Writing and Installing a Security Support Provider

The design of SSPI enables additional SSPs to be written and added to the system. An SSP specific to a security model can be developed with relative ease or great complexity, depending on the level of integration with the operating system. A client SSP that allows connections to a new type of server could be developed very quickly, whereas a full SSP that provides local impersonation would require more effort.

SSPs are installed by updating a REG_SZ value in the registry, located as follows:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\    SecurityProviders = Provider1.dll, Provider2.dll,

            Data type


A single DLL can contain multiple SSPs.

Restrictions around Registering and Installing a Security Package