xref: /freebsd/sys/contrib/openzfs/module/os/freebsd/zfs/crypto_os.c (revision fe6060f10f634930ff71b7c50291ddc610da2475)
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, 0,
176 			    "zfs_crypto", 0);
177 		mtx_unlock(&session->fs_lock);
178 
179 		if (crp->crp_etype == ENOMEM) {
180 			pause("zcrnomem", 1);
181 		} else if (crp->crp_etype != EAGAIN) {
182 			error = crp->crp_etype;
183 			break;
184 		}
185 		crp->crp_etype = 0;
186 		crp->crp_flags &= ~CRYPTO_F_DONE;
187 		session->fs_done = false;
188 #if __FreeBSD_version < 1300087
189 		/*
190 		 * Session ID changed, so we should record that,
191 		 * and try again
192 		 */
193 		session->fs_sid = crp->crp_session;
194 #endif
195 	}
196 	return (error);
197 }
198 static void
199 freebsd_crypt_uio_debug_log(boolean_t encrypt,
200     freebsd_crypt_session_t *input_sessionp,
201     struct zio_crypt_info *c_info,
202     zfs_uio_t *data_uio,
203     crypto_key_t *key,
204     uint8_t *ivbuf,
205     size_t datalen,
206     size_t auth_len)
207 {
208 #ifdef FCRYPTO_DEBUG
209 	struct cryptodesc *crd;
210 	uint8_t *p = NULL;
211 	size_t total = 0;
212 
213 	printf("%s(%s, %p, { %s, %d, %d, %s }, %p, { %d, %p, %u }, "
214 	    "%p, %u, %u)\n",
215 	    __FUNCTION__, encrypt ? "encrypt" : "decrypt", input_sessionp,
216 	    c_info->ci_algname, c_info->ci_crypt_type,
217 	    (unsigned int)c_info->ci_keylen, c_info->ci_name,
218 	    data_uio, key->ck_format, key->ck_data,
219 	    (unsigned int)key->ck_length,
220 	    ivbuf, (unsigned int)datalen, (unsigned int)auth_len);
221 	printf("\tkey = { ");
222 	for (int i = 0; i < key->ck_length / 8; i++) {
223 		uint8_t *b = (uint8_t *)key->ck_data;
224 		printf("%02x ", b[i]);
225 	}
226 	printf("}\n");
227 	for (int i = 0; i < zfs_uio_iovcnt(data_uio); i++) {
228 		printf("\tiovec #%d: <%p, %u>\n", i,
229 		    zfs_uio_iovbase(data_uio, i),
230 		    (unsigned int)zfs_uio_iovlen(data_uio, i));
231 		total += zfs_uio_iovlen(data_uio, i);
232 	}
233 	zfs_uio_resid(data_uio) = total;
234 #endif
235 }
236 /*
237  * Create a new cryptographic session.  This should
238  * happen every time the key changes (including when
239  * it's first loaded).
240  */
241 #if __FreeBSD_version >= 1300087
242 int
243 freebsd_crypt_newsession(freebsd_crypt_session_t *sessp,
244     struct zio_crypt_info *c_info, crypto_key_t *key)
245 {
246 	struct crypto_session_params csp;
247 	int error = 0;
248 
249 #ifdef FCRYPTO_DEBUG
250 	printf("%s(%p, { %s, %d, %d, %s }, { %d, %p, %u })\n",
251 	    __FUNCTION__, sessp,
252 	    c_info->ci_algname, c_info->ci_crypt_type,
253 	    (unsigned int)c_info->ci_keylen, c_info->ci_name,
254 	    key->ck_format, key->ck_data, (unsigned int)key->ck_length);
255 	printf("\tkey = { ");
256 	for (int i = 0; i < key->ck_length / 8; i++) {
257 		uint8_t *b = (uint8_t *)key->ck_data;
258 		printf("%02x ", b[i]);
259 	}
260 	printf("}\n");
261 #endif
262 	bzero(&csp, sizeof (csp));
263 	csp.csp_mode = CSP_MODE_AEAD;
264 	csp.csp_cipher_key = key->ck_data;
265 	csp.csp_cipher_klen = key->ck_length / 8;
266 	switch (c_info->ci_crypt_type) {
267 		case ZC_TYPE_GCM:
268 		csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
269 		csp.csp_ivlen = AES_GCM_IV_LEN;
270 		switch (key->ck_length/8) {
271 		case AES_128_GMAC_KEY_LEN:
272 		case AES_192_GMAC_KEY_LEN:
273 		case AES_256_GMAC_KEY_LEN:
274 			break;
275 		default:
276 			error = EINVAL;
277 			goto bad;
278 		}
279 		break;
280 	case ZC_TYPE_CCM:
281 		csp.csp_cipher_alg = CRYPTO_AES_CCM_16;
282 		csp.csp_ivlen = AES_CCM_IV_LEN;
283 		switch (key->ck_length/8) {
284 		case AES_128_CBC_MAC_KEY_LEN:
285 		case AES_192_CBC_MAC_KEY_LEN:
286 		case AES_256_CBC_MAC_KEY_LEN:
287 			break;
288 		default:
289 			error = EINVAL;
290 			goto bad;
291 			break;
292 		}
293 		break;
294 	default:
295 		error = ENOTSUP;
296 		goto bad;
297 	}
298 
299 	/*
300 	 * Disable the use of hardware drivers on FreeBSD 13 and later since
301 	 * common crypto offload drivers impose constraints on AES-GCM AAD
302 	 * lengths that make them unusable for ZFS, and we currently do not have
303 	 * a mechanism to fall back to a software driver for requests not
304 	 * handled by a hardware driver.
305 	 *
306 	 * On 12 we continue to permit the use of hardware drivers since
307 	 * CPU-accelerated drivers such as aesni(4) register themselves as
308 	 * hardware drivers.
309 	 */
310 	error = crypto_newsession(&sessp->fs_sid, &csp, CRYPTOCAP_F_SOFTWARE);
311 	mtx_init(&sessp->fs_lock, "FreeBSD Cryptographic Session Lock",
312 	    NULL, MTX_DEF);
313 	crypt_sessions++;
314 bad:
315 #ifdef FCRYPTO_DEBUG
316 	if (error)
317 		printf("%s: returning error %d\n", __FUNCTION__, error);
318 #endif
319 	return (error);
320 }
321 
322 int
323 freebsd_crypt_uio(boolean_t encrypt,
324     freebsd_crypt_session_t *input_sessionp,
325     struct zio_crypt_info *c_info,
326     zfs_uio_t *data_uio,
327     crypto_key_t *key,
328     uint8_t *ivbuf,
329     size_t datalen,
330     size_t auth_len)
331 {
332 	struct cryptop *crp;
333 	freebsd_crypt_session_t *session = NULL;
334 	int error = 0;
335 	size_t total = 0;
336 
337 	freebsd_crypt_uio_debug_log(encrypt, input_sessionp, c_info, data_uio,
338 	    key, ivbuf, datalen, auth_len);
339 	for (int i = 0; i < zfs_uio_iovcnt(data_uio); i++)
340 		total += zfs_uio_iovlen(data_uio, i);
341 	zfs_uio_resid(data_uio) = total;
342 	if (input_sessionp == NULL) {
343 		session = kmem_zalloc(sizeof (*session), KM_SLEEP);
344 		error = freebsd_crypt_newsession(session, c_info, key);
345 		if (error)
346 			goto out;
347 	} else
348 		session = input_sessionp;
349 
350 	crp = crypto_getreq(session->fs_sid, M_WAITOK);
351 	if (encrypt) {
352 		crp->crp_op = CRYPTO_OP_ENCRYPT |
353 		    CRYPTO_OP_COMPUTE_DIGEST;
354 	} else {
355 		crp->crp_op = CRYPTO_OP_DECRYPT |
356 		    CRYPTO_OP_VERIFY_DIGEST;
357 	}
358 	crp->crp_flags = CRYPTO_F_CBIFSYNC | CRYPTO_F_IV_SEPARATE;
359 	crypto_use_uio(crp, GET_UIO_STRUCT(data_uio));
360 
361 	crp->crp_aad_start = 0;
362 	crp->crp_aad_length = auth_len;
363 	crp->crp_payload_start = auth_len;
364 	crp->crp_payload_length = datalen;
365 	crp->crp_digest_start = auth_len + datalen;
366 
367 	bcopy(ivbuf, crp->crp_iv, ZIO_DATA_IV_LEN);
368 	error = zfs_crypto_dispatch(session, crp);
369 	crypto_freereq(crp);
370 out:
371 #ifdef FCRYPTO_DEBUG
372 	if (error)
373 		printf("%s: returning error %d\n", __FUNCTION__, error);
374 #endif
375 	if (input_sessionp == NULL) {
376 		freebsd_crypt_freesession(session);
377 		kmem_free(session, sizeof (*session));
378 	}
379 	return (error);
380 }
381 
382 #else
383 int
384 freebsd_crypt_newsession(freebsd_crypt_session_t *sessp,
385     struct zio_crypt_info *c_info, crypto_key_t *key)
386 {
387 	struct cryptoini cria, crie, *crip;
388 	struct enc_xform *xform;
389 	struct auth_hash *xauth;
390 	int error = 0;
391 	crypto_session_t sid;
392 
393 #ifdef FCRYPTO_DEBUG
394 	printf("%s(%p, { %s, %d, %d, %s }, { %d, %p, %u })\n",
395 	    __FUNCTION__, sessp,
396 	    c_info->ci_algname, c_info->ci_crypt_type,
397 	    (unsigned int)c_info->ci_keylen, c_info->ci_name,
398 	    key->ck_format, key->ck_data, (unsigned int)key->ck_length);
399 	printf("\tkey = { ");
400 	for (int i = 0; i < key->ck_length / 8; i++) {
401 		uint8_t *b = (uint8_t *)key->ck_data;
402 		printf("%02x ", b[i]);
403 	}
404 	printf("}\n");
405 #endif
406 	switch (c_info->ci_crypt_type) {
407 	case ZC_TYPE_GCM:
408 		xform = &enc_xform_aes_nist_gcm;
409 		switch (key->ck_length/8) {
410 		case AES_128_GMAC_KEY_LEN:
411 			xauth = &auth_hash_nist_gmac_aes_128;
412 			break;
413 		case AES_192_GMAC_KEY_LEN:
414 			xauth = &auth_hash_nist_gmac_aes_192;
415 			break;
416 		case AES_256_GMAC_KEY_LEN:
417 			xauth = &auth_hash_nist_gmac_aes_256;
418 			break;
419 		default:
420 			error = EINVAL;
421 			goto bad;
422 		}
423 		break;
424 	case ZC_TYPE_CCM:
425 		xform = &enc_xform_ccm;
426 		switch (key->ck_length/8) {
427 		case AES_128_CBC_MAC_KEY_LEN:
428 			xauth = &auth_hash_ccm_cbc_mac_128;
429 			break;
430 		case AES_192_CBC_MAC_KEY_LEN:
431 			xauth = &auth_hash_ccm_cbc_mac_192;
432 			break;
433 		case AES_256_CBC_MAC_KEY_LEN:
434 			xauth = &auth_hash_ccm_cbc_mac_256;
435 			break;
436 		default:
437 			error = EINVAL;
438 			goto bad;
439 			break;
440 		}
441 		break;
442 	default:
443 		error = ENOTSUP;
444 		goto bad;
445 	}
446 #ifdef FCRYPTO_DEBUG
447 	printf("%s(%d): Using crypt %s (key length %u [%u bytes]), "
448 	    "auth %s (key length %d)\n",
449 	    __FUNCTION__, __LINE__,
450 	    xform->name, (unsigned int)key->ck_length,
451 	    (unsigned int)key->ck_length/8,
452 	    xauth->name, xauth->keysize);
453 #endif
454 
455 	bzero(&crie, sizeof (crie));
456 	bzero(&cria, sizeof (cria));
457 
458 	crie.cri_alg = xform->type;
459 	crie.cri_key = key->ck_data;
460 	crie.cri_klen = key->ck_length;
461 
462 	cria.cri_alg = xauth->type;
463 	cria.cri_key = key->ck_data;
464 	cria.cri_klen = key->ck_length;
465 
466 	cria.cri_next = &crie;
467 	crie.cri_next = NULL;
468 	crip = &cria;
469 	// Everything else is bzero'd
470 
471 	error = crypto_newsession(&sid, crip,
472 	    CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE);
473 	if (error != 0) {
474 		printf("%s(%d):  crypto_newsession failed with %d\n",
475 		    __FUNCTION__, __LINE__, error);
476 		goto bad;
477 	}
478 	sessp->fs_sid = sid;
479 	mtx_init(&sessp->fs_lock, "FreeBSD Cryptographic Session Lock",
480 	    NULL, MTX_DEF);
481 	crypt_sessions++;
482 bad:
483 	return (error);
484 }
485 
486 /*
487  * The meat of encryption/decryption.
488  * If sessp is NULL, then it will create a
489  * temporary cryptographic session, and release
490  * it when done.
491  */
492 int
493 freebsd_crypt_uio(boolean_t encrypt,
494     freebsd_crypt_session_t *input_sessionp,
495     struct zio_crypt_info *c_info,
496     zfs_uio_t *data_uio,
497     crypto_key_t *key,
498     uint8_t *ivbuf,
499     size_t datalen,
500     size_t auth_len)
501 {
502 	struct cryptop *crp;
503 	struct cryptodesc *enc_desc, *auth_desc;
504 	struct enc_xform *xform;
505 	struct auth_hash *xauth;
506 	freebsd_crypt_session_t *session = NULL;
507 	int error;
508 
509 	freebsd_crypt_uio_debug_log(encrypt, input_sessionp, c_info, data_uio,
510 	    key, ivbuf, datalen, auth_len);
511 	switch (c_info->ci_crypt_type) {
512 	case ZC_TYPE_GCM:
513 		xform = &enc_xform_aes_nist_gcm;
514 		switch (key->ck_length/8) {
515 		case AES_128_GMAC_KEY_LEN:
516 			xauth = &auth_hash_nist_gmac_aes_128;
517 			break;
518 		case AES_192_GMAC_KEY_LEN:
519 			xauth = &auth_hash_nist_gmac_aes_192;
520 			break;
521 		case AES_256_GMAC_KEY_LEN:
522 			xauth = &auth_hash_nist_gmac_aes_256;
523 			break;
524 		default:
525 			error = EINVAL;
526 			goto bad;
527 		}
528 		break;
529 	case ZC_TYPE_CCM:
530 		xform = &enc_xform_ccm;
531 		switch (key->ck_length/8) {
532 		case AES_128_CBC_MAC_KEY_LEN:
533 			xauth = &auth_hash_ccm_cbc_mac_128;
534 			break;
535 		case AES_192_CBC_MAC_KEY_LEN:
536 			xauth = &auth_hash_ccm_cbc_mac_192;
537 			break;
538 		case AES_256_CBC_MAC_KEY_LEN:
539 			xauth = &auth_hash_ccm_cbc_mac_256;
540 			break;
541 		default:
542 			error = EINVAL;
543 			goto bad;
544 			break;
545 		}
546 		break;
547 	default:
548 		error = ENOTSUP;
549 		goto bad;
550 	}
551 
552 #ifdef FCRYPTO_DEBUG
553 	printf("%s(%d): Using crypt %s (key length %u [%u bytes]), "
554 	    "auth %s (key length %d)\n",
555 	    __FUNCTION__, __LINE__,
556 	    xform->name, (unsigned int)key->ck_length,
557 	    (unsigned int)key->ck_length/8,
558 	    xauth->name, xauth->keysize);
559 #endif
560 
561 	if (input_sessionp == NULL) {
562 		session = kmem_zalloc(sizeof (*session), KM_SLEEP);
563 		error = freebsd_crypt_newsession(session, c_info, key);
564 		if (error)
565 			goto out;
566 	} else
567 		session = input_sessionp;
568 
569 	crp = crypto_getreq(2);
570 	if (crp == NULL) {
571 		error = ENOMEM;
572 		goto bad;
573 	}
574 
575 	auth_desc = crp->crp_desc;
576 	enc_desc = auth_desc->crd_next;
577 
578 	crp->crp_session = session->fs_sid;
579 	crp->crp_ilen = auth_len + datalen;
580 	crp->crp_buf = (void*)GET_UIO_STRUCT(data_uio);
581 	crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC;
582 
583 	auth_desc->crd_skip = 0;
584 	auth_desc->crd_len = auth_len;
585 	auth_desc->crd_inject = auth_len + datalen;
586 	auth_desc->crd_alg = xauth->type;
587 #ifdef FCRYPTO_DEBUG
588 	printf("%s: auth: skip = %u, len = %u, inject = %u\n",
589 	    __FUNCTION__, auth_desc->crd_skip, auth_desc->crd_len,
590 	    auth_desc->crd_inject);
591 #endif
592 
593 	enc_desc->crd_skip = auth_len;
594 	enc_desc->crd_len = datalen;
595 	enc_desc->crd_inject = auth_len;
596 	enc_desc->crd_alg = xform->type;
597 	enc_desc->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
598 	bcopy(ivbuf, enc_desc->crd_iv, ZIO_DATA_IV_LEN);
599 	enc_desc->crd_next = NULL;
600 
601 #ifdef FCRYPTO_DEBUG
602 	printf("%s: enc: skip = %u, len = %u, inject = %u\n",
603 	    __FUNCTION__, enc_desc->crd_skip, enc_desc->crd_len,
604 	    enc_desc->crd_inject);
605 #endif
606 
607 	if (encrypt)
608 		enc_desc->crd_flags |= CRD_F_ENCRYPT;
609 
610 	error = zfs_crypto_dispatch(session, crp);
611 	crypto_freereq(crp);
612 out:
613 	if (input_sessionp == NULL) {
614 		freebsd_crypt_freesession(session);
615 		kmem_free(session, sizeof (*session));
616 	}
617 bad:
618 #ifdef FCRYPTO_DEBUG
619 	if (error)
620 		printf("%s: returning error %d\n", __FUNCTION__, error);
621 #endif
622 	return (error);
623 }
624 #endif
625