Luigi Auriemma

Hey, I'm not advanced in programming much at all... But i figure I have enough time and want to learn pretty much anything.

Anyway, i was wondering if you could give some insight on how the "lin2ed" program works...

Also, I don't know C or C++... So far, I'm only used to plain delphi 7... I'm pretty sure its a python language... But if i need to learn C or C++ then i will learn it :D.

Anyway, any insight on how to decrypt/encrypt files for Lineage 2 would be great... I am aware that 412/413 aren't support by you, which comes to my second question...

What is the best way to try to reverse an encryption? I hear the word reverse engineer alot, I guess that is I want to do... I mean, I would like to find out how the 412/413 encryption works, what would be the best way to find information about them?

Thanks for your time and hopefully I'm making some sense :P
-- fmwyso

If you mean the practically usage, well it's a command-line tool so must be launched from cmd.exe

The 111, 121 file versions use a simple XOR operation, in the first case with the fixed value 0xac while in 121 is used a number retrieved from the chars in the filename

211 and 212 instead use the blowfish algorithm with 2 different fixed keys.

From version 411 instead is used an encryption algorithm with a private and public key (RSA), so in short you can decrypt the files without problems but you can't re-encrypt them because you don't have the corresponding key.
In this case the only solution is modifying the decryption key in the L2 executable with one we have.

Anyway I don't watch the L2 stuff from years.

If i want to make my own program to do the same thing... Would i have to learn C/C++? If so, i got a book to read xD. If not, some explanations on how the blowfish code works would be great :D.

By works, i mean... Where chars does it grab from the charname and how does it accomplish that?


If i need to learn C, do you have any tutorials/sites that could help me learn it?

it's enough simple, the first 28 bytes of each file are the signature while all the rest is the encrypted data that you must pass to Blowfish.
the blowfish key for version 212 is "[;'.]94-&@%!^+]-31==" while for version 211 is "31==-%&@!^+][;'.]94-" included the final NULL byte (in short both the keys are 21 bytes long).
Blowfish is a public known encryption algorithm so doesn't require eplanations, find the decrypter for your language and it's done.

Oh, ok cool thanks ^_^