xref: /freebsd/sys/geom/eli/g_eli_integrity.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/linker.h>
36 #include <sys/module.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/bio.h>
40 #include <sys/sysctl.h>
41 #include <sys/malloc.h>
42 #include <sys/kthread.h>
43 #include <sys/proc.h>
44 #include <sys/sched.h>
45 #include <sys/smp.h>
46 #include <sys/vnode.h>
47 
48 #include <vm/uma.h>
49 
50 #include <geom/geom.h>
51 #include <geom/geom_dbg.h>
52 #include <geom/eli/g_eli.h>
53 #include <geom/eli/pkcs5v2.h>
54 
55 /*
56  * The data layout description when integrity verification is configured.
57  *
58  * One of the most important assumption here is that authenticated data and its
59  * HMAC has to be stored in the same place (namely in the same sector) to make
60  * it work reliable.
61  * The problem is that file systems work only with sectors that are multiple of
62  * 512 bytes and a power of two number.
63  * My idea to implement it is as follows.
64  * Let's store HMAC in sector. This is a must. This leaves us 480 bytes for
65  * data. We can't use that directly (ie. we can't create provider with 480 bytes
66  * sector size). We need another sector from where we take only 32 bytes of data
67  * and we store HMAC of this data as well. This takes two sectors from the
68  * original provider at the input and leaves us one sector of authenticated data
69  * at the output. Not very efficient, but you got the idea.
70  * Now, let's assume, we want to create provider with 4096 bytes sector.
71  * To output 4096 bytes of authenticated data we need 8x480 plus 1x256, so we
72  * need nine 512-bytes sectors at the input to get one 4096-bytes sector at the
73  * output. That's better. With 4096 bytes sector we can use 89% of size of the
74  * original provider. I find it as an acceptable cost.
75  * The reliability comes from the fact, that every HMAC stored inside the sector
76  * is calculated only for the data in the same sector, so its impossible to
77  * write new data and leave old HMAC or vice versa.
78  *
79  * And here is the picture:
80  *
81  * da0: +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+-----+
82  *      |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |256b |
83  *      |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data |
84  *      +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+-----+
85  *      |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |288 bytes |
86  *      +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ |224 unused|
87  *                                                                                                      +----------+
88  * da0.eli: +----+----+----+----+----+----+----+----+----+
89  *          |480b|480b|480b|480b|480b|480b|480b|480b|256b|
90  *          +----+----+----+----+----+----+----+----+----+
91  *          |                 4096 bytes                 |
92  *          +--------------------------------------------+
93  *
94  * PS. You can use any sector size with geli(8). My example is using 4kB,
95  *     because it's most efficient. For 8kB sectors you need 2 extra sectors,
96  *     so the cost is the same as for 4kB sectors.
97  */
98 
99 /*
100  * Code paths:
101  * BIO_READ:
102  *	g_eli_start -> g_eli_auth_read -> g_io_request -> g_eli_read_done -> g_eli_auth_run -> g_eli_auth_read_done -> g_io_deliver
103  * BIO_WRITE:
104  *	g_eli_start -> g_eli_auth_run -> g_eli_auth_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
105  */
106 
107 MALLOC_DECLARE(M_ELI);
108 
109 /*
110  * Here we generate key for HMAC. Every sector has its own HMAC key, so it is
111  * not possible to copy sectors.
112  * We cannot depend on fact, that every sector has its own IV, because different
113  * IV doesn't change HMAC, when we use encrypt-then-authenticate method.
114  */
115 static void
116 g_eli_auth_keygen(struct g_eli_softc *sc, off_t offset, u_char *key)
117 {
118 	SHA256_CTX ctx;
119 
120 	/* Copy precalculated SHA256 context. */
121 	bcopy(&sc->sc_akeyctx, &ctx, sizeof(ctx));
122 	SHA256_Update(&ctx, (uint8_t *)&offset, sizeof(offset));
123 	SHA256_Final(key, &ctx);
124 }
125 
126 /*
127  * The function is called after we read and decrypt data.
128  *
129  * g_eli_start -> g_eli_auth_read -> g_io_request -> g_eli_read_done -> g_eli_auth_run -> G_ELI_AUTH_READ_DONE -> g_io_deliver
130  */
131 static int
132 g_eli_auth_read_done(struct cryptop *crp)
133 {
134 	struct g_eli_softc *sc;
135 	struct bio *bp;
136 
137 	if (crp->crp_etype == EAGAIN) {
138 		if (g_eli_crypto_rerun(crp) == 0)
139 			return (0);
140 	}
141 	bp = (struct bio *)crp->crp_opaque;
142 	bp->bio_inbed++;
143 	if (crp->crp_etype == 0) {
144 		bp->bio_completed += crp->crp_olen;
145 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d) (add=%jd completed=%jd).",
146 		    bp->bio_inbed, bp->bio_children, (intmax_t)crp->crp_olen, (intmax_t)bp->bio_completed);
147 	} else {
148 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
149 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
150 		if (bp->bio_error == 0)
151 			bp->bio_error = crp->crp_etype;
152 	}
153 	sc = bp->bio_to->geom->softc;
154 	g_eli_key_drop(sc, crp->crp_desc->crd_next->crd_key);
155 	/*
156 	 * Do we have all sectors already?
157 	 */
158 	if (bp->bio_inbed < bp->bio_children)
159 		return (0);
160 	if (bp->bio_error == 0) {
161 		u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
162 		u_char *srcdata, *dstdata, *auth;
163 		off_t coroff, corsize;
164 
165 		/*
166 		 * Verify data integrity based on calculated and read HMACs.
167 		 */
168 		/* Sectorsize of decrypted provider eg. 4096. */
169 		decr_secsize = bp->bio_to->sectorsize;
170 		/* The real sectorsize of encrypted provider, eg. 512. */
171 		encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
172 		/* Number of data bytes in one encrypted sector, eg. 480. */
173 		data_secsize = sc->sc_data_per_sector;
174 		/* Number of sectors from decrypted provider, eg. 2. */
175 		nsec = bp->bio_length / decr_secsize;
176 		/* Number of sectors from encrypted provider, eg. 18. */
177 		nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
178 		/* Last sector number in every big sector, eg. 9. */
179 		lsec = sc->sc_bytes_per_sector / encr_secsize;
180 
181 		srcdata = bp->bio_driver2;
182 		dstdata = bp->bio_data;
183 		auth = srcdata + encr_secsize * nsec;
184 		coroff = -1;
185 		corsize = 0;
186 
187 		for (i = 1; i <= nsec; i++) {
188 			data_secsize = sc->sc_data_per_sector;
189 			if ((i % lsec) == 0)
190 				data_secsize = decr_secsize % data_secsize;
191 			if (bcmp(srcdata, auth, sc->sc_alen) != 0) {
192 				/*
193 				 * Curruption detected, remember the offset if
194 				 * this is the first corrupted sector and
195 				 * increase size.
196 				 */
197 				if (bp->bio_error == 0)
198 					bp->bio_error = -1;
199 				if (coroff == -1) {
200 					coroff = bp->bio_offset +
201 					    (dstdata - (u_char *)bp->bio_data);
202 				}
203 				corsize += data_secsize;
204 			} else {
205 				/*
206 				 * No curruption, good.
207 				 * Report previous corruption if there was one.
208 				 */
209 				if (coroff != -1) {
210 					G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
211 					    "bytes of data at offset %jd.",
212 					    sc->sc_name, (intmax_t)corsize,
213 					    (intmax_t)coroff);
214 					coroff = -1;
215 					corsize = 0;
216 				}
217 				bcopy(srcdata + sc->sc_alen, dstdata,
218 				    data_secsize);
219 			}
220 			srcdata += encr_secsize;
221 			dstdata += data_secsize;
222 			auth += sc->sc_alen;
223 		}
224 		/* Report previous corruption if there was one. */
225 		if (coroff != -1) {
226 			G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
227 			    "bytes of data at offset %jd.",
228 			    sc->sc_name, (intmax_t)corsize, (intmax_t)coroff);
229 		}
230 	}
231 	free(bp->bio_driver2, M_ELI);
232 	bp->bio_driver2 = NULL;
233 	if (bp->bio_error != 0) {
234 		if (bp->bio_error == -1)
235 			bp->bio_error = EINVAL;
236 		else {
237 			G_ELI_LOGREQ(0, bp,
238 			    "Crypto READ request failed (error=%d).",
239 			    bp->bio_error);
240 		}
241 		bp->bio_completed = 0;
242 	}
243 	/*
244 	 * Read is finished, send it up.
245 	 */
246 	g_io_deliver(bp, bp->bio_error);
247 	atomic_subtract_int(&sc->sc_inflight, 1);
248 	return (0);
249 }
250 
251 /*
252  * The function is called after data encryption.
253  *
254  * g_eli_start -> g_eli_auth_run -> G_ELI_AUTH_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
255  */
256 static int
257 g_eli_auth_write_done(struct cryptop *crp)
258 {
259 	struct g_eli_softc *sc;
260 	struct g_consumer *cp;
261 	struct bio *bp, *cbp, *cbp2;
262 	u_int nsec;
263 
264 	if (crp->crp_etype == EAGAIN) {
265 		if (g_eli_crypto_rerun(crp) == 0)
266 			return (0);
267 	}
268 	bp = (struct bio *)crp->crp_opaque;
269 	bp->bio_inbed++;
270 	if (crp->crp_etype == 0) {
271 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
272 		    bp->bio_inbed, bp->bio_children);
273 	} else {
274 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
275 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
276 		if (bp->bio_error == 0)
277 			bp->bio_error = crp->crp_etype;
278 	}
279 	sc = bp->bio_to->geom->softc;
280 	g_eli_key_drop(sc, crp->crp_desc->crd_key);
281 	/*
282 	 * All sectors are already encrypted?
283 	 */
284 	if (bp->bio_inbed < bp->bio_children)
285 		return (0);
286 	if (bp->bio_error != 0) {
287 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
288 		    bp->bio_error);
289 		free(bp->bio_driver2, M_ELI);
290 		bp->bio_driver2 = NULL;
291 		cbp = bp->bio_driver1;
292 		bp->bio_driver1 = NULL;
293 		g_destroy_bio(cbp);
294 		g_io_deliver(bp, bp->bio_error);
295 		atomic_subtract_int(&sc->sc_inflight, 1);
296 		return (0);
297 	}
298 	cp = LIST_FIRST(&sc->sc_geom->consumer);
299 	cbp = bp->bio_driver1;
300 	bp->bio_driver1 = NULL;
301 	cbp->bio_to = cp->provider;
302 	cbp->bio_done = g_eli_write_done;
303 
304 	/* Number of sectors from decrypted provider, eg. 1. */
305 	nsec = bp->bio_length / bp->bio_to->sectorsize;
306 	/* Number of sectors from encrypted provider, eg. 9. */
307 	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;
308 
309 	cbp->bio_length = cp->provider->sectorsize * nsec;
310 	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
311 	cbp->bio_data = bp->bio_driver2;
312 
313 	/*
314 	 * We write more than what is requested, so we have to be ready to write
315 	 * more than MAXPHYS.
316 	 */
317 	cbp2 = NULL;
318 	if (cbp->bio_length > MAXPHYS) {
319 		cbp2 = g_duplicate_bio(bp);
320 		cbp2->bio_length = cbp->bio_length - MAXPHYS;
321 		cbp2->bio_data = cbp->bio_data + MAXPHYS;
322 		cbp2->bio_offset = cbp->bio_offset + MAXPHYS;
323 		cbp2->bio_to = cp->provider;
324 		cbp2->bio_done = g_eli_write_done;
325 		cbp->bio_length = MAXPHYS;
326 	}
327 	/*
328 	 * Send encrypted data to the provider.
329 	 */
330 	G_ELI_LOGREQ(2, cbp, "Sending request.");
331 	bp->bio_inbed = 0;
332 	bp->bio_children = (cbp2 != NULL ? 2 : 1);
333 	g_io_request(cbp, cp);
334 	if (cbp2 != NULL) {
335 		G_ELI_LOGREQ(2, cbp2, "Sending request.");
336 		g_io_request(cbp2, cp);
337 	}
338 	return (0);
339 }
340 
341 void
342 g_eli_auth_read(struct g_eli_softc *sc, struct bio *bp)
343 {
344 	struct g_consumer *cp;
345 	struct bio *cbp, *cbp2;
346 	size_t size;
347 	off_t nsec;
348 
349 	bp->bio_pflags = 0;
350 
351 	cp = LIST_FIRST(&sc->sc_geom->consumer);
352 	cbp = bp->bio_driver1;
353 	bp->bio_driver1 = NULL;
354 	cbp->bio_to = cp->provider;
355 	cbp->bio_done = g_eli_read_done;
356 
357 	/* Number of sectors from decrypted provider, eg. 1. */
358 	nsec = bp->bio_length / bp->bio_to->sectorsize;
359 	/* Number of sectors from encrypted provider, eg. 9. */
360 	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;
361 
362 	cbp->bio_length = cp->provider->sectorsize * nsec;
363 	size = cbp->bio_length;
364 	size += sc->sc_alen * nsec;
365 	size += sizeof(struct cryptop) * nsec;
366 	size += sizeof(struct cryptodesc) * nsec * 2;
367 	size += G_ELI_AUTH_SECKEYLEN * nsec;
368 	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
369 	bp->bio_driver2 = malloc(size, M_ELI, M_WAITOK);
370 	cbp->bio_data = bp->bio_driver2;
371 
372 	/*
373 	 * We read more than what is requested, so we have to be ready to read
374 	 * more than MAXPHYS.
375 	 */
376 	cbp2 = NULL;
377 	if (cbp->bio_length > MAXPHYS) {
378 		cbp2 = g_duplicate_bio(bp);
379 		cbp2->bio_length = cbp->bio_length - MAXPHYS;
380 		cbp2->bio_data = cbp->bio_data + MAXPHYS;
381 		cbp2->bio_offset = cbp->bio_offset + MAXPHYS;
382 		cbp2->bio_to = cp->provider;
383 		cbp2->bio_done = g_eli_read_done;
384 		cbp->bio_length = MAXPHYS;
385 	}
386 	/*
387 	 * Read encrypted data from provider.
388 	 */
389 	G_ELI_LOGREQ(2, cbp, "Sending request.");
390 	g_io_request(cbp, cp);
391 	if (cbp2 != NULL) {
392 		G_ELI_LOGREQ(2, cbp2, "Sending request.");
393 		g_io_request(cbp2, cp);
394 	}
395 }
396 
397 /*
398  * This is the main function responsible for cryptography (ie. communication
399  * with crypto(9) subsystem).
400  *
401  * BIO_READ:
402  *	g_eli_start -> g_eli_auth_read -> g_io_request -> g_eli_read_done -> G_ELI_AUTH_RUN -> g_eli_auth_read_done -> g_io_deliver
403  * BIO_WRITE:
404  *	g_eli_start -> G_ELI_AUTH_RUN -> g_eli_auth_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
405  */
406 void
407 g_eli_auth_run(struct g_eli_worker *wr, struct bio *bp)
408 {
409 	struct g_eli_softc *sc;
410 	struct cryptop *crp;
411 	struct cryptodesc *crde, *crda;
412 	u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
413 	off_t dstoff;
414 	u_char *p, *data, *auth, *authkey, *plaindata;
415 	int error;
416 
417 	G_ELI_LOGREQ(3, bp, "%s", __func__);
418 
419 	bp->bio_pflags = wr->w_number;
420 	sc = wr->w_softc;
421 	/* Sectorsize of decrypted provider eg. 4096. */
422 	decr_secsize = bp->bio_to->sectorsize;
423 	/* The real sectorsize of encrypted provider, eg. 512. */
424 	encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
425 	/* Number of data bytes in one encrypted sector, eg. 480. */
426 	data_secsize = sc->sc_data_per_sector;
427 	/* Number of sectors from decrypted provider, eg. 2. */
428 	nsec = bp->bio_length / decr_secsize;
429 	/* Number of sectors from encrypted provider, eg. 18. */
430 	nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
431 	/* Last sector number in every big sector, eg. 9. */
432 	lsec = sc->sc_bytes_per_sector / encr_secsize;
433 	/* Destination offset, used for IV generation. */
434 	dstoff = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
435 
436 	auth = NULL;	/* Silence compiler warning. */
437 	plaindata = bp->bio_data;
438 	if (bp->bio_cmd == BIO_READ) {
439 		data = bp->bio_driver2;
440 		auth = data + encr_secsize * nsec;
441 		p = auth + sc->sc_alen * nsec;
442 	} else {
443 		size_t size;
444 
445 		size = encr_secsize * nsec;
446 		size += sizeof(*crp) * nsec;
447 		size += sizeof(*crde) * nsec;
448 		size += sizeof(*crda) * nsec;
449 		size += G_ELI_AUTH_SECKEYLEN * nsec;
450 		size += sizeof(uintptr_t);	/* Space for alignment. */
451 		data = malloc(size, M_ELI, M_WAITOK);
452 		bp->bio_driver2 = data;
453 		p = data + encr_secsize * nsec;
454 	}
455 	bp->bio_inbed = 0;
456 	bp->bio_children = nsec;
457 
458 #if defined(__mips_n64) || defined(__mips_o64)
459 	p = (char *)roundup((uintptr_t)p, sizeof(uintptr_t));
460 #endif
461 
462 	for (i = 1; i <= nsec; i++, dstoff += encr_secsize) {
463 		crp = (struct cryptop *)p;	p += sizeof(*crp);
464 		crde = (struct cryptodesc *)p;	p += sizeof(*crde);
465 		crda = (struct cryptodesc *)p;	p += sizeof(*crda);
466 		authkey = (u_char *)p;		p += G_ELI_AUTH_SECKEYLEN;
467 
468 		data_secsize = sc->sc_data_per_sector;
469 		if ((i % lsec) == 0) {
470 			data_secsize = decr_secsize % data_secsize;
471 			/*
472 			 * Last encrypted sector of each decrypted sector is
473 			 * only partially filled.
474 			 */
475 			if (bp->bio_cmd == BIO_WRITE)
476 				memset(data + sc->sc_alen + data_secsize, 0,
477 				    encr_secsize - sc->sc_alen - data_secsize);
478 		}
479 
480 		if (bp->bio_cmd == BIO_READ) {
481 			/* Remember read HMAC. */
482 			bcopy(data, auth, sc->sc_alen);
483 			auth += sc->sc_alen;
484 			/* TODO: bzero(9) can be commented out later. */
485 			bzero(data, sc->sc_alen);
486 		} else {
487 			bcopy(plaindata, data + sc->sc_alen, data_secsize);
488 			plaindata += data_secsize;
489 		}
490 
491 		crp->crp_session = wr->w_sid;
492 		crp->crp_ilen = sc->sc_alen + data_secsize;
493 		crp->crp_olen = data_secsize;
494 		crp->crp_opaque = (void *)bp;
495 		crp->crp_buf = (void *)data;
496 		data += encr_secsize;
497 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
498 		if (g_eli_batch)
499 			crp->crp_flags |= CRYPTO_F_BATCH;
500 		if (bp->bio_cmd == BIO_WRITE) {
501 			crp->crp_callback = g_eli_auth_write_done;
502 			crp->crp_desc = crde;
503 			crde->crd_next = crda;
504 			crda->crd_next = NULL;
505 		} else {
506 			crp->crp_callback = g_eli_auth_read_done;
507 			crp->crp_desc = crda;
508 			crda->crd_next = crde;
509 			crde->crd_next = NULL;
510 		}
511 
512 		crde->crd_skip = sc->sc_alen;
513 		crde->crd_len = data_secsize;
514 		crde->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
515 		if ((sc->sc_flags & G_ELI_FLAG_FIRST_KEY) == 0)
516 			crde->crd_flags |= CRD_F_KEY_EXPLICIT;
517 		if (bp->bio_cmd == BIO_WRITE)
518 			crde->crd_flags |= CRD_F_ENCRYPT;
519 		crde->crd_alg = sc->sc_ealgo;
520 		crde->crd_key = g_eli_key_hold(sc, dstoff, encr_secsize);
521 		crde->crd_klen = sc->sc_ekeylen;
522 		if (sc->sc_ealgo == CRYPTO_AES_XTS)
523 			crde->crd_klen <<= 1;
524 		g_eli_crypto_ivgen(sc, dstoff, crde->crd_iv,
525 		    sizeof(crde->crd_iv));
526 
527 		crda->crd_skip = sc->sc_alen;
528 		crda->crd_len = data_secsize;
529 		crda->crd_inject = 0;
530 		crda->crd_flags = CRD_F_KEY_EXPLICIT;
531 		crda->crd_alg = sc->sc_aalgo;
532 		g_eli_auth_keygen(sc, dstoff, authkey);
533 		crda->crd_key = authkey;
534 		crda->crd_klen = G_ELI_AUTH_SECKEYLEN * 8;
535 
536 		crp->crp_etype = 0;
537 		error = crypto_dispatch(crp);
538 		KASSERT(error == 0, ("crypto_dispatch() failed (error=%d)",
539 		    error));
540 	}
541 }
542