net/wireless/lib80211_crypt_ccmp.c - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * lib80211 crypt: host-based CCMP encryption implementation for lib80211
  *
  * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
  * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
  */

 #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 <linux/ieee80211.h>

 #include <linux/crypto.h>
 #include <crypto/aead.h>

 #include <net/lib80211.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 lib80211_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_aead *tfm;

 	/* scratch buffers for virt_to_page() (crypto API) */
 	u8 tx_aad[2 * AES_BLOCK_LEN];
 	u8 rx_aad[2 * AES_BLOCK_LEN];
 };

 static void *lib80211_ccmp_init(int key_idx)
 {
 	struct lib80211_ccmp_data *priv;

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

 	priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(priv->tfm)) {
 		priv->tfm = NULL;
 		goto fail;
 	}

 	return priv;

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

 	return NULL;
 }

 static void lib80211_ccmp_deinit(void *priv)
 {
 	struct lib80211_ccmp_data *_priv = priv;
 	if (_priv && _priv->tfm)
 		crypto_free_aead(_priv->tfm);
 	kfree(priv);
 }

 static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr,
 				const u8 *pn, u8 *iv, u8 *aad)
 {
 	u8 *pos, qc = 0;
 	size_t aad_len;
 	int a4_included, qc_included;

 	a4_included = ieee80211_has_a4(hdr->frame_control);
 	qc_included = ieee80211_is_data_qos(hdr->frame_control);

 	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;
 	}

 	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
 	 * mode authentication are not allowed to collide, yet both are derived
 	 * from the same vector. We only set L := 1 here to indicate that the
 	 * data size can be represented in (L+1) bytes. The CCM layer will take
 	 * care of storing the data length in the top (L+1) bytes and setting
 	 * and clearing the other bits as is required to derive the two IVs.
 	 */
 	iv[0] = 0x1;

 	/* Nonce: QC | A2 | PN */
 	iv[1] = qc;
 	memcpy(iv + 2, hdr->addr2, ETH_ALEN);
 	memcpy(iv + 8, pn, CCMP_PN_LEN);

 	/* 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] = pos[0] & 0x8f;
 	aad[1] = pos[1] & 0xc7;
 	memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
 	pos = (u8 *) & hdr->seq_ctrl;
 	aad[20] = pos[0] & 0x0f;
 	aad[21] = 0;		/* all bits masked */
 	memset(aad + 22, 0, 8);
 	if (a4_included)
 		memcpy(aad + 22, hdr->addr4, ETH_ALEN);
 	if (qc_included) {
 		aad[a4_included ? 28 : 22] = qc;
 		/* rest of QC masked */
 	}
 	return aad_len;
 }

 static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
 			      u8 *aeskey, int keylen, void *priv)
 {
 	struct lib80211_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 lib80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 {
 	struct lib80211_ccmp_data *key = priv;
 	struct ieee80211_hdr *hdr;
 	struct aead_request *req;
 	struct scatterlist sg[2];
 	u8 *aad = key->tx_aad;
 	u8 iv[AES_BLOCK_LEN];
 	int len, data_len, aad_len;
 	int ret;

 	if (skb_tailroom(skb) < CCMP_MIC_LEN || skb->len < hdr_len)
 		return -1;

 	data_len = skb->len - hdr_len;
 	len = lib80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
 	if (len < 0)
 		return -1;

 	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
 	if (!req)
 		return -ENOMEM;

 	hdr = (struct ieee80211_hdr *)skb->data;
 	aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad);

 	skb_put(skb, CCMP_MIC_LEN);

 	sg_init_table(sg, 2);
 	sg_set_buf(&sg[0], aad, aad_len);
 	sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN,
 		   data_len + CCMP_MIC_LEN);

 	aead_request_set_callback(req, 0, NULL, NULL);
 	aead_request_set_ad(req, aad_len);
 	aead_request_set_crypt(req, sg, sg, data_len, iv);

 	ret = crypto_aead_encrypt(req);
 	aead_request_free(req);

 	return ret;
 }

 /*
  * 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 lib80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 {
 	struct lib80211_ccmp_data *key = priv;
 	u8 keyidx, *pos;
 	struct ieee80211_hdr *hdr;
 	struct aead_request *req;
 	struct scatterlist sg[2];
 	u8 *aad = key->rx_aad;
 	u8 iv[AES_BLOCK_LEN];
 	u8 pn[6];
 	int aad_len, ret;
 	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;

 	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
 		key->dot11RSNAStatsCCMPFormatErrors++;
 		return -1;
 	}

 	hdr = (struct ieee80211_hdr *)skb->data;
 	pos = skb->data + hdr_len;
 	keyidx = pos[3];
 	if (!(keyidx & (1 << 5))) {
 		net_dbg_ratelimited("CCMP: received packet without ExtIV flag from %pM\n",
 				    hdr->addr2);
 		key->dot11RSNAStatsCCMPFormatErrors++;
 		return -2;
 	}
 	keyidx >>= 6;
 	if (key->key_idx != keyidx) {
 		net_dbg_ratelimited("CCMP: RX tkey->key_idx=%d frame keyidx=%d\n",
 				    key->key_idx, keyidx);
 		return -6;
 	}
 	if (!key->key_set) {
 		net_dbg_ratelimited("CCMP: received packet from %pM with keyid=%d that does not have a configured key\n",
 				    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)) {
 #ifdef CONFIG_LIB80211_DEBUG
 		net_dbg_ratelimited("CCMP: replay detected: STA=%pM previous PN %02x%02x%02x%02x%02x%02x received PN %02x%02x%02x%02x%02x%02x\n",
 				    hdr->addr2,
 				    key->rx_pn[0], key->rx_pn[1], key->rx_pn[2],
 				    key->rx_pn[3], key->rx_pn[4], key->rx_pn[5],
 				    pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
 #endif
 		key->dot11RSNAStatsCCMPReplays++;
 		return -4;
 	}

 	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
 	if (!req)
 		return -ENOMEM;

 	aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad);

 	sg_init_table(sg, 2);
 	sg_set_buf(&sg[0], aad, aad_len);
 	sg_set_buf(&sg[1], pos, data_len);

 	aead_request_set_callback(req, 0, NULL, NULL);
 	aead_request_set_ad(req, aad_len);
 	aead_request_set_crypt(req, sg, sg, data_len, iv);

 	ret = crypto_aead_decrypt(req);
 	aead_request_free(req);

 	if (ret) {
 		net_dbg_ratelimited("CCMP: decrypt failed: STA=%pM (%d)\n",
 				    hdr->addr2, ret);
 		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 lib80211_ccmp_set_key(void *key, int len, u8 * seq, void *priv)
 {
 	struct lib80211_ccmp_data *data = priv;
 	int keyidx;
 	struct crypto_aead *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];
 		}
 		if (crypto_aead_setauthsize(data->tfm, CCMP_MIC_LEN) ||
 		    crypto_aead_setkey(data->tfm, data->key, CCMP_TK_LEN))
 			return -1;
 	} else if (len == 0)
 		data->key_set = 0;
 	else
 		return -1;

 	return 0;
 }

 static int lib80211_ccmp_get_key(void *key, int len, u8 * seq, void *priv)
 {
 	struct lib80211_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 void lib80211_ccmp_print_stats(struct seq_file *m, void *priv)
 {
 	struct lib80211_ccmp_data *ccmp = priv;

 	seq_printf(m,
 		   "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,
 		   ccmp->tx_pn[0], ccmp->tx_pn[1], ccmp->tx_pn[2],
 		   ccmp->tx_pn[3], ccmp->tx_pn[4], ccmp->tx_pn[5],
 		   ccmp->rx_pn[0], ccmp->rx_pn[1], ccmp->rx_pn[2],
 		   ccmp->rx_pn[3], ccmp->rx_pn[4], ccmp->rx_pn[5],
 		   ccmp->dot11RSNAStatsCCMPFormatErrors,
 		   ccmp->dot11RSNAStatsCCMPReplays,
 		   ccmp->dot11RSNAStatsCCMPDecryptErrors);
 }

 static struct lib80211_crypto_ops lib80211_crypt_ccmp = {
 	.name = "CCMP",
 	.init = lib80211_ccmp_init,
 	.deinit = lib80211_ccmp_deinit,
 	.encrypt_mpdu = lib80211_ccmp_encrypt,
 	.decrypt_mpdu = lib80211_ccmp_decrypt,
 	.encrypt_msdu = NULL,
 	.decrypt_msdu = NULL,
 	.set_key = lib80211_ccmp_set_key,
 	.get_key = lib80211_ccmp_get_key,
 	.print_stats = lib80211_ccmp_print_stats,
 	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
 	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
 	.owner = THIS_MODULE,
 };

 static int __init lib80211_crypto_ccmp_init(void)
 {
 	return lib80211_register_crypto_ops(&lib80211_crypt_ccmp);
 }

 static void __exit lib80211_crypto_ccmp_exit(void)
 {
 	lib80211_unregister_crypto_ops(&lib80211_crypt_ccmp);
 }

 module_init(lib80211_crypto_ccmp_init);
 module_exit(lib80211_crypto_ccmp_exit);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* lib80211 crypt: host-based CCMP encryption implementation for lib80211
	*
	* Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
	* Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
	*/

	#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 <linux/ieee80211.h>

	#include <linux/crypto.h>
	#include <crypto/aead.h>

	#include <net/lib80211.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 lib80211_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_aead *tfm;

	/* scratch buffers for virt_to_page() (crypto API) */
	u8 tx_aad[2 * AES_BLOCK_LEN];
	u8 rx_aad[2 * AES_BLOCK_LEN];
	};

	static void *lib80211_ccmp_init(int key_idx)
	{
	struct lib80211_ccmp_data *priv;

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

	priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(priv->tfm)) {
	priv->tfm = NULL;
	goto fail;
	}

	return priv;

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

	return NULL;
	}

	static void lib80211_ccmp_deinit(void *priv)
	{
	struct lib80211_ccmp_data *_priv = priv;
	if (_priv && _priv->tfm)
	crypto_free_aead(_priv->tfm);
	kfree(priv);
	}

	static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr,
	const u8 pn, u8 iv, u8 *aad)
	{
	u8 *pos, qc = 0;
	size_t aad_len;
	int a4_included, qc_included;

	a4_included = ieee80211_has_a4(hdr->frame_control);
	qc_included = ieee80211_is_data_qos(hdr->frame_control);

	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;
	}

	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
	* mode authentication are not allowed to collide, yet both are derived
	* from the same vector. We only set L := 1 here to indicate that the
	* data size can be represented in (L+1) bytes. The CCM layer will take
	* care of storing the data length in the top (L+1) bytes and setting
	* and clearing the other bits as is required to derive the two IVs.
	*/
	iv[0] = 0x1;

	/* Nonce: QC \| A2 \| PN */
	iv[1] = qc;
	memcpy(iv + 2, hdr->addr2, ETH_ALEN);
	memcpy(iv + 8, pn, CCMP_PN_LEN);

	/* 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] = pos[0] & 0x8f;
	aad[1] = pos[1] & 0xc7;
	memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
	pos = (u8 *) & hdr->seq_ctrl;
	aad[20] = pos[0] & 0x0f;
	aad[21] = 0; /* all bits masked */
	memset(aad + 22, 0, 8);
	if (a4_included)
	memcpy(aad + 22, hdr->addr4, ETH_ALEN);
	if (qc_included) {
	aad[a4_included ? 28 : 22] = qc;
	/* rest of QC masked */
	}
	return aad_len;
	}

	static int lib80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
	u8 aeskey, int keylen, void priv)
	{
	struct lib80211_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 lib80211_ccmp_encrypt(struct sk_buff skb, int hdr_len, void priv)
	{
	struct lib80211_ccmp_data *key = priv;
	struct ieee80211_hdr *hdr;
	struct aead_request *req;
	struct scatterlist sg[2];
	u8 *aad = key->tx_aad;
	u8 iv[AES_BLOCK_LEN];
	int len, data_len, aad_len;
	int ret;

	if (skb_tailroom(skb) < CCMP_MIC_LEN \|\| skb->len < hdr_len)
	return -1;

	data_len = skb->len - hdr_len;
	len = lib80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
	if (len < 0)
	return -1;

	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
	if (!req)
	return -ENOMEM;

	hdr = (struct ieee80211_hdr *)skb->data;
	aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad);

	skb_put(skb, CCMP_MIC_LEN);

	sg_init_table(sg, 2);
	sg_set_buf(&sg[0], aad, aad_len);
	sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN,
	data_len + CCMP_MIC_LEN);

	aead_request_set_callback(req, 0, NULL, NULL);
	aead_request_set_ad(req, aad_len);
	aead_request_set_crypt(req, sg, sg, data_len, iv);

	ret = crypto_aead_encrypt(req);
	aead_request_free(req);

	return ret;
	}

	/*
	* 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 lib80211_ccmp_decrypt(struct sk_buff skb, int hdr_len, void priv)
	{
	struct lib80211_ccmp_data *key = priv;
	u8 keyidx, *pos;
	struct ieee80211_hdr *hdr;
	struct aead_request *req;
	struct scatterlist sg[2];
	u8 *aad = key->rx_aad;
	u8 iv[AES_BLOCK_LEN];
	u8 pn[6];
	int aad_len, ret;
	size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;

	if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
	key->dot11RSNAStatsCCMPFormatErrors++;
	return -1;
	}

	hdr = (struct ieee80211_hdr *)skb->data;
	pos = skb->data + hdr_len;
	keyidx = pos[3];
	if (!(keyidx & (1 << 5))) {
	net_dbg_ratelimited("CCMP: received packet without ExtIV flag from %pM\n",
	hdr->addr2);
	key->dot11RSNAStatsCCMPFormatErrors++;
	return -2;
	}
	keyidx >>= 6;
	if (key->key_idx != keyidx) {
	net_dbg_ratelimited("CCMP: RX tkey->key_idx=%d frame keyidx=%d\n",
	key->key_idx, keyidx);
	return -6;
	}
	if (!key->key_set) {
	net_dbg_ratelimited("CCMP: received packet from %pM with keyid=%d that does not have a configured key\n",
	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)) {
	#ifdef CONFIG_LIB80211_DEBUG
	net_dbg_ratelimited("CCMP: replay detected: STA=%pM previous PN %02x%02x%02x%02x%02x%02x received PN %02x%02x%02x%02x%02x%02x\n",
	hdr->addr2,
	key->rx_pn[0], key->rx_pn[1], key->rx_pn[2],
	key->rx_pn[3], key->rx_pn[4], key->rx_pn[5],
	pn[0], pn[1], pn[2], pn[3], pn[4], pn[5]);
	#endif
	key->dot11RSNAStatsCCMPReplays++;
	return -4;
	}

	req = aead_request_alloc(key->tfm, GFP_ATOMIC);
	if (!req)
	return -ENOMEM;

	aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad);

	sg_init_table(sg, 2);
	sg_set_buf(&sg[0], aad, aad_len);
	sg_set_buf(&sg[1], pos, data_len);

	aead_request_set_callback(req, 0, NULL, NULL);
	aead_request_set_ad(req, aad_len);
	aead_request_set_crypt(req, sg, sg, data_len, iv);

	ret = crypto_aead_decrypt(req);
	aead_request_free(req);

	if (ret) {
	net_dbg_ratelimited("CCMP: decrypt failed: STA=%pM (%d)\n",
	hdr->addr2, ret);
	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 lib80211_ccmp_set_key(void key, int len, u8 seq, void *priv)
	{
	struct lib80211_ccmp_data *data = priv;
	int keyidx;
	struct crypto_aead *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];
	}
	if (crypto_aead_setauthsize(data->tfm, CCMP_MIC_LEN) \|\|
	crypto_aead_setkey(data->tfm, data->key, CCMP_TK_LEN))
	return -1;
	} else if (len == 0)
	data->key_set = 0;
	else
	return -1;

	return 0;
	}

	static int lib80211_ccmp_get_key(void key, int len, u8 seq, void *priv)
	{
	struct lib80211_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 void lib80211_ccmp_print_stats(struct seq_file m, void priv)
	{
	struct lib80211_ccmp_data *ccmp = priv;

	seq_printf(m,
	"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,
	ccmp->tx_pn[0], ccmp->tx_pn[1], ccmp->tx_pn[2],
	ccmp->tx_pn[3], ccmp->tx_pn[4], ccmp->tx_pn[5],
	ccmp->rx_pn[0], ccmp->rx_pn[1], ccmp->rx_pn[2],
	ccmp->rx_pn[3], ccmp->rx_pn[4], ccmp->rx_pn[5],
	ccmp->dot11RSNAStatsCCMPFormatErrors,
	ccmp->dot11RSNAStatsCCMPReplays,
	ccmp->dot11RSNAStatsCCMPDecryptErrors);
	}

	static struct lib80211_crypto_ops lib80211_crypt_ccmp = {
	.name = "CCMP",
	.init = lib80211_ccmp_init,
	.deinit = lib80211_ccmp_deinit,
	.encrypt_mpdu = lib80211_ccmp_encrypt,
	.decrypt_mpdu = lib80211_ccmp_decrypt,
	.encrypt_msdu = NULL,
	.decrypt_msdu = NULL,
	.set_key = lib80211_ccmp_set_key,
	.get_key = lib80211_ccmp_get_key,
	.print_stats = lib80211_ccmp_print_stats,
	.extra_mpdu_prefix_len = CCMP_HDR_LEN,
	.extra_mpdu_postfix_len = CCMP_MIC_LEN,
	.owner = THIS_MODULE,
	};

	static int __init lib80211_crypto_ccmp_init(void)
	{
	return lib80211_register_crypto_ops(&lib80211_crypt_ccmp);
	}

	static void __exit lib80211_crypto_ccmp_exit(void)
	{
	lib80211_unregister_crypto_ops(&lib80211_crypt_ccmp);
	}

	module_init(lib80211_crypto_ccmp_init);
	module_exit(lib80211_crypto_ccmp_exit);