GSM project is up on GitHub
I decided to create a new, separate project for all my GSM research. My goal is to sniff my own data, crack the key, and read the SMS I sent/listen to the voice call I made. I am still hesitating in terms of hardware to use between OsmocomBB phones (a lot better, more accurate hardware for voice especially) and rtl-sdr (much easier to use, and  so far it already showed how awesome it is and how great capabilities it has).
Anyhow, for key cracking you need to have the a51_table files, which are available from torrents. Sadly I wasn’t able to find a correctly formatted file containing MD5 hashes for these 40 files, so I collected all the hashes from the a51 mailing list’s archives and put them in a format that could be used with the Linux utility ‘md5sum’ to automatically check integrity.
https://github.com/domi007/gsm
I will also commit a list containing exact sizes of the table files into this repository, so if you would not like to wait for md5sum you can just check the files based on size.