Affine-Cipher/affine.html at master · wTool/Affine-Cipher · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Affine Cipher</title>
<style type="text/css">
body{text-align:center;}
.center{width:600px;height:500px;position:absolute;left:50%;margin-left:-300px;border:2pxsolid;}
.center2{width:600px;height:550px;position:absolute;left:50%;margin-left:-300px;top:600px;border:2pxsolid;}
.comments{width:50%;overflow:auto;word-break:break-all;}
</style>
</head>
<body>
<h2 style="background-color: pink">Affine Cipher: Encryption - Decrption</h2>
<br>
<div class="center">
	<br>
	<br>
	<form>
		Plaintext:&nbsp;&nbsp;
		<textarea class="comments" rows="10" cols="10" id="input1"></textarea><br>
		k_1:&nbsp;&nbsp;
		<input type="text" name="k_1" id="input2"><br>
		k_2:&nbsp;&nbsp;
		<input type="text" name="k_2" id="input3"><br>
		<button type="button" onclick="eFunction()">Encrypt</button><br>
		Ciphertext:&nbsp;&nbsp;
		<textarea class="comments" rows="10" cols="10" id="output1"></textarea>
	</form>
</div>
<div class="center2">
	<br>
	<br>
		Ciphertext:&nbsp;&nbsp;
	<textarea class="comments" rows="10" cols="10" id="input4"></textarea><br>
		k_1:&nbsp;&nbsp;
	<input type="text" name="k_1" id="input5"><br>
		k_2:&nbsp;&nbsp;
	<input type="text" name="k_2" id="input6"><br>
	<button type="button" onclick="dFunction()">Decrypt</button><br>
		Plaintext:&nbsp;&nbsp;
	<textarea class="comments" rows="10" cols="10" id="output2"></textarea>
</div>
<script type="text/javascript">
function eFunction() {
	var k1;
	var k2;
	var code2 = "";
	var plaintext = document.getElementById("input1").value;
	plaintext = plaintext.toLowerCase();
	var result = "";
	var num;
	k1 = document.getElementById("input2").value;
	k1 = parseInt(k1);
	k2 = document.getElementById("input3").value;
	k2 = parseInt(k2);
	if (k1 < 26 && isNaN(k1) == false && k1 % 2 != 0 && k1 != 13 && k2 >= 0 && k2 <= 25) {
		for (var i = 0; i <= plaintext.length - 1; i++) {
			code = plaintext[i].charCodeAt() - 97;
			code = k1 * code + k2;
			code = code % 26;
			num = code;
			code2 += String.fromCharCode(num + 97);
			result = code2 + ""
		}
		document.getElementById("output1").value = result
	} else {
		document.getElementById("output1").value = "k1 or k2 is not correct"
	}
}
function dFunction() {
	var k1;
	var k11;
	k11 = parseInt(k11);
	var k2;
	var code2 = "";
	var ciphertext = document.getElementById("input4").value;
	ciphertext = ciphertext.toLowerCase();
	var result = "";
	var num;
	k1 = document.getElementById("input5").value;
	k1 = parseInt(k1);
	k2 = document.getElementById("input6").value;
	k2 = parseInt(k2);
	if (k1 < 26 && isNaN(k1) == false && k1 % 2 != 0 && k1 != 13 && k2 >= 0 && k2 <= 25) {
		if (k1 == 1) {
			k11 = 1
		}
		if (k1 == 3) {
			k11 = 9
		}
		if (k1 == 5) {
			k11 = 21
		}
		if (k1 == 7) {
			k11 = 15
		}
		if (k1 == 11) {
			k11 = 19
		}
		if (k1 == 17) {
			k11 = 23
		}
		if (k1 == 25) {
			k11 = 25
		}
		for (var i = 0; i <= ciphertext.length - 1; i++) {
			code = ciphertext[i].charCodeAt() - 97;
			code = k11 * (code - k2);
			code = code % 26;
			if (code < 0) {
				code += 26
			}
			num = code;
			code2 += String.fromCharCode(num + 97);
			result = code2 + ""
		}
		document.getElementById("output2").value = result
	} else {
		document.getElementById("output2").value = "k1 or k2 is not correct"
	}
}
</script>
</body>
</html>