Add SSL Support for MariaDB (#3444)

* Add ssl options for mariadb

* Add ssl mode for mariadb

Add ssl mode as documented in https://mysqlclient.readthedocs.io/user_guide.html#functions-and-attributes

* run linting over settings.py

* Add docs for SSL mode with MariaDB

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Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/paperless/settings.py

@@ -506,7 +506,16 @@ if os.getenv("PAPERLESS_DBHOST"):
     # Leave room for future extensibility
     if os.getenv("PAPERLESS_DBENGINE") == "mariadb":
         engine = "django.db.backends.mysql"
-        options = {"read_default_file": "/etc/mysql/my.cnf", "charset": "utf8mb4"}
+        options = {
+            "read_default_file": "/etc/mysql/my.cnf",
+            "charset": "utf8mb4",
+            "ssl": {
+                "ssl_mode": os.getenv("PAPERLESS_DBSSLMODE", "PREFERRED"),
+                "ca": os.getenv("PAPERLESS_DBSSLROOTCERT", None),
+                "cert": os.getenv("PAPERLESS_DBSSLCERT", None),
+                "key": os.getenv("PAPERLESS_DBSSLKEY", None),
+            },
+        }
 
         # Silence Django error on old MariaDB versions.
         # VARCHAR can support > 255 in modern versions