Two improvements are available that shorten the time that is required to manage SCEP certificates by using the Network Device Enrollment Service in Windows Server 2008

Symptoms

In Windows Server 2008, you are trying to manage Simple Certificate Enrollment Protocol (SCEP) certificates by using the Network Device Enrollment Service (NDES). The NDES is installed as a part of Certificate services in Windows Server 2008. In this scenario, you experience the following issues:

Issue 1

Passwords cannot be reused among devices.

Based on the SCEP protocol, a device is required to send a password when it requests a certificate from an SCEP server for the first time. The SCEP server issues a certificate after validating the password.

The process by which the SCEP server issues a certificate after validating the password is as follows:

1. The administrator logs on to a SCEP administration Web site and requests a password.

2. The SCEP server generates a random password, stores it in the cache, and then displays the password to the administrator.

3. The administrator configures the password on the device.

4. The device sends this password in its initial request for a certificate.
   
   Note This password expires in 60 minutes.

5. The server issues the certificate and then removes the password from the cache. The password can no longer be used by any other devices.

Issue 2

SCEP certificates cannot be re-enrolled automatically after they expire.

Because of these two issues, it may take administrators a long time to request passwords for all devices and to apply SCEP certificates to them.

Resolution

To resolve these two issues, install hotfix 959193. This hotfix introduces the following two improvements:

Improvement 1

After you apply this hotfix, passwords can be reused among devices. The new process to manage passwords is as follows:

1. The SCEP server confirms the registry setting for "Single Password" mode. In this mode, a master password is created and stored in the registry by using encrypted data. The master password never expires.

2. An administrator logs on to an SCEP administration Web site and requests a password. The master password is delivered.

3. The administrator configures the password on the device. Because the password is the same for all devices and because it never expires, the administrator can easily write a script to deploy the password on all devices.

How to enable improvement 1

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 feature, create the following registry entry:
Location: HKEY_LOCAL_MACHINE\Software\Microsoft\Cryptography\MSCEP\UseSinglePassword
Name: UseSinglePassword
Type: REG_DWORD
Value: 1
Note If you are running NDES under the Network Service account, you must grant Full Control permission to the "Network Service" account under the following registry subkey: HKEY_LOCAL_MACHINE\Software\Microsoft\Cryptography\MSCEP.

Improvement 2

Certificates can be re-enrolled automatically after they expire. This feature is enabled automatically after the hotfix is installed.

By default, when you request a certificate renewal by using this feature, the signer certificate must have the same subject name and alternate subject name as the requested certificate. To circumvent this requirement, set the value of the DisableRenewalSubjectNameMatch registry entry under the following subkey to 1.

HKEY_LOCAL_MACHINE\Software\Microsoft\Cryptography\MSCEP\DisableRenewalSubjectNameMatch

Note You may have to create this registry entry by using REG_DWORD type if the registry entry does not exist.

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 SCEP, visit the following Internet Drafts Web site (IETF) Web site:

http://www.ietf.org/proceedings/69/slides/pkix-3.pdf

Note This document will expire on July 25, 2009. For information after this date, search for "SCEP" on the home page of the Web site.

Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.


For more information, 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