Secure pdfs with pdftk

secure_pdfs.sh

for file in Dropbox/Taxes/{,**/,**/**/}*.pdf

do
  protected=0
  passwordworks=1
  pdftk "$file" dump_data output /dev/null dont_ask || protected=1
  
  # not protected so just encrypt
  if [ $protected -eq 0 ]
  then
    pdftk "$file" output "${file/.pdf/}_protected.pdf" user_pw PASS
    mv "$file" "$file.old"
    mv "${file/.pdf/}_protected.pdf" "$file"
    echo "SUCCESS: $file is now protected";
  
  # has password so try to change it 
  else
    pdftk "$file" input_pw OLDPASS dump_data output /dev/null dont_ask || passwordworks=0
  
    # password works, so change it 
    if [ $passwordworks -eq 1 ]
    then
      pdftk "$file" input_pw OLDPASS output "${file/.pdf/}_new.pdf" user_pw PASS
      mv "$file" "$file.old"
      mv "${file/.pdf/}_new.pdf" "$file"
      echo "SUCCESS: $file password is now changed";
    else
      echo "WARNING: $file password does not work";
    fi
  fi
done