Simplify COM server management

apps/desktop/desktop_native/win_webauthn/src/plugin/com.rs

@@ -12,7 +12,7 @@ use std::{
 use windows::{
     core::{implement, interface, ComObjectInterface, IUnknown, GUID, HRESULT},
     Win32::{
-        Foundation::{E_FAIL, E_INVALIDARG, S_OK},
+        Foundation::{E_FAIL, E_INVALIDARG, S_FALSE, S_OK},
         System::Com::*,
     },
 };
@@ -31,6 +31,7 @@ use crate::{
 };
 
 static HANDLER: OnceLock<(GUID, Arc<dyn PluginAuthenticator + Send + Sync>)> = OnceLock::new();
+static SHUTDOWN: OnceLock<bool> = OnceLock::new();
 
 #[implement(IClassFactory)]
 pub struct Factory;
@@ -284,6 +285,40 @@ pub(super) fn register_server<T>(clsid: &GUID, handler: T) -> Result<(), WinWebA
 where
     T: PluginAuthenticator + Send + Sync + 'static,
 {
+    if HANDLER.get().is_some() {
+        return Err(WinWebAuthnError::new(
+            ErrorKind::Other,
+            "server can only be registered one time per process",
+        ));
+    }
+    unsafe {
+        let com_init_result = CoInitializeEx(None, COINIT_APARTMENTTHREADED);
+        match com_init_result {
+            S_OK | S_FALSE => {} // mark initialized,
+            code => {
+                return Err(WinWebAuthnError::with_cause(
+                    ErrorKind::WindowsInternal,
+                    "Could not initialize the COM library",
+                    windows::core::Error::from_hresult(code),
+                ));
+            }
+        }
+
+        if let Err(err) = CoInitializeSecurity(
+            None,
+            -1,
+            None,
+            None,
+            RPC_C_AUTHN_LEVEL_DEFAULT,
+            RPC_C_IMP_LEVEL_IMPERSONATE,
+            None,
+            EOAC_NONE,
+            None,
+        ) {
+            tracing::warn!("Could not initialize COM security: {err}");
+        };
+    }
+
     // Store the handler as a static so it can be initialized
     HANDLER.set((*clsid, Arc::new(handler))).map_err(|_| {
         WinWebAuthnError::new(ErrorKind::WindowsInternal, "Handler already initialized")
@@ -308,43 +343,16 @@ where
     Ok(())
 }
 
-/// Initializes the COM library for use on the calling thread,
-/// and registers + sets the security values.
-pub(super) fn initialize() -> std::result::Result<(), WinWebAuthnError> {
-    let result = unsafe { CoInitializeEx(None, COINIT_APARTMENTTHREADED) };
-
-    if result.is_err() {
-        return Err(WinWebAuthnError::with_cause(
-            ErrorKind::WindowsInternal,
-            "Could not initialize the COM library",
-            windows::core::Error::from_hresult(result),
-        ));
+pub(super) fn shutdown_server() -> std::result::Result<(), WinWebAuthnError> {
+    if HANDLER.get().is_some() {
+        if let Ok(()) = SHUTDOWN.set(true) {
+            unsafe { CoUninitialize() };
+        } else {
+            tracing::debug!("server already shut down");
+        }
+    } else {
+        tracing::debug!("server was not registered. Ignoring.");
     }
-
-    unsafe {
-        CoInitializeSecurity(
-            None,
-            -1,
-            None,
-            None,
-            RPC_C_AUTHN_LEVEL_DEFAULT,
-            RPC_C_IMP_LEVEL_IMPERSONATE,
-            None,
-            EOAC_NONE,
-            None,
-        )
-    }
-    .map_err(|err| {
-        WinWebAuthnError::with_cause(
-            ErrorKind::WindowsInternal,
-            "Could not initialize COM security",
-            err,
-        )
-    })
-}
-
-pub(super) fn uninitialize() -> std::result::Result<(), WinWebAuthnError> {
-    unsafe { CoUninitialize() };
     Ok(())
 }
 

apps/desktop/desktop_native/win_webauthn/src/plugin/mod.rs

@@ -76,10 +76,9 @@ impl WebAuthnPlugin {
         com::register_server(&self.clsid.0, handler)
     }
 
-    /// Initializes the COM library for use on the calling thread,
-    /// and registers + sets the security values.
-    pub fn initialize() -> Result<(), WinWebAuthnError> {
-        com::initialize()
+    /// Uninitializes the COM library for the calling thread.
+    pub fn shutdown_server() -> Result<(), WinWebAuthnError> {
+        com::shutdown_server()
     }
 
     /// Adds this implementation as a Windows WebAuthn plugin.

apps/desktop/desktop_native/windows_plugin_authenticator/src/process.rs

@@ -74,19 +74,16 @@ pub(super) fn add_authenticator() -> Result<(), String> {
 
 pub(super) fn run_server() -> Result<(), String> {
     tracing::debug!("Setting up COM server");
-    let r = WebAuthnPlugin::initialize();
-    tracing::debug!(
-        "Initialized the com library with WebAuthnPlugin::initialize(): {:?}",
-        r
-    );
 
     let clsid = CLSID.try_into().expect("valid GUID string");
     let plugin = WebAuthnPlugin::new(clsid);
 
-    let r = plugin.register_server(BitwardenPluginAuthenticator {
-        client: Mutex::new(None),
-        callbacks: Arc::new(Mutex::new(HashMap::new())),
-    });
+    let r = plugin
+        .register_server(BitwardenPluginAuthenticator {
+            client: Mutex::new(None),
+            callbacks: Arc::new(Mutex::new(HashMap::new())),
+        })
+        .map_err(|err| err.to_string())?;
     tracing::debug!("Registered the com library: {:?}", r);
     Ok(())
 }