[PATCH 12/12] WPA: Extend the fils_pmk_to_ptk() function to also derive HLTK

Extend the fils_pmk_to_ptk() to also derive High Level
Transient Key (HLTK) which can later be used for secure
LTF measurements.

Signed-off-by: Ilan Peer <[email protected]>
---
 src/ap/wpa_auth.c       |  3 ++-
 src/common/wpa_common.c | 30 ++++++++++++++++++++++++++----
 src/common/wpa_common.h |  2 +-
 src/rsn_supp/wpa.c      |  3 ++-
 wlantest/rx_mgmt.c      |  2 +-
 5 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index d77c0b02f6..52eeedea13 100644
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -2313,7 +2313,8 @@ int fils_auth_pmk_to_ptk(struct wpa_state_machine *sm, const u8 *pmk,
 			      snonce, anonce, dhss, dhss_len,
 			      &sm->PTK, ick, &ick_len,
 			      sm->wpa_key_mgmt, sm->pairwise,
-			      fils_ft, &fils_ft_len);
+			      fils_ft, &fils_ft_len,
+			      sm->wpa_auth->conf.hltk ? WPA_HLTK_MAX_LEN : 0);
 	if (res < 0)
 		return res;
 	sm->PTK_valid = TRUE;
diff --git a/src/common/wpa_common.c b/src/common/wpa_common.c
index 24cfcaba50..deae2a35f9 100644
--- a/src/common/wpa_common.c
+++ b/src/common/wpa_common.c
@@ -584,12 +584,12 @@ int fils_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const u8 *spa, const u8 *aa,
 		    const u8 *snonce, const u8 *anonce, const u8 *dhss,
 		    size_t dhss_len, struct wpa_ptk *ptk,
 		    u8 *ick, size_t *ick_len, int akmp, int cipher,
-		    u8 *fils_ft, size_t *fils_ft_len)
+		    u8 *fils_ft, size_t *fils_ft_len, size_t hltk_len)
 {
 	u8 *data, *pos;
 	size_t data_len;
 	u8 tmp[FILS_ICK_MAX_LEN + WPA_KEK_MAX_LEN + WPA_TK_MAX_LEN +
-	       FILS_FT_MAX_LEN];
+	       FILS_FT_MAX_LEN + WPA_HLTK_MAX_LEN];
 	size_t key_data_len;
 	const char *label = "FILS PTK Derivation";
 	int ret = -1;
@@ -600,6 +600,8 @@ int fils_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const u8 *spa, const u8 *aa,
 	 * ICK = L(FILS-Key-Data, 0, ICK_bits)
 	 * KEK = L(FILS-Key-Data, ICK_bits, KEK_bits)
 	 * TK = L(FILS-Key-Data, ICK_bits + KEK_bits, TK_bits)
+	 * HLTK = L(FILS-Key-Data, ICK_bits + KEK_bits + TK_bits, HLTK_bits)
+	 *
 	 * If doing FT initial mobility domain association:
 	 * FILS-FT = L(FILS-Key-Data, ICK_bits + KEK_bits + TK_bits,
 	 *             FILS-FT_bits)
@@ -631,6 +633,19 @@ int fils_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const u8 *spa, const u8 *aa,
 		goto err;
 	key_data_len = *ick_len + ptk->kek_len + ptk->tk_len;
 
+	if (hltk_len) {
+		if (hltk_len > WPA_HLTK_MAX_LEN) {
+			wpa_printf(MSG_ERROR, "FILS: HLTK len=%zu too big",
+				   hltk_len);
+			goto err;
+		}
+
+		ptk->hltk_len = hltk_len;
+		key_data_len += hltk_len;
+	} else {
+		ptk->hltk_len = 0;
+	}
+
 	if (fils_ft && fils_ft_len) {
 		if (akmp == WPA_KEY_MGMT_FT_FILS_SHA256) {
 			*fils_ft_len = 32;
@@ -673,9 +688,16 @@ int fils_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const u8 *spa, const u8 *aa,
 	os_memcpy(ptk->tk, tmp + *ick_len + ptk->kek_len, ptk->tk_len);
 	wpa_hexdump_key(MSG_DEBUG, "FILS: TK", ptk->tk, ptk->tk_len);
 
+	if (ptk->hltk_len) {
+		os_memcpy(ptk->hltk, tmp + *ick_len + ptk->kek_len +
+			  ptk->tk_len, ptk->hltk_len);
+		wpa_hexdump_key(MSG_DEBUG, "FILS: HLTK", ptk->hltk,
+				ptk->hltk_len);
+	}
+
 	if (fils_ft && fils_ft_len) {
-		os_memcpy(fils_ft, tmp + *ick_len + ptk->kek_len + ptk->tk_len,
-			  *fils_ft_len);
+		os_memcpy(fils_ft, tmp + *ick_len + ptk->kek_len + ptk->tk_len +
+			  ptk->hltk_len, *fils_ft_len);
 		wpa_hexdump_key(MSG_DEBUG, "FILS: FILS-FT",
 				fils_ft, *fils_ft_len);
 	}
diff --git a/src/common/wpa_common.h b/src/common/wpa_common.h
index 3815584964..57d47f03eb 100644
--- a/src/common/wpa_common.h
+++ b/src/common/wpa_common.h
@@ -369,7 +369,7 @@ int fils_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const u8 *spa, const u8 *aa,
 		    const u8 *snonce, const u8 *anonce, const u8 *dhss,
 		    size_t dhss_len, struct wpa_ptk *ptk,
 		    u8 *ick, size_t *ick_len, int akmp, int cipher,
-		    u8 *fils_ft, size_t *fils_ft_len);
+		    u8 *fils_ft, size_t *fils_ft_len, size_t hltk_len);
 int fils_key_auth_sk(const u8 *ick, size_t ick_len, const u8 *snonce,
 		     const u8 *anonce, const u8 *sta_addr, const u8 *bssid,
 		     const u8 *g_sta, size_t g_sta_len,
diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
index 6841bcf0a7..4a64fbb455 100644
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -4144,7 +4144,8 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
 			    dh_ss ? wpabuf_len(dh_ss) : 0,
 			    &sm->ptk, ick, &ick_len,
 			    sm->key_mgmt, sm->pairwise_cipher,
-			    sm->fils_ft, &sm->fils_ft_len) < 0) {
+			    sm->fils_ft, &sm->fils_ft_len,
+			    sm->hltk ? WPA_HLTK_MAX_LEN : 0) < 0) {
 		wpa_printf(MSG_DEBUG, "FILS: Failed to derive PTK");
 		goto fail;
 	}
diff --git a/wlantest/rx_mgmt.c b/wlantest/rx_mgmt.c
index 6729371508..561f6b63c1 100644
--- a/wlantest/rx_mgmt.c
+++ b/wlantest/rx_mgmt.c
@@ -494,7 +494,7 @@ static int try_rmsk(struct wlantest *wt, struct wlantest_bss *bss,
 			    sta->snonce, sta->anonce, NULL, 0,
 			    &ptk, ick, &ick_len,
 			    sta->key_mgmt, sta->pairwise_cipher,
-			    NULL, NULL) < 0)
+			    NULL, NULL, 0) < 0)
 		return -1;
 
 	/* Check AES-SIV decryption with the derived key */
-- 
2.17.1