Traceback on unknown TLV

[mathieui]

ChatSecure uses custom TLV values for their OTRDATA protocol, and it exposed a bug in potr:

   File "/usr/lib64/python3.4/site-packages/potr/context.py", line 225, in receiveMessage
     plaintext, tlvs = self.crypto.handleDataMessage(message)
   File "/usr/lib64/python3.4/site-packages/potr/crypt.py", line 192, in handleDataMessage
     tlvs = proto.TLV.parse(tlvData)
   File "/usr/lib64/python3.4/site-packages/potr/proto.py", line 319, in parse
     return [tlvClasses[typ].parsePayload(data[:length])] \
 KeyError: 256

potr should check if the received TLVs are known before trying to get the relevant class. (and maybe return a custom exception when it isn’t known?)

[koolfy]

We should actually raise NotOTRMessage as it's used in the rest of the code.
I'm looking into why it's not the case here exactly, and fix this quickly :)

[koolfy]

Possible fix to test: 1422de3

I basically just implemented a new exception (insead of reusing NotOTRMessage which I didn't find to fit the bill quite right), and added a check against registered values of implemented TLV in the tlvClasses dict.

[mathieui]

Yes, looks good to me

[koolfy]

Great, I'm currently at 32C3 and (intentionally) don't have github credentials on my person :) As soon as I get back, I'll merge the branch and prepare a new release.

[koolfy]

Merged in staging, closing for now.