use argparser

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

@@ -5,6 +5,7 @@ import cryptography.hazmat.primitives.serialization
 import cryptography.x509
 import math
 
+
 def convert_to_sexp(data):
     if isinstance(data, int):
         return convert_to_sexp(data.to_bytes(
@@ -18,7 +19,8 @@ def convert_to_sexp(data):
     else:
         return b'(' + b''.join(convert_to_sexp(i) for i in data) + b')'
 
-def main(argv):
+
+def create_gpg_key():
     backend = cryptography.hazmat.backends.default_backend()
     with open('smartcard-app-id.hex', 'r') as f:
         appid = int(f.read(), 16)
@@ -36,6 +38,22 @@ def main(argv):
     with open('gpg-key.sexp', 'wb') as f:
         f.write(key)
 
+
+def _init_argparser():
+    import argparse
+    argparser = argparse.ArgumentParser(
+        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)',
+    )
+    return argparser
+
+
+def main(argv):
+    argparser = _init_argparser()
+    args = argparser.parse_args(argv[1:])
+    create_gpg_key(**vars(args))
+    return 0
+
 if __name__ == '__main__':
     import sys
     sys.exit(main(sys.argv))