Very simple 2 way encryption?

[aximbigfan]

Hi,

 

I'm codign a log viewer, and I finished up most of the core stuff, and now an doign the extra stuff.

 

One thing is that th password for the configuration system is stored in plain text, in a .ini file. The app does checked to make sure that permission to the file is denied (from the web browser, no preventing it from explorer).

 

Still though, I would really like just a basic 2 way encryption system. Can anyone show me how this is done? Nothing complex, just shift the position of the letters/numbers over like 5 spots or something.

 

It will eventually need to be a bit more complex, but if someone can just show me an outline of how to do it, I'm sure I could pick it up pretty fast. I just haven't done much with this kind of thing...

 

Thanks,

Chris

[mysterbx]

http://lt2.php.net/md5 ?

[Barand]

md5 is one-way

 

An easy 2-way is str_rot13()

 

<?php
$str = 'abcde';

$encrypt = str_rot13($str);

echo $encrypt . '<br/>';           // nopqr

$orig = str_rot13($encrypt);

echo $orig;                        // abcde

?>

[Barand]

A slightly more complex 2-way method is to use xor bitwise operator

 

<?php

        function simpleEncrypt($str, $key)
        {
            $k = strlen ($str) ;
            $encrypt = '';
            for($i=0;$i<$k;$i++) {
                
                 $encrypt .= ($str[$i]^($key));      // Xor each character with the key char
            }
            return $encrypt;
        }


$str = 'abcde';
$key = ch r(128);

$enc = simpleEncrypt($str, $key);

echo $enc, '<br/>';

$orig = simpleEncrypt($enc, $key);

echo $orig;
?>

[aximbigfan]

Ok, perfect! This is exactly what I need, light, simple, easy to understand, just perfect.

 

Thanks!!!

Chris

[aximbigfan]

I'm having trouble with this. Is there anyway to decrypt it without knowing the original string, and just knowing the already encrypted string?

 

Thanks,

Chris

[Barand]

As long as you know the key character that was used

 

$original = simpleEncrypt ($encrypted, $key);

[Daniel0]

You could also use mcrypt.

[aximbigfan]

As long as you know the key character that was used

 

$original = simpleEncrypt ($encrypted, $key);

Bah, I'm sorry, I just wasn't thinking.

 

Topic solved, thanks all.

 

I'll also look at mcrypt....

 

Chris