Centroid.EU Blog

Remember the Venus Glider?

March 24th, 2012

A long time ago, the centroid.eu blog featured my idea of a venus glider. It's not even in the archives anymore but I wanted to touch on the idea again. Basically the planet venus rotates very slowly around its axis. This makes a glider possible that can loiter around the terminator (line between night and day) of venus. It could have payloads such as radar and UV and IR spectrometers. It would likely be somewhat high in the atmosphere due to the atmospheric pressure and more updraft higher in the atmosphere. It may even have a backup propeller that is foldable into its fuselage, this is when mistakes are made in catching sufficient thermals. Solarpanels that are embedded in the wing area can then recharge the batteries when the glider is high above the clouds and on the day side. One good thing about a glider that is falling on venus is that the atmosphere becomes so dense that its rate of descent will slow as it gets lower towards the surface. This venus glider would not be carrying astronauts but rather be entirely electronically and computer driven.

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Checking Randomness on Debian

March 23rd, 2012

I noticed that /dev/*random on Debian and Ubuntu were mode 666. I found a bug report about this too in the debian archives. But I wasn't convinced to prove a point you have to do some work. So I remembered this article on XOR encryption and I thought it could help me with my randomness plotting as well. If there is a pattern I'll see it. Basically randomness should be evenly spread out in a X,Y,Z plot.

So I wrote the program to get the random data from Debian but I first write a string to its /dev/urandom before waiting 10 seconds and reading 512 bytes, here is the program for this:

#include <sys/types.h>

#include <stdio.h>
#include <stdlib.h>

#include <unistd.h>
#include <fcntl.h>

int
main(void)
{

        char buf[512];
        char *string = "OrpheanBeholdersCryDoubt!";
        int len;
        int fd, output;

        fd = open("/dev/urandom", O_RDWR, 0);

        if (fd < 0) {
                perror("open");
                exit(1);
        }

        len = write(fd, string, strlen(string));
        if (len < 0) {
                perror("write");
                exit(1);
        }

        sleep(10);


        output = open("cryptfile", O_APPEND | O_CREAT | O_WRONLY, 0644);
        if (output < 0) {
                perror("open");
                exit(1);
        }

        len = read(fd, buf, sizeof(buf));
        if (len <= 0) {
                perror("read");
                exit(1);
        }

        if (write(output, buf, len) < 0) {
                perror("write 2");
                exit(1);
        }

        close(fd);
        close(output);

        exit(0);
}

On OpenBSD then I did the same program with the write to the device disabled since its permissions are mode 644. The data I gathered I then put through another program that looks like this:

#include <sys/types.h>

#include <stdio.h>
#include <stdlib.h>

#include <unistd.h>
#include <fcntl.h>

int
main(int argc, char *argv[])
{
        char buf[512];
        char *file;
        int fd, len;
        u_int16_t *array;

        if (argc != 2) {
                perror("arguments");
                exit(1);
        }
        
        file = argv[1];
        fd = open(file, O_RDONLY, 0);
        if (fd < 0)  {
                perror("open");
                exit(1);        
        }

        while ((len = read(fd, buf, 6 * 2)) > 0) {
                array = (u_int16_t *)&buf[0];
                
                printf("%d, %d, %d\n%d, %d, %d\n%d, %d, %d\n", 
                        array[0] - array[1], 
                        array[1] - array[2],
                        array[2] - array[3],
                        array[1] - array[2],
                        array[2] - array[3],
                        array[3] - array[4],
                        array[2] - array[3],
                        array[3] - array[4],
                        array[4] - array[5]);
        }

        close(fd);

        exit(0);
}

The instructions on the math involved I got from the article I mentioned above.

I then ran it through gnuplot with the data by calling splot, like so:

gnuplot> splot 'cplot.dat'

And here is the graphs this produced:
OpenBSD (above)
Debian with write to /dev/urandom (above)

All in all this was a very educational event for me, I hope you like the article too!

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Bought Saturn (ACER Aspire One)

March 16th, 2012

It's my birthday. I bought an Acer Aspire One 722 for my family and me. It has 4 GB of RAM and an AMD processor (C-60 1 GHz, 1 MB L2 Cache). I named it saturn. It'll be running windows 7 for a while until next year perhaps when I give it a facelift. Guess what OS I have in mind for it? :-).

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Equinox in 5 days

March 15th, 2012

Equinox is a terrestrial event. It is on this day that the earth's equator is exactly aligned with the sun in a perpendicular fashion. Read more about equinox in the previous mentioned link.

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OpenBSD pre-orders are up!

March 14th, 2012

I just pre-ordered my 5.1 CD set from OpenBSD Europe. Here is the OpenBSD 5.1 Release page, it's a work in progress. The artwork and lyrics for the song are out but I haven't heard the song yet, I can't download it for some reason. Oh well in due time. This time the theme of OpenBSD seems to be Ghostbusters. Only they are Bugbusters. If memory of cartoons serves me right Ghostbusters had a pet ghost called slimey or slimer...guess the OpenBSD team have a pet bug called ... I dunno.

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Looking for work

March 2nd, 2012

I got notice today that I won't get a contract extension come April 30th, of this year. So I'm looking for work again starting May 1st, 2012. I'm willing to do remote sysadmin work for *NIX systems and/or programming on *NIX systems. Why remote? Because I'm unwilling to move away from my family and they never heard of *NIX around here (it seems). Please have a look at my resume. If you know of companies hiring remote employees it would be nice if you let me know.

Due to health issues I'm only able to work 20 to 30 hours weekly max.

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Free the General

February 29th, 2012

If you follow Reggae Music you may have heard that Buju Banton was jailed. For a long time I have carried these words with me and I don't know if I shared them yet, but the resistor codes in electronics stand for:

Buju Banton, Rasta Of Young Generation, Became Victorious, Glorious & Wise

following this is the Electronic Resistor Codes as taught by Canadian Colleges. I know Buju Banton is a resistor! Hang in there sir! Free Buju Banton!

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article test

February 27th, 2012

When searching some articles appeared duplicate, with one not having content. This should fix that.

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100+ Euros donations to some *BSD's

February 26th, 2012

The Marakesh Express came through. Just Kidding! I donated 50 euros to the OpenBSD project and 57 Euros (75 dollars) to the FreeBSD Project. I use both Operating Systems at home and at work and am very satisfied with both projects and their individual directions. I'm still looking to purchase OpenBSD 5.1 when it's up for preorders, so this is a big spend!

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Jupiter and Venus really bright

February 19th, 2012

Today I saw Jupiter and Venus really bright in the South-West-Western sky. I couldn't take a photo but I got a clip of xephem for the memories. Jupiter is in Aries and Venus is in Pisces, and Uranus in Pisces too but it can't be seen with the naked eye.

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