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CAS supports the CAS1 and CAS2 protocols allowing for simple single sign on, as well as proxy authentication. Proxy authentication allows an application, such as a portal, to access additional resources or applications (such as grades) on your behalf without your password and a secure and controlled manner. The addition of SAML 1.1 allows for the exchange of attributes between the CAS server and CAS clients. Partial SAML2 support allows for integration with Google Apps for Education, allowing universities that have deployed CAS to take advantage of institutional GMail.
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