Release Announcements
=====================

This is the first pre release of Samba 4.17.  This is *not*
intended for production environments and is designed for testing
purposes only.  Please report any defects via the Samba bug reporting
system at https://bugzilla.samba.org/.

Samba 4.17 will be the next version of the Samba suite.


UPGRADING
=========


NEW FEATURES/CHANGES
====================

Bronze bit and S4U support with MIT Kerberos 1.20
-------------------------------------------------

In 2020 Microsoft Security Response Team received another Kerberos-related
report. Eventually, that led to a security update of the CVE-2020-17049,
Kerberos KDC Security Feature Bypass Vulnerability, also known as a ‘Bronze
Bit’. With this vulnerability, a compromised service that is configured to use
Kerberos constrained delegation feature could tamper with a service ticket that
is not valid for delegation to force the KDC to accept it.

With the release of MIT Kerberos 1.20, Samba AD DC is able able to mitigate the
‘Bronze Bit’ attack. MIT Kerberos KDC's KDB (Kerberos Database Driver) API was
changed to allow passing more details between KDC and KDB components. When built
against MIT Kerberos, Samba AD DC supports MIT Kerberos 1.19 and 1.20 versions
but 'Bronze Bit' mitigation is provided only with MIT Kerberos 1.20.

In addition to fixing the ‘Bronze Bit’ issue, Samba AD DC now fully supports
S4U2Self and S4U2Proxy Kerberos extensions.

Resource Based Constrained Delegation (RBCD) support
----------------------------------------------------

Samba AD DC built with MIT Kerberos 1.20 offers RBCD support now. With MIT
Kerberos 1.20 we have complete RBCD support passing Sambas S4U testsuite.
Note that samba-tool lacks support for setting this up yet!

To complete RBCD support and make it useful to Administrators we added the
Asserted Identity [1] SID into the PAC for constrained delegation. This is
available for Samba AD compiled with MIT Kerberos 1.20.

[1] https://docs.microsoft.com/en-us/windows-server/security/kerberos/kerberos-constrained-delegation-overview

Customizable DNS listening port
-------------------------------

It is now possible to set a custom listening port for the builtin DNS service,
making easy to host another DNS on the same system that would bind to the
default port and forward the domain-specific queries to Samba using the custom
port. This is the opposite configuration of setting a forwarder in Samba.

It makes possible to use another DNS server as a front and forward to Samba.

Dynamic DNS updates may not be proxied by the front DNS server when forwarding
to Samba. Dynamic DNS update proxying depends on the features of the other DNS
server used as a front.

CTDB changes
------------

* When Samba is configured with both --with-cluster-support and
  --systemd-install-services then a systemd service file for CTDB will
  be installed.

* ctdbd_wrapper has been removed.  ctdbd is now started directly from
  a systemd service file or init script.

* The syntax for the ctdb.tunables configuration file has been
  relaxed.  However, trailing garbage after the value, including
  comments, is no longer permitted.  Please see ctdb-tunables(7) for
  more details.


REMOVED FEATURES
================

LanMan Authentication and password storage removed from the AD DC
-----------------------------------------------------------------

The storage and authentication with LanMan passwords has been entirely
removed from the Samba AD DC, even when "lanman auth = yes" is set.

smb.conf changes
================

  Parameter Name                          Description     Default
  --------------                          -----------     -------
  dns port                                New default     53


KNOWN ISSUES
============

https://wiki.samba.org/index.php/Release_Planning_for_Samba_4.17#Release_blocking_bugs


#######################################
Reporting bugs & Development Discussion
#######################################

Please discuss this release on the samba-technical mailing list or by
joining the #samba-technical:matrix.org matrix room, or
#samba-technical IRC channel on irc.libera.chat

If you do report problems then please try to send high quality
feedback. If you don't provide vital information to help us track down
the problem then you will probably be ignored.  All bug reports should
be filed under the Samba 4.1 and newer product in the project's Bugzilla
database (https://bugzilla.samba.org/).


======================================================================
== Our Code, Our Bugs, Our Responsibility.
== The Samba Team
======================================================================