Using crunch on the Amazon EC2 Cluster

in my previous post i described how to set up a amazon ec2 instance and get pyrit up and running.

even though its not the most sophisticated application, i find myself using crunch wordlist generator alot for simple, incremental brute forcing. However the latest version (3.0.1) doesn't compile out of the box on the ec2 instance. To get it working you have to:

edit the Makefile and change the LFS variable from:
LFS = $(shell getconf POSIX_V6_ILP32_OFFBIG_CFLAGS)
to
LFS = -m64 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64

You may have to install some additional packages via yum (sudo yum install glibc-devel), however if you followed the script in my previous post, that should be installed already.

I also made a quick edit to crunch.cpp to save the status of the generation to a local file every million words, this way i could resume it later on with the -s switch.

Then create a simple script that will start/resume the crack:

SAVE_FILE=session.save
MAX_LEN=14
CHARSET=lalpha-numeric

if [ -f $SAVE_FILE ]; then
    echo Found Save File!
    echo Setting start block to `cat $SAVE_FILE`
    crunch 1 $MAX_LEN -f /usr/bin/charset.lst $CHARSET -s `cat $SAVE_FILE`| pyrit -e SSID -r /home/ec2-user/file.cap -i - --all-handshakes attack_passthrough
else
    crunch 1 $MAX_LEN -f /usr/bin/charset.lst $CHARSET | pyrit -e SSID -r /home/ec2-user/file.cap -i - --all-handshakes attack_passthrough
fi