deleted comment

PKGBUILD

@@ -9,7 +9,6 @@ url="http://tools.suckless.org/slock"
 license=('MIT')
 depends=('libxext' 'libxrandr')
 source=("http://dl.suckless.org/tools/$pkgname-$pkgver.tar.gz")
-#source=("slock-$pkgver.tar.bz2::http://hg.suckless.org/slock/archive/$_pkgver.tar.gz")
 
 sha256sums=('b53849dbc60109a987d7a49b8da197305c29307fd74c12dc18af0d3044392e6a'
             '97c09fd6f7e0aff3002a24dabe57798bcfaa1467a043cf7b7119177f005e5848'

pre/slock-1.4/LICENSE

@@ -0,0 +1,24 @@
+MIT/X Consortium License
+
+© 2015-2016 Markus Teich <markus.teich@stusta.mhn.de>
+© 2014 Dimitris Papastamos <sin@2f30.org>
+© 2006-2014 Anselm R Garbe <anselm@garbe.us>
+© 2014-2016 Laslo Hunhold <dev@frign.de>
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

pre/slock-1.4/Makefile

@@ -0,0 +1,61 @@
+# slock - simple screen locker
+# See LICENSE file for copyright and license details.
+
+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}"
+
+.c.o:
+	@echo CC $<
+	@${CC} -c ${CFLAGS} $<
+
+${OBJ}: config.h config.mk arg.h util.h
+
+config.h:
+	@echo creating $@ from config.def.h
+	@cp config.def.h $@
+
+slock: ${OBJ}
+	@echo CC -o $@
+	@${CC} -o $@ ${OBJ} ${LDFLAGS}
+
+clean:
+	@echo cleaning
+	@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 \
+		${SRC} explicit_bzero.c config.def.h arg.h util.h slock-${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
+
+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
+
+.PHONY: all options clean dist install uninstall

pre/slock-1.4/README

@@ -0,0 +1,24 @@
+slock - simple screen locker
+============================
+simple screen locker utility for X. 
+
+
+Requirements
+------------
+In order to build slock you need the Xlib header files.
+
+
+Installation
+------------
+Edit config.mk to match your local setup (slock is installed into
+the /usr/local namespace by default).
+
+Afterwards enter the following command to build and install slock
+(if necessary as root):
+
+    make clean install
+
+
+Running slock
+-------------
+Simply invoke the 'slock' command. To get out of it, enter your password.

pre/slock-1.4/arg.h

@@ -0,0 +1,65 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN	for (argv0 = *argv, argv++, argc--;\
+					argv[0] && argv[0][0] == '-'\
+					&& argv[0][1];\
+					argc--, argv++) {\
+				char argc_;\
+				char **argv_;\
+				int brk_;\
+				if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+					argv++;\
+					argc--;\
+					break;\
+				}\
+				for (brk_ = 0, argv[0]++, argv_ = argv;\
+						argv[0][0] && !brk_;\
+						argv[0]++) {\
+					if (argv_ != argv)\
+						break;\
+					argc_ = argv[0][0];\
+					switch (argc_)
+
+/* Handles obsolete -NUM syntax */
+#define ARGNUM				case '0':\
+					case '1':\
+					case '2':\
+					case '3':\
+					case '4':\
+					case '5':\
+					case '6':\
+					case '7':\
+					case '8':\
+					case '9'
+
+#define ARGEND			}\
+			}
+
+#define ARGC()		argc_
+
+#define ARGNUMF()	(brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
+
+#define EARGF(x)	((argv[0][1] == '\0' && argv[1] == NULL)?\
+				((x), abort(), (char *)0) :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define ARGF()		((argv[0][1] == '\0' && argv[1] == NULL)?\
+				(char *)0 :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define LNGARG()	&argv[0][0]
+
+#endif

pre/slock-1.4/config.def.h

@@ -0,0 +1,21 @@
+/* user and group to drop privileges to */
+static const char *user  = "nobody";
+static const char *group = "nobody";
+
+static const char *colorname[NUMCOLS] = {
+	[INIT] =   "black",     /* after initialization */
+	[INPUT] =  "#005577",   /* during input */
+	[FAILED] = "#CC3333",   /* wrong password */
+};
+
+/* treat a cleared input like a wrong password (color) */
+static const int failonclear = 1;
+
+/* time in seconds before the monitor shuts down */
+static const int monitortime = 5;
+
+/* treat a cleared input like a wrong password */
+static const int failonclear = 1;
+
+/* time to cancel lock with mouse movement in seconds */
+static const int timetocancel = 3;

pre/slock-1.4/config.h

@@ -0,0 +1,18 @@
+/* user and group to drop privileges to */
+static const char *user  = "nobody";
+static const char *group = "nobody";
+
+static const char *colorname[NUMCOLS] = {
+	[INIT] =   "black",     /* after initialization */
+	[INPUT] =  "#005577",   /* during input */
+	[FAILED] = "#CC3333",   /* wrong password */
+};
+
+/* treat a cleared input like a wrong password (color) */
+static const int failonclear = 1;
+
+/* time in seconds before the monitor shuts down */
+static const int monitortime = 5;
+
+/* time to cancel lock with mouse movement in seconds */
+static const int timetocancel = 3;

pre/slock-1.4/config.mk

@@ -0,0 +1,32 @@
+# slock version
+VERSION = 1.4
+
+# Customize below to fit your system
+
+# paths
+PREFIX = /usr/local
+MANPREFIX = ${PREFIX}/share/man
+
+X11INC = /usr/X11R6/include
+X11LIB = /usr/X11R6/lib
+
+# includes and libs
+INCS = -I. -I/usr/include -I${X11INC}
+LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext -lXrandr
+
+# flags
+CPPFLAGS += -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE -DHAVE_SHADOW_H
+CFLAGS += -std=c99 -pedantic -Wall -Os ${INCS} ${CPPFLAGS}
+LDFLAGS += -s ${LIBS}
+COMPATSRC = explicit_bzero.c
+
+# On OpenBSD and Darwin remove -lcrypt from LIBS
+#LIBS = -L/usr/lib -lc -L${X11LIB} -lX11 -lXext -lXrandr
+# On *BSD remove -DHAVE_SHADOW_H from CPPFLAGS
+# On NetBSD add -D_NETBSD_SOURCE to CPPFLAGS
+#CPPFLAGS += -DVERSION=\"${VERSION}\" -D_BSD_SOURCE -D_NETBSD_SOURCE
+# On OpenBSD set COMPATSRC to empty
+#COMPATSRC =
+
+# compiler and linker
+CC = cc

pre/slock-1.4/explicit_bzero.c

@@ -0,0 +1,19 @@
+/*	$OpenBSD: explicit_bzero.c,v 1.3 2014/06/21 02:34:26 matthew Exp $ */
+/*
+ * Public domain.
+ * Written by Matthew Dempsky.
+ */
+
+#include <string.h>
+
+__attribute__((weak)) void
+__explicit_bzero_hook(void *buf, size_t len)
+{
+}
+
+void
+explicit_bzero(void *buf, size_t len)
+{
+	memset(buf, 0, len);
+	__explicit_bzero_hook(buf, len);
+}

pre/slock-1.4/slock.1

@@ -0,0 +1,39 @@
+.Dd 2016-08-23
+.Dt SLOCK 1
+.Sh NAME
+.Nm slock
+.Nd simple X screen locker
+.Sh SYNOPSIS
+.Nm
+.Op Fl v
+.Op Ar cmd Op Ar arg ...
+.Sh DESCRIPTION
+.Nm
+is a simple X screen locker. If provided,
+.Ar cmd Op Ar arg ...
+is executed after the screen has been locked.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl v
+Print version information to stdout and exit.
+.El
+.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
+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.

pre/slock-1.4/slock.c

@@ -0,0 +1,437 @@
+/* See LICENSE file for license details. */
+#define _XOPEN_SOURCE 500
+#if HAVE_SHADOW_H
+#include <shadow.h>
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/types.h>
+#include <X11/extensions/Xrandr.h>
+#include <X11/extensions/dpms.h>
+#include <X11/keysym.h>
+#include <X11/XF86keysym.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+#include "arg.h"
+#include "util.h"
+
+static time_t tim;
+
+char *argv0;
+
+enum {
+	INIT,
+	INPUT,
+	FAILED,
+	NUMCOLS
+};
+
+struct lock {
+	int screen;
+	Window root, win;
+	Pixmap pmap;
+	unsigned long colors[NUMCOLS];
+};
+
+struct xrandr {
+	int active;
+	int evbase;
+	int errbase;
+};
+
+#include "config.h"
+
+static void
+die(const char *errstr, ...)
+{
+	va_list ap;
+
+	va_start(ap, errstr);
+	vfprintf(stderr, errstr, ap);
+	va_end(ap);
+	exit(1);
+}
+
+#ifdef __linux__
+#include <fcntl.h>
+#include <linux/oom.h>
+
+static void
+dontkillme(void)
+{
+	FILE *f;
+	const char oomfile[] = "/proc/self/oom_score_adj";
+
+	if (!(f = fopen(oomfile, "w"))) {
+		if (errno == ENOENT)
+			return;
+		die("slock: fopen %s: %s\n", oomfile, strerror(errno));
+	}
+	fprintf(f, "%d", OOM_SCORE_ADJ_MIN);
+	if (fclose(f)) {
+		if (errno == EACCES)
+			die("slock: unable to disable OOM killer. "
+			    "Make sure to suid or sgid slock.\n");
+		else
+			die("slock: fclose %s: %s\n", oomfile, strerror(errno));
+	}
+}
+#endif
+
+static const char *
+gethash(void)
+{
+	const char *hash;
+	struct passwd *pw;
+
+	/* Check if the current user has a password entry */
+	errno = 0;
+	if (!(pw = getpwuid(getuid()))) {
+		if (errno)
+			die("slock: getpwuid: %s\n", strerror(errno));
+		else
+			die("slock: cannot retrieve password entry\n");
+	}
+	hash = pw->pw_passwd;
+
+#if HAVE_SHADOW_H
+	if (!strcmp(hash, "x")) {
+		struct spwd *sp;
+		if (!(sp = getspnam(pw->pw_name)))
+			die("slock: getspnam: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = sp->sp_pwdp;
+	}
+#else
+	if (!strcmp(hash, "*")) {
+#ifdef __OpenBSD__
+		if (!(pw = getpwuid_shadow(getuid())))
+			die("slock: getpwnam_shadow: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = pw->pw_passwd;
+#else
+		die("slock: getpwuid: cannot retrieve shadow entry. "
+		    "Make sure to suid or sgid slock.\n");
+#endif /* __OpenBSD__ */
+	}
+#endif /* HAVE_SHADOW_H */
+
+	return hash;
+}
+
+static void
+readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+       const char *hash)
+{
+	XRRScreenChangeNotifyEvent *rre;
+	char buf[32], passwd[256], *inputhash;
+	int num, screen, running, failure, oldc;
+	unsigned int len, color;
+	KeySym ksym;
+	XEvent ev;
+
+	len = 0;
+	running = 1;
+	failure = 0;
+	oldc = INIT;
+
+	while (running && !XNextEvent(dpy, &ev)) {
+		running = !((time(NULL) - tim < timetocancel) && (ev.type == MotionNotify));
+		if (ev.type == KeyPress) {
+			explicit_bzero(&buf, sizeof(buf));
+			num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
+			if (IsKeypadKey(ksym)) {
+				if (ksym == XK_KP_Enter)
+					ksym = XK_Return;
+				else if (ksym >= XK_KP_0 && ksym <= XK_KP_9)
+					ksym = (ksym - XK_KP_0) + XK_0;
+			}
+			if (IsFunctionKey(ksym) ||
+			    IsKeypadKey(ksym) ||
+			    IsMiscFunctionKey(ksym) ||
+			    IsPFKey(ksym) ||
+			    IsPrivateKeypadKey(ksym))
+				continue;
+			switch (ksym) {
+			case XK_Return:
+				passwd[len] = '\0';
+				errno = 0;
+				if (!(inputhash = crypt(passwd, hash)))
+					fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
+				else
+					running = !!strcmp(inputhash, hash);
+				if (running) {
+					XBell(dpy, 100);
+					failure = 1;
+				}
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XK_Escape:
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XF86XK_AudioRaiseVolume:
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
+				break;
+			case XF86XK_AudioLowerVolume:
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
+				break;
+			case XF86XK_AudioMute:
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
+				break;
+			case XF86XK_MonBrightnessUp:
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
+				break;
+			case XF86XK_MonBrightnessDown:
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
+				break;
+			case XK_BackSpace:
+				if (len)
+					passwd[len--] = '\0';
+				break;
+			default:
+				if (num && !iscntrl((int)buf[0]) &&
+				    (len + num < sizeof(passwd))) {
+					memcpy(passwd + len, buf, num);
+					len += num;
+				}
+				break;
+			}
+			color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
+			if (running && oldc != color) {
+				for (screen = 0; screen < nscreens; screen++) {
+					XSetWindowBackground(dpy,
+					                     locks[screen]->win,
+					                     locks[screen]->colors[color]);
+					XClearWindow(dpy, locks[screen]->win);
+				}
+				oldc = color;
+			}
+		} else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
+			rre = (XRRScreenChangeNotifyEvent*)&ev;
+			for (screen = 0; screen < nscreens; screen++) {
+				if (locks[screen]->win == rre->window) {
+					XResizeWindow(dpy, locks[screen]->win,
+					              rre->width, rre->height);
+					XClearWindow(dpy, locks[screen]->win);
+				}
+			}
+		} else for (screen = 0; screen < nscreens; screen++)
+			XRaiseWindow(dpy, locks[screen]->win);
+	}
+}
+
+static struct lock *
+lockscreen(Display *dpy, struct xrandr *rr, int screen)
+{
+	char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
+	int i, ptgrab, kbgrab;
+	struct lock *lock;
+	XColor color, dummy;
+	XSetWindowAttributes wa;
+	Cursor invisible;
+
+	if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
+		return NULL;
+
+	lock->screen = screen;
+	lock->root = RootWindow(dpy, lock->screen);
+
+	for (i = 0; i < NUMCOLS; i++) {
+		XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen),
+		                 colorname[i], &color, &dummy);
+		lock->colors[i] = color.pixel;
+	}
+
+	/* init */
+	wa.override_redirect = 1;
+	wa.background_pixel = lock->colors[INIT];
+	lock->win = XCreateWindow(dpy, lock->root, 0, 0,
+	                          DisplayWidth(dpy, lock->screen),
+	                          DisplayHeight(dpy, lock->screen),
+	                          0, DefaultDepth(dpy, lock->screen),
+	                          CopyFromParent,
+	                          DefaultVisual(dpy, lock->screen),
+	                          CWOverrideRedirect | CWBackPixel, &wa);
+	lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
+	invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
+	                                &color, &color, 0, 0);
+	XDefineCursor(dpy, lock->win, invisible);
+
+	/* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
+	for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
+		if (ptgrab != GrabSuccess) {
+			ptgrab = XGrabPointer(dpy, lock->root, False,
+			                      ButtonPressMask | ButtonReleaseMask |
+			                      PointerMotionMask, GrabModeAsync,
+			                      GrabModeAsync, None, invisible, CurrentTime);
+		}
+		if (kbgrab != GrabSuccess) {
+			kbgrab = XGrabKeyboard(dpy, lock->root, True,
+			                       GrabModeAsync, GrabModeAsync, CurrentTime);
+		}
+
+		/* input is grabbed: we can lock the screen */
+		if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
+			XMapRaised(dpy, lock->win);
+			if (rr->active)
+				XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
+
+			XSelectInput(dpy, lock->root, SubstructureNotifyMask);
+			tim = time(NULL);
+			return lock;
+		}
+
+		/* retry on AlreadyGrabbed but fail on other errors */
+		if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) ||
+		    (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess))
+			break;
+
+		usleep(100000);
+	}
+
+	/* we couldn't grab all input: fail out */
+	if (ptgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n",
+		        screen);
+	if (kbgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab keyboard for screen %d\n",
+		        screen);
+	return NULL;
+}
+
+static void
+monitorreset(Display* dpy, CARD16 standby, CARD16 suspend, CARD16 off)
+{
+	DPMSSetTimeouts(dpy, standby, suspend, off);
+	DPMSForceLevel(dpy, DPMSModeOn);
+	XFlush(dpy);
+}
+
+static void
+usage(void)
+{
+	die("usage: slock [-v] [cmd [arg ...]]\n");
+}
+
+int
+main(int argc, char **argv) {
+	struct xrandr rr;
+	struct lock **locks;
+	struct passwd *pwd;
+	struct group *grp;
+	uid_t duid;
+	gid_t dgid;
+	const char *hash;
+	Display *dpy;
+	int s, nlocks, nscreens;
+	CARD16 standby, suspend, off;
+
+	ARGBEGIN {
+	case 'v':
+		fprintf(stderr, "slock-"VERSION"\n");
+		return 0;
+	default:
+		usage();
+	} ARGEND
+
+	/* validate drop-user and -group */
+	errno = 0;
+	if (!(pwd = getpwnam(user)))
+		die("slock: getpwnam %s: %s\n", user,
+		    errno ? strerror(errno) : "user entry not found");
+	duid = pwd->pw_uid;
+	errno = 0;
+	if (!(grp = getgrnam(group)))
+		die("slock: getgrnam %s: %s\n", group,
+		    errno ? strerror(errno) : "group entry not found");
+	dgid = grp->gr_gid;
+
+#ifdef __linux__
+	dontkillme();
+#endif
+
+	hash = gethash();
+	errno = 0;
+	if (!crypt("", hash))
+		die("slock: crypt: %s\n", strerror(errno));
+
+	if (!(dpy = XOpenDisplay(NULL)))
+		die("slock: cannot open display\n");
+
+	/* drop privileges */
+	if (setgroups(0, NULL) < 0)
+		die("slock: setgroups: %s\n", strerror(errno));
+	if (setgid(dgid) < 0)
+		die("slock: setgid: %s\n", strerror(errno));
+	if (setuid(duid) < 0)
+		die("slock: setuid: %s\n", strerror(errno));
+
+	/* check for Xrandr support */
+	rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
+
+	/* get number of screens in display "dpy" and blank them */
+	nscreens = ScreenCount(dpy);
+	if (!(locks = calloc(nscreens, sizeof(struct lock *))))
+		die("slock: out of memory\n");
+	for (nlocks = 0, s = 0; s < nscreens; s++) {
+		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
+			nlocks++;
+		else
+			break;
+	}
+	XSync(dpy, 0);
+
+	/* did we manage to lock everything? */
+	if (nlocks != nscreens)
+		return 1;
+
+	/* DPMS-magic to disable the monitor */
+	if (!DPMSCapable(dpy))
+		die("slock: DPMSCapable failed\n");
+	if (!DPMSEnable(dpy))
+		die("slock: DPMSEnable failed\n");
+	if (!DPMSGetTimeouts(dpy, &standby, &suspend, &off))
+		die("slock: DPMSGetTimeouts failed\n");
+	if (!standby || !suspend || !off)
+		/* set values if there arent some */
+		standby = suspend = off = 300;
+
+	DPMSSetTimeouts(dpy, monitortime, monitortime, monitortime);
+	XFlush(dpy);
+
+	/* run post-lock command */
+	if (argc > 0) {
+		switch (fork()) {
+		case -1:
+			die("slock: fork failed: %s\n", strerror(errno));
+		case 0:
+			monitorreset(dpy, standby, suspend, off);
+
+			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);
+		}
+	}
+
+	/* everything is now blank. Wait for the correct password */
+	readpw(dpy, &rr, locks, nscreens, hash);
+
+	/* reset DPMS values to inital ones */
+	monitorreset(dpy, standby, suspend, off);
+
+	return 0;
+}

pre/slock-1.4/util.h

@@ -0,0 +1,2 @@
+#undef explicit_bzero
+void explicit_bzero(void *, size_t);

slock-1.2-background-image.diff

@@ -0,0 +1,108 @@
+diff --git config.mk config.mk
+index 8cc3f68..0b2b096 100644
+--- a/config.mk
++++ b/config.mk
+@@ -11,7 +11,7 @@ X11LIB = /usr/X11R6/lib
+ 
+ # includes and libs
+ INCS = -I. -I/usr/include -I${X11INC}
+-LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext
++LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext -lImlib2
+ 
+ # flags
+ CPPFLAGS = -DVERSION=\"${VERSION}\" -DHAVE_SHADOW_H -DCOLOR1=\"black\" -DCOLOR2=\"\#005577\"
+diff --git slock.c slock.c
+index d281965..e1f40a2 100644
+--- a/slock.c
++++ b/slock.c
+@@ -17,6 +17,7 @@
+ #include <X11/keysym.h>
+ #include <X11/Xlib.h>
+ #include <X11/Xutil.h>
++#include <Imlib2.h>
+ 
+ #if HAVE_BSD_AUTH
+ #include <login_cap.h>
+@@ -27,6 +28,7 @@ typedef struct {
+ 	int screen;
+ 	Window root, win;
+ 	Pixmap pmap;
++	Pixmap bgmap;
+ 	unsigned long colors[2];
+ } Lock;
+ 
+@@ -34,6 +36,8 @@ static Lock **locks;
+ static int nscreens;
+ static Bool running = True;
+ 
++Imlib_Image image;
++
+ static void
+ die(const char *errstr, ...) {
+ 	va_list ap;
+@@ -160,7 +164,10 @@ readpw(Display *dpy, const char *pws)
+ 				}
+ 			} else if(llen != 0 && len == 0) {
+ 				for(screen = 0; screen < nscreens; screen++) {
+-					XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[0]);
++					if(locks[screen]->bgmap)
++						XSetWindowBackgroundPixmap(dpy, locks[screen]->win, locks[screen]->bgmap);
++					else
++						XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[0]);
+ 					XClearWindow(dpy, locks[screen]->win);
+ 				}
+ 			}
+@@ -204,12 +211,27 @@ lockscreen(Display *dpy, int screen) {
+ 
+ 	lock->root = RootWindow(dpy, lock->screen);
+ 
++	if(image) {
++		lock->bgmap = XCreatePixmap(dpy, lock->root, DisplayWidth(dpy, lock->screen), DisplayHeight(dpy, lock->screen), DefaultDepth(dpy, lock->screen));
++		imlib_context_set_image(image);
++		imlib_context_set_display(dpy);
++		imlib_context_set_visual(DefaultVisual(dpy, lock->screen));
++		imlib_context_set_colormap(DefaultColormap(dpy, lock->screen));
++		imlib_context_set_drawable(lock->bgmap);
++		imlib_render_image_on_drawable(0, 0);
++		imlib_free_image();
++	}
++
+ 	/* init */
+ 	wa.override_redirect = 1;
+ 	wa.background_pixel = BlackPixel(dpy, lock->screen);
+ 	lock->win = XCreateWindow(dpy, lock->root, 0, 0, DisplayWidth(dpy, lock->screen), DisplayHeight(dpy, lock->screen),
+ 			0, DefaultDepth(dpy, lock->screen), CopyFromParent,
+ 			DefaultVisual(dpy, lock->screen), CWOverrideRedirect | CWBackPixel, &wa);
++
++	if(lock->bgmap)
++		XSetWindowBackgroundPixmap(dpy, lock->win, lock->bgmap);
++
+ 	XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), COLOR2, &color, &dummy);
+ 	lock->colors[1] = color.pixel;
+ 	XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), COLOR1, &color, &dummy);
+@@ -246,7 +268,7 @@ lockscreen(Display *dpy, int screen) {
+ 
+ static void
+ usage(void) {
+-	fprintf(stderr, "usage: slock [-v]\n");
++	fprintf(stderr, "\nusage: slock [options]\noptions:\n\t-v\tPrint version and exit.\n\t-i\t<full path to image file to display>\n");
+ 	exit(EXIT_FAILURE);
+ }
+ 
+@@ -258,8 +280,15 @@ main(int argc, char **argv) {
+ 	Display *dpy;
+ 	int screen;
+ 
+-	if((argc == 2) && !strcmp("-v", argv[1]))
++	if((argc == 2) && !strcmp("-v", argv[1])) {
+ 		die("slock-%s, © 2006-2012 Anselm R Garbe\n", VERSION);
++	}
++	if((argc == 3) && !strcmp("-i", argv[1])) {
++		image = imlib_load_image(argv[2]);
++		if(!image) {
++			die("slock: unable to load image.\n");
++		}
++	}
+ 	else if(argc != 1)
+ 		usage();
+ 

slock-message-20180626-35633d4.diff

@@ -0,0 +1,171 @@
+From 8384a863057f024868bd8455a82013f716197ab0 Mon Sep 17 00:00:00 2001
+From: Blair Drummond <blair.robert.drummond@gmail.com>
+Date: Tue, 26 Jun 2018 15:09:13 -0400
+Subject: [PATCH] Adds [-m message] option to leave a message on the lockscreen
+
+---
+ config.def.h |  9 ++++++
+ slock.1      |  4 +++
+ slock.c      | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--
+ 3 files changed, 87 insertions(+), 3 deletions(-)
+
+diff --git a/config.def.h b/config.def.h
+index 9855e21..7eb7a0d 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -10,3 +10,12 @@ static const char *colorname[NUMCOLS] = {
+ 
+ /* treat a cleared input like a wrong password (color) */
+ static const int failonclear = 1;
++
++/* default message */
++static const char * message = "Suckless: Software that sucks less.";
++
++/* text color */
++static const char * text_color = "#ffffff";
++
++/* text size (must be a valid size) */
++static const char * text_size = "6x10";
+diff --git a/slock.1 b/slock.1
+index 82cdcd6..541a264 100644
+--- a/slock.1
++++ b/slock.1
+@@ -6,6 +6,7 @@
+ .Sh SYNOPSIS
+ .Nm
+ .Op Fl v
++.Op Fl m Ar message
+ .Op Ar cmd Op Ar arg ...
+ .Sh DESCRIPTION
+ .Nm
+@@ -16,6 +17,9 @@ is executed after the screen has been locked.
+ .Bl -tag -width Ds
+ .It Fl v
+ Print version information to stdout and exit.
++.It Fl m Ar message
++Overrides default slock lock message.
++.TP
+ .El
+ .Sh SECURITY CONSIDERATIONS
+ To make sure a locked screen can not be bypassed by switching VTs
+diff --git a/slock.c b/slock.c
+index 5ae738c..6a9a03f 100644
+--- a/slock.c
++++ b/slock.c
+@@ -61,6 +61,71 @@ die(const char *errstr, ...)
+ #include <fcntl.h>
+ #include <linux/oom.h>
+ 
++static void
++writemessage(Display *dpy, Window win, int screen)
++{
++	int len, line_len, width, height, i, j, k, tab_replace, tab_size;
++	XGCValues gr_values;
++	XFontStruct *fontinfo;
++	XColor color, dummy;
++	GC gc;
++	fontinfo = XLoadQueryFont(dpy, text_size);
++	tab_size = 8 * XTextWidth(fontinfo, " ", 1);
++
++	XAllocNamedColor(dpy, DefaultColormap(dpy, screen),
++			 text_color, &color, &dummy);
++
++	gr_values.font = fontinfo->fid;
++	gr_values.foreground = color.pixel;
++	gc=XCreateGC(dpy,win,GCFont+GCForeground, &gr_values);
++
++
++	/*
++	 * Start formatting and drawing text
++	 */
++
++	len = strlen(message);
++
++	/* Max max line length (cut at '\n') */
++	line_len = 0;
++	k = 0;
++	for (i = j = 0; i < len; i++) {
++		if (message[i] == '\n') {
++			if (i - j > line_len)
++				line_len = i - j;
++			k++;
++			i++;
++			j = i;
++		}
++	}
++	/* If there is only one line */
++	if (line_len == 0)
++		line_len = len;
++
++	height = DisplayHeight(dpy, screen)*3/7 - (k*20)/3;
++	width  = (DisplayWidth(dpy, screen) - XTextWidth(fontinfo, message, line_len))/2;
++
++	/* Look for '\n' and print the text between them. */
++	for (i = j = k = 0; i <= len; i++) {
++		/* i == len is the special case for the last line */
++		if (i == len || message[i] == '\n') {
++			tab_replace = 0;
++			while (message[j] == '\t' && j < i) {
++				tab_replace++;
++				j++;
++			}
++
++			XDrawString(dpy, win, gc, width + tab_size*tab_replace, height + 20*k, message + j, i - j);
++			while (i < len && message[i] == '\n') {
++				i++;
++				j = i;
++				k++;
++			}
++		}
++	}
++}
++
++
+ static void
+ dontkillme(void)
+ {
+@@ -194,6 +259,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+ 					                     locks[screen]->win,
+ 					                     locks[screen]->colors[color]);
+ 					XClearWindow(dpy, locks[screen]->win);
++					writemessage(dpy, locks[screen]->win, screen);
+ 				}
+ 				oldc = color;
+ 			}
+@@ -300,7 +366,7 @@ lockscreen(Display *dpy, struct xrandr *rr, int screen)
+ static void
+ usage(void)
+ {
+-	die("usage: slock [-v] [cmd [arg ...]]\n");
++	die("usage: slock [-v] [-m message] [cmd [arg ...]]\n");
+ }
+ 
+ int
+@@ -319,6 +385,9 @@ main(int argc, char **argv) {
+ 	case 'v':
+ 		fprintf(stderr, "slock-"VERSION"\n");
+ 		return 0;
++	case 'm':
++		message = EARGF(usage());
++		break;
+ 	default:
+ 		usage();
+ 	} ARGEND
+@@ -363,10 +432,12 @@ main(int argc, char **argv) {
+ 	if (!(locks = calloc(nscreens, sizeof(struct lock *))))
+ 		die("slock: out of memory\n");
+ 	for (nlocks = 0, s = 0; s < nscreens; s++) {
+-		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
++		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) {
++			writemessage(dpy, locks[s]->win, s);
+ 			nlocks++;
+-		else
++		} else {
+ 			break;
++		}
+ 	}
+ 	XSync(dpy, 0);
+ 
+-- 
+2.17.1
+