def sign_msg(orig_msg):
msg = orig_msg
_id = msg[:3]
_dlc = msg[4:6]
msg = msg[6:]
_key = shm.get_key(_id)
if _key == -1: # no stored key for that msg_id
print('No key for that message ID')
sys.exit(1)
signature = get_signature(_key, msg[6:].encode())
if len(signature) != 8:
signature = pad_signature(signature)
msg = signature + msg[6:]
return _id + '#' + _dlc + msg + orig_msg[6:]
def Validate(pid, signature, data):
_key = shm.get_key(pid)
if _key == -1:
return False # must be a valid frame ID
return shm.get_signature(_key, data) == signature
