From: Jouni Malinen <j@w1.fi>
Date: Sun, 29 Jun 2014 17:16:39 +0000 (+0300)
Subject: AES-CCM: Use os_memcmp_const() for hash/password comparisons
X-Git-Tag: hostap_2_3~215
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=87a5c93bec420ea81bee89f241908a70da9596c5;p=thirdparty%2Fhostap.git

AES-CCM: Use os_memcmp_const() for hash/password comparisons

This makes the implementation less likely to provide useful timing
information to potential attackers from comparisons of information
received from a remote device and private material known only by the
authorized devices.

Signed-off-by: Jouni Malinen <j@w1.fi>
---

diff --git a/src/crypto/aes-ccm.c b/src/crypto/aes-ccm.c
index d14670db8..cf227785c 100644
--- a/src/crypto/aes-ccm.c
+++ b/src/crypto/aes-ccm.c
@@ -203,7 +203,7 @@ int aes_ccm_ad(const u8 *key, size_t key_len, const u8 *nonce,
 
 	aes_encrypt_deinit(aes);
 
-	if (os_memcmp(x, t, M) != 0) {
+	if (os_memcmp_const(x, t, M) != 0) {
 		wpa_printf(MSG_EXCESSIVE, "CCM: Auth mismatch");
 		return -1;
 	}