Add QR code output to the greeter

LICENSE

@@ -1,6 +1,8 @@
 MIT License
 
 Copyright (c) 2018 Karl Entwistle
+Copyright (c) 2017 Maxim Kulkin
+Copyright (c) 2020 Philipp Erbelding
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

lib/ruby_home/accessory_info.rb

@@ -16,11 +16,12 @@ def self.reload
 
     USERNAME = -'Pair-Setup'
 
-    def initialize(device_id: nil, paired_clients: [], password: nil, signature_key: nil)
+    def initialize(device_id: nil, paired_clients: [], password: nil, signature_key: nil, setup_id: nil)
       @device_id = device_id
       @paired_clients = paired_clients
       @password = password
       @signature_key = signature_key
+      @setup_id = setup_id
     end
 
     def username
@@ -62,6 +63,10 @@ def signing_key
       @signing_key ||= RbNaCl::Signatures::Ed25519::SigningKey.new([signature_key].pack('H*'))
     end
 
+    def setup_id
+      @setup_id ||= SetupID.generate
+    end
+
     private
 
       def signature_key
@@ -73,7 +78,8 @@ def persisted_attributes
           device_id: device_id,
           paired_clients: paired_clients,
           password: password,
-          signature_key: signature_key
+          signature_key: signature_key,
+          setup_id: setup_id
         }
       end
   end

lib/ruby_home/dns/service.rb

@@ -15,6 +15,10 @@ def register
         dnssd_service
       end
 
+      def text_record
+        TextRecord.new(accessory_info: accessory_info, configuration: configuration)
+      end
+
       private
 
       attr_reader :configuration
@@ -43,10 +47,6 @@ def host
         configuration.host
       end
 
-      def text_record
-        TextRecord.new(accessory_info: accessory_info, configuration: configuration)
-      end
-
       def accessory_info
         AccessoryInfo.instance
       end

lib/ruby_home/dns/text_record.rb

@@ -1,3 +1,5 @@
+require 'digest'
+require 'base64'
 module RubyHome
   class TextRecord < DNSSD::TextRecord
     def initialize(accessory_info:, configuration:)
@@ -6,6 +8,32 @@ def initialize(accessory_info:, configuration:)
       super(to_hash)
     end
 
+    # Accessory Category Identifier. Required. Indicates the category that best
+    # describes the primary function of the accessory. This must have a range of
+    # 1-65535.
+
+    def accessory_category_identifier
+      2
+    end
+
+    # Protocol version string <major>.<minor> (e.g. "1.0"). Required if value is
+    # not "1.0". The client should check this before displaying an accessory to
+    # the user. If the major version is greater than the major version the client
+    # software was built to support, it should hide the accessory from the user. A
+    # change in the minor version indicates the protocol is still compatible. This
+    # mechanism allows future versions of the protocol to hide itself from older
+    # clients that may not know how to handle it.
+
+    def protocol_version
+      '1.1'
+    end
+
+    # Feature flags (e.g. "0x3" for bits 0 and 1). Required if non-zero.
+
+    def feature_flags
+      0
+    end
+
     private
 
     attr_reader :accessory_info, :configuration
@@ -19,7 +47,8 @@ def to_hash
         'md' => model_name,
         'pv' => protocol_version,
         's#' => current_state_number,
-        'sf' => status_flags
+        'sf' => status_flags,
+        'sh' => setup_hash
       }
     end
 
@@ -33,20 +62,6 @@ def current_configuration_number
       1
     end
 
-    # Accessory Category Identifier. Required. Indicates the category that best
-    # describes the primary function of the accessory. This must have a range of
-    # 1-65535.
-
-    def accessory_category_identifier
-      2
-    end
-
-    # Feature flags (e.g. "0x3" for bits 0 and 1). Required if non-zero.
-
-    def feature_flags
-      0
-    end
-
     # Status flags (e.g. "0x04" for bit 3). Value should be an unsigned integer.
     # Required if non-zero.
 
@@ -78,22 +93,27 @@ def model_name
       configuration.model_name
     end
 
-    # Protocol version string <major>.<minor> (e.g. "1.0"). Required if value is
-    # not "1.0". The client should check this before displaying an accessory to
-    # the user. If the major version is greater than the major version the client
-    # software was built to support, it should hide the accessory from the user. A
-    # change in the minor version indicates the protocol is still compatible. This
-    # mechanism allows future versions of the protocol to hide itself from older
-    # clients that may not know how to handle it.
-
-    def protocol_version
-      1.0
-    end
-
     # Current state number. Required. This must have a value of "1".
 
     def current_state_number
       1
     end
+
+    # Setup id
+
+    def setup_id
+      accessory_info.setup_id
+    end
+
+    def setup_hash
+      # concat setup_id and whatever accessory_info.username is (id field in the record)
+      input = setup_id + device_id
+      # sha512 digest that
+      hashvalue = Digest::SHA2.new(512).digest(input)
+      # first 4 bytes of that
+      payload = hashvalue.slice(0,4)
+      # bas64 to string that
+      Base64.strict_encode64(payload)
+    end
   end
 end

lib/ruby_home/greeter.rb

@@ -1,3 +1,4 @@
+require 'rqrcode'
 module RubyHome
   module Greeter
     class << self
@@ -9,6 +10,7 @@ def run
           puts "    │ " + pin + " │    "
           puts "    └────────────┘     "
           puts "                       "
+          puts ascii_qrcode
         end
       end
 
@@ -23,6 +25,41 @@ def paired?
       def accessory_info
         AccessoryInfo.instance
       end
+
+      def url
+        record = RubyHome.dns_service.text_record
+        category = record.accessory_category_identifier
+        password = accessory_info.password
+        setup_id = accessory_info.setup_id
+
+        version = 0
+        reserved = 0
+        flags = record.feature_flags
+
+        payload = 0
+        payload |= (version & 0x7)
+
+        payload <<= 4
+        payload |= (reserved & 0xf)
+
+        payload <<= 8
+        payload |= (category & 0xff)
+
+        payload <<= 4
+        payload |= (flags & 0xf)
+
+        payload <<= 27
+        payload |= password.gsub('-', '').to_i(10) & 0x7fffffff
+
+        "X-HM://#{payload.to_s(36).rjust(9, '0').upcase}#{setup_id.upcase}"
+      end
+
+      def ascii_qrcode
+        qrcode = RQRCode::QRCode.new(url)
+        terminal_qr = qrcode.to_s
+        terminal_qr.gsub!(' ', '⬜')
+        terminal_qr.gsub!('x', '⬛')
+      end
     end
   end
 end

lib/ruby_home/service.rb

@@ -44,5 +44,9 @@ def characteristic(characteristic_name)
         characteristic.name == characteristic_name
       end
     end
+
+    def to_s
+      "#{@name} - #{@description}"
+    end
   end
 end

lib/ruby_home/setup_id.rb

@@ -0,0 +1,21 @@
+module RubyHome
+  module SetupID
+    class << self
+      # Requirements for Setup ID of the accessory are not completely clear.
+      # A unique random string of letters, generated at every
+      # factory reset and persisted across reboots seems fine.
+
+      def generate(count=4)
+        id = ''
+        count.times {
+          id << random_letter
+        }
+        id
+      end
+
+      def random_letter
+        ('A'..'Z').to_a[rand(26)]
+      end
+    end
+  end
+end

lib/ruby_home/version.rb

@@ -1,3 +1,3 @@
 module RubyHome
-  VERSION = '0.2.4'
+  VERSION = '0.3.0'
 end

rubyhome.gemspec

@@ -31,9 +31,11 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'hkdf', '~> 0.3.0'
   spec.add_dependency 'oj', '~> 3.10'
   spec.add_dependency 'rbnacl', '~> 7.0'
+  spec.add_dependency 'rqrcode', '~> 1.2.0'
   spec.add_dependency 'ruby_home-srp', '~> 1.3'
   spec.add_dependency 'ruby_home-tlv', '~> 0.1'
   spec.add_dependency 'sinatra', '~> 2.0'
+  spec.add_dependency 'webrick', '~> 1.7.0'
   spec.add_dependency 'wisper', '~> 2.0'
 
   spec.add_development_dependency 'byebug', '~> 11.0'

spec/lib/setup_id_spec.rb

@@ -0,0 +1,9 @@
+RSpec.describe RubyHome::SetupID do
+
+  describe 'Setup ID generator' do
+    it 'outputs lenght of 4' do
+      expect(RubyHome::SetupID.generate.length).to eql(4)
+    end
+  end
+
+end