Re: munge / obfuscate ?

On Mar 28, 2008, at 7:15 PM, "Jack Sasportas" <Jack@innovativeinternet.com

wrote:

-----Original Message----- From: Robert Cummings [mailto:robert@interjinn.com] Sent: Thursday, March 27, 2008 10:02 PM To: Joey Cc: PHP Subject: RE: [PHP] munge / obfuscate ? Hi Joey, Please keep responses on the list so others can also benefit from the learning process. Comments below... On Thu, 2008-03-27 at 21:46 -0400, Joey wrote:

-----Original Message----- From: Robert Cummings [mailto:robert@interjinn.com] Sent: Thursday, March 27, 2008 9:28 PM To: Joey Cc: PHP Subject: Re: [PHP] munge / obfuscate ? On Thu, 2008-03-27 at 21:10 -0400, Joey wrote:

Hi All, I have written an app to allow a person to go online and see a

picture

we

take of them. When we link to the picture I don't want it to be

obvious

that the URL is Domain.Com/Pix/123.jpg because the next person we take a picture

of may

be

123.jpg, so I am trying to munge/obfuscate the URL to make it

less

obvious.

<?php $sekret = 'the brown cow stomped on the wittle bug'; $id = isset( $_GET['id'] ) ? (int)$_GET['id'] : 0; $key = isset( $_GET['key'] ) ? (string)$_GET['key'] : ''; if( $key == sha1( $key.':'.$sekret ) )

That should have been:

       if( $key == sha1( $id.':'.$sekret ) )

{

       header( 'Content-Type: image/jpg' );
       readfile( "/images/not/in/web/path/$id.jpg" )
       exit();

} // // Failure... tell them to bugger off :) // header( 'Content-Type: image/jpg' ); readfile( '/images/wherever/you/please/buggerOff.jpg' ); exit(); ?>

Sorry to be such a newbie... I basically would call this function lets say like: munge( $url ); end in the end be returned the munged url, however, I don't

understand the

values you have like the readfile with that url -vs- failure?

I didn't munge... I provided code for a script that sends the

requested

image if it was requested with the appropriate key (presumably set wherever the image was linked). If the key doesn't validate then

another

image is presented. It can say "bugger off", it can say "not found",

it

can say whatever you please. By placing the images outside the web

root

and using a script like this you are virtually guaranteed the visitor can't just request images by making a lucky guess. Let's say the above script was called: getUserImage.php Then you might have the following in your HTML: <img

src="getUserImage.php?id=123&amp;key=4fad1fea72565105d84cb187d1a3ed3bfb9 aba3b"

/>

I understand what is happening here, however I really want something simple like: $link ="http://www.whataver.com/whateverpath/"; $image = "123456"; new_image = munge($image); new_link = $link . $new_image; or maybe new_link = munge($link . $image); Which would encode the whole link. Either way this is what would go into the email message we send out. Thanks! -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php

You could use base64_encode/decode. Or... function bitshift_encode($i) { return $i << 3; } function bitshift_decode($i) { return $i >> 3; }