cli.py 文件源码

def keygen():
    """Key generator."""

    # Parse the CLI options
    parser = OptionParser(usage='usage: %prog [options] keysize',
                          description='Generates a new RSA keypair of "keysize" bits.')

    parser.add_option('--pubout', type='string',
                      help='Output filename for the public key. The public key is '
                           'not saved if this option is not present. You can use '
                           'pyrsa-priv2pub to create the public key file later.')

    parser.add_option('-o', '--out', type='string',
                      help='Output filename for the private key. The key is '
                           'written to stdout if this option is not present.')

    parser.add_option('--form',
                      help='key format of the private and public keys - default PEM',
                      choices=('PEM', 'DER'), default='PEM')

    (cli, cli_args) = parser.parse_args(sys.argv[1:])

    if len(cli_args) != 1:
        parser.print_help()
        raise SystemExit(1)

    try:
        keysize = int(cli_args[0])
    except ValueError:
        parser.print_help()
        print('Not a valid number: %s' % cli_args[0], file=sys.stderr)
        raise SystemExit(1)

    print('Generating %i-bit key' % keysize, file=sys.stderr)
    (pub_key, priv_key) = rsa.newkeys(keysize)

    # Save public key
    if cli.pubout:
        print('Writing public key to %s' % cli.pubout, file=sys.stderr)
        data = pub_key.save_pkcs1(format=cli.form)
        with open(cli.pubout, 'wb') as outfile:
            outfile.write(data)

    # Save private key
    data = priv_key.save_pkcs1(format=cli.form)

    if cli.out:
        print('Writing private key to %s' % cli.out, file=sys.stderr)
        with open(cli.out, 'wb') as outfile:
            outfile.write(data)
    else:
        print('Writing private key to stdout', file=sys.stderr)
        sys.stdout.write(data)