Off the top of my head, rotation is useful for 2 things * reducing the likelihood that an “old” refresh token is still valid (e.g. “found” on some device, log file, source code etc...) * being able to revoke all the active refresh tokens if a refresh token is used twice
...and yes it introduces a higher chance of false positives. https://leastprivilege.com/2020/01/21/hardening-refresh-tokens/ But I agree with the spec - if the refresh token cannot be bound to a client by a secret (looking at you, SPAs) - it should be hardened using sliding expiration, rotation and replay detection. Maybe the wording needs to be clearer. ——— Dominick Baier On 12. March 2020 at 23:15:19, Vittorio Bertocci ( vittorio=40auth0....@dmarc.ietf.org) wrote: Rotation can be used to detect leakage, right? Client credentials offer more guarantees, but unless you are using private JWTs with a non exportable certificate as client cred, a classic client secret _could_ technically leak. Having rotation would alert you if someone got a hold on those. Admittedly it’s a stretch, but not entirely inconceivable. On Thu, Mar 12, 2020 at 13:57 Torsten Lodderstedt <torsten= 40lodderstedt....@dmarc.ietf.org> wrote: > Then why are you rotating refresh tokens? > > Am 12.03.2020 um 20:48 schrieb Pedro Igor Silva <psi...@redhat..com > <psi...@redhat.com>>: > > > A confidential client, as per the `web application` definition in Section > `2.1. Client Types`. > > On Thu, Mar 12, 2020 at 4:39 PM Torsten Lodderstedt < > tors...@lodderstedt.net> wrote: > >> Is that a public client? >> >> Am 12.03.2020 um 20:32 schrieb Pedro Igor Silva <psi...@redhat.com>: >> >> >> I agree with you and recently, we had to deal with an issue where a `web >> application` using rotation (as defined by the draft) was having issues to >> refresh tokens due to multiple concurrent requests at the moment a token is >> about to expire or already expired.. We had to add some controls to deal >> with concurrency and additional complexity + performance penalties. And for >> such clients, I was not sure whether or not rotation makes sense. >> >> >> On Thu, Mar 12, 2020 at 4:05 PM Vittorio Bertocci <Vittorio= >> 40auth0....@dmarc.ietf.org> wrote: >> >>> Thanks for the clarification, Torsten. >>> I believe it's the first time I see use of client credentials positioned >>> as sender constraint; if the intent is saying that confidential clients >>> should use their credentials when redeeming refresh tokens, I am of course >>> in agreement but I think the language should be clearer and state the above >>> explicitly. >>> >>> Re: failure frequency, I know of scenarios were the designers added >>> rotation by default, and after a while it was turned to opt in because of >>> the frequency of errors and impact on user experience/call center. >>> I really believe that putting this as a MUST is justified only for >>> exceedingly vulnerable situations, like SPAs. >>> Native/desktop clients should be free to decide whether they want to opt >>> in without loosing compliance. Just my 2 C >>> >>> On Thu, Mar 12, 2020 at 11:58 AM Torsten Lodderstedt <torsten= >>> 40lodderstedt....@dmarc.ietf.org> wrote: >>> >>>> Hi, >>>> >>>> sender constraining refresh tokens for confidential client means client >>>> authentication + check the binding of the refresh token with the respective >>>> client id. I don’t think this is new as RFC6759 already required ASs to >>>> check this binding. Assuming backends are generally confidential clients >>>> also means no rotation and no cache synchronization needed. >>>> >>>> Rotation should be used for frontends, e.g. native apps and only if >>>> there is there no other option. If a refresh fails, the app must go through >>>> the authorization process again. That’s inconvenient so the question is how >>>> often this happens. What I can say, I have never seen customer complaining >>>> in several years of operation of ASs with refresh token rotation (including >>>> replay detection) for native apps with millions of users. >>>> >>>> best regards, >>>> Torsten. >>>> >>>> Am 12.03..2020 um 19:24 schrieb Vittorio Bertocci <Vittorio= >>>> 40auth0....@dmarc.ietf..org <40auth0....@dmarc.ietf.org>>: >>>> >>>> >>>> Hey guys, >>>> thanks for putting this together. >>>> I am concerned with the real world impact of imposing sender >>>> constraint | rotation as a MUST on refresh tokens in every scenario. >>>> Sender constraint isn't immediately actionable - we just had the >>>> discussion for dPOP, hence I won't go in the details here. >>>> Rotation isn't something that can be added without significant impact >>>> on development and runtime experiences: >>>> >>>> - on distributed scenarios, it introduces the need to serialize >>>> access to shared caches >>>> - network failures can lead to impact on experience- stranding >>>> clients which fail to receive RTn+1 during RTn redemption in a limbo >>>> where >>>> user interaction might become necessary, disrupting experience or >>>> functionality for scenarios where the user isn't available to respond. >>>> - >>>> >>>> >>>> >>>> On Wed, Mar 11, 2020 at 5:28 PM Aaron Parecki <aa...@parecki..com >>>> <aa...@parecki.com>> wrote: >>>> >>>>> I'm happy to share that Dick and Torsten and I have published a first >>>>> draft of OAuth 2.1. We've taken the feedback from the discussions on >>>>> the list and incorporated that into the draft. >>>>> >>>>> https://tools.ietf.org/html/draft-parecki-oauth-v2-1-01 >>>>> >>>>> A summary of the differences between this draft and OAuth 2.0 can be >>>>> found in section 12, and I've copied them here below. >>>>> >>>>> > This draft consolidates the functionality in OAuth 2.0 (RFC6749), >>>>> > OAuth 2.0 for Native Apps (RFC8252), Proof Key for Code Exchange >>>>> > (RFC7636), OAuth 2.0 for Browser-Based Apps >>>>> > (I-D.ietf-oauth-browser-based-apps), OAuth Security Best Current >>>>> > Practice (I-D.ietf-oauth-security-topics), and Bearer Token Usage >>>>> > (RFC6750). >>>>> > >>>>> > Where a later draft updates or obsoletes functionality found in the >>>>> > original [RFC6749], that functionality in this draft is updated >>>>> with >>>>> > the normative changes described in a later draft, or removed >>>>> > entirely. >>>>> > >>>>> > A non-normative list of changes from OAuth 2.0 is listed below: >>>>> > >>>>> > * The authorization code grant is extended with the functionality >>>>> > from PKCE ([RFC7636]) such that the only method of using the >>>>> > authorization code grant according to this specification >>>>> requires >>>>> > the addition of the PKCE mechanism >>>>> > >>>>> > * Redirect URIs must be compared using exact string matching as >>>>> per >>>>> > Section 4.1.3 of [I-D.ietf-oauth-security-topics] >>>>> > >>>>> > * The Implicit grant ("response_type=token") is omitted from this >>>>> > specification as per Section 2.1.2 of >>>>> > [I-D.ietf-oauth-security-topics] >>>>> > >>>>> > * The Resource Owner Password Credentials grant is omitted from >>>>> this >>>>> > specification as per Section 2.4 of >>>>> > [I-D.ietf-oauth-security-topics] >>>>> > >>>>> > * Bearer token usage omits the use of bearer tokens in the query >>>>> > string of URIs as per Section 4.3.2 of >>>>> > [I-D.ietf-oauth-security-topics] >>>>> > >>>>> > * Refresh tokens must either be sender-constrained or one-time use >>>>> > as per Section 4.12.2 of [I-D.ietf-oauth-security-topics] >>>>> >>>>> https://tools.ietf.org/html/draft-parecki-oauth-v2-1-01#section-12 >>>>> >>>>> I'm excited for the direction this is taking, and it has been a >>>>> pleasure working with Dick and Torsten on this so far. My hope is that >>>>> this first draft can serve as a good starting point for our future >>>>> discussions! >>>>> >>>>> ---- >>>>> Aaron Parecki >>>>> aaronparecki.com >>>>> @aaronpk >>>>> >>>>> P.S. This notice was also posted at >>>>> https://aaronparecki.com/2020/03/11/14/oauth-2-1 >>>>> >>>>> _______________________________________________ >>>>> OAuth mailing list >>>>> OAuth@ietf.org >>>>> https://www.ietf.org/mailman/listinfo/oauth >>>>> >>>> _______________________________________________ >>>> OAuth mailing list >>>> OAuth@ietf.org >>>> https://www.ietf.org/mailman/listinfo/oauth >>>> >>>> _______________________________________________ >>> OAuth mailing list >>> OAuth@ietf.org >>> https://www.ietf.org/mailman/listinfo/oauth >>> >> _______________________________________________ >> OAuth mailing list >> OAuth@ietf.org >> https://www.ietf.org/mailman/listinfo/oauth >> >> _______________________________________________ OAuth mailing list OAuth@ietf.org https://www.ietf.org/mailman/listinfo/oauth
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