WNM: Fix GTK/IGTK encoding in WNM-Sleep Mode Exit frame

These subelements do not use AES key wrap (MFP is used instead).

Signed-hostap: Jouni Malinen <j@w1.fi>

diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index 0dc3f58a53b5e7fc96ef682437e68ed59e27554f..2c70149a1818938dc6d5ec4030c3d76db8a978f0 100644 (file)
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -2444,108 +2444,62 @@ void wpa_set_wnmsleep(struct wpa_state_machine *sm, int flag)
 
 int wpa_wnmsleep_gtk_subelem(struct wpa_state_machine *sm, u8 *pos)
 {
-       u8 *subelem;
        struct wpa_group *gsm = sm->group;
-       size_t subelem_len, pad_len;
-       const u8 *key;
-       size_t key_len;
-       u8 keybuf[32];
-
-       /* GTK subslement */
-       key_len = gsm->GTK_len;
-       if (key_len > sizeof(keybuf))
-               return 0;
-
-       /*
-        * Pad key for AES Key Wrap if it is not multiple of 8 bytes or is less
-        * than 16 bytes.
-        */
-       pad_len = key_len % 8;
-       if (pad_len)
-               pad_len = 8 - pad_len;
-       if (key_len + pad_len < 16)
-               pad_len += 8;
-       if (pad_len) {
-               os_memcpy(keybuf, gsm->GTK[gsm->GN - 1], key_len);
-               os_memset(keybuf + key_len, 0, pad_len);
-               keybuf[key_len] = 0xdd;
-               key_len += pad_len;
-               key = keybuf;
-       } else
-               key = gsm->GTK[gsm->GN - 1];
+       u8 *start = pos;
 
        /*
+        * GTK subelement:
         * Sub-elem ID[1] | Length[1] | Key Info[2] | Key Length[1] | RSC[8] |
-        * Key[5..32] | 8 padding.
+        * Key[5..32]
         */
-       subelem_len = 13 + key_len + 8;
-       subelem = os_zalloc(subelem_len);
-       if (subelem == NULL)
-               return 0;
-
-       subelem[0] = WNM_SLEEP_SUBELEM_GTK;
-       subelem[1] = 11 + key_len + 8;
+       *pos++ = WNM_SLEEP_SUBELEM_GTK;
+       *pos++ = 11 + gsm->GTK_len;
        /* Key ID in B0-B1 of Key Info */
-       WPA_PUT_LE16(&subelem[2], gsm->GN & 0x03);
-       subelem[4] = gsm->GTK_len;
-       if (wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN, subelem + 5) != 0)
-       {
-               os_free(subelem);
-               return 0;
-       }
-       if (aes_wrap(sm->PTK.kek, key_len / 8, key, subelem + 13)) {
-               os_free(subelem);
+       WPA_PUT_LE16(pos, gsm->GN & 0x03);
+       pos += 2;
+       *pos++ = gsm->GTK_len;
+       if (wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN, pos) != 0)
                return 0;
-       }
-
-       os_memcpy(pos, subelem, subelem_len);
+       pos += 8;
+       os_memcpy(pos, gsm->GTK[gsm->GN - 1], gsm->GTK_len);
+       pos += gsm->GTK_len;
 
-       wpa_hexdump_key(MSG_DEBUG, "Plaintext GTK",
+       wpa_printf(MSG_DEBUG, "WNM: GTK Key ID %u in WNM-Sleep Mode exit",
+                  gsm->GN);
+       wpa_hexdump_key(MSG_DEBUG, "WNM: GTK in WNM-Sleep Mode exit",
                        gsm->GTK[gsm->GN - 1], gsm->GTK_len);
-       os_free(subelem);
 
-       return subelem_len;
+       return pos - start;
 }
 
 
 #ifdef CONFIG_IEEE80211W
 int wpa_wnmsleep_igtk_subelem(struct wpa_state_machine *sm, u8 *pos)
 {
-       u8 *subelem, *ptr;
        struct wpa_group *gsm = sm->group;
-       size_t subelem_len;
-
-       /* IGTK subelement
-        * Sub-elem ID[1] | Length[1] | KeyID[2] | PN[6] |
-        * Key[16] | 8 padding */
-       subelem_len = 1 + 1 + 2 + 6 + WPA_IGTK_LEN + 8;
-       subelem = os_zalloc(subelem_len);
-       if (subelem == NULL)
-               return 0;
+       u8 *start = pos;
 
-       ptr = subelem;
-       *ptr++ = WNM_SLEEP_SUBELEM_IGTK;
-       *ptr++ = subelem_len - 2;
-       WPA_PUT_LE16(ptr, gsm->GN_igtk);
-       ptr += 2;
-       if (wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN_igtk, ptr) != 0) {
-               os_free(subelem);
+       /*
+        * IGTK subelement:
+        * Sub-elem ID[1] | Length[1] | KeyID[2] | PN[6] | Key[16]
+        */
+       *pos++ = WNM_SLEEP_SUBELEM_IGTK;
+       *pos++ = 2 + 6 + WPA_IGTK_LEN;
+       WPA_PUT_LE16(pos, gsm->GN_igtk);
+       pos += 2;
+       if (wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN_igtk, pos) != 0)
                return 0;
-       }
-       ptr += 6;
-       if (aes_wrap(sm->PTK.kek, WPA_IGTK_LEN / 8,
-                    gsm->IGTK[gsm->GN_igtk - 4], ptr)) {
-               os_free(subelem);
-               return -1;
-       }
+       pos += 6;
 
-       os_memcpy(pos, subelem, subelem_len);
+       os_memcpy(pos, gsm->IGTK[gsm->GN_igtk - 4], WPA_IGTK_LEN);
+       pos += WPA_IGTK_LEN;
 
-       wpa_hexdump_key(MSG_DEBUG, "Plaintext IGTK",
+       wpa_printf(MSG_DEBUG, "WNM: IGTK Key ID %u in WNM-Sleep Mode exit",
+                  gsm->GN_igtk);
+       wpa_hexdump_key(MSG_DEBUG, "WNM: IGTK in WNM-Sleep Mode exit",
                        gsm->IGTK[gsm->GN_igtk - 4], WPA_IGTK_LEN);
-       os_free(subelem);
 
-       return subelem_len;
+       return pos - start;
 }
 #endif /* CONFIG_IEEE80211W */
 #endif /* CONFIG_WNM */