2023-09-01, 11:32:19 +0100, Russell King (Oracle) wrote:

On Fri, Sep 01, 2023 at 12:07:32PM +0200, Sabrina Dubroca wrote:

quoted

2023-09-01, 09:09:06 +0000, Radu Pirea wrote:

quoted

We can do a flush very simple, but to restore the configuration maybe
we should to save the key in the macsec_key structure. I am not sure if
the key can be extracted from crypto_aead structure.

Either that or in the driver. I have a small preference for driver,
because then cases that don't need this restore won't have to keep the
key in memory, reducing the likelihood of accidentally sharing it.
OTOH, if we centralize that code, it's easier to make sure everything
is cleared from kernel memory when we delete the SA.

Maybe consider about doing it as a library function, so drivers that
need this don't have to reimplement the functionality in randomly
buggy ways?

But then the driver would depend on the macsec module, right? It's not
a large module, but that seems a bit undesirable.

I think I'd rather add the key to macsec_key, and only copy it there
in case we're offloading (we currently don't allow enabling offloading
after installing some SAs/keys so that would be fine). Maybe add a
driver flag to request keeping the keys in memory (I don't know if all
drivers will require that -- seems like all PHY drivers would, but what
about the MAC ones?).

-- 
Sabrina