wlantest: Add PTK derivation based on passphrases

Allow pre-configuration of passphrases (-p<passphrase>) to provide
enough information for wlantest to be able to derive PMK for each
BSS and PTK for each STA going through 4-Way Handshake (at least
message 2 and 3 needs to be received).

wlantest/Makefile

@@ -40,6 +40,7 @@ OBJS_lib += ../src/utils/libutils.a
 OBJS_lib += ../src/crypto/libcrypto.a
 
 OBJS += ../src/common/ieee802_11_common.o
+OBJS += ../src/common/wpa_common.o
 
 OBJS += wlantest.o
 OBJS += readpcap.o

wlantest/bss.c

@@ -16,6 +16,7 @@
 
 #include "utils/common.h"
 #include "common/ieee802_11_common.h"
+#include "crypto/sha1.h"
 #include "wlantest.h"
 
 
@@ -35,6 +36,7 @@ struct wlantest_bss * bss_get(struct wlantest *wt, const u8 *bssid)
 	if (bss == NULL)
 		return NULL;
 	dl_list_init(&bss->sta);
+	dl_list_init(&bss->pmk);
 	os_memcpy(bss->bssid, bssid, ETH_ALEN);
 	dl_list_add(&wt->bss, &bss->list);
 	wpa_printf(MSG_DEBUG, "Discovered new BSS - " MACSTR,
@@ -43,17 +45,63 @@ struct wlantest_bss * bss_get(struct wlantest *wt, const u8 *bssid)
 }
 
 
+static void pmk_deinit(struct wlantest_pmk *pmk)
+{
+	dl_list_del(&pmk->list);
+	os_free(pmk);
+}
+
+
 void bss_deinit(struct wlantest_bss *bss)
 {
 	struct wlantest_sta *sta, *n;
+	struct wlantest_pmk *pmk, *np;
 	dl_list_for_each_safe(sta, n, &bss->sta, struct wlantest_sta, list)
 		sta_deinit(sta);
+	dl_list_for_each_safe(pmk, np, &bss->pmk, struct wlantest_pmk, list)
+		pmk_deinit(pmk);
 	dl_list_del(&bss->list);
 	os_free(bss);
 }
 
 
-void bss_update(struct wlantest_bss *bss, struct ieee802_11_elems *elems)
+static void bss_add_pmk(struct wlantest *wt, struct wlantest_bss *bss)
+{
+	struct wlantest_passphrase *p;
+	struct wlantest_pmk *pmk;
+
+	dl_list_for_each(p, &wt->passphrase, struct wlantest_passphrase, list)
+	{
+		if (!is_zero_ether_addr(p->bssid) &&
+		    os_memcmp(p->bssid, bss->bssid, ETH_ALEN) != 0)
+			continue;
+		if (p->ssid_len &&
+		    (p->ssid_len != bss->ssid_len ||
+		     os_memcmp(p->ssid, bss->ssid, p->ssid_len) != 0))
+			continue;
+
+		pmk = os_zalloc(sizeof(*pmk));
+		if (pmk == NULL)
+			break;
+		if (pbkdf2_sha1(p->passphrase, (char *) bss->ssid,
+				bss->ssid_len, 4096,
+				pmk->pmk, sizeof(pmk->pmk)) < 0) {
+			os_free(pmk);
+			continue;
+		}
+
+		wpa_printf(MSG_INFO, "Add possible PMK for BSSID " MACSTR
+			   " based on passphrase '%s'",
+			   MAC2STR(bss->bssid), p->passphrase);
+		wpa_hexdump(MSG_DEBUG, "Possible PMK",
+			    pmk->pmk, sizeof(pmk->pmk));
+		dl_list_add(&bss->pmk, &pmk->list);
+	}
+}
+
+
+void bss_update(struct wlantest *wt, struct wlantest_bss *bss,
+		struct ieee802_11_elems *elems)
 {
 	if (elems->ssid == NULL || elems->ssid_len > 32) {
 		wpa_printf(MSG_INFO, "Invalid or missing SSID in a Beacon "
@@ -62,8 +110,16 @@ void bss_update(struct wlantest_bss *bss, struct ieee802_11_elems *elems)
 		return;
 	}
 
-	os_memcpy(bss->ssid, elems->ssid, elems->ssid_len);
-	bss->ssid_len = elems->ssid_len;
+	if (bss->ssid_len != elems->ssid_len ||
+	    os_memcmp(bss->ssid, elems->ssid, bss->ssid_len) != 0) {
+		wpa_printf(MSG_DEBUG, "Store SSID '%s' for BSSID " MACSTR,
+			   wpa_ssid_txt(elems->ssid, elems->ssid_len),
+			   MAC2STR(bss->bssid));
+		os_memcpy(bss->ssid, elems->ssid, elems->ssid_len);
+		bss->ssid_len = elems->ssid_len;
+		bss_add_pmk(wt, bss);
+	}
+
 
 	if (elems->rsn_ie == NULL) {
 		if (bss->rsnie[0]) {

wlantest/rx_data.c

@@ -59,35 +59,193 @@ static const char * data_stype(u16 stype)
 }
 
 
+static int check_mic(const u8 *kck, int ver, const u8 *data, size_t len)
+{
+	u8 *buf;
+	int ret = -1;
+	struct ieee802_1x_hdr *hdr;
+	struct wpa_eapol_key *key;
+	u8 rx_mic[16];
+
+	buf = os_malloc(len);
+	if (buf == NULL)
+		return -1;
+	os_memcpy(buf, data, len);
+	hdr = (struct ieee802_1x_hdr *) buf;
+	key = (struct wpa_eapol_key *) (hdr + 1);
+
+	os_memcpy(rx_mic, key->key_mic, 16);
+	os_memset(key->key_mic, 0, 16);
+
+	if (wpa_eapol_key_mic(kck, ver, buf, len, key->key_mic) == 0 &&
+	    os_memcmp(rx_mic, key->key_mic, 16) == 0)
+		ret = 0;
+
+	os_free(buf);
+
+	return ret;
+}
+
+
 static void rx_data_eapol_key_1_of_4(struct wlantest *wt, const u8 *dst,
 				     const u8 *src, const u8 *data, size_t len)
 {
+	struct wlantest_bss *bss;
+	struct wlantest_sta *sta;
+	const struct ieee802_1x_hdr *eapol;
+	const struct wpa_eapol_key *hdr;
+
 	wpa_printf(MSG_DEBUG, "EAPOL-Key 1/4 " MACSTR " -> " MACSTR,
 		   MAC2STR(src), MAC2STR(dst));
+	bss = bss_get(wt, src);
+	if (bss == NULL)
+		return;
+	sta = sta_get(bss, dst);
+	if (sta == NULL)
+		return;
+
+	eapol = (const struct ieee802_1x_hdr *) data;
+	hdr = (const struct wpa_eapol_key *) (eapol + 1);
+	os_memcpy(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN);
+}
+
+
+static void derive_ptk(struct wlantest_bss *bss, struct wlantest_sta *sta,
+		       u16 ver, const u8 *data, size_t len)
+{
+	struct wlantest_pmk *pmk;
+
+	dl_list_for_each(pmk, &bss->pmk, struct wlantest_pmk, list) {
+		struct wpa_ptk ptk;
+		size_t ptk_len = 48; /* FIX: 64 for TKIP */
+		wpa_pmk_to_ptk(pmk->pmk, sizeof(pmk->pmk),
+			       "Pairwise key expansion",
+			       bss->bssid, sta->addr, sta->anonce, sta->snonce,
+			       (u8 *) &ptk, ptk_len,
+			       0 /* FIX: SHA256 based on AKM */);
+		if (check_mic(ptk.kck, ver,
+			      data, len) < 0)
+			continue;
+
+		wpa_printf(MSG_INFO, "Derived PTK for STA " MACSTR " BSSID "
+			   MACSTR ")",
+			   MAC2STR(sta->addr), MAC2STR(bss->bssid));
+		os_memcpy(&sta->ptk, &ptk, sizeof(ptk));
+		sta->ptk_set = 1;
+		break;
+	}
 }
 
 
 static void rx_data_eapol_key_2_of_4(struct wlantest *wt, const u8 *dst,
 				     const u8 *src, const u8 *data, size_t len)
 {
+	struct wlantest_bss *bss;
+	struct wlantest_sta *sta;
+	const struct ieee802_1x_hdr *eapol;
+	const struct wpa_eapol_key *hdr;
+	u16 key_info;
+
 	wpa_printf(MSG_DEBUG, "EAPOL-Key 2/4 " MACSTR " -> " MACSTR,
 		   MAC2STR(src), MAC2STR(dst));
+	bss = bss_get(wt, dst);
+	if (bss == NULL)
+		return;
+	sta = sta_get(bss, src);
+	if (sta == NULL)
+		return;
+
+	eapol = (const struct ieee802_1x_hdr *) data;
+	hdr = (const struct wpa_eapol_key *) (eapol + 1);
+	os_memcpy(sta->snonce, hdr->key_nonce, WPA_NONCE_LEN);
+	key_info = WPA_GET_BE16(hdr->key_info);
+	derive_ptk(bss, sta, key_info & WPA_KEY_INFO_TYPE_MASK, data, len);
 }
 
 
 static void rx_data_eapol_key_3_of_4(struct wlantest *wt, const u8 *dst,
 				     const u8 *src, const u8 *data, size_t len)
 {
+	struct wlantest_bss *bss;
+	struct wlantest_sta *sta;
+	const struct ieee802_1x_hdr *eapol;
+	const struct wpa_eapol_key *hdr;
+	int recalc = 0;
+	u16 key_info;
+
 	wpa_printf(MSG_DEBUG, "EAPOL-Key 3/4 " MACSTR " -> " MACSTR,
 		   MAC2STR(src), MAC2STR(dst));
+	bss = bss_get(wt, src);
+	if (bss == NULL)
+		return;
+	sta = sta_get(bss, dst);
+	if (sta == NULL)
+		return;
+
+	eapol = (const struct ieee802_1x_hdr *) data;
+	hdr = (const struct wpa_eapol_key *) (eapol + 1);
+	key_info = WPA_GET_BE16(hdr->key_info);
+	if (os_memcmp(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN) != 0) {
+		wpa_printf(MSG_INFO, "EAPOL-Key ANonce mismatch between 1/4 "
+			   "and 3/4");
+		recalc = 1;
+	}
+	os_memcpy(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN);
+	if (recalc) {
+		derive_ptk(bss, sta, key_info & WPA_KEY_INFO_TYPE_MASK,
+			   data, len);
+	}
+
+	if (!sta->ptk_set) {
+		wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 3/4");
+		return;
+	}
+
+	if (check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
+		      data, len) < 0) {
+		wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 3/4 MIC");
+		return;
+	}
+	wpa_printf(MSG_DEBUG, "Valid MIC found in EAPOL-Key 3/4");
+
+	/* TODO: decrypt Key Data and store GTK, IGTK */
 }
 
 
 static void rx_data_eapol_key_4_of_4(struct wlantest *wt, const u8 *dst,
 				     const u8 *src, const u8 *data, size_t len)
 {
+	struct wlantest_bss *bss;
+	struct wlantest_sta *sta;
+	const struct ieee802_1x_hdr *eapol;
+	const struct wpa_eapol_key *hdr;
+	u16 key_info;
+
 	wpa_printf(MSG_DEBUG, "EAPOL-Key 4/4 " MACSTR " -> " MACSTR,
 		   MAC2STR(src), MAC2STR(dst));
+	bss = bss_get(wt, dst);
+	if (bss == NULL)
+		return;
+	sta = sta_get(bss, src);
+	if (sta == NULL)
+		return;
+
+	eapol = (const struct ieee802_1x_hdr *) data;
+	hdr = (const struct wpa_eapol_key *) (eapol + 1);
+	key_info = WPA_GET_BE16(hdr->key_info);
+
+	if (!sta->ptk_set) {
+		wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 4/4");
+		return;
+	}
+
+	if (sta->ptk_set &&
+	    check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
+		      data, len) < 0) {
+		wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 4/4 MIC");
+		return;
+	}
+	wpa_printf(MSG_DEBUG, "Valid MIC found in EAPOL-Key 4/4");
 }
 
 
@@ -111,16 +269,20 @@ static void rx_data_eapol_key(struct wlantest *wt, const u8 *dst,
 			      const u8 *src, const u8 *data, size_t len,
 			      int prot)
 {
+	const struct ieee802_1x_hdr *eapol;
 	const struct wpa_eapol_key *hdr;
 	u16 key_info, key_length, ver, key_data_length;
 
-	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key", data, len);
+	eapol = (const struct ieee802_1x_hdr *) data;
+	hdr = (const struct wpa_eapol_key *) (eapol + 1);
+
+	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key",
+		    (const u8 *) hdr, len - sizeof(*eapol));
 	if (len < sizeof(*hdr)) {
 		wpa_printf(MSG_INFO, "Too short EAPOL-Key frame from " MACSTR,
 			   MAC2STR(src));
 		return;
 	}
-	hdr = (const struct wpa_eapol_key *) data;
 
 	if (hdr->type == EAPOL_KEY_TYPE_RC4) {
 		/* TODO: EAPOL-Key RC4 for WEP */
@@ -264,7 +426,8 @@ static void rx_data_eapol(struct wlantest *wt, const u8 *dst, const u8 *src,
 		wpa_hexdump(MSG_MSGDUMP, "EAPOL-Logoff", p, length);
 		break;
 	case IEEE802_1X_TYPE_EAPOL_KEY:
-		rx_data_eapol_key(wt, dst, src, p, length, prot);
+		rx_data_eapol_key(wt, dst, src, data, sizeof(*hdr) + length,
+				  prot);
 		break;
 	case IEEE802_1X_TYPE_EAPOL_ENCAPSULATED_ASF_ALERT:
 		wpa_hexdump(MSG_MSGDUMP, "EAPOL - Encapsulated ASF alert",

wlantest/rx_mgmt.c

@@ -76,7 +76,7 @@ static void rx_mgmt_beacon(struct wlantest *wt, const u8 *data, size_t len)
 		return;
 	}
 
-	bss_update(bss, &elems);
+	bss_update(wt, bss, &elems);
 }
 
 
@@ -103,7 +103,7 @@ static void rx_mgmt_probe_resp(struct wlantest *wt, const u8 *data, size_t len)
 		return;
 	}
 
-	bss_update(bss, &elems);
+	bss_update(wt, bss, &elems);
 }
 
 

wlantest/wlantest.c

@@ -20,6 +20,7 @@
 
 
 extern int wpa_debug_level;
+extern int wpa_debug_show_keys;
 
 
 static void wlantest_terminate(int sig, void *signal_ctx)
@@ -30,7 +31,15 @@ static void wlantest_terminate(int sig, void *signal_ctx)
 
 static void usage(void)
 {
-	printf("wlantest [-ddhqq] [-i<ifname>] [-r<pcap file>]\n");
+	printf("wlantest [-ddhqq] [-i<ifname>] [-r<pcap file>] "
+	       "[-p<passphrase>]\n");
+}
+
+
+static void passphrase_deinit(struct wlantest_passphrase *p)
+{
+	dl_list_del(&p->list);
+	os_free(p);
 }
 
 
@@ -38,6 +47,7 @@ static void wlantest_init(struct wlantest *wt)
 {
 	os_memset(wt, 0, sizeof(*wt));
 	wt->monitor_sock = -1;
+	dl_list_init(&wt->passphrase);
 	dl_list_init(&wt->bss);
 }
 
@@ -45,10 +55,29 @@ static void wlantest_init(struct wlantest *wt)
 static void wlantest_deinit(struct wlantest *wt)
 {
 	struct wlantest_bss *bss, *n;
+	struct wlantest_passphrase *p, *pn;
 	if (wt->monitor_sock >= 0)
 		monitor_deinit(wt);
 	dl_list_for_each_safe(bss, n, &wt->bss, struct wlantest_bss, list)
 		bss_deinit(bss);
+	dl_list_for_each_safe(p, pn, &wt->passphrase,
+			      struct wlantest_passphrase, list)
+		passphrase_deinit(p);
+}
+
+
+static void add_passphrase(struct wlantest *wt, const char *passphrase)
+{
+	struct wlantest_passphrase *p;
+	size_t len = os_strlen(passphrase);
+
+	if (len < 8 || len > 63)
+		return;
+	p = os_zalloc(sizeof(*p));
+	if (p == NULL)
+		return;
+	os_memcpy(p->passphrase, passphrase, len);
+	dl_list_add(&wt->passphrase, &p->list);
 }
 
 
@@ -60,6 +89,7 @@ int main(int argc, char *argv[])
 	struct wlantest wt;
 
 	wpa_debug_level = MSG_INFO;
+	wpa_debug_show_keys = 1;
 
 	if (os_program_init())
 		return -1;
@@ -67,7 +97,7 @@ int main(int argc, char *argv[])
 	wlantest_init(&wt);
 
 	for (;;) {
-		c = getopt(argc, argv, "dhi:r:q");
+		c = getopt(argc, argv, "dhi:p:qr:");
 		if (c < 0)
 			break;
 		switch (c) {
@@ -81,6 +111,9 @@ int main(int argc, char *argv[])
 		case 'i':
 			ifname = optarg;
 			break;
+		case 'p':
+			add_passphrase(&wt, optarg);
+			break;
 		case 'q':
 			wpa_debug_level++;
 			break;

wlantest/wlantest.h

@@ -16,10 +16,24 @@
 #define WLANTEST_H
 
 #include "utils/list.h"
+#include "common/wpa_common.h"
 
 struct ieee802_11_elems;
 
 
+struct wlantest_passphrase {
+	struct dl_list list;
+	char passphrase[64];
+	u8 ssid[32];
+	size_t ssid_len;
+	u8 bssid[ETH_ALEN];
+};
+
+struct wlantest_pmk {
+	struct dl_list list;
+	u8 pmk[32];
+};
+
 struct wlantest_sta {
 	struct dl_list list;
 	u8 addr[ETH_ALEN];
@@ -30,6 +44,10 @@ struct wlantest_sta {
 	} state;
 	u16 aid;
 	u8 rsnie[257]; /* WPA/RSN IE */
+	u8 anonce[32]; /* ANonce from the previous EAPOL-Key msg 1/4 or 3/4 */
+	u8 snonce[32]; /* SNonce from the previous EAPOL-Key msg 2/4 */
+	struct wpa_ptk ptk; /* Derived PTK */
+	int ptk_set;
 };
 
 struct wlantest_bss {
@@ -43,11 +61,13 @@ struct wlantest_bss {
 	u8 wpaie[257];
 	u8 rsnie[257];
 	struct dl_list sta; /* struct wlantest_sta */
+	struct dl_list pmk; /* struct wlantest_pmk */
 };
 
 struct wlantest {
 	int monitor_sock;
 
+	struct dl_list passphrase; /* struct wlantest_passphrase */
 	struct dl_list bss; /* struct wlantest_bss */
 
 	unsigned int rx_mgmt;
@@ -66,7 +86,8 @@ void rx_data(struct wlantest *wt, const u8 *data, size_t len);
 
 struct wlantest_bss * bss_get(struct wlantest *wt, const u8 *bssid);
 void bss_deinit(struct wlantest_bss *bss);
-void bss_update(struct wlantest_bss *bss, struct ieee802_11_elems *elems);
+void bss_update(struct wlantest *wt, struct wlantest_bss *bss,
+		struct ieee802_11_elems *elems);
 
 struct wlantest_sta * sta_get(struct wlantest_bss *bss, const u8 *addr);
 void sta_deinit(struct wlantest_sta *sta);