DTLS support in ext/openssl

From the RFC

PHP can encrypt TCP streams with TLS, but it has no way to encrypt UDP traffic. DTLS (Datagram TLS,RFC 6347 and RFC 9147) is the standard answer and is used by CoAP/LwM2M (IoT), WebRTC data channels, SIP, VPNs and syslog. Today a PHP application that has to speak DTLS needs an external process or a C extension. This RFC proposes DTLS stream transports in ext/openssl that work like the existing tls:// transports.