From 761396e4bef0218cd64347976520235f4868fbc7 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Sat, 7 Mar 2015 12:58:19 +0200 Subject: [PATCH] Reject Group Key message 1/2 prior to completion of 4-way handshake Previously, it would have been possible to complete RSN connection by skipping the msg 3/4 and 4/4 completely. This would have resulted in pairwise key not being configured. This is obviously not supposed to happen in practice and could result in unexpected behavior, so reject group key message before the initial 4-way handshake has been completed. Signed-off-by: Jouni Malinen --- src/rsn_supp/wpa.c | 9 +++++++++ src/rsn_supp/wpa_i.h | 1 + 2 files changed, 10 insertions(+) diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c index 37e4b3561..8adeef4af 100644 --- a/src/rsn_supp/wpa.c +++ b/src/rsn_supp/wpa.c @@ -1244,6 +1244,7 @@ static void wpa_supplicant_process_3_of_4(struct wpa_sm *sm, sm->cur_pmksa = sa; } + sm->msg_3_of_4_ok = 1; return; failed: @@ -1436,6 +1437,12 @@ static void wpa_supplicant_process_1_of_2(struct wpa_sm *sm, int rekey, ret; struct wpa_gtk_data gd; + if (!sm->msg_3_of_4_ok) { + wpa_msg(sm->ctx->msg_ctx, MSG_INFO, + "WPA: Group Key Handshake started prior to completion of 4-way handshake"); + goto failed; + } + os_memset(&gd, 0, sizeof(gd)); rekey = wpa_sm_get_state(sm) == WPA_COMPLETED; @@ -2295,6 +2302,8 @@ void wpa_sm_notify_disassoc(struct wpa_sm *sm) /* Keys are not needed in the WPA state machine anymore */ wpa_sm_drop_sa(sm); + + sm->msg_3_of_4_ok = 0; } diff --git a/src/rsn_supp/wpa_i.h b/src/rsn_supp/wpa_i.h index 431bb2075..965a9c1d5 100644 --- a/src/rsn_supp/wpa_i.h +++ b/src/rsn_supp/wpa_i.h @@ -23,6 +23,7 @@ struct wpa_sm { size_t pmk_len; struct wpa_ptk ptk, tptk; int ptk_set, tptk_set; + unsigned int msg_3_of_4_ok:1; u8 snonce[WPA_NONCE_LEN]; u8 anonce[WPA_NONCE_LEN]; /* ANonce from the last 1/4 msg */ int renew_snonce;