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The complexity involved in configuring a large number of available security settings could make security administration impossibly complex. Fortunately, you do not have to start from scratch. Security templates are available that allow you to set up various standard levels of security. You can also analyze a custom security setting by compar ing it against standard templates. Security is always a balance. There is no point in setting up policies on your servers so strict that many of your users, particularly those with legacy client operating systems, cannot access the resources or run the software that they require to do their jobs. However, if security settings do become too restric tive, tools such as Resultant Set Of Policy allow you to quickly identify the source of the problem. The 70-291 examination does not require you to know how to design security systems. You do, however, need to know how to audit systems using security templates, and how to implement predefined security settings for software and security updates. You need to be able to check that security configurations are working correctly, and to troubleshoot them if they are not. You also need to be able to access and analyze secu rity statistics. Finally, you need to be aware that security must present a moving target. What is secure today might not be secure tomorrow, and breached security is usually worse than no security at all.

IL is stack based, which means that all its instructions push operands onto an execution stack and pop results off the stack. Because IL offers no instructions to manipulate registers, compiler developers have an easy time producing IL code; they don t have to think about managing registers, and fewer IL instructions are needed (since none exist for manipulating registers).

Figure 7 1: ILDasm.exe output showing metadata from preceding code 9: Methods Figure 9 1 The IL code for SomeType s constructor method Figure 9 2 The IL code for SomeType s type constructor method 11: Events Figure 11 1 Architecting an application to use events 12: Working with Text Figure 12 1: StringSorting results Figure 12 2: Installing East Asian Language files using the Regional And Language Options Control Panel dialog box Figure 12 3: Result of GetTextElementEnumerator Figure 12 4: Result of ParseCombiningCharacters Figure 12 5: Numeric value formatted correctly to represent Vietnamese currency Figure 12 6: Numeric value formatted to represent a culture neutral currency 14: Arrays Figure 14 1 Arrays of value and reference types in the managed heap 17: Delegates Figure 17 1 ILDasm.exe showing the metadata produced by the compiler for the delegate Figure 17 2 ILDasm.exe proves that the compiler emitted a call to the Set.Feedback delegate type s Invoke method Figure 17 3 Internal representation of delegate chains 18: Exceptions Figure 18 1 PerfMon.exe showing the .NET CLR exception counters Figure 18 2 Microsoft PowerPoint showing its Unhandled Exception dialog box Figure 18 3 An unhandled exception in a window procedure causes Windows Forms to display this dialog box. Figure 18 4 Visual Studio .NET Exceptions dialog box showing the different kinds of exceptions Figure 18 5 Visual Studio .NET Exceptions dialog box showing CLR exceptions by namespace Figure 18 6 Visual Studio .NET Exceptions dialog box showing CLR exceptions defined in the System namespace Figure 18 7 Making Visual Studio .NET aware of your own exception type Figure 18 8 Attaching Visual Studio .NET s debugger to a process Figure 18 9 Selecting the kind of code I want to debug for my project 19: Automatic Memory Management (Garbage Collection) Figure 19 1 Newly initialized managed heap with three objects constructed in it Figure 19 2 Managed heap before a collection 430

<iis_default_root>\Aspnet_client\system_web\<version>\Themes Use this folder for applications running in Internet Information Services (IIS). For example, for the current version of the .NET Framework, you would add your theme to the C:\inetpub\wwwroot\aspnet_client\system_web\4_0_30319\ folder. %systemRoot%\microsoft.nET\Framework\<version>\AsP.nETClientFiles\Themes

all allocations out of a source file, and on a specific line in a source file. In addition, you can have the MemStress extension prompt you with a message box on each allocation asking whether you want this particular allocation to fail, and you can also set the DCRT library flags you'd like in effect for your program. The MemStressDemo program is a sample MFC program (that comes with this book's sample files) that allows you to experiment with setting different options from the MemStress user interface (UI) and see the results. It also serves as the unit test for MemStress itself. Using the MemStress extension is relatively simple. In your code, include BUGSLAYERUTIL.H and call the MEMSTRESSINIT macro with the name of your program. To stop the memory allocation hooking, use the MEMSTRESSTERMINATE macro. You can start and stop the hook as many times as you want when running your program. After you've compiled your program, start the MemStress UI, click the Add Program button, and type the same name that you specified in the MEMSTRESSINIT macro. After you've selected the failure options you want, click the Save Program Settings button to save the settings into MEMSTRESS.INI. Now you can run your program and see how it behaves when it fails memory allocations. You'll probably want to be very selective about using the MemStress extension. For example, if you specify that you want all allocations over 100 bytes to fail and you have the MEMSTRESSINIT macro in your MFC application's InitInstance function, you'll likely take down MFC because it will be unable to initialize. You'll have the best results with the MemStress extension if you limit its use to key areas in your code so that you can test them in isolation. Most of the implementation of MemStress is in the reading and processing of the MEMSTRESS.INI file, in which all the settings for individual programs are stored. From the DCRT library perspective, the important function is the call to _CrtSetAllocHook during the MemStress initialization because this call sets the hook function, AllocationHook, as the allocation hook. If the allocation hook function returns TRUE, the allocation request is allowed to continue. By returning FALSE, the allocation hook can have the DCRT library fail the allocation request. The allocation hook has only one hard requirement from the DCRT library: if the type of block, as specified by the nBlockUse parameter, is marked as a _CRT_BLOCK, the hook function must return TRUE to allow the allocation to take place. The allocation hook gets called on every type of allocation function. The different types, as specified in the first parameter to the hook, are _HOOK_ALLOC, _HOOK_REALLOC, and _HOOK_FREE. In my AllocationHook function, if the type is _HOOK_FREE, I skip all the code that determines whether the memory request should pass or fail. For _HOOK_ALLOC and _HOOK_REALLOC types, my AllocationHook function performs a series of if statements to determine whether any of the failure conditions are met. If a failure condition is met, I return FALSE. Interesting Stress Problems Everything worked great in MemStress on my initial console sample program, and I was feeling fine. As I finished off the MFC-based MemStressDemo program, I noticed a compelling problem. If I elected to have MemStress ask me with a message box whether I wanted allocations to fail, I would hear a series of beeps and MemStressDemo would stop working. I was able to duplicate the problem every time and to duplicate the serious stress the problem was causing me because I didn't see what the issue could be. After a few runs, I finally got a message box to show up. Instead of being in the center of the screen, the message box was down in the lower right-hand corner. When message 645

// Clear the StringBuilder (allocates a new Char array). sb.Length = 0; // Load the uppercase String into the StringBuilder, // and perform more manipulations. sb.Append(s).Insert(8, "Marc-"); // Convert the StringBuilder back to a String. s = sb.ToString(); // Display the String to the user. Console.WriteLine(s); // "JEFFREY-Marc-RICHTER"

string cmdText = SELECT CustomerData FROM MyCustomers"; SqlConnection conn = new SqlConnection(connStr); SqlCommand cmd = new SqlCommand(cmdText, conn); cmd.Connection.Open(); SqlDataReader reader = cmd.ExecuteReader(); while(reader.Read()) { MyCustomer cust = (MyCustomer) reader[0]; // Do some work } cmd.Connection.Close();

Computing results before the program executes and hard-coding them into variables used at run time Computing results before the program executes and putting them into a file that s loaded at run time Computing results once, at program startup, and then referencing them each time they re needed Computing as much as possible before a loop begins, minimizing the work done inside the loop Computing results the first time they re needed and storing them so that you can retrieve them when they re needed again