Are you tired of waiting for ages to build large C++ projects like WebKit? Slow headers are generally the problem. Your C++ source code file #includes a few headers, all those headers #include more, and those headers #include more, and more, and more, and since it’s C++ a bunch of these headers contain lots of complex templates to slow down things even more. Not fun.
It turns out that much of the time spent building large C++ projects is effectively spent parsing the same headers again and again, over, and over, and over, and over, and over….
There are three possible solutions to this problem:
Shred your CPU and buy a new one that’s twice as fast.
Use C++ modules: import instead of #include. This will soon become the best solution, but it’s not standardized yet. For WebKit’s purposes, we can’t use it until it works the same in MSVCC, Clang, and three-year-old versions of GCC. So it’ll be quite a while before we’re able to take advantage of modules.
Use unified builds (sometimes called unity builds).
WebKit has adopted unified builds. This work was done by Keith Miller, from Apple. Thanks, Keith! (If you’ve built WebKit before, you’ll probably want to say that again: thanks, Keith!)
For a release build of WebKitGTK+, on my desktop, our build times used to look like this:
real 62m49.535s
user 407m56.558s
sys 62m17.166s
That was taken using WebKitGTK+ 2.17.90; build times with any 2.18 release would be similar. Now, with trunk (or WebKitGTK+ 2.20, which will be very similar), our build times look like this:
real 33m36.435s
user 214m9.971s
sys 29m55.811s
Twice as fast.
The approach is pretty simple: instead of telling the compiler to build the original C++ source code files that developers see, we instead tell the compiler to build unified source files that look like this:
Since files are included only once per translation unit, we now have to parse the same headers only once for each unified source file, rather than for each individual original source file, and we get a dramatic build speedup. It’s pretty terrible, yet extremely effective.
Now, how many original C++ files should you #include in each unified source file? To get the fastest clean build time, you would want to #include all of your C++ source files in one, that way the compiler sees each header only once. (Meson can do this for you automatically!) But that causes two problems. First, you have to make sure none of the files throughout your entire codebase use conflicting variable names, since the static keyword and anonymous namespaces no longer work to restrict your definitions to a single file. That’s impractical in a large project like WebKit. Second, because there’s now only one file passed to the compiler, incremental builds now take as long as clean builds, which is not fun if you are a WebKit developer and actually need to make changes to it. Unifying more files together will always make incremental builds slower. After some experimentation, Apple determined that, for WebKit, the optimal number of files to include together is roughly eight. At this point, there’s not yet much negative impact on incremental builds, and past here there are diminishing returns in clean build improvement.
In WebKit’s implementation, the files to bundle together are computed automatically at build time using CMake black magic. Adding a new file to the build can change how the files are bundled together, potentially causing build errors in different files if there are symbol clashes. But this is usually easy to fix, because only files from the same directory are bundled together, so random unrelated files will never be built together. The bundles are always the same for everyone building the same version of WebKit, so you won’t see random build failures; only developers who are adding new files will ever have to deal with name conflicts.
To significantly reduce name conflicts, we now limit the scope of using statements. That is, stuff like this:
using namespace JavaScriptCore;
namespace WebCore {
//...
}
Has been changed to this:
namespace WebCore {
using namespace JavaScriptCore;
// ...
}
Some files need to be excluded due to unsolvable name clashes. For example, files that include X11 headers, which contain lots of unnamespaced symbols that conflict with WebCore symbols, don’t really have any chance. But only a few files should need to be excluded, so this does not have much impact on build time. We’ve also opted to not unify most of the GLib API layer, so that we can continue to use conventional GObject names in our implementation, but again, the impact of not unifying a few files is minimal.
We still have some room for further performance improvement, because some significant parts of the build are still not unified, including most of the WebKit layer on top. But I suspect developers who have to regularly build WebKit will already be quite pleased.
So, how do you write a shebang for a Python program? Let’s first set aside the python2/python3 issue and focus on whether to use env. Which of the following is correct?
#!/usr/bin/env python
#!/usr/bin/python
The first option seems to work in all environments, but it is banned in popular distros like Fedora (and I believe also Debian, but I can’t find a reference for this). Using env in shebangs is dangerous because it can result in system packages using non-system versions of python. python is used in so many places throughout modern systems, it’s not hard to see how using #!/usr/bin/env in an important package could badly bork users’ operating systems if they install a custom version of python in /usr/local. Don’t do this.
The second option is broken too, because it doesn’t work in BSD environments. E.g. in FreeBSD, python is installed in /usr/local/bin. So FreeBSD contributors have been upstreaming patches to convert #!/usr/bin/python shebangs to #!/usr/bin/env python. Meanwhile, Fedora has begun automatically rewriting #!/usr/bin/env python to #!/usr/bin/python, but with a warning that this is temporary and that use of #!/usr/bin/env python will eventually become a fatal error causing package builds to fail.
So obviously there’s no way to write a shebang that will work for both major Linux distros and major BSDs. #!/usr/bin/env python seems to work today, but it’s subtly very dangerous. Lovely. I don’t even know what to recommend to upstream projects.
Next problem: python2 versus python3. By now, we should all be well-aware of PEP 394. PEP 394 says you should never write a shebang like this:
#!/usr/bin/env python
#!/usr/bin/python
unless your python script is compatible with both python2 and python3, because you don’t know what version you’re getting. Your python script is almost certainly not compatible with both python2 and python3 (and if you think it is, it’s probably somehow broken, because I doubt you regularly test it with both). Instead, you should write the shebang like this:
#!/usr/bin/env python2
#!/usr/bin/python2
#!/usr/bin/env python3
#!/usr/bin/python3
This works as long as you only care about Linux and BSDs. It doesn’t work on macOS, which provides /usr/bin/python and /usr/bin/python2.7, but still no /usr/bin/python2 symlink, even though it’s now been six years since PEP 394. It’s hard to understate how frustrating this is.
So let’s say you are WebKit, and need to write a python script that will be truly cross-platform. How do you do it? WebKit’s scripts are only needed (a) during the build process or (b) by developers, so we get a pass on the first problem: using /usr/bin/env should be OK, because the scripts should never be installed as part of the OS. Using #!/usr/bin/env python — which is actually what we currently do — is unacceptable, because our scripts are python2 and that’s broken on Arch, and some of our developers use that. Using #!/usr/bin/env python2 would be dead on arrival, because that doesn’t work on macOS. Seems like the option that works for everyone is #!/usr/bin/env python2.7. Then we just have to hope that the Python community sticks to its promise to never release a python2.8 (which seems likely).
If you use macOS, the best way to use a recent development snapshot of WebKit is surely Safari Technology Preview. But until now, there’s been no good way to do so on Linux, short of running a development distribution like Fedora Rawhide.
Enter Epiphany Technology Preview. This is a nightly build of Epiphany, on top of the latest development release of WebKitGTK+, running on the GNOME master Flatpak runtime. The target audience is anyone who wants to assist with Epiphany development by testing the latest code and reporting bugs, so I’ve added the download link to Epiphany’s development page.
Since it uses Flatpak, there are no host dependencies asides from Flatpak itself, so it should work on any system that can run Flatpak. Thanks to the Flatpak sandbox, it’s far more secure than the version of Epiphany provided by your operating system. And of course, you enjoy automatic updates from GNOME Software or any software center that supports Flatpak.
Enjoy!
(P.S. If you want to use the latest stable version instead, with all the benefits provided by Flatpak, get that here.)
The latest stable version of Epiphany is now available on Flathub. Download it here. You should be able to double click the flatpakref to install it in GNOME Software, if you use any modern GNOME operating system not named Ubuntu. But, in my experience, GNOME Software is extremely buggy, and it often as not does not work for me. If you have trouble, you can use the command line:
This has actually been available for quite a while now, but I’ve delayed announcing it because some things needed to be fixed to work well under Flatpak. It’s good now.
I’ve also added a download link to Epiphany’s webpage, so that you can actually, you know, download and install the software. That’s a useful thing to be able to do!
Benefits
The obvious benefit of Flatpak is that you get the latest stable version of Epiphany (currently 3.26.5) and WebKitGTK+ (currently 2.18.3), no matter which version is shipped in your operating system.
The other major benefit of Flatpak is that the browser is protected by Flatpak’s top-class bubblewrap sandbox. This is, of course, a UI process sandbox, which is different from the sandboxing model used in other browsers, where individual browser tabs are sandboxed from each other. In theory, the bubblewrap sandbox should be harder to escape than the sandboxes used in other major browsers, because the attack surface is much smaller: other browsers are vulnerable to attack whenever IPC messages are sent between the web process and the UI process. Such vulnerabilities are mitigated by a UI process sandbox. The disadvantage of this approach is that tabs are not sandboxed from each other, as they would be with a web process sandbox, so it’s easier for a compromised tab to do bad things to your other tabs. I’m not sure which approach is better, but clearly either way is much better than having no sandbox at all. (I still hope to have a web process sandbox working for use when WebKit is used outside of Flatpak, but that’s not close to being ready yet.)
Problems
Now, there are a couple of loose ends. We do not yet have desktop notifications working under Flatpak, and we also don’t block the screen from turning off when you’re watching fullscreen video, so you’ll have to wiggle your mouse every five minutes or so when you’re watching YouTube to keep the lights on. These should not be too hard to fix; I’ll try to get them both working soon. Also, drag and drop does not work. I’m not nearly brave enough to try fixing that, though, so you’ll just have to live without drag and drop if you use the Flatpak version.
Also, unfortunately the stable GNOME runtimes do not receive regular updates. So while you get the latest version of Epiphany, most everything else will be older. This is not good. I try to make sure that WebKit gets updated, so you’ll have all the latest security updates there, but everything else is generally stuck at older versions. For example, the 3.26 runtime uses, for the most part, whatever software versions were current at the time of the 3.26.1 release, and any updates newer than that are just not included. That’s a shame, but the GNOME release team does not maintain GNOME’s Flatpak runtimes: we have three other other redundant places to store the same build information (JHBuild, GNOME Continuous, BuildStream) that we need to take care of, and adding yet another is not going to fly. Hopefully this situation will change soon, though, since we should be able to use BuildStream to replace the current JSON manifest that’s used to generate the Flatpak runtimes and keep everything up to date automatically. In the meantime, this is a problem to be aware of.
Epiphany 3.26 is, unfortunately, not going to be packed with cool new features like 3.24 was. We’ve just been too busy working on improving WebKit this cycle. But there is one cool new thing: Firefox Sync support. You can sync bookmarks, history, passwords, and open tabs with other Epiphany instances and as well as both desktop and mobile Firefox. This is already enabled in 3.25.90. Just go to the Sync tab in Preferences and sign in or create your Firefox account there. Please test it out and report bugs now, so we can quash problems you find before 3.26.0 rather than after.
Some thank yous are in order:
Thanks to Gabriel Ivascu, for writing all the code.
Thanks to Google and Igalia for sponsoring Gabriel’s work.
Thanks to Mozilla. This project would never have been possible if Mozilla had not carefully written its terms of service to allow such use.
In my original blog post On WebKit Security Updates, I identified three separate problems affecting WebKit users on Linux:
Distributions were not providing updates for WebKitGTK+. This was the main focus of that post.
Distributions were shipping a insecure compatibility package for old, unmaintained WebKitGTK+ 2.4 (“WebKit1”).
Distributions were shipping QtWebKit, which was also unmaintained and insecure.
Let’s review these problems one at a time.
Distributions Are Updating WebKitGTK+
Nowadays, most major community distributions are providing regular WebKitGTK+ updates, so this is no longer a problem for the vast majority of Linux users. If you’re using a supported version of Ubuntu (except Ubuntu 14.04), Fedora, or most other mainstream distributions, then you are good to go.
My main concern here is still Debian, but there are reasons to be optimistic. It’s too soon to say what Debian’s policy will be going forward, but I am encouraged that it broke freeze just before the Stretch release to update from WebKitGTK+ 2.14 to 2.16.3. Debian is slow and conservative and so has not yet updated to 2.16.6, which is sad because 2.16.3 is affected by a bug that causes crashes on a huge number of websites, but my understanding is it is likely to be updated in the near future. I’m not sure if Debian will update to 2.18 or not. We’ll have to wait and see.
openSUSE is another holdout. The latest stable version of openSUSE Leap, 42.3, is currently shipping WebKitGTK+ 2.12.5. That is disappointing.
Most other major distributions seem to be current.
Distributions Are Removing WebKitGTK+ 2.4
WebKitGTK+ 2.4 (often informally referred to as “WebKit1”) was the next problem. Tons of desktop applications depended on this old, insecure version of WebKitGTK+, and due to large API changes, upgrading applications was not going to be easy. But this transition is going much smoother and much faster than I expected. Several distributions, including Debian, Fedora, and Arch, have recently removed their compatibility packages. There will be no WebKitGTK+ 2.4 in Debian 10 (Buster) or Fedora 27 (scheduled for release this October). Most noteworthy applications have either ported to modern WebKitGTK+, or have configure flags to disable use of WebKitGTK+. In some cases, such as GnuCash in Fedora, WebKitGTK+ 2.4 is being bundled as part of the application build process. But more often, applications that have not yet ported simply no longer work or have been removed from these distributions.
Soon, users will no longer need to worry that a huge amount of WebKitGTK+ applications are not receiving security updates. That leaves one more problem….
QtWebKit is Back
Upstream QtWebKit has not been receiving security updates for the past four years or thereabouts, since it was abandoned by the Qt project. That is still the status quo for most distributions, but Arch and Fedora have recently switched to Konstantin Tokarev’s fork of QtWebKit, which is based on WebKitGTK+ 2.12. (Thank you Konstantin!) If you are using any supported version of Fedora, you should already have been switched to this fork. I am hopeful that the fork will be rebased on WebKitGTK+ 2.16 or 2.18 in the near future, to bring it current on security updates, but in the meantime, being a year and a half behind is an awful lot better than being four years behind. Now that Arch and Fedora have led the way, other distributions should find little trouble in making the switch to Konstantin’s QtWebKit. It would be a disservice to users to continue shipping the upstream version.
So That’s Cool
Things are better. Some distributions, notably Arch and Fedora, have resolved all of the above problems (or will in the very near future). Yay!
I’ll keep this update short. Debian has decided to ship the latest version of WebKitGTK+, 2.16.3, in its upcoming Stretch release. Since Debian was the last major distribution holding out on providing WebKit security updates, this is a big deal. Huge thanks to Jeremy Bicha for making this possible.
The bad news is that Debian is still considering whether or not to provide periodic security updates after the release, so there might not be any. But maybe there will be. We will have to wait and see. At least releasing with the latest version is a big step in the right direction.
Are you using a sad web browser that integrates poorly with GNOME or elementary OS? Was your sad browser’s GNOME integration theme broken for most of the past year? Does that make you feel sad? Do you wish you were using an awesome web browser that feels right at home in your chosen desktop instead? If so, Epiphany 3.24 might be right for you. It will make you awesome. (Ask your doctor before switching to a new web browser. Results not guaranteed. May cause severe Internet addiction. Some content unsuitable for minors.)
Epiphany was already awesome before, but it just keeps getting better. Let’s look at some of the most-noticeable new features in Epiphany 3.24.
You Can Load Webpages!
Yeah that’s a great start, right? But seriously: some people had trouble with this before, because it was not at all clear how to get to Epiphany’s address bar. If you were in the know, you knew all you had to do was click on the title box, then the address bar would appear. But if you weren’t in the know, you could be stuck. I made the executive decision that the title box would have to go unless we could find a way to solve the discoverability problem, and wound up following through on removing it. Now the address bar is always there at the top of the screen, just like in all those sad browsers. This is without a doubt our biggest user interface change:
Discover GNOME 3! Discover the address bar!
You Can Set a Homepage!
A very small subset of users have complained that Epiphany did not allow setting a homepage, something we removed several years back since it felt pretty outdated. While I’m confident that not many people want this, there’s not really any good reason not to allow it — it’s not like it’s a huge amount of code to maintain or anything — so you can now set a homepage in the preferences dialog, thanks to some work by Carlos García Campos and myself. Retro! Carlos has even added a home icon to the header bar, which appears when you have a homepage set. I honestly still don’t understand why having a homepage is useful, but I hope this allows a wider audience to enjoy Epiphany.
New Bookmarks Interface
There is now a new star icon in the address bar for bookmarking pages, and another new icon for viewing bookmarks. Iulian Radu gutted our old bookmarks system as part of his Google Summer of Code project last year, replacing our old and seriously-broken bookmarks dialog with something much, much nicer. (He also successfully completed a major refactoring of non-bookmarks code as part of his project. Thanks Iulian!) Take a look:
Manage Tons of Tabs
One of our biggest complaints was that it’s hard to manage a large number of tabs. I spent a few hours throwing together the cheapest-possible solution, and the result is actually pretty decent:
Firefox has an equivalent feature, but Chrome does not. Ours is not perfect, since unfortunately the menu is not scrollable, so it still fails if there is a sufficiently-huge number of tabs. (This is actually surprisingly-difficult to fix while keeping the menu a popover, so I’m considering switching it to a traditional non-popover menu as a workaround. Help welcome.) But it works great up until the point where the popover is too big to fit on your monitor.
Note that the New Tab button has been moved to the right side of the header bar when there is only one tab open, so it has less distance to travel to appear in the tab bar when there are multiple open tabs.
Improved Tracking Protection
I modified our adblocker — which has been enabled by default for years — to subscribe to the EasyPrivacy filters provided by EasyList. You can disable it in preferences if you need to, but I haven’t noticed any problems caused by it, so it’s enabled by default, not just in incognito mode. The goal is to compete with Firefox’s Disconnect feature. How well does it work compared to Disconnect? I have no clue! But EasyPrivacy felt like the natural solution, since we already have an adblocker that supports EasyList filters.
Disclaimer: tracking protection on the Web is probably a losing battle, and you absolutely must use the Tor Browser Bundle if you really need anonymity. (And no, configuring Epiphany to use Tor is not clever, it’s very dumb.) But EasyPrivacy will at least make life harder for trackers.
Insecure Password Form Warning
Recently, Firefox and Chrome have started displaying security warnings on webpages that contain password forms but do not use HTTPS. Now, we do too:
I had a hard time selecting the text to use for the warning. I wanted to convey the near-certainty that the insecure communication is being intercepted, but I wound up using the word “cybercriminal” when it’s probably more likely that your password is being gobbled up by various governments. Feel free to suggest changes for 3.26 in the comments.
New Search Engine Manager
Cedric Le Moigne spent a huge amount of time gutting our smart bookmarks code — which allowed adding custom search engines to the address bar dropdown in a convoluted manner that involved creating a bookmark and manually adding %s into its URL — and replacing it with an actual real search engine manager that’s much nicer than trying to add a search engine via bookmarks. Even better, you no longer have to drop down to the command line in order to change the default search engine to something other than DuckDuckGo, Google, or Bing. Yay!
New Icon
Jakub Steiner and Lapo Calamandrei created a great new high-resolution app icon for Epiphany, which makes its debut in 3.24. Take a look.
WebKitGTK+ 2.16
WebKitGTK+ 2.16 improvements are not really an Epiphany 3.24 feature, since users of older versions of Epiphany can and must upgrade to WebKitGTK+ 2.16 as well, but it contains some big improvements that affect Epiphany. (For example, Žan Doberšek landed an important fix for JavaScript garbage collection that has resulted in massive memory reductions in long-running web processes.) But sometimes WebKit improvements are necessary for implementing new Epiphany features. That was true this cycle more than ever. For example:
Carlos García added a new ephemeral mode API to WebKitGTK+, and modified Epiphany to use it in order to make incognito mode much more stable and robust, avoiding corner cases where your browsing data could be leaked on disk.
Carlos García also added a new website data API to WebKitGTK+, and modified Epiphany to use it in the clear data dialog and cookies dialog. There are no user-visible changes in the cookies dialog, but the clear data dialog now exposes HTTP disk cache, HTML local storage, WebSQL, IndexedDB, and offline web application cache. In particular, local storage and the two databases can be thought of as “supercookies”: methods of storing arbitrary data on your computer for tracking purposes, which persist even when you clear your cookies. Unfortunately it’s still not possible to protect against this tracking, but at least you can view and delete it all now, which is not possible in Chrome or Firefox.
Sergio Villar Senin added new API to WebKitGTK+ to improve form detection, and modified Epiphany to use it so that it can now remember passwords on more websites. There’s still room for improvement here, but it’s a big step forward.
I added new API to WebKitGTK+ to improve how we handle giving websites permission to display notifications, and hooked it up in Epiphany. This fixes notification requests appearing inappropriately on websites like the https://riot.im/app/.
Notice the pattern? When there’s something we need to do in Epiphany that requires changes in WebKit, we make it happen. This is a lot more work, but it’s better for both Epiphany and WebKit in the long run. Read more about WebKitGTK+ 2.16 on Carlos García’s blog.
Future Features
Unfortunately, a couple exciting Epiphany features we were working on did not make the cut for Epiphany 3.24. The first is Firefox Sync support. This was developed by Gabriel Ivașcu during his Google Summer of Code project last year, and it’s working fairly well, but there are still a few problems. First, our current Firefox Sync code is only able to sync bookmarks, but we really want it to sync much more before releasing the feature: history and open tabs at the least. Also, although it uses Mozilla’s sync server (please thank Mozilla for their quite liberal terms of service allowing this!), it’s not actually compatible with Firefox. You can sync your Epiphany bookmarks between different Epiphany browser instances using your Firefox account, which is great, but we expect users will be quite confused that they do not sync with your Firefox bookmarks, which are stored separately. Some things, like preferences, will never be possible to sync with Firefox, but we can surely share bookmarks. Gabriel is currently working to address these issues while participating in the Igalia Coding Experience program, and we’re hopeful that sync support will be ready for prime time in Epiphany 3.26.
Also missing is HTTPS Everywhere support. It’s mostly working properly, thanks to lots of hard work from Daniel Brendle (grindhold) who created the libhttpseverywhere library we use, but it breaks a few websites and is not really robust yet, so we need more time to get this properly integrated into Epiphany. The goal is to make sure outdated HTTPS Everywhere rulesets do not break websites by falling back automatically to use of plain, insecure HTTP when a load fails. This will be much less secure than upstream HTTPS Everywhere, but websites that care about security ought to be redirecting users to HTTPS automatically (and also enabling HSTS). Our use of HTTPS Everywhere will just be to gain a quick layer of protection against passive attackers. Otherwise, we would not be able to enable it by default, since the HTTPS Everywhere rulesets are just not reliable enough. Expect HTTPS Everywhere to land for Epiphany 3.26.
Help Out
Are you a computer programmer? Found something less-than-perfect about Epiphany? We’re open for contributions, and would really appreciate it if you would try to fix that bug or add that feature instead of slinking back to using a less-awesome web browser. One frequently-requested feature is support for extensions. This is probably not going to happen anytime soon — we’d like to support WebExtensions, but that would be a huge effort — but if there’s some extension you miss from a sadder browser, ask if we’d allow building it into Epiphany as a regular feature. Replacements for popular extensions like NoScript and Greasemonkey would certainly be welcome.
Not a computer programmer? You can still help by reporting bugs on GNOME Bugzilla. If you have a crash to report, learn how to generate a good-quality stack trace so that we can try to fix it. I’ve credited many programmers for their work on Epiphany 3.24 up above, but programming work only gets us so far if we don’t know about bugs. I want to give a shout-out here to Hussam Al-Tayeb, who regularly built the latest code over the course of the 3.24 development cycle and found lots of problems for us to fix. This release would be much less awesome if not for his testing.
One year ago, I wrote a blog post about WebKit security updates that attracted a fair amount of attention at the time. For a full understanding of the situation, you really have to read the whole thing, but the most important point was that, while WebKitGTK+ — one of the two WebKit ports present in Linux distributions — was regularly releasing upstream security updates, most Linux distributions were ignoring the updates, leaving users vulnerable to various security bugs, mainly of the remote code execution variety. At the time of that blog post, only Arch Linux and Fedora were regularly releasing WebKitGTK+ updates, and Fedora had only very recently begun doing so comprehensively.
Progress report!
So how have things changed in the past year? The best way to see this is to look at the versions of WebKitGTK+ in currently-supported distributions. The latest version of WebKitGTK+ is 2.14.3, which fixes 13 known security issues present in 2.14.2. Do users of the most popular Linux operating systems have the fixes?
Fedora users are good. Both Fedora 24 and Fedora 25 have the latest version, 2.14.3.
If you use Arch, you know you always have the latest stuff.
Ubuntu users rejoice: 2.14.3 updates have been released to users of both Ubuntu 16.04 and 16.10. I’m very pleased that Ubuntu has decided to take my advice and make an exception to its usual stable release update policy to ensure its users have a secure version of WebKit. I can’t give Ubuntu an A grade here because the updates tend to lag behind upstream by several months, but slow updates are much better than no updates, so this is undoubtedly a huge improvement. (Anyway, it’s hardly a bad idea to be cautious when releasing a big update with high regression potential, as is unfortunately the case with even stable WebKit updates.) But if you use the still-supported Ubuntu 14.04 or 12.04, be aware that these versions of Ubuntu cannot ever update WebKit, as it would require a switch to WebKit2, a major API change.
Debian does not update WebKit as a matter of policy. The latest release, Debian 8.7, is still shipping WebKitGTK+ 2.6.2. I count 184 known vulnerabilities affecting it, though that’s an overcount as we did not exclude some Mac-specific security issues from the 2015 security advisories. (Shipping ancient WebKit is not just a security problem, but a user experience problem too. Actually attempting to browse the web with WebKitGTK+ 2.6.2 is quite painful due to bugs that were fixed years ago, so please don’t try to pretend it’s “stable.”) Note that a secure version of WebKitGTK+ is available for those in the know via the backports repository, but this does no good for users who trust Debian to provide them with security updates by default without requiring difficult configuration. Debian testing users also currently have the latest 2.14.3, but you will need to switch to Debian unstable to get security updates for the foreseeable future, as testing is about to freeze.
For openSUSE users, only Tumbleweed has the latest version of WebKit. The current stable release, Leap 42.2, ships with WebKitGTK+ 2.12.5, which is coincidentally affected by exactly 42 known vulnerabilities. (I swear I am not making this up.) The previous stable release, Leap 42.1, originally released with WebKitGTK+ 2.8.5 and later updated to 2.10.7, but never past that. It is affected by 65 known vulnerabilities. (Note: I have to disclose that I told openSUSE I’d try to help out with that update, but never actually did. Sorry!) openSUSE has it a bit harder than other distros because it has decided to use SUSE Linux Enterprise as the source for its GCC package, meaning it’s stuck on GCC 4.8 for the foreseeable future, while WebKit requires GCC 4.9. Still, this is only a build-time requirement; it’s not as if it would be impossible to build with Clang instead, or a custom version of GCC. I would expect WebKit updates to be provided to both currently-supported Leap releases.
Gentoo has the latest version of WebKitGTK+, but only in testing. The latest version marked stable is 2.12.5, so this is a serious problem if you’re following Gentoo’s stable channel.
Mageia has been updating WebKit and released a couple security advisories for Mageia 5, but it seems to be stuck on 2.12.4, which is disappointing, especially since 2.12.5 is a fairly small update. The problem here does not seem to be lack of upstream release monitoring, but rather lack of manpower to prepare the updates, which is a typical problem for small distros.
The enterprise distros from Red Hat, Oracle, and SUSE do not provide any WebKit security updates. They suffer from the same problem as Ubuntu’s old LTS releases: the WebKit2 API change makes updating impossible. See my previous blog post if you want to learn more about that. (SUSE actually does have WebKitGTK+ 2.12.5 as well, but… yeah, 42.)
So results are clearly mixed. Some distros are clearly doing well, and others are struggling, and Debian is Debian. Still, the situation on the whole seems to be much better than it was one year ago. Most importantly, Ubuntu’s decision to start updating WebKitGTK+ means the vast majority of Linux users are now receiving updates. Thanks Ubuntu!
To arrive at the above vulnerability totals, I just counted up the CVEs listed in WebKitGTK+ Security Advisories, so please do double-check my counting if you want. The upstream security advisories themselves are worth mentioning, as we have only been releasing these for two years now, and the first year was pretty rough when we lost our original security contact at Apple shortly after releasing the first advisory: you can see there were only two advisories in all of 2015, and the second one was huge as a result of that. But 2016 seems to have gone decently well. WebKitGTK+ has normally been releasing most security fixes even before Apple does, though the actual advisories and a few remaining fixes normally lag behind Apple by roughly a month or so. Big thanks to my colleagues at Igalia who handle this work.
Challenges ahead
There are still some pretty big problems remaining!
First of all, the distributions that still aren’t releasing regular WebKit updates should start doing so.
Next, we have to do something about QtWebKit, the other big WebKit port for Linux, which stopped receiving security updates in 2013 after the Qt developers decided to abandon the project. The good news is that Konstantin Tokarev has been working on a QtWebKit fork based on WebKitGTK+ 2.12, which is almost (but not quite yet) ready for use in distributions. I hope we are able to switch to use his project as the new upstream for QtWebKit in Fedora 26, and I’d encourage other distros to follow along. WebKitGTK+ 2.12 does still suffer from those 42 vulnerabilities, but this will be a big improvement nevertheless and an important stepping stone for a subsequent release based on the latest version of WebKitGTK+. (Yes, QtWebKit will be a downstream of WebKitGTK+. No, it will not use GTK+. It will work out fine!)
It’s also time to get rid of the old WebKitGTK+ 2.4 (“WebKit1”), which all distributions currently parallel-install alongside modern WebKitGTK+ (“WebKit2”). It’s very unfortunate that a large number of applications still depend on WebKitGTK+ 2.4 — I count 41 such packages in Fedora — but this old version of WebKit is affected by over 200 known vulnerabilities and really has to go sooner rather than later. We’ve agreed to remove WebKitGTK+ 2.4 and its dependencies from Fedora rawhide right after Fedora 26 is branched next month, so they will no longer be present in Fedora 27 (targeted for release in November). That’s bad for you if you use any of the affected applications, but fortunately most of the remaining unported applications are not very important or well-known; the most notable ones that are unlikely to be ported in time are GnuCash (which won’t make our deadline) and Empathy (which is ported in git master, but is not currently in a releasable state; help wanted!). I encourage other distributions to follow our lead here in setting a deadline for removal. The alternative is to leave WebKitGTK+ 2.4 around until no more applications are using it. Distros that opt for this approach should be prepared to be stuck with it for the next 10 years or so, as the remaining applications are realistically not likely to be ported so long as zombie WebKitGTK+ 2.4 remains available.
These are surmountable problems, but they require action by downstream distributions. No doubt some distributions will be more successful than others, but hopefully many distributions will be able to fix these problems in 2017. We shall see!
One of the advantages of maintaining a web browser based on WebKit, like Epiphany, is that the vast majority of complexity is contained within WebKit. Epiphany itself doesn’t have any code for HTML parsing or rendering, multimedia playback, or JavaScript execution, or anything else that’s actually related to displaying web pages: all of the hard stuff is handled by WebKit. That means almost all of the security problems exist in WebKit’s code and not Epiphany’s code. While WebKit has been affected by over 200 CVEs in the past two years, and those issues do affect Epiphany, I believe nobody has reported a security issue in Epiphany’s code during that time. I’m sure a large part of that is simply because only the bad guys are looking, but the attack surface really is much, much smaller than that of WebKit. To my knowledge, the last time we fixed a security issue that affected a stable version of Epiphany was 2014.
Well that streak has unfortunately ended; you need to make sure to update to Epiphany 3.22.6, 3.20.7, or 3.18.11 as soon as possible (or Epiphany 3.23.5 if you’re testing our unstable series). If your distribution is not already preparing an update, insist that it do so. I’m not planning to discuss the embarrassing issue here — you can check the bug report if you’re interested — but rather on why I made new releases on three different branches. That’s quite unlike how we handle WebKitGTK+ updates! Distributions must always update to the very latest version of WebKitGTK+, as it is not practical to backport dozens of WebKit security fixes to older versions of WebKit. This is rarely a problem, because WebKitGTK+ has a strict policy to dictate when it’s acceptable to require new versions of runtime dependencies, designed to ensure roughly three years of WebKit updates without the need to upgrade any of its dependencies. But new major versions of Epiphany are usually incompatible with older releases of system libraries like GTK+, so it’s not practical or expected for distributions to update to new major versions.
My current working policy is to support three stable branches at once: the latest stable release (currently Epiphany 3.22), the previous stable release (currently Epiphany 3.20), and an LTS branch defined by whatever’s currently in Ubuntu LTS and elementary OS (currently Epiphany 3.18). It was nice of elementary OS to make Epiphany its default web browser, and I would hardly want to make it difficult for its users to receive updates.
Three branches can be annoying at times, and it’s a lot more than is typical for a GNOME application, but a web browser is not a typical application. For better or for worse, the majority of our users are going to be stuck on Epiphany 3.18 for a long time, and it would be a shame to leave them completely without updates. That said, the 3.18 and 3.20 branches are very stable and only getting bugfixes and occasional releases for the most serious issues. In contrast, I try to backport all significant bugfixes to the 3.22 branch and do a new release every month or thereabouts.
So that’s why I just released another update for Epiphany 3.18, which was originally released in September 2015. Compare this to the long-term support policies of Chrome (which supports only the latest version of the browser, and only for six weeks) or Firefox (which provides nine months of support for an ESR release), and I think we compare quite favorably. (A stable WebKit series like 2.14 is only supported for six months, but that’s comparable to Firefox.) Not bad?
