[jdev] dialback

Peter Saint-Andre stpeter at jabber.org
Tue Jun 6 11:29:42 CDT 2006


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Ben Turner wrote:
> On Fri, Jun 02, 2006 at 09:02:55AM -0600, Peter Saint-Andre wrote:
>> If Server1 does not support XMPP 1.0 (including TLS), it MUST NOT
>> include the version='1.0' attribute in the stream header it sends to
>> Server2. However, if it supports dialback it MUST include the dialback
>> namespace declaration in the stream header it sends to Server2. So if
>> Server1 supports only dialback and not TLS, it would send:
>>
>> <stream:stream
>>        xmlns='jabber:server'
>>        xmlns:stream='http://etherx.jabber.org/streams'
>>        xmlns:db='jabber:server:dialback'
>>        to='Server1'>
>>
>> If Server2 detects that the stream header from Server1 does not include
>> the version='1.0' attribute but does include the dialback namespace
>> declaration, then it MUST NOT attempt to perform TLS negotiation.
>>
>> If Server2 breaks that rule and attempts to perform TLS negotiation
>> anyway (BAD SERVER, BAD!), Server1 would in all likelihood simply close
>> the stream with </stream:stream> (since it is probably an older server
>> implementation) but it might first send an appropriate stream error,
>> such as <not-authorized/> or <unsupported-stanza-type/> (though in
>> practice this is doubtful).
> 
> Hi Peter,
> 
> Thanks for that bit of info.
> 
> Another quick question. If server1 (which supports TLS) attempts to connect with
> server2 (which _doesn't_ support TLS) and server1 discovers this fact through
> the absence of a version='1.0' in server2's stream header, is server1 supposed
> to keep using the same TCP connection or open a new one? 
> 
> I have noticed that Wildfire opens a new TCP connection once it discovers that
> dialback is required, it even sends a stream header without version='1.0' after
> opening the new TCP connection. Why not just keep using the already opened TCP
> connection?

I see no particular reason to close the TCP connection. Degrading
gracefully to "XMPP 0.9" on the same TCP connection seems preferable.

Peter

- --
Peter Saint-Andre
Jabber Software Foundation
http://www.jabber.org/people/stpeter.shtml

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (Darwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFEha12NF1RSzyt3NURAiqYAJ4+wloJQOwOo4o7/UlqGz2bNxC/IwCgyf2a
gnMDr9+z7wyZ8gZDIDx6HC0=
=/bB1
-----END PGP SIGNATURE-----
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3641 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://mail.jabber.org/pipermail/jdev/attachments/20060606/c365fb38/attachment-0002.bin>


More information about the JDev mailing list