Re: [OAUTH-WG] WGLC review of OAuth 2.0 Security Best Current Practice by Mike Jones

Benjamin Kaduk <> Sat, 23 November 2019 06:46 UTC

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Date: Fri, 22 Nov 2019 22:46:12 -0800
From: Benjamin Kaduk <>
To: Mike Jones <>
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Subject: Re: [OAUTH-WG] WGLC review of OAuth 2.0 Security Best Current Practice by Mike Jones
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On Wed, Nov 20, 2019 at 03:40:34AM +0000, Mike Jones wrote:
> I did a complete read of draft-ietf-oauth-security-topics-13<>.  My review comments follow, divided into substantive and editorial sections.
> Metadata - This section suggests the use of a "resource_servers" metadata value.  This isn't defined by RFC 8414 nor do I see it the IANA OAuth Authorization Server Metadata registry at  Is this something that's been standardized elsewhere?  If so, please add a citation.  If not, please clearly say that this metadata value is not standardized, and is therefore unlikely to be interoperable.

I would go further and say that we should not document "best practices"
that involve non-standardized values.

> Metadata - This section suggests the use a "access_token_resource_server" token response value.  Please likewise clearly say that this parameter isn't a standard.


> Audience Restricted Access Tokens - Delete "basically".
> Many locations - The draft often uses the word "which" when you mean "that"..  For instance, in 4.9.2, please change "which could" to "that could" and in 4.11 change "which are" to "that are".  There's lots of places to look up the difference in meaning, but a rule of thumb that's usually right is that if you don't have a comma before the "which", it should probably be "that".

The RFC Editor uses a "restrictive" vs. "non-restrictive" split for "that"
and "which" -- see .

-Ben (no hats)