X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/dec5017e2e41bb85d559e2b35713f1e294cdde8c..0215ec074083aaa051d45e7fe3a177783ef93df1:/src/README.UPDATING

diff --git a/src/README.UPDATING b/src/README.UPDATING
index 1eb36277e..62d1d2745 100644
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -26,9 +26,12 @@ The rest of this document contains information about changes in 4.xx releases
 that might affect a running system.
 
 
-Exim version 4.78
+Exim version 4.80
 -----------------
 
+ * BEWARE backwards-incompatible changes in SSL libraries, thus the version
+   bump.  See points below for details.
+
  * 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
    of values with embedded newlines, which caused spool file corruption.
@@ -39,6 +42,73 @@ Exim version 4.78
    the message.  No tool has been provided as we believe this is a rare
    occurence.
 
+ * 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
+   incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
+   is infelicitous.  We advise avoiding 1.0.1a.
+
+   "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.
+   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
+   clients which did not gracefully handle the empty fragments, and was
+   initially set in Exim release 4.31 (see ChangeLog, item 37).
+
+   If you still have affected mail-clients, and you see SSL protocol failures
+   with this release of Exim, set:
+     openssl_options = +dont_insert_empty_fragments
+   in the main section of your Exim configuration file.  You're trading off
+   security for compatibility.  Exim is now defaulting to higher security and
+   rewarding more modern clients.
+
+ * 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
+   attribute as a comma-separated list.  Note the distinction from multiple
+   attributes being returned, where each one is a name=value pair.
+
+ * 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
+   they need to talk to servers that are not 8-bit-clean, now need to take
+   explicit configuration action to default this option off.  This is not a
+   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:
+
+     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:
+
+     http://www.gnu.org/software/gnutls/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.
+   A future release will add warnings, before a later still release removes
+   parsing entirely and the presence of the options will be a configuration
+   error.
+
+   Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
+   A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
+   re-enable support, but this is not supported by the Exim maintainers.
+   Our test suite no longer includes MD5-based certificates.
+
+   This rewrite means that Exim will continue to build against GnuTLS in the
+   future, brings Exim closer to other GnuTLS applications and lets us add
+   support for SNI and other features more readily.  We regret that it wasn't
+   feasible to retain the three dropped options.
+
 
 Exim version 4.77
 -----------------
@@ -49,6 +119,9 @@ 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