computer account change password with Windows 2008 domain

[Russ Allbery]

"Tim Alsop" <Tim.Alsop at CyberSafe.Com> writes:

> We have discovered a problem when we try to set/change password for a
> computer account in AD on Windows Server 2008. The computer account is
> created so we can use it for a service/application, and the key is
> created from it's password (randomly generated) and extracted into a key
> table file.
>
> Our code is able to create the account (authenticating to AD using
> SASL/GSS/Kerberos) but when we try and set the computer account's
> password to a random value, the request is rejected, so it looks like AD
> on Windows 2008 has some changes which stop password changes for
> computer accounts, or maybe something which is stopping changes to
> passwords for accounts that use a principal name such as
> name/fqdn at REALM.

You don't say here *how* you're changing the password, but there are two
Active Directory bugs in Windows 2008 that you may be running into:

* Authentication to Active Directory using a principal that contains a
  slash (such as service/foo) from a keytab generated by the Windows tool
  is broken in Windows 2008.  It works fine if there is no slash in the
  principal.  Microsoft has identified this as a bug and is working on a
  fix.

* Microsoft broke password changes via the LDAP protocol with SASL GSSAPI
  binds in Windows 2008.  In Windows 2003, provided that you didn't try to
  negotiate an SASL privacy layer, you could connect via TLS and
  authenticate with GSSAPI and query or set the password attribute
  directly.  In Windows 2008, this no longer works; you always get the
  error from the server that you are not permitted to negotiate a privacy
  layer when using TLS, even though you're not trying to.  We've already
  filed this as a bug.

In both cases, if you have a support contract with Microsoft and this is a
problem that you're running into, please independently open your own bug;
the more customers they know this affects, the more likely we'll get a hot
fix.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>