13], 7 );
c = md4_ff(c, d, a, b, x[i+14], 11);
b = md4_ff(b, c, d, a, x[i+15], 19);
a = md4_gg(a, b, c, d, x[i+ 0], 3 );
d = md4_gg(d, a, b, c, x[i+ 4], 5 );
c = md4_gg(c, d, a, b, x[i+ 8], 9 );
b = md4_gg(b, c, d, a, x[i+12], 13);
a = md4_gg(a, b, c, d, x[i+ 1], 3 );
d = md4_gg(d, a, b, c, x[i+ 5], 5 );
c = md4_gg(c, d, a, b, x[i+ 9], 9 );
b = md4_gg(b, c, d, a, x[i+13], 13);
a = md4_gg(a, b, c, d, x[i+ 2], 3 );
d = md4_gg(d, a, b, c, x[i+ 6], 5 );
c = md4_gg(c, d, a, b, x[i+10], 9 );
b = md4_gg(b, c, d, a, x[i+14], 13);
a = md4_gg(a, b, c, d, x[i+ 3], 3 );
d = md4_gg(d, a, b, c, x[i+ 7], 5 );
c = md4_gg(c, d, a, b, x[i+11], 9 );
b = md4_gg(b, c, d, a, x[i+15], 13);
a = md4_hh(a, b, c, d, x[i+ 0], 3 );
d = md4_hh(d, a, b, c, x[i+ 8], 9 );
c = md4_hh(c, d, a, b, x[i+ 4], 11);
b = md4_hh(b, c, d, a, x[i+12], 15);
a = md4_hh(a, b, c, d, x[i+ 2], 3 );
d = md4_hh(d, a, b, c, x[i+10], 9 );
c = md4_hh(c, d, a, b, x[i+ 6], 11);
b = md4_hh(b, c, d, a, x[i+14], 15);
a = md4_hh(a, b, c, d, x[i+ 1], 3 );
d = md4_hh(d, a, b, c, x[i+ 9], 9 );
c = md4_hh(c, d, a, b, x[i+ 5], 11);
b = md4_hh(b, c, d, a, x[i+13], 15);
a = md4_hh(a, b, c, d, x[i+ 3], 3 );
d = md4_hh(d, a, b, c, x[i+11], 9 );
c = md4_hh(c, d, a, b, x[i+ 7], 11);
b = md4_hh(b, c, d, a, x[i+15], 15);
a = safe_add(a, olda);
b = safe_add(b, oldb);
c = safe_add(c, oldc);
d = safe_add(d, oldd);
}
return Array(a, b, c, d);
}
/*
* These functions implement the basic operation for each round of the
* algorithm.
*/
function md4_cmn(q, a, b, x, s, t)
{
return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}
function md4_ff(a, b, c, d, x, s)
{
return md4_cmn((b & c) | ((~b) & d), a, 0, x, s, 0);
}
function md4_gg(a, b, c, d, x, s)
{
return md4_cmn((b & c) | (b & d) | (c & d), a, 0, x, s, 1518500249);
}
function md4_hh(a, b, c, d, x, s)
{
return md4_cmn(b ^ c ^ d, a, 0, x, s, 1859775393);
}
/*
* Calculate the HMAC-MD4, of a key and some data
*/
function core_hmac_md4(key, data)
{
var bkey = str2binl(key);
if(bkey.length > 16) bkey = core_md4(bkey, key.length * chrsz);
var ipad = Array(16), opad = Array(16);
for(var i = 0; i < 16; i++)
{
ipad[i] = bkey[i] ^ 0x36363636;
opad[i] = bkey[i] ^ 0x5C5C5C5C;
}
var hash = core_md4(ipad.concat(str2binl(data)), 512 + data.length * chrsz);
return core_md4(opad.concat(hash), 512 + 128);
}
/*
* Add integers, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters.
*/
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.
*/
function rol(num, cnt)
{
return (num << cnt) | (num >>> (32 - cnt));
}
/*
* Convert a string to an array of little-endian words
* If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
*/
function str2binl(str)
{
var bin = Array();
var mask = (1 << chrsz) - 1;
for(var i = 0; i < str.length * chrsz; i += chrsz)
bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32);
return bin;
}
/*
* Convert an array of little-endian words to a string
*/
function binl2str(bin)
{
var str = "";
var mask = (1 << chrsz) - 1;
for(var i = 0; i < bin.length * 32; i += chrsz)
str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);
return str;
}
/*
* Convert an array of little-endian words to a hex string.
*/
function binl2hex(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] >> ((i%4)*8+4)) & 0xF) +
hex_tab.charAt((binarray[i>>2] >> ((i%4)*8 )) & 0xF);
}
return str;
}
/*
* Convert an array of little-endian words to a base-64 string
*/
function binl2b64(binarray)
{
var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var str = "";
for(var i = 0; i < binarray.length * 4; i += 3)
{
var triplet = (((binarray[i >> 2] >> 8 * ( i %4)) & 0xFF) << 16)
| (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )
| ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF);
for(var j = 0; j < 4; j++)
{
if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
}
}
return str;
}