replace hard-coded input path with positional arg

create-gpg-shadow-key-from-x509-cert-req.py

@@ -22,9 +22,9 @@ def convert_to_sexp(data):
         return b'(' + b''.join(convert_to_sexp(i) for i in data) + b')'
 
 
-def create_gpg_key(smartcard_app_id_hex):
+def create_gpg_key(input_path, smartcard_app_id_hex):
     backend = cryptography.hazmat.backends.default_backend()
-    with open('cert-request.pem', 'rb') as f:
+    with open(input_path, 'rb') as f:
         req = cryptography.x509.load_pem_x509_csr(f.read(), backend)
     assert req.is_signature_valid
     pubnums = req.public_key().public_numbers()
@@ -45,6 +45,10 @@ def _init_argparser():
         description='create a shadowed-private-key in sexp format for gnupg\'s private-keys-v1.d folder'
             + ' containing the public key of a PEM-encoded X.509 certificate signing request (CSR)',
     )
+    argparser.add_argument(
+        'input_path',
+        help='path to PEM-encoded X.509 signing request',
+    )
     argparser.add_argument(
         '--smartcard-app-id',
         dest='smartcard_app_id_hex',