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When the Suspend activity is encountered, the workflow pauses as with the Delay activity, except the Suspend activity waits for the workflow to be started by some external action (usually by an administrator) That s unlike the Delay activity, which only waits a set period of time When a Suspend activity is encountered, all state information is saved and associated with the current instance The information can be recovered when the workflow execution resumes The Terminate activity immediately stops the workflow You can use this in the event of some fatal error or other unusual situation This would be the same as a Try Catch that stopped your program rather than allowing the user to respond to the error (as in the Suspend activity) When a workflow is terminated, an error is logged, and a message can be provided for more information.

Some databases have dangerous functionality that is enabled by default. For example, a version of Microsoft SQL Server provides SQL commands that allows users to open inbound and outbound network connections. Cesar Cerrudo s Manipulating Microsoft SQL Server Using SQL Injection shows how such functionality can be used by an attacker to copy data to an attacker s database server, upload arbitrary binaries to the victim system for execution, port scan the victim s internal network, and much, much more. To prevent an attacker from having a field day with any extra functionality provided by your database, you should clearly review your database configuration and disable all such functionality by default. In addition, hardening guidelines for the operating system that the database is running on should be followed; for instance, unused services and accounts should be disabled (there is usually no need for a web server to be running on the database host).

these support files could easily be installed on top of each other, a common occurrence leading to broken applications (called DLL hell) The second problem was security A user s computer, when connected to the Internet, could effectively allow code to run, written by anybody, and the ActiveX technology was fully native, not restricted by the Java or HTML sandboxes (more about these in a moment); therefore, a user could innocently go to a web page that downloaded an ActiveX control that wrought havoc or stole vital information from their system As such, many users refused to use them, and many corporate administrators even disallowed them from use within the enterprise.

The prevention strategies for SQL injection introduced in this chapter focus on validating or escaping data before it is used in an SQL query. In addition to this SQL-specific validation or escaping, you should not ignore validation of data at the time it actually enters your system. Following the best practice of constraining all input variables (e.g., query parameters in an HTTP request) as early as possible in your code may well save you from being vulnerable in case a programmer forgot to escape a particular variable that is used in an SQL query. Also, rejecting unreasonably long inputs may prevent an attacker from exploiting a buffer overflow in the SQL parser that you weren t aware of and have not applied patches for. Applying validation both at the entry points to your code and before a query means that you may have to do the work twice. However, this small inefficiency is usually well worth the additional safety margin.

The Suspend and Terminate activities are used most often in exception handling They provide a basis for exception handling with workflows by logging errors and either waiting for user intervention (Suspend activity) or just stopping the workflow altogether (Terminate activity)..

In an attempt to remedy the situation, you could decide not to store passwords in the clear Instead, you could store an encrypted version of the passwords, and decrypt the passwords in the file whenever you need to check them To do so, you could use a symmetric encryption algorithm, such as AES (Advanced Encryption Standard) (We will discuss symmetric encryption algorithms in 12) You would need to keep track of a key used to encrypt the passwords, and then you would need to determine where to store the key Storing the key in the password file itself would be a bad idea, since then an attacker that gets hold of the password file could also decrypt all of the passwords in the file If the key is stored anywhere on the same system as the password file, in fact, that system still becomes an extremely valuable attack target.

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