A user name that contains Unicode characters is not handled correctly during EAP authentication on a Windows XP SP3-based computer

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Article ID: 957218 - View products that this article applies to.
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Symptoms

Assume that on a Windows XP Service Pack 3 (SP3)-based computer, you have a user account that has a user name that contains Unicode characters. When you use this user account, the user name fails Extensible Authentication Protocol (EAP) authentication. Therefore, you cannot access the local network.

Cause

This problem occurs because of the EAPHost architecture in Windows XP SP3. When you try to authenticate, the EAPHost converts the EAP ID message to Unicode. However, the server tries to read the EAP ID message as ASCII. Therefore, if the user identity contains the ASCII characters 128 through 255, EAP authentication fails.

Resolution

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.

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, submit a request to 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:
http://support.microsoft.com/contactus/?ws=support
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 3 installed.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

Registry information

To have us enable this hotfix for you, go to the “Fix it for me” section. If you would rather enable this hotfix yourself, go to the “Let me fix it myself” section.

Fix it for me

To enable this hotfix automatically, click the Fix this problem link. Then, click Run in the File Download dialog box, and follow the steps in this wizard.

Fix this problem


Notes
  • This wizard is temporarily in English only. However, the automatic fix also works for other language versions of Windows.
  • If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.
Now go to the "Did this fix the problem?" section.

Let me fix it myself

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows

To enable this hotfix, 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\EapHost\Configuration
  3. On the Edit menu, point to New, and then click DWORD Value.
  4. Type IdentityEncodingFormat, and then press ENTER.
  5. On the Edit menu, click Modify.
  6. Type 0x1, and then click OK.
  7. Exit Registry Editor.
Now go to the "Did this fix the problem?" section.

Did this fix the problem?

  • Check whether the problem is fixed. If the problem is fixed, you are finished with this article. If the problem is not fixed, you can contact support.
  • We would appreciate your feedback. To provide feedback or to report any issues with this solution, please leave a comment on the "Fix it for me" blog, or send us an e-mail message.

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 with Service Pack 3, x86-based versions
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatformSP requirement
Eappgnui.dll5.1.2600.566394,20826-Aug-200813:36x86SP3
Eapphost.dll5.1.2600.5663180,73626-Aug-200813:36x86SP3

Status

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 EAPHost architecture, visit the following Microsoft Web site:
http://msdn.microsoft.com/en-us/library/aa363523(VS.85).aspx
For more information about Internet Authentication Service (IAS), visit the following Microsoft Web site:
http://technet.microsoft.com/en-us/network/bb643123.aspx
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.

Properties

Article ID: 957218 - Last Review: January 16, 2015 - Revision: 1.0
Applies to
  • Microsoft Windows XP Service Pack 3, when used with:
    • Microsoft Windows XP Home Edition
    • Microsoft Windows XP Professional
Keywords: 
kbnosurvey kbarchive kbfixme kbmsifixme kbfix kbbug kbexpertiseinter kbautohotfix kbqfe kbHotfixServer KB957218

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