<?php

/**
 * mail_fetch/functions.php
 *
 * Copyright (c) 1999-2005 The SquirrelMail Project Team
 * Licensed under the GNU GPL. For full terms see the file COPYING.
 *
 * Functions for the mailfetch plugin.
 *
 * Original code from LexZEUS <lexzeus@mifinca.com>
 * and josh@superfork.com (extracted from php manual)
 * Adapted for MailFetch by Philippe Mingo <mingo@rotedic.com>
 *
 * @version $Id$
 * @package plugins
 * @subpackage mail_fetch
 */

/**
 * hex2bin - document me
 */
function hex2bin( $data ) {

    /* Original code by josh@superfork.com */

    $len = strlen($data);
    $newdata = '';
    for( $i=0; $i < $len; $i += 2 ) {
        $newdata .= pack( "C", hexdec( substr( $data, $i, 2) ) );
    }
    return $newdata;
}

function mf_keyED( $txt ) {

    global $MF_TIT;

    if( !isset( $MF_TIT ) ) {
        $MF_TIT = "MailFetch Secure for SquirrelMail 1.x";
    }

    $encrypt_key = md5( $MF_TIT );
    $ctr = 0;
    $tmp = "";
    for( $i = 0; $i < strlen( $txt ); $i++ ) {
        if( $ctr == strlen( $encrypt_key ) ) $ctr=0;
        $tmp.= substr( $txt, $i, 1 ) ^ substr( $encrypt_key, $ctr, 1 );
        $ctr++;
    }
    return $tmp;
}

function encrypt( $txt ) {

    srand( (double) microtime() * 1000000 );
    $encrypt_key = md5( rand( 0, 32000 ) );
    $ctr = 0;
    $tmp = "";
    for( $i = 0; $i < strlen( $txt ); $i++ ) {
        if ($ctr==strlen($encrypt_key)) $ctr=0;
        $tmp.= substr($encrypt_key,$ctr,1) .
            (substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1));
        $ctr++;
    }
    return bin2hex( mf_keyED( $tmp ) );

}

function decrypt( $txt ) {

    $txt = mf_keyED( hex2bin( $txt ) );
    $tmp = '';
    for ( $i=0; $i < strlen( $txt ); $i++ ) {
        $md5 = substr( $txt, $i, 1 );
        $i++;
        $tmp.= ( substr( $txt, $i, 1 ) ^ $md5 );
    }
    return $tmp;
}

?>