Do the version 5.1 support iterations or custom combination of current hashes?
Now ,I want to crack one hash computed by serveral iterations of HMAC-SHA512.

For example, 
In the first round, hmac-sha512(salt,password) produces h1.
And in the later rounds, the salt is constant and the password is the result of previous round.

I notice the john the ripper support the feature. However, In the implement of HMAC-SHA512 of the jtr, the password is key. and in the hash I want to crack  the salt is key. It also can't work.

So I want to know if the hashcat 5.1 support this feature.
if not, will hashcat support it in the future?
can changing the kernel files solve it?(I saw this method in other post)