Implement SAML2 Artifact Resolution Profile and Protocol.
References: http://docs.oasis-open.org/security/saml/v2.0/saml-profiles-2.0-os.pdf http://docs.oasis-open.org/security/saml/v2.0/saml-core-2.0-os.pdf http://docs.oasis-open.org/security/saml/v2.0/saml-bindings-2.0-os.pdf