Book II 10 in C#

Printing Code 39 Extended in C# Book II 10

In this case, the two classes Sort and Test are contained within the same namespace, MathRoutines, even though they appear in different declarations within the file (or in different files) That namespace is broken into two parts

Normally, Sort and Test would be in different C# source files that you build together into one program The method TestMain() can reference the Sort class without specifying the namespace because the two classes are in the same namespace However, Main() must specify the Paint namespace when referring to PaintColor, as in the call to PaintPaintColorStaticPaint() This process is known as fully qualifying the name Notice that you don t need to take any special steps when referring to blackPaint(), because the class of the black object is specified, namespace and all, in the black declaration

Designing for C#

1: Writing Secure Code 401 2: Accessing Data 415 3: Fishing the FileStream 435 4: Accessing the Internet 455 5: Creating Images 469

Designing for security Building secure Windows and Web applications Digging into SystemSecurity

ecurity is a big topic Ignoring for a moment all the buzzwords surrounding security, I m sure you realize that you need to protect your application from being used by people who shouldn t use it You also need to prevent your application from being used for things it shouldn t be used for At the beginning of the electronic age, security was usually performed by obfuscation If you had an application that you didn t want people peeking at, you just hid it, and no one would know where to find it Thus, it would be secure (Remember War Games, the movie in which the military assumed that no one would find the phone number needed to connect to its mainframes but Matthew Broderick s character did ) That obviously doesn t cut it anymore; now you need to consider security as an integral requirement of every system that you write Your application might not contain sensitive data, but can it be used to get to other information on the machine Can it be used to gain access to a network that it shouldn t The answers to these questions matter The two main parts to security are authentication and authorization Authentication is the process of making sure a user is authentic that the user is who he claims to be The most common method of authentication is to require the use of a username and password, though other ways exist, such as thumbprint scans Authorization is the act of ensuring that a user has the authority to do what he asks to do File permissions are a good example of this users can t delete system-only files, for instance The silent partner of security makes sure that your system can t be fooled into believing a user is authentic or authorized Because of this requirement, there is more to security than inserting username and password text boxes in your program In this chapter, I tell you what tools are available in the NET Framework to help you make sure that your applications are secure

Security takes a fair amount of work to accurately design If you break the process into pieces, you find that it s a lot easier to accomplish The Patterns and Practices team (a group of software architects at Microsoft who devise programming best practices) have created a systematic approach to designing secure programs that I think you will find straightforward, so I describe it in the following sections

Different applications have different artifacts that need protection, but all applications share something that needs protection If you have a database in your application, that is the most important item to protect If your application is a server-based application, the server should rate fairly high when you re determining what to protect Even if your program is just a little single-user application, the software should do no wrong an outsider shouldn t be able to use the application to break into the user s computer