security for compatibility. Exim is now defaulting to higher security and
rewarding more modern clients.
+ If the option tls_dhparams is set and the parameters loaded from the file
+ have a bit-count greater than the new option tls_dh_max_bits, then the file
+ will now be ignored. If this affects you, raise the tls_dh_max_bits limit.
+ We suspect that most folks are using dated defaults and will not be affected.
+
* Ldap lookups returning multi-valued attributes now separate the attributes
with only a comma, not a comma-space sequence. Also, an actual comma within
a returned attribute is doubled. This makes it possible to parse the
new option, you can safely force it off before upgrading, to decouple
configuration changes from the binary upgrade while remaining RFC compliant.
- * The GnuTLS support has been mostly rewritten, to use 2.12.x APIs. As part
- of this, these three options are no longer supported:
+ * The GnuTLS support has been mostly rewritten, to use APIs which don't cause
+ deprecation warnings in GnuTLS 2.12.x. As part of this, these three options
+ are no longer supported:
gnutls_require_kx
gnutls_require_mac
gnutls_require_protocols
- Their functionality is entirely subsumed into tls_require_ciphers, which is
- no longer parsed apart by Exim but is instead given to
- gnutls_priority_init(3), which is no longer an Exim list. See:
+ Their functionality is entirely subsumed into tls_require_ciphers. In turn,
+ tls_require_ciphers is no longer an Exim list and is not parsed by Exim, but
+ is instead given to gnutls_priority_init(3), which expects a priority string;
+ this behaviour is much closer to the OpenSSL behaviour. See:
http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
support for SNI and other features more readily. We regret that it wasn't
feasible to retain the three dropped options.
+ * If built with TLS support, then Exim will now validate the value of
+ the main section tls_require_ciphers option at start-up. Before, this
+ would cause a STARTTLS 4xx failure, now it causes a failure to start.
+ Running with a broken configuration which causes failures that may only
+ be left in the logs has been traded off for something more visible. This
+ change makes an existing problem more prominent, but we do not believe
+ anyone would deliberately be running with an invalid tls_require_ciphers
+ option.
+
+ This also means that library linkage issues caused by conflicts of some
+ kind might take out the main daemon, not just the delivery or receiving
+ process. Conceivably some folks might prefer to continue delivering
+ mail plaintext when their binary is broken in this way, if there is a
+ server that is a candidate to receive such mails that does not advertise
+ STARTTLS. Note that Exim is typically a setuid root binary and given
+ broken linkage problems that cause segfaults, we feel it is safer to
+ fail completely. (The check is not done as root, to ensure that problems
+ here are not made worse by the check).
+
Exim version 4.77
-----------------
problem. Prior to this release, supported values were "TLS1" and "SSL3",
so you should be able to update configuration prior to update.
+ [nb: gnutls_require_protocols removed in Exim 4.80, instead use
+ tls_require_ciphers to provide a priority string; see notes above]
+
* The match_<type>{string1}{string2} expansion conditions no longer subject
string2 to string expansion, unless Exim was built with the new
"EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
git://git.exim.org / exim.git / blobdiff