[linux-2.6-block.git] / drivers / staging / rtl8192u / ieee80211 / ieee80211_crypt_wep.c

/*
 * Host AP crypt: host-based WEP encryption implementation for Host AP driver
 *
 * Copyright (c) 2002-2004, 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/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <asm/string.h>

#include "ieee80211.h"

#include <linux/crypto.h>
    #include <linux/scatterlist.h>
#include <linux/crc32.h>

MODULE_AUTHOR("Jouni Malinen");
MODULE_DESCRIPTION("Host AP crypt: WEP");
MODULE_LICENSE("GPL");

struct prism2_wep_data {
	u32 iv;
#define WEP_KEY_LEN 13
	u8 key[WEP_KEY_LEN + 1];
	u8 key_len;
	u8 key_idx;
	struct crypto_blkcipher *tx_tfm;
	struct crypto_blkcipher *rx_tfm;
};


static void * prism2_wep_init(int keyidx)
{
	struct prism2_wep_data *priv;

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

	priv->tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(priv->tx_tfm)) {
		printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
		       "crypto API arc4\n");
		priv->tx_tfm = NULL;
		goto fail;
	}
	priv->rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(priv->rx_tfm)) {
		printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
		       "crypto API arc4\n");
		priv->rx_tfm = NULL;
		goto fail;
	}

	/* start WEP IV from a random value */
	get_random_bytes(&priv->iv, 4);

	return priv;

fail:
	if (priv) {
		if (priv->tx_tfm)
			crypto_free_blkcipher(priv->tx_tfm);
		if (priv->rx_tfm)
			crypto_free_blkcipher(priv->rx_tfm);
		kfree(priv);
	}

	return NULL;
}


static void prism2_wep_deinit(void *priv)
{
	struct prism2_wep_data *_priv = priv;

	if (_priv) {
		if (_priv->tx_tfm)
			crypto_free_blkcipher(_priv->tx_tfm);
		if (_priv->rx_tfm)
			crypto_free_blkcipher(_priv->rx_tfm);
	}
	kfree(priv);
}

/* Perform WEP encryption on given skb that has at least 4 bytes of headroom
 * for IV and 4 bytes of tailroom for ICV. 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))
 */
static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct prism2_wep_data *wep = priv;
	u32 klen, len;
	u8 key[WEP_KEY_LEN + 3];
	u8 *pos;
	cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
	struct blkcipher_desc desc = {.tfm = wep->tx_tfm};
	u32 crc;
	u8 *icv;
	struct scatterlist sg;
	if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 ||
	    skb->len < hdr_len)
		return -1;

	len = skb->len - hdr_len;
	pos = skb_push(skb, 4);
	memmove(pos, pos + 4, hdr_len);
	pos += hdr_len;

	klen = 3 + wep->key_len;

	wep->iv++;

	/* 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 ((wep->iv & 0xff00) == 0xff00) {
		u8 B = (wep->iv >> 16) & 0xff;
		if (B >= 3 && B < klen)
			wep->iv += 0x0100;
	}

	/* Prepend 24-bit IV to RC4 key and TX frame */
	*pos++ = key[0] = (wep->iv >> 16) & 0xff;
	*pos++ = key[1] = (wep->iv >> 8) & 0xff;
	*pos++ = key[2] = wep->iv & 0xff;
	*pos++ = wep->key_idx << 6;

	/* Copy rest of the WEP key (the secret part) */
	memcpy(key + 3, wep->key, wep->key_len);

	if (!tcb_desc->bHwSec)
	{

		/* Append little-endian CRC32 and encrypt it to produce ICV */
		crc = ~crc32_le(~0, pos, len);
		icv = skb_put(skb, 4);
		icv[0] = crc;
		icv[1] = crc >> 8;
		icv[2] = crc >> 16;
		icv[3] = crc >> 24;

		crypto_blkcipher_setkey(wep->tx_tfm, key, klen);
		sg_init_one(&sg, pos, len+4);

		return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
	}

	return 0;
}


/* Perform WEP decryption on given buffer. Buffer includes whole WEP part of
 * the frame: IV (4 bytes), encrypted payload (including SNAP header),
 * ICV (4 bytes). 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.
 */
static int prism2_wep_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
	struct prism2_wep_data *wep = priv;
	u32  klen, plen;
	u8 key[WEP_KEY_LEN + 3];
	u8 keyidx, *pos;
	cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
	struct blkcipher_desc desc = {.tfm = wep->rx_tfm};
	u32 crc;
	u8 icv[4];
	struct scatterlist sg;
	if (skb->len < hdr_len + 8)
		return -1;

	pos = skb->data + hdr_len;
	key[0] = *pos++;
	key[1] = *pos++;
	key[2] = *pos++;
	keyidx = *pos++ >> 6;
	if (keyidx != wep->key_idx)
		return -1;

	klen = 3 + wep->key_len;

	/* Copy rest of the WEP key (the secret part) */
	memcpy(key + 3, wep->key, wep->key_len);

	/* Apply RC4 to data and compute CRC32 over decrypted data */
	plen = skb->len - hdr_len - 8;

	if (!tcb_desc->bHwSec)
	{
		crypto_blkcipher_setkey(wep->rx_tfm, key, klen);
		sg_init_one(&sg, pos, plen+4);

		if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4))
			return -7;

		crc = ~crc32_le(~0, pos, plen);
		icv[0] = crc;
		icv[1] = crc >> 8;
		icv[2] = crc >> 16;
		icv[3] = crc >> 24;
		if (memcmp(icv, pos + plen, 4) != 0) {
			/* ICV mismatch - drop frame */
			return -2;
		}
	}
	/* Remove IV and ICV */
	memmove(skb->data + 4, skb->data, hdr_len);
	skb_pull(skb, 4);
	skb_trim(skb, skb->len - 4);

	return 0;
}


static int prism2_wep_set_key(void *key, int len, u8 *seq, void *priv)
{
	struct prism2_wep_data *wep = priv;

	if (len < 0 || len > WEP_KEY_LEN)
		return -1;

	memcpy(wep->key, key, len);
	wep->key_len = len;

	return 0;
}


static int prism2_wep_get_key(void *key, int len, u8 *seq, void *priv)
{
	struct prism2_wep_data *wep = priv;

	if (len < wep->key_len)
		return -1;

	memcpy(key, wep->key, wep->key_len);

	return wep->key_len;
}


static char * prism2_wep_print_stats(char *p, void *priv)
{
	struct prism2_wep_data *wep = priv;
	p += sprintf(p, "key[%d] alg=WEP len=%d\n",
		     wep->key_idx, wep->key_len);
	return p;
}


static struct ieee80211_crypto_ops ieee80211_crypt_wep = {
	.name			= "WEP",
	.init			= prism2_wep_init,
	.deinit			= prism2_wep_deinit,
	.encrypt_mpdu		= prism2_wep_encrypt,
	.decrypt_mpdu		= prism2_wep_decrypt,
	.encrypt_msdu		= NULL,
	.decrypt_msdu		= NULL,
	.set_key		= prism2_wep_set_key,
	.get_key		= prism2_wep_get_key,
	.print_stats		= prism2_wep_print_stats,
	.extra_prefix_len	= 4, /* IV */
	.extra_postfix_len	= 4, /* ICV */
	.owner			= THIS_MODULE,
};

int __init ieee80211_crypto_wep_init(void)
{
	return ieee80211_register_crypto_ops(&ieee80211_crypt_wep);
}

void __exit ieee80211_crypto_wep_exit(void)
{
	ieee80211_unregister_crypto_ops(&ieee80211_crypt_wep);
}

void ieee80211_wep_null(void)
{
//	printk("============>%s()\n", __FUNCTION__);
	return;
}
Commit	Line	Data
8fc8598e JC	1	/*
	2	* Host AP crypt: host-based WEP encryption implementation for Host AP driver
	3	*
	4	* Copyright (c) 2002-2004, Jouni Malinen <jkmaline@cc.hut.fi>
	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. See README and COPYING for
	9	* more details.
	10	*/
	11
	12	//#include <linux/config.h>
	13	#include <linux/version.h>
	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/slab.h>
	17	#include <linux/random.h>
	18	#include <linux/skbuff.h>
	19	#include <asm/string.h>
	20
	21	#include "ieee80211.h"
	22
8fc8598e	23	#include <linux/crypto.h>
8fc8598e	24	#include <linux/scatterlist.h>
8fc8598e	25	#include <linux/crc32.h>
8fc8598e	26
8fc8598e JC	27	MODULE_AUTHOR("Jouni Malinen");
	28	MODULE_DESCRIPTION("Host AP crypt: WEP");
	29	MODULE_LICENSE("GPL");
8fc8598e JC	30
	31	struct prism2_wep_data {
	32	u32 iv;
	33	#define WEP_KEY_LEN 13
	34	u8 key[WEP_KEY_LEN + 1];
	35	u8 key_len;
	36	u8 key_idx;
e406322b MCC	37	struct crypto_blkcipher *tx_tfm;
e406322b MCC	38	struct crypto_blkcipher *rx_tfm;
8fc8598e JC	39	};
	40
	41
	42	static void * prism2_wep_init(int keyidx)
	43	{
	44	struct prism2_wep_data *priv;
	45
7a6cb0d5	46	priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
8fc8598e JC	47	if (priv == NULL)
8fc8598e JC	48	goto fail;
8fc8598e JC	49	priv->key_idx = keyidx;
8fc8598e JC	50
8fc8598e	51	priv->tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
e406322b MCC	52	if (IS_ERR(priv->tx_tfm)) {
	53	printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
	54	"crypto API arc4\n");
	55	priv->tx_tfm = NULL;
	56	goto fail;
	57	}
	58	priv->rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
	59	if (IS_ERR(priv->rx_tfm)) {
	60	printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
	61	"crypto API arc4\n");
	62	priv->rx_tfm = NULL;
	63	goto fail;
	64	}
8fc8598e JC	65
	66	/* start WEP IV from a random value */
	67	get_random_bytes(&priv->iv, 4);
	68
	69	return priv;
	70
	71	fail:
8fc8598e	72	if (priv) {
e406322b MCC	73	if (priv->tx_tfm)
	74	crypto_free_blkcipher(priv->tx_tfm);
	75	if (priv->rx_tfm)
	76	crypto_free_blkcipher(priv->rx_tfm);
	77	kfree(priv);
	78	}
f61fb935	79
8fc8598e JC	80	return NULL;
	81	}
	82
	83
	84	static void prism2_wep_deinit(void *priv)
	85	{
	86	struct prism2_wep_data *_priv = priv;
f61fb935	87
8fc8598e	88	if (_priv) {
e406322b MCC	89	if (_priv->tx_tfm)
	90	crypto_free_blkcipher(_priv->tx_tfm);
	91	if (_priv->rx_tfm)
	92	crypto_free_blkcipher(_priv->rx_tfm);
	93	}
8fc8598e JC	94	kfree(priv);
	95	}
	96
	97	/* Perform WEP encryption on given skb that has at least 4 bytes of headroom
	98	* for IV and 4 bytes of tailroom for ICV. Both IV and ICV will be transmitted,
	99	* so the payload length increases with 8 bytes.
	100	*
	101	* WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
	102	*/
	103	static int prism2_wep_encrypt(struct sk_buff skb, int hdr_len, void priv)
	104	{
	105	struct prism2_wep_data *wep = priv;
	106	u32 klen, len;
	107	u8 key[WEP_KEY_LEN + 3];
	108	u8 *pos;
	109	cb_desc tcb_desc = (cb_desc )(skb->cb + MAX_DEV_ADDR_SIZE);
8fc8598e	110	struct blkcipher_desc desc = {.tfm = wep->tx_tfm};
8fc8598e JC	111	u32 crc;
	112	u8 *icv;
	113	struct scatterlist sg;
	114	if (skb_headroom(skb) < 4 \|\| skb_tailroom(skb) < 4 \|\|
	115	skb->len < hdr_len)
	116	return -1;
	117
	118	len = skb->len - hdr_len;
	119	pos = skb_push(skb, 4);
	120	memmove(pos, pos + 4, hdr_len);
	121	pos += hdr_len;
	122
	123	klen = 3 + wep->key_len;
	124
	125	wep->iv++;
	126
	127	/* Fluhrer, Mantin, and Shamir have reported weaknesses in the key
	128	* scheduling algorithm of RC4. At least IVs (KeyByte + 3, 0xff, N)
	129	* can be used to speedup attacks, so avoid using them. */
	130	if ((wep->iv & 0xff00) == 0xff00) {
	131	u8 B = (wep->iv >> 16) & 0xff;
	132	if (B >= 3 && B < klen)
	133	wep->iv += 0x0100;
	134	}
	135
	136	/* Prepend 24-bit IV to RC4 key and TX frame */
	137	*pos++ = key[0] = (wep->iv >> 16) & 0xff;
	138	*pos++ = key[1] = (wep->iv >> 8) & 0xff;
	139	*pos++ = key[2] = wep->iv & 0xff;
	140	*pos++ = wep->key_idx << 6;
	141
	142	/* Copy rest of the WEP key (the secret part) */
	143	memcpy(key + 3, wep->key, wep->key_len);
	144
	145	if (!tcb_desc->bHwSec)
	146	{
	147
	148	/* Append little-endian CRC32 and encrypt it to produce ICV */
8fc8598e	149	crc = ~crc32_le(~0, pos, len);
8fc8598e JC	150	icv = skb_put(skb, 4);
	151	icv[0] = crc;
	152	icv[1] = crc >> 8;
	153	icv[2] = crc >> 16;
	154	icv[3] = crc >> 24;
	155
8fc8598e	156	crypto_blkcipher_setkey(wep->tx_tfm, key, klen);
8fc8598e	157	sg_init_one(&sg, pos, len+4);
f61fb935	158
8fc8598e	159	return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
8fc8598e JC	160	}
	161
	162	return 0;
	163	}
	164
	165
	166	/* Perform WEP decryption on given buffer. Buffer includes whole WEP part of
	167	* the frame: IV (4 bytes), encrypted payload (including SNAP header),
	168	* ICV (4 bytes). len includes both IV and ICV.
	169	*
	170	* Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
	171	* failure. If frame is OK, IV and ICV will be removed.
	172	*/
	173	static int prism2_wep_decrypt(struct sk_buff skb, int hdr_len, void priv)
	174	{
	175	struct prism2_wep_data *wep = priv;
	176	u32 klen, plen;
	177	u8 key[WEP_KEY_LEN + 3];
	178	u8 keyidx, *pos;
	179	cb_desc tcb_desc = (cb_desc )(skb->cb + MAX_DEV_ADDR_SIZE);
8fc8598e	180	struct blkcipher_desc desc = {.tfm = wep->rx_tfm};
8fc8598e JC	181	u32 crc;
	182	u8 icv[4];
	183	struct scatterlist sg;
	184	if (skb->len < hdr_len + 8)
	185	return -1;
	186
	187	pos = skb->data + hdr_len;
	188	key[0] = *pos++;
	189	key[1] = *pos++;
	190	key[2] = *pos++;
	191	keyidx = *pos++ >> 6;
	192	if (keyidx != wep->key_idx)
	193	return -1;
	194
	195	klen = 3 + wep->key_len;
	196
	197	/* Copy rest of the WEP key (the secret part) */
	198	memcpy(key + 3, wep->key, wep->key_len);
	199
	200	/* Apply RC4 to data and compute CRC32 over decrypted data */
	201	plen = skb->len - hdr_len - 8;
	202
	203	if (!tcb_desc->bHwSec)
	204	{
8fc8598e	205	crypto_blkcipher_setkey(wep->rx_tfm, key, klen);
8fc8598e	206	sg_init_one(&sg, pos, plen+4);
f61fb935	207
8fc8598e JC	208	if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4))
8fc8598e JC	209	return -7;
f61fb935	210
8fc8598e	211	crc = ~crc32_le(~0, pos, plen);
8fc8598e JC	212	icv[0] = crc;
	213	icv[1] = crc >> 8;
	214	icv[2] = crc >> 16;
	215	icv[3] = crc >> 24;
	216	if (memcmp(icv, pos + plen, 4) != 0) {
	217	/* ICV mismatch - drop frame */
	218	return -2;
	219	}
	220	}
	221	/* Remove IV and ICV */
	222	memmove(skb->data + 4, skb->data, hdr_len);
	223	skb_pull(skb, 4);
	224	skb_trim(skb, skb->len - 4);
	225
	226	return 0;
	227	}
	228
	229
	230	static int prism2_wep_set_key(void key, int len, u8 seq, void *priv)
	231	{
	232	struct prism2_wep_data *wep = priv;
	233
	234	if (len < 0 \|\| len > WEP_KEY_LEN)
	235	return -1;
	236
	237	memcpy(wep->key, key, len);
	238	wep->key_len = len;
	239
	240	return 0;
	241	}
	242
	243
	244	static int prism2_wep_get_key(void key, int len, u8 seq, void *priv)
	245	{
	246	struct prism2_wep_data *wep = priv;
	247
	248	if (len < wep->key_len)
	249	return -1;
	250
	251	memcpy(key, wep->key, wep->key_len);
	252
	253	return wep->key_len;
	254	}
	255
	256
	257	static char * prism2_wep_print_stats(char p, void priv)
	258	{
	259	struct prism2_wep_data *wep = priv;
	260	p += sprintf(p, "key[%d] alg=WEP len=%d\n",
	261	wep->key_idx, wep->key_len);
	262	return p;
	263	}
	264
	265
	266	static struct ieee80211_crypto_ops ieee80211_crypt_wep = {
	267	.name = "WEP",
	268	.init = prism2_wep_init,
	269	.deinit = prism2_wep_deinit,
	270	.encrypt_mpdu = prism2_wep_encrypt,
	271	.decrypt_mpdu = prism2_wep_decrypt,
	272	.encrypt_msdu = NULL,
	273	.decrypt_msdu = NULL,
	274	.set_key = prism2_wep_set_key,
	275	.get_key = prism2_wep_get_key,
276	.print_stats = prism2_wep_print_stats,
277	.extra_prefix_len = 4, /* IV */
278	.extra_postfix_len = 4, /* ICV */
279	.owner = THIS_MODULE,
280	};
281
f61fb935	282	int __init ieee80211_crypto_wep_init(void)
8fc8598e JC	283	{
	284	return ieee80211_register_crypto_ops(&ieee80211_crypt_wep);
	285	}
	286
f61fb935	287	void __exit ieee80211_crypto_wep_exit(void)
8fc8598e JC	288	{
	289	ieee80211_unregister_crypto_ops(&ieee80211_crypt_wep);
	290	}
	291
	292	void ieee80211_wep_null(void)
	293	{
	294	// printk("============>%s()\n", __FUNCTION__);
e406322b	295	return;
8fc8598e	296	}