Clearwell backup extractor

Extract contents of the proprietary Clearwell (Veritas) .BAK file format

exbak.py - Script to extract .BAK files

format.ksy - Kaitai Struct format definition

If you want to interactively inspect the file format structure using Kaitai Web IDE, you first need to inflate the .BAK files.

You can use the following code to do that:

import os
import zlib

folder_path = '\path\to\folder\with\BAK files'

for file in os.listdir(os.path.abspath(folder_path)):
	filename = os.path.basename(file)
	if filename.endswith('.bak'): 
		print('Processing ' + filename)
		with open(os.path.join(folder_path, filename), 'rb') as f:
			hexdata = f.read().hex()
		deflated_hex = hexdata[hexdata.find('2e62616b7801')+12:] # remove .BAK file header (everything up to '.bakx.' in hex)
		deflated_bytes = bytes.fromhex(deflated_hex)
		inflated_bytes = zlib.decompress(deflated_bytes, -15) # inflate the rest of the file in the 'no headers' mode
		with open(os.path.join(folder_path, filename)[:-4] + '.dat', 'wb') as f:
			f.write(inflated_bytes)

File format diagram