OpenSSL fixes and backwards compat break.

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

diff --git a/src/README.UPDATING b/src/README.UPDATING
index 3ee3035e93461f0895c95d29182df10f27c573f9..5b6bea869ae5ab3a26b634ef742d6d2144873451 100644 (file)
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -26,6 +26,50 @@ The rest of this document contains information about changes in 4.xx releases
 that might affect a running system.
 
 
+Exim version 4.78
+-----------------
+
+ * 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.
+
+   If you have a corrupt spool file and you wish to recover the contents after
+   upgrading, then lock the message, replace the new-lines that should be part
+   of the -tls_peerdn line with the two-character sequence \n and then unlock
+   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.
+
+
 Exim version 4.77
 -----------------