Serverside SNI in PostgreSQL 19

PostgreSQL clients have for a long time been able to indicate the hostname to connect to with the sslsni connection parameter, but the server has not considered this at all. Starting with PostgreSQL 19, the server can read the sslsni value making it possible to present certificate and keys per hostname as opposed to a single certificate for the entire server. In this talk we'll go over what TLS SNI is and how it works in PostgreSQL.