Class: Rex::OLE::MiniFAT

Inherits:
DIFAT
  • Object
show all
Defined in:
lib/rex/ole/minifat.rb

Instance Method Summary collapse

Methods inherited from DIFAT

#+, #<<, #[], #[]=, #each, #initialize, #length, #reset, #slice!, #to_s

Constructor Details

This class inherits a constructor from Rex::OLE::DIFAT

Instance Method Details

#allocate_sectorObject


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# File 'lib/rex/ole/minifat.rb', line 37

def allocate_sector
  idx = @entries.index(SECT_FREE)

  if (not idx)
    # add a sector worth
    idx = @entries.length
    @stg.header.idx_per_sect.times {
      @entries << SECT_FREE
    }
  end

  # default mini-sectors to end of chain
  @entries[idx] = SECT_END
  idx
end

#readObject

low-level functions


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# File 'lib/rex/ole/minifat.rb', line 16

def read
  @entries = []

  visited = []
  sect = @stg.header._sectMiniFatStart
  @stg.header._csectMiniFat.times { |idx|
    break if sect == SECT_END

    if (visited.include?(sect))
      raise RuntimeError, 'Sector chain loop detected (0x%08x)' % sect
    end
    visited << sect

    buf = @stg.read_sector(sect, @stg.header.sector_size)
    @stg.header.idx_per_sect.times { |idx|
      @entries << Util.get32(buf, (idx*4))
    }
    sect = @stg.next_sector(sect)
  }
end

#writeObject


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# File 'lib/rex/ole/minifat.rb', line 53

def write
  return if (@entries.length < 1)

  mf_start = nil
  mfs_count = 0
  prev_sect = nil
  copy = @entries.dup
  while (copy.length > 0)
    part = copy.slice!(0, @stg.header.idx_per_sect)
    sbuf = Util.pack32array(part)
    idx = @stg.write_sector(sbuf, nil, prev_sect)
    mfs_count += 1
    mf_start ||= idx
  end
  @stg.header._sectMiniFatStart = mf_start
  @stg.header._csectMiniFat = mfs_count
end