Authentication fails from a Windows XP-based client if the authentication uses a Windows Server 2003-based IAS server

Authentication fails from a Microsoft Windows XP-based client if the following conditions are true:

• The authentication uses Microsoft Internet Authentication Service (IAS) on a Microsoft Windows Server 2003-based computer.
• The authentication uses Extensible Authentication Protocol-Transport Layer Security (EAP-TLS).
• The client uses a certificate that does not contain an Extended Key Usage (EKU).

This problem occurs because the current EAP-TLS implementation requires the presence of both the server authentication EKU and the client authentication EKU in the certificate that the client uses.

This hotfix has versions for both Windows XP and Windows Server 2003. To resolve the problem, follow these steps:

1. Apply the Windows XP version of this hotfix on the client.
2. Apply the Windows Server 2003 version of this hotfix on the IAS server.
3. Create and enable the TlsServerUseAllPurposeCert registry entry on the IAS server after you apply the hotfixes.

Windows XP

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 this specific problem. 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

To apply this hotfix, you must have Windows XP Service Pack 2 installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows XP, x86-based versionsWindows XP, x64-based versions

Windows Server 2003

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

Create and enable the TlsServerUseAllPurposeCert registry entry after you apply this hotfix. To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate the following registry subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\13
3. Right-click this registry subkey, point to New, and then click DWORD Value.
4. Type TlsServerUseAllPurposeCert as the registry entry name, and then press ENTER.
5. Double-click the TlsServerUseAllPurposeCert registry entry.
6. In the Edit DWORD Value dialog box, click Decimal under Base.
7. In the Value data text box, type 0 or 1, as appropriate for your situation.
   
   Note When this value is set to 1, the IAS server only sends to the client a certificate that does not contain an EKU. When this value is set to 0, the IAS server only sends to the client a certificate that contains an EKU.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

Prerequisites

To apply this hotfix, you must have Windows Server 2003 Service Pack 1 (SP1) installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows Server 2003, x86-based versionsWindows Server 2003, Itanium-based versionsWindows Server 2003, x64-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Server 2003 Service Pack 2.

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