Merge pull request #65 from SuperTux88/refactor-relayable-signatures

Refactor relayable signatures

docs/_entities/comment.md

@@ -16,7 +16,6 @@ See also: [Relayable][relayable]
 | `text`                    | [Markdown][markdown] (65535) | The comment text.                               |
 | `created_at`              | [Timestamp][timestamp]       | The create timestamp of the comment.            |
 | `author_signature`        | [Signature][signature]       | The signature from the author of the comment.   |
-| `parent_author_signature` | [Signature][signature]       | The signature from the parent entity author.    |
 
 ## Optional Properties
 
@@ -26,8 +25,6 @@ See also: [Relayable][relayable]
 
 ## Examples
 
-### From author
-
 ~~~xml
 <comment>
   <author>alice@example.org</author>
@@ -36,21 +33,6 @@ See also: [Relayable][relayable]
   <parent_guid>c3893bf029e7013487753131731751e9</parent_guid>
   <text>this is a very informative comment</text>
   <author_signature>cGIsxB5hU/94+rmgIg/Z+OUvXVYcY/kMOvc267ybpk1pT44P1JiWfnI26F1Mta62UjzIW/SjeAO0RIsJRguaISLpXX/d5DJCMpePAZaZiagUbdgH/w4L++fXiPxBKkSm+PB4txxmHGN8FHjwEUJFHJ1m3VfU4w2JC8+IBU93eag=</author_signature>
-  <parent_author_signature/>
-</comment>
-~~~
-
-### From parent author
-
-~~~xml
-<comment>
-  <author>alice@example.org</author>
-  <guid>5c241a3029f8013487763131731751e9</guid>
-  <created_at>2016-07-12T00:49:06Z</created_at>
-  <parent_guid>c3893bf029e7013487753131731751e9</parent_guid>
-  <text>this is a very informative comment</text>
-  <author_signature>cGIsxB5hU/94+rmgIg/Z+OUvXVYcY/kMOvc267ybpk1pT44P1JiWfnI26F1Mta62UjzIW/SjeAO0RIsJRguaISLpXX/d5DJCMpePAZaZiagUbdgH/w4L++fXiPxBKkSm+PB4txxmHGN8FHjwEUJFHJ1m3VfU4w2JC8+IBU93eag=</author_signature>
-  <parent_author_signature>uzjxUSqR8DQBSBa6abY7R/s9DVzT6UAgTctRcUu5rV5o0iXJD2MR6kp6bsVH3nMbbNvOjwAtrdfz3SVHT2gD8M5PmoFagxK7m5T1c9FB0i+wknoAah0Si0c2sP/BPLnkQ83DgLjF+JZCzMX4sWKvYfyaMjnih1MtQILGyuiwA0E=</parent_author_signature>
 </comment>
 ~~~
 

docs/_entities/like.md

@@ -21,12 +21,9 @@ See also: [Relayable][relayable]
 | `parent_type`             | [Type][type]                 | The entity type of the parent.                      |
 | `positive`                | [Boolean][boolean]           | `true` if it is a like, `false` if it is a dislike. |
 | `author_signature`        | [Signature][signature]       | The signature from the author of the like.          |
-| `parent_author_signature` | [Signature][signature]       | The signature from the parent entity author.        |
 
 ## Examples
 
-### From author
-
 ~~~xml
 <like>
   <positive>true</positive>
@@ -35,21 +32,6 @@ See also: [Relayable][relayable]
   <parent_guid>947a854029f7013487753131731751e9</parent_guid>
   <author>alice@example.org</author>
   <author_signature>gk8e+K7XRjVRblv8B8PVOf7BpURbf5HrXO5rmq8D/AkPO7lA0+Akwouu5JGKAHIhPR3dfXVp0o6bIDD+e8gtMYRdDd5IHRfBGNk3WsQecnbhmesHy40Qca/dCQcdcXd5aeWHJKeyUrSAvS55U6VUpk/DK/4IIEZfnr0T9+jM8I0=</author_signature>
-  <parent_author_signature/>
-</like>
-~~~
-
-### From parent author
-
-~~~xml
-<like>
-  <positive>true</positive>
-  <guid>947a88f029f7013487753131731751e9</guid>
-  <parent_type>Post</parent_type>
-  <parent_guid>947a854029f7013487753131731751e9</parent_guid>
-  <author>alice@example.org</author>
-  <author_signature>gk8e+K7XRjVRblv8B8PVOf7BpURbf5HrXO5rmq8D/AkPO7lA0+Akwouu5JGKAHIhPR3dfXVp0o6bIDD+e8gtMYRdDd5IHRfBGNk3WsQecnbhmesHy40Qca/dCQcdcXd5aeWHJKeyUrSAvS55U6VUpk/DK/4IIEZfnr0T9+jM8I0=</author_signature>
-  <parent_author_signature>0oAjHO8uIn2Z3Gcmo1KF8su0c7bqI6MzTRq5JagGaZVkFVU8WlNqtwamu6xlmpcAoClGpI5xvbnHzyw5YA8NS8KmUy8BUpg67Mq4QsHHBtueNxHuhgRjszN2V0S8BUKFHGJnnvXmZ/P6YGOOomDgp9I/7zIOownvIm5wj2MotWw=</parent_author_signature>
 </like>
 ~~~
 

docs/_entities/poll_participation.md

@@ -15,12 +15,9 @@ See also: [Relayable][relayable]
 | `parent_guid`             | [GUID][guid]                 | The GUID of the [Poll][poll].                              |
 | `poll_answer_guid`        | [GUID][guid]                 | The GUID of the [PollAnswer][poll_answer].                 |
 | `author_signature`        | [Signature][signature]       | The signature from the author of the poll participation.   |
-| `parent_author_signature` | [Signature][signature]       | The signature from the author of the [Poll][poll].         |
 
 ## Examples
 
-### From author
-
 ~~~xml
 <poll_participation>
   <guid>f1eb866029f7013487753131731751e9</guid>
@@ -28,20 +25,6 @@ See also: [Relayable][relayable]
   <author>alice@example.org</author>
   <poll_answer_guid>2a22db2029e9013487753131731751e9</poll_answer_guid>
   <author_signature>dT6KbT7kp0bE+s3//ZErxO1wvVIqtD0lY67i81+dO43B4D2m5kjCdzW240eWt/jZmcHIsdxXf4WHNdrb6ZDnamA8I1FUVnLjHA9xexBITQsSLXrcV88UdammSmmOxl1Ac4VUXqFpdavm6a7/MwOJ7+JHP8TbUO9siN+hMfgUbtY=</author_signature>
-  <parent_author_signature/>
-</poll_participation>
-~~~
-
-### From parent author
-
-~~~xml
-<poll_participation>
-  <guid>f1eb866029f7013487753131731751e9</guid>
-  <parent_guid>2a22d6c029e9013487753131731751e9</parent_guid>
-  <author>alice@example.org</author>
-  <poll_answer_guid>2a22db2029e9013487753131731751e9</poll_answer_guid>
-  <author_signature>dT6KbT7kp0bE+s3//ZErxO1wvVIqtD0lY67i81+dO43B4D2m5kjCdzW240eWt/jZmcHIsdxXf4WHNdrb6ZDnamA8I1FUVnLjHA9xexBITQsSLXrcV88UdammSmmOxl1Ac4VUXqFpdavm6a7/MwOJ7+JHP8TbUO9siN+hMfgUbtY=</author_signature>
-  <parent_author_signature>gWasNPpSnMcKBIMWyzfoVO6sr8eRYkhUqy3PIkkh53n/ki+DM9mnh3ayotI0+6un9aq1N3XkS7Vn05ZD3+nHVby6i21XkYgPnbD8pWYuBBj7VGPyahT70BUs/vSvY8KX8V3wYfsPsaiAgJsAFg2UHYdY3r4/oWdIIbBZc21O3zk=</parent_author_signature>
 </poll_participation>
 ~~~
 

docs/federation/relayable.md

@@ -21,24 +21,25 @@ All relayables have the following properties:
 | `guid`                    | [GUID][guid]                 | The GUID of the relayable.                        |
 | `parent_guid`             | [GUID][guid]                 | The GUID of the parent entity.                    |
 | `author_signature`        | [Signature][signature]       | The signature from the author of the relayable.   |
-| `parent_author_signature` | [Signature][signature]       | The signature from the parent entity author.      |
 
 ## Relaying
 
-The author of the relayable sends the entity to the parent author. The author must include the `author_signature`. The
+If the author is not the same as the parent author, the author of the relayable sends the entity to the parent author
-`parent_author_signature` may be empty or missing.
+and the author must include the `author_signature`.
 
-The parent author then must add the `parent_author_signature` and send the entity to all the recipients of the parent
+The parent author then must envelop it in a new [Magic Envelope][magicsig] and send the entity to all the recipients
-entity.
+of the parent entity. If the author and the parent author are on the same server, the author must sign the
+`author_signature` and the parent author needs to sign the Magic Envelope.
 
-If someone other then the parent author receives an relayable without a valid `parent_author_signature`, it must be
+If someone other then the parent author receives a relayable without a valid Magic Envelope signed from
-ignored. If the `author_signature` is missing or invalid, it also must be ignored.
+the parent author, it must be ignored. If the author is not the same as the parent author and the `author_signature`
+is missing or invalid, it also must be ignored. If the author is the same as the parent author, the `author_signature`
+can be missing, because a valid signature in the Magic Envelope from the author is enough in that case.
 
 ## Signatures
 
-The string to sign is built with the content of all properties (except the `author_signature` and
+The string to sign is built with the content of all properties (except the `author_signature` itself),
-`parent_author_signature` itself), concatenated using `;` as separator in the same order as they appear in the XML. The
+concatenated using `;` as separator in the same order as they appear in the XML. The order in the XML is not specified.
-order in the XML is not specified.
 
 This ensures that relayables even work, if the parent author or another recipient does not know all properties of the
 relayable entity (e.g. older version of diaspora\*).

lib/diaspora_federation/entities/relayable.rb

@@ -28,16 +28,15 @@ module DiasporaFederation
       #   @return [String] parent guid
       #
       # @!attribute [r] author_signature
-      #   Contains a signature of the entity using the private key of the author of a post itself
+      #   Contains a signature of the entity using the private key of the author of a relayable itself.
       #   The presence of this signature is mandatory. Without it the entity won't be accepted by
       #   a target pod.
       #   @return [String] author signature
       #
       # @!attribute [r] parent_author_signature
-      #   Contains a signature of the entity using the private key of the author of a parent post
+      #   Contains a signature of the entity using the private key of the author of a parent post.
-      #   This signature is required only when federating from upstream (parent) post author to
+      #   @deprecated This signature isn't required anymore, because we can check the signature from
-      #   downstream subscribers. This is the case when the parent author has to resend a relayable
+      #     the parent author in the MagicEnvelope.
-      #   received from one of their subscribers to all others.
       #   @return [String] parent author signature
       #
       # @!attribute [r] parent
@@ -71,18 +70,17 @@ module DiasporaFederation
         super(data)
       end
 
-      # Verifies the signatures (+author_signature+ and +parent_author_signature+ if needed).
+      # Verifies the +author_signature+ if needed.
+      # @see DiasporaFederation::Entities::Signable#verify_signature
+      #
       # @raise [SignatureVerificationFailed] if the signature is not valid
       # @raise [PublicKeyNotFound] if no public key is found
-      def verify_signatures
+      def verify_signature
-        verify_signature(author, :author_signature)
+        super(author, :author_signature) unless author == parent.author
-
-        # This happens only on downstream federation.
-        verify_signature(parent.author, :parent_author_signature) unless parent.local
       end
 
       def sender_valid?(sender)
-        sender == author || sender == parent.author
+        (sender == author && parent.local) || sender == parent.author
       end
 
       # @return [String] string representation of this object
@@ -136,7 +134,7 @@ module DiasporaFederation
       def enriched_properties
         super.merge(additional_data).tap do |hash|
           hash[:author_signature] = author_signature || sign_with_author
-          hash[:parent_author_signature] = parent_author_signature || sign_with_parent_author_if_available.to_s
+          hash.delete(:parent_author_signature)
         end
       end
 
@@ -144,7 +142,9 @@ module DiasporaFederation
       #
       # @return [Hash] sorted xml elements
       def xml_elements
-        data = super
+        data = super.tap do |hash|
+          hash[:parent_author_signature] = parent_author_signature || sign_with_parent_author_if_available.to_s
+        end
         order = signature_order + %i(author_signature parent_author_signature)
         order.map {|element| [element, data[element] || ""] }.to_h
       end
@@ -178,7 +178,7 @@ module DiasporaFederation
           additional_data = properties_hash.reject {|key, _| class_props.has_key?(key) }
 
           fetch_parent(properties_hash)
-          new(properties_hash, property_order, additional_data).tap(&:verify_signatures)
+          new(properties_hash, property_order, additional_data).tap(&:verify_signature)
         end
 
         private

lib/diaspora_federation/schemas/federation_entities.json

@@ -46,8 +46,7 @@
             "author": { "type": "string" },
             "guid": { "$ref": "#/definitions/guid" },
             "parent_guid": { "$ref": "#/definitions/guid" },
-            "author_signature": { "$ref": "#/definitions/signature" },
+            "author_signature": { "$ref": "#/definitions/signature" }
-            "parent_author_signature": { "$ref": "#/definitions/signature" }
           },
           "required": [
             "author", "guid", "parent_guid"

spec/integration/comment_integration_spec.rb

@@ -224,7 +224,6 @@ XML
 
       before do
         expect_callback(:fetch_public_key, author).and_return(author_key.public_key)
-        expect_callback(:fetch_public_key, parent.author).and_return(parent_key.public_key)
         expect_callback(:fetch_related_entity, "Post", parent_guid).and_return(parent)
       end
 

spec/lib/diaspora_federation/entities/comment_spec.rb

@@ -32,7 +32,6 @@ XML
     "guid": "#{data[:guid]}",
     "parent_guid": "#{parent.guid}",
     "author_signature": "#{data[:author_signature]}",
-    "parent_author_signature": "#{data[:parent_author_signature]}",
     "text": "#{data[:text]}",
     "created_at": "#{data[:created_at].iso8601}"
   },

spec/lib/diaspora_federation/entities/like_spec.rb

@@ -32,7 +32,6 @@ XML
     "guid": "#{data[:guid]}",
     "parent_guid": "#{parent.guid}",
     "author_signature": "#{data[:author_signature]}",
-    "parent_author_signature": "#{data[:parent_author_signature]}",
     "parent_type": "#{parent.entity_type}",
     "positive": #{data[:positive]}
   },

spec/lib/diaspora_federation/entities/poll_participation_spec.rb

@@ -30,7 +30,6 @@ XML
     "guid": "#{data[:guid]}",
     "parent_guid": "#{parent.guid}",
     "author_signature": "#{data[:author_signature]}",
-    "parent_author_signature": "#{data[:parent_author_signature]}",
     "poll_answer_guid": "#{data[:poll_answer_guid]}"
   },
   "property_order": [

spec/lib/diaspora_federation/entities/relayable_spec.rb

@@ -25,16 +25,15 @@ module DiasporaFederation
       end
     end
 
-    describe "#verify_signatures" do
+    describe "#verify_signature" do
       it "doesn't raise anything if correct signatures were passed" do
         hash[:author_signature] = sign_with_key(author_pkey, signature_data)
         hash[:parent_author_signature] = sign_with_key(parent_pkey, signature_data)
         hash[:parent] = remote_parent
 
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-        expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
 
-        expect { Entities::SomeRelayable.new(hash, signature_order).verify_signatures }.not_to raise_error
+        expect { Entities::SomeRelayable.new(hash, signature_order).verify_signature }.not_to raise_error
       end
 
       it "doesn't raise anything if correct signatures with new property were passed" do
@@ -46,10 +45,9 @@ module DiasporaFederation
         hash[:parent] = remote_parent
 
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-        expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
 
         expect {
-          Entities::SomeRelayable.new(hash, signature_order, "new_property" => new_property).verify_signatures
+          Entities::SomeRelayable.new(hash, signature_order, "new_property" => new_property).verify_signature
         }.not_to raise_error
       end
 
@@ -57,7 +55,7 @@ module DiasporaFederation
         expect_callback(:fetch_public_key, anything).and_return(nil)
 
         expect {
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
+          Entities::SomeRelayable.new(hash, signature_order).verify_signature
         }.to raise_error Entities::Relayable::PublicKeyNotFound
       end
 
@@ -67,66 +65,47 @@ module DiasporaFederation
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
 
         expect {
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
+          Entities::SomeRelayable.new(hash, signature_order).verify_signature
         }.to raise_error Entities::Relayable::SignatureVerificationFailed
       end
 
+      it "doesn't raise when no author signature was passed, but the author is also the parent author" do
+        hash[:author_signature] = nil
+        hash[:parent] = Fabricate(:related_entity, author: author, local: false)
+
+        expect {
+          Entities::SomeRelayable.new(hash, signature_order).verify_signature
+        }.not_to raise_error
+      end
+
       it "raises when bad author signature was passed" do
         hash[:author_signature] = sign_with_key(author_pkey, "bad signed string")
 
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
 
         expect {
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
+          Entities::SomeRelayable.new(hash, signature_order).verify_signature
         }.to raise_error Entities::Relayable::SignatureVerificationFailed
       end
 
-      it "raises when no public key for parent author was fetched" do
+      it "doesn't raise when no parent author signature was passed" do
-        hash[:author_signature] = sign_with_key(author_pkey, signature_data)
-        hash[:parent] = remote_parent
-
-        expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-        expect_callback(:fetch_public_key, remote_parent.author).and_return(nil)
-
-        expect {
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
-        }.to raise_error Entities::Relayable::PublicKeyNotFound
-      end
-
-      it "raises when no parent author signature was passed" do
         hash[:author_signature] = sign_with_key(author_pkey, signature_data)
         hash[:parent_author_signature] = nil
         hash[:parent] = remote_parent
 
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-        expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
 
-        expect {
+        expect { Entities::SomeRelayable.new(hash, signature_order).verify_signature }.not_to raise_error
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
-        }.to raise_error Entities::Relayable::SignatureVerificationFailed
       end
 
-      it "raises when bad parent author signature was passed" do
+      it "doesn't raise when no parent author signature was passed and we're on upstream federation" do
-        hash[:author_signature] = sign_with_key(author_pkey, signature_data)
-        hash[:parent_author_signature] = sign_with_key(parent_pkey, "bad signed string")
-        hash[:parent] = remote_parent
-
-        expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-        expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
-
-        expect {
-          Entities::SomeRelayable.new(hash, signature_order).verify_signatures
-        }.to raise_error Entities::Relayable::SignatureVerificationFailed
-      end
-
-      it "doesn't raise if parent_author_signature isn't set but we're on upstream federation" do
         hash[:author_signature] = sign_with_key(author_pkey, signature_data)
         hash[:parent_author_signature] = nil
         hash[:parent] = local_parent
 
         expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
 
-        expect { Entities::SomeRelayable.new(hash, signature_order).verify_signatures }.not_to raise_error
+        expect { Entities::SomeRelayable.new(hash, signature_order).verify_signature }.not_to raise_error
       end
     end
 
@@ -228,7 +207,6 @@ XML
         before do
           expect_callback(:fetch_related_entity, "Parent", parent_guid).and_return(remote_parent)
           expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-          expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
         end
 
         let(:new_signature_data) { "#{author};#{guid};#{parent_guid};#{new_property};#{property}" }
@@ -329,25 +307,21 @@ XML
         )
       end
 
-      it "computes correct signatures for the entity with new unknown elements" do
+      it "computes correct author_signature for the entity with new unknown elements" do
         expect_callback(:fetch_private_key, author).and_return(author_pkey)
-        expect_callback(:fetch_private_key, local_parent.author).and_return(parent_pkey)
 
         property_order = [:author, :guid, :parent_guid, "new_property", :property]
         signature_data_with_new_property = "#{author};#{guid};#{parent_guid};#{new_property};#{property}"
 
         json_hash = Entities::SomeRelayable.new(hash, property_order, "new_property" => new_property).to_json
         author_signature = json_hash[:entity_data][:author_signature]
-        parent_author_signature = json_hash[:entity_data][:parent_author_signature]
 
         expect(verify_signature(author_pkey, author_signature, signature_data_with_new_property)).to be_truthy
-        expect(verify_signature(parent_pkey, parent_author_signature, signature_data_with_new_property)).to be_truthy
       end
 
-      it "doesn't change signatures if they are already set" do
+      it "doesn't change author_signature if it is already set" do
         json = Entities::SomeRelayable.new(hash_with_fake_signatures).to_json.to_json
         expect(json).to include_json(entity_data: {author_signature: "aa"})
-        expect(json).to include_json(entity_data: {parent_author_signature: "bb"})
       end
 
       it "raises when author_signature not set and key isn't supplied" do
@@ -358,12 +332,11 @@ XML
         }.to raise_error Entities::Relayable::AuthorPrivateKeyNotFound
       end
 
-      it "doesn't set parent_author_signature if key isn't supplied" do
+      it "doesn't contain the parent_author_signature" do
         expect_callback(:fetch_private_key, author).and_return(author_pkey)
-        expect_callback(:fetch_private_key, local_parent.author).and_return(nil)
 
-        json = Entities::SomeRelayable.new(hash).to_json.to_json
+        json = Entities::SomeRelayable.new(hash).to_json
-        expect(json).to include_json(entity_data: {parent_author_signature: ""})
+        expect(json[:entity_data]).not_to include(:parent_author_signature)
       end
     end
 
@@ -374,7 +347,6 @@ XML
         before do
           expect_callback(:fetch_related_entity, "Parent", parent_guid).and_return(remote_parent)
           expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-          expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
         end
 
         context "when properties are sorted and there is an unknown property" do
@@ -475,9 +447,7 @@ XML
       context "fetch parent" do
         before do
           expect_callback(:fetch_public_key, author).and_return(author_pkey.public_key)
-          expect_callback(:fetch_public_key, remote_parent.author).and_return(parent_pkey.public_key)
           expect_callback(:fetch_private_key, author).and_return(author_pkey)
-          expect_callback(:fetch_private_key, remote_parent.author).and_return(parent_pkey)
         end
 
         let(:entity) { Entities::SomeRelayable.new(hash) }
@@ -508,12 +478,18 @@ XML
     end
 
     describe "#sender_valid?" do
-      it "allows author" do
+      it "allows author if the parent is local" do
         entity = Entities::SomeRelayable.new(hash)
 
         expect(entity.sender_valid?(author)).to be_truthy
       end
 
+      it "does not allow the author if the parent is not local" do
+        entity = Entities::SomeRelayable.new(hash.merge(parent: remote_parent))
+
+        expect(entity.sender_valid?(author)).to be_falsey
+      end
+
       it "allows parent author" do
         entity = Entities::SomeRelayable.new(hash)
 

spec/support/helper_methods.rb

@@ -14,7 +14,7 @@ end
 
 # signature methods
 def add_signatures(hash, klass=described_class)
-  properties = klass.new(hash).send(:enriched_properties)
+  properties = klass.new(hash).send(:xml_elements)
   hash[:author_signature] = properties[:author_signature]
   hash[:parent_author_signature] = properties[:parent_author_signature]
 end

spec/support/shared_entity_specs.rb

@@ -1,4 +1,5 @@
 def entity_hash_from(hash)
+  hash.delete(:parent_author_signature)
   hash.map {|key, value|
     if [String, TrueClass, FalseClass, Integer, NilClass].any? {|c| value.is_a? c }
       [key, value]
@@ -136,10 +137,9 @@ shared_examples "a JSON Entity" do
     it "contains JSON properties for each of the entity properties with the entity_data property" do
       entity_data = entity_hash_from(data)
       entity_data.delete(:parent)
-      nested_elements = entity_data.select {|_key, value| value.is_a?(Array) || value.is_a?(Hash) }
+      nested_elements, simple_props = entity_data.partition {|_key, value| value.is_a?(Array) || value.is_a?(Hash) }
-      entity_data.reject! {|_key, value| value.is_a?(Array) || value.is_a?(Hash) }
 
-      expect(to_json_output).to include_json(entity_data: entity_data)
+      expect(to_json_output).to include_json(entity_data: simple_props.to_h)
       nested_elements.each {|key, value|
         type = described_class.class_props[key]
         if value.is_a?(Array)