Persona Assertion Token
draft-ietf-stir-passport-03
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (stir WG) | |
|---|---|---|---|
| Authors | Chris Wendt , Jon Peterson | ||
| Last updated | 2016-06-13 | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text xml htmlized pdfized bibtex | ||
| Reviews | |||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-stir-passport-03
STIR C. Wendt
Internet-Draft Comcast
Intended status: Standards Track J. Peterson
Expires: December 15, 2016 Neustar Inc.
June 13, 2016
Persona Assertion Token
draft-ietf-stir-passport-03
Abstract
This document defines a token format for verifying with non-
repudiation the sender of and authorization to send information
related to the originator of personal communications. A
cryptographic signature is defined to protect the integrity of the
information used to identify the originator of a personal
communications session (e.g. the telephone number or URI) and verify
the accuracy of this information at the destination. The
cryptographic signature is defined with the intention that it can
confidently verify the originating persona even when the signature is
sent to the destination party over an unsecure channel. The Persona
Assertion Token (PASSporT) is particularly useful for many personal
communications applications over IP networks and other multi-hop
interconnection scenarios where the originating and destination
parties may not have a direct trusted relationship.
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 http://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 December 15, 2016.
Wendt & Peterson Expires December 15, 2016 [Page 1]
Internet-Draft PASSporT June 2016
Copyright Notice
Copyright (c) 2016 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
(http://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
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Token Overview . . . . . . . . . . . . . . . . . . . . . . . 4
3. PASSporT Definition . . . . . . . . . . . . . . . . . . . . . 4
3.1. PASSporT Header . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. "typ" (Type) Header Parameter . . . . . . . . . . . . 4
3.1.2. "alg" (Algorithm) Header Parameter . . . . . . . . . 5
3.1.3. "x5u" (X.509 URL) Header Parameter . . . . . . . . . 5
3.2. PASSporT Payload . . . . . . . . . . . . . . . . . . . . 5
3.2.1. JWT defined claims . . . . . . . . . . . . . . . . . 5
3.2.1.1. "iat" - Issued at claim . . . . . . . . . . . . . 5
3.2.2. PASSporT specific claims . . . . . . . . . . . . . . 6
3.2.2.1. Originating and Destination Identities . . . . . 6
3.2.2.2. "mky" - Media Key claim . . . . . . . . . . . . . 7
3.3. PASSporT Signature . . . . . . . . . . . . . . . . . . . 8
4. Extending PASSporT . . . . . . . . . . . . . . . . . . . . . 8
4.1. "ppt" (PASSporT) header parameter . . . . . . . . . . . . 8
4.2. Extended PASSporT Claims . . . . . . . . . . . . . . . . 9
4.3. Alternate PASSporT Extension . . . . . . . . . . . . . . 9
4.4. Registering PASSporT Extensions . . . . . . . . . . . . . 9
5. Deterministic JSON Serialization . . . . . . . . . . . . . . 10
5.1. Example PASSport deterministic JSON form . . . . . . . . 10
6. Human Readability . . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7.1. Avoidance of replay and cut and paste attacks . . . . . . 10
7.2. Solution Considerations . . . . . . . . . . . . . . . . . 11
7.3. Privacy Considerations . . . . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8.1. Media Type Registration . . . . . . . . . . . . . . . . . 12
8.1.1. Media Type Registry Contents Additions Requested . . 12
8.2. JSON Web Token Claims Registration . . . . . . . . . . . 13
8.2.1. Registry Contents Additions Requested . . . . . . . . 13
Wendt & Peterson Expires December 15, 2016 [Page 2]
Internet-Draft PASSporT June 2016
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
Appendix A. Example PASSporT JWS Serialization and Signature . . 15
A.1. X.509 Private Key Certificate for Example . . . . . . . . 17
A.2. X.509 Public Key Certificate for Example . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
In today's IP-enabled telecommunications world, there is a growing
concern about the ability to trust incoming invitations for
communications sessions, including video, voice and messaging. As an
example, modern telephone networks provide the ability to spoof the
calling party telephone number for many legitimate purposes including
providing network features and services on the behalf of a legitimate
telephone number. However, as we have seen, bad actors have taken
advantage of this ability for illegitimate and fraudulent purposes
meant to trick telephone users to believe they are someone they are
not. This problem can be extended to many emerging forms of personal
communications.
This document defines a common method for creating and validating a
token that cryptographically verifies an originating identity, or
more generally a URI or application specific identity string
representing the originator of personal communications. Through
extended profiles other information relevant to the personal
communications can also be attached to the token. The primary goal
of PASSporT is to provide a common framework for signing persona
related information in an extensible way. A secondary goal is to
provide this functionality independent of any specific personal
communications signaling call logic, so that creation and
verification of persona information can be implemented in a flexible
way and can be used in many personal communications applications
including end-to-end applications that require different signaling
protocols. It is anticipated that signaling protocol specific
guidance will be provided in other related documents and
specifications to specify how to use and transport PASSporT tokens,
however this is intentionally out of scope for this document.
Note: As of the authoring of this document,
[I-D.ietf-stir-rfc4474bis] provides details of how to use PASSporT
within SIP signaling for the signing and verification of telephone
numbers.
Wendt & Peterson Expires December 15, 2016 [Page 3]
Internet-Draft PASSporT June 2016
2. Token Overview
Tokens are a convenient way of encapsulating information with
associated digital signatures. They are used in many applications
that require authentication, authorization, encryption, non-
repudiation and other use cases. JSON Web Token (JWT) [RFC7519] and
JSON Web Signature (JWS) [RFC7515] are designed to provide a compact
form for many of these purposes and define a specific method and
syntax for signing a specific set of information or "claims" within
the token and therefore providing an extensible set of claims.
Additionally, JWS provides extensible mechanisms for specifying the
method and cryptographic algorithms used for the associated digital
signatures.
3. PASSporT Definition
The PASSporT is constructed based on JWT [RFC7519] and JWS [RFC7515]
specifications. JWS defines the use of JSON data structures in a
specified canonical format for signing data corresponding to JOSE
header, JWS Payload, and JWS Signature. JWT defines specific set of
claims that are represented by specified key value pairs which can be
extended with custom keys for specific applications.
3.1. PASSporT Header
The JWS token header is a JOSE header [RFC7515] that defines the type
and encryption algorithm used in the token.
An example of the header for the case of an ECDSA P-256 digital
signature would be the following,
{
"typ":"passport",
"alg":"ES256",
"x5u":"https://cert.example.org/passport.cer"
}
3.1.1. "typ" (Type) Header Parameter
JWS defines the "typ" (Type) Header Parameter to declare the media
type [IANA.MediaTypes] of the JWS.
For PASSporT Token the "typ" header MUST minimally include and begin
with "passport". This represents that the encoded token is a JWT of
type passport. Note with extensions explained later in this
document, the typ may be another value if defined as a passport
extension.
Wendt & Peterson Expires December 15, 2016 [Page 4]
Internet-Draft PASSporT June 2016
3.1.2. "alg" (Algorithm) Header Parameter
For PASSporT, the "alg" should be defined as follows, for the
creation and verification of PASSporT tokens and their digital
signatures ES256 MUST be implemented.
Note that JWA [RFC7518] defines other algorithms that may be utilized
or updated in the future depending on cryptographic strength
requirements guided by current security best practice.
3.1.3. "x5u" (X.509 URL) Header Parameter
As defined in JWS, the "x5u" header parameter is used to provide a
URI [RFC3986] referring to the resource for the X.509 public key
certificate or certificate chain [RFC5280] corresponding to the key
used to digitally sign the JWS. Note: The definition of what the URI
represents in terms of the actor serving the X.509 public key is out
of scope of this document. However, generally this would correspond
to an HTTPS or DNSSEC resource with the guidance that it MUST be a
TLS protected, per JWS spec.
3.2. PASSporT Payload
The token payload claims should consist of the information which
needs to be verified at the destination party. This claim should
correspond to a JWT claim [RFC7519] and be encoded as defined by the
JWS Payload [RFC7515]
The PASSporT defines the use of a number of standard JWT defined
headers as well as two new custom headers corresponding to the two
parties associated with personal communications, the originator and
terminator. These headers or key value pairs are detailed below.
3.2.1. JWT defined claims
3.2.1.1. "iat" - Issued at claim
The JSON claim MUST include the "iat" [RFC7519] defined claim issued
at. As defined this should be set to a date cooresponding to the
origination of the personal communications. The time value should be
of the format defined in [RFC7519] Section 2 NumericDate. This is
included for securing the token against replay and cut and paste
attacks, as explained further in the security considerations in
section 7.
Wendt & Peterson Expires December 15, 2016 [Page 5]
Internet-Draft PASSporT June 2016
3.2.2. PASSporT specific claims
3.2.2.1. Originating and Destination Identities
Baseline PASSporT defines claims that convey the identity of the
origination and destination of personal communications represented as
either telephone numbers or Uniform Resource Indicators (URIs). Some
using protocols may require other identifiers for personae; these may
be specified as claims through the PASSporT extensibility mechanisms.
But for telephone numbers and URIs, the following claims should be
used:
3.2.2.1.1. "otn" and "dtn" - Originating and Destination Telephone
Number claim
If the originating identity is a telephone number, the claim "otn"
SHOULD be included. If the destination identity is a telephone
number, the claim "dtn" SHOULD be included.
Telephone Number strings for "otn" and "dtn" claims MUST be
canonicalized according to the procedures specified in
[I-D.ietf-stir-rfc4474bis] Section 6.1.1.
3.2.2.1.2. "ouri" and "duri" - Originating and Destination URI claims
If the originating identity is not a telephone number, the claim
"ouri" SHOULD be included with the string cooresponding to the URI
form of the identity as defined in [RFC3986], alternatively it could
also contain an application specific identity string, if URI format
is not appropriate.
If the destination identity is not a telephone number, the claim
"duri" SHOULD be included. The same string format rules apply as
stated for "ouri".
3.2.2.1.3. "dgrp" - Multiple destination identities
There are multi-party, group, or conference types of calls where
there is a single originating identity or alterntively a "moderator"
identity and a number of destination identities or participants in
the multi-party call. For these scenerios, the "dgrp" key should be
used with a JSON object containing multiple "dtn" or "duri"
identities as defined above.
An example PASSporT payload object with multiple destination
identities would be as follows:
Wendt & Peterson Expires December 15, 2016 [Page 6]
Internet-Draft PASSporT June 2016
{
"iat":"1443208345",
"otn":"12155551212",
"dgrp":{
"duri":"sip:alice@example.com",
"dtn":"12125551212",
"duri":"sip:bob@example.net"
}
}
3.2.2.2. "mky" - Media Key claim
Some protocols that use PASSporT convey hashes for media security
keys within their signaling in order to bind those keys to the
identities established in the signaling layers. One example would be
the DTLS-SRTP key fingerprints carried in SDP via the "a=fingerprint"
attribute; multiple instances of that fingerprint may appear in a
single SDP body corresponding to difference media streams offered.
The "mky" value of PASSporT contains a hexadecimal key presentation
of any hash(es) necessary to establish media security via DTLS-SRTP.
This mky value should be formated in a JSON form including the 'alg'
and 'dig' keys with the corresponding algorithm and hexadecimal
values. Note that per guidance of Section 5 of this document any
whitespace and line feeds must be removed. If there is multiple
fingerprint values, more than one, the fingerprint values should be
constructed as a JSON array denoted by bracket characters. For the
'dig' key value, the hash value should be the hexadecimal value
without any colons, in order to provide a more efficient, compact
form to be encoded in PASSporT token claim.
An example claim with "mky" claim is as follows:
For an SDP offer that includes the following fingerprint values,
a=fingerprint:sha-256 02:1A:CC:54:27:AB:EB:9C:53:3F:3E:4B:65:
2E:7D:46:3F:54:42:CD:54:F1:7A:03:A2:7D:F9:B0:7F:46:19:B2
a=fingerprint:sha-256 4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:
5D:49:6B:19:E5:7C:AB:3E:4B:65:2E:7D:46:3F:54:42:CD:54:F1
the PASSporT Payload object would be:
Wendt & Peterson Expires December 15, 2016 [Page 7]
Internet-Draft PASSporT June 2016
{
"iat":"1443208345",
"otn":"12155551212",
"duri":"sip:alice@example.com",
"mky":[
{
"alg":"sha-256",
"dig":"021ACC5427ABEB9C533F3E4B652E7D463F5442CD54
F17A03A27DF9B07F4619B2"
},
{
"alg":"sha-256",
"dig":"4AADB9B13F82183B540212DF3E5D496B19E57C
AB3E4B652E7D463F5442CD54F1"
}
]
}
3.3. PASSporT Signature
The signature of the PASSporT is created as specified by JWS using
the private key corresponding to the X.509 public key certificate
referenced by the "x5u" header parameter.
4. Extending PASSporT
PASSporT represents the bare minimum set of claims needed to assert
the originating identity, however there will certainly be new and
extended applications and usage of PASSPorT that will need to extend
the claims to represent other information specific to the origination
identities beyond the identity itself.
There are two mechanisms defined to extend PASSporT. The first
includes an extension of the base passport claims to include
additional claims. An alternative method of extending PASSporT is
for applications of PASSporT unrelated to the base set of claims,
that will define it's own set of claims. Both are described below.
4.1. "ppt" (PASSporT) header parameter
For extended profiles of PASSporT, a new JWS header parameter "ppt"
MUST be used with a string that uniquely identifies the profile
specification that defines any new claims that would extend the base
set of claims of PASSporT.
An example header with an extended PASSporT profile of "foo" is as
follows:
Wendt & Peterson Expires December 15, 2016 [Page 8]
Internet-Draft PASSporT June 2016
{
"typ":"passport",
"ppt":"foo",
"alg":"ES256",
"x5u":"https://tel.example.org/passport.cer"
}
4.2. Extended PASSporT Claims
Future specifications that define such extensions to the PASSporT
mechanism MUST explicitly designate what claims they include, the
order in which they will appear, and any further information
necessary to implement the extension. All extensions MUST
incorporate the baseline JWT elements specified in Section 3; claims
may only be appended to the claims object specified; they can never
be subtracted or re-ordered. Specifying new claims follows the
baseline JWT procedures ([RFC7519] Section 10.1). Note that
understanding an extension as a verifier is always optional for
compliance with this specification (though future specifications or
profiles for deployment environments may make other "ppt" values
mandatory). The creator of a PASSporT object cannot assume that
verifiers will understand any given extension. Verifiers that do
support an extension may then trigger appropriate application-level
behavior in the presence of an extension; authors of extensions
should provide appropriate extension-specific guidance to application
developers on this point.
4.3. Alternate PASSporT Extension
Some applications may want to use the mechanism of the PASSporT
digital signature that is not a superset of the base set of claims of
the PASSporT token as defined in Section 3. Rather, a specification
may use PASSporT with its own defined set of claims.
In this case, the specification SHOULD define its own MIME media type
[RFC2046] in the "Media Types" registry [IANA.MediaTypes]. The MIME
subtype SHOULD start with the string "passport-" to signify that it
is related to the PASSporT token. For example, for the "foo"
application the MIME type/sub-type could be defined as "application/
passport-foo".
4.4. Registering PASSporT Extensions
Toward interoperability and to maintain uniqueness of the extended
PASSporT profile header parameter string, there SHOULD be an industry
registry that tracks the definition of the profile strings.
Wendt & Peterson Expires December 15, 2016 [Page 9]
Internet-Draft PASSporT June 2016
5. Deterministic JSON Serialization
In order to provide a deterministic representation of the PASSporT
Header and Claims, particularly if PASSporT is used across multiple
signaling environments, the JSON header object and JSON Claim object
MUST be computed as follows.
The JSON object MUST follow the rules for the construction of the
thumbprint of a JSON Web Key (JWK) as defined in [RFC7638] Section 3.
Each JSON object MUST contain no whitespace or line breaks before or
after any syntactic elements and with the required members ordered
lexicographically by the Unicode [UNICODE] code points of the member
names.
In addition, the JSON header and claim members MUST follow the
lexicographical ordering and character and string rules defined in
[RFC7638] Section 3.3.
5.1. Example PASSport deterministic JSON form
For the example PASSporT Payload shown in Section 3.2.2.2, the
following is the deterministic JSON object form.
{"iat": 1443208345,"otn":"12155551212","duri":
"sip:alice@example.com","mky":[{"alg":"sha-256","dig":"021ACC
5427ABEB9C533F3E4B652E7D463F5442CD54F17A03A27DF9B07F4619B2"},
{"alg":"sha-256","dig":"4AADB9B13F82183B540212DF3E5D496B19E5
7CAB3E4B652E7D463F5442CD54F1"}]}
6. Human Readability
JWT [RFC7519] and JWS [RFC7515] are defined to use Base64 and/or UTF8
encoding to the Header, Payload, and Signature sections. However,
many personal communications protocols, such as SIP and XMPP, use a
"human readable" format to allow for ease of use and ease of
operational debugging and monitoring. As such, specifications using
PASSporT may provide guidance on whether Base64 encoding or plain
text will be used for the construction of the PASSporT Header and
Claim sections.
7. Security Considerations
7.1. Avoidance of replay and cut and paste attacks
There are a number of security considerations for use of the token
for avoidance of replay and cut and paste attacks. PASSporT tokens
must be sent along with other application level protocol information
(e.g. for SIP an INVITE as defined in [RFC3261]). There should be a
Wendt & Peterson Expires December 15, 2016 [Page 10]
Internet-Draft PASSporT June 2016
link between various information provided in the token and
information provided by the application level protocol information.
These would include:
o "iat" claim should closely correspond to a date/time the message
was originated. It should also be within a relative delta time
that is reasonable for clock drift and transmission time
characteristics associated with the application using the PASSporT
token.
o either "dtn" claim or "duri" claim is included to prevent the
ability to use a previously originated message to send to another
destination party
7.2. Solution Considerations
It should be recognized that the use of this token should not, in
it's own right, be considered a full solution for absolute non-
repudiation of the persona being asserted. This only provides non-
repudiation of the signer of PASSporT. If the signer and the persona
are not one in the same, which can and often will be the case in
telecommunications networks today, protecting the destination party
from being spoofed may take some interpretation or additional
verification of the link between the PASSporT signature and the
persona being asserted.
In addition, the telecommunications systems and specifications that
use PASSporT should in practice provide mechanisms for:
o Managing X.509 certificates and X.509 certificate chains to an
authorized trust anchor that can be a trusted entity to all
participants in the telecommunications network
o Accounting for entities that may route calls from other peer or
interconnected telecommunications networks that are not part of
the "trusted" communications network or may not be following the
usage of PASSporT or the profile of PASSporT appropriate to that
network
o Following best practices around management and security of X.509
certificates
7.3. Privacy Considerations
Because PASSporT explicity includes claims of identitifiers of
parties involved in communications, times, and potentially other call
detail, care should be taken outside of traditional protected or
Wendt & Peterson Expires December 15, 2016 [Page 11]
Internet-Draft PASSporT June 2016
private telephony communications paths where there may be concerns
about exposing information to either unintended or illegitimately
intented actors. These identifiers are often exposed through many
communications signaling protocols as of today, but appropriate
precautions should be taken.
8. IANA Considerations
8.1. Media Type Registration
8.1.1. Media Type Registry Contents Additions Requested
This section registers the "application/passport" media type
[RFC2046] in the "Media Types" registry [IANA.MediaTypes] in the
manner described in [RFC6838], which can be used to indicate that the
content is a PASSporT defined JWT and JWS.
o Type name: application
o Subtype name: passport
o Required parameters: n/a
o Optional parameters: n/a
o Encoding considerations: 8bit; application/passport values are
encoded as a series of base64url-encoded values (some of which may
be the empty string), each separated from the next by a single
period ('.') character.
o Security considerations: See the Security Considerations section
of RFC 7515.
o Interoperability considerations: n/a
o Published specification: draft-ietf-stir-passport-00
o Applications that use this media type: STIR and other applications
that require identity related assertion
o Fragment identifier considerations: n/a
o Additional information:
* Magic number(s): n/a
* File extension(s): n/a
Wendt & Peterson Expires December 15, 2016 [Page 12]
Internet-Draft PASSporT June 2016
* Macintosh file type code(s): n/a
o Person and email address to contact for further information: Chris
Wendt, chris-ietf@chriswendt.net
o Intended usage: COMMON
o Restrictions on usage: none
o Author: Chris Wendt, chris-ietf@chriswendt.net
o Change Controller: IESG
o Provisional registration? No
8.2. JSON Web Token Claims Registration
8.2.1. Registry Contents Additions Requested
o Claim Name: "otn"
o Claim Description: Originating Telephone Number String
o Change Controller: IESG
o Specification Document(s): Section 3.2 of draft-ietf-stir-
passport-00
o Claim Name: "dtn"
o Claim Description: Destination Telephone Number String
o Change Controller: IESG
o Specification Document(s): Section 3.2 of draft-ietf-stir-
passport-00
o Claim Name: "ouri"
o Claim Description: Originating URI String
o Change Controller: IESG
o Specification Document(s): Section 3.2 of draft-ietf-stir-
passport-00
o Claim Name: "duri"
Wendt & Peterson Expires December 15, 2016 [Page 13]
Internet-Draft PASSporT June 2016
o Claim Description: Destination URI String
o Change Controller: IESG
o Specification Document(s): Section 3.2 of draft-ietf-stir-
passport-00
o Claim Name: "mky"
o Claim Description: Media Key Fingerprint String
o Change Controller: IESG
o Specification Document(s): Section 3.2 of draft-ietf-stir-
passport-00
9. Acknowledgements
Particular thanks to members of the ATIS and SIP Forum NNI Task Group
including Jim McEchern, Martin Dolly, Richard Shockey, John Barnhill,
Christer Holmberg, Victor Pascual Avila, Mary Barnes, and Eric Burger
for their review, ideas, and contributions. Also thanks to Henning
Schulzrinne, Russ Housley, Alan Johnston, and Richard Barnes for
valuable feedback on the technical and security aspects of the
document. Additional thanks to Harsha Bellur for assistance in
coding the example tokens.
10. References
[I-D.ietf-stir-rfc4474bis]
Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,
"Authenticated Identity Management in the Session
Initiation Protocol (SIP)", draft-ietf-stir-rfc4474bis-07
(work in progress), February 2016.
[IANA.MediaTypes]
"IANA, "Media Types"", <Media Types>.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
DOI 10.17487/RFC2046, November 1996,
<http://www.rfc-editor.org/info/rfc2046>.
[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>.
Wendt & Peterson Expires December 15, 2016 [Page 14]
Internet-Draft PASSporT June 2016
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<http://www.rfc-editor.org/info/rfc5280>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013,
<http://www.rfc-editor.org/info/rfc6838>.
[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <http://www.rfc-editor.org/info/rfc7515>.
[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<http://www.rfc-editor.org/info/rfc7518>.
[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<http://www.rfc-editor.org/info/rfc7519>.
[RFC7638] Jones, M. and N. Sakimura, "JSON Web Key (JWK)
Thumbprint", RFC 7638, DOI 10.17487/RFC7638, September
2015, <http://www.rfc-editor.org/info/rfc7638>.
[UNICODE] "The Unicode Consortium, "The Unicode Standard"",
<http://www.unicode.org/versions/latest/>.
Appendix A. Example PASSporT JWS Serialization and Signature
For PASSporT, there will always be a JWS with the following members:
o "protected", with the value BASE64URL(UTF8(JWS Protected Header))
o "payload", with the value BASE64URL (JWS Payload)
o "signature", with the value BASE64URL(JWS Signature)
Note: there will never be a JWS Unprotected Header for PASSporT.
First, an example PASSporT Protected Header is as follows:
Wendt & Peterson Expires December 15, 2016 [Page 15]
Internet-Draft PASSporT June 2016
{
"typ":"passport",
"alg":"ES256",
"x5u":"https://cert.example.org/passport.cer"
}
This would be serialized to the form:
{"typ":"passport","alg":"ES256","x5u":"https://cert.example.org/
passport.cer"}
Encoding this with UTF8 and BASE64 encoding produces this value:
eyJ0eXAiOiJwYXNzcG9ydCIsImFsZyI6IkVTMjU2IiwieDV1IjoiaHR0cHM6Ly9j
ZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9
Second, an example PASSporT Payload is as follows:
{
"iat":"1443208345",
"otn":"12155551212",
"duri":"sip:alice@example.com"
}
This would be serialized to the form:
{"iat":"1443208345","otn":"12155551212","duri":
"sip:alice@example.com"}
Encoding this with the UTF8 and BASE64 encoding produces this value:
eyJpYXQiOiIxNDQzMjA4MzQ1Iiwib3RuIjoiMTIxNTU1NTEyMTIiLCJkdXJp
Ijoic2lwOmFsaWNlQGV4YW1wbGUuY29tIn0
Computing the digital signature of the PASSporT Signing Input
ASCII(BASE64URL(UTF8(JWS Protected Header)) || '.' || BASE64URL(JWS
Payload))
SQ3r3U9kew2e4Ej-tS4vbWQgs9kSQzHgzqK_xP4TL70al7XwWwF4R2mP9sxQey9n
pZQoYTNx_WZslJJpIc_f_A
The final PASSporT token is produced by concatenating the values in
the order Header.Payload.Signature with period (',') characters. For
the above example values this would produce the following:
Wendt & Peterson Expires December 15, 2016 [Page 16]
Internet-Draft PASSporT June 2016
eyJ0eXAiOiJwYXNzcG9ydCIsImFsZyI6IkVTMjU2IiwieDV1IjoiaHR0cHM6Ly9j
ZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNydCJ9
.
eyJpYXQiOiIxNDQzMjA4MzQ1Iiwib3RuIjoiMTIxNTU1NTEyMTIiLCJkdXJpIjoi
c2lwOmFsaWNlQGV4YW1wbGUuY29tIn0
.
SQ3r3U9kew2e4Ej-tS4vbWQgs9kSQzHgzqK_xP4TL70al7XwWwF4R2mP9sxQey9n
pZQoYTNx_WZslJJpIc_f_A
A.1. X.509 Private Key Certificate for Example
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIFeZ1R208QCvcu5GuYyMfG4W7sH4m99/7eHSDLpdYllFoAoGCCqGSM49
AwEHoUQDQgAE8HNbQd/TmvCKwPKHkMF9fScavGeH78YTU8qLS8I5HLHSSmlATLcs
lQMhNC/OhlWBYC626nIlo7XeebYS7Sb37g==
-----END EC PRIVATE KEY-----
A.2. X.509 Public Key Certificate for Example
-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE8HNbQd/TmvCKwPKHkMF9fScavGeH
78YTU8qLS8I5HLHSSmlATLcslQMhNC/OhlWBYC626nIlo7XeebYS7Sb37g==
-----END PUBLIC KEY-----
Authors' Addresses
Chris Wendt
Comcast
One Comcast Center
Philadelphia, PA 19103
USA
Email: chris-ietf@chriswendt.net
Jon Peterson
Neustar Inc.
1800 Sutter St Suite 570
Concord, CA 94520
US
Email: jon.peterson@neustar.biz
Wendt & Peterson Expires December 15, 2016 [Page 17]