X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/f2de3a3339ee08778dffb98057f1c19bdcf86374..093632c96953bfc8fb96d607e0605534efa64252:/doc/doc-docbook/spec.xfpt?ds=inline diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 990df6241..ed67f8109 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -45,7 +45,7 @@ . Update the Copyright year (only) when changing content. . ///////////////////////////////////////////////////////////////////////////// -.set previousversion "4.80" +.set previousversion "4.84" .include ./local_params .set ACL "access control lists (ACLs)" @@ -5557,7 +5557,7 @@ unreachable. The next two lines are concerned with &'ident'& callbacks, as defined by RFC 1413 (hence their names): .code -rfc1413_query_hosts = * +rfc1413_hosts = * rfc1413_query_timeout = 0s .endd These settings cause Exim to avoid ident callbacks for all incoming SMTP calls. @@ -5567,7 +5567,7 @@ of an incoming SMTP connection. If you have hosts for which you trust RFC1413 and need this information, you can change this. -This line enables an efficiency SMTP option. It is negociated by clients +This line enables an efficiency SMTP option. It is negotiated by clients and not expected to cause problems but can be disabled if needed. .code prdr_enable = true @@ -6875,12 +6875,6 @@ ${lookup dnsdb{ptr=192.168.4.5}{$value}fail} If the data for a PTR record is not a syntactically valid IP address, it is not altered and nothing is added. -.cindex "MX record" "in &(dnsdb)& lookup" -.cindex "SRV record" "in &(dnsdb)& lookup" -For an MX lookup, both the preference value and the host name are returned for -each record, separated by a space. For an SRV lookup, the priority, weight, -port, and host name are returned for each record, separated by spaces. - For any record type, if multiple records are found (or, for A6 lookups, if a single record leads to multiple addresses), the data is returned as a concatenation, with newline as the default separator. The order, of course, @@ -6893,6 +6887,16 @@ ${lookup dnsdb{>: a=host1.example}} It is permitted to specify a space as the separator character. Further white space is ignored. +.cindex "MX record" "in &(dnsdb)& lookup" +.cindex "SRV record" "in &(dnsdb)& lookup" +For an MX lookup, both the preference value and the host name are returned for +each record, separated by a space. For an SRV lookup, the priority, weight, +port, and host name are returned for each record, separated by spaces. +.new +An alternate field separator can be specified using a comma after the main +separator character, followed immediately by the field separator. +.wen + .cindex "TXT record" "in &(dnsdb)& lookup" .cindex "SPF record" "in &(dnsdb)& lookup" For TXT records with multiple items of data, only the first item is returned, @@ -7005,7 +7009,6 @@ ${lookup dnsdb{a=one.host.com:two.host.com}} Thus, in the default case, as long as at least one of the DNS lookups yields some data, the lookup succeeds. -.new .cindex "DNSSEC" "dns lookup" Use of &(DNSSEC)& is controlled by a dnssec modifier. The possible keywords are @@ -7018,7 +7021,6 @@ is treated as equivalent to a temporary DNS error. The default is &"never"&. See also the &$lookup_dnssec_authenticated$& variable. -.wen @@ -7084,7 +7086,6 @@ With sufficiently modern LDAP libraries, Exim supports forcing TLS over regular LDAP connections, rather than the SSL-on-connect &`ldaps`&. See the &%ldap_start_tls%& option. -.new Starting with Exim 4.83, the initialization of LDAP with TLS is more tightly controlled. Every part of the TLS configuration can be configured by settings in &_exim.conf_&. Depending on the version of the client libraries installed on @@ -7094,7 +7095,6 @@ certificates. This revealed a nuance where the current UID that exim was running as could affect which config files it read. With Exim 4.83, these methods become optional, only taking effect if not specifically set in &_exim.conf_&. -.wen .section "LDAP quoting" "SECID68" @@ -7242,9 +7242,7 @@ them. The following names are recognized: &`USER `& set the DN, for authenticating the LDAP bind &`PASS `& set the password, likewise &`REFERRALS `& set the referrals parameter -.new &`SERVERS `& set alternate server list for this query only -.wen &`SIZE `& set the limit for the number of entries returned &`TIME `& set the maximum waiting time for a query .endd @@ -7266,15 +7264,13 @@ Netscape SDK; for OpenLDAP no action is taken. The TIME parameter (also a number of seconds) is passed to the server to set a server-side limit on the time taken to complete a search. -.new The SERVERS parameter allows you to specify an alternate list of ldap servers to use for an individual lookup. The global ldap_servers option provides a default list of ldap servers, and a single lookup can specify a single ldap server to use. But when you need to do a lookup with a list of servers that is different than the default list (maybe different order, maybe a completely different set of servers), the SERVERS parameter allows you to specify this -alternate list. -.wen +alternate list (colon-separated). Here is an example of an LDAP query in an Exim lookup that uses some of these values. This is a single line, folded to fit on the page: @@ -7346,30 +7342,44 @@ If you specify multiple attributes, the result contains space-separated, quoted strings, each preceded by the attribute name and an equals sign. Within the quotes, the quote character, backslash, and newline are escaped with backslashes, and commas are used to separate multiple values for the attribute. +.new +Any commas in attribute values are doubled +(permitting treatment of the values as a comma-separated list). +.wen Apart from the escaping, the string within quotes takes the same form as the output when a single attribute is requested. Specifying no attributes is the same as specifying all of an entry's attributes. +.new Here are some examples of the output format. The first line of each pair is an LDAP query, and the second is the data that is returned. The attribute called -&%attr1%& has two values, whereas &%attr2%& has only one value: +&%attr1%& has two values, one of them with an embedded comma, whereas +&%attr2%& has only one value: .code ldap:///o=base?attr1?sub?(uid=fred) -value1.1, value1.2 +value1.1,value1,,2 ldap:///o=base?attr2?sub?(uid=fred) value two ldap:///o=base?attr1,attr2?sub?(uid=fred) -attr1="value1.1, value1.2" attr2="value two" +attr1="value1.1,value1,,2" attr2="value two" ldap:///o=base??sub?(uid=fred) -objectClass="top" attr1="value1.1, value1.2" attr2="value two" +objectClass="top" attr1="value1.1,value1,,2" attr2="value two" .endd -The &%extract%& operator in string expansions can be used to pick out -individual fields from data that consists of &'key'&=&'value'& pairs. You can +.wen +You can make use of Exim's &%-be%& option to run expansion tests and thereby check the results of LDAP lookups. +The &%extract%& operator in string expansions can be used to pick out +individual fields from data that consists of &'key'&=&'value'& pairs. +.new +The &%listextract%& operator should be used to pick out individual values +of attributes, even when only a single value is expected. +The doubling of embedded commas allows you to use the returned data as a +comma separated list (using the "<," syntax for changing the input list separator). +.wen @@ -8354,7 +8364,6 @@ Both &`+include_unknown`& and &`+ignore_unknown`& may appear in the same list. The effect of each one lasts until the next, or until the end of the list. -.new .section "Mixing wildcarded host names and addresses in host lists" &&& "SECTmixwilhos" .cindex "host list" "mixing names and addresses in" @@ -8390,7 +8399,6 @@ If the first &%accept%& fails, Exim goes on to try the second one. See chapter &`+ignore_unknown`&, which was discussed in depth in the first example in this section. .endlist -.wen .section "Temporary DNS errors when looking up host information" &&& @@ -8885,7 +8893,6 @@ the expansion result is an empty string. If the ACL returns defer the result is a forced-fail. Otherwise the expansion fails. -.new .vitem "&*${certextract{*&<&'field'&>&*}{*&<&'certificate'&>&*}&&& {*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&" .cindex "expansion" "extracting cerificate fields" @@ -8932,8 +8939,10 @@ a right angle-bracket followed immediately by the new separator. Recognised RDN type labels include "CN", "O", "OU" and "DC". The field selectors marked as "time" above -may output a number of seconds since epoch -if the modifier "int" is used. +take an optional modifier of "int" +for which the result is the number of seconds since epoch. +Otherwise the result is a human-readable string +in the timezone selected by the main "timezone" option. The field selectors marked as "list" above return a list, newline-separated by default, @@ -8948,7 +8957,6 @@ which is one of "dns", "uri" or "mail"; if so the elenment tags are omitted. If not otherwise noted field values are presented in human-readable form. -.wen .vitem "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&& {*&<&'arg'&>&*}...}*&" @@ -9501,7 +9509,7 @@ locks out the use of this expansion item in filter files. .cindex "expansion" "inserting from a socket" .cindex "socket, use of in expansion" .cindex "&%readsocket%& expansion item" -This item inserts data from a Unix domain or Internet socket into the expanded +This item inserts data from a Unix domain or TCP socket into the expanded string. The minimal way of using it uses just two arguments, as in these examples: .code @@ -9597,11 +9605,23 @@ expansion item above. {*&<&'string2'&>&*}}*&" .cindex "expansion" "running a command" .cindex "&%run%& expansion item" -The command and its arguments are first expanded separately, and then the -command is run in a separate process, but under the same uid and gid. As in -other command executions from Exim, a shell is not used by default. If you want +The command and its arguments are first expanded as one string. The string is +split apart into individual arguments by spaces, and then the command is run +in a separate process, but under the same uid and gid. As in other command +executions from Exim, a shell is not used by default. If the command requires a shell, you must explicitly code it. +Since the arguments are split by spaces, when there is a variable expansion +which has an empty result, it will cause the situation that the argument will +simply be omitted when the program is actually executed by Exim. If the +script/program requires a specific number of arguments and the expanded +variable could possibly result in this empty expansion, the variable must be +quoted. This is more difficult if the expanded variable itself could result +in a string containing quotes, because it would interfere with the quotes +around the command arguments. A possible guard against this is to wrap the +variable in the &%sg%& operator to change any quote marks to some other +character. + The standard input for the command exists, but is empty. The standard output and standard error are set to the same file descriptor. .cindex "return code" "from &%run%& expansion" @@ -9680,6 +9700,37 @@ the regular expression from string expansion. +.new +.vitem &*${sort{*&<&'string'&>&*}{*&<&'comparator'&>&*}{*&<&'extractor'&>&*}}*& +.cindex sorting a list +.cindex list sorting +After expansion, <&'string'&> is interpreted as a list, colon-separated by +default, but the separator can be changed in the usual way. +The <&'comparator'&> argument is interpreted as the operator +of a two-argument expansion condition. +The numeric operators plus ge, gt, le, lt (and ~i variants) are supported. +The comparison should return true when applied to two values +if the first value should sort before the second value. +The <&'extractor'&> expansion is applied repeatedly to elements of the list, +the element being placed in &$item$&, +to give values for comparison. + +The item result is a sorted list, +with the original list separator, +of the list elements (in full) of the original. + +Examples: +.code +${sort{3:2:1:4}{<}{$item}} +.endd +sorts a list of numbers, and +.code +${sort {$lookup dnsdb{>:,,mx=example.com}} {<} {${listextract{1}{<,$item}}}} +.endd +will sort an MX lookup into priority order. +.wen + + .vitem &*${substr{*&<&'string1'&>&*}{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*& .cindex "&%substr%& expansion item" .cindex "substring extraction" @@ -10997,6 +11048,11 @@ precedes the expansion of the string. For example, the commands available in Exim filter files include an &%if%& command with its own regular expression matching condition. +.vitem "&$acl_arg1$&, &$acl_arg2$&, etc" +Within an acl condition, expansion condition or expansion item +any arguments are copied to these variables, +any unused variables being made empty. + .vitem "&$acl_c...$&" Values can be placed in these variables by the &%set%& modifier in an ACL. They can be given any name that starts with &$acl_c$& and is at least six characters @@ -11018,6 +11074,10 @@ message is received, the values of these variables are saved with the message, and can be accessed by filters, routers, and transports during subsequent delivery. +.vitem &$acl_narg$& +Within an acl condition, expansion condition or expansion item +this variable has the number of arguments. + .vitem &$acl_verify_message$& .vindex "&$acl_verify_message$&" After an address verification has failed, this variable contains the failure @@ -11404,6 +11464,11 @@ the result, the name is not accepted, and &$host_lookup_deferred$& is set to .vindex "&$host_lookup_failed$&" See &$host_lookup_deferred$&. +.vitem &$host_port$& +.vindex "&$host_port$&" +This variable is set to the remote host's TCP port whenever &$host$& is set +for an outbound connection. + .vitem &$inode$& .vindex "&$inode$&" @@ -11556,7 +11621,6 @@ ability to find the amount of free space (only true for experimental systems), the space value is -1. See also the &%check_log_space%& option. -.new .vitem &$lookup_dnssec_authenticated$& .vindex "&$lookup_dnssec_authenticated$&" This variable is set after a DNS lookup done by @@ -11564,7 +11628,6 @@ a dnsdb lookup expansion, dnslookup router or smtp transport. It will be empty if &(DNSSEC)& was not requested, &"no"& if the result was not labelled as authenticated data and &"yes"& if it was. -.wen .vitem &$mailstore_basename$& .vindex "&$mailstore_basename$&" @@ -11652,7 +11715,7 @@ This variable is like &$message_headers$& except that no processing of the contents of header lines is done. .vitem &$message_id$& -This is an old name for &$message_exim_id$&, which is now deprecated. +This is an old name for &$message_exim_id$&. It is now deprecated. .vitem &$message_linecount$& .vindex "&$message_linecount$&" @@ -11869,10 +11932,7 @@ on which interface and/or port is being used for the incoming connection. The values of &$received_ip_address$& and &$received_port$& are saved with any messages that are received, thus making these variables available at delivery time. - -&*Note:*& There are no equivalent variables for outgoing connections, because -the values are unknown (unless they are explicitly set by options of the -&(smtp)& transport). +For outbound connections see &$sending_ip_address$&. .vitem &$received_port$& .vindex "&$received_port$&" @@ -12091,8 +12151,9 @@ the &%-bs%& or &%-bS%& options. .vitem &$sender_host_address$& .vindex "&$sender_host_address$&" -When a message is received from a remote host, this variable contains that -host's IP address. For locally submitted messages, it is empty. +When a message is received from a remote host using SMTP, +this variable contains that +host's IP address. For locally non-SMTP submitted messages, it is empty. .vitem &$sender_host_authenticated$& .vindex "&$sender_host_authenticated$&" @@ -12103,7 +12164,8 @@ received. It is empty if there was no successful authentication. See also .vitem &$sender_host_dnssec$& .vindex "&$sender_host_dnssec$&" -If &$sender_host_name$& has been populated (by reference, &%hosts_lookup%& or +If an attempt to populate &$sender_host_name$& has been made +(by reference, &%hosts_lookup%& or otherwise) then this boolean will have been set true if, and only if, the resolver library states that the reverse DNS was authenticated data. At all other times, this variable is false. @@ -12342,43 +12404,43 @@ on an outbound SMTP connection; the meaning of this depends upon the TLS implementation used. If TLS has not been negotiated, the value will be 0. -.new .vitem &$tls_in_ourcert$& .vindex "&$tls_in_ourcert$&" This variable refers to the certificate presented to the peer of an inbound connection when the message was received. It is only useful as the argument of a -&%certextract%& expansion item, &%md5%& or &%sha1%& operator, -or a &%def%& condition. +.new +&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, .wen +or a &%def%& condition. -.new .vitem &$tls_in_peercert$& .vindex "&$tls_in_peercert$&" This variable refers to the certificate presented by the peer of an inbound connection when the message was received. It is only useful as the argument of a -&%certextract%& expansion item, &%md5%& or &%sha1%& operator, -or a &%def%& condition. +.new +&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, .wen +or a &%def%& condition. -.new .vitem &$tls_out_ourcert$& .vindex "&$tls_out_ourcert$&" This variable refers to the certificate presented to the peer of an outbound connection. It is only useful as the argument of a -&%certextract%& expansion item, &%md5%& or &%sha1%& operator, -or a &%def%& condition. +.new +&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, .wen +or a &%def%& condition. -.new .vitem &$tls_out_peercert$& .vindex "&$tls_out_peercert$&" This variable refers to the certificate presented by the peer of an outbound connection. It is only useful as the argument of a -&%certextract%& expansion item, &%md5%& or &%sha1%& operator, -or a &%def%& condition. +.new +&%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, .wen +or a &%def%& condition. .vitem &$tls_in_certificate_verified$& .vindex "&$tls_in_certificate_verified$&" @@ -12417,6 +12479,24 @@ and then set to the outgoing cipher suite if one is negotiated. See chapter &<>& for details of TLS support and chapter &<>& for details of the &(smtp)& transport. +.vitem &$tls_in_ocsp$& +.vindex "&$tls_in_ocsp$&" +When a message is received from a remote client connection +the result of any OCSP request from the client is encoded in this variable: +.code +0 OCSP proof was not requested (default value) +1 No response to request +2 Response not verified +3 Verification failed +4 Verification succeeded +.endd + +.vitem &$tls_out_ocsp$& +.vindex "&$tls_out_ocsp$&" +When a message is sent to a remote host connection +the result of any OCSP request made is encoded in this variable. +See &$tls_in_ocsp$& for values. + .vitem &$tls_in_peerdn$& .vindex "&$tls_in_peerdn$&" .vindex "&$tls_peerdn$&" @@ -12512,6 +12592,13 @@ This variable contains the result of an expansion lookup, extraction operation, or external command, as described above. It is also used during a &*reduce*& expansion. +.vitem &$verify_mode$& +.vindex "&$verify_mode$&" +While a router or transport is being run in verify mode +or for cutthrough delivery, +contains "S" for sender-verification or "R" for recipient-verification. +Otherwise, empty. + .vitem &$version_number$& .vindex "&$version_number$&" The version number of Exim. @@ -12723,8 +12810,9 @@ option), the interfaces and ports on which it listens are controlled by the following options: .ilist -&%daemon_smtp_ports%& contains a list of default ports. (For backward -compatibility, this option can also be specified in the singular.) +&%daemon_smtp_ports%& contains a list of default ports +or service names. +(For backward compatibility, this option can also be specified in the singular.) .next &%local_interfaces%& contains list of interface IP addresses on which to listen. Each item may optionally also specify a port. @@ -12825,7 +12913,8 @@ value of &%daemon_smtp_ports%& is no longer relevant in this example.) Exim supports the obsolete SSMTP protocol (also known as SMTPS) that was used before the STARTTLS command was standardized for SMTP. Some legacy clients still use this protocol. If the &%tls_on_connect_ports%& option is set to a -list of port numbers, connections to those ports must use SSMTP. The most +list of port numbers or service names, +connections to those ports must use SSMTP. The most common use of this option is expected to be .code tls_on_connect_ports = 465 @@ -14972,16 +15061,21 @@ yourself in the foot in various unpleasant ways. This option should not be adjusted lightly. An unrecognised item will be detected at startup, by invoking Exim with the &%-bV%& flag. +The option affects Exim operating both as a server and as a client. + Historical note: prior to release 4.80, Exim defaulted this value to "+dont_insert_empty_fragments", which may still be needed for compatibility with some clients, but which lowers security by increasing exposure to some now infamous attacks. -An example: +Examples: .code # Make both old MS and old Eudora happy: openssl_options = -all +microsoft_big_sslv3_buffer \ +dont_insert_empty_fragments + +# Disable older protocol versions: +openssl_options = +no_sslv2 +no_sslv3 .endd Possible options may include: @@ -16402,16 +16496,23 @@ See &%tls_verify_hosts%& below. The value of this option is expanded, and must then be the absolute path to a file containing permitted certificates for clients that match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you -are using OpenSSL, you can set &%tls_verify_certificates%& to the name of a -directory containing certificate files. This does not work with GnuTLS; the -option must be set to the name of a single file if you are using GnuTLS. +are using either GnuTLS version 3.3.6 (or later) or OpenSSL, +you can set &%tls_verify_certificates%& to the name of a +directory containing certificate files. +For earlier versions of GnuTLS +the option must be set to the name of a single file. + +With OpenSSL the certificates specified +explicitly +either by file or directory +are added to those given by the system default location. These certificates should be for the certificate authorities trusted, rather than the public cert of individual clients. With both OpenSSL and GnuTLS, if the value is a file then the certificates are sent by Exim as a server to connecting clients, defining the list of accepted certificate authorities. Thus the values defined should be considered public data. To avoid this, -use OpenSSL with a directory. +use the explicit directory version. See &<>& for discussion of when this option might be re-expanded. @@ -16780,6 +16881,48 @@ If the expansion fails (other than forced failure) delivery is deferred. Some of the other precondition options are common special cases that could in fact be specified using &%condition%&. +.new +Historical note: We have &%condition%& on ACLs and on Routers. Routers +are far older, and use one set of semantics. ACLs are newer and when +they were created, the ACL &%condition%& process was given far stricter +parse semantics. The &%bool{}%& expansion condition uses the same rules as +ACLs. The &%bool_lax{}%& expansion condition uses the same rules as +Routers. More pointedly, the &%bool_lax{}%& was written to match the existing +Router rules processing behavior. + +This is best illustrated in an example: +.code +# If used in an ACL condition will fail with a syntax error, but +# in a router condition any extra characters are treated as a string + +$ exim -be '${if eq {${lc:GOOGLE.com}} {google.com}} {yes} {no}}' +true {yes} {no}} + +$ exim -be '${if eq {${lc:WHOIS.com}} {google.com}} {yes} {no}}' + {yes} {no}} +.endd +In each example above, the &%if%& statement actually ends after +&"{google.com}}"&. Since no true or false braces were defined, the +default &%if%& behavior is to return a boolean true or a null answer +(which evaluates to false). The rest of the line is then treated as a +string. So the first example resulted in the boolean answer &"true"& +with the string &" {yes} {no}}"& appended to it. The second example +resulted in the null output (indicating false) with the string +&" {yes} {no}}"& appended to it. + +In fact you can put excess forward braces in too. In the router +&%condition%&, Exim's parser only looks for &"{"& symbols when they +mean something, like after a &"$"& or when required as part of a +conditional. But otherwise &"{"& and &"}"& are treated as ordinary +string characters. + +Thus, in a Router, the above expansion strings will both always evaluate +true, as the result of expansion is a non-empty string which doesn't +match an explicit false value. This can be tricky to debug. By +contrast, in an ACL either of those strings will always result in an +expansion error because the result doesn't look sufficiently boolean. +.wen + .option debug_print routers string&!! unset .cindex "testing" "variables in drivers" @@ -17653,6 +17796,7 @@ delivering in cutthrough mode or testing recipient verification using &%-bv%&. See section &<>& for a list of the order in which preconditions are evaluated. +See also the &$verify_mode$& variable. .option verify_sender routers&!? boolean true @@ -17660,6 +17804,7 @@ If this option is false, the router is skipped when verifying sender addresses or testing sender verification using &%-bvs%&. See section &<>& for a list of the order in which preconditions are evaluated. +See also the &$verify_mode$& variable. .ecindex IIDgenoprou1 .ecindex IIDgenoprou2 @@ -17834,7 +17979,6 @@ when there is a DNS lookup error. -.new .option dnssec_request_domains dnslookup "domain list&!!" unset .cindex "MX record" "security" .cindex "DNSSEC" "MX lookup" @@ -17843,11 +17987,9 @@ when there is a DNS lookup error. DNS lookups for domains matching &%dnssec_request_domains%& will be done with the dnssec request bit set. This applies to all of the SRV, MX A6, AAAA, A lookup sequence. -.wen -.new .option dnssec_require_domains dnslookup "domain list&!!" unset .cindex "MX record" "security" .cindex "DNSSEC" "MX lookup" @@ -17857,7 +17999,6 @@ 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 wil be ignored and logged as a host-lookup failure. This applies to all of the SRV, MX A6, AAAA, A lookup sequence. -.wen @@ -22764,7 +22905,6 @@ See the &%search_parents%& option in chapter &<>& for more details. -.new .option dnssec_request_domains smtp "domain list&!!" unset .cindex "MX record" "security" .cindex "DNSSEC" "MX lookup" @@ -22773,11 +22913,9 @@ details. DNS lookups for domains matching &%dnssec_request_domains%& will be done with the dnssec request bit set. This applies to all of the SRV, MX A6, AAAA, A lookup sequence. -.wen -.new .option dnssec_require_domains smtp "domain list&!!" unset .cindex "MX record" "security" .cindex "DNSSEC" "MX lookup" @@ -22787,7 +22925,6 @@ 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 wil be ignored and logged as a host-lookup failure. This applies to all of the SRV, MX A6, AAAA, A lookup sequence. -.wen @@ -23296,7 +23433,7 @@ unknown state), opens a new one to the same host, and then tries the delivery in clear. -.option tls_try_verify_hosts smtp "host list&!! unset +.option tls_try_verify_hosts smtp "host list&!!" unset .cindex "TLS" "server certificate verification" .cindex "certificate" "verification of server" This option gives a list of hosts for which, on encrypted connections, @@ -23304,7 +23441,7 @@ certificate verification will be tried but need not succeed. The &%tls_verify_certificates%& option must also be set. Note that unless the host is in this list TLS connections will be denied to hosts using self-signed certificates -when &%tls_verify_certificates%& is set. +when &%tls_verify_certificates%& is matched. The &$tls_out_certificate_verified$& variable is set when certificate verification succeeds. @@ -23316,10 +23453,20 @@ certificate verification succeeds. .vindex "&$host_address$&" The value of this option must be the absolute path to a file containing permitted server certificates, for use when setting up an encrypted connection. -Alternatively, if you are using OpenSSL, you can set +Alternatively, +if you are using either GnuTLS version 3.3.6 (or later) or OpenSSL, +you can set &%tls_verify_certificates%& to the name of a directory containing certificate -files. This does not work with GnuTLS; the option must be set to the name of a -single file if you are using GnuTLS. The values of &$host$& and +files. +For earlier versions of GnuTLS the option must be set to the name of a +single file. + +With OpenSSL the certificates specified +explicitly +either by file or directory +are added to those given by the system default location. + +The values of &$host$& and &$host_address$& are set to the name and address of the server during the expansion of this option. See chapter &<>& for details of TLS. @@ -23328,7 +23475,7 @@ if neither tls_verify_hosts nor tls_try_verify_hosts are set and certificate verification fails the TLS connection is closed. -.option tls_verify_hosts smtp "host list&!! unset +.option tls_verify_hosts smtp "host list&!!" unset .cindex "TLS" "server certificate verification" .cindex "certificate" "verification of server" This option gives a list of hosts for which. on encrypted connections, @@ -25378,6 +25525,7 @@ but it is present in many binary distributions. .scindex IIDdcotauth2 "authenticators" "&(dovecot)&" This authenticator is an interface to the authentication facility of the Dovecot POP/IMAP server, which can support a number of authentication methods. +Note that Dovecot must be configured to use auth-client not auth-userdb. If you are using Dovecot to authenticate POP/IMAP clients, it might be helpful to use the same mechanisms for SMTP authentication. This is a server authenticator only. There is only one option: @@ -25800,7 +25948,8 @@ There are some differences in usage when using GnuTLS instead of OpenSSL: .ilist The &%tls_verify_certificates%& option must contain the name of a file, not the -name of a directory (for OpenSSL it can be either). +name of a directory for GnuTLS versions before 3.3.6 +(for later versions, or OpenSSL, it can be either). .next The default value for &%tls_dhparam%& differs for historical reasons. .next @@ -25997,7 +26146,8 @@ The GnuTLS library allows the caller to provide a "priority string", documented as part of the &[gnutls_priority_init]& function. This is very similar to the ciphersuite specification in OpenSSL. -The &%tls_require_ciphers%& option is treated as the GnuTLS priority string. +The &%tls_require_ciphers%& option is treated as the GnuTLS priority string +and controls both protocols and ciphers. The &%tls_require_ciphers%& option is available both as an global option, controlling how Exim behaves as a server, and also as an option of the @@ -26014,6 +26164,12 @@ installed on your system. If you are using GnuTLS 3, &url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string, then the example code) on that site can be used to test a given string. +For example: +.code +# Disable older versions of protocols +tls_require_ciphers = NORMAL:%LATEST_RECORD_VERSION:-VERS-SSL3.0 +.endd + Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three additional options, "&%gnutls_require_kx%&", "&%gnutls_require_mac%&" and "&%gnutls_require_protocols%&". &%tls_require_ciphers%& was an Exim list. @@ -26064,8 +26220,11 @@ tls_privatekey = /some/file/name These options are, in fact, expanded strings, so you can make them depend on the identity of the client that is connected if you wish. The first file contains the server's X509 certificate, and the second contains the private key -that goes with it. These files need to be readable by the Exim user, and must -always be given as full path names. They can be the same file if both the +that goes with it. These files need to be +PEM format and readable by the Exim user, and must +always be given as full path names. +The key must not be password-protected. +They can be the same file if both the certificate and the key are contained within it. If &%tls_privatekey%& is not set, or if its expansion is forced to fail or results in an empty string, this is assumed to be the case. The certificate file may also contain intermediate @@ -26192,7 +26351,7 @@ an identically named option for the &(smtp)& transport. In each case, the value of the option is expanded and must then be the name of a file that contains a CRL in PEM format. The downside is that clients have to periodically re-download a potentially huge -file from every certificate authority the know of. +file from every certificate authority they know of. The way with most moving parts at query time is Online Certificate Status Protocol (OCSP), where the client verifies the certificate @@ -26246,6 +26405,8 @@ file named by &%tls_ocsp_file%&. Note that the proof only covers the terminal server certificate, not any of the chain from CA to it. +There is no current way to staple a proof for a client certificate. + .code A helper script "ocsp_fetch.pl" for fetching a proof from a CA OCSP server is supplied. The server URL may be included in the @@ -26412,7 +26573,7 @@ during TLS session handshake, to permit alternative values to be chosen: &%tls_verify_certificates%& .next .vindex "&%tls_ocsp_file%&" -&%tls_verify_certificates%& +&%tls_ocsp_file%& .endlist Great care should be taken to deal with matters of case, various injection @@ -27609,6 +27770,11 @@ anyway. If the message contains newlines, this gives rise to a multi-line SMTP response. .vindex "&$acl_verify_message$&" +.new +For ACLs that are called by an &%acl =%& ACL condition, the message is +stored in &$acl_verify_message$&, from which the calling ACL may use it. +.wen + If &%message%& is used on a statement that verifies an address, the message specified overrides any message that is generated by the verification process. However, the original message is available in the variable @@ -28183,6 +28349,8 @@ can be appended; they appear within the called ACL in $acl_arg1 to $acl_arg9, and $acl_narg is set to the count of values. Previous values of these variables are restored after the call returns. The name and values are expanded separately. +Note that spaces in complex expansions which are used as arguments +will act as argument separators. If the nested &%acl%& returns &"drop"& and the outer condition denies access, the connection is dropped. If it returns &"discard"&, the verb must be @@ -28414,7 +28582,6 @@ This condition checks whether the sending host (the client) is authorized to send email. Details of how this works are given in section &<>&. -.new .vitem &*verify&~=&~header_names_ascii*& .cindex "&%verify%& ACL condition" .cindex "&ACL;" "verifying header names only ASCII" @@ -28429,7 +28596,6 @@ allowable characters are decimal ASCII values 33 through 126. Exim itself will handle headers with non-ASCII characters, but it can cause problems for downstream applications, so this option will allow their detection and rejection in the DATA ACL's. -.wen .vitem &*verify&~=&~header_sender/*&<&'options'&> .cindex "&%verify%& ACL condition" @@ -30190,9 +30356,13 @@ av_scanner = cmdline:\ .endd .vitem &%drweb%& .cindex "virus scanners" "DrWeb" -The DrWeb daemon scanner (&url(http://www.sald.com/)) interface takes one -argument, either a full path to a UNIX socket, or an IP address and port -separated by white space, as in these examples: +The DrWeb daemon scanner (&url(http://www.sald.com/)) interface +takes one option, +either a full path to a UNIX socket, +or host and port specifiers separated by white space. +The host may be a name or an IP address; the port is either a +single number or a pair of numbers with a dash between. +For example: .code av_scanner = drweb:/var/run/drwebd.sock av_scanner = drweb:192.168.2.20 31337 @@ -30200,6 +30370,17 @@ av_scanner = drweb:192.168.2.20 31337 If you omit the argument, the default path &_/usr/local/drweb/run/drwebd.sock_& is used. Thanks to Alex Miller for contributing the code for this scanner. +.vitem &%f-protd%& +.cindex "virus scanners" "f-protd" +The f-protd scanner is accessed via HTTP over TCP. +One argument is taken, being a space-separated hostname and port number +(or port-range). +For example: +.code +av_scanner = f-protd:localhost 10200-10204 +.endd +If you omit the argument, the default values show above are used. + .vitem &%fsecure%& .cindex "virus scanners" "F-Secure" The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one @@ -32398,6 +32579,9 @@ headers_remove = return-receipt-to:acknowledge-to Multiple &%headers_remove%& options for a single router or transport can be specified; the arguments will append to a single header-names list. Each item is separately expanded. +Note that colons in complex expansions which are used to +form all or part of a &%headers_remove%& list +will act as list separators. When &%headers_add%& or &%headers_remove%& is specified on a router, items are expanded at routing time, @@ -35043,10 +35227,8 @@ or (in case &*-a*& switch is specified) .code exim -bp .endd -.new The &*-C*& option is used to specify an alternate &_exim.conf_& which might contain alternate exim configuration the queue management might be using. -.wen to obtain a queue listing, and then greps the output to select messages that match given criteria. The following selection options are available: @@ -35153,9 +35335,11 @@ given message, or all mail for a given user, or for a given host, for example. The input files can be in Exim log format or syslog format. If a matching log line is not associated with a specific message, it is included in &'exigrep'&'s output without any additional lines. The usage is: +.new .display -&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`& +&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-M] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`& .endd +.wen If no log file names are given on the command line, the standard input is read. The &%-t%& argument specifies a number of seconds. It adds an additional @@ -35175,6 +35359,21 @@ regular expression. The &%-v%& option inverts the matching condition. That is, a line is selected if it does &'not'& match the pattern. +.new +The &%-M%& options means &"related messages"&. &'exigrep'& will show messages +that are generated as a result/response to a message that &'exigrep'& matched +normally. + +Example of &%-M%&: +user_a sends a message to user_b, which generates a bounce back to user_b. If +&'exigrep'& is used to search for &"user_a"&, only the first message will be +displayed. But if &'exigrep'& is used to search for &"user_b"&, the first and +the second (bounce) message will be displayed. Using &%-M%& with &'exigrep'& +when searching for &"user_a"& will show both messages since the bounce is +&"related"& to or a &"result"& of the first message that was found by the +search term. +.wen + If the location of a &'zcat'& command is known from the definition of ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.