Well, this is getting rather fun, but quite time consuming.
My alarm clock is ticking away and my sleep time dwindling as I type, but I just don;t feel the urge to sleep yet. I've got a talk/demo I'm preparing for Wednesday for CSLU and it is getting bigger and bigger workload wise.
I'm hoping this translates to geeky hacky fun though.
The talk is on languages and paradigms, so I'm introducing a load of languages (8 I think, off the top of my head), describing the basic constructs, and then getting the room to build a "99 bottles" program using 3 of the given languages.
The fun, but time consuming, part of this is that I'm building cheat sheets for each language. Done the first one tonight, and it was for C, so quite detailed. Hoping I can cut/paste a lot of stuff for similar languages, and hoping I don't have to fall back to a stock one. It is nice to make a custom one for the group, and also cements my own knowledge, especially of the languages I am unfamiliar with.
After the 99 bottles task, I am going to set some slightly longer challenges which can be made easier using certain paradigms. I have an OO one, which can be done procedurally. It's based around a game scenario. For procedural I will probably do a processing batch type thing. For functional I need to do a little more research.
With the department allowing me to set up a load of VMs for everyone to use too, this should be pretty fun on Wednesday ... so long as I get it all finished in time!
Monday, 22 November 2010
Monday, 27 September 2010
Conference season
September time is conference time it seems and I am currently at UbiComp2010. The UCSE2010 workshop convened yesterday which was very successful and discussion driven.
One of the main technical company sponsor was in the workshop, Autodesk, and gave an interesting talk on how they are opening their whole building's Building Information Model(BIM) to the internet. I would point you to Digital 210 King for more information.
2 weeks ago I was at IPIN, which was hosted for the first time at ETH Zurick. Very successful conference, with lots of content (200+ talks!).
For all those interested, I am putting my slides on slideshare, those being my IPIN talk (30 min ish) and my UCSE talk (5 min). The UCSE presentation has had a slide removed for confidentiality reasons, so the short presentation is even shorter.
Please navigate to http://www.slideshare.net/CarlEllis to view.
C
One of the main technical company sponsor was in the workshop, Autodesk, and gave an interesting talk on how they are opening their whole building's Building Information Model(BIM) to the internet. I would point you to Digital 210 King for more information.
2 weeks ago I was at IPIN, which was hosted for the first time at ETH Zurick. Very successful conference, with lots of content (200+ talks!).
For all those interested, I am putting my slides on slideshare, those being my IPIN talk (30 min ish) and my UCSE talk (5 min). The UCSE presentation has had a slide removed for confidentiality reasons, so the short presentation is even shorter.
Please navigate to http://www.slideshare.net/CarlEllis to view.
C
Monday, 13 September 2010
New Article on Jimhi
I've wrote a small article on my site, about the architecture and motivation behind my site.
More of a meta-article really.
It is pretty short, simple, and written at 2am.
Enjoy!
http://jimhi.com/content/articles/jimhi/
C
More of a meta-article really.
It is pretty short, simple, and written at 2am.
Enjoy!
http://jimhi.com/content/articles/jimhi/
C
Friday, 30 July 2010
Cyber Security Challenge
To all those interested, here is a copy of my email with my solution.
To whom it may concern,
Decoded this from the last challenge!
"
Congratulations youve found and completed the REAL challenge. Your win
code is cyb3r=s3cur1ty*ch@ll3nge+26-07-2010.
Please email this code to our team at
media@cybersecuritychallenge.org.uk. If youre the first person to do so,
and can prove you meet the eligibility criteria (British citizen
currently resident in the UK) we will be in touch to advise how to claim
your prize. Well done and good luck in the Cyber Security Challenge
competitions taking place throughout the rest of the year
"
Figured I would go through the process:
Task one
========
Copied the data into a file.
Created the following perl script:
I then piped the data through the script into another file
At a hunch, checked if it was an image.
Voila!
Task two
========
Noticed the squiggles, zoomed in a lot and noticed it covered 2 pixel
strips, so converted the image to a bitmap, then created a very hacky C
file to grab the data (after checking the wiki page for the file format).
It is quite hacky, but combined with an online binary to ascii
converter, worked well.
The C file was as follows:
- From this I got the following text:
Cyrnfr sbyybj guvf yvax:
uggcf://plorefrphevglpunyyratr.bet.hx/834wgc.ugzy
uggcf://plorefrphevglpunyyratr.bet.hx/834wgc.ugzy
Which after running through the following perl script:
Which led me to ...
Task three
==========
This one was tricky. I looked for ascii values on the data, reversed,
big endian, little endian, looked for 7bit data compacted into 8, 7bit
and parity (odd/even) and then only looking at bits which passed the test.
Early on I noticed there were no '3's in the data, but didn't see the
shocking clue.
Then I tried some basic frequency analysis, but as there were 56 unique
entries it was probably a polyalphabetic cypher if it was. Tried the
kasiski technique, ended up with random numbers, but tried none the
less. I was convinced that the page name was a key, or something simple,
like "cypher". Alas, it was not true. Whilst looking at the binary for
the 500th time looking for patterns of shifts which you could be
employing, but finally I saw the solution. Turns out I was doing the
rookie mistake of starting out complex.
Following is the ruby file used to decode the data:
Those are my workings, 3 hours on the steg stuff probably, and much too
long on the last challenge.
Looking forward to more challenges :-)
Carl Ellis
http://www.jimhi.com
To whom it may concern,
Decoded this from the last challenge!
"
Congratulations youve found and completed the REAL challenge. Your win
code is cyb3r=s3cur1ty*ch@ll3nge+26-07-2010.
Please email this code to our team at
media@cybersecuritychallenge.org.uk. If youre the first person to do so,
and can prove you meet the eligibility criteria (British citizen
currently resident in the UK) we will be in touch to advise how to claim
your prize. Well done and good luck in the Cyber Security Challenge
competitions taking place throughout the rest of the year
"
Figured I would go through the process:
Task one
========
Copied the data into a file.
Created the following perl script:
#!/usr/bin/perl
use MIME::Base64;
while(<STDIN>){
print decode_base64($_);
}
I then piped the data through the script into another file
$ cat data | ./base64.pl > output
At a hunch, checked if it was an image.
$ evince output
Voila!
Task two
========
Noticed the squiggles, zoomed in a lot and noticed it covered 2 pixel
strips, so converted the image to a bitmap, then created a very hacky C
file to grab the data (after checking the wiki page for the file format).
It is quite hacky, but combined with an online binary to ascii
converter, worked well.
The C file was as follows:
#include <stdlib.h>
#include <stdio.h>
void * imgdata;
int datao(int x, int y);
int main(int argc, char *argv[]){
FILE * fp;
int w, h, o, off, i;
int r, g, b, re;
//Read binary data
fp = fopen("output.bmp", "rb");
fseek(fp, 0x0a, SEEK_SET);
o = getc(fp);
printf("1\n", o);
//First
off = o + 1052 * 173;
fseek(fp, off, SEEK_SET);
for(i = 0; i < 350; i++){
r = getc(fp);
g = getc(fp);
b = getc(fp);
if (r+g+b > 600)
re = 1;
else
re = 0;
if((i+1)%8)
printf("%d", re);
else
printf("%d", re);
}
printf("\n2\n", o);
//section section
for(i = 3; i <= 172; i++){
off = o + (1052 * i) + 1047;
fseek(fp, off, SEEK_SET);
r = getc(fp);
g = getc(fp);
b = getc(fp);
if (r+g+b > 600)
re = 0;
else
re = 1;
if((i+1)%8)
printf("%d", re);
else
printf("%d", re);
}
printf("\n3\n", o);
//third section
off = o;
for(i = 349; i >= 0 ; i--){
fseek(fp, off + (i*3), SEEK_SET);
r = getc(fp);
g = getc(fp);
b = getc(fp);
if (r+g+b > 600)
re = 0;
else
re = 1;
if((i+1)%8)
printf("%d", re);
else
printf("%d", re);
}
printf("\n4\n", o);
//forth section
for(i = 172; i >= 3; i--){
off = o + (1052 * i) + 3 ;
fseek(fp, off, SEEK_SET);
r = getc(fp);
g = getc(fp);
b = getc(fp);
if (r+g+b > 600)
re = 0;
else
re = 1;
if((i+1)%8)
printf("%d", re);
else
printf("%d", re);
}
return 0;
}
//offst from data start
int datao(int x, int y){
int width = 350;
int height = 175;
int offset = (y * width * 3) + x*3;
return offset;
}
- From this I got the following text:
Cyrnfr sbyybj guvf yvax:
uggcf://plorefrphevglpunyyratr.bet.hx/834wgc.ugzy
uggcf://plorefrphevglpunyyratr.bet.hx/834wgc.ugzy
Which after running through the following perl script:
#!/usr/bin/perl
use MIME::Base64;
while(<stdin>){
$_ =~ tr/a-zA-Z/n-za-mN-ZA-M/;
print $_;
}
Which led me to ...
Task three
==========
This one was tricky. I looked for ascii values on the data, reversed,
big endian, little endian, looked for 7bit data compacted into 8, 7bit
and parity (odd/even) and then only looking at bits which passed the test.
Early on I noticed there were no '3's in the data, but didn't see the
shocking clue.
Then I tried some basic frequency analysis, but as there were 56 unique
entries it was probably a polyalphabetic cypher if it was. Tried the
kasiski technique, ended up with random numbers, but tried none the
less. I was convinced that the page name was a key, or something simple,
like "cypher". Alas, it was not true. Whilst looking at the binary for
the 500th time looking for patterns of shifts which you could be
employing, but finally I saw the solution. Turns out I was doing the
rookie mistake of starting out complex.
Following is the ruby file used to decode the data:
class Cypherc
attr_accessor :bytearray, :rawdata
def initialize
rawdata =
"68edcdec4e2c8eae8d2c8e2dedcd6e04d2042fedae52ceac04ccedaecd8c042ccd8c046cedad0e8dac8eac8c048e0dac044aa82889046c0d2c8d8daccdecacc5042bedae4e04ee2dcd046ced8cac042d6e04046c2f4c664ea76e666cae4e268e2f456c0d088d8d66cdecac6546c6a506e6a546062606c504a141a1410a8dac2c6eac04acad2c2d8d048e0d2d6e046ced8cac048eed04edae4e048eac2cad042c8e04adac8c2d2c086c2f4cac4e6eac6cae4e2d8e2f6c0d2c8d8daccdecacc5ed4eecc5ae6dc50429cc042fedae524eac048e0dac04cc2d4e6e8e040eac4e6eedcd048eed048ced046eed85042ccd8c046c2ccd040e4eedceac042fedae04adacac8e048e0dac04ac8d2dec2d4c2d8d2d8e2f046c4e2d8eac4e2d2c0405484e2d8e2d6e0d046c2d8e2d4faccd046cae4e4eaccd8e8d2f044eac6e2d8caccd8e042dcd048e0dac04aa692504eeac04ee2d8d8d044cac042dcd048eedae6c0d048eed042c8cce2d6eac040dedee048eed046c8d2c2dad042fedae4e040e4e2d4facc504eaac8d8d048cedcdac042ccd8c04eceded8c048dae6c6d042dcd048e0dac04682f4cac4e046aac6cae4e2d8e2f04680d2c8d8daccdecac046cedad0eac8e2d8e2dedcd6e048e2c6d2dcdec040e8d2c6cac048e0d4eedaeec0dedae8e048e0dac044eac6e8e04edcc048e0dac0
42fac2c4ec5"
@rawdata = rawdata
bytearray = []
(0 ... rawdata.size/2).each do |i|
bytearray << "0x#{rawdata.slice!(0,2)}"
end
@bytearray = bytearray
end
def differencekeysize(length)
diff = []
initial = @bytearray[0]
(1...@bytearray.size).each do |i|
if (i%length < 1)
d = Integer(@bytearray[i]) - Integer(initial)
initial = @bytearray[i]
diff << d
end
end
return diff
end
def asciicharacters
ac = {}
(0...@bytearray.size).each do |i|
if(Integer(bytearray[i]) < 128)
puts "#{i} : #{@bytearray[i]}"
ac[i] = @bytearray[i]
end
end
return ac
end
def paritycheck(byte, type = 1)
#number of 1s
binary = Integer(byte)
tocheck = binary & 0x7f
par = binary >> 7
ones = 0
(0..7).each { |i|
ones += tocheck & 0x01
tocheck = tocheck >> 1
}
ok = false
if(type == 1)
if par == 1 and ones.odd?
ok = true
elsif par == 0 and ones.even?
ok = true
end
elsif(type == 2)
if par == 1 and ones.even?
ok = true
elsif par == 0 and ones.odd?
ok = true
end
end
return ok
end
def bitvalue(byte)
return byte & 0x7f
end
def diffscan(index)
diffs = []
tocheck = @bytearray[index]
(index+1 ... @bytearray.size).each{|b|
diffs << Integer(@bytearray[b]) - Integer(tocheck)
}
return diffs
end
def ngrams(n)
bins = {}
(0...@bytearray.size - n).each { |i|
key = @bytearray.slice(i, n).to_s
if bins[key].nil?
bins[key] = 1
else
bins[key] += 1
end
}
return bins
end
def bincheck
bins = {}
ks = 10
(0 ... rawdata.size/ks).each {|i|
bins[i] = rawdata.slice(ks*i, ks)
t = []
(0 ... bins[i].size/2).each do |j|
t << "0x#{bins[i].slice(j*2,2)}"
end
bins[i] = t
}
comp = []
bins.each{ |k,v| comp << bins[k][0] }
end
def shiftbits(byte)
binary = Integer(byte)
bottom = binary >> 5
top = (binary & 0x1f) << 3
return bottom ^ top
end
def decode
@bytearray.each { |b|
print "#{shiftbits(b).chr}"
}
end
end
c = Cypherc.new
c.decode
Those are my workings, 3 hours on the steg stuff probably, and much too
long on the last challenge.
Looking forward to more challenges :-)
Carl Ellis
http://www.jimhi.com
Friday, 23 July 2010
Cardiff and Lands End
So I decided to go on a week long tour of the good bit of the south, namely, the southwest. First though, a stop off at Cardiff to see an old friend.
As Cardiff had been explored before, and I had the car, first on the list of places to go was a pilgrimage to Barry Island, the place where every Welshman should be scarred with. Not quite sure why it is called an Island, as it was inside a cove, but those southern welshies are fairly off most of the time, like those Taven Ferry folk. Apart from children, dodgy amusements, fish and chip shops, and a dirty beach, there really wasn't much there. Some nice photo opportunities though, soon to be on my public Picasa profile. After a scramble up the headland, we decided to go and find a real beach!
The first one we hit ... had a power station firmly attached to it. Nice. So biting the bullet we continued westward, edging towards Bridgend. Luckily, before we hit that town a sign for Southerndown Beach. This was a brilliant little surfer beach and had some excellent photo spots from atop the cliffs and within the ruined castle on the opposite hilltop. As above, photos incoming.
Finally, we head back to Cardiff for food, narrowly missing the general 10pm restaurant deadline by a mere 45min, we opted for Dominos pizza. Dropping the car off in a 24hour place, I then endured the scariest walk of my life to the flat. Cardiff is scary compared to little old Lancaster, deserted hilltops, dense woodland, etc.
After that, I left for Cornwall! First stop was Newquay and a cliff walk from Watergate Bay to Porth, which was stunning! If you want to learn to surf, this seems like the place. Next day I moved towards a small village called Treen, near Penzance, via most of the southern coast. Amazing little village called Mousehole, where on the beach people had stacked rather flimsy towers of beach rocks, ready to be washed by the tide. It was like an art installation, but seemed so natural.
Treen has a history about it, near its headland is what is called the Logain Stone, which you can rock with your hands due to fine balance! Or you used to be able to, until some chap from the navy in the 1800s decided he wanted to prove the navy could topple it. After much complain by the local tourism industry, he paid to have it put back, but it has never rocked as easily since, which is something I can attest to after daring the rather leery scramble to the rock.
Next day found me at Lands End, doing the usual touristy stuff, but I did get some dirty looks off passers by as I did some undaring bouldering to get a good photo. Then to St. Ives to wonder the streets.
Today back to Newquay, and a day at the Eden Project. Brilliant place, if a little inundated with small children, but then, it is for them. Big kids have to fit in I suppose! After chilling out in Watergate Bay again, Im in the pub writing this (Cornish Ale has nothing compared to Lancastrian). Tomorrow, I go bouldering at Carn Brea. Woo. Then back into the Shire.
EDIT: Photos available here.
As Cardiff had been explored before, and I had the car, first on the list of places to go was a pilgrimage to Barry Island, the place where every Welshman should be scarred with. Not quite sure why it is called an Island, as it was inside a cove, but those southern welshies are fairly off most of the time, like those Taven Ferry folk. Apart from children, dodgy amusements, fish and chip shops, and a dirty beach, there really wasn't much there. Some nice photo opportunities though, soon to be on my public Picasa profile. After a scramble up the headland, we decided to go and find a real beach!
The first one we hit ... had a power station firmly attached to it. Nice. So biting the bullet we continued westward, edging towards Bridgend. Luckily, before we hit that town a sign for Southerndown Beach. This was a brilliant little surfer beach and had some excellent photo spots from atop the cliffs and within the ruined castle on the opposite hilltop. As above, photos incoming.
Finally, we head back to Cardiff for food, narrowly missing the general 10pm restaurant deadline by a mere 45min, we opted for Dominos pizza. Dropping the car off in a 24hour place, I then endured the scariest walk of my life to the flat. Cardiff is scary compared to little old Lancaster, deserted hilltops, dense woodland, etc.
After that, I left for Cornwall! First stop was Newquay and a cliff walk from Watergate Bay to Porth, which was stunning! If you want to learn to surf, this seems like the place. Next day I moved towards a small village called Treen, near Penzance, via most of the southern coast. Amazing little village called Mousehole, where on the beach people had stacked rather flimsy towers of beach rocks, ready to be washed by the tide. It was like an art installation, but seemed so natural.
Treen has a history about it, near its headland is what is called the Logain Stone, which you can rock with your hands due to fine balance! Or you used to be able to, until some chap from the navy in the 1800s decided he wanted to prove the navy could topple it. After much complain by the local tourism industry, he paid to have it put back, but it has never rocked as easily since, which is something I can attest to after daring the rather leery scramble to the rock.
Next day found me at Lands End, doing the usual touristy stuff, but I did get some dirty looks off passers by as I did some undaring bouldering to get a good photo. Then to St. Ives to wonder the streets.
Today back to Newquay, and a day at the Eden Project. Brilliant place, if a little inundated with small children, but then, it is for them. Big kids have to fit in I suppose! After chilling out in Watergate Bay again, Im in the pub writing this (Cornish Ale has nothing compared to Lancastrian). Tomorrow, I go bouldering at Carn Brea. Woo. Then back into the Shire.
EDIT: Photos available here.
Thursday, 15 July 2010
Battery Monitor
I use a rather spartan windowing manager called awesome in all of my machines. This has been a fine setup until I used it on my netbook due to one small issue, battery monitors.
On my desktop machines and the laptop I use gkrellm to monitor cpu and memory and for the laptop it has a handy battery usage label. With the netbook however, screen real estate is quite valuable, so I opted for finding something to sit in the system tray.
After a quick look it seems there was nothing which was lightweight or simple or not requiring me to install the entirety of gnome.
In the end I made my own called rbatmon, then packaged it up for use in the AUR. If you have a substandard flavour of linux, not to worry, You can grab the script from my githib page here.
The most interesting challenge of this was building a package for the first time. There is a great package for Archlinux called abs (available on pacman) which fills /usr/share/pacman with some example PKGBUILDS for standard sources of gettings code from VCS's.
Page on my site regarding this is here.
AUR page is here.
C
On my desktop machines and the laptop I use gkrellm to monitor cpu and memory and for the laptop it has a handy battery usage label. With the netbook however, screen real estate is quite valuable, so I opted for finding something to sit in the system tray.
After a quick look it seems there was nothing which was lightweight or simple or not requiring me to install the entirety of gnome.
In the end I made my own called rbatmon, then packaged it up for use in the AUR. If you have a substandard flavour of linux, not to worry, You can grab the script from my githib page here.
The most interesting challenge of this was building a package for the first time. There is a great package for Archlinux called abs (available on pacman) which fills /usr/share/pacman with some example PKGBUILDS for standard sources of gettings code from VCS's.
Page on my site regarding this is here.
AUR page is here.
C
Wednesday, 30 June 2010
Website Layout
I have modified the layout of jimhi to be user friendly. It still has a bit of improvement to be had, but at least you can find pages other than the start one now!
I shall put a feature in the site which puts it back into ridiculous interaction mode soon.
I shall put a feature in the site which puts it back into ridiculous interaction mode soon.
Tuesday, 8 June 2010
Very basic Makefile for LaTeX documents
So I wanted to make a basic makefile for my tex documents, so I took the Makefile from http://www.acoustics.hut.fi/u/mairas/UltimateLatexMakefile/ and modified it to be amazingly simple.
Heres the Make file:
Fairly simple and lets you choose your toolchain.
C
Heres the Make file:
CC=
FLAGS=
LATEX= latex
BIBTEX= bibtex
DVIPS= dvips
PS2PDF= ps2pdf
SRC := $(shell egrep -l '^[^%]*\\begin\{document\}' *.tex | sed -e 's/.tex//')
TRG = $(SRC).dvi
PSF = $(SRC).ps
all : pdf
dvi :
$(LATEX) $(SRC) && $(BIBTEX) $(SRC) && $(LATEX) $(SRC) && $(LATEX) $(SRC)
ps : dvi
$(DVIPS) $(TRG)
pdf : ps
$(PS2PDF) $(PSF)
clean :
rm *.bbl *.aux *.blg *.dvi *.log *pdf *.ps
Fairly simple and lets you choose your toolchain.
C
Wednesday, 26 May 2010
Blogs and Wonder
Hello!
I have got the barebones of a new site up at http://www.jimhi.com so go and have a bit of a browse!
Also the Lancaster Computing Society has a development blog up!
Find it at http://compsocblog.blogspot.com/
Short post from me, all developmenty stuff is going on the Computing Society blog.
C
I have got the barebones of a new site up at http://www.jimhi.com so go and have a bit of a browse!
Also the Lancaster Computing Society has a development blog up!
Find it at http://compsocblog.blogspot.com/
Short post from me, all developmenty stuff is going on the Computing Society blog.
C
Thursday, 25 March 2010
Article is actually ... up!
Wow, it has been ... 5 months since I said I would write that article? Well ... here it is! A link to it anyway: http://www.jimhi.com/content/articles/ .
Will be writing a nice auto table of contents generator and folding javascript now, so it looks a bit nice and follows the site a bit more.
Probably wise to add a link back too !
Next article to be written will be on a java version of the Enigma machine I wrote. Then I shall write up a maze generator and solver which Stephen Wattam and myself built for the Computing Society.
Laters
Will be writing a nice auto table of contents generator and folding javascript now, so it looks a bit nice and follows the site a bit more.
Probably wise to add a link back too !
Next article to be written will be on a java version of the Enigma machine I wrote. Then I shall write up a maze generator and solver which Stephen Wattam and myself built for the Computing Society.
Laters
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