EvilZone
Hacking and Security => Hacking and Security => : Raavgo May 28, 2013, 02:58:03 PM
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Hello Ez,
To practice my hacking skill I am doing Hacker challenges.
The challenge I will ask you about, gave me a headache for about 3 days now.
I've been googling and thinking about it a lot.
So here it comes:
Challenge Description
Decrypt the PGP file: secretmusic.mp3.asc
Complete your task! (you will find out)
My Questions are:
- How do I decrypt a PGP file (Brute Force?, Rainbow Tables?)
- Do I need to code my own program for the decryption?
If you have some, I would love to get some good Tips.
have a nice day Raavgo
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Is it this challenge -> https://www.hacking-lab.com/cases/7039-music-hero/index.html ?
You aren't going crack pgp itself. That leaves only the other options. I'm not a member of hacking-lab but I managed to get the tarball of the challenge. I was thinking maybe that playing a game of Music Hero with the provided music would reveal the passphrase. Instead of playing I decided to try and brute-force the score. Here's the script for interests sake:
#!/bin/sh
# I'm guessing this can be solved by brute-forcing the perfect score
# that you would obtain by playing the provided mp3 in a game of Music Hero.
SCORE=0
LIMIT=$1
while [ $SCORE -ne $LIMIT ]; do
gpg --no-tty \
--homedir .gnupg/ \
--passphrase $SCORE \
--output secret.mp3 \
--decrypt secretmusic.mp3.asc > /dev/null 2>&1
if [ $? -eq 0 ]; then
echo "KEY FOUND: $SCORE"
exit
fi
SCORE=$(( $SCORE + 1 ))
if [ $(( $SCORE % 1000 )) -eq 0 ]; then
echo -n "$SCORE..."
fi
done
echo "Limit reached, giving up."
After trying roughly 1.7 million scores so far, I haven't found a match. Maybe the score isn't the answer? Can you provide any more info? Also, I'm a complete noob to gpg/pgp so I could be missing something obvious with that script...
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Yeah its that challenge.
I've thought about a dictionary attack or maybe a brute force attack via GPU.
I don't really have more information than the given things :(
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I don't think blind brute-force will work. I only tried the game score because it mentioned Music Hero and provided music files you can play with. I gave up after 2 million, though.
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Well thats why I thought a word list would be good but still I will keep the brute force idea in my mind maybe it is a easy password.. Who knows ;)