20.14. BSD Authentication
This authentication method operates similarly topassword except that it uses BSD Authentication to verify the password. BSD Authentication is used only to validate user name/password pairs. Therefore the user's role must already exist in the database before BSD Authentication can be used for authentication. The BSD Authentication framework is currently only available on OpenBSD.
BSD Authentication inPostgreSQL uses theauth-postgresql login type and authenticates with thepostgresql login class if that's defined inlogin.conf. By default that login class does not exist, andPostgreSQL will use the default login class.
Note
To use BSD Authentication, the PostgreSQL user account (that is, the operating system user running the server) must first be added to theauth group. Theauth group exists by default on OpenBSD systems.