Bug 242002

Summary:	preventSilentAccess throws NotSupportedError
Product:	WebKit	Reporter:	Luke Warlow <lwarlow>
Component:	New Bugs	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	bfulgham, pascoe, rmondello, webkit-bug-importer, wilander
Priority:	P2	Keywords:	InRadar
Version:	Safari 15
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=181082

Description Luke Warlow 2022-06-25 08:25:40 PDT

Safari has "implemented" the `preventSilentAccess` function from the Credential Management API (https://w3c.github.io/webappsec-credential-management/#dom-credentialscontainer-preventsilentaccess).

However, it unconditionally throws a NotSupportedError whenever it's called. This happens on both macOS and iOS from my testing.

The specification doesn't mention this as an expected behaviour and I was surprised to see that the function is implemented but also not implemented, meaning my feature detection looking for the existence of the function fails.

The below code can be pasted into Web Inspector on a secure domain to demonstrate the issue. Both Chromium and Firefox work correctly but Safari fails.

if (navigator.credentials.preventSilentAccess) {
	console.log('preventSilentAccess is implemented');
  navigator.credentials.preventSilentAccess()
		.then(() => {
			console.log('preventSilentAccess succeeded');
		})
    .catch((err) => {
			console.log('preventSilentAccess failed');
      
      console.error(err);
		});
	
} else {
	console.log('preventSilentAccess is NOT implemented');
}

Comment 1 Radar WebKit Bug Importer 2022-06-27 16:32:07 PDT

<rdar://problem/96020741>

Comment 2 Alexey Proskuryakov 2022-06-27 16:35:51 PDT

This is definitely how it is implemented indeed. It's been a long time since this code was added, and I couldn't find any explanation of why it was done this way.

void CredentialsContainer::preventSilentAccess(DOMPromiseDeferred<void>&& promise) const
{
    promise.reject(Exception { NotSupportedError, "Not implemented."_s });
}

Comment 3 Luke Warlow 2023-03-09 09:02:15 PST

Pull request: https://github.com/WebKit/WebKit/pull/11303

Comment 4 EWS 2023-05-22 12:37:22 PDT

Committed 264345@main (40294715d0c0): <https://commits.webkit.org/264345@main>

Reviewed commits have been landed. Closing PR #11303 and removing active labels.