Logging: dnssec status on accept & delivery lines

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index ddb0001a5e9b65bcdb232a9bebb55fe286180d2e..736a45800cc2b5ddcf823c5b8132260825de3ea6 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -16843,8 +16843,8 @@ of the STARTTLS command to set up an encrypted session is advertised in
 response to EHLO only to those client hosts that match this option. See
 chapter &<<CHAPTLS>>& for details of Exim's support for TLS.
 Note that the default value requires that a certificate be supplied
-using the &%tls_certificate%& option.  If no certificate is available then
-the &%tls_advertise_hosts%& option should be set empty.
+using the &%tls_certificate%& option.  If TLS support for incoming connections
+is not required the &%tls_advertise_hosts%& option should be set empty.
 
 
 .option tls_certificate main string&!! unset
@@ -16865,6 +16865,11 @@ if the OpenSSL build supports TLS extensions and the TLS client sends the
 Server Name Indication extension, then this option and others documented in
 &<<SECTtlssni>>& will be re-expanded.
 
+.new
+If this option is unset or empty a fresh self-signed certificate will be
+generated for every connection.
+.wen
+
 .option tls_crl main string&!! unset
 .cindex "TLS" "server certificate revocation list"
 .cindex "certificate" "revocation list for server"
@@ -26958,10 +26963,17 @@ with the error
 If a STARTTLS command is issued within an existing TLS session, it is
 rejected with a 554 error code.
 
-To enable TLS operations on a server, you must set &%tls_advertise_hosts%& to
-match some hosts. You can, of course, set it to * to match all hosts.
-However, this is not all you need to do. TLS sessions to a server won't work
-without some further configuration at the server end.
+To enable TLS operations on a server, the &%tls_advertise_hosts%& option
+must be set to match some hosts. The default is * which matches all hosts.
+
+.new
+If this is all you do, TLS encryption will be enabled but not authentication -
+meaning that the peer has no assurance it is actually you he is talking to.
+You gain protection from a passive sniffer listening on the wire but not
+from someone able to intercept the communication.
+.wen
+
+Further protection requires some further configuration at the server end.
 
 It is rumoured that all existing clients that support TLS/SSL use RSA
 encryption. To make this work you need to set, in the server,
@@ -35516,6 +35528,7 @@ the following table:
 &`CV  `&        certificate verification status
 &`D   `&        duration of &"no mail in SMTP session"&
 &`DN  `&        distinguished name from peer certificate
+&`DS  `&        DNSSEC secured lookups
 &`DT  `&        on &`=>`& lines: time taken for a delivery
 &`F   `&        sender address (on delivery lines)
 &`H   `&        host name and IP address
@@ -35606,6 +35619,7 @@ selection marked by asterisks:
 &` deliver_time               `&  time taken to perform delivery
 &` delivery_size              `&  add &`S=`&&'nnn'& to => lines
 &`*dnslist_defer              `&  defers of DNS list (aka RBL) lookups
+&` dnssec                     `&  DNSSEC secured lookups
 &`*etrn                       `&  ETRN commands
 &`*host_lookup_failed         `&  as it says
 &` ident_timeout              `&  timeout for ident connection
@@ -35713,6 +35727,14 @@ the &"=>"& line, tagged with S=.
 &%dnslist_defer%&: A log entry is written if an attempt to look up a host in a
 DNS black list suffers a temporary error.
 .next
+.cindex log dnssec
+.cindex dnssec logging
+&%dnssec%&: For message acceptance and (attempted) delivery log lines, when
+dns lookups gave secure results a tag of DS is added.
+For acceptance this covers the reverse and forward lookups for host name verification.
+It does not cover helo-name verification.
+For delivery this covers the SRV, MX, A and/or AAAA lookups.
+.next
 .cindex "log" "ETRN commands"
 .cindex "ETRN" "logging"
 &%etrn%&: Every valid ETRN command that is received is logged, before the ACL