Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1275768

Re: [RFC PATCH 2/2] Crypto kernel tls socket

Show all headers | View raw

On (11/23/15 09:43), Dave Watson wrote:
> Currently gcm(aes) represents ~80% of our SSL connections.
> 
> Userspace interface:
> 
> 1) A transform and op socket are created using the userspace crypto interface
> 2) Setsockopt ALG_SET_AUTHSIZE is called
> 3) Setsockopt ALG_SET_KEY is called twice, since we need both send/recv keys
> 4) ALG_SET_IV cmsgs are sent twice, since we need both send/recv IVs.
>    To support userspace heartbeats, changeciphersuite, etc, we would also need
>    to get these back out, use them, then reset them via CMSG.
> 5) ALG_SET_OP cmsg is overloaded to mean FD to read/write from.

[from patch 0/2:]
> If a non application-data TLS record is seen, it is left on the TCP
> socket and an error is returned on the ALG socket, and the record is
> left for userspace to manage.

Interesting approach.

FWIW, I was hoping to discuss solutions for securing traffic tunnelled
over L3 at netdev 1.1, so hopefully we'll be able to go over the
trade-offs there. 

I'm trying to see how your approach would fit with the RDS-type of
use-case. RDS-TCP is mostly similar in concept to kcm,
except that rds has its own header for multiplexing, and has no 
dependancy on BPF for basic things like re-assembling the datagram. 
If I were to try to use this for RDS-TCP, the tls_tcp_read_sock() logic
would be merged into the recv_actor callback for RDS, right?  Thus tls
control-plane message could be seen in the middle of the
data-stream, so we really have to freeze the processing of the data
stream till the control-plane message is processed?

I'm concerned about the possiblilites for async that can happen when
we separate the data-plane from the control-plane (uspace tls
does not have to deal with this), but we now have control plane
separated from data-plane. (And IPsec/IKE has plenty of headaches
from this sort of thing already)

In the tls.c example that you have, the opfd is generated from
the accept() on the AF_ALG socket- how would this work if I wanted
my opfd to be a PF_RDS or a PF_KCM or similar?

One concern is that this patchset provides a solution for the "80%"
case but what about the other 20% (and the non x86 platforms)?
E.g., if I get a cipher-suite request outside the aes-ni, what would
happen (punt to uspace?)

--Sowmini

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC PATCH 0/2] Crypto kernel TLS socket Dave Watson <davejwatson@fb.com> - 2015-11-23 18:50 +0100
  [RFC PATCH 1/2] Crypto support aesni rfc5288 Dave Watson <davejwatson@fb.com> - 2015-11-23 18:50 +0100
    Re: [RFC PATCH 1/2] Crypto support aesni rfc5288 Herbert Xu <herbert@gondor.apana.org.au> - 2015-11-24 11:40 +0100
  [RFC PATCH 2/2] Crypto kernel tls socket Dave Watson <davejwatson@fb.com> - 2015-11-23 18:50 +0100
    Re: [RFC PATCH 2/2] Crypto kernel tls socket Sowmini Varadhan <sowmini.varadhan@oracle.com> - 2015-11-23 20:30 +0100
      Re: [RFC PATCH 2/2] Crypto kernel tls socket Dave Watson <davejwatson@fb.com> - 2015-11-23 22:50 +0100
        Re: [RFC PATCH 2/2] Crypto kernel tls socket Sowmini Varadhan <sowmini.varadhan@oracle.com> - 2015-11-23 23:00 +0100
    Re: [RFC PATCH 2/2] Crypto kernel tls socket Herbert Xu <herbert@gondor.apana.org.au> - 2015-11-24 11:40 +0100
      Re: [RFC PATCH 2/2] Crypto kernel tls socket Stephan Mueller <smueller@chronox.de> - 2015-11-24 12:10 +0100
        Re: [RFC PATCH 2/2] Crypto kernel tls socket Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-24 12:30 +0100
          Re: [RFC PATCH 2/2] Crypto kernel tls socket Phil Sutter <phil@nwl.cc> - 2015-11-24 13:00 +0100
            Re: [RFC PATCH 2/2] Crypto kernel tls socket Stephan Mueller <smueller@chronox.de> - 2015-11-24 13:40 +0100
          Re: [RFC PATCH 2/2] Crypto kernel tls socket Sowmini Varadhan <sowmini.varadhan@oracle.com> - 2015-11-24 13:00 +0100
          Re: [RFC PATCH 2/2] Crypto kernel tls socket Stephan Mueller <smueller@chronox.de> - 2015-11-24 13:40 +0100
  Re: [RFC PATCH 0/2] Crypto kernel TLS socket Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-11-23 20:20 +0100

csiph-web