feat(windows): use ProgramData to store device ID instead of per-user… (#3172)

Fulfills #3159.

This means the device ID is only tied to the Windows install instead of
the user account. I also fixed up the logs and errors for that module
real quick since I was already there.

rust/Cargo.lock

@@ -2053,6 +2053,7 @@ dependencies = [
  "hostname",
  "ipconfig",
  "keyring",
+ "known-folders",
  "rand 0.8.5",
  "ring 0.17.7",
  "secrecy",
@@ -3232,6 +3233,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "known-folders"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4397c789f2709d23cfcb703b316e0766a8d4b17db2d47b0ab096ef6047cae1d8"
+dependencies = [
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "kuchikiki"
 version = "0.8.2"

rust/windows-client/src-tauri/Cargo.toml

@@ -41,6 +41,7 @@ tracing-panic = "0.1.1"
 zip = { version = "0.6.6", features = ["deflate", "time"], default-features = false }
 rand = "0.8.5"
 windows-implement = "0.52.0"
+known-folders = "1.1.0"
 
 # These dependencies are locked behind `cfg(windows)` because they either can't compile at all on Linux, or they need native dependencies like glib that are difficult to get. Try not to add more here.
 

rust/windows-client/src-tauri/src/client/device_id.rs

@@ -1,15 +1,31 @@
+use known_folders::{get_known_folder_path, KnownFolder};
 use tokio::fs;
 
-/// Get the device ID, generating it if it's not already on disk.
+#[derive(thiserror::Error, Debug)]
+pub(crate) enum Error {
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
+    #[error("Can't find well-known folder")]
+    KnownFolder,
+}
+
+/// Returns the device ID, generating it and saving it to disk if needed.
+///
 /// Per <https://github.com/firezone/firezone/issues/2697> and <https://github.com/firezone/firezone/issues/2711>,
 /// clients must generate their own random IDs and persist them to disk, to handle situations like VMs where a hardware ID is not unique or not available.
 ///
+/// # Arguments
+///
+/// * `identifier` - Our Tauri bundle identifier, e.g. "dev.firezone.client"
+///
 /// Returns: The UUID as a String, suitable for sending verbatim to `connlib_client_shared::Session::connect`.
+///
 /// Errors: If the disk is unwritable when initially generating the ID, or unwritable when re-generating an invalid ID.
-pub(crate) async fn device_id(
-    app_local_data_dir: &crate::client::AppLocalDataDir,
-) -> anyhow::Result<String> {
-    let dir = app_local_data_dir.0.join("config");
+pub(crate) async fn device_id(identifier: &str) -> Result<String, Error> {
+    let dir = get_known_folder_path(KnownFolder::ProgramData)
+        .ok_or(Error::KnownFolder)?
+        .join(identifier)
+        .join("config");
     let path = dir.join("device_id.json");
 
     // Try to read it back from disk
@@ -18,8 +34,9 @@ pub(crate) async fn device_id(
         .ok()
         .and_then(|s| serde_json::from_str::<DeviceIdJson>(&s).ok())
     {
-        tracing::debug!("device ID loaded from disk is {}", j.id.to_string());
-        return Ok(j.device_id());
+        let device_id = j.device_id();
+        tracing::debug!(?device_id, "Loaded device ID from disk");
+        return Ok(device_id);
     }
 
     // Couldn't read, it's missing or invalid, generate a new one and save it.
@@ -28,9 +45,14 @@ pub(crate) async fn device_id(
     // TODO: This file write has the same possible problems with power loss as described here https://github.com/firezone/firezone/pull/2757#discussion_r1416374516
     // Since the device ID is random, typically only written once in the device's lifetime, and the read will error out if it's corrupted, it's low-risk.
     fs::create_dir_all(&dir).await?;
-    fs::write(&path, serde_json::to_string(&j)?).await?;
+    fs::write(
+        &path,
+        serde_json::to_string(&j).expect("Device ID should always be serializable"),
+    )
+    .await?;
 
-    tracing::debug!("device ID saved to disk is {}", j.id.to_string());
+    let device_id = j.device_id();
+    tracing::debug!(?device_id, "Saved device ID to disk");
     Ok(j.device_id())
 }
 

rust/windows-client/src-tauri/src/client/gui.rs

@@ -309,7 +309,7 @@ impl Controller {
         advanced_settings: AdvancedSettings,
         notify_controller: Arc<Notify>,
     ) -> Result<Self> {
-        let device_id = client::device_id::device_id(&app_local_data_dir(&app)?).await?;
+        let device_id = client::device_id::device_id(&app.config().tauri.bundle.identifier).await?;
 
         let mut this = Self {
             advanced_settings,