xref: /freebsd/sys/geom/eli/g_eli_integrity.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/linker.h>
33 #include <sys/module.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/bio.h>
37 #include <sys/sysctl.h>
38 #include <sys/kthread.h>
39 #include <sys/proc.h>
40 #include <sys/sched.h>
41 #include <sys/smp.h>
42 #include <sys/vnode.h>
43 
44 #include <vm/uma.h>
45 
46 #include <geom/geom.h>
47 #include <geom/geom_dbg.h>
48 #include <geom/eli/g_eli.h>
49 #include <geom/eli/pkcs5v2.h>
50 
51 /*
52  * The data layout description when integrity verification is configured.
53  *
54  * One of the most important assumption here is that authenticated data and its
55  * HMAC has to be stored in the same place (namely in the same sector) to make
56  * it work reliable.
57  * The problem is that file systems work only with sectors that are multiple of
58  * 512 bytes and a power of two number.
59  * My idea to implement it is as follows.
60  * Let's store HMAC in sector. This is a must. This leaves us 480 bytes for
61  * data. We can't use that directly (ie. we can't create provider with 480 bytes
62  * sector size). We need another sector from where we take only 32 bytes of data
63  * and we store HMAC of this data as well. This takes two sectors from the
64  * original provider at the input and leaves us one sector of authenticated data
65  * at the output. Not very efficient, but you got the idea.
66  * Now, let's assume, we want to create provider with 4096 bytes sector.
67  * To output 4096 bytes of authenticated data we need 8x480 plus 1x256, so we
68  * need nine 512-bytes sectors at the input to get one 4096-bytes sector at the
69  * output. That's better. With 4096 bytes sector we can use 89% of size of the
70  * original provider. I find it as an acceptable cost.
71  * The reliability comes from the fact, that every HMAC stored inside the sector
72  * is calculated only for the data in the same sector, so its impossible to
73  * write new data and leave old HMAC or vice versa.
74  *
75  * And here is the picture:
76  *
77  * da0: +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+-----+
78  *      |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |480b| |32b |256b |
79  *      |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data| |HMAC|Data |
80  *      +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+----+ +----+-----+
81  *      |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |512 bytes| |288 bytes |
82  *      +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ +---------+ |224 unused|
83  *                                                                                                      +----------+
84  * da0.eli: +----+----+----+----+----+----+----+----+----+
85  *          |480b|480b|480b|480b|480b|480b|480b|480b|256b|
86  *          +----+----+----+----+----+----+----+----+----+
87  *          |                 4096 bytes                 |
88  *          +--------------------------------------------+
89  *
90  * PS. You can use any sector size with geli(8). My example is using 4kB,
91  *     because it's most efficient. For 8kB sectors you need 2 extra sectors,
92  *     so the cost is the same as for 4kB sectors.
93  */
94 
95 /*
96  * Code paths:
97  * BIO_READ:
98  *	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
99  * BIO_WRITE:
100  *	g_eli_start -> g_eli_auth_run -> g_eli_auth_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
101  */
102 
103 /*
104  * Here we generate key for HMAC. Every sector has its own HMAC key, so it is
105  * not possible to copy sectors.
106  * We cannot depend on fact, that every sector has its own IV, because different
107  * IV doesn't change HMAC, when we use encrypt-then-authenticate method.
108  */
109 static void
110 g_eli_auth_keygen(struct g_eli_softc *sc, off_t offset, u_char *key)
111 {
112 	SHA256_CTX ctx;
113 
114 	/* Copy precalculated SHA256 context. */
115 	bcopy(&sc->sc_akeyctx, &ctx, sizeof(ctx));
116 	SHA256_Update(&ctx, (uint8_t *)&offset, sizeof(offset));
117 	SHA256_Final(key, &ctx);
118 }
119 
120 /*
121  * The function is called after we read and decrypt data.
122  *
123  * 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
124  */
125 static int
126 g_eli_auth_read_done(struct cryptop *crp)
127 {
128 	struct g_eli_softc *sc;
129 	struct bio *bp;
130 
131 	if (crp->crp_etype == EAGAIN) {
132 		if (g_eli_crypto_rerun(crp) == 0)
133 			return (0);
134 	}
135 	bp = (struct bio *)crp->crp_opaque;
136 	bp->bio_inbed++;
137 	sc = bp->bio_to->geom->softc;
138 	if (crp->crp_etype == 0) {
139 		bp->bio_completed += crp->crp_payload_length;
140 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d) (add=%d completed=%jd).",
141 		    bp->bio_inbed, bp->bio_children, crp->crp_payload_length, (intmax_t)bp->bio_completed);
142 	} else {
143 		u_int nsec, decr_secsize, encr_secsize, rel_sec;
144 		int *errorp;
145 
146 		/* Sectorsize of decrypted provider eg. 4096. */
147 		decr_secsize = bp->bio_to->sectorsize;
148 		/* The real sectorsize of encrypted provider, eg. 512. */
149 		encr_secsize =
150 		    LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
151 		/* Number of sectors from decrypted provider, eg. 2. */
152 		nsec = bp->bio_length / decr_secsize;
153 		/* Number of sectors from encrypted provider, eg. 18. */
154 		nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
155 		/* Which relative sector this request decrypted. */
156 		rel_sec = ((crp->crp_buf.cb_buf + crp->crp_payload_start) -
157 		    (char *)bp->bio_driver2) / encr_secsize;
158 
159 		errorp = (int *)((char *)bp->bio_driver2 + encr_secsize * nsec +
160 		    sizeof(int) * rel_sec);
161 		*errorp = crp->crp_etype;
162 		G_ELI_DEBUG(1,
163 		    "Crypto READ request failed (%d/%d) error=%d.",
164 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
165 		if (bp->bio_error == 0 || bp->bio_error == EINTEGRITY)
166 			bp->bio_error = crp->crp_etype == EBADMSG ?
167 			    EINTEGRITY : crp->crp_etype;
168 	}
169 	if (crp->crp_cipher_key != NULL)
170 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
171 	crypto_freereq(crp);
172 	/*
173 	 * Do we have all sectors already?
174 	 */
175 	if (bp->bio_inbed < bp->bio_children)
176 		return (0);
177 
178 	if (bp->bio_error == 0) {
179 		u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
180 		u_char *srcdata, *dstdata;
181 
182 		/* Sectorsize of decrypted provider eg. 4096. */
183 		decr_secsize = bp->bio_to->sectorsize;
184 		/* The real sectorsize of encrypted provider, eg. 512. */
185 		encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
186 		/* Number of data bytes in one encrypted sector, eg. 480. */
187 		data_secsize = sc->sc_data_per_sector;
188 		/* Number of sectors from decrypted provider, eg. 2. */
189 		nsec = bp->bio_length / decr_secsize;
190 		/* Number of sectors from encrypted provider, eg. 18. */
191 		nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
192 		/* Last sector number in every big sector, eg. 9. */
193 		lsec = sc->sc_bytes_per_sector / encr_secsize;
194 
195 		srcdata = bp->bio_driver2;
196 		dstdata = bp->bio_data;
197 
198 		for (i = 1; i <= nsec; i++) {
199 			data_secsize = sc->sc_data_per_sector;
200 			if ((i % lsec) == 0)
201 				data_secsize = decr_secsize % data_secsize;
202 			bcopy(srcdata + sc->sc_alen, dstdata, data_secsize);
203 			srcdata += encr_secsize;
204 			dstdata += data_secsize;
205 		}
206 	} else if (bp->bio_error == EINTEGRITY) {
207 		u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
208 		int *errorp;
209 		off_t coroff, corsize, dstoff;
210 
211 		/* Sectorsize of decrypted provider eg. 4096. */
212 		decr_secsize = bp->bio_to->sectorsize;
213 		/* The real sectorsize of encrypted provider, eg. 512. */
214 		encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
215 		/* Number of data bytes in one encrypted sector, eg. 480. */
216 		data_secsize = sc->sc_data_per_sector;
217 		/* Number of sectors from decrypted provider, eg. 2. */
218 		nsec = bp->bio_length / decr_secsize;
219 		/* Number of sectors from encrypted provider, eg. 18. */
220 		nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
221 		/* Last sector number in every big sector, eg. 9. */
222 		lsec = sc->sc_bytes_per_sector / encr_secsize;
223 
224 		errorp = (int *)((char *)bp->bio_driver2 + encr_secsize * nsec);
225 		coroff = -1;
226 		corsize = 0;
227 		dstoff = bp->bio_offset;
228 
229 		for (i = 1; i <= nsec; i++) {
230 			data_secsize = sc->sc_data_per_sector;
231 			if ((i % lsec) == 0)
232 				data_secsize = decr_secsize % data_secsize;
233 			if (errorp[i - 1] == EBADMSG) {
234 				/*
235 				 * Corruption detected, remember the offset if
236 				 * this is the first corrupted sector and
237 				 * increase size.
238 				 */
239 				if (coroff == -1)
240 					coroff = dstoff;
241 				corsize += data_secsize;
242 			} else {
243 				/*
244 				 * No corruption, good.
245 				 * Report previous corruption if there was one.
246 				 */
247 				if (coroff != -1) {
248 					G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
249 					    "bytes of data at offset %jd.",
250 					    sc->sc_name, (intmax_t)corsize,
251 					    (intmax_t)coroff);
252 					coroff = -1;
253 					corsize = 0;
254 				}
255 			}
256 			dstoff += data_secsize;
257 		}
258 		/* Report previous corruption if there was one. */
259 		if (coroff != -1) {
260 			G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
261 			    "bytes of data at offset %jd.",
262 			    sc->sc_name, (intmax_t)corsize, (intmax_t)coroff);
263 		}
264 	}
265 	g_eli_free_data(bp);
266 	if (bp->bio_error != 0) {
267 		if (bp->bio_error != EINTEGRITY) {
268 			G_ELI_LOGREQ(0, bp,
269 			    "Crypto READ request failed (error=%d).",
270 			    bp->bio_error);
271 		}
272 		bp->bio_completed = 0;
273 	}
274 	/*
275 	 * Read is finished, send it up.
276 	 */
277 	g_io_deliver(bp, bp->bio_error);
278 	atomic_subtract_int(&sc->sc_inflight, 1);
279 	return (0);
280 }
281 
282 /*
283  * The function is called after data encryption.
284  *
285  * g_eli_start -> g_eli_auth_run -> G_ELI_AUTH_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
286  */
287 static int
288 g_eli_auth_write_done(struct cryptop *crp)
289 {
290 	struct g_eli_softc *sc;
291 	struct g_consumer *cp;
292 	struct bio *bp, *cbp, *cbp2;
293 	u_int nsec;
294 
295 	if (crp->crp_etype == EAGAIN) {
296 		if (g_eli_crypto_rerun(crp) == 0)
297 			return (0);
298 	}
299 	bp = (struct bio *)crp->crp_opaque;
300 	bp->bio_inbed++;
301 	if (crp->crp_etype == 0) {
302 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
303 		    bp->bio_inbed, bp->bio_children);
304 	} else {
305 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
306 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
307 		if (bp->bio_error == 0)
308 			bp->bio_error = crp->crp_etype;
309 	}
310 	sc = bp->bio_to->geom->softc;
311 	if (crp->crp_cipher_key != NULL)
312 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
313 	crypto_freereq(crp);
314 	/*
315 	 * All sectors are already encrypted?
316 	 */
317 	if (bp->bio_inbed < bp->bio_children)
318 		return (0);
319 	if (bp->bio_error != 0) {
320 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
321 		    bp->bio_error);
322 		g_eli_free_data(bp);
323 		cbp = bp->bio_driver1;
324 		bp->bio_driver1 = NULL;
325 		g_destroy_bio(cbp);
326 		g_io_deliver(bp, bp->bio_error);
327 		atomic_subtract_int(&sc->sc_inflight, 1);
328 		return (0);
329 	}
330 	cp = LIST_FIRST(&sc->sc_geom->consumer);
331 	cbp = bp->bio_driver1;
332 	bp->bio_driver1 = NULL;
333 	cbp->bio_to = cp->provider;
334 	cbp->bio_done = g_eli_write_done;
335 
336 	/* Number of sectors from decrypted provider, eg. 1. */
337 	nsec = bp->bio_length / bp->bio_to->sectorsize;
338 	/* Number of sectors from encrypted provider, eg. 9. */
339 	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;
340 
341 	cbp->bio_length = cp->provider->sectorsize * nsec;
342 	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
343 	cbp->bio_data = bp->bio_driver2;
344 
345 	/*
346 	 * We write more than what is requested, so we have to be ready to write
347 	 * more than maxphys.
348 	 */
349 	cbp2 = NULL;
350 	if (cbp->bio_length > maxphys) {
351 		cbp2 = g_duplicate_bio(bp);
352 		cbp2->bio_length = cbp->bio_length - maxphys;
353 		cbp2->bio_data = cbp->bio_data + maxphys;
354 		cbp2->bio_offset = cbp->bio_offset + maxphys;
355 		cbp2->bio_to = cp->provider;
356 		cbp2->bio_done = g_eli_write_done;
357 		cbp->bio_length = maxphys;
358 	}
359 	/*
360 	 * Send encrypted data to the provider.
361 	 */
362 	G_ELI_LOGREQ(2, cbp, "Sending request.");
363 	bp->bio_inbed = 0;
364 	bp->bio_children = (cbp2 != NULL ? 2 : 1);
365 	g_io_request(cbp, cp);
366 	if (cbp2 != NULL) {
367 		G_ELI_LOGREQ(2, cbp2, "Sending request.");
368 		g_io_request(cbp2, cp);
369 	}
370 	return (0);
371 }
372 
373 void
374 g_eli_auth_read(struct g_eli_softc *sc, struct bio *bp)
375 {
376 	struct g_consumer *cp;
377 	struct bio *cbp, *cbp2;
378 	size_t size;
379 	off_t nsec;
380 
381 	G_ELI_SETWORKER(bp->bio_pflags, 0);
382 
383 	cp = LIST_FIRST(&sc->sc_geom->consumer);
384 	cbp = bp->bio_driver1;
385 	bp->bio_driver1 = NULL;
386 	cbp->bio_to = cp->provider;
387 	cbp->bio_done = g_eli_read_done;
388 
389 	/* Number of sectors from decrypted provider, eg. 1. */
390 	nsec = bp->bio_length / bp->bio_to->sectorsize;
391 	/* Number of sectors from encrypted provider, eg. 9. */
392 	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;
393 
394 	cbp->bio_length = cp->provider->sectorsize * nsec;
395 	size = cbp->bio_length;
396 	size += sizeof(int) * nsec;
397 	size += G_ELI_AUTH_SECKEYLEN * nsec;
398 	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
399 	if (!g_eli_alloc_data(bp, size)) {
400 		G_ELI_LOGREQ(0, bp, "Crypto auth read request failed (ENOMEM)");
401 		g_destroy_bio(cbp);
402 		bp->bio_error = ENOMEM;
403 		g_io_deliver(bp, bp->bio_error);
404 		atomic_subtract_int(&sc->sc_inflight, 1);
405 		return;
406 	}
407 	cbp->bio_data = bp->bio_driver2;
408 
409 	/* Clear the error array. */
410 	memset((char *)bp->bio_driver2 + cbp->bio_length, 0,
411 	    sizeof(int) * nsec);
412 
413 	/*
414 	 * We read more than what is requested, so we have to be ready to read
415 	 * more than maxphys.
416 	 */
417 	cbp2 = NULL;
418 	if (cbp->bio_length > maxphys) {
419 		cbp2 = g_duplicate_bio(bp);
420 		cbp2->bio_length = cbp->bio_length - maxphys;
421 		cbp2->bio_data = cbp->bio_data + maxphys;
422 		cbp2->bio_offset = cbp->bio_offset + maxphys;
423 		cbp2->bio_to = cp->provider;
424 		cbp2->bio_done = g_eli_read_done;
425 		cbp->bio_length = maxphys;
426 	}
427 	/*
428 	 * Read encrypted data from provider.
429 	 */
430 	G_ELI_LOGREQ(2, cbp, "Sending request.");
431 	g_io_request(cbp, cp);
432 	if (cbp2 != NULL) {
433 		G_ELI_LOGREQ(2, cbp2, "Sending request.");
434 		g_io_request(cbp2, cp);
435 	}
436 }
437 
438 /*
439  * This is the main function responsible for cryptography (ie. communication
440  * with crypto(9) subsystem).
441  *
442  * BIO_READ:
443  *	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
444  * BIO_WRITE:
445  *	g_eli_start -> G_ELI_AUTH_RUN -> g_eli_auth_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
446  */
447 void
448 g_eli_auth_run(struct g_eli_worker *wr, struct bio *bp)
449 {
450 	struct g_eli_softc *sc;
451 	struct cryptopq crpq;
452 	struct cryptop *crp;
453 	u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
454 	off_t dstoff;
455 	u_char *p, *data, *authkey, *plaindata;
456 	int error __diagused;
457 	bool batch;
458 
459 	G_ELI_LOGREQ(3, bp, "%s", __func__);
460 
461 	G_ELI_SETWORKER(bp->bio_pflags, wr->w_number);
462 	sc = wr->w_softc;
463 	/* Sectorsize of decrypted provider eg. 4096. */
464 	decr_secsize = bp->bio_to->sectorsize;
465 	/* The real sectorsize of encrypted provider, eg. 512. */
466 	encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
467 	/* Number of data bytes in one encrypted sector, eg. 480. */
468 	data_secsize = sc->sc_data_per_sector;
469 	/* Number of sectors from decrypted provider, eg. 2. */
470 	nsec = bp->bio_length / decr_secsize;
471 	/* Number of sectors from encrypted provider, eg. 18. */
472 	nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
473 	/* Last sector number in every big sector, eg. 9. */
474 	lsec = sc->sc_bytes_per_sector / encr_secsize;
475 	/* Destination offset, used for IV generation. */
476 	dstoff = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
477 
478 	plaindata = bp->bio_data;
479 	if (bp->bio_cmd == BIO_READ) {
480 		data = bp->bio_driver2;
481 		p = data + encr_secsize * nsec;
482 		p += sizeof(int) * nsec;
483 	} else {
484 		size_t size;
485 
486 		size = encr_secsize * nsec;
487 		size += G_ELI_AUTH_SECKEYLEN * nsec;
488 		size += sizeof(uintptr_t);	/* Space for alignment. */
489 		if (!g_eli_alloc_data(bp, size)) {
490 			G_ELI_LOGREQ(0, bp, "Crypto request failed (ENOMEM)");
491 			if (bp->bio_driver1 != NULL) {
492 				g_destroy_bio(bp->bio_driver1);
493 				bp->bio_driver1 = NULL;
494 			}
495 			bp->bio_error = ENOMEM;
496 			g_io_deliver(bp, bp->bio_error);
497 			if (sc != NULL)
498 				atomic_subtract_int(&sc->sc_inflight, 1);
499 			return;
500 		}
501 		data = bp->bio_driver2;
502 		p = data + encr_secsize * nsec;
503 	}
504 	bp->bio_inbed = 0;
505 	bp->bio_children = nsec;
506 
507 #if defined(__mips_n64) || defined(__mips_o64)
508 	p = (char *)roundup((uintptr_t)p, sizeof(uintptr_t));
509 #endif
510 
511 	TAILQ_INIT(&crpq);
512 	batch = atomic_load_int(&g_eli_batch) != 0;
513 
514 	for (i = 1; i <= nsec; i++, dstoff += encr_secsize) {
515 		crp = crypto_getreq(wr->w_sid, M_WAITOK);
516 		authkey = (u_char *)p;		p += G_ELI_AUTH_SECKEYLEN;
517 
518 		data_secsize = sc->sc_data_per_sector;
519 		if ((i % lsec) == 0) {
520 			data_secsize = decr_secsize % data_secsize;
521 			/*
522 			 * Last encrypted sector of each decrypted sector is
523 			 * only partially filled.
524 			 */
525 			if (bp->bio_cmd == BIO_WRITE)
526 				memset(data + sc->sc_alen + data_secsize, 0,
527 				    encr_secsize - sc->sc_alen - data_secsize);
528 		} else if (data_secsize + sc->sc_alen != encr_secsize) {
529 			/*
530 			 * If the HMAC size is not a multiple of 128 bits, the
531 			 * per-sector data size is rounded down to ensure that
532 			 * encryption can be performed without requiring any
533 			 * padding.  In this case, each sector contains unused
534 			 * bytes.
535 			 */
536 			if (bp->bio_cmd == BIO_WRITE)
537 				memset(data + sc->sc_alen + data_secsize, 0,
538 				    encr_secsize - sc->sc_alen - data_secsize);
539 		}
540 
541 		if (bp->bio_cmd == BIO_WRITE) {
542 			bcopy(plaindata, data + sc->sc_alen, data_secsize);
543 			plaindata += data_secsize;
544 		}
545 
546 		crypto_use_buf(crp, data, sc->sc_alen + data_secsize);
547 		crp->crp_opaque = (void *)bp;
548 		data += encr_secsize;
549 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
550 		if (bp->bio_cmd == BIO_WRITE) {
551 			crp->crp_callback = g_eli_auth_write_done;
552 			crp->crp_op = CRYPTO_OP_ENCRYPT |
553 			    CRYPTO_OP_COMPUTE_DIGEST;
554 		} else {
555 			crp->crp_callback = g_eli_auth_read_done;
556 			crp->crp_op = CRYPTO_OP_DECRYPT |
557 			    CRYPTO_OP_VERIFY_DIGEST;
558 		}
559 
560 		crp->crp_digest_start = 0;
561 		crp->crp_payload_start = sc->sc_alen;
562 		crp->crp_payload_length = data_secsize;
563 		if ((sc->sc_flags & G_ELI_FLAG_FIRST_KEY) == 0) {
564 			crp->crp_cipher_key = g_eli_key_hold(sc, dstoff,
565 			    encr_secsize);
566 		}
567 		if (g_eli_ivlen(sc->sc_ealgo) != 0) {
568 			crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
569 			g_eli_crypto_ivgen(sc, dstoff, crp->crp_iv,
570 			    sizeof(crp->crp_iv));
571 		}
572 
573 		g_eli_auth_keygen(sc, dstoff, authkey);
574 		crp->crp_auth_key = authkey;
575 
576 		if (batch) {
577 			TAILQ_INSERT_TAIL(&crpq, crp, crp_next);
578 		} else {
579 			error = crypto_dispatch(crp);
580 			KASSERT(error == 0,
581 			    ("crypto_dispatch() failed (error=%d)", error));
582 		}
583 	}
584 
585 	if (batch)
586 		crypto_dispatch_batch(&crpq, 0);
587 }
588