draft-ietf-stir-rph-03.txt   draft-ietf-stir-rph-04.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: August 5, 2018 AT&T Expires: October 27, 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
February 01, 2018 April 25, 2018
PASSporT Extension for Resource-Priority Authorization PASSporT Extension for Resource Priority Authorization
draft-ietf-stir-rph-03 draft-ietf-stir-rph-04
Abstract Abstract
This document extends the Secure Telephone Identity Revisited (STIR) This document extends the PASSporT (Personal Assertion Token)
Personal Assertion Token (PASSporT) specification defined in specification defined in [RFC8225] to allow the inclusion of
[I-D.ietf-stir-passport] to allow the inclusion of cryptographically cryptographically signed assertions of authorization for the values
signed assertions of authorization for the values populated in the populated in the 'Session Initiation Protocol (SIP) Resource-
Session Initiation Protocol (SIP) 'Resource-Priority' header field, Priority' header field, which is used for communications resource
which is used for communications resource prioritization. prioritization.
Status of This Memo Status of This Memo
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Copyright Notice Copyright Notice
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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 . . . . . . . . . . . . . . . . . . . . 4
4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 5 4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Authentication Service Behavior . . . . . . . . . . . . . 5 4.1. Authentication Service Behavior . . . . . . . . . . . . . 5
4.2. Verification Service Behavior . . . . . . . . . . . . . . 5 4.2. Verification Service Behavior . . . . . . . . . . . . . . 6
5. Further Information Associated with 'Resource-Priority' . . . 6 5. Further Information Associated with 'Resource-Priority' . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6.1. PASSporT Extension Claims Registration . . . . . . . . . 6 6.1. PASSporT Extension Claims Registration . . . . . . . . . 7
6.2. 'rph' Types . . . . . . . . . . . . . . . . . . . . . . . 7 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 . . . . . . . . . . . . . . . . . . . . 8 7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 8
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. Normative References . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 8
8.2. Informative References . . . . . . . . . . . . . . . . . 9 8.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
PASSporT [I-D.ietf-stir-passport] is a token format based on JSON Web PASSporT [RFC8225] is a token format based on JSON Web Token (JWT)
Token (JWT) [RFC7519] for conveying cryptographically signed [RFC7519] for conveying cryptographically signed information about
information about the identities involved in personal communications; the identities involved in personal communications; it is used with
it is used with STIR [I-D.ietf-stir-rfc4474bis] to convey a signed STIR [RFC8224] to convey a signed assertion of the identity of the
assertion of the identity of the participants in real-time participants in real-time communications established via a protocol
communications established via a protocol like SIP [RFC3261]. This like SIP [RFC3261]. This specification extends PASSporT to allow
specification extends PASSporT to allow cryptographic-signing of the cryptographic-signing of the 'SIP Resource-Priority' header field
SIP 'Resource-Priority' header field defined in [RFC4412]. [RFC4412], which is used for communications resource prioritization.
[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 by 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 (e.g., to manage scarce network resources during network
spoofed and abused by unauthorized entities. congestion scenarios). However, the 'SIP Resource-Priority' header
field could be spoofed and abused by unauthorized entities, the
threat models and use cases of which are described in [RFC7375] and
[RFC7340], respectively. Compromise of the 'SIP Resource-Priority'
header field [RFC4412] could lead to misuse of network resource
(i.e., during congestion scenarios) resulting in impacts to the
application services supported using the 'SIP Resource-Priority'
header field.
The STIR architecture [RFC7340] assumes that an authority on the [RFC8225] provides a mechanism by which an authority on the
originating side of a call provides a cryptographic assurance of the originating side of a call can provide a cryptographic assurance of
validity of the calling party number in order to prevent the validity of the calling party telephone number in order to
impersonation attacks. The STIR architecture allows extensions that prevent impersonation attacks. [RFC8225] also allows extensions
can be utilized by authorities supporting real-time communication that can be utilized by authorities supporting real-time
services using the 'Resource-Priority' header field to communication services using the 'SIP Resource-Priority' header field
cryptographically sign the SIP 'Resource-Priority' header field and to cryptographically sign the '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' authorization of a particular communication for 'SIP Resource-
can use a PASSPorT claim to cryptographically sign the SIP 'Resource- Priority' can use a PASSPorT claim to cryptographically sign the
Priority' header field and convey an assertion of the authorization 'Resource-Priority' header field and convey an assertion of the
for 'Resource-Priority'. This will allow a receiving entity authorization for 'Resource-Priority'. This will allow a receiving
(including entities located in different network domains/boundaries) entity (including entities located in different network domains/
to verify the validity of assertions authorizing 'Resource-Priority'. boundaries) to verify the validity of assertions authorizing
Cryptographically signed SIP 'Resource-Priority' header fields will 'Resource-Priority'. Cryptographically signed 'SIP Resource-
allow a receiving entity to verify and act on the information with Priority' header field will allow a receiving entity to verify and
confidence that the information has not been spoofed or compromised. act on the information with confidence that the information has not
been spoofed or compromised.
This specification documents an optional extension to PASSporT and This specification documents an extension to PASSporT and the
the associated STIR mechanisms to provide a function to sign the SIP 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 this
optional extension to PASSporT is used for real-time communications extension to PASSporT is used for real-time communications supported
supported using SIP 'Resource-Priority' header field is outside the using 'SIP Resource-Priority' header field is outside the scope of
scope of this document. 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] and document are to be interpreted as described in RFC 2119 [RFC2119] and
in RFC 8174 [RFC8174]. 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 field. 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 based on
Resource-Priority = "Resource-Priority": r-value, where r-value= [RFC4412] and the syntax is:
"namespace "." priority value") based on [RFC4412]. Specifically,
the "rph" claim includes assertion of the priority-level of the user
to be used for a given communication session. The value of the "rph"
claim is an Object with one or more keys. Each key is associated
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' {
header field with a r-value ="namespace "." priority value" of Resource-Priority = "Resource-Priority" : r-value,
"ets.0" and with another r-value= "namespace "." priority value" of r-value= namespace "." r-priority
}
Specifically, the "rph" claim includes assertion of the priority-
level of the user to be used for a given communication session. The
value of the "rph" claim is an Object with one or more keys. Each
key is associated 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'
header field with a r-value of "ets.0" and with another r-value of
"wps.0". "wps.0".
{ {
"orig":{"tn":"12155550112"}, "orig":{"tn":"12155550112"},
"dest":{["tn":"12125550113"]}, "dest":{["tn":"12125550113"]},
"iat":"1443208345", "iat":"1443208345",
"rph":{"auth":["ets.0", "wps.0"]} "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 [RFC8225]
[I-D.ietf-stir-passport] using the full form of PASSPorT. The using the full form of PASSPorT. The credentials (i.e., Certificate)
credentials (e.g., authority responsible for authorizing Resource- used to create the signature must have authority over the namespace
Priority) used to create the signature must have authority over the of the "rph" claim and there is only one authority per claim. The
namespace of the "rph" claim and there is only one authority per authority MUST use its credentials associated with the specific
claim. The authority MUST use its credentials (i.e., CERT) service supported by the resource priority namespace in the claim.
associated with the specific service supported by the SIP namespace If r-values are added or dropped by the intermediaries along the
in the claim. If r-values are added or dropped by the intermediaries path, intermediaries must generate a new "rph" header and sign the
along the path, intermediaries must generate a new "rph" header and claim with its own authority.
sign the claim with its own authority.
The use of the compact form of PASSporT is not specified in this The use of the compact form of PASSporT is not specified in this
document. 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 of this document that are based on
of "rph" claim follows the steps described in Section 4 of [RFC4412]. The construction of "rph" claim follows the steps
[I-D.ietf-stir-rfc4474bis]. described in Section 4.1 of [RFC8224].
The resulting Identity header for "rph" might look as The resulting Identity header for "rph" might look as
follows(backslashes shown for line folding only): follows(backslashes shown for line folding only):
Identity:eyJhbGciOiJFUzI1NiIsInBwdCI6InJwaCIsInR5cCI6InBhc3Nwb3J0\ Identity:eyJhbGciOiJFUzI1NiIsInBwdCI6InJwaCIsInR5cCI6InBhc3Nwb3J0\
IiwieDV1IjoiaHR0cHM6Ly93d3cuZXhhbXBsZS5jb20vY2VydC5jZXIifQo.eyJkZ\ IiwieDV1IjoiaHR0cHM6Ly93d3cuZXhhbXBsZS5jb20vY2VydC5jZXIifQo.eyJkZ\
XN0Ijp7WyJ0biI6IjEyMTI1NTUwMTEzIl19LCJpYXQiOiIxNDQzMjA4MzQ1Iiwib3\ XN0Ijp7WyJ0biI6IjEyMTI1NTUwMTEzIl19LCJpYXQiOiIxNDQzMjA4MzQ1Iiwib3\
JpZyI6eyJ0biI6IjEyMTU1NTUwMTEyIn0sInJwaCI6eyJhdXRoIjpbImV0cy4wIiw\ JpZyI6eyJ0biI6IjEyMTU1NTUwMTEyIn0sInJwaCI6eyJhdXRoIjpbImV0cy4wIiw\
id3BzLjAiXX19Cg.s37S6VC8HM6Dl6YzJeQDsrZcwJ0lizxhUrA7f_98oWBHvo-cl\ id3BzLjAiXX19Cg.s37S6VC8HM6Dl6YzJeQDsrZcwJ0lizxhUrA7f_98oWBHvo-cl\
-n8MIhoCr18vYYFy3blXvs3fslM_oos2P2Dyw;info=<https://www.example.\ -n8MIhoCr18vYYFy3blXvs3fslM_oos2P2Dyw;info=<https://www.example.\
org/cert.cer>;alg=ES256;ppt=rph org/cert.cer>;alg=ES256;ppt="rph"
A SIP authentication service typically will derive the value of "rph" A SIP authentication service will derive the value of "rph" from the
from the 'Resource-Priority' header field based on policy associated 'SIP Resource-Priority' header field based on policy associated with
with service specific use of the "namespace "." priority value" for service specific use of the "namespace "." r-priority" for r-values
r-values based on [RFC4412]. The authentication service derives the based on [RFC4412]. The authentication service derives the value of
value of the PASSPorT claim by verifying the authorization for the PASSPorT claim by verifying the authorization for 'SIP Resource-
'Resource-Priority' (i.e., verifying a calling user privilege for Priority' (i.e., verifying a calling user privilege for 'Resource-
'Resource-Priority' based on its identity) which might be derived Priority' based on its identity) which might be derived from customer
from customer profile data or from access to external services. profile data or from access to external services.
[RFC4412] allows multiple "namespace "." priority value" pairs, [RFC4412] allows multiple "namespace "." priority value" pairs,
either in a single SIP 'Resource-Priority' header field or across either in a single 'SIP Resource-Priority' header field or across
multiple SIP 'Resource-Priority' headers. An authority is multiple 'SIP Resource-Priority' headers. An authority is
responsible for signing all the content of a SIP 'Resource-Priority' responsible for signing all the content of a 'SIP Resource-Priority'
header field for which it has the authority. header field for which it has the authority.
4.2. Verification Service Behavior 4.2. Verification Service Behavior
[I-D.ietf-stir-rfc4474bis] Section 6.2 Step 5 requires that [RFC8224] Section 6.2 Step 5 requires that specifications defining
specifications defining "ppt" values describe any additional verifier "ppt" values describe any additional verifier behavior. The behavior
behavior. The behavior specified for the "ppt" values of "rph" is as 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' as indicated in the claim. This authorized for 'SIP Resource-Priority' as indicated in the claim.
value would in turn be used for priority treatment in accordance with This value would in turn be used for priority treatment in accordance
local policy for the associated communication service. If the with local policy for the associated communication service. If the
signature validation fails, the verification service should infer signature validation fails, the verification service should infer
that the calling party is not authorized for 'Resource-Priority' as that the calling party is not authorized for 'SIP Resource-Priority'
indicated in the claim. In such cases, the priority treatment for as indicated in the claim. In such cases, the priority treatment for
the associated communication service is handled as per the local the associated communication service is handled as per the local
policy. policy of the verifier. In such scenarios, 'SIP Resource-Priority'
header field SHOULD be stripped from SIP request and the network
entities should treat the call as an ordinary call.
In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires In addition, [RFC8224] Section 6.2 Step 4 requires "iat" value in
"iat" value in "rph" claim to be verified. "rph" claim to be verified.
The behavior of a SIP UA 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. veracity of this information.
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 'SIP Resource-
This may include information related to the device subscription of Priority'. This may include information related to the device
the caller, or to any institutions that the caller or device is subscription of the caller, or to any institutions that the caller or
associated with, or even categories of institutions. All of these device is associated with, or even categories of institutions. All
data elements would benefit from the secure attestations provided by of these data elements would benefit from the secure attestations
the STIR and PASSporT frameworks. The specification of the "rph" provided by the STIR and PASSporT frameworks. The specification of
claim could entail the optional presence of one or more such the "rph" claim could entail the optional presence of one or more
additional information fields. such additional information fields applicable to 'SIP Resource-
Priority'.
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. PASSporT Extension Claims Registration 6.1. PASSporT Extension Claims Registration
skipping to change at page 7, line 19 skipping to change at page 7, line 37
This specification also requests that the IANA creates a new registry This specification also requests that the IANA creates a new registry
for "rph" types. Each registry entry must contain two fields: the for "rph" types. Each registry entry must contain two fields: the
name of the "rph" type and the specification in which the type is name of the "rph" type and the specification in which the type is
described. This registry is to be initially populated with a single described. This registry is to be initially populated with a single
value for "auth" which is specified in [RFCThis]. Registration of value for "auth" which is specified in [RFCThis]. Registration of
new "rph" types shall be under the specification required policy. new "rph" types shall be under the specification required policy.
7. Security Considerations 7. Security Considerations
The security considerations discussed in [I-D.ietf-stir-rfc4474bis] The security considerations discussed in [RFC8224] in Section 12 are
in Section 10 are applicable here. 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 field is used to with SIP INVITE when 'Resource-Priority' header field is used to
convey the priority of the communication as defined in [RFC4412]. To convey the priority of the communication as defined in [RFC4412]. To
avoid the replay, and cut and paste attacks, the procedures described avoid replay, and cut and paste attacks, the recommenations provided
in Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed. in Section 12.1 of [RFC8224] MUST be followed.
7.2. Solution Considerations 7.2. Solution Considerations
The use of extension to PASSporT tokens with "ppt" value "rph" based Using extensions to PASSporT tokens with a "ppt" value of "rph"
on the validation of the digital signature and the associated requires knowledge of the authentication, authorization, and
certificate requires consideration of the authentication and reputation of the signer to attest to the identity being asserted,
authority or reputation of the signer to attest to the identity being including validating the digital signature and the associated
asserted. The following considerations should be recognized when certificate chain to a trust anchor. The following considerations
using PASSporT extension with "ppt" value of "rph": should be recognized when using PASSporT extensions with a "ppt"
value of "rph":
o An authority (signer) is only allowed to sign the content of a SIP o A signer is only allowed to sign the content of a 'SIP Resource-
'Resource-Priority' header field for which it has the right Priority' header field for which it has the proper authorization.
authority. The authority that signs the token MUST have a secure Before signing tokens, the signer MUST have a secure method for
method for authentication of the end user or the device. authentication of the end user or the device being granted a
token.
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 that the signer is authoritative for the signed content of the
resource priority namespace in the PASSporT. 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 WG 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 and Ning Zhang for their valuable also like to thank David Hancock and Ning Zhang for their valuable
inputs. inputs.
8. References 8. References
8.1. Normative References 8.1. Normative References
[I-D.ietf-stir-passport]
Wendt, C. and J. Peterson, "Personal Assertion Token
(PASSporT)", February 2017.
[I-D.ietf-stir-rfc4474bis]
Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,
"Authenticated Identity Management in the Session
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, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261, Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002, DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>. <http://www.rfc-editor.org/info/rfc3261>.
skipping to change at page 9, line 5 skipping to change at page 9, line 9
<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>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <http://www.rfc-editor.org/info/rfc8174>. May 2017, <http://www.rfc-editor.org/info/rfc8174>.
[RFC8224] Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,
"Authenticated Identity Management in the Session
Initiation Protocol (SIP)", RFC 8224,
DOI 10.17487/RFC8224, February 2018,
<http://www.rfc-editor.org/info/rfc8224>.
[RFC8225] Wendt, C. and J. Peterson, "PASSporT:Personal Assertion
Token", RFC 8225, DOI 10.17487/RFC8225, February 2018,
<http://www.rfc-editor.org/info/rfc8225>.
8.2. Informative References 8.2. Informative References
[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>.
[RFC7375] Peterson, J., "Secure Telephone Identity Threat Model",
RFC 7375, DOI 10.17487/RFC7375, October 2014,
<http://www.rfc-editor.org/info/rfc7375>.
Authors' Addresses Authors' Addresses
Ray P. Singh Ray P. Singh
Vencore Labs Vencore Labs
150 Mount Airy Road 150 Mount Airy Road
New Jersey, NJ 07920 New Jersey, NJ 07920
USA USA
Email: rsingh@vencorelabs.com Email: rsingh@vencorelabs.com
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