lucamauri.co m Snippets

Calcolare il CIN di un conto corrente

Sun, 08 Jun 2008 16:39:12 GMT

Il CIN (Control Internal Number) è un tipo di check digit che viene usato dalle banche italiane fin dagli anni '90. E' ancora molto utile in quanto deve essere incorporato nel codice IBAN che da metà del 2008 è sostanzialmente indispensabile per le transazioni monetarie elettroniche.
Pare che su internet ci siano pochissime fonti che spieghino come calcolarlo, l'algoritmo che segue si basa su una spiegazione del modulo Contabilità delle ACG di IBM.
L'ho provato su diversi numeri di C/C e funziona regolarmente.

VB.net MD4 Message Digest class

Sun, 02 Mar 2008 21:38:45 GMT

First of all I must tell the story of this class.
In first place this is derived in first place from original RSA algorythm, then this class has been implemented by Norbert Hranitzky in Java. This Java class was used by Oren Novotny as base for his excellent C# implementation, finally this class has been translated in VB.net by someone called Bismark Prods in a post at http://www.derkeiler.com/Newsgroups/microsoft.public.dotnet.security/2004-08/0004.html.
This last class was not working and I extensively modified it to make it running right. So, while I have to give credit to others for their job, I am pleased to say that this piece of code is (apparently) the only working VB.net implementation of a MD4 class.

The code is commented so anyone can figure out how the class works. For the people interested in knowing the mathematics behind the algorithm, I suggest the reqading of the original RFC 1320.

Check and download images

Sun, 11 Nov 2007 16:23:41 GMT

In the following code you can see how to make a conditional download of images.
Let's assume you have a list of image files in a table (from a database, for instance, but any other source will do as well) and the folder on the remote website where the images are.

Those data are set in the very beginning of the file, the only external object you have to instantiate before calling this function is the dataset called dsImgs. Once done, the function will look for all the images in the location and will check if the image already exist on the disk. If this is the case, a check is done on the Last-Modified date and the file is downloaded if the current version is older only.

WOL .net

Tue, 27 Mar 2007 20:22:15 GMT

Wake-On-LAN (WOL) is a feature of the network interface cards since the late '90s
This functionality was initially conceived by IBM and the widely supported by Intel with NIC's and motherboard's chipset

WOL simply works by broadcasting a so called Magic Packet on the LAN where the device you want to wake-up is on. The Magic Packet is made by a leading HEX string followed by 16 repetition of the target MAC Address.
For the following class to works you must simply create an instance, provide the MAC Address and call the method WakeIt.
The class also includes Intellisense description.

Statistic .net

Fri, 02 Mar 2007 08:22:38 GMT

I created this class to help me made the Tag Cloud system for this site. It is a simple class to calculate the arithmetic Mean and the Standard Deviation.

Get information by WHOIS database

Sun, 31 Dec 2006 21:55:12 GMT

This simple class help you to programmatically access IP ranges information from WHOIS database. The enumerator in the class already contains the addresses of the three registrars that amanges IP addresses in the World.

Process text file

Sun, 10 Dec 2006 14:13:19 GMT

A collection of three simple class that allow you to read files from disk and from internet and write a strem back to a file.
It is a simple task for a programmaer, but it may comes in hand from time to time to have it ready-to-use.

Extract ED2K links

Sat, 09 Dec 2006 16:13:19 GMT

Using Regular Expression functions, this class allow you to scan a bunch of text (for esample and HTML page) to extract all the links in ED2K format.
The Collection is exposed by the class.

Process ED2K links

Fri, 08 Dec 2006 14:58:57 GMT

This class show you how to import and process an ED2K link.
ED2K link are links to files in the eDonkey 2000 network, now used both by original vclient and the popular eMule clients.
Every istance of this class represent a single ED2K link that is automatically split into pieces and separated in the proper properties of the class.
From there it is easy to use every single part of the link for your own purpose.