sha1 64 hex with only 8 variables

[MisterY]

Hi all

I have the following constellation:
SHA1(64 bytes) = hash

Known are 56 of these 64 bytes as well as the hash value itself. Is it possible to set up a masked attack with the following specification?
- a length of 64 bytes
- 56 bytes are constant, only 8 bytes are variable
- the possible input is the whole byte range, 0x00 to 0xFF

Thanks a lot for your thoughts

[undeath]

hashcat supports at most 55bytes of plaintext.

[atom]

Right, there's no way to do this with hashcat unless a special new hash-mode is added. This depends on where that hash / salt combination that you talk about is used and if it makes sense to add it to hashcat so that many users can benefit from it. If you think that's the case, please add a trac ticket

[MisterY]

Okay, thanks for your answers. For me it's a quite important single case, but not of public interest.