wlantest: Add support for CCMP protection for injected frames

wlantest/ccmp.c

@@ -222,3 +222,127 @@ void ccmp_get_pn(u8 *pn, const u8 *data)
 	pn[4] = data[1]; /* PN1 */
 	pn[5] = data[0]; /* PN0 */
 }
+
+
+u8 * ccmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
+		  u8 *pn, int keyid, size_t *encrypted_len)
+{
+	u8 aad[2 + 30], nonce[13];
+	size_t aad_len;
+	u8 b[AES_BLOCK_SIZE], x[AES_BLOCK_SIZE], a[AES_BLOCK_SIZE];
+	void *aes;
+	u8 *crypt, *pos, *ppos, *mpos;
+	size_t plen, last;
+	struct ieee80211_hdr *hdr;
+	int i;
+
+	if (len < hdrlen || hdrlen < 24)
+		return NULL;
+	plen = len - hdrlen;
+	last = plen % AES_BLOCK_SIZE;
+
+	crypt = os_malloc(hdrlen + 8 + plen + 8);
+	if (crypt == NULL)
+		return NULL;
+
+	os_memcpy(crypt, frame, hdrlen);
+	hdr = (struct ieee80211_hdr *) crypt;
+	hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
+	pos = crypt + hdrlen;
+	*pos++ = pn[5]; /* PN0 */
+	*pos++ = pn[4]; /* PN1 */
+	*pos++ = 0x20 | (keyid << 6);
+	*pos++ = pn[3]; /* PN2 */
+	*pos++ = pn[2]; /* PN3 */
+	*pos++ = pn[1]; /* PN4 */
+	*pos++ = pn[0]; /* PN5 */
+
+	aes = aes_encrypt_init(tk, 16);
+	if (aes == NULL) {
+		os_free(crypt);
+		return NULL;
+	}
+
+	os_memset(aad, 0, sizeof(aad));
+	ccmp_aad_nonce(hdr, crypt + hdrlen, &aad[2], &aad_len, nonce);
+	WPA_PUT_BE16(aad, aad_len);
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", &aad[2], aad_len);
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
+
+	/* Authentication */
+	/* B_0: Flags | Nonce N | l(m) */
+	b[0] = 0x40 /* Adata */ | (3 /* M' */ << 3) | 1 /* L' */;
+	os_memcpy(&b[1], nonce, 13);
+	WPA_PUT_BE16(&b[14], plen);
+
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_0", b, AES_BLOCK_SIZE);
+	aes_encrypt(aes, b, x); /* X_1 = E(K, B_0) */
+
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_1", aad, AES_BLOCK_SIZE);
+	xor_aes_block(aad, x);
+	aes_encrypt(aes, aad, x); /* X_2 = E(K, X_1 XOR B_1) */
+
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_2", &aad[AES_BLOCK_SIZE],
+		    AES_BLOCK_SIZE);
+	xor_aes_block(&aad[AES_BLOCK_SIZE], x);
+	aes_encrypt(aes, &aad[AES_BLOCK_SIZE], x); /* X_3 = E(K, X_2 XOR B_2)
+						    */
+
+	ppos = frame + hdrlen;
+	for (i = 0; i < plen / AES_BLOCK_SIZE; i++) {
+		/* X_i+1 = E(K, X_i XOR B_i) */
+		xor_aes_block(x, ppos);
+		ppos += AES_BLOCK_SIZE;
+		aes_encrypt(aes, x, x);
+	}
+	if (last) {
+		/* XOR zero-padded last block */
+		for (i = 0; i < last; i++)
+			x[i] ^= *ppos++;
+		aes_encrypt(aes, x, x);
+	}
+
+	/* Encryption */
+
+	/* CCM: M=8 L=2, Adata=1, M' = (M-2)/2 = 3, L' = L-1 = 1 */
+
+	/* A_i = Flags | Nonce N | Counter i */
+	a[0] = 0x01; /* Flags = L' */
+	os_memcpy(&a[1], nonce, 13);
+
+	ppos = crypt + hdrlen + 8;
+
+	/* crypt = msg XOR (S_1 | S_2 | ... | S_n) */
+	mpos = frame + hdrlen;
+	for (i = 1; i <= plen / AES_BLOCK_SIZE; i++) {
+		WPA_PUT_BE16(&a[14], i);
+		/* S_i = E(K, A_i) */
+		aes_encrypt(aes, a, ppos);
+		xor_aes_block(ppos, mpos);
+		ppos += AES_BLOCK_SIZE;
+		mpos += AES_BLOCK_SIZE;
+	}
+	if (last) {
+		WPA_PUT_BE16(&a[14], i);
+		aes_encrypt(aes, a, ppos);
+		/* XOR zero-padded last block */
+		for (i = 0; i < last; i++)
+			*ppos++ ^= *mpos++;
+	}
+
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP T", x, 8);
+	/* U = T XOR S_0; S_0 = E(K, A_0) */
+	WPA_PUT_BE16(&a[14], 0);
+	aes_encrypt(aes, a, b);
+	for (i = 0; i < 8; i++)
+		ppos[i] = x[i] ^ b[i];
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP U", ppos, 8);
+
+	wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen + 8, plen);
+
+	aes_encrypt_deinit(aes);
+
+	*encrypted_len = hdrlen + 8 + plen + 8;
+
+	return crypt;
+}

wlantest/inject.c

@@ -15,6 +15,8 @@
 #include "utils/includes.h"
 
 #include "utils/common.h"
+#include "common/defs.h"
+#include "common/ieee802_11_defs.h"
 #include "wlantest.h"
 
 
@@ -58,11 +60,99 @@ static int inject_frame(int s, const void *data, size_t len)
 }
 
 
+static int is_robust_mgmt(u8 *frame, size_t len)
+{
+	struct ieee80211_mgmt *mgmt;
+	u16 fc, stype;
+	if (len < 24)
+		return 0;
+	mgmt = (struct ieee80211_mgmt *) frame;
+	fc = le_to_host16(mgmt->frame_control);
+	if (WLAN_FC_GET_TYPE(fc) != WLAN_FC_TYPE_MGMT)
+		return 0;
+	stype = WLAN_FC_GET_STYPE(fc);
+	if (stype == WLAN_FC_STYPE_DEAUTH || stype == WLAN_FC_STYPE_DISASSOC)
+		return 1;
+	if (stype == WLAN_FC_STYPE_ACTION) {
+		if (len < 25)
+			return 0;
+		if (mgmt->u.action.category != WLAN_ACTION_PUBLIC)
+			return 1;
+	}
+	return 0;
+}
+
+
+static int wlantest_inject_prot(struct wlantest *wt, struct wlantest_bss *bss,
+				struct wlantest_sta *sta, u8 *frame,
+				size_t len, int incorrect_key)
+{
+	u8 *crypt;
+	size_t crypt_len;
+	int ret;
+	u8 dummy[64];
+	u8 *pn;
+	struct ieee80211_hdr *hdr;
+	u16 fc;
+	int tid = 0;
+	u8 *qos = NULL;
+	int hdrlen;
+
+	if (sta == NULL)
+		return -1; /* TODO: add support for group Data and BIP */
+
+	if (!sta->ptk_set)
+		return -1;
+
+	hdr = (struct ieee80211_hdr *) frame;
+	hdrlen = 24;
+	fc = le_to_host16(hdr->frame_control);
+	if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT)
+		tid = 16;
+	else if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) {
+		if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
+		    (WLAN_FC_TODS | WLAN_FC_FROMDS))
+			hdrlen += ETH_ALEN;
+		if (WLAN_FC_GET_STYPE(fc) & 0x08) {
+			qos = frame + hdrlen;
+			hdrlen += 2;
+			tid = qos[0] & 0x0f;
+		}
+	}
+	if (os_memcmp(hdr->addr2, bss->bssid, ETH_ALEN) == 0)
+		pn = sta->rsc_fromds[tid];
+	else
+		pn = sta->rsc_tods[tid];
+	inc_byte_array(pn, 6);
+
+	os_memset(dummy, 0x11, sizeof(dummy));
+	if (sta->pairwise_cipher == WPA_CIPHER_TKIP)
+		crypt = tkip_encrypt(incorrect_key ? dummy : sta->ptk.tk1,
+				     frame, len, hdrlen, qos, pn, 0,
+				     &crypt_len);
+	else
+		crypt = ccmp_encrypt(incorrect_key ? dummy : sta->ptk.tk1,
+				     frame, len, hdrlen, qos, pn, 0,
+				     &crypt_len);
+
+	if (crypt == NULL)
+		return -1;
+
+	ret = inject_frame(wt->monitor_sock, crypt, crypt_len);
+	os_free(crypt);
+
+	return (ret < 0) ? -1 : 0;
+}
+
+
 int wlantest_inject(struct wlantest *wt, struct wlantest_bss *bss,
 		    struct wlantest_sta *sta, u8 *frame, size_t len,
 		    enum wlantest_inject_protection prot)
 {
 	int ret;
+	struct ieee80211_hdr *hdr;
+	u16 fc;
+	int protectable, protect = 0;
 
 	wpa_hexdump(MSG_DEBUG, "Inject frame", frame, len);
 	if (wt->monitor_sock < 0) {
@@ -71,9 +161,48 @@ int wlantest_inject(struct wlantest *wt, struct wlantest_bss *bss,
 		return -1;
 	}
 
-	/* TODO: encrypt if needed */
-	if (prot != WLANTEST_INJECT_UNPROTECTED)
+	hdr = (struct ieee80211_hdr *) frame;
+	fc = le_to_host16(hdr->frame_control);
+	protectable = WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA ||
+		is_robust_mgmt(frame, len);
+
+	if (prot == WLANTEST_INJECT_PROTECTED ||
+	    prot == WLANTEST_INJECT_INCORRECT_KEY) {
+		if (!sta) {
+			wpa_printf(MSG_INFO, "Broadcast protection not yet "
+				   "implemented");
+			return -1;
+		}
+		if (sta && !sta->ptk_set) {
+			wpa_printf(MSG_INFO, "No PTK known for the STA " MACSTR
+				   " to encrypt the injected frame",
+				   MAC2STR(sta->addr));
+			return -1;
+		}
+		protect = 1;
+	} else if (protectable && prot != WLANTEST_INJECT_UNPROTECTED) {
+		if (sta && sta->ptk_set)
+			protect = 1;
+		else if (!sta) {
+			if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA &&
+			    (bss->gtk_len[1] || bss->gtk_len[2]))
+				protect = 1;
+			if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT &&
+			    (bss->igtk_set[4] || bss->igtk_set[5]))
+				protect = 1;
+		}
+	}
+
+	if ((prot == WLANTEST_INJECT_PROTECTED ||
+	     prot == WLANTEST_INJECT_INCORRECT_KEY) && !protect) {
+		wpa_printf(MSG_INFO, "Cannot protect injected frame");
 		return -1;
+	}
+
+	if (protect)
+		return wlantest_inject_prot(
+			wt, bss, sta, frame, len,
+			prot == WLANTEST_INJECT_INCORRECT_KEY);
 
 	ret = inject_frame(wt->monitor_sock, frame, len);
 	return (ret < 0) ? -1 : 0;

wlantest/tkip.c

@@ -403,3 +403,11 @@ void tkip_get_pn(u8 *pn, const u8 *data)
 	pn[4] = data[0]; /* PN1 */
 	pn[5] = data[2]; /* PN0 */
 }
+
+
+u8 * tkip_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
+		  u8 *pn, int keyid, size_t *encrypted_len)
+{
+	/* TODO */
+	return NULL;
+}

wlantest/wlantest.h

@@ -161,10 +161,14 @@ void sta_update_assoc(struct wlantest_sta *sta,
 
 u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
 		  const u8 *data, size_t data_len, size_t *decrypted_len);
+u8 * ccmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
+		  u8 *pn, int keyid, size_t *encrypted_len);
 void ccmp_get_pn(u8 *pn, const u8 *data);
 
 u8 * tkip_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
 		  const u8 *data, size_t data_len, size_t *decrypted_len);
+u8 * tkip_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
+		  u8 *pn, int keyid, size_t *encrypted_len);
 void tkip_get_pn(u8 *pn, const u8 *data);
 
 int ctrl_init(struct wlantest *wt);