metasploit-framework/lib/rex/ole/direntry.rb

# -*- coding: binary -*-

##
# Rex::OLE - an OLE implementation
# written in 2010 by Joshua J. Drake <jduck [at] metasploit.com>
##

module Rex
module OLE

#
# This class serves as the base class for SubStorage, Stream, and Directory head
#
class DirEntry

  attr_accessor :sid
  attr_accessor :_sidChild, :_sidLeftSib, :_sidRightSib

  def initialize(stg)
    @stg = stg

    # default to a root entry :)
    @sid = 0
    @_ab = "Root Entry"
    @_cb = nil              # NOTE: this is not used until pack
    @_mse = STGTY_ROOT
    @_bflags = 0
    @_sidLeftSib = SECT_FREE
    @_sidRightSib = SECT_FREE
    @_sidChild = SECT_FREE
    @_clsId = CLSID.new
    @_dwUserFlags = 0
    @_ctime = "\x00" * 8
    @_mtime = "\x00" * 8
    @_sectStart = SECT_END
    @_ulSize = 0

    # keep track of logical children (in a tree)
    @children = []
  end


  def length
    @_ulSize
  end

  def <<(expr)
    @children << expr
  end

  def each
    @children.each { |de|
      yield de
    }
  end


  def type
    @_mse
  end
  def type=(arg)
    @_mse = arg
  end

  def name
    @_ab
  end
  def name=(arg)
    # XXX: validate?
    @_ab = arg
  end

  def start_sector
    @_sectStart
  end
  def start_sector=(expr)
    @_sectStart = expr
  end


  # NOTE: this will not look at children
  def find_stream_by_name_and_type(name, type)
    @children.each { |de|
      next if (de.type != type)

      if (de.name == name)
        return de
      end
    }
    nil
  end


  def find_by_sid(sid, de=self)
    if (de.sid == sid)
      return de
    end
    @children.each { |cde|
      ret = find_by_sid(sid, cde)
      if (ret)
        return ret
      end
    }
    nil
  end


  #
  # low-level functions
  #
  def from_s(sid, buf)
    @sid = sid
    @_ab           = Util.getUnicodeString(buf[0x00,64])
    @_cb           = Util.get16(buf, 0x40)

    # too big?
    if (@_cb > 0x40)
      raise RuntimeError, 'Invalid directory entry name length %#x' % @_cb
    end

    # mismatch?
    if (@_ab.length > 0)
      declen = ((@_cb) / 2) - 1
      if (declen != @_ab.length)
        raise RuntimeError, 'Directory entry name and length mismatch (%d != %d)' % [declen, @_ab.length]
      end
    end

    @_mse          = Util.get8(buf, 0x42)
    @_bflags       = Util.get8(buf, 0x43)
    @_sidLeftSib   = Util.get32(buf, 0x44)
    @_sidRightSib  = Util.get32(buf, 0x48)
    @_sidChild     = Util.get32(buf, 0x4c)

    # only used for storages..
    @_clsId = CLSID.new(buf[0x50,16])
    @_dwUserFlags  = Util.get32(buf, 0x60)
    @_ctime        = buf[0x64,8]
    @_mtime        = buf[0x6c,8]

    # only used for streams...
    @_sectStart    = Util.get32(buf, 0x74)
    if (@stg.header._uMajorVersion == 4)
      @_ulSize       = Util.get64(buf, 0x78)
    else
      @_ulSize       = Util.get32(buf, 0x78)
    end

    # ignore _dptPropType and pad
  end


  def pack
    @_sectStart ||= SECT_END
    @_cb = (@_ab.length + 1) * 2

    data = ""
    data << Util.putUnicodeString(@_ab) # gets padded/truncated to 0x40 bytes
    data << Util.pack16(@_cb)
    data << Util.pack8(@_mse)
    data << Util.pack8(@_bflags)
    data << Util.pack32(@_sidLeftSib)
    data << Util.pack32(@_sidRightSib)
    data << Util.pack32(@_sidChild)
    data << @_clsId.pack
    data << Util.pack32(@_dwUserFlags)
    data << @_ctime
    data << @_mtime
    data << Util.pack32(@_sectStart)
    data << Util.pack64(@_ulSize)
    data
  end


  def to_s(extra_spaces=0)
    @_sectStart ||= SECT_END
    @_cb = (@_ab.length + 1) * 2

    spstr = " " * extra_spaces

    ret = "%s{\n" % spstr
    ret << "%s  sid => 0x%x" % [spstr, @sid]
    ret << ",\n"
    ret << "%s  _ab => \"%s\"" % [spstr, Util.Printable(@_ab)]
    ret << ",\n"
    ret << "%s  _cb => 0x%04x" % [spstr, @_cb]
    ret << ",\n"
    ret << "%s  _mse => 0x%02x" % [spstr, @_mse]
    ret << ",\n"
    ret << "%s  _bflags => 0x%02x" % [spstr, @_bflags]
    ret << ",\n"
    ret << "%s  _sidLeftSib => 0x%08x" % [spstr, @_sidLeftSib]
    ret << ",\n"
    ret << "%s  _sidRightSib => 0x%08x" % [spstr, @_sidRightSib]
    ret << ",\n"
    ret << "%s  _sidChild => 0x%08x" % [spstr, @_sidChild]
    ret << ",\n"
    ret << "%s  _clsId => %s" % [spstr, @_clsId.to_s]
    ret << ",\n"
    ret << "%s  _dwUserFlags => 0x%08x" % [spstr, @_dwUserFlags]
    ret << ",\n"
    ret << "%s  _ctime => %s" % [spstr, Rex::Text.to_hex_dump(@_ctime).strip]
    ret << "\n"
    ret << "%s  _mtime => %s" % [spstr, Rex::Text.to_hex_dump(@_mtime).strip]
    ret << "\n"
    ret << "%s  _sectStart => 0x%08x" % [spstr, @_sectStart]
    ret << ",\n"
    ret << "%s  _ulSize => 0x%016x" % [spstr, @_ulSize]
    if (@_mse == STGTY_STREAM)
      ret << ",\n"
      ret << "%s  data =>\n" % spstr
      if (@data)
        #ret << Util.Printable(@data)
        ret << Rex::Text.to_hex_dump(@data).strip
      else
        if (@_ulSize > 0)
          ret << "--NOT OPENED YET--"
        end
      end
    elsif (@_mse == STGTY_STORAGE) or (@_mse == STGTY_ROOT)
      if (@children.length > 0)
        ret << ",\n"
        ret << "%s  *children* =>\n" % spstr
        @children.each { |de|
          ret << de.to_s(extra_spaces+2)
          ret << "\n"
        }
      end
    end
    ret << "\n"
    ret << "%s}" % spstr
  end

end

end
end