Comparing IIS 5.0 Certificate Mapping and Native Windows 2000 Active Directory Certificate Mapping

Internet Information Services (IIS) version 5.0 allows administrators to "map" a client authentication certificate to a Windows 2000 user account. There are two possible ways to do this:

• IIS Certificate Mapping
• Native Windows 2000 Active Directory Mapping

IIS Certificate Mapping

IIS Certificate Mapping is the same mapping that is found in IIS 4.0 and is available for backward compatibility only. It has the following attributes:

• You can set new rules on each virtual server.
• It handles one-to-one mapping (a certificate blob equals one user account).
• It handles many-to-one mapping (a wildcard rule maps to a user account).
• It does not scale as well as Active Directory mapping.
• The administrator must enter the username and password of the account logging on.
• By default, the account used must have the log on locally privilege.
• The request may be delegated to another computer if the account is configured for delegation.

Native Windows 2000 Active Directory Mapping

Active Directory Mapping is a new kind of client certificate mapping available only in Windows 2000. It has the following attributes:

• It scales very well.
• The administrator does not need to know the username or password.
• The user account may not be delegated to another computer even if the account is configured for delegation.

Note: The IIS certificate mapping that is included in IIS 5.0 is for backward compatibility only. This feature may be removed in favor of the Active Directory mapping in a future release of the Web services.

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base: