def encode(spec, encrypt=True):
"""Encode a pydict specification into a OpenThings binary payload"""
# The message is not encrypted, but the CRC is generated here.
payload = []
# HEADER
payload.append(0) # length, fixup later when known
header = spec["header"]
payload.append(header["mfrid"])
payload.append(header["productid"])
if not ("encryptPIP" in header):
if encrypt:
warning("no encryptPIP in header, assuming 0x0100")
encryptPIP = 0x0100
else:
encryptPIP = header["encryptPIP"]
payload.append((encryptPIP&0xFF00)>>8) # MSB
payload.append((encryptPIP&0xFF)) # LSB
sensorId = header["sensorid"]
payload.append((sensorId>>16) & 0xFF) # HIGH
payload.append((sensorId>>8) & 0xFF) # MID
payload.append((sensorId) & 0XFF) # LOW
# RECORDS
for rec in spec["recs"]:
wr = rec["wr"]
paramid = rec["paramid"]
typeid = rec["typeid"]
if "length" in rec:
length = rec["length"]
else:
length = None # auto detect
# PARAMID
if wr:
payload.append(0x80 + paramid) # WRITE
else:
payload.append(paramid) # READ
# TYPE/LENGTH
payload.append((typeid)) # need to back patch length for auto detect
lenpos = len(payload)-1 # for backpatch
# VALUE
valueenc = [] # in case of no value
if "value" in rec:
value = rec["value"]
valueenc = Value.encode(value, typeid, length)
if len(valueenc) > 15:
raise ValueError("value longer than 15 bytes")
for b in valueenc:
payload.append(b)
payload[lenpos] = (typeid) | len(valueenc)
# FOOTER
payload.append(0) # NUL
crc = calcCRC(payload, 5, len(payload)-5)
payload.append((crc>>8) & 0xFF) # MSB
payload.append(crc&0xFF) # LSB
# back-patch the length byte so it is correct
payload[0] = len(payload)-1
if encrypt:
# ENCRYPT
# [0]len,mfrid,productid,pipH,pipL,[5]
crypto.init(crypt_pid, encryptPIP)
crypto.cryptPayload(payload, 5, len(payload)-5) # including CRC
return payload
def encode(spec, encrypt=True):
"""Encode a pydict specification into a OpenThings binary payload"""
# The message is not encrypted, but the CRC is generated here.
payload = []
# HEADER
payload.append(0) # length, fixup later when known
header = spec["header"]
payload.append(header["mfrid"])
payload.append(header["productid"])
if not ("encryptPIP" in header):
if encrypt:
warning("no encryptPIP in header, assuming 0x0100")
encryptPIP = 0x0100
else:
encryptPIP = header["encryptPIP"]
payload.append((encryptPIP & 0xFF00) >> 8) # MSB
payload.append((encryptPIP & 0xFF)) # LSB
sensorId = header["sensorid"]
payload.append((sensorId >> 16) & 0xFF) # HIGH
payload.append((sensorId >> 8) & 0xFF) # MID
payload.append((sensorId) & 0XFF) # LOW
# RECORDS
for rec in spec["recs"]:
wr = rec["wr"]
paramid = rec["paramid"]
typeid = rec["typeid"]
if "length" in rec:
length = rec["length"]
else:
length = None # auto detect
# PARAMID
if wr:
payload.append(0x80 + paramid) # WRITE
else:
payload.append(paramid) # READ
# TYPE/LENGTH
payload.append((typeid)) # need to back patch length for auto detect
lenpos = len(payload) - 1 # for backpatch
# VALUE
valueenc = [] # in case of no value
if "value" in rec:
value = rec["value"]
valueenc = Value.encode(value, typeid, length)
if len(valueenc) > 15:
raise ValueError("value longer than 15 bytes")
for b in valueenc:
payload.append(b)
payload[lenpos] = (typeid) | len(valueenc)
# FOOTER
payload.append(0) # NUL
crc = calcCRC(payload, 5, len(payload) - 5)
payload.append((crc >> 8) & 0xFF) # MSB
payload.append(crc & 0xFF) # LSB
# back-patch the length byte so it is correct
payload[0] = len(payload) - 1
if encrypt:
# ENCRYPT
# [0]len,mfrid,productid,pipH,pipL,[5]
crypto.init(crypt_pid, encryptPIP)
crypto.cryptPayload(payload, 5, len(payload) - 5) # including CRC
return payload
def decode(payload, decrypt=True, receive_timestamp=None):
"""Decode a raw buffer into an OpenThings pydict"""
#Note, decrypt must already have run on this for it to work
length = payload[0]
# CHECK LENGTH
if length+1 != len(payload) or length < 10:
raise OpenThingsException("bad payload length")
##return {
## "type": "BADLEN",
## "len_actual": len(payload),
## "len_expected": length,
## "payload": payload[1:]
##}
# DECODE HEADER
mfrId = payload[1]
productId = payload[2]
encryptPIP = (payload[3]<<8) + payload[4]
header = {
"mfrid" : mfrId,
"productid" : productId,
"encryptPIP": encryptPIP
}
if decrypt:
# DECRYPT PAYLOAD
# [0]len,mfrid,productid,pipH,pipL,[5]
crypto.init(crypt_pid, encryptPIP)
crypto.cryptPayload(payload, 5, len(payload)-5) # including CRC
##printhex(payload)
# sensorId is in encrypted region
sensorId = (payload[5]<<16) + (payload[6]<<8) + payload[7]
header["sensorid"] = sensorId
# CHECK CRC
crc_actual = (payload[-2]<<8) + payload[-1]
crc_expected = calcCRC(payload, 5, len(payload)-(5+2))
##trace("crc actual:%s, expected:%s" %(hex(crc_actual), hex(crc_expected)))
if crc_actual != crc_expected:
raise OpenThingsException("bad CRC")
##return {
## "type": "BADCRC",
## "crc_actual": crc_actual,
## "crc_expected": crc_expected,
## "payload": payload[1:],
##}
# DECODE RECORDS
i = 8
recs = []
while i < length and payload[i] != 0:
# PARAM
param = payload[i]
wr = ((param & 0x80) == 0x80)
paramid = param & 0x7F
if paramid in param_info:
paramname = (param_info[paramid])["n"] # name
paramunit = (param_info[paramid])["u"] # unit
else:
paramname = "UNKNOWN_" + hex(paramid)
paramunit = "UNKNOWN_UNIT"
i += 1
# TYPE/LEN
typeid = payload[i] & 0xF0
plen = payload[i] & 0x0F
i += 1
rec = {
"wr": wr,
"paramid": paramid,
"paramname": paramname,
"paramunit": paramunit,
"typeid": typeid,
"length": plen
}
if plen != 0:
# VALUE
valuebytes = []
for x in range(plen):
valuebytes.append(payload[i])
i += 1
value = Value.decode(valuebytes, typeid, plen)
rec["valuebytes"] = valuebytes
rec["value"] = value
# store rec
recs.append(rec)
m = {
"type": "OK",
"header": header,
"recs": recs
}
if receive_timestamp != None:
m["rxtimestamp"] = receive_timestamp
return Message(m)
def decode(payload, decrypt=True, receive_timestamp=None):
"""Decode a raw buffer into an OpenThings pydict"""
#Note, decrypt must already have run on this for it to work
length = payload[0]
# CHECK LENGTH
if length + 1 != len(payload) or length < 10:
raise OpenThingsException("bad payload length")
##return {
## "type": "BADLEN",
## "len_actual": len(payload),
## "len_expected": length,
## "payload": payload[1:]
##}
# DECODE HEADER
mfrId = payload[1]
productId = payload[2]
encryptPIP = (payload[3] << 8) + payload[4]
header = {"mfrid": mfrId, "productid": productId, "encryptPIP": encryptPIP}
if decrypt:
# DECRYPT PAYLOAD
# [0]len,mfrid,productid,pipH,pipL,[5]
crypto.init(crypt_pid, encryptPIP)
crypto.cryptPayload(payload, 5, len(payload) - 5) # including CRC
##printhex(payload)
# sensorId is in encrypted region
sensorId = (payload[5] << 16) + (payload[6] << 8) + payload[7]
header["sensorid"] = sensorId
# CHECK CRC
crc_actual = (payload[-2] << 8) + payload[-1]
crc_expected = calcCRC(payload, 5, len(payload) - (5 + 2))
##trace("crc actual:%s, expected:%s" %(hex(crc_actual), hex(crc_expected)))
if crc_actual != crc_expected:
raise OpenThingsException("bad CRC")
##return {
## "type": "BADCRC",
## "crc_actual": crc_actual,
## "crc_expected": crc_expected,
## "payload": payload[1:],
##}
# DECODE RECORDS
i = 8
recs = []
while i < length and payload[i] != 0:
# PARAM
param = payload[i]
wr = ((param & 0x80) == 0x80)
paramid = param & 0x7F
if paramid in param_info:
paramname = (param_info[paramid])["n"] # name
paramunit = (param_info[paramid])["u"] # unit
else:
paramname = "UNKNOWN_" + hex(paramid)
paramunit = "UNKNOWN_UNIT"
i += 1
# TYPE/LEN
typeid = payload[i] & 0xF0
plen = payload[i] & 0x0F
i += 1
rec = {
"wr": wr,
"paramid": paramid,
"paramname": paramname,
"paramunit": paramunit,
"typeid": typeid,
"length": plen
}
if plen != 0:
# VALUE
valuebytes = []
for x in range(plen):
valuebytes.append(payload[i])
i += 1
value = Value.decode(valuebytes, typeid, plen)
rec["valuebytes"] = valuebytes
rec["value"] = value
# store rec
recs.append(rec)
m = {"type": "OK", "header": header, "recs": recs}
if receive_timestamp != None:
m["rxtimestamp"] = receive_timestamp
return Message(m)
