PyRarCrack

Bruteforce attack for .rar using unrar

usage: pyrarcrack.py [-h] [--start START] [--stop STOP] [--verbose VERBOSE]
                     [--alphabet ALPHABET] [--file FILE]

Python combination generator to unrar

optional arguments:
  -h, --help           show this help message and exit
  --start START        Number of characters of the initial string [1 -> "a", 2-> "aa"]
  --stop STOP          Number of characters of the final string [3 -> "ßßß"]
  --verbose VERBOSE    Show combintations
  --alphabet ALPHABET  alternative chars to combinations
  --advanced-alphabet ADVANCED_ALPHABET
                        a file contains the own alphabet for a password char (per a line)
  --file FILE          .rar file [file.rar]
  --processes PROCESSES
                        number of workers
  --no-mt               do not use multiprocessing

Performance notes

Implementations

There are multiple implementations. Depends on python module availability, corresponding method to be used:

• unrardll. Shows as most efficient, but the same time the hardest to install. Doing compilation during the installation. Requires /usr/lib/libunrar.so and /usr/include/unrar/dll.hpp (libunrar package).
  With arguments --start 3 --stop 3 --alphabet 0987654321ABCDEFGHIJKLMNOPQRSTUVWXYZ on i7-8565U takes

real  0m10.652s
user  0m9.424s
sys 0m1.178s

• unrar. Second by efficiency method. Does not compile anything during installation. Loads /usr/lib/libunrar.so dynamically in runtime.
  With arguments --start 3 --stop 3 --alphabet 0987654321ABCDEFGHIJKLMNOPQRSTUVWXYZ on i7-8565U takes

real  0m19.029s
user  0m15.776s
sys 0m3.174s

• subprocess. Fallback method. Calling unrar binary in subshell process.
  With arguments --start 3 --stop 3 --alphabet 0987654321ABCDEFGHIJKLMNOPQRSTUVWXYZ on i7-8565U takes

real  3m56.164s
user  2m58.832s
sys 1m14.105s

Note: It is on you to install unrardll or unrar modules.

RAR versions

Noticed that newer archive format has more stronger encryption which affects on bruteforce time.

$ unrar l /var/tmp/test.rar 

UNRAR 6.22 freeware      Copyright (c) 1993-2023 Alexander Roshal

Archive: /var/tmp/test.rar
Details: RAR 5
_________^^^^^^_______

using the same --start 3 --stop 3 --alphabet 0987654321ABCDEFGHIJKLMNOPQRSTUVWXYZ on i7-8565U

RAR format \ method	unrardll	unrar
RAR 5	14m49s	16m3s
RAR 4	10s	20s

Multiprocessing

You still have ability to run with origin algorithm by providing --no-mt argument.

By default number of processes equals to number of CPU cores minus 1.
You can specify the number by providing an --processes NN argument.

Timing measurements with --start 3 --stop 3 --alphabet 0987654321ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef

engine \ no. processes	--no-mt	1	2	3	4
unrardll	17.0s	17.3s	8.6s	5.9s	5.2s

Advanced alphabet

If you know precise length of a password and character variants per a char position, you can use --advanced-alphabet by providing a file contains those variants. Each line of that file should contain an alphabet for a particular letter of a password. Where line number represents a letter position.

Example

$ python pyrarcrack.py --start 10 --stop 10 --file example_path.rar --alphabet 1234567890
Loaded engine: unrardll

Password found: 1234567890
Time: 0.06715750694274902