2008-02-18

S English (EU)   Flyingsim prototype 3 progress  -  Categories: Software  -  @ 13:35:44

The third prototype to flyingsim.com is being worked on and is available at http://flyingsim.com/prototype/3.

It features another simulated flight from Liverpool to Milas Bodrum and uses a real flight plan as basis. All flight data is fetched from ICAO in the DAFIF format and is now using the planned architecture shown in the image below.

Architecture

2008-01-17

S English (EU)   Twitter  -  Categories: Gadgets  -  @ 15:15:49

I've started what is commonly known as micro blogging on Twitter. You can follow me at https://twitter.com/dagfinn_parnas.

Note to self: Evaluate to put Twitter feed on blog

Note to future self: Already done. See top of page

2007-12-18

S English (EU)   Last.fm integration from Ampache and Squeezebox  -  Categories: Gadgets  -  @ 20:39:03

I've just setup a Last.fm account and implemented integration from my Ampache installation at http://mp3.elsewhat.com and my Squeezebox.

You can find my Last.fm account/user at http://www.last.fm/user/DrElsewhat. Feel free to connect to me

It will be interesting to see if Last.FM will make me discover some new exciting artists


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2007-12-07

S English (EU)   Simple brute force password attack on Excel workbooks  -  Categories: Software  -  @ 15:36:21

Recently I received a mail with an excel sheet attached, and the following text:

"On a bus there are 7 kids.
Each of them have 7 backpacks
In each backpack there are 7 large cats
Each large cat has seven kittens
Each cat has 4 legs

Question: How many legs are there on the bus 

The number of legs is the password to open the excel file"

This made me think of writing a brute force attack that increaments a number by one in an infinite loop and using the Visual basic Excel API try to open the file with that password.

And it was actually rather simple as you can see below

To run the program, do the following:
1. Create a new file bruteforce_excel_pwd.vbs with the following content

Option Explicit
On Error Resume Next
Dim objExcel
Set objExcel = WScript.CreateObject("Excel.Application")
objExcel.visible=False
 
Dim count
count=0
Dim bFound
bFound=False
 
Dim objNetwork
Dim objStdOut
Set objNetwork = Wscript.CreateObject("Wscript.Network")
Set objStdOut = WScript.StdOut
 
Dim args
set args = WScript.Arguments
if args.Count <> 1 then
   WScript.Echo "Usage: CScript bruteforce_excel_pwd.vbs <path to excel file>"
   WScript.Quit 1
end if
 
Dim xlsFile
xlsFile=args.Item(0)
objStdOut.WriteLine "Excel file:" & xlsFile

While Not bFound
 objStdOut.WriteLine "Testing solution " & count 
 objExcel.Workbooks.Open xlsFile, , , , count & ""
 
 If Err.Number >  0 then 
  rem objStdOut.WriteLine Err.Description & Err.Number
  Err.Clear
 Else
  bFound=true
  objStdOut.WriteLine "Solved difficult mathematical problem with solution:" & count
 End If
 
 count=count+1
Wend

2. Copy the excel file and the bruteforce_excel_pwd.vbs file in the same folder (this helps increase the speed for some reason)

3. Open a command prompt by clicking Start menu in Windows and selecting run... Then enter cmd

4. Navigate to the folder you placed the excel file and bruteforce_excel_pwd.vbs file using cd <dir>

5. Run cscript bruteforce_excel_pwd.vbs <excel file name>

My computer can attempt 170 keys per second, so it is not really useful when you know nothing of the password. It would for example in average use over 10 days to find a combination of maximum 6 characters
(((26^6) / 170) * seconds) / 2 = 10.5159237 days


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2007-03-22

S English (EU)   Addictive planar graph puzzle  -  Categories: News  -  @ 07:18:18

Through digg I recently discovered an addictive planar graph puzzle at http://www.planarity.net.

Each level starts with a growing number of vertexes (nodes) which have a set of edges to other vertexes (1-4 seems to be normal). Your goal is to make sure no edges cross path. Wikipedia has some technical information about planar graps

It starts out pretty small and nice, but at the later levels it is quite complicated. Below level 12 is shown before and after solving it. Very interesting to see how your mind adapts and find patterns in order to solve the puzzle.

Planar graph level 12 Start

Planar graph level 12 End