Secure Coding: Principles and Practices

2.2. Principles of Security Architecture

We've defined 30 basic principles of security architecture:

1. Start by asking questions

2. Select a destination before stepping on the gas

3. Decide how much security is "just enough"

4. Employ standard engineering techniques

5. Identify your assumptions

6. Engineer security in from day one

7. Design with the enemy in mind

8. Understand and respect the chain of trust

9. Be stingy with privileges

10. Test any proposed action against policy

11. Build in appropriate levels of fault tolerance

12. Address error-handling issues appropriately

13. Degrade gracefully

14. Fail safely

15. Choose safe default actions and values

16. Stay on the simple side

17. Modularize thoroughly

18. Don't rely on obfuscation

19. Maintain minimal retained state

20. Adopt practical measures users can live with

21. Make sure some individual is accountable

22. Self-limit program consumption of resources

23. Make sure it's possible to reconstruct events

24. Eliminate "weak links"

25. Build in multiple layers of defense

26. Treat an application as a holistic whole

27. Reuse code known to be secure

28. Don't rely on off-the-shelf software for security

29. Don't let security needs overwhelm democratic principles

30. Remember to ask, "What did I forget?"

The following sections define these principles in greater detail, and subsequent chapters explain them in the context of different phases of software development.

2.2.1. Start by Asking Questions

Whether you're starting from scratch with a clean sheet of paper or have been handed a complex piece of software that needs fixing or updating, your first step in ...