On Thursday, March 14, 2024 at 2:27:20 PM UTC+1 Ari Chivukula wrote:
Contact emails aric...@chromium.org, wanderv...@chromium.org, johann...@chromium.org, rosh...@google.com Specification https://privacycg.github.io/saa-non-cookie-storage/ Design Doc https://docs.google.com/document/d/19qCGb4qwOcGiNrQM3ptWvRmB4Jtpa TFgFVlWLXNOQ6c/edit Feedback https://github.com/privacycg/saa-non-cookie-storage/issues Intent to Prototype https://groups.google.com/a/chromium.org/g/blink-dev/c/inRN8tI49O0 Intent to Experiment https://groups.google.com/a/chromium.org/g/blink-dev/c/SEL7N-xIE5s https://groups.google.com/a/chromium.org/g/blink-dev/c/AjH7tGxuVuw Summary This launches the proposed extension of the Storage Access API <https://webkit.org/blog/8124/introducing-storage-access-api/> (backwards compatible and currently in OT) to allow access to unpartitioned cookie and non-cookie storage in a third-party context. The current API only provides access to cookies, which have different use-cases than non-cookie storage (discussed more in the Motivation section). The API can be used as follows (JS running in an embedded iframe): // Request a new storage handle via rSA (this may prompt the user) let handle = await document.requestStorageAccess({all: true}); // Write some 1P context sessionstorage handle.sessionStorage.setItem("userid", "1234"); // Write some 1P context localstorage handle.localStorage.setItem("preference", "A"); // Open or create an indexedDB that is shared with the 1P context let messageDB = handle.indexedDB.open("messages"); // Use locks shared with the 1P context await handle.locks.request(“example”, …); The same flow would be used by iframes to get a storage handle when their top-level ancestor successfully called requestStorageAccessFor <https://github.com/privacycg/requestStorageAccessFor>, just that in this case the storage-access permission was already granted and thus the requestStorageAccess call would not require a user gesture or show a prompt, allowing for “hidden” iframes accessing storage. Beyond calling this additional extension, access to non-cookie storage would match the current requirements for cookie access through the Storage Access API. DOM Storage (session and local storage), Indexed DB, Web Locks, Cache Storage, Origin Private File System, Quota, Blob Storage, Broadcast Channel, and SharedWorkers will be available. Blink component Blink>StorageAccessAPI <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EStorageAccessAPI> Motivation There has been increasing developer <https://github.com/GoogleChromeLabs/privacy-sandbox-dev-support/issues/124> and implementer <https://github.com/privacycg/storage-access/issues/102> interest in first-party DOM Storage <https://developer.mozilla.org/en-US/docs/Web/API/Web_Storage_API> and Quota Managed Storage <https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API> being available in third-party contexts the same way that cookies can be today <https://github.com/privacycg/storage-access>. In the absence of such a solution, browsers would in effect be pushing developers to migrate to cookies from other storage mechanisms. There are tradeoffs between cookie and non-cookie storage (size, flexibility, server exposure, network request size, etc.) that could impact user experience from a privacy, security and performance perspective (e.g., cookies are included in HTTP requests and not just available via JavaScript). To prevent sub-optimal use of cookies and to preserve context, we propose a solution for developers to regain 3p access to unpartitioned storage to avoid user-facing breakage in browsers shipping storage partitioning. TAG review https://github.com/w3ctag/design-reviews/issues/906 Compatibility The Storage Access API is already implemented in Safari, Firefox, and Chrome <https://caniuse.com/mdn-api_document_requeststorageaccess>, but the proposed API shape would preserve existing behavior until the web developer adds new arguments. Interoperability Gecko: No Position Yet https://github.com/mozilla/ standards-positions/issues/898 Despite the lack of an official position, the discussion seems encouraging. I sympathize with concerns around "all"'s semantics and their future compat impact. Was this point discussed in the CG or elsewhere? WebKit: No Position Yet https://github.com/WebKit/ standards-positions/issues/262 Web developers: Positive <https://github.com/GoogleChromeLabs/privacy-sandbox-dev-support/issues/124> Debuggability Storage written can be examined in devtools. Is this feature fully tested by web-platform-tests? Yes <https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/storage-access-api/> Tracking bug https://issues.chromium.org/40282415 Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5175585823522816 -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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