Network Working Group                                        C. Jennings
Internet-Draft                                             Cisco Systems
Expires: November 17, 2006                                        K. Ono
                                                         NTT Corporation
                                                          R. Sparks, Ed.
                                                        Estacado Systems
                                                            May 16, 2006


  Example call flows using Session Initiation Protocol (SIP) security
                               mechanisms
                      draft-ietf-sip-sec-flows-00

Status of this Memo

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   applicable patent or other IPR claims of which he or she is aware
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   This Internet-Draft will expire on November 17, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document shows example call flows demonstrating the use of
   Transport Layer Security (TLS), and Secure/Multipurpose Internet Mail
   Extensions (S/MIME) in Session Initiation Protocol (SIP).  It also
   provides information that helps implementers build interoperable SIP



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   software.  To help facilitate interoperability testing, it includes
   certificates used in the example call flows and processes to create
   certificates for testing.


Table of Contents

   1.  Administrive Information . . . . . . . . . . . . . . . . . . .  3
   2.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   4.  Security Considerations  . . . . . . . . . . . . . . . . . . .  4
   5.  Known Problems . . . . . . . . . . . . . . . . . . . . . . . .  4
   6.  Certificates . . . . . . . . . . . . . . . . . . . . . . . . .  4
     6.1.  CA Certificates  . . . . . . . . . . . . . . . . . . . . .  4
     6.2.  Host Certificates  . . . . . . . . . . . . . . . . . . . .  8
     6.3.  User Certificates  . . . . . . . . . . . . . . . . . . . .  9
   7.  Callflow with Message Over TLS . . . . . . . . . . . . . . . . 12
     7.1.  TLS with Server Authentication . . . . . . . . . . . . . . 12
     7.2.  MESSAGE Message Over TLS . . . . . . . . . . . . . . . . . 13
   8.  Callflow with S/MIME-secured Message . . . . . . . . . . . . . 14
     8.1.  MESSAGE Message with Signed Body . . . . . . . . . . . . . 14
     8.2.  MESSAGE Message with Encrypted Body  . . . . . . . . . . . 17
     8.3.  MESSAGE Message with Encrypted and Signed Body . . . . . . 20
   9.  Test Consideration . . . . . . . . . . . . . . . . . . . . . . 25
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 26
   11. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 26
   12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26
     12.1. Normative References . . . . . . . . . . . . . . . . . . . 26
     12.2. Informative References . . . . . . . . . . . . . . . . . . 27
   Appendix A.  Making Test Certificates  . . . . . . . . . . . . . . 27
     A.1.  makeCA script  . . . . . . . . . . . . . . . . . . . . . . 29
     A.2.  makeCert script  . . . . . . . . . . . . . . . . . . . . . 31
   Appendix B.  Certificates for Testing  . . . . . . . . . . . . . . 33
   Appendix C.  Message Dumps . . . . . . . . . . . . . . . . . . . . 36
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 44
   Intellectual Property and Copyright Statements . . . . . . . . . . 45















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1.  Administrive Information

   Please note that this version of the document
   (draft-ietf-sip-sec-flows-00) is ONLY an administrative renaming from
   draft-ietf-sipping-sec-flows.  The outstanding additions to this
   document discussed in those working groups have not yet been captured
   here.


2.  Introduction

   Several different groups are starting to implement the S/MIME[7]
   portion of SIP[2], and SIP with TLS[4], implementations are becoming
   very common.  At several interoperability events, it has become clear
   that it is difficult to write these systems without any test vectors
   or examples of "known good" messages to test against.  Furthermore,
   testing at the events is often hampered by trying to get certificates
   signed by some common test root into the appropriate format for
   various clients.  This document addresses both of these issues by
   providing messages that give detailed examples that implementers can
   use for comparison and that can also be used for testing.  In
   addition, this document provides a common certificate that can be
   used for a Certificate Authority (CA) to reduce the time it takes to
   set up a test at an interoperability event.  The document also
   provides some hints and clarifications for implementers.

   A simple SIP call flow using SIPS URIs and TLS is shown in Section 7.
   The certificates for the hosts used are shown in Section 6.2, and the
   CA certificates used to sign these are shown in Section 6.1.

   The text from Section 8.1 through Section 8.3 shows some simple SIP
   call flows using S/MIME to sign and encrypt the body of the message.
   The user certificates used in these examples are shown in
   Section 6.3.  These host certificates are signed with the same CA
   certificate.

   Section 9 presents a partial list of things implementers should
   consider in order to implement systems that will interoperate.

   A way to make certificates that can be used for interoperability
   testing is presented in Appendix A, along with methods for converting
   these to various formats.

   Binary copies of various messages in this draft that can be used for
   testing appear in Appendix C.






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3.  Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC-2119 [1].


4.  Security Considerations

   Implementers must never use any of the certificates provided in this
   document in anything but a test environment.  Installing the CA root
   certificates used in this document as a trusted root in operational
   software would completely destroy the security of the system while
   giving the user the impression that the system was operating
   securely.

   This document recommends some things that implementers might test or
   verify to improve the security of their implementations.  It is
   impossible to make a comprehensive list of these, and this document
   only suggests some of the most common mistakes that have been seen at
   the SIPit interoperability events.  Just because an implementation
   does everything this document recommends does not make it secure.

   This document does not show the messages to check Certificate
   Revocation Lists (see [3]) as that is not part of the SIP call flow.


5.  Known Problems

   The binary dumps of the messages in Section 7.2 need to be updated to
   match the text of the draft.

   The messages are missing the accept headers.  They should have the
   following header:

      Accept: multipart/signed
      Accept: text/plain
      Accept: application/pkcs7-mime
      Accept: application/sdp
      Accept: multipart/alternative


6.  Certificates

6.1.  CA Certificates

   The certificate used by the CA to sign the other certificates is
   shown below.  This is a X509v3 certificate.  Note that the basic



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   constraints allow it to be used as a CA.


   Version: 3 (0x2)
   Serial Number: 0 (0x0)
   Signature Algorithm: sha1WithRSAEncryption
   Issuer: C=US, ST=California, L=San Jose, O=sipit,
           OU=Sipit Test Certificate Authority
   Validity
       Not Before: Jul 18 12:21:52 2003 GMT
       Not After : Jul 15 12:21:52 2013 GMT
   Subject: C=US, ST=California, L=San Jose, O=sipit,
           OU=Sipit Test Certificate Authority
   Subject Public Key Info:
       Public Key Algorithm: rsaEncryption
       RSA Public Key: (1024 bit)
           Modulus (1024 bit):
               00:c3:22:1e:83:91:c5:03:2c:3c:8a:f4:11:14:c6:
               4b:9d:fa:72:78:c6:b0:95:18:a7:e0:8c:79:ba:5d:
               a4:ae:1e:21:2d:9d:f1:0b:1c:cf:bd:5b:29:b3:90:
               13:73:66:92:6e:df:4c:b3:b3:1c:1f:2a:82:0a:ba:
               07:4d:52:b0:f8:37:7b:e2:0a:27:30:70:dd:f9:2e:
               03:ff:2a:76:cd:df:87:1a:bd:71:eb:e1:99:6a:c4:
               7f:8e:74:a0:77:85:04:e9:41:ad:fc:03:b6:17:75:
               aa:33:ea:0a:16:d9:fb:79:32:2e:f8:cf:4d:c6:34:
               a3:ff:1b:d0:68:28:e1:9d:e5
           Exponent: 65537 (0x10001)
   X509v3 extensions:
     X509v3 Subject Key Identifier:
       6B:46:17:14:EA:94:76:25:80:54:6E:13:54:DA:A1:E3:54:14:A1:B6
     X509v3 Authority Key Identifier:
       6B:46:17:14:EA:94:76:25:80:54:6E:13:54:DA:A1:E3:54:14:A1:B6
       DirName:/C=US/ST=California/L=San Jose/O=sipit/
                OU=Sipit Test Certificate Authority
       serial:00
     X509v3 Basic Constraints:
       CA:TRUE
   Signature Algorithm: sha1WithRSAEncryption
    96:6d:1b:ef:d5:91:93:45:7c:5b:1f:cf:c4:aa:47:52:0b:34:
    a8:50:fa:ec:fa:b4:2a:47:4c:5d:41:a7:3d:c0:d6:3f:9e:56:
    5b:91:1d:ce:a8:07:b3:1b:a4:9f:9a:49:6f:7f:e0:ce:83:94:
    71:42:af:fe:63:a2:34:dc:b4:5e:a5:ce:ca:79:50:e9:6a:99:
    4c:14:69:e9:7c:ab:22:6c:44:cc:8a:9c:33:6b:23:50:42:05:
    1f:e1:c2:81:88:5f:ba:e5:47:bb:85:9b:83:25:ad:84:32:ff:
    2a:5b:8b:70:12:11:83:61:c9:69:15:4f:58:a3:3c:92:d4:e8:
    6f:52





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   The ASN.1 parse of the CA certificate is shown below.



       0:l= 804 cons: SEQUENCE
       4:l= 653 cons:  SEQUENCE
       8:l=   3 cons:   cont [ 0 ]
      10:l=   1 prim:    INTEGER           :02
      13:l=   1 prim:   INTEGER           :00
      16:l=  13 cons:   SEQUENCE
      18:l=   9 prim:    OBJECT            :sha1WithRSAEncryption
      29:l=   0 prim:    NULL
      31:l= 112 cons:   SEQUENCE
      33:l=  11 cons:    SET
      35:l=   9 cons:     SEQUENCE
      37:l=   3 prim:      OBJECT            :countryName
      42:l=   2 prim:      PRINTABLESTRING   :US
      46:l=  19 cons:    SET
      48:l=  17 cons:     SEQUENCE
      50:l=   3 prim:      OBJECT            :stateOrProvinceName
      55:l=  10 prim:      PRINTABLESTRING   :California
      67:l=  17 cons:    SET
      69:l=  15 cons:     SEQUENCE
      71:l=   3 prim:      OBJECT            :localityName
      76:l=   8 prim:      PRINTABLESTRING   :San Jose
      86:l=  14 cons:    SET
      88:l=  12 cons:     SEQUENCE
      90:l=   3 prim:      OBJECT            :organizationName
      95:l=   5 prim:      PRINTABLESTRING   :sipit
     102:l=  41 cons:    SET
     104:l=  39 cons:     SEQUENCE
     106:l=   3 prim:      OBJECT            :organizationalUnitName
     111:l=  32 prim:      PRINTABLESTRING   :
                           Sipit Test Certificate Authority
     145:l=  30 cons:   SEQUENCE
     147:l=  13 prim:    UTCTIME           :030718122152Z
     162:l=  13 prim:    UTCTIME           :130715122152Z
     177:l= 112 cons:   SEQUENCE
     179:l=  11 cons:    SET
     181:l=   9 cons:     SEQUENCE
     183:l=   3 prim:      OBJECT            :countryName
     188:l=   2 prim:      PRINTABLESTRING   :US
     192:l=  19 cons:    SET
     194:l=  17 cons:     SEQUENCE
     196:l=   3 prim:      OBJECT            :stateOrProvinceName
     201:l=  10 prim:      PRINTABLESTRING   :California
     213:l=  17 cons:    SET
     215:l=  15 cons:     SEQUENCE



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     217:l=   3 prim:      OBJECT            :localityName
     222:l=   8 prim:      PRINTABLESTRING   :San Jose
     232:l=  14 cons:    SET
     234:l=  12 cons:     SEQUENCE
     236:l=   3 prim:      OBJECT            :organizationName
     241:l=   5 prim:      PRINTABLESTRING   :sipit
     248:l=  41 cons:    SET
     250:l=  39 cons:     SEQUENCE
     252:l=   3 prim:      OBJECT            :organizationalUnitName
     257:l=  32 prim:      PRINTABLESTRING   :
                           Sipit Test Certificate Authority
     291:l= 159 cons:   SEQUENCE
     294:l=  13 cons:    SEQUENCE
     296:l=   9 prim:     OBJECT            :rsaEncryption
     307:l=   0 prim:     NULL
     309:l= 141 prim:    BIT STRING
   00 30 81 89 02 81 81 00-c3 22 1e 83 91 c5 03 2c   .0.......".....,
   3c 8a f4 11 14 c6 4b 9d-fa 72 78 c6 b0 95 18 a7   <.....K..rx.....
   e0 8c 79 ba 5d a4 ae 1e-21 2d 9d f1 0b 1c cf bd   ..y.]...!-......
   5b 29 b3 90 13 73 66 92-6e df 4c b3 b3 1c 1f 2a   [)...sf.n.L....*
   82 0a ba 07 4d 52 b0 f8-37 7b e2 0a 27 30 70 dd   ....MR..7{..'0p.
   f9 2e 03 ff 2a 76 cd df-87 1a bd 71 eb e1 99 6a   ....*v.....q...j
   c4 7f 8e 74 a0 77 85 04-e9 41 ad fc 03 b6 17 75   ...t.w...A.....u
   aa 33 ea 0a 16 d9 fb 79-32 2e f8 cf 4d c6 34 a3   .3.....y2...M.4.
   ff 1b d0 68 28 e1 9d e5-02 03 01 00 01            ...h(........
     453:l= 205 cons:   cont [ 3 ]
     456:l= 202 cons:    SEQUENCE
     459:l=  29 cons:     SEQUENCE
     461:l=   3 prim:      OBJECT    :X509v3 Subject Key Identifier
     466:l=  22 prim:      OCTET STRING
   04 14 6b 46 17 14 ea 94-76 25 80 54 6e 13 54 da   ..kF....v%.Tn.T.
   a1 e3 54 14 a1 b6                                 ..T...
     490:l= 154 cons:     SEQUENCE
     493:l=   3 prim:      OBJECT    :X509v3 Authority Key Identifier
     498:l= 146 prim:      OCTET STRING
   30 81 8f 80 14 6b 46 17-14 ea 94 76 25 80 54 6e   0....kF....v%.Tn
   13 54 da a1 e3 54 14 a1-b6 a1 74 a4 72 30 70 31   .T...T....t.r0p1
   0b 30 09 06 03 55 04 06-13 02 55 53 31 13 30 11   .0...U....US1.0.
   06 03 55 04 08 13 0a 43-61 6c 69 66 6f 72 6e 69   ..U....Californi
   61 31 11 30 0f 06 03 55-04 07 13 08 53 61 6e 20   a1.0...U....San
   4a 6f 73 65 31 0e 30 0c-06 03 55 04 0a 13 05 73   Jose1.0...U....s
   69 70 69 74 31 29 30 27-06 03 55 04 0b 13 20 53   ipit1)0'..U... S
   69 70 69 74 20 54 65 73-74 20 43 65 72 74 69 66   ipit Test Certif
   69 63 61 74 65 20 41 75-74 68 6f 72 69 74 79 82   icate Authority.
   01                                                .
         0092 - <SPACES/NULS>
     647:l=  12 cons:     SEQUENCE
     649:l=   3 prim:      OBJECT            :X509v3 Basic Constraints



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     654:l=   5 prim:      OCTET STRING
   30 03 01 01 ff                                    0....
     661:l=  13 cons:  SEQUENCE
     663:l=   9 prim:   OBJECT            :sha1WithRSAEncryption
     674:l=   0 prim:   NULL
     676:l= 129 prim:  BIT STRING
   00 96 6d 1b ef d5 91 93-45 7c 5b 1f cf c4 aa 47   ..m.....E|[....G
   52 0b 34 a8 50 fa ec fa-b4 2a 47 4c 5d 41 a7 3d   R.4.P....*GL]A.=
   c0 d6 3f 9e 56 5b 91 1d-ce a8 07 b3 1b a4 9f 9a   ..?.V[..........
   49 6f 7f e0 ce 83 94 71-42 af fe 63 a2 34 dc b4   Io.....qB..c.4..
   5e a5 ce ca 79 50 e9 6a-99 4c 14 69 e9 7c ab 22   ^...yP.j.L.i.|."
   6c 44 cc 8a 9c 33 6b 23-50 42 05 1f e1 c2 81 88   lD...3k#PB......
   5f ba e5 47 bb 85 9b 83-25 ad 84 32 ff 2a 5b 8b   _..G....%..2.*[.
   70 12 11 83 61 c9 69 15-4f 58 a3 3c 92 d4 e8 6f   p...a.i.OX.<...o
   52                                                R

6.2.  Host Certificates

   The certificate for the host example.com is shown below.  Note that
   the Subject Alternative Name is set to example.com and is a DNS type.
   The certificates for the other hosts are shown in Appendix B.






























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   Data:
       Version: 3 (0x2)
       Serial Number:
           01:95:00:71:02:33:00:55
       Signature Algorithm: sha1WithRSAEncryption
       Issuer: C=US, ST=California, L=San Jose, O=sipit,
               OU=Sipit Test Certificate Authority
       Validity
           Not Before: Feb  3 18:49:08 2005 GMT
           Not After : Feb  3 18:49:08 2008 GMT
       Subject: C=US, ST=California, L=San Jose, O=sipit,
                CN=example.com
       Subject Public Key Info:
           Public Key Algorithm: rsaEncryption
           RSA Public Key: (1024 bit)
               Modulus (1024 bit):
                   00:e6:31:76:b5:27:cc:8d:32:85:56:70:f7:c2:33:
                   33:32:26:42:5e:3c:68:71:7b:1f:79:50:d0:72:27:
                   3b:4a:af:f2:ce:d1:0c:bc:c0:5f:31:6a:43:e7:7c:
                   ad:64:bd:c7:e6:25:9f:aa:cd:2d:90:aa:68:84:62:
                   7b:05:be:43:a5:af:bb:ea:9d:a9:5b:a4:53:9d:22:
                   8b:da:96:2e:1f:3f:92:46:b8:cc:c8:24:3c:46:cd:
                   5d:2d:64:85:b1:a4:ca:01:f1:8e:c5:7e:0f:ff:00:
                   91:a3:ea:cb:3e:12:02:75:a4:bb:08:c8:d0:2a:ef:
                   b3:bb:72:7a:98:e5:ff:9f:81
               Exponent: 65537 (0x10001)
       X509v3 extensions:
           X509v3 Subject Alternative Name:
               DNS:example.com
           X509v3 Basic Constraints:
               CA:FALSE
           X509v3 Subject Key Identifier:
               22:EA:CB:38:66:1D:F1:96:0C:9A:47:B6:BB:1C:52:
               44:B0:77:65:8D
   Signature Algorithm: sha1WithRSAEncryption
       ae:eb:49:ed:1e:f1:8d:26:a9:6d:03:82:92:d5:df:44:c4:1e:
       1f:07:75:88:37:e4:76:97:35:12:59:98:79:78:16:6e:3b:b1:
       c0:2b:db:85:02:6b:74:c9:5b:19:92:da:7e:f5:41:0b:bc:d2:
       dd:45:aa:6f:be:24:dc:48:57:66:d9:2e:82:df:9e:8d:70:03:
       73:75:ef:8f:7a:56:4c:cc:42:bd:31:45:b0:5e:ff:d1:3b:c4:
       82:ee:fd:a7:c1:10:34:eb:81:49:1a:6b:86:7e:c7:61:1d:b3:
       b9:0a:02:bd:84:f8:47:af:cf:f1:a8:73:a8:31:1d:20:7a:06:
       7f:ac

6.3.  User Certificates

   The user certificate for fluffy@example.com is shown below.  Note
   that the Subject Alternative Name has a list of names with different



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   URL types such as a sip, im, or pres URL.  This is necessary for
   interoperating with CPIM gateway.  In this example, example.com is
   the domain for fluffy.  The message could be coming from a host
   called atlanta.example.com, and the AOR in the user certificate would
   still be the same.  The others are shown in Appendix B.














































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   Data:
       Version: 3 (0x2)
       Serial Number:
           01:95:00:71:02:33:00:58
       Signature Algorithm: sha1WithRSAEncryption
       Issuer: C=US, ST=California, L=San Jose, O=sipit,
               OU=Sipit Test Certificate Authority
       Validity
           Not Before: Feb  3 18:49:34 2005 GMT
           Not After : Feb  3 18:49:34 2008 GMT
       Subject: C=US, ST=California, L=San Jose, O=sipit,
                CN=fluffy@example.com
       Subject Public Key Info:
           Public Key Algorithm: rsaEncryption
           RSA Public Key: (1024 bit)
               Modulus (1024 bit):
                   00:ca:ab:9b:9b:4e:3c:d5:45:3c:ce:00:a6:36:a8:
                   b9:ec:d2:76:e2:b9:9b:e8:28:aa:ba:86:22:c5:cf:
                   33:3e:4f:6d:56:21:ae:bd:54:84:7c:14:14:f9:7d:
                   99:85:00:4e:93:d6:fd:6b:d4:d1:d4:55:8e:c9:89:
                   b1:af:2b:5f:23:99:4a:95:e5:68:65:64:1d:12:a7:
                   db:d3:d5:97:18:47:35:9c:e6:88:27:9d:a8:6c:ca:
                   2a:84:e6:62:d8:f1:e9:a2:1a:39:7e:0e:0f:90:a5:
                   a6:79:21:bc:2a:67:b4:dd:69:90:82:9a:ae:1f:02:
                   52:8a:58:d3:f5:d0:d4:66:67
               Exponent: 65537 (0x10001)
       X509v3 extensions:
           X509v3 Subject Alternative Name:
               URI:sip:fluffy@example.com, URI:im:fluffy@example.com,
               URI:pres:fluffy@example.com
           X509v3 Basic Constraints:
               CA:FALSE
           X509v3 Subject Key Identifier:
               EC:DA:98:5E:E9:F7:F7:D7:EC:2B:29:4B:DA:25:EE:C7:C7:
               7E:95:70
   Signature Algorithm: sha1WithRSAEncryption
       4c:46:49:6e:01:48:e2:d4:6e:d7:48:a1:f3:7b:c8:a5:98:37:
       a5:44:46:58:9f:4a:37:7d:90:fb:5f:ff:36:bd:67:31:f0:29:
       de:0a:e2:ea:b9:f0:5c:9f:ad:a0:de:e5:4e:42:8f:11:d8:41:
       ea:68:be:db:c2:1e:fa:e5:8a:2d:7f:66:13:29:e9:da:8f:fb:
       80:bf:7e:5e:b6:04:ad:08:5e:58:95:b7:c5:38:85:d5:65:31:
       ad:80:cb:28:a7:4c:ad:11:fd:41:3b:37:77:5a:de:85:96:3d:
       66:eb:5f:9a:f8:60:5f:8e:b1:fc:4a:43:53:b6:11:4d:2e:f4:
       3d:ff







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7.  Callflow with Message Over TLS

7.1.  TLS with Server Authentication

   The flow below shows the edited SSLDump output of the host
   example.com forming a TLS[4] connection to example.net.  In this
   example mutual authentication is not used.  Note that the client
   proposed three protocol suites including TLS_RSA_WITH_AES_128_CBC_SHA
   defined in [6].  The certificate returned by the server contains a
   Subject Alternative Name that is set to example.net.  A detailed
   discussion of TLS can be found in [13].

   This example does not use the Server Extended Hello[5].


   New TCP connection #1: 127.0.0.1(55768) <-> 127.0.0.1(5061)
   1 1  0.0060 (0.0060)  C>SV3.1(49)  Handshake
         ClientHello
           Version 3.1
           random[32]=
             42 16 8c c7 82 cd c5 87 42 ba f5 1c 91 04 fb 7d
             4d 6c 56 f1 db 1d ce 8a b1 25 71 5a 68 01 a2 14
           cipher suites
           TLS_RSA_WITH_AES_256_CBC_SHA
           TLS_RSA_WITH_AES_128_CBC_SHA
           TLS_RSA_WITH_3DES_EDE_CBC_SHA
           compression methods
                     NULL
   1 2  0.0138 (0.0077)  S>CV3.1(74)  Handshake
         ServerHello
           Version 3.1
           random[32]=
             42 16 8c c7 c9 2c 43 42 bb 69 a5 ba f1 2d 69 75
             c3 8d 3a 85 78 19 f2 e4 d9 2b 72 b4 cc dd e4 72
           session_id[32]=
             06 37 e9 22 56 29 e6 b4 3a 6e 53 fe 56 27 ed 1f
             2a 75 34 65 f0 91 fc 79 cf 90 da ac f4 6f 64 b5
           cipherSuite         TLS_RSA_WITH_AES_256_CBC_SHA
           compressionMethod                   NULL
   1 3  0.0138 (0.0000)  S>CV3.1(1477)  Handshake
         Certificate
   1 4  0.0138 (0.0000)  S>CV3.1(4)  Handshake
         ServerHelloDone
   1 5  0.0183 (0.0045)  C>SV3.1(134)  Handshake
         ClientKeyExchange
           EncryptedPreMasterSecret[128]=
             a6 bd d9 4b 76 4b 9d 6f 7b 12 8a e4 52 75 9d 74
             4f 06 e4 b0 bc 69 96 d7 42 ba 77 01 b6 9e 64 b0



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             ea c5 aa de 59 41 e4 f3 9e 1c 1c a9 48 f5 0a 3f
             5e c3 50 23 15 d7 46 1d 69 79 76 ba 5e c8 ac 39
             23 71 d0 0c 18 a6 a9 77 0f 7d 49 61 ef 6f 8d 32
             54 f5 a4 1d 19 33 0a 64 ee 56 91 9b f4 f7 50 b1
             11 4b 81 46 4c 36 df 70 98 04 dc 5c 8a 16 a9 2e
             58 67 ae 5e 7a a9 44 2b 0b 7c 9c 2f 16 25 1a e9
   1 6  0.0183 (0.0000)  C>SV3.1(1)  ChangeCipherSpec
   1 7  0.0183 (0.0000)  C>SV3.1(48)  Handshake
   1 8  0.0630 (0.0447)  S>CV3.1(1)  ChangeCipherSpec
   1 9  0.0630 (0.0000)  S>CV3.1(48)  Handshake
   1 10 0.3274 (0.2643)  C>SV3.1(32)  application_data
   1 11 0.3274 (0.0000)  C>SV3.1(720)  application_data
   1 12 0.3324 (0.0050)  S>CV3.1(32)  application_data
   1 13 0.3324 (0.0000)  S>CV3.1(384)  application_data
   1    9.2491 (8.9166)  C>S  TCP FIN
   1    9.4023 (0.1531)  S>C  TCP FIN

7.2.  MESSAGE Message Over TLS

   Once the TLS session is set up, the following MESSAGE message (as
   defined in [12] is sent from fluffy@example.com to
   kumiko@example.net.  Note that the URI has a SIPS URL and that the
   VIA indicates that TLS was used.  In order to format this document,
   it was necessary to break up some of the lines across continuation
   lines but the original messages have no continuation lines and no
   breaks in the Identity header field value.


   MESSAGE sips:kumiko@example.net SIP/2.0
   To: <sips:kumiko@example.net>
   From: <sips:fluffy@example.com>;tag=03de46e1
   Via: SIP/2.0/TLS 127.0.0.1:5071;
        branch=z9hG4bK-d87543-58c826887160f95f-1--d87543-;rport
   Call-ID: 0dc68373623af98a@Y2ouY2lzY28uc2lwaXQubmV0
   CSeq: 1 MESSAGE
   Contact: <sips:fluffy@127.0.0.1:5071>
   Max-Forwards: 70
   Content-Transfer-Encoding: binary
   Content-Type: text/plain
   Date: Sat, 19 Feb 2005 00:48:07 GMT
   User-Agent: SIPimp.org/0.2.5 (curses)
   Content-Length: 6

   Hello!

   The response is sent from example.net to example.com over the same
   TLS connection.  It is shown below.




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   SIP/2.0 200 OK
   To: <sips:kumiko@example.net>;tag=4c53f1b8
   From: <sips:fluffy@example.com>;tag=03de46e1
   Via: SIP/2.0/TLS 127.0.0.1:5071;
        branch=z9hG4bK-d87543-58c826887160f95f-1--d87543-;
        rport=55768;received=127.0.0.1
   Call-ID: 0dc68373623af98a@Y2ouY2lzY28uc2lwaXQubmV0
   CSeq: 1 MESSAGE
   Contact: <sips:kumiko@127.0.0.1:5061>
   Content-Length: 0




8.  Callflow with S/MIME-secured Message

8.1.  MESSAGE Message with Signed Body

   Example Signed Message.  The value on the Content-Type line has been
   broken across lines to fit on the page but it should not be broken
   across lines in actual implementations.






























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   MESSAGE sip:kumiko@example.net SIP/2.0
   To: <sip:kumiko@example.net>
   From: <sip:fluffy@example.com>;tag=0c523b42
   Via: SIP/2.0/UDP 68.122.119.3:5060;
        branch=z9hG4bK-d87543-16a1192b7960f635-1--d87543-;rport
   Call-ID: 27bb7608596d8914@Y2ouY2lzY28uc2lwaXQubmV0
   CSeq: 1 MESSAGE
   Contact: <sip:fluffy@68.122.119.3:5060>
   Max-Forwards: 70
   Content-Transfer-Encoding: binary
   Content-Type: multipart/signed;boundary=151aa2144df0f6bd;\
                 micalg=sha1;protocol="application/pkcs7-signature"
   Date: Sat, 19 Nov 2005 23:34:50 GMT
   User-Agent: SIPimp.org/0.2.5 (curses)
   Content-Length: 639

   --151aa2144df0f6bd
   Content-Type: text/plain
   Content-Transfer-Encoding: binary

   hello
   --151aa2144df0f6bd
   Content-Type: application/pkcs7-mime;name=smime.p7s
   Content-Disposition: attachment;handling=required;filename=smime.p7s
   Content-Transfer-Encoding: binary

   *******************
   * BINARY BLOB 1   *
   *******************
   --151aa2144df0f6bd--

   It is important to note that the signature is computed across
   includes the header and excludes the boundary.  The value on the
   Message-body line ends with CRLF.  The CRLF is included in the
   boundary and should not be part of the signature computation.  In the
   example below, the signature is computed over data starting with the
   C in the Content-Type and ending with the o in the hello.

   Content-Type: text/plain
   Content-Transfer-Encoding: binary

   hello

   ASN.1 parse of binary Blob 1.  Note that at address 30, the hash for
   the signature is specified as SHA1.  Also note that the sender's
   certificate is not attached as it is optional in [8].

      0:SEQUENCE {



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      4:  OBJECT IDENTIFIER signedData (1 2 840 113549 1 7 2)
     15:  [0] {
     19:    SEQUENCE {
     23:      INTEGER 1
     26:      SET {
     28:        SEQUENCE {
     30:          OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
       :          }
       :        }
     37:      SEQUENCE {
     39:        OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
       :        }
     50:      SET {
     54:        SEQUENCE {
     58:          INTEGER 1
     61:          SEQUENCE {
     63:            SEQUENCE {
     65:              SET {
     67:                SEQUENCE {
     69:                  OBJECT IDENTIFIER countryName (2 5 4 6)
     74:                  PrintableString 'US'
       :                  }
       :                }
     78:              SET {
     80:                SEQUENCE {
     82:                  OBJECT IDENTIFIER stateOrProvinceName(2 5 4 8)
     87:                  PrintableString 'California'
       :                  }
       :                }
     99:              SET {
    101:                SEQUENCE {
    103:                  OBJECT IDENTIFIER localityName (2 5 4 7)
    108:                  PrintableString 'San Jose'
       :                  }
       :                }
    118:              SET {
    120:                SEQUENCE {
    122:                  OBJECT IDENTIFIER organizationName (2 5 4 10)
    127:                  PrintableString 'sipit'
       :                  }
       :                }
    134:              SET {
    136:                SEQUENCE {
    138:                  OBJECT IDENTIFIER
       :                    organizationalUnitName (2 5 4 11)
    143:                  PrintableString
                            'Sipit Test Certificate Authority'
       :                  }



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       :                }
       :              }
    177:            INTEGER 01 95 00 71 02 33 00 58
       :            }
    187:          SEQUENCE {
    189:            OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
       :            }
    196:          SEQUENCE {
    198:            OBJECT IDENTIFIER rsaEncryption
                      (1 2 840 113549 1 1 1)
    209:            NULL
       :            }
    211:          OCTET STRING
       :            C4 0E 40 A5 7F 88 5B 06 90 E7 B2 40 39 DF 33 E3
       :            18 39 C2 9E EC 51 5E 06 E2 D5 DA F0 F6 87 77 1E
       :            F7 F9 C1 26 04 20 F8 30 B8 C0 37 92 F6 5C 64 DD
       :            87 41 43 F8 2D E5 28 20 35 7D 84 72 2B 5E 5F CF
       :            2E 73 93 03 4B DB 35 4C CA 44 CD F8 91 58 A2 4C
       :            65 A1 A6 EA DC E6 1B 1E DD DA BD BE 1A EA 9F 62
       :            12 7A D1 1A E7 27 B5 96 88 B9 E6 EF 79 C0 E5 40
       :            A0 5F 9F 93 09 4C 65 55 DA A8 FE CD 02 10 A9 67
       :          }
       :        }
       :      }
       :    }
       :  }

8.2.  MESSAGE Message with Encrypted Body

   Example encrypted text/plain message that says "hello":





















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   MESSAGE sip:kumiko@example.net SIP/2.0
   To: <sip:kumiko@example.net>
   From: <sip:fluffy@example.com>;tag=6d2a39e4
   Via: SIP/2.0/UDP 68.122.119.3:5060;
        branch=z9hG4bK-d87543-44ddc0a217a51788-1--d87543-;rport
   Call-ID: 031be67669ea9799@Y2ouY2lzY28uc2lwaXQubmV0
   CSeq: 1 MESSAGE
   Contact: <sip:fluffy@68.122.119.3:5060>
   Max-Forwards: 70
   Content-Disposition: attachment;handling=required;filename=smime.p7
   Content-Transfer-Encoding: binary
   Content-Type: application/pkcs7-mime;\
                 smime-type=enveloped-data;name=smime.p7m
   Date: Sat, 19 Nov 2005 23:33:18 GMT
   User-Agent: SIPimp.org/0.2.5 (curses)
   Content-Length: 435

   *****************
   * BINARY BLOB 2 *
   *****************

   ASN.1 parse of binary Blob 2.  Note that at address 324, the
   encryption is set to aes128-CBC.


      0:SEQUENCE {
      4:  OBJECT IDENTIFIER envelopedData (1 2 840 113549 1 7 3)
     15:  [0] {
     19:    SEQUENCE {
     23:      INTEGER 0
     26:      SET {
     30:        SEQUENCE {
     34:          INTEGER 0
     37:          SEQUENCE {
     39:            SEQUENCE {
     41:              SET {
     43:                SEQUENCE {
     45:                  OBJECT IDENTIFIER countryName (2 5 4 6)
     50:                  PrintableString 'US'
       :                  }
       :                }
     54:              SET {
     56:                SEQUENCE {
     58:                  OBJECT IDENTIFIER stateOrProvinceName(2 5 4 8)
     63:                  PrintableString 'California'
       :                  }
       :                }
     75:              SET {



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     77:                SEQUENCE {
     79:                  OBJECT IDENTIFIER localityName (2 5 4 7)
     84:                  PrintableString 'San Jose'
       :                  }
       :                }
     94:              SET {
     96:                SEQUENCE {
     98:                  OBJECT IDENTIFIER organizationName (2 5 4 10)
    103:                  PrintableString 'sipit'
       :                  }
       :                }
    110:              SET {
    112:                SEQUENCE {
    114:                  OBJECT IDENTIFIER
       :                    organizationalUnitName (2 5 4 11)
    119:                  PrintableString
                            'Sipit Test Certificate Authority'
       :                  }
       :                }
       :              }
    153:            INTEGER 01 95 00 71 02 33 00 57
       :            }
    163:          SEQUENCE {
    165:           OBJECT IDENTIFIER rsaEncryption(1 2 840 113549 1 1 1)
    176:           NULL
       :           }
    178:          OCTET STRING
       :            7C F3 8A 02 E8 44 2C A6 9B 3E 64 46 06 D3 95 2D
       :            DF 19 8F 5D 0C 24 6B F7 93 03 E7 3C 98 F1 57 74
       :            67 70 0E 40 F8 05 96 34 06 36 97 61 5C 0B 2D 61
       :            AD CB F0 82 56 23 E5 09 C0 C7 BC A5 F4 A3 B7 59
       :            5D 8B 44 6E 3F 7C DE 50 54 2C 95 73 CC 9A 74 8B
       :            A9 26 68 FD F8 82 01 43 1D 30 3C 0C 40 B2 19 A2
       :            5A 90 06 0F AC 95 CB DF 21 13 F2 26 C8 10 45 A3
       :            F4 AB 54 74 72 FD 91 6C 73 27 BF 62 47 7B EC 58
       :          }
       :        }
    309:      SEQUENCE {
    311:        OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
    322:        SEQUENCE {
    324:          OBJECT IDENTIFIER aes128-CBC (2 16 840 1 101 3 4 1 2)
    335:          OCTET STRING
       :            50 9E 44 AA A5 54 C3 5C 0D 9A DF 65 F7 47 36 99
       :          }
    353:        [0]
       :          55 C5 C7 EA 5D 5A 7C 06 95 3C 24 25 D5 53 08 BB
       :          04 19 B4 BF 84 15 F5 6C 4C 80 05 14 06 3E F3 D1
       :          B7 04 A1 46 4E E3 1E FF 16 35 79 2A 06 DD A8 83



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       :          61 24 E1 62 B0 DA 03 53 78 F8 B7 CD B2 11 68 57
       :          BE 5F 13 49 B9 5E AB 6F 6E 26 2D 8A A5 9E E5 10
       :        }
       :       }
       :    }
       :  }

8.3.  MESSAGE Message with Encrypted and Signed Body

   In the example below, one of the headers is contained in a box and is
   split across two lines.  This was only done to make it fit in the RFC
   format.  This header should not have the box around it and should be
   on one line with no whitespace between the "mime;" and the "smime-
   type".  Note that Content-Type is split across lines for formatting
   but is not split in the real message.




































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   MESSAGE sip:kumiko@example.net SIP/2.0
   To: <sip:kumiko@example.net>
   From: <sip:fluffy@example.com>;tag=361300da
   Via: SIP/2.0/UDP 68.122.119.3:5060;
        branch=z9hG4bK-d87543-0710dbfb18ebb8e6-1--d87543-;rport
   Call-ID: 5eda27a67de6283d@Y2ouY2lzY28uc2lwaXQubmV0
   CSeq: 1 MESSAGE
   Contact: <sip:fluffy@68.122.119.3:5060>
   Max-Forwards: 70
   Content-Transfer-Encoding: binary
   Content-Type: multipart/signed;boundary=1af019eb7754ddf7;\
                 micalg=sha1;protocol="application/pkcs7-signature"
   Date: Sat, 19 Nov 2005 23:35:40 GMT
   User-Agent: SIPimp.org/0.2.5 (curses)
   Content-Length: 1191

   --1af019eb7754ddf7
   |--See note about stuff in this box --------------------|
   |Content-Type: application/pkcs7-mime;                  |
   |              smime-type=enveloped-data;name=smime.p7m |
   |-------------------------------------------------------|
   Content-Disposition: attachment;handling=required;filename=smime.p7
   Content-Transfer-Encoding: binary

   *****************
   * BINARY BLOB 3 *
   *****************
   --1af019eb7754ddf7
   Content-Type: application/pkcs7-mime;name=smime.p7s
   Content-Disposition: attachment;handling=required;filename=smime.p7s
   Content-Transfer-Encoding: binary

   *****************
   * BINARY BLOB 4 *
   *****************
   --1af019eb7754ddf7--

   Binary blob 3


      0:SEQUENCE {
      4:  OBJECT IDENTIFIER envelopedData (1 2 840 113549 1 7 3)
     15:  [0] {
     19:    SEQUENCE {
     23:      INTEGER 0
     26:      SET {
     30:        SEQUENCE {
     34:          INTEGER 0



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     37:          SEQUENCE {
     39:            SEQUENCE {
     41:              SET {
     43:                SEQUENCE {
     45:                  OBJECT IDENTIFIER countryName (2 5 4 6)
     50:                  PrintableString 'US'
       :                  }
       :                }
     54:              SET {
     56:                SEQUENCE {
     58:                  OBJECT IDENTIFIER stateOrProvinceName(2 5 4 8)
     63:                  PrintableString 'California'
       :                  }
       :                }
     75:              SET {
     77:                SEQUENCE {
     79:                  OBJECT IDENTIFIER localityName (2 5 4 7)
     84:                  PrintableString 'San Jose'
       :                  }
       :                }
     94:              SET {
     96:                SEQUENCE {
     98:                  OBJECT IDENTIFIER organizationName (2 5 4 10)
    103:                  PrintableString 'sipit'
       :                  }
       :                }
    110:              SET {
    112:                SEQUENCE {
    114:                  OBJECT IDENTIFIER
       :                    organizationalUnitName (2 5 4 11)
    119:                  PrintableString
                            'Sipit Test Certificate Authority'
       :                  }
       :                }
       :              }
    153:            INTEGER 01 95 00 71 02 33 00 57
       :            }
    163:          SEQUENCE {
    165:           OBJECT IDENTIFIER rsaEncryption(1 2 840 113549 1 1 1)
    176:           NULL
       :           }
    178:          OCTET STRING
       :            69 B3 A3 61 F4 F8 63 4F 46 0A 1A AB 0F 1B 16 09
       :            DB 3A A9 12 3B 23 F0 C9 4E 68 04 15 AB 42 4F 66
       :            FA EF 8D C4 86 88 41 BA 53 A3 88 49 54 E3 0E EB
       :            E3 69 63 5A DF 77 2A 8A 1E 42 7E E4 A7 DB CF 90
       :            7E 90 47 FD 20 C9 B2 3B 2F A5 42 2A 68 66 9A 25
       :            53 D8 FC D9 70 9F 02 0F F2 D2 CB F7 15 7F 6F 4F



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       :            AB 19 0F 55 51 A2 76 24 DA A3 78 F4 1E 31 AA 6A
       :            DF 7C E2 42 3B C5 33 11 E0 EE EE 2E 02 9D 8C 1A
       :          }
       :        }
    309:      SEQUENCE {
    311:        OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
    322:        SEQUENCE {
    324:          OBJECT IDENTIFIER aes128-CBC (2 16 840 1 101 3 4 1 2)
    335:          OCTET STRING
       :            72 71 AE FE 55 12 BA 99 92 EA D3 C5 9C B6 60 69
       :          }
    353:        [0]
       :          9A 9F DD 9E 58 B6 BE 59 BC CA 6C 3E 3E F5 81 A3
       :          30 A0 38 A3 1C 25 92 E3 AA 07 7A 85 7C 36 F0 12
       :          9F 80 DF 98 BD 1E 22 EC BF 8B 03 EB 33 AE 81 75
       :          D3 91 0A 82 1E 13 8C 60 F0 2B 55 DD 03 52 84 52
       :          B1 51 5F E2 F0 CE 8A 94 4B F5 46 CE BF 77 80 8F
       :        }
       :      }
       :    }
       :  }

   Binary Blob 4


      0:SEQUENCE {
      4:  OBJECT IDENTIFIER signedData (1 2 840 113549 1 7 2)
     15:  [0] {
     19:    SEQUENCE {
     23:      INTEGER 1
     26:      SET {
     28:        SEQUENCE {
     30:          OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
       :          }
       :        }
     37:      SEQUENCE {
     39:        OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
       :        }
     50:      SET {
     54:        SEQUENCE {
     58:          INTEGER 1
     61:          SEQUENCE {
     63:            SEQUENCE {
     65:              SET {
     67:                SEQUENCE {
     69:                  OBJECT IDENTIFIER countryName (2 5 4 6)
     74:                  PrintableString 'US'
       :                  }



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       :                }
     78:              SET {
     80:                SEQUENCE {
     82:                  OBJECT IDENTIFIER stateOrProvinceName(2 5 4 8)
     87:                  PrintableString 'California'
       :                  }
       :                }
     99:              SET {
    101:                SEQUENCE {
    103:                  OBJECT IDENTIFIER localityName (2 5 4 7)
    108:                  PrintableString 'San Jose'
       :                  }
       :                }
    118:              SET {
    120:                SEQUENCE {
    122:                  OBJECT IDENTIFIER organizationName (2 5 4 10)
    127:                  PrintableString 'sipit'
       :                  }
       :                }
    134:              SET {
    136:                SEQUENCE {
    138:                  OBJECT IDENTIFIER
       :                    organizationalUnitName (2 5 4 11)
    143:                  PrintableString
                            'Sipit Test Certificate Authority'
       :                  }
       :                }
       :              }
    177:            INTEGER 01 95 00 71 02 33 00 58
       :            }
    187:          SEQUENCE {
    189:            OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
       :            }
    196:          SEQUENCE {
    198:           OBJECT IDENTIFIER rsaEncryption(1 2 840 113549 1 1 1)
    209:           NULL
       :           }
    211:          OCTET STRING
       :            16 85 D7 B8 08 C6 32 D5 85 7D 26 0F F8 89 DA D0
       :            B8 FE 96 FB 40 C9 0E 52 C7 FE A5 87 55 F7 1A 86
       :            29 80 CC B0 75 A3 72 DD 76 80 6B 2C 8B C0 14 EA
       :            49 FE 18 8F A6 27 BC 5B 60 C1 FE 15 4D 2A 42 DD
       :            33 F8 0D D0 77 11 73 82 31 4D 31 66 B1 CF 95 F0
       :            9D EE DF 81 E3 54 DF 8C 7B 63 70 D4 93 B5 AE E0
       :            D4 90 DB BE D8 0B 3B C2 99 6A FE 5A F0 E9 F0 DF
       :            85 F2 A6 8C 28 33 0D 77 04 59 78 06 E5 0E 48 78
       :          }
       :        }



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       :      }
       :    }
       :  }


9.  Test Consideration

   This section describes some common interoperability problems.
   Implementers should verify that their clients do the correct things
   and perhaps make their clients forgiving in what they receive, or at
   least have them produce reasonable error messages when interacting
   with software that has these problems.

   A common problem is that some SIP clients incorrectly only do SSLv3
   and do not support TLS.

   Many SIP clients were found to accept expired certificates with no
   warning or error.

   TLS and S/MIME can provide the identity of the peer that a client is
   communicating with in the Subject Alternative Name in the
   certificate.  The software must check that this name corresponds to
   the identity the server is trying to contact.  If a client is trying
   to set up a TLS connection to good.example.com and it gets a TLS
   connection set up with a server that presents a valid certificate but
   with the name evil.example.com, it must generate an error or warning
   of some type.  Similarly with S/MIME, if a user is trying to
   communicate with sip:fluffy@example.com, one of the items in the
   Subject Alternate Name set in the certificate must match.

   Some implementations used binary MIME encodings while others used
   base64.  The preferred form is binary.

   In several places in this draft, the messages contain the encoding
   for the SHA-1 digest algorithm identifier.  The preferred form for
   encoding as set out in Section 2 of RFC 3370 [10] is the form in
   which the optional AlgorithmIdentifier parameter field is omitted.
   However, RFC 3370 also says the receives need to be able to receive
   the form in which the AlgorithmIdentifier parameter field is present
   and set to NULL.  Examples of the form using NULL can be found in
   Section 4.2 of RFC 4134 [11].  Receivers really do need to be able to
   receive the form that includes the NULL because the NULL form, while
   not preferred, is what was observed as being generated by most
   implementations.  Implementers should also note that if the algorithm
   is MD5 instead of SHA1, then the form that omits the
   AlgorithmIdentifier parameters field is not allowed and the sender
   has to use the form where the NULL is included.




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   The preferred encryption algorithm for S/MIME in SIP is AES as
   defined in RFC 3853 [9].

   Interoperability was generally better when UAs did not attach the
   senders' certificates.  Attaching the certificates significantly
   increases the size of the messages, and since it can not be relied
   on, it does not turn out to be useful in most situations.


10.  IANA Considerations

   No IANA actions are required.


11.  Acknowledgments

   Many thanks to the developers of all the open source software used to
   create these call flows.  This includes the underling crypto and TLS
   software used from openssl.org, the SIP stack from
   www.resiprocate.org, and the SIMPLE IMPP agent from www.sipimp.org.
   The TLS flow dumps were done with SSLDump from
   http://www.rtfm.com/ssldump.  The book "SSL and TLS" [13] was a huge
   help in developing the code for these flows.  It's sad there is no
   second edition.

   Thanks to Jim Schaad, Russ Housley, Eric Rescorla, Dan Wing, Tat
   Chan, and Lyndsay Campbell who all helped find and correct mistakes
   in this document.


12.  References

12.1.  Normative References

   [1]   Bradner, S., "Key words for use in RFCs to Indicate Requirement
         Levels", BCP 14, RFC 2119, March 1997.

   [2]   Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
         Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
         Session Initiation Protocol", RFC 3261, June 2002.

   [3]   Housley, R., Polk, W., Ford, W., and D. Solo, "Internet X.509
         Public Key Infrastructure Certificate and Certificate
         Revocation List (CRL) Profile", RFC 3280, April 2002.

   [4]   Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A., and
         P. Kocher, "The TLS Protocol Version 1.0", RFC 2246,
         January 1999.



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   [5]   Blake-Wilson, S., Nystrom, M., Hopwood, D., Mikkelsen, J., and
         T. Wright, "Transport Layer Security (TLS) Extensions",
         RFC 3546, June 2003.

   [6]   Chown, P., "Advanced Encryption Standard (AES) Ciphersuites for
         Transport Layer Security (TLS)", RFC 3268, June 2002.

   [7]   Ramsdell, B., "Secure/Multipurpose Internet Mail Extensions
         (S/MIME) Version 3.1 Message Specification", RFC 3851,
         July 2004.

   [8]   Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3369,
         August 2002.

   [9]   Peterson, J., "S/MIME Advanced Encryption Standard (AES)
         Requirement for the Session Initiation Protocol (SIP)",
         RFC 3853, July 2004.

   [10]  Housley, R., "Cryptographic Message Syntax (CMS) Algorithms",
         RFC 3370, August 2002.

12.2.  Informative References

   [11]  Hoffman, P., "Examples of S/MIME Messages", RFC 4134,
         July 2005.

   [12]  Campbell, B., Rosenberg, J., Schulzrinne, H., Huitema, C., and
         D. Gurle, "Session Initiation Protocol (SIP) Extension for
         Instant Messaging", RFC 3428, December 2002.

   [13]  Rescorla, E., "SSL and TLS - Designing and Building Secure
         Systems", 2001.


Appendix A.  Making Test Certificates

   These scripts allow you to make certificates for test purposes.  The
   certificates will all share a common CA root so that everyone running
   these scripts can have interoperable certificates.  WARNING - these
   certificates are totally insecure and are for test purposes only.
   All the CA created by this script share the same private key to
   facilitate interoperability testing, but this totally breaks the
   security since the private key of the CA is well known.

   The instructions assume a Unix-like environment with openssl
   installed, but openssl does work in Windows too.  Make sure you have
   openssl installed by trying to run "openssl".  Run the makeCA script
   found in Appendix A.1; this creates a subdirectory called demoCA.  If



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   the makeCA script cannot find where your openssl is installed you
   will have to set an environment variable called OPENSSLDIR to
   whatever directory contains the file openssl.cnf.  You can find this
   with a "locate openssl.cnf".  You are now ready to make certificates.

   To create certs for use with TLS, run the makeCert script found in
   Appendix A.2 with the fully qualified domain name of the proxy you
   are making the certificate for.  For example, "makeCert
   host.example.net".  This will generate a private key and a
   certificate.  The private key will be left in a file named
   domain_key_example.net.pem in pem format.  The certificate will be in
   domain_cert_example.net.pem.  Some programs expect both the
   certificate and private key combined together in a PKCS12 format
   file.  This is created by the script and left in a file named
   example.net.p12.  Some programs expect this file to have a .pfx
   extension instead of .p12 - just rename the file if needed.  A filed
   with a certificate signing request, called example.net.csr, is also
   created and can be used to get the certificate signed by another CA.

   A second argument indicating the number of days for which the
   certificate should be valid can be passed to the makeCert script.  It
   is possible to make an expired certificate using the command
   "makeCert host.example.net 0".

   Anywhere that a password is used to protect a certificate, the
   password is set to the string "password".

   The root certificate for the CA is in the file
   root_cert_fluffyCA.pem.

   For things that need DER format certificates, a certificate can be
   converted from PEM to DER with "openssl x509 -in cert.pem -inform PEM
   -out cert.der -outform DER".

   Some programs expect certificates in PKCS#7 format (with a file
   extension of .p7c).  You can convert these from PEM format to PKCS#7
   with "openssl crl2pkcs7 -nocrl -certfile cert.pem -certfile demoCA/
   cacert.pem -outform DER -out cert.p7c"

   IE, Outlook, and Netscape can import and export .p12 files and .p7c
   files.  You can convert a pkcs7 certificate to PEM format with
   "openssl pkcs7 -in cert.p7c -inform DER -outform PEM -out cert.pem".

   The private key can be converted to pkcs8 format with "openssl pkcs8
   -in a_key.pem -topk8 -outform DER -out a_key.p8c"

   In general, a TLS client will just need the root certificate of the
   CA.  A TLS server will need its private key and its certificate.



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   These could be in two PEM files or one .p12 file.  An S/MIME program
   will need its private key and certificate, the root certificate of
   the CA, and the certificate for every other user it communicates
   with.

A.1.  makeCA script


   #!/bin/sh
   #set -x

   rm -rf demoCA

   mkdir demoCA
   mkdir demoCA/certs
   mkdir demoCA/crl
   mkdir demoCA/newcerts
   mkdir demoCA/private
   echo "01" > demoCA/serial
   hexdump -n 4 -e '4/1 "%04u"' /dev/random > demoCA/serial
   touch demoCA/index.txt

   # You may need to modify this for where your default file is
   # you can find where yours in by typing "openssl ca"
   for D in /etc/ssl /usr/local/ssl /sw/etc/ssl /sw/share/ssl; do
           CONF=${OPENSSLDIR:=$D}/openssl.cnf
           [ -f ${CONF} ] && break
   done

   if [ ! -f $CONF  ]; then
       echo "Can not find file $CONF - set your OPENSSLDIR variable"
       exit
   fi
   cp $CONF openssl.cnf

   cat >> openssl.cnf  <<EOF
   [ cj_cert ]
   subjectAltName=\${ENV::ALTNAME}
   basicConstraints=CA:FALSE
   subjectKeyIdentifier=hash
   #authorityKeyIdentifier=keyid,issuer:always

   [ cj_req ]
   basicConstraints = CA:FALSE
   subjectAltName=\${ENV::ALTNAME}
   subjectKeyIdentifier=hash
   #authorityKeyIdentifier=keyid,issuer:always
   #keyUsage = nonRepudiation, digitalSignature, keyEncipherment



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   EOF

   cat > demoCA/private/cakey.pem <<EOF
   -----BEGIN RSA PRIVATE KEY-----
   Proc-Type: 4,ENCRYPTED
   DEK-Info: DES-EDE3-CBC,4B47A0A73ADE342E

   aHmlPa+ZrOV6v+Jk0SClxzpxoG3j0ZuyoVkF9rzq2bZkzVBKLU6xhWwjMDqwA8dH
   3fCRLhMGIUVnmymXYhTW9svI1gpFxMBQHJcKpV/SmgFn/fbYk98Smo2izHOniIiu
   NOu2zr+bMiaBphOAZ/OCtVUxUOoBDKN9lR39UCDOgkEQzp9Vbw7l736yu5H9GMHP
   JtGLJyx3RhS3TvLfLAJZhjm/wZ/9QM8GjyJEiDhMQRJVeIZGvv4Yr1u6yYHiHfjX
   tX2eds8Luc83HbSvjAyjnkLtJsAZ/8cFzrd7pjFzbogLdWuil+kpkkf5h1uzh7oa
   um0M1EXBE4tcDHsfg1iqEsDMIei/U+/rWfk1PrzYlklwZp8S03vulkDm1fT76W7d
   mRBg4+CrHA6qYn6EPWB37OBtfEqAfINnIcI1dWzso9A0bTPD4EJO0JA0PcZ/2JgT
   PaKySgooHQ8AHNQebelch6M5LFExpaOADJKrqauKcc2HeUxXaYIpac5/7drIl3io
   UloqUnMlGa3eLP7BZIMsZKCfHZ8oqwU4g6mmmJath2gODRDx3mfhH6yaimDL7v4i
   SAIIkrEHXfSyovrTJymfSfQtYxUraVZDqax6oj/eGllRxliGfMLYG9ceU+yU/8FN
   LE7P+Cs19H5tHHzx1LlieaK43u/XvbXHlB5mqL/fZdkUIBJsjbBVx0HR8eQl2CH9
   YJDMOPLADecwHoyKA0AY59oN9d41oF7yZtN9KwNdslROYH7mNJlqMMenhXCLN+Nz
   vVU5/7/ugZFhZqfS46c1WdmSvuqpDp7TBtMeaH/PXjysBr0iZffOxQ==
   -----END RSA PRIVATE KEY-----
   EOF

   cat > demoCA/cacert.pem <<EOF
   -----BEGIN CERTIFICATE-----
   MIIDJDCCAo2gAwIBAgIBADANBgkqhkiG9w0BAQUFADBwMQswCQYDVQQGEwJVUzET
   MBEGA1UECBMKQ2FsaWZvcm5pYTERMA8GA1UEBxMIU2FuIEpvc2UxDjAMBgNVBAoT
   BXNpcGl0MSkwJwYDVQQLEyBTaXBpdCBUZXN0IENlcnRpZmljYXRlIEF1dGhvcml0
   eTAeFw0wMzA3MTgxMjIxNTJaFw0xMzA3MTUxMjIxNTJaMHAxCzAJBgNVBAYTAlVT
   MRMwEQYDVQQIEwpDYWxpZm9ybmlhMREwDwYDVQQHEwhTYW4gSm9zZTEOMAwGA1UE
   ChMFc2lwaXQxKTAnBgNVBAsTIFNpcGl0IFRlc3QgQ2VydGlmaWNhdGUgQXV0aG9y
   aXR5MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDDIh6DkcUDLDyK9BEUxkud
   +nJ4xrCVGKfgjHm6XaSuHiEtnfELHM+9WymzkBNzZpJu30yzsxwfKoIKugdNUrD4
   N3viCicwcN35LgP/KnbN34cavXHr4ZlqxH+OdKB3hQTpQa38A7YXdaoz6goW2ft5
   Mi74z03GNKP/G9BoKOGd5QIDAQABo4HNMIHKMB0GA1UdDgQWBBRrRhcU6pR2JYBU
   bhNU2qHjVBShtjCBmgYDVR0jBIGSMIGPgBRrRhcU6pR2JYBUbhNU2qHjVBShtqF0
   pHIwcDELMAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcT
   CFNhbiBKb3NlMQ4wDAYDVQQKEwVzaXBpdDEpMCcGA1UECxMgU2lwaXQgVGVzdCBD
   ZXJ0aWZpY2F0ZSBBdXRob3JpdHmCAQAwDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0B
   AQUFAAOBgQCWbRvv1ZGTRXxbH8/EqkdSCzSoUPrs+rQqR0xdQac9wNY/nlZbkR3O
   qAezG6Sfmklvf+DOg5RxQq/+Y6I03LRepc7KeVDpaplMFGnpfKsibETMipwzayNQ
   QgUf4cKBiF+65Ue7hZuDJa2EMv8qW4twEhGDYclpFU9YozyS1OhvUg==
   -----END CERTIFICATE-----
   EOF


   # uncomment the following lines to generate your own key pair




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   #openssl req -newkey rsa:1024 -passin pass:password \
   #    -passout pass:password \
   #    -sha1 -x509 -keyout demoCA/private/cakey.pem \
   #    -out demoCA/cacert.pem -days 3650 <<EOF
   #US
   #California
   #San Jose
   #sipit
   #Sipit Test Certificate Authority
   #
   #
   #EOF

   openssl crl2pkcs7 -nocrl -certfile demoCA/cacert.pem \
           -outform DER -out demoCA/cacert.p7c

   cp demoCA/cacert.pem root_cert_fluffyCA.pem

A.2.  makeCert script


   #!/bin/sh
   #set -x

   if [  $# == 1  ]; then
     DAYS=1095
   elif [ $# == 2 ]; then
     DAYS=$2
   else
     echo "Usage: makeCert test.example.org [days]"
     echo "       makeCert alice@example.org [days]"
     echo "days is how long the certificate is valid"
     echo "days set to 0 generates an invalid certificate"
     exit 0
   fi

   ADDR=$1

   echo "making cert for ${ADDR}"

   rm -f ${ADDR}_*.pem
   rm -f ${ADDR}.p12

   case ${ADDR} in
   *:*) ALTNAME="URI:${ADDR}" ;;
   *@*) ALTNAME="URI:sip:${ADDR},URI:im:${ADDR},URI:pres:${ADDR}" ;;
   *)   ALTNAME="DNS:${ADDR}" ;;
   esac



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   rm -f demoCA/index.txt
   touch demoCA/index.txt
   rm -f demoCA/newcerts/*

   export ALTNAME

   openssl genrsa  -out ${ADDR}_key.pem 1024
   openssl req -new  -config openssl.cnf -reqexts cj_req \
           -sha1 -key ${ADDR}_key.pem \
           -out ${ADDR}.csr -days ${DAYS} <<EOF
   US
   California
   San Jose
   sipit

   ${ADDR}



   EOF

   if [ $DAYS == 0 ]; then
   openssl ca -extensions cj_cert -config openssl.cnf \
       -passin pass:password -policy policy_anything \
       -md sha1 -batch -notext -out ${ADDR}_cert.pem \
       -startdate 990101000000Z \
       -enddate 000101000000Z \
        -infiles ${ADDR}.csr
   else
   openssl ca -extensions cj_cert -config openssl.cnf \
       -passin pass:password -policy policy_anything \
       -md sha1 -days ${DAYS} -batch -notext -out ${ADDR}_cert.pem \
        -infiles ${ADDR}.csr
   fi

   openssl pkcs12 -passin pass:password \
       -passout pass:password -export \
       -out ${ADDR}.p12 -in ${ADDR}_cert.pem \
       -inkey ${ADDR}_key.pem -name ${ADDR} -certfile demoCA/cacert.pem

   openssl x509 -in ${ADDR}_cert.pem -noout -text

   case ${ADDR} in
   *@*) mv ${ADDR}_key.pem user_key_${ADDR}.pem;   \
        mv ${ADDR}_cert.pem user_cert_${ADDR}.pem ;;
   *)   mv ${ADDR}_key.pem domain_key_${ADDR}.pem; \
        mv ${ADDR}_cert.pem domain_cert_${ADDR}.pem ;;
   esac



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Appendix B.  Certificates for Testing

   This section contains various certificates used for testing in PEM
   format.

   Fluffy's certificate.


   -----BEGIN CERTIFICATE-----
   MIICzjCCAjegAwIBAgIIAZUAcQIzAFgwDQYJKoZIhvcNAQEFBQAwcDELMAkGA1UE
   BhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcTCFNhbiBKb3NlMQ4w
   DAYDVQQKEwVzaXBpdDEpMCcGA1UECxMgU2lwaXQgVGVzdCBDZXJ0aWZpY2F0ZSBB
   dXRob3JpdHkwHhcNMDUwMjAzMTg0OTM0WhcNMDgwMjAzMTg0OTM0WjBiMQswCQYD
   VQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTERMA8GA1UEBxMIU2FuIEpvc2Ux
   DjAMBgNVBAoTBXNpcGl0MRswGQYDVQQDFBJmbHVmZnlAZXhhbXBsZS5jb20wgZ8w
   DQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAMqrm5tOPNVFPM4ApjaouezSduK5m+go
   qrqGIsXPMz5PbVYhrr1UhHwUFPl9mYUATpPW/WvU0dRVjsmJsa8rXyOZSpXlaGVk
   HRKn29PVlxhHNZzmiCedqGzKKoTmYtjx6aIaOX4OD5ClpnkhvCpntN1pkIKarh8C
   UopY0/XQ1GZnAgMBAAGjfzB9MFEGA1UdEQRKMEiGFnNpcDpmbHVmZnlAZXhhbXBs
   ZS5jb22GFWltOmZsdWZmeUBleGFtcGxlLmNvbYYXcHJlczpmbHVmZnlAZXhhbXBs
   ZS5jb20wCQYDVR0TBAIwADAdBgNVHQ4EFgQU7NqYXun399fsKylL2iXux8d+lXAw
   DQYJKoZIhvcNAQEFBQADgYEATEZJbgFI4tRu10ih83vIpZg3pURGWJ9KN32Q+1//
   Nr1nMfAp3gri6rnwXJ+toN7lTkKPEdhB6mi+28Ie+uWKLX9mEynp2o/7gL9+XrYE
   rQheWJW3xTiF1WUxrYDLKKdMrRH9QTs3d1rehZY9ZutfmvhgX46x/EpDU7YRTS70
   Pf8=
   -----END CERTIFICATE-----

   Fluffy's private key


   -----BEGIN RSA PRIVATE KEY-----
   MIICXAIBAAKBgQDKq5ubTjzVRTzOAKY2qLns0nbiuZvoKKq6hiLFzzM+T21WIa69
   VIR8FBT5fZmFAE6T1v1r1NHUVY7JibGvK18jmUqV5WhlZB0Sp9vT1ZcYRzWc5ogn
   nahsyiqE5mLY8emiGjl+Dg+QpaZ5IbwqZ7TdaZCCmq4fAlKKWNP10NRmZwIDAQAB
   AoGAXgtxwoh0jBZ716/PcS+sTut+xUiRwxIT30fdHONACRr8RmqM1khAzf7XmMoi
   kegJjmrF3+K6l4g4IOcnL3y1wVCtzJ1f2QDTuVzAsvazZqI4+pNB4LaAb+JPNQ+4
   BtrQSXADXv7HfkUakzeZpgnJYw+zHWaVogKjcLDKHWdrbOECQQDpH/G+GsJ4mnrp
   wZF9OxKqKhqBO73ZONHDxu55AukLghGnFh1udqdCQ7EPsaCqLN82RS4gn/WDfnBh
   WB8DRavxAkEA3o6nMOMyKdsuqBbGyEPvaPDVmw973wtEohIj6MgwdYSUOhdKAurR
   hs09yVGy0QpjoNHIE0vi5lUhPxJ1+Xvv1wJBAL0Ry14DFfX6U/WBqB2I63pW62gk
   q7ShAH9nt8EtOxS6SNbaeMQ+Nyjm/ZNc3JEoE2BQezi6gsRCp6JLdduRhgECQD1p
   V7EhwCHUnVc8kbWJKXLnocmbyC6PyWx/XPFK7DRBVTWCX6XWbeKol7gJlzIfj8Y8
   nNzWP9IXA4mH6o3hKRkCQA+1er++Tx24uypEijIi7OK0bfjJUlrhCM9NVWxDKrzO
   3zpuUB7yzuxrbcMZI8JKQIHL0sWz7egscepxS+N61y8=
   -----END RSA PRIVATE KEY-----

   Kumiko's certificate




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   -----BEGIN CERTIFICATE-----
   MIICzjCCAjegAwIBAgIIAZUAcQIzAFcwDQYJKoZIhvcNAQEFBQAwcDELMAkGA1UE
   BhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcTCFNhbiBKb3NlMQ4w
   DAYDVQQKEwVzaXBpdDEpMCcGA1UECxMgU2lwaXQgVGVzdCBDZXJ0aWZpY2F0ZSBB
   dXRob3JpdHkwHhcNMDUwMjAzMTg0OTIzWhcNMDgwMjAzMTg0OTIzWjBiMQswCQYD
   VQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTERMA8GA1UEBxMIU2FuIEpvc2Ux
   DjAMBgNVBAoTBXNpcGl0MRswGQYDVQQDFBJrdW1pa29AZXhhbXBsZS5uZXQwgZ8w
   DQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBANX6dhOhUuf+2I3lymzeuSDwHLZqMqnu
   3ISiIji/VlEoVUBFIHYjtxbmhIi40mEl4cqT+tVI6gY6Pe7VrL835Yr3AoLLeUB7
   4mXa7T152+jAxA4+nCVnIAkMrPxTDeBFEfn+qyCRPWyQ7WEgH3Vd9AufnC7aeafD
   pp+dcAOFZ2pBAgMBAAGjfzB9MFEGA1UdEQRKMEiGFnNpcDprdW1pa29AZXhhbXBs
   ZS5uZXSGFWltOmt1bWlrb0BleGFtcGxlLm5ldIYXcHJlczprdW1pa29AZXhhbXBs
   ZS5uZXQwCQYDVR0TBAIwADAdBgNVHQ4EFgQUNi5qQQ2G6AsiZK79cPEXYmPsqFIw
   DQYJKoZIhvcNAQEFBQADgYEABIFd9N/3/05AD7Kt9kKSdy6vFvncU1IaccuFfdXc
   QPfewY8NWwYKWsu588D4Nu77VQ++6a8AtjlJPSY/742Z4oKq1jfxdA+Uz/Z9cv2v
   6aM4oX7R5FTgJTbHRC0ueH32OhNlcLhSNGHzNWSrS8AbtNOlfLRJipZI3N0W5b6q
   09Q=
   -----END CERTIFICATE-----

   Kumiko's private key


   -----BEGIN RSA PRIVATE KEY-----
   MIICXQIBAAKBgQDV+nYToVLn/tiN5cps3rkg8By2ajKp7tyEoiI4v1ZRKFVARSB2
   I7cW5oSIuNJhJeHKk/rVSOoGOj3u1ay/N+WK9wKCy3lAe+Jl2u09edvowMQOPpwl
   ZyAJDKz8Uw3gRRH5/qsgkT1skO1hIB91XfQLn5wu2nmnw6afnXADhWdqQQIDAQAB
   AoGBANJktWrxyanxC47iLdpEWHVJgoHeA7jQ8yS6orl3cPDVnpVWIufmkCTFPfWM
   /Namv89HF3BVhD3hUHogwP03gcsIdxpccnu1wnmTW7IhSQXjBts0mEDbOw8S+WtS
   9NjRI4m1+86OflE+TVa3DtwCE/pEOKhFvcZHvXiosYMnucABAkEA6xqKEwR1zI/V
   u2B28Lcv0iafkJQDfPB3ooahQ+9qy5qUWgGZzXj6tM8YUusVqR/NCg8auqRC5uWD
   yonN98phQQJBAOj/Pp9yyO2NCVs4Mp5QSXDOlRAOuruMz6vlmURQO/8uBmHvETfC
   nkvqxxHjHW7mmusEY+ZIvRxmFV4RZcYByQECQHiT5/TQ+Mmti2TKmLXkffY+MOAp
   yZAulG0at2LsS82YvjVbVNJ5Fbvd6w+72iQfVz2teXv3+wgI9orOGoDXnwECQGrE
   I58PCzGHkkUBkHhpE+4kS7wK89hjYvpDAKOEHKoHHhecZAhoHv9suwHgT6l09IJD
   BcANjtLHmHz9feRpBwECQQCuIn02CMxFy5yhjj4nlmCRQ6w6KBWjY68xnN4Qj/g3
   SV+1HtmCclS0bK7e/IV6gOKn+MV3C+14JGdSRM+9HqcZ
   -----END RSA PRIVATE KEY-----

   Certificate for example.com












Jennings, et al.        Expires November 17, 2006              [Page 34]


Internet-Draft            SIP Secure Call Flows                 May 2006


   -----BEGIN CERTIFICATE-----
   MIICjDCCAfWgAwIBAgIIAZUAcQIzAFUwDQYJKoZIhvcNAQEFBQAwcDELMAkGA1UE
   BhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcTCFNhbiBKb3NlMQ4w
   DAYDVQQKEwVzaXBpdDEpMCcGA1UECxMgU2lwaXQgVGVzdCBDZXJ0aWZpY2F0ZSBB
   dXRob3JpdHkwHhcNMDUwMjAzMTg0OTA4WhcNMDgwMjAzMTg0OTA4WjBbMQswCQYD
   VQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTERMA8GA1UEBxMIU2FuIEpvc2Ux
   DjAMBgNVBAoTBXNpcGl0MRQwEgYDVQQDEwtleGFtcGxlLmNvbTCBnzANBgkqhkiG
   9w0BAQEFAAOBjQAwgYkCgYEA5jF2tSfMjTKFVnD3wjMzMiZCXjxocXsfeVDQcic7
   Sq/yztEMvMBfMWpD53ytZL3H5iWfqs0tkKpohGJ7Bb5Dpa+76p2pW6RTnSKL2pYu
   Hz+SRrjMyCQ8Rs1dLWSFsaTKAfGOxX4P/wCRo+rLPhICdaS7CMjQKu+zu3J6mOX/
   n4ECAwEAAaNEMEIwFgYDVR0RBA8wDYILZXhhbXBsZS5jb20wCQYDVR0TBAIwADAd
   BgNVHQ4EFgQUIurLOGYd8ZYMmke2uxxSRLB3ZY0wDQYJKoZIhvcNAQEFBQADgYEA
   rutJ7R7xjSapbQOCktXfRMQeHwd1iDfkdpc1ElmYeXgWbjuxwCvbhQJrdMlbGZLa
   fvVBC7zS3UWqb74k3EhXZtkugt+ejXADc3Xvj3pWTMxCvTFFsF7/0TvEgu79p8EQ
   NOuBSRprhn7HYR2zuQoCvYT4R6/P8ahzqDEdIHoGf6w=
   -----END CERTIFICATE-----

   Private key for example.com

   -----BEGIN RSA PRIVATE KEY-----
   MIICXgIBAAKBgQDmMXa1J8yNMoVWcPfCMzMyJkJePGhxex95UNByJztKr/LO0Qy8
   wF8xakPnfK1kvcfmJZ+qzS2QqmiEYnsFvkOlr7vqnalbpFOdIovali4fP5JGuMzI
   JDxGzV0tZIWxpMoB8Y7Ffg//AJGj6ss+EgJ1pLsIyNAq77O7cnqY5f+fgQIDAQAB
   AoGBANtRm2FkRv7seJ/wSA6OS6PnUeqJMZWVklo6xi9M86/oTbYA9VrNCqWBMqtW
   XboTG2dKx4KrtFMWGTiwv7esHLPsUB1jYF7/KEsRh4WoRxfeWoQlAY6VYXycg6b5
   X0uORdFMWL+WRxPmo8IhDKEwNyRyCyGQjfKpMj0724WjEqWxAkEA9MFDUQD+fL3N
   ImRQl9ns3nHIIbcrtfxGCFaj+EJEwsyc5gq7QxRc3niNVt5pogPP7+CxskLaPPKU
   TJmhtwixLQJBAPDE7hcDCPtsn9DIOXf/ZxXjfZAlAfwVsT+ggWQi5r63lGwjIbCT
   qO6TijtbSqqD0QqULTabVwpIdYyknQqQlCUCQGnkG322UmQhsdiJUh0Amex7ibyc
   hPrNVHdTFMnZ0en9oHwedHpHGw7dVTkaLNV9lL8RlY+sQMNRqDuj1EVeK1kCQQCH
   945FLI+b/OHbs9bQb0k10TyNdHjEdTOdrPSlKhiIx39n+gcCgsC5ylQb5RgrZzlb
   8gX+eocS5YyMmkGdP7yJAkEAsmGKAgt4nTfZY5L8PytPK8lCJjBLcyIllI3QEiMY
   K/81YWYQcqsg5/cLBZC26KgNvxkyLwxS220Djlm19HJKGQ==
   -----END RSA PRIVATE KEY-----

   Certificate for example.net















Jennings, et al.        Expires November 17, 2006              [Page 35]


Internet-Draft            SIP Secure Call Flows                 May 2006


   -----BEGIN CERTIFICATE-----
   MIICjDCCAfWgAwIBAgIIAZUAcQIzAFYwDQYJKoZIhvcNAQEFBQAwcDELMAkGA1UE
   BhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExETAPBgNVBAcTCFNhbiBKb3NlMQ4w
   DAYDVQQKEwVzaXBpdDEpMCcGA1UECxMgU2lwaXQgVGVzdCBDZXJ0aWZpY2F0ZSBB
   dXRob3JpdHkwHhcNMDUwMjAzMTg0OTExWhcNMDgwMjAzMTg0OTExWjBbMQswCQYD
   VQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTERMA8GA1UEBxMIU2FuIEpvc2Ux
   DjAMBgNVBAoTBXNpcGl0MRQwEgYDVQQDEwtleGFtcGxlLm5ldDCBnzANBgkqhkiG
   9w0BAQEFAAOBjQAwgYkCgYEA2w4I/bz/vxzVskUEF56EYjf4yUftpG8jhmIiwsA8
   AKLwc7CTnceW+tLmdDfUQLWw+HP4ky0tgQQA6pmviPORUNjuSj91dE7EJk3ZKePE
   3MZ2M5JL6CEFn3HEFnHOQKv3TMKIGSpUZJjHmm15yRPiAlx0Q2vJ29h4W52X1DPM
   62MCAwEAAaNEMEIwFgYDVR0RBA8wDYILZXhhbXBsZS5uZXQwCQYDVR0TBAIwADAd
   BgNVHQ4EFgQUHNoIc7Or6o1iTsM1PmWPdgbxUAwwDQYJKoZIhvcNAQEFBQADgYEA
   VlSod7+XfvSKNsybqtWPaM8VnoRLFVXvukgQbsdv4wuv5bnDfwxdU25rdizBbql+
   m8Us+ky8ORw190v73mSeOro7KMv0mN1u2BaGUB/wjaRsH2HC+UZb0ok3vzZ+W8Re
   ECjcVyHNRGVw5Iu2W5iWcO/a/74vPaVBiFQQJBRSLxg=
   -----END CERTIFICATE-----<

   Private key for example.net

   -----BEGIN RSA PRIVATE KEY-----
   MIICXgIBAAKBgQDbDgj9vP+/HNWyRQQXnoRiN/jJR+2kbyOGYiLCwDwAovBzsJOd
   x5b60uZ0N9RAtbD4c/iTLS2BBADqma+I85FQ2O5KP3V0TsQmTdkp48TcxnYzkkvo
   IQWfccQWcc5Aq/dMwogZKlRkmMeabXnJE+ICXHRDa8nb2HhbnZfUM8zrYwIDAQAB
   AoGBAIrUP1CIutEldi3wXaKWfTI+ZPc0FeFz6mDdy0gAS0bf/WJk03lYqFA434Ni
   aqvEOu+LmEu2gzNUFTyZwE0ciMg3NQ0H57z7OvbnHa0LajiJROo7zkROrmE5GTIV
   v2WstOKJYsMdcTVa4VZd9cHH6zWXHtWDT+Y2MxrIerFnOYxBAkEA72cBQSE4SStZ
   KvodDuMjFXG97Z1F927Xe/47iWnYRKhVB/jwN9uYpJog2cQFgsIsRMltozi3huTP
   L8IKkI5N4QJBAOo95ShiRPcbXIXY1IcUGx1Rulr+paIAJwjuuutwrtCA1CbIKB0j
   vfGVr3mKBGV2XLmz15nNV+5WFiLRBiUgucMCQQCxf+63KnlADurS6ZTH5/KoQKfw
   WE568WzFWy8raBXYefJpsdHxqFiZmklHDIaFd5A5BBvNDA1O77EKGNWablghAkEA
   zbvpPqv4+LRuchy8pZtyKTE0JWHNZlkN79mGEO4ajITqUNmx6c4PsVUQFwayz87C
   qFQdxDdHyMyRiqjd5dQ1cwJAfJsXNGcOhilkV3xBy95tb3IsVP6G5DqwtID4hrYa
   Onf9xrVzh9M29Xp+AHcwS4Y0+UgiNrd5BlbZs+ALZPD/jw==
   -----END RSA PRIVATE KEY-----


Appendix C.  Message Dumps

   This section contains a base64 encoded gzipped, compressed tar file
   of various CMS messages used in this document.  Saving the data in a
   file foo.tgz.b64 then running a command like "openssl base64 -d -in
   foo.tgz.b64 | tar txfz -" would recover the CMS messages and allow
   them to be used as test vectors.

   H4sIAO0RgEMAA+xaybajyLWtMV+Rc5YtBEJIA6/16DvR90y8aETfiR6+3tx7n+3M
   rCpX46r083p1BkI6ARHEjoh9IvbRkHd/Gp7Rn+JgDE7f/T4GHYah6Mf1en2/Hvb3
   6/v3M4ScoTN6RiHsO+iMYAjy3Sf0d3qfL2waxqD/9Om7pJqSZPvx+5bs+az+RT1f
   deo3f8/fyYbPxz969uPw28+Cnzn+CIYhF+jtvrdZcP5j/L+F/cD4x20d5M1f3378



Jennings, et al.        Expires November 17, 2006              [Page 36]


Internet-Draft            SIP Secure Call Flows                 May 2006


   9bkGdVc9/xy19Z+7Z/3r2njD43q5/Nj4n6/Xr9Y/DCMI+t2nbwLi//Px/9ObETTL
   y59IWjd5hidxk373AhLPkwVFknjipPjCE3jK87hv4ZHG7zhjLZTmCWLr89kcybhG
   M4SGLxFFPyS8ZPGzRQNEJpG2La30jutEKttHDSZZylnIVnWICFPg0Ctt4upHWWSS
   zFGWE2KIyJWkXRaAwj3K1jSRXuw9cIkupuhOIqP32slVSi24WgJXS23W3mOSoHxX
   gALH7zyYgXyDIIDY1dujpS7myoXLIlmirEUq8F0yU0gx8Yvz7ku/9BVEKGnDQmoe
   BRyts/Qi2NZOm9KB03vLhCRqMDMcLc1RjXaeSesSfnsvI1aJt2Bm4ulujmBrBagC
   lz7615qEK3cRW0GSri10+t41il7G6skyY8Su1aOW59AkiWbHZSItX1mZs8B9gYg3
   dHFcIYoD4dQrydSjcbRg4NFIpMIUGbuhkKWQdin3SbdY28gdkqdNaVEeYYDxOm37
   SEuzRCSS01Eoso3+A+HQ3EleAzSWYtdmrIARIUp1AYhdO7hzrrrZGOID7rwJ4HbQ
   0PtC2kjtpg/n+OEYR+dNEU9YZXUv6mkh9RbsH2rGk3FgYKRUaOIE7hMiXGvFPQHN
   hSbxhcbxQKYlml+Yt77rkE7gt4Xy+IfvZlnoEoNvoEUIQ+/IH+UmgfMLTuEx8AYg
   p11oJtUsfuofCuvFN9+T6vIJT+tq6A8C8T3oh2Yk9YYV0E+jgOnYWhhBF2oKWY5u
   okvak1vic04lZdxFZ7qqvaebOmExrQs5h5km9LFUhaz/CIBktgkS2w3Ecl4hdikR
   OnP9sZzSEXwWLk5FiDsXSOeY0krOJsMMDHaCzJlOJ+ze3WgNkJWJMPSuzxqM83R4
   n7SWnD3zol9P6i3I9hdFxzzXssl1+Qvwvv5omfr+mvyt1//P5P/mOX5b/r/8wf/f
   xH49/3v//fxPr9/n/8P3H+R/tIqpn8n/8HLhT+F+mtfdHkqLZtAr7RXJZbOSsWNv
   RVbz+TLgNwAXH0uEkWYTPR1wfNQxlVjaw1lATr2UGzSmmoZfu3rOVUW35GIyivs5
   pjFaKBFffKo0gEg+LKHC40rSTINwxwenaOKMmJLIs0Zn+ULB1fUZ3XQ1x6sV0uBZ
   gO/ZxUFh90ypEnCFpZ/L/5Pvav+a/zm55SNM6a/tOTcH6azWjhqn4Wrhy4/zv10Z
   bYyBbjIbojxs4Wt01EC62U2rPxjbnacy1cIhni/LNKNhQyXLGlsw2sf5ToSvCgTq
   mzWA5XZT9OV8h2YMqY2n0reYKM1QLZ8nmAhYizgtRaAPHMyRoOWHUFsi8+6Dzk1/
   AjRZRPbGyTprLyg/wc4RfiPlFJywy6wGNpEzmiYQuvFY0/8b/F8+t99m+/+T/I9i
   yNf8fz5cf/D/N7DP+F838E+qztvHXPsk0t4/Y4CbHtyPi0SqUbXkBmfhtslSazuR
   mpDHnnMTSuGpstn6XO+oJRObsI9if3ookLbdgIW5rUGpNol4LucoqQUffO0GrL3q
   nPaagZlLpeqx+dUEVdgxSsy3c1Dll0RFBXaSdh4QqJXdbWj0eWftpJa4eRiTpKcT
   LrDFdRhAOhXO3WPgNxl/YZiCRc3LQxMwSTWewjWcAPCWJXB51GuYKfUZG57CaTHw
   q2Jc1cZ6vgTJd+yyaq9rfpdu11Nrhh5+t3uZfDmEdBAF4IatycKxuF7EfmQkhzXz
   ZcaeA/dQB4s4F96x1xPpQT8Yr9XX5Om0WoV7V9tztyi9hijgQpOix8eTD9DRV7Vu
   b3xGHUFN3vSN3FitSMROKiAMPs4e9MtZ8ZLG7xJDWRoFJg9EBvha16p7MyANx/Nh
   1I/JypJMUIC0QC/DFqHpC9NWPUKaXLZHtGtTVcVAch3KR6CqogWYQp2NS74+Do7B
   VYrGsogi1XFo7hSvuMnJX90i8fEKTxZ7MME0dbQc7a9IxS4FH5Im8FKuZl6MofF6
   UZD2sh5mENpLx8feVjbaS6tIi9TYpmQRGLZqLRviXLAyCK+fK5aHWwRkan9weGwy
   UuNDz+becssz5jqOXbDYNsvgIdv36nHTKw8cNEnWX9RUnGn7eUwbUtNIDrhfUObB
   g+FJ4cLhHmohVJ4hc5NjrqBjU4l71ajELOdX5N6AaUSmA4lulRaietr7exUCt9QF
   n21koN52HBzYWMU24Q3poWZFPB0vjZn4Hvq4qduoireKFAriEW18VfGIRueSB4in
   29lzPC16DSl6ih6ET8JXMZXntdwey2rAMEQVVX2+c4LIan/5jMZ/cGn9p5f+u/08
   /v+3tv+/hv9h6A/+/yb2C/k/pNLiPqvgiZOdTdc099hA5fKpEHQQLsPtOJfnD3Kh
   FrydiX0QlBhY0fAKTT4k33V8DKlLdMrNhwETBE696gDkbyijwQoqqogNmYNWm3HZ
   XW5mtDbeXpZzC/Cak0SR5kQRir9OsbS0qS9WellLzyB0G4EGjzfkdCq4NSHMZWHj
   J5Z023tv+Zz/+d5SzyQ/jXQV58jiBqKTmDzoqxHEPJn9WlPxBqW4AYXJyRFKCKm8
   F4NfkIucA8FrppUJfNT0BKe7bDHm5i80FOVSisgaxKHYjilz2HAB9AiKXNCVFttL
   XelrGmVN3gZm2BlGRRS8QYoj0w4uth/fI4677o7LjQ5lgh4srT3/7JlG8VbijZUw
   OCI0g74YxugD4tzG1CQVjMveMf/M3GHMfZ4uWO40ni5mNnEqFvk+eZ3QpnCkMenA
   D7pUje2eI9lkqsDjxoslj8qXN/5X2jtqZLmuRqHLu96Zjyx2PetT1YNdwOPCUkzT
   NC79SOJnMuRFAiqAOWHtHqlFgrVh91HvZ7SRbRB1mPyhE7mVTpH0RtNrAl4Rsalw
   auqNq29y6ElsNTFZAIdGrzdnZ5zt1geE6z0ToRtibn0xuV+XFUfxAROjOEoQs0zh
   ZwXDaJGVnSCs0uwND2AP5059zRfwoU9Rtt06f9xEk4YEh5P9qpSxe83SyiUoePNl
   yfV6jS7qYFsaswTbfsNI4MVo8UrF3CZtev4qYjTWztEi4IkwuDIbKVlelTayEtsd



Jennings, et al.        Expires November 17, 2006              [Page 37]


Internet-Draft            SIP Secure Call Flows                 May 2006


   HUOEH2z1yqLUaxl56pL1XgAoTXJfe3vP7hJ8dzsQ56LFuHgQaKW53McoUYX+AOIP
   X6WO8fiv5f++bccP9eeDE0n83+D+N/sJ/j82+9hX/H9Gjtv/4P9vYD+h/1DCm/7T
   wn/Xfw7W/qc08aFMWAxOEcvfBZPP9RLg1wgmn+slwD8EE6NchOW99ge9Eea7FkQS
   lu/KEE/LVdTonV9XhefqFU8z55jNjoYqCHia+JNZoEXacUQy01Uq+FU2heDwrR8+
   6x8+icNXcseFj9Y9E6/sowu6tNAf/eLppaO84xDi1/ctrKtM0ukj1L2XcfSSmZ5z
   SY36vvsmrUj48qGBkZnERB8y1SqaePNR+3Ag/dE1ntGrCNFSDba3mK3qwJGzmLVS
   zbWhgL1vQODqqMSziYRDLGm8WIMPEUqj35DH8Qsr4xRJ5Np7dKb47EqVkUU9qE28
   E7S1llMMgI1wWXvSZsUkLbj66gbGxOX02CT0g5PAu7PVe0nIu98JEwJt+7Auidjy
   4pTGstVTF0BG5pzMoyWSEfSRqiexCWXkEgWzy/UXv3qtHKjEIoFkmtlpAXLDMc+N
   g3a/pq0DJyMKSDl22SGElUX1xN6JVlTYGP3f41l74WSJ50SJgN4Ai6lUcwhC7/Us
   sq6dDgseYQFhJlvwiytswsjGgiTqDwGpIHjWOLBR068e+OL+FwMBHcd/IU3+UmUS
   +Fqa/KXKJPC1NPlPZbImDxw+KnzXvKwFX2jitH+50ID3lYYrxziTTqjP89lnTd1d
   Q+52ol9lbJC70VpqP4C99tKhNdaC6L7I3qmp/LDUEQV44c+dvRrJEW3nBKSUFNVX
   7XUCvSsPIQ/92UWY+LSpLugqiWGbLhGHPKRNKe+WPdhkDdBSK7lEIpEz4BW1nljm
   T5QQwLQ0317OZVzojKW8qOoY6+61+2aclWy20r98SznrD/uF9gPxfxqe/efx/3/+
   XRXwp+I/dIa/iv8IgkJ/xP9vYT+V/9mLI/4Xzx/I/6T//fkfCfp+/ufwFUT+e+d/
   hoX92FRQDCHUIWfX/nFo+joPnvq3A4MvUSY+choQfsQ94f1oK736Gh0VVbYZVbrg
   XRG003M34klEazBtgVf/YvnBVaUdVUPby/r+bGXcYjFqda89Czc71Tk5swXFul0M
   tTAEt97dFN/o3Cpg7RLgdLGB76pdrdlx1NrrnHzGL3YXxdasvbFYrwEfKO5FoVCy
   6poym8muGeVzV/Ji0Gc3ErDazoNOrnZm/QZPJQLH2SLZibvEvAMa05ouSnTOMs2B
   D9V9Dw/gAxCYZZxqVGp/iB2/flrEl3+c8Dw34oQq2n+0gu//s+DzxBImvzx3apD7
   PRnErXrAuTuttxisXPx7o/CPzJJJ+0KYMvxl1KczlGc3ZOY7P0U6S2cd4S7KCKyB
   59MJkPtzIyV4h6R9fu2bxRXAsZWxyixFlY4z4lrnIHzjn+DkiI+/sXctUG5U53l3
   ba+xzNqYDbTQhKMSHgGx1rwfu9jx6Dmj0XskjaSGhtHMSDOS5qF56BU3MeaRFOiB
   JHUaaAIkPtAGWprQFtKU4rQppRQKaSEnPI7rNJTTluRQl8CxT1tMR2vjJ9jGLEvd
   s7/O6Giuru69c+9/v+///3vvbpnUogPdhIwg3kiSgbJVifqsnCLzCR7uF9QYyBf7
   ViWSZFkpZeVpMlewYQm0ZKVaIauuU9e6SqOMYP1g1IwU8Uq+wOGAL1snlqh4SY6U
   4/J/y9XUlrHp/UaBT4X/sSX/f1Hk1PlfPP35nxkey/9e2mLzvyXxoClAJHX0PoiT
   4/90GZOUjFJ06wGIgdueNy+7XKRHJ6udVEd3fTDDqUxTDZbaUaNUDMUYutJ0+jVN
   YVQE0KJtROwUAk6JwRoVLCvjJStJwGjFgikjmfRIFvchWlnACyAKBZpUn0ICerik
   M1QrZWX7hYgcikXreqAzCOez/CCH89EGDZckknLrehgXZKEe8ZlmQBKpTKwKmaGT
   4P9j+sO3v0O4A/zvgDW+bdWA0JEbZ5iD/P9uBRy7s+Rw/k+raCeXg+IYZatVFifF
   bLRc0bJ2J8a8O/+HmJhEpoNwEECpCM46ZIvlpAHWjXV1sQgygii6sbpUFn25bF3u
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Jennings, et al.        Expires November 17, 2006              [Page 38]


Internet-Draft            SIP Secure Call Flows                 May 2006


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Jennings, et al.        Expires November 17, 2006              [Page 39]


Internet-Draft            SIP Secure Call Flows                 May 2006


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Jennings, et al.        Expires November 17, 2006              [Page 40]


Internet-Draft            SIP Secure Call Flows                 May 2006


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Authors' Addresses

   Cullen Jennings
   Cisco Systems
   170 West Tasman Drive
   Mailstop SJC-21/2
   San Jose, CA  95134
   USA

   Phone: +1 408 421 9990
   Email: fluffy@cisco.com


   Kumiko Ono
   NTT Corporation
   Musashino-shi, Tokyo  180-8585
   Japan

   Phone: +81 422 59 4508
   Email: ono.kumiko@lab.ntt.co.jp


   Robert Sparks (editor)
   Estacado Systems

   Email: RjS@estacado.net

























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Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.




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