X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/1f155f8e69b44ee7678dd1009ae0348e5c8d768e..3386088d5af4d4c61faa12ae29560e2c5bd43304:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index c1668c7ac..2f3e494db 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -52,7 +52,7 @@ .set I "    " .macro copyyear -2014 +2015 .endmacro . ///////////////////////////////////////////////////////////////////////////// @@ -9031,6 +9031,30 @@ When compiling a function that is to be used in this way with gcc, you need to add &%-shared%& to the gcc command. Also, in the Exim build-time configuration, you must add &%-export-dynamic%& to EXTRALIBS. + +.vitem "&*${env{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}}*&" +.cindex "expansion" "extracting value from environment" +.cindex "environment" "value from" +The key is first expanded separately, and leading and trailing white space +removed. +This is then searched for as a name in the environment. +If a variable is found then its value is placed in &$value$& +and <&'string1'&> is expanded, otherwise <&'string2'&> is expanded. + +Instead of {<&'string2'&>} the word &"fail"& (not in curly brackets) can +appear, for example: +.code +${env{USER}{$value} fail } +.endd +This forces an expansion failure (see section &<>&); +{<&'string1'&>} must be present for &"fail"& to be recognized. + +If {<&'string2'&>} is omitted an empty string is substituted on +search failure. +If {<&'string1'&>} is omitted the search result is substituted on +search success. + + .vitem "&*${extract{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&& {*&<&'string3'&>&*}}*&" .cindex "expansion" "extracting substrings by key" @@ -11415,7 +11439,7 @@ This variable contains the numerical value of the Exim user id. .new .vitem &$exim_version$& -.vindex "&$exim_uid$&" +.vindex "&$exim_version$&" This variable contains the version string of the Exim build. The first character is a major version number, currently 4. Then after a dot, the next group of digits is a minor version number. @@ -11681,6 +11705,7 @@ the space value is -1. See also the &%check_log_space%& option. .vindex "&$lookup_dnssec_authenticated$&" This variable is set after a DNS lookup done by a dnsdb lookup expansion, dnslookup router or smtp transport. +.cindex "DNS" "DNSSEC" It will be empty if &(DNSSEC)& was not requested, &"no"& if the result was not labelled as authenticated data and &"yes"& if it was. @@ -12198,6 +12223,14 @@ verification either failed or was not requested. A host name in parentheses is the argument of a HELO or EHLO command. This is omitted if it is identical to the verified host name or to the host's IP address in square brackets. +.new +.vitem &$sender_helo_dnssec$& +.vindex "&$sender_helo_dnssec$&" +This boolean variable is true if a successful HELO verification was +.cindex "DNS" "DNSSEC" +done using DNS information the resolver library stated was authenticatied data. +.wen + .vitem &$sender_helo_name$& .vindex "&$sender_helo_name$&" When a message is received from a remote host that has issued a HELO or EHLO @@ -12227,6 +12260,7 @@ resolver library states that both the reverse and forward DNS were authenticated data. At all other times, this variable is false. +.cindex "DNS" "DNSSEC" It is likely that you will need to coerce DNSSEC support on in the resolver library, by setting: .code @@ -14535,14 +14569,17 @@ is an IP literal matching the calling address of the host, or matches the host name that Exim obtains by doing a reverse lookup of the calling host address, or .next -when looked up using &[gethostbyname()]& (or &[getipnodebyname()]& when -available) yields the calling host address. +when looked up in DNS yields the calling host address. .endlist However, the EHLO or HELO command is not rejected if any of the checks fail. Processing continues, but the result of the check is remembered, and can be detected later in an ACL by the &`verify = helo`& condition. +If DNS was used for successful verification, the variable +.cindex "DNS" "DNSSEC" +&$helo_verify_dnssec$& records the DNSSEC status of the lookups. + .option helo_verify_hosts main "host list&!!" unset .cindex "HELO verifying" "mandatory" .cindex "EHLO" "verifying, mandatory" @@ -14916,8 +14953,9 @@ section &<>&. This option sets the path which is used to determine the names of Exim's log files, or indicates that logging is to be to syslog, or both. It is expanded when Exim is entered, so it can, for example, contain a reference to the host -name. If no specific path is set for the log files at compile or run time, they -are written in a sub-directory called &_log_& in Exim's spool directory. +name. If no specific path is set for the log files at compile or run time, +or if the option is unset at run time (i.e. &`log_file_path = `&) +they are written in a sub-directory called &_log_& in Exim's spool directory. Chapter &<>& contains further details about Exim's logging, and section &<>& describes how the contents of &%log_file_path%& are used. If this string is fixed at your installation (contains no expansion @@ -24828,6 +24866,7 @@ AUTH_GSASL=yes AUTH_HEIMDAL_GSSAPI=yes AUTH_PLAINTEXT=yes AUTH_SPA=yes +AUTH_TLS=yes .endd in &_Local/Makefile_&, respectively. The first of these supports the CRAM-MD5 authentication mechanism (RFC 2195), and the second provides an interface to @@ -24842,6 +24881,8 @@ The sixth can be configured to support the PLAIN authentication mechanism (RFC 2595) or the LOGIN mechanism, which is not formally documented, but used by several MUAs. The seventh authenticator supports Microsoft's &'Secure Password Authentication'& mechanism. +The eighth is an Exim authenticator but not an SMTP one; +instead it can use information from a TLS negotiation. The authenticators are configured using the same syntax as other drivers (see section &<>&). If no authenticators are required, no @@ -26048,6 +26089,81 @@ msn: +. //////////////////////////////////////////////////////////////////////////// +. //////////////////////////////////////////////////////////////////////////// + +.new +.chapter "The tls authenticator" "CHAPtlsauth" +.scindex IIDtlsauth1 "&(tls)& authenticator" +.scindex IIDtlsauth2 "authenticators" "&(tls)&" +.cindex "authentication" "Client Certificate" +.cindex "authentication" "X509" +.cindex "Certificate-based authentication" +The &(tls)& authenticator provides server support for +authentication based on client certificates. + +It is not an SMTP authentication mechanism and is not +advertised by the server as part of the SMTP EHLO response. +It is an Exim authenticator in the sense that it affects +the protocol element of the log line, can be tested for +by the &%authenticated%& ACL condition, and can set +the &$authenticated_id$& variable. + +The client must present a verifiable certificate, +for which it must have been requested via the +&%tls_verify_hosts%& or &%tls_try_verify_hosts%& main options +(see &<>&). + +If an authenticator of this type is configured it is +run before any SMTP-level communication is done, +and can authenticate the connection. +If it does, SMTP suthentication is not offered. + +A maximum of one authenticator of this type may be present. + + +.cindex "options" "&(tls)& authenticator (server)" +The &(tls)& authenticator has three server options: + +.option server_param1 tls string&!! unset +.cindex "variables (&$auth1$& &$auth2$& etc)" "in &(tls)& authenticator" +This option is expanded after the TLS negotiation and +the result is placed in &$auth1$&. +If the expansion is forced to fail, authentication fails. Any other expansion +failure causes a temporary error code to be returned. + +.option server_param2 tls string&!! unset +.option server_param3 tls string&!! unset +As above, for &$auth2$& and &$auth3$&. + +&%server_param1%& may also be spelled &%server_param%&. + + +Example: +.code +tls: + driver = tls + server_param1 = ${certextract {subj_altname,mail,>:} \ + {$tls_in_peercert}} + server_condition = ${if forany {$auth1} \ + {!= {0} \ + {${lookup ldap{ldap:///\ + mailname=${quote_ldap_dn:${lc:$item}},\ + ou=users,LDAP_DC?mailid} {$value}{0} \ + } } } } + server_set_id = ${if = {1}{${listcount:$auth1}} {$auth1}{}} +.endd +.ecindex IIDtlsauth1 +.ecindex IIDtlsauth2 +.wen + + +Note that because authentication is traditionally an SMTP operation, +the &%authenticated%& ACL condition cannot be used in +a connect- or helo-ACL. + + + . //////////////////////////////////////////////////////////////////////////// . //////////////////////////////////////////////////////////////////////////// @@ -34634,8 +34750,9 @@ equivalent to the setting: .code log_file_path = $spool_directory/log/%slog .endd -If you do not specify anything at build time or run time, that is where the -logs are written. +If you do not specify anything at build time or run time, +or if you unset the option at run time (i.e. &`log_file_path = `&), +that is where the logs are written. A log file path may also contain &`%D`& or &`%M`& if datestamped log file names are in use &-- see section &<>& below.