Shout out for simplesamlphp, which confusingly comes as two projects: simplesamlephp/simplesamlphp (a full web application which can implement SP or IdP), and s

Shout out for simplesamlphp, which confusingly comes as two projects: simplesamlephp/simplesamlphp (a full web application which can implement SP or IdP), and simplesamlephp/saml2, a library of components for parsing and building SAML messages. I just used the library, which meant building a lot of the logic around what to actually do with the messages, but once you've learned the protocol inside out, it's easy to use ( as ever, the code IS the documentation!) but has a few limitations - because it was built to support a specific application. One very handy feature (relating to others' commenting about SPs that can't parse metadata) is the metadata parsing.