drivers/staging/rtl8192e/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
  33 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
  34     #include <asm/scatterlist.h>
  35 #else
  36     #include <linux/scatterlist.h>
  37 #endif
  38 //#include <asm/scatterlist.h>
  39
  40 MODULE_AUTHOR("Jouni Malinen");
  41 MODULE_DESCRIPTION("Host AP crypt: CCMP");
  42 MODULE_LICENSE("GPL");
  43
  44 #ifndef OPENSUSE_SLED
  45 #define OPENSUSE_SLED 0
  46 #endif
  47
  48 #define AES_BLOCK_LEN 16
  49 #define CCMP_HDR_LEN 8
  50 #define CCMP_MIC_LEN 8
  51 #define CCMP_TK_LEN 16
  52 #define CCMP_PN_LEN 6
  53
  54 struct ieee80211_ccmp_data {
  55         u8 key[CCMP_TK_LEN];
  56         int key_set;
  57
  58         u8 tx_pn[CCMP_PN_LEN];
  59         u8 rx_pn[CCMP_PN_LEN];
  60
  61         u32 dot11RSNAStatsCCMPFormatErrors;
  62         u32 dot11RSNAStatsCCMPReplays;
  63         u32 dot11RSNAStatsCCMPDecryptErrors;
  64
  65         int key_idx;
  66
  67         struct crypto_tfm *tfm;
  68
  69         /* scratch buffers for virt_to_page() (crypto API) */
  70         u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
  71                 tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
  72         u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
  73 };
  74
  75 void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
  76                              const u8 pt[16], u8 ct[16])
  77 {
  78 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
  79         struct scatterlist src, dst;
  80
  81         src.page = virt_to_page(pt);
  82         src.offset = offset_in_page(pt);
  83         src.length = AES_BLOCK_LEN;
  84
  85         dst.page = virt_to_page(ct);
  86         dst.offset = offset_in_page(ct);
  87         dst.length = AES_BLOCK_LEN;
  88
  89         crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
  90 #else
  91         crypto_cipher_encrypt_one((void*)tfm, ct, pt);
  92 #endif
  93 }
  94
  95 static void * ieee80211_ccmp_init(int key_idx)
  96 {
  97         struct ieee80211_ccmp_data *priv;
  98
  99         priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
 100         if (priv == NULL)
 101                 goto fail;
 102         priv->key_idx = key_idx;
 103
 104 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!OPENSUSE_SLED))
 105         priv->tfm = crypto_alloc_tfm("aes", 0);
 106         if (priv->tfm == NULL) {
 107                 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
 108                        "crypto API aes\n");
 109                 goto fail;
 110         }
 111        #else
 112        priv->tfm = (void*)crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
 113         if (IS_ERR(priv->tfm)) {
 114                 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
 115                        "crypto API aes\n");
 116                 priv->tfm = NULL;
 117                 goto fail;
 118         }
 119         #endif
 120         return priv;
 121
 122 fail:
 123         if (priv) {
 124                 if (priv->tfm)
 125                         #if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 126                         crypto_free_tfm(priv->tfm);
 127                     #else
 128                         crypto_free_cipher((void*)priv->tfm);
 129                       #endif
 130                 kfree(priv);
 131         }
 132
 133         return NULL;
 134 }
 135
 136
 137 static void ieee80211_ccmp_deinit(void *priv)
 138 {
 139         struct ieee80211_ccmp_data *_priv = priv;
 140         if (_priv && _priv->tfm)
 141 #if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
 142                 crypto_free_tfm(_priv->tfm);
 143 #else
 144                 crypto_free_cipher((void*)_priv->tfm);
 145 #endif
 146         kfree(priv);
 147 }
 148
 149
 150 static inline void xor_block(u8 *b, u8 *a, size_t len)
 151 {
 152         int i;
 153         for (i = 0; i < len; i++)
 154                 b[i] ^= a[i];
 155 }
 156
 157
 158
 159 static void ccmp_init_blocks(struct crypto_tfm *tfm,
 160                              struct ieee80211_hdr_4addr *hdr,
 161                              u8 *pn, size_t dlen, u8 *b0, u8 *auth,
 162                              u8 *s0)
 163 {
 164         u8 *pos, qc = 0;
 165         size_t aad_len;
 166         u16 fc;
 167         int a4_included, qc_included;
 168         u8 aad[2 * AES_BLOCK_LEN];
 169
 170         fc = le16_to_cpu(hdr->frame_ctl);
 171         a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 172                        (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
 173         /*
 174         qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
 175                        (WLAN_FC_GET_STYPE(fc) & 0x08));
 176         */
 177         // fixed by David :2006.9.6
 178         qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
 179                        (WLAN_FC_GET_STYPE(fc) & 0x80));
 180         aad_len = 22;
 181         if (a4_included)
 182                 aad_len += 6;
 183         if (qc_included) {
 184                 pos = (u8 *) &hdr->addr4;
 185                 if (a4_included)
 186                         pos += 6;
 187                 qc = *pos & 0x0f;
 188                 aad_len += 2;
 189         }
 190         /* CCM Initial Block:
 191          * Flag (Include authentication header, M=3 (8-octet MIC),
 192          *       L=1 (2-octet Dlen))
 193          * Nonce: 0x00 | A2 | PN
 194          * Dlen */
 195         b0[0] = 0x59;
 196         b0[1] = qc;
 197         memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
 198         memcpy(b0 + 8, pn, CCMP_PN_LEN);
 199         b0[14] = (dlen >> 8) & 0xff;
 200         b0[15] = dlen & 0xff;
 201
 202         /* AAD:
 203          * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
 204          * A1 | A2 | A3
 205          * SC with bits 4..15 (seq#) masked to zero
 206          * A4 (if present)
 207          * QC (if present)
 208          */
 209         pos = (u8 *) hdr;
 210         aad[0] = 0; /* aad_len >> 8 */
 211         aad[1] = aad_len & 0xff;
 212         aad[2] = pos[0] & 0x8f;
 213         aad[3] = pos[1] & 0xc7;
 214         memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
 215         pos = (u8 *) &hdr->seq_ctl;
 216         aad[22] = pos[0] & 0x0f;
 217         aad[23] = 0; /* all bits masked */
 218         memset(aad + 24, 0, 8);
 219         if (a4_included)
 220                 memcpy(aad + 24, hdr->addr4, ETH_ALEN);
 221         if (qc_included) {
 222                 aad[a4_included ? 30 : 24] = qc;
 223                 /* rest of QC masked */
 224         }
 225
 226         /* Start with the first block and AAD */
 227         ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
 228         xor_block(auth, aad, AES_BLOCK_LEN);
 229         ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
 230         xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
 231         ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
 232         b0[0] &= 0x07;
 233         b0[14] = b0[15] = 0;
 234         ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
 235 }
 236
 237
 238
 239 static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 240 {
 241         struct ieee80211_ccmp_data *key = priv;
 242         int data_len, i;
 243         u8 *pos;
 244         struct ieee80211_hdr_4addr *hdr;
 245         cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
 246
 247         if (skb_headroom(skb) < CCMP_HDR_LEN ||
 248             skb_tailroom(skb) < CCMP_MIC_LEN ||
 249             skb->len < hdr_len)
 250                 return -1;
 251
 252         data_len = skb->len - hdr_len;
 253         pos = skb_push(skb, CCMP_HDR_LEN);
 254         memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
 255         pos += hdr_len;
 256 //      mic = skb_put(skb, CCMP_MIC_LEN);
 257
 258         i = CCMP_PN_LEN - 1;
 259         while (i >= 0) {
 260                 key->tx_pn[i]++;
 261                 if (key->tx_pn[i] != 0)
 262                         break;
 263                 i--;
 264         }
 265
 266         *pos++ = key->tx_pn[5];
 267         *pos++ = key->tx_pn[4];
 268         *pos++ = 0;
 269         *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */;
 270         *pos++ = key->tx_pn[3];
 271         *pos++ = key->tx_pn[2];
 272         *pos++ = key->tx_pn[1];
 273         *pos++ = key->tx_pn[0];
 274
 275
 276         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 277         if (!tcb_desc->bHwSec)
 278         {
 279                 int blocks, last, len;
 280                 u8 *mic;
 281                 u8 *b0 = key->tx_b0;
 282                 u8 *b = key->tx_b;
 283                 u8 *e = key->tx_e;
 284                 u8 *s0 = key->tx_s0;
 285
 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         }
 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_4addr *hdr;
 319         cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
 320         u8 pn[6];
 321
 322         if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
 323                 key->dot11RSNAStatsCCMPFormatErrors++;
 324                 return -1;
 325         }
 326
 327         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 328         pos = skb->data + hdr_len;
 329         keyidx = pos[3];
 330         if (!(keyidx & (1 << 5))) {
 331                 if (net_ratelimit()) {
 332                         printk(KERN_DEBUG "CCMP: received packet without ExtIV"
 333                                " flag from %pM\n", hdr->addr2);
 334                 }
 335                 key->dot11RSNAStatsCCMPFormatErrors++;
 336                 return -2;
 337         }
 338         keyidx >>= 6;
 339         if (key->key_idx != keyidx) {
 340                 printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
 341                        "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
 342                 return -6;
 343         }
 344         if (!key->key_set) {
 345                 if (net_ratelimit()) {
 346                         printk(KERN_DEBUG "CCMP: received packet from %pM"
 347                                " with keyid=%d that does not have a configured"
 348                                " key\n", hdr->addr2, keyidx);
 349                 }
 350                 return -3;
 351         }
 352
 353         pn[0] = pos[7];
 354         pn[1] = pos[6];
 355         pn[2] = pos[5];
 356         pn[3] = pos[4];
 357         pn[4] = pos[1];
 358         pn[5] = pos[0];
 359         pos += 8;
 360
 361         if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
 362                 if (net_ratelimit()) {
 363                         //printk(KERN_DEBUG "CCMP: replay detected: STA=%pM"
 364                         //       " previous PN %pm received PN %pm\n",
 365                         //       hdr->addr2, key->rx_pn, pn);
 366                 }
 367                 key->dot11RSNAStatsCCMPReplays++;
 368                 return -4;
 369         }
 370         if (!tcb_desc->bHwSec)
 371         {
 372                 size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
 373                 u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
 374                 u8 *b0 = key->rx_b0;
 375                 u8 *b = key->rx_b;
 376                 u8 *a = key->rx_a;
 377                 int i, blocks, last, len;
 378
 379
 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                                 "%pM\n", hdr->addr2);
 403                         }
 404                         key->dot11RSNAStatsCCMPDecryptErrors++;
 405                         return -5;
 406                 }
 407
 408                 memcpy(key->rx_pn, pn, CCMP_PN_LEN);
 409         }
 410         /* Remove hdr and MIC */
 411         memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
 412         skb_pull(skb, CCMP_HDR_LEN);
 413         skb_trim(skb, skb->len - CCMP_MIC_LEN);
 414
 415         return keyidx;
 416 }
 417
 418
 419 static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
 420 {
 421         struct ieee80211_ccmp_data *data = priv;
 422         int keyidx;
 423         struct crypto_tfm *tfm = data->tfm;
 424
 425         keyidx = data->key_idx;
 426         memset(data, 0, sizeof(*data));
 427         data->key_idx = keyidx;
 428         data->tfm = tfm;
 429         if (len == CCMP_TK_LEN) {
 430                 memcpy(data->key, key, CCMP_TK_LEN);
 431                 data->key_set = 1;
 432                 if (seq) {
 433                         data->rx_pn[0] = seq[5];
 434                         data->rx_pn[1] = seq[4];
 435                         data->rx_pn[2] = seq[3];
 436                         data->rx_pn[3] = seq[2];
 437                         data->rx_pn[4] = seq[1];
 438                         data->rx_pn[5] = seq[0];
 439                 }
 440                 crypto_cipher_setkey((void*)data->tfm, data->key, CCMP_TK_LEN);
 441         } else if (len == 0)
 442                 data->key_set = 0;
 443         else
 444                 return -1;
 445
 446         return 0;
 447 }
 448
 449
 450 static int ieee80211_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
 451 {
 452         struct ieee80211_ccmp_data *data = priv;
 453
 454         if (len < CCMP_TK_LEN)
 455                 return -1;
 456
 457         if (!data->key_set)
 458                 return 0;
 459         memcpy(key, data->key, CCMP_TK_LEN);
 460
 461         if (seq) {
 462                 seq[0] = data->tx_pn[5];
 463                 seq[1] = data->tx_pn[4];
 464                 seq[2] = data->tx_pn[3];
 465                 seq[3] = data->tx_pn[2];
 466                 seq[4] = data->tx_pn[1];
 467                 seq[5] = data->tx_pn[0];
 468         }
 469
 470         return CCMP_TK_LEN;
 471 }
 472
 473
 474 static char * ieee80211_ccmp_print_stats(char *p, void *priv)
 475 {
 476         struct ieee80211_ccmp_data *ccmp = priv;
 477         int i;
 478
 479         p += sprintf(p, "key[%d] alg=CCMP key_set=%d tx_pn=",
 480                      ccmp->key_idx, ccmp->key_set);
 481
 482         for (i = 0; i < ARRAY_SIZE(ccmp->tx_pn); i++)
 483                 p += sprintf(p, "%02x", ccmp->tx_pn[i]);
 484
 485         sprintf(p, " rx_pn=");
 486         for (i = 0; i < ARRAY_SIZE(ccmp->rx_pn); i++)
 487                 p += sprintf(p, "%02x", ccmp->tx_pn[i]);
 488
 489         p += sprintf(p, " format_errors=%d replays=%d decrypt_errors=%d\n",
 490                      ccmp->dot11RSNAStatsCCMPFormatErrors,
 491                      ccmp->dot11RSNAStatsCCMPReplays,
 492                      ccmp->dot11RSNAStatsCCMPDecryptErrors);
 493
 494         return p;
 495 }
 496
 497 void ieee80211_ccmp_null(void)
 498 {
 499 //    printk("============>%s()\n", __FUNCTION__);
 500         return;
 501 }
 502
 503 static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
 504         .name                   = "CCMP",
 505         .init                   = ieee80211_ccmp_init,
 506         .deinit                 = ieee80211_ccmp_deinit,
 507         .encrypt_mpdu           = ieee80211_ccmp_encrypt,
 508         .decrypt_mpdu           = ieee80211_ccmp_decrypt,
 509         .encrypt_msdu           = NULL,
 510         .decrypt_msdu           = NULL,
 511         .set_key                = ieee80211_ccmp_set_key,
 512         .get_key                = ieee80211_ccmp_get_key,
 513         .print_stats            = ieee80211_ccmp_print_stats,
 514         .extra_prefix_len       = CCMP_HDR_LEN,
 515         .extra_postfix_len      = CCMP_MIC_LEN,
 516         .owner                  = THIS_MODULE,
 517 };
 518
 519
 520 int __init ieee80211_crypto_ccmp_init(void)
 521 {
 522         return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
 523 }
 524
 525
 526 void ieee80211_crypto_ccmp_exit(void)
 527 {
 528         ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
 529 }
 530
 531 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
 532 //EXPORT_SYMBOL(ieee80211_ccmp_null);
 533 #else
 534 EXPORT_SYMBOL_NOVERS(ieee80211_ccmp_null);
 535 #endif
 536
 537 //module_init(ieee80211_crypto_ccmp_init);
 538 //module_exit(ieee80211_crypto_ccmp_exit);