[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / mac80211 / wep.c

/*
 * Software WEP encryption implementation
 * Copyright 2002, Jouni Malinen <jkmaline@cc.hut.fi>
 * 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, WEP_IV_LEN);

	local->wep_tx_tfm = crypto_alloc_blkcipher("ecb(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_blkcipher("ecb(arc4)", 0,
						CRYPTO_ALG_ASYNC);
	if (IS_ERR(local->wep_rx_tfm)) {
		crypto_free_blkcipher(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_blkcipher(local->wep_tx_tfm);
	if (!IS_ERR(local->wep_rx_tfm))
		crypto_free_blkcipher(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;
	unsigned int hdrlen;
	u8 *newhdr;

	hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);

	if (WARN_ON(skb_tailroom(skb) < WEP_ICV_LEN ||
		    skb_headroom(skb) < WEP_IV_LEN))
		return NULL;

	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	newhdr = skb_push(skb, WEP_IV_LEN);
	memmove(newhdr, newhdr + WEP_IV_LEN, 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 + WEP_IV_LEN, skb->data, hdrlen);
	skb_pull(skb, 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_blkcipher *tfm, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{
	struct blkcipher_desc desc = { .tfm = tfm };
	struct scatterlist sg;
	__le32 icv;

	if (IS_ERR(tfm))
		return -1;

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

	crypto_blkcipher_setkey(tfm, rc4key, klen);
	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);

	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];

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

	len = skb->len - (iv + 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, WEP_ICV_LEN);

	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
					  iv + 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_blkcipher *tfm, u8 *rc4key,
			       size_t klen, u8 *data, size_t data_len)
{
	struct blkcipher_desc desc = { .tfm = tfm };
	struct scatterlist sg;
	__le32 crc;

	if (IS_ERR(tfm))
		return -1;

	crypto_blkcipher_setkey(tfm, rc4key, klen);
	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);

	crc = cpu_to_le32(~crc32_le(~0, data, data_len));
	if (memcmp(&crc, data + data_len, 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 + WEP_IV_LEN + WEP_ICV_LEN)
		return -1;

	len = skb->len - hdrlen - WEP_IV_LEN - 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 + WEP_IV_LEN,
				       len))
		ret = -1;

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

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

	return ret;
}


bool ieee80211_wep_is_weak_iv(struct sk_buff *skb, struct ieee80211_key *key)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	unsigned int hdrlen;
	u8 *ivpos;
	u32 iv;

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

	hdrlen = ieee80211_hdrlen(hdr->frame_control);
	ivpos = skb->data + hdrlen;
	iv = (ivpos[0] << 16) | (ivpos[1] << 8) | ivpos[2];

	return ieee80211_wep_weak_iv(iv, key->conf.keylen);
}

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;

	if (!ieee80211_is_data(hdr->frame_control) &&
	    !ieee80211_is_auth(hdr->frame_control))
		return RX_CONTINUE;

	if (!(status->flag & RX_FLAG_DECRYPTED)) {
		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))
			return RX_DROP_UNUSABLE;
	} else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
		ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
		/* remove ICV */
		skb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN);
	}

	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);

	if (!info->control.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 (info->control.hw_key->flags &
			IEEE80211_KEY_FLAG_GENERATE_IV) {
		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 = tx->skb;
	do {
		if (wep_encrypt_skb(tx, skb) < 0) {
			I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
			return TX_DROP;
		}
	} while ((skb = skb->next));

	return TX_CONTINUE;
}
Commit	Line	Data
f0706e82 JB	1	/*
	2	* Software WEP encryption implementation
	3	* Copyright 2002, Jouni Malinen <jkmaline@cc.hut.fi>
	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 */
	31	get_random_bytes(&local->wep_iv, WEP_IV_LEN);
	32
	33	local->wep_tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
	34	CRYPTO_ALG_ASYNC);
088c8726 JL	35	if (IS_ERR(local->wep_tx_tfm)) {
088c8726 JL	36	local->wep_rx_tfm = ERR_PTR(-EINVAL);
023a04be	37	return PTR_ERR(local->wep_tx_tfm);
088c8726	38	}
f0706e82 JB	39
	40	local->wep_rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
	41	CRYPTO_ALG_ASYNC);
	42	if (IS_ERR(local->wep_rx_tfm)) {
	43	crypto_free_blkcipher(local->wep_tx_tfm);
088c8726	44	local->wep_tx_tfm = ERR_PTR(-EINVAL);
023a04be	45	return PTR_ERR(local->wep_rx_tfm);
f0706e82 JB	46	}
	47
	48	return 0;
	49	}
	50
	51	void ieee80211_wep_free(struct ieee80211_local *local)
	52	{
3473187d JL	53	if (!IS_ERR(local->wep_tx_tfm))
	54	crypto_free_blkcipher(local->wep_tx_tfm);
	55	if (!IS_ERR(local->wep_rx_tfm))
	56	crypto_free_blkcipher(local->wep_rx_tfm);
f0706e82 JB	57	}
f0706e82 JB	58
c6a1fa12	59	static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)
f0706e82	60	{
c6a1fa12 JB	61	/*
c6a1fa12 JB	62	* Fluhrer, Mantin, and Shamir have reported weaknesses in the
f0706e82	63	* key scheduling algorithm of RC4. At least IVs (KeyByte + 3,
c6a1fa12 JB	64	* 0xff, N) can be used to speedup attacks, so avoid using them.
c6a1fa12 JB	65	*/
f0706e82 JB	66	if ((iv & 0xff00) == 0xff00) {
	67	u8 B = (iv >> 16) & 0xff;
	68	if (B >= 3 && B < 3 + keylen)
c6a1fa12	69	return true;
f0706e82	70	}
c6a1fa12	71	return false;
f0706e82 JB	72	}
	73
	74
4f0d18e2	75	static void ieee80211_wep_get_iv(struct ieee80211_local *local,
c9cf0122	76	int keylen, int keyidx, u8 *iv)
f0706e82 JB	77	{
f0706e82 JB	78	local->wep_iv++;
c9cf0122	79	if (ieee80211_wep_weak_iv(local->wep_iv, keylen))
f0706e82 JB	80	local->wep_iv += 0x0100;
	81
	82	if (!iv)
	83	return;
	84
	85	*iv++ = (local->wep_iv >> 16) & 0xff;
	86	*iv++ = (local->wep_iv >> 8) & 0xff;
	87	*iv++ = local->wep_iv & 0xff;
c9cf0122	88	*iv++ = keyidx << 6;
f0706e82 JB	89	}
	90
	91
6a22a59d JB	92	static u8 ieee80211_wep_add_iv(struct ieee80211_local local,
6a22a59d JB	93	struct sk_buff *skb,
c9cf0122	94	int keylen, int keyidx)
f0706e82	95	{
70217d7f HH	96	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	97	unsigned int hdrlen;
f0706e82 JB	98	u8 *newhdr;
f0706e82 JB	99
70217d7f	100	hdr->frame_control \|= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
f0706e82	101
23c0752a JB	102	if (WARN_ON(skb_tailroom(skb) < WEP_ICV_LEN \|\|
	103	skb_headroom(skb) < WEP_IV_LEN))
	104	return NULL;
f0706e82	105
70217d7f	106	hdrlen = ieee80211_hdrlen(hdr->frame_control);
f0706e82 JB	107	newhdr = skb_push(skb, WEP_IV_LEN);
f0706e82 JB	108	memmove(newhdr, newhdr + WEP_IV_LEN, hdrlen);
c9cf0122	109	ieee80211_wep_get_iv(local, keylen, keyidx, newhdr + hdrlen);
f0706e82 JB	110	return newhdr + hdrlen;
	111	}
	112
	113
4f0d18e2 JB	114	static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
	115	struct sk_buff *skb,
	116	struct ieee80211_key *key)
f0706e82	117	{
70217d7f HH	118	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	119	unsigned int hdrlen;
f0706e82	120
70217d7f	121	hdrlen = ieee80211_hdrlen(hdr->frame_control);
f0706e82 JB	122	memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen);
	123	skb_pull(skb, WEP_IV_LEN);
	124	}
	125
	126
	127	/* Perform WEP encryption using given key. data buffer must have tailroom
	128	* for 4-byte ICV. data_len must not include this ICV. Note: this function
	129	* does _not_ add IV. data = RC4(data \| CRC32(data)) */
3473187d JL	130	int ieee80211_wep_encrypt_data(struct crypto_blkcipher tfm, u8 rc4key,
3473187d JL	131	size_t klen, u8 *data, size_t data_len)
f0706e82 JB	132	{
	133	struct blkcipher_desc desc = { .tfm = tfm };
	134	struct scatterlist sg;
860c6e6a	135	__le32 icv;
f0706e82	136
3473187d JL	137	if (IS_ERR(tfm))
	138	return -1;
	139
860c6e6a IK	140	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
860c6e6a IK	141	put_unaligned(icv, (__le32 *)(data + data_len));
f0706e82 JB	142
f0706e82 JB	143	crypto_blkcipher_setkey(tfm, rc4key, klen);
fa05f128	144	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
f0706e82	145	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
3473187d JL	146
3473187d JL	147	return 0;
f0706e82 JB	148	}
	149
	150
	151	/* Perform WEP encryption on given skb. 4 bytes of extra space (IV) in the
	152	* beginning of the buffer 4 bytes of extra space (ICV) in the end of the
	153	* buffer will be added. Both IV and ICV will be transmitted, so the
	154	* payload length increases with 8 bytes.
	155	*
	156	* WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
	157	*/
fffd0934 JB	158	int ieee80211_wep_encrypt(struct ieee80211_local *local,
	159	struct sk_buff *skb,
	160	const u8 *key, int keylen, int keyidx)
f0706e82	161	{
c9cf0122	162	u8 *iv;
f0706e82	163	size_t len;
c9cf0122	164	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
f0706e82	165
c9cf0122 JB	166	iv = ieee80211_wep_add_iv(local, skb, keylen, keyidx);
c9cf0122 JB	167	if (!iv)
f0706e82	168	return -1;
f0706e82 JB	169
	170	len = skb->len - (iv + WEP_IV_LEN - skb->data);
	171
	172	/* Prepend 24-bit IV to RC4 key */
	173	memcpy(rc4key, iv, 3);
	174
	175	/* Copy rest of the WEP key (the secret part) */
c9cf0122	176	memcpy(rc4key + 3, key, keylen);
f0706e82 JB	177
	178	/* Add room for ICV */
	179	skb_put(skb, WEP_ICV_LEN);
	180
3473187d JL	181	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
3473187d JL	182	iv + WEP_IV_LEN, len);
f0706e82 JB	183	}
	184
	185
	186	/* Perform WEP decryption using given key. data buffer includes encrypted
	187	* payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
	188	* Return 0 on success and -1 on ICV mismatch. */
	189	int ieee80211_wep_decrypt_data(struct crypto_blkcipher tfm, u8 rc4key,
	190	size_t klen, u8 *data, size_t data_len)
	191	{
	192	struct blkcipher_desc desc = { .tfm = tfm };
	193	struct scatterlist sg;
	194	__le32 crc;
	195
3473187d JL	196	if (IS_ERR(tfm))
	197	return -1;
	198
f0706e82	199	crypto_blkcipher_setkey(tfm, rc4key, klen);
fa05f128	200	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
f0706e82 JB	201	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);
	202
	203	crc = cpu_to_le32(~crc32_le(~0, data, data_len));
	204	if (memcmp(&crc, data + data_len, WEP_ICV_LEN) != 0)
	205	/* ICV mismatch */
	206	return -1;
	207
	208	return 0;
	209	}
	210
	211
	212	/* Perform WEP decryption on given skb. Buffer includes whole WEP part of
	213	* the frame: IV (4 bytes), encrypted payload (including SNAP header),
	214	* ICV (4 bytes). skb->len includes both IV and ICV.
	215	*
	216	* Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
	217	* failure. If frame is OK, IV and ICV will be removed, i.e., decrypted payload
	218	* is moved to the beginning of the skb and skb length will be reduced.
	219	*/
c9cf0122 JB	220	static int ieee80211_wep_decrypt(struct ieee80211_local *local,
	221	struct sk_buff *skb,
	222	struct ieee80211_key *key)
f0706e82 JB	223	{
f0706e82 JB	224	u32 klen;
730bd83b	225	u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
f0706e82	226	u8 keyidx;
70217d7f HH	227	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	228	unsigned int hdrlen;
f0706e82 JB	229	size_t len;
	230	int ret = 0;
	231
70217d7f	232	if (!ieee80211_has_protected(hdr->frame_control))
f0706e82 JB	233	return -1;
f0706e82 JB	234
70217d7f	235	hdrlen = ieee80211_hdrlen(hdr->frame_control);
d2984872	236	if (skb->len < hdrlen + WEP_IV_LEN + WEP_ICV_LEN)
f0706e82 JB	237	return -1;
f0706e82 JB	238
d2984872	239	len = skb->len - hdrlen - WEP_IV_LEN - WEP_ICV_LEN;
f0706e82 JB	240
	241	keyidx = skb->data[hdrlen + 3] >> 6;
	242
97359d12	243	if (!key \|\| keyidx != key->conf.keyidx)
f0706e82 JB	244	return -1;
f0706e82 JB	245
8f20fc24	246	klen = 3 + key->conf.keylen;
f0706e82	247
f0706e82 JB	248	/* Prepend 24-bit IV to RC4 key */
	249	memcpy(rc4key, skb->data + hdrlen, 3);
	250
	251	/* Copy rest of the WEP key (the secret part) */
8f20fc24	252	memcpy(rc4key + 3, key->conf.key, key->conf.keylen);
f0706e82 JB	253
	254	if (ieee80211_wep_decrypt_data(local->wep_rx_tfm, rc4key, klen,
	255	skb->data + hdrlen + WEP_IV_LEN,
f4ea83dd	256	len))
f0706e82	257	ret = -1;
f0706e82	258
f0706e82 JB	259	/* Trim ICV */
	260	skb_trim(skb, skb->len - WEP_ICV_LEN);
	261
	262	/* Remove IV */
	263	memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen);
	264	skb_pull(skb, WEP_IV_LEN);
	265
	266	return ret;
	267	}
	268
	269
c6a1fa12	270	bool ieee80211_wep_is_weak_iv(struct sk_buff skb, struct ieee80211_key key)
f0706e82	271	{
70217d7f HH	272	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
70217d7f HH	273	unsigned int hdrlen;
f0706e82 JB	274	u8 *ivpos;
	275	u32 iv;
	276
70217d7f	277	if (!ieee80211_has_protected(hdr->frame_control))
c6a1fa12	278	return false;
f0706e82	279
70217d7f	280	hdrlen = ieee80211_hdrlen(hdr->frame_control);
f0706e82 JB	281	ivpos = skb->data + hdrlen;
	282	iv = (ivpos[0] << 16) \| (ivpos[1] << 8) \| ivpos[2];
	283
c6a1fa12	284	return ieee80211_wep_weak_iv(iv, key->conf.keylen);
f0706e82	285	}
4f0d18e2	286
9ae54c84	287	ieee80211_rx_result
5cf121c3	288	ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
4f0d18e2	289	{
eb9fb5b8 JB	290	struct sk_buff *skb = rx->skb;
	291	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
	292	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
358c8d9d HH	293
	294	if (!ieee80211_is_data(hdr->frame_control) &&
	295	!ieee80211_is_auth(hdr->frame_control))
9ae54c84	296	return RX_CONTINUE;
4f0d18e2	297
eb9fb5b8	298	if (!(status->flag & RX_FLAG_DECRYPTED)) {
f4ea83dd	299	if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key))
e4c26add	300	return RX_DROP_UNUSABLE;
eb9fb5b8	301	} else if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
4f0d18e2 JB	302	ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
4f0d18e2 JB	303	/* remove ICV */
d2984872	304	skb_trim(rx->skb, rx->skb->len - WEP_ICV_LEN);
4f0d18e2 JB	305	}
4f0d18e2 JB	306
9ae54c84	307	return RX_CONTINUE;
4f0d18e2	308	}
6a22a59d	309
5cf121c3	310	static int wep_encrypt_skb(struct ieee80211_tx_data tx, struct sk_buff skb)
6a22a59d	311	{
e039fa4a JB	312	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
e039fa4a JB	313
813d7669	314	if (!info->control.hw_key) {
c9cf0122 JB	315	if (ieee80211_wep_encrypt(tx->local, skb, tx->key->conf.key,
	316	tx->key->conf.keylen,
	317	tx->key->conf.keyidx))
6a22a59d	318	return -1;
e4fca007 JL	319	} else if (info->control.hw_key->flags &
e4fca007 JL	320	IEEE80211_KEY_FLAG_GENERATE_IV) {
813d7669 JB	321	if (!ieee80211_wep_add_iv(tx->local, skb,
	322	tx->key->conf.keylen,
	323	tx->key->conf.keyidx))
	324	return -1;
	325	}
	326
6a22a59d JB	327	return 0;
	328	}
	329
9ae54c84	330	ieee80211_tx_result
5cf121c3	331	ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
6a22a59d	332	{
2de8e0d9	333	struct sk_buff *skb;
c6a1fa12	334
5cf121c3	335	ieee80211_tx_set_protected(tx);
6a22a59d	336
2de8e0d9 JB	337	skb = tx->skb;
	338	do {
	339	if (wep_encrypt_skb(tx, skb) < 0) {
	340	I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
	341	return TX_DROP;
6a22a59d	342	}
2de8e0d9	343	} while ((skb = skb->next));
6a22a59d	344
9ae54c84	345	return TX_CONTINUE;
6a22a59d	346	}