crc.py

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