krb5-1.8.2 is released

Tom Yu tlyu at MIT.EDU
Thu Jun 10 17:59:24 EDT 2010

Hash: SHA1

The MIT Kerberos Team announces the availability of MIT Kerberos 5
Release 1.8.2.  Please see below for a list of some major changes
included, or consult the README file in the source tree for a more
detailed list of significant changes.


You may retrieve the Kerberos 5 Release 1.8.2 source from the
following URL:

The homepage for the krb5-1.8.2 release is:

Further information about Kerberos 5 may be found at the following

and at the MIT Kerberos Consortium web site:

DES transition

The krb5-1.8 release disables single-DES cryptosystems by default.  As
a result, you may need to add the libdefaults setting
"allow_weak_crypto = true" to communicate with existing Kerberos
infrastructures if they do not support stronger ciphers.

The Data Encryption Standard (DES) is widely recognized as weak.  The
krb5-1.7 release contains measures to encourage sites to migrate away
- From using single-DES cryptosystems.  Among these is a configuration
variable that enables "weak" enctypes, which now defaults to "false"
beginning with krb5-1.8.  The krb5-1.8 release includes additional
measures to ease the transition away from single-DES.  These
additional measures include:

* enctype config enhancements (so you can do "DEFAULT +des", etc.)
* new API to allow applications (e.g. AFS) to explicitly reenable weak
* easier kadmin history key changes

Major changes in 1.8.2

This is primarily a bugfix release.

* Fix vulnerabilities:
  ** CVE-2010-1320 KDC double free caused by ticket renewal
  ** CVE-2010-1321 GSS-API lib null pointer deref (MITKRB5-SA-2010-005)

* Allow numeric IPv6 addresses for configuring KDC locations.

Major changes in 1.8.1

This is primarily a bugfix release.

* MITKRB5-SA-2010-002 CVE-2010-0628 denial of service in SPNEGO

* Support IPv6 in kpasswd client.

* Fix an authorization data type number assignment that conflicted
  with an undocumented Microsoft usage.

Major changes in 1.8

The krb5-1.8 release contains a large number of changes, featuring
improvements in the following broad areas:

* Code quality
* Developer experience
* Performance
* End-user experience
* Administrator experience
* Protocol evolution

Code quality:

* Move toward test-driven development -- new features have test code,
  or at least written testing procedures.

* Remove applications to a separate distribution to simplify
  independent maintenance.

* Increase conformance to coding style

  + "The great reindent"

  + Selective refactoring

Developer experience:

* Crypto modularity -- vendors can more easily substitute their own
  crypto implementations, which might be hardware-accelerated or
  validated to FIPS 140, for the builtin crypto implementation that
  has historically shipped as part of MIT Kerberos.  Currently, only
  an OpenSSL provider is included, but others are planned for the

* Move toward improved KDB interface

* Improved API for verifying and interrogating authorization data


* Investigate and remedy repeatedly-reported performance bottlenecks.

* Encryption performance -- new crypto API with opaque key structures,
  to allow for optimizations such as caching of derived keys

End-user experience:

* Reduce DNS dependence by implementing an interface that allows
  client library to track whether a KDC supports service principal

Administrator experience:

* Disable DES by default -- this reduces security exposure from using
  an increasingly insecure cipher.

* More versatile crypto configuration, to simplify migration away from
  DES -- new configuration syntax to allow inclusion and exclusion of
  specific algorithms relative to a default set.

* Account lockout for repeated login failures -- mitigates online
  password guessing attacks, and helps with some enterprise regulatory

* Bridge layer to allow Heimdal HDB modules to act as KDB backend
  modules.  This provides a migration path from a Heimdal to an MIT

Protocol evolution:

* FAST enhancements -- preauthentication framework enhancements to
  allow a client to securely negotiate the use of FAST with a KDC of
  unknown capabilities.

* Microsoft Services for User (S4U) compatibility: S4U2Self, also
  known as "protocol transition", allows for service to ask a KDC for
  a ticket to themselves on behalf of a client authenticated via a
  different means; S4U2Proxy allows a service to ask a KDC for a
  ticket to another service on behalf of a client.

* Anonymous PKINIT -- allows the use of public-key cryptography to
  anonymously authenticate to a realm

* Support doing constrained delegation similar to Microsoft's
  S4U2Proxy without the use of the Windows PAC.  This functionality
  uses a protocol compatible with Heimdal.
Version: GnuPG v1.4.8 (SunOS)


kerberos-announce mailing list
kerberos-announce at

More information about the krbdev mailing list