bsd/netinet6/esp_rijndael.c

   1 /*
   2  * Copyright (c) 2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*      $FreeBSD: src/sys/netinet6/esp_rijndael.c,v 1.1.2.1 2001/07/03 11:01:50 ume Exp $       */
  30 /*      $KAME: esp_rijndael.c,v 1.4 2001/03/02 05:53:05 itojun Exp $    */
  31
  32 /*
  33  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. Neither the name of the project nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61 #include <sys/param.h>
  62 #include <sys/systm.h>
  63 #include <sys/socket.h>
  64 #include <sys/queue.h>
  65 #include <sys/syslog.h>
  66 #include <sys/mbuf.h>
  67 #include <sys/mcache.h>
  68
  69 #include <kern/locks.h>
  70
  71 #include <net/if.h>
  72 #include <net/route.h>
  73
  74 #include <netinet6/ipsec.h>
  75 #include <netinet6/esp.h>
  76 #include <netinet6/esp_rijndael.h>
  77
  78 #include <libkern/crypto/aes.h>
  79
  80 #include <netkey/key.h>
  81
  82 #include <net/net_osdep.h>
  83
  84 #define MAX_REALIGN_LEN 2000
  85 #define AES_BLOCKLEN 16
  86
  87 extern lck_mtx_t *sadb_mutex;
  88
  89 int
  90 esp_aes_schedlen(
  91         __unused const struct esp_algorithm *algo)
  92 {
  93
  94         return sizeof(aes_ctx);
  95 }
  96
  97 int
  98 esp_aes_schedule(
  99         __unused const struct esp_algorithm *algo,
 100         struct secasvar *sav)
 101 {
 102
 103         lck_mtx_assert(sadb_mutex, LCK_MTX_ASSERT_OWNED);
 104         aes_ctx *ctx = (aes_ctx*)sav->sched;
 105
 106         aes_decrypt_key((const unsigned char *) _KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->decrypt);
 107         aes_encrypt_key((const unsigned char *) _KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->encrypt);
 108
 109         return 0;
 110 }
 111
 112
 113 /* The following 2 functions decrypt or encrypt the contents of
 114  * the mbuf chain passed in keeping the IP and ESP header's in place,
 115  * along with the IV.
 116  * The code attempts to call the crypto code with the largest chunk
 117  * of data it can based on the amount of source data in
 118  * the current source mbuf and the space remaining in the current
 119  * destination mbuf.  The crypto code requires data to be a multiples
 120  * of 16 bytes.  A separate buffer is used when a 16 byte block spans
 121  * mbufs.
 122  *
 123  * m = mbuf chain
 124  * off = offset to ESP header
 125  *
 126  * local vars for source:
 127  * soff = offset from beginning of the chain to the head of the
 128  *                      current mbuf.
 129  * scut = last mbuf that contains headers to be retained
 130  * scutoff = offset to end of the headers in scut
 131  * s = the current mbuf
 132  * sn = current offset to data in s (next source data to process)
 133  *
 134  * local vars for dest:
 135  * d0 = head of chain
 136  * d = current mbuf
 137  * dn = current offset in d (next location to store result)
 138  */
 139
 140
 141 int
 142 esp_cbc_decrypt_aes(m, off, sav, algo, ivlen)
 143         struct mbuf *m;
 144         size_t off;
 145         struct secasvar *sav;
 146         const struct esp_algorithm *algo;
 147         int ivlen;
 148 {
 149         struct mbuf *s;
 150         struct mbuf *d, *d0, *dp;
 151         int soff;       /* offset from the head of chain, to head of this mbuf */
 152         int sn, dn;     /* offset from the head of the mbuf, to meat */
 153         size_t ivoff, bodyoff;
 154         u_int8_t iv[AES_BLOCKLEN] __attribute__((aligned(4))), *dptr;
 155         u_int8_t sbuf[AES_BLOCKLEN] __attribute__((aligned(4))), *sp, *sp_unaligned, *sp_aligned = NULL;
 156         struct mbuf *scut;
 157         int scutoff;
 158         int     i, len;
 159
 160
 161         if (ivlen != AES_BLOCKLEN) {
 162                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 163                     "unsupported ivlen %d\n", algo->name, ivlen));
 164                 m_freem(m);
 165                 return EINVAL;
 166         }
 167
 168         if (sav->flags & SADB_X_EXT_OLD) {
 169                 /* RFC 1827 */
 170                 ivoff = off + sizeof(struct esp);
 171                 bodyoff = off + sizeof(struct esp) + ivlen;
 172         } else {
 173                 ivoff = off + sizeof(struct newesp);
 174                 bodyoff = off + sizeof(struct newesp) + ivlen;
 175         }
 176
 177         if (m->m_pkthdr.len < bodyoff) {
 178                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: bad len %d/%lu\n",
 179                     algo->name, m->m_pkthdr.len, (u_int32_t)bodyoff));
 180                 m_freem(m);
 181                 return EINVAL;
 182         }
 183         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 184                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 185                     "payload length must be multiple of %d\n",
 186                     algo->name, AES_BLOCKLEN));
 187                 m_freem(m);
 188                 return EINVAL;
 189         }
 190
 191         /* grab iv */
 192         m_copydata(m, ivoff, ivlen, (caddr_t) iv);
 193
 194         s = m;
 195         soff = sn = dn = 0;
 196         d = d0 = dp = NULL;
 197         sp = dptr = NULL;
 198
 199         /* skip header/IV offset */
 200         while (soff < bodyoff) {
 201                 if (soff + s->m_len > bodyoff) {
 202                         sn = bodyoff - soff;
 203                         break;
 204                 }
 205
 206                 soff += s->m_len;
 207                 s = s->m_next;
 208         }
 209         scut = s;
 210         scutoff = sn;
 211
 212         /* skip over empty mbuf */
 213         while (s && s->m_len == 0)
 214                 s = s->m_next;
 215
 216         while (soff < m->m_pkthdr.len) {
 217                 /* source */
 218                 if (sn + AES_BLOCKLEN <= s->m_len) {
 219                         /* body is continuous */
 220                         sp = mtod(s, u_int8_t *) + sn;
 221                         len = s->m_len - sn;
 222                         len -= len % AES_BLOCKLEN;      // full blocks only
 223                 } else {
 224                         /* body is non-continuous */
 225                         m_copydata(s, sn, AES_BLOCKLEN, (caddr_t) sbuf);
 226                         sp = sbuf;
 227                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 228                 }
 229
 230                 /* destination */
 231                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 232                         if (d)
 233                                 dp = d;
 234                         MGET(d, M_DONTWAIT, MT_DATA);
 235                         i = m->m_pkthdr.len - (soff + sn);
 236                         if (d && i > MLEN) {
 237                                 MCLGET(d, M_DONTWAIT);
 238                                 if ((d->m_flags & M_EXT) == 0) {
 239                                         d = m_mbigget(d, M_DONTWAIT);
 240                                         if ((d->m_flags & M_EXT) == 0) {
 241                                                 m_free(d);
 242                                                 d = NULL;
 243                                         }
 244                                 }
 245                         }
 246                         if (!d) {
 247                                 m_freem(m);
 248                                 if (d0)
 249                                         m_freem(d0);
 250                                 return ENOBUFS;
 251                         }
 252                         if (!d0)
 253                                 d0 = d;
 254                         if (dp)
 255                                 dp->m_next = d;
 256
 257                         // try to make mbuf data aligned
 258                         if (!IPSEC_IS_P2ALIGNED(d->m_data)) {
 259                                 m_adj(d, IPSEC_GET_P2UNALIGNED_OFS(d->m_data));
 260                         }
 261
 262                         d->m_len = M_TRAILINGSPACE(d);
 263                         d->m_len -= d->m_len % AES_BLOCKLEN;
 264                         if (d->m_len > i)
 265                                 d->m_len = i;
 266                         dptr = mtod(d, u_int8_t *);
 267                         dn = 0;
 268                 }
 269
 270                 /* adjust len if greater than space available in dest */
 271                 if (len > d->m_len - dn)
 272                         len = d->m_len - dn;
 273
 274                 /* decrypt */
 275                 // check input pointer alignment and use a separate aligned buffer (if sp is unaligned on 4-byte boundary).
 276                 if (IPSEC_IS_P2ALIGNED(sp)) {
 277                         sp_unaligned = NULL;
 278                 } else {
 279                         sp_unaligned = sp;
 280                         if (len > MAX_REALIGN_LEN) {
 281                                 return ENOBUFS;
 282                         }
 283                         if (sp_aligned == NULL) {
 284                                 sp_aligned = (u_int8_t *)_MALLOC(MAX_REALIGN_LEN, M_SECA, M_DONTWAIT);
 285                                 if (sp_aligned == NULL)
 286                                         return ENOMEM;
 287                         }
 288                         sp = sp_aligned;
 289                         memcpy(sp, sp_unaligned, len);
 290                 }
 291                 // no need to check output pointer alignment
 292                 aes_decrypt_cbc(sp, iv, len >> 4, dptr + dn,
 293                                 (aes_decrypt_ctx*)(&(((aes_ctx*)sav->sched)->decrypt)));
 294
 295                 // update unaligned pointers
 296                 if (!IPSEC_IS_P2ALIGNED(sp_unaligned)) {
 297                         sp = sp_unaligned;
 298                 }
 299
 300                 /* udpate offsets */
 301                 sn += len;
 302                 dn += len;
 303
 304                 // next iv
 305                 bcopy(sp + len - AES_BLOCKLEN, iv, AES_BLOCKLEN);
 306
 307                 /* find the next source block */
 308                 while (s && sn >= s->m_len) {
 309                         sn -= s->m_len;
 310                         soff += s->m_len;
 311                         s = s->m_next;
 312                 }
 313
 314         }
 315
 316         /* free un-needed source mbufs and add dest mbufs to chain */
 317         m_freem(scut->m_next);
 318         scut->m_len = scutoff;
 319         scut->m_next = d0;
 320
 321         // free memory
 322         if (sp_aligned != NULL) {
 323                 FREE(sp_aligned, M_SECA);
 324                 sp_aligned = NULL;
 325         }
 326
 327         /* just in case */
 328         bzero(iv, sizeof(iv));
 329         bzero(sbuf, sizeof(sbuf));
 330
 331         return 0;
 332 }
 333
 334 int
 335 esp_cbc_encrypt_aes(
 336         struct mbuf *m,
 337         size_t off,
 338         __unused size_t plen,
 339         struct secasvar *sav,
 340         const struct esp_algorithm *algo,
 341         int ivlen)
 342 {
 343         struct mbuf *s;
 344         struct mbuf *d, *d0, *dp;
 345         int soff;       /* offset from the head of chain, to head of this mbuf */
 346         int sn, dn;     /* offset from the head of the mbuf, to meat */
 347         size_t ivoff, bodyoff;
 348         u_int8_t *ivp, *dptr, *ivp_unaligned;
 349         u_int8_t sbuf[AES_BLOCKLEN] __attribute__((aligned(4))), *sp, *sp_unaligned, *sp_aligned = NULL;
 350         u_int8_t ivp_aligned_buf[AES_BLOCKLEN] __attribute__((aligned(4)));
 351         struct mbuf *scut;
 352         int scutoff;
 353         int i, len;
 354
 355         if (ivlen != AES_BLOCKLEN) {
 356                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 357                     "unsupported ivlen %d\n", algo->name, ivlen));
 358                 m_freem(m);
 359                 return EINVAL;
 360         }
 361
 362         if (sav->flags & SADB_X_EXT_OLD) {
 363                 /* RFC 1827 */
 364                 ivoff = off + sizeof(struct esp);
 365                 bodyoff = off + sizeof(struct esp) + ivlen;
 366         } else {
 367                 ivoff = off + sizeof(struct newesp);
 368                 bodyoff = off + sizeof(struct newesp) + ivlen;
 369         }
 370
 371         /* put iv into the packet */
 372         m_copyback(m, ivoff, ivlen, sav->iv);
 373         ivp = (u_int8_t *) sav->iv;
 374
 375         if (m->m_pkthdr.len < bodyoff) {
 376                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: bad len %d/%lu\n",
 377                     algo->name, m->m_pkthdr.len, (u_int32_t)bodyoff));
 378                 m_freem(m);
 379                 return EINVAL;
 380         }
 381         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 382                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 383                     "payload length must be multiple of %lu\n",
 384                     algo->name, AES_BLOCKLEN));
 385                 m_freem(m);
 386                 return EINVAL;
 387         }
 388
 389         s = m;
 390         soff = sn = dn = 0;
 391         d = d0 = dp = NULL;
 392         sp = dptr = NULL;
 393
 394         /* skip headers/IV */
 395         while (soff < bodyoff) {
 396                 if (soff + s->m_len > bodyoff) {
 397                         sn = bodyoff - soff;
 398                         break;
 399                 }
 400
 401                 soff += s->m_len;
 402                 s = s->m_next;
 403         }
 404         scut = s;
 405         scutoff = sn;
 406
 407         /* skip over empty mbuf */
 408         while (s && s->m_len == 0)
 409                 s = s->m_next;
 410
 411         while (soff < m->m_pkthdr.len) {
 412                 /* source */
 413                 if (sn + AES_BLOCKLEN <= s->m_len) {
 414                         /* body is continuous */
 415                         sp = mtod(s, u_int8_t *) + sn;
 416                         len = s->m_len - sn;
 417                         len -= len % AES_BLOCKLEN;      // full blocks only
 418                 } else {
 419                         /* body is non-continuous */
 420                         m_copydata(s, sn, AES_BLOCKLEN, (caddr_t) sbuf);
 421                         sp = sbuf;
 422                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 423                 }
 424
 425                 /* destination */
 426                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 427                         if (d)
 428                                 dp = d;
 429                         MGET(d, M_DONTWAIT, MT_DATA);
 430                         i = m->m_pkthdr.len - (soff + sn);
 431                         if (d && i > MLEN) {
 432                                 MCLGET(d, M_DONTWAIT);
 433                                 if ((d->m_flags & M_EXT) == 0) {
 434                                         d = m_mbigget(d, M_DONTWAIT);
 435                                         if ((d->m_flags & M_EXT) == 0) {
 436                                                 m_free(d);
 437                                                 d = NULL;
 438                                         }
 439                                 }
 440                         }
 441                         if (!d) {
 442                                 m_freem(m);
 443                                 if (d0)
 444                                         m_freem(d0);
 445                                 return ENOBUFS;
 446                         }
 447                         if (!d0)
 448                                 d0 = d;
 449                         if (dp)
 450                                 dp->m_next = d;
 451
 452                         // try to make mbuf data aligned
 453                         if (!IPSEC_IS_P2ALIGNED(d->m_data)) {
 454                                 m_adj(d, IPSEC_GET_P2UNALIGNED_OFS(d->m_data));
 455                         }
 456
 457                         d->m_len = M_TRAILINGSPACE(d);
 458                         d->m_len -= d->m_len % AES_BLOCKLEN;
 459                         if (d->m_len > i)
 460                                 d->m_len = i;
 461                         dptr = mtod(d, u_int8_t *);
 462                         dn = 0;
 463                 }
 464
 465                 /* adjust len if greater than space available */
 466                 if (len > d->m_len - dn)
 467                         len = d->m_len - dn;
 468
 469                 /* encrypt */
 470                 // check input pointer alignment and use a separate aligned buffer (if sp is not aligned on 4-byte boundary).
 471                 if (IPSEC_IS_P2ALIGNED(sp)) {
 472                         sp_unaligned = NULL;
 473                 } else {
 474                         sp_unaligned = sp;
 475                         if (len > MAX_REALIGN_LEN) {
 476                                 return ENOBUFS;
 477                         }
 478                         if (sp_aligned == NULL) {
 479                                 sp_aligned = (u_int8_t *)_MALLOC(MAX_REALIGN_LEN, M_SECA, M_DONTWAIT);
 480                                 if (sp_aligned == NULL)
 481                                         return ENOMEM;
 482                         }
 483                         sp = sp_aligned;
 484                         memcpy(sp, sp_unaligned, len);
 485                 }
 486                 // check ivp pointer alignment and use a separate aligned buffer (if ivp is not aligned on 4-byte boundary).
 487                 if (IPSEC_IS_P2ALIGNED(ivp)) {
 488                         ivp_unaligned = NULL;
 489                 } else {
 490                         ivp_unaligned = ivp;
 491                         ivp = ivp_aligned_buf;
 492                         memcpy(ivp, ivp_unaligned, AES_BLOCKLEN);
 493                 }
 494                 // no need to check output pointer alignment
 495                 aes_encrypt_cbc(sp, ivp, len >> 4, dptr + dn,
 496                         (aes_encrypt_ctx*)(&(((aes_ctx*)sav->sched)->encrypt)));
 497
 498                 // update unaligned pointers
 499                 if (!IPSEC_IS_P2ALIGNED(sp_unaligned)) {
 500                         sp = sp_unaligned;
 501                 }
 502                 if (!IPSEC_IS_P2ALIGNED(ivp_unaligned)) {
 503                         ivp = ivp_unaligned;
 504                 }
 505
 506                 /* update offsets */
 507                 sn += len;
 508                 dn += len;
 509
 510                 /* next iv */
 511                 ivp = dptr + dn - AES_BLOCKLEN; // last block encrypted
 512
 513                 /* find the next source block and skip empty mbufs */
 514                 while (s && sn >= s->m_len) {
 515                         sn -= s->m_len;
 516                         soff += s->m_len;
 517                         s = s->m_next;
 518                 }
 519         }
 520
 521         /* free un-needed source mbufs and add dest mbufs to chain */
 522         m_freem(scut->m_next);
 523         scut->m_len = scutoff;
 524         scut->m_next = d0;
 525
 526         // free memory
 527         if (sp_aligned != NULL) {
 528                 FREE(sp_aligned, M_SECA);
 529                 sp_aligned = NULL;
 530         }
 531
 532         /* just in case */
 533         bzero(sbuf, sizeof(sbuf));
 534         key_sa_stir_iv(sav);
 535
 536         return 0;
 537 }