The case of the 9 bit AES key (v12.sh)

47 pointsby ledoge2 hours ago16 comments

tptacek 18 minutes 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 29 minutes ago

Rule #1 of rolling your own RNG: don’t.

Rule #2? Please don’t.

j16sdiz 17 minutes ago

That's why we use the system RNG !

JonChesterfield 44 minutes ago

Wonderful.

paulpauper 2 hours ago

it's like the weak hardware wallet entropy bug

jeffbee an hour ago

You'd have to be completely off your rocker to use a PDF tool written in C anyway.

lirolero an hour ago

Genuine question, since I'm not very knowledgeable about this: why is using C for a PDF tool such a bad idea?

recursive 18 minutes ago

buffer overflow vulnerability in code dealing with user generated data and a complex file format.

tptacek 17 minutes ago

I think the claim is hyperbolic, since most people memory-unsafe PDF implementations, but PDF is a monster format, a metaformat that brings in virtually every conceivable display format, and their renderer implementations with them, often poorly-maintained, never-touched reference implementations from the before times. PDF is pretty scary.

cowlevel an hour ago

What are the alternatives?

crote 11 minutes ago

PDF.js, for example. It's what Firefox uses, and most websites with integrated on-page PDF viewing functionality.

advisedwang an hour ago

very VERY few people judge tools like this by the language used to develop them.

jeffbee 38 minutes ago

How many people judge their tools based on the AES key entropy?

OptionX 23 minutes ago

A lot actually.

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

j16sdiz 14 minutes ago

just down vote it.

You can downvote anything not interesting.

If he have list some alternative or give example, it might be interesting.