c11-hash-js/lib/skein.js

c11 javascript hashing algorithm in pure javascript

//from http://www.h2database.com/skein/
// Released under the public domain

var op = require('./op');
var h = require('./helper');

module.exports = function(input, format, output) {
	var msg;
	if (format === 1) {
		msg = input;
	}
	else if (format === 2) {
		msg = h.int32Buffer2Bytes(input);
	}
	else {
		msg = h.string2bytes(input);
	}
	// final: 0x80; first: 0x40; conf: 0x4; msg: 0x30; out: 0x3f
	var tweak = [
			[0, 32],
			[(0x80 + 0x40 + 0x4) << 24, 0]
		],
		c = [];
	var buff = h.string2bytes("SHA3\1\0\0\0\0\2");
	block(c, tweak, buff, 0);
	tweak = [
		[0, 0],
		[(0x40 + 0x30) << 24, 0]
	];
	var len = msg.length,
		pos = 0;
	for (; len > 64; len -= 64, pos += 64) {
		tweak[0][1] += 64;
		block(c, tweak, msg, pos);
		tweak[1][0] = 0x30 << 24;
	}
	tweak[0][1] += len;
	tweak[1][0] |= 0x80 << 24;
	block(c, tweak, msg, pos);
	tweak[0][1] = 8;
	tweak[1][0] = (0x80 + 0x40 + 0x3f) << 24;
	block(c, tweak, [], 0);
	for (var hash = [], i = 0; i < 64; i++) {
		var b = (shiftRight(c[i >> 3], (i & 7) * 8)[1] & 255);
		hash.push(b);
	}
	var out;
  if (output === 2) {
    out = h.bytes2Int32Buffer(hash);
  }
  else if (output === 1) {
    return out;
  }
  else {
    out = h.int8ArrayToHexString(hash);
  }
  return out;
}

function shiftLeft(x, n) {
	if (x == null) return [0, 0];
	if (n > 32) return [x[1] << (n - 32), 0];
	if (n == 32) return [x[1], 0];
	if (n == 0) return x;
	return [(x[0] << n) | (x[1] >>> (32 - n)), x[1] << n];
}

function shiftRight(x, n) {
	if (x == null) return [0, 0];
	if (n > 32) return [0, x[0] >>> (n - 32)];
	if (n == 32) return [0, x[0]];
	if (n == 0) return x;
	return [x[0] >>> n, (x[0] << (32 - n)) | (x[1] >>> n)];
}

function add(x, y) {
	if (y == null) return x;
	var lsw = (x[1] & 0xffff) + (y[1] & 0xffff);
	var msw = (x[1] >>> 16) + (y[1] >>> 16) + (lsw >>> 16);
	var lowOrder = ((msw & 0xffff) << 16) | (lsw & 0xffff);
	lsw = (x[0] & 0xffff) + (y[0] & 0xffff) + (msw >>> 16);
	msw = (x[0] >>> 16) + (y[0] >>> 16) + (lsw >>> 16);
	var highOrder = ((msw & 0xffff) << 16) | (lsw & 0xffff);
	return [highOrder, lowOrder];
}

function xor(a, b) {
	if (b == null) return a;
	return [a[0] ^ b[0], a[1] ^ b[1]];
}

function block(c, tweak, b, off) {
	var R = [46, 36, 19, 37, 33, 42, 14, 27, 17, 49, 36, 39, 44, 56, 54, 9,
		39, 30, 34, 24, 13, 17, 10, 50, 25, 29, 39, 43, 8, 22, 56, 35
	];
	var x = [],
		t = [];
	// c[8] = [0x55555555, 0x55555555];
	c[8] = [0x1BD11BDA, 0xA9FC1A22];
	for (var i = 0; i < 8; i++) {
		for (var j = 7, k = off + i * 8 + 7; j >= 0; j--, k--) {
			t[i] = shiftLeft(t[i], 8);
			t[i][1] |= b[k] & 255;
		}
		x[i] = add(t[i], c[i]);
		c[8] = xor(c[8], c[i]);
	}
	x[5] = add(x[5], tweak[0]);
	x[6] = add(x[6], tweak[1]);
	tweak[2] = xor(tweak[0], tweak[1]);
	for (var round = 1; round <= 18; round++) {
		var p = 16 - ((round & 1) << 4);
		for (var i = 0; i < 16; i++) {
			// m: 0, 2, 4, 6, 2, 0, 6, 4, 4, 6, 0, 2, 6, 4, 2, 0
			var m = 2 * ((i + (1 + i + i) * (i >> 2)) & 3);
			var n = (1 + i + i) & 7;
			var r = R[p + i];
			x[m] = add(x[m], x[n]);
			x[n] = xor(shiftLeft(x[n], r), shiftRight(x[n], 64 - r));
			x[n] = xor(x[n], x[m]);

		}
		for (var i = 0; i < 8; i++)
			x[i] = add(x[i], c[(round + i) % 9]);
		x[5] = add(x[5], tweak[round % 3]);
		x[6] = add(x[6], tweak[(round + 1) % 3]);
		x[7] = add(x[7], [0, round]);
	}
	for (var i = 0; i < 8; i++)
		c[i] = xor(t[i], x[i]);
}