OSF DCE Application Development Guide--Introduction and Style Guide

Introduction to DCE Application Programming

the appropriate action.

The application may choose to implement more than one type of ACL (reﬂecting the

different kinds of objects and resources to be protected), thus resulting in several ACL

type managers.

Although it is up to the application to implement its own ACL storage, testing algorithms

and manager types, there are certain DCE-wide design conventions that should be kept in

mind and departed from only for good reason. Among these are the following:

• Standard DCE ACL entry types: the kinds of entry that can occur in an ACL (for

example, user, group, and so on).

• Standard privileges: the kinds of access that a principal can have to a protected

object (for example, read, write, and so on).

• Standard inheritance rules: these rules govern the default characteristics of ACLs

created for newly created objects.

• Standard access algorithm: the order in which a client’s credentials are matched

against the various possible entry types.

Information about these topics for application developers designing their own ACL

model can be found in the , in which all the DCE authorization conventions are described

in detail.

1.7.4 Servicing the RPC Request

If the client’s request is determined to be properly authorized, then the requested

operation can proceed.

Note that this step and steps D3 and D4 (as discussed in Section 1.2) are somewhat

intertwined. Something like the following could occur:

1. The server wakes up in some routine deﬁned in its manager code. For example, if

the client executed the call my_rpc_op( ), then the server will wake up in the

routine that implements this remote call.

2. Execution of the my_rpc_op( ) routine requires the insert privilege for the

application’s database my_database.Somy_rpc_op() begins by checking the

client’s relevant privilege attribute by making an internal call to the application’s

ACL manager.

3. If the client is found to have the requisite privilege, my_rpc_op() proceeds.

The remote procedure executed in this step is written by the application developer.

1.7.5 Returning the Results and Resuming Listening

At the completion of the operation, the RPC thread that was automatically spawned to

execute it is terminated by the RPC runtime. As far as the server is concerned, it is still

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