X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/38a0a95ff69327042421b9ee6982e386175f141b..d9acfc1ce6:/doc/doc-txt/NewStuff?ds=sidebyside diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 5be3e69bf..e776a4f95 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,40 +1,1184 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.109 2006/09/19 11:28:44 ph10 Exp $ - New Features in Exim -------------------- 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 +test from the snapshots or the Git before the documentation is updated. Once the documentation is updated, this file is reduced to a short list. +Version 4.93 +------------ + + 1. An "external" authenticator, per RFC 4422 Appendix A. + + 2. A JSON lookup type, and JSON variants of the forall/any expansion conditions. + + 3. Variables $tls_in_cipher_std, $tls_out_cipher_std giving the RFC names + for ciphersuites. + + 4. Log_selectors "msg_id" (on by default) and "msg_id_created". + + 5. A case_insensitive option for verify=not_blind. + + +Version 4.92 +-------------- + + 1. ${l_header:} and ${l_h:} expansion items, giving a colon-sep + list when there are multiple headers having a given name. This matters + when individual headers are wrapped onto multiple lines; with previous + facilities hard to parse. + + 2. The ${readsocket } expansion item now takes a "tls" option, doing the + obvious thing. + + 3. EXPERIMENTAL_REQUIRETLS and EXPERIMENTAL_PIPE_CONNECT optional build + features. See the experimental.spec file. + + 4. If built with SUPPORT_I18N a "utf8_downconvert" option on the smtp transport. + + 5. A "pipelining" log_selector. + + 6. Builtin macros for supported log_selector and openssl_options values. + + 7. JSON variants of the ${extract } expansion item. + + 8. A "noutf8" debug option, for disabling the UTF-8 characters in debug output. + + 9. TCP Fast Open support on MacOS. + +Version 4.91 +-------------- + + 1. Dual-certificate stacks on servers now support OCSP stapling, under GnuTLS + version 3.5.6 or later. + + 2. DANE is now supported under GnuTLS version 3.0.0 or later. Both GnuTLS and + OpenSSL versions are moved to mainline support from Experimental. + New SMTP transport option "dane_require_tls_ciphers". + + 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. + + 5. Logging control for DKIM verification. The existing DKIM log line is + controlled by a "dkim_verbose" selector which is _not_ enabled by default. + A new tag "DKIM=" is added to <= lines by default, controlled by + a "dkim" log_selector. + + 6. Receive duration on <= lines, under a new log_selector "receive_time". + + 7. Options "ipv4_only" and "ipv4_prefer" on the dnslookup router and on + routing rules in the manualroute router. + + 8. Expansion item ${sha3:} / ${sha3_:} now also supported + under OpenSSL version 1.1.1 or later. + + 9. DKIM operations can now use the Ed25519 algorithm in addition to RSA, under + GnuTLS 3.6.0 or OpenSSL 1.1.1 or later. + +10. Builtin feature-macros _CRYPTO_HASH_SHA3 and _CRYPTO_SIGN_ED25519, library + version dependent. + +11. "exim -bP macro " returns caller-usable status. + +12. Expansion item ${authresults {}} for creating an + Authentication-Results: header. + +13. EXPERIMENTAL_ARC. See the experimental.spec file. + See also new util/renew-opendmarc-tlds.sh script for use with DMARC/ARC. + +14: A dane:fail event, intended to facilitate reporting. + +15. "Lightweight" support for Redis Cluster. Requires redis_servers list to + contain all the servers in the cluster, all of which must be reachable from + the running exim instance. If the cluster has master/slave replication, the + list must contain all the master and slave servers. + +16. Add an option to the Avast scanner interface: "pass_unscanned". This + allows to treat unscanned files as clean. Files may be unscanned for + several reasons: decompression bombs, broken archives. + + +Version 4.90 +------------ + + 1. PKG_CONFIG_PATH can now be set in Local/Makefile; + wildcards will be expanded, values are collapsed. + + 2. The ${readsocket } expansion now takes an option to not shutdown the + connection after sending the query string. The default remains to do so. + + 3. An smtp transport option "hosts_noproxy_tls" to control whether multiple + deliveries on a single TCP connection can maintain a TLS connection + open. By default disabled for all hosts, doing so saves the cost of + making new TLS sessions, at the cost of having to proxy the data via + another process. Logging is also affected. + + 4. A malware connection type for the FPSCAND protocol. + + 5. An option for recipient verify callouts to hold the connection open for + further recipients and for delivery. + + 6. The reproducible build $SOURCE_DATE_EPOCH environment variable is now + supported. + + 7. Optionally, an alternate format for spool data-files which matches the + wire format - meaning more efficient reception and transmission (at the + cost of difficulty with standard Unix tools). Only used for messages + received using the ESMTP CHUNKING option, and when a new main-section + option "spool_wireformat" (false by default) is set. + + 8. New main configuration option "commandline_checks_require_admin" to + restrict who can use various introspection options. + + 9. New option modifier "no_check" for quota and quota_filecount + appendfile transport. + +10. Variable $smtp_command_history returning a comma-sep list of recent + SMTP commands. + +11. Millisecond timetamps in logs, on log_selector "millisec". Also affects + log elements QT, DT and D, and timstamps in debug output. + +12. TCP Fast Open logging. As a server, logs when the SMTP banner was sent + while still in SYN_RECV state; as a client logs when the connection + is opened with a TFO cookie. + +13. DKIM support for multiple signing, by domain and/or key-selector. + DKIM support for multiple hashes, and for alternate-identity tags. + Builtin macro with default list of signed headers. + Better syntax for specifying oversigning. + The DKIM ACL can override verification status, and status is visible in + the data ACL. + +14. Exipick understands -C|--config for an alternative Exim + configuration file. + +15. TCP Fast Open used, with data-on-SYN, for client SMTP via SOCKS5 proxy, + for ${readsocket } expansions, and for ClamAV. + +16. The "-be" expansion test mode now supports macros. Macros are expanded + in test lines, and new macros can be defined. + +17. Support for server-side dual-certificate-stacks (eg. RSA + ECDSA). + + +Version 4.89 +------------ + + 1. Allow relative config file names for ".include" + + 2. A main-section config option "debug_store" to control the checks on + variable locations during store-reset. Normally false but can be enabled + when a memory corrution issue is suspected on a production system. + + +Version 4.88 +------------ + + 1. The new perl_taintmode option allows to run the embedded perl + interpreter in taint mode. + + 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines. + + 3. Speculative debugging, via a "kill" option to the "control=debug" ACL + modifier. + + 4. New expansion item ${sha3:} / ${sha3_:}. + N can be 224, 256 (default), 384, 512. + With GnuTLS 3.5.0 or later, only. + + 5. Facility for named queues: A command-line argument can specify + the queue name for a queue operation, and an ACL modifier can set + the queue to be used for a message. A $queue_name variable gives + visibility. + + 6. New expansion operators base32/base32d. + + 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight + performance increase and network load decrease. Main config option + chunking_advertise_hosts, and smtp transport option hosts_try_chunking + for control. + + 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa. + + 9. Expansion operator escape8bit, like escape but not touching newline etc.. + +10. Feature macros, generated from compile options. All start with "_HAVE_" + and go on with some roughly recognisable name. Driver macros, for + router, transport and authentication drivers; names starting with "_DRIVER_". + Option macros, for each configuration-file option; all start with "_OPT_". + Use the "-bP macros" command-line option to see what is present. + +11. Integer values for options can take a "G" multiplier. + +12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx + returns from the target back to the initiator, rather than spooling the + message. + +13. New built-in constants available for tls_dhparam and default changed. + +14. If built with EXPERIMENTAL_QUEUEFILE, a queuefile transport, for writing + out copies of the message spool files for use by 3rd-party scanners. + +15. A new option on the smtp transport, hosts_try_fastopen. If the system + supports it (on Linux it must be enabled in the kernel by the sysadmin) + try to use RFC 7413 "TCP Fast Open". No data is sent on the SYN segment + but it permits a peer that also supports the facility to send its SMTP + banner immediately after the SYN,ACK segment rather then waiting for + another ACK - so saving up to one roundtrip time. Because it requires + previous communication with the peer (we save a cookie from it) this + will only become active on frequently-contacted destinations. + +16. A new syslog_pid option to suppress PID duplication in syslog lines. + + +Version 4.87 +------------ + + 1. The ACL conditions regex and mime_regex now capture substrings + into numeric variables $regex1 to 9, like the "match" expansion condition. + + 2. New $callout_address variable records the address used for a spam=, + malware= or verify= callout. + + 3. Transports now take a "max_parallel" option, to limit concurrency. + + 4. Expansion operators ${ipv6norm:} and ${ipv6denorm:}. + The latter expands to a 8-element colon-sep set of hex digits including + leading zeroes. A trailing ipv4-style dotted-decimal set is converted + to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6. + The former operator strips leading zeroes and collapses the longest + set of 0-groups to a double-colon. + + 5. New "-bP config" support, to dump the effective configuration. + + 6. New $dkim_key_length variable. + + 7. New base64d and base64 expansion items (the existing str2b64 being a + synonym of the latter). Add support in base64 for certificates. + + 8. New main configuration option "bounce_return_linesize_limit" to + avoid oversize bodies in bounces. The default value matches RFC + limits. + + 9. New $initial_cwd expansion variable. + + +Version 4.86 +------------ + + 1. Support for using the system standard CA bundle. + + 2. New expansion items $config_file, $config_dir, containing the file + and directory name of the main configuration file. Also $exim_version. + + 3. New "malware=" support for Avast. + + 4. New "spam=" variant option for Rspamd. + + 5. Assorted options on malware= and spam= scanners. + + 6. A command-line option to write a comment into the logfile. + + 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can + be configured to make connections via socks5 proxies. + + 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for + the transmission of UTF-8 envelope addresses. + + 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly + used encoding of Maildir folder names. + +10. A logging option for slow DNS lookups. + +11. New ${env {}} expansion. + +12. A non-SMTP authenticator using information from TLS client certificates. + +13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS. + Patch originally by Wolfgang Breyha. + +14. Main option "dns_trust_aa" for trusting your local nameserver at the + same level as DNSSEC. + + +Version 4.85 +------------ + + 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the + DANE SMTP draft to assess a secure chain of trust of the certificate + used to establish the TLS connection based on a TLSA record in the + domain of the sender. + + 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT + and several new events have been created. The reason is because it has + been expanded beyond just firing events during the transport phase. Any + existing TPDA transport options will have to be rewritten to use a new + $event_name expansion variable in a condition. Refer to the + experimental-spec.txt for details and examples. + + 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that + server certs used for TLS match the result of the MX lookup. It does + not use the same mechanism as DANE. + + +Version 4.84 +------------ + + +Version 4.83 +------------ + + 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be + configured to expect an initial header from a proxy that will make the + actual external source IP:host be used in exim instead of the IP of the + proxy that is connecting to it. + + 2. New verify option header_names_ascii, which will check to make sure + there are no non-ASCII characters in header names. Exim itself handles + those non-ASCII characters, but downstream apps may not, so Exim can + detect and reject if those characters are present. + + 3. New expansion operator ${utf8clean:string} to replace malformed UTF8 + codepoints with valid ones. + + 4. New malware type "sock". Talks over a Unix or TCP socket, sending one + command line and matching a regex against the return data for trigger + and a second regex to extract malware_name. The mail spoolfile name can + be included in the command line. + + 5. The smtp transport now supports options "tls_verify_hosts" and + "tls_try_verify_hosts". If either is set the certificate verification + is split from the encryption operation. The default remains that a failed + verification cancels the encryption. + + 6. New SERVERS override of default ldap server list. In the ACLs, an ldap + lookup can now set a list of servers to use that is different from the + default list. + + 7. New command-line option -C for exiqgrep to specify alternate exim.conf + file when searching the queue. + + 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that. + + 9. Support for DNSSEC on outbound connections. + +10. New variables "tls_(in,out)_(our,peer)cert" and expansion item + "certextract" to extract fields from them. Hash operators md5 and sha1 + work over them for generating fingerprints, and a new sha256 operator + for them added. + +11. PRDR is now supported dy default. + +12. OCSP stapling is now supported by default. + +13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output + Delivery Status Notification messages in MIME format, and negotiate + DSN features per RFC 3461. + + +Version 4.82 +------------ + + 1. New command-line option -bI:sieve will list all supported sieve extensions + of this Exim build on standard output, one per line. + ManageSieve (RFC 5804) providers managing scripts for use by Exim should + query this to establish the correct list to include in the protocol's + SIEVE capability line. + + 2. If the -n option is combined with the -bP option, then the name of an + emitted option is not output, only the value (if visible to you). + For instance, "exim -n -bP pid_file_path" should just emit a pathname + followed by a newline, and no other text. + + 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now + has a "tls_dh_min_bits" option, to set the minimum acceptable number of + bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites) + acceptable for security. (Option accepted but ignored if using OpenSSL). + Defaults to 1024, the old value. May be lowered only to 512, or raised as + far as you like. Raising this may hinder TLS interoperability with other + sites and is not currently recommended. Lowering this will permit you to + establish a TLS session which is not as secure as you might like. + + Unless you really know what you are doing, leave it alone. + + 4. If not built with DISABLE_DNSSEC, Exim now has the main option + dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library + to send the DO flag to your recursive resolver. If you have a recursive + resolver, which can set the Authenticated Data (AD) flag in results, Exim + can now detect this. Exim does not perform validation itself, instead + relying upon a trusted path to the resolver. + + Current status: work-in-progress; $sender_host_dnssec variable added. + + 5. DSCP support for outbound connections: on a transport using the smtp driver, + set "dscp = ef", for instance, to cause the connections to have the relevant + DSCP (IPv4 TOS or IPv6 TCLASS) value in the header. + + Similarly for inbound connections, there is a new control modifier, dscp, + so "warn control = dscp/ef" in the connect ACL, or after authentication. + + Supported values depend upon system libraries. "exim -bI:dscp" to list the + ones Exim knows of. You can also set a raw number 0..0x3F. + + 6. The -G command-line flag is no longer ignored; it is now equivalent to an + ACL setting "control = suppress_local_fixups". The -L command-line flag + is now accepted and forces use of syslog, with the provided tag as the + process name. A few other flags used by Sendmail are now accepted and + ignored. + + 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery" + ACL modifier; works for single-recipient mails which are received on and + deliverable via SMTP. Using the connection made for a recipient verify, + if requested before the verify, or a new one made for the purpose while + the inbound connection is still active. The bulk of the mail item is copied + direct from the inbound socket to the outbound (as well as the spool file). + When the source notifies the end of data, the data acceptance by the destination + is negotiated before the acceptance is sent to the source. If the destination + does not accept the mail item, for example due to content-scanning, the item + is not accepted from the source and therefore there is no need to generate + a bounce mail. This is of benefit when providing a secondary-MX service. + The downside is that delays are under the control of the ultimate destination + system not your own. + + The Received-by: header on items delivered by cutthrough is generated + early in reception rather than at the end; this will affect any timestamp + included. The log line showing delivery is recorded before that showing + reception; it uses a new ">>" tag instead of "=>". + + To support the feature, verify-callout connections can now use ESMTP and TLS. + The usual smtp transport options are honoured, plus a (new, default everything) + hosts_verify_avoid_tls. + + New variable families named tls_in_cipher, tls_out_cipher etc. are introduced + for specific access to the information for each connection. The old names + are present for now but deprecated. + + Not yet supported: IGNOREQUOTA, SIZE, PIPELINING. + + 8. New expansion operators ${listnamed:name} to get the content of a named list + and ${listcount:string} to count the items in a list. + + 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS + rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11 + modules. For some situations this is desirable, but we expect admin in + those situations to know they want the feature. More commonly, it means + that GUI user modules get loaded and are broken by the setuid Exim being + unable to access files specified in environment variables and passed + through, thus breakage. So we explicitly inhibit the PKCS11 initialisation + unless this new option is set. + + Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability, + so have also added a build option which can be used to build Exim with GnuTLS + but without trying to use any kind of PKCS11 support. Uncomment this in the + Local/Makefile: + + AVOID_GNUTLS_PKCS11=yes + +10. The "acl = name" condition on an ACL now supports optional arguments. + New expansion item "${acl {name}{arg}...}" and expansion condition + "acl {{name}{arg}...}" are added. In all cases up to nine arguments + can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL. + Variable $acl_narg contains the number of arguments. If the ACL sets + a "message =" value this becomes the result of the expansion item, + or the value of $value for the expansion condition. If the ACL returns + accept the expansion condition is true; if reject, false. A defer + return results in a forced fail. + +11. Routers and transports can now have multiple headers_add and headers_remove + option lines. The concatenated list is used. + +12. New ACL modifier "remove_header" can remove headers before message gets + handled by routers/transports. + +13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured), + "aaaa" and "a" lookups is done and the full set of results returned. + +14. New expansion variable $headers_added with content from ACL add_header + modifier (but not yet added to message). + +15. New 8bitmime status logging option for received messages. Log field "M8S". + +16. New authenticated_sender logging option, adding to log field "A". + +17. New expansion variables $router_name and $transport_name. Useful + particularly for debug_print as -bt command-line option does not + require privilege whereas -d does. + +18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a + proposed extension to SMTP from Eric Hall. + +19. The pipe transport has gained the force_command option, to allow + decorating commands from user .forward pipe aliases with prefix + wrappers, for instance. + +20. Callout connections can now AUTH; the same controls as normal delivery + connections apply. + +21. Support for DMARC, using opendmarc libs, can be enabled. It adds new + options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file. + It adds new expansion variables $dmarc_ar_header, $dmarc_status, + $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier + dmarc_status. It adds new control flags dmarc_disable_verify and + dmarc_enable_forensic. The default for the dmarc_tld_file option is + "/etc/exim/opendmarc.tlds" and can be changed via EDITME. + +22. Add expansion variable $authenticated_fail_id, which is the username + provided to the authentication method which failed. It is available + for use in subsequent ACL processing (typically quit or notquit ACLs). + +23. New ACL modifier "udpsend" can construct a UDP packet to send to a given + UDP host and port. + +24. New ${hexquote:..string..} expansion operator converts non-printable + characters in the string to \xNN form. + +25. Experimental TPDA (Transport Post Delivery Action) function added. + Patch provided by Axel Rau. + +26. Experimental Redis lookup added. Patch provided by Warren Baker. + + +Version 4.80 +------------ + + 1. New authenticator driver, "gsasl". Server-only (at present). + This is a SASL interface, licensed under GPL, which can be found at + http://www.gnu.org/software/gsasl/. + This system does not provide sources of data for authentication, so + careful use needs to be made of the conditions in Exim. + + 2. New authenticator driver, "heimdal_gssapi". Server-only. + A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME + is no longer honoured for setuid programs by Heimdal. Use the + "server_keytab" option to point to the keytab. + + 3. The "pkg-config" system can now be used when building Exim to reference + cflags and library information for lookups and authenticators, rather + than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and + "LOOKUP_LIBS" directly. Similarly for handling the TLS library support + without adjusting "TLS_INCLUDE" and "TLS_LIBS". + + In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to + find the headers and libraries for PCRE. + + 4. New expansion variable $tls_bits. + + 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will + be joined together with ASCII NUL characters to construct the key to pass + into the DBM library. Can be used with gsasl to access sasldb2 files as + used by Cyrus SASL. + + 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1. + + Avoid release 1.0.1a if you can. Note that the default value of + "openssl_options" is no longer "+dont_insert_empty_fragments", as that + increased susceptibility to attack. This may still have interoperability + implications for very old clients (see version 4.31 change 37) but + administrators can choose to make the trade-off themselves and restore + compatibility at the cost of session security. + + 7. Use of the new expansion variable $tls_sni in the main configuration option + tls_certificate will cause Exim to re-expand the option, if the client + sends the TLS Server Name Indication extension, to permit choosing a + different certificate; tls_privatekey will also be re-expanded. You must + still set these options to expand to valid files when $tls_sni is not set. + + The SMTP Transport has gained the option tls_sni, which will set a hostname + for outbound TLS sessions, and set $tls_sni too. + + A new log_selector, +tls_sni, has been added, to log received SNI values + for Exim as a server. + + 8. The existing "accept_8bitmime" option now defaults to true. This means + that Exim is deliberately not strictly RFC compliant. We're following + Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default. + Those who disagree, or know that they are talking to mail servers that, + even today, are not 8-bit clean, need to turn off this option. + + 9. Exim can now be started with -bw (with an optional timeout, given as + -bw). With this, stdin at startup is a socket that is + already listening for connections. This has a more modern name of + "socket activation", but forcing the activated socket to fd 0. We're + interested in adding more support for modern variants. + +10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix + for numbers indicates multiplication by 1024^3. + +11. The GnuTLS support has been revamped; the three options gnutls_require_kx, + gnutls_require_mac & gnutls_require_protocols are no longer supported. + tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority + string, documentation for which is at: + http://www.gnutls.org/manual/html_node/Priority-Strings.html + + SNI support has been added to Exim's GnuTLS integration too. + + For sufficiently recent GnuTLS libraries, ${randint:..} will now use + gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness. + +12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file + is now available. If the contents of the file are valid, then Exim will + send that back in response to a TLS status request; this is OCSP Stapling. + Exim will not maintain the contents of the file in any way: administrators + are responsible for ensuring that it is up-to-date. + + See "experimental-spec.txt" for more details. + +13. ${lookup dnsdb{ }} supports now SPF record types. They are handled + identically to TXT record lookups. + +14. New expansion variable $tod_epoch_l for higher-precision time. + +15. New global option tls_dh_max_bits, defaulting to current value of NSS + hard-coded limit of DH ephemeral bits, to fix interop problems caused by + GnuTLS 2.12 library recommending a bit count higher than NSS supports. + +16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier. + Option can now be a path or an identifier for a standard prime. + If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23". + Set to "historic" to get the old GnuTLS behaviour of auto-generated DH + primes. + +17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS). + Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL + install was not built with OPENSSL_NO_SSL2 ("no-ssl2"). + + +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 + ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3} + -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2 + + 6. There is a new ACL control called "debug", to enable debug logging. + This allows selective logging of certain incoming transactions within + production environments, with some care. It takes two options, "tag" + and "opts"; "tag" is included in the filename of the log and "opts" + is used as per the -d command-line option. Examples, which + don't all make sense in all contexts: + + control = debug + control = debug/tag=.$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 condition, 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 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 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, analogous to + +ignore_unknown and +include_unknown. These options should be used with + care, probably only in non-critical host lists such as whitelists. + + 8. There's a new option called queue_only_load_latch, which defaults true. + If set false when queue_only_load is greater than zero, Exim re-evaluates + the load for each incoming message in an SMTP session. Otherwise, once one + message is queued, the remainder are also. + + 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most + cases when an SMTP session ends without sending QUIT. However, when Exim + itself is is bad trouble, such as being unable to write to its log files, + this ACL is not run, because it might try to do things (such as write to + log files) that make the situation even worse. + + Like the QUIT ACL, this new ACL is provided to make it possible to gather + statistics. Whatever it returns (accept or deny) is immaterial. The "delay" + modifier is forbidden in this ACL. + + When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set + to a string that indicates the reason for the termination of the SMTP + connection. The possible values are: + + acl-drop Another ACL issued a "drop" command + bad-commands Too many unknown or non-mail commands + command-timeout Timeout while reading SMTP commands + connection-lost The SMTP connection has been lost + data-timeout Timeout while reading message data + local-scan-error The local_scan() function crashed + local-scan-timeout The local_scan() function timed out + signal-exit SIGTERM or SIGINT + synchronization-error SMTP synchronization error + tls-failed TLS failed to start + + In most cases when an SMTP connection is closed without having received + QUIT, Exim sends an SMTP response message before actually closing the + connection. With the exception of acl-drop, the default message can be + overridden by the "message" modifier in the NOTQUIT ACL. In the case of a + "drop" verb in another ACL, it is the message from the other ACL that is + used. + +10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of + servers with individual queries. This is done by starting the query with + "servers=x:y:z;", where each item in the list may take one of two forms: + + (1) If it is just a host name, the appropriate global option (mysql_servers + or pgsql_servers) is searched for a host of the same name, and the + remaining parameters (database, user, password) are taken from there. + + (2) If it contains any slashes, it is taken as a complete parameter set. + + The list of servers is used in exactly the same was as the global list. + Once a connection to a server has happened and a query has been + successfully executed, processing of the lookup ceases. + + This feature is intended for use in master/slave situations where updates + are occurring, and one wants to update a master rather than a slave. If the + masters are in the list for reading, you might have: + + mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw + + In an updating lookup, you could then write + + ${lookup mysql{servers=master; UPDATE ...} + + If, on the other hand, the master is not to be used for reading lookups: + + pgsql_servers = slave1/db/name/pw:slave2/db/name/pw + + you can still update the master by + + ${lookup pgsql{servers=master/db/name/pw; UPDATE ...} + +11. The message_body_newlines option (default FALSE, for backwards + compatibility) can be used to control whether newlines are present in + $message_body and $message_body_end. If it is FALSE, they are replaced by + spaces. + + +Version 4.67 +------------ + + 1. There is a new log selector called smtp_no_mail, which is not included in + the default setting. When it is set, a line is written to the main log + whenever an accepted SMTP connection terminates without having issued a + MAIL command. + + 2. When an item in a dnslists list is followed by = and & and a list of IP + addresses, the behaviour was not clear when the lookup returned more than + one IP address. This has been solved by the addition of == and =& for "all" + rather than the default "any" matching. + + 3. Up till now, the only control over which cipher suites GnuTLS uses has been + for the cipher algorithms. New options have been added to allow some of the + other parameters to be varied. + + 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is + set, Exim compiles a runtime option called disable_fsync. + + 5. There is a new variable called $smtp_count_at_connection_start. + + 6. There's a new control called no_pipelining. + + 7. There are two new variables called $sending_ip_address and $sending_port. + These are set whenever an SMTP connection to another host has been set up. + + 8. The expansion of the helo_data option in the smtp transport now happens + after the connection to the server has been made. + + 9. There is a new expansion operator ${rfc2047d: that decodes strings that + are encoded as per RFC 2047. + +10. There is a new log selector called "pid", which causes the current process + id to be added to every log line, in square brackets, immediately after the + time and date. + +11. Exim has been modified so that it flushes SMTP output before implementing + a delay in an ACL. It also flushes the output before performing a callout, + as this can take a substantial time. These behaviours can be disabled by + obeying control = no_delay_flush or control = no_callout_flush, + respectively, at some earlier stage of the connection. + +12. There are two new expansion conditions that iterate over a list. They are + called forany and forall. + +13. There's a new global option called dsn_from that can be used to vary the + contents of From: lines in bounces and other automatically generated + messages ("delivery status notifications" - hence the name of the option). + +14. The smtp transport has a new option called hosts_avoid_pipelining. + +15. By default, exigrep does case-insensitive matches. There is now a -I option + that makes it case-sensitive. + +16. A number of new features ("addresses", "map", "filter", and "reduce") have + been added to string expansions to make it easier to process lists of + items, typically addresses. + +17. There's a new ACL modifier called "continue". It does nothing of itself, + and processing of the ACL always continues with the next condition or + modifier. It is provided so that the side effects of expanding its argument + can be used. + +18. It is now possible to use newline and other control characters (those with + values less than 32, plus DEL) as separators in lists. + +19. The exigrep utility now has a -v option, which inverts the matching + condition. + +20. The host_find_failed option in the manualroute router can now be set to + "ignore". + + +Version 4.66 +------------ + +No new features were added to 4.66. + + +Version 4.65 +------------ + +No new features were added to 4.65. + Version 4.64 ------------ -1. ACL variables can now be given arbitrary names, as long as they start with - "acl_c" or "acl_m" (for connection variables and message variables) and are - at least 6 characters long. However, only alphanumeric characters and - underscores are allowed. This is a compatible change because the old set of - variables such as acl_m12 are a subset of the allowed names. There may now - be any number of ACL variables. For example: - - set acl_c_foo = something - set acl_ccc = thingsome - set acl_m13 = value for original ACL variable - set acl_m13b = whatever - - What happens if an undefined ACL variable is referenced depends on the - setting of the strict_acl_vars option. If it is false (the default), an - empty string is substituted; if it is true, an error is generated. This - affects all ACL variables, including the "old" ones such as acl_c4. - (Previously there wasn't the concept of an undefined ACL variable.) - - The implementation has been done in such a way that spool files containing - ACL variable settings written by previous releases of Exim are compatible - and can be read by the new release. If only the original numeric names are - used, spool files written by the new release can be read by earlier - releases. + 1. ACL variables can now be given arbitrary names, as long as they start with + "acl_c" or "acl_m" (for connection variables and message variables), are at + least six characters long, with the sixth character being either a digit or + an underscore. + + 2. There is a new ACL modifier called log_reject_target. It makes it possible + to specify which logs are used for messages about ACL rejections. + + 3. There is a new authenticator called "dovecot". This is an interface to the + authentication facility of the Dovecot POP/IMAP server, which can support a + number of authentication methods. + + 4. The variable $message_headers_raw provides a concatenation of all the + messages's headers without any decoding. This is in contrast to + $message_headers, which does RFC2047 decoding on the header contents. + + 5. In a DNS black list, if two domain names, comma-separated, are given, the + second is used first to do an initial check, making use of any IP value + restrictions that are set. If there is a match, the first domain is used, + without any IP value restrictions, to get the TXT record. + + 6. All authenticators now have a server_condition option. + + 7. There is a new command-line option called -Mset. It is useful only in + conjunction with -be (that is, when testing string expansions). It must be + followed by a message id; Exim loads the given message from its spool + before doing the expansions. + + 8. Another similar new command-line option is called -bem. It operates like + -be except that it must be followed by the name of a file that contains a + message. + + 9. When an address is delayed because of a 4xx response to a RCPT command, it + is now the combination of sender and recipient that is delayed in + subsequent queue runs until its retry time is reached. + +10. Unary negation and the bitwise logical operators and, or, xor, not, and + shift, have been added to the eval: and eval10: expansion items. + +11. The variables $interface_address and $interface_port have been renamed + as $received_ip_address and $received_port, to make it clear that they + relate to message reception rather than delivery. (The old names remain + available for compatibility.) + +12. The "message" modifier can now be used on "accept" and "discard" acl verbs + to vary the message that is sent when an SMTP command is accepted. Version 4.63