jlusiardi/tlv8_python

Python module to handle type-length-value (TLV) encoded data 8-bit type, 8-bit length, and N-byte value as described within the Apple HomeKit Accessory Protocol Specification Non-Commercial Version Release R2.

tlv8_python's Issues

Tests are not contained in sdist tarball on pypi.org

Hi! I package this project for Arch Linux.
Like many other downstreams we rely on the sdist tarball on pypi.org and we run a project's test suite to ensure its integration with our Python ecosystem.
Unfortunately the sdist tarball on pypi.org does not contain the tests for this project. Could you add them? :)

Document decode function in readme

enable encoding of bytearray data

For the use in homekit_python it would be of much use to be able to use bytearray instances as data values in tlv8.Entry objects.

Simplify the access to the decoded structure

Think about a way to simplify the handling of this pattern:

    d1 = TLV.decode_bytes(decrypted)
    d1 = TLV.reorder(d1, [TLV.kTLVType_Identifier, TLV.kTLVType_Signature])
    assert d1[0][0] == TLV.kTLVType_Identifier, 'get_session_keys: no identifier'
    assert d1[1][0] == TLV.kTLVType_Signature, 'get_session_keys: no signature'

    # 5) look up pairing by accessory name
    accessory_name = d1[0][1].decode()

• how can we find a way around the TLV.reorder (https://github.com/jlusiardi/homekit_python/blob/81483f587bd460ee28aba020f52ee39a5ecb5e8d/homekit/protocol/tlv.py#L187)?
• d1[0][0] will become d1[0].type_id but how to find the proper index?
• in the accessory_name = d1[0][1].decode() we do not need the decode() anymore if the expectation is set correctly.

Entry::length is not applied during encoding

Found out that I need to specify a specific length for an integer. From the documentation this appears to be the case by passing the length argument to the constructor of Entry. Unfortunately, length is not honored on encoding.

Repro:

import tlv8
entry = tlv8.Entry(42, 1, length=8)
print(entry.encode().hex() # 2a 01 01, expected 2a 08 01 00 00 00 00 00 00 00

tlv8.decode returns list instead of EntryList on empty input

def decode(data, expected=None, strict_mode=False) -> EntryList:
    ...
    if len(data) == 0:
        # no data, nothing to do
        return []
    ...

Oversized TLV8 might be parsed properly.

data = '01ff0601040440371bf8c6cd6a7fb85e77a7b436a1b5300ed2023ca7e23f61303856a57358fd8ac03f288472776854765eb3' \
       'a2fcb4497c8b5497c29c88a574479030ec36b176ae05ff85c337879f0a4146a9cc089e0cb48ba3c9c21af0b206d493b224de' \
       'ee52ff0f9b1d8710db6531748ee6d1d66b8b4a6d0690670fb8f1233010d190c4ede1776cb10806eae66c78881647e82e9ba7' \
       'c806f52184c6f108275719cf425c4f8ea0e86c6534712343f88a1482c986e3dd252715872dee506520903c17d27f02ea8957' \
       '719c255631b78a9f2ecb7af0dc245b370cefef28f4652eebbe34afda0138039714665dd880559d1f2667294207892137820c' \
       'd80533d8c0b22601ffa49d1bdc1b641a33297fe59672a89d69391417c77e31283cd7f0d40920004d1bf1fc38357d9599ac2b' \
       '4d8ce3ac7ab8725a01500d198e94b00da80aac64ead393b266dcf9d4a07c05ff34548f7ebebd63f8a00ae2c82f6ee8ac6bcc' \
       'e0ab1030e9268c36714e2ec11c3bf21331129d62978e069dd087cbbdc31bdd6e0cf4ca825b91ab3c8b240de19aa097fc01cd' \
       '471e8c1b5598044d21be12b84c97a1d70e46681e5ecebbde1c33bae9bbd9b3ad41ba2aff8f1f952d0ef0cfcb8a674d5b4c7f' \
       '515ba94341334e86aac277920bd9080b9bf702e16671a3e41c0930beb8a552aefc28a3a9a7f2818e8fbb84c37ae10fb6c5d2' \
       '2e6ba9899e01f082381c9a3344ecbaf801ff85e33306ec9823e72ec4c93f9a45aa657b16f46757aaaf7c74daf35840e68749' \
       '42c132f4a639562920318b9f9867d8e5b0d50deac48c4e14842c91d565b0dd1fec667d092d123a4e1a05fff0b7070f184b4f' \
       '399532c0d1cc0aaea326efea765bc88ace048040a3e07a741e26ef55203bb3f76c075e3b6d20ede89a2eaa63e23376b0dff4' \
       'ef3a797df34a39d8130f60316e86cafcb264b0b570376ba911dc2bda031328ea1c915a724bc69ad2700623ed19c3ae75f946' \
       '4e3b1669adb916ad58e3252580911db2b535af3f2b2207aea880a0d24f1f759888bd5e25b6cf7b2e5ce825ab0fd943a8378a' \
       'eb12906e0965540af14dc0bfa3fae2eb5361992efaf56501ff6ed5c6e686a4af3c2fa121c810cb84cd5abac94f6d618af493' \
       '29e34fa613d2b758e3bc79eb03cb78328f9cd34df43566589615e42088681b4f69775350c9abf68c107d312b0f2421bb53cf' \
       '05ff50c14d6ff0da74b50d9b080c5c06175d66b24b35eb1e25f940170c0815a0ead23703b86da2103cd1b33021fd981d95c6' \
       'a32a3752dc903b0acba949d7d51a1bcabaebc52941bb25d558132feb1794481c0a5911e53553407a8771503d7673d4c3061a' \
       '4d2d41a2897fe507423509760fbe4847423a51155b99b67bf43c72958ce9409a459b5ce42e61309e96091411b256ec294fb0' \
       'f32782efc80d9d548f3cee4fdb21babd011e118238ec7545b24e5af74317a2670179930156512875653dce4e957e94a7596f' \
       'a7e2b533a3eacb9781634c79c094e2cbfcfc62128a25431f9b56cc40b6097614e7a4b08c32b3a7f2e471f55a295a9a06e5b0' \
       'e07dec2ad282842aa6f176052acd544cb5d67c206a3e38e80e32f560a57edda173892a39b021d616d8f2862a5d111e6610c1e7'

data = binascii.unhexlify(data)
resp_data = tlv8.decode(data, {1: tlv8.DataType.BYTES})

Failed with

2020-05-12 19:56:52,627 pair_ble.py:0075 DEBUG Not enough data left. 45 vs 194
Traceback (most recent call last):
File "homekit/pair_ble.py", line 68, in
finish_pairing(pin_function())
File "/home/jlusiardi/Dokumente/src/homekit_python/homekit/controller/controller.py", line 505, in finish_pairing
response = write_fun(request, expected)
File "/home/jlusiardi/Dokumente/src/homekit_python/homekit/controller/ble_impl/init.py", line 671, in write
expected={AdditionalParameterTypes.Value: tlv8.DataType.BYTES})
File "/home/jlusiardi/Dokumente/src/homekit_python/venv/lib/python3.7/site-packages/tlv8/init.py", line 273, in decode
tmp = _internal_decode(data, strict_mode)
File "/home/jlusiardi/Dokumente/src/homekit_python/venv/lib/python3.7/site-packages/tlv8/init.py", line 219, in _internal_decode
raise ValueError('Not enough data left. {} vs {}'.format(len(remaining_data[2:]), tlv_len))
ValueError: Not enough data left. 45 vs 194

Decode bytearray as well

enable decode function to handle bytearray along bytes data as well.