Custom MD5 types

[MsChievous]

You are right that there is no kernel for md5($salt.md5($pass).md5($salt)). Since this is probably not a very common hash type I don't think the developers will add it, but if you want to write your own kernel you should start by reading this: https://hashcat.net/forum/thread-5302-po...l#pid28754

Unfortunately I have never written my own kernels for hashcat so I have no idea how to do that, but you could try asking in the developer forums, perhaps someone will help you out there. :)