The Directory Server provides the option to automatically authenticate clients that have a secure communication channel, either SSL or StartTLS, and to present their own certificate.
By default, this option is disabled. When enabled, the net effect is as if the client issued a SASL EXTERNAL bind request on that connection.
This option is ignored if the client connection is already authenticated, such as when using StartTLS, but the client had already performed a bind before the StartTLS request. If the bind attempt fails, the connection remains unauthenticated but usable. If the client subsequently sends a bind request on the connection, it's processed as normal, and any automatic authentication is destroyed.