clear passwords with explicit_bzero

[slock.git] / slock.c

diff --git a/slock.c b/slock.c
index 2aa395e294690b843beb8fb870a5c083a66f4e01..a00fbb9a8f37bbca4d40b04ed40cba525d183781 100644 (file)
--- a/slock.c
+++ b/slock.c
@@ -23,6 +23,8 @@
 #include <bsd_auth.h>
 #endif
 
+#include "util.h"
+
 enum {
        INIT,
        INPUT,
@@ -135,7 +137,7 @@ readpw(Display *dpy, const char *pws)
         * timeout. */
        while (running && !XNextEvent(dpy, &ev)) {
                if (ev.type == KeyPress) {
-                       buf[0] = 0;
+                       explicit_bzero(&buf, sizeof(buf));
                        num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
                        if (IsKeypadKey(ksym)) {
                                if (ksym == XK_KP_Enter)
@@ -161,14 +163,16 @@ readpw(Display *dpy, const char *pws)
                                        XBell(dpy, 100);
                                        failure = True;
                                }
+                               explicit_bzero(&passwd, sizeof(passwd));
                                len = 0;
                                break;
                        case XK_Escape:
+                               explicit_bzero(&passwd, sizeof(passwd));
                                len = 0;
                                break;
                        case XK_BackSpace:
                                if (len)
-                                       --len;
+                                       passwd[len--] = 0;
                                break;
                        default:
                                if (num && !iscntrl((int)buf[0]) && (len + num < sizeof(passwd))) {
@@ -273,15 +277,28 @@ lockscreen(Display *dpy, int screen)
        return NULL;
 }
 
-int
-main(int argc, char **argv)
+static void
+usage(void)
 {
+       fprintf(stderr, "usage: slock [-v|POST_LOCK_CMD]\n");
+       exit(1);
+}
+
+int
+main(int argc, char **argv) {
 #ifndef HAVE_BSD_AUTH
        const char *pws;
 #endif
        Display *dpy;
        int screen;
 
+       if ((argc >= 2) && !strcmp("-v", argv[1]))
+               die("version %s, © 2006-2016 slock engineers\n", VERSION);
+
+       /* treat first argument starting with a '-' as option */
+       if ((argc >= 2) && argv[1][0] == '-')
+               usage();
+
 #ifdef __linux__
        dontkillme();
 #endif