From 0adc9b28b39d414d5febfff752f6a1576f785c85 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Sun, 1 Oct 2017 12:32:57 +0300 Subject: [PATCH] Fix PTK rekeying to generate a new ANonce The Authenticator state machine path for PTK rekeying ended up bypassing the AUTHENTICATION2 state where a new ANonce is generated when going directly to the PTKSTART state since there is no need to try to determine the PMK again in such a case. This is far from ideal since the new PTK would depend on a new nonce only from the supplicant. Fix this by generating a new ANonce when moving to the PTKSTART state for the purpose of starting new 4-way handshake to rekey PTK. Signed-off-by: Jouni Malinen --- src/ap/wpa_auth.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c index 4a2aef869..72b562268 100644 --- a/src/ap/wpa_auth.c +++ b/src/ap/wpa_auth.c @@ -1952,6 +1952,21 @@ SM_STATE(WPA_PTK, AUTHENTICATION2) } +static int wpa_auth_sm_ptk_update(struct wpa_state_machine *sm) +{ + if (random_get_bytes(sm->ANonce, WPA_NONCE_LEN)) { + wpa_printf(MSG_ERROR, + "WPA: Failed to get random data for ANonce"); + sm->Disconnect = TRUE; + return -1; + } + wpa_hexdump(MSG_DEBUG, "WPA: Assign new ANonce", sm->ANonce, + WPA_NONCE_LEN); + sm->TimeoutCtr = 0; + return 0; +} + + SM_STATE(WPA_PTK, INITPMK) { u8 msk[2 * PMK_LEN]; @@ -3131,9 +3146,12 @@ SM_STEP(WPA_PTK) SM_ENTER(WPA_PTK, AUTHENTICATION); else if (sm->ReAuthenticationRequest) SM_ENTER(WPA_PTK, AUTHENTICATION2); - else if (sm->PTKRequest) - SM_ENTER(WPA_PTK, PTKSTART); - else switch (sm->wpa_ptk_state) { + else if (sm->PTKRequest) { + if (wpa_auth_sm_ptk_update(sm) < 0) + SM_ENTER(WPA_PTK, DISCONNECTED); + else + SM_ENTER(WPA_PTK, PTKSTART); + } else switch (sm->wpa_ptk_state) { case WPA_PTK_INITIALIZE: break; case WPA_PTK_DISCONNECT: