Add documentation for the -sctp option in command line apps

Reviewed-by: Richard Levitte <[email protected]>
(Merged from openssl#3305)

doc/man1/s_client.pod

@@ -82,6 +82,7 @@ B<openssl> B<s_client>
 [B<-dtls>]
 [B<-dtls1>]
 [B<-dtls1_2>]
+[B<-sctp>]
 [B<-fallback_scsv>]
 [B<-async>]
 [B<-split_send_frag>]
@@ -387,6 +388,12 @@ With B<-dtls>, B<s_client> will negotiate any supported DTLS protocol version,
 whilst B<-dtls1> and B<-dtls1_2> will only support DTLS1.0 and DTLS1.2
 respectively.
 
+=item B<-sctp>
+
+Use SCTP for the transport protocol instead of UDP in DTLS. Must be used in
+conjunction with B<-dtls>, B<-dtls1> or B<-dtls1_2>. This option is only
+available where OpenSSL has support for SCTP enabled.
+
 =item B<-fallback_scsv>
 
 Send TLS_FALLBACK_SCSV in the ClientHello.

doc/man1/s_server.pod

@@ -83,6 +83,7 @@ B<openssl> B<s_server>
 [B<-dtls>]
 [B<-dtls1>]
 [B<-dtls1_2>]
+[B<-sctp>]
 [B<-listen>]
 [B<-async>]
 [B<-split_send_frag>]
@@ -362,6 +363,12 @@ Any without a cookie will be responded to with a HelloVerifyRequest.
 If a ClientHello with a cookie is received then B<s_server> will connect to
 that peer and complete the handshake.
 
+=item B<-sctp>
+
+Use SCTP for the transport protocol instead of UDP in DTLS. Must be used in
+conjunction with B<-dtls>, B<-dtls1> or B<-dtls1_2>. This option is only
+available where OpenSSL has support for SCTP enabled.
+
 =item B<-async>
 
 Switch on asynchronous mode. Cryptographic operations will be performed