Rework logic in _sudo() and add support for sudo-rs

doc/tomb.1

@@ -325,8 +325,8 @@ takes massively longer on regular systems.
 Default is 1 thread (based on the \fIargon2\fR default).
 .B
 .IP "--sudo \fI<executable>\fR"
-Select a different tool than sudo for privilege escalation.
-Alternatives supported so far are: pkexec, doas, sup, sud. For any
+Select a different tool than sudo or doas for privilege escalation.
+Alternatives supported so far are: pkexec, sup, sud, sudo-rs. For any
 alternative to work the executable must be included in the current
 PATH.
 
@@ -419,7 +419,8 @@ user. Tomb executes as super user only when required.
 
 To be made available on multi user systems, the superuser execution of
 the tomb script can be authorized for users without jeopardizing the
-whole system's security: just add such a line to \fI/etc/sudoers\fR:
+whole system's security: In case of sudo just add such a line to
+\fI/etc/sudoers\fR:
 
 .EX
 	username ALL=NOPASSWD: /usr/local/bin/tomb
@@ -432,6 +433,8 @@ To avoid that tomb execution is logged by \fIsyslog\fR also add:
 	Defaults!TOMB !syslog
 .EE
 
+Different tools require other settings to achieve something similar.
+
 .SH PASSWORD INPUT
 
 Password input is handled by the pinentry program: it can be text

tomb

@@ -118,51 +118,53 @@ export TEXTDOMAIN=tomb
 
 # Wrap sudo with a more visible message or apply user-supplied alternative to sudo
 _sudo() {
-	if option_is_set --sudo; then
-		pescmd=`option_value --sudo`
-		case `basename $pescmd` in
-			"doas"|"sup"|"sud"|"pkexec")
-
-				_is_found $pescmd || _failure "::1 pesc:: executable not found" $pescmd
- 				_verbose "Super user execution using ::1 pesc::" $pescmd
-				${pescmd} ${@}
-				return $?
-				;;
-			"skip"|"none")
-				_verbose "Super user execution skipped (SUID caller)"
-				${@}
-				return $?
-				;;
-			 *)
-				_failure "Super user execution not supported: ::1 sudo::" "`option_value --sudo`"
-				;;
-		esac
+	local -a pescmds pe_extras
+	local pescmd
 
-	else
-    if [[ "`id -u`" = "0" ]]; then
-			_verbose "Super user execution skipped (SUID caller)"
-			${@}
-			return $?
-    elif _is_found sudo; then
-		  local msg="[sudo] Enter password for user ::1 user:: to gain superuser privileges"
-		  _is_found gettext && msg="$(gettext -s "$msg")"
-		  msg=${(S)msg//::1*::/$USER}
-		  [[ -n "$SUDO_ASKPASS" ]] && local sudo_askpass="--askpass"
-		  sudo $sudo_askpass -p "
+	[[ "`id -u`" = "0" ]] && {
+		_verbose "Super user execution skipped (SUID caller)"
+		${@}
+		return $?
+	}
+
+	option_is_set --sudo && {
+		pescmds=(`option_value --sudo`)
+	}
+	pescmds+=("sudo" "doas")
+
+	for cmd in "${pescmds[@]}"; do
+		_is_found $cmd && { pescmd=$cmd; break }
+	done
+	[[ -z ${pescmd} ]] &&
+		_failure "Couldn't find a viable privilege escalation tool."
+
+	# Construct message for the tools that allow custom prompts
+	local msg="Enter password for user ::1 user:: to gain superuser privileges"
+	_is_found gettext && msg="$(gettext -s "$msg")"
+	msg=${(S)msg//::1*::/$USER}
+
+	# Adjust call in regards of the chosen tool
+	case `basename $pescmd` in
+		"sudo")
+			[[ -n "$SUDO_ASKPASS" ]] && local sudo_askpass="--askpass"
+			pe_extras=("-p" "
 $msg
+")
+			;;
+		"sudo-rs")
+			pe_extras=("-p" "$msg")
+			;;
+		"doas"|"sup"|"sud"|"pkexec")
+			;;
+		*)
+			_failure "Super user execution not supported: ::1 sudo::" "`option_value --sudo`"
+			;;
+	esac
 
-" ${@}
-		  return $?
-    elif _is_found doas; then
-		  local msg="Enter password for user ::1 user:: to gain superuser privileges"
-		  _is_found gettext && msg="$(gettext -s "$msg")"
-		  msg=${(S)msg//::1*::/$USER}
-      doas ${@}
-      return $?
-    else
-      _failure "No way found to escalate privileges to super user."
-    fi
-	fi
+	# Execute stuff
+	_verbose "Super user execution using ::1 pesc::" $pescmd
+	${pescmd} $sudo_askpass $pe_extras ${@}
+	return $?
 }
 
 # Cleanup anything sensitive before exiting.