| < draft-ietf-geopriv-lbyr-requirements-08.txt | draft-ietf-geopriv-lbyr-requirements-09.txt > | |||
|---|---|---|---|---|
| GeoPriv R. Marshall, Ed. | GeoPriv R. Marshall, Ed. | |||
| Internet-Draft TCS | Internet-Draft TCS | |||
| Intended status: Informational September 2, 2009 | Intended status: Informational November 9, 2009 | |||
| Expires: March 6, 2010 | Expires: May 13, 2010 | |||
| Requirements for a Location-by-Reference Mechanism | Requirements for a Location-by-Reference Mechanism | |||
| draft-ietf-geopriv-lbyr-requirements-08 | draft-ietf-geopriv-lbyr-requirements-09 | |||
| This document may contain material from IETF Documents or IETF | ||||
| Contributions published or made publicly available before November | ||||
| 10, 2008. The person(s) controlling the copyright in some of this | ||||
| material may not have granted the IETF Trust the right to allow | ||||
| modifications of such material outside the IETF Standards Process. | ||||
| Without obtaining an adequate license from the person(s) controlling | ||||
| the copyright in such materials, this document may not be modified | ||||
| outside the IETF Standards Process, and derivative works of it may | ||||
| not be created outside the IETF Standards Process, except to format | ||||
| it for publication as an RFC or to translate it into languages other | ||||
| than English. | ||||
| Abstract | ||||
| This document defines terminology and provides requirements relating | ||||
| to Location-by-Reference approach using a location Uniform Resource | ||||
| Identifier (URI) to handle location information within signaling and | ||||
| other Internet messaging. | ||||
| Status of this Memo | Status of this Memo | |||
| This Internet-Draft is submitted to IETF in full conformance with the | This Internet-Draft is submitted to IETF in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF), its areas, and its working groups. Note that | Task Force (IETF), its areas, and its working groups. Note that | |||
| other groups may also distribute working documents as Internet- | other groups may also distribute working documents as Internet- | |||
| Drafts. | Drafts. | |||
| skipping to change at page 1, line 32 ¶ | skipping to change at page 3, line 33 ¶ | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| The list of current Internet-Drafts can be accessed at | The list of current Internet-Drafts can be accessed at | |||
| http://www.ietf.org/ietf/1id-abstracts.txt. | http://www.ietf.org/ietf/1id-abstracts.txt. | |||
| The list of Internet-Draft Shadow Directories can be accessed at | The list of Internet-Draft Shadow Directories can be accessed at | |||
| http://www.ietf.org/shadow.html. | http://www.ietf.org/shadow.html. | |||
| This Internet-Draft will expire on March 6, 2010. | This Internet-Draft will expire on May 13, 2010. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2009 IETF Trust and the persons identified as the | Copyright (c) 2009 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents in effect on the date of | Provisions Relating to IETF Documents | |||
| publication of this document (http://trustee.ietf.org/license-info). | (http://trustee.ietf.org/license-info) in effect on the date of | |||
| Please review these documents carefully, as they describe your rights | publication of this document. Please review these documents | |||
| and restrictions with respect to this document. | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | ||||
| This document may contain material from IETF Documents or IETF | include Simplified BSD License text as described in Section 4.e of | |||
| Contributions published or made publicly available before November | the Trust Legal Provisions and are provided without warranty as | |||
| 10, 2008. The person(s) controlling the copyright in some of this | described in the BSD License. | |||
| material may not have granted the IETF Trust the right to allow | ||||
| modifications of such material outside the IETF Standards Process. | ||||
| Without obtaining an adequate license from the person(s) controlling | ||||
| the copyright in such materials, this document may not be modified | ||||
| outside the IETF Standards Process, and derivative works of it may | ||||
| not be created outside the IETF Standards Process, except to format | ||||
| it for publication as an RFC or to translate it into languages other | ||||
| than English. | ||||
| Abstract | ||||
| This document defines terminology and provides requirements relating | ||||
| to Location-by-Reference approach using a location Uniform Resource | ||||
| Identifier (URI) to handle location information within signaling and | ||||
| other Internet messaging. | ||||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7 | 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8 | |||
| 3. Overview of Location-by-Reference . . . . . . . . . . . . . . 8 | 3. Overview of Location-by-Reference . . . . . . . . . . . . . . 9 | |||
| 3.1. Location URI Usage . . . . . . . . . . . . . . . . . . . . 9 | 3.1. Location URI Usage . . . . . . . . . . . . . . . . . . . . 10 | |||
| 3.2. Location URI Expiration . . . . . . . . . . . . . . . . . 9 | 3.2. Location URI Expiration . . . . . . . . . . . . . . . . . 10 | |||
| 3.3. Location URI Authorization . . . . . . . . . . . . . . . . 10 | 3.3. Location URI Authorization . . . . . . . . . . . . . . . . 11 | |||
| 3.4. Location URI Construction . . . . . . . . . . . . . . . . 10 | 3.4. Location URI Construction . . . . . . . . . . . . . . . . 11 | |||
| 4. High-Level Requirements . . . . . . . . . . . . . . . . . . . 12 | 4. High-Level Requirements . . . . . . . . . . . . . . . . . . . 13 | |||
| 4.1. Requirements for a Location Configuration Protocol . . . . 12 | 4.1. Requirements for a Location Configuration Protocol . . . . 13 | |||
| 4.2. Requirements for a Location Dereference Protocol . . . . . 14 | 4.2. Requirements for a Location Dereference Protocol . . . . . 15 | |||
| 5. Security Considerations . . . . . . . . . . . . . . . . . . . 15 | 5. Security Considerations . . . . . . . . . . . . . . . . . . . 16 | |||
| 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 | 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 | |||
| 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17 | 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18 | |||
| 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 | 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 | |||
| 8.1. Normative References . . . . . . . . . . . . . . . . . . . 18 | 8.1. Normative References . . . . . . . . . . . . . . . . . . . 19 | |||
| 8.2. Informative References . . . . . . . . . . . . . . . . . . 18 | 8.2. Informative References . . . . . . . . . . . . . . . . . . 19 | |||
| Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 20 | Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 20 | |||
| Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 24 | Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 26 | |||
| 1. Introduction | 1. Introduction | |||
| All location-based services rely on ready access to location | All location-based services rely on ready access to location | |||
| information. Using location information can be done one of two ways, | information. Using location information can be done one of two ways, | |||
| either in a direct, Location-by-Value (LbyV) approach, or using an | either in a direct, Location-by-Value (LbyV) approach, or using an | |||
| indirect, Location-by-Reference (LbyR) model. | indirect, Location-by-Reference (LbyR) model. | |||
| For LbyV, location information is conveyed directly in the form of a | For LbyV, location information is conveyed directly in the form of a | |||
| Presence Information Data Format-Location Object (PIDF-LO) | Presence Information Data Format-Location Object (PIDF-LO) | |||
| ([RFC4119]). Using LbyV might either be infeasible or undesirable in | ([RFC4119]). Using LbyV might either be infeasible or undesirable in | |||
| some circumstances. There are cases where LbyR is better able to | some circumstances. There are cases where LbyR is better able to | |||
| address location requirements for a specific architecture or | address location requirements for a specific architecture or | |||
| application. This document provides a list of requirements for use | application. This document provides a list of requirements for use | |||
| with the LbyR approach, and leaves the LbyV model explicitly out of | with the LbyR approach, and leaves the LbyV model explicitly out of | |||
| scope. | scope. | |||
| As justification for a LbyR model, consider the circumstance that in | As justification for a LbyR model, consider the circumstance that in | |||
| some mobile networks it is not efficient for the end host to | some mobile networks it is not efficient for the end host to | |||
| periodically query the Location Information Server (LIS) for up-to- | periodically query the Location Information Server (LIS) for up-to- | |||
| date location information. This is especially the case when ower | date location information. This is especially the case when power | |||
| availability is a constraint or when a location update is not | availability is a constraint or when a location update is not | |||
| immediately needed. Furthermore, the end host might want to delegate | immediately needed. Furthermore, the end host might want to delegate | |||
| the task of retrieving and publishing location information to a third | the task of retrieving and publishing location information to a third | |||
| party, such as to a presence server. Additionally, in some | party, such as to a presence server. Additionally, in some | |||
| deployments, the network operator may not want to make location | deployments, the network operator may not want to make location | |||
| information widely available. These kinds of location scenarios form | information widely available. These kinds of location scenarios form | |||
| the basis of motivation for the LbyR model. | the basis of motivation for the LbyR model. | |||
| The concept of an LbyR mechanism is simple. An LbyR is made up of a | The concept of an LbyR mechanism is simple. An LbyR is made up of a | |||
| URI scheme, a domain and a randomized component. This combination of | URI scheme, a domain and a randomized component. This combination of | |||
| skipping to change at page 5, line 31 ¶ | skipping to change at page 6, line 31 ¶ | |||
| 4. Dereference of a location URI, a request/response between a | 4. Dereference of a location URI, a request/response between a | |||
| client having a location URI and a location server holding the | client having a location URI and a location server holding the | |||
| location information that the location URI references. | location information that the location URI references. | |||
| 5. Termination of a location URI, either due to expiration or | 5. Termination of a location URI, either due to expiration or | |||
| cancellation within a location server, and which is based on a Target | cancellation within a location server, and which is based on a Target | |||
| cancellation request or some other action, such as timer | cancellation request or some other action, such as timer | |||
| expiration. | expiration. | |||
| Note that this document makes no differentiation between a Location | Note that this document makes no functional differentiation between a | |||
| Server (LS), per [RFC3693], and a Location Information Server (LIS), | Location Server (LS), per [RFC3693], and a Location Information | |||
| as shown in [I-D.ietf-geopriv-l7-lcp-ps]), but may refer to either of | Server (LIS), as shown in [I-D.ietf-geopriv-l7-lcp-ps]), but may | |||
| them as a location server interchangeably. | refer to either of them as a location server interchangeably. | |||
| Location determination, different than location configuration or | Location determination, as distinct from location configuration or | |||
| dereferencing, often includes topics related to manual provisioning | dereferencing, often includes topics related to manual provisioning | |||
| processes, automated location calculations based on a variety of | processes, automated location calculations based on a variety of | |||
| measurement techniques, and/or location transformations, (e.g., geo- | measurement techniques, and/or location transformations, (e.g., geo- | |||
| coding), and is beyond the scope of this document. | coding), and is beyond the scope of this document. | |||
| Location Conveyance for either LbyR or LbyV, as defined within SIP | Location Conveyance for either LbyR or LbyV, as defined within SIP | |||
| signaling is considered out of scope for this document (see | signaling is considered out of scope for this document (see | |||
| [I-D.ietf-sip-location-conveyance] for an explanation of location | [I-D.ietf-sip-location-conveyance] for an explanation of location | |||
| conveyance for either LbyR or LbyV scenarios.) | conveyance for either LbyR or LbyV scenarios.) | |||
| skipping to change at page 7, line 27 ¶ | skipping to change at page 8, line 27 ¶ | |||
| Location Object (LO). Furthermore, the following terms are defined | Location Object (LO). Furthermore, the following terms are defined | |||
| in this document: | in this document: | |||
| Location-by-Value (LbyV): Using location information in the form of | Location-by-Value (LbyV): Using location information in the form of | |||
| a location object (LO), such as a PIDF-LO. | a location object (LO), such as a PIDF-LO. | |||
| Location-by-Reference (LbyR): Representing location information | Location-by-Reference (LbyR): Representing location information | |||
| indirectly using a location URI. | indirectly using a location URI. | |||
| Location Configuration Protocol: A protocol that is used by a Target | Location Configuration Protocol: A protocol that is used by a Target | |||
| to acquire either location or a location URI from a location | to acquire either location object or a location URI from a | |||
| configuration server, based on information unique to the Target. | location configuration server, based on information unique to the | |||
| Target. | ||||
| Location Dereference Protocol: A protocol that is used by a client | Location Dereference Protocol: A protocol that is used by a client | |||
| to query a location server, based on the location URI input and | to query a location server, based on the location URI input and | |||
| which returns location information. | which returns location information. | |||
| Location URI: As defined within this document, an identifier that | Location URI: As defined within this document, an identifier that | |||
| serves as a reference to location information. A location URI is | serves as a reference to location information. A location URI is | |||
| provided by a location server, and is later used as input by a | provided by a location server, and is later used as input by a | |||
| dereference protocol to retrieve location information. | dereference protocol to retrieve location information. | |||
| 3. Overview of Location-by-Reference | 3. Overview of Location-by-Reference | |||
| This section describes the entities and interactions involved in the | This section describes the entities and interactions involved in the | |||
| LbyR model. | LbyR model. | |||
| +---------+---------+ Location +-----------+ | +---------+---------+ Location +-----------+ | |||
| | | | Dereference | Location | | | | | Dereference | Location | | |||
| | LIS - LS +---------------+ Recipient | | | LIS/LS +---------------+ Recipient | | |||
| | | | Protocol | | | | | | Protocol | | | |||
| +----+----+----+----+ (3) +-----+-----+ | +----+----+----+----+ (3) +-----+-----+ | |||
| | * | | | * | | |||
| | Policy * | | | Policy * | | |||
| Location | Exchange * | | Location | Exchange * | | |||
| Configuration | (*) * | Location | Configuration | (*) * | Location | |||
| Protocol | +----+----+ | Conveyance | Protocol | +----+----+ | Conveyance | |||
| (1) | | Rule | | Protocol | (1) | | Rule | | Protocol | |||
| | | Maker | | (2) | | | Maker | | (2) | |||
| +----+----+ +---------+ | | +----+----+ +---------+ | | |||
| skipping to change at page 10, line 19 ¶ | skipping to change at page 11, line 19 ¶ | |||
| requested via a location configuration protocol. The process of | requested via a location configuration protocol. The process of | |||
| dereferencing location URIs will be influenced by the specific | dereferencing location URIs will be influenced by the specific | |||
| authorization model applied by the Location Information Server and | authorization model applied by the Location Information Server and | |||
| the URI scheme that indicates the protocol to be used to resolve the | the URI scheme that indicates the protocol to be used to resolve the | |||
| reference to a location object. | reference to a location object. | |||
| Location URIs manifest themselves in a few different forms. The | Location URIs manifest themselves in a few different forms. The | |||
| different ways that a location URI can be represented is based on | different ways that a location URI can be represented is based on | |||
| local policy, and are depicted in the following four scenarios. | local policy, and are depicted in the following four scenarios. | |||
| 1. No specific information at all: As is typical, a location URI is | 1. No location information included in the URI: As is typical, a | |||
| used to get location information. However, in this case, the URI | location URI is used to get location information. However, in | |||
| representation itself does not need to reveal any specific | this case, the URI representation itself does not need to reveal | |||
| information at all. Location information is acquired by the | any specific information at all. Location information is acquired | |||
| dereferencing operation a location URI. | by the dereferencing operation using a location URI. | |||
| 2. No Target specific information: By default, a location URI MUST | 2. URI does not identify a Target: By default, a location URI MUST | |||
| NOT reveal any information about the Target other than location | NOT reveal any information about the Target other than location | |||
| information. This is true for the URI itself, (or in the document | information. This is true for the URI itself, (or in the document | |||
| acquired by dereferencing), unless policy explicitly permits | acquired by dereferencing), unless policy explicitly permits | |||
| otherwise. | otherwise. | |||
| 3. Access control authorization model: If the "access control | 3. Access control authorization model: If the "access control | |||
| authorization model" is used, the location URI MUST NOT include | authorization model" is used, the location URI MUST NOT include | |||
| any location information in its representation. Location URIs | any location information in its representation. Location URIs | |||
| operating under this model could be widely published to recipients | operating under this model could be widely published to recipients | |||
| that are not authorized to receive this information. | that are not authorized to receive this information. | |||
| skipping to change at page 10, line 49 ¶ | skipping to change at page 11, line 49 ¶ | |||
| confidential information shared between the LIS/LS, the Target and | confidential information shared between the LIS/LS, the Target and | |||
| all authorized Location Recipients. In this case, possession | all authorized Location Recipients. In this case, possession | |||
| implies authorization. Because knowledge of the location URI is | implies authorization. Because knowledge of the location URI is | |||
| used to authenticate and authorize access to location information, | used to authenticate and authorize access to location information, | |||
| the URI needs to include sufficient randomness to make guessing | the URI needs to include sufficient randomness to make guessing | |||
| its value difficult. A possession model URI can include location | its value difficult. A possession model URI can include location | |||
| information in its representation. | information in its representation. | |||
| 3.4. Location URI Construction | 3.4. Location URI Construction | |||
| Depending on local policy, a location URI may be constructed in such | Given scenarios 2 and 4, above, and depending on local policy, a | |||
| a way as to make it difficult to guess. Accordingly, the form of the | location URI may be constructed in such a way as to make it difficult | |||
| URI is then constrained by the degree of randomness and uniqueness | to guess. Accordingly, the form of the URI is then constrained by | |||
| applied to it. In this case, it may be important to protect the | the degree of randomness and uniqueness applied to it. In this case, | |||
| actual location information from inspection by an intermediate node. | it may be important to protect the actual location information from | |||
| Construction of a location URI in such a way as to not reveal any | inspection by an intermediate node. Construction of a location URI | |||
| Target specific, (e.g., user or device), information, with the goal | in such a way as to not reveal any Target specific, (e.g., user or | |||
| of making the location URI appear bland, uninteresting, and generic, | device), information, with the goal of making the location URI appear | |||
| may be helpful to some degree in order to keep location information | bland, uninteresting, and generic, may be helpful to some degree in | |||
| more difficult to detect. Thus, obfuscating the location URI in this | order to keep location information more difficult to detect. Thus, | |||
| way may provide some level of safeguard against the undetected | obfuscating the location URI in this way may provide some level of | |||
| stripping off of what would otherwise be evident location | safeguard against the undetected stripping off of what would | |||
| information, since it forces a dereference operation at the location | otherwise be evident location information, since it forces a | |||
| dereference server, an important step for the purpose of providing | dereference operation at the location dereference server, an | |||
| statistics, audit trails, and general logging for many different | important step for the purpose of providing statistics, audit trails, | |||
| kinds of location based services. | and general logging for many different kinds of location based | |||
| services. | ||||
| 4. High-Level Requirements | 4. High-Level Requirements | |||
| This document outlines the requirements for an Location by Reference | This document outlines the requirements for an Location by Reference | |||
| mechanism which can be used by a number of underlying protocols. | mechanism which can be used by a number of underlying protocols. | |||
| Requirements here address two general types of such protocols, a | Requirements here address two general types of such protocols, a | |||
| general location configuration protocol, and a general location | general location configuration protocol, and a general location | |||
| dereferencing protocol. | dereferencing protocol. | |||
| The requirements are broken into two sections. | The requirements are broken into two sections. | |||
| skipping to change at page 12, line 40 ¶ | skipping to change at page 13, line 40 ¶ | |||
| Motivation: A location URI may not intend to represent a location | Motivation: A location URI may not intend to represent a location | |||
| forever, and the identifier eventually may need to be recycled, or | forever, and the identifier eventually may need to be recycled, or | |||
| may be subject to a specific window of validity, after which the | may be subject to a specific window of validity, after which the | |||
| location reference fails to yield a location, or the location is | location reference fails to yield a location, or the location is | |||
| determined to be kept confidential. | determined to be kept confidential. | |||
| C3. Location URI cancellation: The location configuration protocol | C3. Location URI cancellation: The location configuration protocol | |||
| MUST support the ability to request a cancellation of a specific | MUST support the ability to request a cancellation of a specific | |||
| location URI. | location URI. | |||
| Motivation: If the Target determines that in its best interest to | Motivation: If the Target determines that a location URI should no | |||
| destroy the ability for a location URI to effectively be used to | longer be used to dereference a location, then there should be a | |||
| dereference a location, then there should be a way to nullify the | way to request that the location URI be nullified." | |||
| location URI. | ||||
| C4. Location Information Masking: The location URI MUST, through | C4. Location Information Masking: The location URI MUST ensure, by | |||
| randomization and uniqueness, ensure that the location URI does | default, through randomization and uniqueness, that the location | |||
| not contain location information specific components. | URI does not contain location information specific components. | |||
| Motivation: It is important to keep any location information | Motivation: It is important to keep any location information | |||
| masked from a casual observing node. | masked from a casual observing node. | |||
| C5. Target Identity Protection: The location URI MUST NOT contain | C5. Target Identity Protection: The location URI MUST NOT contain | |||
| information that identifies the Target (e.g., user or device). | information that identifies the Target (e.g., user or device). | |||
| Examples include phone extensions, badge numbers, first or last | Examples include phone extensions, badge numbers, first or last | |||
| names. | names. | |||
| Motivation: It is important to protect caller identity or contact | Motivation: It is important to protect caller identity or contact | |||
| skipping to change at page 13, line 22 ¶ | skipping to change at page 14, line 22 ¶ | |||
| when it is generated. | when it is generated. | |||
| C6. Reuse indicator: There SHOULD be a way to allow a Target to | C6. Reuse indicator: There SHOULD be a way to allow a Target to | |||
| control whether a location URI can be resolved once only, or | control whether a location URI can be resolved once only, or | |||
| multiple times. | multiple times. | |||
| Motivation: The Target requesting a location URI may request a | Motivation: The Target requesting a location URI may request a | |||
| location URI which has a 'one-time-use' only characteristic, as | location URI which has a 'one-time-use' only characteristic, as | |||
| opposed to a location URI having multiple reuse capability. This | opposed to a location URI having multiple reuse capability. This | |||
| would allow the server to return an error with or without location | would allow the server to return an error with or without location | |||
| during the subsequent dereference operation. | information during the subsequent dereference operation. | |||
| C7. Selective disclosure: The location configuration protocol MUST | C7. Selective disclosure: The location configuration protocol MUST | |||
| provide a mechanism to control what information is being disclosed | provide a mechanism that allows the Rule Maker to control what | |||
| about the Target. | information is being disclosed about the Target. | |||
| Motivation: The Rule Maker has to be in control of how much | Motivation: The Rule Maker has to be in control of how much | |||
| information is revealed during the dereferencing step as part of | information is revealed during the dereferencing step as part of | |||
| the privacy features. | the privacy features. | |||
| C8. Location URI Not guessable: As a default, the location | C8. Location URI Not guessable: As a default, the location | |||
| configuration protocol MUST return location URIs that are random | configuration protocol MUST return location URIs that are random | |||
| and unique throughout the indicated lifetime. A location URI with | and unique throughout the indicated lifetime. A location URI with | |||
| 128-bits of randomness is RECOMMENDED. | 128-bits of randomness is RECOMMENDED. | |||
| Motivation: Location URIs should be constructed in such a way that | Motivation: Location URIs should be constructed in such a way that | |||
| an adversary cannot guess them and dereference them without having | an adversary cannot guess them and dereference them without having | |||
| ever obtained them from the Target. | previously obtained them from the Target. | |||
| C9. Location URI Options: In the case of user-provided authorization | C9. Location URI Options: In the case of user-provided authorization | |||
| policies, where anonymous or non-guessable location URIs are not | policies, where anonymous or non-guessable location URIs are not | |||
| warranted, the location configuration protocol MAY support a | warranted, the location configuration protocol MAY support a | |||
| variety of optional location URI conventions, as requested by a | variety of optional location URI conventions, as requested by a | |||
| Target to a location configuration server, (e.g., embedded | Target to a location configuration server, (e.g., embedded | |||
| location information within the location URI). | location information within the location URI). | |||
| Motivation: Users don't always have such strict privacy | Motivation: Users don't always have such strict privacy | |||
| requirements, but may opt to specify their own location URI, or | requirements, but may opt to specify their own location URI, or | |||
| skipping to change at page 14, line 15 ¶ | skipping to change at page 15, line 15 ¶ | |||
| 4.2. Requirements for a Location Dereference Protocol | 4.2. Requirements for a Location Dereference Protocol | |||
| Below, we summarize high-level design requirements needed for a | Below, we summarize high-level design requirements needed for a | |||
| location-by-reference mechanism as used within the location | location-by-reference mechanism as used within the location | |||
| dereference protocol. | dereference protocol. | |||
| D1. Location URI support: The location dereference protocol MUST | D1. Location URI support: The location dereference protocol MUST | |||
| support a location reference in URI form. | support a location reference in URI form. | |||
| Motivation: It is required that there be consistency of use | Motivation: It is required that there be consistency of use | |||
| between location URI formats used in an configuration protocol and | between location URI formats used in a configuration protocol and | |||
| those used by a dereference protocol. | those used by a dereference protocol. | |||
| D2. Authentication: The location dereference protocol MUST include | D2. Authentication: The location dereference protocol MUST include | |||
| mechanisms to authenticate both the client and the server. | mechanisms to authenticate both the client and the server. | |||
| Motivation: Although the implementations must support | Motivation: Although the implementations must support | |||
| authentication of both parties, any given transaction has the | authentication of both parties, any given transaction has the | |||
| option not to authenticate one or both parties. | option not to authenticate one or both parties. | |||
| D3. Dereferenced Location Form: The value returned by the | D3. Dereferenced Location Form: The value returned by the | |||
| skipping to change at page 15, line 13 ¶ | skipping to change at page 16, line 13 ¶ | |||
| HTTPS URI scheme. | HTTPS URI scheme. | |||
| 5. Security Considerations | 5. Security Considerations | |||
| The method of constructing the location URI to include randomized | The method of constructing the location URI to include randomized | |||
| components helps to prevent adversaries from obtaining location | components helps to prevent adversaries from obtaining location | |||
| information without ever retrieving a location URI. In the | information without ever retrieving a location URI. In the | |||
| possession model, a location URI, regardless of its construction, if | possession model, a location URI, regardless of its construction, if | |||
| made publically available, implies no safeguard against anyone being | made publically available, implies no safeguard against anyone being | |||
| able to dereference and get the location. Care has to be paid when | able to dereference and get the location. Care has to be paid when | |||
| distribution such a location URI to the trusted location recipients. | distributing such a location URI to the trusted location recipients. | |||
| When this aspect is of concern then the authorization model has to be | When this aspect is of concern then the authorization model has to be | |||
| chosen. Even in this model care has to be taken on how to construct | chosen. Even in this model care has to be taken on how to construct | |||
| the authorization policies to ensure that only those parties have | the authorization policies to ensure that only those parties have | |||
| access to location information that are considered trustworthy enough | access to location information that are considered trustworthy enough | |||
| to enforce the basic rule set that is attached to location | to enforce the basic rule set that is attached to location | |||
| information in a PIDF-LO document. | information in a PIDF-LO document. | |||
| Any location URI, by necessity, indicates the server (name) that | Any location URI, by necessity, indicates the server (name) that | |||
| hosts the location information. Knowledge of the server in some | hosts the location information. Knowledge of the server in some | |||
| specific domain could therefore reveal something about the location | specific domain could therefore reveal something about the location | |||
| skipping to change at page 18, line 16 ¶ | skipping to change at page 19, line 16 ¶ | |||
| 8.1. Normative References | 8.1. Normative References | |||
| [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
| Requirement Levels", BCP 14, RFC 2119, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
| 8.2. Informative References | 8.2. Informative References | |||
| [I-D.ietf-geopriv-dhcp-lbyr-uri-option] | [I-D.ietf-geopriv-dhcp-lbyr-uri-option] | |||
| Polk, J., "Dynamic Host Configuration Protocol (DHCP) IPv4 | Polk, J., "Dynamic Host Configuration Protocol (DHCP) IPv4 | |||
| and IPv6 Option for a Location Uniform Resource | and IPv6 Option for a Location Uniform Resource Identifier | |||
| Identifier (URI)", | (URI)", draft-ietf-geopriv-dhcp-lbyr-uri-option-06 (work | |||
| draft-ietf-geopriv-dhcp-lbyr-uri-option-05 (work in | in progress), September 2009. | |||
| progress), July 2009. | ||||
| [I-D.ietf-geopriv-http-location-delivery] | [I-D.ietf-geopriv-http-location-delivery] | |||
| Barnes, M., Winterbottom, J., Thomson, M., and B. Stark, | Barnes, M., Winterbottom, J., Thomson, M., and B. Stark, | |||
| "HTTP Enabled Location Delivery (HELD)", | "HTTP Enabled Location Delivery (HELD)", | |||
| draft-ietf-geopriv-http-location-delivery-16 (work in | draft-ietf-geopriv-http-location-delivery-16 (work in | |||
| progress), August 2009. | progress), August 2009. | |||
| [I-D.ietf-geopriv-l7-lcp-ps] | [I-D.ietf-geopriv-l7-lcp-ps] | |||
| Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7 | Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7 | |||
| Location Configuration Protocol; Problem Statement and | Location Configuration Protocol; Problem Statement and | |||
| Requirements", draft-ietf-geopriv-l7-lcp-ps-10 (work in | Requirements", draft-ietf-geopriv-l7-lcp-ps-10 (work in | |||
| progress), July 2009. | progress), July 2009. | |||
| [I-D.ietf-geopriv-loc-filters] | [I-D.ietf-geopriv-loc-filters] | |||
| Mahy, R., Rosen, B., and H. Tschofenig, "A Document Format | Mahy, R., Rosen, B., and H. Tschofenig, "Filtering | |||
| for Filtering and Reporting Location Notications in the | Location Notifications in the Session Initiation Protocol | |||
| Presence Information Document Format Location Object | (SIP)", draft-ietf-geopriv-loc-filters-08 (work in | |||
| (PIDF-LO)", draft-ietf-geopriv-loc-filters-05 (work in | progress), November 2009. | |||
| progress), July 2009. | ||||
| [I-D.ietf-sip-location-conveyance] | [I-D.ietf-sip-location-conveyance] | |||
| Polk, J. and B. Rosen, "Location Conveyance for the | Polk, J. and B. Rosen, "Location Conveyance for the | |||
| Session Initiation Protocol", | Session Initiation Protocol", | |||
| draft-ietf-sip-location-conveyance-13 (work in progress), | draft-ietf-sip-location-conveyance-13 (work in progress), | |||
| March 2009. | March 2009. | |||
| [LLDP-MED] | [LLDP-MED] | |||
| TIA, "ANSI/TIA-1057 Link Layer Discovery Protocol - Media | TIA, "ANSI/TIA-1057 Link Layer Discovery Protocol - Media | |||
| Endpoint Discovery". | Endpoint Discovery". | |||
| [RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and | [RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and | |||
| J. Polk, "Geopriv Requirements", RFC 3693, February 2004. | J. Polk, "Geopriv Requirements", RFC 3693, February 2004. | |||
| [RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object | [RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object | |||
| Format", RFC 4119, December 2005. | Format", RFC 4119, December 2005. | |||
| Appendix A. Change log | Appendix A. Change log | |||
| Changes to this draft in comparison to the previous version (-09 vs. | ||||
| -08), as part of the IESG review process: | ||||
| 1. clarification of missing text, Introduction, (from Alexey | ||||
| Melnikov), change from: "ower", to "power" (as appropriate) text now | ||||
| reads, "This is especially the case when power availability is a | ||||
| constraint" | ||||
| 2. clarify text, Introduction, (from Spencer Dawkins, 06/03/2009), | ||||
| change from: "Location determination, different than location | ||||
| configuration" change to: "Location determination, as distinct from | ||||
| location configuration" | ||||
| 3. insert text, Terminology section, (from Spencer Dawkins, 06/03/ | ||||
| 2009), change from: "to acquire either location or a location URI" | ||||
| change to: "to acquire either location object or a location URI" | ||||
| 4. reword, section 3.3. Location URI Authorization, (from Spencer | ||||
| Dawkins, 06/03/2009), change from: "1. No specific information at | ||||
| all:" change to: "1. No location information included in the URI:" | ||||
| 5. rephrase, (overlay new term), section 3.3. Location URI | ||||
| Authorization, (from Spencer Dawkins, 06/03/2009), Change from: "2. | ||||
| No Target specific information:" Change to: "2. URI does not | ||||
| identify a Target:" | ||||
| 6. Add text ahead of paragraph, section titled, "Location URI | ||||
| Construction", (from Spencer Dawkins, 06/03/2009), change from: | ||||
| "Depending on local policy," change to: "Given scenarios 2 and 4, | ||||
| above, and depending on local policy" | ||||
| 7. reword Motivation text, req. C3, (from Spencer Dawkins, 06/03/ | ||||
| 2009), change from: "Motivation: If the Target determines that in its | ||||
| best interest to destroy the ability for a location URI to | ||||
| effectively be used to dereference a location, then there should be a | ||||
| way to nullify the location URI." change to: "Motivation: If the | ||||
| Target determines that a location URI should no longer be used to | ||||
| dereference a location, then there should be a way to request that | ||||
| the location URI be nullified." | ||||
| 8. reword requirement C7, (from Spencer Dawkins, 06/03/2009), "C7. | ||||
| Selective disclosure: The location configuration protocol MUST | ||||
| provide a mechanism to control what information is being disclosed | ||||
| about the Target." Change to: "C7. Selective disclosure: The | ||||
| location configuration protocol MUST provide a mechanism that allows | ||||
| the Rule Maker to control what information is being disclosed about | ||||
| the Target." | ||||
| 9. replace text s/ever/previously, (from Spencer Dawkins, 06/03/ | ||||
| 2009), change from: "Motivation: Location URIs should be constructed | ||||
| in such a way that an adversary cannot guess them and dereference | ||||
| them without having ever obtained them from the Target." change to: | ||||
| "Motivation: Location URIs should be constructed in such a way that | ||||
| an adversary cannot guess them and dereference them without having | ||||
| previously obtained them from the Target." | ||||
| 10. minor fix, section 4.2, D1., s/in an/in a/1 (from Spencer | ||||
| Dawkins, 06/03/2009), | ||||
| 11. minor fix, section 5. Security Considerations, (from Spencer | ||||
| Dawkins, 06/03/2009), change from: "when distribution such" change | ||||
| to: "when distributing such" | ||||
| 12. qualifying text inserted, req. C4 (from Tin Tsou, Ops Review 10/ | ||||
| 21/2009) change from: "The location URI MUST, through randomization | ||||
| and uniqueness, ensure that the location URI does not contain | ||||
| location information specific components. change to: "The location | ||||
| URI MUST ensure, by default, through randomization and uniqueness, | ||||
| that the location URI does not contain location information specific | ||||
| components. | ||||
| 13. resolve comments from Tina Tsou relating to C4 vs. C9 | ||||
| compatibility, | ||||
| 14. resolve comments from Lisa Dusseault relating to LIS/LS | ||||
| references and note | ||||
| Changes to this draft in comparison to the previous version (-08 vs. | Changes to this draft in comparison to the previous version (-08 vs. | |||
| -07), as part of the IESG review process: | -07), as part of the IESG review process: | |||
| 1. changes sent 09/02/2009 based on IESG Security comments from | 1. changes sent 09/02/2009 based on IESG Security comments from | |||
| Hilarie Orman, 06/08/2009. | Hilarie Orman, 06/08/2009. | |||
| 2. changes sent 09/02/2009 based on Operational Directorate comments | 2. changes sent 09/02/2009 based on Operational Directorate comments | |||
| from Hannes Tschofenig, 06/11/2009. | from Hannes Tschofenig, 06/11/2009. | |||
| Changes to this draft in comparison to the previous version (-07 vs. | Changes to this draft in comparison to the previous version (-07 vs. | |||
| End of changes. 24 change blocks. | ||||
| 97 lines changed or deleted | 177 lines changed or added | |||
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