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Tag Archives: Internet

use PAC file for automatic proxy selection

I will explain how to use automatic proxy selection for a local network.

For example let’s say that you have a proxy server but that proxy is not available all time. In this case the you need to find each time if the proxy is alive (available) and if yes to use it. If not then browser will select direct connection.

The easiest way to use it is to create a PAC file and to add it in the Firefox as automatic proxy selection.

Go to Preferences–>Advanced –> Network –>Settings and choose “Automatic proxy configuration URL”

Then type there the path to a local PAC file. Normally there should be a web page address but if the file is locals works also ( no web server needed)


To create the PAC file use any text editor and create a file called “autoproxy.pac” and put this content:

function FindProxyForURL(url, host)
return “PROXY; DIRECT”;

The Proxy in this case is on local network at (Squid Proxy on port 3128) and Firefox try to use it first . In case it is not responding it will use direct connection.

You can set there multiple proxy servers. The order is important.

In the example below you can have two proxies. If the first one ( is not responding then the second one ( will be selected, and if the second one also do not respond the direct network connection will be used.

function FindProxyForURL(url, host)

The name of the PAC file is not important ( “autoproxy.pac” is name used by me), any name will do.

More details regarding the PAC file , examples, more advanced functions can be found here :




Best parodies for Les Miserables

I think that this are the best parodies for “Les Miserables” movie.

hard passwords but easy to remember

One of the important problems of the modern computing is the security, privacy and the personal data that must be protected .

Usually we are using passwords to protect our data or  accounts ( email, web…).  But one of the main issues is that the passwords must be easy to remember for the owner but very hard to crack for the enemy. So if we choose a password that can be easily remembered, then there is a chance that other persons know it ( like object names, famous places, books quotes…etc).

If we use hard passwords, then it is a risk that we ( owner of the data) forget the password. The alternative is to write down the hard ( complex ) password on a paper and put the paper on a hard to find place. But this solution rise also the problem of the aces to that password. We may need this password in various moments , at random places in time, when we do not have immediate access to our little paper with passwords.

An alternative is to have a easy to remember password but to code it in such a way that the results is a very complex and hard to crack password.

For the people that have access to a computer this is an easy task.

Just an example : we generate the md5sum of a password.

$ echo “password” | md5sum

286755fad04869ca523320acce0dc6a4  –

The md5sum is unique to a input and cannot be cracked. This means that based on the result you cannot recover the input.

If we need only a certain number of characters, we can trim this string to a desired length (example 10 characters), like this:

$ echo “password” | md5sum | head -c 10 ; echo


If we want more, we can go further. As you notice in this string there are only numbers and letters ( small cap letters ). We can now pipe the result to another level of encoding. For example base64 encoding. This type of encoding is reversible ( the input can be found based on output data). The purpose here is to introduce more variation in the string.

$ echo “password” | md5sum | base64 | head -c 25 ; echo

Here we obtain the md5sum of the “password” word and the the result is send to base64 encoding. Then the length of the string is reduced to only 25 characters.

So now we have numbers and letters ( big and small cap).

So , as you can see this results are very hard to remember and crack. But for the owner that know to make this easy steps, the solution is easier.

Now lets suppose that the enemy find the “password” word. Well, whatever he tries, he cannot take the account.

The owner will never remember the Mjg2NzU1ZmFkMDQ4NjljYTUyM password, so even if the enemy force the owner to tell him his password , he cannot get it.


Of course, the secret here is that the “easy to remember password” is processed so that we obtain a hard password. Of course this is just an example.

You can even encode few times the result, mds5sum again few times, cut the length, or even add special characters in certain positions. So the possibilities here are infinite.


So please use hard password !

the dictionary attacks are very common in our days and the computing power is rising every day. ( now the cracking tools use  also GPU for a even faster speed).

make your searches anonymous

You can increase your privacy by using a search engine that do not give your IP address to bad guys, and offer also HPTTS.
But , wait ! Google is the best for search !
So why not combine the privacy with best google service ?

So use

So first of all this search engine is owned by a European company ( no US jurisdiction) and offer HTTPS connection.
See settings in top right corner.

Also a Firefox plugin is available (HTTP and HTTPS ) so you can search directly from Firefox.