Desktop: persist auth token to disk when Credential Manager is restricted (#6303)

Co-authored-by: James Brunton <[email protected]>

frontend/src-tauri/src/commands/auth.rs

@@ -13,6 +13,7 @@ const STORE_FILE: &str = "connection.json";
 const USER_INFO_KEY: &str = "user_info";
 const TOKENS_STORE_FILE: &str = "tokens.json";
 const REFRESH_TOKEN_STORE_KEY: &str = "refresh_token";
+const AUTH_TOKEN_STORE_KEY: &str = "auth_token";
 const KEYRING_SERVICE: &str = "stirling-pdf";
 const KEYRING_TOKEN_KEY: &str = "auth-token";
 const KEYRING_REFRESH_TOKEN_KEY: &str = "refresh-token";
@@ -40,73 +41,134 @@ fn get_refresh_token_keyring_entry() -> Result<Entry, String> {
 }
 
 #[tauri::command]
-pub async fn save_auth_token(_app_handle: AppHandle, token: String) -> Result<(), String> {
+pub async fn save_auth_token(app_handle: AppHandle, token: String) -> Result<(), String> {
     let trimmed = token.trim();
     if trimmed.is_empty() {
         log::warn!("Attempted to save empty auth token");
         return Err("Token cannot be empty".to_string());
     }
 
-    let entry = get_keyring_entry()?;
-
     if trimmed.len() != token.len() {
         log::debug!("Auth token had surrounding whitespace; storing trimmed token");
     }
 
-    entry
-        .set_password(trimmed)
-        .map_err(|e| {
-            log::error!("Failed to set password in keyring: {}", e);
-            format!("Failed to save token to keyring: {}", e)
-        })?;
-
-    // Verify the save worked
-    match entry.get_password() {
-        Ok(retrieved_token) => {
-            if retrieved_token != trimmed {
-                log::error!("Token verification failed: Retrieved token doesn't match");
-                return Err("Token verification failed after save".to_string());
+    // Try keyring first (works in environments where Credential Manager persists writes).
+    // Any failure - including entry creation - falls through to the Tauri Store fallback
+    // below, never an early return, so restricted environments still persist the token.
+    match get_keyring_entry() {
+        Ok(entry) => match entry.set_password(trimmed) {
+            Ok(_) => {
+                // Verify it persists. On managed Win10 Pro environments (GPO restricting
+                // Credential Manager, AV/EDR rules, roaming-profile DPAPI quirks) the
+                // read-back can return the wrong value or NoEntry even when set succeeded.
+                match entry.get_password() {
+                    Ok(saved) if saved == trimmed => {
+                        // Clear any stale fallback copy so the keyring stays authoritative.
+                        if let Ok(store) = app_handle.store(TOKENS_STORE_FILE) {
+                            if store.get(AUTH_TOKEN_STORE_KEY).is_some() {
+                                store.delete(AUTH_TOKEN_STORE_KEY);
+                                let _ = store.save();
+                            }
+                        }
+                        log::info!("Auth token saved to keyring");
+                        return Ok(());
+                    }
+                    _ => {
+                        log::info!("Keyring did not persist auth token - using Tauri Store fallback");
+                    }
+                }
             }
-        }
+            Err(e) => {
+                log::info!("Keyring set failed for auth token: {} - using Tauri Store fallback", e);
+            }
+        },
         Err(e) => {
-            log::error!("Token verification failed: {}", e);
-            return Err(format!("Token verification failed: {}", e));
+            log::info!("Keyring entry unavailable for auth token: {} - using Tauri Store fallback", e);
         }
     }
 
+    // Fallback to Tauri Store (same pattern as save_refresh_token)
+    let store = app_handle
+        .store(TOKENS_STORE_FILE)
+        .map_err(|e| format!("Failed to access tokens store: {}", e))?;
+
+    store.set(
+        AUTH_TOKEN_STORE_KEY,
+        serde_json::to_value(trimmed)
+            .map_err(|e| format!("Failed to serialize token: {}", e))?,
+    );
+
+    store
+        .save()
+        .map_err(|e| format!("Failed to save tokens store: {}", e))?;
+
+    log::info!("Auth token saved to Tauri Store (fallback)");
     Ok(())
 }
 
 #[tauri::command]
-pub async fn get_auth_token(_app_handle: AppHandle) -> Result<Option<String>, String> {
-    let entry = get_keyring_entry()?;
-
-    match entry.get_password() {
-        Ok(token) => Ok(Some(token)),
-        Err(keyring::Error::NoEntry) => Ok(None),
-        Err(e) => {
-            log::error!("Failed to retrieve token from keyring: {}", e);
-            Err(format!("Failed to retrieve token: {}", e))
+pub async fn get_auth_token(app_handle: AppHandle) -> Result<Option<String>, String> {
+    // Try keyring first (production / unrestricted environments). Any failure -
+    // including entry creation - falls through to the Tauri Store fallback below.
+    match get_keyring_entry() {
+        Ok(entry) => match entry.get_password() {
+            Ok(token) => return Ok(Some(token)),
+            Err(keyring::Error::NoEntry) => {
+                log::debug!("No auth token in keyring, trying Tauri Store");
+            }
+            Err(e) => {
+                log::warn!("Keyring error reading auth token: {} - trying Tauri Store", e);
+            }
         },
+        Err(e) => {
+            log::warn!("Keyring entry unavailable for auth token: {} - trying Tauri Store", e);
+        }
     }
+
+    // Fallback to Tauri Store
+    let store = app_handle
+        .store(TOKENS_STORE_FILE)
+        .map_err(|e| format!("Failed to access tokens store: {}", e))?;
+
+    let token: Option<String> = store
+        .get(AUTH_TOKEN_STORE_KEY)
+        .and_then(|v| serde_json::from_value(v.clone()).ok());
+
+    Ok(token)
 }
 
 #[tauri::command]
-pub async fn clear_auth_token(_app_handle: AppHandle) -> Result<(), String> {
-    let entry = get_keyring_entry()?;
-
-    // Delete the token - ignore error if it doesn't exist
-    match entry.delete_credential() {
-        Ok(_) | Err(keyring::Error::NoEntry) => Ok(()),
-        Err(e) => {
-            log::warn!("Failed to delete keyring credential: {}. Attempting overwrite with empty token.", e);
-            // As a fallback, overwrite with an empty token so a stale value cannot be reused
-            match entry.set_password("") {
-                Ok(_) => Ok(()),
-                Err(e2) => Err(format!("Failed to clear token (delete + overwrite failed): {}", e2)),
+pub async fn clear_auth_token(app_handle: AppHandle) -> Result<(), String> {
+    // Clear from keyring (best-effort). Entry creation failure must not block clearing
+    // the disk fallback, otherwise a stale fallback token could survive sign-out.
+    match get_keyring_entry() {
+        Ok(entry) => match entry.delete_credential() {
+            Ok(_) | Err(keyring::Error::NoEntry) => {}
+            Err(e) => {
+                log::warn!("Failed to delete keyring credential: {}. Attempting overwrite with empty token.", e);
+                // Overwrite with an empty token so a stale value cannot be reused
+                if let Err(e2) = entry.set_password("") {
+                    log::warn!("Failed to overwrite keyring auth token: {}", e2);
+                }
             }
         },
+        Err(e) => {
+            log::warn!("Keyring entry unavailable while clearing auth token: {} - clearing Tauri Store fallback only", e);
+        }
     }
+
+    // Clear from Tauri Store fallback
+    let store = app_handle
+        .store(TOKENS_STORE_FILE)
+        .map_err(|e| format!("Failed to access tokens store: {}", e))?;
+
+    store.delete(AUTH_TOKEN_STORE_KEY);
+
+    store
+        .save()
+        .map_err(|e| format!("Failed to save tokens store: {}", e))?;
+
+    Ok(())
 }
 
 #[tauri::command]