Complete command-scoped authentication across update phases

bin/omarchy-security-functions

@@ -0,0 +1,91 @@
+#!/bin/bash
+
+# omarchy:hidden=true
+# omarchy:summary=Provide internal helpers for command-scoped sudo authentication
+
+if [[ ${BASH_SOURCE[0]} == "$0" ]]; then
+  echo "omarchy-security-functions is an internal function library." >&2
+  exit 64
+fi
+
+omarchy_security_require_privileged_bash_startup() {
+  [[ $- == *p* ]] || return 1
+  /usr/bin/env -i /usr/bin/bash -p -c '
+    mapfile -d "" -t argv <"/proc/$1/cmdline" || exit 1
+    executable=$(/usr/bin/readlink -e -- "/proc/$1/exe") || exit 1
+    [[ $executable == "/usr/bin/bash" &&
+      ( ${argv[0]:-} == "/bin/bash" || ${argv[0]:-} == "/usr/bin/bash" ) &&
+      ${argv[1]:-} == "-p" ]]
+  ' omarchy-bash-startup "$$"
+}
+
+omarchy_security_sanitize_bash_environment() {
+  local script=$1
+  shift
+  local entry name environment_fd environment_pid
+  local -a unsets=()
+
+  # Read the raw environment: privileged Bash ignores exported functions, but
+  # leaves their records for ordinary child interpreters to import later.
+  exec {environment_fd}< <(/usr/bin/env -0)
+  environment_pid=$!
+  while IFS= read -r -d '' entry <&"$environment_fd"; do
+    name=${entry%%=*}
+    case "$name" in
+      BASH_ENV|ENV|SHELLOPTS|BASHOPTS|PS4|CDPATH|GLOBIGNORE|BASH_FUNC_*%%)
+        unsets+=(-u "$name")
+        ;;
+    esac
+  done
+  exec {environment_fd}<&-
+  wait "$environment_pid" || return 1
+  if (( ${#unsets[@]} > 0 )); then
+    exec /usr/bin/env "${unsets[@]}" /usr/bin/bash -p -- "$script" "$@"
+  fi
+}
+
+omarchy_security_sudo_supports_no_update() {
+  local help
+  help=$(LC_ALL=C /usr/bin/sudo -h 2>&1) || return 1
+  /usr/bin/grep -Eq '^usage: sudo .*\[[^]]*N[^]]*\]' <<< "$help"
+}
+
+omarchy_security_revoke_sudo_timestamp() {
+  /usr/bin/sudo -k
+}
+
+omarchy_security_exit_with_revoked_sudo() {
+  local status=$1
+  trap - EXIT HUP INT TERM
+  if ! omarchy_security_revoke_sudo_timestamp; then
+    echo "Could not invalidate cached sudo authorization." >&2
+    (( status != 0 )) || status=1
+  fi
+  exit "$status"
+}
+
+omarchy_security_install_signal_exit_traps() {
+  trap 'exit 129' HUP
+  trap 'exit 130' INT
+  trap 'exit 143' TERM
+}
+
+omarchy_security_install_sudo_cleanup_traps() {
+  trap 'omarchy_security_exit_with_revoked_sudo "$?"' EXIT
+  omarchy_security_install_signal_exit_traps
+}
+
+omarchy_security_enable_no_update_sudo() {
+  local wrapper_dir="$OMARCHY_PATH/default/omarchy/sudo-no-update"
+  if ! omarchy_security_sudo_supports_no_update; then
+    echo "This sudo does not support --no-update; refusing mixed-trust work." >&2
+    return 1
+  fi
+  if [[ ! -f $wrapper_dir/sudo || ! -x $wrapper_dir/sudo ]]; then
+    echo "The command-scoped sudo wrapper is missing." >&2
+    return 1
+  fi
+  PATH="$wrapper_dir:$OMARCHY_PATH/bin:/usr/bin:/usr/sbin:/bin:/sbin"
+  OMARCHY_SUDO_NO_UPDATE=1
+  export PATH OMARCHY_SUDO_NO_UPDATE
+}