Adds name parameter to generate_keys so the name can be chosen from terminal

apps/generate_key.py

@@ -1,5 +1,6 @@
 import os.path
-from sys import exit
+from getopt import getopt
+from sys import argv, exit
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
@@ -9,9 +10,6 @@ from cryptography.hazmat.primitives.asymmetric import ec
 # Simple tool to generate an ECDSA private key using the secp256k1 curve and save private and public keys
 # as 'pisa_sk.der' 'and pisa_pk.der', respectively.
 
-SK_FILE_NAME = "../pisa_sk.der"
-PK_FILE_NAME = "../pisa_pk.der"
-
 
 def save_sk(sk, filename):
     der = sk.private_bytes(
@@ -31,6 +29,16 @@ def save_pk(pk, filename):
 
 
 if __name__ == "__main__":
+    name = "pisa"
+
+    opts, _ = getopt(argv[1:], "n:", ["name"])
+    for opt, arg in opts:
+        if opt in ["-n", "--name"]:
+            name = arg
+
+    SK_FILE_NAME = "../{}_sk.der".format(name)
+    PK_FILE_NAME = "../{}_pk.der".format(name)
+
     if os.path.exists(SK_FILE_NAME):
         print('A key with name "{}" already exists. Aborting.'.format(SK_FILE_NAME))
         exit(1)