draft-ietf-stir-passport-shaken-07.txt   draft-ietf-stir-passport-shaken-08.txt 
STIR C. Wendt STIR C. Wendt
Internet-Draft Comcast Internet-Draft Comcast
Intended status: Standards Track M. Barnes Intended status: Standards Track M. Barnes
Expires: August 4, 2019 iconectiv Expires: September 11, 2019 iconectiv
January 31, 2019 March 10, 2019
PASSporT SHAKEN Extension (SHAKEN) PASSporT SHAKEN Extension (SHAKEN)
draft-ietf-stir-passport-shaken-07 draft-ietf-stir-passport-shaken-08
Abstract Abstract
This document extends PASSporT, which is a token object that conveys This document extends PASSporT, which is a token object that conveys
cryptographically-signed information about the participants involved cryptographically-signed information about the participants involved
in communications. The extension is defined, corresponding to the in communications. The extension is defined, corresponding to the
SHAKEN specification, to provide both a specific set of levels-of- SHAKEN specification, to provide both a specific set of levels-of-
confidence in the correctness of the originating identity for a SIP confidence in the correctness of the originating identity for a SIP
based Communication Service Provider (CSP) telephone network based Communication Service Provider (CSP) telephone network
originated call as well as an identifier that allows the CSP to originated call as well as an identifier that allows the CSP to
skipping to change at page 1, line 38 skipping to change at page 1, line 38
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 August 4, 2019. This Internet-Draft will expire on September 11, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 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 25 skipping to change at page 2, line 25
5. PASSporT 'origid' Claim . . . . . . . . . . . . . . . . . . . 4 5. PASSporT 'origid' Claim . . . . . . . . . . . . . . . . . . . 4
6. Example "shaken" PASSporT . . . . . . . . . . . . . . . . . . 4 6. Example "shaken" PASSporT . . . . . . . . . . . . . . . . . . 4
7. Using 'shaken' in SIP . . . . . . . . . . . . . . . . . . . . 4 7. Using 'shaken' in SIP . . . . . . . . . . . . . . . . . . . . 4
8. Order of Claim Keys . . . . . . . . . . . . . . . . . . . . . 4 8. Order of Claim Keys . . . . . . . . . . . . . . . . . . . . . 4
9. Security Considerations . . . . . . . . . . . . . . . . . . . 5 9. Security Considerations . . . . . . . . . . . . . . . . . . . 5
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 5 10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 5
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
11.1. JSON Web Token claims . . . . . . . . . . . . . . . . . 6 11.1. JSON Web Token claims . . . . . . . . . . . . . . . . . 6
11.2. PASSporT Types . . . . . . . . . . . . . . . . . . . . . 6 11.2. PASSporT Types . . . . . . . . . . . . . . . . . . . . . 6
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
13.1. Normative References . . . . . . . . . . . . . . . . . . 6 13.1. Normative References . . . . . . . . . . . . . . . . . . 7
13.2. Informative References . . . . . . . . . . . . . . . . . 7 13.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
The Signature-based Handling of Asserted information using toKENs The Signature-based Handling of Asserted information using toKENs
(SHAKEN) [ATIS-1000074] specification defines a framework for using (SHAKEN) [ATIS-1000074] specification defines a framework for using
Secure Telephone Identity Revisited (STIR) protocols including Secure Telephone Identity Revisited (STIR) protocols including
PASSporT [RFC8225], SIP Authenticated Identity Management [RFC8224] PASSporT [RFC8225], SIP Authenticated Identity Management [RFC8224]
and the STIR certificate framework [RFC8226] for implementing the and the STIR certificate framework [RFC8226] for implementing the
skipping to change at page 4, line 19 skipping to change at page 4, line 19
information the service provider is attesting to. The 'attest' claim information the service provider is attesting to. The 'attest' claim
can be one of the following three values: 'A', 'B', or 'C'. These can be one of the following three values: 'A', 'B', or 'C'. These
values correspond to 'Full Attestation', 'Partial Attestation', and values correspond to 'Full Attestation', 'Partial Attestation', and
'Gateway Attestation', respectively. See [ATIS-1000074] for the 'Gateway Attestation', respectively. See [ATIS-1000074] for the
definitions of these three levels of attestation. definitions of these three levels of attestation.
5. PASSporT 'origid' Claim 5. PASSporT 'origid' Claim
The purpose of the 'origid' claim is described in [ATIS-1000074]. The purpose of the 'origid' claim is described in [ATIS-1000074].
The value of 'origid' claim is a UUID as defined in [RFC4122]. The value of 'origid' claim is a UUID as defined in [RFC4122].
Please refer to Section 10 for a discussion of the privacy
considerations around the use of this value.
6. Example "shaken" PASSporT 6. Example "shaken" PASSporT
Protected Header Protected Header
{ {
"alg":"ES256", "alg":"ES256",
"typ":"passport", "typ":"passport",
"ppt":"shaken", "ppt":"shaken",
"x5u":"https://cert.example.org/passport.cer" "x5u":"https://cert.example.org/passport.cer"
} }
skipping to change at page 5, line 31 skipping to change at page 5, line 33
claims added by this extension are not used in such a validation claims added by this extension are not used in such a validation
step. They are not compared to fields in the SIP message. Instead, step. They are not compared to fields in the SIP message. Instead,
they simply carry additional information from the signer to the they simply carry additional information from the signer to the
consumer of the PASSport. This new information shares the same consumer of the PASSport. This new information shares the same
integrity protection and non-repudiation properties as the base integrity protection and non-repudiation properties as the base
claims in the PASSporT. claims in the PASSporT.
10. Privacy Considerations 10. Privacy Considerations
As detailed in [RFC3261] Section 26, SIP messages inherently carry As detailed in [RFC3261] Section 26, SIP messages inherently carry
identifying information of the caller and callee. The value of the identifying information of the caller and callee. The addition of
'origid' claim, as defined in SHAKEN [ATIS-1000074] and described in STIR cryptographically attests that the signing party vouches for the
this document, is intended to be a opaque and unique identifier of an information given about the callee, as is discussed in the Privacy
element on the path of a given request. This identifier is used by Considerations of [RFC8224].
an originating telephone service provider to identify where within
their network (e.g. a gateway or particular service element) a call SHAKEN [ATIS-1000074] furthermore adds an 'origid' value to the STIR
was initiated. This facilitates identifying and stopping bad actors PASSporT, which is an opaque unique identifier representing an
trying to spoof identities or make fraudulent calls. The opacity of element on the path of a given SIP request. This identifier is
the 'origid' claim value is intended to minimize direct exposure of generated by an originating telephone service provider to identify
information about the origination of a set of calls sharing the where within their network (e.g. a gateway or particular service
'origid' value. It should be recognized, however, that the potential element) a call was initiated; 'origid' can facilitate forensic
for discovering patterns through correlation of those calls exists. analysis of call origins when identifying and stopping bad actors
This could allow a recipient of many calls to, for instance, learn trying to spoof identities or make fraudulent calls.
that a set of callers are using a particular service or coming
through a common gateway. However, this threat already exists in The opacity of the 'origid' claim value is intended to minimize
SIP. There is information in the SIP messages(in the form of Record- exposure of information about the origination of calls labelled with
Route, Via, and potentially History-Info header field values that can an 'origid' value. It is therefore RECOMMENDED that implementations
be analyzed the same way (and may correlate closely with the 'origid' generate a unique 'origid' value per call in such a way that only the
value). If the operator of an element is concerned about the generator of the 'origid' can determine when two 'origid' values
correlation of 'origid' values, the element could be configured to represent the same or different elements. If deployed systems
use a unique 'origid' value per call in such a way that the operator instead use a common or related 'origid' for service elements in
can associate those 'origid' values to the correct element when doing their network, the potential for discovering patterns through
lookups in their backend systems. correlation of those calls exists. This could allow a recipient of
calls to, for instance, learn that a set of callers are using a
particular service or coming through a common gateway. It is
expected that SHAKEN PASSporTs are shared only within an [RFC3324]
trust domain and will be stripped before calls exit that trust
domain, but this information still could be used by analytics on
intermediary and terminating systems to reveal information that could
include geographic location and even device-level information,
depending on how the 'origid' is generated.
11. IANA Considerations 11. IANA Considerations
11.1. JSON Web Token claims 11.1. JSON Web Token claims
This specification requests that the IANA add two new claims to the This specification requests that the IANA add two new claims to the
JSON Web Token Claims registry as defined in [RFC7519]. JSON Web Token Claims registry as defined in [RFC7519].
Claim Name: "attest" Claim Name: "attest"
skipping to change at page 8, line 5 skipping to change at page 8, line 16
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,
<https://www.rfc-editor.org/info/rfc3261>. <https://www.rfc-editor.org/info/rfc3261>.
[RFC3323] Peterson, J., "A Privacy Mechanism for the Session [RFC3323] Peterson, J., "A Privacy Mechanism for the Session
Initiation Protocol (SIP)", RFC 3323, Initiation Protocol (SIP)", RFC 3323,
DOI 10.17487/RFC3323, November 2002, DOI 10.17487/RFC3323, November 2002,
<https://www.rfc-editor.org/info/rfc3323>. <https://www.rfc-editor.org/info/rfc3323>.
[RFC3324] Watson, M., "Short Term Requirements for Network Asserted
Identity", RFC 3324, DOI 10.17487/RFC3324, November 2002,
<https://www.rfc-editor.org/info/rfc3324>.
[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, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
Authors' Addresses Authors' Addresses
Chris Wendt Chris Wendt
Comcast Comcast
One Comcast Center One Comcast Center
Philadelphia, PA 19103 Philadelphia, PA 19103
 End of changes. 7 change blocks. 
29 lines changed or deleted 43 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/