The specification states to return illegal_parameter when a message is
syntactically correct but semantically invalid. (RFC 8446 section 6,
Paragraph 5)
Change TLS 1.3 handling to return missing_extension alert code when
- KeyShare is present but SupportedGroups is missing and
- SupportedGroups is present but KeyShare is missing
Added tests for this.
- Add validation to ensure the cipher suite in the ServerHello matches the one specified in the HelloRetryRequest.
- test_TLSX_CA_NAMES_bad_extension: use the same ciphersuite in HRR and SH