Hi all,

recent updates to the NVMe spec have added definitions for in-band
authentication, and seeing that it provides some real benefit
especially for NVMe-TCP here's an attempt to implement it.

Tricky bit here is that the specification orients itself on TLS 1.3,
but supports only the FFDHE groups. Which of course the kernel doesn't
support. I've been able to come up with a patch for this, but as this
is my first attempt to fix anything in the crypto area I would invite
people more familiar with these matters to have a look.

Also note that this is just for in-band authentication. Secure
concatenation (ie starting TLS with the negotiated parameters) is not
implemented; one would need to update the kernel TLS implementation
for this, which at this time is beyond scope.

As usual, comments and reviews are welcome.

Still no nvme-cli nor nvmetcli :(