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

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 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 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:

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 1, x86-based versions

Windows Server 2003 with Service Pack 2, x86-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

Windows Server 2003 with Service Pack 2, Itanium-based versions

Windows Server 2003, x64-based versions

Windows Server 2003 with Service Pack 2, x64-based versions

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

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.

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\CurrentVersion\EFS
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type EfsOptions, and then press ENTER.
5. Double-click EfsOptions, type 0 in the Value data box, and then click OK.
6. Exit Registry Editor.

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:

1. Start Notepad.
2. Copy and then paste the following text into Notepad.

   CLASS MACHINE 
   CATEGORY "System" 
   CATEGORY "Public Key Policies"
   POLICY "Encrypted File System" 
   KEYNAME "Software\Policies\Microsoft\Windows NT\CurrentVersion\EFS"
   PART "Allow EFS to generate self-signed certificate when a Certificate Authority is not available" CHECKBOX 
   VALUENAME "EfsOptions"
   VALUEON NUMERIC 4
   VALUEOFF NUMERIC 0
   END PART 
   END POLICY 
   END CATEGORY 
   END CATEGORY

3. Save the text file as Efscustom.adm in the following folder:
   %windir%\Inf\
4. Exit Notepad.
5. Open the Group Policy Object Editor. To do this, click Start, click Run, type gpedit.msc, and then click OK.
6. In the console tree, locate Computer Configuration\Administrative Templates.
7. On the Action menu, point to All Tasks, and then click Add/Remove Templates.
8. Click Add.
9. Click to select the Efscustom.adm file that you created in step 3, and then click Open.
10. Click Close.
11. Locate and then open the following policy:
    Computer Configuration\Administrative Templates\System\Public Key Polices\Encrypted File System
12. 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.

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