make linter happy

raps.py

@@ -1,54 +1,83 @@
 #!/usr/bin/env python3
 
+import argparse
+import datetime
+import hashlib
+import os
 import random
 import secrets
-import os
-import hashlib
+import string
+import sys
 
-SECRET_FILE = 'secret'
+DEFAULT_SECRET_PATH = 'secret'
 
 def create_secret():
+    """returns 128 bytes of randomness as hex bytes"""
     return secrets.token_hex(128)
 
 def generate_password():
-    import string
+    """returns a random 24 char password"""
     alphabet = string.ascii_letters + string.digits + '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}'
     return ''.join(random.choice(alphabet) for i in range(24))
 
 def month_timestamp():
-    import datetime
+    """returns the unix timestamp of the first of the current month"""
     today = datetime.datetime.now()
     start_of_month = datetime.datetime(today.year, today.month, 1, 0, 0, 0, 0)
     return int(start_of_month.timestamp())
 
 def generate_seed(secret):
-    m = hashlib.sha256()
-    m.update(bytes.fromhex(secret))
-    m.update(str(month_timestamp()).encode())
-    return m.digest()
+    """returns an rng seed based on the current date"""
+    hash_object = hashlib.sha256()
+    hash_object.update(bytes.fromhex(secret))
+    hash_object.update(str(month_timestamp()).encode())
+    return hash_object.digest()
+
+def generate_secret(secret_path):
+    """generates a secret and writes it as a file"""
+    print('Generating a new secret... ', end='')
+    secret = create_secret()
+    with open(secret_path, 'w') as file:
+        file.write(secret)
+    print('done. Send this to the other party:')
+    print(secret)
 
 def main():
-    import argparse
-    parser = argparse.ArgumentParser(prog='Remote Admin Password Solution', description='Generate rotating passwords based on a shared secret')
+    parser = argparse.ArgumentParser(
+                prog='Remote Admin Password Solution',
+                description='Generate rotating passwords based on a shared secret'
+    )
+    parser.add_argument('--secret', action='store', help='path to secret file')
     parser.add_argument('--new-secret', action='store_true', help='generate a new secret')
 
     args = parser.parse_args()
 
-    secret = ''
-    if not os.path.isfile(SECRET_FILE) or args.new_secret:
-        print('Generating a new secret... ', end='')
-        secret = create_secret()
-        with open(SECRET_FILE, 'w') as f:
-            f.write(secret)
-        print('done. Send this to the other party:')
-        print(secret)
-
+    if args.secret:
+        secret_path = os.path.realpath(args.secret)
     else:
-        secret = open(SECRET_FILE, 'r').read().strip()
-        print('Secret loaded.')
+        secret_path = os.path.realpath(DEFAULT_SECRET_PATH)
+
+    secret = ''
+    if args.new_secret:
+        if os.path.isfile(secret_path):
+            choice = ''
+            while choice.lower() != 'y' and choice.lower() != 'n':
+                choice = input(f'Secret {secret_path} exists! Overwrite? [y/n]: ')
+            if choice.lower() == 'y':
+                generate_secret(secret_path)
+        else:
+            generate_secret(secret_path)
+
+    try:
+        secret = open(secret_path, 'r').read().strip()
+    except FileNotFoundError:
+        print(f'ERROR: Secret file {secret_path} could not be found.')
+        sys.exit(1)
+
+    print(f'Secret {secret_path} loaded.')
 
     random.seed(generate_seed(secret))
-    
+
     print('The password of the month is:')
     print(generate_password())