Commit b41b3745 authored by Pier Angelo Vendrame's avatar Pier Angelo Vendrame 🎃 Committed by brizental
Browse files

BB 43140: Tighten up fonts on Linux. 

We ship a fontconfig configuration to esnure all Linux users have the
same defaults and reduce the chances of fingerprinting.
We used to add this file in tor-browser-build, but some users might
skip it by using the browser executable without the wrapper script.
Therefore, we decided to activate the file with the FontConfig API
instead of the environment variables.

Bug 41043: Hardcode the UI font on Linux

The mechanism to choose the UI font does not play well with our
fontconfig configuration. As a result, the final criterion to choose
the font for the UI was its version.

Since we hardcode Arimo as a default sans-serif on preferences, we use
it also for the UI. FontConfig will fall back to some other font for
scripts Arimo does not cover as expected (we tested with Japanese).

Bug 43141: Hardcode system-ui to Arimo.
parent 6760e001

browser/fonts/fonts.conf

0 → 100644
+183 −0
Original line number Diff line number Diff line 
<?xml version="1.0"?>

<!DOCTYPE fontconfig SYSTEM "fonts.dtd">

<!--

**DO NOT EDIT THIS FILE!**

This file sets Tor Browser's bundled fonts as the only available system fonts

and standardizes rendering settings.

Any changes might deanonymize you, or expose you to fingerprinting vectors.

-->

<!--

Derived from fonts.conf.in of Fontconfig.



Copyright © 2000,2001,2002,2003,2004,2006,2007 Keith Packard

Copyright © 2005 Patrick Lam

Copyright © 2009 Roozbeh Pournader

Copyright © 2008,2009 Red Hat, Inc.

Copyright © 2008 Danilo Šegan

Copyright © 2012 Google, Inc.





Permission to use, copy, modify, distribute, and sell this software and its

documentation for any purpose is hereby granted without fee, provided that

the above copyright notice appear in all copies and that both that

copyright notice and this permission notice appear in supporting

documentation, and that the name of the author(s) not be used in

advertising or publicity pertaining to distribution of the software without

specific, written prior permission.  The authors make no

representations about the suitability of this software for any purpose.  It

is provided "as is" without express or implied warranty.



THE AUTHOR(S) DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,

INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO

EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY SPECIAL, INDIRECT OR

CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,

DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER

TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR

PERFORMANCE OF THIS SOFTWARE.

-->

<fontconfig>



<!-- Font directory list -->



	<dir prefix="cwd">fonts</dir>



<!--

  Accept deprecated 'mono' alias, replacing it with 'monospace'

-->

	<match target="pattern">

		<test qual="any" name="family">

			<string>mono</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>monospace</string>

		</edit>

	</match>



<!--

  Accept alternate 'sans serif' spelling, replacing it with 'sans-serif'

-->

	<match target="pattern">

		<test qual="any" name="family">

			<string>sans serif</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>sans-serif</string>

		</edit>

	</match>



<!--

  Accept deprecated 'sans' alias, replacing it with 'sans-serif'

-->

	<match target="pattern">

		<test qual="any" name="family">

			<string>sans</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>sans-serif</string>

		</edit>

	</match>



<!--

  Set our default generic families.

-->

	<match target="pattern">

		<test qual="any" name="family">

			<string>sans-serif</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Arimo</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>serif</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Tinos</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>monospace</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Cousine</string>

		</edit>

	</match>



<!--

  tor-browser#41799, tor-browser-build#41237: Add some aliases for

  compatibility.

-->

	<match target="pattern">

		<test qual="any" name="family">

			<string>Arial</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Arimo</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>Times New Roman</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Tinos</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>Courier New</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Cousine</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>Helvetica</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Arimo</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>Times</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Tinos</string>

		</edit>

	</match>

	<match target="pattern">

		<test qual="any" name="family">

			<string>Courier</string>

		</test>

		<edit name="family" mode="assign" binding="same">

			<string>Cousine</string>

		</edit>

	</match>



<!-- Font cache directory list -->



	<cachedir prefix="xdg">fontconfig</cachedir>



	<config>

<!--

  Rescan configuration every 30 seconds when FcFontSetList is called

 -->

		<rescan>

			<int>30</int>

		</rescan>

	</config>



	<!-- Standardize rendering settings. -->

	<match target="pattern">

		<edit name="antialias" mode="assign"><bool>true</bool></edit>

		<edit name="autohint" mode="assign"><bool>false</bool></edit>

		<edit name="hinting" mode="assign"><bool>true</bool></edit>

		<edit name="hintstyle" mode="assign"><const>hintfull</const></edit>

		<edit name="lcdfilter" mode="assign"><const>lcddefault</const></edit>

		<edit name="rgba" mode="assign"><const>none</const></edit>

	</match>

</fontconfig>

browser/fonts/moz.build

+3 −0
Original line number Diff line number Diff line
@@ -7,3 +7,6 @@ 
if CONFIG["MOZ_WIDGET_TOOLKIT"] in ("windows", "gtk"):

    DIST_SUBDIR = ""

    FINAL_TARGET_FILES.fonts += ["TwemojiMozilla.ttf"]



if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":

    FINAL_TARGET_FILES.fonts += ["fonts.conf"]

gfx/thebes/gfxFcPlatformFontList.cpp

+5 −3
Original line number Diff line number Diff line
@@ -2219,10 +2219,12 @@ void gfxFcPlatformFontList::GetFontList(nsAtom* aLangGroup, 
FontFamily gfxFcPlatformFontList::GetDefaultFontForPlatform(

    FontVisibilityProvider* aFontVisibilityProvider, const gfxFontStyle* aStyle,

    nsAtom* aLanguage) {

  // Get the default font by using a fake name to retrieve the first

  // scalable font that fontconfig suggests for the given language.

  // We hardcode Arimo also in preferences, and using the original code that

  // tried to resolve a non-existing font did not play well with our fontconfig

  // configuration. See

  // https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/41043

  PrefFontList* prefFonts =

      FindGenericFamilies(aFontVisibilityProvider, "-moz-default"_ns,

      FindGenericFamilies(aFontVisibilityProvider, "Arimo"_ns,

                          aLanguage ? aLanguage : nsGkAtoms::x_western);

  NS_ASSERTION(prefFonts, "null list of generic fonts");

  if (prefFonts && !prefFonts->IsEmpty()) {

gfx/thebes/gfxPlatformFontList.cpp

+5 −0
Original line number Diff line number Diff line
@@ -2124,6 +2124,11 @@ static void GetSystemUIFontFamilies( 
#if defined(XP_MACOSX) || defined(MOZ_WIDGET_UIKIT)

    *aFamilies.AppendElement() = "-apple-system"_ns;

    return;

#elif defined(MOZ_WIDGET_GTK)

    // tor-browser#43141: Hardcode Arimo in case our custom fontconfig is

    // missing.

    *aFamilies.AppendElement() = "Arimo"_ns;

    return;

#elif !defined(MOZ_WIDGET_ANDROID)

    *aFamilies.AppendElement() = "sans-serif"_ns;

    return;

layout/base/nsLayoutUtils.cpp

+3 −1
Original line number Diff line number Diff line
@@ -9662,7 +9662,9 @@ static void GetSpoofedSystemFontForRFP(LookAndFeel::FontID aFontID, 
  // In general, Linux uses some sans-serif, but its size can vary between

  // 12px and 16px. We chose 15px because it is what Firefox is doing for the

  // UI font-size.

  aName = u"sans-serif"_ns;

  // tor-browser#43141: Hardcode Arimo in case our custom fontconfig is

  // missing.

  aName = u"Arimo"_ns;

  aStyle.size = 15;

#else

#  error "Unknown platform"