installer: delete config file with custom action

1 files changed, 97 insertions, 0 deletions

diff --git a/installer/customactions.js b/installer/customactions.js
new file mode 100644
index 00000000..9ca93ca5
--- /dev/null
+++ b/installer/customactions.js
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+var wsh = new ActiveXObject("WScript.Shell");
+var shl = new ActiveXObject("Shell.Application");
+var fso = new ActiveXObject("Scripting.FileSystemObject");
+
+function logMessage(msg) {
+	var record = Installer.CreateRecord(1);
+	record.StringData(0) = "Custom action: [1]";
+	record.StringData(1) = msg.toString();
+	Session.Message(0x04000000, record);
+}
+
+// I'd rather use wsh.Exec, so that we can just do ".Stdout.ReadAll()", but
+// this results in a scary flashing command window. The below is the best
+// workaround we can find yet. We'll keep searching for more clever tricks.
+function runWithNoWindowFlash(command) {
+	//TODO: Seems pretty unlikely that this temp file is secure...
+	var tmpfile = fso.BuildPath(fso.GetSpecialFolder(2), fso.GetTempName());
+	try {
+		//TODO: Obviously cmd and tmpfile are unescaped here...
+		var cmd = fso.BuildPath(fso.GetSpecialFolder(1), "cmd.exe") + " /c " + command + " > " + tmpfile;
+		var ret = wsh.Run(cmd, 0, true);
+		if (ret != 0) {
+			logMessage("Command " + cmd + " exited with error " + ret.toString());
+			return "";
+		}
+		var txt;
+		try {
+			var file = fso.OpenTextFile(tmpfile, 1);
+			txt = file.ReadAll();
+			file.Close();
+		} catch (e) {
+			logMessage("Unable to read temporary file " + tmpfile + " for command " + cmd + ": " + e.message);
+			return "";
+		}
+		return txt;
+	} finally {
+		try {
+			fso.DeleteFile(tmpfile);
+		} catch (e) {}
+	}
+}
+
+function EvaluateWireGuardServices() {
+	var inst = Session.Installer;
+	var db = Session.Database;
+	var view = db.OpenView("INSERT INTO `ServiceControl` (`ServiceControl`, `Name`, `Event`, `Component_`) VALUES(?, ?, ?, ?) TEMPORARY");
+	var rec = inst.CreateRecord(4);
+	var serviceKey = "HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Services";
+	var servicePrefix = "WireGuardTunnel$";
+	var serviceKeyPrefix = serviceKey + "\\" + servicePrefix;
+	var allowedNameFormat = new RegExp("^[a-zA-Z0-9_=+.-]{1,32}$");
+	var msiOperators = new RegExp("[=+-]", "g");
+	var index = 0;
+
+	function insertServiceControl(serviceName) {
+		var flags = 0x2/*msidbServiceControlEventStop*/ | 0x20/*msidbServiceControlEventUninstallStop*/ | 0x80/*msidbServiceControlEventUninstallDelete*/;
+
+		if (shl.IsServiceRunning(serviceName)) {
+			flags |= 0x1/*msidbServiceControlEventStart*/;
+			logMessage("Scheduling stop on upgrade/uninstall and removal on uninstall of service " + serviceName);
+		} else {
+			logMessage("Scheduling removal on uninstall of service " + serviceName);
+		}
+
+		rec.StringData (1/*ServiceControl*/) = serviceName.replace(msiOperators, "_") + (index++).toString();
+		rec.StringData (2/*Name          */) = serviceName;
+		rec.IntegerData(3/*Event         */) = flags;
+		rec.StringData (4/*Component_    */) = "WireGuardExecutable";
+
+		view.Execute(rec);
+	}
+
+	insertServiceControl("WireGuardManager");
+
+	var txt = runWithNoWindowFlash(fso.BuildPath(fso.GetSpecialFolder(1), "reg.exe") + " query \"" + serviceKey + "\"");
+	var lines = txt.split(new RegExp("\r?\n", "g"));
+	for (var i = 0; i < lines.length; ++i) {
+		if (lines[i].length > serviceKeyPrefix.length && lines[i].substring(0, serviceKeyPrefix.length) == serviceKeyPrefix) {
+			var tunnelName = lines[i].substring(serviceKeyPrefix.length);
+			if (tunnelName.match(allowedNameFormat) != null)
+				insertServiceControl(servicePrefix + tunnelName);
+		}
+	}
+}
+
+function RemoveConfigFolder() {
+	try {
+		fso.DeleteFolder(fso.BuildPath(fso.GetSpecialFolder(1), "config\\systemprofile\\AppData\\Local\\WireGuard"), true);
+	} catch(e) {
+		logMessage("Failed to remove configuration on uninstall: " + e.message);
+	}
+}