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 <rjones@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
