[OAUTH-WG] Adam Roach's No Objection on draft-ietf-oauth-mtls-16: (with COMMENT)

[Adam Roach via Datatracker <[e-mail]>]

Adam Roach has entered the following ballot position for
draft-ietf-oauth-mtls-16: No Objection

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COMMENT:
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Thanks for the work that everyone did on this document. I have one suggestion
for clarification, followed by a handful of editorial nits.

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§2.1.2:

>  tls_client_auth_san_ip
>     A string representation of an IP address in either dotted decimal
>     notation (for IPv4) or colon-delimited hexadecimal (for IPv6, as
>     defined in [RFC4291] section 2.2) that is expected to be present
>     as an iPAddress SAN entry in the certificate, which the OAuth
>     client will use in mutual TLS authentication.

This probably needs some text that clarifies expectations around comparison
and/or normalization. For example, if the iPAddress value in the cert is
"20 01 0d b8 00 00 00 00 00 00 00 00 c0 00 02 ca" (and a mask of all F's), one
should presume that this would match both tls_client_auth_san_ip values
"2001:db8:0:0:0:0:c000:2ca" and "2001:DB8::192.0.2.202", right? If no, then
this document needs to talk about normalization of address representation.


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§1:

>  Layering on the abstract flow above, this document standardizes
>  enhanced security options for OAuth 2.0 utilizing client certificate
>  based mutual TLS.

Nit: "client-certificate-based"

>  OAuth 2.0 defines a shared secret method of client authentication but

Nit: "shared-secret"

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§1:

>  This document describes an additional
>  mechanism of client authentication utilizing mutual TLS certificate-
>  based authentication

Nit: "mutual-TLS"

>  Mutual TLS certificate-bound access tokens ensure that only the party

Nit: "Mutual-TLS"

>  Mutual TLS certificate-bound access tokens and mutual TLS client

Nit: "Mutual-TLS... mutual-TLS"

>  Additional client metadata parameters are introduced by this document
>  in support of certificate-bound access tokens and mutual TLS client
>  authentication.

Nit: "mutual-TLS"

The remainder of the document has several other uses of the phrase "mutual
TLS" as an adjective; they should be similarly hyphenated. I will not call
them out individually. (Non-adjectival uses should not contain hyphens, so
this isn't a simple find-and-replace operation.)

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§5:

>  Authorization servers supporting both clients using mutual TLS and
>  conventional clients MAY chose to isolate the server side mutual TLS
>  behaviour to only clients intending to do mutual TLS, thus avoiding

Nit: "behavior" (or adjust other spellings in the document to be consistently
British).