LGTM3 with the same condition. On Wed, Nov 15, 2023 at 6:44 PM Mike Taylor <miketa...@chromium.org> wrote:
> +1, thank you. LGTM2 w/ same condition. > On 11/15/23 12:39 PM, Daniel Bratell wrote: > > Thanks for getting the security people to weigh in on this because that > was really the main question for me. And it will still be controllable by a > finch flag. > > LGTM1 dependent on there being a published document outlining the options > for web developers (i.e. the document you are already working on). > > /Daniel > On 2023-11-10 09:45, Fergal Daly wrote: > > On Fri, 10 Nov 2023 at 17:29, Yoav Weiss <yoavwe...@chromium.org> wrote: > >> Thanks David! >> It's great to see that this will be disabled in modes where we *know* the >> machine is shared. >> >> Fergal - could you address concerns about web developer advice? What >> should we tell web developers to do on their logout pages? >> > > Yes, we are in discussion with dev-rel about this. They were already > looking at producing advice for auth best practices. We will ensure that > this is covered in that, > > F > > > >> >> >> On Fri, Nov 10, 2023 at 8:37 AM David Dworken <ddwor...@google.com> >> wrote: >> >>> Chiming in to say that we discussed the security concerns around this >>> proposal quite extensively internally and overall we believe that with the >>> short timeout, the security risks are acceptable. The residual security >>> risk is for servers that implement purely server-side logouts and is only >>> exploitable for a very short period of time (3 minutes). In addition, other >>> mitigations like this one >>> <https://bugs.chromium.org/p/chromium/issues/detail?id=1468438> further >>> reduce the risk such that we believe it is unlikely that this will lead to >>> new security issues. >>> >>> On Friday, October 13, 2023 at 7:14:46 AM UTC-7 vmp...@chromium.org >>> wrote: >>> >>> On Fri, Oct 13, 2023 at 12:00 AM 'Fergal Daly' via blink-dev < >>> blin...@chromium.org> wrote: >>> >>> On Thu, 12 Oct 2023 at 23:05, Yoav Weiss <yoav...@chromium.org> wrote: >>> >>> >>> >>> On Thu, Oct 12, 2023 at 3:56 PM Vladimir Levin <vmp...@chromium.org> >>> wrote: >>> >>> Are there any spec changes planned for this feature? I'm not sure if the >>> README linked under Specification is meant to make it into WHATWG, maybe to >>> close out https://github.com/whatwg/html/issues/7189 >>> >>> The only spec I could find about CCNS is >>> https://www.rfc-editor.org/rfc/rfc9111#section-5.2.1.5, so I'm not sure >>> how to reconcile possibly contradicting language in the specs >>> >>> >>> Great questions! Fergal - can you answer that? >>> >>> >>> RFC9111 is about HTTP caches. BFCache is not a HTTP cache, so RFC 9111 >>> does not apply. Of course the reality of implementations and expectations >>> vs spec is a problem. Some more discussion here >>> <https://github.com/fergald/explainer-bfcache-ccns/blob/main/README.md#current-interactions-between-bfcache-and-ccns> >>> >>> >>> I'm not sure I agree with this, or the reasoning in the link. First of >>> all, this intent thread is about ignoring CCNS in _some cases_. In other >>> cases, CCNS is respected, so it seems like BFCache is de facto subject to >>> RFC 9111. >>> >>> This is, I guess, a bit philosophical but the spec says: >>> the cache MUST NOT intentionally store the information in non-volatile >>> storage and MUST make a best-effort attempt to remove the information from >>> volatile storage as promptly as possible after forwarding it. >>> >>> Note that the spec here does not make any exceptions for things like >>> cookie state not changing or anything else. The document when frozen is >>> indeed a volatile storage of the server response, processed and stored in >>> some particular format (ie the DOM tree). I admit it's a bit weird to think >>> about it this way, since the live document is technically also this cache. >>> Whereas I agree that BFCache is not strictly an HTTP Cache, I don't quite >>> follow why CCNS should not apply to the BFCache in some cases. >>> >>> To me, BFCache seems like "a better http cache" which already has >>> rendered results, not a completely separate cache that is not subject to >>> CCNS. >>> >>> But I'm late to the game, and I see that the topic of "BFCache is not >>> HTTP Cache" has already been discussed a lot. I'm not convinced by existing >>> arguments, but I also don't think I'll be able to convince anyone of my >>> position. >>> >>> My problem with the consensus in >>> https://github.com/whatwg/html/issues/5744 is the following. People >>> seem to agree that we don't want a *new* api that specifically prevents >>> pages from entering BFCache. I don't believe it's appropriate to draw a >>> conclusion that there is consensus that BFCache should not be subject to >>> any *existing* APIs that prevent pages from entering it. This might be true >>> independently, but I don't think one follows from the other. To quote this >>> comment >>> <https://github.com/whatwg/html/issues/5744#issuecomment-811958634>: >>> "... And what is the problem with the bank case? I'd expect bank may >>> want to ensure its page doesn't enter bfcache, or any other cache, by using >>> no-store (and other) header(s) or something ..." >>> >>> That comment sounds to me like "the status quo is good enough, because >>> there are already ways of preventing any cache, including bfcache." If we >>> were to claim consensus on doing this work, I'd personally want to see a >>> more explicit "let's make it so pages still enter BFCache despite CCNS in >>> these cases." The comment from cdumez you quoted is good, but maybe >>> following-up there is worthwhile. >>> >>> >>> I concede though that I'm by no means an expert here, so I don't want to >>> block moving this forward any longer. I just want to say that it's >>> typically easy to be fast if you show stale data, and shifting the blame to >>> the site for using CCNS instead of refreshing needed content in script >>> doesn't seem appropriate. I personally would not want to be the judge of >>> whether CCNS use is appropriate or not since I don't know what >>> "appropriate" is in this case. >>> >>> >>> >>> >>> BFCache and cases where it can/can't be used are specced in the HTML >>> standard. We have had very little engagement from other vendors on this >>> particular idea but Safari tried to cache all CCNS pages in the past. I am >>> hoping that if we demonstrate a way to cache some of them safely, they >>> would be on board. Also any browser is free to be *more* conservative than >>> the spec while still staying in-spec as BFCaching at all is always optional. >>> >>> Here <https://github.com/whatwg/html/issues/5744#issuecomment-661997090> >>> is cdumez of Safari >>> >>> Safari / WebKit shipped with all pages going into the bfcache no matter >>> what (including cache-control: no-store). The only push back we >>> received was the fact that after you log out of a site, you could still go >>> back and see a page you should no longer be able to see. We agreed that >>> this feedback was valid and our short-term fix was to bypass the bfcache >>> when the page uses cache-control: no-store. Sadly, many sites use this >>> and their intention is likely not to prevent the bfcache. This is not >>> something we like for the long term. >>> >>> F >>> >>> >>> >>> >>> Also, Vlad previously asked about the recommended pattern for folks to >>> handle credential revocation with BFCache and his concerns with the snippet >>> suggested upthread. It'd be great to address that. >>> >>> >>> Thanks! >>> vmpstr >>> >>> On Thu, Oct 12, 2023 at 2:32 AM Yoav Weiss <yoav...@chromium.org> wrote: >>> >>> I just discussed this with Fergal offline: >>> >>> - The risky scenario is one where revocation of sensitive info >>> (logout, access revoked) happens on the server-side only without a >>> client-side update. >>> - In such a scenario on a shared computer, someone could back-button >>> their way into someone else's sensitive info. >>> - It might be interesting to talk to security folks (and maybe >>> Project Zero folks) to see if this is not happening already with content >>> that's not CCNS decorated. >>> - It would be good to run a survey of potentially-sensitive services >>> and try to get a signal from them on how many of them are properly doing >>> revocation on the client side. >>> - I'd love ideas on how we can scale such a survey beyond manual >>> inspection of a few known services. >>> - It could be interesting to try and ship a version of this with a >>> shorter timeout, to minimize the risk of users leaving the machine >>> unattended. >>> - If we go that route, it'd be good to think through how we'd be >>> able to increase that timeout over time, after gaining more >>> confidence that >>> the risky scenario isn't happening in the wild. >>> >>> >>> >>> On Thu, Oct 5, 2023 at 2:36 AM Jason Robbins <jrob...@google.com> wrote: >>> >>> At this morning's API Owners meeting, they asked me to add all review >>> gate types to all of the "web developer facing code change" features that >>> are currently under review, including this one. So, I have added Privacy, >>> Security, Enterprise, Debuggability, and Testing gates to your feature >>> entry. >>> >>> Please click the gate chips in the "Prepare to ship" stage on your >>> feature detail page. For each one, answer survey questions and request >>> that of the cross-functional review. You can request them all in >>> parallel. In cases where you already have the go/launch >>> <https://goto.google.com/launch> bit approved, you can note that in a >>> comment on that gate for a potentially faster review. >>> >>> Thanks, >>> jason! >>> On Monday, October 2, 2023 at 9:09:18 AM UTC-7 Jason Robbins wrote: >>> >>> On Friday, September 29, 2023 at 1:01:54 PM UTC-7 Chris Harrelson wrote: >>> >>> Please also make sure to complete all of the other shipping gate reviews >>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/bqvB1oap0Yc/m/YlO8DEHgAQAJ> >>> . >>> >>> >>> I think a bug in ChromeStatus may have caused some confusion on this >>> feature entry. The feature entry has type "Web developer facing code >>> change", so its bilnk-dev thread should have had subject line prefix >>> "Web-facing change PSA" rather than "Intent to ship". And, according to >>> the launching-features doc >>> <https://www.chromium.org/blink/launching-features/#psa-prepare-to-ship>, >>> it does not require any approvals, which is why there are no other gates >>> offered in the ChromeStatus UI. A fix for that subject-line prefix bug >>> should go live today. >>> >>> Of course, the point of a PSA is to allow concerns to be raised and I >>> see that this is a very active thread. So, all that should be worked >>> through. Its a mater of the the API Owners prerogative to request any >>> other reviews that they think are appropriate, but it is not automatically >>> required by the process for this feature type. Also, I see that the launch >>> entry <https://launch.corp.google.com/launch/4251651> had some >>> approvals. >>> >>> Thanks, >>> jason! >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to blink-dev+...@chromium.org. >>> To view this discussion on the web visit >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfUszpq%3DS%3DOZ4k_GnopJMRcTnL_trq5iF8J-kAzeYEiqKA%40mail.gmail.com >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfUszpq%3DS%3DOZ4k_GnopJMRcTnL_trq5iF8J-kAzeYEiqKA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to blink-dev+...@chromium.org. >>> >>> To view this discussion on the web visit >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAAozHLkA5eFwcvRsTAZhy728KFaBjd5W5EZpP2%3DMmC42ngMUuQ%40mail.gmail.com >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAAozHLkA5eFwcvRsTAZhy728KFaBjd5W5EZpP2%3DMmC42ngMUuQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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