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 AES_BLOCKLEN 16
  85 #define MAX_SBUF_LEN 2000
  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[MAX_SBUF_LEN] __attribute__((aligned(4))), *sp, *sp_unaligned;
 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                         sp = sbuf;
 281                         memcpy(sp, sp_unaligned, len);
 282                 }
 283                 // no need to check output pointer alignment
 284                 aes_decrypt_cbc(sp, iv, len >> 4, dptr + dn,
 285                                 (aes_decrypt_ctx*)(&(((aes_ctx*)sav->sched)->decrypt)));
 286
 287                 // update unaligned pointers
 288                 if (!IPSEC_IS_P2ALIGNED(sp_unaligned)) {
 289                         sp = sp_unaligned;
 290                 }
 291
 292                 /* udpate offsets */
 293                 sn += len;
 294                 dn += len;
 295
 296                 // next iv
 297                 bcopy(sp + len - AES_BLOCKLEN, iv, AES_BLOCKLEN);
 298
 299                 /* find the next source block */
 300                 while (s && sn >= s->m_len) {
 301                         sn -= s->m_len;
 302                         soff += s->m_len;
 303                         s = s->m_next;
 304                 }
 305
 306         }
 307
 308         /* free un-needed source mbufs and add dest mbufs to chain */
 309         m_freem(scut->m_next);
 310         scut->m_len = scutoff;
 311         scut->m_next = d0;
 312
 313         /* just in case */
 314         bzero(iv, sizeof(iv));
 315         bzero(sbuf, sizeof(sbuf));
 316
 317         return 0;
 318 }
 319
 320 int
 321 esp_cbc_encrypt_aes(
 322         struct mbuf *m,
 323         size_t off,
 324         __unused size_t plen,
 325         struct secasvar *sav,
 326         const struct esp_algorithm *algo,
 327         int ivlen)
 328 {
 329         struct mbuf *s;
 330         struct mbuf *d, *d0, *dp;
 331         int soff;       /* offset from the head of chain, to head of this mbuf */
 332         int sn, dn;     /* offset from the head of the mbuf, to meat */
 333         size_t ivoff, bodyoff;
 334         u_int8_t *ivp, *dptr, *ivp_unaligned;
 335         u_int8_t sbuf[MAX_SBUF_LEN] __attribute__((aligned(4))), *sp, *sp_unaligned;
 336         u_int8_t ivp_aligned_buf[AES_BLOCKLEN] __attribute__((aligned(4)));
 337         struct mbuf *scut;
 338         int scutoff;
 339         int i, len;
 340
 341         if (ivlen != AES_BLOCKLEN) {
 342                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 343                     "unsupported ivlen %d\n", algo->name, ivlen));
 344                 m_freem(m);
 345                 return EINVAL;
 346         }
 347
 348         if (sav->flags & SADB_X_EXT_OLD) {
 349                 /* RFC 1827 */
 350                 ivoff = off + sizeof(struct esp);
 351                 bodyoff = off + sizeof(struct esp) + ivlen;
 352         } else {
 353                 ivoff = off + sizeof(struct newesp);
 354                 bodyoff = off + sizeof(struct newesp) + ivlen;
 355         }
 356
 357         /* put iv into the packet */
 358         m_copyback(m, ivoff, ivlen, sav->iv);
 359         ivp = (u_int8_t *) sav->iv;
 360
 361         if (m->m_pkthdr.len < bodyoff) {
 362                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: bad len %d/%lu\n",
 363                     algo->name, m->m_pkthdr.len, (u_int32_t)bodyoff));
 364                 m_freem(m);
 365                 return EINVAL;
 366         }
 367         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 368                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 369                     "payload length must be multiple of %lu\n",
 370                     algo->name, AES_BLOCKLEN));
 371                 m_freem(m);
 372                 return EINVAL;
 373         }
 374
 375         s = m;
 376         soff = sn = dn = 0;
 377         d = d0 = dp = NULL;
 378         sp = dptr = NULL;
 379
 380         /* skip headers/IV */
 381         while (soff < bodyoff) {
 382                 if (soff + s->m_len > bodyoff) {
 383                         sn = bodyoff - soff;
 384                         break;
 385                 }
 386
 387                 soff += s->m_len;
 388                 s = s->m_next;
 389         }
 390         scut = s;
 391         scutoff = sn;
 392
 393         /* skip over empty mbuf */
 394         while (s && s->m_len == 0)
 395                 s = s->m_next;
 396
 397         while (soff < m->m_pkthdr.len) {
 398                 /* source */
 399                 if (sn + AES_BLOCKLEN <= s->m_len) {
 400                         /* body is continuous */
 401                         sp = mtod(s, u_int8_t *) + sn;
 402                         len = s->m_len - sn;
 403                         len -= len % AES_BLOCKLEN;      // full blocks only
 404                 } else {
 405                         /* body is non-continuous */
 406                         m_copydata(s, sn, AES_BLOCKLEN, (caddr_t) sbuf);
 407                         sp = sbuf;
 408                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 409                 }
 410
 411                 /* destination */
 412                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 413                         if (d)
 414                                 dp = d;
 415                         MGET(d, M_DONTWAIT, MT_DATA);
 416                         i = m->m_pkthdr.len - (soff + sn);
 417                         if (d && i > MLEN) {
 418                                 MCLGET(d, M_DONTWAIT);
 419                                 if ((d->m_flags & M_EXT) == 0) {
 420                                         d = m_mbigget(d, M_DONTWAIT);
 421                                         if ((d->m_flags & M_EXT) == 0) {
 422                                                 m_free(d);
 423                                                 d = NULL;
 424                                         }
 425                                 }
 426                         }
 427                         if (!d) {
 428                                 m_freem(m);
 429                                 if (d0)
 430                                         m_freem(d0);
 431                                 return ENOBUFS;
 432                         }
 433                         if (!d0)
 434                                 d0 = d;
 435                         if (dp)
 436                                 dp->m_next = d;
 437
 438                         // try to make mbuf data aligned
 439                         if (!IPSEC_IS_P2ALIGNED(d->m_data)) {
 440                                 m_adj(d, IPSEC_GET_P2UNALIGNED_OFS(d->m_data));
 441                         }
 442
 443                         d->m_len = M_TRAILINGSPACE(d);
 444                         d->m_len -= d->m_len % AES_BLOCKLEN;
 445                         if (d->m_len > i)
 446                                 d->m_len = i;
 447                         dptr = mtod(d, u_int8_t *);
 448                         dn = 0;
 449                 }
 450
 451                 /* adjust len if greater than space available */
 452                 if (len > d->m_len - dn)
 453                         len = d->m_len - dn;
 454
 455                 /* encrypt */
 456                 // check input pointer alignment and use a separate aligned buffer (if sp is not aligned on 4-byte boundary).
 457                 if (IPSEC_IS_P2ALIGNED(sp)) {
 458                         sp_unaligned = NULL;
 459                 } else {
 460                         sp_unaligned = sp;
 461                         sp = sbuf;
 462                         memcpy(sp, sp_unaligned, len);
 463                 }
 464                 // check ivp pointer alignment and use a separate aligned buffer (if ivp is not aligned on 4-byte boundary).
 465                 if (IPSEC_IS_P2ALIGNED(ivp)) {
 466                         ivp_unaligned = NULL;
 467                 } else {
 468                         ivp_unaligned = ivp;
 469                         ivp = ivp_aligned_buf;
 470                         memcpy(ivp, ivp_unaligned, len);
 471                 }
 472                 // no need to check output pointer alignment
 473                 aes_encrypt_cbc(sp, ivp, len >> 4, dptr + dn,
 474                         (aes_encrypt_ctx*)(&(((aes_ctx*)sav->sched)->encrypt)));
 475
 476                 // update unaligned pointers
 477                 if (!IPSEC_IS_P2ALIGNED(sp_unaligned)) {
 478                         sp = sp_unaligned;
 479                 }
 480                 if (!IPSEC_IS_P2ALIGNED(ivp_unaligned)) {
 481                         ivp = ivp_unaligned;
 482                 }
 483
 484                 /* update offsets */
 485                 sn += len;
 486                 dn += len;
 487
 488                 /* next iv */
 489                 ivp = dptr + dn - AES_BLOCKLEN; // last block encrypted
 490
 491                 /* find the next source block and skip empty mbufs */
 492                 while (s && sn >= s->m_len) {
 493                         sn -= s->m_len;
 494                         soff += s->m_len;
 495                         s = s->m_next;
 496                 }
 497
 498         }
 499
 500         /* free un-needed source mbufs and add dest mbufs to chain */
 501         m_freem(scut->m_next);
 502         scut->m_len = scutoff;
 503         scut->m_next = d0;
 504
 505         /* just in case */
 506         bzero(sbuf, sizeof(sbuf));
 507         key_sa_stir_iv(sav);
 508
 509         return 0;
 510 }