Centroid.EU Blog

The xlog is discontinued

July 2nd, 2009

Some people must have gotten hold of an old cache of my blog from 2006/2007 where I offered blog articles in encrypted form. You could order a decrypt CD then to decrypt what was written, however noone at the time was interested. I discontinued offering the blog in encrypted form and no sales were made. I found some bounce mails from people today writing in to the decrypt mailbox (which doesn't exist anymore). Thanks for your interests but the offer is over.

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Natally does AES

June 30th, 2009

Well I have been hacking away at natally the last couple weeks now and I finally got dual mode encryption into it. It now does AES as well as Blowfish encryption. Because of the nature of the code it should be easy now to add other ciphers now too, it just needs to be put in place. I started out with blowfish and then coded my way to AES removing a lot of hard code such as blocksizes which need to be dynamic with multiple ciphers. I'm thinking perhaps I should write a manpage now (ughh) or something.

PS: with revision 50 I committed the NAT state expiration code which was needed to complete this project. Perhaps it'll need a bit of tweaking here and there but the main code is finished.

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Random Hackepedia

June 26th, 2009

If you want to use a sniffer to watch dhcp requests, replace rl0 with your NIC:

To read more about dhcpd read on.

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Random Hackepedia

June 21st, 2009

A Fifo is a named pipe. It is used for IPC. It is created with the mkfifo syscall or command. Fifos reside in the filesystem and require a process to read from it while another process writes to it.

To read more about fifo, go to Hackepedia.

PS: Happy Solstice 6/2009!

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OpenSSL speed

June 21st, 2009

I participated in the Deschall (sp) crack challenge back in 97 or so and the DES cipher was broken by a supercomputer especially built for the task. So now it's 12 years later and a lot has happened. DES was replaced by AES and AES is a lot more secure the literatures write.

But I'm left wondering why the dickens AES is a faster cipher than DES. Pretend you are brute forcing a cipher, wouldn't then a faster cipher produce more attempts per second than a slower cipher? This means a brute force would end sooner to exhaust a cryptogram. Hmm. Here are some stats of DES and AES that I cut from an "openssl speed" command on my home computer.

The 'numbers' are in 1000s of bytes per second processed.
type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes
des cbc          19981.67k    26454.32k    27109.93k    27133.40k    26813.16k
des ede3          9693.15k     9656.40k     9351.31k     9793.71k     9824.77k
blowfish cbc     35115.53k    41062.07k    39941.05k    41949.41k    41771.29k
aes-128 cbc      33001.89k    51473.35k    60324.97k    66089.46k    63121.28k
aes-192 cbc      30109.43k    46625.91k    51426.45k    54773.53k    56143.75k
aes-256 cbc      34359.02k    42632.24k    47491.13k    47512.66k    46742.06k

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HOME

June 19th, 2009

Yesterday I found this movie on youtube and it touched me. It basically warned humanity once again of our ways and said in 10 years the disruption of the harmony of life will be irreversible. The movie has some great footage from all over the world, check it out.

• HOME

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Solstice not too far away

June 17th, 2009

In the northern hemisphere (Europe, North America, Asia) we'll have the Summer Solstice on the 21st of June, which means that on this day at high noon the sun is at its highest angle from the horizon. In the southern hemisphere (parts of South America, Australia, parts of Africa) the sun is at its lowest angle from the horizon (at high noon). Why this is is because of the tilt of our earth. This tilt is responsible for our seasons (at least in the northern hemisphere).

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What's up

June 13th, 2009

Not much is up, I wrote a linux client for natally which seems to work. I improved the openbsd client for natally a bit so that routes can be set up which unfortunately doesn't work on the linux client. I'm going to skip putting up a random hackepedia since there is so little content this week.

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Random Hackepedia

June 6th, 2009

tr stands for translate characters and that's what it does.

To read more about tr go here.

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Natally

June 5th, 2009

Natally is a NAT/VPN program that works on a host that cannot do tun/tap. With iptables available, it'll make a packet socket and run with a raw socket. At the same time one can connect to it and have the session blowfish encrypted. So far there is some problems with performance that I'm working on. It's doggedly slow but I'm positive that it can be sped up.

Natally is now hosted at sourceforge. This is its homepage.

There exists a server written for Linux OpenSuse 10.3 and a client written for OpenBSD 4.5. In the future there may be other clients written for linux perhaps, but it's not a priority for me right now.

Update: Progress. I've replaced the ip and tcp checksumming routines and there now isn't any bad checksums which really were part of the slowness as the implementation had to wait for retransmissions and hope the checksums were alright. Phew am I glad that was found.

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