How to generate hashes for directory content (files) not crack them ?
#1
Hi !

I see hashcat is the one of rare tools using GPU horsepower to speedup cracking passwords but my intention is a bit different. I'm searching for tool that can use GPUs but for hash generation (SHA-256 - has type 1400 by https://hashcat.net/wiki/doku.php?id=example_hashes) not password cracking.

My use case would be scan a ton of archive files and compare the duplicates much faster using GPUs than CPUs.
Current benchmarking proves a i7 type CPU can't saturate more that 1-2GBit/s bandwidth on this task on any type of files (even 100GB each running parallel 16 threads) but testing hashcat on my Dell XPS 15 laptop with a week GT 750M is already 25% faster than the CPU and me having a local and network storage that is ~ 1GB/s (8Gbit/s) capable I would use the GPUs for the task as that would limit the need for so many workstations to do the work. 

Looking at the docs and features I see hashcat is capable of multitasking and even multi node setups but what it would take to add this mode to the feature set in near future ?

Thanks !
Best regards,
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#2
imo this is unlikely to be implemented, but I'm not a hashcat dev.

also see this related thread: https://hashcat.net/forum/thread-7221.html
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#3
In this case, GPUs will actually NOT be faster. Since the archives are very large, you will lose a lot of the things that make GPUs faster for password cracking when trying to load them in and calculate their hashes. Just look at the difference between the optimized speeds(-O) and the pure kernel speeds. For SHA256 the optimized kernel is limited to 55characters i believe, where the pure is out at 256characters for its limit. The drop in speed from a 55char pass to a 256char pass being supported is incredible. Now imagine a password that's 1billion characters long because its actually the binary data from an archive. Yeah, no. Far better off using CPUs imo.
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