Certificate Enrollment and Renewal Methods
Windows 2000 Certificate Services supports the following certificate enrollment and renewal methods:
Manual certificate requests that use the Certificate Request wizard (only for Windows 2000 users and computers).
Automatic certificate requests, which use the Automatic Certificate Request Setup wizard (only for Windows 2000 computer certificates).
Manual certificate requests that use the Web Enrollment Support pages (for Web browser users).
Smart card enrollment, which uses the Smart Card Enrollment Station available in the Web Enrollment Support pages.
Custom certificate enrollment and renewal applications.
The enrollment methods and types of certificates that are supported by third-party certificate services depend on the features and functions of each third-party product. For more information, contact the vendor for the certificate service.
Manual Certificate Requests for Windows 2000–based Clients
You can request or renew certificates for Windows 2000 users and computers by using the Certificate Request wizard that is available in the Certificates console. The Certificate Request wizard does not function unless an enterprise CA is online to process and issue certificate requests. The ACLs for the certificate templates determine which user accounts or computer accounts can enroll for the various types of certificates.
You can also use the Certificate Renewal wizard that is available in the Certificates console to renew certificates either before or after they expire. The Certificate Renewal wizard does not function unless an enterprise CA is online to process and issue certificate requests. You have the option of renewing certificates with the same private key and public key set. You must not renew certificates with the same private and public key sets if the maximum safe key lifetime would be exceeded.
Automatic Computer Certificate Enrollment and Renewal
You can use the Automatic Certificate Request Setup wizard (available from the Public Key section of the Group Policy console) to configure autoenrollment for computer certificates. Autoenrollment is not available for user certificates and does not function unless an enterprise CA is online to process certificate requests. You can configure autoenrollment for Computer, Domain Controller, and IPSec certificates.
When autoenrollment is configured, the specified certificate types are issued automatically to all computers that are within the scope of the Public Key Group Policy and to all computers that have Enroll permissions for that certificate type. Autoenrollment certificates are issued the next time the computer logs on to the network.
For example, if you configure autoenrollment for Computer certificates, the certificates are issued to all computers in the Domain Computers security group that are within the scope of the Public Key Group Policy. By default, all Windows 2000 computers are members of the Domain Computers security group, except for domain controllers, Routing and Remote Access servers, and Internet Authentication Services (IAS) servers. You can control which computers receive the Computer certificates by modifying the ACLs for the Computer certificate templates, for example, to grant Enroll permissions to a special security group composed of computers that you designate. Computers within the scope of the Public Key Group Policy that are members of the special security group are then issued Computer certificates the next time they log on to the network.
In addition, you also can use organizational units (OUs) and Public Key Group Policy for those OUs to restrict autoenrollment to certain groups of computers. For example, you might create an IPSec Authentication OU that contains the Windows 2000 clients that you designate for IPSec authentication with certificates. To limit the scope of autoenrollment for IPSec certificates, configure Public Key Group Policy and autoenrollment for the IPSec Authentication OU.
When autoenrollment is configured, the Computer certificates that are issued by autoenrollment also are automatically renewed from the enterprise issuing CA. You can also renew Computer certificates manually with the Certificate Renewal wizard or through the Certificate Services Web Enrollment Support pages.
Web Enrollment Support Pages
The Windows 2000 Certificate Services Web Enrollment Support pages are composed of Active Server Pages and ActiveX® controls that provide a Web-based user interface to a CA. By default, the Web Enrollment Support pages are automatically installed on the computer where the CA is installed, but you also have the option of installing the Web Enrollment Support pages on another Windows 2000 Server computer.
You can use the Web Enrollment Support pages to perform the following tasks:
Request and obtain a basic user certificate.
Request and obtain other types of certificates by using advanced options.
Request a certificate by using a certificate request file.
Renew certificates by using a certificate renewal request file.
Save a certificate request to a file.
Save the issued certificate to a file.
Check on pending certificate requests.
Retrieve the CA's certificate.
Retrieve the latest certificate revocation list from the CA.
Enroll for smart card certificates on behalf of other users (for use by trusted administrators).
The Web Enrollment Support pages that are installed for stand-alone CAs are similar to the pages that are installed for enterprise CAs, but they differ in the respect that stand-alone CAs do not use certificate templates. For stand-alone CAs, all information about the certificate, including information about the requestor, must be specified in the certificate request. The Web Enrollment Support pages for stand-alone CAs support a number of types of certificates that have much of the same functionality as certificate types that are based on templates. You can deploy stand-alone CAs and Web Enrollment Support pages to issue most of the types of certificates that enterprise CAs can issue. However, certificates for logging on by using smart cards logon and for autoenrollment require an enterprise CA to issue and renew the certificates.
The Web Enrollment Support pages work with Microsoft® Internet Explorer 4 and Microsoft® Internet Explorer 5. Use of the Microsoft Enhanced Cryptographic Provider requires Internet Explorer browsers with nonexportable cryptography. Internet Explorer browsers with exportable cryptography work only with the Microsoft Base Cryptographic Provider.
Netscape Navigator version 4. x and Netscape Communicator version 4. x work with most of the Web Enrollment Support pages. Netscape browsers do not work with the Advanced Certificate Requests form and the Smart Card Enrollment Station page because these pages use ActiveX controls. In addition, Netscape browsers use their own cryptographic security modules rather than CSPs and, therefore, might not support all of the features that are available for the Microsoft CSPs.
Custom Enrollment and Renewal Applications
The standard enrollment and renewal methods that are available in Windows 2000 can meet a wide range of needs. However, if you have special needs, you can develop custom certificate enrollment and renewal applications. The Windows 2000 Certificate Services Entry module supports industry-standard certificate requests by using remote procedure call (RPC) requests or HTTP requests. You can develop custom applications that make certificate requests to Certificate Services CAs. For more information about developing custom applications with Windows 2000 Certificate Services, see the Microsoft Platform SDK link on the Web Resources page at http://windows.microsoft.com/windows2000/reskit/webresources .