Generátor Vigenérova šifrového kódu

<script type="text/javascript">



function VigenerEncode(textToEncypher, codeKey) {

	var retStr = '';

	codeKey = codeKey.toLowerCase();	

	

	var j = 0;

	for (var i = 0; i < textToEncypher.length; i++) {

		var cat = textToEncypher.charCodeAt(i);		

		if (cat > 64 && cat < 91) cat += 32;

		if (cat < 97 || cat > 122) cat = null;

		if (cat != null) {

			var radek = codeKey.charCodeAt(j % codeKey.length) - 96;

			cat += radek - 1;

			if (cat > 122) cat = (cat % 122) + 96;

			retStr += String.fromCharCode(cat);

			j++;

		}

	}

	return retStr;

}



function VigenerDecode(textToDecypher, codeKey) {

	var retStr = '';

	codeKey = codeKey.toLowerCase();	

	for (var i = 0; i < textToDecypher.length; i++) {

		var cat = textToDecypher.charCodeAt(i);

		var radek = codeKey.charCodeAt(i % codeKey.length) - 96;

		cat -= (radek - 1);

		if (cat < 97) cat += 26;

		retStr += String.fromCharCode(cat);

	}

	return retStr;

}



document.write ("Zakodovany text: " + VigenerEncode("Tato zprava je zasifrovana Vigenerovou sifrou!", "heslo") + "<br><br>");

document.write ("Dekodovany text: " + VigenerDecode("aelznwvsgoqirlgpjjzjhrsgwnifpfvzgfgpjjzi", "heslo"));



</script>

<script type="text/javascript">



function VigenerEncode(textToEncypher, codeKey) {

	var retStr = '';

	codeKey = codeKey.toLowerCase();	

	

	var j = 0;

	for (var i = 0; i < textToEncypher.length; i++) {

		var cat = textToEncypher.charCodeAt(i);		

		if (cat > 64 && cat < 91) cat += 32;

		if (cat < 97 || cat > 122) cat = null;

		if (cat != null) {

			var radek = codeKey.charCodeAt(j % codeKey.length) - 96;

			cat += radek - 1;

			if (cat > 122) cat = (cat % 122) + 96;

			retStr += String.fromCharCode(cat);

			j++;

		}

	}

	return retStr;

}



function VigenerDecode(textToDecypher, codeKey) {

	var retStr = '';

	codeKey = codeKey.toLowerCase();	

	for (var i = 0; i < textToDecypher.length; i++) {

		var cat = textToDecypher.charCodeAt(i);

		var radek = codeKey.charCodeAt(i % codeKey.length) - 96;

		cat -= (radek - 1);

		if (cat < 97) cat += 26;

		retStr += String.fromCharCode(cat);

	}

	return retStr;

}



function doIt() {

	var vigIn = document.getElementById('vigIn');

	var pass = document.getElementById('pass');

	var vigOut = document.getElementById('vigOut');

	var typ = document.getElementById('typ').value;

	

	if (typ == 1) vigOut.value = VigenerEncode(vigIn.value, pass.value);

	if (typ == 2) vigOut.value = VigenerDecode(vigIn.value, pass.value);

}



</script>



<form action="#">

	Vlozte text: <input type="text" id="vigIn"><br>

	Vlozte heslo: <input type="text" id="pass"><br><br>

	Vystupni text: <input type="text" id="vigOut"><br><br>

	<select id="typ">

		<option selected="selected" value="1">Zakodovat</option>

		<option value="2">Rozkodovat</option>

	</select><br><br>

	<button onclick="doIt(); return false;">Proved</button>

</form>