FM / net

/opt/cpanel/ea-ruby27/root/usr/share/ruby/ruby-2.7.8/net/

/opt/cpanel/ea-ruby27/root/usr/share/ruby/ruby-2.7.8/net

Name	Size	Mode	Actions
http/	-	0755	rm
pop/	-	0755	rm
smtp/	-	0755	rm
ftp.rb	43851	0644	edit dl rm
http.rb	52750	0644	edit dl rm
https.rb	532	0644	edit dl rm
imap.rb	113759	0644	edit dl rm
pop.rb	27241	0644	edit dl rm
protocol.rb	10953	0644	edit dl rm
smtp.rb	30716	0644	edit dl rm

Edit: /opt/cpanel/ea-ruby27/root/usr/share/ruby/ruby-2.7.8/net/smtp.rb (30716B)

# frozen_string_literal: true
# = net/smtp.rb
#
# Copyright (c) 1999-2007 Yukihiro Matsumoto.
#
# Copyright (c) 1999-2007 Minero Aoki.
#
# Written & maintained by Minero Aoki <aamine@loveruby.net>.
#
# Documented by William Webber and Minero Aoki.
#
# This program is free software. You can re-distribute and/or
# modify this program under the same terms as Ruby itself.
#
# $Id$
#
# See Net::SMTP for documentation.
#

require 'net/protocol'
require 'digest/md5'
require 'timeout'
begin
  require 'openssl'
rescue LoadError
end

module Net

# Module mixed in to all SMTP error classes
  module SMTPError
    # This *class* is a module for backward compatibility.
    # In later release, this module becomes a class.
  end

# Represents an SMTP authentication error.
  class SMTPAuthenticationError < ProtoAuthError
    include SMTPError
  end

# Represents SMTP error code 4xx, a temporary error.
  class SMTPServerBusy < ProtoServerError
    include SMTPError
  end

# Represents an SMTP command syntax error (error code 500)
  class SMTPSyntaxError < ProtoSyntaxError
    include SMTPError
  end

# Represents a fatal SMTP error (error code 5xx, except for 500)
  class SMTPFatalError < ProtoFatalError
    include SMTPError
  end

# Unexpected reply code returned from server.
  class SMTPUnknownError < ProtoUnknownError
    include SMTPError
  end

# Command is not supported on server.
  class SMTPUnsupportedCommand < ProtocolError
    include SMTPError
  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).
  #
  # == What is This Library NOT?
  #
  # This library does NOT provide functions to compose internet mails.
  # You must create them by yourself. If you want better mail support,
  # try RubyMail or TMail or search for alternatives in
  # {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).
  #
  # == Examples
  #
  # === Sending Messages
  #
  # You must open a connection to an SMTP server before sending messages.
  # The first argument is the address of your SMTP server, and the second
  # argument is the port number. Using SMTP.start with a block is the simplest
  # way to do this. This way, the SMTP connection is closed automatically
  # after the block is executed.
  #
  #     require 'net/smtp'
  #     Net::SMTP.start('your.smtp.server', 25) do |smtp|
  #       # Use the SMTP object smtp only in this block.
  #     end
  #
  # Replace 'your.smtp.server' with your SMTP server. Normally
  # your system manager or internet provider supplies a server
  # for you.
  #
  # Then you can send messages.
  #
  #     msgstr = <<END_OF_MESSAGE
  #     From: Your Name <your@mail.address>
  #     To: Destination Address <someone@example.com>
  #     Subject: test message
  #     Date: Sat, 23 Jun 2001 16:26:43 +0900
  #     Message-Id: <unique.message.id.string@example.com>
  #
  #     This is a test message.
  #     END_OF_MESSAGE
  #
  #     require 'net/smtp'
  #     Net::SMTP.start('your.smtp.server', 25) do |smtp|
  #       smtp.send_message msgstr,
  #                         'your@mail.address',
  #                         'his_address@example.com'
  #     end
  #
  # === Closing the Session
  #
  # You MUST close the SMTP session after sending messages, by calling
  # the #finish method:
  #
  #     # using SMTP#finish
  #     smtp = Net::SMTP.start('your.smtp.server', 25)
  #     smtp.send_message msgstr, 'from@address', 'to@address'
  #     smtp.finish
  #
  # You can also use the block form of SMTP.start/SMTP#start.  This closes
  # the SMTP session automatically:
  #
  #     # using block form of SMTP.start
  #     Net::SMTP.start('your.smtp.server', 25) do |smtp|
  #       smtp.send_message msgstr, 'from@address', 'to@address'
  #     end
  #
  # I strongly recommend this scheme.  This form is simpler and more robust.
  #
  # === HELO domain
  #
  # In almost all situations, you must provide a third argument
  # to SMTP.start/SMTP#start. This is the domain name which you are on
  # (the host to send mail from). It is called the "HELO domain".
  # The SMTP server will judge whether it should send or reject
  # the SMTP session by inspecting the HELO domain.
  #
  #     Net::SMTP.start('your.smtp.server', 25,
  #                     'mail.from.domain') { |smtp| ... }
  #
  # === SMTP Authentication
  #
  # The Net::SMTP class supports three authentication schemes;
  # PLAIN, LOGIN and CRAM MD5.  (SMTP Authentication: [RFC2554])
  # To use SMTP authentication, pass extra arguments to
  # SMTP.start/SMTP#start.
  #
  #     # PLAIN
  #     Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
  #                     'Your Account', 'Your Password', :plain)
  #     # LOGIN
  #     Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
  #                     'Your Account', 'Your Password', :login)
  #
  #     # CRAM MD5
  #     Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
  #                     'Your Account', 'Your Password', :cram_md5)
  #
  class SMTP < Protocol

Revision = %q$Revision$.split[1]

# The default SMTP port number, 25.
    def SMTP.default_port
      25
    end

# The default mail submission port number, 587.
    def SMTP.default_submission_port
      587
    end

# The default SMTPS port number, 465.
    def SMTP.default_tls_port
      465
    end

class << self
      alias default_ssl_port default_tls_port
    end

def SMTP.default_ssl_context
      OpenSSL::SSL::SSLContext.new
    end

#
    # Creates a new Net::SMTP object.
    #
    # +address+ is the hostname or ip address of your SMTP
    # server.  +port+ is the port to connect to; it defaults to
    # port 25.
    #
    # This method does not open the TCP connection.  You can use
    # SMTP.start instead of SMTP.new if you want to do everything
    # at once.  Otherwise, follow SMTP.new with SMTP#start.
    #
    def initialize(address, port = nil)
      @address = address
      @port = (port || SMTP.default_port)
      @esmtp = true
      @capabilities = nil
      @socket = nil
      @started = false
      @open_timeout = 30
      @read_timeout = 60
      @error_occurred = false
      @debug_output = nil
      @tls = false
      @starttls = false
      @ssl_context = nil
    end

# Provide human-readable stringification of class state.
    def inspect
      "#<#{self.class} #{@address}:#{@port} started=#{@started}>"
    end

#
    # Set whether to use ESMTP or not.  This should be done before
    # calling #start.  Note that if #start is called in ESMTP mode,
    # and the connection fails due to a ProtocolError, the SMTP
    # object will automatically switch to plain SMTP mode and
    # retry (but not vice versa).
    #
    attr_accessor :esmtp

# +true+ if the SMTP object uses ESMTP (which it does by default).
    alias :esmtp? :esmtp

# true if server advertises STARTTLS.
    # You cannot get valid value before opening SMTP session.
    def capable_starttls?
      capable?('STARTTLS')
    end

def capable?(key)
      return nil unless @capabilities
      @capabilities[key] ? true : false
    end
    private :capable?

# true if server advertises AUTH PLAIN.
    # You cannot get valid value before opening SMTP session.
    def capable_plain_auth?
      auth_capable?('PLAIN')
    end

# true if server advertises AUTH LOGIN.
    # You cannot get valid value before opening SMTP session.
    def capable_login_auth?
      auth_capable?('LOGIN')
    end

# true if server advertises AUTH CRAM-MD5.
    # You cannot get valid value before opening SMTP session.
    def capable_cram_md5_auth?
      auth_capable?('CRAM-MD5')
    end

def auth_capable?(type)
      return nil unless @capabilities
      return false unless @capabilities['AUTH']
      @capabilities['AUTH'].include?(type)
    end
    private :auth_capable?

# Returns supported authentication methods on this server.
    # You cannot get valid value before opening SMTP session.
    def capable_auth_types
      return [] unless @capabilities
      return [] unless @capabilities['AUTH']
      @capabilities['AUTH']
    end

# true if this object uses SMTP/TLS (SMTPS).
    def tls?
      @tls
    end

alias ssl? tls?

# Enables SMTP/TLS (SMTPS: SMTP over direct TLS connection) for
    # this object.  Must be called before the connection is established
    # to have any effect.  +context+ is a OpenSSL::SSL::SSLContext object.
    def enable_tls(context = SMTP.default_ssl_context)
      raise 'openssl library not installed' unless defined?(OpenSSL)
      raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @starttls
      @tls = true
      @ssl_context = context
    end

alias enable_ssl enable_tls

# Disables SMTP/TLS for this object.  Must be called before the
    # connection is established to have any effect.
    def disable_tls
      @tls = false
      @ssl_context = nil
    end

alias disable_ssl disable_tls

# Returns truth value if this object uses STARTTLS.
    # If this object always uses STARTTLS, returns :always.
    # If this object uses STARTTLS when the server support TLS, returns :auto.
    def starttls?
      @starttls
    end

# true if this object uses STARTTLS.
    def starttls_always?
      @starttls == :always
    end

# true if this object uses STARTTLS when server advertises STARTTLS.
    def starttls_auto?
      @starttls == :auto
    end

# Enables SMTP/TLS (STARTTLS) for this object.
    # +context+ is a OpenSSL::SSL::SSLContext object.
    def enable_starttls(context = SMTP.default_ssl_context)
      raise 'openssl library not installed' unless defined?(OpenSSL)
      raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @tls
      @starttls = :always
      @ssl_context = context
    end

# Enables SMTP/TLS (STARTTLS) for this object if server accepts.
    # +context+ is a OpenSSL::SSL::SSLContext object.
    def enable_starttls_auto(context = SMTP.default_ssl_context)
      raise 'openssl library not installed' unless defined?(OpenSSL)
      raise ArgumentError, "SMTPS and STARTTLS is exclusive" if @tls
      @starttls = :auto
      @ssl_context = context
    end

# Disables SMTP/TLS (STARTTLS) for this object.  Must be called
    # before the connection is established to have any effect.
    def disable_starttls
      @starttls = false
      @ssl_context = nil
    end

# The address of the SMTP server to connect to.
    attr_reader :address

# The port number of the SMTP server to connect to.
    attr_reader :port

# Seconds to wait while attempting to open a connection.
    # If the connection cannot be opened within this time, a
    # Net::OpenTimeout is raised. The default value is 30 seconds.
    attr_accessor :open_timeout

# Seconds to wait while reading one block (by one read(2) call).
    # If the read(2) call does not complete within this time, a
    # Net::ReadTimeout is raised. The default value is 60 seconds.
    attr_reader :read_timeout

# Set the number of seconds to wait until timing-out a read(2)
    # call.
    def read_timeout=(sec)
      @socket.read_timeout = sec if @socket
      @read_timeout = sec
    end

#
    # WARNING: This method causes serious security holes.
    # Use this method for only debugging.
    #
    # Set an output stream for debug logging.
    # You must call this before #start.
    #
    #   # example
    #   smtp = Net::SMTP.new(addr, port)
    #   smtp.set_debug_output $stderr
    #   smtp.start do |smtp|
    #     ....
    #   end
    #
    def debug_output=(arg)
      @debug_output = arg
    end

alias set_debug_output debug_output=

#
    # SMTP session control
    #

#
    # Creates a new Net::SMTP object and connects to the server.
    #
    # This method is equivalent to:
    #
    #   Net::SMTP.new(address, port).start(helo_domain, account, password, authtype)
    #
    # === Example
    #
    #     Net::SMTP.start('your.smtp.server') do |smtp|
    #       smtp.send_message msgstr, 'from@example.com', ['dest@example.com']
    #     end
    #
    # === Block Usage
    #
    # If called with a block, the newly-opened Net::SMTP object is yielded
    # to the block, and automatically closed when the block finishes.  If called
    # without a block, the newly-opened Net::SMTP object is returned to
    # the caller, and it is the caller's responsibility to close it when
    # finished.
    #
    # === Parameters
    #
    # +address+ is the hostname or ip address of your smtp server.
    #
    # +port+ is the port to connect to; it defaults to port 25.
    #
    # +helo+ is the _HELO_ _domain_ provided by the client to the
    # server (see overview comments); it defaults to 'localhost'.
    #
    # The remaining arguments are used for SMTP authentication, if required
    # or desired.  +user+ is the account name; +secret+ is your password
    # or other authentication token; and +authtype+ is the authentication
    # type, one of :plain, :login, or :cram_md5.  See the discussion of
    # SMTP Authentication in the overview notes.
    #
    # === Errors
    #
    # This method may raise:
    #
    # * Net::SMTPAuthenticationError
    # * Net::SMTPServerBusy
    # * Net::SMTPSyntaxError
    # * Net::SMTPFatalError
    # * Net::SMTPUnknownError
    # * Net::OpenTimeout
    # * Net::ReadTimeout
    # * IOError
    #
    def SMTP.start(address, port = nil, helo = 'localhost',
                   user = nil, secret = nil, authtype = nil,
                   &block)   # :yield: smtp
      new(address, port).start(helo, user, secret, authtype, &block)
    end

# +true+ if the SMTP session has been started.
    def started?
      @started
    end

#
    # Opens a TCP connection and starts the SMTP session.
    #
    # === Parameters
    #
    # +helo+ is the _HELO_ _domain_ that you'll dispatch mails from; see
    # the discussion in the overview notes.
    #
    # If both of +user+ and +secret+ are given, SMTP authentication
    # will be attempted using the AUTH command.  +authtype+ specifies
    # the type of authentication to attempt; it must be one of
    # :login, :plain, and :cram_md5.  See the notes on SMTP Authentication
    # in the overview.
    #
    # === Block Usage
    #
    # When this methods is called with a block, the newly-started SMTP
    # object is yielded to the block, and automatically closed after
    # the block call finishes.  Otherwise, it is the caller's
    # responsibility to close the session when finished.
    #
    # === Example
    #
    # This is very similar to the class method SMTP.start.
    #
    #     require 'net/smtp'
    #     smtp = Net::SMTP.new('smtp.mail.server', 25)
    #     smtp.start(helo_domain, account, password, authtype) do |smtp|
    #       smtp.send_message msgstr, 'from@example.com', ['dest@example.com']
    #     end
    #
    # The primary use of this method (as opposed to SMTP.start)
    # is probably to set debugging (#set_debug_output) or ESMTP
    # (#esmtp=), which must be done before the session is
    # started.
    #
    # === Errors
    #
    # If session has already been started, an IOError will be raised.
    #
    # This method may raise:
    #
    # * Net::SMTPAuthenticationError
    # * Net::SMTPServerBusy
    # * Net::SMTPSyntaxError
    # * Net::SMTPFatalError
    # * Net::SMTPUnknownError
    # * Net::OpenTimeout
    # * Net::ReadTimeout
    # * IOError
    #
    def start(helo = 'localhost',
              user = nil, secret = nil, authtype = nil)   # :yield: smtp
      if block_given?
        begin
          do_start helo, user, secret, authtype
          return yield(self)
        ensure
          do_finish
        end
      else
        do_start helo, user, secret, authtype
        return self
      end
    end

# Finishes the SMTP session and closes TCP connection.
    # Raises IOError if not started.
    def finish
      raise IOError, 'not yet started' unless started?
      do_finish
    end

private

def tcp_socket(address, port)
      TCPSocket.open address, port
    end

def do_start(helo_domain, user, secret, authtype)
      raise IOError, 'SMTP session already started' if @started
      if user or secret
        check_auth_method(authtype || DEFAULT_AUTH_TYPE)
        check_auth_args user, secret
      end
      s = Timeout.timeout(@open_timeout, Net::OpenTimeout) do
        tcp_socket(@address, @port)
      end
      logging "Connection opened: #{@address}:#{@port}"
      @socket = new_internet_message_io(tls? ? tlsconnect(s) : s)
      check_response critical { recv_response() }
      do_helo helo_domain
      if starttls_always? or (capable_starttls? and starttls_auto?)
        unless capable_starttls?
          raise SMTPUnsupportedCommand,
              "STARTTLS is not supported on this server"
        end
        starttls
        @socket = new_internet_message_io(tlsconnect(s))
        # helo response may be different after STARTTLS
        do_helo helo_domain
      end
      authenticate user, secret, (authtype || DEFAULT_AUTH_TYPE) if user
      @started = true
    ensure
      unless @started
        # authentication failed, cancel connection.
        s.close if s
        @socket = nil
      end
    end

def ssl_socket(socket, context)
      OpenSSL::SSL::SSLSocket.new socket, context
    end

def tlsconnect(s)
      verified = false
      s = ssl_socket(s, @ssl_context)
      logging "TLS connection started"
      s.sync_close = true
      ssl_socket_connect(s, @open_timeout)
      if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
        s.post_connection_check(@address)
      end
      verified = true
      s
    ensure
      s.close unless verified
    end

def new_internet_message_io(s)
      InternetMessageIO.new(s, read_timeout: @read_timeout,
                            debug_output: @debug_output)
    end

def do_helo(helo_domain)
      res = @esmtp ? ehlo(helo_domain) : helo(helo_domain)
      @capabilities = res.capabilities
    rescue SMTPError
      if @esmtp
        @esmtp = false
        @error_occurred = false
        retry
      end
      raise
    end

def do_finish
      quit if @socket and not @socket.closed? and not @error_occurred
    ensure
      @started = false
      @error_occurred = false
      @socket.close if @socket
      @socket = nil
    end

#
    # Message Sending
    #

public

#
    # Sends +msgstr+ as a message.  Single CR ("\r") and LF ("\n") found
    # in the +msgstr+, are converted into the CR LF pair.  You cannot send a
    # binary message with this method. +msgstr+ should include both
    # the message headers and body.
    #
    # +from_addr+ is a String representing the source mail address.
    #
    # +to_addr+ is a String or Strings or Array of Strings, representing
    # the destination mail address or addresses.
    #
    # === Example
    #
    #     Net::SMTP.start('smtp.example.com') do |smtp|
    #       smtp.send_message msgstr,
    #                         'from@example.com',
    #                         ['dest@example.com', 'dest2@example.com']
    #     end
    #
    # === Errors
    #
    # This method may raise:
    #
    # * Net::SMTPServerBusy
    # * Net::SMTPSyntaxError
    # * Net::SMTPFatalError
    # * Net::SMTPUnknownError
    # * Net::ReadTimeout
    # * IOError
    #
    def send_message(msgstr, from_addr, *to_addrs)
      raise IOError, 'closed session' unless @socket
      mailfrom from_addr
      rcptto_list(to_addrs) {data msgstr}
    end

alias send_mail send_message
    alias sendmail send_message   # obsolete

#
    # Opens a message writer stream and gives it to the block.
    # The stream is valid only in the block, and has these methods:
    #
    # puts(str = '')::       outputs STR and CR LF.
    # print(str)::           outputs STR.
    # printf(fmt, *args)::   outputs sprintf(fmt,*args).
    # write(str)::           outputs STR and returns the length of written bytes.
    # <<(str)::              outputs STR and returns self.
    #
    # If a single CR ("\r") or LF ("\n") is found in the message,
    # it is converted to the CR LF pair.  You cannot send a binary
    # message with this method.
    #
    # === Parameters
    #
    # +from_addr+ is a String representing the source mail address.
    #
    # +to_addr+ is a String or Strings or Array of Strings, representing
    # the destination mail address or addresses.
    #
    # === Example
    #
    #     Net::SMTP.start('smtp.example.com', 25) do |smtp|
    #       smtp.open_message_stream('from@example.com', ['dest@example.com']) do |f|
    #         f.puts 'From: from@example.com'
    #         f.puts 'To: dest@example.com'
    #         f.puts 'Subject: test message'
    #         f.puts
    #         f.puts 'This is a test message.'
    #       end
    #     end
    #
    # === Errors
    #
    # This method may raise:
    #
    # * Net::SMTPServerBusy
    # * Net::SMTPSyntaxError
    # * Net::SMTPFatalError
    # * 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
      rcptto_list(to_addrs) {data(&block)}
    end

alias ready open_message_stream   # obsolete

#
    # Authentication
    #

public

DEFAULT_AUTH_TYPE = :plain

def authenticate(user, secret, authtype = DEFAULT_AUTH_TYPE)
      check_auth_method authtype
      check_auth_args user, secret
      send auth_method(authtype), user, secret
    end

def auth_plain(user, secret)
      check_auth_args user, secret
      res = critical {
        get_response('AUTH PLAIN ' + base64_encode("\0#{user}\0#{secret}"))
      }
      check_auth_response res
      res
    end

def auth_login(user, secret)
      check_auth_args user, secret
      res = critical {
        check_auth_continue get_response('AUTH LOGIN')
        check_auth_continue get_response(base64_encode(user))
        get_response(base64_encode(secret))
      }
      check_auth_response res
      res
    end

def auth_cram_md5(user, secret)
      check_auth_args user, secret
      res = critical {
        res0 = get_response('AUTH CRAM-MD5')
        check_auth_continue res0
        crammed = cram_md5_response(secret, res0.cram_md5_challenge)
        get_response(base64_encode("#{user} #{crammed}"))
      }
      check_auth_response res
      res
    end

private

def check_auth_method(type)
      unless respond_to?(auth_method(type), true)
        raise ArgumentError, "wrong authentication type #{type}"
      end
    end

def auth_method(type)
      "auth_#{type.to_s.downcase}".intern
    end

def check_auth_args(user, secret, authtype = DEFAULT_AUTH_TYPE)
      unless user
        raise ArgumentError, 'SMTP-AUTH requested but missing user name'
      end
      unless secret
        raise ArgumentError, 'SMTP-AUTH requested but missing secret phrase'
      end
    end

def base64_encode(str)
      # expects "str" may not become too long
      [str].pack('m0')
    end

IMASK = 0x36
    OMASK = 0x5c

# CRAM-MD5: [RFC2195]
    def cram_md5_response(secret, challenge)
      tmp = Digest::MD5.digest(cram_secret(secret, IMASK) + challenge)
      Digest::MD5.hexdigest(cram_secret(secret, OMASK) + tmp)
    end

CRAM_BUFSIZE = 64

def cram_secret(secret, mask)
      secret = Digest::MD5.digest(secret) if secret.size > CRAM_BUFSIZE
      buf = secret.ljust(CRAM_BUFSIZE, "\0")
      0.upto(buf.size - 1) do |i|
        buf[i] = (buf[i].ord ^ mask).chr
      end
      buf
    end

#
    # SMTP command dispatcher
    #

public

# Aborts the current mail transaction

def rset
      getok('RSET')
    end

def starttls
      getok('STARTTLS')
    end

def helo(domain)
      getok("HELO #{domain}")
    end

def ehlo(domain)
      getok("EHLO #{domain}")
    end

def mailfrom(from_addr)
      getok("MAIL FROM:<#{from_addr}>")
    end

def rcptto_list(to_addrs)
      raise ArgumentError, 'mail destination not given' if to_addrs.empty?
      ok_users = []
      unknown_users = []
      to_addrs.flatten.each do |addr|
        begin
          rcptto addr
        rescue SMTPAuthenticationError
          unknown_users << addr.dump
        else
          ok_users << addr
        end
      end
      raise ArgumentError, 'mail destination not given' if ok_users.empty?
      ret = yield
      unless unknown_users.empty?
        raise SMTPAuthenticationError, "failed to deliver for #{unknown_users.join(', ')}"
      end
      ret
    end

def rcptto(to_addr)
      getok("RCPT TO:<#{to_addr}>")
    end

# This method sends a message.
    # If +msgstr+ is given, sends it as a message.
    # If block is given, yield a message writer stream.
    # You must write message before the block is closed.
    #
    #   # Example 1 (by string)
    #   smtp.data(<<EndMessage)
    #   From: john@example.com
    #   To: betty@example.com
    #   Subject: I found a bug
    #
    #   Check vm.c:58879.
    #   EndMessage
    #
    #   # Example 2 (by block)
    #   smtp.data {|f|
    #     f.puts "From: john@example.com"
    #     f.puts "To: betty@example.com"
    #     f.puts "Subject: I found a bug"
    #     f.puts ""
    #     f.puts "Check vm.c:58879."
    #   }
    #
    def data(msgstr = nil, &block)   #:yield: stream
      if msgstr and block
        raise ArgumentError, "message and block are exclusive"
      end
      unless msgstr or block
        raise ArgumentError, "message or block is required"
      end
      res = critical {
        check_continue get_response('DATA')
        socket_sync_bak = @socket.io.sync
        begin
          @socket.io.sync = false
          if msgstr
            @socket.write_message msgstr
          else
            @socket.write_message_by_block(&block)
          end
        ensure
          @socket.io.flush
          @socket.io.sync = socket_sync_bak
        end
        recv_response()
      }
      check_response res
      res
    end

def quit
      getok('QUIT')
    end

private

def validate_line(line)
      # A bare CR or LF is not allowed in RFC5321.
      if /[\r\n]/ =~ line
        raise ArgumentError, "A line must not contain CR or LF"
      end
    end

def getok(reqline)
      validate_line reqline
      res = critical {
        @socket.writeline reqline
        recv_response()
      }
      check_response res
      res
    end

def get_response(reqline)
      validate_line reqline
      @socket.writeline reqline
      recv_response()
    end

def recv_response
      buf = ''.dup
      while true
        line = @socket.readline
        buf << line << "\n"
        break unless line[3,1] == '-'   # "210-PIPELINING"
      end
      Response.parse(buf)
    end

def critical
      return Response.parse('200 dummy reply code') if @error_occurred
      begin
        return yield()
      rescue Exception
        @error_occurred = true
        raise
      end
    end

def check_response(res)
      unless res.success?
        raise res.exception_class, res.message
      end
    end

def check_continue(res)
      unless res.continue?
        raise SMTPUnknownError, "could not get 3xx (#{res.status}: #{res.string})"
      end
    end

def check_auth_response(res)
      unless res.success?
        raise SMTPAuthenticationError, res.message
      end
    end

def check_auth_continue(res)
      unless res.continue?
        raise res.exception_class, res.message
      end
    end

# This class represents a response received by the SMTP server. Instances
    # of this class are created by the SMTP class; they should not be directly
    # created by the user. For more information on SMTP responses, view
    # {Section 4.2 of RFC 5321}[http://tools.ietf.org/html/rfc5321#section-4.2]
    class Response
      # Parses the received response and separates the reply code and the human
      # readable reply text
      def self.parse(str)
        new(str[0,3], str)
      end

# Creates a new instance of the Response class and sets the status and
      # string attributes
      def initialize(status, string)
        @status = status
        @string = string
      end

# The three digit reply code of the SMTP response
      attr_reader :status

# The human readable reply text of the SMTP response
      attr_reader :string

# Takes the first digit of the reply code to determine the status type
      def status_type_char
        @status[0, 1]
      end

# Determines whether the response received was a Positive Completion
      # reply (2xx reply code)
      def success?
        status_type_char() == '2'
      end

# Determines whether the response received was a Positive Intermediate
      # reply (3xx reply code)
      def continue?
        status_type_char() == '3'
      end

# The first line of the human readable reply text
      def message
        @string.lines.first
      end

# Creates a CRAM-MD5 challenge. You can view more information on CRAM-MD5
      # on Wikipedia: https://en.wikipedia.org/wiki/CRAM-MD5
      def cram_md5_challenge
        @string.split(/ /)[1].unpack1('m')
      end

# Returns a hash of the human readable reply text in the response if it
      # is multiple lines. It does not return the first line. The key of the
      # hash is the first word the value of the hash is an array with each word
      # thereafter being a value in the array
      def capabilities
        return {} unless @string[3, 1] == '-'
        h = {}
        @string.lines.drop(1).each do |line|
          k, *v = line[4..-1].chomp.split
          h[k] = v
        end
        h
      end

# Determines whether there was an error and raises the appropriate error
      # based on the reply code of the response
      def exception_class
        case @status
        when /\A4/  then SMTPServerBusy
        when /\A50/ then SMTPSyntaxError
        when /\A53/ then SMTPAuthenticationError
        when /\A5/  then SMTPFatalError
        else             SMTPUnknownError
        end
      end
    end

def logging(msg)
      @debug_output << msg + "\n" if @debug_output
    end

end   # class SMTP

SMTPSession = SMTP # :nodoc:

end

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