warning when TLS 1.3 only early key share group is configured but connection negotiates TLS 1.2

[matthew-js-porter]

When org.bouncycastle.jsse.client.earlyKeyShares includes X25519MLKEM768 and the connection negotiates TLS 1.2 (e.g. because the server is TLS 1.2-only). a warning is logged on every connection:

WARNING: Candidate early key share not an enabled named group: X25519MLKEM768

Should this be reduced to DEBUG (or suppressed entirely) when the group is only inactive due to the negotiated protocol version?

[peterdettman]

I initially thought the scenario was a 1.3 client falling back to 1.2, but I don't see a path in the code that would raise the log in that situation.

I did however notice that the early key shares were being computed in situations where they are irrelevant (i.e. for a server or for a client that doesn't even offer 1.3), resulting in spurious log messages. This has now been fixed. The log message has also been modified to e.g.:

WARNING: Candidate early key share not an offered named group for this connection: X25519MLKEM768

In case it's relevant, note that the org.bouncycastle.jsse.client.earlyKeyShares property has no effect for a server.