< draft-ietf-geopriv-common-policy-10.txt   draft-ietf-geopriv-common-policy-11.txt >
GEOPRIV H. Schulzrinne GEOPRIV H. Schulzrinne
Internet-Draft Columbia U. Internet-Draft Columbia U.
Expires: November 22, 2006 H. Tschofenig Intended status: Standards Track H. Tschofenig
Siemens Expires: February 11, 2007 Siemens
J. Morris J. Morris
CDT CDT
J. Cuellar J. Cuellar
Siemens Siemens
J. Polk J. Polk
J. Rosenberg
Cisco Cisco
May 21, 2006 J. Rosenberg
Cisco Systems
August 10, 2006
Common Policy: An XML Document Format for Expressing Privacy Preferences Common Policy: A Document Format for Expressing Privacy Preferences
draft-ietf-geopriv-common-policy-10.txt draft-ietf-geopriv-common-policy-11.txt
Status of this Memo Status of this Memo
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aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
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This Internet-Draft will expire on November 22, 2006. This Internet-Draft will expire on February 11, 2007.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The Internet Society (2006).
Abstract Abstract
This document defines a framework for authorization policies This document defines a framework for authorization policies
controlling access to application specific data. This framework controlling access to application specific data. This framework
combines common location- and presence-specific authorization combines common location- and presence-specific authorization
aspects. An XML schema specifies the language in which common policy aspects. An XML schema specifies the language in which common policy
rules are represented. The common policy framework can be extended rules are represented. The common policy framework can be extended
to other application domains. to other application domains.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
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7.1. Identity Condition . . . . . . . . . . . . . . . . . . . . 14 7.1. Identity Condition . . . . . . . . . . . . . . . . . . . . 14
7.1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . 14 7.1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . 14
7.1.2. Matching One Entity . . . . . . . . . . . . . . . . . 14 7.1.2. Matching One Entity . . . . . . . . . . . . . . . . . 14
7.1.3. Matching Multiple Entities . . . . . . . . . . . . . . 15 7.1.3. Matching Multiple Entities . . . . . . . . . . . . . . 15
7.2. Single Entity . . . . . . . . . . . . . . . . . . . . . . 19 7.2. Single Entity . . . . . . . . . . . . . . . . . . . . . . 19
7.3. Sphere . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7.3. Sphere . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.4. Validity . . . . . . . . . . . . . . . . . . . . . . . . . 21 7.4. Validity . . . . . . . . . . . . . . . . . . . . . . . . . 21
8. Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8. Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9. Transformations . . . . . . . . . . . . . . . . . . . . . . . 24 9. Transformations . . . . . . . . . . . . . . . . . . . . . . . 24
10. Procedure for Combining Permissions . . . . . . . . . . . . . 25 10. Procedure for Combining Permissions . . . . . . . . . . . . . 25
10.1. Algorithm . . . . . . . . . . . . . . . . . . . . . . . . 25 10.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . 25
10.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 26 10.2. Algorithm . . . . . . . . . . . . . . . . . . . . . . . . 25
10.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 26
11. Meta Policies . . . . . . . . . . . . . . . . . . . . . . . . 29 11. Meta Policies . . . . . . . . . . . . . . . . . . . . . . . . 29
12. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 12. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
13. XML Schema Definition . . . . . . . . . . . . . . . . . . . . 31 13. XML Schema Definition . . . . . . . . . . . . . . . . . . . . 31
14. Security Considerations . . . . . . . . . . . . . . . . . . . 34 14. Security Considerations . . . . . . . . . . . . . . . . . . . 34
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35
15.1. Common Policy Namespace Registration . . . . . . . . . . . 35 15.1. Common Policy Namespace Registration . . . . . . . . . . . 35
15.2. Content-type registration for 15.2. Content-type registration for
'application/auth-policy+xml' . . . . . . . . . . . . . . 35 'application/auth-policy+xml' . . . . . . . . . . . . . . 35
15.3. Common Policy Schema Registration . . . . . . . . . . . . 37 15.3. Common Policy Schema Registration . . . . . . . . . . . . 37
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 38 16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 38
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for access to application specific data. This framework is the for access to application specific data. This framework is the
result of combining the common aspects of single authorization result of combining the common aspects of single authorization
systems that more specifically control access to presence and systems that more specifically control access to presence and
location information and that previously had been developed location information and that previously had been developed
separately. The benefit of combining these two authorization systems separately. The benefit of combining these two authorization systems
is two-fold. First, it allows to build a system which enhances the is two-fold. First, it allows to build a system which enhances the
value of presence with location information in a natural way and value of presence with location information in a natural way and
reuses the same underlying authorization mechanism. Second, it reuses the same underlying authorization mechanism. Second, it
encourages a more generic authorization framework with mechanisms for encourages a more generic authorization framework with mechanisms for
extensibility. The applicability of the framework specified in this extensibility. The applicability of the framework specified in this
document is not limited to policies controlling access to presence document is not limited to policies controling access to presence and
and location information data, but can be extended to other location information data, but can be extended to other application
application domains. domains.
The general framework defined in this document is intended to be The general framework defined in this document is intended to be
accompanied and enhanced by application-specific policies specified accompanied and enhanced by application-specific policies specified
elsewhere. The common policy framework described here is enhanced by elsewhere. The common policy framework described here is enhanced by
domain-specific policy documents, including presence [7] and location domain-speific policy documents, including presence [7] and location
[8]. This relationship is shown in Figure 1. [8]. This relationship is shown in Figure 1.
+-----------------+ +-----------------+
| | | |
| Common | | Common |
| Policy | | Policy |
| | | |
+---+---------+---+ +---+---------+---+
/|\ /|\ /|\ /|\
| | | |
+-------------------+ | | +-------------------+ +-------------------+ | | +-------------------+
| | | enhance | | | | | | enhance | | |
| Location-specific | | | | Presence-specific | | Location-specific | | | | Presence-specific |
| Policy |----+ +----| Policy | | Policy |----+ +----| Policy |
| | | | | | | |
+-------------------+ +-------------------+ +-------------------+ +-------------------+
Figure 1: Common Policy Enhancements Figure 1: Common Policy Enhancements
This document starts with an introduction to the terminology in This document starts with an introduction to the terminology in
Section 2, an illustration of basic modes of operation in Section 3, Section 2, an illustration of basic modes of operation in Section 3,
a description of goals (see Section 4) and non-goals (see Section 5) a description of goals (see Section 4) and non-goals (see Section 5)
of the policy framework, followed by the data model in Section 6. of the policy framework, followed by the data model in Section 6.
The structure of a rule, namely conditions, actions and The structure of a rule, namely conditions, actions and
transformations, is described in Section 7, in Section 8 and in transformations, are described in Section 7, in Section 8 and in
Section 9. The procedure for combining permissions is explained in Section 9. The procedure for combining permissions is explained in
Section 10 and used when more than one rule fires. A short Section 10 and used when more than one rule fires. A short
description of meta policies is given in Section 11. An example is description of meta policies is given in Section 11. An example is
provided in Section 12. The XML schema will be discussed in provided in Section 12. The XML schema will be discussed in
Section 13. IANA considerations in Section 15 follow the security Section 13. IANA considerations in Section 15 follow security
considerations from Section 14. considerations Section 14.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT","RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT","RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [1]. document are to be interpreted as described in [1].
This document introduces the following terms: This document introduces the following terms:
PT - Presentity / Target: The PT is the entity about whom information PT - Presentity / Target: The PT is the entity about whom
has been requested. RFC 3693 [9] uses the term Target to identify information has been requested.
the object or person of which location information is requested.
The presence model described in RFC 2778 [10] uses the term
presentity to describe the entity that provides presence
information to a presence service. We introduce a neutral term
here to avoid confusion or loose generality.
RM - Rule Maker: RM is an entity that creates the authorization rules RM - Rule Maker: RM is an entity which creates the authorization
which restrict access to data items. rules which restrict access to data items.
PS - (Authorization) Policy Server: This entity has access to both PS - (Authorization) Policy Server: This entity has access to both
the authorization policies and to the data items. In location- the authorization policies and to the data items. In location-
specific applications, the entity PS is labeled as location server specific applications, the entity PS is labeled as location server
(LS). (LS).
WR - Watcher / Recipient: This entity requests access to data items WR - Watcher / Recipient: This entity requests access to data items
of the PT. An access operation might be either be a read, write of the PT. An access operation might be either be a read, write
or be any other operation. In case of access to location or be any other operation. In case of access to location
information is likely to be a read operation. information it might be a read operation.
The receiver of the requested data items is the Location Recipient
(LR) in the terminology of RFC 3693 [9]. A watcher, i.e., an
entity that requests presence information about a presentity, is a
recipient in presence systems (see [10]).
A policy is given by a 'rule set' that contains an unordered list of A policy is given by a 'rule set' that contains an unordered list of
'rules'. A 'rule' has a 'conditions', an 'actions' and a 'rules'. A 'rule' has a 'conditions', an 'actions' and a
'transformations' part. 'transformations' part.
The term 'permission' refers to the action and transformation The term 'permission' indicates the action and transformation
components of a 'rule'. components of a 'rule'.
The term 'using protocol' is defined in [9]. It refers to the The term 'using protocol' is defined in [9]. It refers to the
protocol that is used to request access to and to return privacy protocol which is used to request access to and to return privacy
sensitive data items. sensitive data items.
3. Modes of Operation 3. Modes of Operation
The abstract sequence of operations can roughly be described as The abstract sequence of operations can roughly be described as
follows. The PS receives a query for data items for a particular PT, follows. The PS receives a query for data items for a particular PT,
via the using protocol. The using protocol (or more precisely the via the using protocol. The using protocol (or more precisely the
authentication protocol) provides the identity of the requestor, authentication protocol) provides the identity of the requestor,
either at the time of the query or at the subscription time. The either at the time of the query or at the subscription time. The
authenticated identity of the WR, together with other information authenticated identity of the WR, together with other information
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Event notification adds a subscription phase to the "Active Request- Event notification adds a subscription phase to the "Active Request-
Response - PS as Client (Initiator)" mode of operation. A watcher or Response - PS as Client (Initiator)" mode of operation. A watcher or
subscriber asks to be added to the notification list for a particular subscriber asks to be added to the notification list for a particular
presentity or event. When the presentity changes state or the event presentity or event. When the presentity changes state or the event
occurs, the PS sends a message to the WR containing the updated occurs, the PS sends a message to the WR containing the updated
state. (Presence is a special case of event notification; thus, we state. (Presence is a special case of event notification; thus, we
often use the term interchangeably.) often use the term interchangeably.)
In addition, the subscriber may itself add a filter to the In addition, the subscriber may itself add a filter to the
subscription, limiting the rate or content of the notifications. If subscription, limiting the rate or content of the notifications. If
an event, after filtering by the rule maker-provided rules and by the an event, after filtering by the rulemaker-provided rules and by the
subscriber-provided rules, only produces the same notification subscriber-provided rules, only produces the same notification
content that was sent previously, no event notification is sent. content that was sent previously, no event notification is sent.
A single PS may authorize access to data items in more than one mode. A single PS may authorize access to data items in more than one mode.
Rather than having different rule sets for different modes all three Rather than having different rule sets for different modes all three
modes are supported with a one rule set schema. modes are supported with a one rule set schema. Specific instances
of the rule set can omit elements that are only applicable to the
subscription model.
4. Goals and Assumptions 4. Goals and Assumptions
Below, we summarize our design goals and constraints. Below, we summarize our design goals and constraints.
Table representation: Table representation:
Each rule must be representable as a row in a relational database. Each rule must be representable as a row in a relational database.
This design goal should allow efficient policy implementation by This design goal should allow efficient policy implementation by
utilizing standard database optimization techniques. utilizing standard database optimization techniques.
Permit only: Permit only:
Rules only provide permissions rather than denying them. Removing Rules only provide permissions rather than denying them. Removing
a rule can never increase permissions. Allowing both 'permit' and a rule can never increase permissions. Allowing both 'permit' and
'deny' actions would require some rule ordering that has 'deny' actions would require some rule ordering which had
implications on the update operations executed on these rules. implications on the update operations executed on these rules.
Additionally, it would make distributed rule sets more Additionally, it would make distributed rule sets more
complicated. Hence, only 'permit' actions are allowed that result complicated. Hence, only 'permit' actions are allowed which
in more efficient rule processing. This also implies that rule result in more efficient rule processing. This also implies that
ordering is not important. rule ordering is not important. Consequently, to make a policy
decision requires processing all rules.
Additive permissions: Additive permissions:
A query for access to data items is matched against the rules in A query for access to data items is matched against the rules in
the rule database. If several rules match, then the overall the rule database. If several rules match, then the overall
permissions granted to the WR are the union of those permissions. permissions granted to the WR are the union of those permissions.
A more detailed discussion is provided in Section 10. A more detailed discussion is provided inSection 10.
Upgradeable: Upgradeable:
It should be possible to add additional rules later, without It should be possible to add additional rules later, without
breaking PSs that have not been upgraded. Any such upgrades must breaking PSs that have not been upgraded. Any such upgrades must
not degrade privacy constraints, but PSs not yet upgraded may not degrade privacy constraints, but PSs not yet upgraded may
reveal less information than the rule maker would have chosen. reveal less information than the rulemaker would have chosen.
Capability support: Capability support:
In addition to the previous goal, a RM should be able to determine In addition to the previous goal, a RM should be able to determine
the extensions that are supported by the PS. The mechanism used which extensions are supported by the PS. The mechanism used to
to determine the capability of a PS is outside the scope of this determine the capability of a PS is outside the scope of this
specification. specification.
Protocol-independence: Protocol-independent:
The rule set supports constraints on both notifications or queries The rule set supports constraints on both notifications or queries
as well as subscriptions for event-based systems such as presence as well as subscriptions for event-based systems such as presence
systems. systems.
No false assurance: No false assurance:
It appears more dangerous to give the user the impression that the It appears more dangerous to give the user the impression that the
system will prevent disclosure automatically, but fail to do so system will prevent disclosure automatically, but fail to do so
with a significant probability of operator error or with a significant probability of operator error or
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6. Basic Data Model and Processing 6. Basic Data Model and Processing
A rule set (or synonymously, a policy) consists of zero or more A rule set (or synonymously, a policy) consists of zero or more
rules. The ordering of these rules is irrelevant. The rule set can rules. The ordering of these rules is irrelevant. The rule set can
be stored at the PS and conveyed from RM to PS as a single document, be stored at the PS and conveyed from RM to PS as a single document,
in subsets or as individual rules. A rule consists of three parts - in subsets or as individual rules. A rule consists of three parts -
conditions (see Section 7), actions (see Section 8), and conditions (see Section 7), actions (see Section 8), and
transformations (see Section 9). transformations (see Section 9).
The conditions part is a set of expressions, each of which evaluates The conditions part is a set of expressions, each of which evaluates
to either TRUE or FALSE, i.e., each of which is equipped with a value to either TRUE or FALSE, i.e. each of which is equipped with a value
of either TRUE or FALSE by the PS. When a WR asks for information of either TRUE or FALSE by the PS. When a WR asks for information
about a PT, the PS goes through each rule in the rule set. For each about a PT, the PS goes through each rule in the rule set. For each
rule, it evaluates the expressions in the conditions part. If all of rule, it evaluates the expressions in the conditions part. If all of
the expressions evaluate to TRUE, then the rule is applicable to this the expressions evaluate to TRUE, then the rule is applicable to this
request. Generally, each expression specifies a condition based on request. Generally, each expression specifies a condition based on
some variable that is associated with the context of the request. some variable that is associated with the context of the request.
These variables can include the identity of the WR, the domain of the These variables can include the identity of the WR, the domain of the
WR, the time of day, or even external variables, such as the WR, the time of day, or even external variables, such as the
temperature or the mood of the PT. temperature or the mood of the PT.
Assuming that the rule is applicable to the request, the actions and Assuming that the rule is applicable to the request, the actions and
transformations (commonly referred to as permissions) in the rule transformations (commonly referred to as permissions) in the rule
specify how the PS is supposed to handle this request. If the specify how the PS is supposed to handle this request. If the
request is to view the location of the PT, or to view its presence, request is to view the location of the PT, or to view its presence,
the typical action is "permit" that allows the request to proceed. the typical action is "permit", which allows the request to proceed.
Assuming the action allows the request to proceed, the Assuming the action allows the request to proceed, the
transformations part of the rule specifies how the information about transformations part of the rule specifies how the information about
the PT - their location information, their presence, etc. - is the PT - their location information, their presence, etc. - is
modified before being presented to the WR. These transformations are modified before being presented to the WR. These transformations are
in the form of positive permissions. That is, they always specify a in the form of positive permissions. That is, they always specify a
piece of information that is allowed to be seen by the WR. When a PS piece of information which is allowed to be seen by the WR. When a
processes a request, it takes the transformations specified across PS processes a request, it takes the transformations specified across
all rules that match, and creates the union of them. For computing all rules that match, and creates the union of them. For computing
this union the data type, such as Integer, Boolean, Set, or the Undef this union the data type, such as Integer, Boolean, Set, or the Undef
data type, plays a role. The details of the algorithm for combining data type, plays a role. The details of the algorithm for combining
permissions is described in Section 10. The resulting union permissions is described in Section 10. The resulting union
effectively represents a "mask" - it defines what information is effectively represents a "mask" - it defines what information is
exposed to the WR. This mask is applied to the actual location or exposed to the WR. This mask is applied to the actual location or
presence data for the PT, and the data which is permitted by the mask presence data for the PT, and the data which is permitted by the mask
is shown to the WR. If the WR request a subset of information only is shown to the WR. If the WR request a subset of information only
(such as city-level civil location data only, instead of the full (such as city-level civil location data only, instead of the full
civil location information), the information delivered to the WR MUST civil location information), the information delivered to the WR MUST
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6.1. Identification of Rules 6.1. Identification of Rules
Each rule is equipped with a parameter that identifies the rule. Each rule is equipped with a parameter that identifies the rule.
This rule identifier is an opaque token chosen by the RM. A RM MUST This rule identifier is an opaque token chosen by the RM. A RM MUST
NOT use the same identifier for two rules that are available to the NOT use the same identifier for two rules that are available to the
PS at the same time for a given PT. If more than one RM modifies the PS at the same time for a given PT. If more than one RM modifies the
same rule set then it needs to be ensured that a unique identifier is same rule set then it needs to be ensured that a unique identifier is
chosen for each rule. A RM can accomplish this goal by retrieving chosen for each rule. A RM can accomplish this goal by retrieving
the already specified ruleset and to choose a new identifier for a the already specified ruleset and to choose a new identifier for a
rule that is different from the values used by the rules in the rule rule that is different from the existing rule set.
set.
6.2. Extensions 6.2. Extensions
The policy framework defined in this document is meant to be The policy framework defined in this document is meant to be
extensible towards specific application domains. Such an extension extensible towards specific application domains. Such an extension
is accomplished by defining conditions, actions and transformations is accomplished by defining conditions, actions and transformations
that are specific to the desired application domain. Each extension that are specific to the desired application domain. Each extension
MUST define its own namespace. MUST define its own namespace.
Extensions cannot change the schema defined in this document, and Extensions cannot change the schema defined in this document, and
this schema is not expected to change excepting a revision to this this schema is not expected to change excepting a revision to this
specification, and that no versioning procedures for this schema or specification, and that no versioning procedures for this schema or
namespace are therefore provided. namespace are therfore provided.
7. Conditions 7. Conditions
The access to data items needs to be matched with the rule set stored The access to data items needs to be matched with the rule set stored
at the PS. Each instance of a request has different attributes at the PS. Each instance of a request has different attributes
(e.g., the identity of the requestor) that are used for (e.g., the identity of the requestor) that are used for
authorization. A rule in a rule set might have a number of authorization. A rule in a rule set might have a number of
conditions that need to be met before executing the remaining parts conditions that need to be met before executing the remaining parts
of a rule (i.e., actions and transformations). Details about rule of a rule (i.e., actions and transformations). Details about rule
matching are described in Section 10. This document specifies only a matching are described in Section 10. This document specifies only a
few conditions (i.e., identity, sphere, and validity). Further few conditions (i.e., identity, sphere, and validity). Further
condition elements can be added via extensions to this document. condition elements can be added via extensions to this document.
As noted in Section 5, conditions are matched on equality or "greater
than" style comparisons, rather than regular expressions. Equality
is determined according to the rules for the data type associated
with the element in the schema given in Section 13, unless explicit
comparison steps are included in this document. For xs:anyURI types,
readers may wish to consult [2] for its discussion xs:anyURI, as well
as the text in Section 13.
7.1. Identity Condition 7.1. Identity Condition
7.1.1. Overview 7.1.1. Overview
The identity condition restricts matching of a rule either to a The identity condition restricts matching of a rule either to a
single entity or a group of entities. Only authenticated entities single entity or a group of entitites. Only authenticated entities
can be matched; acceptable means of authentication are defined in can be matched; acceptable means of authentication are defined in
protocol-specific documents. If the <identity> element is absent, or protocol-specific documents. If the <identity> element is absent, or
it is present but is empty (meaning that there are no child it is present but is empty (meaning that there are no child
elements), identities are not considered, and thus, other conditions elements), identities are not considered, and thus, other conditions
in the rule apply to any user, authenticated or not. in the rule apply to any user, authenticated or not.
The <identity> condition is considered TRUE if any of its child The <identity> condition is considered TRUE if any of its child
elements (e.g., the <one/> and the <many/> elements defined in this elements (e.g., the <one/> and the <many/> elements defined in this
document) evaluate to TRUE, i.e., the results of the individual child document) evaluate to TRUE, i.e., the results of the individual child
element are combined using a logical OR. element are combined using a logical OR.
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<many> element then the result of each <except> element is combined <many> element then the result of each <except> element is combined
using a logical OR. using a logical OR.
Common policy MUST either use UTF-8 or UTF-16 to store domain names Common policy MUST either use UTF-8 or UTF-16 to store domain names
in the 'domain' attribute. For non-IDNs, lower-case ASCII SHOULD be in the 'domain' attribute. For non-IDNs, lower-case ASCII SHOULD be
used. For the comparison operation between the value stored in the used. For the comparison operation between the value stored in the
'domain' attribute and the domain value provided via the using 'domain' attribute and the domain value provided via the using
protocol (referred as "protocol domain identifier") the following protocol (referred as "protocol domain identifier") the following
rules are applicable: rules are applicable:
1. If the values of the 'domain' attribute and the value of the 1. Translate percent-encoding for either string.
protocol domain identifier does not begin with xn--, attempt a
string comparison. If the string comparison indicates equality,
the comparison succeeds and the remaining steps are skipped.
2. Translate percent-encoding for either string and repeat (1).
3. Convert both domain strings using the toASCII operation described 2. Convert both domain strings using the toASCII operation described
in RFC 3490 [2]. (Naturally, if one of the strings already in RFC 3490 [3].
begins with the ACE prefix xn--, the conversion operation has
already been performed.)
4. Compare the two domain strings for ASCII equality, for each 3. Compare the two domain strings for ASCII equality, for each
label. If the string comparison for each label indicates label. If the string comparison for each label indicates
equality, the comparison succeeds. Otherwise, the domains are equality, the comparison succeeds. Otherwise, the domains are
not equal. not equal.
If the conversion fails in step (3), the domains are not equal. If the conversion fails in step (2), the domains are not equal.
7.1.3.1. Matching Any Authenticated Identity 7.1.3.1. Matching Any Authenticated Identity
The <many/> element without any child elements or attributes matches The <many/> element without any child elements or attributes matches
any authenticated user. any authenticated user.
The following example shows a rule that matches any authenticated The following example shows such a rule that matches any
user: authenticated user:
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="urn:ietf:params:xml:ns:common-policy"> <ruleset xmlns="urn:ietf:params:xml:ns:common-policy">
<rule id="f3g44r5"> <rule id="f3g44r5">
<conditions> <conditions>
<identity> <identity>
<many/> <many/>
</identity> </identity>
</conditions> </conditions>
<actions/> <actions/>
<transformations/> <transformations/>
</rule> </rule>
</ruleset> </ruleset>
7.1.3.2. Matching Any User, Authenticated and Unauthenticated The following rule, in comparison, would match any user,
authenticated and unauthenticated:
If the <identity> element is used without child elements then it
matches any user, authenticated and unauthenticated. The same is
true for a rule where the <identity> element is omitted.
The following example shows two rules that match any user,
authenticated and unauthenticated.
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="urn:ietf:params:xml:ns:common-policy"> <ruleset xmlns="urn:ietf:params:xml:ns:common-policy">
<rule id="f3g44r5"> <rule id="f3g44r5">
<conditions> <conditions>
<identity/> <identity/>
</conditions> </conditions>
<actions/> <actions/>
<transformations/> <transformations/>
</rule> </rule>
<rule id="f3g44r57">
<conditions/>
<actions/>
<transformations/>
</rule>
</ruleset> </ruleset>
7.1.3.3. Matching Any Authenticated Identity Excepting Enumerated 7.1.3.2. Matching Any Authenticated Identity Excepting Enumerated
Domains/Identities Domains/Identities
The <many> element enclosing one or more <except domain="..."/> The <many> element enclosing one or more <except domain="..."/>
elements matches any user from any domain except those enumerated. elements matches any user from any domain except those enumerated.
The <except id="..."/> element excludes particular users. The The <except id="..."/> element excludes particular users. The
semantic of the 'id' attribute of the <except> element is described semantic of the 'id' attribute of the <except> element is described
in Section 7.2. The results of the child elements of the <many> in Section 7.2. The results of the child elements of the <many>
element are combined using a logical OR. element are combined using a logical OR.
An example is shown below: An example is shown below:
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="urn:ietf:params:xml:ns:common-policy"> <ruleset xmlns="urn:ietf:params:xml:ns:common-policy">
<rule id="f3g44r1"> <rule id="f3g44r1">
<conditions> <conditions>
<sphere value="work"/>
<identity> <identity>
<many> <many>
<except domain="example.com"/> <except domain="example.com"/>
<except domain="example.org"/> <except domain="example.org"/>
<except id="sip:alice@bad.example.net"/> <except id="sip:alice@bad.example.net"/>
<except id="sip:bob@good.example.net"/> <except id="sip:bob@good.example.net"/>
<except id="tel:+1-212-555-1234" /> <except id="tel:+1-212-555-1234" />
<except id="sip:alice@example.com"/> <except id="sip:alice@example.com"/>
</many> </many>
</identity> </identity>
<validity>
<from>2003-12-24T17:00:00+01:00</from>
<until>2003-12-24T19:00:00+01:00</until>
</validity>
</conditions> </conditions>
<actions/> <actions/>
<transformations/> <transformations/>
</rule> </rule>
</ruleset> </ruleset>
This example matches all users except any user in example.com, or any This example matches all users except any user in example.com, or any
user in example.org or the particular users alice@bad.example.net, user in example.org or the particular users alice@bad.example.net,
bob@good.example.net and the user with the telephone number bob@good.example.net and the user with the telephone number
'tel:+1-212-555-1234'. The last 'except' element is redundant since 'tel:+1-212-555-1234'. The last 'except' element is redundant since
alice@example.com is already excluded through the following statement alice@example.com is already excluded through the first line.
<except domain="example.com"/> in the example.
7.1.3.4. Matching Any Authenticated Identity Within a Domain Excepting 7.1.3.3. Matching Any Authenticated Identity Within a Domain Excepting
Enumerated Identities Enumerated Identities
The <many> element with a 'domain' attribute and zero or more <except The <many> element with a 'domain' attribute and zero or more <except
id="..."/> elements matches any authenticated user from the indicated id="..."/> elements matches any authenticated user from the indicated
domain except those explicitly enumerated. The semantic of the 'id' domain except those explicitly enumerated. The semantic of the 'id'
attribute of the <except> element is described in Section 7.2. attribute of the <except> element is described in Section 7.2.
It is nonsensical to have domains in the 'id' attribute that do not It is nonsensical to have domains in the 'id' attribute that do not
match the value of the 'domain' attribute in the enclosing <many> match the value of the 'domain' attribute in the enclosing <many>
element. element.
skipping to change at page 19, line 36 skipping to change at page 19, line 36
7.2. Single Entity 7.2. Single Entity
The 'id' attribute used in the <one> and in the <except> element The 'id' attribute used in the <one> and in the <except> element
refers to a single entity. In the subsequent text we use the term refers to a single entity. In the subsequent text we use the term
'single-user' entity as a placeholder for the <one> and the <except> 'single-user' entity as a placeholder for the <one> and the <except>
element. The <except> element fulfills the purpose of excluding element. The <except> element fulfills the purpose of excluding
elements from the solution set. elements from the solution set.
A single-user entity matches the authenticated identity (as contained A single-user entity matches the authenticated identity (as contained
in the 'id' attribute) of exactly one entity or user. If there is a in the 'id' attribute) of exactly one entity or user. If there is a
match, the single-user entity is considered TRUE. The single-user match, the single-user entity is considered TRUE. The single- user
entity MUST NOT contain a 'domain' attribute. entity MUST NOT contain a 'domain' attribute.
The 'id' attribute contains an identity that MUST be expressed as The 'id' attribute contains an identity that MUST first be expressed
URI. Applications using this framework must describe how the as a URI. Applications using this framework must describe how the
identities they are using can be expressed as a URIs. identities they are using can be expressed as a URIs.
7.3. Sphere 7.3. Sphere
The <sphere> element belongs to the group of condition elements. It The <sphere> element belongs to the group of condition elements. It
can be used to indicate a state (e.g., 'work', 'home', 'meeting', can be used to indicate a state (e.g., 'work', 'home', 'meeting',
'travel') the PT is currently in. A sphere condition matches only if 'travel') the PT is currently in. A sphere condition matches only if
the PT is currently in the state indicated. The state may be the PT is currently in the state indicated. The state may be
conveyed by manual configuration or by some protocol. For example, conveyed by manual configuration or by some protocol. For example,
RPID [11] provides the ability to inform the PS of its current RPID [10] provides the ability to inform the PS of its current
sphere. The application domain needs to describe in more detail how sphere. The application domain needs to describe in more detail how
the sphere state is determined. Switching from one sphere to another the sphere state is determined. Switching from one sphere to another
causes a switch between different modes of visibility. As a result causes a switch between different modes of visibility. As a result
different subsets of rules might be applicable. different subsets of rules might be applicable.
The content of the 'value' attribute of the <sphere> element MAY The content of the 'value' attribute of the <sphere> element MAY
contain more than one token. The individual tokens MUST be separated contain more than one token. The individual tokens MUST be separated
by a blank character. A logical OR is used for the matching the by a blank character. A logical OR is used for the matching the
tokens against the sphere settings of the PT. As an example, if the tokens against the sphere settings of the PT. As an example, if the
content of the 'value' attribute in the sphere attribute contains two the content of the 'value' attribute in the sphere attribute contains
tokens 'work' and 'home' then this part of the rule matches if the two tokens 'work' and 'home' then this part of the rule matches if
sphere for a particular PT is either 'work' or 'home'. To compare the sphere for a particular PT is either 'work' OR 'home'. To
the content of the 'value' attribute in the <sphere> element with the compare the content of the 'value' attribute in the <sphere> element
stored state information about the PT's sphere setting a case with the stored state information about the PT's sphere setting a
insensitive string comparison MUST be used for each individual token. case insensitive string comparison MUST be used for each individual
There is no registry for these values nor a language specific token. There is no registry for these values nor a language specific
indication of the sphere content. As such, the tokens are treated as indication of the sphere content. As such, the tokens are treated as
opaque strings. opaque strings.
The rule example below illustrates that the rule with the entity
andrew@example.com matches if the sphere is been set to 'work'. In
the second rule with the entity allison@example.com matches if the
sphere is set to 'home'. The third rule also matches if the sphere
is set to 'home' since the value in the sphere element also contains
the token 'home'.
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="urn:ietf:params:xml:ns:common-policy"> <ruleset xmlns="urn:ietf:params:xml:ns:common-policy">
<rule id="f3g44r2"> <rule id="f3g44r2">
<conditions> <conditions>
<sphere value="work"/> <sphere value="work"/>
<identity> <identity>
<one id="sip:andrew@example.com"/> <one id="sip:andrew@example.com"/>
</identity> </identity>
</conditions> </conditions>
skipping to change at page 21, line 42 skipping to change at page 21, line 42
<identity> <identity>
<one id="sip:john@doe.example.com"/> <one id="sip:john@doe.example.com"/>
</identity> </identity>
<sphere value="home work"/> <sphere value="home work"/>
</conditions> </conditions>
<actions/> <actions/>
<transformations/> <transformations/>
</rule> </rule>
</ruleset> </ruleset>
The rule example above illustrates that the rule with the entity
andrew@example.com matches if the sphere is been set to 'work'. In
the second rule with the entity allison@example.com matches if the
sphere is set to 'home'. The third rule also matches since the the
value in the sphere element also contains the token 'home'.
7.4. Validity 7.4. Validity
The <validity> element is the third condition element specified in The <validity> element is the third condition element specified in
this document. It expresses the rule validity period by two this document. It expresses the rule validity period by two
attributes, a starting and a ending time. The validity condition is attributes, a starting and a ending time. The validity condition is
TRUE if the current time is greater than or equal to at least one TRUE if the current time is greater than or equal to at least one
<from> child, but less than the <until> child after it. This <from> child, but less than the <until> child after it. This
represents a logical OR operation across each <from> and <until> represents a logical OR operation across each <from> and <until>
pair. Times are expressed in XML dateTime format. pair. Times are expressed in XML dateTime format. A rule maker
might not have always access to the PS to invalidate some rules which
A rule maker might not always have access to the PS to invalidate grant permissions. Hence this mechanism allows to invalidate granted
rules. Hence, this mechanism allows to invalidate granted
permissions automatically without further interaction between the permissions automatically without further interaction between the
rule maker and the PS. The PS does not remove the rules instead the rule maker and the PS. The PS does not remove the rules instead the
rule maker has to clean them up. rule maker has to clean them up.
An example of a rule fragment is shown below: An example of a rule fragment is shown below:
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="urn:ietf:params:xml:ns:common-policy"> <ruleset xmlns="urn:ietf:params:xml:ns:common-policy">
<rule id="f3g44r3"> <rule id="f3g44r3">
skipping to change at page 23, line 17 skipping to change at page 23, line 17
While conditions are the 'if'-part of rules, actions and While conditions are the 'if'-part of rules, actions and
transformations build the 'then'-part of them. The actions and transformations build the 'then'-part of them. The actions and
transformations parts of a rule determine which operations the PS transformations parts of a rule determine which operations the PS
MUST execute after having received from a WR a data access request MUST execute after having received from a WR a data access request
that matches all conditions of this rule. Actions and that matches all conditions of this rule. Actions and
transformations only permit certain operations; there is no 'deny' transformations only permit certain operations; there is no 'deny'
functionality. Transformations exclusively specify PS-side functionality. Transformations exclusively specify PS-side
operations that lead to a modification of the data items requested by operations that lead to a modification of the data items requested by
the WR. Regarding location data items, for instance, a the WR. Regarding location data items, for instance, a
transformation could force the PS to lower the precision of the transformation could force the PS to lower the precision of the
location information that is returned to the WR. location information which is returned to the WR.
Actions, on the other hand, specify all remaining types of operations Actions, on the other hand, specify all remaining types of operations
the PS is obliged to execute, i.e., all operations that are not of the PS is obliged to execute, i.e., all operations that are not of
transformation type. Actions are defined by application specific transformation type. Actions are defined by application specific
usages of this framework. The reader is referred to the usages of this framework. The reader is referred to the
corresponding extensions to see examples of such elements. corresponding extensions to see examples of such elements.
9. Transformations 9. Transformations
Two sub-parts follow the conditions part of a rule: transformations Two sub-parts follow the conditions part of a rule: transformations
skipping to change at page 25, line 7 skipping to change at page 25, line 7
operations that the PS MUST execute and that modify the result which operations that the PS MUST execute and that modify the result which
is returned to the WR. This functionality is particularly helpful in is returned to the WR. This functionality is particularly helpful in
reducing the granularity of information provided to the WR, as for reducing the granularity of information provided to the WR, as for
example required for location privacy. Transformations are defined example required for location privacy. Transformations are defined
by application specific usages of this framework. by application specific usages of this framework.
A simple transformation example is provided in Section 10. A simple transformation example is provided in Section 10.
10. Procedure for Combining Permissions 10. Procedure for Combining Permissions
10.1. Introduction
This section describes the mechanism to evaluate the final result of This section describes the mechanism to evaluate the final result of
a rule evaluation. The result is reflected in the action and a rule evaluation. The result is reflected in the action and
transformation part of a rule. This procedure is sometimes referred transformation part of a rule. This procedure is sometimes referred
as conflict resolution. as conflict resolution.
To simplify the description of the algorithm we introduce the term We use the following terminology (which in parts has already been
'item' to refer to child elements and attributes of these child introduced in previous sections): The term 'permission' stands for an
elements that apear in the condition, action and transformation part action or a transformation. The notion 'attribute' terms a
of a rule. An item has a name and a data type. A value may be condition, an action, or a transformation. An attribute has a name,
assigned to an item or it may be undefined, in case it does not have and a certain data type. A value may be assigned to an attribute or
a value associated with the item. The values of a particular item it may be undefined, in case it does not have a value associated with
have the same data type. For example, the name of the item <sphere> the attribute. For example, the name of the <sphere> attribute
discussed in Section 7 is 'sphere', its data type is 'string', and discussed in Section 7 is 'sphere', its data type is 'string', and
its value may be set to 'home'. To evaluate a condition means to its value may be set to 'home'. To evaluate a condition means to
associate either TRUE or FALSE to the condition. associate either TRUE or FALSE to the condition. Please note that
the <identity> element is a condition whereas the <id> element is a
parameter of that condition. A rule matches if all conditions
contained in the conditions part of a rule evaluate to TRUE.
When the PS receives a request for access to privacy-sensitive data When the PS receives a request for access to privacy-sensitive data
then it needs to be matched against a rule set. The conditions part then it needs to be matched against a rule set. The conditions part
of each individual rule is evaluated and as a result one or more of each individual rule is evaluated and as a result one or more
rules might match. If only a single rule matches then the result is rules might match. If only a single rule matches then the result is
determined by executing the actions and the transformations part determined by executing the actions and the transformations part
following the conditions part of a rule. However, it can also be the following the conditions part of a rule. However, it can also be the
case that two or more matching rules contain a permission of the same case that two or more matching rules contain a permission of the same
name (e.g., two rules contain a permission named 'precision of name (e.g., two rules contain a permission named 'precision of
geospatial location information'), but do not specify the same value geospatial location information'), but do not specify the same value
for that permission (e.g., the two rule might specify values of '10 for that permission (e.g., the two rule might specify values of '10
km' and '200 km', respectively, for the permission named 'precision km' and '200 km', respectively, for the permission named 'precision
of geospatial location information'). This section describes the of geospatial location information'). This section describes the
procedure for combining permissions in such cases. procedure for combining permissions in such cases.
The combining operation will result in the largest value for an 10.2. Algorithm
integer type, the OR operation for a boolean type, and union for a
set.
As such, applications should define values such that, for integers,
the lowest value corresponds to the most privacy, for booleans, false
corresponds to the most privacy, and for sets, the empty set
corresponds to the most privacy.
10.1. Algorithm
The algorithm for combining permissions is simple and depends on the The combining rules are simple and depend on the data types of the
data types of the values of items: Let P be a rule set. Let M be the values of permissions: Let P be a policy. Let M be the subset of P
subset of P consisting of rules r in P that match with respect to a consisting of rules r in P that match with respect to a given
given request. Let n be a name of an item contained in a rule r in request. Let n be a name of a permission contained in a rule r in M,
M, and let M(n) be the subset of M consisting of rules r in M that and let M(n) be the subset of M consisting of rules r in M that have
have a item of name n. For each rule r in M(n), let v(r,n) and a permission of name n. For each rule r in M(n), let v(r,n) and
d(r,n) be the value and the data type, respectively, of the item of r d(r,n) be the value and the data type, respectively, of the attribute
with name n. Finally, let V(n) be the combined value of all the of r with name n. Finally, let V(n) be the combined value of all the
values v(r,n), r in M(n). The algorithm that leads to the resulting permissions values v(r,n), r in M(n). The combining rules that lead
value V(n) is the following: to the resulting value V(n) are the following:
CR 1: If d(r,n)=Boolean for all r in M(n), then V(n) is given as CR 1: If d(r,n)=Boolean for all r in M(n), then V(n) is given as
follows: If there is a r in M(n) with v(r,n)=TRUE, then V(n)=TRUE. follows: If there is a r in M(n) with v(r,n)=TRUE, then V(n)=TRUE.
Otherwise, V(n)=FALSE. Otherwise, V(n)=FALSE.
CR 2: If d(r,n)=Integer for all r in M(n), then V(n) is given as CR 2: If d(r,n)=Integer for all r in M(n), then V(n) is given as
follows: If v(r,n)=undefined for all r in M(n), then V(n) is not follows: If v(r,n)=undefined for all r in M(n), then V(n) is not
specified by this specification. Otherwise, V(n)=max{v(r,n) | r specified by this specification. Otherwise, V(n)=max{v(r,n) | r
in M(n)}. in M(n)}.
CR 3: If d(r,n)=Set for all r in M(n), then V(n) is given as CR 3: If d(r,n)=Set for all r in M(n), then V(n) is given as
follows: V(n)=union of all v(r,n), the union to be computed over all follows: V(n)=union of all v(r,n), the union to be computed over all
r in M(n) with v(r,n)!=undefined. r in M(n) with v(r,n)!=undefined.
10.2. Example The combining operation will result in the largest value for an
Integral type, the OR operation for boolean, and union for set.
In the following example we illustrate the process of the combining As a result, applications should define values such that, for
permissions algorithm. We will consider three items in the integers, the lowest value corresponds to the most privacy, for
conditions part in our example, namely identity, sphere, and booleans, false corresponds to the most privacy, and for sets, the
validity. For editorial reasons the rule set in this example is empty set corresponds to the most privacy.
represented in a table. Furthermore, the domain part of the identity
of the WR is omitted. For actions we use two items in the action
part of the rule with names X and Y. The values of X and Y are of
data types boolean and integer, respectively. For transformations we
use the item with the name Z whose value can be set either to '+'(or
1), 'o' (or 2) or '-' (or 3). Item Z allows us to show the
granularity reduction whereby a value of '+' shows the corresponding
information unrestricted and '-' shows nothing. This item might be
related to location information or other presence attributes like
mood. Internally we use the data type integer for computing the
permission of this item.
Conditions Actions/Transformations 10.3. Example
+---------------------------------+----------------------+
| Id WR-ID sphere from until | X Y Z |
+---------------------------------+----------------------+
| 1 bob home A1 A2 | TRUE 10 o |
| 2 alice work A1 A2 | FALSE 5 + |
| 3 bob work A1 A2 | TRUE 3 - |
| 4 tom work A1 A2 | TRUE 5 + |
| 5 bob work A1 A3 | undef 12 o |
| 6 bob work B1 B2 | FALSE 10 - |
+---------------------------------+----------------------+
For editorial reasons we use the items 'from' and 'until' to refer to In the following example we illustrate the process of combining
validity and we use the following abbreviations for the values: permissions. We will consider three conditions for our purpose,
namely those of name identity, sphere, and validity. For editorial
reasons the rule set in this example is represented in a table.
Furthermore, the domain part of the identity of the WR is omitted.
For actions we use two permissions with names X and Y. The values of
X and Y are of data types Boolean and Integer, respectively.
Permission X might, for example, represent the <sub-handling> action.
For transformations we use the attribute with the name Z whose value
can be set either to '+'(or 1), 'o' (or 2) or '-' (or 3). Permission
Z allows us to show the granularity reduction whereby a value of '+'
shows the corresponding information unrestricted and '-' shows
nothing. This permission might be related to location information or
other presence attributes like mood. Internally we use the data type
Integer for computing the permission of this attribute.
Conditions Actions/Transformations
+---------------------------------+---------------------+
| Id WR-ID sphere from until | X Y Z |
+---------------------------------+---------------------+
| 1 bob home A1 A2 | TRUE 10 o |
| 2 alice work A1 A2 | FALSE 5 + |
| 3 bob work A1 A2 | TRUE 3 - |
| 4 tom work A1 A2 | TRUE 5 + |
| 5 bob work A1 A3 | undef 12 o |
| 6 bob work B1 B2 | FALSE 10 - |
+---------------------------------+---------------------+
Again for editorial reasons, we use the following abbreviations for
the two <validity> attributes 'from' and 'until':
A1=2003-12-24T17:00:00+01:00 A1=2003-12-24T17:00:00+01:00
A2=2003-12-24T21:00:00+01:00 A2=2003-12-24T21:00:00+01:00
A3=2003-12-24T23:30:00+01:00 A3=2003-12-24T23:30:00+01:00
B1=2003-12-22T17:00:00+01:00 B1=2003-12-22T17:00:00+01:00
B2=2003-12-23T17:00:00+01:00 B2=2003-12-23T17:00:00+01:00
Note that B1 < B2 < A1 < A2 < A3. Note that B1 < B2 < A1 < A2 < A3.
The entity 'bob' acts as a WR. The policy P consists of the six The entity 'bob' acts as a WR and requests data items. The policy P
rules shown in the table and identified by the values 1 to 6 in the consists of the six rules shown in the table and identified by the
'Id' column. The PS receives the query at 2003-12-24T17:15:00+01:00 values 1 to 6 in the 'Id' column. The PS receives the query at 2003-
which falls between A1 and A2. The value of the item 'sphere' 12-24T17:15:00+01:00 which falls between A1 and A2. The value of the
indicates that the sphere of PT is currently set to 'work'. attribute with name 'sphere' indicating the state the PT is currently
in is set to 'work'.
Rule 1 does not match since the sphere condition does not match. Rule 1 does not match since the sphere condition does not match.
Rule 2 does not match as the identity of the WR (here 'alice') does Rule 2 does not match as the identity of the WR (here 'alice') does
not equal 'bob'. Rule 3 matches since all conditions evaluate to not equal 'bob'. Rule 3 matches since all conditions evaluate to
TRUE. Rule 4 does not match as the identity of the WR (here 'tom') TRUE. Rule 4 does not match as the identity of the WR (here 'tom')
does not equal 'bob'. Rule 5 matches. Rule 6 does not match since does not equal 'bob'. Rule 5 matches. Rule 6 does not match since
the rule is not valid anymore. Therefore, the set M of matching the rule is not valid anymore. Therefore, the set M of matching
rules consists of the rules 3 and 5. These two rules are used to rules consists of the rules 3 and 5. These two rules are used to
compute the combined permission V(X), V(Y), and V(Z) for each of the compute the combined permission V(X), V(Y), and V(Z) for each of the
permissions X, Y, and Z: permissions X, Y, and Z:
Actions/Transformations Actions/Transformations
+-----+-----------------------+ +-----+-----------------------+
| Id | X Y Z | | Id | X Y Z |
+-----+-----------------------+ +-----+-----------------------+
| 3 | TRUE 3 - | | 3 | TRUE 3 - |
| 5 | undef 12 o | | 5 | undef 12 o |
+-----+-----------------------+ +-----+-----------------------+
The results of the permission combining algorithm is shown below. The results of the permission combining algorithm is shown below.
The combined value V(X) regarding the permission with name X equals The combined value V(X) regarding the permission with name X equals
TRUE according to the first combining rule listed above. The maximum TRUE according to the first combining rule listed above. The maximum
skipping to change at page 29, line 7 skipping to change at page 29, line 7
Actions/Transformations Actions/Transformations
+-----+-----------------------+ +-----+-----------------------+
| Id | X Y Z | | Id | X Y Z |
+-----+-----------------------+ +-----+-----------------------+
| 5 | TRUE 12 - | | 5 | TRUE 12 - |
+-----+-----------------------+ +-----+-----------------------+
11. Meta Policies 11. Meta Policies
Meta policies authorize a rule maker to insert, update or delete a Meta policies authorize a rulemaker to insert, update or delete a
particular rule or an entire rule set. Some authorization policies particular rule or an entire rule set. Some authorization policies
are required to prevent unauthorized modification of rule sets. Meta are required to prevent unauthorized modification of rule sets. Meta
policies are outside the scope of this document. policies are outside the scope of this document.
A simple implementation could restrict access to the rule set only to A simple implementation could restrict access to the rule set only to
the PT but more sophisticated mechanisms could be useful. As an the PT but more sophisticated mechanisms could be useful. As an
example of such policies one could think of parents configuring the example of such policies one could think of parents configuring the
policies for their children. policies for their children.
12. Example 12. Example
skipping to change at page 31, line 10 skipping to change at page 31, line 10
<actions/> <actions/>
<transformations/> <transformations/>
</rule> </rule>
</ruleset> </ruleset>
13. XML Schema Definition 13. XML Schema Definition
This section provides the XML schema definition for the common policy This section provides the XML schema definition for the common policy
markup language described in this document. markup language described in this document.
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="urn:ietf:params:xml:ns:common-policy" <xs:schema targetNamespace="urn:ietf:params:xml:ns:common-policy"
xmlns:cp="urn:ietf:params:xml:ns:common-policy" xmlns:cp="urn:ietf:params:xml:ns:common-policy"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified" attributeFormDefault="unqualified"> elementFormDefault="qualified" attributeFormDefault="unqualified">
<!-- /ruleset --> <!-- /ruleset -->
<xs:element name="ruleset"> <xs:element name="ruleset">
<xs:complexType> <xs:complexType>
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:sequence> <xs:sequence>
<xs:element name="rule" type="cp:ruleType" <xs:element name="rule" type="cp:ruleType"
minOccurs="0" maxOccurs="unbounded"/> minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence> </xs:sequence>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
</xs:element> </xs:element>
<!-- /ruleset/rule --> <!-- /ruleset/rule -->
<xs:complexType name="ruleType"> <xs:complexType name="ruleType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:sequence> <xs:sequence>
<xs:element name="conditions" <xs:element name="conditions"
type="cp:conditionsType" minOccurs="0"/> type="cp:conditionsType" minOccurs="0"/>
<xs:element name="actions" <xs:element name="actions"
type="cp:extensibleType" minOccurs="0"/> type="cp:extensibleType" minOccurs="0"/>
<xs:element name="transformations" <xs:element name="transformations"
type="cp:extensibleType" minOccurs="0"/> type="cp:extensibleType" minOccurs="0"/>
</xs:sequence> </xs:sequence>
<xs:attribute name="id" type="xs:ID" use="required"/> <xs:attribute name="id" type="xs:ID" use="required"/>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //rule/conditions --> <!-- //rule/conditions -->
<xs:complexType name="conditionsType"> <xs:complexType name="conditionsType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:choice maxOccurs="unbounded"> <xs:choice maxOccurs="unbounded">
<xs:element name="identity" <xs:element name="identity"
type="cp:identityType" minOccurs="0"/> type="cp:identityType" minOccurs="0"/>
<xs:element name="sphere" <xs:element name="sphere"
type="cp:sphereType" minOccurs="0"/> type="cp:sphereType" minOccurs="0"/>
<xs:element name="validity" <xs:element name="validity"
type="cp:validityType" minOccurs="0"/> type="cp:validityType" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" <xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/> minOccurs="0" maxOccurs="unbounded"/>
</xs:choice> </xs:choice>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //conditions/identity --> <!-- //conditions/identity -->
<xs:complexType name="identityType"> <xs:complexType name="identityType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="one" type="cp:oneType"/> <xs:element name="one" type="cp:oneType"/>
<xs:element name="many" type="cp:manyType"/> <xs:element name="many" type="cp:manyType"/>
<xs:any namespace="##other" processContents="lax"/> <xs:any namespace="##other" processContents="lax"/>
</xs:choice> </xs:choice>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //identity/one --> <!-- //identity/one -->
<xs:complexType name="oneType"> <xs:complexType name="oneType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:sequence> <xs:sequence>
<xs:any namespace="##other" <xs:any namespace="##other"
minOccurs="0" processContents="lax"/> minOccurs="0" processContents="lax"/>
</xs:sequence> </xs:sequence>
<xs:attribute name="id" <xs:attribute name="id"
type="xs:anyURI" use="required"/> type="xs:anyURI" use="required"/>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //identity/many --> <!-- //identity/many -->
<xs:complexType name="manyType"> <xs:complexType name="manyType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="except" type="cp:exceptType"/> <xs:element name="except" type="cp:exceptType"/>
<xs:any namespace="##other" <xs:any namespace="##other"
minOccurs="0" processContents="lax"/> minOccurs="0" processContents="lax"/>
</xs:choice> </xs:choice>
<xs:attribute name="domain" <xs:attribute name="domain"
use="optional" type="xs:string"/> use="optional" type="xs:string"/>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //many/except --> <!-- //many/except -->
<xs:complexType name="exceptType"> <xs:complexType name="exceptType">
<xs:attribute name="domain" type="xs:string" use="optional"/> <xs:attribute name="domain" type="xs:string" use="optional"/>
<xs:attribute name="id" type="xs:anyURI" use="optional"/> <xs:attribute name="id" type="xs:anyURI" use="optional"/>
</xs:complexType> </xs:complexType>
<!-- //conditions/sphere --> <!-- //conditions/sphere -->
<xs:complexType name="sphereType"> <xs:complexType name="sphereType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:attribute name="value" <xs:attribute name="value"
type="xs:string" use="required"/> type="xs:string" use="required"/>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //conditions/validity --> <!-- //conditions/validity -->
<xs:complexType name="validityType"> <xs:complexType name="validityType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:sequence minOccurs="0" maxOccurs="unbounded"> <xs:sequence minOccurs="0" maxOccurs="unbounded">
<xs:element name="from" type="xs:dateTime"/> <xs:element name="from" type="xs:dateTime"/>
<xs:element name="until" type="xs:dateTime"/> <xs:element name="until" type="xs:dateTime"/>
</xs:sequence> </xs:sequence>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
<!-- //rule/actions or //rule/transformations --> <!-- //rule/actions or //rule/transformations -->
<xs:complexType name="extensibleType"> <xs:complexType name="extensibleType">
<xs:complexContent> <xs:complexContent>
<xs:restriction base="xs:anyType"> <xs:restriction base="xs:anyType">
<xs:sequence> <xs:sequence>
<xs:any namespace="##other" <xs:any namespace="##other"
processContents="lax" minOccurs="0" maxOccurs="unbounded"/> processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence> </xs:sequence>
</xs:restriction> </xs:restriction>
</xs:complexContent> </xs:complexContent>
</xs:complexType> </xs:complexType>
</xs:schema> </xs:schema>
14. Security Considerations 14. Security Considerations
This document describes a framework for policies. This framework is This document describes a framework for policies. This framework is
intended to be enhanced elsewhere towards application domain specific intended to be enhanced elsewhere towards application domain specific
data. Security considerations are to a great extent application data data. Security considerations are to a great extent application data
dependent, and therefore need to be covered by documents that extend dependent, and therefore need to be covered by documents that extend
the framework defined in this specification. RFC 3693 [9] and RFC the framework defined in this specification. However, new action and
3694 [3] are good sources to consider for the type of analysis transformation permissions along with their allowed values must be
required by such documents and applications. defined in a way so that the usage of the permissions combining rules
of Section 10 does not lower the level of privacy protection. See
Extensions to the action and transformation elements must be defined Section 10 for more details on this privacy issue.
in a way so that the usage of the permissions combining rules of
Section 10 does not lower the level of privacy protection. This is
particularly important when defining the semantic of the a more
detailed description of the values for the defined attributes and
elements. See Section 10 for more details on this privacy aspect.
15. IANA Considerations 15. IANA Considerations
This section registers a new XML namespace, a new XML schema and a This section registers a new XML namespace, a new XML schema and a
new MIME-type. This section registers a new XML namespace per the new MIME-type. This section registers a new XML namespace per the
procedures in [4]. procedures in [4].
15.1. Common Policy Namespace Registration 15.1. Common Policy Namespace Registration
URI: urn:ietf:params:xml:ns:common-policy URI: urn:ietf:params:xml:ns:common-policy
Registrant Contact: IETF Geopriv Working Group, Henning Schulzrinne Registrant Contact: IETF Geopriv Working Group, Henning Schulzrinne
(hgs+geopriv@cs.columbia.edu). (hgs+geopriv@cs.columbia.edu).
XML: XML:
BEGIN BEGIN
<?xml version="1.0"?> <?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN" <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd"> "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"> <html xmlns="http://www.w3.org/1999/xhtml">
<head> <head>
skipping to change at page 35, line 47 skipping to change at page 35, line 47
</body> </body>
</html> </html>
END END
15.2. Content-type registration for 'application/auth-policy+xml' 15.2. Content-type registration for 'application/auth-policy+xml'
This specification requests the registration of a new MIME type This specification requests the registration of a new MIME type
according to the procedures of RFC 4288 [5] and guidelines in RFC according to the procedures of RFC 4288 [5] and guidelines in RFC
3023 [6]. 3023 [6].
MIME media type name: application MIME media type name: application
MIME subtype name: auth-policy+xml MIME subtype name: auth-policy+xml
Mandatory parameters: none Mandatory parameters: none
Optional parameters: charset Optional parameters: charset
Indicates the character encoding of enclosed XML. Indicates the character encoding of enclosed XML.
Encoding considerations: Encoding considerations:
Uses XML, which can employ 8-bit characters, depending on the Uses XML, which can employ 8-bit characters, depending on the
character encoding used. See RFC 3023 [6], Section 3.2. character encoding used. See RFC 3023 [6], Section 3.2.
Security considerations: Security considerations:
This content type is designed to carry authorization policies. This content type is designed to carry authorization policies.
Appropriate precautions should be adopted to limit disclosure of Appropriate precautions should be adopted to limit disclosure of
this information. Please refer to Section 14 of RFCXXXX [NOTE TO this information. Please refer to Section 14 of RFCXXXX [NOTE TO
IANA/RFC-EDITOR: Please replace XXXX with the RFC number of this IANA/RFC-EDITOR: Please replace XXXX with the RFC number of this
specification.] and to the security considerations described in specification.] and to the security considerations described in
Section 10 of RFC 3023 [6] for more information. Section 10 of RFC 3023 [6] for more information.
Interoperability considerations: None Interoperability considerations: None
Published specification: RFCXXXX [NOTE TO IANA/RFC-EDITOR: Please Published specification: RFCXXXX [NOTE TO IANA/RFC-EDITOR: Please
replace XXXX with the RFC number of this specification.] this replace XXXX with the RFC number of this specification.] this
document document
Applications which use this media type: Applications which use this media type:
Presence- and location-based systems Presence- and location-based systems
Additional information: Additional information:
Magic Number: None Magic Number: None
File Extension: .apxml File Extension: .apxml
Macintosh file type code: 'TEXT' Macintosh file type code: 'TEXT'
Personal and email address for further information: Hannes Personal and email address for further information: Hannes
Tschofenig, Hannes.Tschofenig@siemens.com Tschofenig, Hannes.Tschofenig@siemens.com
Intended usage: LIMITED USE Intended usage: LIMITED USE
Author/Change controller: Author:
This specification is a work item of the IETF GEOPRIV working This specification is a work item of the IETF GEOPRIV working
group, with mailing list address <geopriv@ietf.org>. group, with mailing list address <geopriv@ietf.org>.
Change controller:
The IESG <iesg@ietf.org>
15.3. Common Policy Schema Registration 15.3. Common Policy Schema Registration
URI: urn:ietf:params:xml:schema:common-policy URI: urn:ietf:params:xml:schema:common-policy
Registrant Contact: IETF Geopriv Working Group, Henning Schulzrinne Registrant Contact: IETF Geopriv Working Group, Henning Schulzrinne
(hgs+geopriv@cs.columbia.edu). (hgs+geopriv@cs.columbia.edu).
XML: The XML schema to be registered is contained in Section 13. Its XML: The XML schema to be registered is contained in Section 13.
first line is Its first line is
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
and its last line is and its last line is
</xs:schema> </xs:schema>
16. References 16. References
16.1. Normative References 16.1. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", March 1997. Levels", March 1997.
[2] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing [2] Duerst, M. and M. Suignard, "Internationalized Resource
Domain Names in Applications (IDNA)", RFC 3490, March 2003. Identifiers (IRIs)", RFC 3987, January 2005.
[3] Danley, M., Mulligan, D., Morris, J., and J. Peterson, "Threat [3] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing
Analysis of the Geopriv Protocol", RFC 3694, February 2004. Domain Names in Applications (IDNA)", RFC 3490, March 2003.
[4] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, [4] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004. January 2004.
[5] Freed, N. and J. Klensin, "Media Type Specifications and [5] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005. Registration Procedures", BCP 13, RFC 4288, December 2005.
[6] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types", [6] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types",
RFC 3023, January 2001. RFC 3023, January 2001.
16.2. Informative References 16.2. Informative References
[7] Rosenberg, J., "Presence Authorization Rules", [7] Rosenberg, J., "Presence Authorization Rules",
draft-ietf-simple-presence-rules-06 (work in progress), draft-ietf-simple-presence-rules-07 (work in progress),
May 2006. June 2006.
[8] Schulzrinne, H., "A Document Format for Expressing Privacy [8] Schulzrinne, H., "A Document Format for Expressing Privacy
Preferences for Location Information", Preferences for Location Information",
draft-ietf-geopriv-policy-08 (work in progress), February 2006. draft-ietf-geopriv-policy-08 (work in progress), February 2006.
[9] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J. [9] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J.
Polk, "Geopriv Requirements", RFC 3693, February 2004. Polk, "Geopriv Requirements", RFC 3693, February 2004.
[10] Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence [10] Schulzrinne, H., Gurbani, V., Kyzivat, P., and J. Rosenberg,
and Instant Messaging", RFC 2778, February 2000. "RPID: Rich Presence Extensions to the Presence Information
Data Format (PIDF)", RFC 4480, July 2006.
[11] Schulzrinne, H., "RPID: Rich Presence Extensions to the
Presence Information Data Format (PIDF)",
draft-ietf-simple-rpid-10 (work in progress), December 2005.
Appendix A. Contributors Appendix A. Contributors
We would like to thank Christian Guenther for his help with initial We would like to thank Christian Guenther for his help with initial
versions of this document. versions of this document.
Appendix B. Acknowledgments Appendix B. Acknowledgments
This document is partially based on the discussions within the IETF This document is partially based on the discussions within the IETF
GEOPRIV working group. Discussions at the Geopriv Interim Meeting GEOPRIV working group. Discussions at the Geopriv Interim Meeting
skipping to change at page 40, line 26 skipping to change at page 40, line 26
Peterson <jon.peterson@neustar.biz> for discussing a number of Peterson <jon.peterson@neustar.biz> for discussing a number of
details with us. They helped us to improve the quality of this details with us. They helped us to improve the quality of this
document. Allison, Ted and Andrew also helped us to make good document. Allison, Ted and Andrew also helped us to make good
progress with the internationalization support of the identifier/ progress with the internationalization support of the identifier/
domain attributes. domain attributes.
Furthermore, we would like to thank the IETF SIMPLE working group for Furthermore, we would like to thank the IETF SIMPLE working group for
their discussions of J. Rosenberg's draft on presence authorization their discussions of J. Rosenberg's draft on presence authorization
policies. We would also like to thank Stefan Berg, Murugaraj policies. We would also like to thank Stefan Berg, Murugaraj
Shanmugam, Christian Schmidt, Martin Thomson, Markus Isomaki, Aki Shanmugam, Christian Schmidt, Martin Thomson, Markus Isomaki, Aki
Niemi, Eva Maria Leppanen, Mark Baker, Tim Polk and Brian Carpenter Niemi, Eva Maria Leppanen and Mark Baker for their comments. Martin
for their comments. Martin Thomson helped us with the XML schema. Thomson helped us with the XML schema. Mark Baker provided a review
Mark Baker provided a review of the media type. Scott Brim provided of the media type. Scott Brim provided a review on behalf of the
a review on behalf of the General Area Review Team. General Area Review Team.
Authors' Addresses Authors' Addresses
Henning Schulzrinne Henning Schulzrinne
Columbia University Columbia University
Department of Computer Science Department of Computer Science
450 Computer Science Building 450 Computer Science Building
New York, NY 10027 New York, NY 10027
USA USA
skipping to change at page 42, line 13 skipping to change at page 42, line 13
Email: Jorge.Cuellar@siemens.com Email: Jorge.Cuellar@siemens.com
James Polk James Polk
Cisco Cisco
2200 East President George Bush Turnpike 2200 East President George Bush Turnpike
Richardson, Texas 75082 Richardson, Texas 75082
USA USA
Email: jmpolk@cisco.com Email: jmpolk@cisco.com
Jonathan Rosenberg Jonathan Rosenberg
Cisco Cisco Systems
600 Lanidex Plaza 600 Lanidex Plaza
Parsippany, New York 07054 Parsippany, New York 07054
USA USA
Email: jdrosen@cisco.com Email: jdrosen@cisco.com
URI: http://www.jdrosen.net URI: http://www.jdrosen.net
Intellectual Property Statement Full Copyright Statement
Copyright (C) The Internet Society (2006).
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 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 The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights 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 might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
skipping to change at page 43, line 29 skipping to change at page 43, line 45
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Disclaimer of Validity
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 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.
Copyright Statement
Copyright (C) The Internet Society (2006). 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.
Acknowledgment Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is provided by the IETF
Internet Society. Administrative Support Activity (IASA).
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