Update Nov 2017 there now appears to be official documentation.

While looking at a bug in Umbraco, I could not find, anywhere, a definitive description of the YouTube oembed service – so I’ve decided to write one up. Please let me know if you find other features, or if this has drifted away from accuracy. Or if I’ve just been incompetent and not found the official API documentation somehow.

The YouTube oembed service is available at https://www.youtube.com/oembed (note https, not http as otherwise advertised, it’s 301 redirected).

Standard parameters (as per oembed specification)

• url – the URL of the resource
• maxwidth – the maximum width. The thumbnail size is not affected. This value, if bigger than the usual video return, will increase the size of the video.
• maxheight – the maximum height. The thumbnail size is not affected. This value will only decrease the size of the video.
• format – “json” or “xml”

Non-standard parameters

• scheme – you can set this to “https” to make the returned code work on a site served over https. (Why the returned data doesn’t use “//youtube.com”, I don’t know…)

Removing SSL 2.0, Adding TLS 1.1 and TLS 1.2 in on Windows 2008 (IIS 7.5)

By default, Windows 2008 R2 has some shonky SSL settings – it enables SSL 2.0, which is broken, and it doesn’t enable the best protocols – TLS 1.1 and 1.2. To disable and enable things as we want them, we need to go digging around in the registry.

I’ve compiled these instructions from this article details how to disable SSL 2.0 and this article with broken instructions on how to enable TLS 1.1 and TLS 1.2. As this process requires a server restart I thought this single article might keep downtime low.

IIS SSL capabilities are controlled at the system level, so this should work for other IIS versions as well.

Editing the registry

The keys we need to alter are in: HKey_Local_Machine\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols

There should already by a key (folder) called SSL 2.0, you need to create two new folders called TLS 1.1 and TLS 1.2.

Underneath these protocol keys, you need another set of keys (folders) called Client and Server. These may already exist for SSL 2.0.

Underneath the Server keys, we need to put a DWORD called Enabled and set it to 0 for SSL 2.0 and to 0xffffffff (Use the hexadecimal radio button) for the two TLS items.

Underneath the Client keys, we need to put a DWORD called DisabledByDefault and set it to 0 for TLS and ffffffff for SSL 2.0.

Reset the server and then check the protocols it now allows – everything should be sorted as more secure – check it using this tool.

Tool that sorts it out for you

If you’re happy installing random tools on your server, then you can get IIS Crypto to make the changes for you.

If I’ve got anything wrong, or you think I could be clearer, please drop me a comment below here! Thanks.

Splitting/cutting an m4a file

Every so often I have an audio file that I need to break into sections. With more files coming as .m4a, the various GUI options I’d used before no longer work.

Now I’ve found a method that doesn’t need a GUI – use command line ffmpeg to split these files. The basics I found from a superuser question that was automatically breaking a file into smaller pieces. Taking out the Ruby sections, here’s the useful snippet.

 ffmpeg -ss 1:01:42 -i c:\Data\temp\in.m4a -vn -c copy -t 1:00:00 out.m4a 

1. The first time (1:01:42) is the start time of the cut.
2. -vn means that only the audio stream is copied from the file.
3. The second time (1:00:00) is the duration of the cut. It can be longer then the length of the whole file.

Note that the cut is made at the nearest point to that time that the stream allows, so it might be a little out.

Clearing DNS caches

When making DNS changes it can often take a while for various DNS caches between yourself and the source to clear. I’ve often found that the last ones to change are the ones in the last few metres – from your router to your browser.

You’ll need to find the one upstream that’s incorrect and fix “backwards” from that – i.e. check your Windows DNS cache first, then work towards the browser.

Browser

According to OpenDNS, all browsers will clear their DNS cache if you use their clear cache functionality, but that’ll take out a lot more than DNS.

Chrome: Visit chrome://net-internals/#dns and press the ‘clear hosts cache’ button. You can also see what IP it’s talking to on this page.

Firefox: Close and re-open browser should do it – otherwise there’s a fiddly method involving about:config. When I’ve tried out the plug-ins I’ll add a suggestion, but if you’ve using one let me know in the comments and I’ll update this.

IE: no independent DNS cache.

Local Windows machine

At command prompt: ipconfig /flushdns

Use ping to see if you’re resolving OK.

Windows Server (if acting as DNS cache)

At command prompt: dnscommand <servername> /clearcache

Checklist for large file upload issues in IIS7 / .net

I had an issue with large(-ish) file uploads yesterday and thought I should write up the things I needed to change, as it’s one of those things that I have to do from time to time and I invariably forget all of the settings.

This is in .net Integrated Pipeline mode – it’s different for Classic ASP.

The following two settings allow files of up to 200MB (value is in kilobytes) taking up to 10 minutes (value is in seconds). See documentation for this

<system.web>
<httpRuntime executionTimeout="600" maxRequestLength="204800" />
</system.web>


You will also need to alter this setting (value is in bytes this time – see the documentation). It defaults to about 30Mb.

<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="209715200" />
</requestFiltering>
</security>
</system.webServer>


My understanding is that these settings are usually kept quite low to avoid DoS attacks, and if you’re admin for a large site you should consider moving your uploads to a different server or at least a different application / application pool.

If there’s anything missing from these settings, or some nuance I’m missing, please let me know in the comments.

Visited Oxford Hackspace, first project idea: stand-up desk

Although I’ve been meaning to get down to see the Oxford Hackspace studio for a while, I only managed to go last Wednesday to help out (a tiny, tiny bit) with improving their space. Since then, I’ve been trying to think of a project – something practical that I can try to build. To prove that I’m not yet in the maker headspace, I have on a separate thread been thinking about replacing my home desk with a stand-up desk for better health and the like. Only today did 1 + 1 = 2, and I realised this might be a good first project. Taking a quick look around the web, it doesn’t seem like a particularly complex task although there are a few constraints for what I would like to do:

• I can’t screw anything into the wall – at least, not the kind of screws that would be needed to make a really secure desk.
• I’d like to avoid just hacking IKEA pieces together – seems to be a common theme out there, but it increases the cost and, well, I want to try something from scratch.

There are other things that would be nice but I think I ought to keep out of my first project – perhaps I can go for a V2.0 if I actually build this thing: adjustable height, cable gutter, proper monitor mounts and bracket for holding PC. Will post progress on this blog, if I ever make any.

If you have a recent HTC phone then you probably find that there’s often a big black bar across the bottom of your screen, taking up space you spent hard cash on getting.

In a way, HTC were doing the right thing and the apps were supposed to change so that it wasn’t necessary. Other manufacturers kept the menu button, though, and so the apps never got changed.

To fix on One X: Slide down the top menu and get to Settings (in top right). Select Display, gestures & buttons, then Recent apps button, then you can choose to either change that button to be the menu button (“Press for menu, press and hold for recent apps”) or you can hold it down to get to the menu (“Press for recent apps, press and hold for menu”).

By the way, if you want a screenshot on an HTC phone, hold the power button and press Home. It should let you know that it’s worked as well.

Cooper Temple Clause – Damage single cover

Unable to find a decent scan of this single when ripping it, I thought I’d put my scans online. Enjoy.

Codility challenge “Psi 2012”

This one more challenging than the last – failed in the initial hour, but knew that I had a bug in my “maze-solving” code. Second go, got the silver within about 20 minutes.