/*
* A JavaScript implementation of the RSA Data Security, Inc. MD4 Message
* Digest Algorithm, as defined in RFC 1320.
* Copyright (C) Jerrad Pierce 2000. Distributed under the LGPL.
* Updated by Paul Johnston 2000 - 2002.
*/

var hex_chr = "0123456789abcdef";
function rhex(num) {
/* Convert a 32-bit number to a hex string with ls-byte first */
var str = "";
for(var j = 0; j <= 3; j++)
str += hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F) +
hex_chr.charAt((num >> (j * 8)) & 0x0F);
return str;
}

function str2blks_MD5(str) {
/* Convert a string to a sequence of 16-word blocks, stored as an array. */
/* Append padding bits and the length, as described in the MD5 standard. */
/* MD5 here is not a typo - this function is borrowed from the MD5 code. */
var nblk = ((str.length + 8) >> 6) + 1;
var blks = new Array(nblk * 16);
for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
for(var i = 0; i < str.length; i++)
blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);
blks[i >> 2] |= 0x80 << ((i % 4) * 8);
blks[nblk * 16 - 2] = str.length * 8;
return blks;
}

function safe_add(x, y) {
/* Add integers, wrapping at 2^32. This uses 16-bit operations */
/* internally to work around bugs in some JS interpreters. */
var lsw = (x & 0xFFFF) + (y & 0xFFFF);
var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}

function rol(num, cnt) {
/* Bitwise rotate a 32-bit number to the left */
return (num << cnt) | (num >>> (32 - cnt));
}

function cmn(q, a, b, x, s, t) {
/* Implements the basic operation for each round of the algorithm. */
return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}

function F_md4(a, b, c, d, x, s) {
/* Function F of MD4, used during round 1. */
return cmn((b & c) | ((~b) & d), a, 0, x, s, 0);
}

function G_md4(a, b, c, d, x, s) {
/* Function G of MD4, used during round 2. */
return cmn((b & c) | (b & d) | (c & d), a, 0, x, s, 1518500249);
}

function H_md4(a, b, c, d, x, s) {
/* Function H of MD4, used during round 3. */
return cmn(b ^ c ^ d, a, 0, x, s, 1859775393);
}


function calcMD4(str) {
/* Take a string and return the hex representation of its MD4. */
var x = str2blks_MD5(str);
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;

/* Round 1 */
a = F_md4(a, b, c, d, x[i+ 0], 3 );
d = F_md4(d, a, b, c, x[i+ 1], 7 );
c = F_md4(c, d, a, b, x[i+ 2], 11);
b = F_md4(b, c, d, a, x[i+ 3], 19);
a = F_md4(a, b, c, d, x[i+ 4], 3 );
d = F_md4(d, a, b, c, x[i+ 5], 7 );
c = F_md4(c, d, a, b, x[i+ 6], 11);
b = F_md4(b, c, d, a, x[i+ 7], 19);
a = F_md4(a, b, c, d, x[i+ 8], 3 );
d = F_md4(d, a, b, c, x[i+ 9], 7 );
c = F_md4(c, d, a, b, x[i+10], 11);
b = F_md4(b, c, d, a, x[i+11], 19);
a = F_md4(a, b, c, d, x[i+12], 3 );
d = F_md4(d, a, b, c, x[i+13], 7 );
c = F_md4(c, d, a, b, x[i+14], 11);
b = F_md4(b, c, d, a, x[i+15], 19);

/* Round 2 */
a = G_md4(a, b, c, d, x[i+ 0], 3 );
d = G_md4(d, a, b, c, x[i+ 4], 5 );
c = G_md4(c, d, a, b, x[i+ 8], 9 );
b = G_md4(b, c, d, a, x[i+12], 13);
a = G_md4(a, b, c, d, x[i+ 1], 3 );
d = G_md4(d, a, b, c, x[i+ 5], 5 );
c = G_md4(c, d, a, b, x[i+ 9], 9 );
b = G_md4(b, c, d, a, x[i+13], 13);
a = G_md4(a, b, c, d, x[i+ 2], 3 );
d = G_md4(d, a, b, c, x[i+ 6], 5 );
c = G_md4(c, d, a, b, x[i+10], 9 );
b = G_md4(b, c, d, a, x[i+14], 13);
a = G_md4(a, b, c, d, x[i+ 3], 3 );
d = G_md4(d, a, b, c, x[i+ 7], 5 );
c = G_md4(c, d, a, b, x[i+11], 9 );
b = G_md4(b, c, d, a, x[i+15], 13);

/* Round 3 */
a = H_md4(a, b, c, d, x[i+ 0], 3 );
d = H_md4(d, a, b, c, x[i+ 8], 9 );
c = H_md4(c, d, a, b, x[i+ 4], 11);
b = H_md4(b, c, d, a, x[i+12], 15);
a = H_md4(a, b, c, d, x[i+ 2], 3 );
d = H_md4(d, a, b, c, x[i+10], 9 );
c = H_md4(c, d, a, b, x[i+ 6], 11);
b = H_md4(b, c, d, a, x[i+14], 15);
a = H_md4(a, b, c, d, x[i+ 1], 3 );
d = H_md4(d, a, b, c, x[i+ 9], 9 );
c = H_md4(c, d, a, b, x[i+ 5], 11);
b = H_md4(b, c, d, a, x[i+13], 15);
a = H_md4(a, b, c, d, x[i+ 3], 3 );
d = H_md4(d, a, b, c, x[i+11], 9 );
c = H_md4(c, d, a, b, x[i+ 7], 11);
b = H_md4(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 rhex(a) + rhex(b) + rhex(c) + rhex(d);
}