[hasannadeem]

These OpenSSL::SSL methods had no signatures:

Method	Signature	Since
SSLContext#ciphersuites=	(String | Array[String]) -> (String | Array[String])	openssl 3.x
SSLContext#tmp_dh=	(PKey::DH) -> PKey::DH	3.x
SSLContext#keylog_cb, #keylog_cb=	(^(SSLSocket ssl, String line) -> void)?	3.x
SSLContext#groups=	(String) -> String	4.0
SSLContext#sigalgs=, #client_sigalgs=	(String) -> String	4.0
SSLSocket#close_read, #close_write	() -> nil	3.x
SSLSocket#export_keying_material	(String label, int length, ?String? context) -> String	3.x
SSLSocket#group, #sigalg, #peer_sigalg	() -> String?	4.0

Notes:

• keylog_cb follows the getter/setter pairs used for the other callbacks (servername_cb, renegotiation_cb). The setter also accepts nil, which clears the callback.
• tmp_dh= rejects other key types at runtime (invalid pkey type ... (expected DH)), so it takes PKey::DH.
• ecdh_curves= is now a deprecated alias of groups=, but this leaves its existing signature alone.

There were no SSLSocket instance tests, so OpenSSLSSLFixtures.connected makes a real TLS connection over loopback TCP with a self-signed EC certificate. The tests check:

• the values after a handshake: the client's group and peer_sigalg are Strings, and its sigalg is nil since only the server signs;
• tmp_dh=, using OpenSSL::PKey.generate_parameters("DH", "group" => "ffdhe2048") so no DH parameters have to be generated.

All 12 new tests fail without the signature change. They pass with openssl 4.0.2 (Ruby 4.0.7), three runs in a row, and with openssl 3.3.0 (Ruby 3.4), where the six openssl 4.0 tests are omitted. With Steep, the setters, export_keying_material, group&.upcase and a lambda keylog_cb pass, and tmp_dh = <EC key> is an error. Annotating core and stdlib from the full v4.0.7 source leaves the file unchanged, and rake validate and rake typecheck_test pass.

Calling SSLSocket#group before the handshake segfaults with OpenSSL 3.6.3. That is an OpenSSL bug (openssl/openssl#32379, fixed by openssl/openssl#32452), so the test calls it only after the handshake.

This PR merges with #3291, #3299 and #3300 without conflicts.