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12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/slab.h>
15#include <linux/random.h>
16#include <linux/skbuff.h>
17#include <linux/string.h>
18#include "rtllib.h"
19
20#include <linux/crypto.h>
21
22#include <linux/scatterlist.h>
23#include <linux/crc32.h>
24
25struct prism2_wep_data {
26 u32 iv;
27#define WEP_KEY_LEN 13
28 u8 key[WEP_KEY_LEN + 1];
29 u8 key_len;
30 u8 key_idx;
31 struct crypto_blkcipher *tx_tfm;
32 struct crypto_blkcipher *rx_tfm;
33};
34
35
36static void *prism2_wep_init(int keyidx)
37{
38 struct prism2_wep_data *priv;
39
40 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
41 if (priv == NULL)
42 goto fail;
43 priv->key_idx = keyidx;
44
45 priv->tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
46 if (IS_ERR(priv->tx_tfm)) {
47 pr_debug("rtllib_crypt_wep: could not allocate crypto API arc4\n");
48 priv->tx_tfm = NULL;
49 goto fail;
50 }
51 priv->rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
52 if (IS_ERR(priv->rx_tfm)) {
53 pr_debug("rtllib_crypt_wep: could not allocate crypto API arc4\n");
54 priv->rx_tfm = NULL;
55 goto fail;
56 }
57
58
59 get_random_bytes(&priv->iv, 4);
60
61 return priv;
62
63fail:
64 if (priv) {
65 if (priv->tx_tfm)
66 crypto_free_blkcipher(priv->tx_tfm);
67 if (priv->rx_tfm)
68 crypto_free_blkcipher(priv->rx_tfm);
69 kfree(priv);
70 }
71 return NULL;
72}
73
74
75static void prism2_wep_deinit(void *priv)
76{
77 struct prism2_wep_data *_priv = priv;
78
79 if (_priv) {
80 if (_priv->tx_tfm)
81 crypto_free_blkcipher(_priv->tx_tfm);
82 if (_priv->rx_tfm)
83 crypto_free_blkcipher(_priv->rx_tfm);
84 }
85 kfree(priv);
86}
87
88
89
90
91
92
93
94static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
95{
96 struct prism2_wep_data *wep = priv;
97 u32 klen, len;
98 u8 key[WEP_KEY_LEN + 3];
99 u8 *pos;
100 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb +
101 MAX_DEV_ADDR_SIZE);
102 struct blkcipher_desc desc = {.tfm = wep->tx_tfm};
103 u32 crc;
104 u8 *icv;
105 struct scatterlist sg;
106
107 if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 ||
108 skb->len < hdr_len){
109 pr_err("Error!!! headroom=%d tailroom=%d skblen=%d hdr_len=%d\n",
110 skb_headroom(skb), skb_tailroom(skb), skb->len, hdr_len);
111 return -1;
112 }
113 len = skb->len - hdr_len;
114 pos = skb_push(skb, 4);
115 memmove(pos, pos + 4, hdr_len);
116 pos += hdr_len;
117
118 klen = 3 + wep->key_len;
119
120 wep->iv++;
121
122
123
124
125
126 if ((wep->iv & 0xff00) == 0xff00) {
127 u8 B = (wep->iv >> 16) & 0xff;
128
129 if (B >= 3 && B < klen)
130 wep->iv += 0x0100;
131 }
132
133
134 *pos++ = key[0] = (wep->iv >> 16) & 0xff;
135 *pos++ = key[1] = (wep->iv >> 8) & 0xff;
136 *pos++ = key[2] = wep->iv & 0xff;
137 *pos++ = wep->key_idx << 6;
138
139
140 memcpy(key + 3, wep->key, wep->key_len);
141
142 if (!tcb_desc->bHwSec) {
143
144
145 crc = ~crc32_le(~0, pos, len);
146 icv = skb_put(skb, 4);
147 icv[0] = crc;
148 icv[1] = crc >> 8;
149 icv[2] = crc >> 16;
150 icv[3] = crc >> 24;
151
152 sg_init_one(&sg, pos, len+4);
153 crypto_blkcipher_setkey(wep->tx_tfm, key, klen);
154 return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
155 }
156
157 return 0;
158}
159
160
161
162
163
164
165
166
167
168static int prism2_wep_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
169{
170 struct prism2_wep_data *wep = priv;
171 u32 klen, plen;
172 u8 key[WEP_KEY_LEN + 3];
173 u8 keyidx, *pos;
174 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb +
175 MAX_DEV_ADDR_SIZE);
176 struct blkcipher_desc desc = {.tfm = wep->rx_tfm};
177 u32 crc;
178 u8 icv[4];
179 struct scatterlist sg;
180
181 if (skb->len < hdr_len + 8)
182 return -1;
183
184 pos = skb->data + hdr_len;
185 key[0] = *pos++;
186 key[1] = *pos++;
187 key[2] = *pos++;
188 keyidx = *pos++ >> 6;
189 if (keyidx != wep->key_idx)
190 return -1;
191
192 klen = 3 + wep->key_len;
193
194
195 memcpy(key + 3, wep->key, wep->key_len);
196
197
198 plen = skb->len - hdr_len - 8;
199
200 if (!tcb_desc->bHwSec) {
201 sg_init_one(&sg, pos, plen+4);
202 crypto_blkcipher_setkey(wep->rx_tfm, key, klen);
203 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4))
204 return -7;
205 crc = ~crc32_le(~0, pos, plen);
206 icv[0] = crc;
207 icv[1] = crc >> 8;
208 icv[2] = crc >> 16;
209 icv[3] = crc >> 24;
210 if (memcmp(icv, pos + plen, 4) != 0) {
211
212 return -2;
213 }
214 }
215
216 memmove(skb->data + 4, skb->data, hdr_len);
217 skb_pull(skb, 4);
218 skb_trim(skb, skb->len - 4);
219
220 return 0;
221}
222
223
224static int prism2_wep_set_key(void *key, int len, u8 *seq, void *priv)
225{
226 struct prism2_wep_data *wep = priv;
227
228 if (len < 0 || len > WEP_KEY_LEN)
229 return -1;
230
231 memcpy(wep->key, key, len);
232 wep->key_len = len;
233
234 return 0;
235}
236
237
238static int prism2_wep_get_key(void *key, int len, u8 *seq, void *priv)
239{
240 struct prism2_wep_data *wep = priv;
241
242 if (len < wep->key_len)
243 return -1;
244
245 memcpy(key, wep->key, wep->key_len);
246
247 return wep->key_len;
248}
249
250
251static void prism2_wep_print_stats(struct seq_file *m, void *priv)
252{
253 struct prism2_wep_data *wep = priv;
254
255 seq_printf(m, "key[%d] alg=WEP len=%d\n", wep->key_idx, wep->key_len);
256}
257
258static struct lib80211_crypto_ops rtllib_crypt_wep = {
259 .name = "R-WEP",
260 .init = prism2_wep_init,
261 .deinit = prism2_wep_deinit,
262 .encrypt_mpdu = prism2_wep_encrypt,
263 .decrypt_mpdu = prism2_wep_decrypt,
264 .encrypt_msdu = NULL,
265 .decrypt_msdu = NULL,
266 .set_key = prism2_wep_set_key,
267 .get_key = prism2_wep_get_key,
268 .print_stats = prism2_wep_print_stats,
269 .extra_mpdu_prefix_len = 4,
270 .extra_mpdu_postfix_len = 4,
271 .owner = THIS_MODULE,
272};
273
274
275static int __init rtllib_crypto_wep_init(void)
276{
277 return lib80211_register_crypto_ops(&rtllib_crypt_wep);
278}
279
280
281static void __exit rtllib_crypto_wep_exit(void)
282{
283 lib80211_unregister_crypto_ops(&rtllib_crypt_wep);
284}
285
286module_init(rtllib_crypto_wep_init);
287module_exit(rtllib_crypto_wep_exit);
288
289MODULE_LICENSE("GPL");
290