[src/trunk]: src/sys/net Use consttime_memequal, not memcmp, to compare secre...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f0c1df1ccb6e
branches:  trunk
changeset: 975048:f0c1df1ccb6e
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Aug 20 21:34:42 2020 +0000

description:
Use consttime_memequal, not memcmp, to compare secrets for equality.

diffstat:

 sys/net/if_wg.c |  22 ++++++++++++----------
 1 files changed, 12 insertions(+), 10 deletions(-)

diffs (92 lines):

diff -r 4d0718d10297 -r f0c1df1ccb6e sys/net/if_wg.c
--- a/sys/net/if_wg.c   Thu Aug 20 21:34:32 2020 +0000
+++ b/sys/net/if_wg.c   Thu Aug 20 21:34:42 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wg.c,v 1.12 2020/08/20 21:34:32 riastradh Exp $     */
+/*     $NetBSD: if_wg.c,v 1.13 2020/08/20 21:34:42 riastradh Exp $     */
 
 /*
  * Copyright (C) Ryota Ozaki <ozaki.ryota%gmail.com@localhost>
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.12 2020/08/20 21:34:32 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.13 2020/08/20 21:34:42 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -1357,7 +1357,7 @@
         * "the responder, ..., must always reject messages with an invalid
         *  msg.mac1"
         */
-       if (memcmp(mac1, wgmi->wgmi_mac1, sizeof(mac1)) != 0) {
+       if (!consttime_memequal(mac1, wgmi->wgmi_mac1, sizeof(mac1))) {
                WG_DLOG("mac1 is invalid\n");
                goto out;
        }
@@ -1373,7 +1373,7 @@
                 *  message"
                 */
                uint8_t zero[WG_MAC_LEN] = {0};
-               if (memcmp(wgmi->wgmi_mac2, zero, sizeof(zero)) == 0) {
+               if (consttime_memequal(wgmi->wgmi_mac2, zero, sizeof(zero))) {
                        WG_TRACE("sending a cookie message: no cookie included");
                        (void)wg_send_cookie_msg(wg, wgp, wgmi->wgmi_sender,
                            wgmi->wgmi_mac1, src);
@@ -1389,7 +1389,7 @@
                wg_algo_mac(mac2, sizeof(mac2), wgp->wgp_last_sent_cookie,
                    WG_COOKIE_LEN, (const uint8_t *)wgmi,
                    offsetof(struct wg_msg_init, wgmi_mac2), NULL, 0);
-               if (memcmp(mac2, wgmi->wgmi_mac2, sizeof(mac2)) != 0) {
+               if (!consttime_memequal(mac2, wgmi->wgmi_mac2, sizeof(mac2))) {
                        WG_DLOG("mac2 is invalid\n");
                        goto out;
                }
@@ -1715,7 +1715,7 @@
         * "the responder, ..., must always reject messages with an invalid
         *  msg.mac1"
         */
-       if (memcmp(mac1, wgmr->wgmr_mac1, sizeof(mac1)) != 0) {
+       if (!consttime_memequal(mac1, wgmr->wgmr_mac1, sizeof(mac1))) {
                WG_DLOG("mac1 is invalid\n");
                goto out;
        }
@@ -1731,7 +1731,7 @@
                 *  message"
                 */
                uint8_t zero[WG_MAC_LEN] = {0};
-               if (memcmp(wgmr->wgmr_mac2, zero, sizeof(zero)) == 0) {
+               if (consttime_memequal(wgmr->wgmr_mac2, zero, sizeof(zero))) {
                        WG_TRACE("sending a cookie message: no cookie included");
                        (void)wg_send_cookie_msg(wg, wgp, wgmr->wgmr_sender,
                            wgmr->wgmr_mac1, src);
@@ -1747,7 +1747,7 @@
                wg_algo_mac(mac2, sizeof(mac2), wgp->wgp_last_sent_cookie,
                    WG_COOKIE_LEN, (const uint8_t *)wgmr,
                    offsetof(struct wg_msg_resp, wgmr_mac2), NULL, 0);
-               if (memcmp(mac2, wgmr->wgmr_mac2, sizeof(mac2)) != 0) {
+               if (!consttime_memequal(mac2, wgmr->wgmr_mac2, sizeof(mac2))) {
                        WG_DLOG("mac2 is invalid\n");
                        goto out;
                }
@@ -1892,7 +1892,8 @@
        int s = pserialize_read_enter();
        /* XXX O(n) */
        WG_PEER_READER_FOREACH(wgp, wg) {
-               if (memcmp(wgp->wgp_pubkey, pubkey, sizeof(wgp->wgp_pubkey)) == 0)
+               if (consttime_memequal(wgp->wgp_pubkey, pubkey,
+                       sizeof(wgp->wgp_pubkey)))
                        break;
        }
        if (wgp != NULL)
@@ -4058,7 +4059,8 @@
                        goto next;
 
                uint8_t psk_zero[WG_PRESHARED_KEY_LEN] = {0};
-               if (memcmp(wgp->wgp_psk, psk_zero, sizeof(wgp->wgp_psk) != 0)) {
+               if (!consttime_memequal(wgp->wgp_psk, psk_zero,
+                       sizeof(wgp->wgp_psk))) {
                        if (!prop_dictionary_set_data(prop_peer,
                                "preshared_key",
                                wgp->wgp_psk, sizeof(wgp->wgp_psk)))