An LDAP bind to a Windows Server 2008-based server fails when the client enables only the "confidentiality protection" bit"

Consider the following scenario:

• You install Active Directory Domain Services (AD DS) or Active Directory Lightweight Directory Services (AD LDS) on a computer that is running Windows Server 2008.
• You enable the option for Lightweight Directory Access Protocol (LDAP) signing on the server. This signing requires an integrity protection mechanism for a LDAP-bind request that uses the Simple Authentication and Security Layer (SASL) authentication.
• A client uses the Generic Security Services Application Programming Interface (GSS-API) and the SASL authentication to perform a LDAP bind operation on the server. The client uses a value of "4" for the security layer field to perform the LDAP bind operation.
  
  Note A value of "4" for the security layer field indicates that the "confidentiality protection" bit is enabled to create a bind to the LDAP server.

In this scenario, the LDAP bind operation fails.

Note The bind operation succeeds if the client uses a value of "6" for the security layer field. A value of "6" for the security layer field indicates that both the "Integrity protection" bit and the "confidentiality protection" bit are enabled.

A request that uses the SASL-layer integrity protection and a request that uses the SASL-layer confidentiality protection are handled differently by AD DS. A server rejects an LDAP bind from a client and returns the "strongAuthRequired" error if the following conditions are true:

• The server is configured to require an integrity protection mechanism.
• The client that performs the bind operation does not request an "integrity protection" bit. Or, the more common scenario when the client requests a "confidentiality protection" bit and does not separately request an "integrity protection" bit.

By default, a server that is running Windows Server 2008 rejects an LDAP blind from a client when these conditions are true. However, some LDAP clients assume that an integrity protection mechanism is also enabled even though the client uses a value of "4" for the security layer field.

For example, assume that a client is running Sun Solaris and uses a value of "4" for the security layer field. In this scenario, a bind operation from this client is rejected by a server that is running Windows Server 2008.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

There are no prerequisites.

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Server 2008 file information notes

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

  Version	Product	SR_Level	Service branch
  6.0.600 1 . 22xxx	Windows Server 2008	SP1	LDR
  6.0.600 2 . 22xxx	Windows Server 2008	SP2	LDR

• Service Pack 1 is integrated into the release version of Windows Server 2008.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008

For all supported x64-based versions of Windows Server 2008

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about the SASL authentication, visit the following Internet Engineering Task Force (IETF) Web site: For more information about how to enable LDAP signing in Windows Server 2008, click the following article number to view the article in the Microsoft Knowledge Base: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Additional file information

Additional file information for Windows Server 2008

Additional files for all supported x86-based versions of Windows Server 2008

Additional files for all supported x64-based versions of Windows Server 2008