The Network Policy Server (NPS) does not authenticate an EAP-MD5 request if the "name" field is empty in the EAP-MD5 challenge response in Windows Server 2008 R2

Applies to: Windows Server 2008 R2 DatacenterWindows Server 2008 R2 EnterpriseWindows Server 2008 R2 Standard


Consider the following scenario:
  • You enable the Network Policy and Access Services server role on a computer that is running Windows Server 2008 R2.
  • A Microsoft Extensible Authentication Protocol-Message Digest 5 (EAP-MD5) request is sent to the Network Policy Server (NPS) for authentication. The name field in the EAP-MD5 challenge response is empty.
In this scenario, the EAP-MD5 authentication fails.


This issue occurs because the Network Policy Server does not support an EAP-MD5 challenge response that has an empty name field. Additionally, this behavior does not comply with Request for Comments (RFC) 1994.

Note The Network Policy Server requires a value of at least one byte for the name field.


Hotfix information

HennieYeHennieYeA 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.


To apply this hotfix, you must be running Windows Server 2008 R2 on your computer. Additionally, you must have the Network Policy and Access Services server role installed on your computer.

Registry information

To use the hotfix, you do not have to change the registry.

Restart requirement

You must 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 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
  • 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 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform


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

More Information

For more information about Request for Comments (RFC) 1994, visit the following Internet Engineering Task Force (IETF) Web site:The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information

Additional file information for Windows Server 2008 R2

Additional files for all supported x64-based versions of Windows Server 2008 R2
File nameAmd64_376df5641b817ec9fda7c8d3bfc5c027_31bf3856ad364e35_6.1.7600.20662_none_174eb6e5caf56c54.manifest
File versionNot applicable
File size699
Date (UTC)09-Mar-2010
Time (UTC)00:53
PlatformNot applicable
File nameAmd64_8192775752d0daecdb047fe89b902aa2_31bf3856ad364e35_6.1.7600.20662_none_1cf9580cd81b8375.manifest
File versionNot applicable
File size1,038
Date (UTC)09-Mar-2010
Time (UTC)00:53
PlatformNot applicable
File nameAmd64_microsoft-windows-raschap_31bf3856ad364e35_6.1.7600.20662_none_6f50343daa0d93be.manifest
File versionNot applicable
File size2,580
Date (UTC)08-Mar-2010
Time (UTC)23:12
PlatformNot applicable
File nameUpdate.mum
File versionNot applicable
File size1,684
Date (UTC)09-Mar-2010
Time (UTC)00:53
PlatformNot applicable
File nameX86_microsoft-windows-raschap_31bf3856ad364e35_6.1.7600.20662_none_133198b9f1b02288.manifest
File versionNot applicable
File size2,576
Date (UTC)08-Mar-2010
Time (UTC)22:11
PlatformNot applicable