Secure Programming

• Paranoia?

  • You don't have to be crazy, but it helps!

• Most programmers expect few users will encounter bug

  • Users avoid triggering the bug
  • Regression testing only exercises expected behaviour
  • Needs more random input testing

• Attackers do the opposite!

  • Use absurd input to trigger a crash
  • Characterise the error condition
  • Abuse the bug(s) to expose a vulnerability