drivers/staging/rtl8187se/ieee80211/ieee80211_crypt_ccmp.c

   1 /*
   2  * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
   3  *
   4  * Copyright (c) 2003-2004, 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 <linux/netdevice.h>
  20 #include <linux/if_ether.h>
  21 #include <linux/if_arp.h>
  22 #include <asm/string.h>
  23 #include <linux/wireless.h>
  24
  25 #include "ieee80211.h"
  26
  27 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
  28 #include "rtl_crypto.h"
  29 #else
  30 #include <linux/crypto.h>
  31 #endif
  32 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
  33     #include <asm/scatterlist.h>
  34 #else
  35     #include <linux/scatterlist.h>
  36 #endif
  37
  38 //#include <asm/scatterlist.h>
  39
  40 MODULE_AUTHOR("Jouni Malinen");
  41 MODULE_DESCRIPTION("Host AP crypt: CCMP");
  42 MODULE_LICENSE("GPL");
  43
  44 #ifdef OPENSUSE_SLED
  45 #ifndef IN_OPENSUSE_SLED
  46 #define IN_OPENSUSE_SLED 1
  47 #endif
  48 #endif
  49
  50 #define AES_BLOCK_LEN 16
  51 #define CCMP_HDR_LEN 8
  52 #define CCMP_MIC_LEN 8
  53 #define CCMP_TK_LEN 16
  54 #define CCMP_PN_LEN 6
  55
  56 struct ieee80211_ccmp_data {
  57         u8 key[CCMP_TK_LEN];
  58         int key_set;
  59
  60         u8 tx_pn[CCMP_PN_LEN];
  61         u8 rx_pn[CCMP_PN_LEN];
  62
  63         u32 dot11RSNAStatsCCMPFormatErrors;
  64         u32 dot11RSNAStatsCCMPReplays;
  65         u32 dot11RSNAStatsCCMPDecryptErrors;
  66
  67         int key_idx;
  68
  69         struct crypto_tfm *tfm;
  70
  71         /* scratch buffers for virt_to_page() (crypto API) */
  72         u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
  73                 tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
  74         u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
  75 };
  76
  77 void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
  78                              const u8 pt[16], u8 ct[16])
  79 {
  80         #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))||(IN_OPENSUSE_SLED))
  81         crypto_cipher_encrypt_one((void *)tfm, ct, pt);
  82         #else
  83         struct scatterlist src, dst;
  84
  85         src.page = virt_to_page(pt);
  86         src.offset = offset_in_page(pt);
  87         src.length = AES_BLOCK_LEN;
  88
  89         dst.page = virt_to_page(ct);
  90         dst.offset = offset_in_page(ct);
  91         dst.length = AES_BLOCK_LEN;
  92
  93         crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
  94         #endif
  95 }
  96
  97 static void * ieee80211_ccmp_init(int key_idx)
  98 {
  99         struct ieee80211_ccmp_data *priv;
 100
 101         priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
 102         if (priv == NULL)
 103                 goto fail;
 104         memset(priv, 0, sizeof(*priv));
 105         priv->key_idx = key_idx;
 106
 107        #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
 108         priv->tfm = crypto_alloc_tfm("aes", 0);
 109         if (priv->tfm == NULL) {
 110                 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
 111                        "crypto API aes\n");
 112                 goto fail;
 113         }
 114        #else
 115        priv->tfm = (void *)crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
 116         if (IS_ERR(priv->tfm)) {
 117                 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
 118                        "crypto API aes\n");
 119                 priv->tfm = NULL;
 120                 goto fail;
 121         }
 122         #endif
 123         return priv;
 124
 125 fail:
 126         if (priv) {
 127                 if (priv->tfm)
 128                         //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 129                         #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
 130                         crypto_free_tfm(priv->tfm);
 131                     #else
 132                         crypto_free_cipher((void *)priv->tfm);
 133                       #endif
 134                 kfree(priv);
 135         }
 136
 137         return NULL;
 138 }
 139
 140
 141 static void ieee80211_ccmp_deinit(void *priv)
 142 {
 143         struct ieee80211_ccmp_data *_priv = priv;
 144         if (_priv && _priv->tfm)
 145                 //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 146                 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
 147                 crypto_free_tfm(_priv->tfm);
 148              #else
 149                 crypto_free_cipher((void *)_priv->tfm);
 150                 #endif
 151         kfree(priv);
 152 }
 153
 154
 155 static inline void xor_block(u8 *b, u8 *a, size_t len)
 156 {
 157         int i;
 158         for (i = 0; i < len; i++)
 159                 b[i] ^= a[i];
 160 }
 161
 162 #ifndef JOHN_CCMP
 163 static void ccmp_init_blocks(struct crypto_tfm *tfm,
 164                              struct ieee80211_hdr *hdr,
 165                              u8 *pn, size_t dlen, u8 *b0, u8 *auth,
 166                              u8 *s0)
 167 {
 168         u8 *pos, qc = 0;
 169         size_t aad_len;
 170         u16 fc;
 171         int a4_included, qc_included;
 172         u8 aad[2 * AES_BLOCK_LEN];
 173
 174         fc = le16_to_cpu(hdr->frame_ctl);
 175         a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 176                        (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
 177         /*
 178         qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
 179                        (WLAN_FC_GET_STYPE(fc) & 0x08));
 180         */
 181         // fixed by David :2006.9.6
 182         qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
 183                        (WLAN_FC_GET_STYPE(fc) & 0x80));
 184         aad_len = 22;
 185         if (a4_included)
 186                 aad_len += 6;
 187         if (qc_included) {
 188                 pos = (u8 *) &hdr->addr4;
 189                 if (a4_included)
 190                         pos += 6;
 191                 qc = *pos & 0x0f;
 192                 aad_len += 2;
 193         }
 194         /* CCM Initial Block:
 195          * Flag (Include authentication header, M=3 (8-octet MIC),
 196          *       L=1 (2-octet Dlen))
 197          * Nonce: 0x00 | A2 | PN
 198          * Dlen */
 199         b0[0] = 0x59;
 200         b0[1] = qc;
 201         memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
 202         memcpy(b0 + 8, pn, CCMP_PN_LEN);
 203         b0[14] = (dlen >> 8) & 0xff;
 204         b0[15] = dlen & 0xff;
 205
 206         /* AAD:
 207          * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
 208          * A1 | A2 | A3
 209          * SC with bits 4..15 (seq#) masked to zero
 210          * A4 (if present)
 211          * QC (if present)
 212          */
 213         pos = (u8 *) hdr;
 214         aad[0] = 0; /* aad_len >> 8 */
 215         aad[1] = aad_len & 0xff;
 216         aad[2] = pos[0] & 0x8f;
 217         aad[3] = pos[1] & 0xc7;
 218         memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
 219         pos = (u8 *) &hdr->seq_ctl;
 220         aad[22] = pos[0] & 0x0f;
 221         aad[23] = 0; /* all bits masked */
 222         memset(aad + 24, 0, 8);
 223         if (a4_included)
 224                 memcpy(aad + 24, hdr->addr4, ETH_ALEN);
 225         if (qc_included) {
 226                 aad[a4_included ? 30 : 24] = qc;
 227                 /* rest of QC masked */
 228         }
 229
 230         /* Start with the first block and AAD */
 231         ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
 232         xor_block(auth, aad, AES_BLOCK_LEN);
 233         ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
 234         xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
 235         ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
 236         b0[0] &= 0x07;
 237         b0[14] = b0[15] = 0;
 238         ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
 239 }
 240 #endif
 241
 242 static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 243 {
 244         struct ieee80211_ccmp_data *key = priv;
 245         int data_len, i;
 246         u8 *pos;
 247         struct ieee80211_hdr *hdr;
 248 #ifndef JOHN_CCMP
 249         int blocks, last, len;
 250         u8 *mic;
 251         u8 *b0 = key->tx_b0;
 252         u8 *b = key->tx_b;
 253         u8 *e = key->tx_e;
 254         u8 *s0 = key->tx_s0;
 255 #endif
 256         if (skb_headroom(skb) < CCMP_HDR_LEN ||
 257             skb_tailroom(skb) < CCMP_MIC_LEN ||
 258             skb->len < hdr_len)
 259                 return -1;
 260
 261         data_len = skb->len - hdr_len;
 262         pos = skb_push(skb, CCMP_HDR_LEN);
 263         memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
 264         pos += hdr_len;
 265 //      mic = skb_put(skb, CCMP_MIC_LEN);
 266
 267         i = CCMP_PN_LEN - 1;
 268         while (i >= 0) {
 269                 key->tx_pn[i]++;
 270                 if (key->tx_pn[i] != 0)
 271                         break;
 272                 i--;
 273         }
 274
 275         *pos++ = key->tx_pn[5];
 276         *pos++ = key->tx_pn[4];
 277         *pos++ = 0;
 278         *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */;
 279         *pos++ = key->tx_pn[3];
 280         *pos++ = key->tx_pn[2];
 281         *pos++ = key->tx_pn[1];
 282         *pos++ = key->tx_pn[0];
 283
 284         hdr = (struct ieee80211_hdr *) skb->data;
 285 #ifndef JOHN_CCMP
 286         //mic is moved to here by john
 287         mic = skb_put(skb, CCMP_MIC_LEN);
 288
 289         ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
 290
 291         blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
 292         last = data_len % AES_BLOCK_LEN;
 293
 294         for (i = 1; i <= blocks; i++) {
 295                 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
 296                 /* Authentication */
 297                 xor_block(b, pos, len);
 298                 ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
 299                 /* Encryption, with counter */
 300                 b0[14] = (i >> 8) & 0xff;
 301                 b0[15] = i & 0xff;
 302                 ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
 303                 xor_block(pos, e, len);
 304                 pos += len;
 305         }
 306
 307         for (i = 0; i < CCMP_MIC_LEN; i++)
 308                 mic[i] = b[i] ^ s0[i];
 309 #endif
 310         return 0;
 311 }
 312
 313
 314 static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 315 {
 316         struct ieee80211_ccmp_data *key = priv;
 317         u8 keyidx, *pos;
 318         struct ieee80211_hdr *hdr;
 319         u8 pn[6];
 320 #ifndef JOHN_CCMP
 321         size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
 322         u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
 323         u8 *b0 = key->rx_b0;
 324         u8 *b = key->rx_b;
 325         u8 *a = key->rx_a;
 326         int i, blocks, last, len;
 327 #endif
 328         if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
 329                 key->dot11RSNAStatsCCMPFormatErrors++;
 330                 return -1;
 331         }
 332
 333         hdr = (struct ieee80211_hdr *) skb->data;
 334         pos = skb->data + hdr_len;
 335         keyidx = pos[3];
 336         if (!(keyidx & (1 << 5))) {
 337                 if (net_ratelimit()) {
 338                         printk(KERN_DEBUG "CCMP: received packet without ExtIV"
 339                                " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
 340                 }
 341                 key->dot11RSNAStatsCCMPFormatErrors++;
 342                 return -2;
 343         }
 344         keyidx >>= 6;
 345         if (key->key_idx != keyidx) {
 346                 printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
 347                        "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
 348                 return -6;
 349         }
 350         if (!key->key_set) {
 351                 if (net_ratelimit()) {
 352                         printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
 353                                " with keyid=%d that does not have a configured"
 354                                " key\n", MAC_ARG(hdr->addr2), keyidx);
 355                 }
 356                 return -3;
 357         }
 358
 359         pn[0] = pos[7];
 360         pn[1] = pos[6];
 361         pn[2] = pos[5];
 362         pn[3] = pos[4];
 363         pn[4] = pos[1];
 364         pn[5] = pos[0];
 365         pos += 8;
 366
 367         if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
 368                 if (net_ratelimit()) {
 369                         printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
 370                                " previous PN %02x%02x%02x%02x%02x%02x "
 371                                "received PN %02x%02x%02x%02x%02x%02x\n",
 372                                MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
 373                                MAC_ARG(pn));
 374                 }
 375                 key->dot11RSNAStatsCCMPReplays++;
 376                 return -4;
 377         }
 378
 379 #ifndef JOHN_CCMP
 380         ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
 381         xor_block(mic, b, CCMP_MIC_LEN);
 382
 383         blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
 384         last = data_len % AES_BLOCK_LEN;
 385
 386         for (i = 1; i <= blocks; i++) {
 387                 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
 388                 /* Decrypt, with counter */
 389                 b0[14] = (i >> 8) & 0xff;
 390                 b0[15] = i & 0xff;
 391                 ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
 392                 xor_block(pos, b, len);
 393                 /* Authentication */
 394                 xor_block(a, pos, len);
 395                 ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
 396                 pos += len;
 397         }
 398
 399         if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
 400                 if (net_ratelimit()) {
 401                         printk(KERN_DEBUG "CCMP: decrypt failed: STA="
 402                                MAC_FMT "\n", MAC_ARG(hdr->addr2));
 403                 }
 404                 key->dot11RSNAStatsCCMPDecryptErrors++;
 405                 return -5;
 406         }
 407
 408         memcpy(key->rx_pn, pn, CCMP_PN_LEN);
 409
 410 #endif
 411         /* Remove hdr and MIC */
 412         memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
 413         skb_pull(skb, CCMP_HDR_LEN);
 414         skb_trim(skb, skb->len - CCMP_MIC_LEN);
 415
 416         return keyidx;
 417 }
 418
 419
 420 static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
 421 {
 422         struct ieee80211_ccmp_data *data = priv;
 423         int keyidx;
 424         struct crypto_tfm *tfm = data->tfm;
 425
 426         keyidx = data->key_idx;
 427         memset(data, 0, sizeof(*data));
 428         data->key_idx = keyidx;
 429         data->tfm = tfm;
 430         if (len == CCMP_TK_LEN) {
 431                 memcpy(data->key, key, CCMP_TK_LEN);
 432                 data->key_set = 1;
 433                 if (seq) {
 434                         data->rx_pn[0] = seq[5];
 435                         data->rx_pn[1] = seq[4];
 436                         data->rx_pn[2] = seq[3];
 437                         data->rx_pn[3] = seq[2];
 438                         data->rx_pn[4] = seq[1];
 439                         data->rx_pn[5] = seq[0];
 440                 }
 441                 crypto_cipher_setkey((void *)data->tfm, data->key, CCMP_TK_LEN);
 442         } else if (len == 0)
 443                 data->key_set = 0;
 444         else
 445                 return -1;
 446
 447         return 0;
 448 }
 449
 450
 451 static int ieee80211_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
 452 {
 453         struct ieee80211_ccmp_data *data = priv;
 454
 455         if (len < CCMP_TK_LEN)
 456                 return -1;
 457
 458         if (!data->key_set)
 459                 return 0;
 460         memcpy(key, data->key, CCMP_TK_LEN);
 461
 462         if (seq) {
 463                 seq[0] = data->tx_pn[5];
 464                 seq[1] = data->tx_pn[4];
 465                 seq[2] = data->tx_pn[3];
 466                 seq[3] = data->tx_pn[2];
 467                 seq[4] = data->tx_pn[1];
 468                 seq[5] = data->tx_pn[0];
 469         }
 470
 471         return CCMP_TK_LEN;
 472 }
 473
 474
 475 static char * ieee80211_ccmp_print_stats(char *p, void *priv)
 476 {
 477         struct ieee80211_ccmp_data *ccmp = priv;
 478         p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
 479                      "tx_pn=%02x%02x%02x%02x%02x%02x "
 480                      "rx_pn=%02x%02x%02x%02x%02x%02x "
 481                      "format_errors=%d replays=%d decrypt_errors=%d\n",
 482                      ccmp->key_idx, ccmp->key_set,
 483                      MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
 484                      ccmp->dot11RSNAStatsCCMPFormatErrors,
 485                      ccmp->dot11RSNAStatsCCMPReplays,
 486                      ccmp->dot11RSNAStatsCCMPDecryptErrors);
 487
 488         return p;
 489 }
 490
 491 void ieee80211_ccmp_null(void)
 492 {
 493 //    printk("============>%s()\n", __FUNCTION__);
 494         return;
 495 }
 496 static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
 497         .name                   = "CCMP",
 498         .init                   = ieee80211_ccmp_init,
 499         .deinit                 = ieee80211_ccmp_deinit,
 500         .encrypt_mpdu           = ieee80211_ccmp_encrypt,
 501         .decrypt_mpdu           = ieee80211_ccmp_decrypt,
 502         .encrypt_msdu           = NULL,
 503         .decrypt_msdu           = NULL,
 504         .set_key                = ieee80211_ccmp_set_key,
 505         .get_key                = ieee80211_ccmp_get_key,
 506         .print_stats            = ieee80211_ccmp_print_stats,
 507         .extra_prefix_len       = CCMP_HDR_LEN,
 508         .extra_postfix_len      = CCMP_MIC_LEN,
 509         .owner                  = THIS_MODULE,
 510 };
 511
 512
 513 int ieee80211_crypto_ccmp_init(void)
 514 {
 515         return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
 516 }
 517
 518
 519 void ieee80211_crypto_ccmp_exit(void)
 520 {
 521         ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
 522 }
 523
 524 #if 0
 525 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 526 EXPORT_SYMBOL(ieee80211_ccmp_null);
 527 #else
 528 EXPORT_SYMBOL_NOVERS(ieee80211_ccmp_null);
 529 #endif
 530 #endif
 531
 532 //module_init(ieee80211_crypto_ccmp_init);
 533 //module_exit(ieee80211_crypto_ccmp_exit);