[rubygems/rubygems] Add WebauthnListener response classes

https://github.com/rubygems/rubygems/commit/0e9a26acb1

lib/rubygems/webauthn_listener/response.rb

@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+##
+# The WebauthnListener Response class is used by the WebauthnListener to print
+# the specified response to the Gem host using the provided socket. It also closes
+# the socket after printing the response.
+#
+# Types of response classes:
+#   - ResponseOk
+#   - ResponseNoContent
+#   - ResponseBadRequest
+#   - ResponseNotFound
+#   - ResponseMethodNotAllowed
+#
+# Example:
+#   socket = TCPSocket.new(host, port)
+#   Gem::WebauthnListener::ResponseOk.send(socket, host)
+#
+
+class Gem::WebauthnListener
+  class Response
+    attr_reader :host
+
+    def initialize(host)
+      @host = host
+    end
+
+    def self.send(socket, host)
+      socket.print new(host).payload
+      socket.close
+    end
+
+    def payload
+      status_line_and_connection + access_control_headers + content
+    end
+
+    private
+
+    def status_line_and_connection
+      <<~RESPONSE
+        HTTP/1.1 #{status}
+        Connection: close
+      RESPONSE
+    end
+
+    def access_control_headers
+      return "" unless add_access_control_headers?
+      <<~RESPONSE
+        Access-Control-Allow-Origin: #{host}
+        Access-Control-Allow-Methods: POST
+        Access-Control-Allow-Headers: Content-Type, Authorization, x-csrf-token
+      RESPONSE
+    end
+
+    def content
+      return "" unless body
+      <<~RESPONSE
+        Content-Type: text/plain
+        Content-Length: #{body.bytesize}
+
+        #{body}
+      RESPONSE
+    end
+
+    def status
+      raise NotImplementedError
+    end
+
+    def add_access_control_headers?
+      false
+    end
+
+    def body; end
+  end
+end

lib/rubygems/webauthn_listener/response/response_bad_request.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require_relative "../response"
+
+class Gem::WebauthnListener::ResponseBadRequest < Gem::WebauthnListener::Response
+  private
+
+  def status
+    "400 Bad Request"
+  end
+
+  def body
+    "missing code parameter"
+  end
+end

lib/rubygems/webauthn_listener/response/response_method_not_allowed.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require_relative "../response"
+
+class Gem::WebauthnListener::ResponseMethodNotAllowed < Gem::WebauthnListener::Response
+  private
+
+  def status
+    "405 Method Not Allowed"
+  end
+
+  def content
+    <<~RESPONSE
+      Allow: GET, OPTIONS
+    RESPONSE
+  end
+end

lib/rubygems/webauthn_listener/response/response_no_content.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require_relative "../response"
+
+class Gem::WebauthnListener::ResponseNoContent < Gem::WebauthnListener::Response
+  private
+
+  def status
+    "204 No Content"
+  end
+
+  def add_access_control_headers?
+    true
+  end
+end

lib/rubygems/webauthn_listener/response/response_not_found.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+require_relative "../response"
+
+class Gem::WebauthnListener::ResponseNotFound < Gem::WebauthnListener::Response
+  private
+
+  def status
+    "404 Not Found"
+  end
+end

lib/rubygems/webauthn_listener/response/response_ok.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require_relative "../response"
+
+class Gem::WebauthnListener::ResponseOk < Gem::WebauthnListener::Response
+  private
+
+  def status
+    "200 OK"
+  end
+
+  def add_access_control_headers?
+    true
+  end
+
+  def body
+    "success"
+  end
+end

test/rubygems/test_webauthn_listener_response.rb

@@ -0,0 +1,107 @@
+# frozen_string_literal: true
+
+require_relative "helper"
+require "rubygems/webauthn_listener/response/response_ok"
+require "rubygems/webauthn_listener/response/response_no_content"
+require "rubygems/webauthn_listener/response/response_bad_request"
+require "rubygems/webauthn_listener/response/response_not_found"
+require "rubygems/webauthn_listener/response/response_method_not_allowed"
+
+class WebauthnListenerResponseTest < Gem::TestCase
+  class MockResponse < Gem::WebauthnListener::Response
+    def payload
+      "hello world"
+    end
+  end
+
+  def setup
+    super
+    @host = "rubygems.example"
+  end
+
+  def test_ok_response_payload
+    payload = Gem::WebauthnListener::ResponseOk.new(@host).payload
+
+    expected_payload = <<~RESPONSE
+      HTTP/1.1 200 OK
+      Connection: close
+      Access-Control-Allow-Origin: rubygems.example
+      Access-Control-Allow-Methods: POST
+      Access-Control-Allow-Headers: Content-Type, Authorization, x-csrf-token
+      Content-Type: text/plain
+      Content-Length: 7
+
+      success
+    RESPONSE
+
+    assert_equal expected_payload, payload
+  end
+
+  def test_no_payload_response_payload
+    payload = Gem::WebauthnListener::ResponseNoContent.new(@host).payload
+
+    expected_payload = <<~RESPONSE
+      HTTP/1.1 204 No Content
+      Connection: close
+      Access-Control-Allow-Origin: rubygems.example
+      Access-Control-Allow-Methods: POST
+      Access-Control-Allow-Headers: Content-Type, Authorization, x-csrf-token
+    RESPONSE
+
+    assert_equal expected_payload, payload
+  end
+
+  def test_method_not_allowed_response_payload
+    payload = Gem::WebauthnListener::ResponseMethodNotAllowed.new(@host).payload
+
+    expected_payload = <<~RESPONSE
+      HTTP/1.1 405 Method Not Allowed
+      Connection: close
+      Allow: GET, OPTIONS
+    RESPONSE
+
+    assert_equal expected_payload, payload
+  end
+
+  def test_method_not_found_response_payload
+    payload = Gem::WebauthnListener::ResponseNotFound.new(@host).payload
+
+    expected_payload = <<~RESPONSE
+      HTTP/1.1 404 Not Found
+      Connection: close
+    RESPONSE
+
+    assert_equal expected_payload, payload
+  end
+
+  def test_bad_request_response_payload
+    payload = Gem::WebauthnListener::ResponseBadRequest.new(@host).payload
+
+    expected_payload = <<~RESPONSE
+      HTTP/1.1 400 Bad Request
+      Connection: close
+      Content-Type: text/plain
+      Content-Length: 22
+
+      missing code parameter
+    RESPONSE
+
+    assert_equal expected_payload, payload
+  end
+
+  def test_send_response
+    server = TCPServer.new "localhost", 5678
+    thread = Thread.new do
+      receive_socket = server.accept
+      Thread.current[:payload] = receive_socket.read
+      receive_socket.close
+    end
+
+    send_socket = TCPSocket.new "localhost", 5678
+    MockResponse.send(send_socket, @host)
+
+    thread.join
+    assert_equal "hello world", thread[:payload]
+    assert_predicate send_socket, :closed?
+  end
+end