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

<?php
require_once( "rc4.php" );

$key = "0123456789abcdef";
$plaintext = "Hello World!";

$ciphertext = rc4( $key, $plaintext );

$decrypted = rc4( $key, $ciphertext );

echo $decrypted . " - " . $plaintext . "\n";

?>

2. Execute the tests and display the results

<?php
require_once( "rc4tests.php" ); // Auto includes rc4.php

echo rc4_tests();

?>

3. Execute the tests as benchmarks and display the results

<?php
require_once( "rc4tests.php" ); // Auto includes rc4.php

echo rc4_benchmark();

?>

About this entry

You’re currently reading “RC4/ARCFOUR Implementation in PHP,” an entry on Weblog of Michael Cutler

Published:
1st March 2006 / 5:03pm
Category:
Projects, Misc, PHP

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