Monthly Archives: November 2005

One example of securing POP3 with SSL

This example comes from Google’s Gmail POP configuration.

Note the checked “Use secure connection (SSL)” on the left image (you will need to click on it to make it readable).

With it, any eavesdropper will see just random bytes instead of a nicely crafted ASCII dialog. So capturing username and password or the nature of the exchanged messages is now quite difficult.

Spanish Research Network Infrastructure

This one is the network UPV is connected to. As you can see (click on the image for a better view) Valencia is connected using several 2.5Gbps channels: Not bad!!

MIME and Transfer-Encoding

Common encoding schemes used by MIME include base64 and quoted-printable. Please note the goal here is to keep the text transmitted using SMTP protocol as 7-bit ASCII code regardless the original message contents. This transfer encoding will be undone on the receiving end to restore the original message. This way, images, sounds and any other binary contents can be sent as SMTP email.

Java Sockets Source Code

I’ve posted some of the Java source code we used in the classroom lately.

As we mentioned in the class, the conversion between bytes and characters depends on the encoding scheme. Most current Operating Systems no longer use ASCII but other schemes like UTF-8 to encode text-file contents. That is why we prefer the use of *Reader and *Writer classes instead of just the byte streams. (Why is encoding important?).

Java Sockets’ Programming

Now you might want to download the JDK to your system so you can compile your own Java code. I know some of you have used other tools, like BlueJ, but the JDK is the real deal and the full class-library docs are here.

HTTP result codes

Detailed list of HTTP result codes. But if you need any more detail you can check the current up to date RFC-2616. Please note that Postscript or PDF versions of the document are available in the same page in case you do not feel comfortable with the ASCII-only version.

First assignment is out

You may want to wait some days before starting to work on it as some topics have yet to covered in the lectures. But your first assignment is available. I want you to remember these are optional exercises you may or may not do. But if you do the assignment right (right meaning that it works), then you get a 0.45 points per assignment to be added to your final mark. If you are in doubt of what that means I suggest you to check the assessment details presented on chapter 0 slides.