Adding server support for the GetAttributes operation

This change adds server support for the GetAttributes operation.
The user can specify an object ID and an attribute list to get
the values of the attributes listed from the specified object.
The user can also omit either argument; the server will default
to using the ID placeholder and all viable attributes respectively.
Only a subset of the standard attributes are supported right now.
New tests have been added to cover the new feature.

Closes #185
Closes #211
Closes #218

kmip/core/messages/payloads/get_attributes.py

@@ -31,19 +31,19 @@ class GetAttributesRequestPayload(primitives.Struct):
     duplicates in the attribute name list.
 
     Attributes:
-        uid: The unique ID of the managed object with which the retrieved
-            attributes should be associated.
+        unique_identifier: The unique ID of the managed object with which the
+            retrieved attributes should be associated.
         attribute_names: A list of strings identifying the names of the
             attributes associated with the managed object.
     """
-    def __init__(self, uid=None, attribute_names=None):
+    def __init__(self, unique_identifier=None, attribute_names=None):
         """
         Construct a GetAttributes request payload.
 
         Args:
-            uid (string): The ID of the managed object with which the
-                retrieved attributes should be associated. Optional, defaults
-                to None.
+            unique_identifier (string): The ID of the managed object with
+                which the retrieved attributes should be associated. Optional,
+                defaults to None.
             attribute_names: A list of strings identifying the names of the
                 attributes associated with the managed object. Optional,
                 defaults to None.
@@ -51,30 +51,30 @@ class GetAttributesRequestPayload(primitives.Struct):
         super(GetAttributesRequestPayload, self).__init__(
             enums.Tags.REQUEST_PAYLOAD)
 
-        self._uid = None
+        self._unique_identifier = None
         self._attribute_names = list()
 
-        self.uid = uid
+        self.unique_identifier = unique_identifier
         self.attribute_names = attribute_names
 
     @property
-    def uid(self):
-        if self._uid:
-            return self._uid.value
+    def unique_identifier(self):
+        if self._unique_identifier:
+            return self._unique_identifier.value
         else:
-            return self._uid
+            return self._unique_identifier
 
-    @uid.setter
-    def uid(self, value):
+    @unique_identifier.setter
+    def unique_identifier(self, value):
         if value is None:
-            self._uid = None
+            self._unique_identifier = None
         elif isinstance(value, six.string_types):
-            self._uid = primitives.TextString(
+            self._unique_identifier = primitives.TextString(
                 value=value,
                 tag=enums.Tags.UNIQUE_IDENTIFIER
             )
         else:
-            raise TypeError("uid must be a string")
+            raise TypeError("unique identifier must be a string")
 
     @property
     def attribute_names(self):
@@ -125,10 +125,12 @@ class GetAttributesRequestPayload(primitives.Struct):
         tstream = utils.BytearrayStream(istream.read(self.length))
 
         if self.is_tag_next(enums.Tags.UNIQUE_IDENTIFIER, tstream):
-            self._uid = primitives.TextString(tag=enums.Tags.UNIQUE_IDENTIFIER)
-            self._uid.read(tstream)
+            self._unique_identifier = primitives.TextString(
+                tag=enums.Tags.UNIQUE_IDENTIFIER
+            )
+            self._unique_identifier.read(tstream)
         else:
-            self._uid = None
+            self._unique_identifier = None
 
         names = list()
         while self.is_tag_next(enums.Tags.ATTRIBUTE_NAME, tstream):
@@ -150,8 +152,8 @@ class GetAttributesRequestPayload(primitives.Struct):
         """
         tstream = utils.BytearrayStream()
 
-        if self._uid:
-            self._uid.write(tstream)
+        if self._unique_identifier:
+            self._unique_identifier.write(tstream)
 
         for attribute_name in self._attribute_names:
             attribute_name.write(tstream)
@@ -161,22 +163,24 @@ class GetAttributesRequestPayload(primitives.Struct):
         ostream.write(tstream.buffer)
 
     def __repr__(self):
-        uid = "uid={0}".format(self.uid)
+        unique_identifier = "unique_identifier={0}".format(
+            self.unique_identifier
+        )
         attribute_names = "attribute_names={0}".format(self.attribute_names)
         return "GetAttributesRequestPayload({0}, {1})".format(
-            uid,
+            unique_identifier,
             attribute_names
         )
 
     def __str__(self):
         return str({
-            'uid': self.uid,
+            'unique_identifier': self.unique_identifier,
             'attribute_names': self.attribute_names
         })
 
     def __eq__(self, other):
         if isinstance(other, GetAttributesRequestPayload):
-            if self.uid == other.uid:
+            if self.unique_identifier == other.unique_identifier:
                 if set(self.attribute_names) == set(other.attribute_names):
                     return True
                 else:
@@ -202,49 +206,49 @@ class GetAttributesResponsePayload(primitives.Struct):
     associated with the aforementioned managed object.
 
     Attributes:
-        uid: The unique ID of the managed object with which the retrieved
-            attributes should be associated.
+        unique_identifier: The unique ID of the managed object with which
+            the retrieved attributes should be associated.
         attributes: The list of attributes associated with managed object
-            identified by the uid above.
+            identified by the unique identifier above.
     """
-    def __init__(self, uid=None, attributes=None):
+    def __init__(self, unique_identifier=None, attributes=None):
         """
         Construct a GetAttributes response payload.
 
         Args:
-            uid (string): The ID of the managed object with which the
-                retrieved attributes should be associated. Optional, defaults
-                to None.
+            unique_identifier (string): The ID of the managed object with
+                which the retrieved attributes should be associated. Optional,
+                defaults to None.
             attributes (list): A list of attribute structures associated with
                 the managed object. Optional, defaults to None.
         """
         super(GetAttributesResponsePayload, self).__init__(
             enums.Tags.RESPONSE_PAYLOAD)
 
-        self._uid = None
+        self._unique_identifier = None
         self._attributes = list()
 
-        self.uid = uid
+        self.unique_identifier = unique_identifier
         self.attributes = attributes
 
     @property
-    def uid(self):
-        if self._uid:
-            return self._uid.value
+    def unique_identifier(self):
+        if self._unique_identifier:
+            return self._unique_identifier.value
         else:
-            return self._uid
+            return self._unique_identifier
 
-    @uid.setter
-    def uid(self, value):
+    @unique_identifier.setter
+    def unique_identifier(self, value):
         if value is None:
-            self._uid = None
+            self._unique_identifier = None
         elif isinstance(value, six.string_types):
-            self._uid = primitives.TextString(
+            self._unique_identifier = primitives.TextString(
                 value=value,
                 tag=enums.Tags.UNIQUE_IDENTIFIER
             )
         else:
-            raise TypeError("uid must be a string")
+            raise TypeError("unique identifier must be a string")
 
     @property
     def attributes(self):
@@ -279,12 +283,14 @@ class GetAttributesResponsePayload(primitives.Struct):
         tstream = utils.BytearrayStream(istream.read(self.length))
 
         if self.is_tag_next(enums.Tags.UNIQUE_IDENTIFIER, tstream):
-            uid = primitives.TextString(tag=enums.Tags.UNIQUE_IDENTIFIER)
-            uid.read(tstream)
-            self.uid = uid.value
+            unique_identifier = primitives.TextString(
+                tag=enums.Tags.UNIQUE_IDENTIFIER
+            )
+            unique_identifier.read(tstream)
+            self.unique_identifier = unique_identifier.value
         else:
             raise exceptions.InvalidKmipEncoding(
-                "expected GetAttributes response uid not found"
+                "expected GetAttributes response unique identifier not found"
             )
 
         self._attributes = list()
@@ -306,11 +312,11 @@ class GetAttributesResponsePayload(primitives.Struct):
         """
         tstream = utils.BytearrayStream()
 
-        if self._uid:
-            self._uid.write(tstream)
+        if self._unique_identifier:
+            self._unique_identifier.write(tstream)
         else:
             raise exceptions.InvalidField(
-                "The GetAttributes response uid is required."
+                "The GetAttributes response unique identifier is required."
             )
 
         for attribute in self._attributes:
@@ -321,16 +327,24 @@ class GetAttributesResponsePayload(primitives.Struct):
         ostream.write(tstream.buffer)
 
     def __repr__(self):
-        uid = "uid={0}".format(self.uid)
+        unique_identifier = "unique_identifier={0}".format(
+            self.unique_identifier
+        )
         names = "attributes={0}".format(self.attributes)
-        return "GetAttributesResponsePayload({0}, {1})".format(uid, names)
+        return "GetAttributesResponsePayload({0}, {1})".format(
+            unique_identifier,
+            names
+        )
 
     def __str__(self):
-        return str({'uid': self.uid, 'attributes': self.attributes})
+        return str({
+            'unique_identifier': self.unique_identifier,
+            'attributes': self.attributes
+        })
 
     def __eq__(self, other):
         if isinstance(other, GetAttributesResponsePayload):
-            if self.uid != other.uid:
+            if self.unique_identifier != other.unique_identifier:
                 return False
             if len(self._attributes) != len(other._attributes):
                 return False