+------------------------------------------
+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.
+
+
+Since version 4.91
+------------------
+
+JH/02 Bug 1007: Avoid doing logging from signal-handlers, as that can result in
+ non-signal-safe functions being used.
+
+JH/03 Bug 2269: When presented with a received message having a stupidly large
+ number of DKIM-Signature headers, disable DKIM verification to avoid
+ a resource-consumption attack. The limit is set at twenty.
+
+JH/05 Bug 2273: Cutthrough delivery left a window where the received messsage
+ files in the spool were present and unlocked. A queue-runner could spot
+ them, resulting in a duplicate delivery. Fix that by doing the unlock
+ after the unlink. Investigation by Tim Stewart.
+
+JH/06 Bug 2275: The MIME ACL unlocked the received message files early, and
+ a queue-runner could start a delivery while other operations were ongoing.
+ Cutthrough delivery was a common victim, resulting in duplicate delivery.
+ Found and investigated by Tim Stewart. Fix by using the open message data
+ file handle rather than opening another, and not locally closing it (which
+ releases a lock) for that case, while creating the temporary .eml format
+ file for the MIME ACL. Also applies to "regex" and "spam" ACL conditions.
+
+JH/08 When generating a selfsigned cert, use serial number 1 since zero is not
+ legitimate.
+
+JH/09 Bug 2274: Fix logging of cmdline args when starting in an unlinked cwd.
+ Previously this would segfault.
+
+JH/10 Fix ARC signing for case when DKIM signing failed. Previously this would
+ segfault.
+
+JH/14 Bug 2284: Fix DKIM signing for body lines starting with a pair of dots.
+
+JH/16 Fix ARC verification to do AS checks in reverse order.
+
+JH/18 Bug 2287: Fix the protocol name (eg utf8esmtp) for multiple messages
+ using the SMTPUTF8 option on their MAIL FROM commands, in one connection.
+ Previously the "utf8" would be re-prepended for every additional message.
+
+JH/20 Bug 2296: Fix cutthrough for >1 address redirection. Previously only
+ one parent address was copied, and bogus data was used at delivery-logging
+ time. Either a crash (after delivery) or bogus log data could result.
+ Discovery and analysis by Tim Stewart.
+
+JH/23 Bug 2318: Fix the noerror command within filters. It wasn't working.
+ The ignore_error flag wasn't being returned from the filter subprocess so
+ was not set for later routers. Investigation and fix by Matthias Kurz.
+
+JH/26 Bug 2311: Fix DANE-TA verification under GnuTLS. Previously it was also
+ requiring a known-CA anchor certificate; make it now rely entirely on the
+ TLSA as an anchor. Checking the name on the leaf cert against the name
+ on the A-record for the host is still done for TA (but not for EE mode).
+
+JH/27 Fix logging of proxy address. Previously, a pointless "PRX=[]:0" would be
+ included in delivery lines for non-proxied connections, when compiled with
+ SUPPORT_SOCKS and running with proxy logging enabled.
+
+JH/31 Fix a bad use of a copy function, which could be used to pointlessly
+ copy a string over itself. The library routine is documented as not
+ supporting overlapping copies, and on MacOS it actually raised a SIGABRT.
+
+JH/33 Bug 2338: Fix the cyrus-sasl authenticator to fill in the
+ $authenticated_fail_id variable on authentication failure. Previously
+ it was unset.
+
+
+Exim version 4.91
+-----------------
+
+GF/01 DEFER rather than ERROR on redis cluster MOVED response.
+ When redis_servers is set to a list of > 1 element, and the Redis servers
+ in that list are in cluster configuration, convert the REDIS_REPLY_ERROR
+ case of MOVED into a DEFER case instead, thus moving the query onto the
+ next server in the list. For a cluster of N elements, all N servers must
+ be defined in redis_servers.
+
+GF/02 Catch and remove uninitialized value warning in exiqsumm
+ Check for existence of @ARGV before looking at $ARGV[0]
+
+JH/01 Replace the store_release() internal interface with store_newblock(),
+ which internalises the check required to safely use the old one, plus
+ the allocate and data copy operations duplicated in both (!) of the
+ extant use locations.
+
+JH/02 Disallow '/' characters in queue names specified for the "queue=" ACL
+ modifier. This matches the restriction on the commandline.
+
+JH/03 Fix pgsql lookup for multiple result-tuples with a single column.
+ Previously only the last row was returned.
+
+JH/04 Bug 2217: Tighten up the parsing of DKIM signature headers. Previously
+ we assumed that tags in the header were well-formed, and parsed the
+ element content after inspecting only the first char of the tag.
+ Assumptions at that stage could crash the receive process on malformed
+ input.
+
+JH/05 Bug 2215: Fix crash associated with dnsdb lookup done from DKIM ACL.
+ While running the DKIM ACL we operate on the Permanent memory pool so that
+ variables created with "set" persist to the DATA ACL. Also (at any time)
+ DNS lookups that fail create cache records using the Permanent pool. But
+ expansions release any allocations made on the current pool - so a dnsdb
+ lookup expansion done in the DKIM ACL releases the memory used for the
+ DNS negative-cache, and bad things result. Solution is to switch to the
+ Main pool for expansions.
+ While we're in that code, add checks on the DNS cache during store_reset,
+ active in the testsuite.
+ Problem spotted, and debugging aided, by Wolfgang Breyha.
+
+JH/06 Fix issue with continued-connections when the DNS shifts unreliably.
+ When none of the hosts presented to a transport match an already-open
+ connection, close it and proceed with the list. Previously we would
+ queue the message. Spotted by Lena with Yahoo, probably involving
+ round-robin DNS.
+
+JH/07 Bug 2214: Fix SMTP responses resulting from non-accept result of MIME ACL.
+ Previously a spurious "250 OK id=" response was appended to the proper
+ failure response.
+
+JH/08 The "support for" informational output now, which built with Content
+ Scanning support, has a line for the malware scanner interfaces compiled
+ in. Interface can be individually included or not at build time.
+
+JH/09 The "aveserver", "kavdaemon" and "mksd" interfaces are now not included
+ by the template makefile "src/EDITME". The "STREAM" support for an older
+ ClamAV interface method is removed.
+
+JH/10 Bug 2223: Fix mysql lookup returns for the no-data case (when the number of
+ rows affected is given instead).
+
+JH/11 The runtime Berkeley DB library version is now additionally output by
+ "exim -d -bV". Previously only the compile-time version was shown.
+
+JH/12 Bug 2230: Fix cutthrough routing for nonfirst messages in an initiating
+ SMTP connection. Previously, when one had more receipients than the
+ first, an abortive onward connection was made. Move to full support for
+ multiple onward connections in sequence, handling cutthrough connection
+ for all multi-message initiating connections.
+
+JH/13 Bug 2229: Fix cutthrough routing for nonstandard port numbers defined by
+ routers. Previously, a multi-recipient message would fail to match the
+ onward-connection opened for the first recipient, and cause its closure.
+
+JH/14 Bug 2174: A timeout on connect for a callout was also erroneously seen as
+ a timeout on read on a GnuTLS initiating connection, resulting in the
+ initiating connection being dropped. This mattered most when the callout
+ was marked defer_ok. Fix to keep the two timeout-detection methods
+ separate.
+
+JH/15 Relax results from ACL control request to enable cutthrough, in
+ unsupported situations, from error to silently (except under debug)
+ ignoring. This covers use with PRDR, frozen messages, queue-only and
+ fake-reject.
+
+HS/01 Fix Buffer overflow in base64d() (CVE-2018-6789)
+
+JH/16 Fix bug in DKIM verify: a buffer overflow could corrupt the malloc
+ metadata, resulting in a crash in free().
+
+PP/01 Fix broken Heimdal GSSAPI authenticator integration.
+ Broken in f2ed27cf5, missing an equals sign for specified-initialisers.
+ Broken also in d185889f4, with init system revamp.
+
+JH/17 Bug 2113: Fix conversation closedown with the Avast malware scanner.
+ Previously we abruptly closed the connection after reading a malware-
+ found indication; now we go on to read the "scan ok" response line,
+ and send a quit.
+
+JH/18 Bug 2239: Enforce non-usability of control=utf8_downconvert in the mail
+ ACL. Previously, a crash would result.
+
+JH/19 Speed up macro lookups during configuration file read, by skipping non-
+ macro text after a replacement (previously it was only once per line) and
+ by skipping builtin macros when searching for an uppercase lead character.
+
+JH/20 DANE support moved from Experimental to mainline. The Makefile control
+ for the build is renamed.
+
+JH/21 Fix memory leak during multi-message connections using STARTTLS. A buffer
+ was allocated for every new TLS startup, meaning one per message. Fix
+ by only allocating once (OpenSSL) or freeing on TLS-close (GnuTLS).
+
+JH/22 Bug 2236: When a DKIM verification result is overridden by ACL, DMARC
+ reported the original. Fix to report (as far as possible) the ACL
+ result replacing the original.
+
+JH/23 Fix memory leak during multi-message connections using STARTTLS under
+ OpenSSL. Certificate information is loaded for every new TLS startup,
+ and the resources needed to be freed.
+
+JH/24 Bug 2242: Fix exim_dbmbuild to permit directoryless filenames.
+
+JH/25 Fix utf8_downconvert propagation through a redirect router. Previously it
+ was not propagated.
+
+JH/26 Bug 2253: For logging delivery lines under PRDR, append the overall
+ DATA response info to the (existing) per-recipient response info for
+ the "C=" log element. It can have useful tracking info from the
+ destination system. Patch from Simon Arlott.
+
+JH/27 Bug 2251: Fix ldap lookups that return a single attribute having zero-
+ length value. Previously this would segfault.
+
+HS/02 Support Avast multiline protoocol, this allows passing flags to
+ newer versions of the scanner.
+
+JH/28 Ensure that variables possibly set during message acceptance are marked
+ dead before release of memory in the daemon loop. This stops complaints
+ about them when the debug_store option is enabled. Discovered specifically
+ for sender_rate_period, but applies to a whole set of variables.
+ Do the same for the queue-runner and queue-list loops, for variables set
+ from spool message files. Do the same for the SMTP per-message loop, for
+ certain variables indirectly set in ACL operations.
+
+JH/29 Bug 2250: Fix a longstanding bug in heavily-pipelined SMTP input (such
+ as a multi-recipient message from a mailinglist manager). The coding had
+ an arbitrary cutoff number of characters while checking for more input;
+ enforced by writing a NUL into the buffer. This corrupted long / fast
+ input. The problem was exposed more widely when more pipelineing of SMTP
+ responses was introduced, and one Exim system was feeding another.
+ The symptom is log complaints of SMTP syntax error (NUL chars) on the
+ receiving system, and refused recipients seen by the sending system
+ (propating to people being dropped from mailing lists).
+ Discovered and pinpointed by David Carter.
+
+JH/30 The (EXPERIMENTAL_DMARC) variable $dmarc_ar_header is withdrawn, being
+ replaced by the ${authresults } expansion.
+
+JH/31 Bug 2257: Fix pipe transport to not use a socket-only syscall.
+
+HS/03 Set a handler for SIGTERM and call exit(3) if running as PID 1. This
+ allows proper process termination in container environments.
+
+JH/32 Bug 2258: Fix spool_wireformat in combination with LMTP transport.
+ Previously the "final dot" had a newline after it; ensure it is CR,LF.
+
+JH/33 SPF: remove support for the "spf" ACL condition outcome values "err_temp"
+ and "err_perm", deprecated since 4.83 when the RFC-defined words
+ "temperror" and "permerror" were introduced.
+
+JH/34 Re-introduce enforcement of no cutthrough delivery on transports having
+ transport-filters or DKIM-signing. The restriction was lost in the
+ consolidation of verify-callout and delivery SMTP handling.
+ Extend the restriction to also cover ARC-signing.
+
+JH/35 Cutthrough: for a final-dot response timeout (and nonunderstood responses)
+ in defer=pass mode supply a 450 to the initiator. Previously the message
+ would be spooled.
+
+PP/02 DANE: add dane_require_tls_ciphers SMTP Transport option; if unset,
+ tls_require_ciphers is used as before.
+
+HS/03 Malware Avast: Better match the Avast multiline protocol. Add
+ "pass_unscanned". Only tmpfails from the scanner are written to
+ the paniclog, as they may require admin intervention (permission
+ denied, license issues). Other scanner errors (like decompression
+ bombs) do not cause a paniclog entry.
+
+JH/36 Fix reinitialisation of DKIM logging variable between messages.
+ Previously it was possible to log spurious information in receive log
+ lines.
+
+JH/37 Bug 2255: Revert the disable of the OpenSSL session caching. This
+ triggered odd behaviour from Outlook Express clients.
+
+PP/03 Add util/renew-opendmarc-tlds.sh script for safe renewal of public
+ suffix list.
+
+JH/38 DKIM: accept Ed25519 pubkeys in SubjectPublicKeyInfo-wrapped form,
+ since the IETF WG has not yet settled on that versus the original
+ "bare" representation.
+
+JH/39 Fix syslog logging for syslog_timestamp=no and log_selector +millisec.
+ Previously the millisecond value corrupted the output.
+ Fix also for syslog_pid=no and log_selector +pid, for which the pid
+ corrupted the output.
+
+
+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.
+
+JH/03 Rework the transport continued-connection mechanism: when TLS is active,
+ do not close it down and have the child transport start it up again on
+ the passed-on TCP connection. Instead, proxy the child (and any
+ subsequent ones) for TLS via a unix-domain socket channel. Logging is
+ affected: the continued delivery log lines do not have any DNSSEC, TLS
+ Certificate or OCSP information. TLS cipher information is still logged.
+
+JH/04 Shorten the log line for daemon startup by collapsing adjacent sets of
+ identical IP addresses on different listening ports. Will also affect
+ "exiwhat" output.
+
+PP/02 Bug 2070: uClibc defines __GLIBC__ without providing glibc headers;
+ add noisy ifdef guards to special-case this sillyness.
+ Patch from Bernd Kuhls.
+
+JH/05 Tighten up the checking in isip4 (et al): dotted-quad components larger
+ than 255 are no longer allowed.
+
+JH/06 Default openssl_options to include +no_ticket, to reduce load on peers.
+ Disable the session-cache too, which might reduce our load. Since we
+ currrectly use a new context for every connection, both as server and
+ client, there is no benefit for these.
+ GnuTLS appears to not support tickets server-side by default (we don't
+ call gnutls_session_ticket_enable_server()) but client side is enabled
+ by default on recent versions (3.1.3 +) unless the PFS priority string
+ is used (3.2.4 +).
+
+PP/03 Add $SOURCE_DATE_EPOCH support for reproducible builds, per spec at
+ <https://reproducible-builds.org/specs/source-date-epoch/>.
+
+JH/07 Fix smtp transport use of limited max_rcpt under mua_wrapper. Previously
+ the check for any unsuccessful recipients did not notice the limit, and
+ erroneously found still-pending ones.
+
+JH/08 Pipeline CHUNKING command and data together, on kernels that support
+ MSG_MORE. Only in-clear (not on TLS connections).
+
+JH/09 Avoid using a temporary file during transport using dkim. Unless a
+ transport-filter is involved we can buffer the headers in memory for
+ creating the signature, and read the spool data file once for the
+ signature and again for transmission.
+
+JH/10 Enable use of sendfile in Linux builds as default. It was disabled in
+ 4.77 as the kernel support then wasn't solid, having issues in 64bit
+ mode. Now, it's been long enough. Add support for FreeBSD also.
+
+JH/11 Bug 2104: Fix continued use of a transport connection with TLS. In the
+ case where the routing stage had gathered several addresses to send to
+ a host before calling the transport for the first, we previously failed
+ to close down TLS in the old transport process before passing the TCP
+ connection to the new process. The new one sent a STARTTLS command
+ which naturally failed, giving a failed delivery and bloating the retry
+ database. Investigation and fix prototype from Wolfgang Breyha.
+
+JH/12 Fix check on SMTP command input synchronisation. Previously there were
+ false-negatives in the check that the sender had not preempted a response
+ or prompt from Exim (running as a server), due to that code's lack of
+ awareness of the SMTP input buffering.
+
+PP/04 Add commandline_checks_require_admin option.
+ Exim drops privileges sanely, various checks such as -be aren't a
+ security problem, as long as you trust local users with access to their
+ own account. When invoked by services which pass untrusted data to
+ Exim, this might be an issue. Set this option in main configuration
+ AND make fixes to the calling application, such as using `--` to stop
+ processing options.
+
+JH/13 Do pipelining under TLS. Previously, although safe, no advantage was
+ taken. Now take care to pack both (client) MAIL,RCPT,DATA, and (server)
+ responses to those, into a single TLS record each way (this usually means
+ a single packet). As a side issue, smtp_enforce_sync now works on TLS
+ connections.
+
+PP/05 OpenSSL/1.1: use DH_bits() for more accurate DH param sizes. This
+ affects you only if you're dancing at the edge of the param size limits.
+ If you are, and this message makes sense to you, then: raise the
+ configured limit or use OpenSSL 1.1. Nothing we can do for older
+ versions.
+
+JH/14 For the "sock" variant of the malware scanner interface, accept an empty
+ cmdline element to get the documented default one. Previously it was
+ inaccessible.
+
+JH/15 Fix a crash in the smtp transport caused when two hosts in succession
+ are unsuable for non-message-specific reasons - eg. connection timeout,
+ banner-time rejection.
+
+JH/16 Fix logging of delivery remote port, when specified by router, under
+ callout/hold.
+
+PP/06 Repair manualroute's ability to take options in any order, even if one
+ is the name of a transport.
+ Fixes bug 2140.
+
+HS/01 Cleanup, prevent repeated use of -p/-oMr (CVE-2017-1000369)
+
+JH/17 Change the list-building routines interface to use the expanding-string
+ triplet model, for better allocation and copying behaviour.
+
+JH/18 Prebuild the data-structure for "builtin" macros, for faster startup.
+ Previously it was constructed the first time a possibly-matching string
+ was met in the configuration file input during startup; now it is done
+ during compilation.
+
+JH/19 Bug 2141: Use the full-complex API for Berkeley DB rather than the legacy-
+ compatible one, to avoid the (poorly documented) possibility of a config
+ file in the working directory redirecting the DB files, possibly correpting
+ some existing file. CVE-2017-10140 assigned for BDB.
+
+JH/20 Bug 2147: Do not defer for a verify-with-callout-and-random which is not
+ cache-hot. Previously, although the result was properly cached, the
+ initial verify call returned a defer.
+
+JH/21 Bug 2151: Avoid using SIZE on the MAIL for a callout verify, on any but
+ the main verify for receipient in uncached-mode.
+
+JH/22 Retire historical build files to an "unsupported" subdir. These are
+ defined as "ones for which we have no current evidence of testing".
+
+JH/23 DKIM: enforce the DNS pubkey record "h" permitted-hashes optional field,
+ if present. Previously it was ignored.
+
+JH/24 Start using specified-initialisers in C structure init coding. This is
+ a C99 feature (it's 2017, so now considered safe).
+
+JH/25 Use one-bit bitfields for flags in the "addr" data structure. Previously
+ if was a fixed-sized field and bitmask ops via macros; it is now more
+ extensible.
+
+PP/07 GitHub PR 56: Apply MariaDB build fix.
+ Patch provided by Jaroslav Škarvada.
+
+PP/08 Bug 2161: Fix regression in sieve quoted-printable handling introduced
+ during Coverity cleanups [4.87 JH/47]
+ Diagnosis and fix provided by Michael Fischer v. Mollard.
+
+JH/26 Fix DKIM bug: when the pseudoheader generated for signing was exactly
+ the right size to place the terminating semicolon on its own folded
+ line, the header hash was calculated to an incorrect value thanks to
+ the (relaxed) space the fold became.
+
+HS/02 Fix Bug 2130: large writes from the transport subprocess where chunked
+ and confused the parent.
+
+JH/27 Fix SOCKS bug: an unitialized pointer was deref'd by the transport process
+ which could crash as a result. This could lead to undeliverable messages.
+
+JH/28 Logging: "next input sent too soon" now shows where input was truncated
+ for log purposes.
+
+JH/29 Fix queue_run_in_order to ignore the PID portion of the message ID. This
+ matters on fast-turnover and PID-randomising systems, which were getting
+ out-of-order delivery.
+
+JH/30 Fix a logging bug on aarch64: an unsafe routine was previously used for
+ a possibly-overlapping copy. The symptom was that "Remote host closed
+ connection in response to HELO" was logged instead of the actual 4xx
+ error for the HELO.
+
+JH/31 Fix CHUNKING code to properly flush the unwanted chunk after an error.
+ Previously only that bufferd was discarded, resulting in SYMTP command
+ desynchronisation.
+
+JH/32 DKIM: when a message has multiple signatures matching an identity given
+ in dkim_verify_signers, run the dkim acl once for each. Previously only
+ one run was done. Bug 2189.
+
+JH/33 Downgrade an unfound-list name (usually a typo in the config file) from
+ "panic the current process" to "deliberately defer". The panic log is
+ still written with the problem list name; the mail and reject logs now
+ get a temp-reject line for the message that was being handled, saying
+ something like "domains check lookup or other defer". The SMTP 451
+ message is still "Temporary local problem".
+
+JH/34 Bug 2199: Fix a use-after-free while reading smtp input for header lines.
+ A crafted sequence of BDAT commands could result in in-use memory beeing
+ freed. CVE-2017-16943.
+
+HS/03 Bug 2201: Fix checking for leading-dot on a line during headers reading
+ from SMTP input. Previously it was always done; now only done for DATA
+ and not BDAT commands. CVE-2017-16944.
+
+JH/35 Bug 2201: Flush received data in BDAT mode after detecting an error fatal
+ to the message (such as an overlong header line). Previously this was
+ not done and we did not exit BDAT mode. Followon from the previous item
+ though a different problem.
+
+
+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.
+
+JH/19 Fix reference counting bug in routing-generated-address tracking.
+
+
+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.