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User Authentication Modules

UAM Architecture

The client UAM and server UAM use the AppleTalk Filing Protocol (AFP) to communicate with each other. Figure 1-1 illustrates the flow of communication between the client UAM and the server UAM.

Figure 1-1 UAM architecture

For an AFP client logging on to an AppleShare file server, the flow of communication between the client and server UAMs occurs in the following sequence:

The AFP client calls AFPServerInfo in order to determine which UAMs the AFP server supports.
If the server supports more than one UAM, the AFP client displays a list of authentication methods for the user to choose from.
If the user chooses an authentication method that requires a UAM, the AFP client loads and starts the selected client UAM.
Using a callback mechanism to the AFP client, the client UAM opens a session with the AFP server and passes a UAM request that identifies the UAM.
The AFP server passes the UAM request to the AppleShare Registry.
The AppleShare Registry calls the server UAM and passes the UAM request as a parameter.
The server UAM calls the Registry to obtain the user's password and authenticates the user.
The server UAM passes the authentication result to the Registry, which returns the result to the AFP server.
The AFP server returns the authentication result to the AFP client.
The client and server UAM may continue to exchange messages in this way until the server UAM is satisfied

For more information about server UAMs, see Server User Authentication Modules For more information about client UAMs, see Client User Authentication Modules