Subject: [SIP] Error in draft-ietf-sip-call-flows-01.txt

From: Neil Deason <[email-masked]>
Date: Thu, 19 Oct 2000 09:59:37 +0100

One of the changes made in draft 01 was to correct all
registrations to have same Call-ID over an authentication
challenge. In sections 2.1.1 and 2.2.1 I think. 
However the CSeqs were not incremented in the second REGISTER
requests carrying the authentication credentials sent by the
Clients. This means the authentication would always fail as the
second REGISTER is actually isomorphic to the first and would
receive the same 401 Unauthorized response.

Corrected call flows for 2.1.1 and 2.2.1 are reproduced below.
Cheers,
Neil
-- 
Ubiquity Software Corporation, UK        http://www.ubiquity.net

--
2.1.1 SIP Client New Registration

F1 REGISTER B -> SIP Server

   REGISTER sip:ss2.wcom.com SIP/2.0
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 1 REGISTER
   Contact: LittleGuy <sip:[email-masked]>
   Contact: sip:[email-masked];user=phone
   Contact: tel:+1-972-555-2222
   Content-Length: 0

   F2 401 Unauthorized SIP Server -> User B

   SIP/2.0 401 Unauthorized
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 1 REGISTER
   WWW-Authenticate: Digest realm="MCI WorldCom SIP",
domain="wcom.com",
    nonce="ea9c8e88df84f1cec4341ae6cbe5a359", opaque="",
stale="FALSE",
    algorithm="MD5"
   Content-Length: 0

   F3 REGISTER B -> SIP Server

   REGISTER sip:ss2.wcom.com SIP/2.0
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 2 REGISTER
   Contact: LittleGuy <sip:[email-masked]>
   Contact: sip:[email-masked];user=phone
   Contact: tel:+1-972-555-2222
   Authorization:Digest username="UserB", realm="MCI WorldCom
SIP",
    nonce="ea9c8e88df84f1cec4341ae6cbe5a359", opaque="",
    uri="sip:ss2.wcom.com",
response="dfe56131d1958046689cd83306477ecc"
   Content-Length: 0

   F4 200 OK SIP Server -> B

   SIP/2.0 200 OK
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 2 REGISTER
   Contact: LittleGuy <sip:[email-masked]>
   Contact: sip:[email-masked];user=phone
   Contact: tel:+1-972-555-2222
   Content-Length: 0

2.2.1 Unsuccessful SIP registration

F1 REGISTER B -> SIP Server

   REGISTER sip:ss2.wcom.com SIP/2.0
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 1 REGISTER
   Contact: LittleGuy <sip:[email-masked]>
   Contact: sip:[email-masked];user=phone
   Contact: tel:+1-972-555-2222
   Content-Length: 0

   F2 Unauthorized SIP Server -> User B
   
   SIP/2.0 401 Unauthorized
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 1 REGISTER
   WWW-Authenticate: Digest realm="MCI WorldCom SIP",
domain="wcom.com",
    nonce="f1cec4341ae6ca9c8e88df84be55a359", opaque="",
stale="FALSE",
    algorithm="MD5"
   Content-Length: 0

   F3 REGISTER B -> SIP Server

   REGISTER sip:ss2.wcom.com SIP/2.0
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 2 REGISTER
   Contact: LittleGuy <sip:[email-masked]>
   Contact: sip:[email-masked];user=phone
   Contact: tel:+1-972-555-2222
   Authorization:Digest username="UserB", realm="MCI WorldCom
SIP",
    nonce="f1cec4341ae6ca9c8e88df84be55a359", opaque="",
    uri="sip:ss2.wcom.com",
response="61f8470ceb87d7ebf508220214ed438b"
   Content-Length: 0

   /*  The response above encodes the incorrect password
_IForgotIt_ */

   F4 401 Unauthorized SIP Server -> User B

   SIP/2.0 401 Unauthorized
   Via: SIP/2.0/UDP there.com:5060
   From: LittleGuy <sip:[email-masked]>
   To: LittleGuy <sip:[email-masked]>
   Call-ID: [email-masked]
   CSeq: 2 REGISTER
   WWW-Authenticate: Digest realm="MCI WorldCom SIP",
domain="wcom.com",
    nonce="84f1c1ae6cbe5ua9c8e88dfa3ecm3459", opaque="",
stale="FALSE",
    algorithm="MD5"
   Content-Length: 0

_______________________________________________
SIP mailing list
[email-masked]
http://lists.bell-labs.com/mailman/listinfo/sip