Remote SSH using Back To My Mac

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One of the less well publicised features of Apple’s iCloud service is Back To My Mac.

This service provides a private IPv6 network which you can use to securely connect all your Mac hosts.

To use BTMM you will need to upgrade all your Macs to OS X Lion and sign them all into the same Apple iCloud account. You will also need your unique BTMM account number.

When you are signed into iCloud you can discover your BTMM account number as follows:

$ dns-sd -E
Looking for recommended registration domains:
Timestamp     Recommended Registration domain
12:07:46.550  Added     (More)               local
12:07:46.550  Added                          icloud.com
                                             - > btmm
                                             - - > members
                                             - - - > 123456789

The final line shows your individual BTMM account number.

For example, if you Computer Name (set in System Preferences > Sharing) is mymac and your BTMM account number is 123456789, then the fully qualified domain name of the host is mymac.123456789.members.btmm.icloud.com.

If you have spaces in your Computer Name then replace them with dashes, e.g. “My Mac” becomes the hostname my-mac.

To test connectivity to your remote host use ping6, e.g.

ping6 mymac.123456789.members.btmm.icloud.com

To list all the SSH enabled hosts on your domain:

dns-sd -B _ssh._tcp

You would SSH into your host using this command:

ssh -2 -6 username@mymac.123456789.members.btmm.icloud.com

Note that you will only be able to communicate with the other hosts on your iCloud private network if the Mac you are using is also signed into the same iCloud account.

You can also use an open SSH connection to access your non-Apple hosts on your internal network by using SSH port forwarding. This tunnels the destination traffic over the BTMM private network via your remote Mac.

For example, if you have a web server running on a host with the IP address 192.168.1.2 then you can use this SSH command to set-up a forwarded port:

ssh -2 -6 -L 8080:192.168.1.2:80 username@mymac.123456789.members.btmm.icloud.com

To access the remote host from your local machine you would go to http://127.0.0.1:8080/

Uninstall Symantec Enterprise Vault Client on Mac OS

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Since Symantec doesn’t provide an uninstaller script for their Enterprise Vault Client, here’s how to remove it on Mac OS.

Open a Terminal window and execute these commands:

launchctl unload -D user /Library/LaunchAgents/com.symantec.ev.daemon.plist
sudo killall -m  "Enterprise Vault .*"
sudo rm -f /Library/LaunchAgents/com.symantec.ev.daemon.plist
sudo rm -rf "/Library/PreferencePanes/Enterprise Vault.prefPane"
sudo rm -rf "/Library/Application Support/Symantec Enterprise Vault"
rm -rf "~/Library/Application Support/Symantec Enterprise Vault"

Holidaylight Robbery

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Center Parcs marketed itself as the original “British holiday the weather can’t spoil”, but they are doing a pretty good job of spoiling holidays without the weather.

Consider the pricing matrix above. What could possibly cause the astronomical price hike in that one specific week? It’s the half-term school holidays.

I do expect to have to pay a premium because of the school holidays. 50% would seem acceptable to me, but a 300% price hike? Even Michael O’Leary would find that hard to defend!

I have studied Economics, I know all about supply and demand and differential pricing. The prices above do not seem to be not reflecting a shortage of supply however. There is no “only x remaining” in the middle week, so I can only deduce that the huge cost spike is a deliberate and cynical manipulation of the pricing model to take account of school holidays.

While some families might bite the bullet and succumb to the exorbitant price tag, their stay must be tinged with bitterness at being financially exploited in this way. If you are being ripped-off so badly before you even arrive, what more do they have in store for you while you’re there? It’s not the kind of business that I would like to spend my money with.

Center Parcs certainly doesn’t have a monopoly on this exploitative behaviour. It’s an industry-wide phenomenon which has been allowed to run wild.

The blatant profiteering at the expense of parents and teachers is discrimination on a massive scale. Isn’t it time the UK Government acted on these unfair business practices?

Android 4.0 turns GET into POST

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After upgrading to Android 4.0 ‘Ice Cream Sandwich‘ I found that some of my existing apps weren’t working as expected.

On deeper investigation I discovered the culprit. When installed on devices running ICS the apps made HTTP POST requests when they were programmed to be GET requests.

It appears that Google have subtly changed the working of the java.net.HttpURLConnection class – without telling anyone!

The Android package reference documentation has this little gem tucked away in the class overview notes:

HTTP Methods

HttpURLConnection uses the GET method by default. It will use POST if setDoOutput(true) has been called. Other HTTP methods (OPTIONS, HEAD, PUT, DELETE and TRACE) can be used with setRequestMethod(String).

My now non-functional Android apps did indeed call setDoOutput, but in Android releases prior to 4.0 this did not result in the HTTP method being changed from a GET to a POST.

Even explicitly setting setRequestMethod("GET") does not fix the problem. Basically if you don’t want your app to POST, you must not call setDoOutput.

The apps have not changed, there is nothing referencing this change in the API Differences Report, but the behaviour is definitely different in Android 4.0.

Could this be what’s behind the flurry of Android Market app updates for ICS-related fixes?

Dropbox & EncFS on OS X Lion

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I previously wrote about a method for creating a super-secure filesystem using Dropbox’s cloud storage.

After updating to Mac OS Lion I struggled to get the MacFusion GUI to work and so I wrote an application to automate the mounting and unmounting of the EncFS filesystem.

I also took the opportunity to switch from the now abandoned MacFUSE to Fuse4X, which is a properly maintained fork of MacFUSE started in June 2011.

The install procedure is much simpler than before, you install Fuse4X and EncFS, but instead of using the MacFusion GUI you just call my script instead.

To the instructions!

First download and install Fuse4X and a version of EncFS which uses the Fuse4X APIs. Thanks to Simone Lehmann for providing an EncFS Mac installer at http://www.lisanet.de/?p=128 (also mirrored here).

To create a new encrypted volume (stored locally at first to prevent the EncFS key from being synchronised with Dropbox):

encfs ~/Desktop/_Encrypted ~/Documents/_DropSec

Answer ‘yes’ when prompted to create the new folders and choose ‘p’ for pre-configured paranoia mode (256-bit AES encryption). Enter a secure EncFS password when prompted and you’re done.

Now the filesystem has been created we can deal with securing the key.

umount ~/Documents/_DropSec
mkdir ~/.keys
mv ~/Desktop/_Encrypted/.encfs6.xml ~/.keys/dropsec.xml

The commands above move your key from the EncFS filesystem into a hidden folder in your (local) home directory

Now move the entire ~/Desktop/_Encrypted folder (minus your key) into your Dropbox:

mv ~/Desktop/_Encrypted ~/Dropbox/

Finally download my DropSec application and copy it to your Applications folder.

The first time you run DropSec it will prompt you for your EncFS password which it stores in your local login keychain. The password must match the secure password you set in a previous step.

To mount or unmount the encrypted filesystem simply run the DropSec app. For convenience copy it to your Mac OS Dock for quick access.

Tips for cyclists

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Wearing team colours won’t help you ride like Lance Armstrong, any more than putting on a Man United shirt helps you score goals like Wayne Rooney.

It doesn’t matter who you are or what shape you are in – Lycra is not flattering.

Try lifting your head and sniffing the air instead of the bum crack of the cyclist in front.

Having a cycle that weighs less than a bag of sugar won’t help you win le Tour de France.

Fitting a bell will not interfere with the delicate balance of your cycle.

Pavements are meant for pedestrians.

The UK road network is designed for motor vehicles. If you’re going to use it, abide by the rules.

You know those mysterious boxes with red, amber & green lights? Those are traffic lights. Yes, they apply to you too.

Ride in single file on narrow or busy roads and when riding round bends – like the Highway Code instructs you to.

Since you don’t pay Road Tax or have third-party insurance, get out of my way and use the cycle lanes provided.

Public urination is just that. Calling it a “nature break” doesn’t make it any less disgusting and unsanitary.

Take a car if you want to get somewhere quickly without dripping and stinking of sweat.

I’ll leave you with some considered words from someone I’d never heard of before, but for whom I now feel a close affinity – ESPN commentator Tony Kornheiser.

The last time I looked, the roads were made for automobiles…We’re going to be dominated as if this was Beijing by hundreds of thousands of bicyclists…They all wear … my God … with the little water bottle in the back and the stupid hats and their shiny shorts. They are the same disgusting poseurs that in the middle of a snowstorm come out with cross-country skiing on your block. Run ‘em down…Let them use the right, I’m okay with that. I don’t take my car and ride on the sidewalk because I understand that’s not for my car… Why do these people think that these roads were built for bicycles? … They dare you to run them down.

Satellite TV Upgrade Pack?

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The image above is of a jiffy bag that I received in the post this morning.

Being the wary soul that I am, I was immediately suspicious of this package and so inspected it in more detail.

On face value it looks like an official upgrade pack, perhaps from the satellite broadcaster BSkyB? They do occasionally update their viewing cards and so this seemed quite likely.

But on closer inspection I spotted this small-print:

This package contains promotional material from Virgin Media.

I should have guessed as much when I saw that it was addressed to “The Occupier”. This is a well known tactic of Virgin Media to stop their tat being classed as addressed mail and thereby sidestepping the Mailing Preference Service. I’ve never been able to shake off Virgin’s junk mail, I don’t think anyone ever has.

So this package isn’t anything to do with satellite TV at all. It’s yet more pointless unsolicited junk mail from Virgin Media.

A quick bit of web searching and I found a recent Advertising Standards Authority (ASA) Adjudication on Virgin Media Limited.

The conclusion of the adjudication was that Virgin Media had breached two Committee of Advertising Practice codes and that their advert was misleading.

The ASA noted the text “This package contains promotional material from Virgin Media” was considerably smaller than the main copy on the front of the envelope, was at 90 degrees to all the other text on the envelope, and was located far to the right of the envelope under a series of reference numbers.  We considered that the combination of those factors meant it was likely to be overlooked by consumers and that consumers would therefore be unaware that the envelope contained promotional material from Virgin.

We noted Virgin considered the text “Please see inside for Legal Stuff” indicated that the envelope contained promotional material.  However, we considered that that statement was unlikely to be understood by consumers to mean that the mailing was a marketing communication. We considered, for instance, that the placement of that statement, combined with the likelihood that consumers might not have noticed the text which identified that the mailing was from Virgin, could lead consumers to think that the envelope contained legal and other information, and possibly technology, from their satellite TV provider which would result in an upgrade to their existing satellite TV package.

We considered the ad did not make clear that it was a marketing communication, or that it was sent with commercial intent, and concluded that it breached the Code.

The ASA adjudication is dated 2nd November 2011, but I received this package today on 16th November 2011.

It looks like Virgin have subtly altered the layout on the envelope and moved the line about it being promotional material, but this doesn’t make it any less misleading.

A complaint to the ASA has been submitted. Let’s see what happens this time!

Update!

The ASA response:

Further to my letter of 21 December, we have now received a response from Virgin Media. They have assured us they will not use the ad or similar ads again and that in future mailings they will make clear that they are marketing communications. We consider that this will resolve the complaint without referring the matter to the ASA Council, and will consequently be closing our file.

In a formal investigation, if the ASA Council decides that an ad is in breach of the Code, the advertisers are told to withdraw or amend it. Because Virgin Media has already assured us that the advertising you complained about has been withdrawn, we consider there is little to be gained from continuing with a formal investigation, which would achieve the same outcome.

So a small victory for the small guy then.