def format_jacc(self, pdu: bytes, info: List[str]) -> None:
n = len(pdu)
if n != 17 and n != 33:
info.append(f'-- invalid length {n}, expected 17 or 23')
return
if self.sm:
for s in self.sm.all():
ppdu = bytes(pdu[0:1] +
lc.crypto.encrypt(s['nwkkey'], pdu[1:]))
mic = lm.get_mic(ppdu)
cmic = lc.crypto.calcMicJoin(s['nwkkey'], ppdu)
if mic == cmic:
appnonce = struct.unpack_from("<I", ppdu, 1)[0] & 0xFFFFFF
netid = struct.unpack_from("<I", ppdu, 1 + 3)[0] & 0xFFFFFF
devaddr, dlset, rxdly = struct.unpack_from(
"<iBB", ppdu, 1 + 3 + 3)
cflist = None if n == 17 else ppdu[-20:-4]
info.append(f'appnonce={appnonce}')
info.append(f'netid={netid}')
info.append(f'addr=0x{devaddr:08x}')
dls = lm.DLSettings.unpack(dlset)
info.append(
f'dlset=RX1DRoff:{dls[0]},RX2DR:{dls[1]},OptNeg:{dls[2]}'
)
info.append(f'rxdly={rxdly}')
info.append(f'mic={mic}:ok')
if cflist:
info.append('cflist=' + self.format_cflist(cflist))
break
else:
info.append('-- unknown session')
def format_da(self, pdu: bytes, info: List[str]) -> None:
n = len(pdu)
if n < 8 + 4:
info.append(f'-- invalid length {n}, expected at least 12')
return
mhdr, addr, fctrl, seqno = struct.unpack_from('<BiBH', pdu)
dndir = int(bool(mhdr & lm.MHdr.DNFLAG))
info.append(f'addr=0x{addr:08x}')
info.append('fctrl=' +
self.format_fctrl(fctrl, not (mhdr & lm.MHdr.DNFLAG)))
info.append(f'fcnt={seqno}')
fol = fctrl & lm.FCtrl.OPTLEN
if fol:
if n < 8 + 4 + fol:
info.append(
f'-- invalid length {n}, expected at least {8+4+fol}')
return
info.append('fopts=' + self.format_opts(pdu[8:8 + fol], dndir))
pl = pdu[8 + fol:-4]
mic = lm.get_mic(pdu)
if pl:
info.append(f'fport={pl[0]}')
info.append(f'plen={len(pl)-1}')
if self.sm:
sessions = self.sm.get(addr)
for s in sessions:
fcnt = seqno # TODO - extend seqno to 32 bit from session context
cmic = lc.crypto.calcMic(s['nwkskey'], addr, fcnt, dndir, pdu)
if cmic == mic:
micstatus = ':ok'
if pl:
ppl = lc.crypto.cipher(
s['appskey'] if pl[0] else s['nwkskey'], addr,
seqno, dndir, pl[1:])
info.append(f'data={ppl.hex()}')
if pl[0] == 0:
info.append(self.format_opts(ppl, dndir))
break
else:
micstatus = ':?'
else:
micstatus = ''
info.append(f'mic={mic}{micstatus}')