metasploit-framework/lib/rex/post/meterpreter/packet_parser.rb

# -*- coding: binary -*-

module Rex
module Post
module Meterpreter

###
#
# This class is responsible for reading in and decrypting meterpreter
# packets that arrive on a socket
#
###
class PacketParser

  #
  # Initializes the packet parser context.
  #
  def initialize
    reset
  end

  #
  # Resets the parser state so that a new packet can begin being parsed.
  #
  def reset
    self.packet = Packet.new(0)
  end

  #
  # Reads data from the socket and parses as much of the packet as possible.
  #
  def recv(sock)
    raw = nil
    if self.packet.raw_bytes_required > 0
      while (raw = sock.read(self.packet.raw_bytes_required))
        self.packet.add_raw(raw)
        break if self.packet.raw_bytes_required == 0
      end
    end

    if self.packet.raw_bytes_required > 0
      if raw == nil
        raise EOFError
      else
        return nil
      end
    end

    packet = self.packet
    reset
    packet
  end

protected
  attr_accessor :cipher, :packet    # :nodoc:

end


end; end; end