feat(core): validate callbacks and event names [TRI-038] [TRI-020] (#21)

Author: lucasfernog

.changes/api-format-callback.md

@@ -0,0 +1,5 @@
+---
+"api": patch
+---
+
+The `formatCallback` helper function now returns a number instead of a string.

.changes/callback-validation.md

@@ -0,0 +1,5 @@
+---
+"tauri": patch
+---
+
+The `callback` and `error` invoke fields, along with other `transformCallback` usages, are now validated to be numeric.

.changes/validate-event-name.md

@@ -0,0 +1,6 @@
+---
+"tauri": "patch"
+---
+
+The event name is now validated. On a IPC message, it returns an error if it fails validation; on the Rust side, it panics.
+It must include only alphanumeric characters, `-`, `/`, `:` and `_`.

core/tauri-runtime/src/webview.rs

@@ -4,12 +4,8 @@
 
 //! Items specific to the [`Runtime`](crate::Runtime)'s webview.
 
-use crate::{window::DetachedWindow, Icon};
+use crate::{menu::Menu, window::DetachedWindow, Icon};
 
-use crate::menu::Menu;
-
-use serde::Deserialize;
-use serde_json::Value as JsonValue;
 use tauri_utils::config::{WindowConfig, WindowUrl};
 
 #[cfg(windows)]
@@ -184,16 +180,3 @@ pub type WebviewIpcHandler<R> = Box<dyn Fn(DetachedWindow<R>, String) + Send>;
 /// File drop handler callback
 /// Return `true` in the callback to block the OS' default behavior of handling a file drop.
 pub type FileDropHandler<R> = Box<dyn Fn(FileDropEvent, DetachedWindow<R>) -> bool + Send>;
-
-#[derive(Debug, Deserialize)]
-pub struct InvokePayload {
-  pub command: String,
-  #[serde(rename = "__tauriModule")]
-  pub tauri_module: Option<String>,
-  pub callback: String,
-  pub error: String,
-  #[serde(rename = "__invokeKey")]
-  pub key: u32,
-  #[serde(flatten)]
-  pub inner: JsonValue,
-}

core/tauri/scripts/bundle.js

@@ -4,11 +4,7 @@
 
 ;(function () {
   function uid() {
-    const length = new Int8Array(1)
-    window.crypto.getRandomValues(length)
-    const array = new Uint8Array(Math.max(16, Math.abs(length[0])))
-    window.crypto.getRandomValues(array)
-    return array.join('')
+    return window.crypto.getRandomValues(new Uint32Array(1))[0]
   }
 
   if (!window.__TAURI__) {

core/tauri/scripts/core.js

@@ -6,9 +6,13 @@
 //!
 //! This module includes utilities to send messages to the JS layer of the webview.
 
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use serde_json::value::RawValue;
 
+/// The `Callback` type is the return value of the `transformCallback` JavaScript function.
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Serialize, Deserialize)]
+pub struct CallbackFn(pub usize);
+
 /// The information about this is quite limited. On Chrome/Edge and Firefox, [the maximum string size is approximately 1 GB](https://stackoverflow.com/a/34958490).
 ///
 /// [From MDN:](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length#description)
@@ -70,8 +74,8 @@ fn escape_json_parse(json: &RawValue) -> String {
 /// ```
 /// use tauri::api::ipc::format_callback;
 /// // callback with a string argument
-/// let cb = format_callback("callback-function-name", &"the string response").unwrap();
-/// assert!(cb.contains(r#"window["callback-function-name"]("the string response")"#));
+/// let cb = format_callback(12345, &"the string response").unwrap();
+/// assert!(cb.contains(r#"window["12345"]("the string response")"#));
 /// ```
 ///
 /// - With types implement [`serde::Serialize`]:
@@ -86,14 +90,14 @@ fn escape_json_parse(json: &RawValue) -> String {
 /// }
 ///
 /// let cb = format_callback(
-///   "callback-function-name",
+///   6789,
 ///   &MyResponse { value: String::from_utf8(vec![b'X'; 10_240]).unwrap()
 /// }).expect("failed to serialize");
 ///
-/// assert!(cb.contains(r#"window["callback-function-name"](JSON.parse('{"value":"XXXXXXXXX"#));
+/// assert!(cb.contains(r#"window["6789"](JSON.parse('{"value":"XXXXXXXXX"#));
 /// ```
-pub fn format_callback<T: Serialize, S: AsRef<str>>(
-  function_name: S,
+pub fn format_callback<T: Serialize>(
+  function_name: CallbackFn,
   arg: &T,
 ) -> crate::api::Result<String> {
   macro_rules! format_callback {
@@ -106,7 +110,7 @@ pub fn format_callback<T: Serialize, S: AsRef<str>>(
             console.warn("[TAURI] Couldn't find callback id {fn} in window. This happens when the app is reloaded while Rust is running an asynchronous operation.")
           }}
         "#,
-        fn = function_name.as_ref(),
+        fn = function_name.0,
         arg = $arg
       )
     }
@@ -169,8 +173,8 @@ pub fn format_callback<T: Serialize, S: AsRef<str>>(
 // TODO: better example to explain
 pub fn format_callback_result<T: Serialize, E: Serialize>(
   result: Result<T, E>,
-  success_callback: impl AsRef<str>,
-  error_callback: impl AsRef<str>,
+  success_callback: CallbackFn,
+  error_callback: CallbackFn,
 ) -> crate::api::Result<String> {
   match result {
     Ok(res) => format_callback(success_callback, &res),
@@ -181,8 +185,15 @@ pub fn format_callback_result<T: Serialize, E: Serialize>(
 #[cfg(test)]
 mod test {
   use crate::api::ipc::*;
+  use quickcheck::{Arbitrary, Gen};
   use quickcheck_macros::quickcheck;
 
+  impl Arbitrary for CallbackFn {
+    fn arbitrary(g: &mut Gen) -> CallbackFn {
+      CallbackFn(usize::arbitrary(g))
+    }
+  }
+
   #[test]
   fn test_escape_json_parse() {
     let dangerous_json = RawValue::from_string(
@@ -205,38 +216,33 @@ mod test {
 
   // check abritrary strings in the format callback function
   #[quickcheck]
-  fn qc_formating(f: String, a: String) -> bool {
-    // can not accept empty strings
-    if !f.is_empty() && !a.is_empty() {
-      // call format callback
-      let fc = format_callback(f.clone(), &a).unwrap();
-      fc.contains(&format!(
-        r#"window["{}"](JSON.parse('{}'))"#,
-        f,
-        serde_json::Value::String(a.clone()),
-      )) || fc.contains(&format!(
-        r#"window["{}"]({})"#,
-        f,
-        serde_json::Value::String(a),
-      ))
-    } else {
-      true
-    }
+  fn qc_formating(f: CallbackFn, a: String) -> bool {
+    // call format callback
+    let fc = format_callback(f, &a).unwrap();
+    fc.contains(&format!(
+      r#"window["{}"](JSON.parse('{}'))"#,
+      f.0,
+      serde_json::Value::String(a.clone()),
+    )) || fc.contains(&format!(
+      r#"window["{}"]({})"#,
+      f.0,
+      serde_json::Value::String(a),
+    ))
   }
 
   // check arbitrary strings in format_callback_result
   #[quickcheck]
-  fn qc_format_res(result: Result<String, String>, c: String, ec: String) -> bool {
-    let resp = format_callback_result(result.clone(), c.clone(), ec.clone())
-      .expect("failed to format callback result");
+  fn qc_format_res(result: Result<String, String>, c: CallbackFn, ec: CallbackFn) -> bool {
+    let resp =
+      format_callback_result(result.clone(), c, ec).expect("failed to format callback result");
     let (function, value) = match result {
       Ok(v) => (c, v),
       Err(e) => (ec, e),
     };
 
     resp.contains(&format!(
       r#"window["{}"]({})"#,
-      function,
+      function.0,
       serde_json::Value::String(value),
     ))
   }

core/tauri/src/api/ipc.rs

@@ -6,6 +6,7 @@
 pub(crate) mod tray;
 
 use crate::{
+  api::ipc::CallbackFn,
   command::{CommandArg, CommandItem},
   hooks::{
     window_invoke_responder, InvokeHandler, InvokeResponder, OnPageLoad, PageLoadPayload, SetupHook,
@@ -702,7 +703,7 @@ impl<R: Runtime> Builder<R> {
   /// That function must take the `command: string` and `args: object` types and send a message to the backend.
   pub fn invoke_system<F>(mut self, initialization_script: String, responder: F) -> Self
   where
-    F: Fn(Window<R>, InvokeResponse, String, String) + Send + Sync + 'static,
+    F: Fn(Window<R>, InvokeResponse, CallbackFn, CallbackFn) + Send + Sync + 'static,
   {
     self.invoke_initialization_script = initialization_script;
     self.invoke_responder = Arc::new(responder);

core/tauri/src/app.rs

@@ -3,24 +3,44 @@
 // SPDX-License-Identifier: MIT
 
 use super::InvokeContext;
-use crate::{sealed::ManagerBase, Manager, Runtime, Window};
-use serde::Deserialize;
+use crate::{
+  api::ipc::CallbackFn, event::is_event_name_valid, sealed::ManagerBase, Manager, Runtime, Window,
+};
+use serde::{de::Deserializer, Deserialize};
 use tauri_macros::CommandModule;
 
+pub struct EventId(String);
+
+impl<'de> Deserialize<'de> for EventId {
+  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+  where
+    D: Deserializer<'de>,
+  {
+    let event_id = String::deserialize(deserializer)?;
+    if is_event_name_valid(&event_id) {
+      Ok(EventId(event_id))
+    } else {
+      Err(serde::de::Error::custom(
+        "Event name must include only alphanumeric characters, `-`, `/`, `:` and `_`.",
+      ))
+    }
+  }
+}
+
 /// The API descriptor.
 #[derive(Deserialize, CommandModule)]
 #[serde(tag = "cmd", rename_all = "camelCase")]
 pub enum Cmd {
   /// Listen to an event.
-  Listen { event: String, handler: String },
+  Listen { event: EventId, handler: CallbackFn },
   /// Unlisten to an event.
   #[serde(rename_all = "camelCase")]
   Unlisten { event_id: u64 },
   /// Emit an event to the webview associated with the given window.
   /// If the window_label is omitted, the event will be triggered on all listeners.
   #[serde(rename_all = "camelCase")]
   Emit {
-    event: String,
+    event: EventId,
     window_label: Option<String>,
     payload: Option<String>,
   },
@@ -29,14 +49,17 @@ pub enum Cmd {
 impl Cmd {
   fn listen<R: Runtime>(
     context: InvokeContext<R>,
-    event: String,
-    handler: String,
+    event: EventId,
+    handler: CallbackFn,
   ) -> crate::Result<u64> {
     let event_id = rand::random();
-    context
-      .window
-      .eval(&listen_js(&context.window, event.clone(), event_id, handler))?;
-    context.window.register_js_listener(event, event_id);
+    context.window.eval(&listen_js(
+      &context.window,
+      event.0.clone(),
+      event_id,
+      handler,
+    ))?;
+    context.window.register_js_listener(event.0, event_id);
     Ok(event_id)
   }
 
@@ -50,17 +73,17 @@ impl Cmd {
 
   fn emit<R: Runtime>(
     context: InvokeContext<R>,
-    event: String,
+    event: EventId,
     window_label: Option<String>,
     payload: Option<String>,
   ) -> crate::Result<()> {
     // dispatch the event to Rust listeners
-    context.window.trigger(&event, payload.clone());
+    context.window.trigger(&event.0, payload.clone());
 
     if let Some(target) = window_label {
-      context.window.emit_to(&target, &event, payload)?;
+      context.window.emit_to(&target, &event.0, payload)?;
     } else {
-      context.window.emit_all(&event, payload)?;
+      context.window.emit_all(&event.0, payload)?;
     }
     Ok(())
   }
@@ -85,7 +108,7 @@ pub fn listen_js<R: Runtime>(
   window: &Window<R>,
   event: String,
   event_id: u64,
-  handler: String,
+  handler: CallbackFn,
 ) -> String {
   format!(
     "if (window['{listeners}'] === void 0) {{
@@ -102,6 +125,6 @@ pub fn listen_js<R: Runtime>(
     listeners = window.manager().event_listeners_object_name(),
     event = event,
     event_id = event_id,
-    handler = handler
+    handler = handler.0
   )
 }

core/tauri/src/endpoints/event.rs

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 
 use super::InvokeContext;
-use crate::Runtime;
+use crate::{api::ipc::CallbackFn, Runtime};
 use serde::Deserialize;
 use tauri_macros::{module_command_handler, CommandModule};
 
@@ -15,11 +15,14 @@ use crate::runtime::GlobalShortcutManager;
 #[serde(tag = "cmd", rename_all = "camelCase")]
 pub enum Cmd {
   /// Register a global shortcut.
-  Register { shortcut: String, handler: String },
+  Register {
+    shortcut: String,
+    handler: CallbackFn,
+  },
   /// Register a list of global shortcuts.
   RegisterAll {
     shortcuts: Vec<String>,
-    handler: String,
+    handler: CallbackFn,
   },
   /// Unregister a global shortcut.
   Unregister { shortcut: String },
@@ -34,7 +37,7 @@ impl Cmd {
   fn register<R: Runtime>(
     context: InvokeContext<R>,
     shortcut: String,
-    handler: String,
+    handler: CallbackFn,
   ) -> crate::Result<()> {
     let mut manager = context.window.app_handle.global_shortcut_manager();
     register_shortcut(context.window, &mut manager, shortcut, handler)?;
@@ -45,16 +48,11 @@ impl Cmd {
   fn register_all<R: Runtime>(
     context: InvokeContext<R>,
     shortcuts: Vec<String>,
-    handler: String,
+    handler: CallbackFn,
   ) -> crate::Result<()> {
     let mut manager = context.window.app_handle.global_shortcut_manager();
     for shortcut in shortcuts {
-      register_shortcut(
-        context.window.clone(),
-        &mut manager,
-        shortcut,
-        handler.clone(),
-      )?;
+      register_shortcut(context.window.clone(), &mut manager, shortcut, handler)?;
     }
     Ok(())
   }
@@ -96,11 +94,11 @@ fn register_shortcut<R: Runtime>(
   window: crate::Window<R>,
   manager: &mut R::GlobalShortcutManager,
   shortcut: String,
-  handler: String,
+  handler: CallbackFn,
 ) -> crate::Result<()> {
   let accelerator = shortcut.clone();
   manager.register(&shortcut, move || {
-    let callback_string = crate::api::ipc::format_callback(&handler, &accelerator)
+    let callback_string = crate::api::ipc::format_callback(handler, &accelerator)
       .expect("unable to serialize shortcut string to json");
     let _ = window.eval(callback_string.as_str());
   })?;