CAS: User's Guide

>Overview
Generating CAS credentials (cas-proxy-init)
Using CAS credentials (cas-wrap)
CAS Service Data
Writing CAS clients
Performance Measurements

Overview

A typical CAS user will use only two CAS-specific commands: cas-proxy-init , which contacts a CAS server and obtains a credential, and cas-wrap , which wraps a grid-enabled client program, causing that client program to use the credential that was previously generated using cas-proxy-init .

For example, a day in the life of a CAS user might look something like this:

1. In the morning, the user runs:

 % grid-proxy-init % cas-proxy-init -t tag  

The first line generates a Globus proxy credential; the second uses that credential to contact the CAS server and retrieve a CAS credential that includes all the permissions granted to the user by the community. The tag argument can be any string and is used to assign a name for that credential ( cas-wrap uses this name to locate the credential).

2. Several times throughout the day, the user runs commands that look like:

% cas-wrap -t tag grid-enabled-program args  

This runs the program grid-enabled-program with arguments args , using the CAS credential that had been created by and assigned the name tag . For example:

% cas-wrap -t my-community gsincftp myhost.edu 

looks for a CAS credential with the name "my-community" (e.g., a credential that had been created using "cas-proxy-init -t my-community") and then runs the command "gsincftp myhost.edu", causing the gsincftp program to use that CAS credential to authenticate.

3. At the end of the day, the user runs:

% cas-wrap -t tag  grid-proxy-destroy 

to destroy the CAS credential, and:

% grid-proxy-destroy 

to destroy the Globus proxy credential.Or the user might simply let both credentials expire.