Re: [stir] RFC 8224

[Christer Holmberg <[e-mail]>]

Hi,

>> Maybe the problem with the To header is the phone-context parameter. The RFC 8224 procedures do not cover the presence of the parameter: the parameter
>> is not removed, nor is it added to the tn. And, the generic SIP canonicalization procedures does not remove the parameter either.
>
> That is not my understanding of RFC 8224 section 8.1 and 8.3.

What is your understanding?

Regards,

Christer



> From: Zerr, Brad <[e-mail]>
> Sent: keskiviikko 7. huhtikuuta 2021 18.26
> To: Chris Wendt <[e-mail]>; Christer Holmberg <[e-mail]>
> Cc: Marc Petit-Huguenin <[e-mail]>; Cullen Jennings <[e-mail]>; IETF STIR Mail List <[e-mail]>; Eric Rescorla <[e-mail]>; Jon Peterson <[e-mail]>; Toy, Arthur <[e-mail]>
> Subject: RE: [stir] RFC 8224
> 
> Hi Chris,
> 
> Here is a little background that got this conversation going.
> 
> One of our customers sent us a SIP INVITE so we could perform the Stir-Shaken Signing for them.  The customer performed the translations on their MMTEL TAS to translate *55 to a 10 digit number.  When we receive the SIP INVITE for signing, it had the REQ-URI with the 10 digit number and the TO header with *55, see below.  Our applications rejected this because of the TO header (whether it is right or wrong is to be determined).  So we start questioning how * and # short codes should be handled.
> 
> FYI, I “x” out information to keep anonymous
> 
> INVITE sip:+xxxxxxxxxx;phone-context=[e-mail];user=phone SIP/2.0
> To: sip:*99;phone-context=[e-mail];user=phone
> From: sip:[e-mail];tag=p65539t1617206731m169121c110882s1_1220390100-1617434405
> Call-ID: p65539t1617206731m169121c110882s2
> CSeq: 1 INVITE
> Max-Forwards: 66
> Content-Length: 896
> Via: SIP/2.0/TCP xxxxxxxxxx:5060;branch=z9hG4bK1a5ca0b3c42536a59ddec4c723f8774fk555555yaaaaacaaaaaaaaaaaaa3Zqkv7yujk3t0qbaaiaiaaaaabqaaaaaaaqaaaaaa
> Via: SIP/2.0/TCP xxxxxxx:5082;branch=z9hG4bK1220390081-337970536
> Route: sip:xxxx.cgah.ims.mncxxx.mccxxx.3gppnetwork.org;callhalf=orig;lr
> Route: sip:3Zqkv7%2FcaGmGRV9neaaaacgloTpN3kFNU6jv2EObabaecaSdeaaaadsip%3A%2Bxxxxxxxx%40ims.mncxxx.mccxxx.3gppnetwork.orgOLxz6Geaeaqxxxxxxxxxxx%40ims.mncxxx.mcc3xxx.3gppnetwork.org@xxxxxxxxxxxx:5060;lr
> Record-Route: sip:3Zqkv7%20caqmGRV9ngaaaaaQjv2E[e-mail]:5060;maddr=xxxxxxxxx;lr
> Contact: sip:p65539t1617206731m169121c110882s1@xxxxxxxx:5082;+g.3gpp.accesstype="cellular";+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel<sip:p65539t1617206731m169121c110882s1@xxxxxxxx:5082;+g.3gpp.accesstype=%22cellular%22;+g.3gpp.icsi-ref=%22urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel>"
> Content-Type: application/sdp
> Allow: REGISTER, REFER, NOTIFY, SUBSCRIBE, INFO, MESSAGE, PRACK, UPDATE, INVITE, ACK, OPTIONS, CANCEL, BYE
> Accept-Contact: *;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"
> Supported: timer, 100rel, path, precondition, replaces
> P-Asserted-Identity: sip:[e-mail]
> P-Asserted-Identity: tel:xxxxxxxxx
> Proxy-Authorization: Digest uri=sip:*99;phone-context=[e-mail];user=phone,response="",nonce="",realm="",username=[e-mail]<mailto:[e-mail]>
> P-Visited-Network-ID: ims.mnc420.mcc312.3gppnetwork.org
> P-Access-Network-Info: 3GPP-E-UTRAN-FDD;local-time-zone="2021-03-31T11:05:31-05:00";utran-cell-id-3gpp=xxxxxxxxxxxxxxxxxxxxxxxx
> Min-SE: 900
> Session-Expires: 1800
> P-Charging-Vector: icid-value=pcscf2.ims.mncxxx.mcc3xxx.3gppnetw-1617-206731-149675;icid-generated-at=pcscf2.ims.mncxxx.mccxxx.3gppnetwork.org;orig-ioi=ims.mncxxx.mccxxxx.3gppnetwork.org
> User-Agent: Ericsson MTAS - CXP2010134/1 R20F14
> P-Charging-Function-Addresses: ccf="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
> P-Served-User: sip:[e-mail];sescase=orig;regstate=reg
> Feature-Caps: *;+g.3gpp.registration-token="<63b9cf28>"
> P-Early-Media: supported
> Session-ID: 7c386176b888d13d404845e189d6885b
> 
> From: Chris Wendt <[e-mail]<mailto:[e-mail]>>
> Sent: Wednesday, April 7, 2021 10:10 AM
> To: Christer Holmberg <[e-mail]<mailto:[e-mail]>>
> Cc: Zerr, Brad <[e-mail]<mailto:[e-mail]>>; Marc Petit-Huguenin <[e-mail]<mailto:[e-mail]>>; Cullen Jennings <[e-mail]<mailto:[e-mail]>>; IETF STIR Mail List <[e-mail]<mailto:[e-mail]>>; Eric Rescorla <[e-mail]<mailto:[e-mail]>>; Jon Peterson <[e-mail]<mailto:[e-mail]>>; Toy, Arthur <[e-mail]<mailto:[e-mail]>>
> Subject: Re: [stir] RFC 8224
> 
> This is a legit question for RFC8224 and agree with the answers, but just in case it’s relevant you would not send these types of SIP URIs as dest in context of STIR/SHAKEN (over NNI/peering relationship) which only supports tel URIs currently.  That may not be your use-case but just wanted to clarify in case it was relevant.  I would be curious to know the context if you are willing to share though, i am guessing intra network use case between device and app server?  Definitely interested in those cases, for me in context of delegate certs.
> 
> -Chris
> 
> 
> 
> On Apr 7, 2021, at 9:52 AM, Christer Holmberg <[e-mail]<mailto:[e-mail]>> wrote:
> 
> Hi,
> 
> ´*´ can be used as such in a SIP-URI, but ‘#’ would have to be escaped.
> 
> So:
> 
> To: sip:*55;phone-context=[e-mail];user=phone
> 
> …is ok, but;
> 
> To: sip:#55;phone-context=[e-mail];user=phone<sip:*55;phone-context=[e-mail];user=phone>
> 
> …is NOT ok. Instead:
> 
> To: sip:%2355;phone-context=[e-mail];user=phone
> 
> …will have to be used.
> 
> Regards,
> 
> Christer
> 
> 
> 
> From: Zerr, Brad <[e-mail]<mailto:[e-mail]>>
> Sent: keskiviikko 7. huhtikuuta 2021 14.27
> To: Christer Holmberg <[e-mail]<mailto:[e-mail]>>; Marc Petit-Huguenin <[e-mail]<mailto:[e-mail]>>; Cullen Jennings <[e-mail]<mailto:[e-mail]>>; IETF STIR Mail List <[e-mail]<mailto:[e-mail]>>
> Cc: [e-mail]<mailto:[e-mail]>; Eric Rescorla <[e-mail]<mailto:[e-mail]>>; Jon Peterson <[e-mail]<mailto:[e-mail]>>; Toy, Arthur <[e-mail]<mailto:[e-mail]>>
> Subject: RE: [stir] RFC 8224
> 
> Good Morning.
> 
> Would you mind providing an example of what the TO header should look like for both a * and # dial to help clear up?  Assume they are leading characters in the TO header.
> 
> Example of what is being sent today:
> 
> To: sip:*55;phone-context=[e-mail];user=phone
> 
> To: sip:#55;phone-context=[e-mail];user=phone<sip:*55;phone-context=[e-mail];user=phone>
> 
> From: Christer Holmberg <[e-mail]<mailto:[e-mail]>>
> Sent: Wednesday, April 7, 2021 3:14 AM
> To: Marc Petit-Huguenin <[e-mail]<mailto:[e-mail]>>; Cullen Jennings <[e-mail]<mailto:[e-mail]>>; Zerr, Brad <[e-mail]<mailto:[e-mail]>>; IETF STIR Mail List <[e-mail]<mailto:[e-mail]>>
> Cc: [e-mail]<mailto:[e-mail]>; Eric Rescorla <[e-mail]<mailto:[e-mail]>>; Jon Peterson <[e-mail]<mailto:[e-mail]>>; Toy, Arthur <[e-mail]<mailto:[e-mail]>>
> Subject: RE: [stir] RFC 8224
> 
> Hi,
> 
>> I think the question was about the format to use before canonicalization.
>>
>> My understanding of RFC 3986 is that `#` should be escaped because it is the delimiter for an URI fragment. Fragments are not defined in SIP URIs, but a generic URI parser may still remove everything after and including '#'.
> 
> "#" will have to be escaped in a SIP-URI, e.g., in a To header field.
> 
> But, Section 8.3 of RFC 8224 has nothing to do with a SIP-URI or the To header field.
> 
> Regards,
> 
> Christer
> 
> 
> 
> 
> 
> 
> 
> OTOH there is no need to escape '*' as it is part of the `sub-delims` rule.
> 
> so
> 
> ....
> To: sip:*55;phone-context=[e-mail];user=phone
> ....
> 
> is fine, but dialing directly an extension would be:
> 
> ....
> To: sip:[e-mail];user=phone
> ....
> 
> On 4/6/21 5:43 AM, Christer Holmberg wrote:
>> Hi,
>>
>> %2A is not the ASCII format of *, it is the escaped (see RFC 3261).
>>
>> And, the syntax allows both * and #, so no need to escape (in fact, it is not even possible to escape in this case):
>>
>> tn-spec = 1*tn-char
>> tn-char = "#" / "*" / DIGIT
>>
>> Also, note that RFC 8224 does not define the syntax of the To header field - that is done in RFC 3261. The telephone number described in Section 8.3 of RFC 8224 will be included in the PASSPort (RFC 8225).
>>
>> Regards,
>>
>> Christer
>>
>> From: stir <[e-mail]<mailto:[e-mail]>> On Behalf Of Cullen Jennings
>> Sent: tiistai 6. huhtikuuta 2021 15.30
>> To: Zerr, Brad <[e-mail]<mailto:[e-mail]>>; IETF STIR Mail List <[e-mail]<mailto:[e-mail]>>
>> Cc: [e-mail]<mailto:[e-mail]>; Eric Rescorla <[e-mail]<mailto:[e-mail]>>; Jon Peterson <[e-mail]<mailto:[e-mail]>>; Toy, Arthur <[e-mail]<mailto:[e-mail]>>
>> Subject: Re: [stir] RFC 8224
>>
>>
>> Adding to STIR mailing list …
>>
>>
>> On Apr 5, 2021, at 9:19 AM, Zerr, Brad <[e-mail]<mailto:[e-mail]<mailto:[e-mail]%3cmailto:[e-mail]>>> wrote:
>>
>> Good Morning.
>>
>> This may not be the correct process, so let me know if I should ask this in a different forum.
>>
>> I had a question regarding section 8.3 when it comes to * and # handling. Is this stating that when a * or # proceeds a digit string (i.e. *55), it should be in ASCI Format for the * (i.e. %2A)
>>
>> <image001.png>
>>
>> So Instead of this:
>>
>> To: sip:*55;phone-context=[e-mail];user=phone
>>
>> It should be this
>>
>> To: sip:%2A55;phone-context=[e-mail];user=phone
>>
>>
>>
> 
> 

-- 
Marc Petit-Huguenin
Email: [e-mail]
Blog: https://protect2.fireeye.com/v1/url?k=247f4226-7be47af4-247f02bd-866132fe445e-1643d035697446bf&q=1&e=752f8e22-1054-4dd1-a34b-0b0d5deca043&u=https%3A%2F%2Fmarc.petit-huguenin.org%2F
Profile: https://www.linkedin.com/in/petithug