decrypt_epever_firmware_prg_files.py

import Crypto.Cipher.AES
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad

from glob import glob

encrypted_firmware_files = glob('/path/to/*.prg')

# Larger 50A - 100A units
# 54726163 72414e43 0cdd527b 05c16b01 ff17cd6f 8c1e3e09 cf1f0c78 87ef8aec
key = bytearray(b'\x54\x72\x61\x63\x72\x41\x4e\x43\x0c\xdd\x52\x7b\x05\xc1\x6b\x01\xff\x17\xcd\x6f\x8c\x1e\x3e\x09\xcf\x1f\x0c\x78\x87\xef\x8a\xec')

# Smaller 10A - 40A units
# 54726952 6f6e2eda 0cdd527b 05c16b01 ff17cd6f 8c1e3e09 cf1f0c78 87ef8aec
key = bytearray(b'\x54\x72\x69\x52\x6f\x6e\x2e\xda\x0c\xdd\x52\x7b\x05\xc1\x6b\x01\xff\x17\xcd\x6f\x8c\x1e\x3e\x09\xcf\x1f\x0c\x78\x87\xef\x8a\xec')

aes = AES.new(key, AES.MODE_CBC, iv=bytearray([0x00] * 16))

for encrypted_firmware_file in encrypted_firmware_files:
    with open(encrypted_firmware_file, 'rb') as rfp:
        encrypted_firmware_data = rfp.read()

    decrypted_firmware_data = aes.decrypt(pad(encrypted_firmware_data[18:], block_size=16, style="pkcs7"))

    with open(encrypted_firmware_file[:-4] + '.bin', 'wb') as fp:
        fp.write(decrypted_firmware_data)