SQL Server Management Studio 20 Preview 1 is out, and the new connection dialog has a big change:
When you click Connect, you’re likely going to get an error:
Read on for the quick-and-easy solution, which brings behavior back to the pre-SSMS 20 default, as well as the long-term solution to prevent it from being an issue at all.
This brings SSMS in line with Azure Data Studio, which has defaulted to requiring certificates for quite some time. Note that you will need to select “Trust server certificate” if you are using a self-signed cert, though self-signed certs remove one of the two benefits of using certificates in the first place. The first is that certificates allow for encrypting the Tabular Data Stream (TDS) packets SQL Server sends over the network. Self-signed certs do just as good a job of that task as certificates you get from a trusted authority.
The second use case of certificates, however, is ensuring that this is definitely the machine and service you intend to connect to. If an attacker takes over the machine and swaps out the certificate with their own, your client should panic a bit because that’s your early-warning indicator that something is wrong.