/*globals document */
function ArrayMD5(n) {
	for (var i = 0; i < n; i += 1) {
		this[i] = 0;
	}
	this.length = n;
}

/* Some basic logical functions had to be rewritten because of a bug in
 * Javascript.. Just try to compute 0xffffffff >> 4 with it..
 * Of course, these functions are slower than the original would be, but
 * at least, they work!
 */

function integer(n) {
	return n % (0xffffffff + 1);
}

function shr(a, b) {
	a = integer(a);
	b = integer(b);
	if (a - 0x80000000 >= 0) {
		a = a % 0x80000000;
		a >>= b;
		a += 0x40000000 >> (b - 1);
	} else {
		a >>= b;
	}
	return a;
}

function shl1(a) {
	a = a % 0x80000000;
	if (a & 0x40000000 === 0x40000000) {
		a -= 0x40000000;  
		a *= 2;
		a += 0x80000000;
	} else {
		a *= 2;
	}
	return a;
}

function shl(a, b) {
	a = integer(a);
	b = integer(b);
	for (var i = 0; i < b; i += 1) {
		a = shl1(a);
	}
	return a;
}

function and(a, b) {
	a = integer(a);
	b = integer(b);
	var t1 = (a - 0x80000000);
	var t2 = (b - 0x80000000);
	if (t1 >= 0) {
		if (t2 >= 0) {
			return ((t1 & t2) + 0x80000000);
	    } else {
		    return (t1 & b);
		}
	} else {
		if (t2 >= 0) {
			return (a & t2);
		} else {
			return (a & b);
		}
	}
}

function or(a, b) {
	a = integer(a);
	b = integer(b);
	var t1 = (a - 0x80000000);
	var t2 = (b - 0x80000000);
	if (t1 >= 0) {
		if (t2 >= 0) {
			return ((t1 | t2) + 0x80000000);
		} else {
			return ((t1 | b) + 0x80000000);
		}
	} else {
		if (t2 >= 0) {
			return ((a | t2) + 0x80000000);
		} else {
			return (a | b);
		}
	}
}

function xor(a, b) {
	a = integer(a);
	b = integer(b);
	var t1 = (a - 0x80000000);
	var t2 = (b - 0x80000000);
	if (t1 >= 0) {
		if (t2 >= 0) {
			return (t1 ^ t2);
		} else {
			return ((t1 ^ b) + 0x80000000);
		}
	} else {
		if (t2 >= 0) {
			return ((a ^ t2) + 0x80000000);
		} else {
			return (a ^ b);
		}
	}
}

function not(a) {
	a = integer(a);
	return (0xffffffff - a);
}

/* Here begin the real algorithm */

var state = new ArrayMD5(4); 
var count = new ArrayMD5(2);
count[0] = 0;
count[1] = 0;                     

var buffer = new ArrayMD5(64); 
var transformBuffer = new ArrayMD5(16); 
var digestBits = new ArrayMD5(16);

var S11 = 7;
var S12 = 12;
var S13 = 17;
var S14 = 22;

var S21 = 5;
var S22 = 9;
var S23 = 14;
var S24 = 20;

var S31 = 4;
var S32 = 11;
var S33 = 16;
var S34 = 23;

var S41 = 6;
var S42 = 10;
var S43 = 15;
var S44 = 21;

function md5F(x, y, z) {
	return or(and(x, y), and(not(x), z));
}

function md5G(x, y, z) {
	return or(and(x, z), and(y, not(z)));
}

function md5H(x, y, z) {
	return xor(xor(x, y), z);
}

function md5I(x, y, z) {
	return xor(y, or(x, not(z)));
}

function rotateLeft(a, n) {
	return or(shl(a, n), shr(a, (32 - n)));
}

function md5FF(a, b, c, d, x, s, ac) {
	a = a + md5F(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a = a + b;
	return a;
}

function md5GG(a, b, c, d, x, s, ac) {
	a = a + md5G(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a = a + b;
	return a;
}

function md5HH(a, b, c, d, x, s, ac) {
	a = a + md5H(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a = a + b;
	return a;
}

function md5II(a, b, c, d, x, s, ac) {
	a = a + md5I(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a = a + b;
	return a;
}

function transform(buf, offset) { 
	var a = 0, b = 0, c = 0, d = 0; 
	var x = transformBuffer;
	
	a = state[0];
	b = state[1];
	c = state[2];
	d = state[3];
	var i, j;
	for (i = 0; i < 16; i += 1) {
		x[i] = and(buf[i * 4 + offset], 0xff);
		for (j = 1; j < 4; j += 1) {
			x[i] += shl(and(buf[i * 4 + j + offset], 0xff), j * 8);
		}
	}

	/* Round 1 */
	a = md5FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
	d = md5FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
	c = md5FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
	b = md5FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
	a = md5FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
	d = md5FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
	c = md5FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
	b = md5FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
	a = md5FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
	d = md5FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
	c = md5FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	b = md5FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	a = md5FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	d = md5FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	c = md5FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	b = md5FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	a = md5GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
	d = md5GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
	c = md5GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	b = md5GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
	a = md5GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
	d = md5GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
	c = md5GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	b = md5GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
	a = md5GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
	d = md5GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	c = md5GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
	b = md5GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
	a = md5GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	d = md5GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
	c = md5GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
	b = md5GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	a = md5HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
	d = md5HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
	c = md5HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	b = md5HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	a = md5HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
	d = md5HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
	c = md5HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
	b = md5HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	a = md5HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	d = md5HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
	c = md5HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
	b = md5HH(b, c, d, a, x[6], S34,  0x4881d05); /* 44 */
	a = md5HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
	d = md5HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	c = md5HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	b = md5HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
	
	/* Round 4 */
	a = md5II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
	d = md5II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
	c = md5II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	b = md5II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
	a = md5II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	d = md5II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
	c = md5II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	b = md5II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
	a = md5II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
	d = md5II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	c = md5II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
	b = md5II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	a = md5II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
	d = md5II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	c = md5II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
	b = md5II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
	
	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;

}

function init() {
	count[0] = count[1] = 0;
	state[0] = 0x67452301;
	state[1] = 0xefcdab89;
	state[2] = 0x98badcfe;
	state[3] = 0x10325476;
	for (var i = 0; i < digestBits.length; i += 1) {
		digestBits[i] = 0;
	}
}

function update(b) {
	var index, i;
	
	index = and(shr(count[0], 3), 0x3f);
	if (count[0] < 0xffffffff - 7) {
		count[0] += 8;
	} else {
		count[1] += 1;
		count[0] -= 0xffffffff + 1;
		count[0] += 8;
	}
	buffer[index] = and(b, 0xff);
	if (index  >= 63) {
		transform(buffer, 0);
	}
}

function finish() {
	var bits = new ArrayMD5(8);
	var	padding; 
	var	i = 0, index = 0, padLen = 0, j;

	for (i = 0; i < 4; i += 1) {
		bits[i] = and(shr(count[0], (i * 8)), 0xff);
	}
	for (i = 0; i < 4; i += 1) {
		bits[i + 4] = and(shr(count[1], (i * 8)), 0xff);
	}
	index = and(shr(count[0], 3), 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	padding = new ArrayMD5(64); 
	padding[0] = 0x80;
	for (i = 0; i < padLen; i += 1) {
		update(padding[i]);
	}
	for (i = 0; i < 8; i += 1) {
		update(bits[i]);
	}

	for (i = 0; i < 4; i += 1) {
		for (j = 0; j < 4; j += 1) {
			digestBits[i * 4 + j] = and(shr(state[i], (j * 8)), 0xff);
		}
	} 
}

/* End of the MD5 algorithm */
function hexa(n) {
	var hexa_h = "0123456789abcdef";
	var hexa_c = ""; 
	var hexa_m = n;
	for (var hexa_i = 0; hexa_i < 8; hexa_i += 1) {
		hexa_c = hexa_h.charAt(Math.abs(hexa_m) % 16) + hexa_c;
		hexa_m = Math.floor(hexa_m / 16);
	}
	return hexa_c;
}

var ascii = "01234567890123456789012345678901" + " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";


function MD5(entree) {
	var i, l, s, k, ka, kb, kc, kd;
	init();
	for (k = 0; k < entree.length; k += 1) {
		l = entree.charAt(k);
		update(ascii.lastIndexOf(l));
	}
	finish();
	ka = kb = kc = kd = 0;
	for (i = 0; i < 4; i += 1) {
		ka += shl(digestBits[15 - i], (i * 8));
	}
	for (i = 4; i < 8; i += 1) {
		kb += shl(digestBits[15 - i], ((i - 4) * 8));
	}
	for (i = 8; i < 12; i += 1) {
		kc += shl(digestBits[15 - i], ((i - 8) * 8));
	}
	for (i = 12; i < 16; i += 1) {
		kd += shl(digestBits[15 - i], ((i - 12) * 8));
	}
	s = hexa(kd) + hexa(kc) + hexa(kb) + hexa(ka);
	return s; 
}

/* This implement the MD5 test suite */
var testOk = false;
function teste() {
	if (testOk) {
		return;
	}
	document.test.o1.value = MD5(document.test.i1.value);
	document.test.o2.value = MD5(document.test.i2.value);
	document.test.o3.value = MD5(document.test.i3.value);
	document.test.o4.value = MD5(document.test.i4.value);
	document.test.o5.value = MD5(document.test.i5.value);
	document.test.o6.value = MD5(document.test.i6.value);
	document.test.o7.value = MD5(document.test.i7.value);
	testOk = true;
}
