Fix.

[libidn.git] / draft-ietf-xmpp-resourceprep-03.txt

Network Working Group                                     P. Saint-Andre
Internet-Draft                                Jabber Software Foundation
Expires: December 3, 2003                                  J. Hildebrand
                                                            Jabber, Inc.
                                                           June 04, 2003


  Resourceprep: A Stringprep Profile for Resource Identifiers in XMPP
                    draft-ietf-xmpp-resourceprep-03

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
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   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
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   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at http://
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   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on December 3, 2003.

Copyright Notice

   Copyright (C) The Internet Society (2003). All Rights Reserved.

Abstract

   This document defines a stringprep profile for resource identifiers
   in the Extensible Messaging and Presence Protocol (XMPP).












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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   1.1 Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   1.2 Discussion Venue . . . . . . . . . . . . . . . . . . . . . . .  3
   1.3 Intellectual Property Notice . . . . . . . . . . . . . . . . .  3
   2.  Character Repertoire . . . . . . . . . . . . . . . . . . . . .  5
   3.  Mapping  . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
   4.  Normalization  . . . . . . . . . . . . . . . . . . . . . . . .  7
   5.  Prohibited Output  . . . . . . . . . . . . . . . . . . . . . .  8
   6.  Bidirectional Characters . . . . . . . . . . . . . . . . . . .  9
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 10
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
       Normative References . . . . . . . . . . . . . . . . . . . . . 12
       Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12
   A.  Revision History . . . . . . . . . . . . . . . . . . . . . . . 13
   A.1 Changes from draft-ietf-xmpp-resourceprep-02 . . . . . . . . . 13
   A.2 Changes from draft-ietf-xmpp-resourceprep-01 . . . . . . . . . 13
   A.3 Changes from draft-ietf-xmpp-resourceprep-00 . . . . . . . . . 13
       Intellectual Property and Copyright Statements . . . . . . . . 14































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1. Introduction

   This document, which defines a profile of stringprep (RFC 3454 [1]),
   specifies processing rules that will enable users to enter
   internationalized resource identifiers in XMPP (see XMPP Core [2])
   and have the highest chance of getting the content of the strings
   correct. These processing rules are intended only for XMPP resource
   identifiers (which are often associated with session names), and are
   not intended for arbitrary text.

   This profile defines the following, as required by RFC 3454 [1]:

   o  The intended applicability of the profile: internationalized
      resource identifiers within XMPP

   o  The character repertoire that is the input and output to
      stringprep: Unicode 3.2, specified in section 2

   o  The mappings used: specified in section 3

   o  The Unicode normalization used: specified in section 4

   o  The characters that are prohibited as output: specified in section
      5

   o  Bidirectional character handling: specified in section 6


1.1 Terminology

   This document inherits the terminology defined in XMPP Core [2].

   The capitalized 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 [3].

1.2 Discussion Venue

   The authors welcome discussion and comments related to the topics
   presented in this document. The preferred forum is the
   <xmppwg@jabber.org> mailing list, for which archives and subscription
   information are available at <http://www.jabber.org/cgi-bin/mailman/
   listinfo/xmppwg/>.

1.3 Intellectual Property Notice

   This document is in full compliance with all provisions of Section 10



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   of RFC 2026. Parts of this specification use the term "jabber" for
   identifying namespaces and other protocol syntax. Jabber[tm] is a
   registered trademark of Jabber, Inc.  Jabber, Inc. grants permission
   to the IETF for use of the Jabber trademark in association with this
   specification and its successors, if any.














































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2. Character Repertoire

   This profile uses Unicode 3.2 with the list of unassigned code points
   being Table A.1, both defined in Appendix A of RFC 3454 [1].















































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3. Mapping

   This profile specifies mapping using the following tables from RFC
   3454 [1]:

      Table B.1













































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4. Normalization

   This profile specifies using Unicode normalization form KC, as
   described in RFC 3454 [1].















































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5. Prohibited Output

   This profile specifies prohibiting use of the following tables from
   RFC 3454 [1].

      Table C.1.2

      Table C.2.1

      Table C.2.2

      Table C.3

      Table C.4

      Table C.5

      Table C.6

      Table C.7

      Table C.8

      Table C.9



























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6. Bidirectional Characters

   This profile specifies checking bidirectional strings as described in
   section 6 of RFC 3454 [1].















































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7. Security Considerations

   The Unicode and ISO/IEC 10646 repertoires have many characters that
   look similar. In many cases, users of security protocols might do
   visual matching, such as when comparing the names of trusted third
   parties.  Because it is impossible to map similar-looking characters
   without a great deal of context such as knowing the fonts used,
   stringprep does nothing to map similar-looking characters together
   nor to prohibit some characters because they look like others.

   A resource identifier can be employed as one part of an entity's
   address in XMPP. One common usage is as the name for an instant
   messaging user's active session; another is as the nickname of a user
   in a multi-user chat room; and many other kinds of entities could use
   resource identifiers as part of their addresses. The security of such
   services could be compromised based on different interpretations of
   the internationalized resource identifier; for example, a user could
   attempt to initiate multiple sessions with the same name, or a user
   could send a message to someone other than the intended recipient in
   a multi-user chat room.































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8. IANA Considerations

   This is a profile of stringprep. If and when it becomes an RFC, it
   should be registered in the stringprep profile registry maintained by
   the IANA [4].

   Name of this profile:

      Resourceprep

   RFC in which the profile is defined:

      This document

   Indicator whether or not this is the newest version of the profile:

      This is the first version of Resourceprep


































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Normative References

   [1]  Hoffman, P. and M. Blanchet, "Preparation of Internationalized
        Strings ("stringprep")", RFC 3454, December 2002.

   [2]  Saint-Andre, P. and J. Miller, "XMPP Core",
        draft-ietf-xmpp-core-13 (work in progress), June 2003.

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

   [4]  Internet Assigned Numbers Authority, "Internet Assigned Numbers
        Authority", January 1998, <http://www.iana.org/>.


Authors' Addresses

   Peter Saint-Andre
   Jabber Software Foundation

   EMail: stpeter@jabber.org
   URI:   http://www.jabber.org/people/stpeter.php


   Joe Hildebrand
   Jabber, Inc.

   EMail: jhildebrand@jabber.com
   URI:   http://www.jabber.org/people/hildjj.php






















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Appendix A. Revision History

   Note to RFC Editor: please remove this entire appendix, and the
   corresponding entries in the table of contents, prior to publication.

A.1 Changes from draft-ietf-xmpp-resourceprep-02

   o  Provided additional examples of resource identifier usage.

   o  Made several small editorial changes.


A.2 Changes from draft-ietf-xmpp-resourceprep-01

   o  Made small editorial changes to address RFC Editor requirements.


A.3 Changes from draft-ietf-xmpp-resourceprep-00

   o  Clarified references to Unicode 3.2 and unassigned code points.

   o  Corrected normalization routine.

   o  Removed reference to section B.2 of RFC 3454 (no case folding
      required).


























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Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
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   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard. Please address the information to the IETF Executive
   Director.


Full Copyright Statement

   Copyright (C) The Internet Society (2003). All Rights Reserved.

   This document and translations of it may be copied and furnished to
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   The limited permissions granted above are perpetual and will not be
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   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION



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   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Acknowledgement

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











































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