OpenSSL fixes and backwards compat break.

[exim.git] / src / README.UPDATING

diff --git a/src/README.UPDATING b/src/README.UPDATING
index 9e3689d84d505a92cb9acf599c35053cd3813dd7..5b6bea869ae5ab3a26b634ef742d6d2144873451 100644 (file)
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -47,6 +47,27 @@ Exim version 4.78
 
    "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
 
 
    "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
 
 
 Exim version 4.77