It does not look like Phabricator supports SSL connections to MySQL (or at least I was not able to find it in docs).
There are two parts of this feature request:
# Add config option to support/require connection to MySQL to be wrapped in ssl (i.e. just specify ca in options, make sure `SHOW STATUS LIKE 'Ssl_cipher';` is not empty)
# Add support for specifying X509 key & cert for connection
(1) is rather important for shared environments (e.g. cloud with hosted MySQL like Google Cloud SQL or Amazon RDS) where there is no or minimal control over the link between app & db server.
(2) is lower priority as in most of the cases it's practically used as longer password.
For more details, see:
- http://dev.mysql.com/doc/refman/5.0/en/ssl-connections.html
- http://php.net/manual/en/mysqli.ssl-set.php