Added support for domainCredentials for authenticating to EventGrid d…

…omains. (#160)

msrest/authentication.py

@@ -250,4 +250,22 @@ def __init__(self, topic_key):
                 self._topic_key_header: topic_key,
             }
         )
-
+
+class DomainCredentials(ApiKeyCredentials):
+    """Event Grid domain authentication.
+
+    :param str domain_key: The Event Grid domain key
+    """
+
+    _domain_key_header = 'aeg-sas-key'
+
+    def __init__(self, domain_key):
+        # type: (str) -> None
+        if not domain_key:
+            raise ValueError("Domain key cannot be None")
+        super(DomainCredentials, self).__init__(
+            in_headers={
+                self._domain_key_header: domain_key,
+            }
+        )
+

tests/test_auth.py

@@ -43,7 +43,8 @@
     OAuthTokenAuthentication,
     ApiKeyCredentials,
     CognitiveServicesCredentials,
-    TopicCredentials
+    TopicCredentials,
+    DomainCredentials
 )
 
 from requests import Request, PreparedRequest
@@ -133,6 +134,12 @@ def test_eventgrid_auth(self):
         prep_req = session.prepare_request(self.request)
         self.assertDictContainsSubset({'aeg-sas-key' : 'mytopickey'}, prep_req.headers)
 
+    def test_eventgrid_domain_auth(self):
+        auth = DomainCredentials("mydomainkey")
+        session = auth.signed_session()
+        prep_req = session.prepare_request(self.request)
+        self.assertDictContainsSubset({'aeg-sas-key' : 'mydomainkey'}, prep_req.headers)
+
 if __name__ == '__main__':
     unittest.main()