package/network/services/hostapd/patches/004-Fix-PTK-rekeying-to-generate-a-new-ANonce.patch

   1 From: Jouni Malinen <j@w1.fi>
   2 Date: Sun, 1 Oct 2017 12:32:57 +0300
   3 Subject: [PATCH] Fix PTK rekeying to generate a new ANonce
   4
   5 The Authenticator state machine path for PTK rekeying ended up bypassing
   6 the AUTHENTICATION2 state where a new ANonce is generated when going
   7 directly to the PTKSTART state since there is no need to try to
   8 determine the PMK again in such a case. This is far from ideal since the
   9 new PTK would depend on a new nonce only from the supplicant.
  10
  11 Fix this by generating a new ANonce when moving to the PTKSTART state
  12 for the purpose of starting new 4-way handshake to rekey PTK.
  13
  14 Signed-off-by: Jouni Malinen <j@w1.fi>
  15 ---
  16
  17 --- a/src/ap/wpa_auth.c
  18 +++ b/src/ap/wpa_auth.c
  19 @@ -1951,6 +1951,21 @@ SM_STATE(WPA_PTK, AUTHENTICATION2)
  20  }
  21
  22
  23 +static int wpa_auth_sm_ptk_update(struct wpa_state_machine *sm)
  24 +{
  25 +       if (random_get_bytes(sm->ANonce, WPA_NONCE_LEN)) {
  26 +               wpa_printf(MSG_ERROR,
  27 +                          "WPA: Failed to get random data for ANonce");
  28 +               sm->Disconnect = TRUE;
  29 +               return -1;
  30 +       }
  31 +       wpa_hexdump(MSG_DEBUG, "WPA: Assign new ANonce", sm->ANonce,
  32 +                   WPA_NONCE_LEN);
  33 +       sm->TimeoutCtr = 0;
  34 +       return 0;
  35 +}
  36 +
  37 +
  38  SM_STATE(WPA_PTK, INITPMK)
  39  {
  40         u8 msk[2 * PMK_LEN];
  41 @@ -3116,9 +3131,12 @@ SM_STEP(WPA_PTK)
  42                 SM_ENTER(WPA_PTK, AUTHENTICATION);
  43         else if (sm->ReAuthenticationRequest)
  44                 SM_ENTER(WPA_PTK, AUTHENTICATION2);
  45 -       else if (sm->PTKRequest)
  46 -               SM_ENTER(WPA_PTK, PTKSTART);
  47 -       else switch (sm->wpa_ptk_state) {
  48 +       else if (sm->PTKRequest) {
  49 +               if (wpa_auth_sm_ptk_update(sm) < 0)
  50 +                       SM_ENTER(WPA_PTK, DISCONNECTED);
  51 +               else
  52 +                       SM_ENTER(WPA_PTK, PTKSTART);
  53 +       } else switch (sm->wpa_ptk_state) {
  54         case WPA_PTK_INITIALIZE:
  55                 break;
  56         case WPA_PTK_DISCONNECT: