kernel/2.6.29.6-aldebaran-rt/drivers/staging/rtl8187se/ieee80211/ieee80211_crypt_wep.c

   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
  23 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
  24 #include "rtl_crypto.h"
  25 #else
  26 #include <linux/crypto.h>
  27 #endif
  28
  29 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
  30     #include <asm/scatterlist.h>
  31 #else
  32     #include <linux/scatterlist.h>
  33 #endif
  34 //#include <asm/scatterlist.h>
  35 #include <linux/crc32.h>
  36
  37 MODULE_AUTHOR("Jouni Malinen");
  38 MODULE_DESCRIPTION("Host AP crypt: WEP");
  39 MODULE_LICENSE("GPL");
  40
  41 #ifdef OPENSUSE_SLED
  42 #ifndef IN_OPENSUSE_SLED
  43 #define IN_OPENSUSE_SLED 1
  44 #endif
  45 #endif
  46
  47
  48 struct prism2_wep_data {
  49         u32 iv;
  50 #define WEP_KEY_LEN 13
  51         u8 key[WEP_KEY_LEN + 1];
  52         u8 key_len;
  53         u8 key_idx;
  54         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
  55         struct crypto_tfm *tfm;
  56         #else
  57         struct crypto_blkcipher *tx_tfm;
  58         struct crypto_blkcipher *rx_tfm;
  59         #endif
  60 };
  61
  62
  63 static void * prism2_wep_init(int keyidx)
  64 {
  65         struct prism2_wep_data *priv;
  66
  67         priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
  68         if (priv == NULL)
  69                 goto fail;
  70         memset(priv, 0, sizeof(*priv));
  71         priv->key_idx = keyidx;
  72         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
  73         priv->tfm = crypto_alloc_tfm("arc4", 0);
  74         if (priv->tfm == NULL) {
  75                 printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
  76                        "crypto API arc4\n");
  77                 goto fail;
  78         }
  79         #else
  80         priv->tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
  81         if (IS_ERR(priv->tx_tfm)) {
  82                 printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
  83                        "crypto API arc4\n");
  84                 priv->tx_tfm = NULL;
  85                 goto fail;
  86         }
  87         priv->rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
  88         if (IS_ERR(priv->rx_tfm)) {
  89                 printk(KERN_DEBUG "ieee80211_crypt_wep: could not allocate "
  90                        "crypto API arc4\n");
  91                 priv->rx_tfm = NULL;
  92                 goto fail;
  93         }
  94         #endif
  95
  96         /* start WEP IV from a random value */
  97         get_random_bytes(&priv->iv, 4);
  98
  99         return priv;
 100
 101 fail:
 102         //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 103         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
 104         if (priv) {
 105                 if (priv->tfm)
 106                         crypto_free_tfm(priv->tfm);
 107                 kfree(priv);
 108         }
 109        #else
 110         if (priv) {
 111                 if (priv->tx_tfm)
 112                         crypto_free_blkcipher(priv->tx_tfm);
 113                 if (priv->rx_tfm)
 114                         crypto_free_blkcipher(priv->rx_tfm);
 115                 kfree(priv);
 116         }
 117         #endif
 118         return NULL;
 119 }
 120
 121
 122 static void prism2_wep_deinit(void *priv)
 123 {
 124         struct prism2_wep_data *_priv = priv;
 125         //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 126         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
 127         if (_priv && _priv->tfm)
 128                 crypto_free_tfm(_priv->tfm);
 129         #else
 130         if (_priv) {
 131                 if (_priv->tx_tfm)
 132                         crypto_free_blkcipher(_priv->tx_tfm);
 133                 if (_priv->rx_tfm)
 134                         crypto_free_blkcipher(_priv->rx_tfm);
 135         }
 136         #endif
 137         kfree(priv);
 138 }
 139
 140
 141 /* Perform WEP encryption on given skb that has at least 4 bytes of headroom
 142  * for IV and 4 bytes of tailroom for ICV. Both IV and ICV will be transmitted,
 143  * so the payload length increases with 8 bytes.
 144  *
 145  * WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
 146  */
 147 static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 148 {
 149         struct prism2_wep_data *wep = priv;
 150 //#if(LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))
 151 #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))||(IN_OPENSUSE_SLED))
 152         struct blkcipher_desc desc = {.tfm = wep->tx_tfm};
 153 #endif
 154         u32 klen, len;
 155         u8 key[WEP_KEY_LEN + 3];
 156         u8 *pos;
 157 #ifndef JOHN_HWSEC
 158         u32 crc;
 159         u8 *icv;
 160         struct scatterlist sg;
 161 #endif
 162         if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 ||
 163             skb->len < hdr_len)
 164                 return -1;
 165
 166         len = skb->len - hdr_len;
 167         pos = skb_push(skb, 4);
 168         memmove(pos, pos + 4, hdr_len);
 169         pos += hdr_len;
 170
 171         klen = 3 + wep->key_len;
 172
 173         wep->iv++;
 174
 175         /* Fluhrer, Mantin, and Shamir have reported weaknesses in the key
 176          * scheduling algorithm of RC4. At least IVs (KeyByte + 3, 0xff, N)
 177          * can be used to speedup attacks, so avoid using them. */
 178         if ((wep->iv & 0xff00) == 0xff00) {
 179                 u8 B = (wep->iv >> 16) & 0xff;
 180                 if (B >= 3 && B < klen)
 181                         wep->iv += 0x0100;
 182         }
 183
 184         /* Prepend 24-bit IV to RC4 key and TX frame */
 185         *pos++ = key[0] = (wep->iv >> 16) & 0xff;
 186         *pos++ = key[1] = (wep->iv >> 8) & 0xff;
 187         *pos++ = key[2] = wep->iv & 0xff;
 188         *pos++ = wep->key_idx << 6;
 189
 190         /* Copy rest of the WEP key (the secret part) */
 191         memcpy(key + 3, wep->key, wep->key_len);
 192
 193 #ifndef JOHN_HWSEC
 194         /* Append little-endian CRC32 and encrypt it to produce ICV */
 195 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 196         crc = ~crc32_le(~0, pos, len);
 197 #else
 198         crc = ~ether_crc_le(len, pos);
 199 #endif
 200         icv = skb_put(skb, 4);
 201         icv[0] = crc;
 202         icv[1] = crc >> 8;
 203         icv[2] = crc >> 16;
 204         icv[3] = crc >> 24;
 205
 206         //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 207         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
 208         crypto_cipher_setkey(wep->tfm, key, klen);
 209         sg.page = virt_to_page(pos);
 210         sg.offset = offset_in_page(pos);
 211         sg.length = len + 4;
 212         crypto_cipher_encrypt(wep->tfm, &sg, &sg, len + 4);
 213
 214         return 0;
 215         #else
 216         crypto_blkcipher_setkey(wep->tx_tfm, key, klen);
 217         #if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24))
 218           sg.page = virt_to_page(pos);
 219           sg.offset = offset_in_page(pos);
 220           sg.length = len + 4;
 221         #else
 222           sg_init_one(&sg, pos, len+4);
 223         #endif
 224         return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
 225         #endif
 226 #endif /* JOHN_HWSEC */
 227         return 0;
 228 }
 229
 230
 231 /* Perform WEP decryption on given buffer. Buffer includes whole WEP part of
 232  * the frame: IV (4 bytes), encrypted payload (including SNAP header),
 233  * ICV (4 bytes). len includes both IV and ICV.
 234  *
 235  * Returns 0 if frame was decrypted successfully and ICV was correct and -1 on
 236  * failure. If frame is OK, IV and ICV will be removed.
 237  */
 238 static int prism2_wep_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 239 {
 240         struct prism2_wep_data *wep = priv;
 241         //#if(LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))
 242         #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))||(IN_OPENSUSE_SLED))
 243         struct blkcipher_desc desc = {.tfm = wep->rx_tfm};
 244         #endif
 245         u32 klen, plen;
 246         u8 key[WEP_KEY_LEN + 3];
 247         u8 keyidx, *pos;
 248 #ifndef JOHN_HWSEC
 249         u32 crc;
 250         u8 icv[4];
 251         struct scatterlist sg;
 252 #endif
 253         if (skb->len < hdr_len + 8)
 254                 return -1;
 255
 256         pos = skb->data + hdr_len;
 257         key[0] = *pos++;
 258         key[1] = *pos++;
 259         key[2] = *pos++;
 260         keyidx = *pos++ >> 6;
 261         if (keyidx != wep->key_idx)
 262                 return -1;
 263
 264         klen = 3 + wep->key_len;
 265
 266         /* Copy rest of the WEP key (the secret part) */
 267         memcpy(key + 3, wep->key, wep->key_len);
 268
 269         /* Apply RC4 to data and compute CRC32 over decrypted data */
 270         plen = skb->len - hdr_len - 8;
 271 #ifndef JOHN_HWSEC
 272 //#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 273 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))&&(!IN_OPENSUSE_SLED))
 274         crypto_cipher_setkey(wep->tfm, key, klen);
 275         sg.page = virt_to_page(pos);
 276         sg.offset = offset_in_page(pos);
 277         sg.length = plen + 4;
 278         crypto_cipher_decrypt(wep->tfm, &sg, &sg, plen + 4);
 279 #else
 280         crypto_blkcipher_setkey(wep->rx_tfm, key, klen);
 281         #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24))
 282           sg.page = virt_to_page(pos);
 283           sg.offset = offset_in_page(pos);
 284           sg.length = plen + 4;
 285         #else
 286           sg_init_one(&sg, pos, plen+4);
 287         #endif
 288         if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4))
 289                 return -7;
 290 #endif
 291
 292 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 293         crc = ~crc32_le(~0, pos, plen);
 294 #else
 295         crc = ~ether_crc_le(plen, pos);
 296 #endif
 297         icv[0] = crc;
 298         icv[1] = crc >> 8;
 299         icv[2] = crc >> 16;
 300         icv[3] = crc >> 24;
 301
 302         if (memcmp(icv, pos + plen, 4) != 0) {
 303                 /* ICV mismatch - drop frame */
 304                 return -2;
 305         }
 306 #endif  /* JOHN_HWSEC */
 307
 308         /* Remove IV and ICV */
 309         memmove(skb->data + 4, skb->data, hdr_len);
 310         skb_pull(skb, 4);
 311         skb_trim(skb, skb->len - 4);
 312         return 0;
 313 }
 314
 315
 316 static int prism2_wep_set_key(void *key, int len, u8 *seq, void *priv)
 317 {
 318         struct prism2_wep_data *wep = priv;
 319
 320         if (len < 0 || len > WEP_KEY_LEN)
 321                 return -1;
 322
 323         memcpy(wep->key, key, len);
 324         wep->key_len = len;
 325
 326         return 0;
 327 }
 328
 329
 330 static int prism2_wep_get_key(void *key, int len, u8 *seq, void *priv)
 331 {
 332         struct prism2_wep_data *wep = priv;
 333
 334         if (len < wep->key_len)
 335                 return -1;
 336
 337         memcpy(key, wep->key, wep->key_len);
 338
 339         return wep->key_len;
 340 }
 341
 342
 343 static char * prism2_wep_print_stats(char *p, void *priv)
 344 {
 345         struct prism2_wep_data *wep = priv;
 346         p += sprintf(p, "key[%d] alg=WEP len=%d\n",
 347                      wep->key_idx, wep->key_len);
 348         return p;
 349 }
 350
 351
 352 static struct ieee80211_crypto_ops ieee80211_crypt_wep = {
 353         .name                   = "WEP",
 354         .init                   = prism2_wep_init,
 355         .deinit                 = prism2_wep_deinit,
 356         .encrypt_mpdu           = prism2_wep_encrypt,
 357         .decrypt_mpdu           = prism2_wep_decrypt,
 358         .encrypt_msdu           = NULL,
 359         .decrypt_msdu           = NULL,
 360         .set_key                = prism2_wep_set_key,
 361         .get_key                = prism2_wep_get_key,
 362         .print_stats            = prism2_wep_print_stats,
 363         .extra_prefix_len       = 4, /* IV */
 364         .extra_postfix_len      = 4, /* ICV */
 365         .owner                  = THIS_MODULE,
 366 };
 367
 368
 369 int ieee80211_crypto_wep_init(void)
 370 {
 371         return ieee80211_register_crypto_ops(&ieee80211_crypt_wep);
 372 }
 373
 374
 375 void ieee80211_crypto_wep_exit(void)
 376 {
 377         ieee80211_unregister_crypto_ops(&ieee80211_crypt_wep);
 378 }
 379
 380
 381 void ieee80211_wep_null(void)
 382 {
 383 //      printk("============>%s()\n", __func__);
 384         return;
 385 }
 386 #if 0
 387 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 388 EXPORT_SYMBOL(ieee80211_wep_null);
 389 #else
 390 EXPORT_SYMBOL_NOVERS(ieee80211_wep_null);
 391 #endif
 392 #endif
 393 //module_init(ieee80211_crypto_wep_init);
 394 //module_exit(ieee80211_crypto_wep_exit);