Re: Doing crypto in small stack buffers (bluetooth vs vmalloc-stack crash, etc)

On Tue, Jun 28, 2016 at 09:23:01AM -0400, George Spelvin wrote:

Wow, I should see how you do that.  I couldn't get it below 3
blocks of temporary, and the dst SG list only gives you
one and a half.

I don't mean that I'm using no temporary buffers at all, just
that the actual crypto only operates on the SG lists.  I'm still
doing the xoring and stitching in temp buffers.  I just counted
and I'm using three blocks like you.

Is net/sunrpc/auth_gss/gss_krb5_mech.c doing something odd?

Yes gss_krb5_crypto.c is the one.

I have a request of you: like Andy, I find the crypto layer an
impenetrable thicket of wrapper structures.  I'm not suggesting there
aren't reasons for it, but it's extremely hard to infer those reasons by
looking at the code.  If I were to draft a (hilariously wrong) overview
document, would you be willing to edit it into correctness?

We have actually gained quite a bit of documentation recently.
Have you looked at Documentation/DocBook/crypto-API.tmpl?

More is always welcome of course.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
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