.vitem &$dkim_verify_status$& &&&
Results of DKIM verification.
-For details see chapter &<<CHAPdkim>>&.
+For details see section &<<SECDKIMVFY>>&.
.vitem &$dkim_cur_signer$& &&&
&$dkim_verify_reason$& &&&
&$dkim_key_notes$& &&&
&$dkim_key_length$&
These variables are only available within the DKIM ACL.
-For details see chapter &<<CHAPdkim>>&.
+For details see section &<<SECDKIMVFY>>&.
.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 &<<CHAPdkim>>&.
+For details see section &<<SECDKIMVFY>>&.
.vitem &$dnslist_domain$& &&&
&$dnslist_matched$& &&&
is compiled with the content-scanning extension. For details, see section
&<<SECTscanspamass>>&.
+.new
+.vitem &$spf_header_comment$& &&&
+ &$spf_received$& &&&
+ &$spf_result$& &&&
+ &$spf_smtp_comment$&
+These variables are only available if Exim is built with SPF support.
+For details see section &<<SECSPF>>&.
+.wen
.vitem &$spool_directory$&
.vindex "&$spool_directory$&"
This option defines the ACL that is run for each DKIM signature
(by default, or as specified in the dkim_verify_signers option)
of a received message.
-See chapter &<<CHAPdkim>>& for further details.
+See section &<<SECDKIMVFY>>& for further details.
.option acl_smtp_etrn main string&!! unset
.cindex "ETRN" "ACL for"
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 &<<CHAPdkim>>&.
+See section &<<SECDKIMVFY>>&.
.option dns_again_means_nonexist main "domain list&!!" unset
chapter &<<CHAPi18n>>& for details of Exim's support for internationalisation.
-.option spamd_address main string "see below"
+.option spamd_address main string "127.0.0.1 783"
This option is available when Exim is compiled with the content-scanning
extension. It specifies how Exim connects to SpamAssassin's &%spamd%& daemon.
-The default value is
-.code
-127.0.0.1 783
-.endd
See section &<<SECTscanspamass>>& for more details.
+.new
+.option spf_guess main string "v=spf1 a/24 mx/24 ptr ?all"
+This option is available when Exim is compiled with SPF support.
+See section &<<SECSPF>>& for more details.
+.wen
+
+
+
.option split_spool_directory main boolean false
.cindex "multiple spool directories"
.cindex "spool directory" "split"
This ACL is evaluated before &%acl_smtp_mime%& and &%acl_smtp_data%&.
-For details on the operation of DKIM, see chapter &<<CHAPdkim>>&.
+For details on the operation of DKIM, see section &<<SECDKIM>>&.
.section "The SMTP MIME ACL" "SECID194"
.cindex "disable DKIM verify"
.cindex "DKIM" "disable verify"
This control turns off DKIM verification processing entirely. For details on
-the operation and configuration of DKIM, see chapter &<<CHAPdkim>>&.
+the operation and configuration of DKIM, see section &<<SECDKIM>>&.
.vitem &*control&~=&~dscp/*&<&'value'&>
. ////////////////////////////////////////////////////////////////////////////
. ////////////////////////////////////////////////////////////////////////////
-.chapter "Support for DKIM (DomainKeys Identified Mail)" "CHAPdkim" &&&
- "DKIM Support"
+.chapter "DKIM and SPF" "CHAPdkim" &&&
+ "DKIM and SPF Support"
.cindex "DKIM"
+.section "DKIM (DomainKeys Identified Mail)" SECDKIM
+
DKIM is a mechanism by which messages sent by some entity can be provably
linked to a domain which that entity controls. It permits reputation to
be tracked on a per-domain basis, rather than merely upon source IP address.
DKIM is documented in RFC 4871.
+.new
+As DKIM relies on the message being unchanged in transit, messages handled
+by a mailing-list (which traditionally adds to the message) will not match
+any original DKIM signature.
+.wen
+
DKIM support is compiled into Exim by default if TLS support is present.
It can be disabled by setting DISABLE_DKIM=yes in &_Local/Makefile_&.
name will be appended.
-.section "Verifying DKIM signatures in incoming mail" "SECID514"
+.section "Verifying DKIM signatures in incoming mail" "SECDKIMVFY"
.cindex "DKIM" "verification"
Verification of DKIM signatures in SMTP incoming email is implemented via the
for more information of what they mean.
.endlist
+
+
+
+.new
+.section "SPF (Sender Policy Framework)" SECSPF
+.cindex SPF verification
+
+SPF is a mechanism whereby a domain may assert which IP addresses may transmit
+messages with its domain in the envelope from, documented by RFC 7208.
+For more information on SPF see &url(http://www.openspf.org).
+
+Messages sent by a system not authorised will fail checking of such assertions.
+This includes retransmissions done by traditional forwarders.
+
+SPF verification support is built into Exim if SUPPORT_SPF=yes is set in
+&_Local/Makefile_&. The support uses the &_libspf2_& library
+&url(http://www.libspf2.org/).
+There is no Exim involvement on the trasmission of messages; publishing certain
+DNS records is all that is required.
+
+For verification, an ACL condition and an expansion lookup are provided.
+
+.cindex SPF "ACL condition"
+.cindex ACL "spf condition"
+The ACL condition "spf" can be used at or after the MAIL ACL.
+It takes as an argument a list of strings giving the outcome of the SPF check,
+and will succeed for any matching outcome.
+Valid strings are:
+.vlist
+.vitem &%pass%&
+The SPF check passed, the sending host is positively verified by SPF.
+
+.vitem &%fail%&
+The SPF check failed, the sending host is NOT allowed to send mail for the
+domain in the envelope-from address.
+
+.vitem &%softfail%&
+The SPF check failed, but the queried domain can't absolutely confirm that this
+is a forgery.
+
+.vitem &%none%&
+The queried domain does not publish SPF records.
+
+.vitem &%neutral%&
+The SPF check returned a "neutral" state. This means the queried domain has
+published a SPF record, but wants to allow outside servers to send mail under
+its domain as well. This should be treated like "none".
+
+.vitem &%permerror%&
+This indicates a syntax error in the SPF record of the queried domain.
+You may deny messages when this occurs. (Changed in 4.83)
+
+.vitem &%temperror%&
+This indicates a temporary error during all processing, including Exim's
+SPF processing. You may defer messages when this occurs.
+(Changed in 4.83)
+
+.vitem &%err_temp%&
+Same as permerror, deprecated in 4.83, will be removed in a future release.
+
+.vitem &%err_perm%&
+Same as temperror, deprecated in 4.83, will be removed in a future release.
+.endlist
+
+You can prefix each string with an exclamation mark to invert
+its meaning, for example "!fail" will match all results but
+"fail". The string list is evaluated left-to-right, in a
+short-circuit fashion.
+
+Example:
+.code
+deny spf = fail
+ message = $sender_host_address is not allowed to send mail from \
+ ${if def:sender_address_domain \
+ {$sender_address_domain}{$sender_helo_name}}. \
+ Please see http://www.openspf.org/Why?scope=\
+ ${if def:sender_address_domain {mfrom}{helo}};\
+ identity=${if def:sender_address_domain \
+ {$sender_address}{$sender_helo_name}};\
+ ip=$sender_host_address
+.endd
+
+When the spf condition has run, it sets up several expansion
+variables:
+
+.cindex SPF "verification variables"
+.vlist
+.vitem &$spf_header_comment$&
+.vindex &$spf_header_comment$&
+ This contains a human-readable string describing the outcome
+ of the SPF check. You can add it to a custom header or use
+ it for logging purposes.
+
+.vitem &$spf_received$&
+.vindex &$spf_received$&
+ This contains a complete Received-SPF: header that can be
+ added to the message. Please note that according to the SPF
+ draft, this header must be added at the top of the header
+ list. Please see section 10 on how you can do this.
+
+ Note: in case of "Best-guess" (see below), the convention is
+ to put this string in a header called X-SPF-Guess: instead.
+
+.vitem &$spf_result$&
+.vindex &$spf_result$&
+ This contains the outcome of the SPF check in string form,
+ one of pass, fail, softfail, none, neutral, permerror or
+ temperror.
+
+.vitem &$spf_smtp_comment$&
+.vindex &$spf_smtp_comment$&
+ This contains a string that can be used in a SMTP response
+ to the calling party. Useful for "fail".
+.endlist
+
+
+.cindex SPF "ACL condition"
+.cindex ACL "spf_guess condition"
+.cindex SPF "best guess"
+In addition to SPF, you can also perform checks for so-called
+"Best-guess". Strictly speaking, "Best-guess" is not standard
+SPF, but it is supported by the same framework that enables SPF
+capability.
+Refer to &url(http://www.openspf.org/FAQ/Best_guess_record)
+for a description of what it means.
+
+To access this feature, simply use the spf_guess condition in place
+of the spf one. For example:
+
+.code
+deny spf_guess = fail
+ message = $sender_host_address doesn't look trustworthy to me
+.endd
+
+In case you decide to reject messages based on this check, you
+should note that although it uses the same framework, "Best-guess"
+is not SPF, and therefore you should not mention SPF at all in your
+reject message.
+
+When the spf_guess condition has run, it sets up the same expansion
+variables as when spf condition is run, described above.
+
+Additionally, since Best-guess is not standardized, you may redefine
+what "Best-guess" means to you by redefining the main configuration
+&%spf_guess%& option.
+For example, the following:
+
+.code
+spf_guess = v=spf1 a/16 mx/16 ptr ?all
+.endd
+
+would relax host matching rules to a broader network range.
+
+
+.cindex SPF "lookup expansion"
+.cindex lookup spf
+A lookup expansion is also available. It takes an email
+address as the key and an IP address as the database:
+
+.code
+ ${lookup {username@domain} spf {ip.ip.ip.ip}}
+.endd
+
+The lookup will return the same result strings as they can appear in
+&$spf_result$& (pass,fail,softfail,neutral,none,err_perm,err_temp).
+Currently, only IPv4 addresses are supported.
+
+
+. wen-for SPF section
+.wen
+
+
. ////////////////////////////////////////////////////////////////////////////
. ////////////////////////////////////////////////////////////////////////////
3. Feature macros for the compiled-in set of malware scanner interfaces.
+ 4. SPF support is promoted from Experimental to mainline status. The template
+ src/EDITME makefile does not enable its inclusion.
+
Version 4.90
------------
-Sender Policy Framework (SPF) support
---------------------------------------------------------------
-
-To learn more about SPF, visit http://www.openspf.org. This
-document does not explain the SPF fundamentals, you should
-read and understand the implications of deploying SPF on your
-system before doing so.
-
-SPF support is added via the libspf2 library. Visit
-
- http://www.libspf2.org/
-
-to obtain a copy, then compile and install it. By default,
-this will put headers in /usr/local/include and the static
-library in /usr/local/lib.
-
-To compile Exim with SPF support, set these additional flags in
-Local/Makefile:
-
-EXPERIMENTAL_SPF=yes
-CFLAGS=-DSPF -I/usr/local/include
-EXTRALIBS_EXIM=-L/usr/local/lib -lspf2
-
-This assumes that the libspf2 files are installed in
-their default locations.
-
-You can now run SPF checks in incoming SMTP by using the "spf"
-ACL condition in either the MAIL, RCPT or DATA ACLs. When
-using it in the RCPT ACL, you can make the checks dependent on
-the RCPT address (or domain), so you can check SPF records
-only for certain target domains. This gives you the
-possibility to opt-out certain customers that do not want
-their mail to be subject to SPF checking.
-
-The spf condition takes a list of strings on its right-hand
-side. These strings describe the outcome of the SPF check for
-which the spf condition should succeed. Valid strings are:
-
- o pass The SPF check passed, the sending host
- is positively verified by SPF.
- o fail The SPF check failed, the sending host
- is NOT allowed to send mail for the domain
- in the envelope-from address.
- o softfail The SPF check failed, but the queried
- domain can't absolutely confirm that this
- is a forgery.
- o none The queried domain does not publish SPF
- records.
- o neutral The SPF check returned a "neutral" state.
- This means the queried domain has published
- a SPF record, but wants to allow outside
- servers to send mail under its domain as well.
- This should be treated like "none".
- o permerror This indicates a syntax error in the SPF
- record of the queried domain. You may deny
- messages when this occurs. (Changed in 4.83)
- o temperror This indicates a temporary error during all
- processing, including Exim's SPF processing.
- You may defer messages when this occurs.
- (Changed in 4.83)
- o err_temp Same as permerror, deprecated in 4.83, will be
- removed in a future release.
- o err_perm Same as temperror, deprecated in 4.83, will be
- removed in a future release.
-
-You can prefix each string with an exclamation mark to invert
-its meaning, for example "!fail" will match all results but
-"fail". The string list is evaluated left-to-right, in a
-short-circuit fashion. When a string matches the outcome of
-the SPF check, the condition succeeds. If none of the listed
-strings matches the outcome of the SPF check, the condition
-fails.
-
-Here is an example to fail forgery attempts from domains that
-publish SPF records:
-
-/* -----------------
-deny message = $sender_host_address is not allowed to send mail from ${if def:sender_address_domain {$sender_address_domain}{$sender_helo_name}}. \
- Please see http://www.openspf.org/Why?scope=${if def:sender_address_domain {mfrom}{helo}};identity=${if def:sender_address_domain {$sender_address}{$sender_helo_name}};ip=$sender_host_address
- spf = fail
---------------------- */
-
-You can also give special treatment to specific domains:
-
-/* -----------------
-deny message = AOL sender, but not from AOL-approved relay.
- sender_domains = aol.com
- spf = fail:neutral
---------------------- */
-
-Explanation: AOL publishes SPF records, but is liberal and
-still allows non-approved relays to send mail from aol.com.
-This will result in a "neutral" state, while mail from genuine
-AOL servers will result in "pass". The example above takes
-this into account and treats "neutral" like "fail", but only
-for aol.com. Please note that this violates the SPF draft.
-
-When the spf condition has run, it sets up several expansion
-variables.
-
- $spf_header_comment
- This contains a human-readable string describing the outcome
- of the SPF check. You can add it to a custom header or use
- it for logging purposes.
-
- $spf_received
- This contains a complete Received-SPF: header that can be
- added to the message. Please note that according to the SPF
- draft, this header must be added at the top of the header
- list. Please see section 10 on how you can do this.
-
- Note: in case of "Best-guess" (see below), the convention is
- to put this string in a header called X-SPF-Guess: instead.
-
- $spf_result
- This contains the outcome of the SPF check in string form,
- one of pass, fail, softfail, none, neutral, permerror or
- temperror.
-
- $spf_smtp_comment
- This contains a string that can be used in a SMTP response
- to the calling party. Useful for "fail".
-
-In addition to SPF, you can also perform checks for so-called
-"Best-guess". Strictly speaking, "Best-guess" is not standard
-SPF, but it is supported by the same framework that enables SPF
-capability. Refer to http://www.openspf.org/FAQ/Best_guess_record
-for a description of what it means.
-
-To access this feature, simply use the spf_guess condition in place
-of the spf one. For example:
-
-/* -----------------
-deny message = $sender_host_address doesn't look trustworthy to me
- spf_guess = fail
---------------------- */
-
-In case you decide to reject messages based on this check, you
-should note that although it uses the same framework, "Best-guess"
-is NOT SPF, and therefore you should not mention SPF at all in your
-reject message.
-
-When the spf_guess condition has run, it sets up the same expansion
-variables as when spf condition is run, described above.
-
-Additionally, since Best-guess is not standardized, you may redefine
-what "Best-guess" means to you by redefining spf_guess variable in
-global config. For example, the following:
-
-/* -----------------
-spf_guess = v=spf1 a/16 mx/16 ptr ?all
---------------------- */
-
-would relax host matching rules to a broader network range.
-
-
-A lookup expansion is also available. It takes an email
-address as the key and an IP address as the database:
-
- ${lookup {username@domain} spf {ip.ip.ip.ip}}
-
-The lookup will return the same result strings as they can appear in
-$spf_result (pass,fail,softfail,neutral,none,err_perm,err_temp).
-Currently, only IPv4 addresses are supported.
-
-
-
SRS (Sender Rewriting Scheme) Support
--------------------------------------------------------------
# EXPERIMENTAL_DCC=yes
-# Uncomment the following lines to add SPF support. You need to have libspf2
-# installed on your system (www.libspf2.org). Depending on where it is installed
-# you may have to edit the CFLAGS and LDFLAGS lines.
-
-# EXPERIMENTAL_SPF=yes
-# CFLAGS += -I/usr/local/include
-# LDFLAGS += -lspf2
-
# Uncomment the following lines to add SRS (Sender rewriting scheme) support.
# You need to have libsrs_alt installed on your system (srs.mirtol.com).
# Depending on where it is installed you may have to edit the CFLAGS and
# LDFLAGS += -lidn -lidn2
+#------------------------------------------------------------------------------
+# Uncomment the following lines to add SPF support. You need to have libspf2
+# installed on your system (www.libspf2.org). Depending on where it is installed
+# you may have to edit the CFLAGS and LDFLAGS lines.
+
+# SUPPORT_SPF=yes
+# CFLAGS += -I/usr/local/include
+# LDFLAGS += -lspf2
+
+
#------------------------------------------------------------------------------
# Support for authentication via Radius is also available. The Exim support,
# which is intended for use in conjunction with the SMTP AUTH facilities,
#ifdef WITH_CONTENT_SCAN
ACLC_SPAM,
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
ACLC_SPF,
ACLC_SPF_GUESS,
#endif
(1<<ACL_WHERE_NOTSMTP)),
},
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
[ACLC_SPF] = { US"spf", TRUE, FALSE,
(1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|
(1<<ACL_WHERE_HELO)|
break;
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
case ACLC_SPF:
rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
break;
#define SUPPORT_PAM
#define SUPPORT_PROXY
#define SUPPORT_SOCKS
+#define SUPPORT_SPF
#define SUPPORT_TLS
#define SUPPORT_TRANSLATE_IP_ADDRESS
#define DMARC_TLD_FILE "/etc/exim/opendmarc.tlds"
#define EXPERIMENTAL_LMDB
#define EXPERIMENTAL_QUEUEFILE
-#define EXPERIMENTAL_SPF
#define EXPERIMENTAL_SRS
#include "exim.h"
#ifdef EXPERIMENTAL_DMARC
-# if !defined EXPERIMENTAL_SPF
+# if !defined SUPPORT_SPF
# error SPF must also be enabled for DMARC
# elif defined DISABLE_DKIM
# error DKIM must also be enabled for DMARC
return hdr_tmp;
}
-# endif /* EXPERIMENTAL_SPF */
+# endif /* SUPPORT_SPF */
#endif /* EXPERIMENTAL_DMARC */
/* vi: aw ai sw=2
*/
#ifdef EXPERIMENTAL_DMARC
# include "opendmarc/dmarc.h"
-# ifdef EXPERIMENTAL_SPF
+# ifdef SUPPORT_SPF
# include "spf2/spf.h"
-# endif /* EXPERIMENTAL_SPF */
+# endif /* SUPPORT_SPF */
/* prototypes */
int dmarc_init();
#if defined(EXPERIMENTAL_LMDB)
extern lookup_module_info lmdb_lookup_module_info;
#endif
-#if defined(EXPERIMENTAL_SPF)
+#if defined(SUPPORT_SPF)
extern lookup_module_info spf_lookup_module_info;
#endif
#if defined(LOOKUP_SQLITE) && LOOKUP_SQLITE!=2
addlookupmodule(NULL, &lmdb_lookup_module_info);
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
addlookupmodule(NULL, &spf_lookup_module_info);
#endif
#ifdef SUPPORT_SOCKS
fprintf(f, " SOCKS");
#endif
+#ifdef SUPPORT_SPF
+ fprintf(f, " SPF");
+#endif
#ifdef TCP_FASTOPEN
deliver_init();
if (tcp_fastopen_ok) fprintf(f, " TCP_Fast_Open");
#ifdef EXPERIMENTAL_QUEUEFILE
fprintf(f, " Experimental_QUEUEFILE");
#endif
-#ifdef EXPERIMENTAL_SPF
- fprintf(f, " Experimental_SPF");
-#endif
#ifdef EXPERIMENTAL_SRS
fprintf(f, " Experimental_SRS");
#endif
#ifdef EXPERIMENTAL_BRIGHTMAIL
# include "bmi_spam.h"
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
# include "spf.h"
#endif
#ifdef EXPERIMENTAL_SRS
{ "spam_score", vtype_stringptr, &spam_score },
{ "spam_score_int", vtype_stringptr, &spam_score_int },
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
{ "spf_guess", vtype_stringptr, &spf_guess },
{ "spf_header_comment", vtype_stringptr, &spf_header_comment },
{ "spf_received", vtype_stringptr, &spf_received },
uschar *spam_score = NULL;
uschar *spam_score_int = NULL;
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
uschar *spf_guess = US"v=spf1 a/24 mx/24 ptr ?all";
uschar *spf_header_comment = NULL;
uschar *spf_received = NULL;
extern uschar *spam_score; /* the spam score (float) */
extern uschar *spam_score_int; /* spam_score * 10 (int) */
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
extern uschar *spf_guess; /* spf best-guess record */
extern uschar *spf_header_comment; /* spf header comment */
extern uschar *spf_received; /* Received-SPF: header */
#include "../exim.h"
-#ifndef EXPERIMENTAL_SPF
+#ifndef SUPPORT_SPF
static void dummy(int x);
static void dummy2(int x) { dummy(x-1); }
static void dummy(int x) { dummy2(x-1); }
static lookup_info *_lookup_list[] = { &_lookup_info };
lookup_module_info spf_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
-#endif /* EXPERIMENTAL_SPF */
+#endif /* SUPPORT_SPF */
#ifdef EXPERIMENTAL_LMDB
builtin_macro_create(US"_HAVE_LMDB");
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
builtin_macro_create(US"_HAVE_SPF");
#endif
#ifdef EXPERIMENTAL_SRS
#ifdef WITH_CONTENT_SCAN
{ "spamd_address", opt_stringptr, &spamd_address },
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
{ "spf_guess", opt_stringptr, &spf_guess },
#endif
{ "split_spool_directory", opt_bool, &split_spool_directory },
#ifndef DISABLE_PRDR
prdr_requested = FALSE;
#endif
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
spf_header_comment = NULL;
spf_received = NULL;
spf_result = NULL;
}
}
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
/* set up SPF context */
spf_init(sender_helo_name, sender_host_address);
#endif
/* Code for calling spf checks via libspf-alt. Called from acl.c. */
#include "exim.h"
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
/* must be kept in numeric order */
static spf_result_id spf_result_id_list[] = {
Copyright (c) The Exim Maintainers 2016
*/
-#ifdef EXPERIMENTAL_SPF
+#ifdef SUPPORT_SPF
/* Yes, we do have ns_type. spf.h redefines it if we don't set this. Doh */
#ifndef HAVE_NS_TYPE
-support Experimental_SPF
+support SPF
git://git.exim.org / exim.git / commitdiff