Microsoft KB Archive/930499

= You cannot prevent EFS from generating a self-signed certificate when you try to encrypt an EFS file on a Windows Server 2003-based computer =

Article ID: 930499

Article Last Modified on 12/4/2007

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APPLIES TO


 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Web Edition
 * Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Datacenter x64 Edition
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems

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Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



SYMPTOMS
Consider the following scenario:
 * You try to encrypt an EFS file on a Microsoft Windows Server 2003-based computer.
 * The EFS certificate is unavailable in the local certificate store.
 * No certification authority (CA) is available to issue an EFS certificate.

In this scenario, the Encrypting File System (EFS) generates a self-signed certificate to encrypt the file.

However, there is no option to disable this behavior in Windows Server 2003. In this scenario, you cannot prevent EFS from generating a self-signed certificate. This design makes it difficult for enterprise users to manage EFS implementation.



Hotfix information
A supported hotfix is now 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 service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or 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. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
To apply this hotfix, you must have Windows Server 2003 Service Pack 1 or Windows Server 2003 Service Pack 2 installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 How to obtain the latest service pack for Windows Server 2003

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 with Service Pack 2, x64-based versions


STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
After you install the hotfix, you can prevent EFS from generating self-signed certificates. To do this, use one of the following methods.

Method 1
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.  Click Start, click Run, type regedit, and then click OK. Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\CurrentVersion\EFS

 On the Edit menu, point to New, and then click DWORD Value. Type EfsOptions, and then press ENTER. Double-click EfsOptions, type 0 in the Value data box, and then click OK. Exit Registry Editor.</li></ol>

Note To re-enable EFS to generate self-signed certificates, set the EfsOptions registry entry to a value of 4.

Method 2
Create a custom Administrative Template to define a new policy. The new policy will enable you to centrally manage this option. To do this, follow these steps: <ol> Start Notepad.</li>  Copy and then paste the following text into Notepad. CLASS MACHINE CATEGORY &quot;System&quot; CATEGORY &quot;Public Key Policies&quot; POLICY &quot;Encrypted File System&quot; KEYNAME &quot;Software\Policies\Microsoft\Windows NT\CurrentVersion\EFS&quot; PART &quot;Allow EFS to generate self-signed certificate when a Certificate Authority is not available&quot; CHECKBOX VALUENAME &quot;EfsOptions&quot; VALUEON NUMERIC 4 VALUEOFF NUMERIC 0 END PART END POLICY END CATEGORY END CATEGORY </li> Save the text file as Efscustom.adm in the following folder:

%windir%\Inf\

</li> Exit Notepad.</li> Open the Group Policy Object Editor. To do this, click Start, click Run, type gpedit.msc, and then click OK.</li> In the console tree, locate Computer Configuration\Administrative Templates.</li> On the Action menu, point to All Tasks, and then click Add/Remove Templates.</li> Click Add.</li> Click to select the Efscustom.adm file that you created in step 3, and then click Open.</li> Click Close.</li> Locate and then open the following policy:

Computer Configuration\Administrative Templates\System\Public Key Polices\Encrypted File System

</li> To prevent EFS from generating self-signed certificates, click to clear the Allow EFS to generate self-signed certificate when a Certificate Authority is not available check box.</li></ol>

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