crypto: introduce new module for TLS anonymous credentials

Introduce a QCryptoTLSCredsAnon class which is used to
manage anonymous TLS credentials. Use of this class is
generally discouraged since it does not offer strong
security, but it is required for backwards compatibility
with the current VNC server implementation.

Simple example CLI configuration:

 $QEMU -object tls-creds-anon,id=tls0,endpoint=server

Example using pre-created diffie-hellman parameters

 $QEMU -object tls-creds-anon,id=tls0,endpoint=server,\
               dir=/path/to/creds/dir

The 'id' value in the -object args will be used to associate the
credentials with the network services. For example, when the VNC
server is later converted it would use

 $QEMU -object tls-creds-anon,id=tls0,.... \
       -vnc 127.0.0.1:1,tls-creds=tls0

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Daniel P. Berrange 2015-03-13 17:39:26 +00:00
parent a090187de1
commit e00adf6c3e
5 changed files with 359 additions and 0 deletions

View file

@ -3571,6 +3571,26 @@ the @option{virtio-rng} device. The @option{chardev} parameter is
the unique ID of a character device backend that provides the connection
to the RNG daemon.
@item -object tls-creds-anon,id=@var{id},endpoint=@var{endpoint},dir=@var{/path/to/cred/dir},verify-peer=@var{on|off}
Creates a TLS anonymous credentials object, which can be used to provide
TLS support on network backends. The @option{id} parameter is a unique
ID which network backends will use to access the credentials. The
@option{endpoint} is either @option{server} or @option{client} depending
on whether the QEMU network backend that uses the credentials will be
acting as a client or as a server. If @option{verify-peer} is enabled
(the default) then once the handshake is completed, the peer credentials
will be verified, though this is a no-op for anonymous credentials.
The @var{dir} parameter tells QEMU where to find the credential
files. For server endpoints, this directory may contain a file
@var{dh-params.pem} providing diffie-hellman parameters to use
for the TLS server. If the file is missing, QEMU will generate
a set of DH parameters at startup. This is a computationally
expensive operation that consumes random pool entropy, so it is
recommended that a persistent set of parameters be generated
upfront and saved.
@end table
ETEXI