//--
//-- Crypto functions and associated conversion routines
//--

// Crypto 'namespace'
function Crypto() {}

// Convert a string to an array of big-endian 32-bit words
Crypto.strToBe32s = function(str)
{
	var be=[];
	var len=Math.floor(str.length/4);
	var i, j;
	for(i=0, j=0; i<len; i++, j+=4) {
		be[i]=((str.charCodeAt(j)&0xff) << 24)|((str.charCodeAt(j+1)&0xff) << 16)|((str.charCodeAt(j+2)&0xff) << 8)|(str.charCodeAt(j+3)&0xff);
	}
	while(j<str.length) {
		be[j>>2] |= (str.charCodeAt(j)&0xff)<<(24-(j*8)%32);
		j++;
	}
	return be;
};

// Convert an array of big-endian 32-bit words to a string
Crypto.be32sToStr = function(be)
{
	var str='';
	for(var i=0;i<be.length*32;i+=8) {
		str += String.fromCharCode((be[i>>5]>>>(24-i%32)) & 0xff);
	}
	return str;
};

// Convert an array of big-endian 32-bit words to a hex string
Crypto.be32sToHex = function(be)
{
	var hex='0123456789ABCDEF';
	var str='';
	for(var i=0;i<be.length*4;i++) {
		str += hex.charAt((be[i>>2]>>((3-i%4)*8+4))&0xF) + hex.charAt((be[i>>2]>>((3-i%4)*8))&0xF);
	}
	return str;
};

// Return, in hex, the SHA-1 hash of a string
Crypto.hexSha1Str = function(str)
{
	return Crypto.be32sToHex(Crypto.sha1Str(str));
};

// Return the SHA-1 hash of a string
Crypto.sha1Str = function(str)
{
	return Crypto.sha1(Crypto.strToBe32s(str),str.length);
};

// Calculate the SHA-1 hash of an array of blen bytes of big-endian 32-bit words
Crypto.sha1 = function(x,blen)
{
	// Add 32-bit integers, wrapping at 32 bits
	//# Uses 16-bit operations internally to work around bugs in some JavaScript interpreters.
	function add32(a,b)
	{
		var lsw=(a&0xFFFF)+(b&0xFFFF);
		var msw=(a>>16)+(b>>16)+(lsw>>16);
		return (msw<<16)|(lsw&0xFFFF);
	}
	//# Cryptographic round helper function. Add five 32-bit integers, wrapping at 32 bits, second parameter is rotated left 5 bits before the addition
	//# Uses 16-bit operations internally to work around bugs in some JavaScript interpreters.
	function AA(a,b,c,d,e)
	{
		b=(b>>>27)|(b<<5);
		var lsw=(a&0xFFFF)+(b&0xFFFF)+(c&0xFFFF)+(d&0xFFFF)+(e&0xFFFF);
		var msw=(a>>16)+(b>>16)+(c>>16)+(d>>16)+(e>>16)+(lsw>>16);
		return (msw<<16)|(lsw&0xFFFF);
	}
	//# Cryptographic round helper function.
	function RR(w,j)
	{
		var n=w[j-3]^w[j-8]^w[j-14]^w[j-16];
		return (n>>>31)|(n<<1);
	}

	var len=blen*8;
	//# Append padding so length in bits is 448 mod 512
	x[len>>5] |= 0x80 << (24-len%32);
	//# Append length
	x[((len+64>>9)<<4)+15]=len;
	var w=new Array(80);

	var k1=0x5A827999;
	var k2=0x6ED9EBA1;
	var k3=0x8F1BBCDC;
	var k4=0xCA62C1D6;

	var h0=0x67452301;
	var h1=0xEFCDAB89;
	var h2=0x98BADCFE;
	var h3=0x10325476;
	var h4=0xC3D2E1F0;

	for(var i=0;i<x.length;i+=16) {
		var j=0;
		var t;
		var a=h0;
		var b=h1;
		var c=h2;
		var d=h3;
		var e=h4;
		while(j<16) {
			w[j]=x[i+j];
			t=AA(e,a,d^(b&(c^d)),w[j],k1);
			e=d; d=c; c=(b>>>2)|(b<<30); b=a; a=t; j++;
		}
		while(j<20) {
			w[j]=RR(w,j);
			t=AA(e,a,d^(b&(c^d)),w[j],k1);
			e=d; d=c; c=(b>>>2)|(b<<30); b=a; a=t; j++;
		}
		while(j<40) {
			w[j]=RR(w,j);
			t=AA(e,a,b^c^d,w[j],k2);
			e=d; d=c; c=(b>>>2)|(b<<30); b=a; a=t; j++;
		}
		while(j<60) {
			w[j]=RR(w,j);
			t=AA(e,a,(b&c)|(d&(b|c)),w[j],k3);
			e=d; d=c; c=(b>>>2)|(b<<30); b=a; a=t; j++;
		}
		while(j<80) {
			w[j]=RR(w,j);
			t=AA(e,a,b^c^d,w[j],k4);
			e=d; d=c; c=(b>>>2)|(b<<30); b=a; a=t; j++;
		}
		h0=add32(h0,a);
		h1=add32(h1,b);
		h2=add32(h2,c);
		h3=add32(h3,d);
		h4=add32(h4,e);
	}
	return [h0,h1,h2,h3,h4];
};