Add SMTPUTF8 support

lib/net/smtp.rb

@@ -81,12 +81,23 @@ class SMTPUnsupportedCommand < ProtocolError
     include SMTPError
   end
 
+  # Represents a need to use SMTPUTF8 when the server does not support it
+  class SMTPUTF8RequiredError < SMTPUnsupportedCommand
+  end
+
   #
   # == What is This Library?
   #
   # This library provides functionality to send internet
   # mail via SMTP, the Simple Mail Transfer Protocol. For details of
-  # SMTP itself, see [RFC2821] (http://www.ietf.org/rfc/rfc2821.txt).
+  # SMTP itself, see [RFC5321] (http://www.ietf.org/rfc/rfc5321.txt).
+  # This library also implements SMTP authentication, which is often
+  # necessary for message composers to submit messages to their
+  # outgoing SMTP server, see
+  # [RFC6409](http://www.ietf.org/rfc/rfc6503.txt),
+  # and [SMTPUTF8](http://www.ietf.org/rfc/rfc6531.txt), which is
+  # necessary to send messages to/from addresses containing characters
+  # outside the ASCII range.
   #
   # == What is This Library NOT?
   #
@@ -96,7 +107,7 @@ class SMTPUnsupportedCommand < ProtocolError
   # {RubyGems.org}[https://rubygems.org/] or {The Ruby
   # Toolbox}[https://www.ruby-toolbox.com/].
   #
-  # FYI: the official documentation on internet mail is: [RFC2822] (http://www.ietf.org/rfc/rfc2822.txt).
+  # FYI: the official specification on internet mail is: [RFC5322] (http://www.ietf.org/rfc/rfc5322.txt).
   #
   # == Examples
   #
@@ -720,6 +731,18 @@ def do_finish
       @socket = nil
     end
 
+    def requires_smtputf8(address)
+      if address.kind_of? Address
+        !address.address.ascii_only?
+      else
+        !address.ascii_only?
+      end
+    end
+
+    def any_require_smtputf8(addresses)
+      addresses.any?{ |a| requires_smtputf8(a) }
+    end
+
     #
     # Message Sending
     #
@@ -758,13 +781,14 @@ def do_finish
     # * Net::SMTPServerBusy
     # * Net::SMTPSyntaxError
     # * Net::SMTPFatalError
+    # * Net::SMTPUTF8RequiredError
     # * Net::SMTPUnknownError
     # * Net::ReadTimeout
     # * IOError
     #
     def send_message(msgstr, from_addr, *to_addrs)
       raise IOError, 'closed session' unless @socket
-      mailfrom from_addr
+      mailfrom from_addr, any_require_smtputf8(to_addrs)
       rcptto_list(to_addrs) {data msgstr}
     end
 
@@ -811,13 +835,14 @@ def send_message(msgstr, from_addr, *to_addrs)
     # * Net::SMTPServerBusy
     # * Net::SMTPSyntaxError
     # * Net::SMTPFatalError
+    # * Net::SMTPUTF8RequiredError
     # * Net::SMTPUnknownError
     # * Net::ReadTimeout
     # * IOError
     #
     def open_message_stream(from_addr, *to_addrs, &block)   # :yield: stream
       raise IOError, 'closed session' unless @socket
-      mailfrom from_addr
+      mailfrom from_addr, any_require_smtputf8(to_addrs)
       rcptto_list(to_addrs) {data(&block)}
     end
 
@@ -940,8 +965,13 @@ def ehlo(domain)
     end
 
     # +from_addr+ is +String+ or +Net::SMTP::Address+
-    def mailfrom(from_addr)
-      addr = Address.new(from_addr)
+    def mailfrom(from_addr, require_smtputf8 = false)
+      addr = if require_smtputf8 || requires_smtputf8(from_addr)
+               raise SMTPUTF8RequiredError, "Message requires SMTPUTF8 but server does not support that" unless capable? "SMTPUTF8"
+               Address.new(from_addr, "SMTPUTF8")
+             else
+               Address.new(from_addr)
+             end
       getok((["MAIL FROM:<#{addr.address}>"] + addr.parameters).join(' '))
     end
 
@@ -1196,8 +1226,9 @@ def initialize(address, *args, **kw_args)
           @parameters = address.parameters
         else
           @address = address
-          @parameters = (args + [kw_args]).map{|param| Array(param)}.flatten(1).map{|param| Array(param).compact.join('=')}
+          @parameters = []
         end
+        @parameters = (parameters + args + [kw_args]).map{|param| Array(param)}.flatten(1).map{|param| Array(param).compact.join('=')}
       end
 
       def to_s

test/net/smtp/test_smtp.rb

@@ -1,3 +1,4 @@
+# coding: utf-8
 # frozen_string_literal: true
 require 'net/smtp'
 require 'stringio'
@@ -9,6 +10,16 @@ class TestSMTP < Test::Unit::TestCase
     SERVER_KEY = File.expand_path("../fixtures/server.key", __dir__)
     SERVER_CERT = File.expand_path("../fixtures/server.crt", __dir__)
 
+    class FakeIO
+      def sync
+        nil
+      end
+      def sync=(unused)
+      end
+      def flush
+      end
+    end
+
     class FakeSocket
       attr_reader :write_io
 
@@ -26,6 +37,16 @@ def readline
         raise 'ran out of input' unless line
         line.chop
       end
+
+      def io
+        return @io ||= FakeIO.new
+      end
+
+      def write_message(unused)
+      end
+
+      def write_message_by_block
+      end
     end
 
     def setup
@@ -76,13 +97,13 @@ def test_server_capabilities
         smtp = Net::SMTP.start('localhost', port, starttls: false)
         assert_equal({"STARTTLS"=>[], "AUTH"=>["PLAIN"]}, smtp.capabilities)
         assert_equal(true, smtp.capable?('STARTTLS'))
-        assert_equal(false, smtp.capable?('SMTPUTF8'))
+        assert_equal(false, smtp.capable?('DOES-NOT-EXIST'))
       else
         port = fake_server_start
         smtp = Net::SMTP.start('localhost', port, starttls: false)
         assert_equal({"AUTH"=>["PLAIN"]}, smtp.capabilities)
         assert_equal(false, smtp.capable?('STARTTLS'))
-        assert_equal(false, smtp.capable?('SMTPUTF8'))
+        assert_equal(false, smtp.capable?('DOES-NOT-EXIST'))
       end
       smtp.finish
     end
@@ -560,6 +581,51 @@ def test_start_instance_invalid_number_of_arguments
       assert_equal('wrong number of arguments (given 5, expected 0..4)', err.message)
     end
 
+    def test_send_smtputf_sender_without_server
+      sock = FakeSocket.new("220 OK\r\n250-test\r\n250 SMTPUTF8\r\n")
+      smtp = Net::SMTP.new 'localhost', 25
+      smtp.instance_variable_set :@socket, sock
+      assert_raise(Net::SMTPUTF8RequiredError) do
+        smtp.send_message('message', 'rené@example.com')
+      end
+    end
+
+    def test_send_smtputf8_sender
+      smtp = Net::SMTP.new 'localhost', 25
+      smtp.instance_variable_set :@capabilities, {"SMTPUTF8"=>[]}
+      sock = FakeSocket.new("250 OK\r\n250 OK\r\n354 Blah\r\n250 Queued, in a way\r\n")
+      smtp.instance_variable_set :@socket, sock
+      smtp.send_message('message', 'rené@example.com', '[email protected]')
+      assert sock.write_io.string.include? "MAIL FROM:<rené@example.com> SMTPUTF8\r\n"
+    end
+
+    def test_send_smtputf8_sender_with_size
+      smtp = Net::SMTP.new 'localhost', 25
+      smtp.instance_variable_set :@capabilities, {"SMTPUTF8"=>[]}
+      sock = FakeSocket.new("250 OK\r\n250 OK\r\n354 Blah\r\n250 Queued, in a way\r\n")
+      smtp.instance_variable_set :@socket, sock
+      smtp.send_message('message', Net::SMTP::Address.new('rené@example.com', 'SIZE=42'), '[email protected]')
+      assert sock.write_io.string.include? "MAIL FROM:<rené@example.com> SIZE=42 SMTPUTF8\r\n"
+    end
+
+    def test_send_smtputf_recipient
+      smtp = Net::SMTP.new 'localhost', 25
+      smtp.instance_variable_set :@capabilities, {"SMTPUTF8"=>[]}
+      sock = FakeSocket.new("250 MAIL OK\r\n250 RCPT OK\r\n354 Blah\r\n250 Queued, in a way\r\n")
+      smtp.instance_variable_set :@socket, sock
+      smtp.send_message('message', '[email protected]', 'rené@example.com')
+      assert sock.write_io.string.include? "MAIL FROM:<[email protected]> SMTPUTF8\r\n"
+    end
+
+    def test_mailfrom_with_smtputf_detection
+      sock = FakeSocket.new
+      smtp = Net::SMTP.new 'localhost', 25
+      smtp.instance_variable_set :@socket, sock
+      smtp.instance_variable_set :@capabilities, {"SMTPUTF8"=>""}
+      smtp.mailfrom("rené@example.com")
+      assert sock.write_io.string.include? "MAIL FROM:<rené@example.com> SMTPUTF8\r\n"
+    end
+
     private
 
     def accept(servers)