Usage: pyrsa-verify [options] public_key signature_file

Verifies a signature, exits with status 0 upon success, prints an error message and exits with
status 1 upon error.

Options:
  -h, --help            show this help message and exit
  -i INPUT, --input=INPUT
                        Name of the file to verify. Reads from stdin if not specified.
  --keyform=KEYFORM     Key format of the public key - default PEM