Update the documentation for the new SSL_OP_ALLOW_NO_DHE_KEX option

Also the associated configuration parameters and command line switches.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3833)

doc/man1/s_client.pod

@@ -93,6 +93,7 @@ B<openssl> B<s_client>
 [B<-bugs>]
 [B<-comp>]
 [B<-no_comp>]
+[B<-allow_no_dhe_kex>]
 [B<-sigalgs sigalglist>]
 [B<-curves curvelist>]
 [B<-cipher cipherlist>]

doc/man1/s_server.pod

@@ -102,6 +102,7 @@ B<openssl> B<s_server>
 [B<-legacy_server_connect>]
 [B<-no_resumption_on_reneg>]
 [B<-no_legacy_server_connect>]
+[B<-allow_no_dhe_kex>]
 [B<-strict>]
 [B<-sigalgs val>]
 [B<-client_sigalgs val>]

doc/man3/SSL_CONF_cmd.pod

@@ -186,6 +186,11 @@ permits or prohibits the use of unsafe legacy renegotiation for OpenSSL
 clients only. Equivalent to setting or clearing B<SSL_OP_LEGACY_SERVER_CONNECT>.
 Set by default.
 
+=item B<-allow_no_dhe_kex>
+
+In TLSv1.3 allow a non-(ec)dhe based key exchange mode on resumption. This means
+that there will be no forward secrecy for the resumed session.
+
 =item B<-strict>
 
 enables strict mode protocol handling. Equivalent to setting
@@ -399,6 +404,10 @@ B<EncryptThenMac>: use encrypt-then-mac extension, enabled by
 default. Inverse of B<SSL_OP_NO_ENCRYPT_THEN_MAC>: that is,
 B<-EncryptThenMac> is the same as setting B<SSL_OP_NO_ENCRYPT_THEN_MAC>.
 
+B<AllowNoDHEKEX>: In TLSv1.3 allow a non-(ec)dhe based key exchange mode on
+resumption. This means that there will be no forward secrecy for the resumed
+session. Equivalent to B<SSL_OP_ALLOW_NO_DHE_KEX>.
+
 =item B<VerifyMode>
 
 The B<value> argument is a comma separated list of flags to set.

doc/man3/SSL_CTX_set_options.pod

@@ -175,6 +175,11 @@ propose, and servers will not accept the extension.
 Disable all renegotiation in TLSv1.2 and earlier. Do not send HelloRequest
 messages, and ignore renegotiation requests via ClientHello.
 
+=item SSL_OP_ALLOW_NO_DHE_KEX
+
+In TLSv1.3 allow a non-(ec)dhe based key exchange mode on resumption. This means
+that there will be no forward secrecy for the resumed session.
+
 =back
 
 The following options no longer have any effect but their identifiers are