Generating a serial?

[Dracil]

Im using _Crypt_HashData($code,$CALG_MD5) to generate a hash code, but how do i make sepcific algorym, or i mean add some extra letters so the hash dont end up all like everyone else who uses crypt hashdata on autoit =)

Edited January 16, 2010 by Dracil

[KaFu]

In SMF I use this to create a UUID (Universally Unique Identifier) ...

#include <WinApi.au3>
MsgBox(0,"",_UuidCreat())

; http://www.autoitscript.com/forum/index.php?showtopic=92844&view=findpost&p=715421
; Smashly
; http://msdn.microsoft.com/en-us/library/aa379205%28VS.85%29.aspx

Func _UuidCreat()
    Local $tGUID, $pGUID
    $tGUID = DllStructCreate($tagGUID)
    $pGUID = DllStructGetPtr($tGUID)
    DllCall("rpcrt4.dll", "int", "UuidCreate", "ptr", $pGUID)
    If Not @error Then Return _WinAPI_StringFromGUID($pGUID)
EndFunc   ;==>_UuidCreat

[Dracil]

does this change the hash algorythm ?

[KaFu]

md5 hashing is a one-way encryption, you can't decrypt the result anymore. Using the same $code will always produce the same hash... my example above just generates a different results on each call. I use it by checking if a serial has been set in an ini file and if not then generate one. This way each client gets it's unique id.

If that doesn't solve you problem, explain in more detail what you want to achieve exactly...

Edited January 16, 2010 by KaFu

[jchd]

Im using _Crypt_HashData($code,$CALG_MD5) to generate a hash code, but how do i make sepcific algorym, or i mean add some extra letters so the hash dont end up all like everyone else who uses crypt hashdata on autoit =)

Do _not_ try to invent a new hash algorithm by yourself! This would be the worst move you could do.

Now if you want a standard, proven algorithm to produce an essentially unique hash on a given block of data, just add "salt".

The idea is, like you suggested, prefix your data with some "secret" custom value. Don't forget either that your AutoIt executable can be reverse-engineered quite easily, so there is little point in using a very sophisticated solution as it can't be hidden completely (NTW, nothing can be!).

Don't listen to the reports than MD5 is "broken" because one can produce collisions. This is for specialists only and MD5 is still a decently robust solution to hash for most uses except crypto-level.