Re: [RFC PATCH] rt2800lib: unconditionally enable MFP

[Stanislaw Gruszka <stf_xl@wp.pl>]

Hello

On Mon, May 25, 2020 at 12:14:54PM +0100, Rui Salvaterra wrote:
> > If someone is willing to implement mt76 approach to have HW encryption offload
> > for MFP+CCMP, I'll be happy to review patch. From other hand, most people will
> > use MFP with modern ciphers anyway, so I'm not sure how much need is for such
> > patch.
> 
> I've been having a look at how mt76 solves the problem, but I haven't
> fully understood it yet. I feel it's out of my league, since I only
> started looking at wireless drivers very recently (I don't grasp all
> the concepts and the architecture).

Yeah, it's somewhat complicated.

> But one thing that also bugs me
> about software fallbacks is that for most of the older CPUs we don't
> have SIMD implementations of the required crypto. So, not only we fall
> back to software, but we're also stuck with scalar C algorithms on
> CPUs which are already slow.

If we talk about x86, we have AES-NI instructions since 2008:
https://en.wikipedia.org/wiki/AES_instruction_set
Which make CPU crypto quite fast. Though it can be a bottleneck,
I think, if wifi encryption is performed together with other encryption
applications like SSL .

Stanislaw