A small update: The correct feature link is: https://www.chromestatus.com/feature/5630916006248448 (also updated below)
On Thu, Oct 14, 2021 at 5:43 PM Matt Reichhoff <mreichh...@chromium.org> wrote: > Contact emails > > mreichh...@chromium.org, b...@chromium.org, miketa...@chromium.org, > jadekess...@chromium.org > > Explainer > > https://github.com/WICG/ua-client-hints#user-agent-client-hints > > Specification > > https://wicg.github.io/ua-client-hints/#create-arbitrary-brands-section > > https://wicg.github.io/ua-client-hints/#grease > > API spec > > Yes > > Summary > > This proposal seeks to align our implementation of GREASE in User Agent > Client Hints with the current spec, which includes additional GREASE > characters beyond the current semicolon and space, and which recommends > varying the arbitrary version. > > Blink component > > Privacy>Fingerprinting > <https://bugs.chromium.org/p/chromium/issues/list?q=component%3APrivacy%3EFingerprinting> > > Motivation > > User-Agent GREASE is intended to discourage arbitrary user agent > blocklists and other assumptions being built on top of the User-Agent > header. A similar concept exists in TLS > <https://tools.ietf.org/html/draft-ietf-tls-grease>. This practice is > currently implemented in Chromium, but today’s implementation differs > slightly from the current spec. If implemented, this proposal would enable > additional GREASE characters (the full list includes the following ASCII > characters: 0x20 (SP), 0x28 (left parenthesis), 0x29 (right parenthesis), > 0x2D (-), 0x2E (.), 0x2F (/), 0x3A (:), 0x3B (;), 0x3D (=), 0x3F (?), 0x5F > (_)) and vary the arbitrary version over time. Note that the GREASE portion > of the header would remain constant per major version, in accordance with > the spec. > > TAG review > > UA-CH is currently in review > <https://github.com/w3ctag/design-reviews/issues/640>. > > Risks > > The prior inclusion of escaped ASCII 0x22 (double quote) and 0x5C > (backslash) proved to be web incompatible > <https://bugs.chromium.org/p/chromium/issues/detail?id=1091285> and was > rolled back > <https://bugs.chromium.org/p/chromium/issues/detail?id=1149575>. While we > do not anticipate similar problems with the updated character list, we will > take the following actions to validate this assumption: > > - > > Pre-launch testing of the new characters against known-common sites, > which will include tests against the components known to have been > incompatible with the prior implementation. > - > > A phased rollout along with monitoring of HTTP 4XX response rates. > > > Interoperability and Compatibility > > WebKit: No official position; mild positive signals. > <https://lists.webkit.org/pipermail/webkit-dev/2020-May/031198.html> > > Firefox: UA Client hints considered non-harmful > <https://mozilla.github.io/standards-positions/#ua-client-hints> > > > > Is this feature fully tested by web-platform-tests? > > We will be adding web-platform-tests to validate this functionality. > > Tracking bug > > https://crbug.com/1164423 > > Link to entry on the Chrome Platform Status > > https://www.chromestatus.com/feature/5630916006248448 > -- 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/CAGg35aybo7VwXZyiJzDvt-o5yOG_kOJg2FsBwoRzGLkHCoA8HA%40mail.gmail.com.
