- From: Eric Chen <eric.chen@sv.cmu.edu>
- Date: Wed, 29 Aug 2012 10:40:55 -0700
- To: "Hill, Brad" <bhill@paypal-inc.com>
- Cc: Odin Hørthe Omdal <odinho@opera.com>, "public-webappsec@w3.org" <public-webappsec@w3.org>
- Message-ID: <CAF8haazETb-NBP4b4P4KDRO-mk7vRYUNwX=15Rcb3HRYB-nZVQ@mail.gmail.com>
What if we use a UI similar to mixed content, where we let users to re-enable their extensions. On Wed, Aug 29, 2012 at 10:33 AM, Hill, Brad <bhill@paypal-inc.com> wrote: > Extensions run with the intent and at the behest of the user.**** > > ** ** > > In a conflict between user intent and resource policy, user intent wins.** > ** > > ** ** > > *From:* Eric Chen [mailto:eric.chen@sv.cmu.edu] > *Sent:* Wednesday, August 29, 2012 10:29 AM > *To:* Odin Hørthe Omdal > *Cc:* public-webappsec@w3.org > *Subject:* Re: [CSP] Extensions and user script? (Some feedback)**** > > ** ** > > I'm not sure if this idea has been discussed before, but why not have a > CSP policy that disables extensions? Disabling extensions entirely is > probably better than half-breaking extensions. > > > -- > -EC**** > > ** ** > > On Wed, Aug 29, 2012 at 4:34 AM, Odin Hørthe Omdal <odinho@opera.com> > wrote:**** > > Hello all :-) > > I've gotten some internal web site author feedback trying to implement CSP > on a web email service that I'd like to share and discuss. > > There's of course a few minor things that will get better with time. Like > browsers using prefixes and different implementations of different > versions of the spec. As well as some potential bugs found, such as using > an same-domain iframe with an email in it, and then rewriting links > therein to do target=_blank, and it was suddenly blocked. They had to open > up frame-src: * in order for the links to open. From my cursory reading of > the spec, it does seem like this is in fact intended behaviour, but I'm > not sure. > > The biggest problem however is the interference of pages' CSP policies > when an extension goes mucking around the page doing whatever it likes to > do. > > This is not the same as having a CSP-profile on the extension, as Chrome > is doing, but the other way around:**** > > Extensions can > inject arbitrary javascript, css into the page and modify the DOM in any > way. Depending on the CSP policy, those will potentially be blocked. The > most annoying thing is that those might break your extension or the page > in subtle ways because some things the extension does work (DOM > manipulations), but other things fail (scripts/css injection). > Additionally changes that do fail will generate heaps of false positive > feedback reports, making the reporting feature a pain to sift through > and work out "now is this a problem with my CSP poilicy, or is it some > extension the users installed that's trying to modify the page in some > way". > > I don't see any realistic solution to this. You'd have to track a whole > bunch of manipulations and changes to the DOM as either "done by the > page" or "done by an extension" to work out if they should be allowed or > not. > > So at first I thought "what a great idea", but after two days of messing > around and actually trying to use it, I decided that it might be > bordering on unuseable in the real world**** > > > > > I have not looked into it myself, but this is a very valid concern if we > were to implement it in Opera. What have you that have implemented this > already done about it? How does it work? Is really extensions crippled in > such a way, do they have to think about it? > > -- > Odin Hørthe Omdal (Velmont/odinho) · Core, Opera Software, > http://opera.com**** > -- -Eric
Received on Wednesday, 29 August 2012 17:41:22 UTC