Bruteforce GPG passphrase using script

Question

I have forgotten my passphrase for my gpg key on linux. Can someone please help me write a simple script to use bruteforce to crack the key? I remember some of the words which MIGHT be in the passphrase, so hopefully, it will not take long for my computer to bruteforce it.

All is not lost if I can't recover the passphrase, it just means I will not be able to work on my project for the next 10 days until I get back to work to get another copy of the files, but this time with a new key for which I will remember to passphrase.

However, it will be nice to be able to work on my project in these 10 days.

Answer 1

Maybe something like:

#!/bin/bash
#

# try all word in words.txt
for word in $(cat words.txt); do 

  # try to decrypt with word
  echo "${word}" | gpg --passphrase-fd 0 --no-tty --decrypt somegpgfile.gpg --output somegpgfile;

  # if decrypt is successfull; stop
  if [ $? -eq 0 ]; then

    echo "GPG passphrase is: ${word}";
    exit 0;

  fi

done;

exit 1;