--- 1/draft-ietf-stir-rph-01.txt 2018-01-04 08:13:42.888898971 -0800 +++ 2/draft-ietf-stir-rph-02.txt 2018-01-04 08:13:42.908899447 -0800 @@ -1,55 +1,51 @@ STIR R. Singh Internet-Draft Vencore Labs Intended status: Standards Track M. Dolly -Expires: March 18, 2018 AT&T +Expires: July 8, 2018 AT&T S. Das Vencore Labs A. Nguyen Office of Emergency Communication/DHS - September 14, 2017 + January 04, 2018 PASSporT Extension for Resource-Priority Authorization - draft-ietf-stir-rph-01 + draft-ietf-stir-rph-02 Abstract - This document extends the PASSporT object to convey - cryptographically-signed assertions of authorization for - communications 'Resource-Priority'. It extends PASSporT to allow - cryptographic-signing of the SIP 'Resource-Priority" header field - which is used for communications resource prioritization. It also - describes how the PASSPorT extension is used in SIP signaling to - convey assertions of authorization of the information in the SIP - 'Resource-Priority' header field. + This document extends the STIR PASSporT specification to allow the + inclusion of cryptographically-signed assertions of authorization for + the values populated in the SIP 'Resource-Priority' header field, + which is used for communications resource prioritization. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on March 18, 2018. + This Internet-Draft will expire on July 8, 2018. Copyright Notice - Copyright (c) 2017 IETF Trust and the persons identified as the + Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as @@ -61,66 +57,66 @@ 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. PASSporT 'rph' Claim . . . . . . . . . . . . . . . . . . . . 3 4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Authentication Service Behavior . . . . . . . . . . . . . 4 4.2. Verification Service Behavior . . . . . . . . . . . . . . 5 5. Further Information Associated with Resource-Priority . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6.1. JSON Web Token Claims Registration . . . . . . . . . . . 6 6.2. PASSporT 'rph' Types . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 - 7.1. Avoidance of replay and cut and past attacks . . . . . . 7 + 7.1. Avoidance of replay and cut and paste attacks . . . . . . 7 7.2. Solution Considerations . . . . . . . . . . . . . . . . . 7 7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 8.1. Normative References . . . . . . . . . . . . . . . . . . 8 + 8.1. Normative References . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction PASSporT [I-D.ietf-stir-passport] is a token format based on JWT [RFC7519] for conveying cryptographically-signed information about the identities involved in personal communications; it is used with STIR [I-D.ietf-stir-rfc4474bis] to convey a signed assertion of the identity of the participants in real-time communications established via a protocol like SIP. This specification extends PASSporT to allow cryptographic-signing of the SIP 'Resource-Priority' header field defined in [RFC4412]. [RFC4412] defines the SIP 'Resource-Priority' header field for communications Resource Priority. As specified in [RFC4412], the - 'Resource-Priority' header field may be used by SIP user agents, - including, Public Switched Telephone Network (PSTN) gateways and - terminals, and SIP proxy servers to influence prioritization afforded - to communication sessions,including PSTN calls. However, the SIP - 'Resource-Priority' header field could be spoofed and abused by - unauthorized entities. + 'Resource-Priority' header field may be used by SIP user agents + [RFC3261], including, Public Switched Telephone Network (PSTN) + gateways and terminals, and SIP proxy servers to influence + prioritization afforded to communication sessions,including PSTN + calls. However, the SIP 'Resource-Priority' header field could be + spoofed and abused by unauthorized entities. - The STIR architecture assumes that an authority on the originating - side of a call provides a cryptographic assurance of the validity of - the calling party number in order to prevent impersonation attacks. - The STIR architecture allows extension that can be utilized by - authorities supporting real-time communication services using the - 'Resource-Priority' header field to cryptographically sign the SIP - 'Resource-Priority' header field and convey assertion of the - authorization for 'Resource-Priority'. For example, the authority on - the originating side verifying the authorization of a particular - communication for Resource-Priority can use a PASSPorT claim to - cryptographically-sign the SIP 'Resource-Priority' header field and - convey an assertion of the authorization for 'Resource-Priority'. - This will allow a receiving entity (including entities located in - different network domains/boundaries) to verify the validity of - assertions authorizating Resource-Priority. Cryptographically-signed - SIP 'Resource-Priority' headers will allow a receiving entity to - verify and act on the information with confidence that the - information have not been spoofed or compromised. + The STIR architecture [RFC7340]assumes that an authority on the + originating side of a call provides a cryptographic assurance of the + validity of the calling party number in order to prevent + impersonation attacks. The STIR architecture allows extension that + can be utilized by authorities supporting real-time communication + services using the 'Resource-Priority' header field to + cryptographically sign the SIP 'Resource-Priority' header field and + convey assertion of the authorization for 'Resource-Priority'. For + example, the authority on the originating side verifying the + authorization of a particular communication for Resource-Priority can + use a PASSPorT claim to cryptographically-sign the SIP 'Resource- + Priority' header field and convey an assertion of the authorization + for 'Resource-Priority'. This will allow a receiving entity + (including entities located in different network domains/boundaries) + to verify the validity of assertions authorizing Resource-Priority. + Cryptographically-signed SIP 'Resource-Priority' headers will allow a + receiving entity to verify and act on the information with confidence + that the information have not been spoofed or compromised. This specification documents an optional extension to PASSporT and the associated STIR mechanisms to provide a function to sign the SIP 'Resource-Priority' header field. This PASSporT object is used to provide attestation of a calling user authorization for priority communications. This is necessary in addition to the PASSporT object that is used for calling user telephone number attestation. How the optional extension to PASSporT is used for real-time communications supported using SIP 'Resource-Priority' header field is defined in other documents and is outside the scope of this document. @@ -134,77 +130,79 @@ 3. PASSporT 'rph' Claim This specification defines a new JSON Web Token claim for "rph", which provides an assertion for information in SIP 'Resource- Priority'header. 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 contain a "rph" claim, and any entities verifying the PASSporT object 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: { "typ":"passport", "ppt":"rph", "alg":"ES256", "x5u":"https://www.example.org/cert.cer"} The "rph" claim will provide an assertion of authorization,"auth", for information in the SIP "Resource-Priority" header field (i.e., Resource-Priority: namespace "." r-priority) 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 array containing one or more of JSON objects for the content of the SIP 'Resource-Priority' header that is being asserted of which one of the "rph" object, is mandatory. The following is an example "rph" claim for a SIP "Resource-Priority" - header field with a "namespace "." r-priority" value of "ets.0". + header field with a "namespace "." r-priority" value of "ets.0" and + with a "namespace "." r-priority" value of "wps.0". { "orig":{"tn":"12155551212"} - "dest":{"tn":"12125551213"}, + "dest":{["tn":"12125551213"]}, "iat":1443208345, - "rph":{"auth":"ets.0"}} + "rph":{"auth":["ets.0","wps.0"]} After the header and claims PASSporT objects have been constructed, their signature is generated normally per the guidance in [I-D.ietf-stir-passport] using the full form of PASSPorT. The - credentials (e.g., authority responsible for authorizating Resource- + credentials (e.g., authority responsible for authorizing Resource- Priority) used to create the signature must have authority over the "rph" claim and there is only one authority per claim. The authority MUST use its credentials (i.e., CERT) associated with the specific service supported by the SIP namespace in the claim. 4. 'rph' in SIP This section specifies SIP-specific usage for the "rph" claim in PASSporT. 4.1. Authentication Service Behavior The Authentication Service will create the "rph" claim using the values discussed in section 3 based on [RFC4412]. The construction of "rph" claim follows the steps described in Section 4 of [I-D.ietf-stir-rfc4474bis]. The resulting Identity header for "rph" might look as follows: -"eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleUowZVhBaU9pSndZWE56Y0c5eW -RDSXNEUW9pY0hCMElqb2ljbkJvSWl3TkNpSmhiR2NpT2lKRlV6STFOaUlzRFFvaWVEVjFJanBvZE -hSd2N6b3ZMM2QzZHk1bGVHRnRjR3hsTG1OdmJTOWpaWEowTG1ObGNuME5DZz09IHx84oCZLuKAmX -x8IGV5SnZjbWxuSWpwN0luUnVJam9pTVRJeE5UVTFOVEV5TVRJaWZTd2dEUW9pYVdGMElqb2lNVF -EwTXpJd09ETTBOU0lzSUEwS0ltUmxjM1FpT25zaWRHNGlPaUl4TWpFMU5UVTFNVEl4TXlKOURRb2 -ljbkJvSWpwN0ltRjFkR2dpT2lKbGRITXVNQ0o5RFFvTkNnMEsgICAgIiwibmJmIjoxNDk4NDg5MT -U5LCJleHAiOjE0OTg0OTI3NTksImlhdCI6MTQ5ODQ4OTE1OX0.oia2-qJTlDJICsJ_Af2A5slhO2 -iJU-kAHG-HRVVhRiUea6acIoD0w2Bc3Ap4iZ6izx7haRj55MtKKCwY5_bItA"; -info= "https://www.example.org/cert.cer";alg=ES256;ppt="rph" + "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleUowZVhBaU9pSnd + ZWE56Y0c5eWRDSXNEUW9pY0hCMElqb2ljbkJvSWl3TkNpSmhiR2NpT2lKRlV6STFO + aUlzRFFvaWVEVjFJanBvZEhSd2N6b3ZMM2QzZHk1bGVHRnRjR3hsTG1OdmJTOWpaW + EowTG1ObGNuME5DZzBLIHx84oCZLuKAmXx8IGV5QWliM0pwWnlJNmV5SjBiaUk2SW + pFeU1UVTFOVFV4TWpFeUluME5DaUprWlhOMElqcDdXeUowYmlJNklqRXlNVEkxTlR + VeE1qRXpJbDE5TEEwS0ltbGhkQ0k2TVRRME16SXdPRE0wTlN3TkNpSnljR2dpT25z + aVlYVjBhQ0k2V3lKbGRITXVNQ0lzSW5kd2N5NHdJbDE5RFFvPSJ9.s37S6VC8HM6D + 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" from the 'Resource-Priority' header field based on policy associated with service specific use of the "namespace "." r-priority" values based on [RFC4412]. The authentication service derives the value of the PASSPorT claim by verifying the authorization for Resource- Priority (i.e., verifying a calling user privilege for Resource- Priority based on its identity) which might be derived from customer profile data or from access to external services. @@ -225,28 +223,20 @@ follows: The verification service MUST extract the value associated with the "auth" key in a full form PASSPorT with a "ppt" value of "rph". If the signature validates, then the verification service can use the value of the "rph" claim as validation that the calling party is authorized for Resource-Priority, which would in turn be used for priority treatment in accordance with local policy for the associated communication service. - The verification service MUST extract the value associated with the - "auth" key in a full form PASSPorT with a "ppt" value of "rph". If - the signature validates, then the verification service can use the - value of the "rph" claim as validation that the calling party is - authorized for Resource-Priority, which would in turn be used for - priority treatment in accordance with local policy for the associated - communication service. - In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires "iat" value in "rph" claim to be verified. The behavior of a SIP UAs upon receiving an INVITE containing a PASSporT object with a "rph" claim will largely remain a matter of implementation policy for the specific communication service. In most cases,implementations would act based on confidence in the veracity of this information. The use of the compact form of PASSporT is not specified in this document. @@ -267,42 +257,42 @@ have one or more such additional information field(s). Details of such "rph" claim to encompass other data elements are left for future version of this specification. 6. IANA Considerations 6.1. JSON Web Token Claims Registration o Claim Name: "rph" - o Claim Description: Resource Priority Header + o Claim Description: Resource Priority Header Authorization o Change Controller: IESG o Specification Document(s): Section 3 of [RFCThis] 6.2. PASSporT 'rph' Types This document requests that the IANA add a new entry to the PASSporT Types registry for the type "rph" which is specified in [RFCThis]. This specification also requests that the IANA create a new registry for PASSporT "rph" types. Registration of new PASSporT "rph" types shall be under the specification required policy. This registry is to be initially populated with a single value for "auth" which is specified in [RFCThis]. 7. Security Considerations The security considerations discussed in [I-D.ietf-stir-rfc4474bis] in Section 10 are applicable here. -7.1. Avoidance of replay and cut and past attacks +7.1. Avoidance of replay and cut and paste attacks 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 priority of the communication as defined in [RFC4412]. To avoid the replay, and cut and paste attacks, the procedures described in Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed. 7.2. Solution Considerations The use of extension to PASSporT tokens with "ppt" value "rph" based @@ -355,39 +346,34 @@ . 8.2. Informative References [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, . - [RFC6919] Barnes, R., Kent, S., and E. Rescorla, "Further Key Words - for Use in RFCs to Indicate Requirement Levels", RFC 6919, - DOI 10.17487/RFC6919, April 2013, - . - [RFC7340] Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure Telephone Identity Problem Statement and Requirements", RFC 7340, DOI 10.17487/RFC7340, September 2014, . Authors' Addresses + Ray P. Singh Vencore Labs 150 Mount Airy Road New Jersey, NJ 07920 USA Email: rsingh@vencorelabs.com - Martin Dolly AT&T 200 Laurel Avenue Middletown, NJ 07748 USA Email: md3135@att.com Subir Das Vencore Labs