When implementing the authentication protocol, a configuration UI may also be provided. The configuration UI may be implemented in the same DLL as the authentication protocol, or in a separate DLL. Also, the DLL that implements the configuration UI may support more than one authentication protocol. The path to the DLL for the configuration UI is stored in the RAS_EAP_VALUENAME_CONFIGUIregistry value, under the key for the authentication protocol. For more information about creating this registry value, see EAP Installation.

The DLL for the configuration UI should export entry points for the following functions.

• RasEapInvokeConfigUI
  
  
• RasEapFreeMemory
  
  

When the user creates an entry for a particular RAS server in the Dial-Up Networking UI, the user is able to select the authentication protocol that RAS should use with that entry. If the authentication protocol is configurable, the Dial-Up Networking UI calls RasEapInvokeConfigUIto invoke the configuration UI. The Dial-Up Networking UI stores the configuration information returned by RasEapInvokeConfigUIin the entry.

The configuration information stored in the entry should be generic to all users on the client computer. Information specific to a particular user or users should not be stored in the entry. The authentication protocol should obtain user-specific information by using the identity functions or interactive UI. The authentication protocol can store this information in the registry by passing it to RAS in the pEapOutputparameter of RasEapMakeMessage.

The configuration information should also not be specific to the current desktop computer; it should be portable from computer to computer.

When RAS calls the RasEapBeginfunction for the authentication protocol, it passes a PPP_EAP_INPUTstructure that contains a pointer to the configuration information. After RasEapBeginreturns, RAS calls RasEapFreeMemoryto free the memory occupied by the configuration information. Therefore, the authentication protocol should copy the configuration information into a private memory buffer during the call to RasEapBegin.

A value under the registry key for the authentication protocol may be added that specifies default configuration information for the protocol. A value can also be added that specifies whether the user is required to enter configuration information when they create an entry. For more information, see EAP Registry Settings.

See Also