Bug #5926: Allow JS locale to be set to English/C. (fdef2783) · Commits · The Tor Project / Applications / Tor Browser

browser/base/content/test/general/mochitest.ini

+1 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ support-files =

		[test_bug364677.html]
		[test_bug395533.html]
		[test_bug_jsdefaultlocale.html]
		[test_contextmenu.html]
		skip-if = toolkit == "gtk2" \|\| toolkit == "gtk3" \|\| (os == 'mac' && os_version != '10.6') # disabled on Linux due to bug 513558, on Mac after 10.6 due to bug 792304
		[test_contextmenu_input.html]

browser/base/content/test/general/test_bug_jsdefaultlocale.html

0 → 100644

+41 −0

Original line number	Diff line number	Diff line
		<!DOCTYPE HTML>
		<html>
		<!--
		https://bugs.torproject.org/13019
		-->
		<head>
		<meta charset="utf-8">
		<title>Test for Tor Bug #13019: Prevent fingerprinting of JS-exposed locale</title>
		<script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
		<script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
		<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
		</head>
		<body>
		<a target="_blank" href="https://bugs.torproject.org">Bug 13019</a>
		<p id="display"></p>
		<pre id="test"></pre>
		<script type="application/javascript;version=1.8">
		let prefName = "javascript.use_us_english_locale",
		originalPrefValue = null,
		date = new Date();
		// Read the current pref value.
		try {
		originalPrefValue = SpecialPowers.getBoolPref(prefName);
		} catch (e) { }
		// Enable pref "javascript.use_us_english_locale".
		SpecialPowers.setBoolPref(prefName, true);
		// Test that we are getting en-US locale everywhere it is exposed in JavaScript
		is(Intl.Collator().resolvedOptions().locale, "en-US", "content JS locale from Intl.Collator");
		is(Intl.DateTimeFormat().resolvedOptions().locale, "en-US", "content JS locale Intl.DateTimeFormat");
		is(Intl.NumberFormat().resolvedOptions().locale, "en-US", "content JS locale from Intl.NumberFormat");
		is(date.toLocaleString(), date.toLocaleString("en-US"), "Date formatted by JS locale");
		// Return pref to its original value, if it had one.
		if (originalPrefValue === null) {
		SpecialPowers.clearUserPref(prefName);
		} else {
		SpecialPowers.setBoolPref(prefName, originalPrefValue);
		}

		</script>
		</body>
		</html>

js/src/jsapi.cpp

+7 −0

Original line number	Diff line number	Diff line
		@@ -5217,6 +5217,13 @@ JS_SetDefaultLocale(JSRuntime* rt, const char* locale)
		return rt->setDefaultLocale(locale);
		}

		JS_PUBLIC_API(const char*)
		JS_GetDefaultLocale(JSRuntime *rt)
		{
		AssertHeapIsIdle(rt);
		return rt->getDefaultLocale();
		}

		JS_PUBLIC_API(void)
		JS_ResetDefaultLocale(JSRuntime* rt)
		{

js/src/jsapi.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -4265,6 +4265,15 @@ JS_ParseJSONWithReviver(JSContext* cx, JS::HandleString str, JS::HandleValue rev
		extern JS_PUBLIC_API(bool)
		JS_SetDefaultLocale(JSRuntime* rt, const char* locale);

		/*
		* Returns the default locale for the ECMAScript Internationalization API
		* (Intl.Collator, Intl.NumberFormat, Intl.DateTimeFormat).
		* Note that the Internationalization API encourages clients to
		* specify their own locales.
		*/
		extern JS_PUBLIC_API(const char*)
		JS_GetDefaultLocale(JSRuntime *rt);

		/*
		* Reset the default locale to OS defaults.
		*/

xpcom/build/XPCOMInit.cpp

+68 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@

		#include "mozilla/Atomics.h"
		#include "mozilla/Poison.h"
		#include "mozilla/Preferences.h"
		#include "mozilla/XPCOM.h"
		#include "nsXULAppAPI.h"

		@@ -43,6 +44,8 @@
		#include "nsSupportsPrimitives.h"
		#include "nsConsoleService.h"

		#include "nsIJSRuntimeService.h"

		#include "nsComponentManager.h"
		#include "nsCategoryManagerUtils.h"
		#include "nsIServiceManager.h"
		@@ -485,6 +488,67 @@ NS_IMPL_ISUPPORTS(NesteggReporter, nsIMemoryReporter)
		CountingAllocatorBase<NesteggReporter>::sAmount(0);
		#endif /* MOZ_WEBM */

		// Anonymous namespace for customizing the default locale that JavaScript
		// uses, according to the value of the "javascript.use_us_english_locale" pref.
		// The current default locale can be detected in JavaScript by calling
		// `Intl.DateTimeFormat().resolvedOptions().locale`
		namespace {

		#define USE_US_ENGLISH_LOCALE_PREF "javascript.use_us_english_locale"

		static char* sSystemLocale;
		static char* sJSLocale;

		// Returns a pointer to the current JS Runtime.
		static
		JSRuntime* GetRuntime() {
		nsresult rv;
		nsCOMPtr<nsIJSRuntimeService> rts = do_GetService("@mozilla.org/js/xpc/RuntimeService;1", &rv);
		if (NS_FAILED(rv)) return NULL;
		JSRuntime* rt;
		rts->GetRuntime(&rt);
		return rt;
		}

		// If the USE_US_ENGLISH_LOCALE_PREF is active, set all locales to US English.
		// Otherwise, fall back to the default system and JS locales.
		static
		void UseUSEnglishLocalePrefChangedCallback(const char* /* pref /, void /* closure */) {
		// Get a pointer to the default JS Runtime.
		JSRuntime* rt = GetRuntime();
		if (rt) {
		// Read the pref to see if we will use US English locale.
		bool useUSEnglishLocale = mozilla::Preferences::GetBool(USE_US_ENGLISH_LOCALE_PREF, false);
		// Set the application-wide C-locale. Needed for Date.toLocaleFormat().
		setlocale(LC_ALL, useUSEnglishLocale ? "C" : sSystemLocale);
		// Now override the JavaScript Runtime Locale that is used by the Intl API
		// as well as Date.toLocaleString, Number.toLocaleString, and String.localeCompare.
		JS_SetDefaultLocale(rt, useUSEnglishLocale ? "en-US" : sJSLocale);
		}
		}

		static
		void StartWatchingUseUSEnglishLocalePref() {
		// Get the default system locale. To be used if US English locale pref is deactivated.
		sSystemLocale = strdup(setlocale(LC_ALL,NULL));
		// Store the default JavaScript locale.
		JSRuntime* rt = GetRuntime();
		if (rt) {
		sJSLocale = strdup(JS_GetDefaultLocale(rt));
		}
		// Now keep the locale updated with the current pref value.
		mozilla::Preferences::RegisterCallbackAndCall(UseUSEnglishLocalePrefChangedCallback, USE_US_ENGLISH_LOCALE_PREF);
		}

		static
		void StopWatchingUseUSEnglishLocalePref() {
		mozilla::Preferences::UnregisterCallback(UseUSEnglishLocalePrefChangedCallback, USE_US_ENGLISH_LOCALE_PREF);
		if (sSystemLocale) free(sSystemLocale);
		if (sJSLocale) JS_free(nullptr, sJSLocale);
		}

		} // anonymous namespace for locale hiding

		// Note that on OSX, aBinDirectory will point to .app/Contents/Resources/browser
		EXPORT_XPCOM_API(nsresult)
		NS_InitXPCOM2(nsIServiceManager** aResult,
		@@ -766,6 +830,8 @@ NS_InitXPCOM2(nsIServiceManager** aResult,
		mozilla::eventtracer::Init();
		#endif

		// Start watching the "javascript.use_us_english_locale" pref.
		StartWatchingUseUSEnglishLocalePref();
		return NS_OK;
		}

		@@ -1038,6 +1104,8 @@ ShutdownXPCOM(nsIServiceManager* aServMgr)
		delete sExitManager;
		sExitManager = nullptr;

		StopWatchingUseUSEnglishLocalePref();

		Omnijar::CleanUp();

		HangMonitor::Shutdown();