[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 <jkmaline@cc.hut.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/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_tfm *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 void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
				       const u8 pt[16], u8 ct[16])
{
	struct scatterlist src, dst;

	src.page = virt_to_page(pt);
	src.offset = offset_in_page(pt);
	src.length = AES_BLOCK_LEN;

	dst.page = virt_to_page(ct);
	dst.offset = offset_in_page(ct);
	dst.length = AES_BLOCK_LEN;

	crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
}

static void *ieee80211_ccmp_init(int key_idx)
{
	struct ieee80211_ccmp_data *priv;

	priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
	if (priv == NULL)
		goto fail;
	memset(priv, 0, sizeof(*priv));
	priv->key_idx = key_idx;

	priv->tfm = crypto_alloc_tfm("aes", 0);
	if (priv->tfm == NULL) {
		printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
		       "crypto API aes\n");
		goto fail;
	}

	return priv;

      fail:
	if (priv) {
		if (priv->tfm)
			crypto_free_tfm(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_tfm(_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_tfm *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;
}

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 (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
		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_tfm *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	*
	4	* Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
	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
b453872c JG	12	#include <linux/module.h>
	13	#include <linux/init.h>
	14	#include <linux/slab.h>
	15	#include <linux/random.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/netdevice.h>
	18	#include <linux/if_ether.h>
	19	#include <linux/if_arp.h>
	20	#include <asm/string.h>
	21	#include <linux/wireless.h>
	22
	23	#include <net/ieee80211.h>
	24
b453872c JG	25	#include <linux/crypto.h>
	26	#include <asm/scatterlist.h>
	27
	28	MODULE_AUTHOR("Jouni Malinen");
	29	MODULE_DESCRIPTION("Host AP crypt: CCMP");
	30	MODULE_LICENSE("GPL");
	31
	32	#define AES_BLOCK_LEN 16
	33	#define CCMP_HDR_LEN 8
	34	#define CCMP_MIC_LEN 8
	35	#define CCMP_TK_LEN 16
	36	#define CCMP_PN_LEN 6
	37
	38	struct ieee80211_ccmp_data {
	39	u8 key[CCMP_TK_LEN];
	40	int key_set;
	41
	42	u8 tx_pn[CCMP_PN_LEN];
	43	u8 rx_pn[CCMP_PN_LEN];
	44
	45	u32 dot11RSNAStatsCCMPFormatErrors;
	46	u32 dot11RSNAStatsCCMPReplays;
	47	u32 dot11RSNAStatsCCMPDecryptErrors;
	48
	49	int key_idx;
	50
	51	struct crypto_tfm *tfm;
	52
	53	/* scratch buffers for virt_to_page() (crypto API) */
	54	u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
0edd5b44	55	tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
b453872c JG	56	u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
	57	};
	58
e157249d AB	59	static void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
e157249d AB	60	const u8 pt[16], u8 ct[16])
b453872c JG	61	{
	62	struct scatterlist src, dst;
	63
	64	src.page = virt_to_page(pt);
	65	src.offset = offset_in_page(pt);
	66	src.length = AES_BLOCK_LEN;
	67
	68	dst.page = virt_to_page(ct);
	69	dst.offset = offset_in_page(ct);
	70	dst.length = AES_BLOCK_LEN;
	71
	72	crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
	73	}
	74
6eb6edf0	75	static void *ieee80211_ccmp_init(int key_idx)
b453872c JG	76	{
	77	struct ieee80211_ccmp_data *priv;
	78
	79	priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
	80	if (priv == NULL)
	81	goto fail;
	82	memset(priv, 0, sizeof(*priv));
	83	priv->key_idx = key_idx;
	84
	85	priv->tfm = crypto_alloc_tfm("aes", 0);
	86	if (priv->tfm == NULL) {
	87	printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
	88	"crypto API aes\n");
	89	goto fail;
	90	}
	91
	92	return priv;
	93
0edd5b44	94	fail:
b453872c JG	95	if (priv) {
	96	if (priv->tfm)
	97	crypto_free_tfm(priv->tfm);
	98	kfree(priv);
	99	}
	100
	101	return NULL;
	102	}
	103
b453872c JG	104	static void ieee80211_ccmp_deinit(void *priv)
	105	{
	106	struct ieee80211_ccmp_data *_priv = priv;
	107	if (_priv && _priv->tfm)
	108	crypto_free_tfm(_priv->tfm);
	109	kfree(priv);
	110	}
	111
0edd5b44	112	static inline void xor_block(u8 * b, u8 * a, size_t len)
b453872c JG	113	{
	114	int i;
	115	for (i = 0; i < len; i++)
	116	b[i] ^= a[i];
	117	}
	118
b453872c	119	static void ccmp_init_blocks(struct crypto_tfm *tfm,
ee34af37	120	struct ieee80211_hdr_4addr *hdr,
0edd5b44	121	u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
b453872c JG	122	{
	123	u8 *pos, qc = 0;
	124	size_t aad_len;
	125	u16 fc;
	126	int a4_included, qc_included;
	127	u8 aad[2 * AES_BLOCK_LEN];
	128
	129	fc = le16_to_cpu(hdr->frame_ctl);
	130	a4_included = ((fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
	131	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS));
	132	qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
0df78612	133	(WLAN_FC_GET_STYPE(fc) & IEEE80211_STYPE_QOS_DATA));
b453872c JG	134	aad_len = 22;
	135	if (a4_included)
	136	aad_len += 6;
	137	if (qc_included) {
0edd5b44	138	pos = (u8 *) & hdr->addr4;
b453872c JG	139	if (a4_included)
	140	pos += 6;
	141	qc = *pos & 0x0f;
	142	aad_len += 2;
	143	}
	144
	145	/* CCM Initial Block:
	146	* Flag (Include authentication header, M=3 (8-octet MIC),
	147	* L=1 (2-octet Dlen))
	148	* Nonce: 0x00 \| A2 \| PN
	149	* Dlen */
	150	b0[0] = 0x59;
	151	b0[1] = qc;
	152	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	153	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	154	b0[14] = (dlen >> 8) & 0xff;
	155	b0[15] = dlen & 0xff;
	156
	157	/* AAD:
	158	* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	159	* A1 \| A2 \| A3
	160	* SC with bits 4..15 (seq#) masked to zero
	161	* A4 (if present)
	162	* QC (if present)
	163	*/
	164	pos = (u8 *) hdr;
0edd5b44	165	aad[0] = 0; /* aad_len >> 8 */
b453872c JG	166	aad[1] = aad_len & 0xff;
	167	aad[2] = pos[0] & 0x8f;
	168	aad[3] = pos[1] & 0xc7;
	169	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
0edd5b44	170	pos = (u8 *) & hdr->seq_ctl;
b453872c	171	aad[22] = pos[0] & 0x0f;
0edd5b44	172	aad[23] = 0; /* all bits masked */
b453872c JG	173	memset(aad + 24, 0, 8);
	174	if (a4_included)
	175	memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	176	if (qc_included) {
	177	aad[a4_included ? 30 : 24] = qc;
	178	/* rest of QC masked */
	179	}
	180
	181	/* Start with the first block and AAD */
	182	ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
	183	xor_block(auth, aad, AES_BLOCK_LEN);
	184	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	185	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	186	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	187	b0[0] &= 0x07;
	188	b0[14] = b0[15] = 0;
	189	ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
	190	}
	191
9184d934 ZY	192	static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
9184d934 ZY	193	u8 aeskey, int keylen, void priv)
b453872c JG	194	{
b453872c JG	195	struct ieee80211_ccmp_data *key = priv;
31b59eae JK	196	int i;
31b59eae JK	197	u8 *pos;
b453872c	198
31b59eae	199	if (skb_headroom(skb) < CCMP_HDR_LEN \|\| skb->len < hdr_len)
b453872c JG	200	return -1;
b453872c JG	201
9184d934 ZY	202	if (aeskey != NULL && keylen >= CCMP_TK_LEN)
	203	memcpy(aeskey, key->key, CCMP_TK_LEN);
	204
b453872c JG	205	pos = skb_push(skb, CCMP_HDR_LEN);
	206	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	207	pos += hdr_len;
b453872c JG	208
	209	i = CCMP_PN_LEN - 1;
	210	while (i >= 0) {
	211	key->tx_pn[i]++;
	212	if (key->tx_pn[i] != 0)
	213	break;
	214	i--;
	215	}
	216
	217	*pos++ = key->tx_pn[5];
	218	*pos++ = key->tx_pn[4];
	219	*pos++ = 0;
0edd5b44	220	pos++ = (key->key_idx << 6) \| (1 << 5) / Ext IV included */ ;
b453872c JG	221	*pos++ = key->tx_pn[3];
	222	*pos++ = key->tx_pn[2];
	223	*pos++ = key->tx_pn[1];
	224	*pos++ = key->tx_pn[0];
	225
31b59eae JK	226	return CCMP_HDR_LEN;
	227	}
	228
	229	static int ieee80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
	230	{
	231	struct ieee80211_ccmp_data *key = priv;
	232	int data_len, i, blocks, last, len;
	233	u8 pos, mic;
	234	struct ieee80211_hdr_4addr *hdr;
	235	u8 *b0 = key->tx_b0;
	236	u8 *b = key->tx_b;
	237	u8 *e = key->tx_e;
	238	u8 *s0 = key->tx_s0;
	239
	240	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	241	return -1;
	242
	243	data_len = skb->len - hdr_len;
9184d934	244	len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
31b59eae JK	245	if (len < 0)
	246	return -1;
	247
	248	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	249	mic = skb_put(skb, CCMP_MIC_LEN);
ee34af37	250	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	251	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
	252
	253	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	254	last = data_len % AES_BLOCK_LEN;
	255
	256	for (i = 1; i <= blocks; i++) {
	257	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	258	/* Authentication */
	259	xor_block(b, pos, len);
	260	ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
	261	/* Encryption, with counter */
	262	b0[14] = (i >> 8) & 0xff;
	263	b0[15] = i & 0xff;
	264	ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
	265	xor_block(pos, e, len);
	266	pos += len;
	267	}
	268
	269	for (i = 0; i < CCMP_MIC_LEN; i++)
	270	mic[i] = b[i] ^ s0[i];
	271
	272	return 0;
	273	}
	274
b453872c JG	275	static int ieee80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
	276	{
	277	struct ieee80211_ccmp_data *key = priv;
	278	u8 keyidx, *pos;
ee34af37	279	struct ieee80211_hdr_4addr *hdr;
b453872c JG	280	u8 *b0 = key->rx_b0;
	281	u8 *b = key->rx_b;
	282	u8 *a = key->rx_a;
	283	u8 pn[6];
	284	int i, blocks, last, len;
	285	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	286	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
	287
	288	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	289	key->dot11RSNAStatsCCMPFormatErrors++;
	290	return -1;
	291	}
	292
ee34af37	293	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	294	pos = skb->data + hdr_len;
	295	keyidx = pos[3];
	296	if (!(keyidx & (1 << 5))) {
	297	if (net_ratelimit()) {
	298	printk(KERN_DEBUG "CCMP: received packet without ExtIV"
	299	" flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
	300	}
	301	key->dot11RSNAStatsCCMPFormatErrors++;
	302	return -2;
	303	}
	304	keyidx >>= 6;
	305	if (key->key_idx != keyidx) {
	306	printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
	307	"keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
	308	return -6;
	309	}
	310	if (!key->key_set) {
	311	if (net_ratelimit()) {
	312	printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
	313	" with keyid=%d that does not have a configured"
	314	" key\n", MAC_ARG(hdr->addr2), keyidx);
	315	}
	316	return -3;
	317	}
	318
	319	pn[0] = pos[7];
	320	pn[1] = pos[6];
	321	pn[2] = pos[5];
	322	pn[3] = pos[4];
	323	pn[4] = pos[1];
	324	pn[5] = pos[0];
	325	pos += 8;
	326
	327	if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
	328	if (net_ratelimit()) {
	329	printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
	330	" previous PN %02x%02x%02x%02x%02x%02x "
	331	"received PN %02x%02x%02x%02x%02x%02x\n",
	332	MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
	333	MAC_ARG(pn));
	334	}
	335	key->dot11RSNAStatsCCMPReplays++;
	336	return -4;
	337	}
	338
	339	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	340	xor_block(mic, b, CCMP_MIC_LEN);
	341
	342	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	343	last = data_len % AES_BLOCK_LEN;
	344
	345	for (i = 1; i <= blocks; i++) {
	346	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	347	/* Decrypt, with counter */
	348	b0[14] = (i >> 8) & 0xff;
	349	b0[15] = i & 0xff;
	350	ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
	351	xor_block(pos, b, len);
	352	/* Authentication */
	353	xor_block(a, pos, len);
	354	ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
	355	pos += len;
	356	}
	357
358	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
359	if (net_ratelimit()) {
360	printk(KERN_DEBUG "CCMP: decrypt failed: STA="
361	MAC_FMT "\n", MAC_ARG(hdr->addr2));
362	}
363	key->dot11RSNAStatsCCMPDecryptErrors++;
364	return -5;
365	}
366
367	memcpy(key->rx_pn, pn, CCMP_PN_LEN);
368
369	/* Remove hdr and MIC */
370	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
371	skb_pull(skb, CCMP_HDR_LEN);
372	skb_trim(skb, skb->len - CCMP_MIC_LEN);
373
374	return keyidx;
375	}
376
0edd5b44	377	static int ieee80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
b453872c JG	378	{
	379	struct ieee80211_ccmp_data *data = priv;
	380	int keyidx;
	381	struct crypto_tfm *tfm = data->tfm;
	382
	383	keyidx = data->key_idx;
	384	memset(data, 0, sizeof(*data));
	385	data->key_idx = keyidx;
	386	data->tfm = tfm;
	387	if (len == CCMP_TK_LEN) {
	388	memcpy(data->key, key, CCMP_TK_LEN);
	389	data->key_set = 1;
	390	if (seq) {
	391	data->rx_pn[0] = seq[5];
	392	data->rx_pn[1] = seq[4];
	393	data->rx_pn[2] = seq[3];
	394	data->rx_pn[3] = seq[2];
	395	data->rx_pn[4] = seq[1];
	396	data->rx_pn[5] = seq[0];
	397	}
	398	crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	399	} else if (len == 0)
	400	data->key_set = 0;
	401	else
	402	return -1;
	403
	404	return 0;
	405	}
	406
0edd5b44	407	static int ieee80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
b453872c JG	408	{
	409	struct ieee80211_ccmp_data *data = priv;
	410
	411	if (len < CCMP_TK_LEN)
	412	return -1;
	413
	414	if (!data->key_set)
	415	return 0;
	416	memcpy(key, data->key, CCMP_TK_LEN);
	417
	418	if (seq) {
	419	seq[0] = data->tx_pn[5];
	420	seq[1] = data->tx_pn[4];
	421	seq[2] = data->tx_pn[3];
	422	seq[3] = data->tx_pn[2];
	423	seq[4] = data->tx_pn[1];
	424	seq[5] = data->tx_pn[0];
	425	}
	426
	427	return CCMP_TK_LEN;
	428	}
	429
0edd5b44	430	static char ieee80211_ccmp_print_stats(char p, void *priv)
b453872c JG	431	{
	432	struct ieee80211_ccmp_data *ccmp = priv;
	433	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
	434	"tx_pn=%02x%02x%02x%02x%02x%02x "
	435	"rx_pn=%02x%02x%02x%02x%02x%02x "
	436	"format_errors=%d replays=%d decrypt_errors=%d\n",
	437	ccmp->key_idx, ccmp->key_set,
	438	MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
	439	ccmp->dot11RSNAStatsCCMPFormatErrors,
	440	ccmp->dot11RSNAStatsCCMPReplays,
	441	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	442
	443	return p;
	444	}
	445
b453872c	446	static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
74079fdc JK	447	.name = "CCMP",
	448	.init = ieee80211_ccmp_init,
	449	.deinit = ieee80211_ccmp_deinit,
31b59eae	450	.build_iv = ieee80211_ccmp_hdr,
74079fdc JK	451	.encrypt_mpdu = ieee80211_ccmp_encrypt,
	452	.decrypt_mpdu = ieee80211_ccmp_decrypt,
	453	.encrypt_msdu = NULL,
	454	.decrypt_msdu = NULL,
	455	.set_key = ieee80211_ccmp_set_key,
	456	.get_key = ieee80211_ccmp_get_key,
	457	.print_stats = ieee80211_ccmp_print_stats,
1264fc04 JK	458	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
1264fc04 JK	459	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
74079fdc	460	.owner = THIS_MODULE,
b453872c JG	461	};
b453872c JG	462
b453872c JG	463	static int __init ieee80211_crypto_ccmp_init(void)
	464	{
	465	return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
	466	}
	467
b453872c JG	468	static void __exit ieee80211_crypto_ccmp_exit(void)
	469	{
	470	ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
	471	}
	472
b453872c JG	473	module_init(ieee80211_crypto_ccmp_init);
b453872c JG	474	module_exit(ieee80211_crypto_ccmp_exit);