hashcat Forum

I have a specific use case in mind which I am not sure how helpful hashcat will be to me.

I have a pattern of hash inputs (which can be expressed as a hash mask), and I am interested in knowing whether or not, given a particular hash ouput, that hash output could have been generated from a string input which matches the hashmask. I don't need to know what the actual string was, just that there exists a string which could have given the hash as output. It takes too long to run through all the hashes every time I want to check a hash, so I was thinking that I could precompute and generate a dictionary of some sort (really a set, as there are no key -> value pairs), which could be queried afterwards to see if a hash is contained within in (from hashcat or an external program).

Is this possible using hashcat?

yes you could do this.

just start by doing a standard mask attack against the hash. if you don't want to see what the input was, just use -o /dev/null --disable-potfile and hashcat will simply print a message saying it cracked the hash without telling you what the input was, and exit with the appropriate return code.

you could use maskprocessor to pre-compute this; however, you wouldn't want to actually do this, because for one it will likely require a massive amount of disk space, and second, on-gpu candidate generation is several orders of magnitude faster than running through a straight wordlist.