This is a tool used to recover the passphrase of a GPG secret (a.k.a private) key.
bruteforce-gpg [-h] [-v] [-t NUM_THREADS] -f WORDLIST GPG_SECRET_KEY
This tool depends on the libgpgme library.
On Kali
$ sudo apt install libgpgme-dev
On Arch Linux
$ sudo pacman -S gpgme
$ git clone https://github.com/mathewmarcus/bruteforce-gpg.git
$ cd bruteforce-gpg
$ make
bruteforce-gpg
will be installed in the /usr/local/bin/
directory, so you may want to ensure it is included in your PATH
environment variable.
make install
With the default (i.e. 1) threads
$ bruteforce-gpg -f /usr/share/wordlists/rockyou.txt private_key.asc
With 8 threads
$ bruteforce-gpg -t 8 -f /usr/share/wordlists/rockyou.txt private_key.asc