Diff: draft-ietf-stir-rph-02.txt - draft-ietf-stir-rph-03.txt

	draft-ietf-stir-rph-02.txt	draft-ietf-stir-rph-03.txt

	STIR R. Singh	STIR R. Singh
	Internet-Draft Vencore Labs	Internet-Draft Vencore Labs
	Intended status: Standards Track M. Dolly	Intended status: Standards Track M. Dolly

	Expires: July 8, 2018 AT&T	Expires: August 5, 2018 AT&T
	S. Das	S. Das
	Vencore Labs	Vencore Labs
	A. Nguyen	A. Nguyen
	Office of Emergency Communication/DHS	Office of Emergency Communication/DHS

	January 04, 2018	February 01, 2018

	PASSporT Extension for Resource-Priority Authorization	PASSporT Extension for Resource-Priority Authorization

	draft-ietf-stir-rph-02	draft-ietf-stir-rph-03

	Abstract	Abstract


	This document extends the STIR PASSporT specification to allow the	This document extends the Secure Telephone Identity Revisited (STIR)
	inclusion of cryptographically-signed assertions of authorization for	Personal Assertion Token (PASSporT) specification defined in
	the values populated in the SIP 'Resource-Priority' header field,	[I-D.ietf-stir-passport] to allow the inclusion of cryptographically
		signed assertions of authorization for the values populated in the
		Session Initiation Protocol (SIP) 'Resource-Priority' header field,
	which is used for communications resource prioritization.	which is used for communications resource prioritization.

	Status of This Memo	Status of This Memo

	This Internet-Draft is submitted in full conformance with the	This Internet-Draft is submitted 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). Note that other groups may also distribute	Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-	working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.	Drafts is at https://datatracker.ietf.org/drafts/current/.

	Internet-Drafts are draft documents valid for a maximum of six months	Internet-Drafts are draft documents valid for a maximum of six months
	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."


	This Internet-Draft will expire on July 8, 2018.	This Internet-Draft will expire on August 5, 2018.

	Copyright Notice	Copyright Notice

	Copyright (c) 2018 IETF Trust and the persons identified as the	Copyright (c) 2018 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	Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of	(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents	publication of this document. Please review these documents

	skipping to change at page 2, line 14 ¶	skipping to change at page 2, line 16 ¶
	to this document. Code Components extracted from this document must	to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of	include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as	the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.	described in the Simplified BSD License.

	Table of Contents	Table of Contents

	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. PASSporT 'rph' Claim . . . . . . . . . . . . . . . . . . . . 3	3. PASSporT 'rph' Claim . . . . . . . . . . . . . . . . . . . . 3

	4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 4	4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 5
	4.1. Authentication Service Behavior . . . . . . . . . . . . . 4	4.1. Authentication Service Behavior . . . . . . . . . . . . . 5
	4.2. Verification Service Behavior . . . . . . . . . . . . . . 5	4.2. Verification Service Behavior . . . . . . . . . . . . . . 5

	5. Further Information Associated with Resource-Priority . . . . 6	5. Further Information Associated with 'Resource-Priority' . . . 6
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6

	6.1. JSON Web Token Claims Registration . . . . . . . . . . . 6	6.1. PASSporT Extension Claims Registration . . . . . . . . . 6
	6.2. PASSporT 'rph' Types . . . . . . . . . . . . . . . . . . 6	6.2. 'rph' Types . . . . . . . . . . . . . . . . . . . . . . . 7
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 7	7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
	7.1. Avoidance of replay and cut and paste attacks . . . . . . 7	7.1. Avoidance of replay and cut and paste attacks . . . . . . 7
	7.2. Solution Considerations . . . . . . . . . . . . . . . . . 7	7.2. Solution Considerations . . . . . . . . . . . . . . . . . 7

	7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 7	7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 8
	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
	8.1. Normative References . . . . . . . . . . . . . . . . . . 7	8.1. Normative References . . . . . . . . . . . . . . . . . . 8
	8.2. Informative References . . . . . . . . . . . . . . . . . 8	8.2. Informative References . . . . . . . . . . . . . . . . . 9
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9

	1. Introduction	1. Introduction


	PASSporT [I-D.ietf-stir-passport] is a token format based on JWT	PASSporT [I-D.ietf-stir-passport] is a token format based on JSON Web
	[RFC7519] for conveying cryptographically-signed information about	Token (JWT) [RFC7519] for conveying cryptographically signed
	the identities involved in personal communications; it is used with	information about the identities involved in personal communications;
	STIR [I-D.ietf-stir-rfc4474bis] to convey a signed assertion of the	it is used with STIR [I-D.ietf-stir-rfc4474bis] to convey a signed
	identity of the participants in real-time communications established	assertion of the identity of the participants in real-time
	via a protocol like SIP. This specification extends PASSporT to	communications established via a protocol like SIP [RFC3261]. This
	allow cryptographic-signing of the SIP 'Resource-Priority' header	specification extends PASSporT to allow cryptographic-signing of the
	field defined in [RFC4412].	SIP 'Resource-Priority' header field defined in [RFC4412].

	[RFC4412] defines the SIP 'Resource-Priority' header field for	[RFC4412] defines the SIP 'Resource-Priority' header field for
	communications Resource Priority. As specified in [RFC4412], the	communications Resource Priority. As specified in [RFC4412], the
	'Resource-Priority' header field may be used by SIP user agents	'Resource-Priority' header field may be used by SIP user agents

	[RFC3261], including, Public Switched Telephone Network (PSTN)	[RFC3261], including Public Switched Telephone Network (PSTN)
	gateways and terminals, and SIP proxy servers to influence	gateways and terminals, and by SIP proxy servers, to influence
	prioritization afforded to communication sessions,including PSTN	prioritization afforded to communication sessions, including PSTN
	calls. However, the SIP 'Resource-Priority' header field could be	calls. However, the SIP 'Resource-Priority' header field could be
	spoofed and abused by unauthorized entities.	spoofed and abused by unauthorized entities.


	The STIR architecture [RFC7340]assumes that an authority on the	The STIR architecture [RFC7340] assumes that an authority on the
	originating side of a call provides a cryptographic assurance of the	originating side of a call provides a cryptographic assurance of the
	validity of the calling party number in order to prevent	validity of the calling party number in order to prevent

	impersonation attacks. The STIR architecture allows extension that	impersonation attacks. The STIR architecture allows extensions that
	can be utilized by authorities supporting real-time communication	can be utilized by authorities supporting real-time communication
	services using the 'Resource-Priority' header field to	services using the 'Resource-Priority' header field to
	cryptographically sign the SIP 'Resource-Priority' header field and	cryptographically sign the SIP 'Resource-Priority' header field and
	convey assertion of the authorization for 'Resource-Priority'. For	convey assertion of the authorization for 'Resource-Priority'. For
	example, the authority on the originating side verifying the	example, the authority on the originating side verifying the

	authorization of a particular communication for Resource-Priority can	authorization of a particular communication for 'Resource-Priority'
	use a PASSPorT claim to cryptographically-sign the SIP 'Resource-	can use a PASSPorT claim to cryptographically sign the SIP 'Resource-
	Priority' header field and convey an assertion of the authorization	Priority' header field and convey an assertion of the authorization
	for 'Resource-Priority'. This will allow a receiving entity	for 'Resource-Priority'. This will allow a receiving entity
	(including entities located in different network domains/boundaries)	(including entities located in different network domains/boundaries)

	to verify the validity of assertions authorizing Resource-Priority.	to verify the validity of assertions authorizing 'Resource-Priority'.
	Cryptographically-signed SIP 'Resource-Priority' headers will allow a	Cryptographically signed SIP 'Resource-Priority' header fields will
	receiving entity to verify and act on the information with confidence	allow a receiving entity to verify and act on the information with
	that the information have not been spoofed or compromised.	confidence that the information has not been spoofed or compromised.

	This specification documents an optional extension to PASSporT and	This specification documents an optional extension to PASSporT and
	the associated STIR mechanisms to provide a function to sign the SIP	the associated STIR mechanisms to provide a function to sign the SIP
	'Resource-Priority' header field. This PASSporT object is used to	'Resource-Priority' header field. This PASSporT object is used to
	provide attestation of a calling user authorization for priority	provide attestation of a calling user authorization for priority
	communications. This is necessary in addition to the PASSporT object	communications. This is necessary in addition to the PASSporT object
	that is used for calling user telephone number attestation. How the	that is used for calling user telephone number attestation. How the
	optional extension to PASSporT is used for real-time communications	optional extension to PASSporT is used for real-time communications

	supported using SIP 'Resource-Priority' header field is defined in	supported using SIP 'Resource-Priority' header field is outside the
	other documents and is outside the scope of this document.	scope of this document.

	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 [RFC2119].	document are to be interpreted as described in RFC 2119 [RFC2119] and
		in RFC 8174 [RFC8174].

	3. PASSporT 'rph' Claim	3. PASSporT 'rph' Claim

	This specification defines a new JSON Web Token claim for "rph",	This specification defines a new JSON Web Token claim for "rph",
	which provides an assertion for information in SIP 'Resource-	which provides an assertion for information in SIP 'Resource-

	Priority'header.	Priority' header field.

	The creator of a PASSporT object adds a "ppt" value of "rph" to the	The creator of a PASSporT object adds a "ppt" value of "rph" to the
	header of a PASSporT object, in which case the PASSporT claims MUST	header of a PASSporT object, in which case the PASSporT claims MUST
	contain a "rph" claim, and any entities verifying the PASSporT object	contain a "rph" claim, and any entities verifying the PASSporT object
	will be required to understand the "ppt" extension in order to	will be required to understand the "ppt" extension in order to
	process the PASSporT in question. A PASSPorT header with the "ppt"	process the PASSporT in question. A PASSPorT header with the "ppt"
	included will look as follows:	included will look as follows:


	{ "typ":"passport",	{
		"typ":"passport",
	"ppt":"rph",	"ppt":"rph",
	"alg":"ES256",	"alg":"ES256",

	"x5u":"https://www.example.org/cert.cer"}	"x5u":"https://www.example.org/cert.cer"
		}


	The "rph" claim will provide an assertion of authorization,"auth",	The "rph" claim will provide an assertion of authorization, "auth",
	for information in the SIP "Resource-Priority" header field (i.e.,	for information in the SIP 'Resource-Priority' header field (i.e.,
	Resource-Priority: namespace "." r-priority) based on [RFC4412].	Resource-Priority = "Resource-Priority": r-value, where r-value=
	Specifically, the "rph" claim includes assertion of the priority-	"namespace "." priority value") based on [RFC4412]. Specifically,
	level of the user to be used for a given communication session. The	the "rph" claim includes assertion of the priority-level of the user
	value of the "rph" claim is an array containing one or more of JSON	to be used for a given communication session. The value of the "rph"
	objects for the content of the SIP 'Resource-Priority' header that is	claim is an Object with one or more keys. Each key is associated
	being asserted of which one of the "rph" object, is mandatory.	with a JSON Array. These arrays contain Strings that correspond to
		the r-values indicated in the SIP 'Resource-Priority' header field.


	The following is an example "rph" claim for a SIP "Resource-Priority"	The following is an example "rph" claim for a SIP 'Resource-Priority'
	header field with a "namespace "." r-priority" value of "ets.0" and	header field with a r-value ="namespace "." priority value" of
	with a "namespace "." r-priority" value of "wps.0".	"ets.0" and with another r-value= "namespace "." priority value" of
		"wps.0".


	{ "orig":{"tn":"12155551212"}	{
	"dest":{["tn":"12125551213"]},	"orig":{"tn":"12155550112"},
	"iat":1443208345,	"dest":{["tn":"12125550113"]},
	"rph":{"auth":["ets.0","wps.0"]}	"iat":"1443208345",
		"rph":{"auth":["ets.0", "wps.0"]}
		}

	After the header and claims PASSporT objects have been constructed,	After the header and claims PASSporT objects have been constructed,
	their signature is generated normally per the guidance in	their signature is generated normally per the guidance in
	[I-D.ietf-stir-passport] using the full form of PASSPorT. The	[I-D.ietf-stir-passport] using the full form of PASSPorT. The
	credentials (e.g., authority responsible for authorizing Resource-	credentials (e.g., authority responsible for authorizing Resource-
	Priority) used to create the signature must have authority over the	Priority) used to create the signature must have authority over the

	"rph" claim and there is only one authority per claim. The authority	namespace of the "rph" claim and there is only one authority per
	MUST use its credentials (i.e., CERT) associated with the specific	claim. The authority MUST use its credentials (i.e., CERT)
	service supported by the SIP namespace in the claim.	associated with the specific service supported by the SIP namespace
		in the claim. If r-values are added or dropped by the intermediaries
		along the path, intermediaries must generate a new "rph" header and
		sign the claim with its own authority.

		The use of the compact form of PASSporT is not specified in this
		document.

	4. 'rph' in SIP	4. 'rph' in SIP

	This section specifies SIP-specific usage for the "rph" claim in	This section specifies SIP-specific usage for the "rph" claim in
	PASSporT.	PASSporT.

	4.1. Authentication Service Behavior	4.1. Authentication Service Behavior

	The Authentication Service will create the "rph" claim using the	The Authentication Service will create the "rph" claim using the
	values discussed in section 3 based on [RFC4412]. The construction	values discussed in section 3 based on [RFC4412]. The construction
	of "rph" claim follows the steps described in Section 4 of	of "rph" claim follows the steps described in Section 4 of
	[I-D.ietf-stir-rfc4474bis].	[I-D.ietf-stir-rfc4474bis].


	The resulting Identity header for "rph" might look as follows:	The resulting Identity header for "rph" might look as
		follows(backslashes shown for line folding only):


	"eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleUowZVhBaU9pSnd	Identity:eyJhbGciOiJFUzI1NiIsInBwdCI6InJwaCIsInR5cCI6InBhc3Nwb3J0\
	ZWE56Y0c5eWRDSXNEUW9pY0hCMElqb2ljbkJvSWl3TkNpSmhiR2NpT2lKRlV6STFO	IiwieDV1IjoiaHR0cHM6Ly93d3cuZXhhbXBsZS5jb20vY2VydC5jZXIifQo.eyJkZ\
	aUlzRFFvaWVEVjFJanBvZEhSd2N6b3ZMM2QzZHk1bGVHRnRjR3hsTG1OdmJTOWpaW	XN0Ijp7WyJ0biI6IjEyMTI1NTUwMTEzIl19LCJpYXQiOiIxNDQzMjA4MzQ1Iiwib3\
	EowTG1ObGNuME5DZzBLIHx84oCZLuKAmXx8IGV5QWliM0pwWnlJNmV5SjBiaUk2SW	JpZyI6eyJ0biI6IjEyMTU1NTUwMTEyIn0sInJwaCI6eyJhdXRoIjpbImV0cy4wIiw\
	pFeU1UVTFOVFV4TWpFeUluME5DaUprWlhOMElqcDdXeUowYmlJNklqRXlNVEkxTlR	id3BzLjAiXX19Cg.s37S6VC8HM6Dl6YzJeQDsrZcwJ0lizxhUrA7f_98oWBHvo-cl\
	VeE1qRXpJbDE5TEEwS0ltbGhkQ0k2TVRRME16SXdPRE0wTlN3TkNpSnljR2dpT25z	-n8MIhoCr18vYYFy3blXvs3fslM_oos2P2Dyw;info=<https://www.example.\
	aVlYVjBhQ0k2V3lKbGRITXVNQ0lzSW5kd2N5NHdJbDE5RFFvPSJ9.s37S6VC8HM6D	org/cert.cer>;alg=ES256;ppt=rph
	l6YzJeQDsrZcwJ0lizxhUrA7f_98oWBHvo-cl-n8MIhoCr18vYYFy3blXvs3fslM_
	oos2P2Dyw"; info= "https://www.example.org/cert.cer";alg=ES256;
	ppt="rph"

	A SIP authentication service typically will derive the value of "rph"	A SIP authentication service typically will derive the value of "rph"
	from the 'Resource-Priority' header field based on policy associated	from the 'Resource-Priority' header field based on policy associated

	with service specific use of the "namespace "." r-priority" values	with service specific use of the "namespace "." priority value" for
	based on [RFC4412]. The authentication service derives the value of	r-values based on [RFC4412]. The authentication service derives the
	the PASSPorT claim by verifying the authorization for Resource-	value of the PASSPorT claim by verifying the authorization for
	Priority (i.e., verifying a calling user privilege for Resource-	'Resource-Priority' (i.e., verifying a calling user privilege for
	Priority based on its identity) which might be derived from customer	'Resource-Priority' based on its identity) which might be derived
	profile data or from access to external services.	from customer profile data or from access to external services.


	[RFC4412] allows multiple "namespace "." r-priority" pairs, either in	[RFC4412] allows multiple "namespace "." priority value" pairs,
	a single SIP Resource-Priority header or across multiple SIP	either in a single SIP 'Resource-Priority' header field or across
	Resource-Priority headers. However, it is not necessary to sign all	multiple SIP 'Resource-Priority' headers. An authority is
	content of a SIP Resource-Priority header or all SIP Resource-	responsible for signing all the content of a SIP 'Resource-Priority'
	Priority headers in a given SIP message. An authority is only	header field for which it has the authority.
	responsible for signing the content of a SIP Resource-Priority header
	for which it has authority (e.g., a specific "namespace "."
	r-priority").

	4.2. Verification Service Behavior	4.2. Verification Service Behavior

	[I-D.ietf-stir-rfc4474bis] Section 6.2 Step 5 requires that	[I-D.ietf-stir-rfc4474bis] Section 6.2 Step 5 requires that
	specifications defining "ppt" values describe any additional verifier	specifications defining "ppt" values describe any additional verifier
	behavior. The behavior specified for the "ppt" values of "rph" is as	behavior. The behavior specified for the "ppt" values of "rph" is as
	follows:	follows:

	The verification service MUST extract the value associated with the	The verification service MUST extract the value associated with the
	"auth" key in a full form PASSPorT with a "ppt" value of "rph". If	"auth" key in a full form PASSPorT with a "ppt" value of "rph". If
	the signature validates, then the verification service can use the	the signature validates, then the verification service can use the
	value of the "rph" claim as validation that the calling party is	value of the "rph" claim as validation that the calling party is

	authorized for Resource-Priority, which would in turn be used for	authorized for 'Resource-Priority' as indicated in the claim. This
	priority treatment in accordance with local policy for the associated	value would in turn be used for priority treatment in accordance with
	communication service.	local policy for the associated communication service. If the
		signature validation fails, the verification service should infer
		that the calling party is not authorized for 'Resource-Priority' as
		indicated in the claim. In such cases, the priority treatment for
		the associated communication service is handled as per the local
		policy.

	In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires	In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires
	"iat" value in "rph" claim to be verified.	"iat" value in "rph" claim to be verified.


	The behavior of a SIP UAs upon receiving an INVITE containing a	The behavior of a SIP UA upon receiving an INVITE containing a
	PASSporT object with a "rph" claim will largely remain a matter of	PASSporT object with a "rph" claim will largely remain a matter of
	implementation policy for the specific communication service. In	implementation policy for the specific communication service. In

	most cases,implementations would act based on confidence in the	most cases, implementations would act based on confidence in the
	veracity of this information. The use of the compact form of	veracity of this information.
	PASSporT is not specified in this document.


	5. Further Information Associated with Resource-Priority	5. Further Information Associated with 'Resource-Priority'

	There may be additional information about the calling party or the	There may be additional information about the calling party or the

	call that could be relevant to authorization for Resource-Priority.	call that could be relevant to authorization for 'Resource-Priority'.
	This may include information related to the device subscription of	This may include information related to the device subscription of
	the caller, or to any institutions that the caller or device is	the caller, or to any institutions that the caller or device is
	associated with, or even categories of institutions. All of these	associated with, or even categories of institutions. All of these
	data elements would benefit from the secure attestations provided by	data elements would benefit from the secure attestations provided by
	the STIR and PASSporT frameworks. The specification of the "rph"	the STIR and PASSporT frameworks. The specification of the "rph"
	claim could entail the optional presence of one or more such	claim could entail the optional presence of one or more such
	additional information fields.	additional information fields.

	A new IANA registry has been defined to hold potential values of the	A new IANA registry has been defined to hold potential values of the
	"rph" array; see Section 6.2. The definition of the "rph" claim may	"rph" array; see Section 6.2. The definition of the "rph" claim may
	have one or more such additional information field(s). Details of	have one or more such additional information field(s). Details of
	such "rph" claim to encompass other data elements are left for future	such "rph" claim to encompass other data elements are left for future
	version of this specification.	version of this specification.

	6. IANA Considerations	6. IANA Considerations


	6.1. JSON Web Token Claims Registration	6.1. PASSporT Extension Claims Registration

		This document registers a new "ppt" value for the "Personal Assertion
		Token (PASSporT) Extensions" table.

	o Claim Name: "rph"	o Claim Name: "rph"

	o Claim Description: Resource Priority Header Authorization	o Claim Description: Resource Priority Header Authorization


	o Change Controller: IESG	o Change Controller: IESG

	o Specification Document(s): Section 3 of [RFCThis]	o Specification Document(s): Section 3 of [RFCThis]


	6.2. PASSporT 'rph' Types	6.2. 'rph' Types


	This document requests that the IANA add a new entry to the PASSporT	This specification also requests that the IANA creates a new registry
	Types registry for the type "rph" which is specified in [RFCThis].	for "rph" types. Each registry entry must contain two fields: the
	This specification also requests that the IANA create a new registry	name of the "rph" type and the specification in which the type is
	for PASSporT "rph" types. Registration of new PASSporT "rph" types	described. This registry is to be initially populated with a single
	shall be under the specification required policy. This registry is	value for "auth" which is specified in [RFCThis]. Registration of
	to be initially populated with a single value for "auth" which is	new "rph" types shall be under the specification required policy.
	specified in [RFCThis].

	7. Security Considerations	7. Security Considerations

	The security considerations discussed in [I-D.ietf-stir-rfc4474bis]	The security considerations discussed in [I-D.ietf-stir-rfc4474bis]
	in Section 10 are applicable here.	in Section 10 are applicable here.

	7.1. Avoidance of replay and cut and paste attacks	7.1. Avoidance of replay and cut and paste attacks

	The PASSporT extension with a "ppt" value of "rph" MUST only be sent	The PASSporT extension with a "ppt" value of "rph" MUST only be sent

	with SIP INVITE when 'Resource-Priority' header is used to convey the	with SIP INVITE when 'Resource-Priority' header field is used to
	priority of the communication as defined in [RFC4412]. To avoid the	convey the priority of the communication as defined in [RFC4412]. To
	replay, and cut and paste attacks, the procedures described in	avoid the replay, and cut and paste attacks, the procedures described
	Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed.	in Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed.

	7.2. Solution Considerations	7.2. Solution Considerations

	The use of extension to PASSporT tokens with "ppt" value "rph" based	The use of extension to PASSporT tokens with "ppt" value "rph" based
	on the validation of the digital signature and the associated	on the validation of the digital signature and the associated
	certificate requires consideration of the authentication and	certificate requires consideration of the authentication and
	authority or reputation of the signer to attest to the identity being	authority or reputation of the signer to attest to the identity being
	asserted. The following considerations should be recognized when	asserted. The following considerations should be recognized when
	using PASSporT extension with "ppt" value of "rph":	using PASSporT extension with "ppt" value of "rph":

	o An authority (signer) is only allowed to sign the content of a SIP	o An authority (signer) is only allowed to sign the content of a SIP

	'Resource-Priority' header for which it has the right authority.	'Resource-Priority' header field for which it has the right
	The authority that signs the token MUST have a secure method for	authority. The authority that signs the token MUST have a secure
	authentication of the end user or the device.	method for authentication of the end user or the device.

	o The verification of the signature MUST include means of verifying	o The verification of the signature MUST include means of verifying

	that the signer is authoritative for the signed content of the SIP	that the signer is authoritative for the signed content of the
	'Resource-Priority' header.	resource priority namespace in the PASSporT.

	7.3. Acknowledgements	7.3. Acknowledgements

	We would like to thank STIR members, ATIS/SIP Forum Task Force on	We would like to thank STIR members, ATIS/SIP Forum Task Force on
	IPNNI members, and the NS/EP Priority Services community for	IPNNI members, and the NS/EP Priority Services community for
	contributions to this problem statement and specification. We would	contributions to this problem statement and specification. We would

	also like to thank David Hancock for his valuable inputs.	also like to thank David Hancock and Ning Zhang for their valuable
		inputs.

	8. References	8. References

	8.1. Normative References	8.1. Normative References

	[I-D.ietf-stir-passport]	[I-D.ietf-stir-passport]
	Wendt, C. and J. Peterson, "Personal Assertion Token	Wendt, C. and J. Peterson, "Personal Assertion Token
	(PASSporT)", February 2017.	(PASSporT)", February 2017.

	[I-D.ietf-stir-rfc4474bis]	[I-D.ietf-stir-rfc4474bis]
	Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,	Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,
	"Authenticated Identity Management in the Session	"Authenticated Identity Management in the Session
	Initiation Protocol (SIP)", February 2017.	Initiation Protocol (SIP)", February 2017.

	[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,	Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,	DOI 10.17487/RFC2119, March 1997,
	<http://www.rfc-editor.org/info/rfc2119>.	<http://www.rfc-editor.org/info/rfc2119>.


		[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
		A., Peterson, J., Sparks, R., Handley, M., and E.
		Schooler, "SIP: Session Initiation Protocol", RFC 3261,
		DOI 10.17487/RFC3261, June 2002,
		<http://www.rfc-editor.org/info/rfc3261>.

	[RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource	[RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource
	Priority for the Session Initiation Protocol (SIP)",	Priority for the Session Initiation Protocol (SIP)",
	RFC 4412, DOI 10.17487/RFC4412, February 2006,	RFC 4412, DOI 10.17487/RFC4412, February 2006,
	<http://www.rfc-editor.org/info/rfc4412>.	<http://www.rfc-editor.org/info/rfc4412>.

	[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token	[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
	(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,	(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
	<http://www.rfc-editor.org/info/rfc7519>.	<http://www.rfc-editor.org/info/rfc7519>.


	8.2. Informative References	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
		May 2017, <http://www.rfc-editor.org/info/rfc8174>.


	[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,	8.2. Informative References
	A., Peterson, J., Sparks, R., Handley, M., and E.
	Schooler, "SIP: Session Initiation Protocol", RFC 3261,
	DOI 10.17487/RFC3261, June 2002,
	<http://www.rfc-editor.org/info/rfc3261>.

	[RFC7340] Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure	[RFC7340] Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure
	Telephone Identity Problem Statement and Requirements",	Telephone Identity Problem Statement and Requirements",
	RFC 7340, DOI 10.17487/RFC7340, September 2014,	RFC 7340, DOI 10.17487/RFC7340, September 2014,
	<http://www.rfc-editor.org/info/rfc7340>.	<http://www.rfc-editor.org/info/rfc7340>.

	Authors' Addresses	Authors' Addresses

	Ray P. Singh	Ray P. Singh
	Vencore Labs	Vencore Labs

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