+------------------------------------------
+This document describes *changes* to previous versions, that might
+affect Exim's operation, with an unchanged configuration file. For new
+options, and new features, see the NewStuff file next to this ChangeLog.
+
+
+Exim version 4.90
+-----------------
+
+JH/01 Rework error string handling in TLS interface so that the caller in
+ more cases is responsible for logging. This permits library-sourced
+ string to be attached to addresses during delivery, and collapses
+ pairs of long lines into single ones.
+
+PP/01 Allow PKG_CONFIG_PATH to be set in Local/Makefile and use it correctly
+ during configuration. Wildcards are allowed and expanded.
+
+JH/02 Rework error string handling in DKIM to pass more info back to callers.
+ This permits better logging.
+
+
+Exim version 4.89
+-----------------
+
+JH/01 Bug 1922: Support IDNA2008. This has slightly different conversion rules
+ than -2003 did; needs libidn2 in addition to libidn.
+
+JH/02 The path option on a pipe transport is now expanded before use.
+
+PP/01 GitHub PR 50: Do not call ldap_start_tls_s on ldapi:// connections.
+ Patch provided by "Björn", documentation fix added too.
+
+JH/03 Bug 2003: fix Proxy Protocol v2 handling: the address size field was
+ missing a wire-to-host endian conversion.
+
+JH/04 Bug 2004: fix CHUNKING in non-PIPELINEING mode. Chunk data following
+ close after a BDAT command line could be taken as a following command,
+ giving a synch failure. Fix by only checking for synch immediately
+ before acknowledging the chunk.
+
+PP/02 GitHub PR 52: many spelling fixes, which include fixing parsing of
+ no_require_dnssec option and creation of _HAVE_TRANSPORT_APPEND_MAILDIR
+ macro. Patches provided by Josh Soref.
+
+JH/05 Have the EHLO response advertise VRFY, if there is a vrfy ACL defined.
+ Previously we did not; the RFC seems ambiguous and VRFY is not listed
+ by IANA as a service extension. However, John Klensin suggests that we
+ should.
+
+JH/06 Bug 2017: Fix DKIM verification in -bh test mode. The data feed into
+ the dkim code may be unix-mode line endings rather than smtp wire-format
+ CRLF, so prepend a CR to any bare LF.
+
+JH/07 Rationalise the coding for callout smtp conversations and transport ones.
+ As a side-benfit, callouts can now use PIPELINING hence fewer round-trips.
+
+JH/08 Bug 2016: Fix DKIM verification vs. CHUNKING. Any BDAT commands after
+ the first were themselves being wrongly included in the feed into dkim
+ processing; with most chunk sizes in use this resulted in an incorrect
+ body hash calculated value.
+
+JH/09 Bug 2014: permit inclusion of a DKIM-Signature header in a received
+ DKIM signature block, for verification. Although advised against by
+ standards it is specifically not ruled illegal.
+
+JH/10 Bug 2025: Fix reception of (quoted) local-parts with embedded spaces.
+
+JH/11 Bug 2029: Fix crash in DKIM verification when a message signature block is
+ missing a body hash (the bh= tag).
+
+JH/12 Bug 2018: Re-order Proxy Protocol startup versus TLS-on-connect startup.
+ It seems that HAProxy sends the Proxy Protocol information in clear and
+ only then does a TLS startup, so do the same.
+
+JH/13 Bug 2027: Avoid attempting to use TCP Fast Open for non-transport client
+ TCP connections (such as for Spamd) unless the daemon successfully set
+ Fast Open mode on its listening sockets. This fixes breakage seen on
+ too-old kernels or those not configured for Fast Open, at the cost of
+ requiring both directions being enabled for TFO, and TFO never being used
+ by non-daemon-related Exim processes.
+
+JH/14 Bug 2000: Reject messages recieved with CHUNKING but with malformed line
+ endings, at least on the first header line. Try to canonify any that get
+ past that check, despite the cost.
+
+JH/15 Angle-bracket nesting (an error inserted by broken sendmails) levels are
+ now limited to an arbitrary five deep, while parsing addresses with the
+ strip_excess_angle_brackets option enabled.
+
+PP/03 Bug 2018: For Proxy Protocol and TLS-on-connect, do not over-read and
+ instead leave the unprompted TLS handshake in socket buffer for the
+ TLS library to consume.
+
+PP/04 Bug 2018: Also handle Proxy Protocol v2 safely.
+
+PP/05 FreeBSD compat: handle that Ports no longer create /usr/bin/perl
+
+JH/16 Drop variables when they go out of scope. Memory management drops a whole
+ region in one operation, for speed, and this leaves assigned pointers
+ dangling. Add checks run only under the testsuite which checks all
+ variables at a store-reset and panics on a dangling pointer; add code
+ explicitly nulling out all the variables discovered. Fixes one known
+ bug: a transport crash, where a dangling pointer for $sending_ip_address
+ originally assigned in a verify callout, is re-used.
+
+PP/06 Drop '.' from @INC in various Perl scripts.
+
+PP/07 Switch FreeBSD iconv to always use the base-system libc functions.
+
+PP/08 Reduce a number of compilation warnings under clang; building with
+ CC=clang CFLAGS+=-Wno-dangling-else -Wno-logical-op-parentheses
+ should be warning-free.
+
+JH/17 Fix inbound CHUNKING when DKIM disabled at runtime.
+
+HS/01 Fix portability problems introduced by PP/08 for platforms where
+ realloc(NULL) is not equivalent to malloc() [SunOS et al].
+
+HS/02 Bug 1974: Fix missing line terminator on the last received BDAT
+ chunk. This allows us to accept broken chunked messages. We need a more
+ general solution here.
+
+PP/09 Wrote util/chunking_fixqueue_finalnewlines.pl to help recover
+ already-broken messages in the queue.
+
+JH/18 Bug 2061: Fix ${extract } corrupting an enclosing ${reduce } $value.
+
+
+Exim version 4.88
+-----------------
+
+JH/01 Use SIZE on MAIL FROM in a cutthrough connection, if the destination
+ supports it and a size is available (ie. the sending peer gave us one).
+
+JH/02 The obsolete acl condition "demime" is removed (finally, after ten
+ years of being deprecated). The replacements are the ACLs
+ acl_smtp_mime and acl_not_smtp_mime.
+
+JH/03 Upgrade security requirements imposed for hosts_try_dane: previously
+ a downgraded non-dane trust-anchor for the TLS connection (CA-style)
+ or even an in-clear connection were permitted. Now, if the host lookup
+ was dnssec and dane was requested then the host is only used if the
+ TLSA lookup succeeds and is dnssec. Further hosts (eg. lower priority
+ MXs) will be tried (for hosts_try_dane though not for hosts_require_dane)
+ if one fails this test.
+ This means that a poorly-configured remote DNS will make it incommunicado;
+ but it protects against a DNS-interception attack on it.
+
+JH/04 Bug 1810: make continued-use of an open smtp transport connection
+ non-noisy when a race steals the message being considered.
+
+JH/05 If main configuration option tls_certificate is unset, generate a
+ self-signed certificate for inbound TLS connections.
+
+JH/06 Bug 165: hide more cases of password exposure - this time in expansions
+ in rewrites and routers.
+
+JH/07 Retire gnutls_require_mac et.al. These were nonfunctional since 4.80
+ and logged a warning sing 4.83; now they are a configuration file error.
+
+JH/08 Bug 1836: Fix crash in VRFY handling when handed an unqualified name
+ (lacking @domain). Apply the same qualification processing as RCPT.
+
+JH/09 Bug 1804: Avoid writing msglog files when in -bh or -bhc mode.
+
+JH/10 Support ${sha256:} applied to a string (as well as the previous
+ certificate).
+
+JH/11 Cutthrough: avoid using the callout hints db on a verify callout when
+ a cutthrough deliver is pending, as we always want to make a connection.
+ This also avoids re-routing the message when later placing the cutthrough
+ connection after a verify cache hit.
+ Do not update it with the verify result either.
+
+JH/12 Cutthrough: disable when verify option success_on_redirect is used, and
+ when routing results in more than one destination address.
+
+JH/13 Cutthrough: expand transport dkim_domain option when testing for dkim
+ signing (which inhibits the cutthrough capability). Previously only
+ the presence of an option was tested; now an expansion evaluating as
+ empty is permissible (obviously it should depend only on data available
+ when the cutthrough connection is made).
+
+JH/14 Fix logging of errors under PIPELINING. Previously the log line giving
+ the relevant preceding SMTP command did not note the pipelining mode.
+
+JH/15 Fix counting of empty lines in $body_linecount and $message_linecount.
+ Previously they were not counted.
+
+JH/16 DANE: treat a TLSA lookup response having all non-TLSA RRs, the same
+ as one having no matching records. Previously we deferred the message
+ that needed the lookup.
+
+JH/17 Fakereject: previously logged as a normal message arrival "<="; now
+ distinguished as "(=".
+
+JH/18 Bug 1867: make the fail_defer_domains option on a dnslookup router work
+ for missing MX records. Previously it only worked for missing A records.
+
+JH/19 Bug 1850: support Radius libraries that return REJECT_RC.
+
+JH/20 Bug 1872: Ensure that acl_smtp_notquit is run when the connection drops
+ after the data-go-ahead and data-ack. Patch from Jason Betts.
+
+JH/21 Bug 1846: Send DMARC forensic reports for reject and quarantine results,
+ even for a "none" policy. Patch from Tony Meyer.
+
+JH/22 Fix continued use of a connection for further deliveries. If a port was
+ specified by a router, it must also match for the delivery to be
+ compatible.
+
+JH/23 Bug 1874: fix continued use of a connection for further deliveries.
+ When one of the recipients of a message was unsuitable for the connection
+ (has no matching addresses), we lost track of needing to mark it
+ deferred. As a result mail would be lost.
+
+JH/24 Bug 1832: Log EHLO response on getting conn-close response for HELO.
+
+JH/25 Decoding ACL controls is now done using a binary search; the source code
+ takes up less space and should be simpler to maintain. Merge the ACL
+ condition decode tables also, with similar effect.
+
+JH/26 Fix problem with one_time used on a redirect router which returned the
+ parent address unchanged. A retry would see the parent address marked as
+ delivered, so not attempt the (identical) child. As a result mail would
+ be lost.
+
+JH/27 Fix a possible security hole, wherein a process operating with the Exim
+ UID can gain a root shell. Credit to http://www.halfdog.net/ for
+ discovery and writeup. Ubuntu bug 1580454; no bug raised against Exim
+ itself :(
+
+JH/28 Enable {spool,log} filesystem space and inode checks as default.
+ Main config options check_{log,spool}_{inodes,space} are now
+ 100 inodes, 10MB unless set otherwise in the configuration.
+
+JH/29 Fix the connection_reject log selector to apply to the connect ACL.
+ Previously it only applied to the main-section connection policy
+ options.
+
+JH/30 Bug 1897: fix callouts connection fallback from TLS to cleartext.
+
+PP/01 Changed default Diffie-Hellman parameters to be Exim-specific, created
+ by me. Added RFC7919 DH primes as an alternative.
+
+PP/02 Unbreak build via pkg-config with new hash support when crypto headers
+ are not in the system include path.
+
+JH/31 Fix longstanding bug with aborted TLS server connection handling. Under
+ GnuTLS, when a session startup failed (eg because the client disconnected)
+ Exim did stdio operations after fclose. This was exposed by a recent
+ change which nulled out the file handle after the fclose.
+
+JH/32 Bug 1909: Fix OCSP proof verification for cases where the proof is
+ signed directly by the cert-signing cert, rather than an intermediate
+ OCSP-signing cert. This is the model used by LetsEncrypt.
+
+JH/33 Bug 1914: Ensure socket is nonblocking before draining after SMTP QUIT.
+
+HS/01 Fix leak in verify callout under GnuTLS, about 3MB per recipient on
+ an incoming connection.
+
+HS/02 Bug 1802: Do not half-close the connection after sending a request
+ to rspamd.
+
+HS/03 Use "auto" as the default EC curve parameter. For OpenSSL < 1.0.2
+ fallback to "prime256v1".
+
+JH/34 SECURITY: Use proper copy of DATA command in error message.
+ Could leak key material. Remotely exploitable. CVE-2016-9963.
+
+
+Exim version 4.87
+-----------------
+
+JH/01 Bug 1664: Disable OCSP for GnuTLS library versions at/before 3.3.16
+ and 3.4.4 - once the server is enabled to respond to an OCSP request
+ it does even when not requested, resulting in a stapling non-aware
+ client dropping the TLS connection.
+
+TF/01 Code cleanup: Overhaul the debug_selector and log_selector machinery to
+ support variable-length bit vectors. No functional change.
+
+TF/02 Improve the consistency of logging incoming and outgoing interfaces.
+ The I= interface field on outgoing lines is now after the H= remote
+ host field, same as incoming lines. There is a separate
+ outgoing_interface log selector which allows you to disable the
+ outgoing I= field.
+
+JH/02 Bug 728: Close logfiles after a daemon-process "exceptional" log write.
+ If not running log_selector +smtp_connection the mainlog would be held
+ open indefinitely after a "too many connections" event, including to a
+ deleted file after a log rotate. Leave the per net connection logging
+ leaving it open for efficiency as that will be quickly detected by the
+ check on the next write.
+
+HS/01 Bug 1671: Fix post transport crash.
+ Processing the wait-<transport> messages could crash the delivery
+ process if the message IDs didn't exist for some reason. When
+ using 'split_spool_directory=yes' the construction of the spool
+ file name failed already, exposing the same netto behaviour.
+
+JH/03 Bug 425: Capture substrings in $regex1, $regex2 etc from regex &
+ mime_regex ACL conditions.
+
+JH/04 Bug 1686: When compiled with EXPERIMENTAL_DSN_INFO: Add extra information
+ to DSN fail messages (bounces): remote IP, remote greeting, remote response
+ to HELO, local diagnostic string.
+
+JH/05 Downgrade message for a TLS-certificate-based authentication fail from
+ log line to debug. Even when configured with a tls authenticator many
+ client connections are expected to not authenticate in this way, so
+ an authenticate fail is not an error.
+
+HS/02 Add the Exim version string to the process info. This way exiwhat
+ gives some more detail about the running daemon.
+
+JH/06 Bug 1395: time-limit caching of DNS lookups, to the TTL value. This may
+ matter for fast-change records such as DNSBLs.
+
+JH/07 Bug 1678: Always record an interface option value, if set, as part of a
+ retry record, even if constant. There may be multiple transports with
+ different interface settings and the retry behaviour needs to be kept
+ distinct.
+
+JH/08 Bug 1586: exiqgrep now refuses to run if there are unexpected arguments.
+
+JH/09 Bug 1700: ignore space & tab embedded in base64 during decode.
+
+JH/10 Bug 840: fix log_defer_output option of pipe transport
+
+JH/11 Bug 830: use same host for all RCPTS of a message, even under
+ hosts_randomize. This matters a lot when combined with mua_wrapper.
+
+JH/12 Bug 1706: percent and underbar characters are no longer escaped by the
+ ${quote_pgsql:<string>} operator.
+
+JH/13 Bug 1708: avoid misaligned access in cached lookup.
+
+JH/14 Change header file name for freeradius-client. Relevant if compiling
+ with Radius support; from the Gentoo tree and checked under Fedora.
+
+JH/15 Bug 1712: Introduce $prdr_requested flag variable
+
+JH/16 Bug 1714: Permit an empty string as expansion result for transport
+ option transport_filter, meaning no filtering.
+
+JH/17 Bug 1713: Fix non-PDKIM_DEBUG build. Patch from Jasen Betts.
+
+JH/18 Bug 1709: When built with TLS support, the tls_advertise_hosts option now
+ defaults to "*" (all hosts). The variable is now available when not built
+ with TLS, default unset, mainly to enable keeping the testsuite sane.
+ If a server certificate is not supplied (via tls_certificate) an error is
+ logged, and clients will find TLS connections fail on startup. Presumably
+ they will retry in-clear.
+ Packagers of Exim are strongly encouraged to create a server certificate
+ at installation time.
+
+HS/03 Add -bP config_file as a synonym for -bP configure_file, for consistency
+ with the $config_file variable.
+
+JH/19 Two additional event types: msg:rcpt:defer and msg:rcpt:host:defer. Both
+ in transport context, after the attempt, and per-recipient. The latter type
+ is per host attempted. The event data is the error message, and the errno
+ information encodes the lookup type (A vs. MX) used for the (first) host,
+ and the trailing two digits of the smtp 4xx response.
+
+GF/01 Bug 1715: Fix for race condition in exicyclog, where exim could attempt
+ to write to mainlog (or rejectlog, paniclog) in the window between file
+ creation and permissions/ownership being changed. Particularly affects
+ installations where exicyclog is run as root, rather than exim user;
+ result is that the running daemon panics and dies.
+
+JH/20 Bug 1701: For MySQL lookups, support MySQL config file option group names.
+
+JH/21 Bug 1720: Add support for priority groups and weighted-random proxy
+ selection for the EXPERIMENTAL_SOCKS feature, via new per-proxy options
+ "pri" and "weight". Note that the previous implicit priority given by the
+ list order is no longer honoured.
+
+JH/22 Bugs 963, 1721: Fix some corner cases in message body canonicalization
+ for DKIM processing.
+
+JH/23 Move SOCKS5 support from Experimental to mainline, enabled for a build
+ by defining SUPPORT_SOCKS.
+
+JH/26 Move PROXY support from Experimental to mainline, enabled for a build
+ by defining SUPPORT_PROXY. Note that the proxy_required_hosts option
+ is renamed to hosts_proxy, and the proxy_{host,target}_{address,port}.
+ variables are renamed to proxy_{local,external}_{address,port}.
+
+JH/27 Move Internationalisation support from Experimental to mainline, enabled
+ for a build by defining SUPPORT_I18N
+
+JH/28 Bug 1745: Fix redis lookups to handle (quoted) spaces embedded in parts
+ of the query string, and make ${quote_redis:} do that quoting.
+
+JH/29 Move Events support from Experimental to mainline, enabled by default
+ and removable for a build by defining DISABLE_EVENT.
+
+JH/30 Updated DANE implementation code to current from Viktor Dukhovni.
+
+JH/31 Fix bug with hosts_connection_nolog and named-lists which were wrongly
+ cached by the daemon.
+
+JH/32 Move Redis support from Experimental to mainline, enabled for a build
+ by defining LOOKUP_REDIS. The libhiredis library is required.
+
+JH/33 Bug 1748: Permit ACL dnslists= condition in non-smtp ACLs if explicit
+ keys are given for lookup.
+
+JH/34 Bug 1192: replace the embedded copy of PolarSSL RSA routines in the DKIM
+ support, by using OpenSSL or GnuTLS library ones. This means DKIM is
+ only supported when built with TLS support. The PolarSSL SHA routines
+ are still used when the TLS library is too old for convenient support.
+
+JH/35 Require SINGLE_DH_USE by default in OpenSSL (main config option
+ openssl_options), for security. OpenSSL forces this from version 1.1.0
+ server-side so match that on older versions.
+
+JH/36 Bug 1778: longstanding bug in memory use by the ${run } expansion: A fresh
+ allocation for $value could be released as the expansion processing
+ concluded, but leaving the global pointer active for it.
+
+JH/37 Bug 1769: Permit a VRFY ACL to override the default 252 response,
+ and to use the domains and local_parts ACL conditions.
+
+JH/38 Fix cutthrough bug with body lines having a single dot. The dot was
+ incorrectly not doubled on cutthrough transmission, hence seen as a
+ body-termination at the receiving system - resulting in truncated mails.
+ Commonly the sender saw a TCP-level error, and retransmitted the message
+ via the normal store-and-forward channel. This could result in duplicates
+ received - but deduplicating mailstores were liable to retain only the
+ initial truncated version.
+
+JH/39 Bug 1781: Fix use of DKIM private-keys having trailing '=' in the base-64.
+
+JH/40 Fix crash in queryprogram router when compiled with EXPERIMENTAL_SRS.
+
+JH/41 Bug 1792: Fix selection of headers to sign for DKIM: bottom-up. While
+ we're in there, support oversigning also; bug 1309.
+
+JH/42 Bug 1796: Fix error logged on a malware scanner connection failure.
+
+HS/04 Add support for keep_environment and add_environment options.
+
+JH/43 Tidy coding issues detected by gcc --fsanitize=undefined. Some remain;
+ either intentional arithmetic overflow during PRNG, or testing config-
+ induced overflows.
+
+JH/44 Bug 1800: The combination of a -bhc commandline option and cutthrough
+ delivery resulted in actual delivery. Cancel cutthrough before DATA
+ stage.
+
+JH/45 Fix cutthrough, when connection not opened by verify and target hard-
+ rejects a recipient: pass the reject to the originator.
+
+JH/46 Multiple issues raised by Coverity. Some were obvious or plausible bugs.
+ Many were false-positives and ignorable, but it's worth fixing the
+ former class.
+
+JH/47 Fix build on HP-UX and older Solaris, which need (un)setenv now also
+ for the new environment-manipulation done at startup. Move the routines
+ from being local to tls.c to being global via the os.c file.
+
+JH/48 Bug 1807: Fix ${extract } for the numeric/3-string case. While preparsing
+ an extract embedded as result-arg for a map, the first arg for extract
+ is unavailable so we cannot tell if this is a numbered or keyed
+ extraction. Accept either.