Merge pull request #5305 from storytold/fix/sec-export-settings-no-passwords

Export for Screens: keep PDF passwords out of remembered settings

crates/engine/src/cmd/fileio/screens.rs

@@ -698,6 +698,8 @@ fn preset_settings(s: &Session, cmd: &str, given: &Map<String, Value>) -> Result
     // Refuse what an export would refuse, now rather than when the preset is used.
     check_settings(s, &Value::Object(settings.clone())).map_err(|e| bad(cmd, e.to_string()))?;
     Folders::of(&ScreenParams::of(&Value::Object(settings.clone()))?).map_err(|e| bad(cmd, e.to_string()))?;
+    let mut settings = settings;
+    remove_passwords(&mut settings);
     Ok(settings)
 }
 
@@ -1275,9 +1277,33 @@ fn remember(s: &mut Session, p: &Value) {
     let _ = store_settings(s, settings);
 }
 
+/// The PDF passwords an export may be given (`security` of a PDF row or of `settings.pdf`).
+const PASSWORD_KEYS: [&str; 2] = ["openPassword", "permissionsPassword"];
+
+/// `settings` without the PDF passwords anywhere in them: settings kept in the document (which
+/// native saves write) or in the preferences hold the export's choices, never its secrets, as
+/// the PDF settings themselves are saved without them.
+fn remove_passwords(settings: &mut Map<String, Value>) {
+    for key in PASSWORD_KEYS {
+        settings.remove(key);
+    }
+    for v in settings.values_mut() {
+        remove_passwords_in(v);
+    }
+}
+
+fn remove_passwords_in(v: &mut Value) {
+    match v {
+        Value::Object(m) => remove_passwords(m),
+        Value::Array(items) => items.iter_mut().for_each(remove_passwords_in),
+        _ => {}
+    }
+}
+
 /// Make `settings` the document's export settings. Not an undo step (like the settings of any
 /// export); the document has changed only if they differ.
-pub(crate) fn store_settings(s: &mut Session, settings: Map<String, Value>) -> Result<()> {
+pub(crate) fn store_settings(s: &mut Session, mut settings: Map<String, Value>) -> Result<()> {
+    remove_passwords(&mut settings);
     let st = s.doc_mut()?;
     if st.doc.export_settings != settings {
         Arc::make_mut(&mut st.doc).export_settings = settings;
@@ -1334,4 +1360,21 @@ mod tests {
         assert_eq!(safe_file_name("lpt9  .png"), "lpt9-.png");
         assert_eq!(safe_file_name("My CON .png"), "My CON .png");
     }
+
+    /// The settings an export leaves in the document keep its PDF security choices but not its
+    /// passwords, in a row or in `settings.pdf`.
+    #[test]
+    fn stored_settings_leave_out_pdf_passwords() {
+        let mut s = crate::Session::new();
+        s.execute("file.new", &serde_json::json!({"width": 100, "height": 100})).unwrap();
+        let given = serde_json::json!({
+            "formats": [{"format": "pdf", "security": {"openPassword": "open sesame", "permissionsPassword": "owner", "printing": "low"}}],
+            "settings": {"pdf": {"security": {"openPassword": "open sesame", "copy": false}}},
+        });
+        super::store_settings(&mut s, given.as_object().unwrap().clone()).unwrap();
+        let kept = serde_json::Value::Object(s.doc().unwrap().doc.export_settings.clone());
+        assert!(!kept.to_string().contains("Password"), "{kept}");
+        assert_eq!(kept["formats"][0]["security"]["printing"], "low");
+        assert_eq!(kept["settings"]["pdf"]["security"]["copy"], false);
+    }
 }