git.openwrt.org Git - openwrt/staging/chunkeey.git/blob

   1 From a6ea665300919d6a3af22b1f4237203647fda93a Mon Sep 17 00:00:00 2001
   2 From: Jouni Malinen <j@w1.fi>
   3 Date: Tue, 17 Oct 2017 00:01:11 +0300
   4 Subject: [PATCH] Additional consistentcy checks for PTK component lengths
   5
   6 Verify that TK, KCK, and KEK lengths are set to consistent values within
   7 struct wpa_ptk before using them in supplicant. This is an additional
   8 layer of protection against unexpected states.
   9
  10 Signed-off-by: Jouni Malinen <j@w1.fi>
  11 ---
  12  src/common/wpa_common.c |  6 ++++++
  13  src/rsn_supp/wpa.c      | 26 ++++++++++++++++++++------
  14  2 files changed, 26 insertions(+), 6 deletions(-)
  15
  16 --- a/src/common/wpa_common.c
  17 +++ b/src/common/wpa_common.c
  18 @@ -100,6 +100,12 @@ int wpa_eapol_key_mic(const u8 *key, siz
  19  {
  20         u8 hash[SHA512_MAC_LEN];
  21
  22 +       if (key_len == 0) {
  23 +               wpa_printf(MSG_DEBUG,
  24 +                          "WPA: KCK not set - cannot calculate MIC");
  25 +               return -1;
  26 +       }
  27 +
  28         switch (ver) {
  29  #ifndef CONFIG_FIPS
  30         case WPA_KEY_INFO_TYPE_HMAC_MD5_RC4:
  31 --- a/src/rsn_supp/wpa.c
  32 +++ b/src/rsn_supp/wpa.c
  33 @@ -725,6 +725,11 @@ static int wpa_supplicant_install_ptk(st
  34
  35         alg = wpa_cipher_to_alg(sm->pairwise_cipher);
  36         keylen = wpa_cipher_key_len(sm->pairwise_cipher);
  37 +       if (keylen <= 0 || (unsigned int) keylen != sm->ptk.tk_len) {
  38 +               wpa_printf(MSG_DEBUG, "WPA: TK length mismatch: %d != %lu",
  39 +                          keylen, (long unsigned int) sm->ptk.tk_len);
  40 +               return -1;
  41 +       }
  42         rsclen = wpa_cipher_rsc_len(sm->pairwise_cipher);
  43
  44         if (sm->proto == WPA_PROTO_RSN || sm->proto == WPA_PROTO_OSEN) {
  45 @@ -745,6 +750,7 @@ static int wpa_supplicant_install_ptk(st
  46
  47         /* TK is not needed anymore in supplicant */
  48         os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
  49 +       sm->ptk.tk_len = 0;
  50         sm->ptk.installed = 1;
  51
  52         if (sm->wpa_ptk_rekey) {
  53 @@ -1717,9 +1723,10 @@ static int wpa_supplicant_verify_eapol_k
  54         os_memcpy(mic, key + 1, mic_len);
  55         if (sm->tptk_set) {
  56                 os_memset(key + 1, 0, mic_len);
  57 -               wpa_eapol_key_mic(sm->tptk.kck, sm->tptk.kck_len, sm->key_mgmt,
  58 -                                 ver, buf, len, (u8 *) (key + 1));
  59 -               if (os_memcmp_const(mic, key + 1, mic_len) != 0) {
  60 +               if (wpa_eapol_key_mic(sm->tptk.kck, sm->tptk.kck_len,
  61 +                                     sm->key_mgmt,
  62 +                                     ver, buf, len, (u8 *) (key + 1)) < 0 ||
  63 +                   os_memcmp_const(mic, key + 1, mic_len) != 0) {
  64                         wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
  65                                 "WPA: Invalid EAPOL-Key MIC "
  66                                 "when using TPTK - ignoring TPTK");
  67 @@ -1742,9 +1749,10 @@ static int wpa_supplicant_verify_eapol_k
  68
  69         if (!ok && sm->ptk_set) {
  70                 os_memset(key + 1, 0, mic_len);
  71 -               wpa_eapol_key_mic(sm->ptk.kck, sm->ptk.kck_len, sm->key_mgmt,
  72 -                                 ver, buf, len, (u8 *) (key + 1));
  73 -               if (os_memcmp_const(mic, key + 1, mic_len) != 0) {
  74 +               if (wpa_eapol_key_mic(sm->ptk.kck, sm->ptk.kck_len,
  75 +                                     sm->key_mgmt,
  76 +                                     ver, buf, len, (u8 *) (key + 1)) < 0 ||
  77 +                   os_memcmp_const(mic, key + 1, mic_len) != 0) {
  78                         wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
  79                                 "WPA: Invalid EAPOL-Key MIC - "
  80                                 "dropping packet");
  81 @@ -4167,6 +4175,11 @@ int fils_process_assoc_resp(struct wpa_s
  82
  83         alg = wpa_cipher_to_alg(sm->pairwise_cipher);
  84         keylen = wpa_cipher_key_len(sm->pairwise_cipher);
  85 +       if (keylen <= 0 || (unsigned int) keylen != sm->ptk.tk_len) {
  86 +               wpa_printf(MSG_DEBUG, "FILS: TK length mismatch: %u != %lu",
  87 +                          keylen, (long unsigned int) sm->ptk.tk_len);
  88 +               goto fail;
  89 +       }
  90         rsclen = wpa_cipher_rsc_len(sm->pairwise_cipher);
  91         wpa_hexdump_key(MSG_DEBUG, "FILS: Set TK to driver",
  92                         sm->ptk.tk, keylen);
  93 @@ -4183,6 +4196,7 @@ int fils_process_assoc_resp(struct wpa_s
  94          * takes care of association frame encryption/decryption. */
  95         /* TK is not needed anymore in supplicant */
  96         os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
  97 +       sm->ptk.tk_len = 0;
  98         sm->ptk.installed = 1;
  99
 100         /* FILS HLP Container */