config/chroot_local-includes/usr/local/lib/tails-shell-library/tor-browser.sh

   1 #!/bin/sh
   2
   3 TBB_INSTALL=/usr/local/lib/tor-browser
   4 # shellcheck disable=SC2034
   5 TBB_PROFILE=/etc/tor-browser/profile
   6 # shellcheck disable=SC2034
   7 TBB_EXT=/usr/local/share/tor-browser-extensions
   8
   9 # For strings it's up to the caller to add double-quotes ("") around
  10 # the value.
  11 set_mozilla_pref() {
  12     local file name value prefix
  13     file="${1}"
  14     name="${2}"
  15     value="${3}"
  16     # Sometimes we might want to do e.g. user_pref
  17     prefix="${4:-pref}"
  18     [ -e "${file}" ] && sed -i "/^${prefix}(\"${name}\",/d" "${file}"
  19     echo "${prefix}(\"${name}\", ${value});" >> "${file}"
  20 }
  21
  22 exec_firefox_helper() {
  23     local binary="${1}"; shift
  24
  25     export LD_LIBRARY_PATH="${TBB_INSTALL}"
  26     export GNOME_ACCESSIBILITY=1
  27
  28     # Don't let Tor Browser manage the tor daemon: we do it ourselves.
  29     export TOR_SKIP_LAUNCH=1
  30
  31     # The Tor Browser often assumes that the current directory is
  32     # where the browser lives, e.g. for the fixed set of fonts set by
  33     # fontconfig above.
  34     cd "${TBB_INSTALL}"
  35
  36     # Environment stuff from the upstream start-browser script:
  37
  38     # Do not (try to) connect to the session manager.  Otherwise it
  39     # does (and fails) but if it succeeded it would be "very bad",
  40     # although details on why are missing.
  41     # https://gitlab.torproject.org/legacy/trac/-/issues/5261
  42     unset SESSION_MANAGER
  43
  44     # Enable bundled fonts to decrease fingerprint.
  45     # https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/13313
  46     export FONTCONFIG_PATH="${TBB_INSTALL}/fontconfig"
  47     export FONTCONFIG_FILE="fonts.conf"
  48
  49     # Avoid overwriting user's dconf values.
  50     # https://gitlab.torproject.org/legacy/trac/-/issues/27903
  51     export GSETTINGS_BACKEND=memory
  52
  53     exec "${TBB_INSTALL}"/"${binary}" "${@}"
  54 }
  55
  56 exec_firefox() {
  57     exec_firefox_helper firefox.real "${@}"
  58 }
  59
  60 guess_best_tor_browser_locale() {
  61     local long_locale short_locale similar_locale
  62     long_locale="$(echo "${LANG}" | sed -e 's/\..*$//' -e 's/_/-/')"
  63     short_locale="$(echo "${long_locale}" | cut -d"-" -f1)"
  64     if locale_is_supported_by_tor_browser "$long_locale"; then
  65         echo "${long_locale}"
  66         return
  67     elif locale_is_supported_by_tor_browser "$short_locale"; then
  68         echo "${short_locale}"
  69         return
  70     fi
  71     # If we use locale xx-YY and Tor Browser supports neither xx-YY nor xx,
  72     # there may be a similar locale xx-ZZ that we should use instead.
  73     # shellcheck disable=SC2012
  74     similar_locale=$(
  75         supported_tor_browser_locales | \
  76             grep --max-count=1 --extended-regexp --line-regexp \
  77                  "${short_locale}-[A-Z]+" \
  78     ) || :
  79     if [ -n "${similar_locale:-}" ]; then
  80         echo "${similar_locale}"
  81         return
  82     fi
  83
  84     echo 'en-US'
  85 }
  86
  87 configure_best_tor_browser_locale() {
  88     local profile best_locale
  89     profile="${1}"
  90     best_locale="$(guess_best_tor_browser_locale)"
  91     cat "/etc/tor-browser/locale-profiles/${best_locale}.js" \
  92         >> "${profile}/prefs.js"
  93 }
  94
  95 supported_tor_browser_locales() {
  96     tmp=$(mktemp -d)
  97     7z e -tzip -o"$tmp" -- "${TBB_INSTALL}/omni.ja" res/multilocale.txt >/dev/null
  98     tr ',' "\n" < "$tmp"/multilocale.txt
  99     rm -rf "$tmp"
 100 }
 101
 102 locale_is_supported_by_tor_browser() {
 103     local mozilla_locale
 104     mozilla_locale="${1}"
 105
 106     supported_tor_browser_locales \
 107         | grep --quiet --fixed-strings --line-regexp "$mozilla_locale"
 108 }
 109
 110 set_firefox_content_process_count() {
 111     local profile="$1"
 112     local count="$2"
 113
 114     set_mozilla_pref "${profile}/prefs.js" \
 115                      "dom.ipc.processCount" "$count" \
 116                      user_pref
 117 }
 118
 119 configure_tor_browser_memory_usage() {
 120     local profile="${1}"
 121
 122     # Unit: KiB
 123     system_ram=$(awk '/^MemTotal:/ { print $2 }' /proc/meminfo)
 124
 125     if [ "$system_ram" -lt "$((3 * 1024 * 1024))" ]; then
 126         set_firefox_content_process_count "$profile" 2
 127     fi
 128 }