crc.py

   1 import binascii
   2
   3
   4 def insert_crc(i_filename, fbi_mode=False, o_filename=None):
   5     if o_filename is None:
   6         o_filename = i_filename
   7
   8     with open(i_filename, 'rb') as f:
   9         fdata = f.read()
  10     fcrc = binascii.crc32(fdata).to_bytes(4, byteorder="big")
  11     flength = len(fdata).to_bytes(4, byteorder="big")
  12
  13     with open(o_filename, 'wb') as f:
  14         if fbi_mode:
  15             f.write(flength)
  16             f.write(fcrc)
  17             f.write(fdata)
  18         else:
  19             f.write(fdata)
  20             f.write(fcrc)