npn_protocol()
Returns the protocol string that was finally selected by the client during the handshake.
static VALUE ossl_ssl_npn_protocol(VALUE self) { SSL *ssl; const unsigned char *out; unsigned int outlen; GetSSL(self, ssl); SSL_get0_next_proto_negotiated(ssl, &out, &outlen); if (!outlen) return Qnil; else return rb_str_new((const char *) out, outlen); }