[sr-dev] MSRP relay authentication
Daniel-Constantin Mierla
miconda at gmail.com
Thu Oct 25 16:08:06 CEST 2012
Hello,
On 10/25/12 1:40 PM, Peter Dunkley wrote:
> Hi,
>
> I am doing some work on this module right now myself.
>
> I did think of putting a bit of code into the auth module that, where
> the method is selected, checks to see if the request is an MSRP one
> and, if it is, selects the method using the same mechanism as for
> $msrp(method).
I would avoid to put lot of dependent code in auth -- maybe in the
future we need to refactor how msrp packets are presented or to auth
some other protocol. It should be easier to maintain just to pass the
relevant tokens from outside.
>
> I am also looking at the handling of the To-Path: header as I am not
> sure that is correct. If I have two MSRP clients connected to the
> same relay my To-Path: header in a SEND will be:
> To-Path: msrps://relay_address:relay_port/foo \ <-- From the Use-Path: in response to _MY_ AUTH
> msrps://relay_address:relay_port/bar \ <-- From the Use-Path: in response to peers AUTH
> msrps://client_address:client_port/wibble <-- Peer
>
> This is based on RFC 4967 section 5.1 paragraph three:
> ... To form the To-Path header for outgoing
> requests, the client takes the list of URIs in the Use-Path header
> after the outermost authentication and appends the list of URIs
> provided in the path attribute in the peer's session description. ...
>
> The example event_route[] in the MSRP README contains the following
> logic for SEND handling:
> if($msrp(nexthops)>1)
> {
> msrp_reply("200", "Received");
> msrp_relay();
> exit;
> }
> $var(sessid) = $msrp(sessid);
> if($sht(msrp=>$var(sessid)::srcaddr) == $null)
> {
> # one more hop, but we don't have address in htable
> msrp_reply("481", "No Such Session");
> exit;
> }
> msrp_relay_flags("1");
> msrp_set_dst("$sht(msrp=>$var(sessid)::srcaddr)",
> "$sht(msrp=>$var(sessid)::srcsock)");
> msrp_relay();
> exit;
> }
>
> But I seem to have problems with this as the msrp_relay() when
> $msrp(nexthops) > 1 fails (this could be related to my changes for WS
> support as it is a problem finding/creating a TCP connection to the
> next relay). However, ideally the MSRP relay should spot that the
> first two URIs on the To-Path: are itself and eat them both - setting
> $msrp(...) appropriately - rather than looping MSRP requests back to
> itself.
Indeed, it would be good to skip all local paths, but even not, opening
connection to itself should work. If you have troubles, then maybe
something else got broken.
>
> Also, I think the same handling should be performed for routing REPORT
> requests too - so the overall logic of the MSRP event_route[] should be:
>
> if (msrp_is_reply())
> msrp_relay();
> else if ($msrp(method) == "AUTH") {
> ...
> } else if ($msrp(method) == "SEND" || $msrp(method) == "REPORT") {
> ...
> } else
> msrp_reply("501", "Request-method-not-understood");
>
Is REPORT end to end?
Cheers,
Daniel
>
> Regards,
>
> Peter
>
>
> On Thu, 2012-10-25 at 13:16 +0200, Daniel-Constantin Mierla wrote:
>> Hello,
>>
>> just remembered about this one ...
>>
>> hmm, I would say now that the right method would be AUTH, not MSRP,
>> but as you pointed, in SIP and HTTP the method is the first token in
>> request. I guess you had no chance to test with some client or look
>> at specs to see if they clarify somehow.
>>
>> In both cases, the method seems to be static anyhow, either AUTH or
>> MSRP (iirc, the authentication is done only for AUTH). Both have the
>> same length, so a quick hack would be to replace internally MSRP with
>> AUTH for this case. But probably the safest is to extend the auth api
>> with a function that takes the method as parameter, which is
>> eventually used from inside msrp module.
>>
>> Probably before the next release I will put some efforts in this
>> module, as the interest on it seems to increase, one of the goals
>> being to add an internal hash table to track the connections - it
>> should bring some performance improvement versus using htable in
>> config...
>>
>> Cheers,
>> Daniel
>>
>> On 10/19/12 3:58 PM, Peter Dunkley wrote:
>>
>>> Hi,
>>>
>>> MSRP AUTH requests must be authenticated using HTTP Digest
>>> authentication. Part of the concatenated data when doing this
>>> authentication is the method name. Because of the way MSRP requests
>>> are formatted, the part of the request-line that would contain the
>>> method name in HTTP or SIP requests is always MSRP. The MSRP method
>>> name (AUTH in this case) is at the end of the request-line. When
>>> Kamailio converts an MSRP request to SIP it has a method name of MSRP.
>>>
>>> This means that when Kamailio authenticates an MSRP request it uses
>>> "MSRP" as the method name, not the actual MSRP method name (AUTH).
>>>
>>> Is this correct?
>>>
>>> Should MSRP requests be authenticated with a method name of "MSRP"
>>> (which kind-of makes sense as this is the string at the start of the
>>> MSRP request line - which is where the method names are in HTTP and
>>> SIP) or should the MSRP method name of "AUTH" be used?
>>>
>>> If it is the later, does anyone know of an easy way to add this to
>>> Kamailio?
>>>
>>> Regards,
>>>
>>> Peter
>>>
>>> --
>>> Peter Dunkley
>>> Technical Director
>>> Crocodile RCS Ltd
>>>
>>>
>>>
>>> _______________________________________________
>>> sr-dev mailing list
>>> sr-dev at lists.sip-router.org <mailto:sr-dev at lists.sip-router.org>
>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
>>
>> --
>> Daniel-Constantin Mierla -http://www.asipto.com
>> http://twitter.com/#!/miconda <http://twitter.com/#%21/miconda> -http://www.linkedin.com/in/miconda
>> Kamailio Advanced Training, Berlin, Nov 5-8, 2012 -http://asipto.com/u/kat
>> Kamailio Advanced Training, Miami, USA, Nov 12-14, 2012 -http://asipto.com/u/katu
>
> --
> Peter Dunkley
> Technical Director
> Crocodile RCS Ltd
>
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Training, Berlin, Nov 5-8, 2012 - http://asipto.com/u/kat
Kamailio Advanced Training, Miami, USA, Nov 12-14, 2012 - http://asipto.com/u/katu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-dev/attachments/20121025/14e4a9ce/attachment.htm>
More information about the sr-dev
mailing list