net/ieee80211/ieee80211_crypt_ccmp.c - pub/scm/linux/kernel/git/herbert/crypto-2.6 - Git at Google

 /*
  * 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) & 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);
	/*
	* 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) & 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);