1 files changed, 4 insertions, 2 deletions

diff --git a/slock.c b/slock.c
index 2dce109..d150009 100644
--- a/slock.c
+++ b/slock.c
@@ -50,9 +50,9 @@ getpw(void) { /* only run as root */
         const char *rval;
         struct passwd *pw;
 
-        if(geteuid() != 0)
-                die("cannot retrieve password entry (make sure to suid slock)");
         pw = getpwuid(getuid());
+        if(!pw)
+                die("cannot retrieve password entry (make sure to suid or sgid slock)");
         endpwent();
         rval =  pw->pw_passwd;
 
@@ -60,6 +60,8 @@ getpw(void) { /* only run as root */
         {
                 struct spwd *sp;
                 sp = getspnam(getenv("USER"));
+                if(!sp)
+                        die("slock: cannot retrieve shadow entry (make sure to suid or sgid slock)\n");
                 endspent();
                 rval = sp->sp_pwdp;
         }