desplodocus_mt

A multithreaded DES password cracker that performs dictionary-based brute-force attacks. Given a dictionary of plaintext passwords and a file of DES password hashes, it tries all possible 2-character salt combinations (4096) with every dictionary word to find matches. Work is distributed across threads using dynamic load balancing with a shared mutex-protected index.

Prerequisites

• GCC
• libmagic (file type detection)
• libcrypt (DES hashing via crypt_rn())
• POSIX threads (pthread)

Installing dependencies (Debian/Ubuntu)

sudo apt install gcc libmagic-dev libcrypt-dev

Building

make

To clean build artifacts:

make clean

Usage

./desplodocus_mt -i <hash_file> -p <password_file> [options]

Options

Flag	Description
-i file	Hash file (required) — one DES hash per line
-p file	Password dictionary file (required) — one password per line
-o file	Output file (default: stdout)
-t #	Number of threads (default: 1)
-n	Be nice (increase process nice value)
-v	Enable verbose mode
-h	Show help text

Input File Formats

Password dictionary (passwords.txt) — one plaintext password per line:

password
123456
letmein
dragon

Hash file (hashes.txt) — one DES hash per line (without the 2-character salt prefix):

FlsQMRbOqsSxY
rl1/EzGqilVgo

Example

./desplodocus_mt -i hashes.txt -p passwords.txt -t 4

Example Output

Cracked passwords are printed to stdout (or the file specified with -o):

cracked: FlsQMRbOqsSxY : password
cracked: rl1/EzGqilVgo : letmein
*** failed: x9Jf8k2lPqRsT

Per-thread and total statistics are printed to stderr:

thread:  0      1.23 sec  cracked:       1    failed:       0   total:       1
thread:  1      1.45 sec  cracked:       1    failed:       0   total:       1
thread:  2      0.98 sec  cracked:       0    failed:       1   total:       1
thread:  3      0.02 sec  cracked:       0    failed:       0   total:       0
total :  4      1.45 sec  cracked:       2    failed:       1   total:       3

Author

Alejandro Alvarado — CS 333, Intro to Operating Systems