Tuesday, January 13, 2009


Hi, and welcome at yet another blog :)

I needed some space to share some thoughts, some things I learn and some tools. Last months I have been playing around with rainbow tables, hashing algorithms, brute forcers and other related topics. This has resulted in a couple of topics that I plan to blog about:

* A new set of rainbow tables that are currently generated by the Free Rainbow Tables project (link at the right). This set covers passwords from a special character set, specifically for LM hashes.

* rcracki_mt, a multi-threaded version of the tool rcracki, used for 'cracking' password hashes with the rainbow tables generated by the Free Rainbow Tables project.

* A tool for doing not only case correction with a cracked LM hash and the accompanying NTLM hash, but also do something I call unicode correction. I still need to release this tool, but I already implemented the code in rcracki_mt.

* A first attempt at optimizing the MD4 hashing algorithm that is used for NTLM hashes, using code provided by other people. My version is not that useful, but I learned some nice things.

* A SHA-1 implementation optimized for cracking passwords with a length < 16. First meant for use in rcracki_mt, but then I started liking optimizations. So by now I have sort of a SHA-1 brute forcer, using SSE2 and with the last 3 steps reversed, the first 4 steps unrolled and precalculated as much as possible. I got some tips, hints and directions from Svarychevski Michail Aleksandrovich regarding the use of SSE2, tnx for that. Btw, he has an awfully fast MD5 brute forcer, for both CPU (SSE2 optimized) and for GPU (both CUDA (nVidia) and Brook (AMD/ATI).

I plan to blog about these topics in the coming [days... eh, no, weeks... nooo,] months. I'll also post the tools I made along with the code, so maybe other people might profit from the things I learned as well. Or just so others that actually do have some l33t programming skills might optimize things even more. So, check back later and feel free to leave a note :)

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