The case of the 9 bit AES key

 (v12.sh)

40 points | by ledoge 1 hour ago

5 comments

  • tptacek 1 minute ago
    "MuPDF versions before 1.28.5 use an implementation of the drand48 family" yeah, ok, so they're basically not doing real encryption. The number of bits in the key space isn't the real story; the keys simply aren't cryptographically random.
  • ubutler 12 minutes ago
    Rule #1 of rolling your own RNG: don’t.

    Rule #2? Please don’t.

  • JonChesterfield 26 minutes ago
    Wonderful.
  • paulpauper 1 hour ago
    it's like the weak hardware wallet entropy bug
  • jeffbee 53 minutes ago
    You'd have to be completely off your rocker to use a PDF tool written in C anyway.
    [-]
    • advisedwang 30 minutes ago
      very VERY few people judge tools like this by the language used to develop them.
      [-]
      • jeffbee 21 minutes ago
        How many people judge their tools based on the AES key entropy?
        [-]
        • OptionX 6 minutes ago
          A lot actually.

          You're confusing just assuming by default its enough for purpose rather than not caring at all.

    • cowlevel 38 minutes ago
      What are the alternatives?
    • lirolero 43 minutes ago
      Genuine question, since I'm not very knowledgeable about this: why is using C for a PDF tool such a bad idea?
      [-]
      • recursive 0 minutes ago
        buffer overflow vulnerability in code dealing with user generated data and a complex file format.