OpenSSL 4.1.0: What’s new, what’s removed, and what’s still broken

The OpenSSL project released version 4.1.0, adding support for DTLS 1.3 and listing four known bugs in the DTLS code that ships with it. DTLS is the variant of TLS built for datagram transports such as UDP, and version 1.3 is defined in RFC 9147. The bugs fall on developers who adopt DTLS 1.3 or the DTLS support newly added to OpenSSL’s SSL listener API.