Bug 32369

Summary:

Support for storage and databases in sandboxed iframes

Product:

WebKit

Reporter:

Patrik Persson <patrik.j.persson>

Component:

Frames

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

abarth, commit-queue, darin, dglazkov, webkit.review.bot

Priority:

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Attachments:

Description	Flags
Patch for updated HTML5 sandbox support	abarth: review-
Patch that builds with Chromium	none

Patrik Persson

Reported 2009-12-10 02:18:50 PST

This is a followup to bug 21288, which concerned the implementation of the HTML5 iframe sandbox attribute. How should WebKit interpret the HTML5 spec regarding sandboxed storage and databases? I believe the HTML5 spec does not say much explicitly on this, but rather relies on the origin sandboxing. Here is my interpretation. * I think sessionStorage would make sense with sandboxed origins. * I think localStorage would end up equivalent to sessionStorage in a sandboxed frame, making it somewhat less useful. (The unique origin of a sandboxed frame means, in my interpretation, that the same frame would not be able to access its own localStorage in another session.) * Similarly, I think a sandboxed database would be useful only within a session. The database could be reclaimed when the session ends. This defeats much of the purpose of databases, but perhaps it would still be useful for compatibility. The current implementation disables storage and databases in sandboxed frames. There is some more discussion in the thread for bug 21288, comments 43..49: https://bugs.webkit.org/show_bug.cgi?id=21288#c43

Attachments
Patch for updated HTML5 sandbox support (10.43 KB, patch) 2010-03-12 06:52 PST, Patrik Persson	abarth: review-	Details Formatted Diff Diff
Patch that builds with Chromium (13.96 KB, patch) 2010-03-15 07:37 PDT, Patrik Persson	no flags	Details Formatted Diff Diff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Adam Barth

Comment 1 2010-01-09 00:38:33 PST

I'll forward this question to the What WG.

Patrik Persson

Comment 2 2010-03-12 06:52:07 PST

Created attachment 50593 [details] Patch for updated HTML5 sandbox support

Patrik Persson

Comment 3 2010-03-12 06:53:58 PST

(This comment really concerns the patch just submitted in comment #2. I was a bit quick on the "submit" button.) Adam, thanks for bringing this up in the What WG. http://www.mail-archive.com/whatwg@lists.whatwg.org/msg19786.html This is a patch to match the updated HTML5 spec wrt. iframe sandboxing. The patch does two things: - Enables window.sessionStorage in sandboxed iframes. (Removed sandboxing check.) - Raises SECURITY_ERR exceptions when window.localStorage or window.openDatabase() is accessed in a sandboxed iframe. (Note: window.sessionStorage does not raise exceptions.) The patched behavior is in accordance with HTML5: http://dev.w3.org/html5/webstorage/ (sections 4.2 and 4.3) http://dev.w3.org/html5/webdatabase/ (section 4.1) Raising exceptions in situations where WebKit would previously return null could raise questions about compatibility. However, iframe sandboxing is a recent experimental feature, currently implemented only by WebKit.

WebKit Review Bot

Comment 4 2010-03-12 07:10:43 PST

Attachment 50593 [details] did not build on chromium: Build output: http://webkit-commit-queue.appspot.com/results/656025

Adam Barth

Comment 5 2010-03-12 09:06:28 PST

Comment on attachment 50593 [details] Patch for updated HTML5 sandbox support This patch looks good, thanks. If you'd be willing to fix the chromium build error, we'll be good to go.

Patrik Persson

Comment 6 2010-03-15 07:37:52 PDT

Created attachment 50700 [details] Patch that builds with Chromium Sorry about the build error. Here's an updated patch that builds on Chromium. Apart from the Chromium fix, this patch is identical to the previous one.

Darin Adler

Comment 7 2010-03-15 09:51:22 PDT

Comment on attachment 50700 [details] Patch that builds with Chromium > - bool isLocalStorage = (frame->domWindow()->localStorage() == storage); > + ExceptionCode ec = 0; > + bool isLocalStorage = (frame->domWindow()->localStorage(ec) == storage && !ec);' > - bool isLocalStorage = storage->frame()->domWindow()->localStorage() == storage; > + ExceptionCode ec = 0; > + bool isLocalStorage = (storage->frame()->domWindow()->localStorage(ec) == storage && !ec); Since the localStorage function returns 0 when there is an error, the !ec check seems unnecessary. > - for (unsigned i = 0; i < frames.size(); ++i) > - frames[i]->document()->enqueueStorageEvent(StorageEvent::create(eventNames().storageEvent, key, oldValue, newValue, sourceFrame->document()->url(), frames[i]->domWindow()->localStorage())); > + for (unsigned i = 0; i < frames.size(); ++i) { > + ExceptionCode ec = 0; > + Storage* storage = frames[i]->domWindow()->localStorage(ec); > + if (!ec) > + frames[i]->document()->enqueueStorageEvent(StorageEvent::create(eventNames().storageEvent, key, oldValue, newValue, sourceFrame->document()->url(), storage)); > + } I think it would be cleaner to just check the returned storage object to see if it's 0 rather than checking ec. We do need the ExceptionCode to communicate with the JavaScript binding, but I don't think we need to use it inside the engine itself. Minor issues. r=me based on my own reading of the code, the EWS results, and Adam Barth’s earlier review

WebKit Commit Bot

Comment 8 2010-03-15 10:14:16 PDT

Comment on attachment 50700 [details] Patch that builds with Chromium Clearing flags on attachment: 50700 Committed r56002: <http://trac.webkit.org/changeset/56002>

WebKit Commit Bot

Comment 9 2010-03-15 10:14:21 PDT

All reviewed patches have been landed. Closing bug.

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