SIPPING WG V. Gurbani, Ed.
Internet-Draft Bell Laboratories, Alcatel-Lucent
Intended status: Informational C. Boulton
Expires: September 6, 2007 Ubiquity Software Corporation
R. Sparks
Estacado Systems
March 5, 2007
Session Initiation Protocol (SIP) Torture Test Messages for Internet
Protocol Version 6 (IPv6)
draft-ietf-sipping-ipv6-torture-tests-01
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This Internet-Draft will expire on September 6, 2007.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This informational document provides examples of Session Initiation
Protocol (SIP) test messages designed to exercise and "torture" the
code of a SIP implementation that parses IPv6 addresses.
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This work is being discussed on the sipping@ietf.org mailing list.
Table of Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Document conventions . . . . . . . . . . . . . . . . . . . . . 3
3. SIP and IPv6 network configuration . . . . . . . . . . . . . . 4
4. Parser torture tests . . . . . . . . . . . . . . . . . . . . . 4
4.1. Valid SIP message with an IPv6 reference . . . . . . . . . 5
4.2. Invalid SIP message with an IPv6 reference . . . . . . . . 5
4.3. Port ambiguous in a URI . . . . . . . . . . . . . . . . . 6
4.4. Port umabiguous in a URI . . . . . . . . . . . . . . . . . 6
4.5. IPv6 reference delimiters in Via header addresses . . . . 7
4.6. SIP request with IPv6 addresses in SDP body . . . . . . . 8
4.7. Multiple IP addresses in SIP headers . . . . . . . . . . . 9
4.8. Multiple IP addresses in SDP . . . . . . . . . . . . . . . 10
5. Security considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative references . . . . . . . . . . . . . . . . . . . 11
8.2. Informative references . . . . . . . . . . . . . . . . . . 11
Appendix A. Bit-exact archive of each test message . . . . . . . 12
A.1. Encoded reference messages . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
Intellectual Property and Copyright Statements . . . . . . . . . . 15
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1. Overview
This document is informational, and is NOT NORMATIVE on any aspect of
SIP.
This document contains test messages based on the current version
(2.0) of the Session Initiation Protocol as defined in [RFC3261].
This document is expected to be used as a companion document to the
more general SIP torture test document [RFC4475], which does not
include specific tests for IPv6 network identifiers.
This document does not attempt to catalog every way to make an
invalid message, nor does it attempt to be comprehensive in exploring
unusual, but valid, messages. Instead, it tries to focus on areas
that may cause interoperability problems in IPv6 deployments.
2. Document conventions
This document contains many example SIP messages. The appendix
contains an encoded binary form containing the bit-exact
representation of the messages and the algorithm needed to decode
them into separate files.
The IPv6 addresses used in this document correspond to the 2001:
DB8::/32 address prefix reserved for documentation [RFC3489].
Likewise, the IPv4 addresses used in this document correspond to the
192.0.2.0/24 address block as described in [RFC3330].
Although SIP is a text-based protocol, some of these examples cannot
be unambiguously rendered without additional markup due to the
constraints placed on the formatting of RFCs. This document uses the
markup convention established in [RFC4475] to avoid
ambiguity and meet the Internet-Draft layout requirements. For the
sake of completeness, the text defining this markup from Section 2.1
of [RFC4475] is reproduced in its entirety below:
"Several of these examples contain unfolded lines longer than 72
characters. These are captured between tags. The
single unfolded line is reconstructed by directly concatenating all
lines appearing between the tags (discarding any line feeds or
carriage returns). There will be no whitespace at the end of lines.
Any whitespace appearing at a fold-point will appear at the beginning
of a line.
"The following represent the same string of bits:
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Header-name: first value, reallylongsecondvalue, third value
Header-name: first value,
reallylongsecondvalue
, third value
Header-name: first value,
reallylong
second
value,
third value
"Note that this is NOT SIP header-line folding, where different
strings of bits have equivalent meaning."
3. SIP and IPv6 network configuration
System-level issues like deploying a dual-stack proxy server,
populating DNS with A and AAAA RRs, zero-configuration discovery of
outbound proxies for IPv4 and IPv6 networks, when should a dual-stack
proxy Record-Route itself, and media issues also play a major part in
the transition to IPv6. This document does not, however, address
these issues. Instead, a companion document [ID.sip-trans] provides
more guidance on these.
4. Parser torture tests
The test messages are organized into several sections. Some stress
only a SIP parser and others stress both the parser and the
application above it. Some messages are valid, and some are not.
Each example clearly calls out what makes any invalid messages
incorrect.
Please refer to the ABNF in [RFC3261] on representing IPv6 references
in SIP. IPv6 references are delimited by a "[" and "]". For Uniform
Resource Identifiers (URI), RFC3261 mandates that the "IPv6reference"
production rule be used when recognizing tokens that comprise an IPv6
reference. More specifically, the ABNF states:
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SIP-URI = "sip:" [ userinfo ] hostport
uri-parameters [ headers ]
hostport = host [ ":" port ]
host = hostname / IPv4address / IPv6reference
IPv6reference = "[" IPv6address "]"
IPv6address = hexpart [ ":" IPv4address ]
hexpart = hexseq / hexseq "::" [ hexseq ] / "::" [ hexseq ]
hexseq = hex4 *( ":" hex4)
hex4 = 1*4HEXDIG
4.1. Valid SIP message with an IPv6 reference
The request below is well-formatted according to the grammar in
RFC3261. An IPv6 reference appears in the Request-URI (R-URI), Via
header, and Contact header.
Message Details: ipv6-good
REGISTER sip:[2001:db8::10] SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Max-Forwards: 70
Contact: "Caller"
CSeq: 98176 REGISTER
Content-Length: 0
4.2. Invalid SIP message with an IPv6 reference
The request below is not well-formatted according to the grammar in
RFC3261. The IPv6 reference in the R-URI does not contain the
mandated delimiters for an IPv6 reference ("[" and "]").
An element receiving this request should respond with a 400 Bad
Request error.
Message Details: ipv6-bad
REGISTER sip:2001:db8::10 SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Max-Forwards: 70
Contact: "Caller"
CSeq: 98176 REGISTER
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Content-Length: 0
4.3. Port ambiguous in a URI
IPv6 uses the colon to delimit octets. This may lead to ambiguity if
the port number on which to contact a SIP server is inadvertently
conflated with the IPv6 reference. Consider the REGISTER request
below. The sender of the request intended to specify a port number
(5070) to contact a server, but inadvertently, put the port number
inside the closing "]" of the IPv6 reference. Unfortunately, since
the IPv6 address in the R-URI is compressed, the intended port number
becomes the last octet of the reference.
From a parsing perspective, the request below is well-formed.
However, from a semantic point of view, it will not yield the desired
result. Implementations must take care to ensure that when a raw
IPv6 address appears in a SIP URI, then any port number, if it is
required, appears outside the closing "]" delimiting the IPv6
reference.
Message Details: port-ambiguous
REGISTER sip:[2001:db8::10:5070] SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Contact: "Caller"
Max-Forwards: 70
CSeq: 98176 REGISTER
Content-Length: 0
4.4. Port umabiguous in a URI
In contrast to the example in Section 4.3, the following REGISTER
request leaves no ambiguity whatsoever on where the IPv6 address ends
and the port number begins. This REGISTER request is well formatted
per the grammar in RFC3261.
Message Details: port-umabiguous
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REGISTER sip:[2001:db8::10]:5070 SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Contact: "Caller"
Max-Forwards: 70
CSeq: 98176 REGISTER
Content-Length: 0
4.5. IPv6 reference delimiters in Via header addresses
IPv6 references can also appear in Via headers; more specifically in
the "sent-by" production rule and the "via-received" production rule.
In the "sent-by" production rule, the sequence of octets comprising
the IPv6 address is defined to appear as an "IPv6reference" non-
terminal, thereby mandating the "[" and "]" delimiters. However,
this is not the case for the "via-received" non-terminal. The "via-
received" production rule is defined thusly:
via-received = "received" EQUAL (IPv4address / IPv6address)
The "IPv6address" non-terminal is defined not to include the
delimiting "[" and "]". This has lead to the situation documented
during the 18th SIP Interoperability Event [Email-SIPit]:
Those testing IPv6 made different assumptions about enclosing
literal v6 addresses in Vias in []. By the end of the event, most
implementations were accepting either. Its about 50/50 on what
gets sent.
While it would be beneficial if the same non-terminal
("IPv6reference") was used for both the "sent-by" and "via-received"
production rules, there has not been a consensus in the working group
to that effect. Thus, the best that can be suggested is that
implementations must follow the Robustness Principle [RFC1122] and be
liberal in accepting a "received" parameter with or without the
delimiting "[" and "]" tokens. When sending a request,
implementations must not put the delimiting "[" and "]" tokens.
The two test cases below are designed to stress this behavior. An
element receiving either of these messages must parse them
successfully.
The request below contains an IPv6 address in the Via received
parameter. The IPv6 address is delimited by "[" and "]". Even
though this is not a valid request based on a strict interpretation
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of the grammar in RFC3261, robust implementations must nonetheless be
able to parse the topmost Via header and continue processing the
request.
Message Details: param-1
BYE sip:[2001:db8::10] SIP/2.0
To: sip:user@example.com;tag=bd76ya
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];received=[2001:db8::9:255];
branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Max-Forwards: 70
CSeq: 321 BYE
Content-Length: 0
The OPTIONS request below contains an IPv6 address in the Via
received parameter without the adorning "[" and "]". This request is
valid according to the grammar in RFC3261.
Message Details: param-2
OPTIONS sip:[2001:db8::10] SIP/2.0
To: sip:user@example.com
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];received=2001:db8::9:255;
branch=z9hG4bKas3
Call-ID: SSG95523997077@hlau_4100
Max-Forwards: 70
Contact: "Caller"
CSeq: 921 OPTIONS
Content-Length: 0
4.6. SIP request with IPv6 addresses in SDP body
This request below is valid and well-formed according to the grammar
in RFC3261. Note that the IPv6 addresses in the SDP body do not have
the delimiting "[" and "]".
Message Details: ipv6-in-sdp
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INVITE sip:user@[2001:db8::10] SIP/2.0
To: sip:user@[2001:db8::10]
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Contact: "Caller"
CSeq: 8612 INVITE
Max-Forwards: 70
Content-Type: application/sdp
Content-Length: 268
v=0
o=assistant 971731711378798081 0 IN IP6 2001:db8::20
s=Live video feed for today's meeting
c=IN IP6 2001:db8::1
t=3338481189 3370017201
m=audio 6000 RTP/AVP 2
a=rtpmap:2 G726-32/8000
m=video 6024 RTP/AVP 107
a=rtpmap:107 H263-1998/90000
4.7. Multiple IP addresses in SIP headers
Th request below is valid and well-formed according to the grammar in
RFC3261. The Via list contains a mix of IPv4 addresses and IPv6
references.
Message Details: mult-ip-in-header
BYE sip:user@host.example.com SIP/2.0
Via: SIP/2.0/UDP [2001:db8::9:1]:6050;branch=z9hG4bKas3-111
Via: SIP/2.0/UDP 192.0.2.1;branch=z9hG4bKjhja8781hjuaij65144
Via: SIP/2.0/TCP [2001:db8::9:255];branch=z9hG4bK451jj;
received=192.0.2.200
Call-ID: 997077@lau_4100
Max-Forwards: 70
CSeq: 89187 BYE
To: sip:user@example.net;tag=9817--94
From: sip:user@example.com;tag=81x2
Content-Length: 0
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4.8. Multiple IP addresses in SDP
The request below is valid and well-formed according to the grammar
in RFC3261. The SDP contains multiple media lines, and each media
line is identified by a different network connection address.
Message Details: mult-ip-in-sdp
INVITE sip:user@[2001:db8::10] SIP/2.0
To: sip:user@[2001:db8::10]
From: sip:user@example.com;tag=81x2
Via: SIP/2.0/UDP [2001:db8::9:1];branch=z9hG4bKas3-111
Call-ID: SSG9559905523997077@hlau_4100
Contact: "Caller"
Max-Forwards: 70
CSeq: 8912 INVITE
Content-Type: application/sdp
Content-Length: 181
v=0
o=bob 280744730 28977631 IN IP4 host.example.com
s=
t=0 0
m=audio 22334 RTP/AVP 0
c=IN IP4 192.0.2.1
m=video 6024 RTP/AVP 107
c=IN IP6 2001:db8::1
a=rtpmap:107 H263-1998/90000
5. Security considerations
This document presents NON-NORMATIVE examples of SIP session
establishment. The security considerations in [RFC3261] apply.
Parsers must carefully consider edge conditions and malicious input
as part of their design. Attacks on many Internet systems use
crafted input to cause implementations to behave in undesirable ways.
Many of the messages in this draft are designed to stress a parser
implementation at points traditionally used for such attacks. This
document does not, however, attempt to be comprehensive. It contains
some common pitfalls that the authors have discovered while parsing
IPv6 identifiers in SIP implementations.
6. IANA considerations
This document does not contain any actions for IANA.
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7. Acknowledgments
The authors thank Jeroen van Bemmel, Dennis Bijwaard, Gonzalo
Camarillo, Bob Gilligan, Alan Jeffrey, Larry Kollasch, Erik Nordmark,
Kumiko Ono, Pekka Pessi, and other members of the SIP-related working
groups for input provided during the construction of the document and
discussion of the test cases.
8. References
8.1. Normative references
[RFC1122] Braden, R., "Requirements for Internet Hosts -
Communication Layers", STD 3, RFC 1122, October 1989.
[RFC3261] 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.
[RFC3330] IANA, "Special-Use IPv4 Addresses", RFC 3330,
September 2002.
[RFC3489] Rosenberg, J., Weinberger, J., Huitema, C., and R. Mahy,
"STUN - Simple Traversal of User Datagram Protocol (UDP)
Through Network Address Translators (NATs)", RFC 3489,
March 2003.
[RFC4475] Sparks, R., Hawrylyshen, A., Johnston, A., Rosenberg, J.,
and H. Schulzrinne, "Session Initiation Protocol (SIP)
Torture Test Messages", RFC 4475, May 2006.
8.2. Informative references
[ID.sip-trans]
Camarillo, G., El Malki, K., and V. Gurbani, "IPv6
Transition in the Session Initiation Protocol (SIP)",
draft-ietf-sipping-v6-transition-04.txt (work in
progress), September 2006.
[Email-SIPit]
Sparks, R., "preliminary report: SIPit 18", Electronic
Mail archived at http://www1.ietf.org/mail-archive/web/
sip/current/msg14103.html, April 2006.
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Appendix A. Bit-exact archive of each test message
The following text block is an encoded, gzip compressed TAR archive
of files that represent each of the example messages discussed in
Section 4.
To recover the compressed archive file intact, the text of this
document may be passed as input to the following Perl script (the
output should be redirected to a file or piped to "tar -xzvf -").
#!/usr/bin/perl
use strict;
my $bdata = "";
use MIME::Base64;
while(<>) {
if (/-- BEGIN MESSAGE ARCHIVE --/ .. /-- END MESSAGE ARCHIVE --/) {
if ( m/^\s*[^\s]+\s*$/) {
$bdata = $bdata . $_;
}
}
}
print decode_base64($bdata);
Alternatively, the base-64 encoded block can be edited by hand to
remove document structure lines and fed as input to any base-64
decoding utility.
A.1. Encoded reference messages
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-- BEGIN MESSAGE ARCHIVE --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====
-- END MESSAGE ARCHIVE --
Authors' Addresses
Vijay K. Gurbani (editor)
Bell Laboratories, Alcatel-Lucent
2701 Lucent Lane
Rm 9F-546
Lisle, IL 60532
USA
Phone: +1 630 224 0216
Email: vkg@alcatel-lucent.com
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Chris Boulton
Ubiquity Software Corporation
Building 3
West Fawr Lane
St Mellons
Cardiff, South Wales CF3 5EA
Email: cboulton@ubiquitysoftware.com
Robert J. Sparks
Estacado Systems
Email: RjS@estacado.net
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