openwrt/package/network/services/hostapd/patches/011-Additional-consistentcy-checks-for-PTK-component-len.patch
Stijn Tintel 2127425434 hostapd: backport extra changes related to KRACK
While these changes are not included in the advisory, upstream
encourages users to merge them.
See http://lists.infradead.org/pipermail/hostap/2017-October/037989.html

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
2017-10-17 17:24:47 +03:00

101 lines
3.6 KiB
Diff

From a6ea665300919d6a3af22b1f4237203647fda93a Mon Sep 17 00:00:00 2001
From: Jouni Malinen <j@w1.fi>
Date: Tue, 17 Oct 2017 00:01:11 +0300
Subject: [PATCH] Additional consistentcy checks for PTK component lengths
Verify that TK, KCK, and KEK lengths are set to consistent values within
struct wpa_ptk before using them in supplicant. This is an additional
layer of protection against unexpected states.
Signed-off-by: Jouni Malinen <j@w1.fi>
---
src/common/wpa_common.c | 6 ++++++
src/rsn_supp/wpa.c | 26 ++++++++++++++++++++------
2 files changed, 26 insertions(+), 6 deletions(-)
--- a/src/common/wpa_common.c
+++ b/src/common/wpa_common.c
@@ -100,6 +100,12 @@ int wpa_eapol_key_mic(const u8 *key, siz
{
u8 hash[SHA512_MAC_LEN];
+ if (key_len == 0) {
+ wpa_printf(MSG_DEBUG,
+ "WPA: KCK not set - cannot calculate MIC");
+ return -1;
+ }
+
switch (ver) {
#ifndef CONFIG_FIPS
case WPA_KEY_INFO_TYPE_HMAC_MD5_RC4:
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -725,6 +725,11 @@ static int wpa_supplicant_install_ptk(st
alg = wpa_cipher_to_alg(sm->pairwise_cipher);
keylen = wpa_cipher_key_len(sm->pairwise_cipher);
+ if (keylen <= 0 || (unsigned int) keylen != sm->ptk.tk_len) {
+ wpa_printf(MSG_DEBUG, "WPA: TK length mismatch: %d != %lu",
+ keylen, (long unsigned int) sm->ptk.tk_len);
+ return -1;
+ }
rsclen = wpa_cipher_rsc_len(sm->pairwise_cipher);
if (sm->proto == WPA_PROTO_RSN || sm->proto == WPA_PROTO_OSEN) {
@@ -745,6 +750,7 @@ static int wpa_supplicant_install_ptk(st
/* TK is not needed anymore in supplicant */
os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
+ sm->ptk.tk_len = 0;
sm->ptk.installed = 1;
if (sm->wpa_ptk_rekey) {
@@ -1717,9 +1723,10 @@ static int wpa_supplicant_verify_eapol_k
os_memcpy(mic, key + 1, mic_len);
if (sm->tptk_set) {
os_memset(key + 1, 0, mic_len);
- wpa_eapol_key_mic(sm->tptk.kck, sm->tptk.kck_len, sm->key_mgmt,
- ver, buf, len, (u8 *) (key + 1));
- if (os_memcmp_const(mic, key + 1, mic_len) != 0) {
+ if (wpa_eapol_key_mic(sm->tptk.kck, sm->tptk.kck_len,
+ sm->key_mgmt,
+ ver, buf, len, (u8 *) (key + 1)) < 0 ||
+ os_memcmp_const(mic, key + 1, mic_len) != 0) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"WPA: Invalid EAPOL-Key MIC "
"when using TPTK - ignoring TPTK");
@@ -1742,9 +1749,10 @@ static int wpa_supplicant_verify_eapol_k
if (!ok && sm->ptk_set) {
os_memset(key + 1, 0, mic_len);
- wpa_eapol_key_mic(sm->ptk.kck, sm->ptk.kck_len, sm->key_mgmt,
- ver, buf, len, (u8 *) (key + 1));
- if (os_memcmp_const(mic, key + 1, mic_len) != 0) {
+ if (wpa_eapol_key_mic(sm->ptk.kck, sm->ptk.kck_len,
+ sm->key_mgmt,
+ ver, buf, len, (u8 *) (key + 1)) < 0 ||
+ os_memcmp_const(mic, key + 1, mic_len) != 0) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"WPA: Invalid EAPOL-Key MIC - "
"dropping packet");
@@ -4167,6 +4175,11 @@ int fils_process_assoc_resp(struct wpa_s
alg = wpa_cipher_to_alg(sm->pairwise_cipher);
keylen = wpa_cipher_key_len(sm->pairwise_cipher);
+ if (keylen <= 0 || (unsigned int) keylen != sm->ptk.tk_len) {
+ wpa_printf(MSG_DEBUG, "FILS: TK length mismatch: %u != %lu",
+ keylen, (long unsigned int) sm->ptk.tk_len);
+ goto fail;
+ }
rsclen = wpa_cipher_rsc_len(sm->pairwise_cipher);
wpa_hexdump_key(MSG_DEBUG, "FILS: Set TK to driver",
sm->ptk.tk, keylen);
@@ -4183,6 +4196,7 @@ int fils_process_assoc_resp(struct wpa_s
* takes care of association frame encryption/decryption. */
/* TK is not needed anymore in supplicant */
os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
+ sm->ptk.tk_len = 0;
sm->ptk.installed = 1;
/* FILS HLP Container */