Information on key material for IPsec security services is maintained in a security associations database (SADB). Security associations (SAs) protect inbound packets and outbound packets. The SADBs are maintained by a user process, or possibly multiple cooperating processes, that send messages over a special kind of socket. This method of maintaining SADBs is analogous to the method that is described in the route(7P) man page. Only superuser or a user who has assumed an equivalent role can access the database.
The in.iked daemon and the ipseckey command use the PF_KEY socket interface to maintain SADBs. For more information on how SADBs handle requests and messages, see the pf_key(7P) man page.