fix: minimize and zeroize owned password buffers

src/connection.rs

@@ -9,6 +9,7 @@ use ratatui::{
     text::{Line, Span, Text},
     widgets::{Block, Clear, List, ListItem, ListState, Paragraph, Wrap},
 };
+use zeroize::{Zeroize, Zeroizing};
 
 use crate::{
     Result,
@@ -373,18 +374,21 @@ pub fn run(terminal: &mut DefaultTerminal, initial: Option<Database>) -> Result<
                     }
                 }
             }
-            Event::Paste(_) if info.is_some() || help.is_some() || remove.is_some() => {}
+            Event::Paste(mut text) if info.is_some() || help.is_some() || remove.is_some() => text.zeroize(),
             Event::Paste(text) if show_form => {
+                let text = Zeroizing::new(text);
                 form.error = None;
                 if let Some(input) = form.input_mut() {
                     input.paste(&text);
                 }
             }
             Event::Paste(text) if focus == Focus::Query => {
+                let text = Zeroizing::new(text);
                 if let Some(browser) = &mut browser {
                     browser.paste_query(&text);
                 }
             }
+            Event::Paste(mut text) => text.zeroize(),
             _ => {}
         }
     }
@@ -643,13 +647,25 @@ impl Profiles {
     }
 
     fn save(&mut self, form: &Form) -> Result<()> {
-        let mut saved = form.clone();
-        saved.clear_password();
-        saved.reconnect = false;
-        saved.error = None;
-        saved.name = Input::from(saved.name.value.trim());
+        let mut saved = Form {
+            id: form.id,
+            name: Input::from(form.name.value.trim()),
+            provider: form.provider,
+            focus: form.focus,
+            postgres: std::array::from_fn(|index| {
+                if index == 4 {
+                    Input::default()
+                } else {
+                    form.postgres[index].clone()
+                }
+            }),
+            tls: form.tls,
+            path: form.path.clone(),
+            error: None,
+            reconnect: false,
+        };
         if form.provider == 0 {
-            form.postgres_config()?;
+            saved.postgres_config()?;
         } else if form.path.value.is_empty() {
             return Err("Enter a SQLite database file path.".into());
         } else {
@@ -803,7 +819,8 @@ impl Form {
     }
 
     fn clear_password(&mut self) {
-        self.postgres[4] = Input::default();
+        self.postgres[4].value.zeroize();
+        self.postgres[4].cursor = 0;
     }
 
     fn edit(&mut self, key: KeyEvent) {
@@ -1076,6 +1093,12 @@ pub(crate) struct Input {
     cursor: usize,
 }
 
+impl Drop for Input {
+    fn drop(&mut self) {
+        self.value.zeroize();
+    }
+}
+
 impl From<&str> for Input {
     fn from(value: &str) -> Self {
         Self {
@@ -1240,7 +1263,7 @@ impl Input {
                 self.value.remove(self.cursor);
             }
             KeyCode::Char('u') if key.modifiers.contains(KeyModifiers::CONTROL) => {
-                self.value.clear();
+                self.value.zeroize();
                 self.cursor = 0;
             }
             KeyCode::Char(character)
@@ -1257,20 +1280,24 @@ impl Input {
     }
 
     fn paste(&mut self, value: &str) {
-        let text: String = value
-            .chars()
-            .filter(|character| !character.is_control())
-            .collect();
+        let text = Zeroizing::new(
+            value
+                .chars()
+                .filter(|character| !character.is_control())
+                .collect::<String>(),
+        );
         self.value.insert_str(self.cursor, &text);
         self.cursor += text.len();
     }
 
     pub(crate) fn paste_multiline(&mut self, value: &str) {
-        let text: String = value
-            .chars()
-            .map(|character| if character == '\t' { ' ' } else { character })
-            .filter(|character| *character == '\n' || !character.is_control())
-            .collect();
+        let text = Zeroizing::new(
+            value
+                .chars()
+                .map(|character| if character == '\t' { ' ' } else { character })
+                .filter(|character| *character == '\n' || !character.is_control())
+                .collect::<String>(),
+        );
         self.value.insert_str(self.cursor, &text);
         self.cursor += text.len();
     }
@@ -1347,6 +1374,30 @@ impl Input {
 #[cfg(test)]
 mod tests {
     use super::*;
+
+    #[test]
+    fn clearing_passwords_wipes_the_live_buffer_and_resets_unicode_cursor() {
+        for cancel in [true, false] {
+            let mut form = Form::default();
+            form.postgres[4].paste("secret-é界");
+            let length = form.postgres[4].value.len();
+            if cancel {
+                form.clear_password();
+            } else {
+                form.postgres[4].edit(KeyEvent::new(KeyCode::Char('u'), KeyModifiers::CONTROL));
+            }
+            let input = &mut form.postgres[4];
+            assert!(input.value.is_empty());
+            assert_eq!(input.position(), (1, 1));
+            assert!(input.value.capacity() >= length);
+            // The allocation is still owned, and zeroize initialized its former contents to zero.
+            let wiped = unsafe { std::slice::from_raw_parts(input.value.as_ptr(), length) };
+            assert!(wiped.iter().all(|byte| *byte == 0));
+            input.paste("next");
+            assert_eq!(input.value, "next");
+            assert_eq!(input.position(), (1, 5));
+        }
+    }
     #[test]
     fn sql_gutter_tracks_scrolling_digits_and_cursor_without_entering_sql() -> Result<()> {
         use ratatui::{Terminal, backend::TestBackend};

src/main.rs

@@ -103,6 +103,8 @@ Navigation:
   Left/Right changes TLS when focused. Enter connects and updates that saved entry
   only on success; failures keep the previous settings and connection. Esc discards edits.
   Passwords are masked, never saved, and clear on success or cancellation.
+  Owned input buffers are zeroized on clear/drop; profile saving does not copy passwords.
+  This does not erase driver copies, prior input allocations, or protect a compromised host.
   Ctrl-U clears a field; pasting is supported.
   Enter the database user explicitly; the operating-system username is not used.
   Configurations persist in $XDG_CONFIG_HOME/dbdash/connections.sqlite3, falling