Class: Rex::OLE::Directory

Inherits:
DirEntry show all
Defined in:
lib/rex/ole/directory.rb

Overview

This class serves as the root directory entry in addition to an abstraction around the concept of a directory as a whole.

Instance Attribute Summary collapse

Attributes inherited from DirEntry

#_sidChild, #_sidLeftSib, #_sidRightSib, #sid

Instance Method Summary collapse

Methods inherited from DirEntry

#<<, #each, #find_by_sid, #find_stream_by_name_and_type, #length, #name, #name=, #pack, #start_sector, #start_sector=, #to_s, #type, #type=

Constructor Details

#initialize(stg) ⇒ Directory

Returns a new instance of Directory


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# File 'lib/rex/ole/directory.rb', line 22

def initialize(stg)
  super

  @num_entries = 1
end

Instance Attribute Details

#num_entriesObject

XXX: num_entries is not maintained once a stream/storage is added!


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# File 'lib/rex/ole/directory.rb', line 20

def num_entries
  @num_entries
end

Instance Method Details

#each_entry(&block) ⇒ Object


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# File 'lib/rex/ole/directory.rb', line 36

def each_entry(&block)
  yield_entries(self, &block)
end

#flatten_tree(entries, parent) ⇒ Object

NOTE: this may not be necessary if we were to use each_entry


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# File 'lib/rex/ole/directory.rb', line 169

def flatten_tree(entries, parent)
  entries << parent
  parent.each { |el|
    flatten_tree(entries, el)
  }
end

#from_s(sid, buf) ⇒ Object

low-level functions


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# File 'lib/rex/ole/directory.rb', line 82

def from_s(sid, buf)
  super

  if (@_sidRightSib != DIR_NOSTREAM)
    raise RuntimeError, 'Root Entry is invalid! (has right sibling)'
  end
  if (@_sidLeftSib != DIR_NOSTREAM)
    raise RuntimeError, 'Root Entry is invalid! (has left sibling)'
  end
end

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# File 'lib/rex/ole/directory.rb', line 46

def link_item(parent, child)
  # set sid, advance count
  child.sid = @num_entries
  @num_entries += 1

  # link item to siblings and/or parent
  if (parent._sidChild == DIR_NOSTREAM)
    parent._sidChild = child.sid
    dlog("Linking #{child.name} as THE child of #{parent.name} as sid #{child.sid}", 'rex', LEV_3)
  else
    sib = nil
    parent.each { |el|
      if (el._sidLeftSib == DIR_NOSTREAM)
        sib = el
        el._sidLeftSib = child.sid
        dlog("Linking #{child.name} as the LEFT sibling of #{sib.name} as sid #{child.sid}", 'rex', LEV_3)
        break
      end
      if (el._sidRightSib == DIR_NOSTREAM)
        sib = el
        el._sidRightSib = child.sid
        dlog("Linking #{child.name} as the RIGHT sibling of #{sib.name} as sid #{child.sid}", 'rex', LEV_3)
        break
      end
    }
    if (not sib)
      raise RuntimeError, 'Unable to find a sibling to link to in the directory'
    end
  end
  parent << child
end

#populate_children(entries, parent, sid) ⇒ Object

recursively add entries to their proper parents :)


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# File 'lib/rex/ole/directory.rb', line 153

def populate_children(entries, parent, sid)
  node = entries[sid]
  dlog("populate_children(entries, \"#{parent.name}\", #{sid}) - node: #{node.name}", 'rex', LEV_3)
  parent << node
  if (node.type == STGTY_STORAGE) and (node._sidChild != DIR_NOSTREAM)
    populate_children(entries, node, node._sidChild)
  end
  if (node._sidLeftSib != DIR_NOSTREAM)
    populate_children(entries, parent, node._sidLeftSib)
  end
  if (node._sidRightSib != DIR_NOSTREAM)
    populate_children(entries, parent, node._sidRightSib)
  end
end

#readObject


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# File 'lib/rex/ole/directory.rb', line 93

def read
  @children = []
  visited = []
  entries = []
  root_node = nil
  sect = @stg.header._sectDirStart
  while (sect != SECT_END)

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

    sbuf = @stg.read_sector(sect, @stg.header.sector_size)
    while (sbuf.length >= DIRENTRY_SZ)
      debuf = sbuf.slice!(0, DIRENTRY_SZ)

      type = Util.get8(debuf, 0x42)
      case type
      when STGTY_ROOT
        if (entries.length != 0)
          raise RuntimeError, 'Root Entry found, but not first encountered!'
        end
        if (root_node)
          raise RuntimeError, 'Multiple root directory sectors detected (0x%08x)' % sect
        end
        de = self
        root_node = de

      when STGTY_STORAGE
        de = SubStorage.new @stg

      when STGTY_STREAM
        de = Stream.new @stg

      when STGTY_INVALID
        # skip invalid entries
        next

      else
        raise RuntimeError, 'Unsupported directory entry type (0x%02x)' % type
      end

      # read content
      de.from_s(entries.length, debuf)
      entries << de
    end
    sect = @stg.next_sector(sect)
  end

  @num_entries = entries.length

  # sort out the tree structure, starting with the root
  if (@_sidChild != DIR_NOSTREAM)
    populate_children(entries, root_node, @_sidChild)
  end
end

#set_ministream_params(start, size) ⇒ Object


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# File 'lib/rex/ole/directory.rb', line 41

def set_ministream_params(start, size)
  @_sectStart = start
  @_ulSize = size
end

#writeObject


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# File 'lib/rex/ole/directory.rb', line 177

def write
  # flatten the directory again
  entries = []
  flatten_tree(entries, self)
  dlog("flattened tree has #{entries.length} entries...", 'rex', LEV_3)

  # count directory sectors
  ds_count = entries.length / 4
  if ((entries.length % 4) > 0)
    # one more sector to hold the rest
    ds_count += 1
  end

  # put the root entry first
  sbuf = self.pack

  # add the rest
  prev_sect = nil
  dir_start = nil
  entries.each { |de|
    # we already got the root entry, no more!
    next if (de.type == STGTY_ROOT)

    dir = de.pack
    dlog("writing dir entry #{de.name}", 'rex', LEV_3)
    sbuf << dir

    if (sbuf.length == @stg.header.sector_size)
      # we have a full sector, add it!
      sect = @stg.write_sector(sbuf, nil, prev_sect)
      prev_sect = sect
      dir_start ||= sect
      # reset..
      sbuf = ""
    end
  }

  # still a partial sector left?
  if (sbuf.length > 0)
    # add it! (NOTE: it will get padded with nul bytes if its not sector sized)
    sect = @stg.write_sector(sbuf, nil, prev_sect)
    prev_sect = sect
    dir_start ||= sect
  end

  @stg.header._sectDirStart = dir_start
end

#yield_entries(de, &block) ⇒ Object

woop, recursive each


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# File 'lib/rex/ole/directory.rb', line 30

def yield_entries(de, &block)
  block.call(de)
  de.each { |el|
    yield_entries(el, &block)
  }
end