Implement challenge response auth in a custom StartupHandler

[gmilleramilar]

How do I implement a challenge/response auth workflow in a StartupHandler if on_startup() only hands over a Sink (and not something like a stream)? I need to send a message requesting--say--password before I return from on_startup, correct?

My use case is simply authenticating against a local user on a Linux server when connecting with psql?

[sunng87]

actually this on_startup function will be called multiple times with different input of PgwireFrontendMessage depends on the authentication method.

first you will need to choose a standard postgres authentication that is already supported by psql. You can start with cleartext password, and implement your own AuthSource trait. You can check the sqlite example for reference.