Google::SAML::Request will parse (and, for the sake of completeness,
create) SAML requests as used by Google. Please note that
Google::SAML::Request is by no means a full implementation of the SAML
2.0 standard. But if you want to talk to Google to authenticate users,
you should be fine.

WWW: http://search.cpan.org/dist/Google-SAML-Request/