Re: [stir] Review of: draft-ietf-stir-passport-05

[Chris Wendt <[e-mail]>]

Hi Dave,

Thanks for the review, and apologize for delay for proper response, i just got back from vacation on Saturday.   i have gone through all of your comments and will be submitting a new 06 version of passport, just to make it easier to diff.

Many of the comments/ambiguities were related to some relics of how passport has changed over various revisions, so appreciate the chance to clean them up.  Of course included many clean up of syntax in general, so good to clean them up as well. 

There are a couple of places where I left the text the same, and look for further comment.  In addition, some of the reference and more proceedural stuff i will plan to update in next version.

Comments and actions i took are given inline below, but refer to 06 document for specific changes in text.

Again, thanks for detailed comments.

-Chris

> On Jul 28, 2016, at 1:37 PM, Dave Crocker <[e-mail]> wrote:
> 
> 
> 
> Review of:  draft-ietf-stir-passport-05
> Date:       27 July 2016
> Revied by:  D. Crocker <[e-mail]>
> 
> 
> Summary:
> 
> The 'Persona Assertion Token' specification defines an object containing
> multiple attributes that are intended to be used for authentication,
> integrity and non-repudiation, such as validating the originator of a
> SIP telephone call. The object is intended to be application- and
> transport-independent. In effect, the object links certification details
> to application details and/or transport details.
> 
> Although the text provides details of 'how' to compose a passport token,
> it never actually says what passport is. There are some later comments
> that imply what it is, or seem to assume a knowledge of what it is, but
> it's never defined as a technical construct. By way of example, how does
> it differ from the function of an X.509 cert?
> 
> The specification has problems with its explanation of purpose and its
> apparent scope, as well as occasional lack of clarity or
> correctness. It even has quite a few typographical errors that would
> have been trivially detected by a spelling corrector.
> 
> The document was only first produced in February, with 4 revisions in
> the last 3 months, including one during Last Call. And the recent
> revisions have included quite substantive changes. Discussion about the
> draft on the wg mailing list has been thin. Also, during the wg session
> in Berlin, discussion seemed to include a fair amount of reference to
> what 'might' be done -- eg, tailoring use through profiles or encoding
> for SIP or... -- rather than clarity about how this specification would
> definitely be used. It suggests the possibility of less stability in
> community understanding of the specification than one would wish for an
> IETF proposed standard.
> 
> The document is /not/ ready for publication.
> 
> 
> 
> This appears to be a specification for something that is for far more
> general use than simply doing caller-id authentication; as such it
> appears to go beyond the scope of the working group's charter. This
> might be acceptable, if the solution provided adequately covered what
> /is/ in scope and were still timely and sufficiently 'efficient'. However the working group has taken 3 years to produce this work and there are no other use-cases presented and no other specifications for use, to justify the purported generality. As such, the generality is purely theoretical. Worse, there is a poor track-record of such efforts proving successful at being more general. Instead, they impose the overhead of generality without the benefit.
> 
> The document is written with the apparent expectation that the reader
> has quite a bit of prior knowledge but it isn't stated explicitly. This
> needs to be written for a wider audience than just those already in the
> wg and more than those already familiar with the work. If there are
> specific details the reader must know ahead of time, state or cite them
> early and explicitly
> 
> As an example, the document is really built on top of JWT but doesn't
> introduce the reference or details about this until section 3. (The
> passing reference in section 2 does not explain that JWT is foundational
> to the current work.)
> 
> As to the choice of JWT, it seems odd, since it isn't natural to the SIP context, which is essential for the chartered work, and therefore requires an additional layer of translation for use with SIP.
> 
> The document title and the content use the term 'persona' but there is
> nothing in this document that pertains to any of the normal, technical
> -- or even informal -- uses of the term. So it might be a clever turn of
> phrase, but it appears to be significantly inappropriate, or at least
> misleading. (Perhaps the goal is to sustain the unusual choices that SIP
> made, such as with the term 'identity', deviating from usages in the
> world of online identity?...)
> 
> The document desperately needs a carefully-written terminology section.
> 
> The specification is dominated by heavy focus on the details and
> mechanisms, without much that covers purposes and functions. The text is
> heavy with redundant acronyms usage, to the point of distraction.
> (Imagine specifying http by having every paragraph say that ASCII (or
> Unicode or whatever) is being used. Assert packaging-related details
> only where needed, rather than feeling that every bit of technical
> information must be seasoned with references to JWT, JWS, or whatever.
> 
> Algorithmic details often are specified in non-linear sequence, eg, if B
> do C after doing A and before doing C. This makes it difficult to
> acquire an simple understanding of the sequence. Algorithms need to be
> presented in as linear a fashion as possible, and preferable include
> pseudo-code, to be that much more concise.
> 
> In terms of pragmatics, here are two operational questions that I can't
> answer, based on this specification, and yet they are fundamental to the
> utility of this work.
> 
>      How is key rollover done?
> 
>      How is delegation done, such as for use by authorized third
>      parties?
> 
> As an example that the document needs much more careful proofreading,
> the terms header and headers appear to be used inconsistently and
> possibly incorrectly.
> 
> Also I note that a revision of the draft was posted during Last Call.
> This can create confusion or extra work, to reconcile things. From a
> quick scan of the revision's diff, it doesn't appear that the changes
> affect this review... maybe.
> 
> Also, having a Last Call that overlaps with an IETF meeting is not a
> good way to encourage adequate attention to the production of reviews,
> although the document really needed them.
> 
> 
> 
> 
> 
> Detailed Comments
> -----------------
> 
> 
>> STIR                                                            C. Wendt
>> Internet-Draft                                                   Comcast
>> Intended status: Standards Track                             J. Peterson
>> Expires: January 23, 2017                                   Neustar Inc.
>>                                                           July 22, 2016
>> 
>> 
>>                        Persona Assertion Token
>>                      draft-ietf-stir-passport-05
>> 
>> Abstract
>> 
>>   This document defines a token format for verifying with non-
> 
>  [format] remove  or remove [token]

replied with token object

> 
> Is the timestamp the basis of claiming non-repudiation?

Partially, depending on your interpretation of how non-repudiation is achieved.  The digital signature based on a certificate is the non-repudiation of the original assertion and signing of the token.  The timestamp and including the destination identity adds the ability to further validate that there wasn’t someone illegitimate that simply replayed the sending of the token.

> 
> 
>>   repudiation the sender of and authorization to send information
>>   related to the originator of personal communications.  A
> 
> 'info related to'... what does this mean?

Yes this was a bit too broad and the abstract text wasn’t updated when the scope was reduced.

replaced with:
'non-repudiation the author of the token, their authority to author the token and, minimally, the asserted originating identity or persona contained within the token corresponding specifically to the originator of personal communications'

> 
> 
>>   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
> 
> 'accuracy'?  validates authorship, not validity, I suspect.
> 
> A signature's primary purpose usually is authenticate origination, authorship, or the like, where integrity is a side-effect of the methodology.  Integrity as the primary function would typically occur only when the identity of the signer need be no more than something like 'whomever I interacted with previously'.  I suspect that such a session-limited identity semantic is not, in fact, the intent here.

replaced with ‘assertion of the identity information’

> 
> 
>>   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
> 
>    unsecure -> insecure  (unless the intend is reference to a loan?)

fixed

> 
> 
>>   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 January 23, 2017.
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 1]
>> 
>> Internet-Draft                  PASSporT                       July 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 Identity Claims . . .   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
>>   5.  Deterministic JSON Serialization  . . . . . . . . . . . . . .   9
>>     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 . . . . . . . . . . . . . . . . . . . . .  11
>>     8.1.  Media Type Registration . . . . . . . . . . . . . . . . .  11
>>       8.1.1.  Media Type Registry Contents Additions Requested  . .  11
>>     8.2.  JSON Web Token Claims Registration  . . . . . . . . . . .  13
>>       8.2.1.  Registry Contents Additions Requested . . . . . . . .  13
>>   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
>>   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 2]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>     10.1.  Normative References . . . . . . . . . . . . . . . . . .  14
>>     10.2.  Informative References . . . . . . . . . . . . . . . . .  14
>>   Appendix A.  Example PASSporT JWS Serialization and Signature . .  15
>>     A.1.  X.509 Private Key Certificate for Example . . . . . . . .  16
>>     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.
>>   [RFC7340] 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
> 
> [common] delete

fixed

> 
> 
>>   token that cryptographically verifies an originating identity, or
>>   more generally a URI or application specific identity string
> 
> 'identity string'?  what does this mean?
> 
> 'app string id'? what does this mean?

Removed and replaced with 'URI or telephone number'

> 
> 
>>   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
> 
> What is a 'persona'?  Where is this construct introduced or cited and explained?

‘persona’ replaced with 'originating identity'

> 
> 'profiles'?  Where is this construct introduced or cited and explained?

replaced with 'Through extensions defined in this document'

> 
> 
>>   related information in an extensible way.  A secondary goal is to
> 
> It seems to also be primary.
> 
> (PPT provides a framework for signing related information) ?
> 
> 
>>   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,
> 
> specs to spec...  awkward phrasing
> 
> as always, a specification that declares what is 'anticipated' moves into purely hypothetical, which too-often proves to be wishful fantasy. The reference doesn't specify anything and it creates a dependency that well might not be satisfied.
> 
> 'tokens'?  Where is this constructed introduced, cited or explained? Use of a term like this implies that there is some distinctive meaning, but really there isn't.  This is a format specification.  That's all.
> 
> If there is a claim that the term token does have significance here, then please explain it.  For example, how is this token to be used?
> 
> If the term is used merely as an inheritance from JWT, then cite that early, to justify the term.

Cleaned up phrasing and defined 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.
> 
> remove Note.  Or make it a note to RFC Editor to remove it, or rephrase so it's useful 10 years from now.

Would probably like a reference here, don’t want to just remove.

> 
> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 3]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 2.  Token Overview
>> 
>>   Tokens are a convenient way of encapsulating information with
> 
> Why?  What are the alternatives?  Why is this the starting point?
> 
> 
>>   associated digital signatures.  They are used in many applications
> 
> Such as?
> 
> Anyhow, this section seems to take the construct of 'token' as being an established term of art.  It isn't.  Or, at least, I've no idea what is meant here that distinguishes a token from anything else, such as other forms of encapsulation.  Say/cite what a token is, if it is such a distinctive thing.  Say/cite how it differs from alternatives, if its superiority is going to be touted.
> 
> 
>>   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.
> 
> Note that there is nothing in the above text that actually explains what a token is or how it differs from things that aren't tokens.

I would challenge the fact that ‘token’ is a term of art, but i suppose maybe it depends on what crowd you run with.  In either case, I defined it as a canonical string object at the beginning of the document.

> 
> 
>> 3.  PASSporT Definition
> 
> This section is not a definition.  It's more like structure, or format, or foundation or encoding.

‘Passport Components'

> 
> 
>>   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
> 
>       specific set -> a set

fixed

> 
> 
>>   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.
> 
> The section starts with structure detail and ends with purpose. This should be swapped.

swapped example and added some text to preface the header parameters

> 
> 
>>   An example of the header for the case of an ECDSA P-256 digital
>>   signature would be the following,
> 
> How is reader to know what that long string means? Is the doc only for
> the cognoscenti? if so, which cognoscenti?

removed cognoscenti terms

> 
> 
>>       {
>>           "typ":"passport",
>>           "alg":"ES256",
>>           "x5u":"https://cert.example.org/passport.cer"
>>       }
> 
>   *** EXPLAIN EXAMPLES, PLEASE ***
> 
> 
>> 3.1.1.  "typ" (Type) Header Parameter
>> 
>>   JWS defines the "typ" (Type) Header Parameter to declare the media
>>   type of the JWS.
> 
> media type?  IANA citation needed.  (It was in an earlier version of the draft!)

was guided to remove it

> 
> 
>>   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.
> 
> Is it possible to begin with it and not include it?  That is, 'include' is redundant.  'minimally' is also not information, but it raises the question: The other two attributes aren't required???

Yes, missed this in last edits, fixed it to only be “passport” no other option.

> 
> Also, this subsection is part of an Overview.  Why does it have normative content?  Or is this not really an overview?
> 

not part of overview, overview is section 2

> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 4]
>> 
>> Internet-Draft                  PASSporT                       July 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
> 
> So this service uses a classic X.509 authentication hierarchy?  That's a key design point, only mentioned in a third-level section.

clarified this in overview

> 
> 
>>   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
> 
> 'actor serving the X.509 public key' ? what does that mean?

removed

> 
> 
>>   of scope of this document.  However, generally this would correspond
>>   to an HTTPS or DNSSEC resource with the guidance that it MUST be a
> 
>    [a] remove

fixed

> 
> 
>>   TLS protected, per JWS spec.
> 
> This /object/ specification (that is transport independent) dictates /transport/ security???  This is probably wrong, but at least needs careful explanation.
> 

This is mostly a comment towards security consideration recommendation.  I could remove the comment if it’s bothering folks.

> 
>> 
>> 3.2.  PASSporT Payload
>> 
>>   The token payload claims should consist of the information which
> 
> [payload] remove; at best it's redundant
> 
> 'should'?  not MUST?  why?

fixed

> 
>>   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]
> 
> should? why
> 
> correspond???  what does that mean, in technical terms?

fixed to be follows the definition of a JWT claim

> 
> 
>>   The PASSporT defines the use of a number of standard JWT defined
> 
> "The PASSporT" is an affectation.  Both the 'the' and the use of case.

fixed

> 
> 
>>   headers as well as two new custom headers corresponding to the two
> 
> header/s/?
> 
> corresponding?  referring? describing? identifying?  addressing?

fixed

> 
> 
>>   parties associated with personal communications, the originator and
>>   terminator.  These headers or key value pairs are detailed below.
> 
>    These headers or key value pairs are -> This information is
> 

fixed

> 
>>   Key values outside the US-ASCII range should be encoded using percent
>>   encoding as described in section 2.1 of RFC 3986, case normalized as
>>   described in 6.2.2.1 of [RFC3986].  Matching of these values should
>>   use string exact match.
>> 
>> 3.2.1.  JWT defined claims
> 
> When something like this is imported from another spec, there needs to
> be a precise pointer to the specific part of the spec defining it.

This was the text provided by Ted based on discussion in Berlin, but beyond that i’m not seeing what isn’t specific enough.

> 
> 
>> 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
> 
>   issued at -> "Issued At".
> 
> It would be better to explicitly cite section 4.1.6 in that RFC. Readers should not have to search an entire document to find the detail being referenced.

fixed

> 
> Also, note the MUST here.  I suspect this conflicts with the normative language above in the 'overview’.

I believe i resolved this.

> 
> 
>>   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
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 5]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>   attacks, as explained further in the security considerations in
>>   section 7.
>> 
>> 3.2.2.  PASSporT specific claims
>> 
>> 3.2.2.1.  Originating and Destination Identity Claims
>> 
>>   Baseline PASSporT defines claims that convey the identity of the
> 
> "Baseline PASSporT defines claims" ?  First reference in a 4th-level section???

Removed baseline

> 
> 
>>   origination and destination of personal communications.  There are
> 
> 'personal'?  so this can't be used by and between companies?  Really, there is nothing about any of this that pertains to the type of users or even the content of the communication.

defined ‘personal communications'

> 
> What is the exact definition or origination and destination?  For example, there is an important distinction between the person making a call vs. the device they are using, versus the provider they are going through.  Which is meant here and how is the reader to know? (cf, call for a terminology section.)

we don’t want to make the distinction here, it’s only about the identity, URI or TN.  whether device or network.  we don’t want to predetermine what the end to end architecture is, this is protocol only.

> 
> 
>>   two claims that are required for PASSporT, the "orig" and "dest"
>>   claims.  Both "orig" and "dest" should have values that are JSON
>>   objects that include identities represented by key value pairs, where
> 
> 'key value pairs' aren't 'claims'?
> 
> should and not must? why?
> 

changed to MUST and clarified

> 
>>   the key represents an identity type and the value is the identity
>>   string.  Currently, these identities can be represented as either
> 
> So, there is expectation of other types?  There needs to be a pointer to an IANA registry.

we do have IANA request for these types, will add text once i figure out how to point to that

> 
> 
>>   telephone numbers or Uniform Resource Indicators (URIs).  The
>>   definition of how telephone numbers or URIs and examples are provided
>>   below.
>> 
>>   The "orig" JSON object MUST only have one key value pair representing
>>   the asserted identity of any type (currently either "tn" or "uri") of
>>   the originator of the personal communications signaling.
>> 
>>   The "dest" JSON object MUST have at least have one key value pair,
>>   but could have multiple identity types (i.e. "tn" and/or "uri") but
>>   only one of each.  Additionaly, in the case of "dest" only, the
>>   identity type key value MUST be an array signaled by standard JSON
>>   brackets, even when there is a single identity value in the identity
>>   type key value.
>> 
>> 3.2.2.1.1.  "tn" - Telephone Number identity
> 
> A document that uses five-levels of section numbering warrants reconsideration of its structure.

fair point, looking for suggestion

> 
> 
>> 
>>   If the originating or destination identity is a telephone number, the
>>   key representing the identity should be "tn".
> 
> should and not must???  why?

fixed

> 
> 
>>   Telephone Number strings for "tn" MUST be canonicalized according to
>>   the procedures specified in [I-D.ietf-stir-rfc4474bis] Section 7.2.
> 
> Actually, this dependency on 4474bis seems odd.
> 
> Given that the phone number construct is at the core of the work here and this is the essential data object, and this object is presumably intended for use outside of 4474bis, I'd expect that canonicalization algorithm to be here.
> 
> If 4474 needs to cite/use the algorithm, it can cite here, which it already will have to do.  There is no other normative use of 4474 in this document.
> 

needs discussion

> 
> 
>> 3.2.2.1.2.  "uri" - URI identity
>> 
>>   If any of the originating or destination identities is of the form
>>   URI, as defined in [RFC3986], the key representing the identity
>>   should be "uri" URI form of the identity.
> 
> should and not must?  why?

fixed

> 
> 
>> 3.2.2.1.3.  Future identity forms
>> 
>>   We recognize that in the future there may be other standard
>>   mechanisms for representing identities.  The "orig" and "dest" JSON
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 6]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>   objects with "tn" and "uri" allow for other identity types with
>>   unique keys to represent these forms.
> 
> Recognition is dandy, but where is the specification detail to support the extensibility?

clarified text

> 
> 
>> 3.2.2.1.4.  Examples
> 
>  *** Explain these examples, so they aren't merely syntax detail ***
> 
> 
>>   Single Originator to Single Destination example:
>> 
>>       {
>>           "dest":{"uri":["sip:[e-mail]"]},
>>           "iat":"1443208345",
>>           "orig":{"tn":"12155551212"}
>>       }
>> 
>>   Single Originator to Multiple Destination Identities example:
>> 
>>       {
>>           "dest":{
>>                   "tn":["12125551212"],
>>                   "uri":["sip:[e-mail]",
>>                       "sip:[e-mail]"]
>>           },
>>           "iat":"1443208345",
>>           "orig":{"tn":"12155551212"}
>>       }
>> 
>> 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.
> 
>        difference -> different?
> 
> The above text belongs elsewhere, explaining the overall set of capabilities, use cases, and the like  In a definitions section like this, focus on definitions, not discussions about use.
> 
> First use of 'SDP', with no explanation of its meaning.

Added citation

> 
> 'DTLS-SRTP' citation?
> 
> And again, how does this citation slip into a transport-independent object signing spec?

Meant to be a useful/likely used example.

> 
> 
> 
>>   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
> 
> forward pointer.  Sometimes these are necessary, but in general they impede reading comprehension.
> 
> Redundant specification.  Saying here something that is also specified elsewhere in the document invites divergence in reader understanding. Cite, perhaps, but do /not/ summarize.
> 
> Is all of this summary?  Anything new here?  The reader can't tell.
> 
>   "If there is multiple fingerprint values, more than one,"? huh?
> 
> Where do 'dig' and 'alg' come from?  They are not explicitly introduced, even with a citation.

clarified

> 
> 
>>   fingerprint values, more than one, the fingerprint values should be
> 
> should and not must?  why?

fixed

> 
> 
>>   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.
> 
> "in order to provide a more efficient, compact form" is marketing language.  It invites debate while offering no useful technical substance.

removed

> 
> 
>>   An example claim with "mky" claim is as follows:
>> 
>>   For an SDP offer that includes the following fingerprint values,
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 7]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>       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:
>> 
>>       {
>>           "dest":{"uri":["sip:[e-mail]"]},
>>           "iat":"1443208345",
>>           "mky":[
>>           {
>>              "alg":"sha-256",
>>              "dig":"021ACC5427ABEB9C533F3E4B652E7D463F5442CD54
>>               F17A03A27DF9B07F4619B2"
>>           },
>>           {
>>              "alg":"sha-256",
>>              "dig":"4AADB9B13F82183B540212DF3E5D496B19E57C
>>               AB3E4B652E7D463F5442CD54F1"
>>           }
>>           ],
>>           "orig":{"tn":"12155551212"}
>>       }
>> 
>> 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.
> 
> 'corresponding to' vs. 'included in’?

corresponding to, public key vs. private key

> 
> 
>> 4.  Extending PASSporT
>> 
>>   PASSporT represents the bare minimum set of claims needed to assert
> 
> represents vs. is or has?
> 
> (FWIW, this isn't quibbling.  It is an example of the difference between regular prose writing and direct, specification language.)

changed to includes

> 
> 
>>   the originating identity and support the secure propoerties discussed
>>   in various parts of this document, however there will certainly be
>>   both new uses and ways of extending the application and usage of
>>   PASSPorT that requires the ability to extend the defined base set of
>>   claims to represent other information requiring assertion or
>>   validation beyond the identity itself.
> 
> there's that 'certainly' again and this time it's predicting the future.
> tsk. don't do that. also, new and extended tends towards redundancy, as
> does the entire sentence's structure. I think the technical statement is:
> 
>      Passport can be extended to support additional claims.
> 
> If you want to get really flowery, you might 'as needed' at the end…

I re-wrote the last sentence here and included 'as needed’ just for the ability to be “flowery” ;)

> 
> 
>> 4.1.  "ppt" (PASSporT) header parameter
>> 
>>   For the extension of the base set of claims defined in this document,
> 
>    For the -> For

fixed

> 
> 
>>   a new JWS header parameter "ppt" MUST be used with a string that
>>   uniquely identifies and points to a profile specification that
>>   defines any new claims that would extend the base set of claims of
>>   PASSporT.
> 
>   extension == profile ??
> 
> What is a profile of Passport?  Where is this defined?
> 
> ('jws header parameter'.)
> 
> What is the purpose of a profile and a profile label?  How is it used?
> 
> 
>   'identifies and points to'?  what does points to mean?

clarified this text

> 
> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 8]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>   An example header with an extended PASSporT profile of "foo" is as
> 
>     profile of -> profile name

changed to PASSporT extension

> 
> 
>>   follows:
>> 
>>       {
>>           "alg":"ES256",
>>           "ppt":"foo",
>>           "typ":"passport",
>>           "x5u":"https://tel.example.org/passport.cer"
>>       }
>> 
>> 4.2.  Extended PASSporT Claims
>> 
>>   Future specifications that define such extensions to the PASSporT
> 
>   [Future] remove
> 
>  [such] remove.  there's no context for it.

removed 

> 
> 
>>   mechanism MUST explicitly designate what claims they include beyond
> 
> designate -> specify  (it's defining, not appointing)

fixed

> 
> 
>>   the base set of claims from this document, 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
> 
> If all extensions include the baseline, then 'must incorporate' is an odd way to say that

changed to include

> 
> This seems best and first handled by earlier in the spec, by providing a syntax (and text) that shows the base set and then an optional extended set.  With that setup, it is clear that extensions are always /in addition to/ the base.

JSON sort of provides this capability inherently, so would prefer to keep it simple rather than adding more protocol.

> 
> 
>>   object specified; they can never be subtracted or re-ordered.
> 
> What does it mean to be subtracted?  Perhaps 'removed'? Or are they subject to arithmetic modification?

changed to removed, it’s simply just new key value pairs, no manipulation of values.

> 
> 
>>   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
> 
> That's not a 'note'; that's a fundamental construct.  It needs to be stated much earlier and much more distinctly and as an explicitly normative assertion.
> 
> Also, this seems to be the first reference to the verifier!
> 
> Also we need a description of the handling of a passport object in terms of creation and consumption.)

modified and clarified

> 
> 
>>   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.
>> 
>> 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 implication that there can be non-deterministic representations is
> pretty odd and at least needs explanation, assuming the issue is real.

JSON as a canonical format can include spaces and line breaks, etc and make it, from a string format non-deterministic.

We are simply defining a method of authoring JSON deterministically.

In either case, i clarified the message here.

> 
> 
>>   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.
> 
> mumble.

?

> 
> 
>>   In addition, the JSON header and claim members MUST follow the
>>   lexicographical ordering and character and string rules defined in
>>   [RFC7638] Section 3.3.
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017                [Page 9]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 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.
>> 
>>       {"dest":{"uri":["sip:[e-mail]"],"iat": 1443208345,"mky"
>>       :[{"alg":"sha-256","dig":"021ACC5427ABEB9C533F3E4B652E7D463F5442
>>       CD54F17A03A27DF9B07F4619B2"},{"alg":"sha-256","dig":"4AADB9B13F8
>>       2183B540212DF3E5D496B19E57CAB3E4B652E7D463F5442CD54F1"}],
>>       "orig":{"tn":"12155551212"}}
> 
> Perhaps explain the steps followed to produce this? Perhaps show the
> intermediate forms?
> 

will discuss the need for more explicit instructions, to me, it’s following the spec, but could improve if folks think it’s necessary.

> 
> 
>> 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
> 
> And email and FTP and HTTP and...
> 
> Actually the use of the form has nothing to do with the purpose of the
> application. As noted, it merely makes debugging and monitoring easier.
> 
> 
>>   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.
> 
> The section is mislabeled and probably out of scope. It's trying to say
> there there can be alternative encodings of this json object and that
> this spec won't prohibit that happening by other specs.
> 
> In all likelihood, this section should be removed. It doesn't specify
> anything.

removed

> 
> 
>> 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
> 
> I suspect they are not 'security considerations' as much as 'mechanisms' or 'provisions'
> 
> 
>>   for avoidance of replay and cut and paste attacks.  PASSporT tokens
>>   must be sent along with other application level protocol information
> 
> Huh?  You are trying to dictate application-level transport behavior?
> 
> This smacks of layer/scoping violation.

changed to should and removed along, but don’t want to remove this consideration.

> 
> 
>>   (e.g. for SIP an INVITE as defined in [RFC3261]).  There should be a
>>   link between various information provided in the token and
>>   information provided by the application level protocol information.
> 
> Why?

explained

> 
> 
>>   These would include:
>> 
>>   o  "iat" claim should closely correspond to a date/time the message
> 
> The semantics of iat are defined earlier. Either there is compliance or
> there isn't. The discussion here, therefore, should probably say
> something like "a valid iat claim aids in detecting re-use at a later time.”

i am explaining the ‘why’ here, added a sentence about validation and correlation to network time variances.

> 
> 
>>      was originated.  It should also be within a relative delta time
> 
> What is a delta time?  How is the reader to know?  Where is it defined? I suspect what is meant is that it's deviation from time of origination should be small.  If this has a more precise technical definition, then cite it.

removed delta

> 
> 
>>      that is reasonable for clock drift and transmission time
>>      characteristics associated with the application using the PASSporT
>>      token.
> >
>>   o  "dest" claim is included to prevent the ability to use a
>>      previously originated message to send to another destination party
> 
>     the ability to -> using  (or use of)

fixed with ‘valid re-use'

> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 10]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 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
> 
> huh?  So the originator isn't really being validated, as claimed???

This is only a statement to recognize that you are only trusting the signer and certificate owner to tell the truth about the originating identity.  If you are familiar with how certificates work, this is an obvious statement, but just a word of consideration.

> 
> 
>>   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
> 
> Touching this sort of topic is, at the very best, redundant with
> specifications devoted to X.509. Just cite them and don't attempt to
> repeat them.

I see this as helpful, we can discuss if it’s not needed, but I recall being asked by working group to include text to inform the reader.

> 
> 
>>   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
> 
> Passport doesn't do calls.  Dictating activity involving calls is out of scope.
> 
> On the other hand, perhaps this qualifies for a discussion about transferring passport objects across administrative (trust) domain boundaries?
> 
> At best, this section seems to be trying to compensate for the lack of a framework discussion about the problem domain and the practical uses of the various specifications being produced.

similar to above comment, this is meant to be a cautionary statement and something to consider if you are an implementer.  If you understand the limits of what X.509 based certificate signing and PKI can represent in terms of trust, these are obvious statements, but I think it’s good to include none-the-less.

> 
> 
>>   o  Following best practices around management and security of X.509
>>      certificates
> 
> cf, above, about redundancies. Perhaps this is the bullet that should
> remain, while deleting the other one?

same comment as above.

> 
> 
>> 7.3.  Privacy Considerations
>> 
>>   Because PASSporT explicity includes claims of identitifiers of
> 
>    explicity -> explicitly
> 
>    identitifiers -> identifiers
> 
> 
>>   parties involved in communications, times, and potentially other call
>>   detail, care should be taken outside of traditional protected or
>>   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.
> 
>    intented -> intended
> 
> 
> awk.
> 
> Illegitimately intended?  What does that mean?

changed to illegitimate

> 
> More fundamentally it isn't clear to me what this is really saying.

pure cautionary/disclaimer text that potential privacy information could be exposed, user beware.

> 
> 
>> 8.  IANA Considerations
> 
> This section just sits here, uncited anywhere else in the document? Each item specified should be referenced in the body of the main specification, with a pointer into this section.

ok, need to investigate proper way to do that

> 
> 
>> 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 in the manner described in
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 11]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>   [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 outside
>>      the US-ASCII range are encoded using percent encoding as described
>>      in section 2.1 of RFC 3986 (some values 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-05
>> 
>>   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
>> 
>>      *  Macintosh file type code(s): n/a
>> 
>>   o  Person and email address to contact for further information: Chris
>>      Wendt, [e-mail]
>> 
>>   o  Intended usage: COMMON
>> 
>>   o  Restrictions on usage: none
>> 
>>   o  Author: Chris Wendt, [e-mail]
>> 
>>   o  Change Controller: IESG
>> 
>>   o  Provisional registration?  No
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 12]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 8.2.  JSON Web Token Claims Registration
>> 
>> 8.2.1.  Registry Contents Additions Requested
>> 
>>   o  Claim Name: "orig"
>> 
>>   o  Claim Description: Originating Identity String
>> 
>>   o  Change Controller: IESG
>> 
>>   o  Specification Document(s): Section 3.2 of draft-ietf-stir-
>>      passport-05
>> 
>>   o  Claim Name: "dest"
>> 
>>   o  Claim Description: Destination Identity String
>> 
>>   o  Change Controller: IESG
>> 
>>   o  Specification Document(s): Section 3.2 of draft-ietf-stir-
>>      passport-05
>> 
>>   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-05
>> 
>> 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, Eric Burger for
>>   their review, ideas, and contributions also thanks to Henning
>>   Schulzrinne, Russ Housley, Alan Johnston, Richard Barnes, Mark
>>   Miller, and Ted Hardie 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
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 13]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 10.1.  Normative 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-10
>>              (work in progress), July 2016.
>> 
>>   [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>.
>> 
>>   [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>.
>> 
>>   [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/>.
>> 
>> 10.2.  Informative References
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 14]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>   [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>.
>> 
>>   [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>.
>> 
>>   [RFC7340]  Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure
>>              Telephone Identity Problem Statement and Requirements",
>>              RFC 7340, DOI 10.17487/RFC7340, September 2014,
>>              <http://www.rfc-editor.org/info/rfc7340>.
>> 
>> 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:
>> 
>>       {
>>           "typ":"passport",
>>           "alg":"ES256",
>>           "x5u":"https://cert.example.org/passport.cer"
>>       }
>> 
>>   This would be serialized to the form:
>> 
>>       {"alg":"ES256","typ":"passport","x5u":"https://cert.example.org/
>>           passport.cer"}
>> 
>>   Encoding this with UTF8 and BASE64 encoding produces this value:
>> 
>>       eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1IjoiaHR0cHM6Ly9j
>>       ZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9
>> 
>>   Second, an example PASSporT Payload is as follows:
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 15]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>>       {
>>           "dest":{"uri":["sip:[e-mail]"]}
>>           "iat":"1443208345",
>>           "orig":{"tn":"12155551212"}
>>       }
>> 
>>   This would be serialized to the form:
>> 
>>       {"dest":{"uri":["sip:[e-mail]"]},"iat":"1443208345",
>>           "orig":{"tn":"12155551212"}}
>> 
>>   Encoding this with the UTF8 and BASE64 encoding produces this value:
>> 
>>       eyJkZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhd
>>       CI6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0
>> 
>>   Computing the digital signature of the PASSporT Signing Input
>>   ASCII(BASE64URL(UTF8(JWS Protected Header)) || '.' || BASE64URL(JWS
>>   Payload))
>> 
>>       rq3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYso
>>       jNCpTzO3QfPOlckGaS6hEck7w
>> 
>>   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:
>> 
>>       eyJhbGciOiJFUzI1NiIsInR5cCI6InBhc3Nwb3J0IiwieDV1IjoiaHR0cHM6Ly
>>       9jZXJ0LmV4YW1wbGUub3JnL3Bhc3Nwb3J0LmNlciJ9
>>       .
>>       eyJkZXN0Ijp7InVyaSI6WyJzaXA6YWxpY2VAZXhhbXBsZS5jb20iXX0sImlhd
>>       CI6IjE0NDMyMDgzNDUiLCJvcmlnIjp7InRuIjoiMTIxNTU1NTEyMTIifX0
>>       .
>>       rq3pjT1hoRwakEGjHCnWSwUnshd0-zJ6F1VOgFWSjHBr8Qjpjlk-cpFYpFYso
>>       jNCpTzO3QfPOlckGaS6hEck7w
>> 
>> A.1.  X.509 Private Key Certificate for Example
>> 
>>       -----BEGIN EC PRIVATE KEY-----
>>       MHcCAQEEIFeZ1R208QCvcu5GuYyMfG4W7sH4m99/7eHSDLpdYllFoAoGCCqGSM49
>>       AwEHoUQDQgAE8HNbQd/TmvCKwPKHkMF9fScavGeH78YTU8qLS8I5HLHSSmlATLcs
>>       lQMhNC/OhlWBYC626nIlo7XeebYS7Sb37g==
>>       -----END EC PRIVATE KEY-----
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 16]
>> 
>> Internet-Draft                  PASSporT                       July 2016
>> 
>> 
>> 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: [e-mail]
>> 
>> 
>>   Jon Peterson
>>   Neustar Inc.
>>   1800 Sutter St Suite 570
>>   Concord, CA  94520
>>   US
>> 
>>   Email: [e-mail]
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Wendt & Peterson        Expires January 23, 2017               [Page 17]
> 
> -- 
> 
>   Dave Crocker
>   Brandenburg InternetWorking
>   bbiw.net
> 
> -- 
> 
>  Dave Crocker
>  Brandenburg InternetWorking
>  bbiw.net
> 
> _______________________________________________
> stir mailing list
> [e-mail]
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