[linux-2.6-block.git] / net / wireless / lib80211_crypt_ccmp.c

/*
 * lib80211 crypt: host-based CCMP encryption implementation for lib80211
 *
 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <asm/string.h>
#include <linux/wireless.h>

#include <linux/ieee80211.h>

#include <linux/crypto.h>

#include <net/lib80211.h>

MODULE_AUTHOR("Jouni Malinen");
MODULE_DESCRIPTION("Host AP crypt: CCMP");
MODULE_LICENSE("GPL");

#define AES_BLOCK_LEN 16
#define CCMP_HDR_LEN 8
#define CCMP_MIC_LEN 8
#define CCMP_TK_LEN 16
#define CCMP_PN_LEN 6

struct lib80211_ccmp_data {
	u8 key[CCMP_TK_LEN];
	int key_set;

	u8 tx_pn[CCMP_PN_LEN];
	u8 rx_pn[CCMP_PN_LEN];

	u32 dot11RSNAStatsCCMPFormatErrors;
	u32 dot11RSNAStatsCCMPReplays;
	u32 dot11RSNAStatsCCMPDecryptErrors;

	int key_idx;

	struct crypto_cipher *tfm;

	/* scratch buffers for virt_to_page() (crypto API) */
	u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
	    tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
	u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
};

static inline void lib80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
					      const u8 pt[16], u8 ct[16])
{
	crypto_cipher_encrypt_one(tfm, ct, pt);
}

static void *lib80211_ccmp_init(int key_idx)
{
	struct lib80211_ccmp_data *priv;

	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
	if (priv == NULL)
		goto fail;
	priv->key_idx = key_idx;

	priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(priv->tfm)) {
		priv->tfm = NULL;
		goto fail;
	}

	return priv;

      fail:
	if (priv) {
		if (priv->tfm)
			crypto_free_cipher(priv->tfm);
		kfree(priv);
	}

	return NULL;
}

static void lib80211_ccmp_deinit(void *priv)
{
	struct lib80211_ccmp_data *_priv = priv;
	if (_priv && _priv->tfm)
		crypto_free_cipher(_priv->tfm);
	kfree(priv);
}

static inline void xor_block(u8 * b, u8 * a, size_t len)
{
	int i;
	for (i = 0; i < len; i++)
		b[i] ^= a[i];
}

static void ccmp_init_blocks(struct crypto_cipher *tfm,
			     struct ieee80211_hdr *hdr,
			     u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
{
	u8 *pos, qc = 0;
	size_t aad_len;
	int a4_included, qc_included;
	u8 aad[2 * AES_BLOCK_LEN];

	a4_included = ieee80211_has_a4(hdr->frame_control);
	qc_included = ieee80211_is_data_qos(hdr->frame_control);

	aad_len = 22;
	if (a4_included)
		aad_len += 6;
	if (qc_included) {
		pos = (u8 *) & hdr->addr4;
		if (a4_included)
			pos += 6;
		qc = *pos & 0x0f;
		aad_len += 2;
	}

	/* CCM Initial Block:
	 * Flag (Include authentication header, M=3 (8-octet MIC),
	 *       L=1 (2-octet Dlen))
	 * Nonce: 0x00 | A2 | PN
	 * Dlen */
	b0[0] = 0x59;
	b0[1] = qc;
	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	b0[14] = (dlen >> 8) & 0xff;
	b0[15] = dlen & 0xff;

	/* AAD:
	 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	 * A1 | A2 | A3
	 * SC with bits 4..15 (seq#) masked to zero
	 * A4 (if present)
	 * QC (if present)
	 */
	pos = (u8 *) hdr;
	aad[0] = 0;		/* aad_len >> 8 */
	aad[1] = aad_len & 0xff;
	aad[2] = pos[0] & 0x8f;
	aad[3] = pos[1] & 0xc7;
	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
	pos = (u8 *) & hdr->seq_ctrl;
	aad[22] = pos[0] & 0x0f;
	aad[23] = 0;		/* all bits masked */
	memset(aad + 24, 0, 8);
	if (a4_included)
		memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	if (qc_included) {
		aad[a4_included ? 30 : 24] = qc;
		/* rest of QC masked */
	}

	/* Start with the first block and AAD */
	lib80211_ccmp_aes_encrypt(tfm, b0, auth);
	xor_block(auth, aad, AES_BLOCK_LEN);
	lib80211_ccmp_aes_encrypt(tfm, auth, auth);
	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	lib80211_ccmp_aes_encrypt(tfm, auth, auth);
	b0[0] &= 0x07;
	b0[14] = b0[15] = 0;
	lib80211_ccmp_aes_encrypt(tfm, b0, s0);
}

static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
			      u8 *aeskey, int keylen, void *priv)
{
	struct lib80211_ccmp_data *key = priv;
	int i;
	u8 *pos;

	if (skb_headroom(skb) < CCMP_HDR_LEN || skb->len < hdr_len)
		return -1;

	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
		memcpy(aeskey, key->key, CCMP_TK_LEN);

	pos = skb_push(skb, CCMP_HDR_LEN);
	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	pos += hdr_len;

	i = CCMP_PN_LEN - 1;
	while (i >= 0) {
		key->tx_pn[i]++;
		if (key->tx_pn[i] != 0)
			break;
		i--;
	}

	*pos++ = key->tx_pn[5];
	*pos++ = key->tx_pn[4];
	*pos++ = 0;
	*pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
	*pos++ = key->tx_pn[3];
	*pos++ = key->tx_pn[2];
	*pos++ = key->tx_pn[1];
	*pos++ = key->tx_pn[0];

	return CCMP_HDR_LEN;
}

static int lib80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct lib80211_ccmp_data *key = priv;
	int data_len, i, blocks, last, len;
	u8 *pos, *mic;
	struct ieee80211_hdr *hdr;
	u8 *b0 = key->tx_b0;
	u8 *b = key->tx_b;
	u8 *e = key->tx_e;
	u8 *s0 = key->tx_s0;

	if (skb_tailroom(skb) < CCMP_MIC_LEN || skb->len < hdr_len)
		return -1;

	data_len = skb->len - hdr_len;
	len = lib80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
	if (len < 0)
		return -1;

	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	hdr = (struct ieee80211_hdr *)skb->data;
	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);

	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
	last = data_len % AES_BLOCK_LEN;

	for (i = 1; i <= blocks; i++) {
		len = (i == blocks && last) ? last : AES_BLOCK_LEN;
		/* Authentication */
		xor_block(b, pos, len);
		lib80211_ccmp_aes_encrypt(key->tfm, b, b);
		/* Encryption, with counter */
		b0[14] = (i >> 8) & 0xff;
		b0[15] = i & 0xff;
		lib80211_ccmp_aes_encrypt(key->tfm, b0, e);
		xor_block(pos, e, len);
		pos += len;
	}

	mic = skb_put(skb, CCMP_MIC_LEN);
	for (i = 0; i < CCMP_MIC_LEN; i++)
		mic[i] = b[i] ^ s0[i];

	return 0;
}

/*
 * deal with seq counter wrapping correctly.
 * refer to timer_after() for jiffies wrapping handling
 */
static inline int ccmp_replay_check(u8 *pn_n, u8 *pn_o)
{
	u32 iv32_n, iv16_n;
	u32 iv32_o, iv16_o;

	iv32_n = (pn_n[0] << 24) | (pn_n[1] << 16) | (pn_n[2] << 8) | pn_n[3];
	iv16_n = (pn_n[4] << 8) | pn_n[5];

	iv32_o = (pn_o[0] << 24) | (pn_o[1] << 16) | (pn_o[2] << 8) | pn_o[3];
	iv16_o = (pn_o[4] << 8) | pn_o[5];

	if ((s32)iv32_n - (s32)iv32_o < 0 ||
	    (iv32_n == iv32_o && iv16_n <= iv16_o))
		return 1;
	return 0;
}

static int lib80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct lib80211_ccmp_data *key = priv;
	u8 keyidx, *pos;
	struct ieee80211_hdr *hdr;
	u8 *b0 = key->rx_b0;
	u8 *b = key->rx_b;
	u8 *a = key->rx_a;
	u8 pn[6];
	int i, blocks, last, len;
	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;

	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
		key->dot11RSNAStatsCCMPFormatErrors++;
		return -1;
	}

	hdr = (struct ieee80211_hdr *)skb->data;
	pos = skb->data + hdr_len;
	keyidx = pos[3];
	if (!(keyidx & (1 << 5))) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "CCMP: received packet without ExtIV"
			       " flag from %pM\n", hdr->addr2);
		}
		key->dot11RSNAStatsCCMPFormatErrors++;
		return -2;
	}
	keyidx >>= 6;
	if (key->key_idx != keyidx) {
		printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
		       "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
		return -6;
	}
	if (!key->key_set) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "CCMP: received packet from %pM"
			       " with keyid=%d that does not have a configured"
			       " key\n", hdr->addr2, keyidx);
		}
		return -3;
	}

	pn[0] = pos[7];
	pn[1] = pos[6];
	pn[2] = pos[5];
	pn[3] = pos[4];
	pn[4] = pos[1];
	pn[5] = pos[0];
	pos += 8;

	if (ccmp_replay_check(pn, key->rx_pn)) {
#ifdef CONFIG_LIB80211_DEBUG
		if (net_ratelimit()) {
			printk(KERN_DEBUG "CCMP: replay detected: STA=%pM "
				 "previous PN %02x%02x%02x%02x%02x%02x "
				 "received PN %02x%02x%02x%02x%02x%02x\n",
				 hdr->addr2,
				 key->rx_pn[0], key->rx_pn[1], key->rx_pn[2],
				 key->rx_pn[3], key->rx_pn[4], key->rx_pn[5],
				 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
		}
#endif
		key->dot11RSNAStatsCCMPReplays++;
		return -4;
	}

	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	xor_block(mic, b, CCMP_MIC_LEN);

	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
	last = data_len % AES_BLOCK_LEN;

	for (i = 1; i <= blocks; i++) {
		len = (i == blocks && last) ? last : AES_BLOCK_LEN;
		/* Decrypt, with counter */
		b0[14] = (i >> 8) & 0xff;
		b0[15] = i & 0xff;
		lib80211_ccmp_aes_encrypt(key->tfm, b0, b);
		xor_block(pos, b, len);
		/* Authentication */
		xor_block(a, pos, len);
		lib80211_ccmp_aes_encrypt(key->tfm, a, a);
		pos += len;
	}

	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "CCMP: decrypt failed: STA="
			       "%pM\n", hdr->addr2);
		}
		key->dot11RSNAStatsCCMPDecryptErrors++;
		return -5;
	}

	memcpy(key->rx_pn, pn, CCMP_PN_LEN);

	/* Remove hdr and MIC */
	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
	skb_pull(skb, CCMP_HDR_LEN);
	skb_trim(skb, skb->len - CCMP_MIC_LEN);

	return keyidx;
}

static int lib80211_ccmp_set_key(void *key, int len, u8 * seq, void *priv)
{
	struct lib80211_ccmp_data *data = priv;
	int keyidx;
	struct crypto_cipher *tfm = data->tfm;

	keyidx = data->key_idx;
	memset(data, 0, sizeof(*data));
	data->key_idx = keyidx;
	data->tfm = tfm;
	if (len == CCMP_TK_LEN) {
		memcpy(data->key, key, CCMP_TK_LEN);
		data->key_set = 1;
		if (seq) {
			data->rx_pn[0] = seq[5];
			data->rx_pn[1] = seq[4];
			data->rx_pn[2] = seq[3];
			data->rx_pn[3] = seq[2];
			data->rx_pn[4] = seq[1];
			data->rx_pn[5] = seq[0];
		}
		crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	} else if (len == 0)
		data->key_set = 0;
	else
		return -1;

	return 0;
}

static int lib80211_ccmp_get_key(void *key, int len, u8 * seq, void *priv)
{
	struct lib80211_ccmp_data *data = priv;

	if (len < CCMP_TK_LEN)
		return -1;

	if (!data->key_set)
		return 0;
	memcpy(key, data->key, CCMP_TK_LEN);

	if (seq) {
		seq[0] = data->tx_pn[5];
		seq[1] = data->tx_pn[4];
		seq[2] = data->tx_pn[3];
		seq[3] = data->tx_pn[2];
		seq[4] = data->tx_pn[1];
		seq[5] = data->tx_pn[0];
	}

	return CCMP_TK_LEN;
}

static char *lib80211_ccmp_print_stats(char *p, void *priv)
{
	struct lib80211_ccmp_data *ccmp = priv;

	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
		     "tx_pn=%02x%02x%02x%02x%02x%02x "
		     "rx_pn=%02x%02x%02x%02x%02x%02x "
		     "format_errors=%d replays=%d decrypt_errors=%d\n",
		     ccmp->key_idx, ccmp->key_set,
		     ccmp->tx_pn[0], ccmp->tx_pn[1], ccmp->tx_pn[2],
		     ccmp->tx_pn[3], ccmp->tx_pn[4], ccmp->tx_pn[5],
		     ccmp->rx_pn[0], ccmp->rx_pn[1], ccmp->rx_pn[2],
		     ccmp->rx_pn[3], ccmp->rx_pn[4], ccmp->rx_pn[5],
		     ccmp->dot11RSNAStatsCCMPFormatErrors,
		     ccmp->dot11RSNAStatsCCMPReplays,
		     ccmp->dot11RSNAStatsCCMPDecryptErrors);

	return p;
}

static struct lib80211_crypto_ops lib80211_crypt_ccmp = {
	.name = "CCMP",
	.init = lib80211_ccmp_init,
	.deinit = lib80211_ccmp_deinit,
	.encrypt_mpdu = lib80211_ccmp_encrypt,
	.decrypt_mpdu = lib80211_ccmp_decrypt,
	.encrypt_msdu = NULL,
	.decrypt_msdu = NULL,
	.set_key = lib80211_ccmp_set_key,
	.get_key = lib80211_ccmp_get_key,
	.print_stats = lib80211_ccmp_print_stats,
	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
	.owner = THIS_MODULE,
};

static int __init lib80211_crypto_ccmp_init(void)
{
	return lib80211_register_crypto_ops(&lib80211_crypt_ccmp);
}

static void __exit lib80211_crypto_ccmp_exit(void)
{
	lib80211_unregister_crypto_ops(&lib80211_crypt_ccmp);
}

module_init(lib80211_crypto_ccmp_init);
module_exit(lib80211_crypto_ccmp_exit);
Commit	Line	Data
b453872c	1	/*
274bfb8d	2	* lib80211 crypt: host-based CCMP encryption implementation for lib80211
b453872c	3	*
85d32e7b	4	* Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
274bfb8d	5	* Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
b453872c JG	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation. See README and COPYING for
	10	* more details.
	11	*/
	12
172589cc	13	#include <linux/kernel.h>
f12cc209	14	#include <linux/err.h>
b453872c JG	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/slab.h>
	18	#include <linux/random.h>
	19	#include <linux/skbuff.h>
	20	#include <linux/netdevice.h>
	21	#include <linux/if_ether.h>
	22	#include <linux/if_arp.h>
	23	#include <asm/string.h>
	24	#include <linux/wireless.h>
	25
274bfb8d	26	#include <linux/ieee80211.h>
b453872c	27
b453872c	28	#include <linux/crypto.h>
b453872c	29
274bfb8d JL	30	#include <net/lib80211.h>
274bfb8d JL	31
b453872c JG	32	MODULE_AUTHOR("Jouni Malinen");
	33	MODULE_DESCRIPTION("Host AP crypt: CCMP");
	34	MODULE_LICENSE("GPL");
	35
	36	#define AES_BLOCK_LEN 16
	37	#define CCMP_HDR_LEN 8
	38	#define CCMP_MIC_LEN 8
	39	#define CCMP_TK_LEN 16
	40	#define CCMP_PN_LEN 6
	41
274bfb8d	42	struct lib80211_ccmp_data {
b453872c JG	43	u8 key[CCMP_TK_LEN];
	44	int key_set;
	45
	46	u8 tx_pn[CCMP_PN_LEN];
	47	u8 rx_pn[CCMP_PN_LEN];
	48
	49	u32 dot11RSNAStatsCCMPFormatErrors;
	50	u32 dot11RSNAStatsCCMPReplays;
	51	u32 dot11RSNAStatsCCMPDecryptErrors;
	52
	53	int key_idx;
	54
f12cc209	55	struct crypto_cipher *tfm;
b453872c JG	56
	57	/* scratch buffers for virt_to_page() (crypto API) */
	58	u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
0edd5b44	59	tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
b453872c JG	60	u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
	61	};
	62
274bfb8d	63	static inline void lib80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
f12cc209	64	const u8 pt[16], u8 ct[16])
b453872c	65	{
f12cc209	66	crypto_cipher_encrypt_one(tfm, ct, pt);
b453872c JG	67	}
b453872c JG	68
274bfb8d	69	static void *lib80211_ccmp_init(int key_idx)
b453872c	70	{
274bfb8d	71	struct lib80211_ccmp_data *priv;
b453872c	72
0da974f4	73	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
b453872c JG	74	if (priv == NULL)
b453872c JG	75	goto fail;
b453872c JG	76	priv->key_idx = key_idx;
b453872c JG	77
f12cc209 HX	78	priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
f12cc209 HX	79	if (IS_ERR(priv->tfm)) {
f12cc209	80	priv->tfm = NULL;
b453872c JG	81	goto fail;
	82	}
	83
	84	return priv;
	85
0edd5b44	86	fail:
b453872c JG	87	if (priv) {
b453872c JG	88	if (priv->tfm)
f12cc209	89	crypto_free_cipher(priv->tfm);
b453872c JG	90	kfree(priv);
	91	}
	92
	93	return NULL;
	94	}
	95
274bfb8d	96	static void lib80211_ccmp_deinit(void *priv)
b453872c	97	{
274bfb8d	98	struct lib80211_ccmp_data *_priv = priv;
b453872c	99	if (_priv && _priv->tfm)
f12cc209	100	crypto_free_cipher(_priv->tfm);
b453872c JG	101	kfree(priv);
	102	}
	103
0edd5b44	104	static inline void xor_block(u8 * b, u8 * a, size_t len)
b453872c JG	105	{
	106	int i;
	107	for (i = 0; i < len; i++)
	108	b[i] ^= a[i];
	109	}
	110
f12cc209	111	static void ccmp_init_blocks(struct crypto_cipher *tfm,
274bfb8d	112	struct ieee80211_hdr *hdr,
0edd5b44	113	u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
b453872c JG	114	{
	115	u8 *pos, qc = 0;
	116	size_t aad_len;
b453872c JG	117	int a4_included, qc_included;
	118	u8 aad[2 * AES_BLOCK_LEN];
	119
274bfb8d JL	120	a4_included = ieee80211_has_a4(hdr->frame_control);
	121	qc_included = ieee80211_is_data_qos(hdr->frame_control);
	122
b453872c JG	123	aad_len = 22;
	124	if (a4_included)
	125	aad_len += 6;
	126	if (qc_included) {
0edd5b44	127	pos = (u8 *) & hdr->addr4;
b453872c JG	128	if (a4_included)
	129	pos += 6;
	130	qc = *pos & 0x0f;
	131	aad_len += 2;
	132	}
	133
	134	/* CCM Initial Block:
	135	* Flag (Include authentication header, M=3 (8-octet MIC),
	136	* L=1 (2-octet Dlen))
	137	* Nonce: 0x00 \| A2 \| PN
	138	* Dlen */
	139	b0[0] = 0x59;
	140	b0[1] = qc;
	141	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	142	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	143	b0[14] = (dlen >> 8) & 0xff;
	144	b0[15] = dlen & 0xff;
	145
	146	/* AAD:
	147	* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	148	* A1 \| A2 \| A3
	149	* SC with bits 4..15 (seq#) masked to zero
	150	* A4 (if present)
	151	* QC (if present)
	152	*/
	153	pos = (u8 *) hdr;
0edd5b44	154	aad[0] = 0; /* aad_len >> 8 */
b453872c JG	155	aad[1] = aad_len & 0xff;
	156	aad[2] = pos[0] & 0x8f;
	157	aad[3] = pos[1] & 0xc7;
	158	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
274bfb8d	159	pos = (u8 *) & hdr->seq_ctrl;
b453872c	160	aad[22] = pos[0] & 0x0f;
0edd5b44	161	aad[23] = 0; /* all bits masked */
b453872c JG	162	memset(aad + 24, 0, 8);
	163	if (a4_included)
	164	memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	165	if (qc_included) {
	166	aad[a4_included ? 30 : 24] = qc;
	167	/* rest of QC masked */
	168	}
	169
	170	/* Start with the first block and AAD */
274bfb8d	171	lib80211_ccmp_aes_encrypt(tfm, b0, auth);
b453872c	172	xor_block(auth, aad, AES_BLOCK_LEN);
274bfb8d	173	lib80211_ccmp_aes_encrypt(tfm, auth, auth);
b453872c	174	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
274bfb8d	175	lib80211_ccmp_aes_encrypt(tfm, auth, auth);
b453872c JG	176	b0[0] &= 0x07;
b453872c JG	177	b0[14] = b0[15] = 0;
274bfb8d	178	lib80211_ccmp_aes_encrypt(tfm, b0, s0);
b453872c JG	179	}
b453872c JG	180
274bfb8d	181	static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
9184d934	182	u8 aeskey, int keylen, void priv)
b453872c	183	{
274bfb8d	184	struct lib80211_ccmp_data *key = priv;
31b59eae JK	185	int i;
31b59eae JK	186	u8 *pos;
b453872c	187
31b59eae	188	if (skb_headroom(skb) < CCMP_HDR_LEN \|\| skb->len < hdr_len)
b453872c JG	189	return -1;
b453872c JG	190
9184d934 ZY	191	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
	192	memcpy(aeskey, key->key, CCMP_TK_LEN);
	193
b453872c JG	194	pos = skb_push(skb, CCMP_HDR_LEN);
	195	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	196	pos += hdr_len;
b453872c JG	197
	198	i = CCMP_PN_LEN - 1;
	199	while (i >= 0) {
	200	key->tx_pn[i]++;
	201	if (key->tx_pn[i] != 0)
	202	break;
	203	i--;
	204	}
	205
	206	*pos++ = key->tx_pn[5];
	207	*pos++ = key->tx_pn[4];
	208	*pos++ = 0;
0edd5b44	209	pos++ = (key->key_idx << 6) \| (1 << 5) / Ext IV included */ ;
b453872c JG	210	*pos++ = key->tx_pn[3];
	211	*pos++ = key->tx_pn[2];
	212	*pos++ = key->tx_pn[1];
	213	*pos++ = key->tx_pn[0];
	214
31b59eae JK	215	return CCMP_HDR_LEN;
	216	}
	217
274bfb8d	218	static int lib80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
31b59eae	219	{
274bfb8d	220	struct lib80211_ccmp_data *key = priv;
31b59eae JK	221	int data_len, i, blocks, last, len;
31b59eae JK	222	u8 pos, mic;
274bfb8d	223	struct ieee80211_hdr *hdr;
31b59eae JK	224	u8 *b0 = key->tx_b0;
	225	u8 *b = key->tx_b;
	226	u8 *e = key->tx_e;
	227	u8 *s0 = key->tx_s0;
	228
	229	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	230	return -1;
	231
	232	data_len = skb->len - hdr_len;
274bfb8d	233	len = lib80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
31b59eae JK	234	if (len < 0)
	235	return -1;
	236
	237	pos = skb->data + hdr_len + CCMP_HDR_LEN;
274bfb8d	238	hdr = (struct ieee80211_hdr *)skb->data;
b453872c JG	239	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
b453872c JG	240
172589cc	241	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
b453872c JG	242	last = data_len % AES_BLOCK_LEN;
	243
	244	for (i = 1; i <= blocks; i++) {
	245	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	246	/* Authentication */
	247	xor_block(b, pos, len);
274bfb8d	248	lib80211_ccmp_aes_encrypt(key->tfm, b, b);
b453872c JG	249	/* Encryption, with counter */
	250	b0[14] = (i >> 8) & 0xff;
	251	b0[15] = i & 0xff;
274bfb8d	252	lib80211_ccmp_aes_encrypt(key->tfm, b0, e);
b453872c JG	253	xor_block(pos, e, len);
	254	pos += len;
	255	}
	256
d0833a6a	257	mic = skb_put(skb, CCMP_MIC_LEN);
b453872c JG	258	for (i = 0; i < CCMP_MIC_LEN; i++)
	259	mic[i] = b[i] ^ s0[i];
	260
	261	return 0;
	262	}
	263
b4328d87 ZY	264	/*
	265	* deal with seq counter wrapping correctly.
	266	* refer to timer_after() for jiffies wrapping handling
	267	*/
	268	static inline int ccmp_replay_check(u8 pn_n, u8 pn_o)
	269	{
	270	u32 iv32_n, iv16_n;
	271	u32 iv32_o, iv16_o;
	272
	273	iv32_n = (pn_n[0] << 24) \| (pn_n[1] << 16) \| (pn_n[2] << 8) \| pn_n[3];
	274	iv16_n = (pn_n[4] << 8) \| pn_n[5];
	275
	276	iv32_o = (pn_o[0] << 24) \| (pn_o[1] << 16) \| (pn_o[2] << 8) \| pn_o[3];
	277	iv16_o = (pn_o[4] << 8) \| pn_o[5];
	278
	279	if ((s32)iv32_n - (s32)iv32_o < 0 \|\|
	280	(iv32_n == iv32_o && iv16_n <= iv16_o))
	281	return 1;
	282	return 0;
	283	}
	284
274bfb8d	285	static int lib80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
b453872c	286	{
274bfb8d	287	struct lib80211_ccmp_data *key = priv;
b453872c	288	u8 keyidx, *pos;
274bfb8d	289	struct ieee80211_hdr *hdr;
b453872c JG	290	u8 *b0 = key->rx_b0;
	291	u8 *b = key->rx_b;
	292	u8 *a = key->rx_a;
	293	u8 pn[6];
	294	int i, blocks, last, len;
	295	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	296	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
	297
	298	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	299	key->dot11RSNAStatsCCMPFormatErrors++;
	300	return -1;
	301	}
	302
274bfb8d	303	hdr = (struct ieee80211_hdr *)skb->data;
b453872c JG	304	pos = skb->data + hdr_len;
	305	keyidx = pos[3];
	306	if (!(keyidx & (1 << 5))) {
	307	if (net_ratelimit()) {
	308	printk(KERN_DEBUG "CCMP: received packet without ExtIV"
e174961c	309	" flag from %pM\n", hdr->addr2);
b453872c JG	310	}
	311	key->dot11RSNAStatsCCMPFormatErrors++;
	312	return -2;
	313	}
	314	keyidx >>= 6;
	315	if (key->key_idx != keyidx) {
	316	printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
	317	"keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
	318	return -6;
	319	}
	320	if (!key->key_set) {
	321	if (net_ratelimit()) {
e174961c	322	printk(KERN_DEBUG "CCMP: received packet from %pM"
b453872c	323	" with keyid=%d that does not have a configured"
e174961c	324	" key\n", hdr->addr2, keyidx);
b453872c JG	325	}
	326	return -3;
	327	}
	328
	329	pn[0] = pos[7];
	330	pn[1] = pos[6];
	331	pn[2] = pos[5];
	332	pn[3] = pos[4];
	333	pn[4] = pos[1];
	334	pn[5] = pos[0];
	335	pos += 8;
	336
b4328d87	337	if (ccmp_replay_check(pn, key->rx_pn)) {
6f16bf3b	338	#ifdef CONFIG_LIB80211_DEBUG
274bfb8d JL	339	if (net_ratelimit()) {
274bfb8d JL	340	printk(KERN_DEBUG "CCMP: replay detected: STA=%pM "
0795af57 JP	341	"previous PN %02x%02x%02x%02x%02x%02x "
0795af57 JP	342	"received PN %02x%02x%02x%02x%02x%02x\n",
e174961c	343	hdr->addr2,
0795af57 JP	344	key->rx_pn[0], key->rx_pn[1], key->rx_pn[2],
	345	key->rx_pn[3], key->rx_pn[4], key->rx_pn[5],
	346	pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
b453872c	347	}
6f16bf3b	348	#endif
b453872c JG	349	key->dot11RSNAStatsCCMPReplays++;
	350	return -4;
	351	}
	352
	353	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	354	xor_block(mic, b, CCMP_MIC_LEN);
	355
172589cc	356	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
b453872c JG	357	last = data_len % AES_BLOCK_LEN;
	358
	359	for (i = 1; i <= blocks; i++) {
	360	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	361	/* Decrypt, with counter */
	362	b0[14] = (i >> 8) & 0xff;
	363	b0[15] = i & 0xff;
274bfb8d	364	lib80211_ccmp_aes_encrypt(key->tfm, b0, b);
b453872c JG	365	xor_block(pos, b, len);
	366	/* Authentication */
	367	xor_block(a, pos, len);
274bfb8d	368	lib80211_ccmp_aes_encrypt(key->tfm, a, a);
b453872c JG	369	pos += len;
	370	}
	371
	372	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
	373	if (net_ratelimit()) {
	374	printk(KERN_DEBUG "CCMP: decrypt failed: STA="
e174961c	375	"%pM\n", hdr->addr2);
b453872c JG	376	}
	377	key->dot11RSNAStatsCCMPDecryptErrors++;
	378	return -5;
	379	}
	380
	381	memcpy(key->rx_pn, pn, CCMP_PN_LEN);
	382
	383	/* Remove hdr and MIC */
	384	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
	385	skb_pull(skb, CCMP_HDR_LEN);
	386	skb_trim(skb, skb->len - CCMP_MIC_LEN);
	387
	388	return keyidx;
	389	}
	390
274bfb8d	391	static int lib80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
b453872c	392	{
274bfb8d	393	struct lib80211_ccmp_data *data = priv;
b453872c	394	int keyidx;
f12cc209	395	struct crypto_cipher *tfm = data->tfm;
b453872c JG	396
	397	keyidx = data->key_idx;
	398	memset(data, 0, sizeof(*data));
	399	data->key_idx = keyidx;
	400	data->tfm = tfm;
	401	if (len == CCMP_TK_LEN) {
	402	memcpy(data->key, key, CCMP_TK_LEN);
	403	data->key_set = 1;
	404	if (seq) {
	405	data->rx_pn[0] = seq[5];
	406	data->rx_pn[1] = seq[4];
	407	data->rx_pn[2] = seq[3];
	408	data->rx_pn[3] = seq[2];
	409	data->rx_pn[4] = seq[1];
	410	data->rx_pn[5] = seq[0];
	411	}
	412	crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	413	} else if (len == 0)
	414	data->key_set = 0;
	415	else
	416	return -1;
	417
	418	return 0;
	419	}
	420
274bfb8d	421	static int lib80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
b453872c	422	{
274bfb8d	423	struct lib80211_ccmp_data *data = priv;
b453872c JG	424
	425	if (len < CCMP_TK_LEN)
	426	return -1;
	427
	428	if (!data->key_set)
	429	return 0;
	430	memcpy(key, data->key, CCMP_TK_LEN);
	431
	432	if (seq) {
	433	seq[0] = data->tx_pn[5];
	434	seq[1] = data->tx_pn[4];
	435	seq[2] = data->tx_pn[3];
	436	seq[3] = data->tx_pn[2];
	437	seq[4] = data->tx_pn[1];
	438	seq[5] = data->tx_pn[0];
	439	}
	440
	441	return CCMP_TK_LEN;
	442	}
	443
274bfb8d	444	static char lib80211_ccmp_print_stats(char p, void *priv)
b453872c	445	{
274bfb8d	446	struct lib80211_ccmp_data *ccmp = priv;
0795af57	447
b453872c JG	448	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
	449	"tx_pn=%02x%02x%02x%02x%02x%02x "
	450	"rx_pn=%02x%02x%02x%02x%02x%02x "
	451	"format_errors=%d replays=%d decrypt_errors=%d\n",
	452	ccmp->key_idx, ccmp->key_set,
0795af57 JP	453	ccmp->tx_pn[0], ccmp->tx_pn[1], ccmp->tx_pn[2],
	454	ccmp->tx_pn[3], ccmp->tx_pn[4], ccmp->tx_pn[5],
	455	ccmp->rx_pn[0], ccmp->rx_pn[1], ccmp->rx_pn[2],
	456	ccmp->rx_pn[3], ccmp->rx_pn[4], ccmp->rx_pn[5],
b453872c JG	457	ccmp->dot11RSNAStatsCCMPFormatErrors,
	458	ccmp->dot11RSNAStatsCCMPReplays,
	459	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	460
	461	return p;
	462	}
	463
274bfb8d	464	static struct lib80211_crypto_ops lib80211_crypt_ccmp = {
74079fdc	465	.name = "CCMP",
274bfb8d JL	466	.init = lib80211_ccmp_init,
274bfb8d JL	467	.deinit = lib80211_ccmp_deinit,
274bfb8d JL	468	.encrypt_mpdu = lib80211_ccmp_encrypt,
274bfb8d JL	469	.decrypt_mpdu = lib80211_ccmp_decrypt,
74079fdc JK	470	.encrypt_msdu = NULL,
74079fdc JK	471	.decrypt_msdu = NULL,
274bfb8d JL	472	.set_key = lib80211_ccmp_set_key,
	473	.get_key = lib80211_ccmp_get_key,
	474	.print_stats = lib80211_ccmp_print_stats,
1264fc04 JK	475	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
1264fc04 JK	476	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
74079fdc	477	.owner = THIS_MODULE,
b453872c JG	478	};
b453872c JG	479
274bfb8d	480	static int __init lib80211_crypto_ccmp_init(void)
b453872c	481	{
274bfb8d	482	return lib80211_register_crypto_ops(&lib80211_crypt_ccmp);
b453872c JG	483	}
b453872c JG	484
274bfb8d	485	static void __exit lib80211_crypto_ccmp_exit(void)
b453872c	486	{
274bfb8d	487	lib80211_unregister_crypto_ops(&lib80211_crypt_ccmp);
b453872c JG	488	}
b453872c JG	489
274bfb8d JL	490	module_init(lib80211_crypto_ccmp_init);
274bfb8d JL	491	module_exit(lib80211_crypto_ccmp_exit);