Hi Ben,

See below for some thoughts.

> I'm having trouble understanding the precise URL structures that are used 
> here.  Can client_uri include a nontrivial path?  Why is it necessary to 
> repeat client_uri in the response JSON?

The intent here is to follow how "OAuth 2.0 authorization metadata" works (RFC 
8414) which requires the client resolving the authorization server metadata to 
check that the issuer in the resolved document matches the issuer URL they 
started the resolution with, see below for the relevant extract from RFC 8414.

"

The "issuer" value returned MUST be identical to the authorization
   server's issuer identifier value into which the well-known URI string
   was inserted to create the URL used to retrieve the metadata.  If
   these values are not identical, the data contained in the response
   MUST NOT be used.


"

So the equivalent with our draft is to require the authorization server to 
validate that the client_uri returned in the clients metadata response matches 
the URL that was used to retrieve the metadata.

> The use of .well-known is a bit unusual.  Why not just host the JSON at the 
> client_uri?

Just to clarify it is, just under a well-known path? e.g if the client uri is 
https://client.example.com then the metadata would be published at 
https://client.example.com/.well-known/oauth-client

> Finally, I note that the section on Impersonation Attacks doesn't mention the 
> client_name or logo_uri.  If these are to be shown to the user, they present 
> a very serious impersonation risk that ought to be discussed.  (The 
> client_name also might need to be localized, which could be done by fetching 
> the JSON document with an appropriate Accept-Language request header.)

Yes absolutely agree this is an important security consideration to highlight, 
I will capture an issue.


Thanks,

[Mattr 
website]<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscanmail.trustwave.com%2F%3Fc%3D15517%26d%3Dw46s4eMXULV_ns1ZfAKYLbVKcqey_PHiW1WeN4boYw%26u%3Dhttps%253a%252f%252fmattr.global%252f&data=04%7C01%7CSteve.Lowes%40mbie.govt.nz%7C5a65fe33c70b41fd8ba908d976f3a2f1%7C78b2bd11e42b47eab0112e04c3af5ec1%7C0%7C0%7C637671611076709977%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=tKqCMzLUQNCeORd908YqfqZoT7tCy%2FMVwXdjpch1sDY%3D&reserved=0>



Tobias Looker

MATTR
CTO

+64 (0) 27 378 0461
tobias.looker@mattr.global<mailto:tobias.looker@mattr.global>

[Mattr 
website]<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscanmail.trustwave.com%2F%3Fc%3D15517%26d%3Dw46s4eMXULV_ns1ZfAKYLbVKcqey_PHiW1WeN4boYw%26u%3Dhttps%253a%252f%252fmattr.global%252f&data=04%7C01%7CSteve.Lowes%40mbie.govt.nz%7C5a65fe33c70b41fd8ba908d976f3a2f1%7C78b2bd11e42b47eab0112e04c3af5ec1%7C0%7C0%7C637671611076709977%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=tKqCMzLUQNCeORd908YqfqZoT7tCy%2FMVwXdjpch1sDY%3D&reserved=0>

[Mattr on 
LinkedIn]<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscanmail.trustwave.com%2F%3Fc%3D15517%26d%3Dw46s4eMXULV_ns1ZfAKYLbVKcqey_PHiW1SbN9fvNg%26u%3Dhttps%253a%252f%252fwww.linkedin.com%252fcompany%252fmattrglobal&data=04%7C01%7CSteve.Lowes%40mbie.govt.nz%7C5a65fe33c70b41fd8ba908d976f3a2f1%7C78b2bd11e42b47eab0112e04c3af5ec1%7C0%7C0%7C637671611076719975%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=t%2BidOI32oaKuTJf1AkcG%2B%2FirIJwbrgzXVZnjOAC52Hs%3D&reserved=0>

[Mattr on 
Twitter]<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscanmail.trustwave.com%2F%3Fc%3D15517%26d%3Dw46s4eMXULV_ns1ZfAKYLbVKcqey_PHiW1WdMte6ZA%26u%3Dhttps%253a%252f%252ftwitter.com%252fmattrglobal&data=04%7C01%7CSteve.Lowes%40mbie.govt.nz%7C5a65fe33c70b41fd8ba908d976f3a2f1%7C78b2bd11e42b47eab0112e04c3af5ec1%7C0%7C0%7C637671611076729970%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BD9WWyXEjVGlbpbCja93yW%2FzLJZpe%2Ff8lGooe8V6i7w%3D&reserved=0>

[Mattr on 
Github]<https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscanmail.trustwave.com%2F%3Fc%3D15517%26d%3Dw46s4eMXULV_ns1ZfAKYLbVKcqey_PHiWwGdMoDtMw%26u%3Dhttps%253a%252f%252fgithub.com%252fmattrglobal&data=04%7C01%7CSteve.Lowes%40mbie.govt.nz%7C5a65fe33c70b41fd8ba908d976f3a2f1%7C78b2bd11e42b47eab0112e04c3af5ec1%7C0%7C0%7C637671611076729970%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=4AhRuXZCnU5i3hcngo4H3UiNayYUtXpRcImV4slS1mw%3D&reserved=0>

This communication, including any attachments, is confidential. If you are not 
the intended recipient, you should not read it - please contact me immediately, 
destroy it, and do not copy or use any part of this communication or disclose 
anything about it. Thank you. Please note that this communication does not 
designate an information system for the purposes of the Electronic Transactions 
Act 2002.

________________________________
From: Ben Schwartz <bemasc=40google....@dmarc.ietf.org>
Sent: 10 November 2022 07:04
To: Tobias Looker <tobias.looker@mattr.global>
Cc: oauth@ietf.org <oauth@ietf.org>
Subject: Re: [OAUTH-WG] OAuth2 Client Discovery

EXTERNAL EMAIL: This email originated outside of our organisation. Do not click 
links or open attachments unless you recognise the sender and know the content 
is safe.

_______________________________________________
OAuth mailing list
OAuth@ietf.org
https://www.ietf.org/mailman/listinfo/oauth

Reply via email to