Add to_dict and from_dict conversions to managed objects

This patch centralizes the managed objects conversion in order to be
used across multiple key_manager backends.

Change-Id: Ia2e15d46eb2e504b815a7f51173aecaf82978402
Signed-off-by: Moisés Guimarães de Medeiros <moguimar@redhat.com>

castellan/common/exception.py

@@ -64,6 +64,14 @@ class ManagedObjectNotFoundError(CastellanException):
     message = _("Key not found, uuid: %(uuid)s")
 
 
+class InvalidManagedObjectDictError(CastellanException):
+    message = _("Dict has no field '%(field)s'.")
+
+
+class UnknownManagedObjectTypeError(CastellanException):
+    message = _("Type not found, type: %(type)s")
+
+
 class AuthTypeInvalidError(CastellanException):
     message = _("Invalid auth_type was specified, auth_type: %(type)s")
 

castellan/common/objects/__init__.py

@@ -0,0 +1,49 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from castellan.common import exception
+from castellan.common.objects import opaque_data
+from castellan.common.objects import passphrase
+from castellan.common.objects import private_key
+from castellan.common.objects import public_key
+from castellan.common.objects import symmetric_key
+from castellan.common.objects import x_509
+
+_managed_objects_by_type = {
+    cls.managed_type(): cls for cls in [
+        opaque_data.OpaqueData,
+        passphrase.Passphrase,
+        private_key.PrivateKey,
+        public_key.PublicKey,
+        symmetric_key.SymmetricKey,
+        x_509.X509,
+    ]
+}
+
+
+def from_dict(obj, id=None):
+    try:
+        managed_object_type = obj["type"]
+    except KeyError:
+        raise exception.InvalidManagedObjectDictError(field="type")
+
+    try:
+        cls = _managed_objects_by_type[managed_object_type]
+    except KeyError:
+        raise exception.UnknownManagedObjectTypeError(type=managed_object_type)
+
+    try:
+        managed_object = cls.from_dict(obj, id)
+    except KeyError as e:
+        raise exception.InvalidManagedObjectDictError(field=str(e))
+
+    return managed_object

castellan/common/objects/key.py

@@ -22,14 +22,17 @@ from Java.
 """
 
 import abc
+import binascii
 
+from castellan.common.objects import exception
 from castellan.common.objects import managed_object
 
 
 class Key(managed_object.ManagedObject):
     """Base class to represent all keys."""
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def algorithm(self):
         """Returns the key's algorithm.
 
@@ -38,7 +41,8 @@ class Key(managed_object.ManagedObject):
         """
         pass
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def bit_length(self):
         """Returns the key's bit length.
 
@@ -47,3 +51,33 @@ class Key(managed_object.ManagedObject):
         the length of the modulus.
         """
         pass
+
+    def to_dict(self):
+        dict_fields = super().to_dict()
+
+        dict_fields["algorithm"] = self.algorithm
+        dict_fields["bit_length"] = self.bit_length
+
+        return dict_fields
+
+    @classmethod
+    def from_dict(cls, dict_fields, id=None, metadata_only=False):
+        try:
+            value = None
+
+            # NOTE(moguimar): the managed object's value is exported as
+            # a hex string. For now, this is a compatibility thing with
+            # the already existent vault_key_manager backend.
+            if not metadata_only and dict_fields["value"] is not None:
+                value = binascii.unhexlify(dict_fields["value"])
+
+            return cls(
+                algorithm=dict_fields["algorithm"],
+                bit_length=dict_fields["bit_length"],
+                key=value,
+                name=dict_fields["name"],
+                created=dict_fields["created"],
+                id=id,
+            )
+        except KeyError as e:
+            raise exception.InvalidManagedObjectDictError(field=str(e))

castellan/common/objects/managed_object.py

@@ -19,7 +19,11 @@ Base ManagedObject Class
 This module defines the ManagedObject class. The ManagedObject class
 is the base class to represent all objects managed by the key manager.
 """
+
 import abc
+import binascii
+
+from castellan.common import exception
 
 
 class ManagedObject(object, metaclass=abc.ABCMeta):
@@ -69,7 +73,8 @@ class ManagedObject(object, metaclass=abc.ABCMeta):
         """
         return self._created
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def format(self):
         """Returns the encoding format.
 
@@ -78,6 +83,11 @@ class ManagedObject(object, metaclass=abc.ABCMeta):
         """
         pass
 
+    @property
+    def value(self):
+        """Returns the managed object value."""
+        return self.get_encoded()
+
     @abc.abstractmethod
     def get_encoded(self):
         """Returns the encoded object.
@@ -90,3 +100,63 @@ class ManagedObject(object, metaclass=abc.ABCMeta):
     def is_metadata_only(self):
         """Returns if the associated object is only metadata or not."""
         return self.get_encoded() is None
+
+    @classmethod
+    @abc.abstractmethod
+    def managed_type(cls):
+        """Returns the managed object type identifier.
+
+        Returns the object's type identifier for serialization purpose.
+        """
+        pass
+
+    @classmethod
+    def from_dict(cls, dict_fields, id=None, metadata_only=False):
+        """Returns an instance of this class based on a dict object.
+
+        :param dict_fields: The dictionary containing all necessary params
+                            to create one instance.
+        :param id: The optional param 'id' to be passed to the constructor.
+        :param metadata_only: A switch to create an instance with metadata
+                              only, without the secret itself.
+        """
+        try:
+            value = None
+
+            # NOTE(moguimar): the managed object's value is exported as
+            # a hex string. For now, this is a compatibility thing with
+            # the already existent vault_key_manager backend.
+            if not metadata_only and dict_fields["value"] is not None:
+                value = binascii.unhexlify(dict_fields["value"])
+
+            return cls(
+                value,
+                name=dict_fields["name"],
+                created=dict_fields["created"],
+                id=id,
+            )
+        except KeyError as e:
+            raise exception.InvalidManagedObjectDictError(field=str(e))
+
+    def to_dict(self, metadata_only=False):
+        """Returns a dict that can be used with the from_dict() method.
+
+        :param metadata_only: A switch to create an dictionary with metadata
+                              only, without the secret itself.
+
+        :rtype: dict
+        """
+        value = None
+
+        # NOTE(moguimar): the managed object's value is exported as
+        # a hex string. For now, this is a compatibility thing with
+        # the already existent vault_key_manager backend.
+        if not metadata_only and self.value is not None:
+            value = binascii.hexlify(self.value).decode("utf-8")
+
+        return {
+            "type": self.managed_type(),
+            "name": self.name,
+            "created": self.created,
+            "value": value,
+        }

castellan/common/objects/opaque_data.py

@@ -31,15 +31,17 @@ class OpaqueData(managed_object.ManagedObject):
         Expected type for data is a bytestring.
         """
         self._data = data
-        super(OpaqueData, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "opaque"
 
     @property
     def format(self):
-        """This method returns 'Opaque'."""
         return "Opaque"
 
     def get_encoded(self):
-        """Returns the data in its original format."""
         return self._data
 
     def __eq__(self, other):

castellan/common/objects/passphrase.py

@@ -31,15 +31,17 @@ class Passphrase(managed_object.ManagedObject):
         The expected type for the passphrase is a bytestring.
         """
         self._passphrase = passphrase
-        super(Passphrase, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "passphrase"
 
     @property
     def format(self):
-        """This method returns 'RAW'."""
         return "RAW"
 
     def get_encoded(self):
-        """Returns the data in a bytestring."""
         return self._passphrase
 
     def __eq__(self, other):

castellan/common/objects/private_key.py

@@ -35,25 +35,25 @@ class PrivateKey(key.Key):
         self._alg = algorithm
         self._bit_length = bit_length
         self._key = key
-        super(PrivateKey, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "private"
 
     @property
     def algorithm(self):
-        """Returns the algorithm for asymmetric encryption."""
         return self._alg
 
     @property
     def format(self):
-        """This method returns 'PKCS8'."""
         return "PKCS8"
 
     @property
     def bit_length(self):
-        """Returns the key length."""
         return self._bit_length
 
     def get_encoded(self):
-        """Returns the key in DER encoded format."""
         return self._key
 
     def __eq__(self, other):

castellan/common/objects/public_key.py

@@ -36,25 +36,25 @@ class PublicKey(key.Key):
         self._alg = algorithm
         self._bit_length = bit_length
         self._key = key
-        super(PublicKey, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "public"
 
     @property
     def algorithm(self):
-        """Returns the algorithm for asymmetric encryption."""
         return self._alg
 
     @property
     def format(self):
-        """This method returns 'SubjectPublicKeyInfo'."""
         return "SubjectPublicKeyInfo"
 
     def get_encoded(self):
-        """Returns the key in its encoded format."""
         return self._key
 
     @property
     def bit_length(self):
-        """Returns the key length."""
         return self._bit_length
 
     def __eq__(self, other):

castellan/common/objects/symmetric_key.py

@@ -35,25 +35,25 @@ class SymmetricKey(key.Key):
         self._alg = algorithm
         self._bit_length = bit_length
         self._key = key
-        super(SymmetricKey, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "symmetric"
 
     @property
     def algorithm(self):
-        """Returns the algorithm for symmetric encryption."""
         return self._alg
 
     @property
     def format(self):
-        """This method returns 'RAW'."""
         return "RAW"
 
     def get_encoded(self):
-        """Returns the key in its encoded format."""
         return self._key
 
     @property
     def bit_length(self):
-        """Returns the key length."""
         return self._bit_length
 
     def __eq__(self, other):

castellan/common/objects/x_509.py

@@ -31,15 +31,17 @@ class X509(certificate.Certificate):
         The data should be in a bytestring.
         """
         self._data = data
-        super(X509, self).__init__(name=name, created=created, id=id)
+        super().__init__(name=name, created=created, id=id)
+
+    @classmethod
+    def managed_type(cls):
+        return "certificate"
 
     @property
     def format(self):
-        """This method returns 'X.509'."""
         return "X.509"
 
     def get_encoded(self):
-        """Returns the data in its encoded format."""
         return self._data
 
     def __eq__(self, other):

castellan/tests/unit/objects/__init__.py

@@ -0,0 +1,37 @@
+# Copyright 2020 Red Hat, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+Test cases for Managed Objects.
+"""
+from castellan.common import exception
+from castellan.common import objects
+from castellan.tests import base
+
+
+class ManagedObjectFromDictTestCase(base.TestCase):
+    def test_invalid_dict(self):
+        self.assertRaises(
+            exception.InvalidManagedObjectDictError,
+            objects.from_dict,
+            {},
+        )
+
+    def test_unknown_type(self):
+        self.assertRaises(
+            exception.UnknownManagedObjectTypeError,
+            objects.from_dict,
+            {"type": "non-existing-managed-object-type"},
+        )

castellan/tests/unit/objects/test_opaque.py

@@ -16,6 +16,7 @@
 """
 Test cases for the opaque data class.
 """
+from castellan.common import objects
 from castellan.common.objects import opaque_data
 from castellan.tests import base
 
@@ -80,3 +81,7 @@ class OpaqueDataTestCase(base.TestCase):
     def test___ne___data(self):
         other_opaque = opaque_data.OpaqueData(b'other data', self.name)
         self.assertTrue(self.opaque_data != other_opaque)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.opaque_data.to_dict())
+        self.assertEqual(self.opaque_data, other)

castellan/tests/unit/objects/test_passphrase.py

@@ -16,6 +16,7 @@
 """
 Test cases for the passphrase class.
 """
+from castellan.common import objects
 from castellan.common.objects import passphrase
 from castellan.tests import base
 
@@ -80,3 +81,7 @@ class PassphraseTestCase(base.TestCase):
     def test___ne___data(self):
         other_phrase = passphrase.Passphrase(b"other passphrase", self.name)
         self.assertTrue(self.passphrase != other_phrase)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.passphrase.to_dict())
+        self.assertEqual(self.passphrase, other)

castellan/tests/unit/objects/test_private_key.py

@@ -16,6 +16,7 @@
 """
 Test cases for the private key class.
 """
+from castellan.common import objects
 from castellan.common.objects import private_key
 from castellan.tests import base
 from castellan.tests import utils
@@ -116,3 +117,7 @@ class PrivateKeyTestCase(base.KeyTestCase):
                                            different_encoded,
                                            self.name)
         self.assertTrue(self.key != other_key)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.key.to_dict())
+        self.assertEqual(self.key, other)

castellan/tests/unit/objects/test_public_key.py

@@ -16,6 +16,7 @@
 """
 Test cases for the public key class.
 """
+from castellan.common import objects
 from castellan.common.objects import public_key
 from castellan.tests import base
 from castellan.tests import utils
@@ -116,3 +117,7 @@ class PublicKeyTestCase(base.KeyTestCase):
                                          different_encoded,
                                          self.name)
         self.assertTrue(self.key != other_key)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.key.to_dict())
+        self.assertEqual(self.key, other)

castellan/tests/unit/objects/test_symmetric_key.py

@@ -16,6 +16,7 @@
 """
 Test cases for the symmetric key class.
 """
+from castellan.common import objects
 from castellan.common.objects import symmetric_key as sym_key
 from castellan.tests import base
 
@@ -115,3 +116,7 @@ class SymmetricKeyTestCase(base.KeyTestCase):
                                          different_encoded,
                                          self.name)
         self.assertTrue(self.key != other_key)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.key.to_dict())
+        self.assertEqual(self.key, other)

castellan/tests/unit/objects/test_x_509.py

@@ -16,6 +16,7 @@
 """
 Test cases for the X.509 certificate class.
 """
+from castellan.common import objects
 from castellan.common.objects import x_509
 from castellan.tests import base
 from castellan.tests import utils
@@ -80,3 +81,7 @@ class X509TestCase(base.CertificateTestCase):
     def test___ne___data(self):
         other_x509 = x_509.X509(b'\x00\x00\x00', self.name)
         self.assertTrue(self.cert != other_x509)
+
+    def test_to_and_from_dict(self):
+        other = objects.from_dict(self.cert.to_dict())
+        self.assertEqual(self.cert, other)

releasenotes/notes/add-to-dict-and-from-dict-conversions-to-managed-objects-95a9f0fdbd371a87.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    Historically, the vault key manager backend converts its managed objects
+    to dictionaries in order to send them as a json object.  To promote
+    cross-backend compatibility, suck feature should be migrated to managed
+    objects.  Methods from_dict() and to_dict() added to class ManagedObject.
+    The Method from_dict() is a class method to create instances based on a
+    dictionary while the method to_dict() is an instance method to translate
+    an instance to a dictionary.