X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/f90a9fd133ac62eb3fa1e834b3bff16360d23500..1508acb8629a6ac1517ab524a9f29257a2335d5e:/src/README.UPDATING

diff --git a/src/README.UPDATING b/src/README.UPDATING
index 7ce35dff8..6a820bc7c 100644
--- a/src/README.UPDATING
+++ b/src/README.UPDATING
@@ -31,6 +31,7 @@ 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
@@ -66,12 +67,23 @@ Exim version 4.80
    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
    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
@@ -111,6 +123,40 @@ Exim version 4.80
    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).
+
+ * 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
 -----------------