From a6ea665300919d6a3af22b1f4237203647fda93a Mon Sep 17 00:00:00 2001 From: Jouni Malinen 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 --- 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 */