bump version to 1.7

Valid argument of ctype(3) functions must be either EOF or non-negative
value within the range representable as unsigned char. Invalid values
leads to undefined behavior.

Cast all such uses to avoid that.

At least in NetBSD 11 ctype(3) abuses will always crash and permit
to break slock screen locking.

LICENSE

@@ -4,6 +4,7 @@ MIT/X Consortium License
 © 2014 Dimitris Papastamos <sin@2f30.org>
 © 2006-2014 Anselm R Garbe <anselm@garbe.us>
 © 2014-2016 Laslo Hunhold <dev@frign.de>
+© 2016-2023 Hiltjo Posthuma <hiltjo@codemadness.org>
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),

Makefile

@@ -6,56 +6,41 @@ include config.mk
 SRC = slock.c ${COMPATSRC}
 OBJ = ${SRC:.c=.o}
 
-all: options slock
-
-options:
-	@echo slock build options:
-	@echo "CFLAGS   = ${CFLAGS}"
-	@echo "LDFLAGS  = ${LDFLAGS}"
-	@echo "CC       = ${CC}"
+all: slock
 
 .c.o:
-	@echo CC $<
-	@${CC} -c ${CFLAGS} $<
+	${CC} -c ${CFLAGS} $<
 
 ${OBJ}: config.h config.mk arg.h util.h
 
 config.h:
-	@echo creating $@ from config.def.h
-	@cp config.def.h $@
+	cp config.def.h $@
 
 slock: ${OBJ}
-	@echo CC -o $@
-	@${CC} -o $@ ${OBJ} ${LDFLAGS}
+	${CC} -o $@ ${OBJ} ${LDFLAGS}
 
 clean:
-	@echo cleaning
-	@rm -f slock ${OBJ} slock-${VERSION}.tar.gz
+	rm -f slock ${OBJ} slock-${VERSION}.tar.gz
 
 dist: clean
-	@echo creating dist tarball
-	@mkdir -p slock-${VERSION}
-	@cp -R LICENSE Makefile README slock.1 config.mk \
+	mkdir -p slock-${VERSION}
+	cp -R LICENSE Makefile README slock.1 config.mk \
 		${SRC} config.def.h arg.h util.h slock-${VERSION}
-	@tar -cf slock-${VERSION}.tar slock-${VERSION}
-	@gzip slock-${VERSION}.tar
-	@rm -rf slock-${VERSION}
+	tar -cf slock-${VERSION}.tar slock-${VERSION}
+	gzip slock-${VERSION}.tar
+	rm -rf slock-${VERSION}
 
 install: all
-	@echo installing executable file to ${DESTDIR}${PREFIX}/bin
-	@mkdir -p ${DESTDIR}${PREFIX}/bin
-	@cp -f slock ${DESTDIR}${PREFIX}/bin
-	@chmod 755 ${DESTDIR}${PREFIX}/bin/slock
-	@chmod u+s ${DESTDIR}${PREFIX}/bin/slock
-	@echo installing manual page to ${DESTDIR}${MANPREFIX}/man1
-	@mkdir -p ${DESTDIR}${MANPREFIX}/man1
-	@sed "s/VERSION/${VERSION}/g" <slock.1 >${DESTDIR}${MANPREFIX}/man1/slock.1
-	@chmod 644 ${DESTDIR}${MANPREFIX}/man1/slock.1
+	mkdir -p ${DESTDIR}${PREFIX}/bin
+	cp -f slock ${DESTDIR}${PREFIX}/bin
+	chmod 755 ${DESTDIR}${PREFIX}/bin/slock
+	chmod u+s ${DESTDIR}${PREFIX}/bin/slock
+	mkdir -p ${DESTDIR}${MANPREFIX}/man1
+	sed "s/VERSION/${VERSION}/g" <slock.1 >${DESTDIR}${MANPREFIX}/man1/slock.1
+	chmod 644 ${DESTDIR}${MANPREFIX}/man1/slock.1
 
 uninstall:
-	@echo removing executable file from ${DESTDIR}${PREFIX}/bin
-	@rm -f ${DESTDIR}${PREFIX}/bin/slock
-	@echo removing manual page from ${DESTDIR}${MANPREFIX}/man1
-	@rm -f ${DESTDIR}${MANPREFIX}/man1/slock.1
+	rm -f ${DESTDIR}${PREFIX}/bin/slock
+	rm -f ${DESTDIR}${MANPREFIX}/man1/slock.1
 
-.PHONY: all options clean dist install uninstall
+.PHONY: all clean dist install uninstall

config.mk

@@ -1,5 +1,5 @@
 # slock version
-VERSION = 1.5
+VERSION = 1.7
 
 # Customize below to fit your system
 
@@ -27,6 +27,3 @@ COMPATSRC = explicit_bzero.c
 #CPPFLAGS = -DVERSION=\"${VERSION}\" -D_BSD_SOURCE -D_NETBSD_SOURCE
 # On OpenBSD set COMPATSRC to empty
 #COMPATSRC =
-
-# compiler and linker
-CC = cc

slock.1

@@ -1,5 +1,6 @@
-.Dd 2016-08-23
+.Dd October 6, 2023
 .Dt SLOCK 1
+.Os
 .Sh NAME
 .Nm slock
 .Nd simple X screen locker
@@ -9,31 +10,36 @@
 .Op Ar cmd Op Ar arg ...
 .Sh DESCRIPTION
 .Nm
-is a simple X screen locker. If provided,
-.Ar cmd Op Ar arg ...
+is a simple X screen locker.
+If provided,
+.Ar cmd
 is executed after the screen has been locked.
-.Sh OPTIONS
+.Pp
+The options are as follows:
 .Bl -tag -width Ds
 .It Fl v
 Print version information to stdout and exit.
 .El
+.Sh EXIT STATUS
+.Ex -std
+.Sh EXAMPLES
+$
+.Nm
+/usr/sbin/s2ram
 .Sh SECURITY CONSIDERATIONS
 To make sure a locked screen can not be bypassed by switching VTs
 or killing the X server with Ctrl+Alt+Backspace, it is recommended
 to disable both in
 .Xr xorg.conf 5
 for maximum security:
-.Bd -literal -offset left
+.Bd -literal
 Section "ServerFlags"
 	Option "DontVTSwitch" "True"
 	Option "DontZap"      "True"
 EndSection
 .Ed
-.Sh EXAMPLES
-$
-.Nm
-/usr/sbin/s2ram
 .Sh CUSTOMIZATION
 .Nm
 can be customized by creating a custom config.h from config.def.h and
-(re)compiling the source code. This keeps it fast, secure and simple.
+(re)compiling the source code.
+This keeps it fast, secure and simple.

slock.c

@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <spawn.h>
 #include <sys/types.h>
 #include <X11/extensions/Xrandr.h>
 #include <X11/keysym.h>
@@ -180,10 +181,13 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 					passwd[--len] = '\0';
 				break;
 			default:
-				if (num && !iscntrl((int)buf[0]) &&
+				if (num && !iscntrl((unsigned char)buf[0]) &&
 				    (len + num < sizeof(passwd))) {
 					memcpy(passwd + len, buf, num);
 					len += num;
+				} else if (buf[0] == '\025') { /* ctrl-u clears input */
+					explicit_bzero(&passwd, sizeof(passwd));
+					len = 0;
 				}
 				break;
 			}
@@ -317,7 +321,7 @@ main(int argc, char **argv) {
 
 	ARGBEGIN {
 	case 'v':
-		fprintf(stderr, "slock-"VERSION"\n");
+		puts("slock-"VERSION);
 		return 0;
 	default:
 		usage();
@@ -376,15 +380,12 @@ main(int argc, char **argv) {
 
 	/* run post-lock command */
 	if (argc > 0) {
-		switch (fork()) {
-		case -1:
-			die("slock: fork failed: %s\n", strerror(errno));
-		case 0:
-			if (close(ConnectionNumber(dpy)) < 0)
-				die("slock: close: %s\n", strerror(errno));
-			execvp(argv[0], argv);
-			fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
-			_exit(1);
+		pid_t pid;
+		extern char **environ;
+		int err = posix_spawnp(&pid, argv[0], NULL, NULL, argv, environ);
+		if (err) {
+			die("slock: failed to execute post-lock command: %s: %s\n",
+			    argv[0], strerror(err));
 		}
 	}