def decode(cls, data):
"Decodes the PDU from the given data bytes"
new_pdu = cls()
idx = 0
for member in cls._orderedKeys:
if not member.startswith("__") and not callable(getattr(cls, member)):
M = getattr(cls, member)
if Integer == type(M): # in [Integer, CString, String, TLV]
s = data[idx:idx+M.length]
idx = idx + M.length
setattr(new_pdu, member, Integer.decode(s))
elif CString == type(M):
# Need to find the next NULL character which is the string's end
try:
nidx = data.index(b'\x00', idx)
s = data[idx:nidx+1]
idx = nidx + 1
setattr(new_pdu, member, CString.decode(s))
except:
raise RuntimeError("Cannot find end for CString type")
elif String == type(M):
# TODO: Since string fields can either be fixed length or have a corresponding
# length field specifying their length, decoding this requires some info to
# be passed from within the PDU class.
pass
elif TLV == type(M):
pass
return new_pdu
def test_04_cstring_decode():
"Test to check CString decoding"
assert b"Hello" == CString.decode(b'Hello\x00').value
assert b"123456789" == CString.decode(b'123456789\x00').value
assert b"A2F5ED278FC" == CString.decode(b'A2F5ED278FC\x00').value
