Step editing PHP Function that uses Encode Bytecode

Some premium wordpress theme that we purchase often deliberately offered with Bytecode encoding by the developer (PHP files), examples are premuim wordpress theme that I got this.

Examples of my wordpress themes contained Bytecode decoding, for instance:

<?php $ _F=__FILE__$ _X='Pz48P3A5cA0KDQo3dW5jdGlvbiAwcHQ5M20zc25vMF9zM3R0aW5ncygkazN5KSB7DQoNCglnOG9iNTggJHMzdHRpbmdzOw0KDQoJMjN0dTJuICRzM3R0aW5nc1skazN5XTsNCg0KfQ0'eval(base64_decode('JF9YPWJhc2U2NF9kZWNvZGUoJF9YKTskX1g9c3RydHIo........................

base64_decode('JF9YPWJhc2U2NF9kZWNvZGUoJF9YKTskX1g9c3RydHIoJF9YLCdqd3ZhcmhlZmw4NzM5MjU0MDYnLCc2MDQ1MjkzNzhsZmVocmF2d2onKTskX1I9ZXJlZ19yZXBsYWNlKF9fRklMRV9fLCRfRiwkX1gpO2V2YWwoJF9SKTskX1I9MDskX1g9MDs=')) ?>

With Bytecode encoding implies it can not if we want to change the layout of a function or a specific element of the code of this theme, even if we've paid for it, we can not.

Naturally this is a bit frustrating, but it is attainable to reverse engineer the file as follows to make the modifications you require. I myself need to have two days to discover a way on the web. And here I will share with you now.

Right here are the methods you want to do to modify the PHP function that is secured by encoding Bytecode:

• The 3 element components

Each and every file has 3 main components to it:

$ _F=__FILE__

$ _X='a-string-of-text-and-numbers'

eval(base64_decode('a-string-of-text-and-numbers')

These components are as follows:

$ _F - a holder to do the ereg_replace of the obfuscater code with the unencryption keys

$ _X - the encrypted PHP code

eval(base64_decode() - the decryption code for $ _X

• Receiving the decryption code

To get the decryption code, we want to adjust the eval(base64_decode()) code to be an echo rather.

In our case above this would be:

echo(base64_decode(‘a-string-of-text-and-numbers’) and this offers us the decryption code for the principal $ _X values

$ _X=base64_decode($ _X)$ _X=strtr($ _X,'123456aouie','aouie123456')$ _R=ereg_replace('__FILE__',"'".$ _F."'",$ _X)eval($ _R)$ _R=$ _X=

If we break this apart into it’s core lines we have:

//decode our principal string with base64_decode
$ _X=base64_decode($ _X)

//replace obfuscater characters in the result with the appropriate ones
$ _X=strtr($ _X,'123456aouie','aouie123456')

//replace the contents of $ _R with our unencrypted file/PHP code
$ _R=ereg_replace('__FILE__',"'".$ _F."'",$ _X)

//run the contents of the unencrypted file/PHP code
eval($ _R)

//clear the contents of $ _R so you can't access it
$ _R=

//clear the contents of $ _X so you cannot access it
$ _X=

• Decrypting the encoded code

So now we just need to run the decryption code as far as it replacing the contents of $ _R with the un-encrypted result, and echo that out to the screen.

• Here’s the code:

//decode our principal string with base64_decode
$ _X=base64_decode($ _X)

//replace obfuscater characters in the outcome with the correct ones
$ _X=strtr($ _X,'123456aouie','aouie123456')

//replace the contents of $ _R with our unencrypted file/PHP code
$ _R=ereg_replace('__FILE__',"'".$ _F."'",$ _X)

//print the contents of the unencrypted file/PHP code
echo($ _R)

• Final code

So we end up with:

<?php
$ _F=__FILE__
$ _X='a-string-of-text-and-numbers'
$ _X=base64_decode($ _X)
$ _X=strtr($ _X,'123456aouie','aouie123456')
$ _R=ereg_replace('__FILE__',"'".$ _F."'",$ _X)
echo $ _R
?>

Accomplished.. And we can now make the modifications we need to have. 

NOTE: The use of this article is not my responsibility, but entirely your personal duty

Title: Step editing PHP Function that uses Encode Bytecode
Rating: 910109 Votes

Posted by: Admin Updated at: 5:39 AM

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