def lzma_cable_extractor(self, fname): # Try extracting the LZMA file without modification first if not self.binwalk.extractor.execute(self.original_cmd, fname): out_name = os.path.splitext(fname)[0] + '-patched' + os.path.splitext(fname)[1] fp_out = BlockFile(out_name, 'w') fp_in = BlockFile(fname) fp_in.MAX_TRAILING_SIZE = 0 i = 0 while i < fp_in.length: (data, dlen) = fp_in.read_block() if i == 0: out_data = data[0:5] + self.FAKE_LZMA_SIZE + data[5:] else: out_data = data fp_out.write(out_data) i += dlen fp_in.close() fp_out.close() # Overwrite the original file so that it can be cleaned up if -r was specified shutil.move(out_name, fname) self.binwalk.extractor.execute(self.original_cmd, fname)
def _dd(self, file_name, offset, size, extension, output_file_name=None):
'''
Extracts a file embedded inside the target file.
@file_name - Path to the target file.
@offset - Offset inside the target file where the embedded file begins.
@size - Number of bytes to extract.
@extension - The file exension to assign to the extracted file on disk.
@output_file_name - The requested name of the output file.
Returns the extracted file name.
'''
total_size = 0
# Default extracted file name is <hex offset>.<extension>
default_bname = "%X" % offset
if self.max_size and size > self.max_size:
size = self.max_size
if not output_file_name or output_file_name is None:
bname = default_bname
else:
# Strip the output file name of invalid/dangerous characters (like file paths)
bname = os.path.basename(output_file_name)
fname = unique_file_name(bname, extension)
try:
# Open the target file and seek to the offset
fdin = BlockFile(file_name, 'r', length=size)
fdin.seek(offset)
# Open the output file
try:
fdout = BlockFile(fname, 'w')
except Exception as e:
# Fall back to the default name if the requested name fails
fname = unique_file_name(default_bname, extension)
fdout = BlockFile(fname, 'w')
while total_size < size:
(data, dlen) = fdin.read_block()
fdout.write(str2bytes(data[:dlen]))
total_size += dlen
# Cleanup
fdout.close()
fdin.close()
except Exception as e:
raise Exception("Extractor.dd failed to extract data from '%s' to '%s': %s" % (file_name, fname, str(e)))
return fname
