source: trunk/third/krb5/README @ 17533

                  Kerberos Version 5, Release 1.2.5

                            Release Notes

                        The MIT Kerberos Team

Unpacking the Source Distribution
---------------------------------

The source distribution of Kerberos 5 comes in a gzipped tarfile,
krb5-1.2.5.tar.gz.  Instruction on how to extract the entire
distribution follow.  These directions assume that you want to extract
into a directory called DIST.

If you have the GNU tar program and gzip installed, you can simply do:

        mkdir DIST
        cd DIST
        gtar zxpf krb5-1.2.5.tar.gz

If you don't have GNU tar, you will need to get the FSF gzip
distribution and use gzcat:

        mkdir DIST
        cd DIST
        gzcat krb5-1.2.5.tar.gz | tar xpf -

Both of these methods will extract the sources into DIST/krb5-1.2.5/src
and the documentation into DIST/krb5-1.2.5/doc.

Building and Installing Kerberos 5
----------------------------------

The first file you should look at is doc/install-guide.ps; it contains
the notes for building and installing Kerberos 5.  The info file
krb5-install.info has the same information in info file format.  You
can view this using the GNU emacs info-mode, or by using the
standalone info file viewer from the Free Software Foundation.  This
is also available as an HTML file, install.html.

Other good files to look at are admin-guide.ps and user-guide.ps,
which contain the system administrator's guide, and the user's guide,
respectively.  They are also available as info files
kerberos-admin.info and krb5-user.info, respectively.  These files are
also available as HTML files.

If you are attempting to build under Windows, please see the
src/windows/README file.

Reporting Bugs
--------------

Please report any problems/bugs/comments using the krb5-send-pr
program.  The krb5-send-pr program will be installed in the sbin
directory once you have successfully compiled and installed Kerberos
V5 (or if you have installed one of our binary distributions).

If you are not able to use krb5-send-pr because you haven't been able
compile and install Kerberos V5 on any platform, you may send mail to
krb5-bugs@mit.edu.

Notes, Major Changes, and Known Bugs for 1.2.5
----------------------------------------------

Major Changes:

* On MacOS X, we have reviewed the list of exported symbol names.  As
  in earlier MacOS releases, and the Windows releases, but unlike the
  UNIX releases, the list of exported names accessible to applications
  is reduced to a predefined set of symbols.  We are attempting to
  define a "stable" subset of the API we feel confident about
  providing, as opposed to giving applications access to half of the
  packet-manipulation functions we have.

  In future releases, we may investigate applying a similar export
  list under some UNIX shared library implementations.

  If a function you use is not exported, we probably figured it was
  functionality that should be internal to the library, or something
  that should be done with a different interface, or something we
  didn't know anyone was using at the moment and thought we'd like to
  clean up the interface later on.  If you need it, and there isn't a
  cleaner way, contact us about getting it added back in to the export
  list.

  A few things are marked "deprecated" in the header file, but will
  continue to be provided under "#if KRB5_DEPRECATED" because even
  though they're ugly, we also know they're in use and we can't phase
  them out fast enough.  We may replace the implementation later on
  with a shim on top of some cleaner mechanism.

* For Heimdal (and possibly Microsoft) compatibility, we now accept
  encrypted delegated credentials in gssapi.  Historically, the MIT
  implementation has sent delegated gssapi credentials "in the clear",
  but still encrypted in the AP-REQ.

* IP address checks have been removed from rd_cred; this improves
  compatibility with Heimdal.

Minor changes:

* A null pointer dereference in the krb5 library has been fixed.

Known bugs:

* Most of the other known bugs from 1.2.3 and 1.2.4 are unchanged.

Notes, Major Changes, and Known Bugs for 1.2.4
----------------------------------------------

Notes:

* Like the 1.2.3 release, this is a patch release.  One critical login
  problem is fixed, and a problem with interoperability with
  Microsoft software is worked around.

Major Changes:

* The one-character bug introduced into the login.krb5 program that
  caused 8-character usernames to be rejected in some circumstances
  has been fixed.

* The handling of key version numbers has been modified in places.
  The current formats of the keytab and srvtab files, as well as parts
  of the remote kadmin protocol, handle key version numbers as 8-bit
  quantities, when in fact they are 32-bit quantities.

  * In the keytab and srvtab support for krb5, searching for the
    "highest numbered" key version now has some heuristics to deal
    with the 8-bit kvno wrapping from 255 to 0 to 1....  If a kvno
    greater than 240 is found, the kvno values are assumed to range
    from 128 to 383 (127+256).  This should handle cases like storing
    kvno values 255 and 256 in the file.

  * In the keytab and srvtab support for krb5, when looking for a key
    with a specific version number, the low 8 bits of the requested
    kvno are compared against the value stored in the file.

  * The "ktutil" program also has a new heuristic for choosing the
    "highest numbered" key in a keytab to be written out into a krb4
    srvtab file.

  These heuristics all assume that key version numbers will be
  assigned sequentially, and that there will not be a large set of key
  version numbers in use at one time for any given principal in a
  keytab file.

  These changes were prompted by the discovery by Microsoft (while
  trying to write tools to generate MIT-style keytab files) that we
  could not store arbitrary 32-bit version numbers for keys.

* Some issues with multiple enctype support in GSSAPI credential
  forwarding have been fixed.

Minor Changes:

* A few compilation problems have been fixed.

* New test cases have been added to the test suite to exercise some of
  the new changes.

Known Bugs:

* Non-sequential key version numbering will confuse the new kvno
  handling heuristics.

* Long-standing but newly recognized:

  * The remote kadmin protocol will produce incorrect results when key
    version numbers greater than 255 are being retrieved or stored.
    The kadmin.local program does not suffer from this problem.

  * We do not support storing multiple key versions for a principal in
    a srvtab file.

  * We do not support acquiring krb4 tickets using a srvtab or keytab
    file without acquiring krb5 tickets at the same time (i.e., the
    old krb4 "ksrvtgt" program).

* most of the other known bugs from 1.2.3

Notes, Major Changes, and Known Bugs for 1.2.3
----------------------------------------------

Notes:

* This release is a patch release; some non-critical bugs and feature
  requests have not been incorporated.  We have focussed mainly on
  important security fixes and usability fixes.

Major Changes:

* Certain problems with shared library builds have been eliminated or
  reduced on Linux and HP-UX.

* Various bugs in single-DES enctype similarity have been fixed; the
  1.0.x behavior of treating all single-DES enctype as equivalent has
  been restored for now.  This may go away in a future release.  Note
  that SUPPORT_DESMD5 will be treated as always false for now.

* The KDC will now log a number of enctype parameters associated with
  KDC requests, in order to allow easier debugging of enctype-related
  problems.

* A client will no longer attempt obtain a forwarded TGT with a
  session key enctype that the target server won't understand.

* Triple-DES should work on Windows now.  The SHA-1 implementation had
  a Windows-specific bug preventing it from working in most cases.

* Various bugs in pty handling have been fixed.

* Bogus utmp files with garbage characters in their names should not
  get created on Solaris.  Also, utmp/wtmp handling code has been
  mostly rewritten, eliminating numerous bugs.

* Potential buffer-overrun problems and null-pointer dereferences have
  been fixed in ftpd, telnetd, login.krb5, and SHA-1.  The first three
  may be exploitable under certain conditions; the SHA-1 bug probably
  isn't, as far as we know.

* For multiple-hop interrealm authentication, the realm transit path
  checking has been rewritten.  The old code had a serious bug where
  some of the transited realms may not have been checked against the
  computed path.  It was therefore possible to forge a remote client
  name in certain cases.  We strongly recommend updating application
  server code where non-local principals may be found on ACLs.

* In conjunction with the above fix, we've implemented KDC checking of
  the realm transit path, as described in the IETF's current
  kerberos-revisions draft, and set up the KDC to refuse to issue
  tickets with unacceptable transit paths.  (Strictly speaking,
  according to the Kerberos specification, enforcement of these checks
  is supposed to be left to the application servers.)  Thus, if your
  application servers can't be updated promptly but your KDC can, you
  can still prevent such tickets from being issued.  This checking is
  controlled by a per-realm flag, and is enabled by default.

* On AIX systems, the rlogin server should no longer hang when
  control-C is pressed.

* New databases will be created in btree format by default.  We
  believe the btree code to be less buggy than the hash format code we
  have been using.  This should not affect the use of any existing
  databases, only newly created ones, and even that should be a
  transparent change.

Known Bugs:

* There may be problems with running a KDC on 64-bit platforms
  (environments where size_t and long are wider than 32 bits, such as
  alpha/Tru64, or Solaris/SPARC in SPARCv9 mode, for example), as
  indicated by the util/db2 tests not passing.  These problems may
  also extend to the rpc library, which may prevent the kadmin
  protocol from functioning.  These are being investigated.

* ETYPE_INFO preauthentication data returned from the KDC are not
  sorted in the order requested by the client.  This may result in
  preauthentication failure when encrypted timestamp preauthentication
  is required but the client doesn't understand some of the enctypes
  of the keys stored for it in the database.

* The gssftp daemon and client, when running in krb4 mode, are
  inconsistent with respect to port numbers passed to the
  {mk,rd}_{priv,safe} functions.  As a result, there is a small but
  nonzero probability that krb4 ftp with client and server on the same
  IP address will fail with a "Time is out of bounds" error.  This
  includes the tests/dejagnu test suite, which tests the krb4 ftp
  functionality.  The probability of this occuring seems to be less
  than 50%.

* The gss-sample test application suite is known to not communicate
  with the gss-sample suite in 1.1.x and earlier releases.  This is
  the result of changes to gss-sample to increase its functionality;
  fixes to allow for backwards compatibility will occur in a later
  release.

* BSD/OS 4.x may have some problems compiling.  These are being
  investigated.

Notes, Major Changes, and Known Bugs for 1.2.2
----------------------------------------------

Notes:

* This release is a patch release; some non-critical bugs and feature
  requests have not been incorporated.

Major Changes:

* The KDC dump format has been updated to include per-principal policy
  information.  This will require updating your slave KDCs before your
  master if you want things to still work.

* A library bug that prevented kprop from working properly with DES3
  keys has been fixed.

* kpasswd should no longer coredump when there is no kadmin_server
  line in krb5.conf.

* ASN.1 parsing has been improved to deal with indefinite encodings,
  such as those emitted by DCE-1.0 derived systems.

* Preauthentication handling code in the initial ticket APIs has been
  fixed to handle zero-length ETYPE_INFO sequences without causing a
  NULL pointer dereference.

* The replay cache should no longer leak temporary files.  Related
  hard-to-analyze filename bugs in the rcache code should also be
  fixed.

* Library builds should now work on AIX.

* KDC local address search code should now work on AIX.

* The yacc grammar for the ftp daemon has been modified to be
  compilable on HP/UX with Bison; namespace pollution from system
  headers was causing trouble before.

Known Bugs:

* The gss-sample test application suite is known to not communicate
  with the gss-sample suite in 1.1.x and earlier releases.  This is
  the result of changes to increase functionality; fixes to allow for
  backwards compatibility will occur in a later release.

* Handling of utmp and utmpx updates is known to be broken on some
  systems, such as Solaris 8.  We are investigating possible solutions
  to this problem.

* Tru64 Unix 5.0 (aka OSF/1 5.0), at least, has some problems with
  revoke() returning ENOTTY in open_slave in the pty library.  One
  possible workaround is to insert

        vfs:
                revoke_tty_only = 0

  in /etc/sysconfigtab.  It is not known whether this workaround will
  cause other problems.

* BSD/OS 4.x may have some problems compiling.  These are being
  investigated.

Notes, Major Changes, and Known Bugs for 1.2.1 and 1.2
------------------------------------------------------

* Triple DES support, for session keys as well as user or service
  keys, should be nearly complete in this release.  Much of the work
  that has been needed is generic multiple-cryptosystem support, so
  the addition of another cryptosystem should be much easier.

  * GSSAPI support for 3DES has been added.  An Internet Draft is
    being worked on that will describe how this works; it is not
    currently standardized.  Some backwards-compatibility issues in
    this area mean that enabling 3DES support must be done with
    caution; service keys that are used for GSSAPI must not be updated
    to 3DES until the services themselves are upgraded to support 3DES
    under GSSAPI.

* DNS support for locating KDCs is enabled by default.  DNS support
  for looking up the realm of a host is compiled in but disabled by
  default (due to some concerns with DNS spoofing).

  We recommend that you publish your KDC information through DNS even
  if you intend to rely on config files at your own site; otherwise,
  sites that wish to communicate with you will have to keep their
  config files updated with your information.  One of the goals of
  this code is to reduce the client-side configuration maintenance
  requirements as much as is possible, without compromising security.

  See the administrator's guide for information on setting up DNS
  information for your realm.

  One important effect of this for developers is that on many systems,
  "-lresolv" must be added to the compiler command line when linking
  Kerberos programs.

  Configure-time options are available to control the inclusion of the
  DNS code and the setting of the defaults.  Entries in krb5.conf will
  also modify the behavior if the code has been compiled in.

* Numerous buffer-overrun problems have been found and fixed.  Many of
  these were in locations we don't expect can be exploited in any
  useful way (for example, overrunning a buffer of MAXPATHLEN bytes if
  a compiled-in pathname is too long, in a program that has no special
  privileges).  It may be possible to exploit a few of these to
  compromise system security.

* Partial support for IPv6 addresses has been added.  It can be
  enabled or disabled at configure time with --enable-ipv6 or
  --disable-ipv6; by default, the configure script will search for
  certain types and macros, and enable the IPv6 code if they're found.
  The IPv6 support at this time mostly consists of including the
  addresses in credentials.

* A protocol change has been made to the "rcmd" suite (rlogin, rsh,
  rcp) to address several security problems described in Kris
  Hildrum's paper presented at NDSS 2000.  New command-line options
  have been added to control the selection of protocol, since the
  revised protocol is not compatible with the old one.

* A security problem in login.krb5 has been fixed.  This problem was
  only present if the krb4 compatibility code was not compiled in.

* A security problem with ftpd has been fixed.  An error in the in the
  yacc grammar permitted potential root access.

* The client programs kinit, klist and kdestroy have been changed to
  incorporate krb4 support.  New command-line options control whether
  krb4 behavior, krb5 behavior, or both are used.

* Patches from Frank Cusack for much better hardware preauth support
  have been incorporated.

* Patches from Matt Crawford extend the kadmin ACL syntax so that
  restrictions can be imposed on what certain administrators may do to
  certain accounts.

* A KDC on a host with multiple network addresses will now respond to
  a client from the address that the client used to contact it.  The
  means used to implement this will however cause the KDC not to
  listen on network addresses configured after the KDC has started.

Minor changes
-------------

* The shell code for searching for the Tcl package at configure time
  has been modified.  If a tclConfig.sh can be found, the information
  it contains is used, otherwise the old searching method is tried.
  Let us know if this new scheme causes any problems.

* Shared library builds may work on HPUX, Rhapsody/MacOS X, and newer
  Alpha systems now.

* The Windows build will now include kvno and gss-sample.

* The routine krb5_secure_config_files has been disabled.  A new
  routine, krb5_init_secure_context, has been added in its place.

* The routine decode_krb5_ticket is now being exported as
  krb5_decode_ticket.  Any programs that used the old name (which
  should be few) should be changed to use the new name; we will
  probably eliminate the old name in the future.

* The CCAPI-based credentials cache code has been changed to store the
  local-clock time of issue and expiration rather than the KDC-clock
  times.

* On systems with large numbers of IP addresses, "kinit" should do a
  better job of acquiring those addresses to put in the user's
  credentials.

* Several memory leaks in error cases in the gssrpc code have been
  fixed.

* A bug with login clobbering some internal static storage on AIX has
  been fixed.

* Per-library initialization and cleanup functions have been added,
  for use in configurations that dynamically load and unload these
  libraries.

* Many compile-time warnings have been fixed.

* The GSS sample programs have been updated to exercise more of the
  API.

* The telnet server should produce a more meaningful error message if
  authentication is required but not provided.

* Changes have been made to ksu to make it more difficult to use it to
  leak information the user does not have access to.

* The sample config file information for the CYGNUS.COM realm has been
  updated, and the GNU.ORG realm has been added.

* A configure-time option has been added to enable a replay cache in
  the KDC.  We recommend its use when hardware preauthentication is
  being used.  It is enabled by default, and can be disabled if
  desired with the configure-time option --disable-kdc-replay-cache.

* Some new routines have been added to the library and krb5.h.

* A new routine has been added to the prompter interface to allow the
  application to determine which of the strings prompted for is the
  user's password, in case it is needed for other purposes.

* The remote kadmin interface has been enhanced to support the
  specification of key/salt types for a principal.

* New keytab entries' key values can now be specified manually with a
  new command in the ktutil program.

* A longstanding bug where certain krb4 exchanges using the
  compatibility library between systems with different byte orders
  would fail half the time has been fixed.

* A source file under the GPL has been replaced with an equivalent
  under the BSD license.  The file, strftime.c, was part of one of the
  OpenVision admin system applications, and was only used on systems
  that don't have strftime() in their C libraries.

* Many bug reports are still outstanding in our database.  We are
  continuing to work on this backlog.


Copyright Notice and Legal Administrivia
----------------------------------------

Copyright (C) 1985-2001 by the Massachusetts Institute of Technology.

All rights reserved.

Export of this software from the United States of America may require
a specific license from the United States Government.  It is the
responsibility of any person or organization contemplating export to
obtain such a license before exporting.

WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
distribute this software and its documentation for any purpose and
without fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright notice and
this permission notice appear in supporting documentation, and that
the name of M.I.T. not be used in advertising or publicity pertaining
to distribution of the software without specific, written prior
permission.  Furthermore if you modify this software you must label
your software as modified software and not distribute it in such a
fashion that it might be confused with the original MIT software.
M.I.T. makes no representations about the suitability of this software
for any purpose.  It is provided "as is" without express or implied
warranty.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

Individual source code files are copyright MIT, Cygnus Support,
OpenVision, Oracle, Sun Soft, FundsXpress, and others.

Project Athena, Athena, Athena MUSE, Discuss, Hesiod, Kerberos, Moira,
and Zephyr are trademarks of the Massachusetts Institute of Technology
(MIT).  No commercial use of these trademarks may be made without
prior written permission of MIT.

"Commercial use" means use of a name in a product or other for-profit
manner.  It does NOT prevent a commercial firm from referring to the
MIT trademarks in order to convey information (although in doing so,
recognition of their trademark status should be given).

----

The following copyright and permission notice applies to the
OpenVision Kerberos Administration system located in kadmin/create,
kadmin/dbutil, kadmin/passwd, kadmin/server, lib/kadm5, and portions
of lib/rpc:

   Copyright, OpenVision Technologies, Inc., 1996, All Rights Reserved

   WARNING: Retrieving the OpenVision Kerberos Administration system 
   source code, as described below, indicates your acceptance of the 
   following terms.  If you do not agree to the following terms, do not 
   retrieve the OpenVision Kerberos administration system.

   You may freely use and distribute the Source Code and Object Code
   compiled from it, with or without modification, but this Source
   Code is provided to you "AS IS" EXCLUSIVE OF ANY WARRANTY,
   INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR
   FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER WARRANTY, WHETHER
   EXPRESS OR IMPLIED.  IN NO EVENT WILL OPENVISION HAVE ANY LIABILITY
   FOR ANY LOST PROFITS, LOSS OF DATA OR COSTS OF PROCUREMENT OF 
   SUBSTITUTE GOODS OR SERVICES, OR FOR ANY SPECIAL, INDIRECT, OR
   CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, INCLUDING, 
   WITHOUT LIMITATION, THOSE RESULTING FROM THE USE OF THE SOURCE 
   CODE, OR THE FAILURE OF THE SOURCE CODE TO PERFORM, OR FOR ANY 
   OTHER REASON.

   OpenVision retains all copyrights in the donated Source Code. OpenVision
   also retains copyright to derivative works of the Source Code, whether
   created by OpenVision or by a third party. The OpenVision copyright 
   notice must be preserved if derivative works are made based on the 
   donated Source Code.

   OpenVision Technologies, Inc. has donated this Kerberos 
   Administration system to MIT for inclusion in the standard 
   Kerberos 5 distribution.  This donation underscores our 
   commitment to continuing Kerberos technology development 
   and our gratitude for the valuable work which has been 
   performed by MIT and the Kerberos community.

----

    Portions contributed by Matt Crawford <crawdad@fnal.gov> were
    work performed at Fermi National Accelerator Laboratory, which is
    operated by Universities Research Association, Inc., under
    contract DE-AC02-76CHO3000 with the U.S. Department of Energy.

Acknowledgements
----------------

Appreciation Time!!!!  There are far too many people to try to thank
them all; many people have contributed to the development of Kerberos
V5.  This is only a partial listing....

Thanks to Paul Vixie and the Internet Software Consortium for funding
the work of Barry Jaspan.  This funding was invaluable for the OV
administration server integration, as well as the 1.0 release
preparation process.

Thanks to John Linn, Scott Foote, and all of the folks at OpenVision
Technologies, Inc., who donated their administration server for use in
the MIT release of Kerberos.

Thanks to Jeff Bigler, Mark Eichin, Marc Horowitz, Nancy Gilman, Ken
Raeburn, and all of the folks at Cygnus Support, who provided
innumerable bug fixes and portability enhancements to the Kerberos V5
tree.  Thanks especially to Jeff Bigler, for the new user and system
administrator's documentation.

Thanks to Doug Engert from ANL for providing many bug fixes, as well
as testing to ensure DCE interoperability.

Thanks to Ken Hornstein at NRL for providing many bug fixes and
suggestions.

Thanks to Matt Crawford at FNAL for bugfixes and enhancements.

Thanks to Sean Mullan and Bill Sommerfeld from Hewlett Packard for
their many suggestions and bug fixes.

Thanks to Nalin Dahyabhai of RedHat and Chris Evans for locating and
providing patches for numerous buffer overruns.

Thanks to Christopher Thompson and Marcus Watts for discovering the
ftpd security bug.

Thanks to the members of the Kerberos V5 development team at MIT, both
past and present: Danilo Almeida, Jay Berkenbilt, Richard Basch, Mitch
Berger, John Carr, Don Davis, Alexandra Ellwood, Nancy Gilman, Matt
Hancher, Sam Hartman, Paul Hill, Marc Horowitz, Eva Jacobus, Miroslav
Jurisic, Barry Jaspan, Geoffrey King, John Kohl, Peter Litwack, Scott
McGuire, Kevin Mitchell, Cliff Neuman, Paul Park, Ezra Peisach, Chris
Provenzano, Ken Raeburn, Jon Rochlis, Jeff Schiller, Jen Selby, Brad
Thompson, Harry Tsai, Ted Ts'o, Marshall Vale, Tom Yu.