class Rex::OLE::DIFAT

Public Class Methods

new(stg) click to toggle source
# File lib/rex/ole/difat.rb, line 12
def initialize stg
  @stg = stg
  @entries = []
end

Public Instance Methods

+(expr) click to toggle source
# File lib/rex/ole/difat.rb, line 28
def +(expr)
  @entries += expr
  self
end
<<(expr) click to toggle source
# File lib/rex/ole/difat.rb, line 33
def <<(expr)
  @entries << expr
end
[](idx) click to toggle source
# File lib/rex/ole/difat.rb, line 24
def [](idx)
  @entries[idx]
end
[]=(idx,expr) click to toggle source

convenience access to entries

# File lib/rex/ole/difat.rb, line 20
def []=(idx,expr)
  @entries[idx] = expr
end
each() { |el| ... } click to toggle source
# File lib/rex/ole/difat.rb, line 49
def each
  @entries.each { |el|
    yield el
  }
end
length() click to toggle source
# File lib/rex/ole/difat.rb, line 37
def length
  @entries.length
end
read() click to toggle source

low-level functions

# File lib/rex/ole/difat.rb, line 82
def read
  @entries = []

  # start with the header part
  @entries += @stg.header._sectFat

  # double indirect fat
  sect = @stg.header._sectDifStart
  while (sect != SECT_END)
    if (@entries.include?(sect))
      raise RuntimeError, 'Sector chain loop detected (0x%08x)' % sect
    end

    @entries << sect
    buf = @stg.read_sector(sect, @stg.header.sector_size)

    # the last sect ptr in the block becomes the next entry
    sect = Util.get32(buf, ((@stg.header.idx_per_sect)-1) * 4)
  end

  # don't need these free ones, but it doesn't hurt to keep them.
  #@difat.delete(SECT_FREE)
end
reset() click to toggle source
# File lib/rex/ole/difat.rb, line 45
def reset
  @entries = []
end
slice!(start,stop) click to toggle source
# File lib/rex/ole/difat.rb, line 41
def slice!(start,stop)
  @entries.slice!(start,stop)
end
to_s() click to toggle source

woop

# File lib/rex/ole/difat.rb, line 58
def to_s
  ret = "{ "
  @entries.each { |el|
    ret << ", " if (ret.length > 2)
    case el
    when SECT_END
      ret << "END"
    when SECT_DIF
      ret << "DIF"
    when SECT_FAT
      ret << "FAT"
    when SECT_FREE
      ret << "FREE"
    else
      ret << "0x%x" % el
    end
  }
  ret << " }"
  ret
end
write() click to toggle source
# File lib/rex/ole/difat.rb, line 106
def write
  len = @entries.length
  first109 = @entries.dup

  rest = nil
  if (len > 109)
    rest = first109.slice!(109,len)
  end

  @stg.header._sectFat = []
  @stg.header._sectFat += first109
  if (len < 109)
    need = 109 - len
    need.times {
      @stg.header._sectFat << SECT_FREE
    }
  end

  if (rest and rest.length > 0)
    raise RuntimeError, 'TODO: support writing DIF properly!'
    # may require adding more fat sectors :-/
    #@stg.header._csectDif = rest.length
    #@stg.header._sectDifStart = idx
  end

  @stg.header._csectFat = len
end