07-08-2012, 01:45 PM
With the LinkedIn list it would be very difficult (outside the realm of probability) to detect that those hashes were not crackable, because they are valid hashes by all accounts. They were the right length and contained the correct characters.
For mixed hashes it's even more difficult because it's impossible to distinguish between e.g. lm, nt, md4, md5, double md5, md5 of sha1, whatever.
If you know for certain that you have a list of SHA1 hashes plus maybe some other garbage, the best you can do is something like: egrep '^[a-f0-9]{40}$' list >cleanlist But that wouldn't help in a LinkedIn-type scenario.
For mixed hashes it's even more difficult because it's impossible to distinguish between e.g. lm, nt, md4, md5, double md5, md5 of sha1, whatever.
If you know for certain that you have a list of SHA1 hashes plus maybe some other garbage, the best you can do is something like: egrep '^[a-f0-9]{40}$' list >cleanlist But that wouldn't help in a LinkedIn-type scenario.