Network Working Group                                        Y. Bernet
Request for Comments: 2872                                  R. Pabbati
Category: Standards Track                                    Microsoft
                                                             June 2000

      Application and Sub Application Identity Policy Element for
                             Use with RSVP

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Conventions used in this document

   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 [RFC2119].

Abstract

   RSVP [RFC 2205] signaling messages typically include policy data
   objects, which in turn contain policy elements. Policy elements may
   describe user and/or application information, which may be used by
   RSVP aware network elements to apply appropriate policy decisions to
   a traffic flow. This memo details the usage of policy elements that
   provide application information.

1. Overview

   RSVP aware network elements may act as policy enforcement points
   (PEPs). These work together with policy decision points (PDPs) to
   enforce QoS policy. Briefly, PEPs extract policy information from
   RSVP signaling requests and compare the information against
   information stored by a PDP in a (possibly remotely located) policy
   database or directory. A policy decision is made based on the results
   of the comparison.

   One type of policy information describes the application on behalf of
   which an RSVP signaling request is generated. When application policy
   information is available, network administrators are able to manage
   QoS based on application type. So, for example, a network
   administrator may establish a policy that prioritizes known mission-
   critical applications over games.

   This memo describes a structure for a policy element that can be used
   to identify application traffic flows. The policy element includes a
   number of attributes, one of which is a policy locator. This policy
   locator includes the following hierarchically ordered sub-elements
   (in descending levels of hierarchy):

      1. identifier that uniquely identifies the application vendor
      2. identifier of the application
      3. version number of the application
      4. sub-application identifier

   An arbitrary number of sub-application identifiers may be included in
   the policy locator. An example of such an identifier is 'print
   transaction'.

   This memo specifies the structure of the application policy element
   and proposes keywords for the sub-elements at each level of the
   hierarchy. It does not enumerate specific values for the sub-
   elements: such an enumeration is beyond the scope of this memo.

2. Simple Application Identity Policy Element Structure

   General application identity policy elements are defined in
   [RFC2752]. These are policy elements with a P-type of AUTH_APP.
   Following the policy element header is a list of authentication
   attributes.

   The first authentication attribute is of the A-type POLICY_LOCATOR.
   The sub-type of the POLICY_LOCATOR attribute is of type ASCII_DN
   [RFC1779] or UNICODE_DN. The actual attribute data is formatted as an
   X.500 distinguished name (DN), representing a globally unique
   identifier, the application, version number and sub-application in a
   hierarchical structure. The POLICY_LOCATOR attribute contains
   keywords as described in section 2. For further details on the format
   of the POLICY_LOCATOR attribute, see [RFC2752].

   The second authentication attribute is of the A-type CREDENTIAL. The
   sub-type of the CREDENTIAL attribute is of type ASCII_ID or
   UNICODE_ID. The actual attribute data is an ASCII or Unicode string
   representing the application name. This structure is illustrated in
   the following diagram:

               0              1               2               3
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    PE Length (8)              |   P-type = AUTH_APP           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Attribute Length           |   A-type =    |  Sub-type =   |
      |                               | POLICY_LOCATOR|   ASCII_DN    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Application policy locator attribute data in X.500 DN format  |
      |                         (see below)                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Attribute Length           |   A-type =    |  Sub-type =   |
      |                               |   CREDENTIAL  |   ASCII_ID    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 Application name as ASCII string              |
      |                         (e.g. SAP.EXE)                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The following keywords are recommended although others MAY be used:

   Key  Attribute
   --------------
   GUID Globally Unique Identifier (optional)
   APP  Application Name
   VER  Application Version Number
   SAPP Sub Application (optional)

   The following are examples of conformant policy locators:

   "APP=SAP, VER=1.1, SAPP=Print"

   "GUID=http://www.microsoft.com/apps, APP=MyApplication, VER=1.2.3"

   The APP, VER and SAPP attributes SHOULD describe the application to a
   human reader in as unique and unambiguous a way as possible. The GUID
   attribute MAY be used when absolute uniqueness of application
   identification is required and its contents MUST be an identifier
   from a globally-unique source (e.g. domain names as assigned by the
   corresponding registration authorities). Note that publication of the
   chosen identifiers in a suitable format is strongly encouraged.

3. Security Considerations

   The proposed simple policy element does not guarantee that element is
   indeed associated with the application it claims to be associated
   with. In order to provide such guarantees, it is necessary to sign
   applications. Signed application policy elements may be proposed at a
   future date. Note that, typically, the application policy element
   will be included in an RSVP message with an encrypted and
   authenticated user policy element. A level of security is provided by
   trusting the application policy element only if the user policy
   element is trusted.

   All RSVP integrity considerations apply to the message containing the
   application policy element.

4. References

   [RFC2205] Braden, R., Zhang, L., Berson, L., Herzog, S. and S. Jamin,
             "Resource Reservation Protocol (RSVP) - Version 1
             Functional Specification", RFC 2205, September 1997.

   [RFC1779] Kille, S., "A String Representation of Distinguished
             Names", RFC 1779, March 1995.

   [RFC2752] Yadav, S., Yavatkar, R., Pabbati, R,. Ford, P., Moore, T.
             and S. Herzog, "Identity Representation for RSVP", RFC
             2752, January 2000.

   [ASCII]   Coded Character Set -- 7-Bit American Standard Code for
             Information Interchange, ANSI X3.4-1986.

   [UNICODE] The Unicode Consortium, "The Unicode Standard, Version
             2.0", Addison-Wesley, Reading, MA, 1996.

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

5.  Acknowledgments

   Thanks to Tim Moore, Shai Mohaban, Andrew Smith, Ulrich Homann and
   other contributors to the IETF's RAP WG for their input.

6. Authors' Addresses

   Yoram Bernet
   Microsoft
   One Microsoft Way
   Redmond, WA 98052

   Phone: (425) 936-9568
   EMail: yoramb@microsoft.com

   Ramesh Pabbati
   One Microsoft Way
   Redmond, WA 98052

   EMail: rameshpa@microsoft.com

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   Copyright (C) The Internet Society (2000).  All Rights Reserved.

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Acknowledgement

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