Scrypt

[b8vr]

Hi,

I have a Scrypt hash, mode 8900, that has N, r, p values of 16 for each. For example, it looks like SCRYPT:16:16:16:SALT:HASH. When I try to crack it with hashcat using a wordlist that I know contains the password, I get a "Salt value exception". If I try to crack it with N, r, p values more like 1024, 1, 1 then it finds the password no problem. I took a quick look at the Scrypt code in hashcat and saw that if N isn't a multiple of 1024, then hashcat throws that salt value exception. But, I think the Scrypt spec doesn't require N to be a multiple of 1024. So, an N value of 16, while unusual, is valid, I believe. So, is there another way to crack the hash for N values that aren't multiples of of 1024, namely when N, r, p are 16?

Thanks!

I would say you're right:

  The CPU/Memory cost parameter N
   ("costParameter") must be larger than 1, a power of 2, and less than
   2^(128 * r / 8).

https://www.hjp.at/doc/rfc/rfc7914.html