Monday, June 4, 2012

Defcon 20 QUALS - urandom 300

Connect to the given host and port, with the provided password.

The problem is as follow:
  Here come 100000 uint16_t, please tell me how to sort them into
  ascending order by sending me pairs of indicies to exchange, one
  per line, in the format: <index1>:<index2>
  For example to exchange elements 123 and 9821 you should send:
  Valid indicies are in the range 0..99999 inclusive. Send a blank
  line when you are done. If you correctly sort the array in
  sufficiently few moves I will give you a key!
  You have about 10 seconds to finish, and a 5 minute wait between
  successive connections.

Defcon 20 QUALS - Grab Bag 200

We have a jpeg file and its __MACOSX AppleDouble encoded Macintosh friend:

  • 115e0ba3c3d72647fcb9a53ae90e47a6.jpg
  • __MACOSX/._115e0ba3c3d72647fcb9a53ae90e47a6.jpg

The second file tells us that the jpeg comes from

Defcon 20 QUALS - Forensics 400

Execute photorec on the memory dump:
$ photorec for400/memory.dmp
Scan for Intel/Whole Disk/Other

During the recovery, notice some gpg files recovered:
$ find . -name "*.gpg"

$ file ./recup_dir.5/f1459128.gpg
./recup_dir.5/f1459128.gpg: PGP key security ring

This seems very good!