[thirdparty/hostap.git] / wlantest / ccmp.c

/*
 * CTR with CBC-MAC Protocol (CCMP)
 * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "common/ieee802_11_defs.h"
#include "crypto/aes.h"
#include "wlantest.h"


static void ccmp_aad_nonce(const struct ieee80211_hdr *hdr, const u8 *data,
			   u8 *aad, size_t *aad_len, u8 *nonce)
{
	u16 fc, stype, seq;
	int qos = 0, addr4 = 0;
	u8 *pos;

	nonce[0] = 0;

	fc = le_to_host16(hdr->frame_control);
	stype = WLAN_FC_GET_STYPE(fc);
	if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
	    (WLAN_FC_TODS | WLAN_FC_FROMDS))
		addr4 = 1;

	if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) {
		fc &= ~0x0070; /* Mask subtype bits */
		if (stype & 0x08) {
			const u8 *qc;
			qos = 1;
			fc &= ~WLAN_FC_ORDER;
			qc = (const u8 *) (hdr + 1);
			if (addr4)
				qc += ETH_ALEN;
			nonce[0] = qc[0] & 0x0f;
		}
	} else if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT)
		nonce[0] |= 0x10; /* Management */

	fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
	fc |= WLAN_FC_ISWEP;
	WPA_PUT_LE16(aad, fc);
	pos = aad + 2;
	os_memcpy(pos, hdr->addr1, 3 * ETH_ALEN);
	pos += 3 * ETH_ALEN;
	seq = le_to_host16(hdr->seq_ctrl);
	seq &= ~0xfff0; /* Mask Seq#; do not modify Frag# */
	WPA_PUT_LE16(pos, seq);
	pos += 2;

	os_memcpy(pos, hdr + 1, addr4 * ETH_ALEN + qos * 2);
	pos += addr4 * ETH_ALEN;
	if (qos) {
		pos[0] &= ~0x70;
		if (1 /* FIX: either device has SPP A-MSDU Capab = 0 */)
			pos[0] &= ~0x80;
		pos++;
		*pos++ = 0x00;
	}

	*aad_len = pos - aad;

	os_memcpy(nonce + 1, hdr->addr2, ETH_ALEN);
	nonce[7] = data[7]; /* PN5 */
	nonce[8] = data[6]; /* PN4 */
	nonce[9] = data[5]; /* PN3 */
	nonce[10] = data[4]; /* PN2 */
	nonce[11] = data[1]; /* PN1 */
	nonce[12] = data[0]; /* PN0 */
}


static void xor_aes_block(u8 *dst, const u8 *src)
{
	u32 *d = (u32 *) dst;
	u32 *s = (u32 *) src;
	*d++ ^= *s++;
	*d++ ^= *s++;
	*d++ ^= *s++;
	*d++ ^= *s++;
}


u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
		  const u8 *data, size_t data_len, size_t *decrypted_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;
	const u8 *m, *mpos, *mic;
	size_t mlen, last;
	int i;
	u8 *plain, *ppos;
	u8 t[8];

	if (data_len < 8 + 8)
		return NULL;

	plain = os_malloc(data_len + AES_BLOCK_SIZE);
	if (plain == NULL)
		return NULL;

	aes = aes_encrypt_init(tk, 16);
	if (aes == NULL) {
		os_free(plain);
		return NULL;
	}

	m = data + 8;
	mlen = data_len - 8 - 8;
	last = mlen % AES_BLOCK_SIZE;

	os_memset(aad, 0, sizeof(aad));
	ccmp_aad_nonce(hdr, data, &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);

	/* 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);

	/* Decryption */

	mic = data + data_len - 8;
	wpa_hexdump(MSG_EXCESSIVE, "CCMP U", mic, 8);
	/* U = T XOR S_0; S_0 = E(K, A_0) */
	WPA_PUT_BE16(&a[14], 0);
	aes_encrypt(aes, a, x);
	for (i = 0; i < 8; i++)
		t[i] = mic[i] ^ x[i];
	wpa_hexdump(MSG_EXCESSIVE, "CCMP T", t, 8);

	/* plaintext = msg XOR (S_1 | S_2 | ... | S_n) */
	ppos = plain;
	mpos = m;
	for (i = 1; i <= mlen / 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 decrypted", plain, mlen);

	/* 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], mlen);

	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 = plain;
	for (i = 0; i < mlen / 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);
	}

	aes_encrypt_deinit(aes);

	if (os_memcmp(x, t, 8) != 0) {
		u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
		wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
			   " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
			   MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
			   MAC2STR(hdr->addr3),
			   WLAN_GET_SEQ_SEQ(seq_ctrl),
			   WLAN_GET_SEQ_FRAG(seq_ctrl));
		wpa_hexdump(MSG_DEBUG, "CCMP decrypted", plain, mlen);
		os_free(plain);
		return NULL;
	}

	*decrypted_len = mlen;
	return plain;
}


void ccmp_get_pn(u8 *pn, const u8 *data)
{
	pn[0] = data[7]; /* PN5 */
	pn[1] = data[6]; /* PN4 */
	pn[2] = data[5]; /* PN3 */
	pn[3] = data[4]; /* PN2 */
	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 + AES_BLOCK_SIZE);
	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++ = 0x00; /* Rsvd */
	*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;
}
Commit	Line	Data
d318c534 JM	1	/*
	2	* CTR with CBC-MAC Protocol (CCMP)
	3	* Copyright (c) 2010, Jouni Malinen <j@w1.fi>
	4	*
0f3d578e JM	5	* This software may be distributed under the terms of the BSD license.
0f3d578e JM	6	* See README for more details.
d318c534 JM	7	*/
	8
	9	#include "utils/includes.h"
	10
	11	#include "utils/common.h"
	12	#include "common/ieee802_11_defs.h"
	13	#include "crypto/aes.h"
	14	#include "wlantest.h"
	15
	16
	17	static void ccmp_aad_nonce(const struct ieee80211_hdr hdr, const u8 data,
	18	u8 aad, size_t aad_len, u8 *nonce)
	19	{
	20	u16 fc, stype, seq;
	21	int qos = 0, addr4 = 0;
	22	u8 *pos;
	23
	24	nonce[0] = 0;
	25
	26	fc = le_to_host16(hdr->frame_control);
	27	stype = WLAN_FC_GET_STYPE(fc);
	28	if ((fc & (WLAN_FC_TODS \| WLAN_FC_FROMDS)) ==
	29	(WLAN_FC_TODS \| WLAN_FC_FROMDS))
	30	addr4 = 1;
	31
	32	if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) {
	33	fc &= ~0x0070; /* Mask subtype bits */
	34	if (stype & 0x08) {
	35	const u8 *qc;
	36	qos = 1;
	37	fc &= ~WLAN_FC_ORDER;
	38	qc = (const u8 *) (hdr + 1);
	39	if (addr4)
	40	qc += ETH_ALEN;
	41	nonce[0] = qc[0] & 0x0f;
	42	}
	43	} else if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT)
	44	nonce[0] \|= 0x10; /* Management */
	45
	46	fc &= ~(WLAN_FC_RETRY \| WLAN_FC_PWRMGT \| WLAN_FC_MOREDATA);
	47	fc \|= WLAN_FC_ISWEP;
	48	WPA_PUT_LE16(aad, fc);
	49	pos = aad + 2;
	50	os_memcpy(pos, hdr->addr1, 3 * ETH_ALEN);
	51	pos += 3 * ETH_ALEN;
	52	seq = le_to_host16(hdr->seq_ctrl);
	53	seq &= ~0xfff0; /* Mask Seq#; do not modify Frag# */
	54	WPA_PUT_LE16(pos, seq);
	55	pos += 2;
	56
	57	os_memcpy(pos, hdr + 1, addr4 * ETH_ALEN + qos * 2);
	58	pos += addr4 * ETH_ALEN;
	59	if (qos) {
ef44a08b	60	pos[0] &= ~0x70;
d318c534	61	if (1 /* FIX: either device has SPP A-MSDU Capab = 0 */)
ef44a08b	62	pos[0] &= ~0x80;
d318c534 JM	63	pos++;
	64	*pos++ = 0x00;
	65	}
	66
	67	*aad_len = pos - aad;
	68
	69	os_memcpy(nonce + 1, hdr->addr2, ETH_ALEN);
	70	nonce[7] = data[7]; /* PN5 */
	71	nonce[8] = data[6]; /* PN4 */
	72	nonce[9] = data[5]; /* PN3 */
	73	nonce[10] = data[4]; /* PN2 */
	74	nonce[11] = data[1]; /* PN1 */
	75	nonce[12] = data[0]; /* PN0 */
	76	}
	77
	78
	79	static void xor_aes_block(u8 dst, const u8 src)
	80	{
	81	u32 d = (u32 ) dst;
	82	u32 s = (u32 ) src;
	83	d++ ^= s++;
	84	d++ ^= s++;
	85	d++ ^= s++;
	86	d++ ^= s++;
	87	}
	88
	89
	90	u8 * ccmp_decrypt(const u8 tk, const struct ieee80211_hdr hdr,
	91	const u8 data, size_t data_len, size_t decrypted_len)
	92	{
	93	u8 aad[2 + 30], nonce[13];
	94	size_t aad_len;
	95	u8 b[AES_BLOCK_SIZE], x[AES_BLOCK_SIZE], a[AES_BLOCK_SIZE];
	96	void *aes;
	97	const u8 m, mpos, *mic;
	98	size_t mlen, last;
	99	int i;
	100	u8 plain, ppos;
	101	u8 t[8];
	102
	103	if (data_len < 8 + 8)
	104	return NULL;
	105
71a7e936	106	plain = os_malloc(data_len + AES_BLOCK_SIZE);
d318c534 JM	107	if (plain == NULL)
	108	return NULL;
	109
	110	aes = aes_encrypt_init(tk, 16);
	111	if (aes == NULL) {
	112	os_free(plain);
	113	return NULL;
	114	}
	115
	116	m = data + 8;
	117	mlen = data_len - 8 - 8;
	118	last = mlen % AES_BLOCK_SIZE;
	119
	120	os_memset(aad, 0, sizeof(aad));
	121	ccmp_aad_nonce(hdr, data, &aad[2], &aad_len, nonce);
	122	WPA_PUT_BE16(aad, aad_len);
	123	wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", &aad[2], aad_len);
	124	wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
	125
	126	/* CCM: M=8 L=2, Adata=1, M' = (M-2)/2 = 3, L' = L-1 = 1 */
	127
	128	/* A_i = Flags \| Nonce N \| Counter i */
	129	a[0] = 0x01; /* Flags = L' */
	130	os_memcpy(&a[1], nonce, 13);
	131
	132	/* Decryption */
	133
	134	mic = data + data_len - 8;
	135	wpa_hexdump(MSG_EXCESSIVE, "CCMP U", mic, 8);
	136	/* U = T XOR S_0; S_0 = E(K, A_0) */
	137	WPA_PUT_BE16(&a[14], 0);
	138	aes_encrypt(aes, a, x);
	139	for (i = 0; i < 8; i++)
	140	t[i] = mic[i] ^ x[i];
	141	wpa_hexdump(MSG_EXCESSIVE, "CCMP T", t, 8);
	142
	143	/* plaintext = msg XOR (S_1 \| S_2 \| ... \| S_n) */
	144	ppos = plain;
	145	mpos = m;
	146	for (i = 1; i <= mlen / AES_BLOCK_SIZE; i++) {
	147	WPA_PUT_BE16(&a[14], i);
	148	/* S_i = E(K, A_i) */
	149	aes_encrypt(aes, a, ppos);
	150	xor_aes_block(ppos, mpos);
	151	ppos += AES_BLOCK_SIZE;
	152	mpos += AES_BLOCK_SIZE;
	153	}
	154	if (last) {
	155	WPA_PUT_BE16(&a[14], i);
	156	aes_encrypt(aes, a, ppos);
	157	/* XOR zero-padded last block */
	158	for (i = 0; i < last; i++)
	159	ppos++ ^= mpos++;
	160	}
	161	wpa_hexdump(MSG_EXCESSIVE, "CCMP decrypted", plain, mlen);
	162
	163	/* Authentication */
	164	/* B_0: Flags \| Nonce N \| l(m) */
	165	b[0] = 0x40 /* Adata / \| (3 / M' / << 3) \| 1 / L' */;
	166	os_memcpy(&b[1], nonce, 13);
	167	WPA_PUT_BE16(&b[14], mlen);
	168
	169	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_0", b, AES_BLOCK_SIZE);
	170	aes_encrypt(aes, b, x); /* X_1 = E(K, B_0) */
171
172	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_1", aad, AES_BLOCK_SIZE);
173	xor_aes_block(aad, x);
174	aes_encrypt(aes, aad, x); /* X_2 = E(K, X_1 XOR B_1) */
175
176	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_2", &aad[AES_BLOCK_SIZE],
177	AES_BLOCK_SIZE);
178	xor_aes_block(&aad[AES_BLOCK_SIZE], x);
179	aes_encrypt(aes, &aad[AES_BLOCK_SIZE], x); /* X_3 = E(K, X_2 XOR B_2)
180	*/
181
182	ppos = plain;
183	for (i = 0; i < mlen / AES_BLOCK_SIZE; i++) {
184	/* X_i+1 = E(K, X_i XOR B_i) */
185	xor_aes_block(x, ppos);
186	ppos += AES_BLOCK_SIZE;
187	aes_encrypt(aes, x, x);
188	}
189	if (last) {
190	/* XOR zero-padded last block */
191	for (i = 0; i < last; i++)
192	x[i] ^= *ppos++;
193	aes_encrypt(aes, x, x);
194	}
195
196	aes_encrypt_deinit(aes);
197
198	if (os_memcmp(x, t, 8) != 0) {
3558c41e JM	199	u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
	200	wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
	201	" A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
	202	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	203	MAC2STR(hdr->addr3),
	204	WLAN_GET_SEQ_SEQ(seq_ctrl),
	205	WLAN_GET_SEQ_FRAG(seq_ctrl));
	206	wpa_hexdump(MSG_DEBUG, "CCMP decrypted", plain, mlen);
d318c534 JM	207	os_free(plain);
	208	return NULL;
	209	}
	210
	211	*decrypted_len = mlen;
	212	return plain;
	213	}
2edd5c23 JM	214
	215
	216	void ccmp_get_pn(u8 pn, const u8 data)
	217	{
	218	pn[0] = data[7]; /* PN5 */
	219	pn[1] = data[6]; /* PN4 */
	220	pn[2] = data[5]; /* PN3 */
	221	pn[3] = data[4]; /* PN2 */
	222	pn[4] = data[1]; /* PN1 */
	223	pn[5] = data[0]; /* PN0 */
	224	}
571ab37b JM	225
	226
	227	u8 * ccmp_encrypt(const u8 tk, u8 frame, size_t len, size_t hdrlen, u8 *qos,
	228	u8 pn, int keyid, size_t encrypted_len)
	229	{
	230	u8 aad[2 + 30], nonce[13];
	231	size_t aad_len;
	232	u8 b[AES_BLOCK_SIZE], x[AES_BLOCK_SIZE], a[AES_BLOCK_SIZE];
	233	void *aes;
	234	u8 crypt, pos, ppos, mpos;
	235	size_t plen, last;
	236	struct ieee80211_hdr *hdr;
	237	int i;
	238
	239	if (len < hdrlen \|\| hdrlen < 24)
	240	return NULL;
	241	plen = len - hdrlen;
	242	last = plen % AES_BLOCK_SIZE;
	243
71a7e936	244	crypt = os_malloc(hdrlen + 8 + plen + 8 + AES_BLOCK_SIZE);
571ab37b JM	245	if (crypt == NULL)
	246	return NULL;
	247
	248	os_memcpy(crypt, frame, hdrlen);
	249	hdr = (struct ieee80211_hdr *) crypt;
	250	hdr->frame_control \|= host_to_le16(WLAN_FC_ISWEP);
	251	pos = crypt + hdrlen;
	252	pos++ = pn[5]; / PN0 */
	253	pos++ = pn[4]; / PN1 */
81d59891	254	pos++ = 0x00; / Rsvd */
571ab37b JM	255	*pos++ = 0x20 \| (keyid << 6);
	256	pos++ = pn[3]; / PN2 */
	257	pos++ = pn[2]; / PN3 */
	258	pos++ = pn[1]; / PN4 */
	259	pos++ = pn[0]; / PN5 */
	260
	261	aes = aes_encrypt_init(tk, 16);
	262	if (aes == NULL) {
	263	os_free(crypt);
	264	return NULL;
	265	}
	266
	267	os_memset(aad, 0, sizeof(aad));
	268	ccmp_aad_nonce(hdr, crypt + hdrlen, &aad[2], &aad_len, nonce);
	269	WPA_PUT_BE16(aad, aad_len);
	270	wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", &aad[2], aad_len);
	271	wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
	272
	273	/* Authentication */
	274	/* B_0: Flags \| Nonce N \| l(m) */
	275	b[0] = 0x40 /* Adata / \| (3 / M' / << 3) \| 1 / L' */;
	276	os_memcpy(&b[1], nonce, 13);
	277	WPA_PUT_BE16(&b[14], plen);
	278
	279	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_0", b, AES_BLOCK_SIZE);
	280	aes_encrypt(aes, b, x); /* X_1 = E(K, B_0) */
	281
	282	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_1", aad, AES_BLOCK_SIZE);
	283	xor_aes_block(aad, x);
	284	aes_encrypt(aes, aad, x); /* X_2 = E(K, X_1 XOR B_1) */
	285
	286	wpa_hexdump(MSG_EXCESSIVE, "CCMP B_2", &aad[AES_BLOCK_SIZE],
	287	AES_BLOCK_SIZE);
	288	xor_aes_block(&aad[AES_BLOCK_SIZE], x);
	289	aes_encrypt(aes, &aad[AES_BLOCK_SIZE], x); /* X_3 = E(K, X_2 XOR B_2)
	290	*/
	291
	292	ppos = frame + hdrlen;
	293	for (i = 0; i < plen / AES_BLOCK_SIZE; i++) {
	294	/* X_i+1 = E(K, X_i XOR B_i) */
	295	xor_aes_block(x, ppos);
	296	ppos += AES_BLOCK_SIZE;
	297	aes_encrypt(aes, x, x);
	298	}
	299	if (last) {
	300	/* XOR zero-padded last block */
	301	for (i = 0; i < last; i++)
	302	x[i] ^= *ppos++;
	303	aes_encrypt(aes, x, x);
	304	}
	305
	306	/* Encryption */
	307
	308	/* CCM: M=8 L=2, Adata=1, M' = (M-2)/2 = 3, L' = L-1 = 1 */
	309
	310	/* A_i = Flags \| Nonce N \| Counter i */
	311	a[0] = 0x01; /* Flags = L' */
	312	os_memcpy(&a[1], nonce, 13);
	313
	314	ppos = crypt + hdrlen + 8;
	315
	316	/* crypt = msg XOR (S_1 \| S_2 \| ... \| S_n) */
	317	mpos = frame + hdrlen;
	318	for (i = 1; i <= plen / AES_BLOCK_SIZE; i++) {
319	WPA_PUT_BE16(&a[14], i);
320	/* S_i = E(K, A_i) */
321	aes_encrypt(aes, a, ppos);
322	xor_aes_block(ppos, mpos);
323	ppos += AES_BLOCK_SIZE;
324	mpos += AES_BLOCK_SIZE;
325	}
326	if (last) {
327	WPA_PUT_BE16(&a[14], i);
328	aes_encrypt(aes, a, ppos);
329	/* XOR zero-padded last block */
330	for (i = 0; i < last; i++)
331	ppos++ ^= mpos++;
332	}
333
334	wpa_hexdump(MSG_EXCESSIVE, "CCMP T", x, 8);
335	/* U = T XOR S_0; S_0 = E(K, A_0) */
336	WPA_PUT_BE16(&a[14], 0);
337	aes_encrypt(aes, a, b);
338	for (i = 0; i < 8; i++)
339	ppos[i] = x[i] ^ b[i];
340	wpa_hexdump(MSG_EXCESSIVE, "CCMP U", ppos, 8);
341
342	wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen + 8, plen);
343
344	aes_encrypt_deinit(aes);
345
346	*encrypted_len = hdrlen + 8 + plen + 8;
347
348	return crypt;
349	}