metasploit-framework/lib/rex/peparsey/image_source/disk.rb

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#!/usr/bin/env ruby
require 'rex/peparsey/image_source/image_source'
require 'rex/struct2'
module Rex
module PeParsey
module ImageSource
class Disk < ImageSource
attr_accessor :file, :file_offset, :size
WINDOW_SIZE = 4096
WINDOW_OVERLAP = 64
def initialize(_file, _offset = 0, _len = nil)
_len = _file.stat.size if !_len
self.file = _file
self.file_offset = _offset
self.size = _len
end
def read(offset, len)
if offset < 0 || offset+len > size
raise RangeError, "Offset #{offset} outside of image source", caller
end
file.seek(file_offset + offset)
file.read(len)
end
def index(search, offset = 0)
# do a sliding window search across the disk
while offset < size
# get a full window size if we can, we
# don't want to read past our boundaries
wsize = size - offset
wsize = WINDOW_SIZE if wsize > WINDOW_SIZE
window = self.read(offset, wsize)
res = window.index(search)
return res + offset if res
offset += WINDOW_SIZE - WINDOW_OVERLAP
end
end
def subsource(offset, len)
self.class.new(file, file_offset+offset, len)
end
def close
file.close
end
end
end end end