[OTR-dev] Fwd: Re: pidgin-otr problems receiving packets

[Moritz Warning]

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I think this was intended to go to the list. :)

- -------- Original Message --------
Subject: Re: [OTR-dev] pidgin-otr problems receiving packets
Date: Mon, 21 Oct 2013 21:47:32 +0200
From: Moritz Warning <moritzwarning at web.de>
To: Paul Wouters <paul at cypherpunks.ca>

On 10/21/2013 09:07 PM, Paul Wouters wrote:
> On Mon, 21 Oct 2013, Moritz Warning wrote:
>
>>> That looks like a bug. OTR fragments start with "?OTR|", not "?OTR:"
>>> So your first packet appears to be unfragmented according to the
>>> protocol. The second message should also start with a "?OTR|" prefix.
>>>
>>> It looks like the message got fragmentated at another layer?
>>>
>>> Paul
>>
>> Ok, if I understand you correctly, then OTR fragments packages itself.
>> But how does OTR know on what size/when to fragment the packets?
>>
>> I just get a big string, split it up and transmit it.
>> On the other size both packets are received as independent messages.
>>
>> There is a way to tell the caller (OTR in this case)
>> that the message is too long. That is I have to return -E2BIG.
>> But that didn't seem to have an effect on the OTR plugin.
>
> Since OTR is protocol agnostic, the fragment size is someting you need
> to tell OTR, as it depends on the transport used. IRC and SMS and XMPP
> and MSN have different packet sizes.
>
> I assume pidgin-otr has these hardcoded per transport protocol, and just
> informs libotr of these. You'd have to check the code.
>
> Paul
>

I've poked around the otr-plugin code and found the table.
These seem to be the supported protocols:
 mmsPairs[] = {{"prpl-msn", 1409}, {"prpl-icq", 2346},
	{"prpl-aim", 2343}, {"prpl-yahoo", 799}, {"prpl-gg", 1999},
	{"prpl-irc", 417}, {"prpl-oscar", 2343},
	{"prpl-novell", 1792}, {NULL, 0}};

Won't it be possible to just reduce the message size as long
the protocol sending function returns -E2BIG?
I don't have much hope for my puny protocol to be included in
the list above.

yup,
mwarning


Btw.: The code is a mix of tabs and spaces. :>
Maybe apply something like this:
astyle --lineend=linux --suffix=none --style=kr --indent=force-tab --formatted --recursive "*.c" "*.h"

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