[rsyslog] TLS certificates

[RB]

On Tue, Dec 2, 2008 at 06:55, Juan Miscaro <jmiscaro at gmail.com> wrote:
> "neither the client nor the server are authenticated. So while the
> message transfer is encrypted, you can not be sure which peer you are
> talking to"

I'm hoping Rainer will jump in and clarify precisely how much
handshake validation he's implemented.  The fact that the client must
have a copy of the CA's public material seems to indicate he is at
least verifying that the server's certificate was issued by the CA.
It's possible to not do so, but the result is rather susceptible to
MITM.

> Also, how can client encrypt without having any keys specified in its config?

This isn't the forum to discuss the particulars of the SSL handshake,
but suffice it to say that SSL incorporates a challenge/response
mechanism (using the server's presented certificate) followed by
negotiation of an ephemeral session key.  See also: public-key
cryptography.

> $DefaultNetstreamDriverCAFile /path/to/contrib/gnutls/ca.pem
> $ActionSendStreamDriverAuthMode anon # server is NOT authenticated
>
> 2nd question: Why is the server not authenticated?

Without looking at the code, I presume the 'anon' AuthMode is the
switch used to tell the SSL library whether or not to check the server
certificate against the CA.  If so, it should make specifying the CA
public key redundant - the client just accepts whatever certificate
the server (or MITM) presents and starts encrypting to it.