Closes canonical#218

Signed-off-by: Stéphane Graber <stgraber@stgraber.org>
Signed-off-by: Mark Laing <mark.laing@canonical.com>

The test as it was written was quite incorrect.

core.trust_ca_certificates causes valid certificates to be implictly
trusted and not get a certificate store entry.

But as the test was run immediately after a configuration where
core.trust_ca_certificates was not set, there was a leftover entry in
the trust store which the test was then checking.

This corrects the test by clearing the trust store after the initial
test and by further making sure that when using
core.trust_ca_certificates, no trust store entries get created.

Signed-off-by: Stéphane Graber <stgraber@stgraber.org>
Signed-off-by: Mark Laing <mark.laing@canonical.com>

…ler.

Previously we ran the access handler regardless of whether a request was
authenticated. This would usually fail because there would be no
username in the request context. However we need to be careful that a
user is authenticated if predicating access on the presence of a CA
certificate.

Signed-off-by: Mark Laing <mark.laing@canonical.com>