My problem is that the UA doesn't seem to be able to handle to long nonces
so it takes as many chars as it can handle and uses that.

In the nonce that our proxy sends, there are a timestamp (according to
Digest RFC) to be able to validate if the nonce is supposed to be valid or
not. When the UA removes characters from the nonce there is no way for the
proxy to know if it should accept it or not (it cant read the timestamp and
validate it). If it sends a new 407 it will get the same response again
(with a short nonce) and it will keep doing so. To prevent this (the
challenge will always fail unless the proxy creates a shorter nonce) what
can it send instead? I guess you could always send 400 Bad Request but is
there a more specified response to send?

Regards,
Andreas

-----Original Message-----
From: Scott Lawrence [mailto:[EMAIL PROTECTED]
Sent: den 16 oktober 2003 16:05
To: Andreas Bystr�m
Cc: Sip Implemators
Subject: Re: [Sip-implementors] Wrong nonce in challenge response


Andreas Bystr�m <[EMAIL PROTECTED]> writes:

> What to do if the proxy receives a different nonce that the one that
> it sent in a challenge? Whould it just send a new 407 or should it
> send something else?

> Example
> Proxy A receives an Invite. A sends 407 back to UA with a challenge
> containing the nonce="12345". When A then receives the Invite again, there
> is a response to the challenge. But in that response the nonce is "123".
> Should A just send a new 407 ?

It's up to the server to decide whether or not the nonce it receives
is acceptable to it.  The server may use any criteria it likes for
that decision.  It can return a new challenge (407 for proxy
authentication, or 401 for server authentication), or decide to accept
the nonce as valid.

If it doesn't like the nonce, it should return the 40[17].  If the
nonce might once have been valid (such as one whose nc value is
outside the range acceptable to the server, or one that is too old),
the server has the option of computing whether or not the credentials
used to construct the response value with that nonce were good, and if
so return 'stale=true' to indicate that a retry using the same
credentials and the new nonce should succeed, but it is not required
to do that check.

--
Scott Lawrence
  Pingtel Corp.

_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to