smtp_tls.rb

require "openssl"
require "net/smtp"

Net::SMTP.class_eval do
  private
  def do_start(helodomain, user, secret, authtype)
    raise IOError, 'SMTP session already started' if @started
    #check_auth_args user, secret, authtype if user or secret

    no_args = method(:check_auth_args).arity

    if no_args == 2
      check_auth_args user, secret if user or secret
    else
      check_auth_args user, secret, authtype if user or secret
    end

    sock = timeout(@open_timeout) { TCPSocket.open(@address, @port) }
    @socket = Net::InternetMessageIO.new(sock)
    @socket.read_timeout = 60 #@read_timeout
    @socket.debug_output = STDERR #@debug_output

    check_response(critical { recv_response() })
    do_helo(helodomain)

    raise 'openssl library not installed' unless defined?(OpenSSL)
    starttls
    ssl = OpenSSL::SSL::SSLSocket.new(sock)
    ssl.sync_close = true
    ssl.connect
    @socket = Net::InternetMessageIO.new(ssl)
    @socket.read_timeout = 60 #@read_timeout
    @socket.debug_output = STDERR #@debug_output
    do_helo(helodomain)

    authenticate user, secret, authtype if user

    @started = true
  ensure
    unless @started
      # authentication failed, cancel connection.
        @socket.close if not @started and @socket and not @socket.closed?
      @socket = nil
    end
  end

  def do_helo(helodomain)
     begin
      if @esmtp
        ehlo helodomain
      else
        helo helodomain
      end
    rescue Net::ProtocolError
      if @esmtp
        @esmtp = false
        @error_occured = false
        retry
      end
      raise
    end
  end

  def starttls
    getok('STARTTLS')
  end

  def quit
    begin
      getok('QUIT')
    rescue EOFError
    end
  end
end