[deliverable/linux.git] / net / ieee80211 / ieee80211_crypt_ccmp.c

/*
 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
 *
 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
 *
 * 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/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 <net/ieee80211.h>

#include <linux/crypto.h>
#include <asm/scatterlist.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 ieee80211_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 ieee80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
					      const u8 pt[16], u8 ct[16])
{
	crypto_cipher_encrypt_one(tfm, ct, pt);
}

static void *ieee80211_ccmp_init(int key_idx)
{
	struct ieee80211_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)) {
		printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
		       "crypto API aes\n");
		priv->tfm = NULL;
		goto fail;
	}

	return priv;

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

	return NULL;
}

static void ieee80211_ccmp_deinit(void *priv)
{
	struct ieee80211_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_4addr *hdr,
			     u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
{
	u8 *pos, qc = 0;
	size_t aad_len;
	u16 fc;
	int a4_included, qc_included;
	u8 aad[2 * AES_BLOCK_LEN];

	fc = le16_to_cpu(hdr->frame_ctl);
	a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
		       (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
	qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
		       (WLAN_FC_GET_STYPE(fc) & IEEE80211_STYPE_QOS_DATA));
	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_ctl;
	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 */
	ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
	xor_block(auth, aad, AES_BLOCK_LEN);
	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	b0[0] &= 0x07;
	b0[14] = b0[15] = 0;
	ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
}

static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
			      u8 *aeskey, int keylen, void *priv)
{
	struct ieee80211_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 ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct ieee80211_ccmp_data *key = priv;
	int data_len, i, blocks, last, len;
	u8 *pos, *mic;
	struct ieee80211_hdr_4addr *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 = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
	if (len < 0)
		return -1;

	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	mic = skb_put(skb, CCMP_MIC_LEN);
	hdr = (struct ieee80211_hdr_4addr *)skb->data;
	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);

	blocks = (data_len + AES_BLOCK_LEN - 1) / 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);
		ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
		/* Encryption, with counter */
		b0[14] = (i >> 8) & 0xff;
		b0[15] = i & 0xff;
		ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
		xor_block(pos, e, len);
		pos += 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 ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct ieee80211_ccmp_data *key = priv;
	u8 keyidx, *pos;
	struct ieee80211_hdr_4addr *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_4addr *)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 " MAC_FMT "\n", MAC_ARG(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 " MAC_FMT
			       " with keyid=%d that does not have a configured"
			       " key\n", MAC_ARG(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)) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
			       " previous PN %02x%02x%02x%02x%02x%02x "
			       "received PN %02x%02x%02x%02x%02x%02x\n",
			       MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
			       MAC_ARG(pn));
		}
		key->dot11RSNAStatsCCMPReplays++;
		return -4;
	}

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

	blocks = (data_len + AES_BLOCK_LEN - 1) / 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;
		ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
		xor_block(pos, b, len);
		/* Authentication */
		xor_block(a, pos, len);
		ieee80211_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="
			       MAC_FMT "\n", MAC_ARG(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 ieee80211_ccmp_set_key(void *key, int len, u8 * seq, void *priv)
{
	struct ieee80211_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 ieee80211_ccmp_get_key(void *key, int len, u8 * seq, void *priv)
{
	struct ieee80211_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 *ieee80211_ccmp_print_stats(char *p, void *priv)
{
	struct ieee80211_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,
		     MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
		     ccmp->dot11RSNAStatsCCMPFormatErrors,
		     ccmp->dot11RSNAStatsCCMPReplays,
		     ccmp->dot11RSNAStatsCCMPDecryptErrors);

	return p;
}

static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
	.name = "CCMP",
	.init = ieee80211_ccmp_init,
	.deinit = ieee80211_ccmp_deinit,
	.build_iv = ieee80211_ccmp_hdr,
	.encrypt_mpdu = ieee80211_ccmp_encrypt,
	.decrypt_mpdu = ieee80211_ccmp_decrypt,
	.encrypt_msdu = NULL,
	.decrypt_msdu = NULL,
	.set_key = ieee80211_ccmp_set_key,
	.get_key = ieee80211_ccmp_get_key,
	.print_stats = ieee80211_ccmp_print_stats,
	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
	.owner = THIS_MODULE,
};

static int __init ieee80211_crypto_ccmp_init(void)
{
	return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
}

static void __exit ieee80211_crypto_ccmp_exit(void)
{
	ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
}

module_init(ieee80211_crypto_ccmp_init);
module_exit(ieee80211_crypto_ccmp_exit);
Commit	Line	Data
b453872c JG	1	/*
	2	* Host AP crypt: host-based CCMP encryption implementation for Host AP driver
	3	*
85d32e7b	4	* Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
b453872c JG	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation. See README and COPYING for
	9	* more details.
	10	*/
	11
f12cc209	12	#include <linux/err.h>
b453872c JG	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/slab.h>
	16	#include <linux/random.h>
	17	#include <linux/skbuff.h>
	18	#include <linux/netdevice.h>
	19	#include <linux/if_ether.h>
	20	#include <linux/if_arp.h>
	21	#include <asm/string.h>
	22	#include <linux/wireless.h>
	23
	24	#include <net/ieee80211.h>
	25
b453872c JG	26	#include <linux/crypto.h>
	27	#include <asm/scatterlist.h>
	28
	29	MODULE_AUTHOR("Jouni Malinen");
	30	MODULE_DESCRIPTION("Host AP crypt: CCMP");
	31	MODULE_LICENSE("GPL");
	32
	33	#define AES_BLOCK_LEN 16
	34	#define CCMP_HDR_LEN 8
	35	#define CCMP_MIC_LEN 8
	36	#define CCMP_TK_LEN 16
	37	#define CCMP_PN_LEN 6
	38
	39	struct ieee80211_ccmp_data {
	40	u8 key[CCMP_TK_LEN];
	41	int key_set;
	42
	43	u8 tx_pn[CCMP_PN_LEN];
	44	u8 rx_pn[CCMP_PN_LEN];
	45
	46	u32 dot11RSNAStatsCCMPFormatErrors;
	47	u32 dot11RSNAStatsCCMPReplays;
	48	u32 dot11RSNAStatsCCMPDecryptErrors;
	49
	50	int key_idx;
	51
f12cc209	52	struct crypto_cipher *tfm;
b453872c JG	53
	54	/* scratch buffers for virt_to_page() (crypto API) */
	55	u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
0edd5b44	56	tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
b453872c JG	57	u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
	58	};
	59
f12cc209 HX	60	static inline void ieee80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
f12cc209 HX	61	const u8 pt[16], u8 ct[16])
b453872c	62	{
f12cc209	63	crypto_cipher_encrypt_one(tfm, ct, pt);
b453872c JG	64	}
b453872c JG	65
6eb6edf0	66	static void *ieee80211_ccmp_init(int key_idx)
b453872c JG	67	{
	68	struct ieee80211_ccmp_data *priv;
	69
0da974f4	70	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
b453872c JG	71	if (priv == NULL)
b453872c JG	72	goto fail;
b453872c JG	73	priv->key_idx = key_idx;
b453872c JG	74
f12cc209 HX	75	priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
f12cc209 HX	76	if (IS_ERR(priv->tfm)) {
b453872c JG	77	printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
b453872c JG	78	"crypto API aes\n");
f12cc209	79	priv->tfm = NULL;
b453872c JG	80	goto fail;
	81	}
	82
	83	return priv;
	84
0edd5b44	85	fail:
b453872c JG	86	if (priv) {
b453872c JG	87	if (priv->tfm)
f12cc209	88	crypto_free_cipher(priv->tfm);
b453872c JG	89	kfree(priv);
	90	}
	91
	92	return NULL;
	93	}
	94
b453872c JG	95	static void ieee80211_ccmp_deinit(void *priv)
	96	{
	97	struct ieee80211_ccmp_data *_priv = priv;
	98	if (_priv && _priv->tfm)
f12cc209	99	crypto_free_cipher(_priv->tfm);
b453872c JG	100	kfree(priv);
	101	}
	102
0edd5b44	103	static inline void xor_block(u8 * b, u8 * a, size_t len)
b453872c JG	104	{
	105	int i;
	106	for (i = 0; i < len; i++)
	107	b[i] ^= a[i];
	108	}
	109
f12cc209	110	static void ccmp_init_blocks(struct crypto_cipher *tfm,
ee34af37	111	struct ieee80211_hdr_4addr *hdr,
0edd5b44	112	u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
b453872c JG	113	{
	114	u8 *pos, qc = 0;
	115	size_t aad_len;
	116	u16 fc;
	117	int a4_included, qc_included;
	118	u8 aad[2 * AES_BLOCK_LEN];
	119
	120	fc = le16_to_cpu(hdr->frame_ctl);
	121	a4_included = ((fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
	122	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS));
	123	qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
0df78612	124	(WLAN_FC_GET_STYPE(fc) & IEEE80211_STYPE_QOS_DATA));
b453872c JG	125	aad_len = 22;
	126	if (a4_included)
	127	aad_len += 6;
	128	if (qc_included) {
0edd5b44	129	pos = (u8 *) & hdr->addr4;
b453872c JG	130	if (a4_included)
	131	pos += 6;
	132	qc = *pos & 0x0f;
	133	aad_len += 2;
	134	}
	135
	136	/* CCM Initial Block:
	137	* Flag (Include authentication header, M=3 (8-octet MIC),
	138	* L=1 (2-octet Dlen))
	139	* Nonce: 0x00 \| A2 \| PN
	140	* Dlen */
	141	b0[0] = 0x59;
	142	b0[1] = qc;
	143	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	144	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	145	b0[14] = (dlen >> 8) & 0xff;
	146	b0[15] = dlen & 0xff;
	147
	148	/* AAD:
	149	* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	150	* A1 \| A2 \| A3
	151	* SC with bits 4..15 (seq#) masked to zero
	152	* A4 (if present)
	153	* QC (if present)
	154	*/
	155	pos = (u8 *) hdr;
0edd5b44	156	aad[0] = 0; /* aad_len >> 8 */
b453872c JG	157	aad[1] = aad_len & 0xff;
	158	aad[2] = pos[0] & 0x8f;
	159	aad[3] = pos[1] & 0xc7;
	160	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
0edd5b44	161	pos = (u8 *) & hdr->seq_ctl;
b453872c	162	aad[22] = pos[0] & 0x0f;
0edd5b44	163	aad[23] = 0; /* all bits masked */
b453872c JG	164	memset(aad + 24, 0, 8);
	165	if (a4_included)
	166	memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	167	if (qc_included) {
	168	aad[a4_included ? 30 : 24] = qc;
	169	/* rest of QC masked */
	170	}
	171
	172	/* Start with the first block and AAD */
	173	ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
	174	xor_block(auth, aad, AES_BLOCK_LEN);
	175	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	176	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	177	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	178	b0[0] &= 0x07;
	179	b0[14] = b0[15] = 0;
	180	ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
	181	}
	182
9184d934 ZY	183	static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
9184d934 ZY	184	u8 aeskey, int keylen, void priv)
b453872c JG	185	{
b453872c JG	186	struct ieee80211_ccmp_data *key = priv;
31b59eae JK	187	int i;
31b59eae JK	188	u8 *pos;
b453872c	189
31b59eae	190	if (skb_headroom(skb) < CCMP_HDR_LEN \|\| skb->len < hdr_len)
b453872c JG	191	return -1;
b453872c JG	192
9184d934 ZY	193	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
	194	memcpy(aeskey, key->key, CCMP_TK_LEN);
	195
b453872c JG	196	pos = skb_push(skb, CCMP_HDR_LEN);
	197	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	198	pos += hdr_len;
b453872c JG	199
	200	i = CCMP_PN_LEN - 1;
	201	while (i >= 0) {
	202	key->tx_pn[i]++;
	203	if (key->tx_pn[i] != 0)
	204	break;
	205	i--;
	206	}
	207
	208	*pos++ = key->tx_pn[5];
	209	*pos++ = key->tx_pn[4];
	210	*pos++ = 0;
0edd5b44	211	pos++ = (key->key_idx << 6) \| (1 << 5) / Ext IV included */ ;
b453872c JG	212	*pos++ = key->tx_pn[3];
	213	*pos++ = key->tx_pn[2];
	214	*pos++ = key->tx_pn[1];
	215	*pos++ = key->tx_pn[0];
	216
31b59eae JK	217	return CCMP_HDR_LEN;
	218	}
	219
	220	static int ieee80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
	221	{
	222	struct ieee80211_ccmp_data *key = priv;
	223	int data_len, i, blocks, last, len;
	224	u8 pos, mic;
	225	struct ieee80211_hdr_4addr *hdr;
	226	u8 *b0 = key->tx_b0;
	227	u8 *b = key->tx_b;
	228	u8 *e = key->tx_e;
	229	u8 *s0 = key->tx_s0;
	230
	231	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	232	return -1;
	233
	234	data_len = skb->len - hdr_len;
9184d934	235	len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
31b59eae JK	236	if (len < 0)
	237	return -1;
	238
	239	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	240	mic = skb_put(skb, CCMP_MIC_LEN);
ee34af37	241	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	242	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
	243
	244	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	245	last = data_len % AES_BLOCK_LEN;
	246
	247	for (i = 1; i <= blocks; i++) {
	248	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	249	/* Authentication */
	250	xor_block(b, pos, len);
	251	ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
	252	/* Encryption, with counter */
	253	b0[14] = (i >> 8) & 0xff;
	254	b0[15] = i & 0xff;
	255	ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
	256	xor_block(pos, e, len);
	257	pos += len;
	258	}
	259
	260	for (i = 0; i < CCMP_MIC_LEN; i++)
	261	mic[i] = b[i] ^ s0[i];
	262
	263	return 0;
	264	}
	265
b4328d87 ZY	266	/*
	267	* deal with seq counter wrapping correctly.
	268	* refer to timer_after() for jiffies wrapping handling
	269	*/
	270	static inline int ccmp_replay_check(u8 pn_n, u8 pn_o)
	271	{
	272	u32 iv32_n, iv16_n;
	273	u32 iv32_o, iv16_o;
	274
	275	iv32_n = (pn_n[0] << 24) \| (pn_n[1] << 16) \| (pn_n[2] << 8) \| pn_n[3];
	276	iv16_n = (pn_n[4] << 8) \| pn_n[5];
	277
	278	iv32_o = (pn_o[0] << 24) \| (pn_o[1] << 16) \| (pn_o[2] << 8) \| pn_o[3];
	279	iv16_o = (pn_o[4] << 8) \| pn_o[5];
	280
	281	if ((s32)iv32_n - (s32)iv32_o < 0 \|\|
	282	(iv32_n == iv32_o && iv16_n <= iv16_o))
	283	return 1;
	284	return 0;
	285	}
	286
b453872c JG	287	static int ieee80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
	288	{
	289	struct ieee80211_ccmp_data *key = priv;
	290	u8 keyidx, *pos;
ee34af37	291	struct ieee80211_hdr_4addr *hdr;
b453872c JG	292	u8 *b0 = key->rx_b0;
	293	u8 *b = key->rx_b;
	294	u8 *a = key->rx_a;
	295	u8 pn[6];
	296	int i, blocks, last, len;
	297	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	298	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
	299
	300	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	301	key->dot11RSNAStatsCCMPFormatErrors++;
	302	return -1;
	303	}
	304
ee34af37	305	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	306	pos = skb->data + hdr_len;
	307	keyidx = pos[3];
	308	if (!(keyidx & (1 << 5))) {
	309	if (net_ratelimit()) {
	310	printk(KERN_DEBUG "CCMP: received packet without ExtIV"
	311	" flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
	312	}
	313	key->dot11RSNAStatsCCMPFormatErrors++;
	314	return -2;
	315	}
	316	keyidx >>= 6;
	317	if (key->key_idx != keyidx) {
	318	printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
	319	"keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
	320	return -6;
	321	}
	322	if (!key->key_set) {
	323	if (net_ratelimit()) {
	324	printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
	325	" with keyid=%d that does not have a configured"
	326	" key\n", MAC_ARG(hdr->addr2), keyidx);
	327	}
	328	return -3;
	329	}
	330
	331	pn[0] = pos[7];
	332	pn[1] = pos[6];
	333	pn[2] = pos[5];
	334	pn[3] = pos[4];
	335	pn[4] = pos[1];
	336	pn[5] = pos[0];
	337	pos += 8;
	338
b4328d87	339	if (ccmp_replay_check(pn, key->rx_pn)) {
b453872c JG	340	if (net_ratelimit()) {
	341	printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
	342	" previous PN %02x%02x%02x%02x%02x%02x "
	343	"received PN %02x%02x%02x%02x%02x%02x\n",
	344	MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
	345	MAC_ARG(pn));
	346	}
	347	key->dot11RSNAStatsCCMPReplays++;
	348	return -4;
	349	}
	350
	351	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	352	xor_block(mic, b, CCMP_MIC_LEN);
	353
	354	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	355	last = data_len % AES_BLOCK_LEN;
	356
	357	for (i = 1; i <= blocks; i++) {
	358	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	359	/* Decrypt, with counter */
	360	b0[14] = (i >> 8) & 0xff;
	361	b0[15] = i & 0xff;
	362	ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
	363	xor_block(pos, b, len);
	364	/* Authentication */
	365	xor_block(a, pos, len);
	366	ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
	367	pos += len;
	368	}
	369
	370	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
	371	if (net_ratelimit()) {
	372	printk(KERN_DEBUG "CCMP: decrypt failed: STA="
	373	MAC_FMT "\n", MAC_ARG(hdr->addr2));
	374	}
	375	key->dot11RSNAStatsCCMPDecryptErrors++;
	376	return -5;
	377	}
	378
	379	memcpy(key->rx_pn, pn, CCMP_PN_LEN);
	380
	381	/* Remove hdr and MIC */
	382	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
	383	skb_pull(skb, CCMP_HDR_LEN);
	384	skb_trim(skb, skb->len - CCMP_MIC_LEN);
	385
	386	return keyidx;
	387	}
	388
0edd5b44	389	static int ieee80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
b453872c JG	390	{
	391	struct ieee80211_ccmp_data *data = priv;
	392	int keyidx;
f12cc209	393	struct crypto_cipher *tfm = data->tfm;
b453872c JG	394
	395	keyidx = data->key_idx;
	396	memset(data, 0, sizeof(*data));
	397	data->key_idx = keyidx;
	398	data->tfm = tfm;
	399	if (len == CCMP_TK_LEN) {
	400	memcpy(data->key, key, CCMP_TK_LEN);
	401	data->key_set = 1;
	402	if (seq) {
	403	data->rx_pn[0] = seq[5];
	404	data->rx_pn[1] = seq[4];
	405	data->rx_pn[2] = seq[3];
	406	data->rx_pn[3] = seq[2];
	407	data->rx_pn[4] = seq[1];
	408	data->rx_pn[5] = seq[0];
	409	}
	410	crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	411	} else if (len == 0)
	412	data->key_set = 0;
	413	else
	414	return -1;
	415
	416	return 0;
	417	}
	418
0edd5b44	419	static int ieee80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
b453872c JG	420	{
	421	struct ieee80211_ccmp_data *data = priv;
	422
	423	if (len < CCMP_TK_LEN)
	424	return -1;
	425
	426	if (!data->key_set)
	427	return 0;
	428	memcpy(key, data->key, CCMP_TK_LEN);
	429
	430	if (seq) {
	431	seq[0] = data->tx_pn[5];
	432	seq[1] = data->tx_pn[4];
	433	seq[2] = data->tx_pn[3];
	434	seq[3] = data->tx_pn[2];
	435	seq[4] = data->tx_pn[1];
	436	seq[5] = data->tx_pn[0];
	437	}
	438
	439	return CCMP_TK_LEN;
	440	}
	441
0edd5b44	442	static char ieee80211_ccmp_print_stats(char p, void *priv)
b453872c JG	443	{
	444	struct ieee80211_ccmp_data *ccmp = priv;
	445	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
	446	"tx_pn=%02x%02x%02x%02x%02x%02x "
	447	"rx_pn=%02x%02x%02x%02x%02x%02x "
	448	"format_errors=%d replays=%d decrypt_errors=%d\n",
	449	ccmp->key_idx, ccmp->key_set,
	450	MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
	451	ccmp->dot11RSNAStatsCCMPFormatErrors,
	452	ccmp->dot11RSNAStatsCCMPReplays,
	453	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	454
	455	return p;
	456	}
	457
b453872c	458	static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
74079fdc JK	459	.name = "CCMP",
	460	.init = ieee80211_ccmp_init,
	461	.deinit = ieee80211_ccmp_deinit,
31b59eae	462	.build_iv = ieee80211_ccmp_hdr,
74079fdc JK	463	.encrypt_mpdu = ieee80211_ccmp_encrypt,
	464	.decrypt_mpdu = ieee80211_ccmp_decrypt,
	465	.encrypt_msdu = NULL,
	466	.decrypt_msdu = NULL,
	467	.set_key = ieee80211_ccmp_set_key,
	468	.get_key = ieee80211_ccmp_get_key,
	469	.print_stats = ieee80211_ccmp_print_stats,
1264fc04 JK	470	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
1264fc04 JK	471	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
74079fdc	472	.owner = THIS_MODULE,
b453872c JG	473	};
b453872c JG	474
b453872c JG	475	static int __init ieee80211_crypto_ccmp_init(void)
	476	{
	477	return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
	478	}
	479
b453872c JG	480	static void __exit ieee80211_crypto_ccmp_exit(void)
	481	{
	482	ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
	483	}
	484
b453872c JG	485	module_init(ieee80211_crypto_ccmp_init);
b453872c JG	486	module_exit(ieee80211_crypto_ccmp_exit);