/*
* A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
* in FIPS 180-2
* Version 2.2 Copyright Angel Marin, Paul Johnston 2000 - 2009.
* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
* Distributed under the BSD License
* See http://pajhome.org.uk/crypt/md5 for details.
* Also http://anmar.eu.org/projects/jssha2/
*/
var sha256 = {
	/*
	* Configurable variables. You may need to tweak these to be compatible with
	* the server-side, but the defaults work in most cases.
	*/
	hexcase:0,  /* hex output format. 0 - lowercase; 1 - uppercase        */
	b64pad:"", /* base-64 pad character. "=" for strict RFC compliance   */

	/*
	* These are the functions you'll usually want to call
	* They take string arguments and return either hex or base-64 encoded strings
	*/
	hex_sha256:function(s)    { return this.rstr2hex(this.rstr_sha256(this.str2rstr_utf8(s))); },
	b64_sha256:function(s)    { return this.rstr2b64(this.rstr_sha256(this.str2rstr_utf8(s))); },
	any_sha256:function(s, e) { return this.rstr2any(this.rstr_sha256(this.str2rstr_utf8(s)), e); },
	hex_hmac_sha256:function(k, d)
	{ return this.rstr2hex(this.rstr_hmac_sha256(this.str2rstr_utf8(k), this.str2rstr_utf8(d))); },
	b64_hmac_sha256:function(k, d)
	{ return this.rstr2b64(this.rstr_hmac_sha256(this.str2rstr_utf8(k), this.str2rstr_utf8(d))); },
	any_hmac_sha256:function(k, d, e)
	{ return this.rstr2any(this.rstr_hmac_sha256(this.str2rstr_utf8(k), this.str2rstr_utf8(d)), e); },

	hex_sha224:function(s)    { return this.rstr2hex(this.rstr_sha224(this.str2rstr_utf8(s))); },
	b64_sha224:function(s)    { return this.rstr2b64(this.rstr_sha224(this.str2rstr_utf8(s))); },
	any_sha224:function(s, e) { return this.rstr2any(this.rstr_sha224(this.str2rstr_utf8(s)), e); },
	hex_hmac_sha224:function(k, d)
	{ return this.rstr2hex(this.rstr_hmac_sha224(this.str2rstr_utf8(k), this.str2rstr_utf8(d))); },
	b64_hmac_sha224:function(k, d)
	{ return this.rstr2b64(this.rstr_hmac_sha224(this.str2rstr_utf8(k), this.str2rstr_utf8(d))); },
	any_hmac_sha224:function(k, d, e)
	{ return this.rstr2any(this.rstr_hmac_sha224(this.str2rstr_utf8(k), this.str2rstr_utf8(d)), e); },

	/*
	* Perform a simple self-test to see if the VM is working
	*/
	sha256_vm_test:function()
	{
		return this.hex_sha256("abc").toLowerCase() ==
		"ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad";
	},

	/*
	* Calculate the sha256 of a raw string
	*/
	rstr_sha256:function(s)
	{
		return this.binb2rstr(this.binb_sha256(this.rstr2binb(s), s.length * 8));
	},
	
	rstr_sha224:function(s)
	{
		return this.binb2rstr(this.binb_sha224(this.rstr2binb(s), s.length * 8));
	},

	/*
	* Calculate the HMAC-sha256 of a key and some data (raw strings)
	*/
	rstr_hmac_sha256:function(key, data)
	{
		var bkey = this.rstr2binb(key);
		if(bkey.length > 16) bkey = this.binb_sha256(bkey, key.length * 8);
		
		var ipad = Array(16), opad = Array(16);
		for(var i = 0; i < 16; i++)
		{
			ipad[i] = bkey[i] ^ 0x36363636;
			opad[i] = bkey[i] ^ 0x5C5C5C5C;
		}
		
		var hash = this.binb_sha256(ipad.concat(this.rstr2binb(data)), 512 + data.length * 8);
		return this.binb2rstr(this.binb_sha256(opad.concat(hash), 512 + 256));
	},

	rstr_hmac_sha224:function(key, data)
	{
		var bkey = this.rstr2binb(key);
		if(bkey.length > 16) bkey = this.binb_sha224(bkey, key.length * 8);
		
		var ipad = Array(16), opad = Array(16);
		for(var i = 0; i < 16; i++)
		{
			ipad[i] = bkey[i] ^ 0x36363636;
			opad[i] = bkey[i] ^ 0x5C5C5C5C;
		}
		
		var hash = this.binb_sha224(ipad.concat(this.rstr2binb(data)), 512 + data.length * 8);
		return this.binb2rstr(this.binb_sha224(opad.concat(hash), 512 + 256));
	},

	/*
	* Convert a raw string to a hex string
	*/
	rstr2hex:function(input)
	{
		try { this.hexcase } catch(e) { this.hexcase=0; }
		var hex_tab = this.hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
		var output = "";
		var x;
		for(var i = 0; i < input.length; i++)
		{
			x = input.charCodeAt(i);
			output += hex_tab.charAt((x >>> 4) & 0x0F)
			+  hex_tab.charAt( x        & 0x0F);
		}
		return output;
	},

	/*
	* Convert a raw string to a base-64 string
	*/
	rstr2b64:function(input)
	{
		try { this.b64pad } catch(e) { this.b64pad=''; }
		var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
		var output = "";
		var len = input.length;
		for(var i = 0; i < len; i += 3)
		{
			var triplet = (input.charCodeAt(i) << 16)
			| (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
			| (i + 2 < len ? input.charCodeAt(i+2)      : 0);
			for(var j = 0; j < 4; j++)
			{
				if(i * 8 + j * 6 > input.length * 8) output += this.b64pad;
				else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
			}
		}
		return output;
	},

	/*
	* Convert a raw string to an arbitrary string encoding
	*/
	rstr2any:function(input, encoding)
	{
		var divisor = encoding.length;
		var remainders = Array();
		var i, q, x, quotient;
		
		/* Convert to an array of 16-bit big-endian values, forming the dividend */
		var dividend = Array(Math.ceil(input.length / 2));
		for(i = 0; i < dividend.length; i++)
		{
			dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
		}
		
		/*
		* Repeatedly perform a long division. The binary array forms the dividend,
		* the length of the encoding is the divisor. Once computed, the quotient
		* forms the dividend for the next step. We stop when the dividend is zero.
		* All remainders are stored for later use.
		*/
		while(dividend.length > 0)
		{
			quotient = Array();
			x = 0;
			for(i = 0; i < dividend.length; i++)
			{
				x = (x << 16) + dividend[i];
				q = Math.floor(x / divisor);
				x -= q * divisor;
				if(quotient.length > 0 || q > 0)
					quotient[quotient.length] = q;
			}
			remainders[remainders.length] = x;
			dividend = quotient;
		}
		
		/* Convert the remainders to the output string */
		var output = "";
		for(i = remainders.length - 1; i >= 0; i--)
			output += encoding.charAt(remainders[i]);
		
		/* Append leading zero equivalents */
		var full_length = Math.ceil(input.length * 8 /
		(Math.log(encoding.length) / Math.log(2)))
		for(i = output.length; i < full_length; i++)
			output = encoding[0] + output;
		
		return output;
	},

	/*
	* Encode a string as utf-8.
	* For efficiency, this assumes the input is valid utf-16.
	*/
	str2rstr_utf8:function(input)
	{
		var output = "";
		var i = -1;
		var x, y;
		
		while(++i < input.length)
		{
			/* Decode utf-16 surrogate pairs */
			x = input.charCodeAt(i);
			y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
			if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF)
			{
				x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
				i++;
			}
			
			/* Encode output as utf-8 */
			if(x <= 0x7F)
				output += String.fromCharCode(x);
			else if(x <= 0x7FF)
				output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),
											0x80 | ( x         & 0x3F));
			else if(x <= 0xFFFF)
				output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
											0x80 | ((x >>> 6 ) & 0x3F),
											0x80 | ( x         & 0x3F));
			else if(x <= 0x1FFFFF)
				output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
												0x80 | ((x >>> 12) & 0x3F),
												0x80 | ((x >>> 6 ) & 0x3F),
												0x80 | ( x         & 0x3F));
		}
		return output;
	},

	/*
	* Encode a string as utf-16
	*/
	str2rstr_utf16le:function(input)
	{
		var output = "";
		for(var i = 0; i < input.length; i++)
			output += String.fromCharCode( input.charCodeAt(i)        & 0xFF,
										(input.charCodeAt(i) >>> 8) & 0xFF);
										return output;
	},

	str2rstr_utf16be:function(input)
	{
		var output = "";
		for(var i = 0; i < input.length; i++)
			output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,
										input.charCodeAt(i)        & 0xFF);
										return output;
	},

	/*
	* Convert a raw string to an array of big-endian words
	* Characters >255 have their high-byte silently ignored.
	*/
	rstr2binb:function(input)
	{
		var output = Array(input.length >> 2);
		for(var i = 0; i < output.length; i++)
			output[i] = 0;
		for(var i = 0; i < input.length * 8; i += 8)
			output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32);
		return output;
	},

	/*
	* Convert an array of big-endian words to a string
	*/
	binb2rstr:function(input)
	{
		var output = "";
		for(var i = 0; i < input.length * 32; i += 8)
			output += String.fromCharCode((input[i>>5] >>> (24 - i % 32)) & 0xFF);
		return output;
	},

	/*
	* Main sha256 function, with its support functions
	*/
	sha256_S:function(X, n) {return ( X >>> n ) | (X << (32 - n));},
	sha256_R:function(X, n) {return ( X >>> n );},
	sha256_Ch:function(x, y, z) {return ((x & y) ^ ((~x) & z));},
	sha256_Maj:function(x, y, z) {return ((x & y) ^ (x & z) ^ (y & z));},
	sha256_Sigma0256:function(x) {return (this.sha256_S(x, 2) ^ this.sha256_S(x, 13) ^ this.sha256_S(x, 22));},
	sha256_Sigma1256:function(x) {return (this.sha256_S(x, 6) ^ this.sha256_S(x, 11) ^ this.sha256_S(x, 25));},
	sha256_Gamma0256:function(x) {return (this.sha256_S(x, 7) ^ this.sha256_S(x, 18) ^ this.sha256_R(x, 3));},
	sha256_Gamma1256:function(x) {return (this.sha256_S(x, 17) ^ this.sha256_S(x, 19) ^ this.sha256_R(x, 10));},
	sha256_Sigma0512:function(x) {return (this.sha256_S(x, 28) ^ this.sha256_S(x, 34) ^ this.sha256_S(x, 39));},
	sha256_Sigma1512:function(x) {return (this.sha256_S(x, 14) ^ this.sha256_S(x, 18) ^ this.sha256_S(x, 41));},
	sha256_Gamma0512:function(x) {return (this.sha256_S(x, 1)  ^ this.sha256_S(x, 8) ^ this.sha256_R(x, 7));},
	sha256_Gamma1512:function(x) {return (this.sha256_S(x, 19) ^ this.sha256_S(x, 61) ^ this.sha256_R(x, 6));},

	sha256_K:Array
	(
	1116352408, 1899447441, -1245643825, -373957723, 961987163, 1508970993,
	-1841331548, -1424204075, -670586216, 310598401, 607225278, 1426881987,
	1925078388, -2132889090, -1680079193, -1046744716, -459576895, -272742522,
	264347078, 604807628, 770255983, 1249150122, 1555081692, 1996064986,
	-1740746414, -1473132947, -1341970488, -1084653625, -958395405, -710438585,
	113926993, 338241895, 666307205, 773529912, 1294757372, 1396182291,
	1695183700, 1986661051, -2117940946, -1838011259, -1564481375, -1474664885,
	-1035236496, -949202525, -778901479, -694614492, -200395387, 275423344,
	430227734, 506948616, 659060556, 883997877, 958139571, 1322822218,
	1537002063, 1747873779, 1955562222, 2024104815, -2067236844, -1933114872,
	-1866530822, -1538233109, -1090935817, -965641998
	),


	binb_sha224:function(m, l)
	{
		var HASH = new Array(0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
							0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4);
		var W = new Array(64);
		var a, b, c, d, e, f, g, h;
		var i, j, T1, T2;
		
		/* append padding */
		m[l >> 5] |= 0x80 << (24 - l % 32);
		m[((l + 64 >> 9) << 4) + 15] = l;
		
		for(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(j = 0; j < 64; j++)
			{
				if (j < 16) W[j] = m[j + i];
				else W[j] = this.safe_add(this.safe_add(this.safe_add(this.sha256_Gamma1256(W[j - 2]), W[j - 7]),
					this.sha256_Gamma0256(W[j - 15])), W[j - 16]);
			
				T1 = this.safe_add(this.safe_add(this.safe_add(this.safe_add(h, this.sha256_Sigma1256(e)), this.sha256_Ch(e, f, g)),
												this.sha256_K[j]), W[j]);
				T2 = this.safe_add(this.sha256_Sigma0256(a), this.sha256_Maj(a, b, c));
				h = g;
				g = f;
				f = e;
				e = this.safe_add(d, T1);
				d = c;
				c = b;
				b = a;
				a = this.safe_add(T1, T2);
			}
			
			HASH[0] = this.safe_add(a, HASH[0]);
			HASH[1] = this.safe_add(b, HASH[1]);
			HASH[2] = this.safe_add(c, HASH[2]);
			HASH[3] = this.safe_add(d, HASH[3]);
			HASH[4] = this.safe_add(e, HASH[4]);
			HASH[5] = this.safe_add(f, HASH[5]);
			HASH[6] = this.safe_add(g, HASH[6]);
			HASH[7] = this.safe_add(h, HASH[7]);
		}
		return HASH.splice(0,7);
	},
	
		binb_sha256:function(m, l)
	{
		var HASH = new Array(1779033703, -1150833019, 1013904242, -1521486534,
							1359893119, -1694144372, 528734635, 1541459225);
		var W = new Array(64);
		var a, b, c, d, e, f, g, h;
		var i, j, T1, T2;
		
		/* append padding */
		m[l >> 5] |= 0x80 << (24 - l % 32);
		m[((l + 64 >> 9) << 4) + 15] = l;
		
		for(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(j = 0; j < 64; j++)
			{
				if (j < 16) W[j] = m[j + i];
				else W[j] = this.safe_add(this.safe_add(this.safe_add(this.sha256_Gamma1256(W[j - 2]), W[j - 7]),
					this.sha256_Gamma0256(W[j - 15])), W[j - 16]);
			
				T1 = this.safe_add(this.safe_add(this.safe_add(this.safe_add(h, this.sha256_Sigma1256(e)), this.sha256_Ch(e, f, g)),
												this.sha256_K[j]), W[j]);
				T2 = this.safe_add(this.sha256_Sigma0256(a), this.sha256_Maj(a, b, c));
				h = g;
				g = f;
				f = e;
				e = this.safe_add(d, T1);
				d = c;
				c = b;
				b = a;
				a = this.safe_add(T1, T2);
			}
			
			HASH[0] = this.safe_add(a, HASH[0]);
			HASH[1] = this.safe_add(b, HASH[1]);
			HASH[2] = this.safe_add(c, HASH[2]);
			HASH[3] = this.safe_add(d, HASH[3]);
			HASH[4] = this.safe_add(e, HASH[4]);
			HASH[5] = this.safe_add(f, HASH[5]);
			HASH[6] = this.safe_add(g, HASH[6]);
			HASH[7] = this.safe_add(h, HASH[7]);
		}
		return HASH;
	},


	safe_add:function(x, y)
	{
		var lsw = (x & 0xFFFF) + (y & 0xFFFF);
		var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
		return (msw << 16) | (lsw & 0xFFFF);
	}
};