module/os/freebsd/zfs/crypto_os.c

   1 /*
   2  * Copyright (c) 2005-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   3  * Copyright (c) 2018 Sean Eric Fagan <sef@ixsystems.com>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * Portions of this file are derived from sys/geom/eli/g_eli_hmac.c
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include <sys/types.h>
  34 #include <sys/errno.h>
  35
  36 #ifdef _KERNEL
  37 #include <sys/libkern.h>
  38 #include <sys/malloc.h>
  39 #include <sys/sysctl.h>
  40 #include <opencrypto/cryptodev.h>
  41 #include <opencrypto/xform.h>
  42 #else
  43 #include <strings.h>
  44 #endif
  45
  46 #include <sys/zio_crypt.h>
  47 #include <sys/fs/zfs.h>
  48 #include <sys/zio.h>
  49
  50 #include <sys/freebsd_crypto.h>
  51
  52 #define SHA512_HMAC_BLOCK_SIZE  128
  53
  54 static int crypt_sessions = 0;
  55 SYSCTL_DECL(_vfs_zfs);
  56 SYSCTL_INT(_vfs_zfs, OID_AUTO, crypt_sessions, CTLFLAG_RD,
  57         &crypt_sessions, 0, "Number of cryptographic sessions created");
  58
  59 void
  60 crypto_mac_init(struct hmac_ctx *ctx, const crypto_key_t *c_key)
  61 {
  62         uint8_t k_ipad[SHA512_HMAC_BLOCK_SIZE],
  63             k_opad[SHA512_HMAC_BLOCK_SIZE],
  64             key[SHA512_HMAC_BLOCK_SIZE];
  65         SHA512_CTX lctx;
  66         int i;
  67         size_t cl_bytes = CRYPTO_BITS2BYTES(c_key->ck_length);
  68
  69         /*
  70          * This code is based on the similar code in geom/eli/g_eli_hmac.c
  71          */
  72         explicit_bzero(key, sizeof (key));
  73         if (c_key->ck_length  == 0)
  74                 /* do nothing */;
  75         else if (cl_bytes <= SHA512_HMAC_BLOCK_SIZE)
  76                 bcopy(c_key->ck_data, key, cl_bytes);
  77         else {
  78                 /*
  79                  * If key is longer than 128 bytes reset it to
  80                  * key = SHA512(key).
  81                  */
  82                 SHA512_Init(&lctx);
  83                 SHA512_Update(&lctx, c_key->ck_data, cl_bytes);
  84                 SHA512_Final(key, &lctx);
  85         }
  86
  87         /* XOR key with ipad and opad values. */
  88         for (i = 0; i < sizeof (key); i++) {
  89                 k_ipad[i] = key[i] ^ 0x36;
  90                 k_opad[i] = key[i] ^ 0x5c;
  91         }
  92         explicit_bzero(key, sizeof (key));
  93
  94         /* Start inner SHA512. */
  95         SHA512_Init(&ctx->innerctx);
  96         SHA512_Update(&ctx->innerctx, k_ipad, sizeof (k_ipad));
  97         explicit_bzero(k_ipad, sizeof (k_ipad));
  98         /* Start outer SHA512. */
  99         SHA512_Init(&ctx->outerctx);
 100         SHA512_Update(&ctx->outerctx, k_opad, sizeof (k_opad));
 101         explicit_bzero(k_opad, sizeof (k_opad));
 102 }
 103
 104 void
 105 crypto_mac_update(struct hmac_ctx *ctx, const void *data, size_t datasize)
 106 {
 107         SHA512_Update(&ctx->innerctx, data, datasize);
 108 }
 109
 110 void
 111 crypto_mac_final(struct hmac_ctx *ctx, void *md, size_t mdsize)
 112 {
 113         uint8_t digest[SHA512_DIGEST_LENGTH];
 114
 115         /* Complete inner hash */
 116         SHA512_Final(digest, &ctx->innerctx);
 117
 118         /* Complete outer hash */
 119         SHA512_Update(&ctx->outerctx, digest, sizeof (digest));
 120         SHA512_Final(digest, &ctx->outerctx);
 121
 122         explicit_bzero(ctx, sizeof (*ctx));
 123         /* mdsize == 0 means "Give me the whole hash!" */
 124         if (mdsize == 0)
 125                 mdsize = SHA512_DIGEST_LENGTH;
 126         bcopy(digest, md, mdsize);
 127         explicit_bzero(digest, sizeof (digest));
 128 }
 129
 130 void
 131 crypto_mac(const crypto_key_t *key, const void *in_data, size_t in_data_size,
 132     void *out_data, size_t out_data_size)
 133 {
 134         struct hmac_ctx ctx;
 135
 136         crypto_mac_init(&ctx, key);
 137         crypto_mac_update(&ctx, in_data, in_data_size);
 138         crypto_mac_final(&ctx, out_data, out_data_size);
 139 }
 140
 141 static int
 142 freebsd_zfs_crypt_done(struct cryptop *crp)
 143 {
 144         freebsd_crypt_session_t *ses;
 145
 146         ses = crp->crp_opaque;
 147         mtx_lock(&ses->fs_lock);
 148         ses->fs_done = true;
 149         mtx_unlock(&ses->fs_lock);
 150         wakeup(crp);
 151         return (0);
 152 }
 153
 154 void
 155 freebsd_crypt_freesession(freebsd_crypt_session_t *sess)
 156 {
 157         mtx_destroy(&sess->fs_lock);
 158         crypto_freesession(sess->fs_sid);
 159         explicit_bzero(sess, sizeof (*sess));
 160 }
 161
 162 static int
 163 zfs_crypto_dispatch(freebsd_crypt_session_t *session,   struct cryptop *crp)
 164 {
 165         int error;
 166
 167         crp->crp_opaque = session;
 168         crp->crp_callback = freebsd_zfs_crypt_done;
 169         for (;;) {
 170                 error = crypto_dispatch(crp);
 171                 if (error)
 172                         break;
 173                 mtx_lock(&session->fs_lock);
 174                 while (session->fs_done == false)
 175                         msleep(crp, &session->fs_lock, PRIBIO,
 176                             "zfs_crypto", hz/5);
 177                 mtx_unlock(&session->fs_lock);
 178
 179                 if (crp->crp_etype != EAGAIN) {
 180                         error = crp->crp_etype;
 181                         break;
 182                 }
 183                 crp->crp_etype = 0;
 184                 crp->crp_flags &= ~CRYPTO_F_DONE;
 185                 session->fs_done = false;
 186 #if __FreeBSD_version < 1300087
 187                 /*
 188                  * Session ID changed, so we should record that,
 189                  * and try again
 190                  */
 191                 session->fs_sid = crp->crp_session;
 192 #endif
 193         }
 194         return (error);
 195 }
 196 static void
 197 freebsd_crypt_uio_debug_log(boolean_t encrypt,
 198     freebsd_crypt_session_t *input_sessionp,
 199     struct zio_crypt_info *c_info,
 200     uio_t *data_uio,
 201     crypto_key_t *key,
 202     uint8_t *ivbuf,
 203     size_t datalen,
 204     size_t auth_len)
 205 {
 206 #ifdef FCRYPTO_DEBUG
 207         struct cryptodesc *crd;
 208         uint8_t *p = NULL;
 209         size_t total = 0;
 210
 211         printf("%s(%s, %p, { %s, %d, %d, %s }, %p, { %d, %p, %u }, "
 212             "%p, %u, %u)\n",
 213             __FUNCTION__, encrypt ? "encrypt" : "decrypt", input_sessionp,
 214             c_info->ci_algname, c_info->ci_crypt_type,
 215             (unsigned int)c_info->ci_keylen, c_info->ci_name,
 216             data_uio, key->ck_format, key->ck_data,
 217             (unsigned int)key->ck_length,
 218             ivbuf, (unsigned int)datalen, (unsigned int)auth_len);
 219         printf("\tkey = { ");
 220         for (int i = 0; i < key->ck_length / 8; i++) {
 221                 uint8_t *b = (uint8_t *)key->ck_data;
 222                 printf("%02x ", b[i]);
 223         }
 224         printf("}\n");
 225         for (int i = 0; i < data_uio->uio_iovcnt; i++) {
 226                 printf("\tiovec #%d: <%p, %u>\n", i,
 227                     data_uio->uio_iov[i].iov_base,
 228                     (unsigned int)data_uio->uio_iov[i].iov_len);
 229                 total += data_uio->uio_iov[i].iov_len;
 230         }
 231         data_uio->uio_resid = total;
 232 #endif
 233 }
 234 /*
 235  * Create a new cryptographic session.  This should
 236  * happen every time the key changes (including when
 237  * it's first loaded).
 238  */
 239 #if __FreeBSD_version >= 1300087
 240 int
 241 freebsd_crypt_newsession(freebsd_crypt_session_t *sessp,
 242     struct zio_crypt_info *c_info, crypto_key_t *key)
 243 {
 244         struct crypto_session_params csp;
 245         int error = 0;
 246
 247 #ifdef FCRYPTO_DEBUG
 248         printf("%s(%p, { %s, %d, %d, %s }, { %d, %p, %u })\n",
 249             __FUNCTION__, sessp,
 250             c_info->ci_algname, c_info->ci_crypt_type,
 251             (unsigned int)c_info->ci_keylen, c_info->ci_name,
 252             key->ck_format, key->ck_data, (unsigned int)key->ck_length);
 253         printf("\tkey = { ");
 254         for (int i = 0; i < key->ck_length / 8; i++) {
 255                 uint8_t *b = (uint8_t *)key->ck_data;
 256                 printf("%02x ", b[i]);
 257         }
 258         printf("}\n");
 259 #endif
 260         bzero(&csp, sizeof (csp));
 261         csp.csp_mode = CSP_MODE_AEAD;
 262         csp.csp_cipher_key = key->ck_data;
 263         csp.csp_cipher_klen = key->ck_length / 8;
 264         switch (c_info->ci_crypt_type) {
 265                 case ZC_TYPE_GCM:
 266                 csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
 267                 csp.csp_ivlen = AES_GCM_IV_LEN;
 268                 switch (key->ck_length/8) {
 269                 case AES_128_GMAC_KEY_LEN:
 270                 case AES_192_GMAC_KEY_LEN:
 271                 case AES_256_GMAC_KEY_LEN:
 272                         break;
 273                 default:
 274                         error = EINVAL;
 275                         goto bad;
 276                 }
 277                 break;
 278         case ZC_TYPE_CCM:
 279                 csp.csp_cipher_alg = CRYPTO_AES_CCM_16;
 280                 csp.csp_ivlen = AES_CCM_IV_LEN;
 281                 switch (key->ck_length/8) {
 282                 case AES_128_CBC_MAC_KEY_LEN:
 283                 case AES_192_CBC_MAC_KEY_LEN:
 284                 case AES_256_CBC_MAC_KEY_LEN:
 285                         break;
 286                 default:
 287                         error = EINVAL;
 288                         goto bad;
 289                         break;
 290                 }
 291                 break;
 292         default:
 293                 error = ENOTSUP;
 294                 goto bad;
 295         }
 296         error = crypto_newsession(&sessp->fs_sid, &csp,
 297             CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE);
 298         mtx_init(&sessp->fs_lock, "FreeBSD Cryptographic Session Lock",
 299             NULL, MTX_DEF);
 300         crypt_sessions++;
 301 bad:
 302 #ifdef FCRYPTO_DEBUG
 303         if (error)
 304                 printf("%s: returning error %d\n", __FUNCTION__, error);
 305 #endif
 306         return (error);
 307 }
 308
 309 int
 310 freebsd_crypt_uio(boolean_t encrypt,
 311     freebsd_crypt_session_t *input_sessionp,
 312     struct zio_crypt_info *c_info,
 313     uio_t *data_uio,
 314     crypto_key_t *key,
 315     uint8_t *ivbuf,
 316     size_t datalen,
 317     size_t auth_len)
 318 {
 319         struct cryptop *crp;
 320         freebsd_crypt_session_t *session = NULL;
 321         int error = 0;
 322         size_t total = 0;
 323
 324         freebsd_crypt_uio_debug_log(encrypt, input_sessionp, c_info, data_uio,
 325             key, ivbuf, datalen, auth_len);
 326         for (int i = 0; i < data_uio->uio_iovcnt; i++)
 327                 total += data_uio->uio_iov[i].iov_len;
 328         data_uio->uio_resid = total;
 329         if (input_sessionp == NULL) {
 330                 session = kmem_zalloc(sizeof (*session), KM_SLEEP);
 331                 error = freebsd_crypt_newsession(session, c_info, key);
 332                 if (error)
 333                         goto out;
 334         } else
 335                 session = input_sessionp;
 336
 337         crp = crypto_getreq(session->fs_sid, M_WAITOK);
 338         if (encrypt) {
 339                 crp->crp_op = CRYPTO_OP_ENCRYPT |
 340                     CRYPTO_OP_COMPUTE_DIGEST;
 341         } else {
 342                 crp->crp_op = CRYPTO_OP_DECRYPT |
 343                     CRYPTO_OP_VERIFY_DIGEST;
 344         }
 345         crp->crp_flags = CRYPTO_F_CBIFSYNC | CRYPTO_F_IV_SEPARATE;
 346         crp->crp_buf_type = CRYPTO_BUF_UIO;
 347         crp->crp_uio = (void*)data_uio;
 348         crp->crp_ilen = data_uio->uio_resid;
 349
 350         crp->crp_aad_start = 0;
 351         crp->crp_aad_length = auth_len;
 352         crp->crp_payload_start = auth_len;
 353         crp->crp_payload_length = datalen;
 354         crp->crp_digest_start = auth_len + datalen;
 355
 356         bcopy(ivbuf, crp->crp_iv, ZIO_DATA_IV_LEN);
 357         error = zfs_crypto_dispatch(session, crp);
 358         crypto_freereq(crp);
 359 out:
 360 #ifdef FCRYPTO_DEBUG
 361         if (error)
 362                 printf("%s: returning error %d\n", __FUNCTION__, error);
 363 #endif
 364         if (input_sessionp == NULL) {
 365                 freebsd_crypt_freesession(session);
 366                 kmem_free(session, sizeof (*session));
 367         }
 368         return (error);
 369 }
 370
 371 #else
 372 int
 373 freebsd_crypt_newsession(freebsd_crypt_session_t *sessp,
 374     struct zio_crypt_info *c_info, crypto_key_t *key)
 375 {
 376         struct cryptoini cria, crie, *crip;
 377         struct enc_xform *xform;
 378         struct auth_hash *xauth;
 379         int error = 0;
 380         crypto_session_t sid;
 381
 382 #ifdef FCRYPTO_DEBUG
 383         printf("%s(%p, { %s, %d, %d, %s }, { %d, %p, %u })\n",
 384             __FUNCTION__, sessp,
 385             c_info->ci_algname, c_info->ci_crypt_type,
 386             (unsigned int)c_info->ci_keylen, c_info->ci_name,
 387             key->ck_format, key->ck_data, (unsigned int)key->ck_length);
 388         printf("\tkey = { ");
 389         for (int i = 0; i < key->ck_length / 8; i++) {
 390                 uint8_t *b = (uint8_t *)key->ck_data;
 391                 printf("%02x ", b[i]);
 392         }
 393         printf("}\n");
 394 #endif
 395         switch (c_info->ci_crypt_type) {
 396         case ZC_TYPE_GCM:
 397                 xform = &enc_xform_aes_nist_gcm;
 398                 switch (key->ck_length/8) {
 399                 case AES_128_GMAC_KEY_LEN:
 400                         xauth = &auth_hash_nist_gmac_aes_128;
 401                         break;
 402                 case AES_192_GMAC_KEY_LEN:
 403                         xauth = &auth_hash_nist_gmac_aes_192;
 404                         break;
 405                 case AES_256_GMAC_KEY_LEN:
 406                         xauth = &auth_hash_nist_gmac_aes_256;
 407                         break;
 408                 default:
 409                         error = EINVAL;
 410                         goto bad;
 411                 }
 412                 break;
 413         case ZC_TYPE_CCM:
 414                 xform = &enc_xform_ccm;
 415                 switch (key->ck_length/8) {
 416                 case AES_128_CBC_MAC_KEY_LEN:
 417                         xauth = &auth_hash_ccm_cbc_mac_128;
 418                         break;
 419                 case AES_192_CBC_MAC_KEY_LEN:
 420                         xauth = &auth_hash_ccm_cbc_mac_192;
 421                         break;
 422                 case AES_256_CBC_MAC_KEY_LEN:
 423                         xauth = &auth_hash_ccm_cbc_mac_256;
 424                         break;
 425                 default:
 426                         error = EINVAL;
 427                         goto bad;
 428                         break;
 429                 }
 430                 break;
 431         default:
 432                 error = ENOTSUP;
 433                 goto bad;
 434         }
 435 #ifdef FCRYPTO_DEBUG
 436         printf("%s(%d): Using crypt %s (key length %u [%u bytes]), "
 437             "auth %s (key length %d)\n",
 438             __FUNCTION__, __LINE__,
 439             xform->name, (unsigned int)key->ck_length,
 440             (unsigned int)key->ck_length/8,
 441             xauth->name, xauth->keysize);
 442 #endif
 443
 444         bzero(&crie, sizeof (crie));
 445         bzero(&cria, sizeof (cria));
 446
 447         crie.cri_alg = xform->type;
 448         crie.cri_key = key->ck_data;
 449         crie.cri_klen = key->ck_length;
 450
 451         cria.cri_alg = xauth->type;
 452         cria.cri_key = key->ck_data;
 453         cria.cri_klen = key->ck_length;
 454
 455         cria.cri_next = &crie;
 456         crie.cri_next = NULL;
 457         crip = &cria;
 458         // Everything else is bzero'd
 459
 460         error = crypto_newsession(&sid, crip,
 461             CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE);
 462         if (error != 0) {
 463                 printf("%s(%d):  crypto_newsession failed with %d\n",
 464                     __FUNCTION__, __LINE__, error);
 465                 goto bad;
 466         }
 467         sessp->fs_sid = sid;
 468         mtx_init(&sessp->fs_lock, "FreeBSD Cryptographic Session Lock",
 469             NULL, MTX_DEF);
 470         crypt_sessions++;
 471 bad:
 472         return (error);
 473 }
 474
 475 /*
 476  * The meat of encryption/decryption.
 477  * If sessp is NULL, then it will create a
 478  * temporary cryptographic session, and release
 479  * it when done.
 480  */
 481 int
 482 freebsd_crypt_uio(boolean_t encrypt,
 483     freebsd_crypt_session_t *input_sessionp,
 484     struct zio_crypt_info *c_info,
 485     uio_t *data_uio,
 486     crypto_key_t *key,
 487     uint8_t *ivbuf,
 488     size_t datalen,
 489     size_t auth_len)
 490 {
 491         struct cryptop *crp;
 492         struct cryptodesc *enc_desc, *auth_desc;
 493         struct enc_xform *xform;
 494         struct auth_hash *xauth;
 495         freebsd_crypt_session_t *session = NULL;
 496         int error;
 497
 498         freebsd_crypt_uio_debug_log(encrypt, input_sessionp, c_info, data_uio,
 499             key, ivbuf, datalen, auth_len);
 500         switch (c_info->ci_crypt_type) {
 501         case ZC_TYPE_GCM:
 502                 xform = &enc_xform_aes_nist_gcm;
 503                 switch (key->ck_length/8) {
 504                 case AES_128_GMAC_KEY_LEN:
 505                         xauth = &auth_hash_nist_gmac_aes_128;
 506                         break;
 507                 case AES_192_GMAC_KEY_LEN:
 508                         xauth = &auth_hash_nist_gmac_aes_192;
 509                         break;
 510                 case AES_256_GMAC_KEY_LEN:
 511                         xauth = &auth_hash_nist_gmac_aes_256;
 512                         break;
 513                 default:
 514                         error = EINVAL;
 515                         goto bad;
 516                 }
 517                 break;
 518         case ZC_TYPE_CCM:
 519                 xform = &enc_xform_ccm;
 520                 switch (key->ck_length/8) {
 521                 case AES_128_CBC_MAC_KEY_LEN:
 522                         xauth = &auth_hash_ccm_cbc_mac_128;
 523                         break;
 524                 case AES_192_CBC_MAC_KEY_LEN:
 525                         xauth = &auth_hash_ccm_cbc_mac_192;
 526                         break;
 527                 case AES_256_CBC_MAC_KEY_LEN:
 528                         xauth = &auth_hash_ccm_cbc_mac_256;
 529                         break;
 530                 default:
 531                         error = EINVAL;
 532                         goto bad;
 533                         break;
 534                 }
 535                 break;
 536         default:
 537                 error = ENOTSUP;
 538                 goto bad;
 539         }
 540
 541 #ifdef FCRYPTO_DEBUG
 542         printf("%s(%d): Using crypt %s (key length %u [%u bytes]), "
 543             "auth %s (key length %d)\n",
 544             __FUNCTION__, __LINE__,
 545             xform->name, (unsigned int)key->ck_length,
 546             (unsigned int)key->ck_length/8,
 547             xauth->name, xauth->keysize);
 548 #endif
 549
 550         if (input_sessionp == NULL) {
 551                 session = kmem_zalloc(sizeof (*session), KM_SLEEP);
 552                 error = freebsd_crypt_newsession(session, c_info, key);
 553                 if (error)
 554                         goto out;
 555         } else
 556                 session = input_sessionp;
 557
 558         crp = crypto_getreq(2);
 559         if (crp == NULL) {
 560                 error = ENOMEM;
 561                 goto bad;
 562         }
 563
 564         auth_desc = crp->crp_desc;
 565         enc_desc = auth_desc->crd_next;
 566
 567         crp->crp_session = session->fs_sid;
 568         crp->crp_ilen = auth_len + datalen;
 569         crp->crp_buf = (void*)data_uio;
 570         crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC;
 571
 572         auth_desc->crd_skip = 0;
 573         auth_desc->crd_len = auth_len;
 574         auth_desc->crd_inject = auth_len + datalen;
 575         auth_desc->crd_alg = xauth->type;
 576 #ifdef FCRYPTO_DEBUG
 577         printf("%s: auth: skip = %u, len = %u, inject = %u\n",
 578             __FUNCTION__, auth_desc->crd_skip, auth_desc->crd_len,
 579             auth_desc->crd_inject);
 580 #endif
 581
 582         enc_desc->crd_skip = auth_len;
 583         enc_desc->crd_len = datalen;
 584         enc_desc->crd_inject = auth_len;
 585         enc_desc->crd_alg = xform->type;
 586         enc_desc->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
 587         bcopy(ivbuf, enc_desc->crd_iv, ZIO_DATA_IV_LEN);
 588         enc_desc->crd_next = NULL;
 589
 590 #ifdef FCRYPTO_DEBUG
 591         printf("%s: enc: skip = %u, len = %u, inject = %u\n",
 592             __FUNCTION__, enc_desc->crd_skip, enc_desc->crd_len,
 593             enc_desc->crd_inject);
 594 #endif
 595
 596         if (encrypt)
 597                 enc_desc->crd_flags |= CRD_F_ENCRYPT;
 598
 599         error = zfs_crypto_dispatch(session, crp);
 600         crypto_freereq(crp);
 601 out:
 602         if (input_sessionp == NULL) {
 603                 freebsd_crypt_freesession(session);
 604                 kmem_free(session, sizeof (*session));
 605         }
 606 bad:
 607 #ifdef FCRYPTO_DEBUG
 608         if (error)
 609                 printf("%s: returning error %d\n", __FUNCTION__, error);
 610 #endif
 611         return (error);
 612 }
 613 #endif