Re: [OAUTH-WG] Call for Adoption: OAuth 2.0 Mix-Up Mitigation

[Nov Matake <[e-mail]>]

It doen't say anything about the first request which initiate the login flow.
It is still a reasonable assumption that RP puts a "login with FB" button on a non TLS-protected page.

nov

> On Jan 26, 2016, at 10:45, Phil Hunt <[e-mail]> wrote:
> 
> I would find it hard to believe that is true.
> 
> From 6749 Sec 3.1 
>    Since requests to the authorization endpoint result in user
>    authentication and the transmission of clear-text credentials (in the
>    HTTP response), the authorization server MUST require the use of TLS
>    as described in Section 1.6 when sending requests to the
>    authorization endpoint.
> 
> Sec 3.1.2.1 
>    The redirection endpoint SHOULD require the use of TLS as described
>    in Section 1.6 when the requested response type is "code" or "token",
>    or when the redirection request will result in the transmission of
>    sensitive credentials over an open network.  This specification does
>    not mandate the use of TLS because at the time of this writing,
>    requiring clients to deploy TLS is a significant hurdle for many
>    client developers.  If TLS is not available, the authorization server
>    SHOULD warn the resource owner about the insecure endpoint prior to
>    redirection (e.g., display a message during the authorization
>    request).
> 
>    Lack of transport-layer security can have a severe impact on the
>    security of the client and the protected resources it is authorized
>    to access.  The use of transport-layer security is particularly
>    critical when the authorization process is used as a form of
>    delegated end-user authentication by the client (e.g., third-party
>    sign-in service).
> 
> Section 10.5 talks about transmission of authorization codes in connection with redirects.
> 
> Also see 6819, Sec 4.4.1.1 regarding eavesdropping or leaking of authz codes.
> 
> 
> Phil
> 
> @independentid
> www.independentid.com
> [e-mail]
> 
> 
> 
> 
> 
>> On Jan 25, 2016, at 4:52 PM, nov matake <[e-mail]> wrote:
>> 
>> The first assumption is coming from the original security report at http://arxiv.org/abs/1601.01229.
>> RFC 6749 requires TLS between RS and AS, and also between UA and AS, but not between UA and RS.
>> 
>> The blog post is based on my Japanese post, and it describes multi-AS case.
>> Nat's another post describes the case which can affect single-AS case too.
>> http://nat.sakimura.org/2016/01/22/code-phishing-attack-on-oauth-2-0-rfc6749/
>> 
>> nov
>> 
>>> On Jan 26, 2016, at 08:22, Phil Hunt <[e-mail]> wrote:
>>> 
>>> Sorry, meant to reply-all.
>>> 
>>> Phil
>>> 
>>> @independentid
>>> www.independentid.com
>>> [e-mail]
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> Begin forwarded message:
>>>> 
>>>> From: Phil Hunt <[e-mail]>
>>>> Subject: Re: [OAUTH-WG] Call for Adoption: OAuth 2.0 Mix-Up Mitigation
>>>> Date: January 25, 2016 at 3:20:19 PM PST
>>>> To: Nat Sakimura <[e-mail]>
>>>> 
>>>> I am having trouble with the very first assumption. The user-agent sets up a non TLS protected connection to the RP? That’s a fundamental violation of 6749.
>>>> 
>>>> Also, the second statement says the RP (assuming it acts as OAuth client) is talking to two IDPs.  That’s still a multi-AS case is it not?
>>>> 
>>>> Phil
>>>> 
>>>> @independentid
>>>> www.independentid.com
>>>> [e-mail]
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> On Jan 25, 2016, at 2:58 PM, Nat Sakimura <[e-mail]> wrote:
>>>>> 
>>>>> Hi Phil, 
>>>>> 
>>>>> Since I was not in Darmstadt, I really do not know what was discussed there, but with the compromised developer documentation described in http://nat.sakimura.org/2016/01/15/idp-mix-up-attack-on-oauth-rfc6749/, all RFC6749 clients with a naive implementer will be affected. The client does not need to be talking to multiple IdPs. 
>>>>> 
>>>>> Nat
>>>>> 
>>>>> 2016年1月26日(火) 3:58 Phil Hunt (IDM) <[e-mail]>:
>>>>>> I recall making this point in Germany. 99% of existing use is fine. OIDC is probably the largest community that *might* have an issue.
>>>>>> 
>>>>>> I recall proposing a new security document that covers oauth security for dynamic scenarios. "Dynamic" being broadly defined to mean:
>>>>>> * clients who have configured at runtime or install time (including clients that do discovery)
>>>>>> * clients that communicate with more than one endpoint
>>>>>> * clients that are deployed in large volume and may update frequently (more discussion of "public" cases)
>>>>>> * clients that are script based (loaded into browser on the fly)
>>>>>> * others?
>>>>>> 
>>>>>> Phil
>>>>>> 
>>>>>> > On Jan 25, 2016, at 10:39, George Fletcher <[e-mail]> wrote:
>>>>>> >
>>>>>> > would
>>>>>> 
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