Provide a commandline utility to decode hash parameters

[gvegidy]

Each hash method has it's own way to encode parameters like cost and salt. For auditing and monitoring purposes it would be nice to have a generic tool which could decode them.

I think of something like this:

> gethashparam $y$jCT$4NdgJN...
method: yescrypt
salt: 1asdfasfda...
r: 32
N: 32768
p: 1
t: 0
g: 0

If I planned to transition to a more strict hashing policy, such a tool would be the base for a script which told me which users have to re-hash their password. Also I could monitor for salt reuse.

I know that there are plans to enforce hash policy with crypt.conf, but I think such a tool could be complementary as you won't be able to enforce a policy which excludes most of your users.

[melak]

+1