UNIX Authentication on the Client Side
When a caller creates a new RPC client handle, the authentication handle of the appropriate transport is set to the default by the authnone_create subroutine.
The default for an RPC authentication handle is NULL. After creating the client handle, the client can select UNIX authentication with the authunix_create routine. This routine creates an authentication handle with operating system permissions and causes each remote procedure call associated with the handle to carry UNIX credentials.
Note: Authentication information can be destroyed with the auth_destroy subroutine. Authentication information should be destroyed if one
is attempting to conserve memory.
For more information, see the Using UNIX Authentication Example.