Escaping the Adobe AIR sandbox

Adobe’s Mike Chambers has an article and sample code for calling native operating system APIs from AIR applications, which use the Flash runtime outside the browser.

I took a look at the native side of the code, which is written in C# and compiled smoothly in Visual Studio 2008. The concept is simple. Instead of launching an AIR application directly, you start the “Command Proxy” application. The Command Proxy launches the AIR application, passing a port number and optionally an authorization string. Next, the Command Proxy creates a TCP socket which listens on the specified port. The AIR application can then use its socket API to send commands to the Command Proxy, which is outside the AIR sandbox.

It’s a neat idea though Microsoft’s Scott Barnes gave the design a C- on security grounds. He clarified his point thus:

The communication channel between the command proxy and AIR application looks like a potential vulnerability. One of the things application developers should worry about with security is insecure cross-process communication mechanisms hanging around on someone’s machine. For example if a process listens on a named pipe, and that named pipe has no ACLs and no validation of inbound communication, the process is vulnerable to all kinds of attacks when garbage is sent down the pipe. In the example on using the command proxy how do you secure it so that it doesn’t turn into a general purpose process launcher?

Barnes has an obvious incentive to cast doubt on AIR solutions (he’s a Microsoft RIA Silverlight evangelist), but nevertheless this is a good debate to have. How difficult is it to do this in a secure manner? It is also interesting to note the opening remarks in Chambers’ post:

Two of the most requested features for Adobe AIR have been the ability to launch native executables from an AIR application, and the ability to integrate native libraries into an AIR application. Unfortunately, neither feature will be included in Adobe AIR 1.0.

This is really one feature: access to native code. I remain somewhat perplexed by AIR in this respect. Is the inability to call native code a security feature, or a way of promoting cross-platform purity, or simply a feature on the to-do list? I don’t think it is really a security feature, since AIR applications have the same access to the file system as the user. This means they can execute native code, just not immediately. For example, an AIR app could download an executable and pop it into the user’s startup folder on Windows. That being the case, why not follow Java’s lead and provide a clean mechanism for calling native code? Adobe could add the usual obligatory warnings about how this breaks cross-platform compatibility and so on.

Van Morrison fan site under attack by Web Sheriff

A popular Van Morrison fan site has received a letter demanding that the site be closed. Here’s an extract from a post by the site’s founder.

This site began as a personal hobby about 12 years ago, an expression of my own enthusiasm for Mr. Morrison’s music, which I hoped to share with other fans…The tone is respectful; there is no advertising on the site — never has been; there is no facilitation or encouragement of piracy; in fact the site has long contained a statement to the effect that bootlegging was “not condoned”. Any fair-minded visitor to the site is likely to have concluded that the site promoted, and helped fans to better understand, Mr. Morrison’s work.

Despite this history, despite all of these facts, on Monday, January 14 I received a message from someone working for an outfit named WebSheriff, who claimed to represent Van Morrison and Exile Productions. According to the message, this website stands accused of (and I quote): “numerous infringements of our said clients’ IP [ed: Intellectual Property] rights including, but not limited to, the infringement of copyrights, trademarks, goodwill, performers rights, moral rights, publicity rights, privacy rights and the wholesale facilitation of further, numerous infringements by third parties on a grand scale (such as providing access to bootleg / unauthorised / illegal recordings)” end quote. I’ll repeat for emphasis: “wholesale facilitation of”; “on a grand scale”.

It looks like this is the Web Sheriff in question:

It was through the acute need and demand for the protection of on-line rights against infringements and abuse, that Web Sheriff was set-up by its parent company, Entertainment Law Associates. Web Sheriff is one of the few specialist, companies that operate in the field of internet policing and has become a market-leader through offering truly across-the-board solutions, from on-line legal enforcement to high tech anti-piracy.

There is quite possibly some degree of copyright infringement on the site in question; but attacking your biggest fans, who are doing unpaid promotion, is silly. The site is well-regarded and was apparently featured in the BBC’s “Best of the Web” guide, among other recommendations.

The site owner received this unwelcome missive on January 14th. It was also sent to his employer, a university, presumably because the site was hosted on its servers. He took the site offline as “an expression of goodwill” and pending receipt of guidelines for making the site legal, which he was told to expect within 48 hours. They did not appear, and he decided to reopen the site, but at a new home, so as not to involve the university any further.

No doubt this controversy will get the Unofficial Van Morrison website many new visitors to enjoy these “grand scale” infringements.

Update: It looks as if the site is offline again.

Changing the motherboard or storage controller underneath Windows XP and Vista

Can you change your motherboard without reinstalling your operating system? Sometimes you can, sometimes you can’t. Last week I decided it was time to upgrade the desktop PC on which I do much of my work. The old motherboard was nearly three years old – an Intel 915PBL, which I purchased in order to run 64-bit Windows XP. At the time I was indignant because the BIOS swallowed a full 1GB of my RAM.

Technology has moved on, so I purchased an Intel DP35DP board (I still have a high regard for Intel’s manufacturing quality) and a core 2 quad Q6600 processor. I appreciate that this is now not quite leading edge, but it has been out long enough to be a reasonable price. So I backed up my files, performed the motherboard surgery, and switched on.

For sure I was not depending on being able to continue without reinstalling the operating system. This is not a supported procedure. On the other hand, I figured it would be interesting to try; and so it proved. After all, I’ve had enough trouble installing things like Visual Studio 6 and Adobe Creative Suite 3, not to want to repeat the experience.

My desktop PC is a little complex. There are three SATA drives and three Windows installations. One is Window XP x64 (the original installation); one is Windows XP Pro 32-bit; and one is Windows Vista Pro 32-bit. I work mostly in Vista. Initially, none of these worked with my new motherboard. Attempting to boot Vista caused an immediate restart, and both XP installations blue screened.

The key problem is the storage controller. Typically, you will get a STOP 0x0000007B if your new motherboard has a different storage controller than the old one. The above link is to a Microsoft knowledgebase article for Windows XP, and you will see that it suggests two solutions. One is to perform an in-place upgrade, also known as a repair install. This is where you reinstall Windows to the same location, and it sorts out the device drivers and other critical problems without blowing away your documents or applications. The other is to do a new clean install – not really a fix, more an admission of failure.

Vista no longer supports repair installs. More on this later.

Note that the main issue is getting Windows to boot. Once it does boot, you will likely get all sorts of device errors, but these can usually be fixed. Fixing stuff if you cannot boot at all is more challenging.

Health warning

Since you are still reading, I assume you are in one of two categories. Either you are inquisitive about the innards of Windows; or you have a problem because Windows will not boot. Here’s my disclaimer. The steps I describe below are not supported, guaranteed ways to rescue Windows; and if you experiment with a working Windows installation, you could break it. If you try any of them, it’s at your own risk.

The AHCI problem

Intel’s new boards usually have three settings for the SATA controller. One is IDE, which is best for legacy compatibility. One is AHCI (Advanced Host Controller Interface), which is best for features. The third is RAID, which combines AHCI and a sort of hardware RAID (sometimes known as fakeRAID because it isn’t really hardware RAID, but never mind). Intel boards used to default to IDE, but this one defaulted to RAID which is now Intel’s recommendation. Even if you only have one drive, you can easily set up RAID later if you start with that setting. If you plan to install Linux, you might be better off with plain AHCI.

Repair Install on XP x64

For my first experiment, I tried a repair install on XP x64. It did not go well. There was some minor awkwardness. Intel supplies the crucial RAID drivers on antiquated media called floppy disk. You need this during Windows setup (press F6). However, the motherboard has no Floppy Disk connector; you have to use USB. Luckily I have a USB external floppy which came with a laptop some years ago, so that bit worked. Unfortunately, the repair install seemed to hang on a screen which said “Installing Devices” and promised to complete in 35 minutes. I left it overnight and it said the same thing in the morning, though it had not technically crashed and who knows, perhaps it would have completed one day.

If you ever hit this issue, read this thread. What you have to do is to restart the machine and press F8 to get the advanced startup options. Timing this may be tricky, since setup configures itself for immediate startup. If you get really stuck, find some way to edit boot.ini to insert a delay. Once you have pressed F8, choose the Debugging mode. The repair install will now complete within a sane time. There’s another solution discussed in the thread I’ve referenced above, which involves identifying which device is causing the hang and then preventing setup from attempting to install it; but the Debugging option worked fine for me.

As it happens, I didn’t discover this fix until later. I got diverted by 32-bit XP.

Fixing 32-bit Windows

After getting stuck on XP x64, I took a look at 32-bit XP. The X64 repair install had mucked up the boot menu; but that’s easy to fix from a recovery console. Being a little discouraged, I decided to try the legacy IDE settings for the SATA controller. Good old XP Pro then started, no hassle, no need for a repair install. It detected various new devices, and I ran the Intel driver utility from the CD that came with the motherboard. I also had to reinstall the NVidia graphics driver. My first success.

First attempt with Vista

Vista on the other hand still would not work. It is less amenable than XP to controller changes; I gather this may be something to do with speeding up the boot process by disabling “unnecessary” drivers. Anyway, it blue-screened irrespective of the setting for the SATA controller. It was then I discovered that Vista has removed the option for a repair install. What you do instead is to boot from the setup CD or DVD and choose the option to “Repair your computer”. Then it runs a Startup Repair wizard which tries to fix your Vista. I tried this on all the SATA settings, and it failed. On the first try it thought it might have succeeded and invited me to restart Windows, but it still blue-screened. On subsequent attempts the wizard made some lengthy disk-checking efforts only to inform me that I had a corrupt volume and should give up.

I’m not impressed with Startup Repair. I think XP’s Repair Install is brilliant, and Vista’s Startup Repair is brain dead. I’ll explain shortly.

You can do a sort-of repair install with Vista by “upgrading” an existing install – but you can only start an upgrade from within the instance of Windows that you want to upgrade. In other words, if you can’t boot then this is not an option. Do NOT do an over-the-top clean install. You will lose all your settings.

At this point I nearly gave up and did a clean install of Vista. I still had the nagging thought that if only I could get Vista to load the right storage controller driver, it would probably start up. So I left it for the moment and went back to 32-bit XP, my success story. I wanted to discover if I could switch to the SATA RAID option without breaking it.

Switching an installed Windows OS to AHCI or RAID

This thought led me to an illuminating discussion. This explains that if you want to switch Windows to use a different storage controller, for which the driver is not installed, you do so by manually copying the driver to system32\drivers; and editing the registry so that Windows can use the new driver when booting. For this to work, you need to know the hardware ID of your controller. This is something like:


One way to find this ID is to clean install a second copy of Windows to a temporary location, and then look at the storage controller properties in device manager. Alternatively you can experiment with some likely values, or try several at once. The discussion I’ve linked provides some reg files which show the critical entries.

This looked interesting, so I followed the steps in the first post of the thread, shut down, then restarted with the BIOS setting changed to AHCI. Success – XP Pro started, and I was able to run Intel’s driver setup to clean up the installation.

Getting more confident now, I found the hardware ID for the RAID controller (the hardware ID changes when you change the BIOS setting) and added that to the registry. The actual driver is the same. Success again – XP now started using the Intel Matrix Storage RAID.

XP was done now, especially as I also discovered the fix for x64 described above. But Vista, the one that mattered to me most, was still broken. Nevertheless, I now had a much better idea of how to fix it.

Offline registry editing

Now is the moment to mention a little-known feature of the Windows registry editor. 99% of the time, you edit the Windows registry from within a running instance of Windows. However, the registry editor has an entry in the File menu called Load Hive. The way this works is not particularly intuitive. You select the root of HKEY_LOCAL_MACHINE, then choose Load Hive and navigate to a registry database file that is not part of the active registry. In my case, the hive I needed to load was SYSTEM, located in System32\Config. You may possibly know this if you have ever had to recover Windows when it will not boot because of registry corruption. When you click OK to load the hive, the registry editor prompts you for a key name. Enter something like “Vista Repair”. The loaded hive then appears as a sub-folder under HKEY_LOCAL_MACHINE.

There is no Save; simply make the edits you want, then select the top level of the loaded hive – eg. “Vista Repair” – and choose File – Unload Hive.

This had to be worth a try. I booted my poorly machine into Windows XP, then went to another machine on the network running Vista. I copied the SYSTEM hive from the broken Vista across the network, made a backup, then loaded it into registry editor. Finally, I manually made the changes pretty much as in the reg file used to migrate XP to a new storage controller, though what I actually did was to pattern the changes on an existing storage controller entry in the working Vista registry. Note that an offline registry has no “Current Control Set” hive. This is actually a runtime link to ControlSet01. So, for offline editing, you edit ControlSet01.

I also made the normal registry fix for enabling AHCI on Vista. Then I unloaded the hive and copied it back to my broken Vista. I also added the actual driver to system32\drivers, of course. In my case the driver is called iastor.sys, from Intel’s floppy disk.

Vista boots

The result was amazing. I restarted the PC with the new motherboard, and instead of a blue screen I got:

Press CTRL+ALT+DELETE to log on

Nothing much to add now. I logged  on, installed various drivers, and everything works. I have a quad core CPU:

and an Intel RAID storage controller:

Vista itself seems fine. It is solid and significantly faster than before, as you would expect.

Thoughts on Vista Startup Repair

Despite my success, I’m not impressed with the Vista Startup Repair. First, why couldn’t Microsoft’s wizard do what I did manually? Second, why has the excellent Repair Install option disappeared from Vista? Vista’s repair and restore options seem to presume that the hardware has not changed; yet I’d have thought a replaced motherboard would be one of the more common scenarios where you would want to repair a Vista installation.

The whole business of changed hardware is something of a dark secret in Windows backup and restore. In an enterprise environment it is not so bad, because you have redundancy, and a single failed machine (server or workstation) should not be a problem. Something like Small Business Server is different, because typically this is a single, business-critical machine. If your 2-year old Small Business Server box disappears in the night, and you purchase a new box and stuff in your backup tapes, it will not necessarily be easy to restore.

Still, I must also credit Windows with considerable resilience once it can find a working storage controller driver. It pretty much sorts itself out after that.

Coming next: a clean install of 64-bit Vista. It makes sense.


Anyone interested in this esoteric topic is also advised to read this article on ArsTechnica and this related thread. Note the advice on removing non-present devices from device manager. There’s also this Microsoft article (non-Vista) which is a variant on the Repair Install. Let me also note the main area of uncertainty regarding repair installs: it may not be safe with regard to recovering a fully patched system. In principle you can re-apply service packs or hotfixes, but what if Windows Update thinks a hotfix has already been applied when in fact it has been undone? It’s a good question and I’m not sure at the moment what the answer is.

The Microsoft article above also makes an interesting point about OEM licenses. If you replace the motherboard with something other than the same model, it is considered a new computer and OEM licenses cannot be transferred.

Sun gets a database manager, but Oracle owns its InnoDB engine

Sun now has a database manager. It’s been a long time coming. Oracle has … Oracle, IBM has DB2, Microsoft has SQL Server; it’s been obvious for years that Sun had a gap to fill. Now Sun has MySQL.

This is interesting to me as I was a relatively early user of the product. I didn’t much like it. It was missing important features like transactions, stored procedures and triggers. I still used it though because of a few appealing characteristics:

  • It was free
  • It was very fast
  • It was lightweight
  • It was the M in LAMP

I should expand slightly on the last of these. The great thing about MySQL was that you did not need to think about installation, PHP drivers, or anything like that. It all came pretty much by default. If you decided that you could not bear MySQL’s limitations, you could use Postgres instead, but it was more effort and less quick.

The ascent of MySQL is a sort of software development parable. Like PHP, MySQL came about from one person’s desire to fix a problem. That person was Michael “Monty” Widenius. He wanted something a little better than mSQL, a popular small database engine at the time:

We once started off with the intention to use mSQL to connect to our own fast low level (ISAM) tables. However, after some testing we came to the conclusion that mSQL was not fast or flexible enough for our needs. This resulted in a new SQL interface to our database but with almost the same API interface as mSQL. This API was chosen to ease porting of third-party code.

Why did MySQL take off when there were better database engines already out there? It was partly to do with the nature of many LAMP applications in the early days. They were often not mission-critical (mine certainly were not), and they were typically weighted towards reading rather than writing data. If you are building a web site, you want pages served as quickly as possible. MySQL did that, and without consuming too many resources. Many database engines were better, but not many were faster.

MySQL today has grown up in many ways, though transactions are still an issue. To use them you need to use an alternate back-end storage engine, either InnoDB or BDB. BDB is deprecated, and InnoDB is included by default in current releases of MySQL. InnoDB is owned by Oracle, which could prove interesting given how this deal changes the dynamics of Sun’s relationship with Oracle, though both MySQL and InnoDB are open source and published under the GPL. Will Sun try to find an alternative to InnoDB?

While I agree with most commentators that this is a good move for Sun, it’s worth noting that MySQL was not originally designed to meet Enterprise needs, which is where most of the money is.

Update: as Barry Carr comments below, there is a planned replacement for InnoDB called Falcon.

How to debug into .NET Framework source code

Shawn Burke has posted the steps needed to step through the .NET Framework source when debugging your application.

Good news for a couple of reasons. The first is the most obvious: if you are getting surprising or perplexing behaviour, you now have a better chance of working out why.

Second, and perhaps more important, this makes it easier to submit bug reports or feature requests to Microsoft along the lines of “why does your code do this when it could or should do that“?

All going well, this should improve quality. For example, the .NET Framework library code is huge, and I’ve heard it muttered that there is considerable duplication within it. Separate teams working on different parts of the library may solve the same problem with different code, causing bloat and possibly inconsistency. Opening up the library to public scrutiny makes it more likely that issues like this will get fixed.

Daniel Moth has a screencast.

My Mac day: Jobs of the print variety

While Steve Jobs was extolling the merits of thin laptops (I prefer small to thin, but tastes differ), I was in the depths of /var/log fixing a print issue with a friend’s Mac Mini and her LexMark printer.

It was almost the same issue as described here by Ted Landau, though I got there a bit quicker thanks in part to his post. Symptom: you hit print, but get a printer stopped message. You can restart the print job but it immediately stops again.

It wasn’t obvious what was wrong, especially as the printer passed all its self-tests including printing its test page. There were no clues in the OS X GUI. The USB cable was OK.

I was helped by familiarity with other Unix-like operating systems. The first thing to look for is an error log, and in this case there was one sensibly located at /var/log/cups. It told me that a cartridge change had been detected and the new cartridge was not yet aligned, a condition that the driver treated as a fatal error. At this point the user confessed that the black cartridge was new, and that the printer had not worked since. However, she had run the alignment utility, several times in fact. Getting warm.

In Landau’s case, there was old ink in the cartridge bay preventing a good connection. In my case, the cartridge itself was faulty; a replacement worked fine. The deceptive aspect is that the cartridge had ink and could print; it just could not register its alignment for some reason.

Landau has a little rant about this:

Neither Lexmark’s nor Apple’s software were able to get the relevant error message to pop up anywhere where a user would be likely to see it. Having no message at all in the Printer Queue and having the key message buried in a cups log file is not the ideal situation.

His underlying point is correct. The cuddly GUI hides huge complexity. Windows is the same of course.

The point I will make is that both operating systems do a poor job of surfacing error logs. In Windows most logs are accessible through the Event Viewer GUI, but only advanced users find this. When a hard drive fails, you sometimes find that the event log (presuming you recover it sufficiently to read it) has been reporting bad blocks for ages, but the user was unaware.

In this case I suspect the real issue is Lexmark’s poor driver, which could have reported this problem in a sane manner.

How did we fix computers pre-Google?

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Burton Group slams ODF, praises OOXML

Fighting talk from Burton Group on ODF vs OOXML:

ODF is insufficient for complex real-world enterprise requirements, and it is indirectly controlled by Sun Microsystems, despite also being an ISO standard. It’s possible that IBM, Novell, and other vendors may be able to put ODF on a more customer-oriented trajectory in the future and more completely integrate it with the W3C content model, but for now ODF should be seen as more of an anti-Microsoft political statement than an objective technology selection.

You can download the free report here, though I found I had to exaggerate my annual revenue to get past the compulsory fields on the registration form.

Wonder what Becta thinks about this?

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Does Google rot your brain?

According to Prof Brabazon (via Danny Sullivan) it does:

She said: “I want students to sit down and read. It’s not the same when you read it online. I want them to experience the pages and the print as much as the digitisation and the pixels. Both are fine but I want them to have both, not one or the other, not a cheap solution.”

She will be giving a lecture on the issue, called Google Is White Bread For The Mind, at the Sallis Benney Theatre in Grand Parade, Brighton, on Wednesday at 6.30pm.

I’d like to hear more detail of her argument before passing judgment. I’ll observe though that there seem to be a couple of things confused here. One is about print versus online, as in the quotation above. The other is about how to research online:

Too many students don’t use their own brains enough. We need to bring back the important values of research and analysis.

She said thousands of students across the country, including those at the universities of Brighton and Sussex, were churning out banal and mediocre work by using what search engines provided them.

Here, I agree. It is easy to get mediocre or simply wrong answers from a quick Google search. It’s especially dangerous because of the internet’s echo effect. Misinformation can spread rapidly when it is something people want to believe. This then looks superficially like corroboration. For example, a poorly-researched paper on DRM in Vista was widely treated as authoritative because the story, that Microsoft broke Vista for the sake of DRM, was so compelling. See here for more on this. I am not making a point about DRM in Vista here. I am making the point that arriving at the truth takes a great deal more work than simply reading the first article you find, even if it is widely quoted.

This implies a need to educating students in how to do research, rather than banning online sources. I agree though that a trip to the library is also important. Not everything is in Google’s index, yet.

Great anecdote in the Economist about the decline of the CD

The Economist has a report on change in the music industry, which kicks off with this anecdote:

IN 2006 EMI, the world’s fourth-biggest recorded-music company, invited some teenagers into its headquarters in London to talk to its top managers about their listening habits. At the end of the session the EMI bosses thanked them for their comments and told them to help themselves to a big pile of CDs sitting on a table. But none of the teens took any of the CDs, even though they were free. “That was the moment we realised the game was completely up,” says a person who was there.