Add ARC signing caveats

[users/heiko/exim.git] / src / README.UPDATING

diff --git a/src/README.UPDATING b/src/README.UPDATING
index e685b8ec3d4aed6544f8c3067d85fb2c7d6805dc..05b3d9d97eb8e0f77becc88ed397c9703846fac4 100644 (file)
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -26,11 +26,75 @@ The rest of this document contains information about changes in 4.xx releases
 that might affect a running system.
 
 
 that might affect a running system.
 
 

+Exim version 4.89
+-----------------
+
+ * SMTP CHUNKING in Exim 4.88 did not ensure that received mails had a final
+   newline; attempts to deliver such messages onwards to non-chunking hosts
+   would probably hang, as Exim does not insert the newline before a ".".
+   In 4.89, the newline is added upon receipt.  For already-received messages
+   in your queue, try util/chunking_fixqueue_finalnewlines.pl
+   to walk the queue, fixing any affected messages.  Note that because a
+   delivery attempt will be hanging, attempts to lock the messages for fixing
+   them will stall; stopping all queue-runners temporarily is recommended.
+
+ * OpenSSL: oldest supported release series is now 1.0.2, which is the oldest
+   supported by the OpenSSL project.  If you can build Exim with an older
+   release series, congratulations.  If you can't, then upgrade.
+   The file doc/openssl.txt contains instructions for installing a current
+   OpenSSL outside the system library paths and building Exim to use it.
+
+ * FreeBSD: we now always use the system iconv in libc, as all versions of
+   FreeBSD supported by the FreeBSD project provide this functionality.
+
+
+Exim version 4.88
+-----------------
+
+ * The "demime" ACL condition, deprecated for the past 10 years, has
+   now been removed.
+
+ * Old GnuTLS configuration options "gnutls_require_kx", "gnutls_require_mac",
+   and "gnutls_require_protocols" have now been removed.  (Inoperative from
+   4.80, per below; logging warnings since 4.83, again per below).
+
+
+Exim version 4.83
+-----------------
+
+ * SPF condition results renamed "permerror" and "temperror".  The old
+   names are still accepted for back-compatability, for this release.
+
+ * TLS details are now logged on rejects, subject to log selectors.
+
+ * Items in headers_remove lists must now have any embedded list-separators
+   doubled.
+
+ * Attempted use of the deprecated options "gnutls_require_kx" et. al.
+   now result in logged warning.
+
+
+Exim version 4.82
+-----------------
+
+ * New option gnutls_allow_auto_pkcs11 defaults false; if you have GnuTLS 2.12.0
+   or later and do want PKCS11 modules to be autoloaded, then set this option.
+
+ * A per-transport wait-<name> database is no longer updated if the transport
+   sets "connection_max_messages" to 1, as it can not be used and causes
+   unnecessary serialisation and load.  External tools tracking the state of
+   Exim by the hints databases may need modification to take this into account.
+
+ * The av_scanner option can now accept multiple clamd TCP targets, all other
+   setting limitations remain.
+
+

 Exim version 4.80
 -----------------
 
  * BEWARE backwards-incompatible changes in SSL libraries, thus the version
    bump.  See points below for details.
 Exim version 4.80
 -----------------
 
  * BEWARE backwards-incompatible changes in SSL libraries, thus the version
    bump.  See points below for details.

+   Also an LDAP data returned format change.

 
  * The value of $tls_peerdn is now print-escaped when written to the spool file
    in a -tls_peerdn line, and unescaped when read back in.  We received reports
 
  * The value of $tls_peerdn is now print-escaped when written to the spool file
    in a -tls_peerdn line, and unescaped when read back in.  We received reports


@@ -42,6 +106,12 @@ Exim version 4.80
    the message.  No tool has been provided as we believe this is a rare
    occurence.
 
    the message.  No tool has been provided as we believe this is a rare
    occurence.
 

+ * For OpenSSL, SSLv2 is now disabled by default.  (GnuTLS does not support
+   SSLv2).  RFC 6176 prohibits SSLv2 and some informal surveys suggest no
+   actual usage.  You can re-enable with the "openssl_options" Exim option,
+   in the main configuration section.  Note that supporting SSLv2 exposes
+   you to ciphersuite downgrade attacks.
+

  * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2.  If built
    against 1.0.1a then you will get a warning message and the
    "openssl_options" value will not parse "no_tlsv1_1": the value changes
  * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2.  If built
    against 1.0.1a then you will get a warning message and the
    "openssl_options" value will not parse "no_tlsv1_1": the value changes


@@ -51,8 +121,9 @@ Exim version 4.80
    "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
 
    COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
    "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
 
    COMPATIBILITY WARNING: The default value of "openssl_options" is no longer

-   "+dont_insert_empty_fragments".  We default to unset.  That old default was
-   grandfathered in from before openssl_options became a configuration option.
+   "+dont_insert_empty_fragments".  We default to "+no_sslv2".
+   That old default was grandfathered in from before openssl_options became a
+   configuration option.

    Empty fragments are inserted by default through TLS1.0, to partially defend
    against certain attacks; TLS1.1+ change the protocol so that this is not
    needed.  The DIEF SSL option was required for some old releases of mail
    Empty fragments are inserted by default through TLS1.0, to partially defend
    against certain attacks; TLS1.1+ change the protocol so that this is not
    needed.  The DIEF SSL option was required for some old releases of mail


@@ -77,6 +148,12 @@ Exim version 4.80
    attribute as a comma-separated list.  Note the distinction from multiple
    attributes being returned, where each one is a name=value pair.
 
    attribute as a comma-separated list.  Note the distinction from multiple
    attributes being returned, where each one is a name=value pair.
 

+   If you are currently splitting the results from LDAP upon a comma, then you
+   should check carefully to see if adjustments are needed.
+
+   This change lets cautious folks distinguish "comma used as separator for
+   joining values" from "comma inside the data".
+

  * accept_8bitmime now defaults on, which is not RFC compliant but is better
    suited to today's Internet.  See http://cr.yp.to/smtp/8bitmime.html for a
    sane rationale.  Those who wish to be strictly RFC compliant, or know that
  * accept_8bitmime now defaults on, which is not RFC compliant but is better
    suited to today's Internet.  See http://cr.yp.to/smtp/8bitmime.html for a
    sane rationale.  Those who wish to be strictly RFC compliant, or know that


@@ -98,7 +175,7 @@ Exim version 4.80
    is instead given to gnutls_priority_init(3), which expects a priority string;
    this behaviour is much closer to the OpenSSL behaviour.  See:
 
    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
+     http://www.gnutls.org/manual/html_node/Priority-Strings.html

 
    for fuller documentation of the strings parsed.  The three gnutls_require_*
    options are still parsed by Exim and, for this release, silently ignored.
 
    for fuller documentation of the strings parsed.  The three gnutls_require_*
    options are still parsed by Exim and, for this release, silently ignored.


@@ -135,6 +212,21 @@ Exim version 4.80
    fail completely.  (The check is not done as root, to ensure that problems
    here are not made worse by the check).
 
    fail completely.  (The check is not done as root, to ensure that problems
    here are not made worse by the check).
 

+ * The "tls_dhparam" option has been updated, so that it can now specify a
+   path or an identifier for a standard DH prime from one of a few RFCs.
+   The default for OpenSSL is no longer to not use DH but instead to use
+   one of these standard primes.  The default for GnuTLS is no longer to use
+   a file in the spool directory, but to use that same standard prime.
+   The option is now used by GnuTLS too.  If it points to a path, then
+   GnuTLS will use that path, instead of a file in the spool directory;
+   GnuTLS will attempt to create it if it does not exist.
+
+   To preserve the previous behaviour of generating files in the spool
+   directory, set "tls_dhparam = historic".  Since prior releases of Exim
+   ignored tls_dhparam when using GnuTLS, this can safely be done before
+   the upgrade.
+
+

 
 Exim version 4.77
 -----------------
 
 Exim version 4.77
 -----------------


@@ -471,7 +563,7 @@ Version 4.23
 3. Version 4.23 saves the contents of the ACL variables with the message, so
    that they can be used later. If one of these variables contains a newline,
    there will be a newline character in the spool that will not be interpreted
 3. Version 4.23 saves the contents of the ACL variables with the message, so
    that they can be used later. If one of these variables contains a newline,
    there will be a newline character in the spool that will not be interpreted

-   correctely by a previous version of Exim. (Exim ignores keyed spool file
+   correctly by a previous version of Exim. (Exim ignores keyed spool file

    items that it doesn't understand - precisely for this kind of problem - but
    it expects them all to be on one line.)
 
    items that it doesn't understand - precisely for this kind of problem - but
    it expects them all to be on one line.)