Re:encryption algs

Hi all,

That's correct, the "MD5" implementation on most modern *NIXes (including 
most Linux distros) is a salted hash, that incorporates the userID as part 
of the salt, and then encodes the result as Base64.
A "pure" MD5 hash for a given plaintext is always the same, a salted hash 
isn't.

I miss the point about "NT-MD5" someone mentioned. If you mean NTLM, it's 
not MD5. It's an MD4 hash from the unicode representation of the password.

Feel free to experiment with Lepton's Crack (of which, incidentally, I'm 
one of the authors ;-) available at http://freshmeat.net/lcrack/

I recommend also reading the 2 password sections of ISSAF 
(http://www.oissg.org/issaf/).

Cheers,

Miguel Dilaj (Nekromancer)
Vice-President of IT Security Research, OISSG






"Ghaith Nasrawi" <libero@aucegypt.edu>
28/01/2005 09:42

 
        To:     "postbase" <postbase@mail.ru>
        cc:     "security-basics" <security-basics@securityfocus.com>, (bcc: 
Miguel 
Dilaj/PH/Novartis)
        Subject:        Re:encryption algs


UNIX-MD5? I "think" the MD5 algorithm used in most current *nix
systems is a salted hash algorithm. 
{snip}