code styling

app/util.py

@@ -0,0 +1,17 @@
+try:
+    # Crypto | Cryptodome on Debian
+    from Crypto.PublicKey import RSA
+    from Crypto.PublicKey.RSA import RsaKey
+except ModuleNotFoundError:
+    from Cryptodome.PublicKey import RSA
+    from Cryptodome.PublicKey.RSA import RsaKey
+
+
+def load_file(filename) -> bytes:
+    with open(filename, 'rb') as file:
+        content = file.read()
+    return content
+
+
+def load_key(filename) -> RsaKey:
+    return RSA.import_key(extern_key=load_file(filename), passphrase=None)