def _parse_aux_sec_header(self, data):
security_control, frame_counter = struct.unpack("<BL", data.read(5))
security_level = security_control & 0x07
key_id_mode = (security_control & 0x18) >> 3
if key_id_mode == 0:
key_id = data.read(9)
elif key_id_mode == 1:
key_id = data.read(1)
elif key_id_mode == 2:
key_id = data.read(5)
else:
key_source = None
key_index = None
return AuxiliarySecurityHeader(key_id_mode, security_level, frame_counter, key_id, big_endian=False)
def _parse_aux_sec_header(self, data):
security_control, frame_counter = struct.unpack("<BL", data.read(5))
security_level = security_control & 0x07
key_id_mode = (security_control & 0x18) >> 3
if key_id_mode == 0:
raise KeyIdMode0Exception
elif key_id_mode == 1:
key_id = data.read(1)
elif key_id_mode == 2:
key_id = data.read(5)
elif key_id_mode == 3:
key_id = data.read(9)
else:
pass
return AuxiliarySecurityHeader(
key_id_mode,
security_level,
frame_counter,
key_id,
big_endian=False,
)