Month: October 2014

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GNOME Web 3.14

It’s already been a few weeks since the release of GNOME Web 3.14, so it’s a bit late to blog about the changes it brings, but better late than never. Unlike 3.12, this release doesn’t contain big user interface changes, so the value of the upgrade may not be as immediately clear as it was for 3.12. But this release is still a big step forward: the focus this cycle has just been on polish and safety instead of UI changes. Let’s take a look at some of the improvements since 3.12.1.

Safety First

The most important changes help keep you safer when browsing the web.

Safer Handling of TLS Authentication Failures

When you try to connect securely to a web site (via HTTPS), the site presents identification in the form of a chain of digital certificates to prove that your connection has not been maliciously intercepted. If the last certificate in the chain is not signed by one of the certificates your browser has on file, the browser decides that the connection is not secure: this could be a harmless server configuration error, but it could also be an attacker intercepting your connection. (To be precise, your connection would be secure, but it would be a secure connection to an attacker.) Previously, Web would bet on the former, displaying an insecure lock icon next to the address in the header bar, but loading the page anyway. The problem with this approach is that if there really is an attacker, simply loading the page gives the attacker access to secure cookies, most notably the session cookies used to keep you logged in to a particular web site. Once the attacker controls your session, he can trick the web site into thinking he’s you, change your settings, perhaps make purchases with your account if you’re on a shopping site, for example. Moreover, the lock icon is hardly noticeable enough to warn the user of danger. And let’s face it, we all ignore those warnings anyway, right? Web 3.14 is much stricter: once it decides that an attacker may be in control of a secure connection, it blocks access to the page, like all major browsers already do:

Screenshot from 2014-10-17 19:52:53
Click for full size

(The white text on the button is probably a recent compatibility issue with GTK+ master: it’s fine in 3.14.)

Safety team members will note that this will obviously break sites with self-signed certificates, and is incompatible with a trust-on-first-use approach to certificate validation. As much as I agree that the certificate authority system is broken and provides only a moderate security guarantee, I’m also very skeptical of trust-on-first-use. We can certainly discuss this further, but it seemed best to start off with an approach similar to what major browsers already do.

The Load Anyway button is non-ideal, since many users will just click it, but this provides good protection for anyone who doesn’t. So, why don’t we get rid of that Load Anyway button? Well, different browsers have different strategies for validating TLS certificates (a good topic for a future blog post), which is why Web sometimes claims a connection is insecure even though Firefox loads the page fine. If you think this may be the case, and you don’t care about the security of your connection (including any passwords you use on the site), then go ahead and click the button. Needless to say, don’t do this if you’re using somebody else’s Wi-Fi access point, or on an email or banking or shopping site… when you use this button, the address in the address bar does not matter: there’s no telling who you’re really connected to.

But all of the above only applies to your main connection to a web site. When you load a web page, your browser actually creates very many connections to grab subresources (like images, CSS, or trackers) needed to display the page. Prior to 3.14, Web would completely ignore TLS errors for subresources. This means that the secure lock icon was basically worthless, since an attacker could control the page by modifying any script loaded by the page without being detected. (Fortunately, this attack is somewhat unlikely, since major browsers would all block this.) Web 3.14 will verify all TLS certificates used to encrypt subresources, and will block those resources if verification fails. This can cause web pages to break unexpectedly, but it’s how all major browsers I’ve tested behave, and it’s certainly the right thing to do. (We may want to experiment with displaying a warning, though, so that it’s clear what’s gone wrong.)

And if you’re a distributor, please read this mail to learn how not to break TLS verification in your distribution. I’m looking at you, Debian and derivatives.

Fewer TLS Authentication Failures

With glib-networking 2.42, corresponding to GNOME 3.14, Web will now accept certificate chains when the certificates are sent out of order. Sites that do this are basically broken, but all major browsers nevertheless support unordered chains. Sending certificates out of order is a harmless configuration mistake, not a security flaw, so the only harm in accepting unordered certificates is that this makes sites even less likely than before to notice their configuration mistake, harming TLS clients that don’t permute the certificates.

This change should greatly reduce the number of TLS verification failures you experience when using Web. Unfortunately, there are still too many differences in how certificate verification is performed for me to be comfortable with removing the Load Anyway button, but that is definitely the long-term goal.

HTTP Authentication

WebKitGTK+ 2.6.1 plugs a serious HTTP authentication vulnerability. Previously, when a secure web page would require a password before the user could load the page, Web would not validate the page’s TLS certificate until after prompting the user for a password and sending it to the server.

Mixed Content Detection

If a secure (HTTPS) web page displays insecure content (usually an image or video) or executes an insecure script, Web now displays a warning icon instead of a lock icon. This means that the lock icon now indicates that your connection is completely private, with the exception that a passive adversary can always know the web site that you are visiting (but not which page you are visiting on the site). If the warning icon is displayed, then an adversary can compromise some (and possibly all) of the page, and has also learned something that might reveal which page of the site you are visiting, or the contents of the page.

If you’re curious where the insecure content is coming from and don’t mind leaving behind Web’s normally simple user interface, you can check using the web inspector:

Screenshot from 2014-10-17 21:07:52
The screenshot is leaked to an attacker, revealing that you’re on the home page. Click for full size.

The focus on safety will continue to drive the development of Web 3.16. Most major browsers, with the notable exception of Safari, take mixed content detection one step further by actively blocking some more dangerous forms of insecure content, such as scripts, on secure pages, and we certainly intend to do so as well. We’re also looking into support for strict transport security (HSTS), to ensure that your connection to HSTS-enabled sites is safe even if you tried to connect via HTTP instead of HTTPS. This is what you normally do when you type an address into the address bar. Many sites will redirect you from an HTTP URL to an HTTPS URL, but an attacker isn’t going to do this kindness for you. Since all HTTP pages are insecure, you get no security warning. This problem is thwarted by strict transport security. We’re currently hoping to have both mixed content blocking and strict transport security complete in time for 3.16.

UI Changes

Of course, security hasn’t been the only thing we’ve been working on.

  • The most noticeable user experience change is not actually a change in Web at all, but in GNOME Document Viewer 3.14. The new Document Viewer browser plugin allows you to read PDFs in Web without having to download the file and open it in Document Viewer. (This is similar to the proprietary Adobe Reader browser plugin.) This is made possible by new support in WebKitGTK+ 2.6 for GTK+ 3 browser plugins.
  • The refresh button has been moved from the address bar and is now next to the new tab button, where it’s always accessible. Previously, you would need to click to show the address bar before the refresh button would appear.
  • The lock icon now opens a little popover to display the security status of the web page, instead of directly presenting the confusing certificate dialog. You can also now click the lock when the title of the page is displayed, without needing to switch to the address bar.

Bugfixes

3.14 also contains some notable bugfixes that will improve your browsing experience.

  • We fixed a race condition that caused the ad blocker to accidentally delete its list of filters, so ad block will no longer randomly stop working when enabled (it’s off by default). (We still need one additional fix in order to clean this up automatically if it’s already broken, but in the meantime you can reset your filters by deleting ~/.config/epiphany/adblock if you’re affected.)
  • We (probably!) fixed a bug that caused pages to disappear from history after the browser was closed.
  • We fixed a bug in Web’s aggressive removal of tracking parameters from URLs when the do not track preference is enabled (it’s off by default), which caused compatibility issues with some web sites.
  • We fixed a bug that caused Web to sometimes not offer to remember passwords.

These issues have all been backported to our 3.12 branch, but were never released. We’ll need to consider making more frequent stable releases, to ensure that bugfixes reach users more quickly in the future.

Polish

  • There are new context menu entries when right-clicking on an HTML video. Notably, this adds the ability to easily download a copy of the video for watching it offline.
  • Better web app support. Recent changes in 3.14.1 make it much harder for a web app to escape application mode, and ensure that links to other sites open in the default browser when in application mode.
  • Plus a host of smaller improvements: The subtitle of the header bar now changes at the same time as the title, and the URL in the address bar will now always match the current page when you switch to address bar mode. Opening multiple links in quick succession from an external application is now completely reliable (with WebKitGTK+ 2.6.1); previously, some pages would load twice or not at all. The search provider now exits one minute after you search for something in the GNOME Shell overview, rather than staying alive forever. The new history dialog that was added in 3.12 now allows you to sort history by title and URL, not just date. The image buttons in the new cookies, history, and passwords dialogs now have explanitory tooltips. Saving an image, video, or web page over top of an existing file now works properly (with Web 3.14.1). And of course there are also a few memory usage and crash fixes.

As always, the best place to send feedback is <epiphany-list@gnome.org>, or Bugzilla if you’ve found a bug. Comments on this post work too. Happy browsing!

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3.14 Games Updates

So, what new things happened to our games in GNOME 3.14?

Hitori

GNOME Hitori has actually been around for a while, but it wasn’t until this cycle that I discovered it. After chatting with Philip Withnall, we agreed that with a minor redesign, the result would be appropriate for GNOME 3. And here it is:

Screenshot from 2014-10-17 18:03:30

The gameplay is similar to Sudoku, but much faster-paced. The goal is to paint squares such that the same digit appears in each row and column no more than once, without ever painting two horizontally- or vertically-adjacent squares and without ever creating a set of unpainted squares that is disconnected both horizontally and vertically from the rest of the unpainted squares. (This sounds a lot more complicated than it is: think about it for a bit and it’s really quite intuitive.) You can usually win each game in a minute or two, depending on the selected board size.

Mines

For Mines, the screenshots speak for themselves. The new design is by Allan Day, and was implemented by Robert Roth.

Screenshot from 2014-10-17 18:09:10
3.12
Screenshot from 2014-10-17 18:08:06
3.14

There is only one gameplay change: you can no longer get a hint to help you out of a tough spot at the cost of a small time penalty. You’ll have to actually guess which squares have mines now.

Right now, the buttons on the right disappear when the game is in progress. This may have been a mistake, which we’ll revisit in 3.16. You can comment in Bug #729250 if you want to join our healthy debate on whether or not to use colored numbers.

Sudoku

Sudoku has been rewritten in Vala with the typical GNOME emphasis on simplicity and ease of use. The design is again by Allan Day. Christopher Baines started work on the port for a Google Summer of Code project in 2012, and Parin Porecha completed the work this summer for his own Google Summer of Code project.

Screenshot from 2014-10-17 18:19:02
3.12 (note: not possible to get rid of the wasted space on the sides)
Screenshot from 2014-10-17 18:20:25
3.14

We’re also using a new Sudoku generator, QQwing, for puzzle generation. This allows us to avoid reimplementing bugs in our old Sudoku generator (which is documented to have generated at least one impossible puzzle, and sometimes did a very poor job of determining difficulty), and instead rely on a project completely focused on correct Sudoku generation. Stephen Ostermiller is the author of QQwing, and he worked with us to make sure QQwing met our needs by implementing symmetric puzzle generation and merging changes to make it a shared library. QQwing is fairly fast at generating puzzles, so we’ve dropped the store of pregenerated puzzles that Sudoku 3.12 used and now generate puzzles on the fly instead. This means a small (1-10 second) wait if you’re printing dozens of puzzles at once, but it ensures that you no longer get the same puzzle twice, as sometimes occurred in 3.12.

If you noticed from the screenshot, QQwing often uses more interesting symmetries than our old generator did. For the most part, I think this is exciting — symmetric puzzles are intended to be artistic — but I’m interested in comments from players on whether we should disable some of the symmetry options QQwing provides if they’re too flashy. We also need feedback on whether the difficulty levels are set appropriately; I have a suspicion that QQwing’s difficulty rating may not be as refined as our old one (when it was working properly), but I could be completely wrong: we really need player feedback to be sure.

A few features from Sudoku 3.12 did not survive the redesign, or changed significantly. Highlighter mode is now always active and uses a subtle gray instead of rainbow colors. I’m considering making it a preference in 3.16 and turning it off by default, since it’s primarily helpful for keyboard users and seems to get in the way when playing with a mouse. The old notes are now restricted to digits in the top row of the cell, and you set them by right-clicking in a square. (The Ctrl+digit shortcuts will still work.) This feels a lot better, but we need to figure out how to make notes more discoverable to users.  Most notably, the Track Additions feature is completely gone, the victim of our desire to actually ship this update. If you used Track Additions and want it back, we’d really appreciate comments in Bug #731640. Implementation help would be even better. We’d also like to bring back the hint feature, which we removed because the hints in 3.12 were only useful when an easy move exists, and not very helpful in a tough position. Needless to say, we’re definitely open to feedback on all of these changes.

Other Games

We received a Lights Off bug report that the seven-segment display at the bottom of the screen was difficult to read, and didn’t clearly indicate that it corresponded to the current level. With the magic of GtkHeaderBar, we were able to remove it. The result:

Screenshot from 2014-10-17 18:34:59
3.12
Screenshot from 2014-10-17 18:31:37
3.14

Robots was our final game (from the historical gnome-games package, so discounting Aisleriot) with a GNOME 2 menu bar. No longer:

Screenshot from 2014-10-17 18:36:36
3.12
Screenshot from 2014-10-17 18:42:33
3.14

It doesn’t look as slick as Mines or Sudoku, but it’s still a nice modernization.

I think that’s enough screenshots for one blog post, but I’ll also mention that Swell Foop has switched to using the dark theme (which blends in better with its background), Klotski grew a header bar (so now all of the historical gnome-games have a header bar as well), and Chess will now prompt the player at the first opportunity to claim a draw, allowing us to remove the confusing Claim Draw menu item and also the gear menu with it. (It’s been replaced by a Resign button.)

Easier Easy Modes

The computer player in Four-in-a-row used to be pratically impossible to defeat, even on level one. Nikhar Agrawal wrote a new artificial intelligence for this game as part of his Google Summer of Code project, so now it’s actually possible to win at connect four. And beginning with Iagno 3.14.1, the computer player is much easier to beat when set to level one (the default). Our games are supposed to be simple to play, and it’s not fun when the easiest difficulty level is overwhelming.

Teaser

There have also been plenty of smaller improvements to other games. In particular, Arnaud Bonatti has fixed several Iagno and Sudoku bugs, and improved the window layouts for several of our games. He also wrote a new game that will appear in GNOME 3.16.  But that has nothing to do with 3.14, so I can’t show you that just yet, now can I? For now, I will just say that it will prominently feature the Internet’s favorite animal.

Happy gaming!

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A Blog

Oh my, it’s a new GNOME blog. I’ll initially be using this space to show off some of the new features we have in GNOME 3.14. Stay tuned…