X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=slock.c;h=97a80c5b63fb0b06ad12f3541699a31edcb8f51e;hb=8322f22871ee1da82546dfcdea484ef9db6d4942;hp=866400d3d4d401a781f01d223b0c4337d9803acb;hpb=0f1157d7e6cabe0394ffc35a0a58a30507af8ebd;p=slock.git

diff --git a/slock.c b/slock.c
index 866400d..97a80c5 100644
--- a/slock.c
+++ b/slock.c
@@ -1,14 +1,13 @@
-/* (C)opyright MMIV-MMV Anselm R. Garbe <garbeam at gmail dot com>
+/* (C)opyright MMVI-MMVII Anselm R. Garbe <garbeam at gmail dot com>
  * See LICENSE file for license details.
  */
-#define _XOPEN_SOURCE
-
+#define _XOPEN_SOURCE 500
 #if HAVE_SHADOW_H
 #include <shadow.h>
-#else
-#include <pwd.h>
 #endif
 
+#include <ctype.h>
+#include <pwd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -18,23 +17,48 @@
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 
+const char *
+get_password() { /* only run as root */
+	const char *rval;
+	struct passwd *pw;
+
+	if(geteuid() != 0) {
+		fputs("slock: cannot retrieve password entry (make sure to suid slock)\n", stderr);
+		exit(EXIT_FAILURE);
+	}
+	pw = getpwuid(getuid());
+	endpwent();
+	rval =  pw->pw_passwd;
+
+#if HAVE_SHADOW_H
+	{
+		struct spwd *sp;
+		sp = getspnam(getenv("USER"));
+		endspent();
+		rval = sp->sp_pwdp;
+	}
+#endif
+	/* drop privileges */
+	if(setgid(pw->pw_gid) < 0 || setuid(pw->pw_uid) < 0) {
+		fputs("slock: cannot drop privileges\n",stdout);
+		exit(EXIT_FAILURE);
+	}
+	return rval;
+}
+
 int
 main(int argc, char **argv) {
 	char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
 	char buf[32], passwd[256];
-	int num, prev_nitem, screen;
-#if HAVE_SHADOW_H
-	struct spwd *sp;
-#else
-	struct passwd *pw;
-#endif
-	unsigned int i, len;
+	int num, screen;
+	const char *pws;
+	unsigned int len;
 	Bool running = True;
 	Cursor invisible;
 	Display *dpy;
 	KeySym ksym;
 	Pixmap pmap;
-	Window w;
+	Window root, w;
 	XColor black, dummy;
 	XEvent ev;
 	XSetWindowAttributes wa;
@@ -43,33 +67,18 @@ main(int argc, char **argv) {
 		fputs("slock-"VERSION", (C)opyright MMVI Anselm R. Garbe\n", stdout);
 		exit(EXIT_SUCCESS);
 	}
-	if(geteuid() != 0) {
-		fputs("slock: cannot retrieve password entry (make sure to suid slock)\n", stderr);
-		exit(EXIT_FAILURE);
-	}
-#if HAVE_SHADOW_H
-	sp = getspnam(getenv("USER"));
-	endspent();
-#else
-	pw = getpwuid(getuid());
-	endpwent();
-#endif
+	pws = get_password();
 	if(!(dpy = XOpenDisplay(0))) {
 		fputs("slock: cannot open display\n", stderr);
 		exit(EXIT_FAILURE);
 	}
 	screen = DefaultScreen(dpy);
+	root = RootWindow(dpy, screen);
 
 	/* init */
-	passwd[0] = 0;
-	while(XGrabKeyboard(dpy, RootWindow(dpy, screen), True, GrabModeAsync,
-			 GrabModeAsync, CurrentTime) != GrabSuccess)
-		usleep(1000);
-
 	wa.override_redirect = 1;
 	wa.background_pixel = BlackPixel(dpy, screen);
-	w = XCreateWindow(dpy, RootWindow(dpy, screen), 0, 0,
-			DisplayWidth(dpy, screen), DisplayHeight(dpy, screen),
+	w = XCreateWindow(dpy, root, 0, 0, DisplayWidth(dpy, screen), DisplayHeight(dpy, screen),
 			0, DefaultDepth(dpy, screen), CopyFromParent,
 			DefaultVisual(dpy, screen), CWOverrideRedirect | CWBackPixel, &wa);
 
@@ -78,57 +87,56 @@ main(int argc, char **argv) {
 	invisible = XCreatePixmapCursor(dpy, pmap, pmap, &black, &black, 0, 0);
 	XDefineCursor(dpy, w, invisible);
 	XMapRaised(dpy, w);
+	for(len = 1000; len; len--) {
+		if(XGrabPointer(dpy, w, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
+			GrabModeAsync, GrabModeSync, None, invisible, CurrentTime) == GrabSuccess)
+			break;
+		usleep(1000);
+	}
+	if((running = running && (len > 0))) {
+		for(len = 1000; len; len--) {
+			if(XGrabKeyboard(dpy, w, True, GrabModeAsync, GrabModeAsync, CurrentTime)
+				== GrabSuccess)
+				break;
+			usleep(1000);
+		}
+		running = (len > 0);
+	}
+	len = 0;
 	XSync(dpy, False);
 
 	/* main event loop */
 	while(running && !XNextEvent(dpy, &ev))
 		if(ev.type == KeyPress) {
-			len = strlen(passwd);
 			buf[0] = 0;
-			num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
+			num = XLookupString(&ev.xkey, buf, sizeof buf, &ksym, 0);
 			if(IsFunctionKey(ksym) || IsKeypadKey(ksym)
 					|| IsMiscFunctionKey(ksym) || IsPFKey(ksym)
 					|| IsPrivateKeypadKey(ksym))
 				continue;
-			/* first check if a control mask is omitted */
-			if(ev.xkey.state & ControlMask) {
-				switch (ksym) {
-				case XK_h:
-				case XK_H: ksym = XK_BackSpace;
-					break;
-				case XK_u:
-				case XK_U: passwd[0] = 0;
-					continue;
-				}
-			}
 			switch(ksym) {
 			case XK_Return:
-#if HAVE_SHADOW_H
-				if((running = strncmp(crypt(passwd, sp->sp_pwdp), sp->sp_pwdp, sizeof(passwd))))
-#else
-				if((running = strncmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd, sizeof(passwd))))
-#endif
+				passwd[len] = 0;
+				if((running = strcmp(crypt(passwd, pws), pws)) != 0)
 					XBell(dpy, 100);
-				passwd[0] = 0;
+				len = 0;
 				break;
 			case XK_Escape:
-				passwd[0] = 0;
+				len = 0;
 				break;
 			case XK_BackSpace:
 				if(len)
-					passwd[--len] = 0;
+					--len;
 				break;
 			default:
-				if(num && !iscntrl((int) buf[0])) {
-					buf[num] = 0;
-					if(len)
-						strncat(passwd, buf, sizeof(passwd));
-					else
-						strncpy(passwd, buf, sizeof(passwd));
+				if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) { 
+					memcpy(passwd + len, buf, num);
+					len += num;
 				}
 				break;
 			}
 		}
+	XUngrabPointer(dpy, CurrentTime);
 	XFreePixmap(dpy, pmap);
 	XDestroyWindow(dpy, w);
 	XCloseDisplay(dpy);