[erlang-questions] dtls error when used with chrome webrtc

Joe K goodjoe2049@REDACTED
Mon Jan 1 19:11:51 CET 2018 

Sorry for bothering you, Danil, but I was trying to make something like
`dtls:ssl_accept` work on udp sockets and then thought I would get more
STUN requests to keep the connection in NATs "alive" after I finally
`sslaccept` the socket. Would I have to somehow downgrade the dtls session
back to udp? Or is there some other way?

Right now I'm thinking about a hacky approach: forking erlang's ssl library
and checking for STUN packets in every `handle_datagram` call in
`dtls_udp_listener`.

And thank you again, you've been incredibly helpful.

On Fri, Dec 29, 2017 at 5:55 PM, Facundo Olano <
facundo.olano@REDACTED> wrote:

> Hi Danil!
>
> The server code is for signaling (using websockets), but it also includes
> processone/stun <https://github.com/processone/stun> as a dependency, so
> it handles STUN/TURN as well. It also contains a couple of example
> applications that server javascript clients that connect to the server
> (both for signaling and ICE). The multiparty example uses a mesh.
>
> To be honest I don't know what DTLS+SRTP is about :P
>
> Thanks,
> Facundo.
>
> On Fri, Dec 29, 2017 at 11:47 AM, Danil Zagoskin <z@REDACTED> wrote:
>
>> Hi Federico!
>>
>> Is it just signalling server?
>> E.g. do you handle all the DTLS+SRTP stuff or just build a full mesh of
>> participants?
>>
>> On Fri, Dec 29, 2017 at 4:48 PM, Federico Carrone <
>> federico.carrone@REDACTED> wrote:
>>
>>> Joe,
>>>
>>> We are creating an open source erlang webrtc server replacement for
>>> appear.in. You can check it here: https://github.com/lambdaclass
>>> /webrtc-server
>>>
>>> We are using the processone stun library. I am not sure if this mail is
>>> of any help but might be interested in checking it since it is working fine.
>>>
>>> Regards,
>>> Federico.
>>>
>>> On Fri, Dec 29, 2017 at 9:15 AM, Joe K <goodjoe2049@REDACTED> wrote:
>>>
>>>> Tried this, hoped it would work, but it didn't ...
>>>>
>>>>     1> {ok, Socket} = gen_udp:open(9090, [binary, {active, false}]).
>>>>     {ok,#Port<0.441>}
>>>>     2> dtls:connect(Socket, []).
>>>>     {error,{options,{not_supported,{packet,0}}}}
>>>>
>>>> On Fri, Dec 29, 2017 at 2:21 PM, Joe K <goodjoe2049@REDACTED> wrote:
>>>>
>>>>> > Also you may try using external STUN server (check RTCPeerConnection
>>>>> docs) and hope browser starts with DTLS hello.
>>>>>
>>>>> I've tried that, but the browser still sends STUN binding requests to
>>>>> the DTLS process. And it uses the STUN server just to find out it's address.
>>>>>
>>>>> > It should be quite easy to implement and it would be consistent
>>>>> with ssl:connect/2 and ssl:ssl_accept for TCP sockets.
>>>>>
>>>>> Will try this now. Thank you.
>>>>>
>>>>> On Thu, Dec 28, 2017 at 4:34 PM, Danil Zagoskin <z@REDACTED> wrote:
>>>>>
>>>>>> > But now I don't know how to reply to both STUN binding request and
>>>>>> then setup a DTLS session using erlang's ssl module.
>>>>>> Yes, dtls implementation lacks support of starting/accepting a
>>>>>> handshake over existing socket.
>>>>>> It should be quite easy to implement and it would be consistent with
>>>>>> ssl:connect/2 and ssl:ssl_accept for TCP sockets.
>>>>>>
>>>>>> Also you may try using external STUN server (check RTCPeerConnection
>>>>>> docs) and hope browser starts with DTLS hello.
>>>>>> If you try this, please share the results.
>>>>>>
>>>>>> On Thu, Dec 28, 2017 at 3:26 PM, Joe K <goodjoe2049@REDACTED> wrote:
>>>>>>
>>>>>>> Oops, I forgot to reply to the mailing list in my last email.
>>>>>>>
>>>>>>> The response was
>>>>>>>
>>>>>>>   > Maybe browser sends STUN requests to your port when you expect
>>>>>>> DTLS hello?
>>>>>>>   You are absolutely right, Wireshark shows that there are lots of
>>>>>>> STUN binding requests being made, I didn't think of that.
>>>>>>>
>>>>>>>   > Do you use external STUN server?
>>>>>>>   I don't use external STUN servers ... For some reason, I didn't
>>>>>>> think I would need them.
>>>>>>>
>>>>>>>   > Also try checking chrome://webrtc-internals and chrome://webrtc-logs
>>>>>>> for browser's view on what's going on.
>>>>>>>   chrome://webrtc-logs is empty for the webrtc whole session.
>>>>>>>
>>>>>>> But now I don't know how to reply to both STUN binding request and
>>>>>>> then setup a DTLS session using erlang's ssl module.
>>>>>>>
>>>>>>> On Thu, Dec 28, 2017 at 1:28 AM, Danil Zagoskin <z@REDACTED> wrote:
>>>>>>>
>>>>>>>> Hi!
>>>>>>>> What do you see in Wireshark?
>>>>>>>> Did you see handshake between two browsers?
>>>>>>>> Is your application ready to receive the packet sent by browser?
>>>>>>>> Do you use external STUN server?
>>>>>>>> Maybe browser sends STUN requests to your port when you expect DTLS
>>>>>>>> hello?
>>>>>>>>
>>>>>>>> Also try checking chrome://webrtc-internals and chrome://webrtc-logs
>>>>>>>> for browser's view on what's going on.
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, Dec 28, 2017 at 12:09 AM, Joe K <goodjoe2049@REDACTED>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> I'm trying to implement parts of webrtc stack with elixir/erlang
>>>>>>>>> and currently am stuck with setting up a dtls session.
>>>>>>>>>
>>>>>>>>> The minimal example is, I think, the following (in console, erlang
>>>>>>>>> 20.2.2):
>>>>>>>>>
>>>>>>>>>     2> ssl:start().
>>>>>>>>>     ok
>>>>>>>>>     3> {ok, ListenSocket} = ssl:listen(8090, [
>>>>>>>>>     3>   binary,
>>>>>>>>>     3>   {ip, {0, 0, 0, 0}},
>>>>>>>>>     3>   {protocol, dtls},
>>>>>>>>>     3>   {keyfile, <<"priv/server.key">>},
>>>>>>>>>     3>   {certfile, <<"priv/server.pem">>},
>>>>>>>>>     3>   {active, false}
>>>>>>>>>     3> ]).
>>>>>>>>>     {ok, ...}
>>>>>>>>>     4> {ok, AcceptSocket} = ssl:transport_accept(ListenSocket).
>>>>>>>>>     {ok,...}
>>>>>>>>>     5> ssl:ssl_accept(AcceptSocket).
>>>>>>>>>     {error,{tls_alert,"record overflow"}}
>>>>>>>>>
>>>>>>>>> And js (with chrome canary): https://gist.github.c
>>>>>>>>> om/idi-ot/a07b7330ff02f90373a2dcfe83883afa
>>>>>>>>>
>>>>>>>>> After {error,{tls_alert,"record overflow"}} the
>>>>>>>>> RTCPeerConnection's iceConnectionState becomes "failed" and the connection
>>>>>>>>> itself "closed".
>>>>>>>>>
>>>>>>>>> I wonder what I am doing wrong.
>>>>>>>>>
>>>>>>>>>     openssl s_client -dtls1 -connect 127.0.0.1:8089 -debug
>>>>>>>>>
>>>>>>>>> works fine with the code snippet above.
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> erlang-questions mailing list
>>>>>>>>> erlang-questions@REDACTED
>>>>>>>>> http://erlang.org/mailman/listinfo/erlang-questions
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Danil Zagoskin | z@REDACTED
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Danil Zagoskin | z@REDACTED
>>>>>>
>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> erlang-questions mailing list
>>>> erlang-questions@REDACTED
>>>> http://erlang.org/mailman/listinfo/erlang-questions
>>>>
>>>>
>>>
>>
>>
>> --
>> Danil Zagoskin | z@REDACTED
>>
>> _______________________________________________
>> erlang-questions mailing list
>> erlang-questions@REDACTED
>> http://erlang.org/mailman/listinfo/erlang-questions
>>
>>
>
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