If possible, can you share this document on this thread when it is available?
On Wed, Nov 15, 2023 at 12:52 PM Yoav Weiss <yoavwe...@chromium.org> wrote: > 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. > To unsubscribe from this group and stop receiving emails from it, send an > email to blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfXz6RHMEbN4uVKw9pcS7nNyZT-zoQAwf1iSoS6THqAcfw%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfXz6RHMEbN4uVKw9pcS7nNyZT-zoQAwf1iSoS6THqAcfw%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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