[deliverable/linux.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 <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))
		return -ENOMEM;

	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);
		return -ENOMEM;
	}

	return 0;
}

void ieee80211_wep_free(struct ieee80211_local *local)
{
	crypto_free_blkcipher(local->wep_tx_tfm);
	crypto_free_blkcipher(local->wep_rx_tfm);
}

static inline int 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 1;
	}
	return 0;
}


static void ieee80211_wep_get_iv(struct ieee80211_local *local,
				 struct ieee80211_key *key, u8 *iv)
{
	local->wep_iv++;
	if (ieee80211_wep_weak_iv(local->wep_iv, key->conf.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++ = key->conf.keyidx << 6;
}


static u8 *ieee80211_wep_add_iv(struct ieee80211_local *local,
				struct sk_buff *skb,
				struct ieee80211_key *key)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 fc;
	int hdrlen;
	u8 *newhdr;

	fc = le16_to_cpu(hdr->frame_control);
	fc |= IEEE80211_FCTL_PROTECTED;
	hdr->frame_control = cpu_to_le16(fc);

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

	hdrlen = ieee80211_get_hdrlen(fc);
	newhdr = skb_push(skb, WEP_IV_LEN);
	memmove(newhdr, newhdr + WEP_IV_LEN, hdrlen);
	ieee80211_wep_get_iv(local, key, 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;
	u16 fc;
	int hdrlen;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	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)) */
void 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;

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


/* 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,
			  struct ieee80211_key *key)
{
	u32 klen;
	u8 *rc4key, *iv;
	size_t len;

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

	klen = 3 + key->conf.keylen;
	rc4key = kmalloc(klen, GFP_ATOMIC);
	if (!rc4key)
		return -1;

	iv = ieee80211_wep_add_iv(local, skb, key);
	if (!iv) {
		kfree(rc4key);
		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->conf.key, key->conf.keylen);

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

	ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, klen,
				   iv + WEP_IV_LEN, len);

	kfree(rc4key);

	return 0;
}


/* 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;

	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.
 */
int ieee80211_wep_decrypt(struct ieee80211_local *local, struct sk_buff *skb,
			  struct ieee80211_key *key)
{
	u32 klen;
	u8 *rc4key;
	u8 keyidx;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 fc;
	int hdrlen;
	size_t len;
	int ret = 0;

	fc = le16_to_cpu(hdr->frame_control);
	if (!(fc & IEEE80211_FCTL_PROTECTED))
		return -1;

	hdrlen = ieee80211_get_hdrlen(fc);

	if (skb->len < 8 + hdrlen)
		return -1;

	len = skb->len - hdrlen - 8;

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

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

	klen = 3 + key->conf.keylen;

	rc4key = kmalloc(klen, GFP_ATOMIC);
	if (!rc4key)
		return -1;

	/* 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)) {
		if (net_ratelimit())
			printk(KERN_DEBUG "WEP decrypt failed (ICV)\n");
		ret = -1;
	}

	kfree(rc4key);

	/* 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;
}


u8 * ieee80211_wep_is_weak_iv(struct sk_buff *skb, struct ieee80211_key *key)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 fc;
	int hdrlen;
	u8 *ivpos;
	u32 iv;

	fc = le16_to_cpu(hdr->frame_control);
	if (!(fc & IEEE80211_FCTL_PROTECTED))
		return NULL;

	hdrlen = ieee80211_get_hdrlen(fc);
	ivpos = skb->data + hdrlen;
	iv = (ivpos[0] << 16) | (ivpos[1] << 8) | ivpos[2];

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

	return NULL;
}

ieee80211_rx_result
ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
{
	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
	    ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
	     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH))
		return RX_CONTINUE;

	if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
		if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key)) {
#ifdef CONFIG_MAC80211_DEBUG
			if (net_ratelimit())
				printk(KERN_DEBUG "%s: RX WEP frame, decrypt "
				       "failed\n", rx->dev->name);
#endif /* CONFIG_MAC80211_DEBUG */
			return RX_DROP_UNUSABLE;
		}
	} else if (!(rx->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 - 4);
	}

	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);

	info->control.iv_len = WEP_IV_LEN;
	info->control.icv_len = WEP_ICV_LEN;

	if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
		if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
			return -1;
	} else {
		info->control.hw_key = &tx->key->conf;
		if (tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) {
			if (!ieee80211_wep_add_iv(tx->local, skb, tx->key))
				return -1;
		}
	}
	return 0;
}

ieee80211_tx_result
ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
{
	ieee80211_tx_set_protected(tx);

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

	if (tx->extra_frag) {
		int i;
		for (i = 0; i < tx->num_extra_frag; i++) {
			if (wep_encrypt_skb(tx, tx->extra_frag[i]) < 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 <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>
f0706e82 JB	20
	21	#include <net/mac80211.h>
	22	#include "ieee80211_i.h"
	23	#include "wep.h"
	24
	25
	26	int ieee80211_wep_init(struct ieee80211_local *local)
	27	{
	28	/* start WEP IV from a random value */
	29	get_random_bytes(&local->wep_iv, WEP_IV_LEN);
	30
	31	local->wep_tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
	32	CRYPTO_ALG_ASYNC);
	33	if (IS_ERR(local->wep_tx_tfm))
	34	return -ENOMEM;
	35
	36	local->wep_rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
	37	CRYPTO_ALG_ASYNC);
	38	if (IS_ERR(local->wep_rx_tfm)) {
	39	crypto_free_blkcipher(local->wep_tx_tfm);
	40	return -ENOMEM;
	41	}
	42
	43	return 0;
	44	}
	45
	46	void ieee80211_wep_free(struct ieee80211_local *local)
	47	{
	48	crypto_free_blkcipher(local->wep_tx_tfm);
	49	crypto_free_blkcipher(local->wep_rx_tfm);
	50	}
	51
	52	static inline int ieee80211_wep_weak_iv(u32 iv, int keylen)
	53	{
	54	/* Fluhrer, Mantin, and Shamir have reported weaknesses in the
	55	* key scheduling algorithm of RC4. At least IVs (KeyByte + 3,
	56	* 0xff, N) can be used to speedup attacks, so avoid using them. */
	57	if ((iv & 0xff00) == 0xff00) {
	58	u8 B = (iv >> 16) & 0xff;
	59	if (B >= 3 && B < 3 + keylen)
	60	return 1;
	61	}
	62	return 0;
	63	}
	64
	65
4f0d18e2 JB	66	static void ieee80211_wep_get_iv(struct ieee80211_local *local,
4f0d18e2 JB	67	struct ieee80211_key key, u8 iv)
f0706e82 JB	68	{
f0706e82 JB	69	local->wep_iv++;
8f20fc24	70	if (ieee80211_wep_weak_iv(local->wep_iv, key->conf.keylen))
f0706e82 JB	71	local->wep_iv += 0x0100;
	72
	73	if (!iv)
	74	return;
	75
	76	*iv++ = (local->wep_iv >> 16) & 0xff;
	77	*iv++ = (local->wep_iv >> 8) & 0xff;
	78	*iv++ = local->wep_iv & 0xff;
8f20fc24	79	*iv++ = key->conf.keyidx << 6;
f0706e82 JB	80	}
	81
	82
6a22a59d JB	83	static u8 ieee80211_wep_add_iv(struct ieee80211_local local,
	84	struct sk_buff *skb,
	85	struct ieee80211_key *key)
f0706e82 JB	86	{
	87	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	88	u16 fc;
	89	int hdrlen;
	90	u8 *newhdr;
	91
	92	fc = le16_to_cpu(hdr->frame_control);
	93	fc \|= IEEE80211_FCTL_PROTECTED;
	94	hdr->frame_control = cpu_to_le16(fc);
	95
23c0752a JB	96	if (WARN_ON(skb_tailroom(skb) < WEP_ICV_LEN \|\|
	97	skb_headroom(skb) < WEP_IV_LEN))
	98	return NULL;
f0706e82 JB	99
	100	hdrlen = ieee80211_get_hdrlen(fc);
	101	newhdr = skb_push(skb, WEP_IV_LEN);
	102	memmove(newhdr, newhdr + WEP_IV_LEN, hdrlen);
	103	ieee80211_wep_get_iv(local, key, newhdr + hdrlen);
	104	return newhdr + hdrlen;
	105	}
	106
	107
4f0d18e2 JB	108	static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
	109	struct sk_buff *skb,
	110	struct ieee80211_key *key)
f0706e82 JB	111	{
	112	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	113	u16 fc;
	114	int hdrlen;
	115
	116	fc = le16_to_cpu(hdr->frame_control);
	117	hdrlen = ieee80211_get_hdrlen(fc);
	118	memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen);
	119	skb_pull(skb, WEP_IV_LEN);
	120	}
	121
	122
	123	/* Perform WEP encryption using given key. data buffer must have tailroom
	124	* for 4-byte ICV. data_len must not include this ICV. Note: this function
	125	* does _not_ add IV. data = RC4(data \| CRC32(data)) */
	126	void ieee80211_wep_encrypt_data(struct crypto_blkcipher tfm, u8 rc4key,
	127	size_t klen, u8 *data, size_t data_len)
	128	{
	129	struct blkcipher_desc desc = { .tfm = tfm };
	130	struct scatterlist sg;
	131	__le32 *icv;
	132
	133	icv = (__le32 *)(data + data_len);
	134	*icv = cpu_to_le32(~crc32_le(~0, data, data_len));
	135
	136	crypto_blkcipher_setkey(tfm, rc4key, klen);
fa05f128	137	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
f0706e82 JB	138	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
	139	}
	140
	141
	142	/* Perform WEP encryption on given skb. 4 bytes of extra space (IV) in the
	143	* beginning of the buffer 4 bytes of extra space (ICV) in the end of the
	144	* buffer will be added. Both IV and ICV will be transmitted, so the
	145	* payload length increases with 8 bytes.
	146	*
	147	* WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
	148	*/
	149	int ieee80211_wep_encrypt(struct ieee80211_local local, struct sk_buff skb,
	150	struct ieee80211_key *key)
	151	{
	152	u32 klen;
	153	u8 rc4key, iv;
	154	size_t len;
	155
8f20fc24	156	if (!key \|\| key->conf.alg != ALG_WEP)
f0706e82 JB	157	return -1;
f0706e82 JB	158
8f20fc24	159	klen = 3 + key->conf.keylen;
f0706e82 JB	160	rc4key = kmalloc(klen, GFP_ATOMIC);
	161	if (!rc4key)
	162	return -1;
	163
	164	iv = ieee80211_wep_add_iv(local, skb, key);
	165	if (!iv) {
	166	kfree(rc4key);
	167	return -1;
	168	}
	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) */
8f20fc24	176	memcpy(rc4key + 3, key->conf.key, key->conf.keylen);
f0706e82 JB	177
	178	/* Add room for ICV */
	179	skb_put(skb, WEP_ICV_LEN);
	180
	181	ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, klen,
	182	iv + WEP_IV_LEN, len);
	183
	184	kfree(rc4key);
	185
	186	return 0;
	187	}
	188
	189
	190	/* Perform WEP decryption using given key. data buffer includes encrypted
	191	* payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
	192	* Return 0 on success and -1 on ICV mismatch. */
	193	int ieee80211_wep_decrypt_data(struct crypto_blkcipher tfm, u8 rc4key,
	194	size_t klen, u8 *data, size_t data_len)
	195	{
	196	struct blkcipher_desc desc = { .tfm = tfm };
	197	struct scatterlist sg;
	198	__le32 crc;
	199
	200	crypto_blkcipher_setkey(tfm, rc4key, klen);
fa05f128	201	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
f0706e82 JB	202	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);
	203
	204	crc = cpu_to_le32(~crc32_le(~0, data, data_len));
	205	if (memcmp(&crc, data + data_len, WEP_ICV_LEN) != 0)
	206	/* ICV mismatch */
	207	return -1;
	208
	209	return 0;
	210	}
	211
	212
	213	/* Perform WEP decryption on given skb. Buffer includes whole WEP part of
	214	* the frame: IV (4 bytes), encrypted payload (including SNAP header),
	215	* ICV (4 bytes). skb->len includes both IV and ICV.
	216	*
	217	* Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
	218	* failure. If frame is OK, IV and ICV will be removed, i.e., decrypted payload
	219	* is moved to the beginning of the skb and skb length will be reduced.
	220	*/
	221	int ieee80211_wep_decrypt(struct ieee80211_local local, struct sk_buff skb,
	222	struct ieee80211_key *key)
	223	{
	224	u32 klen;
	225	u8 *rc4key;
	226	u8 keyidx;
	227	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	228	u16 fc;
	229	int hdrlen;
	230	size_t len;
	231	int ret = 0;
	232
	233	fc = le16_to_cpu(hdr->frame_control);
	234	if (!(fc & IEEE80211_FCTL_PROTECTED))
	235	return -1;
	236
	237	hdrlen = ieee80211_get_hdrlen(fc);
	238
	239	if (skb->len < 8 + hdrlen)
	240	return -1;
	241
	242	len = skb->len - hdrlen - 8;
	243
	244	keyidx = skb->data[hdrlen + 3] >> 6;
	245
8f20fc24	246	if (!key \|\| keyidx != key->conf.keyidx \|\| key->conf.alg != ALG_WEP)
f0706e82 JB	247	return -1;
f0706e82 JB	248
8f20fc24	249	klen = 3 + key->conf.keylen;
f0706e82 JB	250
	251	rc4key = kmalloc(klen, GFP_ATOMIC);
	252	if (!rc4key)
	253	return -1;
	254
	255	/* Prepend 24-bit IV to RC4 key */
	256	memcpy(rc4key, skb->data + hdrlen, 3);
	257
	258	/* Copy rest of the WEP key (the secret part) */
8f20fc24	259	memcpy(rc4key + 3, key->conf.key, key->conf.keylen);
f0706e82 JB	260
	261	if (ieee80211_wep_decrypt_data(local->wep_rx_tfm, rc4key, klen,
	262	skb->data + hdrlen + WEP_IV_LEN,
	263	len)) {
53cb4791 AG	264	if (net_ratelimit())
53cb4791 AG	265	printk(KERN_DEBUG "WEP decrypt failed (ICV)\n");
f0706e82 JB	266	ret = -1;
	267	}
	268
	269	kfree(rc4key);
	270
	271	/* Trim ICV */
	272	skb_trim(skb, skb->len - WEP_ICV_LEN);
	273
	274	/* Remove IV */
	275	memmove(skb->data + WEP_IV_LEN, skb->data, hdrlen);
	276	skb_pull(skb, WEP_IV_LEN);
	277
	278	return ret;
	279	}
	280
	281
f0706e82 JB	282	u8 * ieee80211_wep_is_weak_iv(struct sk_buff skb, struct ieee80211_key key)
	283	{
	284	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	285	u16 fc;
	286	int hdrlen;
	287	u8 *ivpos;
	288	u32 iv;
	289
	290	fc = le16_to_cpu(hdr->frame_control);
	291	if (!(fc & IEEE80211_FCTL_PROTECTED))
	292	return NULL;
	293
	294	hdrlen = ieee80211_get_hdrlen(fc);
	295	ivpos = skb->data + hdrlen;
	296	iv = (ivpos[0] << 16) \| (ivpos[1] << 8) \| ivpos[2];
	297
8f20fc24	298	if (ieee80211_wep_weak_iv(iv, key->conf.keylen))
f0706e82 JB	299	return ivpos;
	300
	301	return NULL;
	302	}
4f0d18e2	303
9ae54c84	304	ieee80211_rx_result
5cf121c3	305	ieee80211_crypto_wep_decrypt(struct ieee80211_rx_data *rx)
4f0d18e2 JB	306	{
	307	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
	308	((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT \|\|
	309	(rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH))
9ae54c84	310	return RX_CONTINUE;
4f0d18e2	311
5cf121c3	312	if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
4f0d18e2	313	if (ieee80211_wep_decrypt(rx->local, rx->skb, rx->key)) {
7f3ad894	314	#ifdef CONFIG_MAC80211_DEBUG
4f0d18e2 JB	315	if (net_ratelimit())
	316	printk(KERN_DEBUG "%s: RX WEP frame, decrypt "
	317	"failed\n", rx->dev->name);
7f3ad894	318	#endif /* CONFIG_MAC80211_DEBUG */
e4c26add	319	return RX_DROP_UNUSABLE;
4f0d18e2	320	}
5cf121c3	321	} else if (!(rx->status->flag & RX_FLAG_IV_STRIPPED)) {
4f0d18e2 JB	322	ieee80211_wep_remove_iv(rx->local, rx->skb, rx->key);
	323	/* remove ICV */
	324	skb_trim(rx->skb, rx->skb->len - 4);
	325	}
	326
9ae54c84	327	return RX_CONTINUE;
4f0d18e2	328	}
6a22a59d	329
5cf121c3	330	static int wep_encrypt_skb(struct ieee80211_tx_data tx, struct sk_buff skb)
6a22a59d	331	{
e039fa4a JB	332	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	333
	334	info->control.iv_len = WEP_IV_LEN;
	335	info->control.icv_len = WEP_ICV_LEN;
	336
6a22a59d JB	337	if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) {
	338	if (ieee80211_wep_encrypt(tx->local, skb, tx->key))
	339	return -1;
	340	} else {
2b212141	341	info->control.hw_key = &tx->key->conf;
6a22a59d JB	342	if (tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) {
	343	if (!ieee80211_wep_add_iv(tx->local, skb, tx->key))
	344	return -1;
	345	}
	346	}
	347	return 0;
	348	}
	349
9ae54c84	350	ieee80211_tx_result
5cf121c3	351	ieee80211_crypto_wep_encrypt(struct ieee80211_tx_data *tx)
6a22a59d	352	{
5cf121c3	353	ieee80211_tx_set_protected(tx);
6a22a59d JB	354
	355	if (wep_encrypt_skb(tx, tx->skb) < 0) {
	356	I802_DEBUG_INC(tx->local->tx_handlers_drop_wep);
9ae54c84	357	return TX_DROP;
6a22a59d JB	358	}
6a22a59d JB	359
5cf121c3	360	if (tx->extra_frag) {
6a22a59d	361	int i;
5cf121c3 JB	362	for (i = 0; i < tx->num_extra_frag; i++) {
5cf121c3 JB	363	if (wep_encrypt_skb(tx, tx->extra_frag[i]) < 0) {
6a22a59d JB	364	I802_DEBUG_INC(tx->local->
6a22a59d JB	365	tx_handlers_drop_wep);
9ae54c84	366	return TX_DROP;
6a22a59d JB	367	}
	368	}
	369	}
	370
9ae54c84	371	return TX_CONTINUE;
6a22a59d	372	}