Hi, It sounds FFDHE groups are already supported [1] But the tools, like s_client, also support them. Run the command: openssl s_client -tls1_3 -groups ffdhe2048 host:port it just raised the issue: Error with command: "-groups ffdhe2048" If using P-256 or X25519, it worked fine.
I also tried option "-groups FFDHE2048". The same error raised again. [1] https://github.com/openssl/openssl/pull/8178
