On Wed, Sep 8, 2021 at 12:58 PM Ari Chivukula <[email protected]> wrote:
> Contact emails > > [email protected], [email protected], [email protected] > > Design Doc > > > https://docs.google.com/document/d/1U3P9yvaT1NXG_qRmY3Lp6Me7M5kTnd3QrBb1yFUVNNk/edit > > Specification > > https://wicg.github.io/client-hints-infrastructure/ > > Summary > > To support variable fonts > <https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Fonts/Variable_Fonts_Guide>, > color vector fonts <https://www.chromestatus.com/feature/5638148514119680>, > responsive images > <https://github.com/w3c/webappsec-permissions-policy/issues/55#issuecomment-406627096>, > and other third-party content which requires client information lost by the > user > agent reduction > <https://groups.google.com/a/chromium.org/g/blink-dev/c/R0xKm1B7qoQ> > implementation we need a way to extend client hints > <https://wicg.github.io/ua-client-hints/>. For example: variable fonts > <https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Fonts/Variable_Fonts_Guide> > allow significantly less font information to be transferred without loss of > functionality, but only works on specific operating systems. > > > > Blink component > > Privacy>Fingerprinting > <https://bugs.chromium.org/p/chromium/issues/list?q=component%3APrivacy%3EFingerprinting> > > > > Motivation > > It’s already possible to set a Permissions Policy > <https://wicg.github.io/ua-client-hints/#delegation> in the HTTP response > header, but for sites without the ability to modify HTTP headers a HTML > solution would be ideal. This proposal prototypes a metadata meta tag which > allows delegation of client hints to third-party origins. These tags could > be included in code-snippets for embedded third-party content for ease of > use. > > > > For example, to specify third party requests to `https://foo.bar` must > include `sec-ch-width` you could include: > > <meta name="accept-ch" content="sec-ch-width=('self' 'https://foo.bar')"> > > You may still omit the permission policy and rely on the default allowlist > as follows: > > <meta name="accept-ch" content="sec-ch-width"> > > Note that this is the equivalent of the following today: > > <meta http-equiv="accept-ch" content="sec-ch-width"> > > TAG review > > Not needed > I feel like a TAG review would be especially helpful here, as there are several architectural implications of exposing a so-far-HTTP-only feature through HTML. And, as noted below, there's an important question about name="" (usually used for metadata) vs. http-equiv="" (usually used for changing behavior). Wider design input would be valuable for that sort of thing. > > Risks > > This extension makes it easier for web developers to expose client hints > to third-party content, but does not increase the surface area from what > was already allowed via HTTP response headers > <https://wicg.github.io/ua-client-hints/#delegation>. Blink currently > implements first party client hints via a `http-equiv` meta tag. This > extension will have to co-exist with (as a `name` meta tag) or > replace/remove that iteration upon final implementation. > > > Interoperability and Compatibility > > > > Gecko: No official position on implementation (Client Hints considered > non-harmful <https://github.com/mozilla/standards-positions/issues/79>; User > Agent Client Hints considered harmful > <https://github.com/mozilla/standards-positions/issues/202>) > > > > WebKit: No official position on implementation > > > > Web developers: Positive interest from Cloudinary > <https://bugs.chromium.org/p/chromium/issues/detail?id=1219359#c10> > > Debuggability > > Any improperly formatted client hint meta tags will be flagged in the > Issues tab. > > Is this feature fully tested by web-platform-tests? > > No, but it will be as part of prototyping. > > Tracking bug > > https://crbug.com/1219359 > > Link to entry on the Chrome Platform Status > > https://www.chromestatus.com/features/5684289032159232 > > -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5D%2BDQCwmfg-efW11Ms7DQgjy2tUOd3AELg1He6ovqbFWLQ%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGpy5D%2BDQCwmfg-efW11Ms7DQgjy2tUOd3AELg1He6ovqbFWLQ%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 [email protected]. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAM0wra8bsHDC5wye4QWyup5F8yPBw%3DpFaKirpRzphbOg8wD7sA%40mail.gmail.com.
