X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=doc%2Fdoc-docbook%2Fspec.xfpt;h=4f2052c87eda95e491940157c4f60a0bc064b5a1;hp=83c2bafec7240ff5d0e7c114ee15ab313f1b8dc9;hb=c6325f903e41289f9b418cfc7535533ade2d1cc9;hpb=99a0dc9358699cbe049cdd97874b17c263174f86;ds=sidebyside diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 83c2bafec..4f2052c87 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -52,7 +52,7 @@ .set I "    " .macro copyyear -2014 +2015 .endmacro . ///////////////////////////////////////////////////////////////////////////// @@ -1985,9 +1985,12 @@ Two different types of DNS record for handling IPv6 addresses have been defined. AAAA records (analogous to A records for IPv4) are in use, and are currently seen as the mainstream. Another record type called A6 was proposed as better than AAAA because it had more flexibility. However, it was felt to be -over-complex, and its status was reduced to &"experimental"&. Exim used to +over-complex, and its status was reduced to &"experimental"&. +.new +Exim used to have a compile option for including A6 record support but this has now been withdrawn. +.wen @@ -4648,12 +4651,14 @@ this option. This option is interpreted by Sendmail to cause debug information to be sent to the named file. It is ignored by Exim. +.new .vitem &%-z%&&~<&'log-line'&> .oindex "&%-z%&" This option writes its argument to Exim's logfile. Use is restricted to administrators; the intent is for operational notes. Quotes should be used to maintain a multi-word item as a single argument, under most shells. +.wen .endlist .ecindex IIDclo1 @@ -5010,7 +5015,8 @@ message_size_limit = 50M message_size_limit = 100M .endif .endd -sets a message size limit of 50M if the macro &`AAA`& is defined, and 100M +sets a message size limit of 50M if the macro &`AAA`& is defined +(or &`A`& or &`AA`&), and 100M otherwise. If there is more than one macro named on the line, the condition is true if any of them are defined. That is, it is an &"or"& condition. To obtain an &"and"& condition, you need to use nested &`.ifdef`&s. @@ -5232,7 +5238,7 @@ list items, it is not ignored when parsing the list. The space after the first colon in the example above is necessary. If it were not there, the list would be interpreted as the two items 127.0.0.1:: and 1. -.section "Changing list separators" "SECID53" +.section "Changing list separators" "SECTlistsepchange" .cindex "list separator" "changing" .cindex "IPv6" "addresses in lists" Doubling colons in IPv6 addresses is an unwelcome chore, so a mechanism was @@ -5598,6 +5604,15 @@ find that they send unqualified addresses. The two commented-out options: show how you can specify hosts that are permitted to send unqualified sender and recipient addresses, respectively. +.new +The &%log_selector%& option is used to increase the detail of logging +over the default: +.code +log_selector = +smtp_protocol_error +smtp_syntax_error \ + +tls_certificate_verified +.endd +.wen + The &%percent_hack_domains%& option is also commented out: .code # percent_hack_domains = @@ -6878,9 +6893,11 @@ is used on its own as the result. If the lookup does not succeed, the &`fail`& keyword causes a &'forced expansion failure'& &-- see section &<>& for an explanation of what this means. +.new The supported DNS record types are A, CNAME, MX, NS, PTR, SOA, SPF, SRV, TLSA and TXT, and, when Exim is compiled with IPv6 support, AAAA. If no type is given, TXT is assumed. +.wen For any record type, if multiple records are found, the data is returned as a concatenation, with newline as the default separator. The order, of course, @@ -6928,6 +6945,7 @@ ${lookup dnsdb{spf=example.org}} It is permitted to specify a space as the separator character. Further white space is ignored. +.new .cindex "SOA record" "in &(dnsdb)& lookup" For an SOA lookup, while no result is obtained the lookup is redone with successively more leading components dropped from the given domain. @@ -6936,6 +6954,7 @@ specified. .code ${lookup dnsdb{>:,; soa=a.b.example.com}} .endd +.wen .section "Dnsdb lookup modifiers" "SECTdnsdb_mod" .cindex "dnsdb modifiers" @@ -6976,6 +6995,7 @@ The default is &"never"&. See also the &$lookup_dnssec_authenticated$& variable. +.new .cindex timeout "dns lookup" .cindex "DNS" timeout Timeout for the dnsdb lookup can be controlled by a retrans modifier. @@ -6986,6 +7006,7 @@ The default value is set by the main configuration option &%dns_retrans%&. Retries for the dnsdb lookup can be controlled by a retry modifier. The form if &"retry_VAL"& where VAL is an integer. The default count is set by the main configuration option &%dns_retry%&. +.wen .section "Pseudo dnsdb record types" "SECID66" @@ -7661,6 +7682,12 @@ host, email address, or local part, respectively. In the sections below, the different types of pattern for each case are described, but first we cover some general facilities that apply to all four kinds of list. +.new +Note that other parts of Exim use a &'string list'& which does not +support all the complexity availible in +domain, host, address and local part lists. +.wen + .section "Expansion of lists" "SECID75" @@ -8965,7 +8992,7 @@ The field selectors marked as "RFC4514" above output a Distinguished Name string which is not quite parseable by Exim as a comma-separated tagged list -(the exceptions being elements containin commas). +(the exceptions being elements containing commas). RDN elements of a single type may be selected by a modifier of the type label; if so the expansion result is a list (newline-separated by default). @@ -9031,6 +9058,32 @@ When compiling a function that is to be used in this way with gcc, you need to add &%-shared%& to the gcc command. Also, in the Exim build-time configuration, you must add &%-export-dynamic%& to EXTRALIBS. + +.new +.vitem "&*${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. +.wen + + .vitem "&*${extract{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&& {*&<&'string3'&>&*}}*&" .cindex "expansion" "extracting substrings by key" @@ -11318,6 +11371,36 @@ This variable is available when Exim is compiled with the content-scanning extension and the obsolete &%demime%& condition. For details, see section &<>&. +.new +.vitem &$dkim_cur_signer$& &&& + &$dkim_verify_status$& &&& + &$dkim_verify_reason$& &&& + &$dkim_domain$& &&& + &$dkim_identity$& &&& + &$dkim_selector$& &&& + &$dkim_algo$& &&& + &$dkim_canon_body$& &&& + &$dkim_canon_headers$& &&& + &$dkim_copiedheaders$& &&& + &$dkim_bodylength$& &&& + &$dkim_created$& &&& + &$dkim_expires$& &&& + &$dkim_headernames$& &&& + &$dkim_key_testing$& &&& + &$dkim_key_nosubdomains$& &&& + &$dkim_key_srvtype$& &&& + &$dkim_key_granularity$& &&& + &$dkim_key_notes$& +These variables are only available within the DKIM ACL. +For details see chapter &<>&. + +.vitem &$dkim_signers$& +.vindex &$dkim_signers$& +When a message has been received this variable contains +a colon-separated list of signer domains and identities for the message. +For details see chapter &<>&. +.wen + .vitem &$dnslist_domain$& &&& &$dnslist_matched$& &&& &$dnslist_text$& &&& @@ -11415,7 +11498,7 @@ This variable contains the numerical value of the Exim user id. .new .vitem &$exim_version$& -.vindex "&$exim_uid$&" +.vindex "&$exim_version$&" This variable contains the version string of the Exim build. The first character is a major version number, currently 4. Then after a dot, the next group of digits is a minor version number. @@ -11681,9 +11764,15 @@ the space value is -1. See also the &%check_log_space%& option. .vindex "&$lookup_dnssec_authenticated$&" This variable is set after a DNS lookup done by a dnsdb lookup expansion, dnslookup router or smtp transport. +.cindex "DNS" "DNSSEC" It will be empty if &(DNSSEC)& was not requested, &"no"& if the result was not labelled as authenticated data and &"yes"& if it was. +.new +Results that are labelled as authoritive answer that match +the &%dns_trust_aa%& configuration variable count also +as authenticated data. +.wen .vitem &$mailstore_basename$& .vindex "&$mailstore_basename$&" @@ -12198,6 +12287,14 @@ verification either failed or was not requested. A host name in parentheses is the argument of a HELO or EHLO command. This is omitted if it is identical to the verified host name or to the host's IP address in square brackets. +.new +.vitem &$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$&" When a message is received from a remote host that has issued a HELO or EHLO @@ -12223,9 +12320,11 @@ received. It is empty if there was no successful authentication. See also If an attempt to populate &$sender_host_name$& has been made (by reference, &%hosts_lookup%& or otherwise) then this boolean will have been set true if, and only if, the -resolver library states that the reverse DNS was authenticated data. At all +resolver library states that both +the reverse and forward DNS were authenticated data. At all other times, this variable is false. +.cindex "DNS" "DNSSEC" It is likely that you will need to coerce DNSSEC support on in the resolver library, by setting: .code @@ -12235,9 +12334,6 @@ dns_dnssec_ok = 1 Exim does not perform DNSSEC validation itself, instead leaving that to a validating resolver (eg, unbound, or bind with suitable configuration). -Exim does not (currently) check to see if the forward DNS was also secured -with DNSSEC, only the reverse DNS. - If you have changed &%host_lookup_order%& so that &`bydns`& is not the first mechanism in the list, then this variable will be false. @@ -12475,8 +12571,10 @@ inbound connection when the message was received. It is only useful as the argument of a &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, or a &%def%& condition. +.new If certificate verification fails it may refer to a failing chain element which is not the leaf. +.wen .vitem &$tls_out_ourcert$& .vindex "&$tls_out_ourcert$&" @@ -12491,8 +12589,10 @@ This variable refers to the certificate presented by the peer of an outbound connection. It is only useful as the argument of a &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, or a &%def%& condition. +.new If certificate verification fails it may refer to a failing chain element which is not the leaf. +.wen .vitem &$tls_in_certificate_verified$& .vindex "&$tls_in_certificate_verified$&" @@ -12556,8 +12656,10 @@ When a message is received from a remote host over an encrypted SMTP connection, and Exim is configured to request a certificate from the client, the value of the Distinguished Name of the certificate is made available in the &$tls_in_peerdn$& during subsequent processing. +.new If certificate verification fails it may refer to a failing chain element which is not the leaf. +.wen The deprecated &$tls_peerdn$& variable refers to the inbound side except when used in the context of an outbound SMTP delivery, when it refers to @@ -12569,8 +12671,10 @@ When a message is being delivered to a remote host over an encrypted SMTP connection, and Exim is configured to request a certificate from the server, the value of the Distinguished Name of the certificate is made available in the &$tls_out_peerdn$& during subsequent processing. +.new If certificate verification fails it may refer to a failing chain element which is not the leaf. +.wen .vitem &$tls_in_sni$& .vindex "&$tls_in_sni$&" @@ -13369,6 +13473,7 @@ listed in more than one group. .row &%tls_crl%& "certificate revocation list" .row &%tls_dh_max_bits%& "clamp D-H bit count suggestion" .row &%tls_dhparam%& "DH parameters for server" +.row &%tls_eccurve%& "EC curve selection for server" .row &%tls_ocsp_file%& "location of server certificate status proof" .row &%tls_on_connect_ports%& "specify SSMTP (SMTPS) ports" .row &%tls_privatekey%& "location of server private key" @@ -13423,6 +13528,7 @@ listed in more than one group. See also the &'Policy controls'& section above. .table2 +.row &%dkim_verify_signers%& "DKIM domain for which DKIM ACL is run" .row &%host_lookup%& "host name looked up for these hosts" .row &%host_lookup_order%& "order of DNS and local name lookups" .row &%recipient_unqualified_hosts%& "may send unqualified recipients" @@ -13516,6 +13622,7 @@ See also the &'Policy controls'& section above. .row &%dns_ipv4_lookup%& "only v4 lookup for these domains" .row &%dns_retrans%& "parameter for resolver" .row &%dns_retry%& "parameter for resolver" +.row &%dns_trust_aa%& "DNS zones trusted as authentic" .row &%dns_use_edns0%& "parameter for resolver" .row &%hold_domains%& "hold delivery for these domains" .row &%local_interfaces%& "for routing checks" @@ -13631,6 +13738,14 @@ is run for each recipient after an SMTP DATA command has been processed and the message itself has been received, but before the acknowledgment is sent. See chapter &<>& for further details. +.new +.option acl_smtp_dkim main string&!! unset +.cindex DKIM "ACL for" +This option defines the ACL that is run for each DKIM signature +of a received message. +See chapter &<>& for further details. +.wen + .option acl_smtp_etrn main string&!! unset .cindex "ETRN" "ACL for" This option defines the ACL that is run when an SMTP ETRN command is @@ -13665,11 +13780,13 @@ This option is available when Exim is built with the content-scanning extension. It defines the ACL that is run for each MIME part in a message. See section &<>& for details. +.new .option acl_smtp_notquit main string&!! unset .cindex "not-QUIT, ACL for" This option defines the ACL that is run when an SMTP session ends without a QUIT command being received. See chapter &<>& for further details. +.wen .option acl_smtp_predata main string&!! unset This option defines the ACL that is run when an SMTP DATA command is @@ -14106,6 +14223,16 @@ etc. are ignored. If IP literals are enabled, the &(ipliteral)& router declines to handle IPv6 literal addresses. +.new +.option dkim_verify_signers main "domain list&!!" $dkim_signers +.cindex DKIM "controlling calls to the ACL" +This option gives a list of DKIM domains for which the DKIM ACL is run. +It is expanded after the message is received; by default it runs +the ACL once for each signature in the message. +See chapter &<>&. +.wen + + .option dns_again_means_nonexist main "domain list&!!" unset .cindex "DNS" "&""try again""& response; overriding" DNS lookups give a &"try again"& response for the DNS errors @@ -14192,13 +14319,43 @@ take. I haven't found any documentation about timeouts on DNS lookups; these parameter values are available in the external resolver interface structure, but nowhere does it seem to describe how they are used or what you might want to set in them. +.new See also the &%slow_lookup_log%& option. +.wen .option dns_retry main integer 0 See &%dns_retrans%& above. +.new +.option dns_trust_aa main "domain list&!!" unset +.cindex "DNS" "resolver options" +.cindex "DNS" "DNSSEC" +If this option is set then lookup results marked with the AA bit +(Authoritative Answer) are trusted the same way as if they were +DNSSEC-verified. The authority section's name of the answer must +match with this expanded domain list. + +Use this option only if you talk directly to a resolver that is +authoritive for some zones and does not set the AD (Authentic Data) +bit in the answer. Some DNS servers may have an configuration option to +mark the answers from their own zones as verified (they set the AD bit). +Others do not have this option. It is considered as poor practice using +a resolver that is an authoritive server for some zones. + +Use this option only if you really have to (e.g. if you want +to use DANE for remote delivery to a server that is listed in the DNS +zones that your resolver is authoritive for). + +If the DNS answer packet has the AA bit set and contains resource record +in the answer section, the name of the first NS record appearing in the +authority section is compared against the list. If the answer packet is +authoritive but the answer section is empty, the name of the first SOA +record in the authoritive section is used instead. +.wen + +.cindex "DNS" "resolver options" .option dns_use_edns0 main integer -1 .cindex "DNS" "resolver options" .cindex "DNS" "EDNS0" @@ -14537,14 +14694,17 @@ 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" @@ -14918,8 +15078,9 @@ 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 @@ -15306,7 +15467,7 @@ not count as protocol errors (see &%smtp_max_synprot_errors%&). This option can be used to enable the Per-Recipient Data Response extension to SMTP, defined by Eric Hall. If the option is set, PRDR is advertised by Exim when operating as a server. -If the client requests PRDR, and more than one recipient, for a message +If the client requests PRDR, and more than one recipient, for a message an additional ACL is called for each recipient after the message content is recieved. See section &<>&. @@ -15752,6 +15913,7 @@ it qualifies them only if the message came from a host that matches using TCP/IP), and the &%-bnq%& option was not set. +.new .option slow_lookup_log main integer 0 .cindex "logging" "slow lookups" .cindex "dns" "logging slow lookups" @@ -15759,6 +15921,7 @@ This option controls logging of slow lookups. If the value is nonzero it is taken as a number of milliseconds and lookups taking longer than this are logged. Currently this applies only to DNS lookups. +.wen @@ -16152,9 +16315,11 @@ SMTP data timeout on connection from... The former means that Exim was expecting to read an SMTP command; the latter means that it was in the DATA phase, reading the contents of a message. +.new If the first character of the option is a &"$"& the option is expanded before use and may depend on &$sender_host_name$&, &$sender_host_address$& and &$sender_host_port$&. +.wen .oindex "&%-os%&" @@ -16541,7 +16706,24 @@ prior to the 4.80 release, as Debian used to patch Exim to raise the minimum acceptable bound from 1024 to 2048. +.new +.option tls_eccurve main string&!! prime256v1 +.cindex TLS "EC cryptography" +If built with a recent-enough version of OpenSSL, +this option selects a EC curve for use by Exim. + +Curve names of the form &'prime256v1'& are accepted. +For even more-recent library versions, names of the form &'P-512'& +are also accepted, plus the special value &'auto'& +which tell the library to choose. + +If the option is set to an empty string, no EC curves will be enabled. +.wen + + .option tls_ocsp_file main string&!! unset +.cindex TLS "certificate status" +.cindex TLS "OCSP proof file" This option must if set expand to the absolute path to a file which contains a current status proof for the server's certificate, as obtained from the @@ -16549,6 +16731,8 @@ Certificate Authority. .option tls_on_connect_ports main "string list" unset +.cindex SSMTP +.cindex SMTPS This option specifies a list of incoming SSMTP (aka SMTPS) ports that should operate the obsolete SSMTP (SMTPS) protocol, where a TLS session is immediately set up without waiting for the client to issue a STARTTLS command. For @@ -17058,6 +17242,7 @@ or for any deliveries caused by this router. You should not set this option unless you really, really know what you are doing. See also the generic transport option of the same name. +.new .option dnssec_request_domains routers "domain list&!!" unset .cindex "MX record" "security" .cindex "DNSSEC" "MX lookup" @@ -17076,6 +17261,7 @@ DNS lookups for domains matching &%dnssec_request_domains%& will be done with the dnssec request bit set. Any returns not having the Authenticated Data bit (AD bit) set will be ignored and logged as a host-lookup failure. This applies to all of the SRV, MX, AAAA, A lookup sequence. +.wen .option domains routers&!? "domain list&!!" unset @@ -17295,6 +17481,13 @@ removal requests are deleted when the address is passed on to subsequent routers, and this can lead to problems with duplicates -- see the similar warning for &%headers_add%& above. +.new +&*Warning 3*&: Because of the separate expansion of the list items, +items that contain a list separator must have it doubled. +To avoid this, change the list separator (&<>&). +.wen + + .option ignore_target_hosts routers "host list&!!" unset .cindex "IP address" "discarding" @@ -18048,8 +18241,10 @@ There are a few cases where a &(dnslookup)& router will decline to accept an address; if such a router is expected to handle "all remaining non-local domains", then it is important to set &%no_more%&. +.new The router will defer rather than decline if the domain is found in the &%fail_defer_domains%& router option. +.wen Reasons for a &(dnslookup)& router to decline currently include: .ilist @@ -18130,6 +18325,7 @@ when there is a DNS lookup error. +.new .option fail_defer_domains dnslookup "domain list&!!" unset .cindex "MX record" "not found" DNS lookups for domains matching &%fail_defer_domains%& @@ -18139,6 +18335,7 @@ This maybe be useful for queueing messages for a newly created domain while the DNS configuration is not ready. However, it will result in any message with mistyped domains also being queued. +.wen .option mx_domains dnslookup "domain list&!!" unset @@ -20351,6 +20548,10 @@ errors and cause the delivery to be deferred. Unlike most options, &%headers_remove%& can be specified multiple times for a router; all listed headers are removed. +&*Warning*&: Because of the separate expansion of the list items, +items that contain a list separator must have it doubled. +To avoid this, change the list separator (&<>&). + .option headers_rewrite transports string unset @@ -24412,12 +24613,14 @@ A server unexpectedly closed the SMTP connection. There may, of course, legitimate reasons for this (host died, network died), but if it repeats a lot for the same host, it indicates something odd. +.new .vitem &%lookup%& A DNS lookup for a host failed. Note that a &%dnslookup%& router will need to have matched its &%fail_defer_domains%& option for this retry type to be usable. Also note that a &%manualroute%& router will probably need its &%host_find_failed%& option set to &%defer%&. +.wen .vitem &%refused_MX%& A connection to a host obtained from an MX record was refused. @@ -24830,6 +25033,7 @@ 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 @@ -24844,6 +25048,10 @@ 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. +.new +The eighth is an Exim authenticator but not an SMTP one; +instead it can use information from a TLS negotiation. +.wen The authenticators are configured using the same syntax as other drivers (see section &<>&). If no authenticators are required, no @@ -25563,7 +25771,7 @@ cyrusless_crammd5: driver = cram_md5 public_name = CRAM-MD5 server_secret = ${lookup{$auth1:mail.example.org:userPassword}\ - dbmjz{/etc/sasldb2}} + dbmjz{/etc/sasldb2}{$value}fail} server_set_id = $auth1 .endd @@ -26050,6 +26258,81 @@ msn: +. //////////////////////////////////////////////////////////////////////////// +. //////////////////////////////////////////////////////////////////////////// + +.new +.chapter "The tls authenticator" "CHAPtlsauth" +.scindex IIDtlsauth1 "&(tls)& authenticator" +.scindex IIDtlsauth2 "authenticators" "&(tls)&" +.cindex "authentication" "Client Certificate" +.cindex "authentication" "X509" +.cindex "Certificate-based authentication" +The &(tls)& authenticator provides server support for +authentication based on client certificates. + +It is not an SMTP authentication mechanism and is not +advertised by the server as part of the SMTP EHLO response. +It is an Exim authenticator in the sense that it affects +the protocol element of the log line, can be tested for +by the &%authenticated%& ACL condition, and can set +the &$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. + + + . //////////////////////////////////////////////////////////////////////////// . //////////////////////////////////////////////////////////////////////////// @@ -26978,6 +27261,7 @@ options in the main part of the configuration. These options are: .cindex "EXPN" "ACL for" .cindex "HELO" "ACL for" .cindex "EHLO" "ACL for" +.cindex "DKIM" "ACL for" .cindex "MAIL" "ACL for" .cindex "QUIT, ACL for" .cindex "RCPT" "ACL for" @@ -26996,6 +27280,7 @@ options in the main part of the configuration. These options are: .irow &%acl_smtp_connect%& "ACL for start of SMTP connection" .irow &%acl_smtp_data%& "ACL after DATA is complete" .irow &%acl_smtp_data_prdr%& "ACL for each recipient, after DATA is complete" +.irow &%acl_smtp_dkim%& "ACL for each DKIM signer" .irow &%acl_smtp_etrn%& "ACL for ETRN" .irow &%acl_smtp_expn%& "ACL for EXPN" .irow &%acl_smtp_helo%& "ACL for HELO or EHLO" @@ -27171,8 +27456,11 @@ the feature was not requested by the client. .cindex "QUIT, ACL for" The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL does not affect the response code to QUIT, which is always 221. Thus, the ACL -does not in fact control any access. For this reason, it may only accept +does not in fact control any access. +.new +For this reason, it may only accept or warn as its final result. +.wen This ACL can be used for tasks such as custom logging at the end of an SMTP session. For example, you can use ACL variables in other ACLs to count @@ -28089,8 +28377,10 @@ This option requests delivery be attempted while the item is being received. The option is usable in the RCPT ACL. If enabled for a message recieved via smtp and routed to an smtp transport, +.new and only one transport, interface, destination host and port combination is used for all recipients of the message, +.wen then the delivery connection is made while the receiving connection is open and data is copied from one to the other. @@ -28098,7 +28388,9 @@ An attempt to set this option for any recipient but the first for a mail will be quietly ignored. If a recipient-verify callout connection is subsequently requested in the same ACL it is held open and used for +.new any subsequent receipients and the data, +.wen otherwise one is made after the initial RCPT ACL completes. Note that routers are used in verify mode, @@ -28110,7 +28402,9 @@ Headers may be modified by routers (subject to the above) and transports. Cutthrough delivery is not supported via transport-filters or when DKIM signing of outgoing messages is done, because it sends data to the ultimate destination before the entire message has been received from the source. +.new It is not supported for messages recieved with the SMTP PRDR option in use. +.wen Should the ultimate destination system positively accept or reject the mail, a corresponding indication is given to the source system and nothing is queued. @@ -28919,8 +29213,10 @@ Verification ensures that the host name obtained from a reverse DNS lookup, or one of its aliases, does, when it is itself looked up in the DNS, yield the original IP address. +.new There is one possible option, &`defer_ok`&. If this is present and a DNS operation returns a temporary error, the verify condition succeeds. +.wen If this condition is used for a locally generated message (that is, when there is no client host involved), it always succeeds. @@ -29525,7 +29821,7 @@ The &%per_rcpt%& option causes Exim to limit the rate at which recipients are accepted. It can be used in the &%acl_smtp_rcpt%&, &%acl_smtp_predata%&, &%acl_smtp_mime%&, &%acl_smtp_data%&, or &%acl_smtp_rcpt%& ACLs. In &%acl_smtp_rcpt%& the rate is updated one recipient at a time; in the other -ACLs the rate is updated with the total recipient count in one go. Note that +ACLs the rate is updated with the total (accepted) recipient count in one go. Note that in either case the rate limiting engine will see a message with many recipients as a large high-speed burst. @@ -30516,7 +30812,7 @@ is used. If you use a remote host, you need to make Exim's spool directory available to it, as the scanner is passed a file path, not file contents. -For information about available commands and their options you may use +For information about available commands and their options you may use .code $ socat UNIX:/var/run/avast/scan.sock STDIO: FLAGS @@ -30827,7 +31123,7 @@ score and a report for the message. .new Support is also provided for Rspamd. -For more information about installation and configuration of SpamAssassin or +For more information about installation and configuration of SpamAssassin or Rspamd refer to their respective websites at &url(http://spamassassin.apache.org) and &url(http://www.rspamd.com) .wen @@ -30841,7 +31137,7 @@ documentation to see how you can tweak it. The default installation should work nicely, however. .oindex "&%spamd_address%&" -By default, SpamAssassin listens on 127.0.0.1, TCP port 783 and if you +By default, SpamAssassin listens on 127.0.0.1, TCP port 783 and if you intend to use an instance running on the local host you do not need to set &%spamd_address%&. If you intend to use another host or port for SpamAssassin, you must set the &%spamd_address%& option in the global part of the Exim @@ -30949,15 +31245,17 @@ right-hand side. The name allows you to use per-domain or per-user antispam profiles in principle, but this is not straightforward in practice, because a message may have multiple recipients, not necessarily all in the same domain. Because the -&%spam%& condition has to be called from a DATA ACL in order to be able to +&%spam%& condition has to be called from a DATA-time ACL in order to be able to read the contents of the message, the variables &$local_part$& and &$domain$& are not set. +.new Careful enforcement of single-recipient messages (eg. by responding with defer in the recipient ACL for all recipients after the first), or the use of PRDR, .cindex "PRDR" "use for per-user SpamAssassin profiles" are needed to use this feature. +.wen The right-hand side of the &%spam%& condition is expanded before being used, so you can put lookups or conditions there. When the right-hand side evaluates to @@ -30981,7 +31279,11 @@ it always return &"true"& by appending &`:true`& to the username. .cindex "spam scanning" "returned variables" When the &%spam%& condition is run, it sets up a number of expansion -variables. These variables are saved with the received message, thus they are +variables. +.new +Except for &$spam_report$&, +.wen +these variables are saved with the received message so are available for use at delivery time. .vlist @@ -31004,6 +31306,9 @@ headers, since MUAs can match on such strings. .vitem &$spam_report$& A multiline text table, containing the full SpamAssassin report for the message. Useful for inclusion in headers or reject messages. +.new +This variable is only usable in a DATA-time ACL. +.wen .new .vitem &$spam_action$& @@ -31197,7 +31502,11 @@ containing the decoded data. This is perhaps the most important of the MIME variables. It contains a proposed filename for an attachment, if one was found in either the &'Content-Type:'& or &'Content-Disposition:'& headers. The filename will be -RFC2047 or RFC2231 decoded, but no additional sanity checks are done. +RFC2047 +.new +or RFC2231 +.wen +decoded, but no additional sanity checks are done. If no filename was found, this variable contains the empty string. @@ -34636,8 +34945,9 @@ 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. @@ -35137,7 +35447,9 @@ selection marked by asterisks: &`*etrn `& ETRN commands &`*host_lookup_failed `& as it says &` ident_timeout `& timeout for ident connection +.new &` incoming_interface `& local interface on <= and => lines +.wen &` incoming_port `& remote port on <= lines &`*lost_incoming_connection `& as it says (includes timeouts) &` outgoing_port `& add remote port to => lines @@ -35266,7 +35578,9 @@ to the &"<="& line as an IP address in square brackets, tagged by I= and followed by a colon and the port number. The local interface and port are also added to other SMTP log lines, for example &"SMTP connection from"& and to rejection lines +.new and (despite the name) the local interface is added to &"=>"& lines.. +.wen .next .cindex "log" "incoming remote port" .cindex "port" "logging remote" @@ -35610,7 +35924,7 @@ exim -bp The &*-C*& option is used to specify an alternate &_exim.conf_& which might contain alternate exim configuration the queue management might be using. -to obtain a queue listing, and then greps the output to select messages +to obtain a queue listing, and then greps the output to select messages that match given criteria. The following selection options are available: .vlist