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
  68 #include <kern/locks.h>
  69
  70 #include <net/if.h>
  71 #include <net/route.h>
  72
  73 #include <netinet6/ipsec.h>
  74 #include <netinet6/esp.h>
  75 #include <netinet6/esp_rijndael.h>
  76
  77 #include <crypto/aes/aes.h>
  78
  79 #include <netkey/key.h>
  80
  81 #include <net/net_osdep.h>
  82
  83 #define AES_BLOCKLEN 16
  84
  85 extern lck_mtx_t *sadb_mutex;
  86
  87 int
  88 esp_aes_schedlen(
  89         __unused const struct esp_algorithm *algo)
  90 {
  91
  92         return sizeof(aes_ctx);
  93 }
  94
  95 int
  96 esp_aes_schedule(
  97         __unused const struct esp_algorithm *algo,
  98         struct secasvar *sav)
  99 {
 100
 101         lck_mtx_assert(sadb_mutex, LCK_MTX_ASSERT_OWNED);
 102         aes_ctx *ctx = (aes_ctx*)sav->sched;
 103
 104         aes_decrypt_key((const unsigned char *) _KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->decrypt);
 105         aes_encrypt_key((const unsigned char *) _KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->encrypt);
 106
 107         return 0;
 108 }
 109
 110
 111 /* The following 2 functions decrypt or encrypt the contents of
 112  * the mbuf chain passed in keeping the IP and ESP header's in place,
 113  * along with the IV.
 114  * The code attempts to call the crypto code with the largest chunk
 115  * of data it can based on the amount of source data in
 116  * the current source mbuf and the space remaining in the current
 117  * destination mbuf.  The crypto code requires data to be a multiples
 118  * of 16 bytes.  A separate buffer is used when a 16 byte block spans
 119  * mbufs.
 120  *
 121  * m = mbuf chain
 122  * off = offset to ESP header
 123  *
 124  * local vars for source:
 125  * soff = offset from beginning of the chain to the head of the
 126  *                      current mbuf.
 127  * scut = last mbuf that contains headers to be retained
 128  * scutoff = offset to end of the headers in scut
 129  * s = the current mbuf
 130  * sn = current offset to data in s (next source data to process)
 131  *
 132  * local vars for dest:
 133  * d0 = head of chain
 134  * d = current mbuf
 135  * dn = current offset in d (next location to store result)
 136  */
 137
 138
 139 int
 140 esp_cbc_decrypt_aes(m, off, sav, algo, ivlen)
 141         struct mbuf *m;
 142         size_t off;
 143         struct secasvar *sav;
 144         const struct esp_algorithm *algo;
 145         int ivlen;
 146 {
 147         struct mbuf *s;
 148         struct mbuf *d, *d0, *dp;
 149         int soff;       /* offset from the head of chain, to head of this mbuf */
 150         int sn, dn;     /* offset from the head of the mbuf, to meat */
 151         size_t ivoff, bodyoff;
 152         u_int8_t iv[AES_BLOCKLEN], *dptr;
 153         u_int8_t sbuf[AES_BLOCKLEN], *sp;
 154         struct mbuf *scut;
 155         int scutoff;
 156         int     i, len;
 157
 158
 159         if (ivlen != AES_BLOCKLEN) {
 160                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 161                     "unsupported ivlen %d\n", algo->name, ivlen));
 162                 m_freem(m);
 163                 return EINVAL;
 164         }
 165
 166         if (sav->flags & SADB_X_EXT_OLD) {
 167                 /* RFC 1827 */
 168                 ivoff = off + sizeof(struct esp);
 169                 bodyoff = off + sizeof(struct esp) + ivlen;
 170         } else {
 171                 ivoff = off + sizeof(struct newesp);
 172                 bodyoff = off + sizeof(struct newesp) + ivlen;
 173         }
 174
 175         if (m->m_pkthdr.len < bodyoff) {
 176                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: bad len %d/%lu\n",
 177                     algo->name, m->m_pkthdr.len, (u_int32_t)bodyoff));
 178                 m_freem(m);
 179                 return EINVAL;
 180         }
 181         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 182                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 183                     "payload length must be multiple of %d\n",
 184                     algo->name, AES_BLOCKLEN));
 185                 m_freem(m);
 186                 return EINVAL;
 187         }
 188
 189         /* grab iv */
 190         m_copydata(m, ivoff, ivlen, (caddr_t) iv);
 191
 192         s = m;
 193         soff = sn = dn = 0;
 194         d = d0 = dp = NULL;
 195         sp = dptr = NULL;
 196
 197         /* skip header/IV offset */
 198         while (soff < bodyoff) {
 199                 if (soff + s->m_len > bodyoff) {
 200                         sn = bodyoff - soff;
 201                         break;
 202                 }
 203
 204                 soff += s->m_len;
 205                 s = s->m_next;
 206         }
 207         scut = s;
 208         scutoff = sn;
 209
 210         /* skip over empty mbuf */
 211         while (s && s->m_len == 0)
 212                 s = s->m_next;
 213
 214         while (soff < m->m_pkthdr.len) {
 215                 /* source */
 216                 if (sn + AES_BLOCKLEN <= s->m_len) {
 217                         /* body is continuous */
 218                         sp = mtod(s, u_int8_t *) + sn;
 219                         len = s->m_len - sn;
 220                         len -= len % AES_BLOCKLEN;      // full blocks only
 221                 } else {
 222                         /* body is non-continuous */
 223                         m_copydata(s, sn, AES_BLOCKLEN, (caddr_t) sbuf);
 224                         sp = sbuf;
 225                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 226                 }
 227
 228                 /* destination */
 229                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 230                         if (d)
 231                                 dp = d;
 232                         MGET(d, M_DONTWAIT, MT_DATA);
 233                         i = m->m_pkthdr.len - (soff + sn);
 234                         if (d && i > MLEN) {
 235                                 MCLGET(d, M_DONTWAIT);
 236                                 if ((d->m_flags & M_EXT) == 0) {
 237                                         d = m_mbigget(d, M_DONTWAIT);
 238                                         if ((d->m_flags & M_EXT) == 0) {
 239                                                 m_free(d);
 240                                                 d = NULL;
 241                                         }
 242                                 }
 243                         }
 244                         if (!d) {
 245                                 m_freem(m);
 246                                 if (d0)
 247                                         m_freem(d0);
 248                                 return ENOBUFS;
 249                         }
 250                         if (!d0)
 251                                 d0 = d;
 252                         if (dp)
 253                                 dp->m_next = d;
 254                         d->m_len = M_TRAILINGSPACE(d);
 255                         d->m_len -= d->m_len % AES_BLOCKLEN;
 256                         if (d->m_len > i)
 257                                 d->m_len = i;
 258                         dptr = mtod(d, u_int8_t *);
 259                         dn = 0;
 260                 }
 261
 262                 /* adjust len if greater than space available in dest */
 263                 if (len > d->m_len - dn)
 264                         len = d->m_len - dn;
 265
 266                 /* decrypt */
 267                 aes_decrypt_cbc(sp, iv, len >> 4, dptr + dn,
 268                                 (aes_decrypt_ctx*)(&(((aes_ctx*)sav->sched)->decrypt)));
 269
 270                 /* udpate offsets */
 271                 sn += len;
 272                 dn += len;
 273
 274                 // next iv
 275                 bcopy(sp + len - AES_BLOCKLEN, iv, AES_BLOCKLEN);
 276
 277                 /* find the next source block */
 278                 while (s && sn >= s->m_len) {
 279                         sn -= s->m_len;
 280                         soff += s->m_len;
 281                         s = s->m_next;
 282                 }
 283
 284         }
 285
 286         /* free un-needed source mbufs and add dest mbufs to chain */
 287         m_freem(scut->m_next);
 288         scut->m_len = scutoff;
 289         scut->m_next = d0;
 290
 291         /* just in case */
 292         bzero(iv, sizeof(iv));
 293         bzero(sbuf, sizeof(sbuf));
 294
 295         return 0;
 296 }
 297
 298 int
 299 esp_cbc_encrypt_aes(
 300         struct mbuf *m,
 301         size_t off,
 302         __unused size_t plen,
 303         struct secasvar *sav,
 304         const struct esp_algorithm *algo,
 305         int ivlen)
 306 {
 307         struct mbuf *s;
 308         struct mbuf *d, *d0, *dp;
 309         int soff;       /* offset from the head of chain, to head of this mbuf */
 310         int sn, dn;     /* offset from the head of the mbuf, to meat */
 311         size_t ivoff, bodyoff;
 312         u_int8_t *ivp, *dptr;
 313         u_int8_t sbuf[AES_BLOCKLEN], *sp;
 314         struct mbuf *scut;
 315         int scutoff;
 316         int i, len;
 317
 318         if (ivlen != AES_BLOCKLEN) {
 319                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 320                     "unsupported ivlen %d\n", algo->name, ivlen));
 321                 m_freem(m);
 322                 return EINVAL;
 323         }
 324
 325         if (sav->flags & SADB_X_EXT_OLD) {
 326                 /* RFC 1827 */
 327                 ivoff = off + sizeof(struct esp);
 328                 bodyoff = off + sizeof(struct esp) + ivlen;
 329         } else {
 330                 ivoff = off + sizeof(struct newesp);
 331                 bodyoff = off + sizeof(struct newesp) + ivlen;
 332         }
 333
 334         /* put iv into the packet */
 335         m_copyback(m, ivoff, ivlen, sav->iv);
 336         ivp = (u_int8_t *) sav->iv;
 337
 338         if (m->m_pkthdr.len < bodyoff) {
 339                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: bad len %d/%lu\n",
 340                     algo->name, m->m_pkthdr.len, (u_int32_t)bodyoff));
 341                 m_freem(m);
 342                 return EINVAL;
 343         }
 344         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 345                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 346                     "payload length must be multiple of %lu\n",
 347                     algo->name, AES_BLOCKLEN));
 348                 m_freem(m);
 349                 return EINVAL;
 350         }
 351
 352         s = m;
 353         soff = sn = dn = 0;
 354         d = d0 = dp = NULL;
 355         sp = dptr = NULL;
 356
 357         /* skip headers/IV */
 358         while (soff < bodyoff) {
 359                 if (soff + s->m_len > bodyoff) {
 360                         sn = bodyoff - soff;
 361                         break;
 362                 }
 363
 364                 soff += s->m_len;
 365                 s = s->m_next;
 366         }
 367         scut = s;
 368         scutoff = sn;
 369
 370         /* skip over empty mbuf */
 371         while (s && s->m_len == 0)
 372                 s = s->m_next;
 373
 374         while (soff < m->m_pkthdr.len) {
 375                 /* source */
 376                 if (sn + AES_BLOCKLEN <= s->m_len) {
 377                         /* body is continuous */
 378                         sp = mtod(s, u_int8_t *) + sn;
 379                         len = s->m_len - sn;
 380                         len -= len % AES_BLOCKLEN;      // full blocks only
 381                 } else {
 382                         /* body is non-continuous */
 383                         m_copydata(s, sn, AES_BLOCKLEN, (caddr_t) sbuf);
 384                         sp = sbuf;
 385                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 386                 }
 387
 388                 /* destination */
 389                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 390                         if (d)
 391                                 dp = d;
 392                         MGET(d, M_DONTWAIT, MT_DATA);
 393                         i = m->m_pkthdr.len - (soff + sn);
 394                         if (d && i > MLEN) {
 395                                 MCLGET(d, M_DONTWAIT);
 396                                 if ((d->m_flags & M_EXT) == 0) {
 397                                         d = m_mbigget(d, M_DONTWAIT);
 398                                         if ((d->m_flags & M_EXT) == 0) {
 399                                                 m_free(d);
 400                                                 d = NULL;
 401                                         }
 402                                 }
 403                         }
 404                         if (!d) {
 405                                 m_freem(m);
 406                                 if (d0)
 407                                         m_freem(d0);
 408                                 return ENOBUFS;
 409                         }
 410                         if (!d0)
 411                                 d0 = d;
 412                         if (dp)
 413                                 dp->m_next = d;
 414
 415                         d->m_len = M_TRAILINGSPACE(d);
 416                         d->m_len -= d->m_len % AES_BLOCKLEN;
 417                         if (d->m_len > i)
 418                                 d->m_len = i;
 419                         dptr = mtod(d, u_int8_t *);
 420                         dn = 0;
 421                 }
 422
 423                 /* adjust len if greater than space available */
 424                 if (len > d->m_len - dn)
 425                         len = d->m_len - dn;
 426
 427                 /* encrypt */
 428                 aes_encrypt_cbc(sp, ivp, len >> 4, dptr + dn,
 429                         (aes_encrypt_ctx*)(&(((aes_ctx*)sav->sched)->encrypt)));
 430
 431                 /* update offsets */
 432                 sn += len;
 433                 dn += len;
 434
 435                 /* next iv */
 436                 ivp = dptr + dn - AES_BLOCKLEN; // last block encrypted
 437
 438                 /* find the next source block and skip empty mbufs */
 439                 while (s && sn >= s->m_len) {
 440                         sn -= s->m_len;
 441                         soff += s->m_len;
 442                         s = s->m_next;
 443                 }
 444
 445         }
 446
 447         /* free un-needed source mbufs and add dest mbufs to chain */
 448         m_freem(scut->m_next);
 449         scut->m_len = scutoff;
 450         scut->m_next = d0;
 451
 452         /* just in case */
 453         bzero(sbuf, sizeof(sbuf));
 454         key_sa_stir_iv(sav);
 455
 456         return 0;
 457 }