Login attempts could repeat depending on SSLMode and leads to incorrect count of attempts

[TianzeMYou]

Description

For the lockout-after-a-specific-number-of-login-attempts example, login attempts could increment by 2 depending on SSLMode

https://www.postgresql.org/message-id/flat/17032-7ad69968e744de35%40postgresql.org#:~:text=It%20tries%20to%20connect%20with%20encryption%20and%20fails%2C%20then%20tries%20to%20connect%0Awithout%20encryption%20and%20also%20fails

Steps to reproduce

Run the example here with sslmode set to allow/prefer https://github.com/aws/pg_tle/blob/main/examples/client_lockout/client_lockout--1.0.sql

Expected outcome

Client should be locked out after 5 attempts

Actual outcome

Client is locked out before 5 attempts

Analysis

Could potentially check the SSLMode in hook sql, which requires a C code change. https://github.com/aws/pg_tle/blob/main/src/clientauth.c#L144-L166

[adamguo0]

Since this is an expected and documented client-side behaviour [1], we shouldn't try to change this on the pg_tle side. However it's worth adding a note in the example for users to be aware.

[1] https://www.postgresql.org/docs/devel/libpq-connect.html#LIBPQ-CONNECT-SSLMODE