resumption. This means that there will be no forward secrecy for the resumed
session. Equivalent to B<SSL_OP_ALLOW_NO_DHE_KEX>.
+B<MiddleboxCompat>: If set then dummy Change Cipher Spec (CCS) messages are sent
+in TLSv1.3. This has the effect of making TLSv1.3 look more like TLSv1.2 so that
+middleboxes that do not understand TLSv1.3 will not drop the connection. This
+option is set by default. A future version of OpenSSL may not set this by
+default. Equivalent to B<SSL_OP_ENABLE_MIDDLEBOX_COMPAT>.
+
=item B<VerifyMode>
The B<value> argument is a comma separated list of flags to set.
B<Once> requests a certificate from a client only on the initial connection:
not when renegotiating. Servers only.
+B<RequestPostHandshake> configures the connection to support requests but does
+not require a certificate from the client post-handshake. A certificate will
+not be requested during the initial handshake. The server application must
+provide a mechanism to request a certificate post-handshake. Servers only.
+TLSv1.3 only.
+
+B<RequiresPostHandshake> configures the connection to support requests and
+requires a certificate from the client post-handshake: an error occurs if the
+client does not present a certificate. A certificate will not be requested
+during the initial handshake. The server application must provide a mechanism
+to request a certificate post-handshake. Servers only. TLSv1.3 only.
+
=item B<ClientCAFile>, B<ClientCAPath>
A file or directory of certificates in PEM format whose names are used as the