Re: [Qemu-devel] [PATCH] crypto: Implement TLS Pre-Shared Keys (PSK).

[Daniel P . Berrangé]

On Mon, Jun 25, 2018 at 06:07:15PM +0100, Richard W.M. Jones wrote:
> Pre-Shared Keys (PSK) is a simpler mechanism for enabling TLS
> connections than using certificates.  It requires only a simple secret
> key:
> 
>   $ mkdir -m 0700 /tmp/keys
>   $ psktool -u rjones -p /tmp/keys/keys.psk
>   $ cat /tmp/keys/keys.psk
>   rjones:d543770c15ad93d76443fb56f501a31969235f47e999720ae8d2336f6a13fcbc
> 
> The key can be secretly shared between clients and servers.  Clients
> must specify the directory containing the "keys.psk" file and a
> username (defaults to "qemu").  Servers must specify only the
> directory.
> 
> Example NBD client:
> 
>   $ qemu-img info \
>     --object 
> tls-creds-psk,id=tls0,dir=/tmp/keys,username=rjones,endpoint=client \
>     --image-opts \
>     
> file.driver=nbd,file.host=localhost,file.port=10809,file.tls-creds=tls0,file.export=/
> 
> Example NBD server using qemu-nbd:
> 
>   $ qemu-nbd -t -x / \
>     --object tls-creds-psk,id=tls0,endpoint=server,dir=/tmp/keys \
>     --tls-creds tls0 \
>     image.qcow2
> 
> Example NBD server using nbdkit:
> 
>   $ nbdkit -n -e / -fv \
>     --tls=on --tls-psk=/tmp/keys/keys.psk \
>     file file=disk.img
> 
> Signed-off-by: Richard W.M. Jones <address@hidden>
> ---
>  crypto/Makefile.objs         |   1 +
>  crypto/tlscredspsk.c         | 300 
> +++++++++++++++++++++++++++++++++++++++++++
>  crypto/tlssession.c          |  38 ++++++
>  crypto/trace-events          |   3 +
>  include/crypto/tlscredspsk.h | 106 +++++++++++++++
>  5 files changed, 448 insertions(+)

Not done a proper code review yet but just a docs point...

Can you describe the new object type in qemu-options.hx - look for the
existing entry related to tls-creds-x509

Also in qemu-doc.texi at approx

  "@section TLS setup for network services"

we'll need something added related to PSK to describe how to set it
up. I guess we'll want to put what's there already under an "x509"
section, and add a PSK section


Regards,
Daniel
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