docs: def decrypt(source, dest=None, passphrase=None):
      """Attempts to decrypt a file"""
      if not os.path.exists(source):
          raise CryptoritoError("Encrypted file %s not found" % source)
  
      cmd = [gnupg_bin(), gnupg_verbose(), "--decrypt", gnupg_home(),
             passphrase_file(passphrase)]
  
      if dest:
          cmd.append(["--output", dest])
  
      cmd.append([source])
      stderr_output(flatten(cmd))
      return True