[tor-commits] [meek/webextension] Try deleting the registry key before exiting.

[dcf at torproject.org]

commit e80c5b3217914a033bfc2303f5e043a4bdb3488c
Author: David Fifield <david at bamsoftware.com>
Date:   Thu Mar 7 15:46:54 2019 -0700

    Try deleting the registry key before exiting.
---
 meek-client-torbrowser/linux.go                  |  6 ++++++
 meek-client-torbrowser/mac.go                    |  6 ++++++
 meek-client-torbrowser/meek-client-torbrowser.go | 13 ++++++++++++-
 meek-client-torbrowser/windows.go                | 15 ++++++++-------
 4 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/meek-client-torbrowser/linux.go b/meek-client-torbrowser/linux.go
index f728f1d..69ee7b7 100644
--- a/meek-client-torbrowser/linux.go
+++ b/meek-client-torbrowser/linux.go
@@ -29,3 +29,9 @@ func osSpecificCommandSetup(cmd *exec.Cmd) {
 func installHelperNativeManifest() error {
 	return writeNativeManifestToFile(helperNativeManifestDir, helperNativeExecutablePath)
 }
+
+func uninstallHelperNativeManifest() error {
+	// Nothing to do here: the host manifest file is written inside the
+	// browser directory, so we assume we don't have to clean it up.
+	return nil
+}
diff --git a/meek-client-torbrowser/mac.go b/meek-client-torbrowser/mac.go
index 995aca5..918a62e 100644
--- a/meek-client-torbrowser/mac.go
+++ b/meek-client-torbrowser/mac.go
@@ -42,3 +42,9 @@ func installHelperNativeManifest() error {
 	// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Native_manifests#Mac_OS_X
 	return writeNativeManifestToFile(filepath.Join(homeDir, "Mozilla", "NativeMessagingHosts"), helperNativeExecutablePath)
 }
+
+func uninstallHelperNativeManifest() error {
+	// Nothing to do here: the host manifest file is written inside the
+	// browser directory, so we assume we don't have to clean it up.
+	return nil
+}
diff --git a/meek-client-torbrowser/meek-client-torbrowser.go b/meek-client-torbrowser/meek-client-torbrowser.go
index 37dcf6e..f482fb3 100644
--- a/meek-client-torbrowser/meek-client-torbrowser.go
+++ b/meek-client-torbrowser/meek-client-torbrowser.go
@@ -15,6 +15,11 @@
 // executed as given, except that a --helper option is added that points to the
 // port number read from firefox.
 //
+// On Windows, this program assumes that is has exclusive control over the
+// HKEY_CURRENT_USER\SOFTWARE\Mozilla\NativeMessagingHosts\meek.http.helper
+// registry key. It creates the key when run and tries to delete it when
+// exiting.
+//
 // This program proxies stdin and stdout to and from meek-client, so it is
 // actually meek-client that drives the pluggable transport negotiation with
 // tor.
@@ -375,7 +380,13 @@ func main() {
 		log.Print(err)
 		return
 	}
-	defer logKill(firefoxCmd.Process)
+	defer func() {
+		logKill(firefoxCmd.Process)
+		err := uninstallHelperNativeManifest()
+		if err != nil {
+			log.Printf("uninstalling native host manifest: %v", err)
+		}
+	}()
 
 	// Find out the helper's listening address.
 	addrChan := make(chan string)
diff --git a/meek-client-torbrowser/windows.go b/meek-client-torbrowser/windows.go
index 907d1dc..c5c52a5 100644
--- a/meek-client-torbrowser/windows.go
+++ b/meek-client-torbrowser/windows.go
@@ -22,6 +22,7 @@ const (
 	// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Native_manifests#Windows
 	helperNativeManifestDir    = "TorBrowser/Data/Browser/.mozilla/native-messaging-hosts"
 	helperNativeExecutablePath = "TorBrowser/Tor/PluggableTransports/meek-http-helper.exe"
+	registryKey                = `SOFTWARE\Mozilla\NativeMessagingHosts\`+nativeAppName
 )
 
 func osSpecificCommandSetup(cmd *exec.Cmd) {
@@ -39,16 +40,16 @@ func installHelperNativeManifest() error {
 		return err
 	}
 
-	// TODO: Find a way to do this without having to write to the registry.
-	// https://bugs.torproject.org/29347#comment:9
+	// On Windows we must set a registry key pointing to the host manifest.
+	// We'll attempt to delete the key in uninstallHelperNativeManifest.
 	// https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Native_manifests#Windows
-	k, _, err := registry.CreateKey(
-		registry.CURRENT_USER,
-		`SOFTWARE\Mozilla\NativeMessagingHosts\`+nativeAppName,
-		registry.WRITE,
-	)
+	k, _, err := registry.CreateKey(registry.CURRENT_USER, registryKey, registry.WRITE)
 	if err != nil {
 		return err
 	}
 	return k.SetStringValue("", absManifestPath)
 }
+
+func uninstallHelperNativeManifest() error {
+	return registry.DeleteKey(registry.CURRENT_USER, registryKey)
+}