[GitHub/mt8127/android_kernel_alcatel_ttab.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/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 <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 = 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);
		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()) {
			IEEE80211_DEBUG_DROP("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 = 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;
		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
172589cc	12	#include <linux/kernel.h>
f12cc209	13	#include <linux/err.h>
b453872c JG	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/slab.h>
	17	#include <linux/random.h>
	18	#include <linux/skbuff.h>
	19	#include <linux/netdevice.h>
	20	#include <linux/if_ether.h>
	21	#include <linux/if_arp.h>
	22	#include <asm/string.h>
	23	#include <linux/wireless.h>
	24
	25	#include <net/ieee80211.h>
	26
b453872c JG	27	#include <linux/crypto.h>
	28	#include <asm/scatterlist.h>
	29
	30	MODULE_AUTHOR("Jouni Malinen");
	31	MODULE_DESCRIPTION("Host AP crypt: CCMP");
	32	MODULE_LICENSE("GPL");
	33
	34	#define AES_BLOCK_LEN 16
	35	#define CCMP_HDR_LEN 8
	36	#define CCMP_MIC_LEN 8
	37	#define CCMP_TK_LEN 16
	38	#define CCMP_PN_LEN 6
	39
	40	struct ieee80211_ccmp_data {
	41	u8 key[CCMP_TK_LEN];
	42	int key_set;
	43
	44	u8 tx_pn[CCMP_PN_LEN];
	45	u8 rx_pn[CCMP_PN_LEN];
	46
	47	u32 dot11RSNAStatsCCMPFormatErrors;
	48	u32 dot11RSNAStatsCCMPReplays;
	49	u32 dot11RSNAStatsCCMPDecryptErrors;
	50
	51	int key_idx;
	52
f12cc209	53	struct crypto_cipher *tfm;
b453872c JG	54
	55	/* scratch buffers for virt_to_page() (crypto API) */
	56	u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
0edd5b44	57	tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
b453872c JG	58	u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
	59	};
	60
f12cc209 HX	61	static inline void ieee80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
f12cc209 HX	62	const u8 pt[16], u8 ct[16])
b453872c	63	{
f12cc209	64	crypto_cipher_encrypt_one(tfm, ct, pt);
b453872c JG	65	}
b453872c JG	66
6eb6edf0	67	static void *ieee80211_ccmp_init(int key_idx)
b453872c JG	68	{
	69	struct ieee80211_ccmp_data *priv;
	70
0da974f4	71	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
b453872c JG	72	if (priv == NULL)
b453872c JG	73	goto fail;
b453872c JG	74	priv->key_idx = key_idx;
b453872c JG	75
f12cc209 HX	76	priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
f12cc209 HX	77	if (IS_ERR(priv->tfm)) {
b453872c JG	78	printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
b453872c JG	79	"crypto API aes\n");
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
b453872c JG	96	static void ieee80211_ccmp_deinit(void *priv)
	97	{
	98	struct ieee80211_ccmp_data *_priv = priv;
	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,
ee34af37	112	struct ieee80211_hdr_4addr *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;
	117	u16 fc;
	118	int a4_included, qc_included;
	119	u8 aad[2 * AES_BLOCK_LEN];
	120
	121	fc = le16_to_cpu(hdr->frame_ctl);
	122	a4_included = ((fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
	123	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS));
	124	qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
0df78612	125	(WLAN_FC_GET_STYPE(fc) & IEEE80211_STYPE_QOS_DATA));
b453872c JG	126	aad_len = 22;
	127	if (a4_included)
	128	aad_len += 6;
	129	if (qc_included) {
0edd5b44	130	pos = (u8 *) & hdr->addr4;
b453872c JG	131	if (a4_included)
	132	pos += 6;
	133	qc = *pos & 0x0f;
	134	aad_len += 2;
	135	}
	136
	137	/* CCM Initial Block:
	138	* Flag (Include authentication header, M=3 (8-octet MIC),
	139	* L=1 (2-octet Dlen))
	140	* Nonce: 0x00 \| A2 \| PN
	141	* Dlen */
	142	b0[0] = 0x59;
	143	b0[1] = qc;
	144	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	145	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	146	b0[14] = (dlen >> 8) & 0xff;
	147	b0[15] = dlen & 0xff;
	148
	149	/* AAD:
	150	* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	151	* A1 \| A2 \| A3
	152	* SC with bits 4..15 (seq#) masked to zero
	153	* A4 (if present)
	154	* QC (if present)
	155	*/
	156	pos = (u8 *) hdr;
0edd5b44	157	aad[0] = 0; /* aad_len >> 8 */
b453872c JG	158	aad[1] = aad_len & 0xff;
	159	aad[2] = pos[0] & 0x8f;
	160	aad[3] = pos[1] & 0xc7;
	161	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
0edd5b44	162	pos = (u8 *) & hdr->seq_ctl;
b453872c	163	aad[22] = pos[0] & 0x0f;
0edd5b44	164	aad[23] = 0; /* all bits masked */
b453872c JG	165	memset(aad + 24, 0, 8);
	166	if (a4_included)
	167	memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	168	if (qc_included) {
	169	aad[a4_included ? 30 : 24] = qc;
	170	/* rest of QC masked */
	171	}
	172
	173	/* Start with the first block and AAD */
	174	ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
	175	xor_block(auth, aad, AES_BLOCK_LEN);
	176	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	177	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	178	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	179	b0[0] &= 0x07;
	180	b0[14] = b0[15] = 0;
	181	ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
	182	}
	183
9184d934 ZY	184	static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
9184d934 ZY	185	u8 aeskey, int keylen, void priv)
b453872c JG	186	{
b453872c JG	187	struct ieee80211_ccmp_data *key = priv;
31b59eae JK	188	int i;
31b59eae JK	189	u8 *pos;
b453872c	190
31b59eae	191	if (skb_headroom(skb) < CCMP_HDR_LEN \|\| skb->len < hdr_len)
b453872c JG	192	return -1;
b453872c JG	193
9184d934 ZY	194	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
	195	memcpy(aeskey, key->key, CCMP_TK_LEN);
	196
b453872c JG	197	pos = skb_push(skb, CCMP_HDR_LEN);
	198	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	199	pos += hdr_len;
b453872c JG	200
	201	i = CCMP_PN_LEN - 1;
	202	while (i >= 0) {
	203	key->tx_pn[i]++;
	204	if (key->tx_pn[i] != 0)
	205	break;
	206	i--;
	207	}
	208
	209	*pos++ = key->tx_pn[5];
	210	*pos++ = key->tx_pn[4];
	211	*pos++ = 0;
0edd5b44	212	pos++ = (key->key_idx << 6) \| (1 << 5) / Ext IV included */ ;
b453872c JG	213	*pos++ = key->tx_pn[3];
	214	*pos++ = key->tx_pn[2];
	215	*pos++ = key->tx_pn[1];
	216	*pos++ = key->tx_pn[0];
	217
31b59eae JK	218	return CCMP_HDR_LEN;
	219	}
	220
	221	static int ieee80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
	222	{
	223	struct ieee80211_ccmp_data *key = priv;
	224	int data_len, i, blocks, last, len;
	225	u8 pos, mic;
	226	struct ieee80211_hdr_4addr *hdr;
	227	u8 *b0 = key->tx_b0;
	228	u8 *b = key->tx_b;
	229	u8 *e = key->tx_e;
	230	u8 *s0 = key->tx_s0;
	231
	232	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	233	return -1;
	234
	235	data_len = skb->len - hdr_len;
9184d934	236	len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
31b59eae JK	237	if (len < 0)
	238	return -1;
	239
	240	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	241	mic = skb_put(skb, CCMP_MIC_LEN);
ee34af37	242	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	243	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
b453872c JG	244
172589cc	245	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
b453872c JG	246	last = data_len % AES_BLOCK_LEN;
	247
	248	for (i = 1; i <= blocks; i++) {
	249	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	250	/* Authentication */
	251	xor_block(b, pos, len);
	252	ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
	253	/* Encryption, with counter */
	254	b0[14] = (i >> 8) & 0xff;
	255	b0[15] = i & 0xff;
	256	ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
	257	xor_block(pos, e, len);
	258	pos += len;
	259	}
	260
	261	for (i = 0; i < CCMP_MIC_LEN; i++)
	262	mic[i] = b[i] ^ s0[i];
	263
	264	return 0;
	265	}
	266
b4328d87 ZY	267	/*
	268	* deal with seq counter wrapping correctly.
	269	* refer to timer_after() for jiffies wrapping handling
	270	*/
	271	static inline int ccmp_replay_check(u8 pn_n, u8 pn_o)
	272	{
	273	u32 iv32_n, iv16_n;
	274	u32 iv32_o, iv16_o;
	275
	276	iv32_n = (pn_n[0] << 24) \| (pn_n[1] << 16) \| (pn_n[2] << 8) \| pn_n[3];
	277	iv16_n = (pn_n[4] << 8) \| pn_n[5];
	278
	279	iv32_o = (pn_o[0] << 24) \| (pn_o[1] << 16) \| (pn_o[2] << 8) \| pn_o[3];
	280	iv16_o = (pn_o[4] << 8) \| pn_o[5];
	281
	282	if ((s32)iv32_n - (s32)iv32_o < 0 \|\|
	283	(iv32_n == iv32_o && iv16_n <= iv16_o))
	284	return 1;
	285	return 0;
	286	}
	287
b453872c JG	288	static int ieee80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
	289	{
	290	struct ieee80211_ccmp_data *key = priv;
	291	u8 keyidx, *pos;
ee34af37	292	struct ieee80211_hdr_4addr *hdr;
b453872c JG	293	u8 *b0 = key->rx_b0;
	294	u8 *b = key->rx_b;
	295	u8 *a = key->rx_a;
	296	u8 pn[6];
	297	int i, blocks, last, len;
	298	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	299	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
	300
	301	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	302	key->dot11RSNAStatsCCMPFormatErrors++;
	303	return -1;
	304	}
	305
ee34af37	306	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	307	pos = skb->data + hdr_len;
	308	keyidx = pos[3];
	309	if (!(keyidx & (1 << 5))) {
	310	if (net_ratelimit()) {
	311	printk(KERN_DEBUG "CCMP: received packet without ExtIV"
	312	" flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
	313	}
	314	key->dot11RSNAStatsCCMPFormatErrors++;
	315	return -2;
	316	}
	317	keyidx >>= 6;
	318	if (key->key_idx != keyidx) {
	319	printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
	320	"keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
	321	return -6;
	322	}
	323	if (!key->key_set) {
	324	if (net_ratelimit()) {
	325	printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
	326	" with keyid=%d that does not have a configured"
	327	" key\n", MAC_ARG(hdr->addr2), keyidx);
	328	}
	329	return -3;
	330	}
	331
	332	pn[0] = pos[7];
	333	pn[1] = pos[6];
	334	pn[2] = pos[5];
	335	pn[3] = pos[4];
	336	pn[4] = pos[1];
	337	pn[5] = pos[0];
	338	pos += 8;
	339
b4328d87	340	if (ccmp_replay_check(pn, key->rx_pn)) {
b453872c	341	if (net_ratelimit()) {
aeb998c1	342	IEEE80211_DEBUG_DROP("CCMP: replay detected: STA=" MAC_FMT
b453872c JG	343	" previous PN %02x%02x%02x%02x%02x%02x "
	344	"received PN %02x%02x%02x%02x%02x%02x\n",
	345	MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
	346	MAC_ARG(pn));
	347	}
	348	key->dot11RSNAStatsCCMPReplays++;
	349	return -4;
	350	}
	351
	352	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	353	xor_block(mic, b, CCMP_MIC_LEN);
	354
172589cc	355	blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
b453872c JG	356	last = data_len % AES_BLOCK_LEN;
	357
	358	for (i = 1; i <= blocks; i++) {
	359	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	360	/* Decrypt, with counter */
	361	b0[14] = (i >> 8) & 0xff;
	362	b0[15] = i & 0xff;
	363	ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
	364	xor_block(pos, b, len);
	365	/* Authentication */
	366	xor_block(a, pos, len);
	367	ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
	368	pos += len;
	369	}
	370
	371	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
	372	if (net_ratelimit()) {
	373	printk(KERN_DEBUG "CCMP: decrypt failed: STA="
	374	MAC_FMT "\n", MAC_ARG(hdr->addr2));
	375	}
	376	key->dot11RSNAStatsCCMPDecryptErrors++;
	377	return -5;
	378	}
	379
	380	memcpy(key->rx_pn, pn, CCMP_PN_LEN);
	381
	382	/* Remove hdr and MIC */
	383	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
	384	skb_pull(skb, CCMP_HDR_LEN);
	385	skb_trim(skb, skb->len - CCMP_MIC_LEN);
	386
	387	return keyidx;
	388	}
	389
0edd5b44	390	static int ieee80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
b453872c JG	391	{
	392	struct ieee80211_ccmp_data *data = priv;
	393	int keyidx;
f12cc209	394	struct crypto_cipher *tfm = data->tfm;
b453872c JG	395
	396	keyidx = data->key_idx;
	397	memset(data, 0, sizeof(*data));
	398	data->key_idx = keyidx;
	399	data->tfm = tfm;
	400	if (len == CCMP_TK_LEN) {
	401	memcpy(data->key, key, CCMP_TK_LEN);
	402	data->key_set = 1;
	403	if (seq) {
	404	data->rx_pn[0] = seq[5];
	405	data->rx_pn[1] = seq[4];
	406	data->rx_pn[2] = seq[3];
	407	data->rx_pn[3] = seq[2];
	408	data->rx_pn[4] = seq[1];
	409	data->rx_pn[5] = seq[0];
	410	}
	411	crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	412	} else if (len == 0)
	413	data->key_set = 0;
	414	else
	415	return -1;
	416
	417	return 0;
	418	}
	419
0edd5b44	420	static int ieee80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
b453872c JG	421	{
	422	struct ieee80211_ccmp_data *data = priv;
	423
	424	if (len < CCMP_TK_LEN)
	425	return -1;
	426
	427	if (!data->key_set)
	428	return 0;
	429	memcpy(key, data->key, CCMP_TK_LEN);
	430
	431	if (seq) {
	432	seq[0] = data->tx_pn[5];
	433	seq[1] = data->tx_pn[4];
	434	seq[2] = data->tx_pn[3];
	435	seq[3] = data->tx_pn[2];
	436	seq[4] = data->tx_pn[1];
	437	seq[5] = data->tx_pn[0];
	438	}
	439
	440	return CCMP_TK_LEN;
	441	}
	442
0edd5b44	443	static char ieee80211_ccmp_print_stats(char p, void *priv)
b453872c JG	444	{
	445	struct ieee80211_ccmp_data *ccmp = priv;
	446	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
	447	"tx_pn=%02x%02x%02x%02x%02x%02x "
	448	"rx_pn=%02x%02x%02x%02x%02x%02x "
	449	"format_errors=%d replays=%d decrypt_errors=%d\n",
	450	ccmp->key_idx, ccmp->key_set,
	451	MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
	452	ccmp->dot11RSNAStatsCCMPFormatErrors,
	453	ccmp->dot11RSNAStatsCCMPReplays,
	454	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	455
	456	return p;
	457	}
	458
b453872c	459	static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
74079fdc JK	460	.name = "CCMP",
	461	.init = ieee80211_ccmp_init,
	462	.deinit = ieee80211_ccmp_deinit,
31b59eae	463	.build_iv = ieee80211_ccmp_hdr,
74079fdc JK	464	.encrypt_mpdu = ieee80211_ccmp_encrypt,
	465	.decrypt_mpdu = ieee80211_ccmp_decrypt,
	466	.encrypt_msdu = NULL,
	467	.decrypt_msdu = NULL,
	468	.set_key = ieee80211_ccmp_set_key,
	469	.get_key = ieee80211_ccmp_get_key,
	470	.print_stats = ieee80211_ccmp_print_stats,
1264fc04 JK	471	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
1264fc04 JK	472	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
74079fdc	473	.owner = THIS_MODULE,
b453872c JG	474	};
b453872c JG	475
b453872c JG	476	static int __init ieee80211_crypto_ccmp_init(void)
	477	{
	478	return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
	479	}
	480
b453872c JG	481	static void __exit ieee80211_crypto_ccmp_exit(void)
	482	{
	483	ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
	484	}
	485
b453872c JG	486	module_init(ieee80211_crypto_ccmp_init);
b453872c JG	487	module_exit(ieee80211_crypto_ccmp_exit);