This function retrieves a list of the authentication services registered when the process called CoInitializeSecurity.
HRESULT CoQueryAuthenticationServices( DWORD* pcAuthSvc, SOLE_AUTHENTICATION_SERVICE** asAuthSvc );
[out] Pointer to return the number of entries returned in the rgAuthSvc array. May not be NULL.
CoQueryAuthenticationServices retrieves a list of the authentication services currently registered.
If the process calls CoInitializeSecurity, these are the services registered through that call.
If the application does not call it, CoInitializeSecurity is called automatically by COM, registering the default security package, the first time an interface is marshaled or unmarshaled.
This function returns only the authentication services registered with CoInitializeSecurity. It does not return all of the authentication services installed on the machine. CoQueryAuthenticationServices is primarily useful for custom marshalers, to determine which principal names an application can use.
Different authentication services help support different levels of security. For example, NTLMSSP does not support delegation or mutual authentication while Kerberos does.
The application is responsible only for registering authentication services that provide the features the application needs. This function provides a way to find out which services have been registered with CoInitializeSecurity.
To determine whether the platform supports this function, see Determining Supported COM APIs.