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GEOPRIV                                              H. Schulzrinne, Ed.
Internet-Draft                                       Columbia University
Intended status: Standards Track                      H. Tschofenig, Ed.
Expires: December 17, 2008                        Nokia Siemens Networks
                                                               J. Morris
                                                                     CDT
                                                              J. Cuellar
                                                                 Siemens
                                                                 J. Polk
                                                                   Cisco
                                                           June 15, 2008


Geolocation Policy: A Document Format for Expressing Privacy Preferences
                        for Location Information
                    draft-ietf-geopriv-policy-16.txt

Status of this Memo

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   This Internet-Draft will expire on December 17, 2008.










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Abstract

   This document defines an authorization policy language for
   controlling access to location information.  It extends the Common
   Policy authorization framework to provide location-specific access
   control.  More specifically, this document defines condition elements
   specific to location information in order to restrict access based on
   the current location of the Target.  Furthermore, it offers location-
   specific transformation elements to reduce the granularity of the
   returned location information.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  6
   3.  Generic Processing . . . . . . . . . . . . . . . . . . . . . .  8
     3.1.  Structure of Geolocation Authorization Documents . . . . .  8
     3.2.  Rule Transport . . . . . . . . . . . . . . . . . . . . . .  8
   4.  Location-specific Conditions . . . . . . . . . . . . . . . . .  9
     4.1.  Geodetic Location Condition Profile  . . . . . . . . . . .  9
     4.2.  Civic Location Condition Profile . . . . . . . . . . . . . 10
   5.  Actions  . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
   6.  Transformations  . . . . . . . . . . . . . . . . . . . . . . . 12
     6.1.  Set Retransmission-Allowed . . . . . . . . . . . . . . . . 12
     6.2.  Set Retention-Expiry . . . . . . . . . . . . . . . . . . . 12
     6.3.  Set Note-Well  . . . . . . . . . . . . . . . . . . . . . . 12
     6.4.  Keep Ruleset Reference . . . . . . . . . . . . . . . . . . 13
     6.5.  Provide Location . . . . . . . . . . . . . . . . . . . . . 13
       6.5.1.  Civic Location Profile . . . . . . . . . . . . . . . . 14
       6.5.2.  Geodetic Location Profile  . . . . . . . . . . . . . . 15
   7.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     7.1.  Rule Example with Civic Location Condition . . . . . . . . 16
     7.2.  Rule Example with Geodetic Location Condition  . . . . . . 17
     7.3.  Rule Example with Civic and Geodetic Location Condition  . 17
     7.4.  Rule Example with Location-based Transformations . . . . . 18
   8.  XML Schema for Basic Location Profiles . . . . . . . . . . . . 20
   9.  XML Schema for Geolocation Policy  . . . . . . . . . . . . . . 21
   10. XCAP Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 23
     10.1. Application Unique ID  . . . . . . . . . . . . . . . . . . 23
     10.2. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . 23
     10.3. Default Namespace  . . . . . . . . . . . . . . . . . . . . 23
     10.4. MIME Type  . . . . . . . . . . . . . . . . . . . . . . . . 23
     10.5. Validation Constraints . . . . . . . . . . . . . . . . . . 23
     10.6. Data Semantics . . . . . . . . . . . . . . . . . . . . . . 23
     10.7. Naming Conventions . . . . . . . . . . . . . . . . . . . . 23
     10.8. Resource Interdependencies . . . . . . . . . . . . . . . . 24
     10.9. Authorization Policies . . . . . . . . . . . . . . . . . . 24



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   11. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 25
     11.1. Geolocation Policy XML Schema Registration . . . . . . . . 25
     11.2. Geolocation Policy Namespace Registration  . . . . . . . . 25
     11.3. Geolocation Policy Location Profile Registry . . . . . . . 26
     11.4. Basic Location Profile XML Schema Registration . . . . . . 26
     11.5. Basic Location Profile Namespace Registration  . . . . . . 27
     11.6. XCAP Application Usage ID  . . . . . . . . . . . . . . . . 27
   12. Security Considerations  . . . . . . . . . . . . . . . . . . . 29
   13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 30
     13.1. Normative References . . . . . . . . . . . . . . . . . . . 30
     13.2. Informative References . . . . . . . . . . . . . . . . . . 30
   Appendix A.  Acknowledgments . . . . . . . . . . . . . . . . . . . 32
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33
   Intellectual Property and Copyright Statements . . . . . . . . . . 35





































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1.  Introduction

   Location information needs to be protected against unauthorized
   access to preserve the privacy of humans.  In RFC 3693 [7], a
   protocol-independent model for access to geographic information is
   defined.  The model includes a Location Generator (LG) that
   determines location information, a Location Server (LS) that
   authorizes access to location information, a Location Recipient (LR)
   that requests and receives location information, and a Rule Maker
   (RM) that writes authorization policies.  An authorization policy is
   a set of rules that regulates an entity's activities with respect to
   privacy-sensitive information, such as location information.

   The data object containing location information in the context of
   this document is referred to as a Location Object (LO).  The basic
   rule set defined in the Presence Information Data Format Location
   Object (PIDF-LO) [8] can restrict how long the Location Recipient is
   allowed to retain the information, and it can prohibit further
   distribution.  It also contains a reference to an enhanced rule set
   and a human readable privacy policy.  The basic rule set, however,
   does not allow to control access to location information based on
   specific Location Recipients.  This document describes an enhanced
   rule set that provides richer constraints on the distribution of LOs.

   The rule set allows the entity that uses the rules defined in this
   document to restrict the retention and to enforce access restrictions
   on location data, including prohibiting any dissemination to
   particular individuals, during particular times or when the Target is
   located in a specific region.  The RM can also stipulate that only
   certain parts of the Location Object are to be distributed to
   recipients or that the resolution of parts of the Location Object is
   reduced.

   The typical sequence of operations is as follows.  A Location Server
   receives a query for location information for a particular Target,
   via the using protocol [7].  The using protocol provides the identity
   of the requestor, either at the time of the query or when subscribing
   to the location information.  The authenticated identity of the
   Location Recipient, together with other information provided by the
   using protocol or generally available to the server, is then used for
   searching through the rule set.  If more than one rule matches the
   condition element, then the combined permission is evaluated
   according to the description in Section 10 of [1].  The result of the
   rule evalation is applied to the location information, yielding a
   possibly modified Location Object that is delivered to the Location
   Recipient.

   This document does not describe the protocol used to convey location



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   information from the Location Server to the Location Recipient (i.e.,
   the using protocol; see RFC 3693 [7]).

   This document extends the Common Policy framework defined in [1].
   That document provides an abstract framework for expressing
   authorization rules.  As specified there, each such rule consists of
   conditions, actions and transformations.  Conditions determine under
   which circumstances the entity executing the rules, for example a
   Location Server, is permitted to apply actions and transformations.
   Transformations regulate in a location information context how a
   Location Server modifies the information elements that are returned
   to the requestor, for example, by reducing the granularity of
   returned location information.

   The XML schema defined in Section 9 extends the Common Policy schema
   by introducing new child elements to the condition and transformation
   elements.  This document does not define child elements for the
   action part of a rule.

































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2.  Terminology

   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 [2].

   This document reuses the terminology of RFC 3693 [7], such as
   Location Server (LS), Location Recipient (LR), Rule Maker (RM),
   Target, Location Generator (LG) and Location Object (LO).  This
   document uses the following terminology:

   Presentity or Target:

      RFC 3693 [7] uses the term Target to identify the object or person
      of which location information is required.  The presence model
      described in RFC 2778 [9] uses the term presentity to describe the
      entity that provides presence information to a presence service.
      A Presentity in a presence system is a Target in a location
      information system.


   Watcher or Location Recipient:

      The receiver of location information is the Location Recipient
      (LR) in the terminology of RFC 3693 [7].  A watcher in a presence
      system, i.e., an entity that requests presence information about a
      presentity, is a Location Recipient in a location information
      system.


   Authorization policy:

      An authorization policy is given by a rule set.  A rule set
      contains an unordered list of (policy) rules.  Each rule has a
      condition, an action and a transformation component.


   Permission:

      The term permission refers to the action and transformation
      components of a rule.

   The term 'using protocol' is defined in [7] and refers to the
   protocol that is used to request access to and to return privacy
   sensitive data items.

   In this document we use the term Location Servers as the entities
   that evaluate the geolocation authorization policies.  The



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   geolocation privacy architecture is, as motivated in RFC 4079 [10],
   aligned with the presence architecture and a Presence Server is
   therefore an entity that distributes location information along with
   other presence-specific XML data elements.















































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3.  Generic Processing

3.1.  Structure of Geolocation Authorization Documents

   A geolocation authorization document is an XML document, formatted
   according to the schema defined in [1].  Geolocation authorization
   documents inherit the MIME type of common policy documents,
   application/auth-policy+xml.  As described in [1], this document is
   composed of rules which contain three parts - conditions, actions,
   and transformations.  Each action or transformation, which is also
   called a permission, has the property of being a positive grant of
   information to the Location Recipient.  As a result, there is a well-
   defined mechanism for combining actions and transformations obtained
   from several sources.  This mechanism is privacy safe, since the lack
   of any action or transformation can only result in less information
   being presented to a Location Recipient.

3.2.  Rule Transport

   There are two ways how the authorization rules described in this
   document may be conveyed between different parties:

   o  RFC 4119 [8] allows enhanced authorization policies to be
      referenced via a Uniform Resource Locator (URL) in the 'ruleset-
      reference' element.  The ruleset-reference' element is part of the
      basic rules that always travel with the Location Object.

   o  Authorization policies might, for example, also be stored at a
      Location Server / Presence Server.  The Rule Maker therefore needs
      to use a protocol to create, modify and delete the authorization
      policies defined in this document.  Such a protocol is available
      with the Extensible Markup Language (XML) Configuration Access
      Protocol (XCAP) [11].


















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4.  Location-specific Conditions

   This section describes the location-specific conditions of a rule,
   namely the civic and geodetic location conditions.  The <conditions>
   element contains zero, one or an unbounded number of <location-
   condition> child element(s).  Providing more than one <location-
   condition> child element may not be useful since all child elements
   of the <conditions> element must evaluate to TRUE in order for the
   <conditions> element to be TRUE.  The <location-condition> element
   MUST contain at least one <location> child element.  The <location-
   condition> element evaluates to TRUE if any of its child elements is
   TRUE, i.e., a logical OR.

   A location profile needs to describe under what conditions each
   <location> element evaluates to TRUE.  This document defines two
   location profiles, one civic and one geodetic location profile.

   The <location-condition> and the <location> elements provide
   extension points.  If an extension is not understood by the entity
   evaluating the rules then this rule evaluates to FALSE.

4.1.  Geodetic Location Condition Profile

   The geodetic location profile is identified by the token 'geodetic-
   condition'.  Rule Makers use this profile by placing a GML [3]
   <Circle> element within the <location> element (as described in
   Section 5.2.3 of [4]).

   The <location> element containing the information for the geodetic
   location profile evaluates to TRUE if the current location of the
   Target is within the described location.  Note that the Target's
   actual location might be represented by any of the location shapes
   described in [4].  If the geodetic location of the Target is unknown
   then the <location> element containing the information for the
   geodetic location profile evaluates to FALSE.

   Implementations are REQUIRED to support the following coordinate
   reference system based on WGS 84 [5] based on the European Petroleum
   Survey Group (EPSG) Geodetic Parameter Dataset (as formalized by the
   Open Geospatial Consortium (OGC)):

   2D:  WGS 84 (latitude, longitude), as identified by the URN
      "urn:ogc:def:crs:EPSG::4326".  This is a two dimensional CRS.

   A CRS MUST be specified using the above URN notation only,
   implementations do not need to support user-defined CRSs.

   Implementations MUST specify the CRS using the "srsName" attribute on



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   the outermost geometry element.  The CRS MUST NOT be changed for any
   sub-elements.  The "srsDimension" attribute MUST be omitted, since
   the number of dimensions in these CRSs is known.

4.2.  Civic Location Condition Profile

   The civic location profile is identified by the token 'civic-
   condition'.  Rule Makers use this profile by placing a <civicAddress>
   element, defined in [6], within the <location> element.

   All child elements of <location> element that carry civicAddress
   elements MUST evaluate to TRUE (i.e., logical AND) in order for the
   <location> element to evaluate to TRUE.  For each child element, the
   value of that element is compared to the value of the same element in
   the Target's civic location.  The child element evaluates to TRUE if
   the two values are identical based on a bit-by-bit comparison.

   If the civic location of the Target is unknown, then the <location>
   element containing the information for the civic location profile
   evaluates to FALSE.  This case may occur, for example, if location
   information has been removed by earlier transmitters of location
   information or if only the geodetic location is known.  In general,
   it is RECOMMENDED behavior for a LS not to apply a translation from
   geodetic location to civic location (i.e., geocode the location).



























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5.  Actions

   This document does not define location-specific actions.
















































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6.  Transformations

   This document defines several elements that allow Rule Makers to
   specify transformations that

   o  reduce the accuracy of the returned location information, and

   o  set the basic authorization policies carried inside the PIDF-LO.

6.1.  Set Retransmission-Allowed

   This element asks the LS to change or set the value of the
   <retransmission-allowed> element in the PIDF-LO.  The data type of
   the <set-retransmission-allowed> element is a boolean.

   If the value of the <set-retransmission-allowed> element is set to
   TRUE then the <retransmission-allowed> element in the PIDF-LO MUST be
   set to TRUE.  If the value of the <set-retransmission-allowed>
   element is set to FALSE, then the <retransmission-allowed> element in
   the PIDF-LO MUST be set to FALSE.

   If the <set-retransmission-allowed> element is absent then the value
   of the <retransmission-allowed> element in the PIDF-LO MUST be kept
   unchanged or, if the PIDF-LO is created for the first time, then the
   value MUST be set to FALSE.

6.2.  Set Retention-Expiry

   This transformation asks the LS to change or set the value of the
   <retention-expiry> element in the PIDF-LO.  The data type of the
   <set-retention-expiry> element is an integer.

   The value provided with the <set-retention-expiry> element indicates
   seconds and these seconds are added to the current date.

   If the <set-retention-expiry> element is absent then the value of the
   <retention-expiry> element in the PIDF-LO is kept unchanged or, if
   the PIDF-LO is created for the first time, then the value MUST be set
   to the current date.

6.3.  Set Note-Well

   This transformation asks the LS to change or set the value of the
   <note-well> element in the PIDF-LO.  The data type of the <set-note-
   well> element is a string.

   The value provided with the <set-note-well> element contains a
   privacy statement as a human readable text string and an 'xml:lang'



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   attribute denotes the language of the human readable text.

   If the <set-note-well> element is absent, then the value of the
   <note-well> element in the PIDF-LO is kept unchanged or, if the
   PIDF-LO is created for the first time, then no content is provided
   for the <note-well> element.

6.4.  Keep Ruleset Reference

   This transformation allows to influence whether the <external-
   ruleset> element in the PIDF-LO carries the extended authorization
   rules defined in [1].  The data type of the <keep-rule-reference>
   element is Boolean.

   If the value of the <keep-rule-reference> element is set to TRUE,
   then the <external-ruleset> element in the PIDF-LO is kept unchanged
   when included.  If the value of the <keep-rule-reference> element is
   set to FALSE, then the <external-ruleset> element in the PIDF-LO MUST
   NOT contain a reference to an external rule set.  The reference to
   the ruleset is removed and no rules are carried as MIME bodies (in
   case of CID URIs).

   If the <keep-rule-reference> element is absent, then the value of the
   <external-ruleset> element in the PIDF-LO is kept unchanged when
   available or, if the PIDF-LO is created for the first time then the
   <external-ruleset> element MUST NOT be included.

6.5.  Provide Location

   The <provide-location> element contains child elements of a specific
   location profile that controls the granularity of returned location
   information.  This document defines two location profiles, namely:


   o  If the <provide-location> element has a <provide-civic> child
      element then civic location information is disclosed as described
      in Section 6.5.1, subject to availability.


   o  If the <provide-location> element has a <provide-geo> child
      element then geodetic location information is disclosed as
      described in Section 6.5.2, subject to availability.


   The <provide-location> element MUST contain the 'profile' attribute
   if it contains child elements and the 'profile' attribute MUST match
   with the contained child elements.  The <provide-location> element
   MUST contain the 'profile' attribute if it contains child elements.



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   If the <provide-location> element has no child elements then civic,
   as well as, geodetic location information is disclosed without
   reducing its granularity, subject to availability.  In this case the
   profile attribute MUST NOT be included.

6.5.1.  Civic Location Profile

   This profile uses the token 'civic-transformation'.  This profile
   allows civic location transformations to be specified by means of the
   <provide-civic> element that restricts the level of civic location
   information the LS is permitted to disclose.  The symbols of these
   levels are: 'country', 'region', 'city', 'building', 'full'.  Each
   level is given by a set of civic location data items such as
   <country> and <A1>, ..., <POM>, as defined in [6].  Each level
   includes all elements included by the lower levels.

   The 'country' level includes only the <country> element; the 'region'
   level adds the <A1> element; the 'city' level adds the <A2> and <A3>
   elements; the 'building' level and the 'full' level add further civic
   location data as shown below.


                              full
      {<country>, <A1>, <A2>, <A3>, <A4>, <A5>, <A6>, <PRD>, <POD>,
       <STS>, <HNO>, <HNS>, <LMK>, <LOC>, <PC>, <NAM>, <FLR>,
       <BLD>,<UNIT>,<ROOM>,<PLC>, <PCN>, <POBOX>, <ADDCODE>, <SEAT>
       <RD>, <RDSEC>, <RDBR>, <RDSUBBR>, <PRM>, <POM>}
                               |
                               |
                            building
         {<country>, <A1>, <A2>, <A3>, <A4>, <A5>, <A6>, <PRD>
         <POD>, <STS>, <HNO>, <HNS>, <LMK>, <PC>,
         <RD>, <RDSEC>, <RDBR>, <RDSUBBR> <PRM>, <POM>}
                               |
                               |
                             city
                     {<country>, <A1>, <A2>, <A3>}
                               |
                               |
                             region
                        {<country>, <A1>}
                               |
                               |
                            country
                          {<country>}
                               |
                               |
                              none



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                              {}

   The default value is "none".

   The schema of the <provide-civic> element is defined in Section 8.

6.5.2.  Geodetic Location Profile

   This profile uses the token 'geodetic-transformation' and refers only
   to the Coordinate Reference System (CRS) WGS 84
   (urn:ogc:def:crs:EPSG::4326, 2D).  This profile allows geodetic
   location transformations to be specified by means of the <provide-
   geo> element that may restrict the returned geodetic location
   information based on the value provided in the 'radius' attribute.
   The value of the 'radius' attribute expresses the radius in meters.

   The schema of the <provide-geo> element is defined in Section 8.

   For each rule in the policy specification containing a <provide-geo>
   element, the LS chooses a circle with a radius F given by the
   'radius' attribute of the <provide-geo> element.  The center of the
   circle is chosen randomly, under the constraint that the circle MUST
   contain the Target's location, which may be a point or another
   location shape.  In response to queries matching this rule, the LS
   MUST return a shape containing this circle; while the returned shape
   may change from one query to another, the chosen circle remains
   constant.  An LS may, for example, store the location of the center
   or compute it based on a hash function that includes the target's
   identity.

   The above-described procedure aims to satisfy the following design
   goals:

   1.  The circle returned must contain the actual location of the
       Target.

   2.  In general, no point in the circle must be more likely than
       others to contain the Target.

   3.  Repeated queries must not reveal the likely location of the
       Target.










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7.  Examples

   This section provides a few examples for authorization rules using
   the extensions defined in this document.

7.1.  Rule Example with Civic Location Condition

   This example illustrates a single rule that employs the civic
   location condition.  It matches if the current location of the Target
   equal the content of the child elements of the <location> element.
   Requests match only if the Target is at a civic location with country
   set to 'Germany', state (A1) set to 'Bavaria', city (A3) set to
   'Munich', city division (A4) set to 'Perlach', street name (A6) set
   to 'Otto-Hahn-Ring' and house number (HNO) set to '6'.

   No actions and transformation child elements are provided in this
   rule example.  The actions and transformation could include presence
   specific information when the Geolocation Policy framework is applied
   to the Presence Policy framework (see [12]).


   <?xml version="1.0" encoding="UTF-8"?>
   <ruleset xmlns="urn:ietf:params:xml:ns:common-policy"
     xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy">

     <rule id="AA56i09">
       <conditions>
         <gp:location-condition>
           <gp:location profile="civic-condition"
             xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
             <country>DE</country>
             <A1>Bavaria</A1>
             <A3>Munich</A3>
             <A4>Perlach</A4>
             <A6>Otto-Hahn-Ring</A6>
             <HNO>6</HNO>
           </gp:location>
         </gp:location-condition>
       </conditions>
       <actions/>
       <transformations/>
     </rule>
   </ruleset>








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7.2.  Rule Example with Geodetic Location Condition

   This example illustrates a rule that employs the geodetic location
   condition.  The rule matches if the current location of the Target is
   inside the area specified by the polygon.  The polygon uses the EPSG
   4326 coordinate reference system.  No altitude is included in this
   example.


   <?xml version="1.0" encoding="UTF-8"?>
   <ruleset
     xmlns="urn:ietf:params:xml:ns:common-policy"
     xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy"
     xmlns:gml="http://www.opengis.net/gml"
     xmlns:gs="http://www.opengis.net/pidflo/1.0">

     <rule id="BB56A19">
       <conditions>
         <gp:location-condition>
           <gp:location profile="geodetic-condition">
             <gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
               <gml:pos>-34.410649 150.87651</gml:pos>
               <gs:radius uom="urn:ogc:def:uom:EPSG::9001">1500
               </gs:radius>
             </gs:Circle>
           </gp:location>
         </gp:location-condition>
       </conditions>
       <transformations/>
     </rule>
   </ruleset>

7.3.  Rule Example with Civic and Geodetic Location Condition

   This example illustrates a rule that employs a mixed civic and
   geodetic location condition.  Depending on the available type of
   location information, namely civic or geodetic location information,
   one of the location elements may match.













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   <?xml version="1.0" encoding="UTF-8"?>
   <ruleset
     xmlns="urn:ietf:params:xml:ns:common-policy"
     xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy"
     xmlns:gml="http://www.opengis.net/gml"
     xmlns:gs="http://www.opengis.net/pidflo/1.0">

     <rule id="AA56i09">
       <conditions>
         <gp:location-condition>
           <gp:location profile="civic-condition"
             xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
             <country>DE</country>
             <A1>Bavaria</A1>
             <A3>Munich</A3>
             <A4>Perlach</A4>
             <A6>Otto-Hahn-Ring</A6>
             <HNO>6</HNO>
           </gp:location>
           <gp:location profile="geodetic-condition">
             <gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
                <gml:pos>-34.410649 150.87651</gml:pos>
                <gs:radius uom="urn:ogc:def:uom:EPSG::9001">1500
                </gs:radius>
             </gs:Circle>
           </gp:location>
         </gp:location-condition>
       </conditions>
       <actions/>
       <transformations/>
     </rule>
   </ruleset>

7.4.  Rule Example with Location-based Transformations

   This example shows the transformations specified in this document.
   The <provide-civic> element indicates that the available civic
   location information is reduced to building level granularity.  If
   geodetic location information is requested then a granularity
   reduction is provided as well.











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   <?xml version="1.0" encoding="UTF-8"?>
   <ruleset xmlns="urn:ietf:params:xml:ns:common-policy"
     xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy"
     xmlns:lp="urn:ietf:params:xml:ns:basic-location-profiles">

     <rule id="AA56i09">
       <conditions/>
       <actions/>
       <transformations>
         <gp:set-retransmission-allowed>false
         </gp:set-retransmission-allowed>
         <gp:set-retention-expiry>86400</gp:set-retention-expiry>
         <gp:set-note-well xml:lang="en">My privacy policy goes in here.
         </gp:set-note-well>
         <gp:keep-rule-reference>false
         </gp:keep-rule-reference>

         <gp:provide-location
           profile="civic-transformation">
           <lp:provide-civic>building</lp:provide-civic>
         </gp:provide-location>

         <gp:provide-location
           profile="geodetic-transformation">
           <lp:provide-geo radius="500"/>
         </gp:provide-location>

       </transformations>
     </rule>
   </ruleset>

   The following rule describes the short-hand notation for making the
   current location of the Target available to Location Recipients
   without granularity reduction.


   <?xml version="1.0" encoding="UTF-8"?>
   <ruleset xmlns="urn:ietf:params:xml:ns:common-policy"
       xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy">

       <rule id="AA56ia9">
           <conditions/>
           <actions/>
           <transformations>
               <gp:provide-location/>
           </transformations>
       </rule>
   </ruleset>



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8.  XML Schema for Basic Location Profiles

   This section defines the location profiles used as child elements of
   the transformation element.


   <?xml version="1.0" encoding="UTF-8"?>
   <xs:schema
       targetNamespace="urn:ietf:params:xml:ns:basic-location-profiles"
       xmlns:xs="http://www.w3.org/2001/XMLSchema"
       elementFormDefault="qualified"
       attributeFormDefault="unqualified">

       <!-- profile="civic-transformation" -->

       <xs:element name="provide-civic" default="none">
           <xs:simpleType>
               <xs:restriction base="xs:string">
                   <xs:enumeration value="full"/>
                   <xs:enumeration value="building"/>
                   <xs:enumeration value="city"/>
                   <xs:enumeration value="region"/>
                   <xs:enumeration value="country"/>
                   <xs:enumeration value="none"/>
               </xs:restriction>
           </xs:simpleType>
       </xs:element>

       <!-- profile="geodetic-transformation" -->

       <xs:element name="provide-geo">
           <xs:complexType>
               <xs:attribute name="radius" type="xs:integer"/>
           </xs:complexType>
       </xs:element>

   </xs:schema>














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9.  XML Schema for Geolocation Policy

   This section presents the XML schema that defines the Geolocation
   Policy schema described in this document.  The Geolocation Policy
   schema extends the Common Policy schema (see [1]).


   <?xml version="1.0" encoding="UTF-8"?>
   <xs:schema
     targetNamespace="urn:ietf:params:xml:ns:geolocation-policy"
     xmlns:gp="urn:ietf:params:xml:ns:geolocation-policy"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     elementFormDefault="qualified"
     attributeFormDefault="unqualified">

     <!-- Import Common Policy-->
     <xs:import namespace="urn:ietf:params:xml:ns:common-policy"/>

     <!-- This import brings in the XML language attribute xml:lang-->
     <xs:import namespace="http://www.w3.org/XML/1998/namespace"
       schemaLocation="http://www.w3.org/2001/xml.xsd"/>

     <!-- Geopriv Conditions -->

     <xs:element name="location-condition"
       type="gp:locationconditionType"/>

     <xs:complexType name="locationconditionType">
       <xs:complexContent>
           <xs:restriction base="xs:anyType">
             <xs:choice minOccurs="1" maxOccurs="unbounded">
               <xs:element name="location" type="gp:locationType"
                 minOccurs="1" maxOccurs="unbounded"/>
               <xs:any namespace="##other" processContents="lax"
                 minOccurs="0" maxOccurs="unbounded"/>
             </xs:choice>
           </xs:restriction>
         </xs:complexContent>
     </xs:complexType>

     <xs:complexType name="locationType">
       <xs:complexContent>
         <xs:restriction base="xs:anyType">
           <xs:choice minOccurs="1" maxOccurs="unbounded">
             <xs:any namespace="##other" processContents="lax"
               minOccurs="0" maxOccurs="unbounded"/>
           </xs:choice>
           <xs:attribute name="profile" type="xs:string"/>



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         </xs:restriction>
       </xs:complexContent>
     </xs:complexType>

     <!-- Geopriv transformations -->
     <xs:element name="set-retransmission-allowed"
       type="xs:boolean" default="false"/>
     <xs:element name="set-retention-expiry"
       type="xs:integer" default="0"/>
     <xs:element name="set-note-well"
       type="gp:notewellType"/>
     <xs:element name="keep-rule-reference"
       type="xs:boolean" default="false"/>

     <xs:element name="provide-location"
       type="gp:providelocationType"/>

     <xs:complexType name="notewellType">
       <xs:simpleContent>
         <xs:extension base="xs:string">
           <xs:attribute ref="xml:lang" />
         </xs:extension>
       </xs:simpleContent>
     </xs:complexType>


     <xs:complexType name="providelocationType">
       <xs:complexContent>
         <xs:restriction base="xs:anyType">
           <xs:choice minOccurs="0" maxOccurs="unbounded">
           <xs:any namespace="##other" processContents="lax"
             minOccurs="0" maxOccurs="unbounded"/>
           </xs:choice>
           <xs:attribute name="profile" type="xs:string" />
         </xs:restriction>
       </xs:complexContent>
     </xs:complexType>

   </xs:schema>












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10.  XCAP Usage

   The following section defines the details necessary for clients to
   manipulate geolocation privacy documents from a server using XCAP.
   If used as part of a presence system, it uses the same AUID as those
   rules.  See [12] for a description of the XCAP usage in context with
   presence authorization rules.

10.1.  Application Unique ID

   XCAP requires application usages to define a unique application usage
   ID (AUID) in either the IETF tree or a vendor tree.  This
   specification defines the "geolocation-policy" AUID within the IETF
   tree, via the IANA registration in Section 11.

10.2.  XML Schema

   XCAP requires application usages to define a schema for their
   documents.  The schema for geolocation authorization documents is
   described in Section 9.

10.3.  Default Namespace

   XCAP requires application usages to define the default namespace for
   their documents.  The default namespace is
   urn:ietf:params:xml:ns:geolocation-policy.

10.4.  MIME Type

   XCAP requires application usages to defined the MIME type for
   documents they carry.  Geolocation privacy authorization documents
   inherit the MIME type of common policy documents, application/
   auth-policy+xml.

10.5.  Validation Constraints

   This specification does not define additional constraints.

10.6.  Data Semantics

   This document discusses the semantics of a geolocation privacy
   authorization.

10.7.  Naming Conventions

   When a Location Server receives a request to access location
   information of some user foo, it will look for all documents within
   http://[xcaproot]/geolocation-policy/users/foo, and use all documents



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   found beneath that point to guide authorization policy.

10.8.  Resource Interdependencies

   This application usage does not define additional resource
   interdependencies.

10.9.  Authorization Policies

   This application usage does not modify the default XCAP authorization
   policy, which is that only a user can read, write or modify his/her
   own documents.  A server can allow privileged users to modify
   documents that they do not own, but the establishment and indication
   of such policies is outside the scope of this document.





































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11.  IANA Considerations

   There are several IANA considerations associated with this
   specification.

11.1.  Geolocation Policy XML Schema Registration

   URI:  urn:ietf:params:xml:schema:geolocation-policy

   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@nsn.com).

   XML:  The XML schema to be registered is contained in Section 9.  Its
      first line is

   <?xml version="1.0" encoding="UTF-8"?>

      and its last line is

   </xs:schema>

11.2.  Geolocation Policy Namespace Registration

   URI:  urn:ietf:params:xml:ns:geolocation-policy

   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@nsn.com).

   XML:






















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   BEGIN
   <?xml version="1.0"?>
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
     "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
     <meta http-equiv="content-type"
           content="text/html;charset=iso-8859-1"/>
     <title>Geolocation Policy Namespace</title>
   </head>
   <body>
     <h1>Namespace for Geolocation Authorization Policies</h1>
     <h2>urn:ietf:params:xml:schema:geolocation-policy</h2>
   <p>See <a href="[URL of published RFC]">RFCXXXX
       [NOTE TO IANA/RFC-EDITOR:
        Please replace XXXX with the RFC number of this
       specification.]</a>.</p>
   </body>
   </html>
   END

11.3.  Geolocation Policy Location Profile Registry

   This document seeks to create a registry of location profile names
   for the Geolocation Policy framework.  Profile names are XML tokens.
   This registry will operate in accordance with RFC 2434 [13],
   Standards Action.

   This document defines the following profile names:

   geodetic-condition:  Defined in Section 4.1.

   civic-condition:  Defined in Section 4.2.

   geodetic-transformation:  Defined in Section 6.5.2.

   civic-transformation:  Defined in Section 6.5.1.

11.4.  Basic Location Profile XML Schema Registration

   URI:  urn:ietf:params:xml:schema:basic-location-profiles

   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@nsn.com).







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   XML:  The XML schema to be registered is contained in Section 8.  Its
      first line is

   <?xml version="1.0" encoding="UTF-8"?>

      and its last line is

   </xs:schema>

11.5.  Basic Location Profile Namespace Registration

   URI:  urn:ietf:params:xml:ns:basic-location-profiles

   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@nsn.com).

   XML:

   BEGIN
   <?xml version="1.0"?>
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
     "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
     <meta http-equiv="content-type"
           content="text/html;charset=iso-8859-1"/>
     <title>Basic Location Profile Namespace</title>
   </head>
   <body>
     <h1>Namespace for Basic Location Profile</h1>
     <h2>urn:ietf:params:xml:schema:basic-location-profiles</h2>
   <p>See <a href="[URL of published RFC]">RFCXXXX
       [NOTE TO IANA/RFC-EDITOR:
        Please replace XXXX with the RFC number of this
       specification.]</a>.</p>
   </body>
   </html>
   END

11.6.  XCAP Application Usage ID

   This section registers an XCAP Application Usage ID (AUID) according
   to the IANA procedures defined in [11].

   Name of the AUID: geolocation-policy

   Description: Geolocation privacy rules are documents that describe
   the permissions that a Target has granted to Location Recipients that



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   access information about his/her geographic location.


















































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12.  Security Considerations

   This document aims to make it simple for users to prevent the
   unintended disclosure of private information to third parties.  This
   is accomplished through the usage of authorization policies.
   Security requirements are described in [7] and a discussion of
   generic security threats is available with [14].  Aspects of
   combining permissions in cases of multiple occurrence are treated in
   [1]).

   When the Target is moving then the location transformations reveal
   information when switching from one privacy region to another one.
   For example, when a transformation indicates that civic location is
   provided at a 'building' level of granularity.  Hence, room numbers,
   floors etc. would be hidden.  However, when the Target moves from one
   building to the next one then the movement would still be
   recognizable as the disclosed location information would be reflected
   by the new civic location information indicating the new building.
   With additional knowledge about building entrances and streets it
   would be possible to learn a certain amont of information.  It is
   therefore important to ensure that selected privacy regions are not
   chosen too small when mobility is a concern and that a random number
   to is added to the position of the Target, with an absolute value of
   half the privacy region.  The latter aspect is only applicable for
   geodetic information or when geodetic information is translated to
   civic information by the Location Server.

























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13.  References

13.1.  Normative References

   [1]   Schulzrinne, H., Tschofenig, H., Morris, J., Cuellar, J., Polk,
         J., and J. Rosenberg, "Common Policy: A Document Format for
         Expressing Privacy Preferences", RFC 4745, February 2007.

   [2]   Bradner, S., "Key words for use in RFCs to Indicate Requirement
         Levels", March 1997.

   [3]   OpenGIS, "OpenGIS Geography Markup Language (GML)
         Implementation Specification, Version 3.00, OGC 02 023r4",
          http://www.opengeospatial.org/docs/02-023r4.pdf, January 2003.

   [4]   Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV
         PIDF-LO Usage Clarification, Considerations and
         Recommendations", draft-ietf-geopriv-pdif-lo-profile-11 (work
         in progress), February 2008.

   [5]   OpenGIS, "US National Imagery and Mapping Agency, "Department
         of Defense (DoD) World Geodetic System 1984 (WGS 84), Third
         Edition, NIMA TR8350.2",   , January 2000.

   [6]   Thomson, M. and J. Winterbottom, "Revised Civic Location Format
         for PIDF-LO", draft-ietf-geopriv-revised-civic-lo-07 (work in
         progress), December 2007.

13.2.  Informative References

   [7]   Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J.
         Polk, "Geopriv Requirements", RFC 3693, February 2004.

   [8]   Peterson, J., "A Presence-based GEOPRIV Location Object
         Format", RFC 4119, December 2005.

   [9]   Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence
         and Instant Messaging", RFC 2778, February 2000.

   [10]  Peterson, J., "A Presence Architecture for the Distribution of
         GEOPRIV Location Objects", RFC 4079, July 2005.

   [11]  Rosenberg, J., "The Extensible Markup Language (XML)
         Configuration Access Protocol (XCAP)", RFC 4825, May 2007.

   [12]  Rosenberg, J., "Presence Authorization Rules", RFC 5025,
         December 2007.




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   [13]  Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
         Considerations Section in RFCs", BCP 26, RFC 2434,
         October 1998.

   [14]  Danley, M., Mulligan, D., Morris, J., and J. Peterson, "Threat
         Analysis of the Geopriv Protocol", RFC 3694, February 2004.

   [15]  Thomson, M., "Geodetic Shapes for the Representation of
         Uncertainty in PIDF-LO", draft-thomson-geopriv-geo-shape-03
         (work in progress), December 2006.

   [16]  Thomson, M. and J. Winterbottom, "Representation of Uncertainty
         and Confidence in PIDF-LO",
         draft-thomson-geopriv-uncertainty-01 (work in progress),
         June 2008.




































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Appendix A.  Acknowledgments

   This document is informed by the discussions within the IETF GEOPRIV
   working group, including discussions at the GEOPRIV interim meeting
   in Washington, D.C., in 2003.

   We particularly want to thank Allison Mankin <mankin@psg.com>,
   Randall Gellens <rg+ietf@qualcomm.com>, Andrew Newton
   <anewton@ecotroph.net>, Ted Hardie <hardie@qualcomm.com>, Jon
   Peterson <jon.peterson@neustar.biz> for their help in improving the
   quality of this document.

   We would like to thank Christian Guenther for his help with an
   earlier version of this document.  Furthermore, we would like to
   thank Johnny Vrancken for his document reviews in September 2006,
   December 2006 and January 2007.  James Winterbottom provided a
   detailed review in November 2006.  Richard Barnes gave a detailed
   review in February 2008.

   This document uses text from [15].  Therefore, we would like to thank
   Martin Thomson for his work in [15].  We would also like to thank
   Martin Thomson, Matt Lepinski and Richard Barnes for their comments
   regarding the geodetic location transformation procedure.

   We would like to thank Dan Romascanu, Yoshiko Chong and Jari
   Urpalainen for their last call comments.

   Finally, we would like to thank the following individuals for their
   feedback as part of the IESG, GenArt, and SecDir review: Jari Arkko,
   Eric Gray, Russ Housley, Carl Reed, Martin Thomson, Lisa Dusseault,
   Chris Newman, Jon Peterson, Sam Hartman, Cullen Jennings, Tim Polk,
   and Brian Rosen.



















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Authors' Addresses

   Henning Schulzrinne (editor)
   Columbia University
   Department of Computer Science
   450 Computer Science Building
   New York, NY  10027
   USA

   Phone: +1 212 939 7042
   Email: schulzrinne@cs.columbia.edu
   URI:   http://www.cs.columbia.edu/~hgs


   Hannes Tschofenig (editor)
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  02600
   Finland

   Phone: +358 (50) 4871445
   Email: Hannes.Tschofenig@gmx.net
   URI:   http://www.tschofenig.priv.at


   John B. Morris, Jr.
   Center for Democracy and Technology
   1634 I Street NW, Suite 1100
   Washington, DC  20006
   USA

   Email: jmorris@cdt.org
   URI:   http://www.cdt.org


   Jorge R. Cuellar
   Siemens
   Otto-Hahn-Ring 6
   Munich, Bavaria  81739
   Germany

   Email: Jorge.Cuellar@siemens.com









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   James Polk
   Cisco
   2200 East President George Bush Turnpike
   Richardson, Texas  75082
   USA

   Email: jmpolk@cisco.com












































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Full Copyright Statement

   Copyright (C) The IETF Trust (2008).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights 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
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.











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