bsd/netinet6/esp_rijndael.c

   1 /*      $FreeBSD: src/sys/netinet6/esp_rijndael.c,v 1.1.2.1 2001/07/03 11:01:50 ume Exp $       */
   2 /*      $KAME: esp_rijndael.c,v 1.4 2001/03/02 05:53:05 itojun Exp $    */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/socket.h>
  36 #include <sys/queue.h>
  37 #include <sys/syslog.h>
  38 #include <sys/mbuf.h>
  39
  40 #include <kern/locks.h>
  41
  42 #include <net/if.h>
  43 #include <net/route.h>
  44
  45 #include <netinet6/ipsec.h>
  46 #include <netinet6/esp.h>
  47 #include <netinet6/esp_rijndael.h>
  48
  49 #include <crypto/aes/aes.h>
  50
  51 #include <net/net_osdep.h>
  52
  53 #define AES_BLOCKLEN 16
  54
  55 extern lck_mtx_t *sadb_mutex;
  56
  57 int
  58 esp_aes_schedlen(algo)
  59         const struct esp_algorithm *algo;
  60 {
  61
  62         return sizeof(aes_ctx);
  63 }
  64
  65 int
  66 esp_aes_schedule(algo, sav)
  67         const struct esp_algorithm *algo;
  68         struct secasvar *sav;
  69 {
  70         aes_ctx *ctx = (aes_ctx*)sav->sched;
  71
  72         gen_tabs();
  73         aes_decrypt_key(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->decrypt);
  74         aes_encrypt_key(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc), &ctx->encrypt);
  75
  76         return 0;
  77 }
  78
  79
  80 /* The following 2 functions decrypt or encrypt the contents of
  81  * the mbuf chain passed in keeping the IP and ESP header's in place,
  82  * along with the IV.
  83  * The code attempts to call the crypto code with the largest chunk
  84  * of data it can based on the amount of source data in
  85  * the current source mbuf and the space remaining in the current
  86  * destination mbuf.  The crypto code requires data to be a multiples
  87  * of 16 bytes.  A separate buffer is used when a 16 byte block spans
  88  * mbufs.
  89  *
  90  * m = mbuf chain
  91  * off = offset to ESP header
  92  *
  93  * local vars for source:
  94  * soff = offset from beginning of the chain to the head of the
  95  *                      current mbuf.
  96  * scut = last mbuf that contains headers to be retained
  97  * scutoff = offset to end of the headers in scut
  98  * s = the current mbuf
  99  * sn = current offset to data in s (next source data to process)
 100  *
 101  * local vars for dest:
 102  * d0 = head of chain
 103  * d = current mbuf
 104  * dn = current offset in d (next location to store result)
 105  */
 106
 107
 108 int
 109 esp_cbc_decrypt_aes(m, off, sav, algo, ivlen)
 110         struct mbuf *m;
 111         size_t off;
 112         struct secasvar *sav;
 113         const struct esp_algorithm *algo;
 114         int ivlen;
 115 {
 116         struct mbuf *s;
 117         struct mbuf *d, *d0, *dp;
 118         int soff;       /* offset from the head of chain, to head of this mbuf */
 119         int sn, dn;     /* offset from the head of the mbuf, to meat */
 120         size_t ivoff, bodyoff;
 121         u_int8_t iv[AES_BLOCKLEN], *dptr;
 122         u_int8_t sbuf[AES_BLOCKLEN], *sp;
 123         struct mbuf *scut;
 124         int scutoff;
 125         int     i, len;
 126
 127
 128         if (ivlen != AES_BLOCKLEN) {
 129                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 130                     "unsupported ivlen %d\n", algo->name, ivlen));
 131                 m_freem(m);
 132                 return EINVAL;
 133         }
 134
 135         if (sav->flags & SADB_X_EXT_OLD) {
 136                 /* RFC 1827 */
 137                 ivoff = off + sizeof(struct esp);
 138                 bodyoff = off + sizeof(struct esp) + ivlen;
 139         } else {
 140                 ivoff = off + sizeof(struct newesp);
 141                 bodyoff = off + sizeof(struct newesp) + ivlen;
 142         }
 143
 144         if (m->m_pkthdr.len < bodyoff) {
 145                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: bad len %d/%lu\n",
 146                     algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
 147                 m_freem(m);
 148                 return EINVAL;
 149         }
 150         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 151                 ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
 152                     "payload length must be multiple of %d\n",
 153                     algo->name, AES_BLOCKLEN));
 154                 m_freem(m);
 155                 return EINVAL;
 156         }
 157
 158         /* grab iv */
 159         m_copydata(m, ivoff, ivlen, iv);
 160
 161         lck_mtx_unlock(sadb_mutex);
 162         s = m;
 163         soff = sn = dn = 0;
 164         d = d0 = dp = NULL;
 165         sp = dptr = NULL;
 166
 167         /* skip header/IV offset */
 168         while (soff < bodyoff) {
 169                 if (soff + s->m_len > bodyoff) {
 170                         sn = bodyoff - soff;
 171                         break;
 172                 }
 173
 174                 soff += s->m_len;
 175                 s = s->m_next;
 176         }
 177         scut = s;
 178         scutoff = sn;
 179
 180         /* skip over empty mbuf */
 181         while (s && s->m_len == 0)
 182                 s = s->m_next;
 183
 184         while (soff < m->m_pkthdr.len) {
 185                 /* source */
 186                 if (sn + AES_BLOCKLEN <= s->m_len) {
 187                         /* body is continuous */
 188                         sp = mtod(s, u_int8_t *) + sn;
 189                         len = s->m_len - sn;
 190                         len -= len % AES_BLOCKLEN;      // full blocks only
 191                 } else {
 192                         /* body is non-continuous */
 193                         m_copydata(s, sn, AES_BLOCKLEN, sbuf);
 194                         sp = sbuf;
 195                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 196                 }
 197
 198                 /* destination */
 199                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 200                         if (d)
 201                                 dp = d;
 202                         MGET(d, M_DONTWAIT, MT_DATA);
 203                         i = m->m_pkthdr.len - (soff + sn);
 204                         if (d && i > MLEN) {
 205                                 MCLGET(d, M_DONTWAIT);
 206                                 if ((d->m_flags & M_EXT) == 0) {
 207                                         m_free(d);
 208                                         d = NULL;
 209                                 }
 210                         }
 211                         if (!d) {
 212                                 m_freem(m);
 213                                 if (d0)
 214                                         m_freem(d0);
 215                                 lck_mtx_lock(sadb_mutex);
 216                                 return ENOBUFS;
 217                         }
 218                         if (!d0)
 219                                 d0 = d;
 220                         if (dp)
 221                                 dp->m_next = d;
 222                         d->m_len = M_TRAILINGSPACE(d);
 223                         d->m_len -= d->m_len % AES_BLOCKLEN;
 224                         if (d->m_len > i)
 225                                 d->m_len = i;
 226                         dptr = mtod(d, u_int8_t *);
 227                         dn = 0;
 228                 }
 229
 230                 /* adjust len if greater than space available in dest */
 231                 if (len > d->m_len - dn)
 232                         len = d->m_len - dn;
 233
 234                 /* decrypt */
 235                 aes_decrypt_cbc(sp, iv, len >> 4, dptr + dn,
 236                                 (aes_decrypt_ctx*)(&(((aes_ctx*)sav->sched)->decrypt)));
 237
 238                 /* udpate offsets */
 239                 sn += len;
 240                 dn += len;
 241
 242                 // next iv
 243                 bcopy(sp + len - AES_BLOCKLEN, iv, AES_BLOCKLEN);
 244
 245                 /* find the next source block */
 246                 while (s && sn >= s->m_len) {
 247                         sn -= s->m_len;
 248                         soff += s->m_len;
 249                         s = s->m_next;
 250                 }
 251
 252         }
 253
 254         /* free un-needed source mbufs and add dest mbufs to chain */
 255         m_freem(scut->m_next);
 256         scut->m_len = scutoff;
 257         scut->m_next = d0;
 258
 259         /* just in case */
 260         bzero(iv, sizeof(iv));
 261         bzero(sbuf, sizeof(sbuf));
 262         lck_mtx_lock(sadb_mutex);
 263
 264         return 0;
 265 }
 266
 267 int
 268 esp_cbc_encrypt_aes(m, off, plen, sav, algo, ivlen)
 269         struct mbuf *m;
 270         size_t off;
 271         size_t plen;
 272         struct secasvar *sav;
 273         const struct esp_algorithm *algo;
 274         int ivlen;
 275 {
 276         struct mbuf *s;
 277         struct mbuf *d, *d0, *dp;
 278         int soff, doff; /* offset from the head of chain, to head of this mbuf */
 279         int sn, dn;     /* offset from the head of the mbuf, to meat */
 280         size_t ivoff, bodyoff;
 281         u_int8_t *ivp, *dptr;
 282         u_int8_t sbuf[AES_BLOCKLEN], *sp;
 283         struct mbuf *scut;
 284         int scutoff;
 285         int i, len;
 286
 287         if (ivlen != AES_BLOCKLEN) {
 288                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 289                     "unsupported ivlen %d\n", algo->name, ivlen));
 290                 m_freem(m);
 291                 return EINVAL;
 292         }
 293
 294         if (sav->flags & SADB_X_EXT_OLD) {
 295                 /* RFC 1827 */
 296                 ivoff = off + sizeof(struct esp);
 297                 bodyoff = off + sizeof(struct esp) + ivlen;
 298         } else {
 299                 ivoff = off + sizeof(struct newesp);
 300                 bodyoff = off + sizeof(struct newesp) + ivlen;
 301         }
 302
 303         /* put iv into the packet */
 304         m_copyback(m, ivoff, ivlen, sav->iv);
 305         ivp = sav->iv;
 306
 307         if (m->m_pkthdr.len < bodyoff) {
 308                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: bad len %d/%lu\n",
 309                     algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
 310                 m_freem(m);
 311                 return EINVAL;
 312         }
 313         if ((m->m_pkthdr.len - bodyoff) % AES_BLOCKLEN) {
 314                 ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
 315                     "payload length must be multiple of %lu\n",
 316                     algo->name, AES_BLOCKLEN));
 317                 m_freem(m);
 318                 return EINVAL;
 319         }
 320         lck_mtx_unlock(sadb_mutex);
 321
 322         s = m;
 323         soff = sn = dn = 0;
 324         d = d0 = dp = NULL;
 325         sp = dptr = NULL;
 326
 327         /* skip headers/IV */
 328         while (soff < bodyoff) {
 329                 if (soff + s->m_len > bodyoff) {
 330                         sn = bodyoff - soff;
 331                         break;
 332                 }
 333
 334                 soff += s->m_len;
 335                 s = s->m_next;
 336         }
 337         scut = s;
 338         scutoff = sn;
 339
 340         /* skip over empty mbuf */
 341         while (s && s->m_len == 0)
 342                 s = s->m_next;
 343
 344         while (soff < m->m_pkthdr.len) {
 345                 /* source */
 346                 if (sn + AES_BLOCKLEN <= s->m_len) {
 347                         /* body is continuous */
 348                         sp = mtod(s, u_int8_t *) + sn;
 349                         len = s->m_len - sn;
 350                         len -= len % AES_BLOCKLEN;      // full blocks only
 351                 } else {
 352                         /* body is non-continuous */
 353                         m_copydata(s, sn, AES_BLOCKLEN, sbuf);
 354                         sp = sbuf;
 355                         len = AES_BLOCKLEN;                     // 1 block only in sbuf
 356                 }
 357
 358                 /* destination */
 359                 if (!d || dn + AES_BLOCKLEN > d->m_len) {
 360                         if (d)
 361                                 dp = d;
 362                         MGET(d, M_DONTWAIT, MT_DATA);
 363                         i = m->m_pkthdr.len - (soff + sn);
 364                         if (d && i > MLEN) {
 365                                 MCLGET(d, M_DONTWAIT);
 366                                 if ((d->m_flags & M_EXT) == 0) {
 367                                         m_free(d);
 368                                         d = NULL;
 369                                 }
 370                         }
 371                         if (!d) {
 372                                 m_freem(m);
 373                                 if (d0)
 374                                         m_freem(d0);
 375                                 lck_mtx_lock(sadb_mutex);
 376                                 return ENOBUFS;
 377                         }
 378                         if (!d0)
 379                                 d0 = d;
 380                         if (dp)
 381                                 dp->m_next = d;
 382
 383                         d->m_len = M_TRAILINGSPACE(d);
 384                         d->m_len -= d->m_len % AES_BLOCKLEN;
 385                         if (d->m_len > i)
 386                                 d->m_len = i;
 387                         dptr = mtod(d, u_int8_t *);
 388                         dn = 0;
 389                 }
 390
 391                 /* adjust len if greater than space available */
 392                 if (len > d->m_len - dn)
 393                         len = d->m_len - dn;
 394
 395                 /* encrypt */
 396                 aes_encrypt_cbc(sp, ivp, len >> 4, dptr + dn,
 397                         (aes_encrypt_ctx*)(&(((aes_ctx*)sav->sched)->encrypt)));
 398
 399                 /* update offsets */
 400                 sn += len;
 401                 dn += len;
 402
 403                 /* next iv */
 404                 ivp = dptr + dn - AES_BLOCKLEN; // last block encrypted
 405
 406                 /* find the next source block and skip empty mbufs */
 407                 while (s && sn >= s->m_len) {
 408                         sn -= s->m_len;
 409                         soff += s->m_len;
 410                         s = s->m_next;
 411                 }
 412
 413         }
 414
 415         /* free un-needed source mbufs and add dest mbufs to chain */
 416         m_freem(scut->m_next);
 417         scut->m_len = scutoff;
 418         scut->m_next = d0;
 419
 420         /* just in case */
 421         bzero(sbuf, sizeof(sbuf));
 422         lck_mtx_lock(sadb_mutex);
 423         key_sa_stir_iv(sav);
 424
 425         return 0;
 426 }