Is it possible to verify the client using PSK?

On the stunnel server I specify a PSKsecrets file with two lines in it, one for client01 and one for client02. The secret is about 36 characters long.

On a client, I have a similar PSKsecrets file, but only containing the client01 line.

Now, if I try to connect with, say, a client03, i.e., any client that does not have a matching line in the server's PSKsecrets file, how can I assure that the client connection will be rejected?

What I'd like to see would be the following: any client that tries to connect, and does not present a PSK that is present in the server's PSKsecrets file, then that client's connection request is rejected, with an appropriate message logged.

Can I do that with the current stunnel?

thx.