Stop world-writable browser policy directories

Chromium managed policy is mandatory for every profile. World-writable
dirs let any local uid plant policy, including force-installed
extensions. Write goes through the omarchy-browser-policy group at 2775
so theme colour still works without other-write.

bin/omarchy-install-browser

@@ -6,9 +6,12 @@
 
 set -e
 
-setup_policy_directory() {
+source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
-  sudo mkdir -p "$1"
+
-  sudo chmod a+rw "$1"
+setup_chromium_policy_directory() {
+  browser_policy_setup_group
+  browser_policy_grant_user "${USER:-$(id -un)}"
+  browser_policy_setup_dir "$1"
 }
 
 announce_browser_installed() {
@@ -23,13 +26,6 @@ copy_chromium_flags() {
   omarchy-install-chromium-ytdlp
 }
 
-setup_firefox_preferences() {
-  local distribution_dir="$1"
-
-  setup_policy_directory "$distribution_dir"
-  sudo cp -f "$OMARCHY_PATH/default/firefox/policies.json" "$distribution_dir/policies.json"
-}
-
 setup_firefox_wayland() {
   mkdir -p ~/.config/environment.d
   echo "MOZ_ENABLE_WAYLAND=1" > ~/.config/environment.d/omarchy-firefox-wayland.conf
@@ -40,7 +36,7 @@ chromium)
   echo "Installing Chromium..."
   omarchy-pkg-add chromium
 
-  setup_policy_directory /etc/chromium/policies/managed
+  setup_chromium_policy_directory /etc/chromium/policies/managed
   copy_chromium_flags ~/.config/chromium-flags.conf
   omarchy-theme-set-browser
   announce_browser_installed "Chromium"
@@ -49,7 +45,7 @@ chrome)
   echo "Installing Chrome..."
   omarchy-pkg-aur-add google-chrome || exit 1
 
-  setup_policy_directory /etc/opt/chrome/policies/managed
+  setup_chromium_policy_directory /etc/opt/chrome/policies/managed
   copy_chromium_flags ~/.config/chrome-flags.conf
   omarchy-theme-set-browser
   announce_browser_installed "Chrome"
@@ -58,7 +54,7 @@ edge)
   echo "Installing Edge..."
   omarchy-pkg-aur-add microsoft-edge-stable-bin || exit 1
 
-  setup_policy_directory /etc/opt/edge/policies/managed
+  setup_chromium_policy_directory /etc/opt/edge/policies/managed
   copy_chromium_flags ~/.config/microsoft-edge-stable-flags.conf
   omarchy-theme-set-browser
   announce_browser_installed "Edge"
@@ -67,7 +63,7 @@ brave)
   echo "Installing Brave..."
   omarchy-pkg-aur-add brave-bin || exit 1
 
-  setup_policy_directory /etc/brave/policies/managed
+  setup_chromium_policy_directory /etc/brave/policies/managed
   copy_chromium_flags ~/.config/brave-flags.conf
   omarchy-theme-set-browser
   announce_browser_installed "Brave"
@@ -76,7 +72,7 @@ brave-origin)
   echo "Installing Brave Origin..."
   omarchy-pkg-aur-add brave-origin-bin || exit 1
 
-  setup_policy_directory /etc/brave/policies/managed
+  setup_chromium_policy_directory /etc/brave/policies/managed
   copy_chromium_flags ~/.config/brave-origin-flags.conf
   omarchy-theme-set-browser
   announce_browser_installed "Brave Origin"
@@ -85,7 +81,7 @@ firefox)
   echo "Installing Firefox..."
   omarchy-pkg-add firefox || exit 1
 
-  setup_firefox_preferences /usr/lib/firefox/distribution
+  browser_policy_setup_firefox_distribution /usr/lib/firefox/distribution
   setup_firefox_wayland
   announce_browser_installed "Firefox"
   ;;
@@ -93,7 +89,7 @@ zen)
   echo "Installing Zen..."
   omarchy-pkg-aur-add zen-browser-bin || exit 1
 
-  setup_firefox_preferences /opt/zen-browser/distribution
+  browser_policy_setup_firefox_distribution /opt/zen-browser/distribution
   setup_firefox_wayland
   announce_browser_installed "Zen"
   ;;

bin/omarchy-provision-owner

@@ -742,6 +742,15 @@ create_user() {
   # for specific commands), and a duplicate grant is harmless.
   echo "%wheel ALL=(ALL:ALL) ALL" >/etc/sudoers.d/00-omarchy-wheel
   chmod 440 /etc/sudoers.d/00-omarchy-wheel
+
+  source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
+  OMARCHY_INSTALL_USER=$username
+  OMARCHY_PROVISIONING_DIR=$PROVISIONING_DIR
+  browser_policy_setup_group
+  for dir in "${BROWSER_POLICY_MANAGED_DIRS[@]}"; do
+    [[ -d $dir ]] || continue
+    browser_policy_setup_dir "$dir"
+  done
 }
 
 install_authorized_keys() {

bin/omarchy-theme-set-browser

@@ -13,11 +13,10 @@ else
   THEME_HEX_COLOR="#1c2027"
 fi
 
-set_browser_policy() {
+source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
-  local policy_dir="$1"
 
-  [[ -d $policy_dir ]] || return
+set_browser_policy() {
-  echo "{\"BrowserThemeColor\": \"$THEME_HEX_COLOR\", \"BrowserColorScheme\": \"device\"}" | tee "$policy_dir/color.json" >/dev/null
+  browser_policy_write_color "$1" "$THEME_HEX_COLOR"
 }
 
 refresh_running_browser() {
@@ -30,17 +29,20 @@ refresh_running_browser() {
   fi
 }
 
-set_browser_policy /etc/chromium/policies/managed
+failed=0
+set_browser_policy /etc/chromium/policies/managed || failed=1
 refresh_running_browser chromium chromium
 
-set_browser_policy /etc/opt/chrome/policies/managed
+set_browser_policy /etc/opt/chrome/policies/managed || failed=1
 refresh_running_browser chrome google-chrome-stable || refresh_running_browser chrome google-chrome
 
-set_browser_policy /etc/opt/edge/policies/managed
+set_browser_policy /etc/opt/edge/policies/managed || failed=1
 refresh_running_browser msedge microsoft-edge-stable
 
-set_browser_policy /etc/brave/policies/managed
+set_browser_policy /etc/brave/policies/managed || failed=1
 refresh_running_browser brave brave
 # Match on the binary path: the running process is named plain "brave", and a
 # bare -f brave-origin pattern would also match the installer's own terminal.
 refresh_running_browser /opt/brave-origin-bin/ brave-origin -f
+
+exit "$failed"

bin/omarchy-upgrade-to-quattro

@@ -1312,7 +1312,22 @@ apply_system_transition() {
     /usr/share/icons/Yaru/scalable/actions/go-next-symbolic.svg
   as_root gtk-update-icon-cache /usr/share/icons/Yaru >/dev/null 2>&1 || true
 
-  as_root install -d -m 0777 /etc/chromium/policies/managed
+  local browser_policy_helper=/usr/share/omarchy/install/helpers/browser-policy.sh
+  if ! as_root test -f "$browser_policy_helper"; then
+    warn "$browser_policy_helper is unavailable; Chromium policy directories were not hardened."
+  else
+    as_root env OMARCHY_PATH=/usr/share/omarchy OMARCHY_INSTALL_USER="$target_user" \
+      bash -euo pipefail -c '
+        source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
+        browser_policy_setup_group
+        browser_policy_setup_dir /etc/chromium/policies/managed
+        for dir in "${BROWSER_POLICY_MANAGED_DIRS[@]}"; do
+          [[ $dir == "/etc/chromium/policies/managed" ]] && continue
+          [[ -d $dir ]] || continue
+          browser_policy_setup_dir "$dir"
+        done
+      '
+  fi
   as_root install -d -m 0755 /usr/lib/chromium
   printf '%s\n' '{"browser":{"theme":{"color_scheme":0,"color_scheme2":0}}}' | \
     as_root tee /usr/lib/chromium/initial_preferences >/dev/null
@@ -2306,6 +2321,11 @@ refresh_current_theme_after_upgrade() {
   # hooks because one of them runs `hyprctl reload`. Still poke terminal
   # emulators so the active upgrade terminal picks up generated theme files.
   run_as_user_omarchy omarchy-restart-terminal >/dev/null 2>&1 || true
+
+  # apply_system_transition purged user-owned color.json. Headless theme-set
+  # skipped omarchy-theme-set-browser, so rewrite the colour here.
+  run_as_user_omarchy omarchy-theme-set-browser >/dev/null 2>&1 ||
+    warn "Could not apply browser theme colour. Run 'omarchy theme set \"$theme_name\"' after reboot if Chromium's theme looks stale."
 }
 
 # Everything below mutates the system, so a non-zero exit from here on leaves a

install/config/all.sh

@@ -1,4 +1,5 @@
 run_logged "$OMARCHY_INSTALL/config/theme-system.sh"
+run_logged "$OMARCHY_INSTALL/config/browser-policy.sh"
 run_logged "$OMARCHY_INSTALL/config/increase-lockout-limit.sh"
 run_logged "$OMARCHY_INSTALL/config/lockscreen-pam.sh"
 run_logged "$OMARCHY_INSTALL/config/fix-powerprofilesctl-shebang.sh"

install/config/browser-policy.sh

@@ -0,0 +1,3 @@
+source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
+browser_policy_setup_group
+browser_policy_setup_dir /etc/chromium/policies/managed

install/config/theme-system.sh

@@ -6,10 +6,6 @@ ln -snf /usr/share/icons/Adwaita/symbolic/actions/go-next-symbolic.svg \
           /usr/share/icons/Yaru/scalable/actions/go-next-symbolic.svg
 gtk-update-icon-cache /usr/share/icons/Yaru &>/dev/null || true
 
-# Chromium policy directory for theme
-mkdir -p /etc/chromium/policies/managed
-chmod a+rw /etc/chromium/policies/managed
-
 # Default Chromium to follow system appearance ("device") instead of dark
 mkdir -p /usr/lib/chromium
 echo '{"browser":{"theme":{"color_scheme":0,"color_scheme2":0}}}' > \

install/helpers/as-root.sh

@@ -0,0 +1,7 @@
+as_root() {
+  if (( EUID == 0 )); then
+    "$@"
+  else
+    sudo "$@"
+  fi
+}

install/helpers/browser-policy.sh

@@ -0,0 +1,171 @@
+# Chromium-family machine policy is mandatory for every profile. A dedicated
+# group at 2775 lets every Omarchy user write color.json and every other uid
+# read; other-write stays off. Setgid so new files inherit the group.
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/as-root.sh"
+
+BROWSER_POLICY_GROUP=omarchy-browser-policy
+
+BROWSER_POLICY_MANAGED_DIRS=(
+  /etc/chromium/policies/managed
+  /etc/opt/chrome/policies/managed
+  /etc/opt/edge/policies/managed
+  /etc/brave/policies/managed
+)
+
+BROWSER_POLICY_FIREFOX_DIRS=(
+  /usr/lib/firefox/distribution
+  /opt/zen-browser/distribution
+)
+
+browser_policy_setup_group() {
+  local provisioning_dir="${OMARCHY_PROVISIONING_DIR:-/var/lib/omarchy/provisioning}"
+
+  as_root groupadd --system --force "$BROWSER_POLICY_GROUP"
+  as_root mkdir -p "$provisioning_dir"
+  if ! grep -qxF "$BROWSER_POLICY_GROUP" "$provisioning_dir/groups" 2>/dev/null; then
+    printf '%s\n' "$BROWSER_POLICY_GROUP" | as_root tee -a "$provisioning_dir/groups" >/dev/null
+  fi
+
+  if [[ -n ${OMARCHY_INSTALL_USER:-} ]] && getent passwd "$OMARCHY_INSTALL_USER" >/dev/null; then
+    as_root usermod -aG "$BROWSER_POLICY_GROUP" "$OMARCHY_INSTALL_USER"
+  fi
+}
+
+browser_policy_grant_user() {
+  local user=${1:-}
+
+  if [[ -z $user || $user == "root" ]]; then
+    user=${SUDO_USER:-}
+  fi
+
+  [[ -n $user && $user != "root" ]] || return 0
+  getent passwd "$user" >/dev/null || return 0
+  as_root usermod -aG "$BROWSER_POLICY_GROUP" "$user"
+}
+
+browser_policy_purge_dir() {
+  local dir=$1
+
+  as_root find "$dir" -mindepth 1 -maxdepth 1 ! -user root -exec rm -rf -- {} +
+}
+
+browser_policy_dir_hardened() {
+  local dir=$1
+
+  [[ -d $dir ]] || return 1
+  [[ $(stat -c '%a' "$dir") == "2775" ]] || return 1
+  [[ $(stat -c '%U' "$dir") == "root" ]] || return 1
+  [[ $(stat -c '%G' "$dir") == $BROWSER_POLICY_GROUP ]] || return 1
+}
+
+browser_policy_setup_dir() {
+  local dir=$1
+
+  as_root install -d -m 2775 -o root -g "$BROWSER_POLICY_GROUP" "$dir"
+  browser_policy_purge_dir "$dir"
+}
+
+browser_policy_file_owner() {
+  local user
+
+  if [[ -n ${OMARCHY_INSTALL_USER:-} && $OMARCHY_INSTALL_USER != "root" ]]; then
+    printf '%s\n' "$OMARCHY_INSTALL_USER"
+    return
+  fi
+  if [[ -n ${SUDO_USER:-} && $SUDO_USER != "root" ]]; then
+    printf '%s\n' "$SUDO_USER"
+    return
+  fi
+  if [[ -n ${PKEXEC_UID:-} ]]; then
+    user=$(getent passwd "$PKEXEC_UID" | cut -d: -f1)
+    if [[ -n $user && $user != "root" ]]; then
+      printf '%s\n' "$user"
+      return
+    fi
+  fi
+  user=${USER:-$(id -un)}
+  if [[ $user != "root" ]]; then
+    printf '%s\n' "$user"
+  fi
+}
+
+# sudo when this process has a controlling terminal (fd 0 is /dev/null under
+# `bash -lc cmd &`, but /dev/tty still works). pkexec when it does not.
+browser_policy_elevate() {
+  if (( EUID == 0 )); then
+    "$@"
+  elif { exec 3</dev/tty; } 2>/dev/null; then
+    exec 3<&-
+    sudo "$@"
+  else
+    pkexec "$@"
+  fi
+}
+
+browser_policy_write_color() {
+  local policy_dir=$1
+  local hex=$2
+  local dest=$policy_dir/color.json
+  local payload
+  local tmp
+  local owner
+
+  [[ -d $policy_dir ]] || return 0
+
+  payload=$(printf '{"BrowserThemeColor": "%s", "BrowserColorScheme": "device"}\n' "$hex")
+  tmp=$(mktemp) || return 1
+  printf '%s' "$payload" >"$tmp"
+
+  # A planted symlink or directory must not be written through or into.
+  if [[ -L $dest || -d $dest ]]; then
+    if ! rm -rf -- "$dest" 2>/dev/null; then
+      if ! browser_policy_elevate rm -rf -- "$dest"; then
+        rm -f "$tmp"
+        echo "omarchy-theme-set-browser: cannot replace $dest (need group $BROWSER_POLICY_GROUP)" >&2
+        return 1
+      fi
+    fi
+  fi
+
+  if install -m 664 -T "$tmp" "$dest" 2>/dev/null; then
+    rm -f "$tmp"
+    return 0
+  fi
+
+  owner=$(browser_policy_file_owner)
+  [[ -n $owner ]] || owner=root
+  if browser_policy_elevate install -m 664 -o "$owner" -g "$BROWSER_POLICY_GROUP" -T "$tmp" "$dest"; then
+    rm -f "$tmp"
+    return 0
+  fi
+
+  rm -f "$tmp"
+  echo "omarchy-theme-set-browser: cannot write $dest (need group $BROWSER_POLICY_GROUP)" >&2
+  return 1
+}
+
+browser_policy_firefox_hardened() {
+  local dir=$1
+
+  [[ -d $dir ]] || return 1
+  [[ $(stat -c '%a' "$dir") == "755" ]] || return 1
+  [[ $(stat -c '%U' "$dir") == "root" ]] || return 1
+  [[ -f $dir/policies.json && ! -L $dir/policies.json ]] || return 1
+}
+
+browser_policy_install_firefox_policies() {
+  local distribution_dir=$1
+  local policies=${2:-$OMARCHY_PATH/default/firefox/policies.json}
+
+  as_root install -m 644 -o root -g root -T "$policies" "$distribution_dir/policies.json"
+}
+
+browser_policy_setup_firefox_distribution() {
+  local distribution_dir=$1
+  local policies=${2:-$OMARCHY_PATH/default/firefox/policies.json}
+
+  as_root install -d -m 0755 -o root -g root "$distribution_dir"
+  browser_policy_purge_dir "$distribution_dir"
+  browser_policy_install_firefox_policies "$distribution_dir" "$policies"
+}

migrations/1787515927.sh

@@ -0,0 +1,24 @@
+echo "Stop world-writable Chromium and Firefox policy directories"
+
+source "$OMARCHY_PATH/install/helpers/browser-policy.sh"
+
+browser_policy_setup_group
+browser_policy_grant_user "${USER:-$(id -un)}"
+
+repaired=0
+for dir in "${BROWSER_POLICY_MANAGED_DIRS[@]}"; do
+  [[ -d $dir ]] || continue
+  browser_policy_dir_hardened "$dir" && continue
+  browser_policy_setup_dir "$dir"
+  repaired=1
+done
+
+if (( repaired )); then
+  omarchy-theme-set-browser
+fi
+
+for dir in "${BROWSER_POLICY_FIREFOX_DIRS[@]}"; do
+  [[ -d $dir ]] || continue
+  browser_policy_firefox_hardened "$dir" && continue
+  browser_policy_setup_firefox_distribution "$dir"
+done

test/shell.d/browser-policy-dir-test.sh

@@ -0,0 +1,244 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+test_tmp=$(mktemp -d)
+trap 'rm -rf "$test_tmp"' EXIT
+
+mock_bin=$test_tmp/bin
+mkdir -p "$mock_bin"
+elev_log=$test_tmp/elev.log
+cat >"$mock_bin/sudo" <<SH
+#!/bin/bash
+printf 'SUDO %s\\n' "\$*" >>"$elev_log"
+[[ \${OMARCHY_TEST_SUDO_FAIL:-} == 1 ]] && exit 1
+exit 0
+SH
+cat >"$mock_bin/pkexec" <<SH
+#!/bin/bash
+printf 'PKEXEC %s\\n' "\$*" >>"$elev_log"
+[[ \${OMARCHY_TEST_SUDO_FAIL:-} == 1 ]] && exit 1
+exit 0
+SH
+chmod +x "$mock_bin/sudo" "$mock_bin/pkexec"
+export PATH="$mock_bin:$PATH"
+: >"$elev_log"
+export OMARCHY_PATH="$ROOT"
+export OMARCHY_PROVISIONING_DIR="$test_tmp/provisioning"
+
+source "$ROOT/install/helpers/browser-policy.sh"
+
+# Temp dirs are user-owned; drop -o/-g so install(1) can run unprivileged.
+unprivileged_as_root() {
+  if [[ $1 == "install" ]]; then
+    shift
+    local args=()
+    local skip=0
+    local arg
+    for arg in "$@"; do
+      if (( skip )); then
+        skip=0
+        continue
+      fi
+      case $arg in
+        -o|-g) skip=1 ;;
+        *) args+=("$arg") ;;
+      esac
+    done
+    command install "${args[@]}"
+  else
+    "$@"
+  fi
+}
+
+write_dir=$test_tmp/writable
+mkdir -p "$write_dir"
+browser_policy_write_color "$write_dir" "#aabbcc" ||
+  fail "theme colour writes into a writable policy directory"
+grep -F '"BrowserThemeColor": "#aabbcc"' "$write_dir/color.json" >/dev/null ||
+  fail "theme colour writes BrowserThemeColor"
+mode=$(stat -c '%a' "$write_dir/color.json")
+[[ $mode == "664" ]] || fail "theme colour creates a group-writable policy file" "mode=$mode"
+pass "theme colour writes a group-writable color.json"
+
+if (( EUID == 0 )); then
+  pass "running as root; skipping the mktemp-failure check"
+else
+  chmod u+w "$write_dir"
+  export TMPDIR=$test_tmp/missing-tmp
+  if browser_policy_write_color "$write_dir" "#dead00" 2>/dev/null; then
+    fail "theme colour fails when mktemp cannot create a file"
+  fi
+  unset TMPDIR
+  grep -F '"BrowserThemeColor": "#aabbcc"' "$write_dir/color.json" >/dev/null ||
+    fail "a failed mktemp leaves an existing color.json intact"
+  pass "a failed mktemp does not truncate color.json"
+fi
+
+printf 'original\n' >"$test_tmp/pwn"
+rm -f "$write_dir/color.json"
+ln -s "$test_tmp/pwn" "$write_dir/color.json"
+browser_policy_write_color "$write_dir" "#aabbcc" ||
+  fail "theme colour replaces a planted color.json symlink"
+[[ -f $write_dir/color.json && ! -L $write_dir/color.json ]] ||
+  fail "theme colour unlinks a planted color.json symlink instead of writing through it"
+grep -Fxq 'original' "$test_tmp/pwn" || fail "theme colour leaves the symlink target unchanged"
+pass "theme colour does not follow a planted color.json symlink"
+
+plant_write=$test_tmp/plant-dir
+mkdir -p "$plant_write/color.json/nested"
+printf 'inside\n' >"$plant_write/color.json/nested/x"
+browser_policy_write_color "$plant_write" "#aabbcc" ||
+  fail "theme colour replaces a planted color.json directory"
+[[ -f $plant_write/color.json && ! -d $plant_write/color.json ]] ||
+  fail "theme colour does not write into a planted color.json directory"
+pass "theme colour does not write into a planted color.json directory"
+
+missing_dir=$test_tmp/missing
+browser_policy_write_color "$missing_dir" "#aabbcc" ||
+  fail "theme colour skips a policy directory that does not exist"
+[[ ! -e $missing_dir ]] || fail "theme colour does not create a missing policy directory"
+pass "theme colour skips a missing policy directory"
+
+if (( EUID == 0 )); then
+  pass "running as root; skipping elevation checks"
+else
+  denied_dir=$test_tmp/denied
+  mkdir -p "$denied_dir"
+  chmod a-w "$denied_dir"
+  owner=${USER:-$(id -un)}
+  : >"$elev_log"
+  browser_policy_write_color "$denied_dir" "#aabbcc" ||
+    fail "elevated install reports success from pkexec"
+  grep -E "^PKEXEC install -m 664 -o $owner -g omarchy-browser-policy -T .+ $denied_dir/color.json$" "$elev_log" >/dev/null ||
+    fail "without a controlling tty, colour write elevates through pkexec as the owner" "$(cat "$elev_log")"
+  if grep -E '^SUDO ' "$elev_log" >/dev/null; then
+    fail "without a controlling tty, colour write does not call sudo" "$(cat "$elev_log")"
+  fi
+  pass "without a controlling tty, colour write elevates through pkexec"
+
+  : >"$elev_log"
+  export OMARCHY_TEST_SUDO_FAIL=1
+  if browser_policy_write_color "$denied_dir" "#aabbcc" 2>"$test_tmp/write.err"; then
+    fail "theme colour fails when the policy directory is not writable"
+  fi
+  unset OMARCHY_TEST_SUDO_FAIL
+  grep -F 'omarchy-browser-policy' "$test_tmp/write.err" >/dev/null ||
+    fail "theme colour names the group when the write is denied"
+  pass "theme colour reports a denied policy write"
+
+  if command -v script >/dev/null; then
+    : >"$elev_log"
+    cat >"$test_tmp/tty-write.sh" <<EOF
+source "$ROOT/install/helpers/browser-policy.sh"
+browser_policy_write_color "$denied_dir" "#aabbcc"
+EOF
+    script -q -c "PATH='$mock_bin:$PATH' OMARCHY_PATH='$ROOT' bash '$test_tmp/tty-write.sh'" /dev/null >/dev/null
+    grep -E "^SUDO install -m 664 -o $owner -g omarchy-browser-policy -T .+ $denied_dir/color.json$" "$elev_log" >/dev/null ||
+      fail "with a controlling tty, colour write elevates through sudo" "$(cat "$elev_log")"
+    if grep -E '^PKEXEC ' "$elev_log" >/dev/null; then
+      fail "with a controlling tty, colour write does not call pkexec" "$(cat "$elev_log")"
+    fi
+    pass "with a controlling tty, colour write elevates through sudo"
+  else
+    pass "script(1) unavailable; skipping the controlling-tty elevation check"
+  fi
+fi
+
+planted_dir=$test_tmp/planted
+mkdir -p "$planted_dir/evil"
+printf 'evil\n' >"$planted_dir/evil/f"
+printf 'old\n' >"$planted_dir/color.json"
+as_root() { unprivileged_as_root "$@"; }
+browser_policy_setup_dir "$planted_dir"
+[[ ! -e $planted_dir/evil ]] || fail "policy setup drops a non-empty non-root subdirectory"
+[[ ! -e $planted_dir/color.json ]] || fail "policy setup drops a non-root color.json"
+[[ -d $planted_dir ]] || fail "policy setup leaves the managed directory in place"
+pass "policy setup drops non-root files and non-empty subdirectories"
+
+owned=$test_tmp/not-root
+mkdir -p "$owned"
+chmod 2775 "$owned"
+BROWSER_POLICY_GROUP=$(id -gn)
+if browser_policy_dir_hardened "$owned"; then
+  fail "a user-owned 2775 directory is not treated as hardened"
+fi
+BROWSER_POLICY_GROUP=omarchy-browser-policy
+pass "a hardened directory must be root-owned"
+
+dist=$test_tmp/distribution
+mkdir -p "$dist"
+printf 'original\n' >"$test_tmp/firefox-pwn"
+ln -s "$test_tmp/firefox-pwn" "$dist/policies.json"
+as_root() { unprivileged_as_root "$@"; }
+browser_policy_install_firefox_policies "$dist" ||
+  fail "Firefox policy install replaces a planted policies.json symlink"
+[[ -f $dist/policies.json && ! -L $dist/policies.json ]] ||
+  fail "Firefox policy install unlinks a planted policies.json symlink instead of writing through it"
+grep -Fxq 'original' "$test_tmp/firefox-pwn" || fail "Firefox policy install leaves the symlink target unchanged"
+grep -q '"policies"' "$dist/policies.json" || fail "Firefox policy install writes the stock policies"
+pass "Firefox policy install does not follow a planted policies.json symlink"
+
+dir_dist=$test_tmp/distribution-dir
+mkdir -p "$dir_dist"
+mkdir "$dir_dist/policies.json"
+as_root() { unprivileged_as_root "$@"; }
+if browser_policy_install_firefox_policies "$dir_dist" 2>/dev/null; then
+  fail "Firefox policy install refuses a planted policies.json directory"
+fi
+[[ -d $dir_dist/policies.json ]] || fail "Firefox policy install leaves a planted policies.json directory in place"
+pass "Firefox policy install does not write into a planted policies.json directory"
+
+grant_log=$test_tmp/usermod.calls
+as_root() {
+  if [[ $1 == "usermod" ]]; then
+    printf '%s\n' "$*" >>"$grant_log"
+    return 0
+  fi
+  unprivileged_as_root "$@"
+}
+invoker=${USER:-$(id -un)}
+: >"$grant_log"
+SUDO_USER=$invoker
+browser_policy_grant_user root
+unset SUDO_USER
+grep -qx -- "usermod -aG omarchy-browser-policy $invoker" "$grant_log" ||
+  fail "granting as root uses SUDO_USER" "$(cat "$grant_log")"
+: >"$grant_log"
+OMARCHY_INSTALL_USER=""
+browser_policy_grant_user ""
+[[ ! -s $grant_log ]] || fail "an empty grant does not usermod"
+pass "sudo install browser grants the invoking user, not root"
+
+grep -F 'exit "$failed"' "$ROOT/bin/omarchy-theme-set-browser" >/dev/null ||
+  fail "omarchy-theme-set-browser exits non-zero when a policy write fails"
+pass "omarchy-theme-set-browser exits non-zero when a policy write fails"
+
+policy_files=(
+  "$ROOT/bin/omarchy-install-browser"
+  "$ROOT/bin/omarchy-provision-owner"
+  "$ROOT/bin/omarchy-theme-set-browser"
+  "$ROOT/bin/omarchy-upgrade-to-quattro"
+  "$ROOT/install/config/theme-system.sh"
+  "$ROOT/install/config/browser-policy.sh"
+  "$ROOT/install/helpers/browser-policy.sh"
+  "$ROOT/migrations/1787515927.sh"
+)
+if grep -nE 'chmod a\+rwx\b|chmod a\+rw\b|chmod a\+w\b|chmod o\+w|chmod ugo\+w|chmod 2777\b|chmod 0777\b|chmod 777\b|install -d -m 0?[27]?777' "${policy_files[@]}" >/dev/null; then
+  fail "browser policy setup is not world-writable"
+fi
+pass "browser policy setup is not world-writable"
+
+mapfile -t migrations < <(rg -l 'Stop world-writable Chromium and Firefox policy directories' "$ROOT/migrations")
+(( ${#migrations[@]} == 1 )) || fail "exactly one migration locks existing policy directories" "${migrations[*]}"
+grep -F 'browser_policy_dir_hardened' "${migrations[0]}" >/dev/null ||
+  fail "the policy-directory migration no-ops a machine already repaired"
+grep -F 'browser_policy_grant_user' "${migrations[0]}" >/dev/null ||
+  fail "the policy-directory migration still grants the current user the group"
+grep -F 'BROWSER_POLICY_FIREFOX_DIRS' "${migrations[0]}" >/dev/null ||
+  fail "the policy-directory migration covers Firefox and Zen"
+grep -F '/opt/zen-browser/distribution' "$ROOT/install/helpers/browser-policy.sh" >/dev/null ||
+  fail "the shared helper names the Zen distribution directory"
+pass "a migration locks existing policy directories"

test/shell.d/default-apps-test.sh

@@ -61,11 +61,13 @@ if [[ $installer == "omarchy-install-browser" && ${OMARCHY_TEST_REAL_BROWSER_INS
 fi
 
 case $installer in
-omarchy-pkg-add)
+omarchy-pkg-add|omarchy-pkg-aur-add)
   package=$1
   printf 'pkg:%s\n' "$package" >>"$OMARCHY_TEST_INSTALL_LOG"
   case $package in
   chromium) command=chromium ;;
+  firefox) command=firefox ;;
+  zen-browser-bin) command=zen-browser ;;
   cursor-bin) command=cursor ;;
   sublime-text-4) command=sublime_text ;;
   vim) command=vim ;;
@@ -107,6 +109,7 @@ SH
 
 for installer in \
   omarchy-pkg-add \
+  omarchy-pkg-aur-add \
   omarchy-install-browser \
   omarchy-install-terminal \
   omarchy-install-editor-vscode \
@@ -205,10 +208,14 @@ OMARCHY_TEST_REAL_BROWSER_INSTALL=true omarchy-default-browser --install chromiu
 [[ $(omarchy-default-browser) == "chromium" ]] || fail "Chromium becomes the default after its full installer succeeds"
 cmp -s "$ROOT/config/chromium-flags.conf" "$test_home/.config/chromium-flags.conf" ||
   fail "Chromium browser installer copies the default flags"
-grep -Fxq 'sudo:mkdir -p /etc/chromium/policies/managed' "$setup_log" ||
+grep -Fxq 'sudo:groupadd --system --force omarchy-browser-policy' "$setup_log" ||
-  fail "Chromium browser installer creates its policy directory"
+  fail "Chromium browser installer creates the browser-policy group"
-grep -Fxq 'sudo:chmod a+rw /etc/chromium/policies/managed' "$setup_log" ||
+grep -Fxq 'sudo:install -d -m 2775 -o root -g omarchy-browser-policy /etc/chromium/policies/managed' "$setup_log" ||
-  fail "Chromium browser installer makes its policy directory writable"
+  fail "Chromium browser installer creates a group-writable managed policy directory"
+grep -Fxq 'sudo:find /etc/chromium/policies/managed -mindepth 1 -maxdepth 1 ! -user root -exec rm -rf -- {} +' "$setup_log" ||
+  fail "Chromium browser installer drops non-root files from its policy directory"
+grep -Fxq "sudo:usermod -aG omarchy-browser-policy ${USER:-$(id -un)}" "$setup_log" ||
+  fail "Chromium browser installer grants the installing user the browser-policy group"
 grep -Fxq 'omarchy-install-chromium-copy-url:' "$setup_log" ||
   fail "Chromium browser installer registers the Copy URL host"
 grep -Fxq 'omarchy-install-chromium-ytdlp:' "$setup_log" ||
@@ -217,6 +224,36 @@ grep -Fxq 'omarchy-theme-set-browser:' "$setup_log" ||
   fail "Chromium browser installer applies the current theme"
 pass "Chromium browser installer restores the complete Omarchy setup"
 
+: >"$install_log"
+: >"$setup_log"
+rm -f "$installed_dir/firefox"
+OMARCHY_TEST_REAL_BROWSER_INSTALL=true omarchy-default-browser --install firefox >/dev/null
+[[ $(<"$install_log") == "pkg:firefox" ]] || fail "Firefox browser installer installs the package"
+[[ $(omarchy-default-browser) == "firefox" ]] || fail "Firefox becomes the default after its full installer succeeds"
+grep -Fxq 'sudo:install -d -m 0755 -o root -g root /usr/lib/firefox/distribution' "$setup_log" ||
+  fail "Firefox browser installer creates its distribution directory"
+grep -Fxq 'sudo:find /usr/lib/firefox/distribution -mindepth 1 -maxdepth 1 ! -user root -exec rm -rf -- {} +' "$setup_log" ||
+  fail "Firefox browser installer drops non-root files from its distribution directory"
+grep -Fxq "sudo:install -m 644 -o root -g root -T $ROOT/default/firefox/policies.json /usr/lib/firefox/distribution/policies.json" "$setup_log" ||
+  fail "Firefox browser installer copies policies.json without following a destination symlink"
+[[ -e $installed_dir/firefox ]] || fail "Firefox browser installer marks firefox installed"
+pass "Firefox browser installer restores the complete Omarchy setup"
+
+: >"$install_log"
+: >"$setup_log"
+rm -f "$installed_dir/zen-browser"
+OMARCHY_TEST_REAL_BROWSER_INSTALL=true omarchy-default-browser --install zen >/dev/null
+[[ $(<"$install_log") == "pkg:zen-browser-bin" ]] || fail "Zen browser installer installs the package"
+[[ $(omarchy-default-browser) == "zen" ]] || fail "Zen becomes the default after its full installer succeeds"
+grep -Fxq 'sudo:install -d -m 0755 -o root -g root /opt/zen-browser/distribution' "$setup_log" ||
+  fail "Zen browser installer creates its distribution directory"
+grep -Fxq 'sudo:find /opt/zen-browser/distribution -mindepth 1 -maxdepth 1 ! -user root -exec rm -rf -- {} +' "$setup_log" ||
+  fail "Zen browser installer drops non-root files from its distribution directory"
+grep -Fxq "sudo:install -m 644 -o root -g root -T $ROOT/default/firefox/policies.json /opt/zen-browser/distribution/policies.json" "$setup_log" ||
+  fail "Zen browser installer copies policies.json without following a destination symlink"
+[[ -e $installed_dir/zen-browser ]] || fail "Zen browser installer marks zen-browser installed"
+pass "Zen browser installer restores the complete Omarchy setup"
+
 omarchy-default-browser zen
 rm -f "$installed_dir/chromium"
 if OMARCHY_TEST_REAL_BROWSER_INSTALL=true OMARCHY_TEST_INSTALL_FAIL=true \

test/shell.d/provisioning-groups-test.sh

@@ -27,16 +27,40 @@ cat >"$TMPDIR/bin/usermod" <<STUB
 #!/bin/bash
 echo "\$@" >>"$TMPDIR/usermod.calls"
 STUB
-chmod +x "$TMPDIR/bin/getent" "$TMPDIR/bin/usermod"
+cat >"$TMPDIR/bin/groupadd" <<STUB
+#!/bin/bash
+echo "\$@" >>"$TMPDIR/groupadd.calls"
+STUB
+cat >"$TMPDIR/bin/install" <<STUB
+#!/bin/bash
+echo "\$@" >>"$TMPDIR/install.calls"
+STUB
+cat >"$TMPDIR/bin/find" <<STUB
+#!/bin/bash
+echo "\$@" >>"$TMPDIR/find.calls"
+STUB
+cat >"$TMPDIR/bin/sudo" <<STUB
+#!/bin/bash
+echo "\$@" >>"$TMPDIR/sudo.calls"
+exec "\$@"
+STUB
+chmod +x "$TMPDIR/bin"/{getent,usermod,groupadd,install,find,sudo}
 export PATH="$TMPDIR/bin:$PATH"
+export OMARCHY_PATH="$ROOT"
 
-# No install user (deferred-provisioning install): input recorded, usermod not called.
+# No install user (deferred-provisioning install): groups recorded, usermod not called.
 OMARCHY_INSTALL_USER="" bash -eE "$ROOT/install/config/docker.sh"
 OMARCHY_INSTALL_USER="" bash -eE "$ROOT/install/hardware/input-group.sh"
+OMARCHY_INSTALL_USER="" bash -eE "$ROOT/install/config/browser-policy.sh"
 
 [[ -f $OMARCHY_PROVISIONING_DIR/groups ]] || fail "groups file written without an install user"
 grep -qxF input "$OMARCHY_PROVISIONING_DIR/groups" || fail "input group recorded"
+grep -qxF omarchy-browser-policy "$OMARCHY_PROVISIONING_DIR/groups" || fail "browser-policy group recorded"
 [[ ! -f $TMPDIR/usermod.calls ]] || fail "usermod not called without an install user"
+grep -F -- '--system --force omarchy-browser-policy' "$TMPDIR/groupadd.calls" >/dev/null ||
+  fail "browser-policy group is created as a system group"
+grep -F -- '-d -m 2775 -o root -g omarchy-browser-policy /etc/chromium/policies/managed' "$TMPDIR/install.calls" >/dev/null ||
+  fail "browser-policy directory is created group-writable"
 pass "deferred provisioning records groups without calling usermod"
 
 # The docker group is root-equivalent and must never be granted automatically.
@@ -45,17 +69,24 @@ pass "docker group is not recorded at install"
 
 # Missing user (defensive): no usermod either.
 OMARCHY_INSTALL_USER=ghost bash -eE "$ROOT/install/hardware/input-group.sh"
+OMARCHY_INSTALL_USER=ghost bash -eE "$ROOT/install/config/browser-policy.sh"
 [[ ! -f $TMPDIR/usermod.calls ]] || fail "usermod not called for a missing user"
 pass "missing install user defers group grants"
 
 # Re-running never duplicates entries.
 OMARCHY_INSTALL_USER="" bash -eE "$ROOT/install/hardware/input-group.sh"
 [[ $(grep -cxF input "$OMARCHY_PROVISIONING_DIR/groups") == 1 ]] || fail "input group recorded once"
+OMARCHY_INSTALL_USER="" bash -eE "$ROOT/install/config/browser-policy.sh"
+[[ $(grep -cxF omarchy-browser-policy "$OMARCHY_PROVISIONING_DIR/groups") == 1 ]] ||
+  fail "browser-policy group recorded once"
 pass "group recording is idempotent"
 
 # Existing user: usermod applies the recorded groups, and docker is never among them.
 OMARCHY_INSTALL_USER=existing bash -eE "$ROOT/install/config/docker.sh"
 OMARCHY_INSTALL_USER=existing bash -eE "$ROOT/install/hardware/input-group.sh"
+OMARCHY_INSTALL_USER=existing bash -eE "$ROOT/install/config/browser-policy.sh"
 grep -qx -- "-aG input existing" "$TMPDIR/usermod.calls" || fail "usermod grants input to the install user"
+grep -qx -- "-aG omarchy-browser-policy existing" "$TMPDIR/usermod.calls" ||
+  fail "usermod grants browser-policy to the install user"
 ! grep -q -- "docker" "$TMPDIR/usermod.calls" || fail "usermod must not grant docker to the install user"
-pass "existing install user gets input but never docker"
+pass "existing install user gets input and browser-policy but never docker"

test/shell.d/upgrade-to-quattro-test.sh

@@ -67,6 +67,23 @@ grep -F 'OMARCHY_INSTALL_USER="$target_user"' "$upgrade_to_quattro" >/dev/null
 grep -F '"$apply_lock"' "$upgrade_to_quattro" >/dev/null
 pass "Omarchy 4 upgrade configures lock screen authentication for the target user"
 
+grep -F 'install/helpers/browser-policy.sh' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade uses the shared browser-policy helper"
+grep -F 'as_root test -f "$browser_policy_helper"' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade survives a packaged tree without the browser-policy helper"
+grep -F 'browser_policy_setup_group' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade creates the browser-policy group"
+grep -F 'browser_policy_setup_dir /etc/chromium/policies/managed' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade creates a group-writable Chromium policy directory"
+grep -F 'BROWSER_POLICY_MANAGED_DIRS' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade hardens every Chromium-family policy directory"
+grep -F 'run_as_user_omarchy omarchy-theme-set-browser' "$upgrade_to_quattro" >/dev/null ||
+  fail "Omarchy 4 upgrade rewrites browser theme colour after a headless theme-set"
+if grep -E 'install -d -m 0?[27]?777 /etc/.*/policies|chmod a\+rw' "$upgrade_to_quattro" >/dev/null; then
+  fail "Omarchy 4 upgrade does not create a world-writable Chromium policy directory"
+fi
+pass "Omarchy 4 upgrade locks the Chromium policy directory to the browser-policy group"
+
 grep -F 'OMARCHY_UPGRADE_TO_QUATTRO_LIVE=1' "$upgrade_to_quattro" >/dev/null
 grep -F 'systemd-networkd.service' "$upgrade_to_quattro" >/dev/null
 grep -F 'systemd-networkd.socket' "$upgrade_to_quattro" >/dev/null