Hey,

I'm fixing some bugs in Filter::CBC and I encountered a problem...
The code is encrypted if ran for the first time, it should be left alone the second time. Now how to detect if the code is encrypted the first time? (similar behaviour to Acme::Bleach)
  1. I tried checking for ; but the encrypted data can contain ;s as well (altho probably not as much - ignoring ObFus).
  2. Another try was to check for keywords. print,my and if came to mind but it seemed that a program without those keywords is still possible (altho unlikely).
  3. A thought that crossed my mind was to have some comment on an unencrypted line noting that the code was encrypted, but the user might remove it, change it, etc...
  4. My last attempt included eval. By eval'ing the current line you could see if it was more or less valid perl. Problem would be : code spread over multiple lines, empty lines, POD, variables declared earlier, blocks, etc. Also the meaning of the module is not to verify the code is valid but to make sure no double encryptions happen.
So I'm pretty much stuck. The 'checking-for-keywords' method will probably return the fewest false positives.
Any suggestions would be appreciated alot :)

Greetz
Beatnik
... Quidquid perl dictum sit, altum viditur.

In reply to What data is code? by Beatnik

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