In Windows 2000, public-key objects such as certificates, CRLs, and CTLs are stored in certificate stores for use by users, services, and computers. The Windows 2000 certificate stores include physical stores and logical stores.
The physical certificate stores are where public-key objects such as certificates, CRLs, and CTLs are physically stored either locally in the system registry of the computer or remotely in Active Directory. Many of the public-key objects in the physical stores are shared among users, services, and computers through the use of logical certificate stores.
Logical certificate stores group certificates together in logical, functional categories for users, computers, and services. Logical certificate stores contain pointers to the physical certificate stores. Use the Certificates console (an MMC snap-in) to manage certificates in certificate stores. Changes to the logical certificate stores are made to the appropriate physical stores that are located in either the system registry or Active Directory. Because you use only the logical certificate store for a user, service, or computer, you neither have to keep track of where the certificates are actually stored, nor do you have to edit the system registry to manage the certificate stores.
The use of logical certificate stores eliminates the necessity of storing duplicates of common public key objects, such as trusted root certificates, CTLs, and CRLs for users, computers, and services. Users and services share many public key policy objects in common with the local computer. The common public-key objects are stored in sections of the registry of the local computer. However, some certificates, CTLs, or CRLs, are issued for use only by an individual service, user, or local computer. Therefore, users, computers, and services also have individual stores that provide a place to store certificates, CTLs, or CRLs that are not shared in common. For example, a user can request and obtain a certificate or a CRL, which appears in the individual's logical store and is physically stored in the user's unique certificate store in the registry. Such individual user certificates and CRLs are not shared with local computers or with services.
In addition, some public-key objects, such as trusted root certificates and CTLs, can be distributed through Public Key Group Policy. Public key objects that are distributed through Group Policy are stored in special areas of the system registry and appear in the logical stores for users, computers, and services. When you use Group Policy, separate CTLs can be created for users and computers. The CTLs for users are not shared with services or the computer. However, the CTLs for computers are shared with users and services.
The logical certificate stores include the following categories for users, computers, and services:
Personal . Contains individual certificates for the user, service, or computer. For example, when an enterprise CA issues you a User certificate, the certificate is installed in the Personal store for your user account.
Trusted Root Certification Authorities . Contains certificates for root CAs. Certificates with a certification path to a root CA certificate are trusted by the computer for all valid purposes of the certificate.
Enterprise Trust . Contains CTLs. Certificates with a certification path to a CTL are trusted by the computer for purposes specified in the CTL.
Intermediate Certification Authorities . Contains certificates for CAs that are not trusted root certificates (for example, certificates of subordinate CAs), but that are required to validate certification paths. This store also contains CRLs for use by the user, service, or computer.
Active Directory User Object . Contains certificates that are published in Active Directory for the user. This store appears in the Certificates console for users only, not for computers or services.
Request . Contains pending or rejected certificate requests. This store appears only in the Certificates console after a certificate request has been made for the user, computer, or service.
SPC . Contains certificates for software publishers that are trusted by the computer. Software that has been digitally signed by publishers with certificates in this store is downloaded without prompting the user. By default, this store is empty. When Microsoft® Internet Explorer downloads software that has been signed by a software publisher for the first time, users are prompted to choose whether they want to trust all software that is signed by this publisher. If a user chooses to trust all software signed by the publisher, the publisher's software publisher certificate (SPC) is added to the SPC store. This store appears in the Certificates console for the local computer only, not for users or services.