v.23.4Improvement

Add Fallback to Password Authentication After SSL User Certificate Failure

Add fallback to password authentication when authentication with SSL user certificate has failed. Closes #48974. #48989 (Nikolay Degterinsky).
Adds a fallback mechanism to password authentication if authentication using an SSL user certificate fails.

Why it matters

This feature addresses situations where SSL certificate-based authentication might fail by allowing a fallback to traditional password authentication, improving connection reliability and flexibility for users.

How to use it

Users simply attempt to connect with SSL certificate authentication as usual; if this fails, ClickHouse will automatically try to authenticate using the configured user password without requiring additional configuration.