sha256.js

/// METEOR WRAPPER
//
// XXX this should get packaged and moved into the Meteor.crypto
// namespace, along with other hash functions.
module.exports = SHA256 = (function () {


/**
*
*  Secure Hash Algorithm (SHA256)
*  http://www.webtoolkit.info/javascript-sha256.html
*  http://anmar.eu.org/projects/jssha2/
*
*  Original code by Angel Marin, Paul Johnston.
*
**/
 
function SHA256(s){
 
	var chrsz   = 8;
	var hexcase = 0;
 
	function safe_add (x, y) {
		var lsw = (x & 0xFFFF) + (y & 0xFFFF);
		var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
		return (msw << 16) | (lsw & 0xFFFF);
	}
 
	function S (X, n) { return ( X >>> n ) | (X << (32 - n)); }
	function R (X, n) { return ( X >>> n ); }
	function Ch(x, y, z) { return ((x & y) ^ ((~x) & z)); }
	function Maj(x, y, z) { return ((x & y) ^ (x & z) ^ (y & z)); }
	function Sigma0256(x) { return (S(x, 2) ^ S(x, 13) ^ S(x, 22)); }
	function Sigma1256(x) { return (S(x, 6) ^ S(x, 11) ^ S(x, 25)); }
	function Gamma0256(x) { return (S(x, 7) ^ S(x, 18) ^ R(x, 3)); }
	function Gamma1256(x) { return (S(x, 17) ^ S(x, 19) ^ R(x, 10)); }
 
	function core_sha256 (m, l) {
		var K = new Array(0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 0xE49B69C1, 0xEFBE4786, 0xFC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x6CA6351, 0x14292967, 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2);
		var HASH = new Array(0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19);
		var W = new Array(64);
		var a, b, c, d, e, f, g, h, i, j;
		var T1, T2;
 
		m[l >> 5] |= 0x80 << (24 - l % 32);
		m[((l + 64 >> 9) << 4) + 15] = l;
 
		for ( var i = 0; i<m.length; i+=16 ) {
			a = HASH[0];
			b = HASH[1];
			c = HASH[2];
			d = HASH[3];
			e = HASH[4];
			f = HASH[5];
			g = HASH[6];
			h = HASH[7];
 
			for ( var j = 0; j<64; j++) {
				if (j < 16) W[j] = m[j + i];
				else W[j] = safe_add(safe_add(safe_add(Gamma1256(W[j - 2]), W[j - 7]), Gamma0256(W[j - 15])), W[j - 16]);
 
				T1 = safe_add(safe_add(safe_add(safe_add(h, Sigma1256(e)), Ch(e, f, g)), K[j]), W[j]);
				T2 = safe_add(Sigma0256(a), Maj(a, b, c));
 
				h = g;
				g = f;
				f = e;
				e = safe_add(d, T1);
				d = c;
				c = b;
				b = a;
				a = safe_add(T1, T2);
			}
 
			HASH[0] = safe_add(a, HASH[0]);
			HASH[1] = safe_add(b, HASH[1]);
			HASH[2] = safe_add(c, HASH[2]);
			HASH[3] = safe_add(d, HASH[3]);
			HASH[4] = safe_add(e, HASH[4]);
			HASH[5] = safe_add(f, HASH[5]);
			HASH[6] = safe_add(g, HASH[6]);
			HASH[7] = safe_add(h, HASH[7]);
		}
		return HASH;
	}
 
	function str2binb (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) << (24 - i%32);
		}
		return bin;
	}
 
	function Utf8Encode(string) {
		// METEOR change:
		// The webtoolkit.info version of this code added this
		// Utf8Encode function (which does seem necessary for dealing
		// with arbitrary Unicode), but the following line seems
		// problematic:
		//
		// string = string.replace(/\r\n/g,"\n");
		var utftext = "";
 
		for (var n = 0; n < string.length; n++) {
 
			var c = string.charCodeAt(n);
 
			if (c < 128) {
				utftext += String.fromCharCode(c);
			}
			else if((c > 127) && (c < 2048)) {
				utftext += String.fromCharCode((c >> 6) | 192);
				utftext += String.fromCharCode((c & 63) | 128);
			}
			else {
				utftext += String.fromCharCode((c >> 12) | 224);
				utftext += String.fromCharCode(((c >> 6) & 63) | 128);
				utftext += String.fromCharCode((c & 63) | 128);
			}
 
		}
 
		return utftext;
	}
 
	function binb2hex (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] >> ((3 - i%4)*8+4)) & 0xF) +
			hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8  )) & 0xF);
		}
		return str;
	}
 
	s = Utf8Encode(s);
	return binb2hex(core_sha256(str2binb(s), s.length * chrsz));
 
}

/// METEOR WRAPPER
return SHA256;
})();