Subject: [Sip] SIP-URL params parsing issue

From: "Gayraud, Richard" <[email-masked]>
Date: Wed, 13 Jun 2001 14:24:17 +0200

Hi,

In reading the Contact header ABNF, I noticed that a SIP-URL
can be immediately followed by generic-params.

I also noticed that SIP-URL can be ended by similar parameters 
(almost the same syntax, separated by ';'). 

Therefore I wonder how a general purpose SIP parser could 
determine whether a given parameter is part of the SIP-URL 
or is a generic-param of the Contact header field.

Here is an example of such an ambiguous header:

  Contact: [email-masked];my_param=my_value

Note that adding an extra LWS after the URI may solve the 
issue, but the spec does not require it.

I noticed the same problem for the From and To headers. Some 
other headers, like Alert-Info are safe, as they force the URI to 
be enclosed between '<' and  '>'.

Thanks in advance for your help,

Richard Gayraud.

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---

From: Alexandre Charest <[email-masked]>
Date: Wed, 13 Jun 2001 08:38:02 -0400

Look just behind the ABNF for the contact at page 46 of the ps. It is
written:
"Event if the "display-name" is empty, the "name-addr" form MUST be used if
the "addr-spec" contains a comma, semicolon or question mark."

So Contact is safe too. You can find the same sentence in the From and To
headers description.

-----Original Message-----
From: Gayraud, Richard [mailto:[email-masked]]
Sent: Wednesday, June 13, 2001 8:24 AM
To: [email-masked]'
Subject: [Sip] SIP-URL params parsing issue

Hi,

Richard Gayraud.