Implementasi cipher dengan PHP

Kemarin kebetulan belajar keamanan informasi tentang enkripsi, dan di ajarkan beberapa enkripsi yaitu caesar cipher dan vigenere cipher. tiba tiba terfikir ingin mencoba membuat cipher dengan PHP, berhubung saya sedang menggemari bahasa tersebut. ya alhamdulillah setelah beberapa hari akhirnya jadi juga ๐Ÿ˜€

untuk menjelaskan programnya satu persatu, mungkin akan memakan banyak waktu, jadi saya cuma copas listing programnya saja, untuk penjelasan mengenail syntaxnya banyak sekali di temukan di Google atau di W3schools.

yang pertama buat file untuk convertnya, beri nama convert.php

<?php
/*
 *      convert.php
 *      
 *      Copyright 2011 Ahmad Zafrullah Mardiansyah <zaf@zaf-laptop>
 *      
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *      
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *      
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *      MA 02110-1301, USA.
 */
 
function char_to_dec($a){
	$i=ord($a);
	if ($i>=97 && $i<=122){
		return ($i-96);
	} else if ($i>=65 && $i<=90){
		return ($i-38);
	} else {
		return null;
	}
}

function dec_to_char($a){
	if ($a>=1 && $a<=26){
		return (chr($a+96));
	} else if ($a>=27 && $a<=52){
		return (chr($a+38));
	} else {
		return null;
	}
}

function tabel_vigenere_encrypt($a, $b){
	$i=$a+$b-1;
	if ($i>26){
		$i=$i-26;
	}
	return (dec_to_char($i));
}
function tabel_vigenere_decrypt($a, $b){
	$i=$a-$b+1;
	if ($i<1){
		$i=$i+26;
	}
	return (dec_to_char($i));
}

?>


kemudian untukย  index.php nya

<?php
/*
 *      index.php
 *      
 *      Copyright 2011 Ahmad Zafrullah Mardiansyah <zaf@zaf-laptop>
 *      
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *      
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *      
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *      MA 02110-1301, USA.
 */
 
include "convert.php";

?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>
	<title>cipher | 23Pstars</title>
	<meta http-equiv="content-type" content="text/html;charset=utf-8" />
	<meta name="generator" content="Geany 0.18" />
	<style type="text/css">
	a:link {color: #000000; text-decoration: none}
	a:visited {color: #000000; text-decoration: none}
	a:hover {color: #FF0000; text-decoration: underline}
	</style>
	<script type="text/javascript">
	function SelectAll(id){
		document.getElementById(id).focus();
		document.getElementById(id).select();
	}
	function Info(){
		alert("Original code by :"+'\n\n'+"Ahmad Zafrullah Mardiansyah");
	}
	function InfoCaesar(){
		alert("Key hanya berupa kombinasi angka,"+'\n'+"dan plan text tidak boleh mengandung angka!");
	}
	function InfoVigenere(){
		alert("Key hanya berupa kombinasi kata, tidak boleh mengandung angka,"+'\n'+"dan plan text tidak boleh mengandung angka!");
	}
	</script>
</head>

<body>
	<center>
	<h2>Simple cipher implementation with PHP</h2>
	<h4><a onclick="Info()">by 23Pstars</a></h4>
	</center>
	<table width="600" align="center">
	<tr><td width="50%" valign="top">
	<fieldset>
	<legend><b>Caesar</b></legend>
	<form action="" method="post">
	<input type="text" name="key_caesar" id="key_caesar" value="the key..." onclick="SelectAll('key_caesar')" />
	<input type="submit" value="?" onclick="InfoCaesar()" /><br/>
	<textarea rows="4" name="plantext_caesar" id="plantext_caesar" cols="33" onclick="SelectAll('plantext_caesar')" >plan text...</textarea><br/>
	<input type="submit" name="encrypt_caesar" value="Encrypt" /><input type="submit" name="decrypt_caesar" value="Decrypt" /><input type="reset" value="Reset" />
	</form>
	</fieldset>
	</td><td valign="top" colspan="3">
	<fieldset>
	<legend><b>Result</b></legend>
	<?php
	//----------------------------------------------------------------//
	// caesar														  //
	//----------------------------------------------------------------//
		if((isset($_POST['key_caesar'])) && (isset($_POST['plantext_caesar'])) && isset($_POST['encrypt_caesar'])){
			$key=$_POST['key_caesar'];
			$plantext=$_POST['plantext_caesar'];
			$split_key=str_split($key);
			$i=0;
			$split_chr=str_split($plantext);
			while ($key>52){
				$key=$key-52;
			}
			foreach($split_chr as $chr){
				if (char_to_dec($chr)!=null){
					$split_nmbr[$i]=char_to_dec($chr);
				} else {
					$split_nmbr[$i]=$chr;
				}
				$i++;
			}
			echo '<textarea rows="4" id="result" cols="33" onclick="SelectAll(\'result\')" >';
			foreach($split_nmbr as $nmbr){
				if (($nmbr+$key)>52){
					if (dec_to_char($nmbr)!=null){
						echo dec_to_char(($nmbr+$key)-52);
					} else {
						echo $nmbr;
					}
				} else {
					if (dec_to_char($nmbr)!=null){
						echo dec_to_char($nmbr+$key);
					} else {
						echo $nmbr;
					}
				}
			}
			echo '</textarea><br/>';
		} else if ((isset($_POST['key_caesar'])) && (isset($_POST['plantext_caesar'])) && isset($_POST['decrypt_caesar'])){
			$key=$_POST['key_caesar'];
			$plantext=$_POST['plantext_caesar'];
			$i=0;
			$split_chr=str_split($plantext);
			while ($key>52){
				$key=$key-52;
			}
			foreach($split_chr as $chr){
				if (char_to_dec($chr)!=null){
					$split_nmbr[$i]=char_to_dec($chr);
				} else {
					$split_nmbr[$i]=$chr;
				}
				$i++;
			}
			echo '<textarea rows="4" id="result" cols="33" onclick="SelectAll(\'result\')" >';
			foreach($split_nmbr as $nmbr){
				if (($nmbr-$key)<1){
					if (dec_to_char($nmbr)!=null){
						echo dec_to_char(($nmbr-$key)+52);
					} else {
						echo $nmbr;
					}
				} else {
					if (dec_to_char($nmbr)!=null){
						echo dec_to_char($nmbr-$key);
					} else {
						echo $nmbr;
					}
				}
			}
			echo '</textarea><br/>';
			
	//----------------------------------------------------------------//
	// vigenere														  //
	//----------------------------------------------------------------//
		} else if ((isset($_POST['key_vigenere'])) && (isset($_POST['plantext_vigenere'])) && (isset($_POST['encrypt_vigenere']))){
			$key=$_POST['key_vigenere'];
			$plantext=$_POST['plantext_vigenere'];
			$len_key=strlen($key);
			$len_plantext=strlen($plantext);
			$split_key=str_split($key);
			$split_plantext=str_split($plantext);
			
			echo '<textarea rows="4" id="result" cols="33" onclick="SelectAll(\'result\')" >';
			$i=0;
			for($j=0;$j<$len_plantext;$j++){
				if ($i==$len_key){
					$i=0;
				}
				$split_key2[$j]=$split_key[$i];
				$i++;
			}
			for($k=0;$k<$len_plantext;$k++){
				$a=char_to_dec($split_key2[$k]);
				$b=char_to_dec($split_plantext[$k]);
				if (($a && $b)!=null){
					echo (tabel_vigenere_encrypt($a, $b));
				} else {
					echo $split_plantext[$k];
				}
			}
			echo '</textarea><br/>';
		} else if ((isset($_POST['key_vigenere'])) && (isset($_POST['plantext_vigenere'])) && (isset($_POST['decrypt_vigenere']))){
			$key=$_POST['key_vigenere'];
			$plantext=$_POST['plantext_vigenere'];
			$len_key=strlen($key);
			$len_plantext=strlen($plantext);
			$split_key=str_split($key);
			$split_plantext=str_split($plantext);
			
			echo '<textarea rows="4" id="result" cols="33" onclick="SelectAll(\'result\')" >';
			$i=0;
			for($j=0;$j<$len_plantext;$j++){
				if ($i==$len_key){
					$i=0;
				}
				$split_key2[$j]=$split_key[$i];
				$i++;
			}
			
			for($k=0;$k<$len_plantext;$k++){
				$a=char_to_dec($split_key2[$k]);
				$b=char_to_dec($split_plantext[$k]);
				if (($a && $b)!=null){
					echo (tabel_vigenere_decrypt($b, $a));
				} else {
					echo $split_plantext[$k];
				}
			}
			
			echo '</textarea><br/>';

		} else {
			echo "result here...";
		}
	?>
	</fieldset>
	</td></tr>
	<tr><td valign="top">
	<fieldset>
	<legend><b>Vigenere</b></legend>
	<form action="" method="post">
	<input type="text" name="key_vigenere" id="key_vigenere" value="the key..." onclick="SelectAll('key_vigenere')" />
	<input type="submit" value="?" onclick="InfoVigenere()" /><br/>
	<textarea rows="4" name="plantext_vigenere" id="plantext_vigenere" cols="33" onclick="SelectAll('plantext_vigenere')" >plan text...</textarea><br/>
	<input type="submit" name="encrypt_vigenere" value="Encrypt" /><input type="submit" name="decrypt_vigenere" value="Decrypt" /><input type="reset" value="Reset" />
	</form>
	</fieldset>
	</td></tr>
	<!-- masih dalam pengerjaan :p
	<tr><td valign="top">
	<fieldset>
	<legend><b>Playfair</b></legend>
	<form action="" method="post">
	<input type="text" name="key_playfair" id="key_playfair" value="the key..." onclick="SelectAll('key_playfair')" /><br/>
	<textarea rows="4" name="plantext_playfair" id="plantext_playfair" cols="33" onclick="SelectAll('plantext_playfair')" >plan text...</textarea><br/>
	<input type="submit" name="encrypt_playfair" value="Encrypt" /><input type="submit" name="Decrypt_playfair" value="Decrypt" /><input type="reset" value="Reset" />
	</form>
	</fieldset>
	</td></tr>
	-->
	</table>
</body>
</html>

kemudian untuk hasil jadinya bisa di lihat di http://zaf.web.id/labs/cipher

17 thoughts on “Implementasi cipher dengan PHP

  1. Maaf pak mau nanya,,
    Misalnya :
    Plaintextnya : saya ingin bertanya
    Kata kuncinya: 12345
    Kira2 bisa gak di enkripsi dan dekripsi?

    Terima kasih

  2. Halo kak numpang tanya dong, khususnya untuk kriptografi VIGENERE, saya ingin mengimplementasikannya pada database toko online mohon bantuannya kak

  3. Pingback: tutorial program caesar chiper menggunakan PHP | Online Coding

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