Adding GetAttributes support to the PyKMIP clients

This change adds support for the GetAttributes operation to the
PyKMIP clients. Demo scripts showing how to use the new operation
will be included in a future update. Client test cases have been
added and updated to reflect the new operation.

kmip/services/kmip_client.py

@@ -19,6 +19,7 @@ from kmip.services.results import CreateKeyPairResult
 from kmip.services.results import DestroyResult
 from kmip.services.results import DiscoverVersionsResult
 from kmip.services.results import GetResult
+from kmip.services.results import GetAttributesResult
 from kmip.services.results import GetAttributeListResult
 from kmip.services.results import LocateResult
 from kmip.services.results import OperationResult
@@ -52,6 +53,7 @@ from kmip.core.messages.payloads import create_key_pair
 from kmip.core.messages.payloads import destroy
 from kmip.core.messages.payloads import discover_versions
 from kmip.core.messages.payloads import get
+from kmip.core.messages.payloads import get_attributes
 from kmip.core.messages.payloads import get_attribute_list
 from kmip.core.messages.payloads import locate
 from kmip.core.messages.payloads import query
@@ -302,6 +304,32 @@ class KMIPProxy(KMIP):
             key_wrapping_specification=key_wrapping_specification,
             credential=credential)
 
+    def get_attributes(self, uuid=None, attribute_names=None):
+        """
+        Send a GetAttributes request to the server.
+
+        Args:
+            uuid (string): The ID of the managed object with which the
+                retrieved attributes should be associated. Optional, defaults
+                to None.
+            attribute_names (list): A list of AttributeName values indicating
+                what object attributes the client wants from the server.
+                Optional, defaults to None.
+
+        Returns:
+            result (GetAttributesResult): A structure containing the results
+                of the operation.
+        """
+        batch_item = self._build_get_attributes_batch_item(
+            uuid,
+            attribute_names
+        )
+
+        request = self._build_request_message(None, [batch_item])
+        response = self._send_and_receive_message(request)
+        results = self._process_batch_items(response)
+        return results[0]
+
     def get_attribute_list(self, uid=None):
         """
         Send a GetAttributeList request to the server.
@@ -475,6 +503,22 @@ class KMIPProxy(KMIP):
             operation=operation, request_payload=payload)
         return batch_item
 
+    def _build_get_attributes_batch_item(
+            self,
+            uuid=None,
+            attribute_names=None
+    ):
+        operation = Operation(OperationEnum.GET_ATTRIBUTES)
+        payload = get_attributes.GetAttributesRequestPayload(
+            uuid,
+            attribute_names
+        )
+        batch_item = messages.RequestBatchItem(
+            operation=operation,
+            request_payload=payload
+        )
+        return batch_item
+
     def _build_get_attribute_list_batch_item(self, uid=None):
         operation = Operation(OperationEnum.GET_ATTRIBUTE_LIST)
         payload = get_attribute_list.GetAttributeListRequestPayload(uid)
@@ -508,6 +552,8 @@ class KMIPProxy(KMIP):
             return self._process_response_error
         elif operation == OperationEnum.CREATE_KEY_PAIR:
             return self._process_create_key_pair_batch_item
+        elif operation == OperationEnum.GET_ATTRIBUTES:
+            return self._process_get_attributes_batch_item
         elif operation == OperationEnum.GET_ATTRIBUTE_LIST:
             return self._process_get_attribute_list_batch_item
         elif operation == OperationEnum.REKEY_KEY_PAIR:
@@ -520,6 +566,24 @@ class KMIPProxy(KMIP):
             raise ValueError("no processor for operation: {0}".format(
                 operation))
 
+    def _process_get_attributes_batch_item(self, batch_item):
+        payload = batch_item.response_payload
+
+        uuid = None
+        attributes = None
+
+        if payload:
+            uuid = payload.unique_identifier
+            attributes = payload.attributes
+
+        return GetAttributesResult(
+            batch_item.result_status,
+            batch_item.result_reason,
+            batch_item.result_message,
+            uuid,
+            attributes
+        )
+
     def _process_get_attribute_list_batch_item(self, batch_item):
         payload = batch_item.response_payload