=begin

= net/smtp.rb version 1.2.0

  Copyright (C) 1999-2001 Yukihiro Matsumoto

  written & maintained by Minero Aoki <aamine@dp.u-netsurf.ne.jp>

  This program is free software. You can re-distribute and/or
  modify this program under the same terms as Ruby itself,
  GNU General Public License or Ruby License.

  Japanese version of this document is in "net" full package.
  You can get it from RAA (Ruby Application Archive). RAA is:
  http://www.ruby-lang.org/en/raa.html


== Net::SMTP

=== Super Class

Net::Protocol

=== Class Methods

: new( address = 'localhost', port = 25 )
  creates a new Net::SMTP object.

: start( address = 'localhost', port = 25, *protoargs )
: start( address = 'localhost', port = 25, *protoargs ) {|smtp| .... }
  is equal to Net::SMTP.new( address, port ).start( *protoargs )

=== Methods

: start( helo_domain = Socket.gethostname, account = nil, password = nil, authtype = nil )
: start( helo_domain = Socket.gethostname, account = nil, password = nil, authtype = nil ) {|smtp| .... }
  opens TCP connection and starts SMTP session.
  If protocol had been started, do nothing and return false.

  When this methods is called with block, give a SMTP object to block and
  close session after block call finished.

  If account and password are given, is trying to get authentication
  by using AUTH command. "authtype" is :plain (symbol) or :cram_md5.

: send_mail( mailsrc, from_addr, *to_addrs )
: sendmail( mailsrc, from_addr, *to_addrs )
  This method sends 'mailsrc' as mail. SMTP read strings
  from 'mailsrc' by calling 'each' iterator, and convert them
  into "\r\n" terminated string when write.

  from_addr must be String.
  to_addrs must be a String(s) or an Array of String.

  Exceptions which SMTP raises are:
      * Net::ProtoSyntaxError: syntax error (errno.500)
      * Net::ProtoFatalError: fatal error (errno.550)
      * Net::ProtoUnknownError: unknown error
      * Net::ProtoServerBusy: temporary error (errno.420/450)

    # usage example

    Net::SMTP.start( 'localhost', 25 ) do |smtp|
      smtp.send_mail mail_string, 'from-addr@foo.or.jp', 'to-addr@bar.or.jp'
    end

: ready( from_addr, to_addrs ) {|adapter| .... }
  This method stands by the SMTP object for sending mail.
  "adapter" object accepts only "write" method.

    # usage example

    Net::SMTP.start( 'localhost', 25 ) do |smtp|
      smtp.ready( from, to ) do |adapter|
        adapter.write str1
        adapter.write str2
        adapter.write str3
      end
    end

: finish
  finishes SMTP session.
  If SMTP session had not started, do nothing and return false.

=end

require 'net/protocol'
require 'md5'


module Net


  class SMTP < Protocol

    protocol_param :port,         '25'
    protocol_param :command_type, '::Net::NetPrivate::SMTPCommand'


    def initialize( addr = nil, port = nil )
      super
      @esmtp = true
    end

    attr :esmtp

    def send_mail( mailsrc, from_addr, *to_addrs )
      do_ready from_addr, to_addrs.flatten
      @command.write_mail mailsrc, nil
    end

    alias sendmail send_mail

    def ready( from_addr, *to_addrs, &block )
      do_ready from_addr, to_addrs.flatten
      @command.write_mail nil, block
    end


    private


    def do_ready( from_addr, to_addrs )
      if to_addrs.empty? then
        raise ArgumentError, 'mail destination does not given'
      end
      @command.mailfrom from_addr
      @command.rcpt to_addrs
      @command.data
    end

    def do_start( helodom = nil,
                  user = nil, secret = nil, authtype = nil )
      helodom ||= ::Socket.gethostname
      unless helodom then
        raise ArgumentError,
          "cannot get localhost name; try 'smtp.start(local_host_name)'"
      end

      begin
        if @esmtp then
          @command.ehlo helodom
        else
          @command.helo helodom
        end
      rescue ProtocolError
        if @esmtp then
          @esmtp = false
          @command.error_ok
          retry
        else
          raise
        end
      end

      if user or secret then
        (user and secret) or
            raise ArgumentError, "both of account and password are required"

        mid = 'auth_' + (authtype || 'cram_md5').to_s
        @command.respond_to? mid or
            raise ArgumentError, "wrong auth type #{authtype.to_s}"

        @command.__send__ mid, user, secret
      end
    end

  end

  SMTPSession = SMTP



  module NetPrivate


  class SMTPCommand < Command

    def initialize( sock )
      super
      critical {
        check_reply SuccessCode
      }
    end


    def helo( fromdom )
      critical {
        getok sprintf( 'HELO %s', fromdom )
      }
    end


    def ehlo( fromdom )
      critical {
        getok sprintf( 'EHLO %s', fromdom )
      }
    end


    # "PLAIN" authentication [RFC2554]
    def auth_plain( user, secret )
      critical {
        getok sprintf( 'AUTH PLAIN %s',
                       ["\0#{user}\0#{secret}"].pack('m').chomp )
      }
    end

    # "CRAM-MD5" authentication [RFC2195]
    def auth_cram_md5( user, secret )
      critical {
        rep = getok( 'AUTH CRAM-MD5', ContinueCode )
        challenge = rep.msg.split(' ')[1].unpack('m')[0]
        secret = MD5.new( secret ).digest if secret.size > 64

        isecret = secret + "\0" * (64 - secret.size)
        osecret = isecret.dup
        0.upto( 63 ) do |i|
          isecret[i] ^= 0x36
          osecret[i] ^= 0x5c
        end
        tmp = MD5.new( isecret + challenge ).digest
        tmp = MD5.new( osecret + tmp ).hexdigest

        getok [user + ' ' + tmp].pack('m').chomp
      }
    end


    def mailfrom( fromaddr )
      critical {
        getok sprintf( 'MAIL FROM:<%s>', fromaddr )
      }
    end


    def rcpt( toaddrs )
      toaddrs.each do |i|
        critical {
          getok sprintf( 'RCPT TO:<%s>', i )
        }
      end
    end


    def data
      return unless begin_critical
      getok 'DATA', ContinueCode
    end

    def write_mail( mailsrc, block )
      @socket.write_pendstr mailsrc, block
      check_reply SuccessCode
      end_critical
    end


    def quit
      critical {
        getok 'QUIT'
      }
    end


    private


    def get_reply
      arr = read_reply
      stat = arr[0][0,3]

      klass = case stat[0]
              when ?2 then SuccessCode
              when ?3 then ContinueCode
              when ?4 then ServerErrorCode
              when ?5 then
                case stat[1]
                when ?0 then SyntaxErrorCode
                when ?3 then AuthErrorCode
                when ?5 then FatalErrorCode
                end
              end
      klass ||= UnknownCode

      Response.new( klass, stat, arr.join('') )
    end


    def read_reply
      arr = []
      while true do
        str = @socket.readline
        break unless str[3] == ?-   # ex: "210-..."
        arr.push str
      end
      arr.push str

      arr
    end

  end


  end   # module Net::NetPrivate

end   # module Net