How do I configure SSO by SAML?
This is a very old question but worth solving it.

By:


  I also try to did this by simplesaml "Test configured authentication sources", but I got the same result.


It seems that @misha-from-lviv didn't configure simpleSAMLphp correctly. 


  $metadata['name'] = array( 'SingleSignOnService' => 'url_login', 'SingleLogoutService' => 'url_logout', 'certFingerprint' => 'key', );


The metadata is incomplete

The process to configure the simplesamlphp is way more complex that the 5 steps described there. This Vagrant box setup simplesAMLphp (as an SP and IdP) and Drupal 7 for you and let's you start testing SAML right away. 

Disclaimer: I created the box