i figured where the problem is , but couldn't fix it

the problem is that the signature changes for each ISP

but i wasn't able to extract them as this guide shows

cause after adding them to the decode_keystore.py which should extract the keys from HEX strings it shows me this error

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd2 in position 1: invalid continuation byte

in the Attached Files : the python script that is used for decryption and the firmware that i extracted the keys from and the decode_keystore.py and the four files

1. libxmlapi.so
   
2. libhttpapi.so
   
3. libcfmapi.so
   
4. libmsgapi.so

dg8045 decrypt python script

decode_keystore.py

Thanks