I've been trying to integrate MediaWiki and SimpleSAMLPHP with both extensions available (MultiAuthPlugin and SAMLAuth). However, I get the same error of 'State information lost' after trying to login via the Wiki in both cases.
I've tried to change the store.type to memcache and sql, but I still get the 'State information lost' error.
Was anyone out there able to integrate MediaWiki and SimpleSAMLPHP?
Changing store.type should help. Can you confirm that login does work when you use the test authentication source feature in SimpleSamlPhp? If that doesn't work, your problem is not with a MediaWiki extension.
I wrote yet another SAML extension for MediaWiki; the ones already there did not solve my problem. I am not saying that you will succeed with that one, but I can confirm that it works for me. You can find it at https://github.com/yorn/mwSimpleSamlAuth/.