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Top-bar beehive design

Here’s a Google Sketchup design for a simple top-bar beehive.

Some pics:


Notes:

Only 2 measurements really matter in the design of a top-bar beehive: the angle of the side panels (70 degrees) & the width of the top bars 35mm. They both pertain to bee behavior and this design has them both optimized. From what I gather, other measures are quite forgiving.

This design is simple & well researched, I do not know yet how it will fare in practice, more to come on that.

Material:

All you’ll need as far as wood is concerned is a couple of 2x12x16 and a 3/4″ sheet of plywood:

Lastly, all units are in millimeters but based on standard lumber sizes available at the hardware store.

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Robin & the Eagle from the White Mountain

My wife & I have just released our first children story! As an app for iOS devices. This is the achievement of what started innocently as a small project reading stories to mp3. Months of work, huge investment for the art, it feels great to have put this project behind us.

My only hope now is that the market gods will treat us well.

Here it is in all its glory:
English version: http://itunes.apple.com/us/app/id480065432
Hungarian version: http://itunes.apple.com/us/app/id480080998
French version: http://itunes.apple.com/us/app/id480175112

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Poor man’s 2FA: a simpler 2-factor authentication mechanism for SSH

The problem with PAM based 2FA:
  • PAM does not get called when the SSH daemon does key based authentication. So your 2FA there only works with password authentication. This might be something you want but maybe not.
  • A PAM module based solution to 2FA is harder to implement
The solution: Poor man’s 2FA!

It is possible to add the ForceCommand directive to your sshd_config. Like the name suggests it simply runs a command after authentication and before the shell is spawned. This is a good spot to add an extra check, say another factor for authentication.

The code:
#!/bin/bash
trap "echo "I'm sorry Dave. I'm afraid I can't do that."; sleep 1 ; kill -9 $PPID ; exit 1" 2 20
code=`od -a -A n /dev/urandom | head -2 | tr -d ' ' | tr -d 'n' | sed 's/[^a-zA-Z0-9]//g' | awk '{print substr($0,1,5)}'`
echo -e "Subject:$code\nFrom:root@server <root@server.com>\n2FA code in subject" | sendmail phone_number@carrier.com
read input
if [ $code = $input ];
then
    `awk -F: '($1 == $LOGNAME) { print $7 }' /etc/passwd`
else
kill -9 $PPID
fi

That’s it really, save this to an executable file, replace the obvious variables and ForceCommand its ass.