+This file contains descriptions of new features that have been added to Exim.
+Before a formal release, there may be quite a lot of detail so that people can
+test from the snapshots or the CVS before the documentation is updated. Once
+the documentation is updated, this file is reduced to a short list.
+
+Version 4.77
+------------
+
+ 1. New options for the ratelimit ACL condition: /count= and /unique=.
+ The /noupdate option has been replaced by a /readonly option.
+
+ 2. The SMTP transport's protocol option may now be set to "smtps", to
+ use SSL-on-connect outbound.
+
+ 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
+ there is a problem talking to the AV scanner, or the AV scanner running.
+
+ 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
+ and check if the search item is a member of the list. This does not
+ support named lists, but does subject the list part to string expansion.
+
+ 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
+ built, Exim no longer performs string expansion on the second string of
+ the match_* expansion conditions: "match_address", "match_domain",
+ "match_ip" & "match_local_part". Named lists can still be used.
+
+
+Version 4.76
+------------
+
+ 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
+ or off in the resolver library.
+
+
+Version 4.75
+------------
+
+ 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
+ is now LDAP/TLS support, given sufficiently modern OpenLDAP client
+ libraries. The following global options have been added in support of
+ this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
+ ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
+
+ 2. The pipe transport now takes a boolean option, "freeze_signal", default
+ false. When true, if the external delivery command exits on a signal then
+ Exim will freeze the message in the queue, instead of generating a bounce.
+
+ 3. Log filenames may now use %M as an escape, instead of %D (still available).
+ The %M pattern expands to yyyymm, providing month-level resolution.
+
+ 4. The $message_linecount variable is now updated for the maildir_tag option,
+ in the same way as $message_size, to reflect the real number of lines,
+ including any header additions or removals from transport.
+
+ 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
+ Exim now selects entries randomly, to better scale in a cluster setup.
+
+
+Version 4.74
+------------
+
+ 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
+ the flaw permitted the Exim run-time user to cause root to append to
+ arbitrary files of the attacker's choosing, with the content based
+ on content supplied by the attacker.
+
+ 2. Exim now supports loading some lookup types at run-time, using your
+ platform's dlopen() functionality. This has limited platform support
+ and the intention is not to support every variant, it's limited to
+ dlopen(). This permits the main Exim binary to not be linked against
+ all the libraries needed for all the lookup types.
+
+
+Version 4.73
+------------
+
+ NOTE: this version is not guaranteed backwards-compatible, please read the
+ items below carefully
+
+ 1. A new main configuration option, "openssl_options", is available if Exim
+ is built with SSL support provided by OpenSSL. The option allows
+ administrators to specify OpenSSL options to be used on connections;
+ typically this is to set bug compatibility features which the OpenSSL
+ developers have not enabled by default. There may be security
+ consequences for certain options, so these should not be changed
+ frivolously.
+
+ 2. A new pipe transport option, "permit_coredumps", may help with problem
+ diagnosis in some scenarios. Note that Exim is typically installed as
+ a setuid binary, which on most OSes will inhibit coredumps by default,
+ so that safety mechanism would have to be overridden for this option to
+ be able to take effect.
+
+ 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
+ Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
+ Note that this switches Exim to use a new API ("INSTREAM") and a future
+ release of ClamAV will remove support for the old API ("STREAM").
+
+ The av_scanner option, when set to "clamd", now takes an optional third
+ part, "local", which causes Exim to pass a filename to ClamAV instead of
+ the file content. This is the same behaviour as when clamd is pointed at
+ a Unix-domain socket. For example:
+
+ av_scanner = clamd:192.0.2.3 1234:local
+
+ ClamAV's ExtendedDetectionInfo response format is now handled.
+
+ 4. There is now a -bmalware option, restricted to admin users. This option
+ takes one parameter, a filename, and scans that file with Exim's
+ malware-scanning framework. This is intended purely as a debugging aid
+ to ensure that Exim's scanning is working, not to replace other tools.
+ Note that the ACL framework is not invoked, so if av_scanner references
+ ACL variables without a fallback then this will fail.
+
+ 5. There is a new expansion operator, "reverse_ip", which will reverse IP
+ addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
+
+ ${reverse_ip:192.0.2.4}
+ -> 4.2.0.192
+ ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
+ -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
+
+ 6. There is a new ACL control called "debug", to enable debug logging.
+ This allows selective logging of certain incoming transactions within
+ production environments, with some care. It takes two options, "tag"
+ and "opts"; "tag" is included in the filename of the log and "opts"
+ is used as per the -d<options> command-line option. Examples, which
+ don't all make sense in all contexts:
+
+ control = debug
+ control = debug/tag=.$sender_host_address
+ control = debug/opts=+expand+acl
+ control = debug/tag=.$message_exim_id/opts=+expand
+
+ 7. It has always been implicit in the design and the documentation that
+ "the Exim user" is not root. src/EDITME said that using root was
+ "very strongly discouraged". This is not enough to keep people from
+ shooting themselves in the foot in days when many don't configure Exim
+ themselves but via package build managers. The security consequences of
+ running various bits of network code are severe if there should be bugs in
+ them. As such, the Exim user may no longer be root. If configured
+ statically, Exim will refuse to build. If configured as ref:user then Exim
+ will exit shortly after start-up. If you must shoot yourself in the foot,
+ then henceforth you will have to maintain your own local patches to strip
+ the safeties off.
+
+ 8. There is a new expansion operator, bool_lax{}. Where bool{} uses the ACL
+ condition logic to determine truth/failure and will fail to expand many
+ strings, bool_lax{} uses the router condition logic, where most strings
+ do evaluate true.
+ Note: bool{00} is false, bool_lax{00} is true.
+
+ 9. Routers now support multiple "condition" tests,
+
+10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
+ Setting this allows an admin to define which entry in the tcpwrappers
+ config file will be used to control access to the daemon. This option
+ is only available when Exim is built with USE_TCP_WRAPPERS. The
+ default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
+ build option.
+
+11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
+ the Exim run-time user, instead of root.
+
+12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
+ is forced on. This is mitigated by the new build option
+ TRUSTED_CONFIG_LIST which defines a list of configuration files which
+ are trusted; one per line. If a config file is owned by root and matches
+ a pathname in the list, then it may be invoked by the Exim build-time
+ user without Exim relinquishing root privileges.
+
+13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
+ trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
+ forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
+ include the main config. As a transition mechanism, we are temporarily
+ providing a work-around: the new build option WHITELIST_D_MACROS provides
+ a colon-separated list of macro names which may be overridden by the Exim
+ run-time user. The values of these macros are constrained to the regex
+ ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
+
+
+Version 4.72
+------------
+
+ 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
+ writable, the other to locking of MBX folders (not mbox).
+
+ 2. MySQL stored procedures are now supported.
+
+ 3. The dkim_domain transport option is now a list, not a single string, and
+ messages will be signed for each element in the list (discarding
+ duplicates).
+
+ 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
+ in the presence of multiple character strings within the RR. Prior to 4.70,
+ only the first string would be returned. The dnsdb lookup now, by default,
+ preserves the pre-4.70 semantics, but also now takes an extended output
+ separator specification. The separator can be followed by a semicolon, to
+ concatenate the individual text strings together with no join character,
+ or by a comma and a second separator character, in which case the text
+ strings within a TXT record are joined on that second character.
+ Administrators are reminded that DNS provides no ordering guarantees
+ between multiple records in an RRset. For example:
+
+ foo.example. IN TXT "a" "b" "c"
+ foo.example. IN TXT "d" "e" "f"
+
+ ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
+ ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
+ ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
+
+
+Version 4.70 / 4.71
+-------------------
+
+ 1. Native DKIM support without an external library.
+ (Note that if no action to prevent it is taken, a straight upgrade will
+ result in DKIM verification of all signed incoming emails. See spec
+ for details on conditionally disabling)
+
+ 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
+
+ 3. There is now a bool{} expansion condition which maps certain strings to
+ true/false condition values (most likely of use in conjunction with the
+ and{} expansion operator).
+
+ 4. The $spam_score, $spam_bar and $spam_report variables are now available
+ at delivery time.
+
+ 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
+ options, provided that Exim is invoked by an admin_user.
+
+ 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
+ which increases compatibility with older clients at the cost of decreased
+ security. Don't set this unless you need to support such clients.
+
+ 7. There is a new expansion operator, ${randint:...} which will produce a
+ "random" number less than the supplied integer. This randomness is
+ not guaranteed to be cryptographically strong, but depending upon how
+ Exim was built may be better than the most naive schemes.
+
+ 8. Exim now explicitly ensures that SHA256 is available when linked against
+ OpenSSL.
+
+ 9. The transport_filter_timeout option now applies to SMTP transports too.
+
+
+Version 4.69
+------------
+
+ 1. Preliminary DKIM support in Experimental.
+
+
+Version 4.68
+------------
+
+ 1. The body_linecount and body_zerocount C variables are now exported in the
+ local_scan API.
+
+ 2. When a dnslists lookup succeeds, the key that was looked up is now placed
+ in $dnslist_matched. When the key is an IP address, it is not reversed in
+ this variable (though it is, of course, in the actual lookup). In simple
+ cases, for example:
+
+ deny dnslists = spamhaus.example
+
+ the key is also available in another variable (in this case,
+ $sender_host_address). In more complicated cases, however, this is not
+ true. For example, using a data lookup might generate a dnslists lookup
+ like this:
+
+ deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
+
+ If this condition succeeds, the value in $dnslist_matched might be
+ 192.168.6.7 (for example).
+
+ 3. Authenticators now have a client_condition option. When Exim is running as
+ a client, it skips an authenticator whose client_condition expansion yields
+ "0", "no", or "false". This can be used, for example, to skip plain text
+ authenticators when the connection is not encrypted by a setting such as:
+
+ client_condition = ${if !eq{$tls_cipher}{}}
+
+ Note that the 4.67 documentation states that $tls_cipher contains the
+ cipher used for incoming messages. In fact, during SMTP delivery, it
+ contains the cipher used for the delivery. The same is true for
+ $tls_peerdn.
+
+ 4. There is now a -Mvc <message-id> option, which outputs a copy of the
+ message to the standard output, in RFC 2822 format. The option can be used
+ only by an admin user.
+
+ 5. There is now a /noupdate option for the ratelimit ACL condition. It
+ computes the rate and checks the limit as normal, but it does not update
+ the saved data. This means that, in relevant ACLs, it is possible to lookup
+ the existence of a specified (or auto-generated) ratelimit key without
+ incrementing the ratelimit counter for that key.
+
+ In order for this to be useful, another ACL entry must set the rate
+ for the same key somewhere (otherwise it will always be zero).
+
+ Example:
+
+ acl_check_connect:
+ # Read the rate; if it doesn't exist or is below the maximum
+ # we update it below
+ deny ratelimit = 100 / 5m / strict / noupdate
+ log_message = RATE: $sender_rate / $sender_rate_period \
+ (max $sender_rate_limit)
+
+ [... some other logic and tests...]
+
+ warn ratelimit = 100 / 5m / strict / per_cmd
+ log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
+ (max $sender_rate_limit)
+ condition = ${if le{$sender_rate}{$sender_rate_limit}}
+
+ accept
+
+ 6. The variable $max_received_linelength contains the number of bytes in the
+ longest line that was received as part of the message, not counting the
+ line termination character(s).
+
+ 7. Host lists can now include +ignore_defer and +include_defer, analagous to
+ +ignore_unknown and +include_unknown. These options should be used with
+ care, probably only in non-critical host lists such as whitelists.
git://git.exim.org / exim.git / blobdiff