Solved

How to hide/encrypt http arguments in php?

Posted on 2008-06-17
6
271 Views
Last Modified: 2008-06-17
Hi

lets consider we are passing one argument like below

http://thegurbani.com/audio/index.php?file=http://www.thegurbani.com/audio/audio/kirtan/4.mp3

argument : "file=http://www.thegurbani.com/audio/audio/kirtan/4.mp3"

I want you to encrypt this argument and then at target location decrypt it.

Plz note I need this argument in normal form becoz I am catching it at target location into a php_variable.
0
Comment
Question by:theredcode
  • 4
6 Comments
 
LVL 49

Expert Comment

by:Roonaan
ID: 21804633
Do you have access to a database? Then you could just use file=123 or file=456 based on an primairy auto increment key.
0
 
LVL 29

Expert Comment

by:rdivilbiss
ID: 21804636
Use the AES encrypt function, which is part of the mcrypt library.
0
 

Author Comment

by:theredcode
ID: 21804775
well no database, simple argument passing

can u provide code for encrypting and decrypting.
0
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

 
LVL 29

Expert Comment

by:rdivilbiss
ID: 21804805
Yes, a moment please.
0
 
LVL 29

Accepted Solution

by:
rdivilbiss earned 500 total points
ID: 21805440

<?PHP
 
$iv = mcrypt_create_iv(16, MCRYPT_RAND);
$key = substr($fieldHash,0,mcrypt_get_key_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB));
 
// need to use the same key and iv to decode so save to session	
$_SESSION['key']=$key;
$_SESSION['iv']=$iv;
 
//have to pad your string to be at least 64 chars.  Can be longer.
$text = str_pad("http://www.thegurbani.com/audio/audio/kirtan/4.mp3",64);
 
//Need to Base64 encode the encrypted string or it won't pass as a URL.
$param = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $text, MCRYPT_MODE_ECB, $iv));
 
//  how to decrypt...using saved values and base64 decrypt
$href = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $_SESSION['key'], base64_decode($param), MCRYPT_MODE_ECB, $_SESSION['iv']);
 
 
?>
<html>
 
<head>
<meta http-equiv="Content-Language" content="en-us">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>The link</title>
</head>
 
<body>
<p>Link with encoded param: <a href="aeslink2.php?p=<?=$param?>">The link</a></p>
<p>Decoded Param: <?=$href?></p>
</body>
 
</html>

Open in new window

0
 
LVL 29

Expert Comment

by:rdivilbiss
ID: 21808637
That code isn't good for your purposes.  See below for better.
<?PHP
session_start();
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
// save these for decoding
$_SESSION["iv"] = $iv;
 
$key = "This is a very secret key";
$_SESSION["key"] = $key;
 
//$text = "Who framed Roger Rabbit";
$text = addcslashes("http://www.thegurbani.com/audio/4.mp3","\0..\37");
 
// we will pass the length...nothing given away with that.
$len = strlen($text);
 
$crypttext = urlencode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_ECB, $iv));
?>
<html>
 
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>Send Encrypted URL Parameter</title>
</head>
 
<body>
<p>Hover over the URL to see what is passed.</p>
<a href="page2.php?file=<?=$crypttext?>&len=<?=$len?>">Pass It</a>
</body>
 
</html>
 
 
 
<?PHP
// page2.php
session_start();
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
 
// We need the originals
$iv = $_SESSION["iv"];
$key = $_SESSION["key"];
 
// get the encrypted filename
$param=$_GET["file"];
 
// get its length
$len=$_GET["len"];
 
// decode, decrypt and perform substr to get the original file name
$filex = substr(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, urldecode($param), MCRYPT_MODE_ECB, $iv),0,$len);
?>
 
<html>
 
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>Receive Encrypted File Name</title>
</head>
 
<body>
<?=$filex?>
</body>
 
</html>

Open in new window

0

Featured Post

Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction HTML checkboxes provide the perfect way for a web developer to receive client input when the client's options might be none, one or many.  But the PHP code for processing the checkboxes can be confusing at first.  What if a checkbox is…
I imagine that there are some, like me, who require a way of getting currency exchange rates for implementation in web project from time to time, so I thought I would share a solution that I have developed for this purpose. It turns out that Yaho…
The viewer will learn how to count occurrences of each item in an array.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

786 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question