[linux.git] / net / mac80211 / wep.c

/*
 * Software WEP encryption implementation
 * Copyright 2002, Jouni Malinen <[email protected]>
 * Copyright 2003, Instant802 Networks, Inc.
 *
 * 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.
 */

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/random.h>
#include <linux/compiler.h>
#include <linux/crc32.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <asm/unaligned.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "wep.h"


int ieee80211_wep_init(struct ieee80211_local *local)
{
	/* start WEP IV from a random value */
	get_random_bytes(&local->wep_iv, IEEE80211_WEP_IV_LEN);

	local->wep_tx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(local->wep_tx_tfm)) {
		local->wep_rx_tfm = ERR_PTR(-EINVAL);
		return PTR_ERR(local->wep_tx_tfm);
	}

	local->wep_rx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(local->wep_rx_tfm)) {
		crypto_free_cipher(local->wep_tx_tfm);
		local->wep_tx_tfm = ERR_PTR(-EINVAL);
		return PTR_ERR(local->wep_rx_tfm);
	}

	return 0;
}

void ieee80211_wep_free(struct ieee80211_local *local)
{
	if (!IS_ERR(local->wep_tx_tfm))
		crypto_free_cipher(local->wep_tx_tfm);
	if (!IS_ERR(local->wep_rx_tfm))
		crypto_free_cipher(local->wep_rx_tfm);
}

static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)
{
	/*
	 * Fluhrer, Mantin, and Shamir have reported weaknesses in the
	 * key scheduling algorithm of RC4. At least IVs (KeyByte + 3,
	 * 0xff, N) can be used to speedup attacks, so avoid using them.
	 */
	if ((iv & 0xff00) == 0xff00) {
		u8 B = (iv >> 16) & 0xff;
		if (B >= 3 && B < 3 + keylen)
			return true;
	}
	return false;
}


static void ieee80211_wep_get_iv(struct ieee80211_local *local,
				 int keylen, int keyidx, u8 *iv)
{
	local->wep_iv++;
	if (ieee80211_wep_weak_iv(local->wep_iv, keylen))
		local->wep_iv += 0x0100;

	if (!iv)
		return;

	*iv++ = (local->wep_iv >> 16) & 0xff;
	*iv++ = (local->wep_iv >> 8) & 0xff;
	*iv++ = local->wep_iv & 0xff;
	*iv++ = keyidx << 6;
}


static u8 *ieee80211_wep_add_iv(struct ieee80211_local *local,
				struct sk_buff *skb,
				int keylen, int keyidx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	unsigned int hdrlen;
	u8 *newhdr;

	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);

	if (WARN_ON(skb_headroom(skb) < IEEE80211_WEP_IV_LEN))
		return NULL;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	newhdr = skb_push(skb, IEEE80211_WEP_IV_LEN);
	memmove(newhdr, newhdr + IEEE80211_WEP_IV_LEN, hdrlen);

	/* the HW only needs room for the IV, but not the actual IV */
	if (info->control.hw_key &&
	    (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
		return newhdr + hdrlen;

	ieee80211_wep_get_iv(local, keylen, keyidx, newhdr + hdrlen);
	return newhdr + hdrlen;
}


static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
				    struct sk_buff *skb,
				    struct ieee80211_key *key)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	unsigned int hdrlen;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	memmove(skb->data + IEEE80211_WEP_IV_LEN, skb->data, hdrlen);
	skb_pull(skb, IEEE80211_WEP_IV_LEN);
}


/* Perform WEP encryption using given key. data buffer must have tailroom
 * for 4-byte ICV. data_len must not include this ICV. Note: this function
 * does _not_ add IV. data = RC4(data | CRC32(data)) */
int ieee80211_wep_encrypt_data(struct crypto_cipher *tfm, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{
	__le32 icv;
	int i;

	if (IS_ERR(tfm))
		return -1;

	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
	put_unaligned(icv, (__le32 *)(data + data_len));

	crypto_cipher_setkey(tfm, rc4key, klen);
	for (i = 0; i < data_len + IEEE80211_WEP_ICV_LEN; i++)
		crypto_cipher_encrypt_one(tfm, data + i, data + i);

	return 0;
}


/* Perform WEP encryption on given skb. 4 bytes of extra space (IV) in the
 * beginning of the buffer 4 bytes of extra space (ICV) in the end of the
 * buffer will be added. Both IV and ICV will be transmitted, so the
 * payload length increases with 8 bytes.
 *
 * WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
 */
int ieee80211_wep_encrypt(struct ieee80211_local *local,
			  struct sk_buff *skb,
			  const u8 *key, int keylen, int keyidx)
{
	u8 *iv;
	size_t len;
	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];

	if (WARN_ON(skb_tailroom(skb) < IEEE80211_WEP_ICV_LEN))
		return -1;

	iv = ieee80211_wep_add_iv(local, skb, keylen, keyidx);
	if (!iv)
		return -1;

	len = skb->len - (iv + IEEE80211_WEP_IV_LEN - skb->data);

	/* Prepend 24-bit IV to RC4 key */
	memcpy(rc4key, iv, 3);

	/* Copy rest of the WEP key (the secret part) */
	memcpy(rc4key + 3, key, keylen);

	/* Add room for ICV */
	skb_put(skb, IEEE80211_WEP_ICV_LEN);

	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
					  iv + IEEE80211_WEP_IV_LEN, len);
}


/* Perform WEP decryption using given key. data buffer includes encrypted
 * payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
 * Return 0 on success and -1 on ICV mismatch. */
int ieee80211_wep_decrypt_data(struct crypto_cipher *tfm, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{
	__le32 crc;
	int i;

	if (IS_ERR(tfm))
		return -1;

	crypto_cipher_setkey(tfm, rc4key, klen);
	for (i = 0; i < data_len + IEEE80211_WEP_ICV_LEN; i++)
		crypto_cipher_decrypt_one(tfm, data + i, data + i);

	crc = cpu_to_le32(~crc32_le(~0, data, data_len));
	if (memcmp(&crc, data + data_len, IEEE80211_WEP_ICV_LEN) != 0)
		/* ICV mismatch */
		return -1;

	return 0;
}


/* Perform WEP decryption on given skb. Buffer includes whole WEP part of
 * the frame: IV (4 bytes), encrypted payload (including SNAP header),
 * ICV (4 bytes). skb->len includes both IV and ICV.
 *
 * Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
 * failure. If frame is OK, IV and ICV will be removed, i.e., decrypted payload
 * is moved to the beginning of the skb and skb length will be reduced.
 */
static int ieee80211_wep_decrypt(struct ieee80211_local *local,
				 struct sk_buff *skb,
				 struct ieee80211_key *key)
{
	u32 klen;
	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
	u8 keyidx;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	unsigned int hdrlen;
	size_t len;
	int ret = 0;

	if (!ieee80211_has_protected(hdr->frame_control))
		return -1;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	if (skb->len < hdrlen + IEEE80211_WEP_IV_LEN + IEEE80211_WEP_ICV_LEN)
		return -1;

	len = skb->len - hdrlen - IEEE80211_WEP_IV_LEN - IEEE80211_WEP_ICV_LEN;

	keyidx = skb->data[hdrlen + 3] >> 6;

	if (!key || keyidx != key->conf.keyidx)
		return -1;

	klen = 3 + key->conf.keylen;

	/* Prepend 24-bit IV to RC4 key */
	memcpy(rc4key, skb->data + hdrlen, 3);

	/* Copy rest of the WEP key (the secret part) */
	memcpy(rc4key + 3, key->conf.key, key->conf.keylen);

	if (ieee80211_wep_decrypt_data(local->wep_rx_tfm, rc4key, klen,
				       skb->data + hdrlen +
				       IEEE80211_WEP_IV_LEN, len))
		ret = -1;

	/* Trim ICV */
	skb_trim(skb, skb->len - IEEE80211_WEP_ICV_LEN);

	/* Remove IV */
	memmove(skb->data + IEEE80211_WEP_IV_LEN, skb->data, hdrlen);
	skb_pull(skb, IEEE80211_WEP_IV_LEN);

	return ret;
}

ieee80211_rx_result
ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
{
	struct sk_buff *skb = rx->skb;
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	__le16 fc = hdr->frame_control;

	if (!ieee80211_is_data(fc) && !ieee80211_is_auth(fc))
		return RX_CONTINUE;

	if (!(status->flag & RX_FLAG_DECRYPTED)) {
		if (skb_linearize(rx->skb))
			return RX_DROP_UNUSABLE;
		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))
			return RX_DROP_UNUSABLE;
	} else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
		if (!pskb_may_pull(rx->skb, ieee80211_hdrlen(fc) +
					    IEEE80211_WEP_IV_LEN))
			return RX_DROP_UNUSABLE;
		ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
		/* remove ICV */
		if (!(status->flag & RX_FLAG_ICV_STRIPPED) &&
		    pskb_trim(rx->skb, rx->skb->len - IEEE80211_WEP_ICV_LEN))
			return RX_DROP_UNUSABLE;
	}

	return RX_CONTINUE;
}

static int wep_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_key_conf *hw_key = info->control.hw_key;

	if (!hw_key) {
		if (ieee80211_wep_encrypt(tx->local, skb, tx->key->conf.key,
					  tx->key->conf.keylen,
					  tx->key->conf.keyidx))
			return -1;
	} else if ((hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) ||
		   (hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
		if (!ieee80211_wep_add_iv(tx->local, skb,
					  tx->key->conf.keylen,
					  tx->key->conf.keyidx))
			return -1;
	}

	return 0;
}

ieee80211_tx_result
ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
{
	struct sk_buff *skb;

	ieee80211_tx_set_protected(tx);

	skb_queue_walk(&tx->skbs, skb) {
		if (wep_encrypt_skb(tx, skb) < 0) {
			I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
			return TX_DROP;
		}
	}

	return TX_CONTINUE;
}
Commit	Line	Data
f0706e82 JB	1	/*
	2	* Software WEP encryption implementation
	3	* Copyright 2002, Jouni Malinen <[email protected]>
	4	* Copyright 2003, Instant802 Networks, Inc.
	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.
	9	*/
	10
	11	#include <linux/netdevice.h>
	12	#include <linux/types.h>
	13	#include <linux/random.h>
	14	#include <linux/compiler.h>
	15	#include <linux/crc32.h>
	16	#include <linux/crypto.h>
	17	#include <linux/err.h>
	18	#include <linux/mm.h>
11763609	19	#include <linux/scatterlist.h>
5a0e3ad6	20	#include <linux/slab.h>
860c6e6a	21	#include <asm/unaligned.h>
f0706e82 JB	22
	23	#include <net/mac80211.h>
	24	#include "ieee80211_i.h"
	25	#include "wep.h"
	26
	27
	28	int ieee80211_wep_init(struct ieee80211_local *local)
	29	{
	30	/* start WEP IV from a random value */
4325f6ca	31	get_random_bytes(&local->wep_iv, IEEE80211_WEP_IV_LEN);
f0706e82	32
5f9f1812	33	local->wep_tx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
088c8726 JL	34	if (IS_ERR(local->wep_tx_tfm)) {
088c8726 JL	35	local->wep_rx_tfm = ERR_PTR(-EINVAL);
023a04be	36	return PTR_ERR(local->wep_tx_tfm);
088c8726	37	}
f0706e82	38
5f9f1812	39	local->wep_rx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
f0706e82	40	if (IS_ERR(local->wep_rx_tfm)) {
5f9f1812	41	crypto_free_cipher(local->wep_tx_tfm);
088c8726	42	local->wep_tx_tfm = ERR_PTR(-EINVAL);
023a04be	43	return PTR_ERR(local->wep_rx_tfm);
f0706e82 JB	44	}
	45
	46	return 0;
	47	}
	48
	49	void ieee80211_wep_free(struct ieee80211_local *local)
	50	{
3473187d	51	if (!IS_ERR(local->wep_tx_tfm))
5f9f1812	52	crypto_free_cipher(local->wep_tx_tfm);
3473187d	53	if (!IS_ERR(local->wep_rx_tfm))
5f9f1812	54	crypto_free_cipher(local->wep_rx_tfm);
f0706e82 JB	55	}
f0706e82 JB	56
c6a1fa12	57	static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)
f0706e82	58	{
c6a1fa12 JB	59	/*
c6a1fa12 JB	60	* Fluhrer, Mantin, and Shamir have reported weaknesses in the
f0706e82	61	* key scheduling algorithm of RC4. At least IVs (KeyByte + 3,
c6a1fa12 JB	62	* 0xff, N) can be used to speedup attacks, so avoid using them.
c6a1fa12 JB	63	*/
f0706e82 JB	64	if ((iv & 0xff00) == 0xff00) {
	65	u8 B = (iv >> 16) & 0xff;
	66	if (B >= 3 && B < 3 + keylen)
c6a1fa12	67	return true;
f0706e82	68	}
c6a1fa12	69	return false;
f0706e82 JB	70	}
	71
	72
4f0d18e2	73	static void ieee80211_wep_get_iv(struct ieee80211_local *local,
c9cf0122	74	int keylen, int keyidx, u8 *iv)
f0706e82 JB	75	{
f0706e82 JB	76	local->wep_iv++;
c9cf0122	77	if (ieee80211_wep_weak_iv(local->wep_iv, keylen))
f0706e82 JB	78	local->wep_iv += 0x0100;
	79
	80	if (!iv)
	81	return;
	82
	83	*iv++ = (local->wep_iv >> 16) & 0xff;
	84	*iv++ = (local->wep_iv >> 8) & 0xff;
	85	*iv++ = local->wep_iv & 0xff;
c9cf0122	86	*iv++ = keyidx << 6;
f0706e82 JB	87	}
	88
	89
6a22a59d JB	90	static u8 ieee80211_wep_add_iv(struct ieee80211_local local,
6a22a59d JB	91	struct sk_buff *skb,
c9cf0122	92	int keylen, int keyidx)
f0706e82	93	{
70217d7f	94	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
ee70108f	95	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
70217d7f	96	unsigned int hdrlen;
f0706e82 JB	97	u8 *newhdr;
f0706e82 JB	98
70217d7f	99	hdr->frame_control \|= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
f0706e82	100
47b4e1fc	101	if (WARN_ON(skb_headroom(skb) < IEEE80211_WEP_IV_LEN))
23c0752a	102	return NULL;
f0706e82	103
70217d7f	104	hdrlen = ieee80211_hdrlen(hdr->frame_control);
4325f6ca JB	105	newhdr = skb_push(skb, IEEE80211_WEP_IV_LEN);
4325f6ca JB	106	memmove(newhdr, newhdr + IEEE80211_WEP_IV_LEN, hdrlen);
ee70108f JD	107
	108	/* the HW only needs room for the IV, but not the actual IV */
	109	if (info->control.hw_key &&
	110	(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
	111	return newhdr + hdrlen;
	112
c9cf0122	113	ieee80211_wep_get_iv(local, keylen, keyidx, newhdr + hdrlen);
f0706e82 JB	114	return newhdr + hdrlen;
	115	}
	116
	117
4f0d18e2 JB	118	static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
	119	struct sk_buff *skb,
	120	struct ieee80211_key *key)
f0706e82	121	{
70217d7f HH	122	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	123	unsigned int hdrlen;
f0706e82	124
70217d7f	125	hdrlen = ieee80211_hdrlen(hdr->frame_control);
4325f6ca JB	126	memmove(skb->data + IEEE80211_WEP_IV_LEN, skb->data, hdrlen);
4325f6ca JB	127	skb_pull(skb, IEEE80211_WEP_IV_LEN);
f0706e82 JB	128	}
	129
	130
	131	/* Perform WEP encryption using given key. data buffer must have tailroom
	132	* for 4-byte ICV. data_len must not include this ICV. Note: this function
	133	* does _not_ add IV. data = RC4(data \| CRC32(data)) */
5f9f1812	134	int ieee80211_wep_encrypt_data(struct crypto_cipher tfm, u8 rc4key,
3473187d	135	size_t klen, u8 *data, size_t data_len)
f0706e82	136	{
860c6e6a	137	__le32 icv;
5f9f1812	138	int i;
f0706e82	139
3473187d JL	140	if (IS_ERR(tfm))
	141	return -1;
	142
860c6e6a IK	143	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
860c6e6a IK	144	put_unaligned(icv, (__le32 *)(data + data_len));
f0706e82	145
5f9f1812	146	crypto_cipher_setkey(tfm, rc4key, klen);
4325f6ca	147	for (i = 0; i < data_len + IEEE80211_WEP_ICV_LEN; i++)
5f9f1812	148	crypto_cipher_encrypt_one(tfm, data + i, data + i);
3473187d JL	149
3473187d JL	150	return 0;
f0706e82 JB	151	}
	152
	153
	154	/* Perform WEP encryption on given skb. 4 bytes of extra space (IV) in the
	155	* beginning of the buffer 4 bytes of extra space (ICV) in the end of the
	156	* buffer will be added. Both IV and ICV will be transmitted, so the
	157	* payload length increases with 8 bytes.
	158	*
	159	* WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
	160	*/
fffd0934 JB	161	int ieee80211_wep_encrypt(struct ieee80211_local *local,
	162	struct sk_buff *skb,
	163	const u8 *key, int keylen, int keyidx)
f0706e82	164	{
c9cf0122	165	u8 *iv;
f0706e82	166	size_t len;
c9cf0122	167	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
f0706e82	168
47b4e1fc JD	169	if (WARN_ON(skb_tailroom(skb) < IEEE80211_WEP_ICV_LEN))
	170	return -1;
	171
c9cf0122 JB	172	iv = ieee80211_wep_add_iv(local, skb, keylen, keyidx);
c9cf0122 JB	173	if (!iv)
f0706e82	174	return -1;
f0706e82	175
4325f6ca	176	len = skb->len - (iv + IEEE80211_WEP_IV_LEN - skb->data);
f0706e82 JB	177
	178	/* Prepend 24-bit IV to RC4 key */
	179	memcpy(rc4key, iv, 3);
	180
	181	/* Copy rest of the WEP key (the secret part) */
c9cf0122	182	memcpy(rc4key + 3, key, keylen);
f0706e82 JB	183
f0706e82 JB	184	/* Add room for ICV */
4325f6ca	185	skb_put(skb, IEEE80211_WEP_ICV_LEN);
f0706e82	186
3473187d	187	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
4325f6ca	188	iv + IEEE80211_WEP_IV_LEN, len);
f0706e82 JB	189	}
	190
	191
	192	/* Perform WEP decryption using given key. data buffer includes encrypted
	193	* payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
	194	* Return 0 on success and -1 on ICV mismatch. */
5f9f1812	195	int ieee80211_wep_decrypt_data(struct crypto_cipher tfm, u8 rc4key,
f0706e82 JB	196	size_t klen, u8 *data, size_t data_len)
f0706e82 JB	197	{
f0706e82	198	__le32 crc;
5f9f1812	199	int i;
f0706e82	200
3473187d JL	201	if (IS_ERR(tfm))
	202	return -1;
	203
5f9f1812	204	crypto_cipher_setkey(tfm, rc4key, klen);
4325f6ca	205	for (i = 0; i < data_len + IEEE80211_WEP_ICV_LEN; i++)
5f9f1812	206	crypto_cipher_decrypt_one(tfm, data + i, data + i);
f0706e82 JB	207
f0706e82 JB	208	crc = cpu_to_le32(~crc32_le(~0, data, data_len));
4325f6ca	209	if (memcmp(&crc, data + data_len, IEEE80211_WEP_ICV_LEN) != 0)
f0706e82 JB	210	/* ICV mismatch */
	211	return -1;
	212
	213	return 0;
	214	}
	215
	216
	217	/* Perform WEP decryption on given skb. Buffer includes whole WEP part of
	218	* the frame: IV (4 bytes), encrypted payload (including SNAP header),
	219	* ICV (4 bytes). skb->len includes both IV and ICV.
	220	*
	221	* Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
	222	* failure. If frame is OK, IV and ICV will be removed, i.e., decrypted payload
	223	* is moved to the beginning of the skb and skb length will be reduced.
	224	*/
c9cf0122 JB	225	static int ieee80211_wep_decrypt(struct ieee80211_local *local,
	226	struct sk_buff *skb,
	227	struct ieee80211_key *key)
f0706e82 JB	228	{
f0706e82 JB	229	u32 klen;
730bd83b	230	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
f0706e82	231	u8 keyidx;
70217d7f HH	232	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	233	unsigned int hdrlen;
f0706e82 JB	234	size_t len;
	235	int ret = 0;
	236
70217d7f	237	if (!ieee80211_has_protected(hdr->frame_control))
f0706e82 JB	238	return -1;
f0706e82 JB	239
70217d7f	240	hdrlen = ieee80211_hdrlen(hdr->frame_control);
4325f6ca	241	if (skb->len < hdrlen + IEEE80211_WEP_IV_LEN + IEEE80211_WEP_ICV_LEN)
f0706e82 JB	242	return -1;
f0706e82 JB	243
4325f6ca	244	len = skb->len - hdrlen - IEEE80211_WEP_IV_LEN - IEEE80211_WEP_ICV_LEN;
f0706e82 JB	245
	246	keyidx = skb->data[hdrlen + 3] >> 6;
	247
97359d12	248	if (!key \|\| keyidx != key->conf.keyidx)
f0706e82 JB	249	return -1;
f0706e82 JB	250
8f20fc24	251	klen = 3 + key->conf.keylen;
f0706e82	252
f0706e82 JB	253	/* Prepend 24-bit IV to RC4 key */
	254	memcpy(rc4key, skb->data + hdrlen, 3);
	255
	256	/* Copy rest of the WEP key (the secret part) */
8f20fc24	257	memcpy(rc4key + 3, key->conf.key, key->conf.keylen);
f0706e82 JB	258
f0706e82 JB	259	if (ieee80211_wep_decrypt_data(local->wep_rx_tfm, rc4key, klen,
4325f6ca JB	260	skb->data + hdrlen +
4325f6ca JB	261	IEEE80211_WEP_IV_LEN, len))
f0706e82	262	ret = -1;
f0706e82	263
f0706e82	264	/* Trim ICV */
4325f6ca	265	skb_trim(skb, skb->len - IEEE80211_WEP_ICV_LEN);
f0706e82 JB	266
f0706e82 JB	267	/* Remove IV */
4325f6ca JB	268	memmove(skb->data + IEEE80211_WEP_IV_LEN, skb->data, hdrlen);
4325f6ca JB	269	skb_pull(skb, IEEE80211_WEP_IV_LEN);
f0706e82 JB	270
	271	return ret;
	272	}
	273
9ae54c84	274	ieee80211_rx_result
5cf121c3	275	ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
4f0d18e2	276	{
eb9fb5b8 JB	277	struct sk_buff *skb = rx->skb;
	278	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
	279	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
a8286911	280	__le16 fc = hdr->frame_control;
358c8d9d	281
a8286911	282	if (!ieee80211_is_data(fc) && !ieee80211_is_auth(fc))
9ae54c84	283	return RX_CONTINUE;
4f0d18e2	284
eb9fb5b8	285	if (!(status->flag & RX_FLAG_DECRYPTED)) {
a8286911 JB	286	if (skb_linearize(rx->skb))
a8286911 JB	287	return RX_DROP_UNUSABLE;
f4ea83dd	288	if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))
e4c26add	289	return RX_DROP_UNUSABLE;
eb9fb5b8	290	} else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
4325f6ca JB	291	if (!pskb_may_pull(rx->skb, ieee80211_hdrlen(fc) +
4325f6ca JB	292	IEEE80211_WEP_IV_LEN))
a8286911	293	return RX_DROP_UNUSABLE;
4f0d18e2 JB	294	ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
4f0d18e2 JB	295	/* remove ICV */
cef0acd4 DS	296	if (!(status->flag & RX_FLAG_ICV_STRIPPED) &&
cef0acd4 DS	297	pskb_trim(rx->skb, rx->skb->len - IEEE80211_WEP_ICV_LEN))
a8286911	298	return RX_DROP_UNUSABLE;
4f0d18e2 JB	299	}
4f0d18e2 JB	300
9ae54c84	301	return RX_CONTINUE;
4f0d18e2	302	}
6a22a59d	303
5cf121c3	304	static int wep_encrypt_skb(struct ieee80211_tx_data tx, struct sk_buff skb)
6a22a59d	305	{
e039fa4a	306	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
ee70108f	307	struct ieee80211_key_conf *hw_key = info->control.hw_key;
e039fa4a	308
ee70108f	309	if (!hw_key) {
c9cf0122 JB	310	if (ieee80211_wep_encrypt(tx->local, skb, tx->key->conf.key,
	311	tx->key->conf.keylen,
	312	tx->key->conf.keyidx))
6a22a59d	313	return -1;
ee70108f JD	314	} else if ((hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) \|\|
ee70108f JD	315	(hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
813d7669 JB	316	if (!ieee80211_wep_add_iv(tx->local, skb,
	317	tx->key->conf.keylen,
	318	tx->key->conf.keyidx))
	319	return -1;
	320	}
	321
6a22a59d JB	322	return 0;
	323	}
	324
9ae54c84	325	ieee80211_tx_result
5cf121c3	326	ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
6a22a59d	327	{
2de8e0d9	328	struct sk_buff *skb;
c6a1fa12	329
5cf121c3	330	ieee80211_tx_set_protected(tx);
6a22a59d	331
252b86c4	332	skb_queue_walk(&tx->skbs, skb) {
2de8e0d9 JB	333	if (wep_encrypt_skb(tx, skb) < 0) {
	334	I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
	335	return TX_DROP;
6a22a59d	336	}
252b86c4	337	}
6a22a59d	338
9ae54c84	339	return TX_CONTINUE;
6a22a59d	340	}