Weblog of Michael Cutler » PHP http://blog.lobstertechnology.com "I felt a great disturbance in the Force, as if millions of peers suddenly cried out in terror and were suddenly silenced." Tue, 17 Oct 2006 14:40:43 +0000 http://wordpress.org/?v=2.8.4 en hourly 1 RC4/ARCFOUR Implementation in PHP http://blog.lobstertechnology.com/2006/03/01/rc4-arcfour-implementation-in-php/ http://blog.lobstertechnology.com/2006/03/01/rc4-arcfour-implementation-in-php/#comments Wed, 01 Mar 2006 17:05:38 +0000 Michael Cutler http://blog.lobstertechnology.com/2006/03/01/rc4-arcfour-implementation-in-php/ I wrote this RC4/ARCFOUR implementation in PHP - based on the original C source code posted on usenet in 1994. The rc4() call itself is completely self-contained, two other methods rc4_test() and rc4_benchmark() have been provided for testing and are optional.

My motivation for writing it was to replace the dependency on MCrypt in my SpamKit plugin for Wordpress - see Gerry's site for the updated TBT code I will wrap in the next SpamKit Plugin release.

This is software is completely public domain, all I ask for is a simple credit for my work if you find it useful.

View Source: rc4.php
View Source: rc4tests.php

Examples:

1. Simple encryption & decryption

PLAIN TEXT
PHP:
  1. <?php
  2. require_once( "rc4.php" );
  3.  
  4. $key = "0123456789abcdef";
  5. $plaintext = "Hello World!";
  6.  
  7. $ciphertext = rc4( $key, $plaintext );
  8.  
  9. $decrypted = rc4( $key, $ciphertext );
  10.  
  11. echo $decrypted . " - " . $plaintext . "\n";
  12.  
  13. ?>

2. Execute the tests and display the results

PLAIN TEXT
PHP:
  1. <?php
  2. require_once( "rc4tests.php" ); // Auto includes rc4.php
  3.  
  4. echo rc4_tests();
  5.  
  6. ?>

3. Execute the tests as benchmarks and display the results

PLAIN TEXT
PHP:
  1. <?php
  2. require_once( "rc4tests.php" ); // Auto includes rc4.php
  3.  
  4. echo rc4_benchmark();
  5.  
  6. ?>

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