Bug 1440573 - Policy: Disable safe mode. r=jimm,felipe

This policy disables the safe-mode UI entry points. In addition, only on Windows when using GPO, it also disables entering Safe Mode by holding down the Shift Key

browser/base/content/utilityOverlay.js

@@ -832,6 +832,9 @@ function buildHelpMenu() {
   document.getElementById("feedbackPage")
           .disabled = !Services.policies.isAllowed("feedbackCommands");
 
+  document.getElementById("helpSafeMode")
+          .disabled = !Services.policies.isAllowed("safeMode");
+
   // Enable/disable the "Report Web Forgery" menu item.
   if (typeof gSafeBrowsing != "undefined") {
     gSafeBrowsing.setReportPhishingMenu();

browser/components/enterprisepolicies/Policies.jsm

@@ -215,6 +215,14 @@ var Policies = {
     }
   },
 
+  "DisableSafeMode": {
+    onBeforeUIStartup(manager, param) {
+      if (param) {
+        manager.disallowFeature("safeMode");
+      }
+    }
+  },
+
   "DisableSysAddonUpdate": {
     onBeforeAddons(manager, param) {
       if (param) {

browser/components/enterprisepolicies/schemas/policies-schema.json

@@ -170,6 +170,13 @@
       "type": "boolean"
     },
 
+    "DisableSafeMode": {
+      "description": "Prevents ability to restart in safe mode.",
+      "first_available": "60.0",
+
+      "type": "boolean"
+    },
+
     "DisableSysAddonUpdate": {
       "description": "Prevent the browser from installing and updating system addons.",
       "first_available": "60.0",

browser/components/enterprisepolicies/tests/browser/browser.ini

@@ -32,6 +32,7 @@ support-files =
 [browser_policy_disable_pdfjs.js]
 [browser_policy_disable_pocket.js]
 [browser_policy_disable_privatebrowsing.js]
+[browser_policy_disable_safemode.js]
 [browser_policy_disable_shield.js]
 [browser_policy_display_bookmarks.js]
 [browser_policy_display_menu.js]

browser/components/enterprisepolicies/tests/browser/browser_policy_disable_safemode.js

@@ -0,0 +1,42 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+add_task(async function setup() {
+  await setupPolicyEngineWithJson({
+    "policies": {
+      "DisableSafeMode": true
+    }
+  });
+});
+
+add_task(async function test_help_menu() {
+  buildHelpMenu();
+  let safeModeMenu = document.getElementById("helpSafeMode");
+  is(safeModeMenu.getAttribute("disabled"), "true",
+     "The `Restart with Add-ons Disabled...` item should be disabled");
+});
+
+add_task(async function test_safemode_from_about_support() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:support");
+
+  await ContentTask.spawn(tab.linkedBrowser, null, async function() {
+    let button = content.document.getElementById("restart-in-safe-mode-button");
+    is(button.getAttribute("disabled"), "true",
+       "The `Restart with Add-ons Disabled...` button should be disabled");
+  });
+
+  await BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function test_safemode_from_about_profiles() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, "about:profiles");
+
+  await ContentTask.spawn(tab.linkedBrowser, null, async function() {
+    let button = content.document.getElementById("restart-in-safe-mode-button");
+    is(button.getAttribute("disabled"), "true",
+       "The `Restart with Add-ons Disabled...` button should be disabled");
+  });
+
+  await BrowserTestUtils.removeTab(tab);
+});

testing/marionette/harness/marionette_harness/tests/unit/test_cli_arguments.py

@@ -5,6 +5,14 @@
 from __future__ import absolute_import
 
 import copy
+import platform
+try:
+    import winreg
+except ImportError:
+    try:
+        import _winreg as winreg
+    except ImportError:
+        pass
 
 from marionette_harness import MarionetteTestCase
 
@@ -34,9 +42,36 @@ class TestCommandLineArguments(MarionetteTestCase):
 
               return Services.appinfo.inSafeMode;
             """)
-
             self.assertTrue(safe_mode, "Safe Mode has not been enabled")
 
+    def test_safe_mode_blocked_by_policy(self):
+        if platform.system() != 'Windows':
+            return
+
+        reg_policies = winreg.OpenKeyEx(winreg.HKEY_CURRENT_USER, "SOFTWARE\\Policies", 0, winreg.KEY_WRITE)
+        reg_mozilla = winreg.CreateKeyEx(reg_policies, "Mozilla", 0, winreg.KEY_WRITE)
+        reg_firefox = winreg.CreateKeyEx(reg_mozilla, "Firefox", 0, winreg.KEY_WRITE)
+        winreg.SetValueEx(reg_firefox, "DisableSafeMode", 0, winreg.REG_DWORD, 1)
+
+        self.marionette.instance.app_args.append("-safe-mode")
+
+        self.marionette.quit()
+        self.marionette.start_session()
+
+        with self.marionette.using_context("chrome"):
+            safe_mode = self.marionette.execute_script("""
+              Cu.import("resource://gre/modules/Services.jsm");
+
+              return Services.appinfo.inSafeMode;
+            """)
+            self.assertFalse(safe_mode, "Safe Mode has been enabled")
+
+        winreg.CloseKey(reg_firefox)
+        winreg.DeleteKey(reg_mozilla, "Firefox")
+        winreg.CloseKey(reg_mozilla)
+        winreg.DeleteKey(reg_policies, "Mozilla")
+        winreg.CloseKey(reg_policies)
+
     def test_startup_timeout(self):
         startup_timeout = self.marionette.startup_timeout
 

toolkit/content/aboutProfiles.js

@@ -85,7 +85,11 @@ function refreshUI() {
   createButton.onclick = createProfileWizard;
 
   let restartSafeModeButton = document.getElementById("restart-in-safe-mode-button");
-  restartSafeModeButton.onclick = function() { restart(true); };
+  if (!Services.policies || Services.policies.isAllowed("safeMode")) {
+    restartSafeModeButton.onclick = function() { restart(true); };
+  } else {
+    restartSafeModeButton.setAttribute("disabled", "true");
+  }
 
   let restartNormalModeButton = document.getElementById("restart-button");
   restartNormalModeButton.onclick = function() { restart(false); };

toolkit/content/aboutSupport.js

@@ -1206,6 +1206,10 @@ function populateActionBox() {
   if (!Services.appinfo.inSafeMode && AppConstants.platform !== "android") {
     $("safe-mode-box").style.display = "block";
     $("action-box").style.display = "block";
+
+    if (Services.policies && !Services.policies.isAllowed("safeMode")) {
+      $("restart-in-safe-mode-button").setAttribute("disabled", "true");
+    }
   }
 }
 

toolkit/xre/nsAppRunner.cpp

@@ -3154,6 +3154,40 @@ public:
 #endif
 };
 
+#ifdef XP_WIN
+namespace {
+
+bool PolicyHasRegValue(HKEY aKey, LPCTSTR aName, DWORD* aValue)
+{
+  HKEY hkey = NULL;
+  LONG ret = RegOpenKeyExW(aKey,
+    L"SOFTWARE\\Policies\\Mozilla\\Firefox", 0, KEY_READ, &hkey);
+  if (ret != ERROR_SUCCESS) {
+     return false;
+  }
+  nsAutoRegKey key(hkey);
+  DWORD len = sizeof(aValue);
+  ret = RegQueryValueExW(hkey, aName, 0, NULL, (LPBYTE)aValue, &len);
+  RegCloseKey(key);
+  return ret == ERROR_SUCCESS;
+}
+
+bool SafeModeBlockedByPolicy()
+{
+  LPCTSTR policyName = L"DisableSafeMode";
+  DWORD value;
+  if (PolicyHasRegValue(HKEY_LOCAL_MACHINE, policyName, &value)) {
+    return value == 1;
+  }
+  if (PolicyHasRegValue(HKEY_CURRENT_USER, policyName, &value)) {
+    return value == 1;
+  }
+  return false;
+}
+
+} // anonymous namespace
+#endif // XP_WIN
+
 /*
  * XRE_mainInit - Initial setup and command line parameter processing.
  * Main() will exit early if either return value != 0 or if aExitFlag is
@@ -3490,12 +3524,6 @@ XREMain::XRE_mainInit(bool* aExitFlag)
   gRestartArgv[gRestartArgc] = nullptr;
 
 
-  if (EnvHasValue("MOZ_SAFE_MODE_RESTART")) {
-    gSafeMode = true;
-    // unset the env variable
-    SaveToEnv("MOZ_SAFE_MODE_RESTART=");
-  }
-
   ar = CheckArg("safe-mode", true);
   if (ar == ARG_BAD) {
     PR_fprintf(PR_STDERR, "Error: argument --safe-mode is invalid when argument --osint is specified\n");
@@ -3525,6 +3553,20 @@ XREMain::XRE_mainInit(bool* aExitFlag)
     gSafeMode = true;
 #endif
 
+#ifdef XP_WIN
+if (gSafeMode && SafeModeBlockedByPolicy()) {
+    gSafeMode = false;
+  }
+#endif
+
+  // The Safe Mode Policy should not be enforced for the env var case
+  // (used by updater and crash-recovery).
+  if (EnvHasValue("MOZ_SAFE_MODE_RESTART")) {
+    gSafeMode = true;
+    // unset the env variable
+    SaveToEnv("MOZ_SAFE_MODE_RESTART=");
+  }
+
 #ifdef XP_WIN
   {
     // Add CPU microcode version to the crash report as "CPUMicrocodeVersion".