[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/config.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_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) & 0x08));
	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, 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;

	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, 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
	12	#include <linux/config.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
	52	struct crypto_tfm *tfm;
	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
e157249d AB	60	static void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
e157249d AB	61	const u8 pt[16], u8 ct[16])
b453872c JG	62	{
	63	struct scatterlist src, dst;
	64
	65	src.page = virt_to_page(pt);
	66	src.offset = offset_in_page(pt);
	67	src.length = AES_BLOCK_LEN;
	68
	69	dst.page = virt_to_page(ct);
	70	dst.offset = offset_in_page(ct);
	71	dst.length = AES_BLOCK_LEN;
	72
	73	crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
	74	}
	75
6eb6edf0	76	static void *ieee80211_ccmp_init(int key_idx)
b453872c JG	77	{
	78	struct ieee80211_ccmp_data *priv;
	79
	80	priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
	81	if (priv == NULL)
	82	goto fail;
	83	memset(priv, 0, sizeof(*priv));
	84	priv->key_idx = key_idx;
	85
	86	priv->tfm = crypto_alloc_tfm("aes", 0);
	87	if (priv->tfm == NULL) {
	88	printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
	89	"crypto API aes\n");
	90	goto fail;
	91	}
	92
	93	return priv;
	94
0edd5b44	95	fail:
b453872c JG	96	if (priv) {
	97	if (priv->tfm)
	98	crypto_free_tfm(priv->tfm);
	99	kfree(priv);
	100	}
	101
	102	return NULL;
	103	}
	104
b453872c JG	105	static void ieee80211_ccmp_deinit(void *priv)
	106	{
	107	struct ieee80211_ccmp_data *_priv = priv;
	108	if (_priv && _priv->tfm)
	109	crypto_free_tfm(_priv->tfm);
	110	kfree(priv);
	111	}
	112
0edd5b44	113	static inline void xor_block(u8 * b, u8 * a, size_t len)
b453872c JG	114	{
	115	int i;
	116	for (i = 0; i < len; i++)
	117	b[i] ^= a[i];
	118	}
	119
b453872c	120	static void ccmp_init_blocks(struct crypto_tfm *tfm,
ee34af37	121	struct ieee80211_hdr_4addr *hdr,
0edd5b44	122	u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
b453872c JG	123	{
	124	u8 *pos, qc = 0;
	125	size_t aad_len;
	126	u16 fc;
	127	int a4_included, qc_included;
	128	u8 aad[2 * AES_BLOCK_LEN];
	129
	130	fc = le16_to_cpu(hdr->frame_ctl);
	131	a4_included = ((fc & (IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS)) ==
	132	(IEEE80211_FCTL_TODS \| IEEE80211_FCTL_FROMDS));
	133	qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
	134	(WLAN_FC_GET_STYPE(fc) & 0x08));
	135	aad_len = 22;
	136	if (a4_included)
	137	aad_len += 6;
	138	if (qc_included) {
0edd5b44	139	pos = (u8 *) & hdr->addr4;
b453872c JG	140	if (a4_included)
	141	pos += 6;
	142	qc = *pos & 0x0f;
	143	aad_len += 2;
	144	}
	145
	146	/* CCM Initial Block:
	147	* Flag (Include authentication header, M=3 (8-octet MIC),
	148	* L=1 (2-octet Dlen))
	149	* Nonce: 0x00 \| A2 \| PN
	150	* Dlen */
	151	b0[0] = 0x59;
	152	b0[1] = qc;
	153	memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
	154	memcpy(b0 + 8, pn, CCMP_PN_LEN);
	155	b0[14] = (dlen >> 8) & 0xff;
	156	b0[15] = dlen & 0xff;
	157
	158	/* AAD:
	159	* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
	160	* A1 \| A2 \| A3
	161	* SC with bits 4..15 (seq#) masked to zero
	162	* A4 (if present)
	163	* QC (if present)
	164	*/
	165	pos = (u8 *) hdr;
0edd5b44	166	aad[0] = 0; /* aad_len >> 8 */
b453872c JG	167	aad[1] = aad_len & 0xff;
	168	aad[2] = pos[0] & 0x8f;
	169	aad[3] = pos[1] & 0xc7;
	170	memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
0edd5b44	171	pos = (u8 *) & hdr->seq_ctl;
b453872c	172	aad[22] = pos[0] & 0x0f;
0edd5b44	173	aad[23] = 0; /* all bits masked */
b453872c JG	174	memset(aad + 24, 0, 8);
	175	if (a4_included)
	176	memcpy(aad + 24, hdr->addr4, ETH_ALEN);
	177	if (qc_included) {
	178	aad[a4_included ? 30 : 24] = qc;
	179	/* rest of QC masked */
	180	}
	181
	182	/* Start with the first block and AAD */
	183	ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
	184	xor_block(auth, aad, AES_BLOCK_LEN);
	185	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	186	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
	187	ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
	188	b0[0] &= 0x07;
	189	b0[14] = b0[15] = 0;
	190	ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
	191	}
	192
31b59eae	193	static int ieee80211_ccmp_hdr(struct sk_buff skb, int hdr_len, 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
b453872c JG	202	pos = skb_push(skb, CCMP_HDR_LEN);
	203	memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
	204	pos += hdr_len;
b453872c JG	205
	206	i = CCMP_PN_LEN - 1;
	207	while (i >= 0) {
	208	key->tx_pn[i]++;
	209	if (key->tx_pn[i] != 0)
	210	break;
	211	i--;
	212	}
	213
	214	*pos++ = key->tx_pn[5];
	215	*pos++ = key->tx_pn[4];
	216	*pos++ = 0;
0edd5b44	217	pos++ = (key->key_idx << 6) \| (1 << 5) / Ext IV included */ ;
b453872c JG	218	*pos++ = key->tx_pn[3];
	219	*pos++ = key->tx_pn[2];
	220	*pos++ = key->tx_pn[1];
	221	*pos++ = key->tx_pn[0];
	222
31b59eae JK	223	return CCMP_HDR_LEN;
	224	}
	225
	226	static int ieee80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
	227	{
	228	struct ieee80211_ccmp_data *key = priv;
	229	int data_len, i, blocks, last, len;
	230	u8 pos, mic;
	231	struct ieee80211_hdr_4addr *hdr;
	232	u8 *b0 = key->tx_b0;
	233	u8 *b = key->tx_b;
	234	u8 *e = key->tx_e;
	235	u8 *s0 = key->tx_s0;
	236
	237	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	238	return -1;
	239
	240	data_len = skb->len - hdr_len;
	241	len = ieee80211_ccmp_hdr(skb, hdr_len, priv);
	242	if (len < 0)
	243	return -1;
	244
	245	pos = skb->data + hdr_len + CCMP_HDR_LEN;
	246	mic = skb_put(skb, CCMP_MIC_LEN);
ee34af37	247	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	248	ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
	249
	250	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	251	last = data_len % AES_BLOCK_LEN;
	252
	253	for (i = 1; i <= blocks; i++) {
	254	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	255	/* Authentication */
	256	xor_block(b, pos, len);
	257	ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
	258	/* Encryption, with counter */
	259	b0[14] = (i >> 8) & 0xff;
	260	b0[15] = i & 0xff;
	261	ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
	262	xor_block(pos, e, len);
	263	pos += len;
	264	}
	265
	266	for (i = 0; i < CCMP_MIC_LEN; i++)
	267	mic[i] = b[i] ^ s0[i];
	268
	269	return 0;
	270	}
	271
b453872c JG	272	static int ieee80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
	273	{
	274	struct ieee80211_ccmp_data *key = priv;
	275	u8 keyidx, *pos;
ee34af37	276	struct ieee80211_hdr_4addr *hdr;
b453872c JG	277	u8 *b0 = key->rx_b0;
	278	u8 *b = key->rx_b;
	279	u8 *a = key->rx_a;
	280	u8 pn[6];
	281	int i, blocks, last, len;
	282	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
	283	u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
	284
	285	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	286	key->dot11RSNAStatsCCMPFormatErrors++;
	287	return -1;
	288	}
	289
ee34af37	290	hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c JG	291	pos = skb->data + hdr_len;
	292	keyidx = pos[3];
	293	if (!(keyidx & (1 << 5))) {
	294	if (net_ratelimit()) {
	295	printk(KERN_DEBUG "CCMP: received packet without ExtIV"
	296	" flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
	297	}
	298	key->dot11RSNAStatsCCMPFormatErrors++;
	299	return -2;
	300	}
	301	keyidx >>= 6;
	302	if (key->key_idx != keyidx) {
	303	printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
	304	"keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
	305	return -6;
	306	}
	307	if (!key->key_set) {
	308	if (net_ratelimit()) {
	309	printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
	310	" with keyid=%d that does not have a configured"
	311	" key\n", MAC_ARG(hdr->addr2), keyidx);
	312	}
	313	return -3;
	314	}
	315
	316	pn[0] = pos[7];
	317	pn[1] = pos[6];
	318	pn[2] = pos[5];
	319	pn[3] = pos[4];
	320	pn[4] = pos[1];
	321	pn[5] = pos[0];
	322	pos += 8;
	323
	324	if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
	325	if (net_ratelimit()) {
	326	printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
	327	" previous PN %02x%02x%02x%02x%02x%02x "
	328	"received PN %02x%02x%02x%02x%02x%02x\n",
	329	MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
	330	MAC_ARG(pn));
	331	}
	332	key->dot11RSNAStatsCCMPReplays++;
	333	return -4;
	334	}
	335
	336	ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
	337	xor_block(mic, b, CCMP_MIC_LEN);
	338
	339	blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
	340	last = data_len % AES_BLOCK_LEN;
	341
	342	for (i = 1; i <= blocks; i++) {
	343	len = (i == blocks && last) ? last : AES_BLOCK_LEN;
	344	/* Decrypt, with counter */
	345	b0[14] = (i >> 8) & 0xff;
	346	b0[15] = i & 0xff;
	347	ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
	348	xor_block(pos, b, len);
	349	/* Authentication */
	350	xor_block(a, pos, len);
	351	ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
	352	pos += len;
	353	}
	354
355	if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
356	if (net_ratelimit()) {
357	printk(KERN_DEBUG "CCMP: decrypt failed: STA="
358	MAC_FMT "\n", MAC_ARG(hdr->addr2));
359	}
360	key->dot11RSNAStatsCCMPDecryptErrors++;
361	return -5;
362	}
363
364	memcpy(key->rx_pn, pn, CCMP_PN_LEN);
365
366	/* Remove hdr and MIC */
367	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
368	skb_pull(skb, CCMP_HDR_LEN);
369	skb_trim(skb, skb->len - CCMP_MIC_LEN);
370
371	return keyidx;
372	}
373
0edd5b44	374	static int ieee80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
b453872c JG	375	{
	376	struct ieee80211_ccmp_data *data = priv;
	377	int keyidx;
	378	struct crypto_tfm *tfm = data->tfm;
	379
	380	keyidx = data->key_idx;
	381	memset(data, 0, sizeof(*data));
	382	data->key_idx = keyidx;
	383	data->tfm = tfm;
	384	if (len == CCMP_TK_LEN) {
	385	memcpy(data->key, key, CCMP_TK_LEN);
	386	data->key_set = 1;
	387	if (seq) {
	388	data->rx_pn[0] = seq[5];
	389	data->rx_pn[1] = seq[4];
	390	data->rx_pn[2] = seq[3];
	391	data->rx_pn[3] = seq[2];
	392	data->rx_pn[4] = seq[1];
	393	data->rx_pn[5] = seq[0];
	394	}
	395	crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
	396	} else if (len == 0)
	397	data->key_set = 0;
	398	else
	399	return -1;
	400
	401	return 0;
	402	}
	403
0edd5b44	404	static int ieee80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
b453872c JG	405	{
	406	struct ieee80211_ccmp_data *data = priv;
	407
	408	if (len < CCMP_TK_LEN)
	409	return -1;
	410
	411	if (!data->key_set)
	412	return 0;
	413	memcpy(key, data->key, CCMP_TK_LEN);
	414
	415	if (seq) {
	416	seq[0] = data->tx_pn[5];
	417	seq[1] = data->tx_pn[4];
	418	seq[2] = data->tx_pn[3];
	419	seq[3] = data->tx_pn[2];
	420	seq[4] = data->tx_pn[1];
	421	seq[5] = data->tx_pn[0];
	422	}
	423
	424	return CCMP_TK_LEN;
	425	}
	426
0edd5b44	427	static char ieee80211_ccmp_print_stats(char p, void *priv)
b453872c JG	428	{
	429	struct ieee80211_ccmp_data *ccmp = priv;
	430	p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
	431	"tx_pn=%02x%02x%02x%02x%02x%02x "
	432	"rx_pn=%02x%02x%02x%02x%02x%02x "
	433	"format_errors=%d replays=%d decrypt_errors=%d\n",
	434	ccmp->key_idx, ccmp->key_set,
	435	MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
	436	ccmp->dot11RSNAStatsCCMPFormatErrors,
	437	ccmp->dot11RSNAStatsCCMPReplays,
	438	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	439
	440	return p;
	441	}
	442
b453872c	443	static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
74079fdc JK	444	.name = "CCMP",
	445	.init = ieee80211_ccmp_init,
	446	.deinit = ieee80211_ccmp_deinit,
31b59eae	447	.build_iv = ieee80211_ccmp_hdr,
74079fdc JK	448	.encrypt_mpdu = ieee80211_ccmp_encrypt,
	449	.decrypt_mpdu = ieee80211_ccmp_decrypt,
	450	.encrypt_msdu = NULL,
	451	.decrypt_msdu = NULL,
	452	.set_key = ieee80211_ccmp_set_key,
	453	.get_key = ieee80211_ccmp_get_key,
	454	.print_stats = ieee80211_ccmp_print_stats,
1264fc04 JK	455	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
1264fc04 JK	456	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
74079fdc	457	.owner = THIS_MODULE,
b453872c JG	458	};
b453872c JG	459
b453872c JG	460	static int __init ieee80211_crypto_ccmp_init(void)
	461	{
	462	return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
	463	}
	464
b453872c JG	465	static void __exit ieee80211_crypto_ccmp_exit(void)
	466	{
	467	ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
	468	}
	469
b453872c JG	470	module_init(ieee80211_crypto_ccmp_init);
b453872c JG	471	module_exit(ieee80211_crypto_ccmp_exit);