An SSL, or Secure Socket Layer, is technology that has been developed that allows web browsers and web servers to communicate over a secured connection.

The system uses cryptography that uses two keys to encrypt data  a public key known to everyone and a private or secret key known only to the recipient of the message. It’s a way to encrypt data, like credit cards numbers (as well other personally identifiable information), which prevents the "bad guys" from stealing your information for malicious intent.

The recently introduced SSL v3 improved upon SSL v2 by adding SHA-1 based ciphers, and support for certificate authentication. SSL v2 was known to be flawed in a variety of ways. Identical cryptographic keys are used for message authentication and encryption. The older version did not have any protection for the handshake, meaning a Man-in-the-middle downgrade attack could go undetected.

SSL has recently been succeeded by Transport Layer Security (TLS), which is based on SSL and is included as part of both the Microsoft and Netscape browsers and most Web server products. SSL uses the public-and-private key encryption system from RSA, which also includes the use of a digital certificate.

SSL-enabled client software can use standard techniques of public-key cryptography to check that a server's certificate and public ID are valid and have been issued by a certificate authority (CA) listed in the client's list of trusted CAs. Client authentication allows a server to confirm a user's identity. It’s a way to assure a client that they are dealing with the real server they intended to connect to. It can prevent any unauthorized clients from connecting to the server, preventing anyone from meddling with data going to or coming from the server.

From the very beginning SSL was designed to provide security between client and server, and to avoid any kind of 3-way man-in-the-middle attack.

Conceptually it’s quite simple: it negotiates the cryptography algorithms and keys between two sides of a communication, and establishes an encrypted tunnel through which other protocols (like HTTP) can be transported. It can also be easily passed through firewalls and proxies, as well as through NAT (Network Address Translation) without issues.

Like a lot of web developers, I'm not always that disciplined when it comes to the file naming convention I use and I sometimes end up with a situation whereby I have some files that are in lowercase, some that begin with a capital, and some that are a bit of a mixture.

One web site I maintain contains about 2000 web pages and has about 20,000 hyperlinks. As you can imagine, I had one of those sinking feelings when I was told that in order to migrate the web site to a new content management system, all the file names and hyperlinks would need to be changed to lowercase.

Whenever I am presented with a problem like this, my instinct is always to write a Perl script using one or more regular expressions to solve the problem. This particular situation was no exception.

Change a string to lowercase

The following regular expression changes all the characters in a string to lowercase. The first part of the regular expression finds a hyperlink, and the second part converts the string. (Just in case this article is not displayed correctly, there should be a single backslash in front of the 'L$1').

Change a filename to lowercase

Likewise, changing a filename itself is very simple. The following two lines perform the task quite nicely:

(Again, there should be a single backslash in front of the 'L$name'.)

If you need more information on how to incorporate the above code snippets into a complete script, feel free to contact me directly.

Rack mount servers are essentially systems that are in a modern server and are used to mount different sizes and kinds of electronic modules. Rack mount servers would be ideal for individuals who need to set or probably pack a couple of personal computers to a smaller space.

This kind of server is commonly employed in many areas and countries globally for a lot of purposes and reasons. Rack mount servers are used wherever an application of computers has to be used for a wider and larger application, which could star t from video editing suites to computer animations to the other kinds of three-dimensional tasks.

These rack mount servers are also utilized for the installation of different Internet service providers or ISPs in the field of telecommunications as well as in the other types of communication and for different database houses. They are created and are designed to be able to fit in an open PC or probably in a closed cabinet. One advantage for the use and implementation of a rack mount server would be that they could really prove to be very functional and useful if someone needs or wants to save some space. The space-saving design of rack mount servers allows the user to maximize the space he or she has.

The role of these servers is crucial, as proper and adequate setting and support of hardware to a well-built storage space would ensure that they are would be well-protected from any external elements and other factors.