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+--- Thread: DES hash-value exception (/thread-3809.html)
DES hash-value exception - nelicacs - 11-05-2014
Got two DES hashes from an embedded device running uClinux:
abvQyXa0CDjIA ("uClinux")
ab4tUGw1MFHR1 (unknown plaintext)
both cudaHashcat and oclHashcat successfully brute-force the first one, but give an exception with the second hash:
Quote:$ ./cudaHashcat64.bin -m 1500 pwd.txt
cudaHashcat v1.31 starting...
WARNING: Hashfile 'pwd.txt' in line 2 (ab4tUGw1MFHR1): Hash-value exception
Could it be an issue with hashcat or the crypt() algorithm on that (specific?) version of uClinux produces a non-standard hash?
RE: DES hash-value exception - atom - 11-05-2014
yeah well the reason is that the 64 bit des crypttext is not divisible by 6 (from base64 encode). therefore there's 2 bit in the end that should be zero. if they are not one could declare it as an invalid hash as it seems the buffer used for encoding was somehow not zero'd before using. that's not neccessarily a failure but hashcat checks it.