Issue objects as custom facts

examples/fact_request/custom_objects.rb

@@ -0,0 +1,67 @@
+# Copyright 2020 Self Group Ltd. All Rights Reserved.
+
+# frozen_string_literal: true
+
+require_relative '../../lib/selfsdk'
+
+# Process input data
+abort("provide self_id to request information to") if ARGV.length != 1
+user = ARGV.first
+SelfSDK.logger = ::Logger.new($stdout).tap do |log|
+  log.progname = "SelfSDK examples"
+end if ENV.has_key?'LOGS'
+
+# You can point to a different environment by passing optional values to the initializer
+opts = ENV.has_key?('SELF_ENV') ? { env: ENV["SELF_ENV"] } : {}
+storage_dir = "#{File.expand_path("..", File.dirname(__FILE__))}/self_storage"
+
+# Connect your app to Self network, get your connection details creating a new
+# app on https://developer.selfsdk.net/
+puts 'connecting...'
+@app = SelfSDK::App.new(ENV["SELF_APP_ID"], ENV["SELF_APP_DEVICE_SECRET"], ENV["STORAGE_KEY"], storage_dir, opts).start
+
+# Create a custom fact and send it to the user.
+puts 'issuing custom facts'
+
+
+begin
+  data = File.binread("my_image.png")
+rescue => e
+  puts "\u26A0 You must provide a PNG image to be stored as a user's fact"
+  exit!
+end
+obj = @app.new_object("my_image", data, "image/png")
+
+my_fact = SelfSDK::Services::Facts::Fact.new(
+  "display image",
+  obj,
+  "source12")
+
+@app.facts.issue(user, [my_fact])
+sleep 5
+
+# Request the custom fact
+begin
+  @app.facts.request(user, [{ fact: my_fact.key, issuers: [ENV["SELF_APP_ID"]] }]) do |res|
+    # Information request has been rejected by the user
+    if res.status == "rejected"
+      puts 'Information request rejected'
+      exit!
+    end
+
+    # Response comes in form of facts easy to access with facts method
+    hash = res.attestation(my_fact.key.to_sym).value
+    puts "Your stored fact is #{res.attestation(my_fact.key.to_sym).value}!"
+    o = res.object(hash)
+
+    o.save("/tmp/received.jpg")
+    puts "Received object hash is #{o.object_hash}"
+    exit!
+  end
+rescue => e
+  puts "ERROR : #{e}"
+  exit!
+end
+
+# Wait for asyncrhonous process to finish
+sleep 1000

lib/chat/file_object.rb

@@ -6,7 +6,7 @@
 module SelfSDK
   module Chat
     class FileObject
-      attr_accessor :name, :link, :mime, :content, :key, :nonce, :ciphertext
+      attr_accessor :name, :link, :mime, :content, :object_hash, :key, :nonce, :ciphertext
 
       def initialize(token, url)
         @token = token
@@ -17,6 +17,7 @@ def build_from_data(name, data, mime, opts = {})
         @key = SelfCrypto::Util.aead_xchacha20poly1305_ietf_keygen
         @nonce = SelfCrypto::Util.aead_xchacha20poly1305_ietf_nonce
         @content = data
+        @object_hash = calculate_hash(@content)
         @name = name
         @mime = mime
 
@@ -54,6 +55,7 @@ def build_from_object(input)
         end
 
         @content = ciphertext
+
         @key = nil
         @nonce = nil
         if input.key?(:key) && !input[:key].empty?
@@ -65,6 +67,11 @@ def build_from_object(input)
           @content = SelfCrypto::Util.aead_xchacha20poly1305_ietf_decrypt(@key, @nonce, ciphertext)
         end
 
+        @object_hash = calculate_hash(@content)
+        if @object_hash != input[:object_hash]
+          raise "File hash does not match the originally signed hash."
+        end
+
         @name =  input[:name]
         @link =  input[:link]
         @mime =  input[:mime]
@@ -81,7 +88,8 @@ def to_payload
           key: k,
           mime: @mime,
           expires: @expires,
-          public: (k == "")
+          public: (k == ""),
+          object_hash: @object_hash
         }
       end
 
@@ -111,6 +119,12 @@ def extract_key(shareable_key)
         { key: k[0, 32],
           nonce: k[32, (k.length - 32)] }
       end
+
+      def calculate_hash(ct)
+        d = Digest::SHA256.digest(ct)
+        Base64.urlsafe_encode64(d).gsub(/=+\Z/, '')
+      end
+
     end
   end
 end

lib/client.rb

@@ -80,7 +80,7 @@ def post(endpoint, body)
 
     def get(endpoint)
       safe_request do
-        HTTParty.get("#{@self_url}#{endpoint}", 
+        HTTParty.get("#{@self_url}#{endpoint}",
                      headers: {
                         'Content-Type'  => 'application/json',
                         'Authorization' => "Bearer #{@jwt.auth_token}"

lib/messages/fact_issue.rb

@@ -25,6 +25,7 @@ def populate(selfid, facts, opts)
         @from = @jwt.id
         @to = selfid
         @attestations = build_attestations!(facts)
+        @objects = build_objects(facts)
       end
 
       def body
@@ -42,6 +43,7 @@ def body
         }
         # viewers
         b[:viewers] = @viewers unless @viewers.nil?
+        b[:objects] = @objects unless @objects.empty?
         b
       end
 
@@ -68,7 +70,8 @@ def build_attestations!(facts)
         raise 'facts must be provided in the form of an array' unless facts.kind_of?(Array)
 
         attestations = []
-        facts.each do |fact|
+        facts.each do |f|
+          fact = f.to_hash
           att = fact.transform_keys(&:to_sym)
           raise 'invalid attestation : does not provide a key' if !att.has_key?(:key) || att[:key].empty?
 
@@ -81,6 +84,16 @@ def build_attestations!(facts)
         attestations
       end
 
+      def build_objects(facts)
+        objects = []
+        facts.each do |fact|
+          if fact.respond_to? :object and !fact.object.nil?
+            objects << fact.object.to_payload
+          end
+        end
+        objects
+      end
+
       def sign(source, facts)
         fact = { jti: SecureRandom.uuid,
                  sub: @to,

lib/messages/fact_response.rb

@@ -113,12 +113,13 @@ def auth_response?
 
       def object(hash)
         payload[:objects].each do |o|
-          if o[:image_hash] == hash
+          if o[:object_hash] == hash || o[:image_hash] == hash
             return SelfSDK::Chat::FileObject.new(
               @messaging.client.jwt.auth_token,
               @messaging.client.self_url).build_from_object(o)
           end
         end
+        return nil
       end
     end
   end

lib/selfsdk.rb

@@ -132,6 +132,12 @@ def close
       @messaging_client.close
     end
 
+    def new_object(name, content, mime)
+      o = SelfSDK::Chat::FileObject.new(client.jwt.auth_token, client.self_url)
+      o.build_from_data(name, content, mime)
+      o
+    end
+
     protected
 
       def requester
@@ -152,9 +158,9 @@ def messaging_url(opts)
 
       def cleanup_key(key)
         return key unless key.include? '_'
-  
+
         key.split('_').last
       end
-    
+
   end
 end

lib/services/facts.rb

@@ -100,24 +100,26 @@ def generate_deep_link(facts, callback, opts = {})
       # @param facts [Array<Fact>] facts to be sent to the user
       # @option opts [String] :viewers list of self identifiers for the user that will have access to this facts.
       def issue(selfid, facts, opts = {})
-        hased_facts = []
-        facts.each do |f|
-          hased_facts << f.to_hash
-        end
-
         SelfSDK.logger.info "issuing facts for #{selfid}"
         msg = SelfSDK::Messages::FactIssue.new(@requester.messaging)
-        msg.populate(selfid, hased_facts, opts)
+        msg.populate(selfid, facts, opts)
 
         msg.send_message
       end
 
       # Facts to be issued
       class Fact
-        attr_accessor :key, :value, :group
+        attr_accessor :key, :value, :group, :object
 
 
         def initialize(key, value, source, opts = {})
+          if value.is_a?(SelfSDK::Chat::FileObject)
+            @object = value
+            value = @object.object_hash
+          elsif !value.is_a?(String)
+            raise "supported values are strings and FileObject"
+          end
+
           @key = key
           @value = value
           @source = source

test/messages/fact_test.rb

@@ -39,7 +39,7 @@ def test_parse
 
         assert_equal "display_name", parsed_fact[:fact]
         assert_equal "==", parsed_fact[:operator]
-        assert_equal nil, parsed_fact[:attestations]
+        assert_nil parsed_fact[:attestations]
         assert_equal "lol", parsed_fact[:expected_value]
       end
     end