Summary

There many levels of examination and analysis that can help you understand and fix security bugs in your applications. Simple approaches involve the observation of programs in use to study their behavior and do not require you to understand the inner workings of the code. Reverse engineering requires a higher level of understanding of the code and its implementation details and, if the source code is not available, the use of a debugger and/ or decompiler/disassembler to reveal its inner workings.

Remember also that reverse engineering enables attackers with access to the binary to obtain all of the implementation details of the code. In addition to understanding the binarys implementation to find security flaws, reverse engineering can be used to modify a programs original behavior to fix bugs or to bypass software-imposed restrictions. Obfuscation and other techniques that attempt to prevent reverse engineering might make the process more difficult, but they cannot completely prevent it. Examination of your code by the methods discussed in this chapter is a valuable tool for understanding how others might exploit the binaries you ship.