cryptography: Fix umask while creating private key

- It should disable group write, not group read
- It should not disable exec as it affects only directories

certgen/__init__.py

@@ -2,7 +2,7 @@
 Sentinel:Certgen python package
 """
 
-__version__ = '6.1.1'
+__version__ = '6.1.2'
 
 
 DEFAULT_CERT_API_HOSTNAME = "sentinel.turris.cz"

certgen/cryptography.py

@@ -80,7 +80,7 @@ def generate_priv_key_file(key_path):
             backend=default_backend()
     )
 
-    old_umask = os.umask(0o057)
+    old_umask = os.umask(0o027)
     with open(key_path, "wb") as f:
         f.write(key.private_bytes(
             encoding=serialization.Encoding.PEM,