.cindex "SHA-1 hash"
.cindex "expansion" "SHA-1 hashing"
.cindex certificate fingerprint
-.cindex "&%sha2%& expansion item"
+.cindex "&%sha1%& expansion item"
The &%sha1%& operator computes the SHA-1 hash value of the string, and returns
it as a 40-digit hexadecimal number, in which any letters are in upper case.
returns the SHA-1 hash fingerprint of the certificate.
-.vitem &*${sha256:*&<&'certificate'&>&*}*&
+.vitem &*${sha256:*&<&'string'&>&*}*&
.cindex "SHA-256 hash"
.cindex certificate fingerprint
.cindex "expansion" "SHA-256 hashing"
.cindex "&%sha256%& expansion item"
-The &%sha256%& operator computes the SHA-256 hash fingerprint of the
-certificate,
+.new
+The &%sha256%& operator computes the SHA-256 hash value of the string
+and returns
+it as a 64-digit hexadecimal number, in which any letters are in upper case.
+.wen
+
+If the string is a single variable of type certificate,
+returns the SHA-256 hash fingerprint of the certificate.
+
+
+.new
+.vitem &*${sha3:*&<&'string'&>&*}*& &&&
+ &*${sha3_<n>:*&<&'string'&>&*}*&
+.cindex "SHA3 hash"
+.cindex "expansion" "SHA3 hashing"
+.cindex "&%sha3%& expansion item"
+The &%sha3%& operator computes the SHA3-256 hash value of the string
and returns
it as a 64-digit hexadecimal number, in which any letters are in upper case.
-Only arguments which are a single variable of certificate type are supported.
+
+If a number is appended, separated by an underbar, it specifies
+the output length. Values of 224, 256, 384 and 512 are accepted;
+with 256 being the default.
+
+The &%sha3%& expansion item is only supported if Exim has been
+compiled with GnuTLS 3.5.0 or later.
+.wen
.vitem &*${stat:*&<&'string'&>&*}*&
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
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"
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,
&'debuglog'&. The filename can be adjusted with the &'tag'& option, which
may access any variables already defined. The logging may be adjusted with
the &'opts'& option, which takes the same values as the &`-d`& command-line
-option. Some examples (which depend on variables that don't exist in all
+option.
+.new
+Logging may be stopped, and the file removed, with the &'kill'& option.
+.wen
+Some examples (which depend on variables that don't exist in all
contexts):
.code
control = debug
control = debug/tag=.$sender_host_address
control = debug/opts=+expand+acl
control = debug/tag=.$message_exim_id/opts=+expand
+ control = debug/kill
.endd
&`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
&` 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
&%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
Log lines and Received-by: header lines will acquire a "utf8"
prefix on the protocol element, eg. utf8esmtp.
-The following expansion operator can be used:
+The following expansion operators can be used:
.code
${utf8_domain_to_alabel:str}
${utf8_domain_from_alabel:str}
git://git.exim.org / users / heiko / exim.git / blobdiff