Update the "Connected Commands" section of s_client/s_server docs

Fixes #6307

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6330)

1 files changed, 29 insertions, 4 deletions

diff --git a/doc/man1/s_client.pod b/doc/man1/s_client.pod
index 19a8139c1b..373b2d760c 100644
--- a/doc/man1/s_client.pod
+++ b/doc/man1/s_client.pod
@@ -667,10 +667,35 @@ on port 4433.
 
 If a connection is established with an SSL server then any data received
 from the server is displayed and any key presses will be sent to the
-server. When used interactively (which means neither B<-quiet> nor B<-ign_eof>
-have been given), the session will be renegotiated if the line begins with an
-B<R>, and if the line begins with a B<Q> or if end of file is reached, the
-connection will be closed down.
+server. If end of file is reached then the connection will be closed down. When
+used interactively (which means neither B<-quiet> nor B<-ign_eof> have been
+given), then certain commands are also recognized which perform special
+operations. These commands are a letter which must appear at the start of a
+line. They are listed below.
+
+=over 4
+
+=item B<Q>
+
+End the current SSL connection and exit.
+
+=item B<R>
+
+Renegotiate the SSL session (TLSv1.2 and below only).
+
+=item B<B>
+
+Send a heartbeat message to the server (DTLS only)
+
+=item B<k>
+
+Send a key update message to the server (TLSv1.3 only)
+
+=item B<K>
+
+Send a key update message to the server and request one back (TLSv1.3 only)
+
+=back
 
 =head1 NOTES