From a7afade1701a809f6a33b53525d59dd29b38d381 Mon Sep 17 00:00:00 2001 From: Hiltjo Posthuma Date: Sun, 31 Jul 2016 13:43:00 +0200 Subject: clear passwords with explicit_bzero Make sure to explicitly clear memory that is used for password input. memset is often optimized out by the compiler. Brought to attention by the OpenBSD community, see: https://marc.info/?t=146989502600003&r=1&w=2 Thread subject: x11/slock: clear passwords with explicit_bzero Changes: - explicit_bzero.c import from libressl-portable. - Makefile: add COMPATSRC for compatibility src. - config.mk: add separate *BSD section in config.mk to simply uncomment it on these platforms. --- slock.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'slock.c') diff --git a/slock.c b/slock.c index c9cdee2..a00fbb9 100644 --- a/slock.c +++ b/slock.c @@ -23,6 +23,8 @@ #include #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))) { -- cgit v1.2.3-70-g09d2