refactor(core): load APPIMAGE and APPDIR env vars on startup [TRI-007] [TRI-041]

Author: lucasfernog

.changes/core-env.md

@@ -0,0 +1,5 @@
+---
+"tauri": patch
+---
+
+The `process`, `path` and `updater` APIs now takes a `tauri::Env` argument, used to force environment variables load on startup to prevent env var update attacks.

core/tauri-utils/src/lib.rs

@@ -37,6 +37,28 @@ impl PackageInfo {
   }
 }
 
+/// Information about environment variables.
+#[derive(Debug, Clone)]
+pub struct Env {
+  /// The APPIMAGE environment variable.
+  #[cfg(target_os = "linux")]
+  pub appimage: Option<std::ffi::OsString>,
+  /// The APPDIR environment variable.
+  #[cfg(target_os = "linux")]
+  pub appdir: Option<std::ffi::OsString>,
+}
+
+impl Default for Env {
+  fn default() -> Self {
+    Self {
+      #[cfg(target_os = "linux")]
+      appimage: std::env::var_os("APPIMAGE"),
+      #[cfg(target_os = "linux")]
+      appdir: std::env::var_os("APPDIR"),
+    }
+  }
+}
+
 /// The result type of `tauri-utils`.
 pub type Result<T> = std::result::Result<T, Error>;
 

core/tauri-utils/src/platform.rs

@@ -4,12 +4,9 @@
 
 //! Platform helper functions.
 
-use std::{
-  env,
-  path::{PathBuf, MAIN_SEPARATOR},
-};
+use std::path::{PathBuf, MAIN_SEPARATOR};
 
-use crate::PackageInfo;
+use crate::{Env, PackageInfo};
 
 /// Try to determine the current target triple.
 ///
@@ -76,7 +73,7 @@ pub fn target_triple() -> crate::Result<String> {
 /// `${exe_dir}/../lib/${exe_name}`.
 ///
 /// On MacOS, it's `${exe_dir}../Resources` (inside .app).
-pub fn resource_dir(package_info: &PackageInfo) -> crate::Result<PathBuf> {
+pub fn resource_dir(package_info: &PackageInfo, env: &Env) -> crate::Result<PathBuf> {
   let exe = std::env::current_exe()?;
   let exe_dir = exe.parent().expect("failed to get exe directory");
   let curr_dir = exe_dir.display().to_string();
@@ -93,10 +90,11 @@ pub fn resource_dir(package_info: &PackageInfo) -> crate::Result<PathBuf> {
     if curr_dir.ends_with("/data/usr/bin") {
       // running from the deb bundle dir
       Ok(exe_dir.join(format!("../lib/{}", package_info.package_name())))
-    } else if let Ok(appdir) = env::var("APPDIR") {
+    } else if let Some(appdir) = &env.appdir {
+      let appdir: &std::path::Path = appdir.as_ref();
       Ok(PathBuf::from(format!(
         "{}/usr/lib/{}",
-        appdir,
+        appdir.display(),
         package_info.package_name()
       )))
     } else {

core/tauri/src/api/path.rs

@@ -9,7 +9,7 @@ use std::{
   path::{Component, Path, PathBuf},
 };
 
-use crate::{Config, PackageInfo};
+use crate::{Config, Env, PackageInfo};
 
 use serde_repr::{Deserialize_repr, Serialize_repr};
 
@@ -83,6 +83,7 @@ pub enum BaseDirectory {
 ///     authors: "tauri",
 ///     description: "a tauri test",
 ///   },
+///   &Default::default(),
 ///   "path/to/something",
 ///   Some(BaseDirectory::Config)
 ///  ).expect("failed to resolve path");
@@ -91,6 +92,7 @@ pub enum BaseDirectory {
 pub fn resolve_path<P: AsRef<Path>>(
   config: &Config,
   package_info: &PackageInfo,
+  env: &Env,
   path: P,
   dir: Option<BaseDirectory>,
 ) -> crate::api::Result<PathBuf> {
@@ -113,7 +115,7 @@ pub fn resolve_path<P: AsRef<Path>>(
       BaseDirectory::Runtime => runtime_dir(),
       BaseDirectory::Template => template_dir(),
       BaseDirectory::Video => video_dir(),
-      BaseDirectory::Resource => resource_dir(package_info),
+      BaseDirectory::Resource => resource_dir(package_info, env),
       BaseDirectory::App => app_dir(config),
       BaseDirectory::Current => Some(env::current_dir()?),
       BaseDirectory::Log => log_dir(config),
@@ -229,8 +231,8 @@ pub fn video_dir() -> Option<PathBuf> {
 }
 
 /// Returns the path to the resource directory of this app.
-pub fn resource_dir(package_info: &PackageInfo) -> Option<PathBuf> {
-  crate::utils::platform::resource_dir(package_info).ok()
+pub fn resource_dir(package_info: &PackageInfo, env: &Env) -> Option<PathBuf> {
+  crate::utils::platform::resource_dir(package_info, env).ok()
 }
 
 /// Returns the path to the suggested directory for your app config files.

core/tauri/src/api/process.rs

@@ -4,6 +4,8 @@
 
 //! Types and functions related to child processes management.
 
+use crate::Env;
+
 use std::{
   env,
   path::PathBuf,
@@ -16,12 +18,13 @@ mod command;
 pub use command::*;
 
 /// Gets the current binary.
-pub fn current_binary() -> Option<PathBuf> {
+#[allow(unused_variables)]
+pub fn current_binary(env: &Env) -> Option<PathBuf> {
   let mut current_binary = None;
 
   // if we are running with an APP Image, we should return the app image path
   #[cfg(target_os = "linux")]
-  if let Some(app_image_path) = env::var_os("APPIMAGE") {
+  if let Some(app_image_path) = &env.appimage {
     current_binary = Some(PathBuf::from(app_image_path));
   }
 
@@ -37,8 +40,8 @@ pub fn current_binary() -> Option<PathBuf> {
 }
 
 /// Restarts the process.
-pub fn restart() {
-  if let Some(path) = current_binary() {
+pub fn restart(env: &Env) {
+  if let Some(path) = current_binary(env) {
     StdCommand::new(path)
       .spawn()
       .expect("application failed to start");

core/tauri/src/app.rs

@@ -19,8 +19,8 @@ use crate::{
     Dispatch, ExitRequestedEventAction, RunEvent, Runtime,
   },
   sealed::{ManagerBase, RuntimeOrDispatch},
-  utils::assets::Assets,
   utils::config::{Config, WindowUrl},
+  utils::{assets::Assets, Env},
   Context, Invoke, InvokeError, InvokeResponse, Manager, StateManager, Window,
 };
 
@@ -150,14 +150,15 @@ impl<R: Runtime> GlobalWindowEvent<R> {
 /// The path resolver is a helper for the application-specific [`crate::api::path`] APIs.
 #[derive(Debug, Clone)]
 pub struct PathResolver {
+  env: Env,
   config: Arc<Config>,
   package_info: PackageInfo,
 }
 
 impl PathResolver {
   /// Returns the path to the resource directory of this app.
   pub fn resource_dir(&self) -> Option<PathBuf> {
-    crate::api::path::resource_dir(&self.package_info)
+    crate::api::path::resource_dir(&self.package_info, &self.env)
   }
 
   /// Returns the path to the suggested directory for your app config files.
@@ -407,6 +408,7 @@ macro_rules! shared_app_impl {
       /// The path resolver for the application.
       pub fn path_resolver(&self) -> PathResolver {
         PathResolver {
+          env: self.state::<Env>().inner().clone(),
           config: self.manager.config(),
           package_info: self.manager.package_info().clone(),
         }
@@ -432,6 +434,11 @@ macro_rules! shared_app_impl {
         self.manager.package_info()
       }
 
+      /// Gets the managed [`Env`].
+      pub fn env(&self) -> Env {
+        self.state::<Env>().inner().clone()
+      }
+
       /// The application's asset resolver.
       pub fn asset_resolver(&self) -> AssetResolver<R> {
         AssetResolver {
@@ -990,6 +997,8 @@ impl<R: Runtime> Builder<R> {
       },
     };
 
+    app.manage(Env::default());
+
     #[cfg(feature = "system-tray")]
     if let Some(system_tray) = self.system_tray {
       let mut ids = HashMap::new();

core/tauri/src/endpoints.rs

@@ -75,17 +75,21 @@ impl Module {
           .and_then(|r| r.json)
           .map_err(InvokeError::from)
       }),
-      Self::Process(cmd) => resolver
-        .respond_async(async move { cmd.run().and_then(|r| r.json).map_err(InvokeError::from) }),
+      Self::Process(cmd) => resolver.respond_async(async move {
+        cmd
+          .run(window)
+          .and_then(|r| r.json)
+          .map_err(InvokeError::from)
+      }),
       Self::Fs(cmd) => resolver.respond_async(async move {
         cmd
-          .run(config, &package_info)
+          .run(window, config, &package_info)
           .and_then(|r| r.json)
           .map_err(InvokeError::from)
       }),
       Self::Path(cmd) => resolver.respond_async(async move {
         cmd
-          .run(config, &package_info)
+          .run(window, config, &package_info)
           .and_then(|r| r.json)
           .map_err(InvokeError::from)
       }),