Automatic SSL certificate provisioning for localhost

Gemfile

@@ -23,3 +23,4 @@ if %w(2.2.7 2.2.8 2.2.9 2.2.10 2.3.4 2.4.1).include? RUBY_VERSION
 end
 
 gem 'm'
+gem "localhost", require: false

README.md

@@ -187,6 +187,21 @@ Need a bit of security? Use SSL sockets:
 ```
 $ puma -b 'ssl://127.0.0.1:9292?key=path_to_key&cert=path_to_cert'
 ```
+#### Self-signed SSL certificates (via _localhost_ gem, for development use): 
+
+Puma supports [localhost](https://github.com/socketry/localhost) gem for self-signed certificates. This is particularly useful if you want to use Puma with SSL locally, and self-signed certificates will work for your use-case. Currently, `localhost-authority` can be used only in MRI. To use [localhost](https://github.com/socketry/localhost), you have to `require "localhost/authority"`: 
+
+```ruby
+# config.ru
+require './app'
+require 'localhost/authority'
+run Sinatra::Application
+
+...
+
+$ puma -b 'ssl://localhost:9292' config.ru
+```
+
 
 #### Controlling SSL Cipher Suites
 

lib/puma/binder.rb

@@ -57,6 +57,7 @@ def initialize(events, conf = Configuration.new)
 
       @envs = {}
       @ios = []
+      localhost_authority
     end
 
     attr_reader :ios
@@ -227,7 +228,13 @@ def parse(binds, logger, log_msg = 'Listening')
           raise "Puma compiled without SSL support" unless HAS_SSL
 
           params = Util.parse_query uri.query
-          ctx = MiniSSL::ContextBuilder.new(params, @events).context
+
+          # If key and certs are not defined and localhost gem is required.
+          # localhost gem will be used for self signed
+          # Load localhost authority if not loaded.
+          ctx = localhost_authority && localhost_authority_context if params.empty?
+
+          ctx ||= MiniSSL::ContextBuilder.new(params, @events).context
 
           if fd = @inherited_fds.delete(str)
             logger.log "* Inherited #{str}"
@@ -285,6 +292,22 @@ def parse(binds, logger, log_msg = 'Listening')
       end
     end
 
+    def localhost_authority
+      @localhost_authority ||= Localhost::Authority.fetch if defined?(Localhost::Authority) && !Puma::IS_JRUBY
+    end
+
+    def localhost_authority_context
+      return unless localhost_authority
+
+      key_path, crt_path = if [:key_path, :certificate_path].all? { |m| localhost_authority.respond_to?(m) }
+        [localhost_authority.key_path, localhost_authority.certificate_path]
+      else
+        local_certificates_path = File.expand_path("~/.localhost")
+        [File.join(local_certificates_path, "localhost.key"), File.join(local_certificates_path, "localhost.crt")]
+      end
+      MiniSSL::ContextBuilder.new({ "key" => key_path, "cert" => crt_path }, @events).context
+    end
+
     # Tell the server to listen on host +host+, port +port+.
     # If +optimize_for_latency+ is true (the default) then clients connecting
     # will be optimized for latency over throughput.
@@ -302,6 +325,7 @@ def add_tcp_listener(host, port, optimize_for_latency=true, backlog=1024)
 
       host = host[1..-2] if host and host[0..0] == '['
       tcp_server = TCPServer.new(host, port)
+
       if optimize_for_latency
         tcp_server.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
       end
@@ -323,6 +347,8 @@ def add_ssl_listener(host, port, ctx,
                          optimize_for_latency=true, backlog=1024)
 
       raise "Puma compiled without SSL support" unless HAS_SSL
+      # Puma will try to use local authority context if context is supplied nil
+      ctx ||= localhost_authority_context
 
       if host == "localhost"
         loopback_addresses.each do |addr|
@@ -350,6 +376,8 @@ def add_ssl_listener(host, port, ctx,
 
     def inherit_ssl_listener(fd, ctx)
       raise "Puma compiled without SSL support" unless HAS_SSL
+      # Puma will try to use local authority context if context is supplied nil
+      ctx ||= localhost_authority_context
 
       s = fd.kind_of?(::TCPServer) ? fd : ::TCPServer.for_fd(fd)
 

test/test_puma_localhost_authority.rb

@@ -0,0 +1,106 @@
+# Nothing in this file runs if Puma isn't compiled with ssl support
+#
+# helper is required first since it loads Puma, which needs to be
+# loaded so HAS_SSL is defined
+require_relative "helper"
+require "localhost/authority"
+
+if ::Puma::HAS_SSL && !Puma::IS_JRUBY
+  require "puma/minissl"
+  require "puma/events"
+  require "net/http"
+
+  class SSLEventsHelper < ::Puma::Events
+    attr_accessor :addr, :cert, :error
+
+    def ssl_error(error, ssl_socket)
+      self.error = error
+      self.addr = ssl_socket.peeraddr.last rescue "<unknown>"
+      self.cert = ssl_socket.peercert
+    end
+  end
+
+  # net/http (loaded in helper) does not necessarily load OpenSSL
+  require "openssl" unless Object.const_defined? :OpenSSL
+end
+
+class TestPumaLocalhostAuthority < Minitest::Test
+  parallelize_me!
+  def setup
+    @http = nil
+    @server = nil
+  end
+
+  def teardown
+    @http.finish if @http && @http.started?
+    @server.stop(true) if @server
+  end
+
+  # yields ctx to block, use for ctx setup & configuration
+  def start_server
+    @host = "localhost"
+    app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
+
+    @events = SSLEventsHelper.new STDOUT, STDERR
+    @server = Puma::Server.new app, @events
+    @server.app = app
+    @server.add_ssl_listener @host, 0,nil
+    @http = Net::HTTP.new @host, @server.connected_ports[0]
+
+    @http.use_ssl = true
+    # Disabling verification since its self signed
+    @http.verify_mode = OpenSSL::SSL::VERIFY_NONE
+    # @http.verify_mode = OpenSSL::SSL::VERIFY_NONE
+
+    @server.run
+  end
+
+  def test_localhost_authority_file_generated
+    # Initiate server to create localhost authority
+    unless File.exist?(File.join(Localhost::Authority.path,"localhost.key"))
+      start_server
+    end
+    assert_equal(File.exist?(File.join(Localhost::Authority.path,"localhost.key")), true)
+    assert_equal(File.exist?(File.join(Localhost::Authority.path,"localhost.crt")), true)
+  end
+
+end if ::Puma::HAS_SSL &&  !Puma::IS_JRUBY
+
+class TestPumaSSLLocalhostAuthority < Minitest::Test
+  def test_self_signed_by_localhost_authority
+    @host = "localhost"
+
+    app = lambda { |env| [200, {}, [env['rack.url_scheme']]] }
+
+    @events = SSLEventsHelper.new STDOUT, STDERR
+
+    @server = Puma::Server.new app, @events
+    @server.app = app
+
+    @server.add_ssl_listener @host, 0,nil
+
+    @http = Net::HTTP.new @host, @server.connected_ports[0]
+    @http.use_ssl = true
+
+    OpenSSL::PKey::RSA.new File.read(File.join(Localhost::Authority.path,"localhost.key"))
+    local_authority_crt = OpenSSL::X509::Certificate.new File.read(File.join(Localhost::Authority.path,"localhost.crt"))
+
+    @http.verify_mode = OpenSSL::SSL::VERIFY_NONE
+    @server.run
+    @cert = nil
+    begin
+      @http.start do
+        req = Net::HTTP::Get.new "/", {}
+        @http.request(req)
+        @cert = @http.peer_cert
+      end
+    rescue OpenSSL::SSL::SSLError, EOFError, Errno::ECONNRESET
+      # Errno::ECONNRESET TruffleRuby
+      # closes socket if open, may not close on error
+      @http.send :do_finish
+    end
+    sleep 0.1
+
+    assert_equal(@cert.to_pem, local_authority_crt.to_pem)
+  end
+end  if ::Puma::HAS_SSL && !Puma::IS_JRUBY