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<font face="Times New Roman, Times, serif"><font face="Times New
Roman, Times, serif">Date header has been part of <a
moz-do-not-send="true"
href="https://datatracker.ietf.org/doc/html/rfc3261.html">RFC-3261
SIP</a> for 19 years now, but was not used all that much. </font>IAT
and Date are both part of the specs and more recent RFC's that
define stir-shaken. So the seldom-used but long time defined
Date: header is now required. Furthermore, IAT is part of the
formal JSON in the Identity header and must be present, or the
claims are not valid. <br>
<br>
Normally, IAT would restate the Date with Unix Epoch date. IAT
is signed, but the Date header is not signed. <br>
<br>
When a call is received and Verified, the the plain-text signed
JSON is validated. If verified IAT is stale, the call is
rejected. True, someone could mess with Date header along the
route or SIP From header or PAI. And for that matter, someone
could mess with the JSON attributes that are signed. But then
the verification would fail, and the call should not be
delivered. That's part of the beauty of the system. <br>
<br>
Best regards,<br>
</font>
<blockquote><font face="Times New Roman, Times, serif">John</font><br>
</blockquote>
<br>
<div class="moz-cite-prefix">On 7/1/2021 12:29, Joseph Jackson
wrote:<br>
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cite="mid:82561198239b424ca7643498001f760c@MBX080-W1-CO-1.exch080.serverpod.net">
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<p class="MsoNormal"><span style="color:#44546A">I’ve heard that
TNSi also counts on the date header being present.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#44546A">So far we don’t
see a lot of people passing tokens with the date header.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#44546A"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
VoiceOps [<a class="moz-txt-link-freetext" href="mailto:voiceops-bounces@voiceops.org">mailto:voiceops-bounces@voiceops.org</a>]
<b>On Behalf Of </b>Matthew Yaklin<br>
<b>Sent:</b> Thursday, July 01, 2021 12:25 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:voiceops@voiceops.org">voiceops@voiceops.org</a><br>
<b>Subject:</b> [VoiceOps] question about stir/shaken -
iat and DATE header<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">All,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Pretty simple question here. When you do a
verify request are you filling in the iat with your sbc’s
current date/time or using the DATE information from the
invite?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">With Neustar the iat is currently optional.
IQNT is basically removing the DATE header in a test we are
doing by sending them a call and getting it back in a
different region.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It really does not make sense to me to use
the DATE header because it could be messed with by anyone in
the path. It is untrusted. The iat is trusted so when you
verify it makes more sense to use the current date/time of
your SBC because the limitation is 60 seconds from AS to VS.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I imagine Neustar made it optional because
their own system has some intelligence when it comes to this
expiration of the AS.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">On top of that Metaswitch is not prepared
for this situation. They are basically counting on that DATE
header to be there in their recommended perimeta SBC config.
They plan to fix it by using the current date/time.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Just looking for how others are handling
this. Just leaving it blank for now?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Matt<o:p></o:p></p>
</div>
<br>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
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