src/patches/wpa_supplicant/rebased-v2.6-0005-Fix-PTK-rekeying-to-generate-a-new-ANonce.patch

   1 From 12fac09b437a1dc8a0f253e265934a8aaf4d2f8b Mon Sep 17 00:00:00 2001
   2 From: Jouni Malinen <j@w1.fi>
   3 Date: Sun, 1 Oct 2017 12:32:57 +0300
   4 Subject: [PATCH 5/8] Fix PTK rekeying to generate a new ANonce
   5
   6 The Authenticator state machine path for PTK rekeying ended up bypassing
   7 the AUTHENTICATION2 state where a new ANonce is generated when going
   8 directly to the PTKSTART state since there is no need to try to
   9 determine the PMK again in such a case. This is far from ideal since the
  10 new PTK would depend on a new nonce only from the supplicant.
  11
  12 Fix this by generating a new ANonce when moving to the PTKSTART state
  13 for the purpose of starting new 4-way handshake to rekey PTK.
  14
  15 Signed-off-by: Jouni Malinen <j@w1.fi>
  16 ---
  17  src/ap/wpa_auth.c | 24 +++++++++++++++++++++---
  18  1 file changed, 21 insertions(+), 3 deletions(-)
  19
  20 diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
  21 index 707971d..bf10cc1 100644
  22 --- a/src/ap/wpa_auth.c
  23 +++ b/src/ap/wpa_auth.c
  24 @@ -1901,6 +1901,21 @@ SM_STATE(WPA_PTK, AUTHENTICATION2)
  25  }
  26
  27
  28 +static int wpa_auth_sm_ptk_update(struct wpa_state_machine *sm)
  29 +{
  30 +       if (random_get_bytes(sm->ANonce, WPA_NONCE_LEN)) {
  31 +               wpa_printf(MSG_ERROR,
  32 +                          "WPA: Failed to get random data for ANonce");
  33 +               sm->Disconnect = TRUE;
  34 +               return -1;
  35 +       }
  36 +       wpa_hexdump(MSG_DEBUG, "WPA: Assign new ANonce", sm->ANonce,
  37 +                   WPA_NONCE_LEN);
  38 +       sm->TimeoutCtr = 0;
  39 +       return 0;
  40 +}
  41 +
  42 +
  43  SM_STATE(WPA_PTK, INITPMK)
  44  {
  45         u8 msk[2 * PMK_LEN];
  46 @@ -2458,9 +2473,12 @@ SM_STEP(WPA_PTK)
  47                 SM_ENTER(WPA_PTK, AUTHENTICATION);
  48         else if (sm->ReAuthenticationRequest)
  49                 SM_ENTER(WPA_PTK, AUTHENTICATION2);
  50 -       else if (sm->PTKRequest)
  51 -               SM_ENTER(WPA_PTK, PTKSTART);
  52 -       else switch (sm->wpa_ptk_state) {
  53 +       else if (sm->PTKRequest) {
  54 +               if (wpa_auth_sm_ptk_update(sm) < 0)
  55 +                       SM_ENTER(WPA_PTK, DISCONNECTED);
  56 +               else
  57 +                       SM_ENTER(WPA_PTK, PTKSTART);
  58 +       } else switch (sm->wpa_ptk_state) {
  59         case WPA_PTK_INITIALIZE:
  60                 break;
  61         case WPA_PTK_DISCONNECT:
  62 --
  63 2.7.4
  64