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

   1 From a00e946c1c9a1f9cc65c72900d2a444ceb1f872e Mon Sep 17 00:00:00 2001
   2 From: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
   3 Date: Thu, 5 Oct 2017 23:53:01 +0200
   4 Subject: [PATCH] WPA: Extra defense against PTK reinstalls in 4-way handshake
   5
   6 Currently, reinstallations of the PTK are prevented by (1) assuring the
   7 same TPTK is only set once as the PTK, and (2) that one particular PTK
   8 is only installed once. This patch makes it more explicit that point (1)
   9 is required to prevent key reinstallations. At the same time, this patch
  10 hardens wpa_supplicant such that future changes do not accidentally
  11 break this property.
  12
  13 Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
  14 ---
  15  src/rsn_supp/wpa.c | 8 ++++++++
  16  1 file changed, 8 insertions(+)
  17
  18 --- a/src/rsn_supp/wpa.c
  19 +++ b/src/rsn_supp/wpa.c
  20 @@ -1728,6 +1728,14 @@ static int wpa_supplicant_verify_eapol_k
  21                         sm->ptk_set = 1;
  22                         os_memcpy(&sm->ptk, &sm->tptk, sizeof(sm->ptk));
  23                         os_memset(&sm->tptk, 0, sizeof(sm->tptk));
  24 +                       /*
  25 +                        * This assures the same TPTK in sm->tptk can never be
  26 +                        * copied twice to sm->pkt as the new PTK. In
  27 +                        * combination with the installed flag in the wpa_ptk
  28 +                        * struct, this assures the same PTK is only installed
  29 +                        * once.
  30 +                        */
  31 +                       sm->renew_snonce = 1;
  32                 }
  33         }
  34