This is much more complex than the TLS Extension/OCSP cases. We need to
first alter the certificate and remove the extension from it, before
extracting the tbscert. Furthermore, we need the key hash of the issuing
certificate to be able to validate the proof - which means that we need
a valid certificate chain.
Missing: documentation, nice integration so that we can just add a
script and use this in Bro.
This commit add the table SSL::ct_logs to Bro. This table is populated
with information about the currently active certificate transparency
logs (data from Google). The data can, e.g., be used to identify which
Logs are being used in SCTs.
This is a tiny bit evil because it uses parts of the SSL protocol
analyzer in the X.509 certificate parser. Which is the fault of the
protocol, which replicates the functionality.
