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-rw-r--r--slock.c80
1 files changed, 43 insertions, 37 deletions
diff --git a/slock.c b/slock.c
index 164a464..6541b70 100644
--- a/slock.c
+++ b/slock.c
@@ -3,32 +3,55 @@
*/
#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>
#include <unistd.h>
+#if HAVE_SHADOW_H
+#include <shadow.h>
+#endif
#include <sys/types.h>
#include <X11/keysym.h>
#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, screen;
-#if HAVE_SHADOW_H
- struct spwd *sp;
-#else
- struct passwd *pw;
-#endif
+ const char *pws;
unsigned int len;
Bool running = True;
Cursor invisible;
@@ -44,17 +67,7 @@ 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);
@@ -62,7 +75,7 @@ main(int argc, char **argv) {
screen = DefaultScreen(dpy);
/* init */
- passwd[0] = 0;
+ len = 0;
wa.override_redirect = 1;
wa.background_pixel = BlackPixel(dpy, screen);
@@ -89,7 +102,6 @@ main(int argc, char **argv) {
/* 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);
if(IsFunctionKey(ksym) || IsKeypadKey(ksym)
@@ -98,28 +110,22 @@ main(int argc, char **argv) {
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));
+ memcpy(passwd + len,buf,num);
+ len += num;
}
break;
}