Adds support for RequestedAuthnContext SSO kwarg

Author: pandafy

djangosaml2/views.py

@@ -250,14 +250,21 @@ def get(self, request, *args, **kwargs):
 
         # SSO options
         sign_requests = getattr(conf, '_sp_authn_requests_signed', False)
-        if sign_requests:
+        if  sign_requests:
             sso_kwargs["sigalg"] = getattr(conf, '_sp_signing_algorithm',
                                            saml2.xmldsig.SIG_RSA_SHA256
             )
             sso_kwargs["digest_alg"] = getattr(conf,
                                                '_sp_digest_algorithm',
                                                saml2.xmldsig.DIGEST_SHA256
             )
+        csc = getattr(settings, 'SAML_CONFIG', {}).get(
+                'service',
+                {}
+            ).get('sp', None)
+        if csc:
+            sso_kwargs['requested_authn_context'] = csc.get('requested_authn_context', None)
+
         # pysaml needs a string otherwise: "cannot serialize True (type bool)"
         if getattr(conf, '_sp_force_authn', False):
             sso_kwargs['force_authn'] = "true"