/**
* Fichero con funciones comunes de JavaScript
*
* Para acceder a las funciones que contiene este fichero, hay que incluirlo
* en el tag head de la página que va a hacer las llamadas a las funciones:
*
* <script type="text/javascript" src="functions.js"></script>
*
* Si este fichero está en una carpeta distinta de la del script HTML que lo
* va a llamar, hay que especificar la ruta en la llamada.
*/

/**
* Las tres siguientes funciones sirven para redimensionar un div y un iframe a su contenido.
*
* Funcionamiento: tenemos un div, que contiene un iframe en el que se carga una página dinámica.
* Como la página es dinámica, su contenido puede variar y, a consecuencia, variará también su
* tamaño. A causa de ésto, no podemos establecer de antemano el tamaño del iframe ni del div que
* contienen dicha página. Para solucionarlo, se usan estas tres funciones, que llamadas en el
* evento onLoad del tag body de la página, ajustan el tamaño del div y del iframe al cargar la
* página.
*
* Para usar estas funciones, sólo hay que incluír la llamada a la función principal "ResizeMan()"
* en el evento onLoad del tag body de la página que queramos cargar dentro del iframe. Se le
* pasarán como parámetros las referencias al div, al iframe y a un objeto dentro de la ventana
* que se usará como referencia para medir su tamaño (ej. una tabla). Esto queda así:
*
* <body onLoad="ResizeMan(document.getElementById('ref'),document.getElementById('div'),document.getElementById('iframe'))">
*
* El div, el iframe y el objeto de referencia, se pasan mediante el uso de la instrucción estándar W3C: document.getElementById()
*
* NOTA: El orden de los parámetros es: ElementoReferencia, DIV, IFRAME
* NOTA 2: Aún no ha sido probado en Firefox, ni en Exploter 7.
*
* NOTA 3: Para usar esta función y cualquier otra de las que contiene este fichero, hay que incluír la referencia al mismo en
* el tag head de la página en cuestión.
*/
function ResizeMan_X(CtrlRef,CtrlX)
{
	var espacio_iframe;
	if (window.innerWidth) //FF
		espacio_iframe = window.innerWidth;
	else
	{
		if (CtrlRef.clientWidth) //IE
			espacio_iframe = CtrlRef.clientWidth;
		else //Crap
			espacio_iframe = 666;
	}

	CtrlX.style.width = espacio_iframe + 20; //Working
	//parent.document.getElementById('DetalleProducto').style.width = espacio_iframe + 20;
}

function ResizeMan_Y(CtrlRef,CtrlY)
{
	var espacio_iframe;
	if (window.innerHeight) //FF
		espacio_iframe = window.innerHeight;
	else
	{
		if (CtrlRef.clientHeight) //IE
			espacio_iframe = CtrlRef.clientHeight;
		else //Crap
			espacio_iframe = 666;
	}

	//parent.document.getElementById('DivProductosSolicitud').style.height = espacio_iframe + 20;
	CtrlY.style.height = espacio_iframe + 20; //Working
}

function ResizeMan(CtrlRef,CtrlX,CtrlY)
{
	ResizeMan_X(CtrlRef,CtrlX);
	ResizeMan_Y(CtrlRef,CtrlY);
}

/*
function replaces extended characters of 'text' with its character entities.
call the function by default with output = false. if you switch it to true
it will format the source code for output in a textarea.
*/
function replaceExtChars(text,output)
{
	text = text.replace(eval("/&/g"), "&amp;");
	var fromTo = new Array("&AElig;", "Æ", "&Aacute;", "Á", "&Acirc;", "Â", "&Agrave;", "À", "&Aring;", "Å", "&Atilde;", "Ã", "&Auml;", "Ä", "&Ccedil;", "Ç", "&ETH;", "Ð", "&Eacute;", "É", "&Ecirc;", "Ê", "&Egrave;", "È", "&Euml;", "Ë", "&Iacute;", "Í", "&Icirc;", "Î", "&Igrave;", "Ì", "&Iuml;", "Ï", "&Ntilde;", "Ñ", "&Oacute;", "Ó", "&Ocirc;", "Ô", "&Ograve;", "Ò", "&Oslash;", "Ø", "&Otilde;", "Õ", "&Ouml;", "Ö", "&THORN;", "Þ", "&Uacute;", "Ú", "&Ucirc;", "Û", "&Ugrave;", "Ù", "&Uuml;", "Ü", "&Yacute;", "Ý", "&aacute;", "á", "&acirc;", "â", "&aelig;", "æ", "&agrave;", "à", "&aring;", "å", "&atilde;", "ã", "&auml;", "ä", "&brvbar;", "¦", "&ccedil;", "ç", "&cent;", "¢", "&copy;", "©", "&deg;", "°", "&eacute;", "é", "&ecirc;", "ê", "&egrave;", "è", "&eth;", "ð", "&euml;", "ë", "&frac12;", "½", "&frac14;", "¼", "&frac34;", "¾", "&gt;", ">", "&iacute;", "í", "&icirc;", "î", "&iexcl;", "¡", "&igrave;", "ì", "&iquest;", "¿", "&iuml;", "ï", "&laquo;", "«", "&lt;", "<", "&mdash;", "—", "&micro;", "µ", "&middot;", "·", "&ndash;", "–", "&not;", "¬", "&ntilde;", "ñ", "&oacute;", "ó", "&ocirc;", "ô", "&ograve;", "ò", "&oslash;", "ø", "&otilde;", "õ", "&ouml;", "ö", "&para;", "¶", "&plusmn;", "±", "&pound;", "£", "&quot;", "\"", "&raquo;", "»", "&reg;", "®", "&sect;", "§", "&shy;", "*", "&sup1;", "¹", "&sup2;", "²", "&sup3;", "³", "&szlig;", "ß", "&thorn;", "þ", "&tilde;", "˜", "&trade;", "™", "&uacute;", "ú", "&ucirc;", "û", "&ugrave;", "ù", "&uuml;", "ü", "&yacute;", "ý", "&yen;", "¥", "&yuml;", "ÿ");

	if (output)
	{
		fromTo[fromTo.length] = "&amp;";
		fromTo[fromTo.length] = "&";
	}
	for (var i=0; i < fromTo.length; i=i+2)
	{
		while (text.indexOf(fromTo[i + 1]) != -1)
		{
			text = text.replace(fromTo[i + 1], fromTo[i]); //Castañazo total
		}
	}

	return text;
}

//Función que comprueba si el texto que se le pasa es un valor numérico
function IsNumeric(strString, nodecimals)
{
	var strValidChars;
	if (nodecimals == true)
		strValidChars = "0123456789";
	else
		//strValidChars = "0123456789.-";
		strValidChars = "0123456789,";//Cambiamos el punto decimal por la coma decimal y pasamos de poner valores negativos
	var strChar;
	var blnResult = true;

	if (strString.length == 0) return false;

	//  test strString consists of valid characters listed above
	for (i = 0; i < strString.length && blnResult == true; i++)
	{
		strChar = strString.charAt(i);
		if (strValidChars.indexOf(strChar) == -1)
		{
			blnResult = false;
		}
	}
	return blnResult;
}

/**
* Función que comprueba si el valor del campo de texto que se le pasa como
* parámetro es numérico. La comprobación se va haciendo a medida que el
* usuario va tecleando sobre el campo de texto, usando el evento OnKeyUp()
*
* Esta función hace uso de la función declarada anteriormente
*/
function ValidateNumericField(inputman)
{
	var stringman = new String;

	for(var i = 0; i < inputman.value.length; i++)
	{
		if(IsNumeric(inputman.value.charAt(i),false) == true)
			stringman = stringman + inputman.value.charAt(i);
	}

	//Comprobamos que no se mete más de una coma decimal
	if (inputman.value.charAt(inputman.value.length - 1) == ",") //Si el último carácter que hemos tecleado es la coma decimal, comprobamos que no haya metido ninguna coma previamente
	{
		if(inputman.value.indexOf(",") > -1 && inputman.value.indexOf(",") < inputman.value.length - 1)
			stringman = stringman.substr(0,stringman.length - 1);
	}
	inputman.value = stringman;
}

/**
* Código para validar fechas. Originalmente servía para validar fechas en formato
* americano, aunque se ha modificado para validar fechas en formato europeo.
*
*
* Ejemplo de uso de la función isDate() en un formulario:
*
* function ValidateForm()
* {
*   var dt=document.frmSample.txtDate;
*
*	if (isDate(dt.value)==false) //Aquí está el meollo
*	{
*	  dt.focus();
*	  return false;
*	}
*   return true;
* }
*/
// Declaring valid date character, minimum year and maximum year
var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s)
{
	var i;
    for (i = 0; i < s.length; i++)
	{
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag)
{
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
	{   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year)
{
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}

function DaysArray(n)
{
	for (var i = 1; i <= n; i++)
	{
		this[i] = 31;
		if (i==4 || i==6 || i==9 || i==11) this[i] = 30;
		if (i==2) this[i] = 29;
   } 
   return this;
}

function isDate(dtStr)
{
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	//En el caso de querer usar el formato americano o el europeo, hay que hacer cambios en las dos líneas siguientes. Actualmente está para fechas europeas.
	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
	var strYear=dtStr.substring(pos2+1);
	strYr=strYear;
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1);
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1);
	for (var i = 1; i <= 3; i++)
	{
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1);
	}
	month=parseInt(strMonth);
	day=parseInt(strDay);
	year=parseInt(strYr);
	if (pos1==-1 || pos2==-1)
	{
		alert("El formato de fecha debe ser: dd/mm/aaaa");
		return false;
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month])
	{
		alert("Introduzca un día válido");
		return false;
	}
	if (strMonth.length<1 || month<1 || month>12)
	{
		alert("Introduzca un mes válido");
		return false;
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear)
	{
		alert("Introduzca un año válido (4 dígitos) entre "+minYear+" y "+maxYear);
		return false;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false)
	{
		alert("Introduzca una fecha válida");
		return false;
	}
	return true;
}

/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/

var Base64 = {

	// private property
	_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

	// public method for encoding
	encode : function (input) {
		var output = "";
		var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
		var i = 0;

		input = Base64._utf8_encode(input);

		while (i < input.length) {

			chr1 = input.charCodeAt(i++);
			chr2 = input.charCodeAt(i++);
			chr3 = input.charCodeAt(i++);

			enc1 = chr1 >> 2;
			enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
			enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
			enc4 = chr3 & 63;

			if (isNaN(chr2)) {
				enc3 = enc4 = 64;
			} else if (isNaN(chr3)) {
				enc4 = 64;
			}

			output = output +
			this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
			this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);

		}

		return output;
	},

	// public method for decoding
	decode : function (input) {
		var output = "";
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;

		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

		while (i < input.length) {

			enc1 = this._keyStr.indexOf(input.charAt(i++));
			enc2 = this._keyStr.indexOf(input.charAt(i++));
			enc3 = this._keyStr.indexOf(input.charAt(i++));
			enc4 = this._keyStr.indexOf(input.charAt(i++));

			chr1 = (enc1 << 2) | (enc2 >> 4);
			chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
			chr3 = ((enc3 & 3) << 6) | enc4;

			output = output + String.fromCharCode(chr1);

			if (enc3 != 64) {
				output = output + String.fromCharCode(chr2);
			}
			if (enc4 != 64) {
				output = output + String.fromCharCode(chr3);
			}

		}

		output = Base64._utf8_decode(output);

		return output;

	},

	// private method for UTF-8 encoding
	_utf8_encode : function (string) {
		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;
	},

	// private method for UTF-8 decoding
	_utf8_decode : function (utftext) {
		var string = "";
		var i = 0;
		var c = c1 = c2 = 0;

		while ( i < utftext.length ) {

			c = utftext.charCodeAt(i);

			if (c < 128) {
				string += String.fromCharCode(c);
				i++;
			}
			else if((c > 191) && (c < 224)) {
				c2 = utftext.charCodeAt(i+1);
				string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
				i += 2;
			}
			else {
				c2 = utftext.charCodeAt(i+1);
				c3 = utftext.charCodeAt(i+2);
				string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
				i += 3;
			}

		}

		return string;
	}

}

/*
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */

/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
var hexcase = 0;  /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad  = ""; /* base-64 pad character. "=" for strict RFC compliance   */
var chrsz   = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
function md5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz));} //Alias de la función hex_md5, para simplificar las cosas
function hex_md5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz));}
function b64_md5(s){ return binl2b64(core_md5(str2binl(s), s.length * chrsz));}
function str_md5(s){ return binl2str(core_md5(str2binl(s), s.length * chrsz));}
function hex_hmac_md5(key, data) { return binl2hex(core_hmac_md5(key, data)); }
function b64_hmac_md5(key, data) { return binl2b64(core_hmac_md5(key, data)); }
function str_hmac_md5(key, data) { return binl2str(core_hmac_md5(key, data)); }

/*
 * Perform a simple self-test to see if the VM is working
 */
function md5_vm_test()
{
  return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72";
}

/*
 * Calculate the MD5 of an array of little-endian words, and a bit length
 */
function core_md5(x, len)
{
  /* append padding */
  x[len >> 5] |= 0x80 << ((len) % 32);
  x[(((len + 64) >>> 9) << 4) + 14] = len;

  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;

  for(var i = 0; i < x.length; i += 16)
  {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;

    a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
    d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
    c = md5_ff(c, d, a, b, x[i+ 2], 17,  606105819);
    b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
    a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
    d = md5_ff(d, a, b, c, x[i+ 5], 12,  1200080426);
    c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
    b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
    a = md5_ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
    d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
    c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
    b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
    a = md5_ff(a, b, c, d, x[i+12], 7 ,  1804603682);
    d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
    c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
    b = md5_ff(b, c, d, a, x[i+15], 22,  1236535329);

    a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
    d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
    c = md5_gg(c, d, a, b, x[i+11], 14,  643717713);
    b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
    a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
    d = md5_gg(d, a, b, c, x[i+10], 9 ,  38016083);
    c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
    b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
    a = md5_gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
    d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
    c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
    b = md5_gg(b, c, d, a, x[i+ 8], 20,  1163531501);
    a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
    d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
    c = md5_gg(c, d, a, b, x[i+ 7], 14,  1735328473);
    b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);

    a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
    d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
    c = md5_hh(c, d, a, b, x[i+11], 16,  1839030562);
    b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
    a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
    d = md5_hh(d, a, b, c, x[i+ 4], 11,  1272893353);
    c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
    b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
    a = md5_hh(a, b, c, d, x[i+13], 4 ,  681279174);
    d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
    c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
    b = md5_hh(b, c, d, a, x[i+ 6], 23,  76029189);
    a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
    d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
    c = md5_hh(c, d, a, b, x[i+15], 16,  530742520);
    b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);

    a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
    d = md5_ii(d, a, b, c, x[i+ 7], 10,  1126891415);
    c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
    b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
    a = md5_ii(a, b, c, d, x[i+12], 6 ,  1700485571);
    d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
    c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
    b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
    a = md5_ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
    d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
    c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
    b = md5_ii(b, c, d, a, x[i+13], 21,  1309151649);
    a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
    d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
    c = md5_ii(c, d, a, b, x[i+ 2], 15,  718787259);
    b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
  }
  return Array(a, b, c, d);

}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function md5_cmn(q, a, b, x, s, t)
{
  return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);
}
function md5_ff(a, b, c, d, x, s, t)
{
  return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t)
{
  return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_hh(a, b, c, d, x, s, t)
{
  return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t)
{
  return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}

/*
 * Calculate the HMAC-MD5, of a key and some data
 */
function core_hmac_md5(key, data)
{
  var bkey = str2binl(key);
  if(bkey.length > 16) bkey = core_md5(bkey, key.length * chrsz);

  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 = core_md5(ipad.concat(str2binl(data)), 512 + data.length * chrsz);
  return core_md5(opad.concat(hash), 512 + 128);
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_add(x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function bit_rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}

/*
 * Convert a string to an array of little-endian words
 * If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
 */
function str2binl(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) << (i%32);
  return bin;
}

/*
 * Convert an array of little-endian words to a string
 */
function binl2str(bin)
{
  var str = "";
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);
  return str;
}

/*
 * Convert an array of little-endian words to a hex string.
 */
function binl2hex(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] >> ((i%4)*8+4)) & 0xF) +
           hex_tab.charAt((binarray[i>>2] >> ((i%4)*8  )) & 0xF);
  }
  return str;
}

/*
 * Convert an array of little-endian words to a base-64 string
 */
function binl2b64(binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i += 3)
  {
    var triplet = (((binarray[i   >> 2] >> 8 * ( i   %4)) & 0xFF) << 16)
                | (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )
                |  ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF);
    for(var j = 0; j < 4; j++)
    {
      if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
      else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
    }
  }
  return str;
}


