Introduce alternative form of the account migration message

In the alternative form author can be the new diaspora user

docs/_entities/account_migration.md

@@ -8,9 +8,16 @@ This entity is sent when a person changes their diaspora* ID (e.g. when a user m
 
 | Property    | Type                         | Description                                                                          |
 | ----------- | ---------------------------- | ------------------------------------------------------------------------------------ |
-| `author`    | [diaspora\* ID][diaspora-id] | The diaspora\* ID of the closed account.                                             |
+| `author`    | [diaspora\* ID][diaspora-id] | The diaspora\* ID of the sender of the entity. The entity may be sent by either old user identity or new user identity. |
-| `person`    | [Profile][profile]           | New profile of a person                                                              |
+| `person`    | [Profile][profile]           | New profile of a person. |
-| `signature` | [Signature][signature]       | Signature that validates original and target diaspora* IDs with the new key of person |
+| `signature` | [Signature][signature]       | Signature that validates original and target diaspora* IDs with the private key of the second identity, other than the entity author. So if the author is the old identity then this signature is made with the new identity key, and vice versa. |
+
+## Optional Properties
+
+| Property    | Type                         | Description                                                                          |
+| ----------- | ---------------------------- | ------------------------------------------------------------------------------------ |
+| `old_identity`    | [diaspora\* ID][diaspora-id] | The diaspora\* ID of the closed account. This field is mandatory if the author of the entity is the new identity. |
+
 
 ### Signature
 
@@ -51,6 +58,7 @@ AccountMigration:old-diaspora-id@example.org:new-diaspora-id@example.com
   <signature>
     07b1OIY6sTUQwV5pbpgFK0uz6W4cu+oQnlg410Q4uISUOdNOlBdYqhZJm62VFhgvzt4TZXfiJgoupFkRjP0BsaVaZuP2zKMNvO3ngWOeJRf2oRK4Ub5cEA/g7yijkRc+7y8r1iLJ31MFb1czyeCsLxw9Ol8SvAJddogGiLHDhjE=
   </signature>
+  <old_identity>alice@example.org</old_identity>
 </account_migration>
 ~~~
 

lib/diaspora_federation/entities/account_migration.rb

@@ -8,7 +8,9 @@ module DiasporaFederation
       include AccountMigration::Signable
 
       # @!attribute [r] author
-      #   The old diaspora* ID of the person who changes their ID
+      #   Sender of the AccountMigration message. Usually it is the old diaspora* ID of the person who changes their ID.
+      #   This property is also allowed to be the new diaspora* ID, which is equal to the author of the included
+      #   profile.
       #   @see Person#author
       #   @return [String] author diaspora* ID
       property :author, :string
@@ -19,14 +21,31 @@ module DiasporaFederation
       entity :profile, Entities::Profile
 
       # @!attribute [r] signature
-      #   Signature that validates original and target diaspora* IDs with the new key of person
+      #   Signature that validates original and target diaspora* IDs with the private key of the second identity, other
+      #   than the entity author. So if the author is the old identity then this signature is made with the new identity
+      #   key, and vice versa.
       #   @return [String] signature
       property :signature, :string, default: nil
 
-      def old_user_id
+      # @!attribute [r] old_identity
+      #   Optional attribute which keeps old diaspora* ID. Must be present when author attribute contains new diaspora*
+      #   ID.
+      #   @return [String] old identity
+      property :old_identity, :string, default: nil
+
+      # Returns diaspora* ID of the old person identity.
+      # @return [String] diaspora* ID of the old person identity
+      def old_identity
+        return @old_identity if author_is_new_id?
         author
       end
 
+      # Returns diaspora* ID of the new person identity.
+      # @return [String] diaspora* ID of the new person identity
+      def new_identity
+        profile.author
+      end
+
       # @return [String] string representation of this object
       alias to_s unique_migration_descriptor
 
@@ -46,33 +65,33 @@ module DiasporaFederation
 
       private
 
-      def new_user_id
+      def author_is_new_id?
-        profile.author
+        author == new_identity
       end
 
       def signer_id
-        new_user_id
+        author_is_new_id? ? @old_identity : new_identity
       end
 
       def enriched_properties
         super.tap do |hash|
-          hash[:signature] = signature || sign_with_new_key
+          hash[:signature] = signature || sign_with_respective_key
         end
       end
 
-      # Sign with new user's key
+      # Sign with the key of the #signer_id identity
-      # @raise [NewPrivateKeyNotFound] if the new user's private key is not found
+      # @raise [PrivateKeyNotFound] if the signer's private key is not found
       # @return [String] A Base64 encoded signature of #signature_data with key
-      def sign_with_new_key
+      def sign_with_respective_key
         privkey = DiasporaFederation.callbacks.trigger(:fetch_private_key, signer_id)
-        raise NewPrivateKeyNotFound, "signer=#{signer_id} obj=#{self}" if privkey.nil?
+        raise PrivateKeyNotFound, "signer=#{signer_id} obj=#{self}" if privkey.nil?
         sign_with_key(privkey).tap do
           logger.info "event=sign status=complete signature=signature signer=#{signer_id} obj=#{self}"
         end
       end
 
       # Raised, if creating the signature fails, because the new private key of a user was not found
-      class NewPrivateKeyNotFound < RuntimeError
+      class PrivateKeyNotFound < RuntimeError
       end
     end
   end

lib/diaspora_federation/test/factories.rb

@@ -42,6 +42,7 @@ module DiasporaFederation
       Fabricator(:account_migration_entity, class_name: DiasporaFederation::Entities::AccountMigration) do
         author { Fabricate.sequence(:diaspora_id) }
         profile { Fabricate(:profile_entity) }
+        old_identity { Fabricate.sequence(:diaspora_id) }
       end
 
       Fabricator(:person_entity, class_name: DiasporaFederation::Entities::Person) do

lib/diaspora_federation/validators/account_migration_validator.rb

@@ -7,6 +7,8 @@ module DiasporaFederation
       rule :author, :diaspora_id
 
       rule :profile, :not_nil
+
+      rule :old_identity, :diaspora_id
     end
   end
 end

spec/lib/diaspora_federation/entities/account_migration_spec.rb

@@ -1,21 +1,185 @@
 module DiasporaFederation
   describe Entities::AccountMigration do
-    let(:new_diaspora_id) { alice.diaspora_id }
+    let(:old_user) { Fabricate(:user) }
-    let(:new_author_pkey) { alice.private_key }
+    let(:new_user) { Fabricate(:user) }
-    let(:hash) {
+    let(:old_diaspora_id) { old_user.diaspora_id }
-      Fabricate.attributes_for(:account_deletion_entity).merge(
+    let(:new_diaspora_id) { new_user.diaspora_id }
-        profile: Fabricate(:profile_entity, author: new_diaspora_id)
+
-      )
-    }
     let(:data) {
       hash.tap {|hash|
         properties = described_class.new(hash).send(:enriched_properties)
         hash[:signature] = properties[:signature]
       }
     }
-    let(:signature_data) { "AccountMigration:#{hash[:author]}:#{new_diaspora_id}" }
+    let(:signature_data) { "AccountMigration:#{old_diaspora_id}:#{new_diaspora_id}" }
+    let(:string) { signature_data }
 
-    let(:xml) { <<-XML }
+    shared_examples_for "an account migration entity" do
+      it_behaves_like "an Entity subclass"
+
+      it_behaves_like "an XML Entity"
+
+      describe "#to_xml" do
+        it "computes signature when no signature was provided" do
+          expect_callback(:fetch_private_key, signer_id).and_return(signer_pkey)
+
+          entity = Entities::AccountMigration.new(hash)
+          xml = entity.to_xml
+
+          signature = xml.at_xpath("signature").text
+          expect(verify_signature(signer_pkey, signature, entity.to_s)).to be_truthy
+        end
+
+        it "doesn't change signature if it is already set" do
+          hash[:signature] = "aa"
+
+          xml = Entities::AccountMigration.new(hash).to_xml
+
+          expect(xml.at_xpath("signature").text).to eq("aa")
+        end
+
+        it "raises when signature isn't set and key isn't supplied" do
+          expect_callback(:fetch_private_key, signer_id).and_return(nil)
+
+          expect {
+            Entities::AccountMigration.new(hash).to_xml
+          }.to raise_error Entities::AccountMigration::PrivateKeyNotFound
+        end
+      end
+
+      describe "#verify_signature" do
+        it "doesn't raise anything if correct signature was passed" do
+          hash[:signature] = sign_with_key(signer_pkey, signature_data)
+          expect_callback(:fetch_public_key, signer_id).and_return(signer_pkey)
+          expect { Entities::AccountMigration.new(hash).verify_signature }.not_to raise_error
+        end
+
+        it "raises when no public key for author was fetched" do
+          expect_callback(:fetch_public_key, anything).and_return(nil)
+
+          expect {
+            Entities::AccountMigration.new(hash).verify_signature
+          }.to raise_error Entities::AccountMigration::PublicKeyNotFound
+        end
+
+        it "raises when bad author signature was passed" do
+          hash[:signature] = "abcdef"
+
+          expect_callback(:fetch_public_key, signer_id).and_return(signer_pkey.public_key)
+
+          expect {
+            Entities::AccountMigration.new(hash).verify_signature
+          }.to raise_error Entities::AccountMigration::SignatureVerificationFailed
+        end
+      end
+
+      describe ".from_hash" do
+        it "calls #verify_signature" do
+          expect_any_instance_of(Entities::AccountMigration).to receive(:freeze)
+          expect_any_instance_of(Entities::AccountMigration).to receive(:verify_signature)
+          Entities::AccountMigration.from_hash(hash)
+        end
+
+        it "raises when bad author signature was passed" do
+          hash[:signature] = "abcdef"
+
+          expect_callback(:fetch_public_key, signer_id).and_return(signer_pkey.public_key)
+
+          expect {
+            Entities::AccountMigration.from_hash(hash)
+          }.to raise_error Entities::AccountMigration::SignatureVerificationFailed
+        end
+      end
+    end
+
+    context "with old identity as author" do
+      let(:signer_id) { new_diaspora_id }
+      let(:signer_pkey) { new_user.private_key }
+
+      let(:hash) {
+        {
+          author:       old_diaspora_id,
+          profile:      Fabricate(:profile_entity, author: new_diaspora_id),
+          old_identity: old_diaspora_id
+        }
+      }
+
+      let(:xml) { <<-XML }
+<account_migration>
+  <author>#{data[:author]}</author>
+  <profile>
+    <author>#{data[:profile].author}</author>
+    <first_name>#{data[:profile].first_name}</first_name>
+    <image_url>#{data[:profile].image_url}</image_url>
+    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+    <image_url_small>#{data[:profile].image_url}</image_url_small>
+    <bio>#{data[:profile].bio}</bio>
+    <birthday>#{data[:profile].birthday}</birthday>
+    <gender>#{data[:profile].gender}</gender>
+    <location>#{data[:profile].location}</location>
+    <searchable>#{data[:profile].searchable}</searchable>
+    <public>#{data[:profile].public}</public>
+    <nsfw>#{data[:profile].nsfw}</nsfw>
+    <tag_string>#{data[:profile].tag_string}</tag_string>
+  </profile>
+  <signature>#{data[:signature]}</signature>
+  <old_identity>#{data[:old_identity]}</old_identity>
+</account_migration>
+XML
+
+      it_behaves_like "an account migration entity"
+    end
+
+    context "with new identity as author" do
+      let(:signer_id) { old_diaspora_id }
+      let(:signer_pkey) { old_user.private_key }
+
+      let(:hash) {
+        {
+          author:       new_diaspora_id,
+          profile:      Fabricate(:profile_entity, author: new_diaspora_id),
+          old_identity: old_diaspora_id
+        }
+      }
+
+      let(:xml) { <<-XML }
+<account_migration>
+  <author>#{data[:author]}</author>
+  <profile>
+    <author>#{data[:profile].author}</author>
+    <first_name>#{data[:profile].first_name}</first_name>
+    <image_url>#{data[:profile].image_url}</image_url>
+    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+    <image_url_small>#{data[:profile].image_url}</image_url_small>
+    <bio>#{data[:profile].bio}</bio>
+    <birthday>#{data[:profile].birthday}</birthday>
+    <gender>#{data[:profile].gender}</gender>
+    <location>#{data[:profile].location}</location>
+    <searchable>#{data[:profile].searchable}</searchable>
+    <public>#{data[:profile].public}</public>
+    <nsfw>#{data[:profile].nsfw}</nsfw>
+    <tag_string>#{data[:profile].tag_string}</tag_string>
+  </profile>
+  <signature>#{data[:signature]}</signature>
+  <old_identity>#{data[:old_identity]}</old_identity>
+</account_migration>
+XML
+
+      it_behaves_like "an account migration entity"
+    end
+
+    context "when author is the new identity and old_identity prop is missing" do
+      let(:signer_id) { old_diaspora_id }
+      let(:signer_pkey) { old_user.private_key }
+
+      let(:hash) {
+        {
+          author:  new_diaspora_id,
+          profile: Fabricate(:profile_entity, author: new_diaspora_id)
+        }
+      }
+
+      let(:xml) { <<-XML }
 <account_migration>
   <author>#{data[:author]}</author>
   <profile>
@@ -37,81 +201,16 @@ module DiasporaFederation
 </account_migration>
 XML
 
-    let(:string) { "AccountMigration:#{data[:author]}:#{data[:profile].author}" }
+      it "fails validation on construction" do
-
-    it_behaves_like "an Entity subclass"
-
-    it_behaves_like "an XML Entity"
-
-    describe "#to_xml" do
-      it "computes signature when no signature was provided" do
-        expect_callback(:fetch_private_key, new_diaspora_id).and_return(new_author_pkey)
-
-        entity = Entities::AccountMigration.new(hash)
-        xml = entity.to_xml
-
-        signature = xml.at_xpath("signature").text
-        expect(verify_signature(new_author_pkey, signature, entity.to_s)).to be_truthy
-      end
-
-      it "doesn't change signature if it is already set" do
-        hash[:signature] = "aa"
-
-        xml = Entities::AccountMigration.new(hash).to_xml
-
-        expect(xml.at_xpath("signature").text).to eq("aa")
-      end
-
-      it "raises when signature isn't set and key isn't supplied" do
-        expect_callback(:fetch_private_key, new_diaspora_id).and_return(nil)
-
         expect {
-          Entities::AccountMigration.new(hash).to_xml
+          described_class.new(hash)
-        }.to raise_error Entities::AccountMigration::NewPrivateKeyNotFound
+        }.to raise_error Entity::ValidationError
-      end
-    end
-
-    describe "#verify_signature" do
-      it "doesn't raise anything if correct signatures were passed" do
-        hash[:signature] = sign_with_key(new_author_pkey, signature_data)
-        expect_callback(:fetch_public_key, new_diaspora_id).and_return(new_author_pkey)
-        expect { Entities::AccountMigration.new(hash).verify_signature }.not_to raise_error
       end
 
-      it "raises when no public key for author was fetched" do
+      it "fails validation on parsing" do
-        expect_callback(:fetch_public_key, anything).and_return(nil)
-
         expect {
-          Entities::AccountMigration.new(hash).verify_signature
+          DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(xml).root)
-        }.to raise_error Entities::AccountMigration::PublicKeyNotFound
+        }.to raise_error Entity::ValidationError
-      end
-
-      it "raises when bad author signature was passed" do
-        hash[:signature] = "abcdef"
-
-        expect_callback(:fetch_public_key, new_diaspora_id).and_return(new_author_pkey.public_key)
-
-        expect {
-          Entities::AccountMigration.new(hash).verify_signature
-        }.to raise_error Entities::AccountMigration::SignatureVerificationFailed
-      end
-    end
-
-    describe ".from_hash" do
-      it "calls #verify_signature" do
-        expect_any_instance_of(Entities::AccountMigration).to receive(:freeze)
-        expect_any_instance_of(Entities::AccountMigration).to receive(:verify_signature)
-        Entities::AccountMigration.from_hash(hash)
-      end
-
-      it "raises when bad author signature was passed" do
-        hash[:signature] = "abcdef"
-
-        expect_callback(:fetch_public_key, new_diaspora_id).and_return(new_author_pkey.public_key)
-
-        expect {
-          Entities::AccountMigration.from_hash(hash)
-        }.to raise_error Entities::AccountMigration::SignatureVerificationFailed
       end
     end
   end

spec/lib/diaspora_federation/validators/account_migration_validator_spec.rb

@@ -8,12 +8,18 @@ module DiasporaFederation
       let(:property) { :author }
     end
 
-    describe "#person" do
+    describe "#profile" do
       it_behaves_like "a property with a value validation/restriction" do
         let(:property) { :profile }
         let(:wrong_values) { [nil] }
         let(:correct_values) { [] }
       end
     end
+
+    describe "#old_identity" do
+      it_behaves_like "a diaspora* ID validator" do
+        let(:property) { :old_identity }
+      end
+    end
   end
 end