nullpointer.dk

Just the other day, I was confronted with a problem at the university where disk I/O operations were unavoidable. It is a fact that the HDD is slower than RAM, of course, so a mounted FS in RAM was used instead. If one has tried this in FreeBSD or Linux before then this is quite similar and just as easy.

To create a RAM disk the following is done:

% hdid -nomount ram://SECTORS

In 1996 it was discovered that the MD5 hash-algorithm had problems. Furthermore, an algorithm was devised to generate these collisions in 2005.

As a continuation of the previous entry about the implementation of SHA-1, I've now implemented the last three algorithms as well. These are SHA-256, SHA-384, and SHA-512. SHA-1 provided a 160-bit digest, SHA-256 provides a 256-bit digest, SHA-384 provides a 384-bit digest, and, believe it or not, SHA-512 provides a 512-bit digest. These algorithms are described in FIPS 180-2.

The usage is the same as for SHA-1, except for a little detail of specifying the exact algorithm to use:

>>> import sha

As a bit of fun I implemented the Secure Hash Algorithm (SHA) 1 late last night. It was done using Python3 and accordingly to FIPS 180-1.

Below is shown how to use it:

>>> import sha1
>>> data = sha1.str2bin("All your base are belong to us!")
>>> sha1.digest(data)
'1110101011101101100000101101000101010000110001110110110010000011
 1101011101110100101001110011011101001110011110001100111000000111
 11010001110010001100100010100110'
>>> sha1.hex_digest(data)

Reading Reddit, I stumpled upon this article explaining AES using stick figures. I found it so interesting and nicely drawn, that I think you should have a look at it as well. Of course, it is not cover all the "dirty" details but it makes some relevant observation points.

So here it is: http://www.moserware.com/2009/09/stick-figure-guide-to-advanced.html

I was just reading the programming blog at reddit, as I often do, and then I stumpled upon this title:

Remember the good old days of the 1990s, when you could teardrop attack any Windows user who'd annoyed you and bluescreen them? Microsoft reintroduces this popular feature in Windows 7, courtesy the rewritten TCP/IP and SMB2 stacks.

The problem is that Windows 7 (and Vista) now ships with a new version of SMB (version 2). Here it is possible to send a (special) malformed SMB header to a target computer, and thereby making it crash with a B.S.O.D. The only requirement for the target system is that it has to have SMB2 enabled.

The following review of Mac OS X 10.6, which also goes by the name Snow Leopard, can be found here: http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars.

It really is a nice review talking about topics such as the LLVM/Clang transition, the introduction of Blocks in C-style languages, Grand Central Dispatch (GCD) and OpenCL. Read it!

Last Thursday i got my Free Software Foundation (FSF) membership card, which is a credit card sized USB drive. It looks like the following:

Salutations!

This is the relaunch of nullpointer.dk. There has been made some changes to the infrastructure. First, the site has been moved to another location (courtesy of fbh). Second, instead of using Wordpress I'm giving Drupal a spin of the wheel and it looks good so far.