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File: crypt.class.php

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File: crypt.class.php
Role: Auxiliary script
Content type: text/plain
Description: Crypt class by Michael Dransfield <mike@blueroot.net> for Advanced Anti-Spam
Class: Anti-Spam
Protection against e-mail address harvesting
Author: By
Last change:
Date: 20 years ago
Size: 5,019 bytes
 

Contents

Class file image Download
<?php
//
// +----------------------------------------------------------------------+
// | PHP Version 4 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2002 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.02 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Michael Dransfield <mike@blueroot.net> |
// +----------------------------------------------------------------------+
//


/**
 * PEAR::HTML_Crypt
 *
 * The PEAR::HTML_Crypt provides methods to encrypt text, which
 * can be later be decrypted using JavaScript on the client side
 *
 * This is very useful to prevent spam robots collecting email
 * addresses from your site, included is a method to add mailto
 * links to the text being generated
 *
 * a basic example to encrypt an email address
 * $c = new HTML_Crypt('yourname@emailaddress.com', 8);
 * $c->addMailTo();
 * $c->output();
 *
 * @author Michael Dransfield <mike@blueroot.net>
 * @package HTML_Crypt
 * @version $Revision: 1.1 $
 */
 
 
class HTML_Crypt{

   
// {{{ properties

    /**
     * The unencrypted text
     *
     * @access public
     * @var string
     * @see setText()
     */
    
    
var $text = '';
    
   
/**
     * The full javascript to be sent to the browser
     *
     * @access public
     * @var string
     * @see getScript()
     */
    
    
var $script = '';
    
    
   
/**
     * The text encrypted - without any js
     *
     * @access public
     * @var string
     * @see cyrptText
     */
    
    
var $cryptString = '';
    
    
   
/**
     * The number to offset the text by
     *
     * @access public
     * @var int
     */
    
    
var $offset;
    
   
// }}}
    // {{{ HTML_Crypt()

    /**
     * Constructor
     *
     * @access public
     * @param string $text The text to encrypt
     * @param int $offset The offset used to encrypt/decrypt
     */
    
   
function HTML_Crypt($text='', $offset=3){
       
$this->offset = $offset;
       
$this->text = $text;
       
$this->script = '';
    }
   
   
// }}}
    // {{{ setText()

    /**
     * Set name of the current realm
     *
     * @access public
     * @param string $text The text to be encrypted
     */
   
function setText($text){
       
$this->text = $text;
    }
   
   
// }}}
    // {{{ addMailTo()

    /**
     * Turns the text into a mailto link (make sure
     * the text only contains an email)
     *
     * @access public
     */
   
function addMailTo(){
   
$email = $this->text;
   
$this->text = '<a href="mailto:'.$email.'">'.$email.'</a>';
    }
   
   
// }}}
    // {{{ cryptText()

    /**
     * Encrypts the text
     *
     * @access private
     */
   
function cryptText(){
       
$length = strlen($this->text);
        for (
$i=0;$i<$length;$i++)
        {
       
$current_chr = substr($this->text, $i, 1);
       
$inter = ord($current_chr)+$this->offset;
       
$enc_string .= chr($inter);
        }
       
$this->cryptString = $enc_string;
    }
   
   
// }}}
    // {{{ getScript()

    /**
     * Set name of the current realm
     *
     * @access public
     * @return string $script The javascript generated
     */
   
function getScript(){
    if (
$this->cryptString=='' && $this->text != ''){
   
$this->cryptText();
    }
           
// get a random string to use as a function name
           
srand ((float) microtime() * 10000000);
           
$letters = array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z');
           
$rnd = $letters[array_rand($letters)] . md5(time());
           
// the actual js (in one line to confuse)
           
$script = "<script language=\"JavaScript\" type=\"text/JavaScript\">var a,s,n;function $rnd(s){r='';for(i=0;i<s.length;i++){n=s.charCodeAt(i);if(n>=8364){n=128;}r+=String.fromCharCode(n-".$this->offset.");}return r;}a='".$this->cryptString."';document.write ($rnd(a));</script>";
           
$this->script = $script;
            return
$script;
    }
   
   
// }}}
    // {{{ output()

    /**
     * Outputs the full JS to the browser
     *
     * @access public
     */
   
function output(){
        if (
$this->script == ''){
       
$this->getScript();
        }
        return
$this->script;
    }
}
   
   
?>