1.5 Files/client protection

Hi again, Today i am going tutorial how to protect your client files so please follow cautiously!

1)First of all please download this program and install: http://www.slavasoft.com/zip/hashcalc.zip
*This program uses for calculate our files SHA1 with HMAC key.
2)After you install HashCalc open it and enable the check box of SHA1 and also of HMAC if disabled.
3)The HMAC key that MAIET set on Gunz source is "gunzkingJJang":

Quote:

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(HMAC_SHA1.h)

#define GUNZ_HMAC_KEY "gunzkingJJang"

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*If you want you can change this string to anything you want.

4)Now, load any file you want to "protect" on HashCalc example fmod.dll and then add on the HMAC
this key: gunzkingJJang

Picture:

http://puu.sh/a1IQc/ac4bc89313.png

This is my fmod.dll sha1: 888f1f7b7e3c43384f4b80b577fe091ac045383c
So we should change sha1 to:
0x88,0x8f,0x1f,0x7b,0x7e,0x3c,0x43,0x38,0x4f,0x4b,0x80,0xb5,0x77,0xfe,0x09,0x1a,0xc0,0x45,0x38,0x3c

Open Main.cpp and search for:

BYTE SHA_fmod[20] =

and here you can add more files to check, Example:

Quote:

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//Check for system.mrs
BYTE SHA_system[20] = {here your sha1};

!CheckDll("system.mrs", SHA_system) ||

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Credits: MAIET and me for this tutorial.

You can do md5 checker too(same). Anyway good release.

i have this to but only with MD5 ,

thanks for this realy usefull :)

how to make anyone not decompile.

Quote:

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Originally Posted by etropulus

how to make anyone not decompile.

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Replace the Mrs file type, / recode it so mrs de-compilers will no longer work.

Quote:

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Originally Posted by Secured

Replace the Mrs file type, / recode it so mrs de-compilers will no longer work.

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how to? thanks for helping me.

This is fucking useless. All you're doing is making sure that for whatever minor update, you need to update AND recompile GunZ with the new SHA1 key of the compiled MRS file, not to mention the obvious fact that it can be bypassed easier than I can fart in the wind.

Quote:

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Originally Posted by etropulus

how to? thanks for helping me.

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The fact that you asked this question means that you're not capable of replacing the entire filesystem. You can either change the RecoveryChar() and ConvertChar() functions, or completely rebuild the GunZ filesystem with a new compression and encryption method.

Quote:

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Originally Posted by [S]pirit

This is fucking useless. All you're doing is making sure that for whatever minor update, you need to update AND recompile GunZ with the new SHA1 key of the compiled MRS file, not to mention the obvious fact that it can be bypassed easier than I can fart in the wind.

The fact that you asked this question means that you're not capable of replacing the entire filesystem. You can either change the RecoveryChar() and ConvertChar() functions, or completely rebuild the GunZ filesystem with a new compression and encryption method.

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Thanks , How to Make .mrs files?

Quote:

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Originally Posted by etropulus

Thanks , How to Make .mrs files?

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ugh.
http://www.pkware.com/documents/casestudies/APPNOTE.TXT
Implement a normal ZIP compressor/decompressor (hint: zlib DEFLATE), then make sure the central directory, fileheader, and local fileheader are all "encrypted" using ConvertChar().