function md5cycle(x, k) {
	var a = x[0], b = x[1], c = x[2], d = x[3];

	a = ff(a, b, c, d, k[0], 7, -680876936);
	d = ff(d, a, b, c, k[1], 12, -389564586);
	c = ff(c, d, a, b, k[2], 17,  606105819);
	b = ff(b, c, d, a, k[3], 22, -1044525330);
	a = ff(a, b, c, d, k[4], 7, -176418897);
	d = ff(d, a, b, c, k[5], 12,  1200080426);
	c = ff(c, d, a, b, k[6], 17, -1473231341);
	b = ff(b, c, d, a, k[7], 22, -45705983);
	a = ff(a, b, c, d, k[8], 7,  1770035416);
	d = ff(d, a, b, c, k[9], 12, -1958414417);
	c = ff(c, d, a, b, k[10], 17, -42063);
	b = ff(b, c, d, a, k[11], 22, -1990404162);
	a = ff(a, b, c, d, k[12], 7,  1804603682);
	d = ff(d, a, b, c, k[13], 12, -40341101);
	c = ff(c, d, a, b, k[14], 17, -1502002290);
	b = ff(b, c, d, a, k[15], 22,  1236535329);

	a = gg(a, b, c, d, k[1], 5, -165796510);
	d = gg(d, a, b, c, k[6], 9, -1069501632);
	c = gg(c, d, a, b, k[11], 14,  643717713);
	b = gg(b, c, d, a, k[0], 20, -373897302);
	a = gg(a, b, c, d, k[5], 5, -701558691);
	d = gg(d, a, b, c, k[10], 9,  38016083);
	c = gg(c, d, a, b, k[15], 14, -660478335);
	b = gg(b, c, d, a, k[4], 20, -405537848);
	a = gg(a, b, c, d, k[9], 5,  568446438);
	d = gg(d, a, b, c, k[14], 9, -1019803690);
	c = gg(c, d, a, b, k[3], 14, -187363961);
	b = gg(b, c, d, a, k[8], 20,  1163531501);
	a = gg(a, b, c, d, k[13], 5, -1444681467);
	d = gg(d, a, b, c, k[2], 9, -51403784);
	c = gg(c, d, a, b, k[7], 14,  1735328473);
	b = gg(b, c, d, a, k[12], 20, -1926607734);

	a = hh(a, b, c, d, k[5], 4, -378558);
	d = hh(d, a, b, c, k[8], 11, -2022574463);
	c = hh(c, d, a, b, k[11], 16,  1839030562);
	b = hh(b, c, d, a, k[14], 23, -35309556);
	a = hh(a, b, c, d, k[1], 4, -1530992060);
	d = hh(d, a, b, c, k[4], 11,  1272893353);
	c = hh(c, d, a, b, k[7], 16, -155497632);
	b = hh(b, c, d, a, k[10], 23, -1094730640);
	a = hh(a, b, c, d, k[13], 4,  681279174);
	d = hh(d, a, b, c, k[0], 11, -358537222);
	c = hh(c, d, a, b, k[3], 16, -722521979);
	b = hh(b, c, d, a, k[6], 23,  76029189);
	a = hh(a, b, c, d, k[9], 4, -640364487);
	d = hh(d, a, b, c, k[12], 11, -421815835);
	c = hh(c, d, a, b, k[15], 16,  530742520);
	b = hh(b, c, d, a, k[2], 23, -995338651);

	a = ii(a, b, c, d, k[0], 6, -198630844);
	d = ii(d, a, b, c, k[7], 10,  1126891415);
	c = ii(c, d, a, b, k[14], 15, -1416354905);
	b = ii(b, c, d, a, k[5], 21, -57434055);
	a = ii(a, b, c, d, k[12], 6,  1700485571);
	d = ii(d, a, b, c, k[3], 10, -1894986606);
	c = ii(c, d, a, b, k[10], 15, -1051523);
	b = ii(b, c, d, a, k[1], 21, -2054922799);
	a = ii(a, b, c, d, k[8], 6,  1873313359);
	d = ii(d, a, b, c, k[15], 10, -30611744);
	c = ii(c, d, a, b, k[6], 15, -1560198380);
	b = ii(b, c, d, a, k[13], 21,  1309151649);
	a = ii(a, b, c, d, k[4], 6, -145523070);
	d = ii(d, a, b, c, k[11], 10, -1120210379);
	c = ii(c, d, a, b, k[2], 15,  718787259);
	b = ii(b, c, d, a, k[9], 21, -343485551);

	x[0] = add32(a, x[0]);
	x[1] = add32(b, x[1]);
	x[2] = add32(c, x[2]);
	x[3] = add32(d, x[3]);

}

function cmn(q, a, b, x, s, t) {
	a = add32(add32(a, q), add32(x, t));
	return add32((a << s) | (a >>> (32 - s)), b);
}

function ff(a, b, c, d, x, s, t) {
	return cmn((b & c) | ((~b) & d), a, b, x, s, t);
}

function gg(a, b, c, d, x, s, t) {
	return cmn((b & d) | (c & (~d)), a, b, x, s, t);
}

function hh(a, b, c, d, x, s, t) {
	return cmn(b ^ c ^ d, a, b, x, s, t);
}

function ii(a, b, c, d, x, s, t) {
	return cmn(c ^ (b | (~d)), a, b, x, s, t);
}

function md51(s) {
	txt = '';
	var n = s.length,
	state = [1732584193, -271733879, -1732584194, 271733878], i;
	for (i=64; i<=s.length; i+=64) {
		md5cycle(state, md5blk(s.substring(i-64, i)));
	}
	s = s.substring(i-64);
	var tail = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
	for (i=0; i<s.length; i++)
	tail[i>>2] |= s.charCodeAt(i) << ((i%4) << 3);
	tail[i>>2] |= 0x80 << ((i%4) << 3);
	if (i > 55) {
		md5cycle(state, tail);
		for (i=0; i<16; i++) tail[i] = 0;
	}
	tail[14] = n*8;
	md5cycle(state, tail);
	return state;
}
function md5blk(s) { /* I figured global was faster.   */
	var md5blks = [], i; /* Andy King said do it this way. */
	for (i=0; i<64; i+=4) {
		md5blks[i>>2] = s.charCodeAt(i)
		+ (s.charCodeAt(i+1) << 8)
		+ (s.charCodeAt(i+2) << 16)
		+ (s.charCodeAt(i+3) << 24);
	}
	return md5blks;
}

var hex_chr = '0123456789abcdef'.split('');

function rhex(n)
{
	var s='', j=0;
	for(; j<4; j++)
	s += hex_chr[(n >> (j * 8 + 4)) & 0x0F]
	+ hex_chr[(n >> (j * 8)) & 0x0F];
	return s;
}

function hex(x) {
	for (var i=0; i<x.length; i++)
	x[i] = rhex(x[i]);
	return x.join('');
}

function md5(s) {
	return hex(md51(s));
}

function add32(a, b) {
	return (a + b) & 0xFFFFFFFF;
}

if (md5('hello') != '5d41402abc4b2a76b9719d911017c592') {
	function add32(x, y) {
		var lsw = (x & 0xFFFF) + (y & 0xFFFF),
		msw = (x >> 16) + (y >> 16) + (lsw >> 16);
		return (msw << 16) | (lsw & 0xFFFF);
	}
}