xref: /freebsd/sys/opencrypto/ktls_ocf.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Netflix Inc.
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 AUTHOR 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 REGENTS 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/counter.h>
35 #include <sys/endian.h>
36 #include <sys/kernel.h>
37 #include <sys/ktls.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/sysctl.h>
44 #include <sys/uio.h>
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_param.h>
48 #include <opencrypto/cryptodev.h>
49 
50 struct ocf_session {
51 	crypto_session_t sid;
52 	crypto_session_t mac_sid;
53 	struct mtx lock;
54 	int mac_len;
55 	bool implicit_iv;
56 
57 	/* Only used for TLS 1.0 with the implicit IV. */
58 #ifdef INVARIANTS
59 	bool in_progress;
60 	uint64_t next_seqno;
61 #endif
62 	char iv[AES_BLOCK_LEN];
63 };
64 
65 struct ocf_operation {
66 	struct ocf_session *os;
67 	bool done;
68 };
69 
70 static MALLOC_DEFINE(M_KTLS_OCF, "ktls_ocf", "OCF KTLS");
71 
72 SYSCTL_DECL(_kern_ipc_tls);
73 SYSCTL_DECL(_kern_ipc_tls_stats);
74 
75 static SYSCTL_NODE(_kern_ipc_tls_stats, OID_AUTO, ocf,
76     CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
77     "Kernel TLS offload via OCF stats");
78 
79 static COUNTER_U64_DEFINE_EARLY(ocf_tls10_cbc_crypts);
80 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls10_cbc_crypts,
81     CTLFLAG_RD, &ocf_tls10_cbc_crypts,
82     "Total number of OCF TLS 1.0 CBC encryption operations");
83 
84 static COUNTER_U64_DEFINE_EARLY(ocf_tls11_cbc_crypts);
85 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls11_cbc_crypts,
86     CTLFLAG_RD, &ocf_tls11_cbc_crypts,
87     "Total number of OCF TLS 1.1/1.2 CBC encryption operations");
88 
89 static COUNTER_U64_DEFINE_EARLY(ocf_tls12_gcm_crypts);
90 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls12_gcm_crypts,
91     CTLFLAG_RD, &ocf_tls12_gcm_crypts,
92     "Total number of OCF TLS 1.2 GCM encryption operations");
93 
94 static COUNTER_U64_DEFINE_EARLY(ocf_tls12_chacha20_crypts);
95 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls12_chacha20_crypts,
96     CTLFLAG_RD, &ocf_tls12_chacha20_crypts,
97     "Total number of OCF TLS 1.2 Chacha20-Poly1305 encryption operations");
98 
99 static COUNTER_U64_DEFINE_EARLY(ocf_tls13_gcm_crypts);
100 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls13_gcm_crypts,
101     CTLFLAG_RD, &ocf_tls13_gcm_crypts,
102     "Total number of OCF TLS 1.3 GCM encryption operations");
103 
104 static COUNTER_U64_DEFINE_EARLY(ocf_tls13_chacha20_crypts);
105 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls13_chacha20_crypts,
106     CTLFLAG_RD, &ocf_tls13_chacha20_crypts,
107     "Total number of OCF TLS 1.3 Chacha20-Poly1305 encryption operations");
108 
109 static COUNTER_U64_DEFINE_EARLY(ocf_inplace);
110 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, inplace,
111     CTLFLAG_RD, &ocf_inplace,
112     "Total number of OCF in-place operations");
113 
114 static COUNTER_U64_DEFINE_EARLY(ocf_separate_output);
115 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, separate_output,
116     CTLFLAG_RD, &ocf_separate_output,
117     "Total number of OCF operations with a separate output buffer");
118 
119 static COUNTER_U64_DEFINE_EARLY(ocf_retries);
120 SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, retries, CTLFLAG_RD,
121     &ocf_retries,
122     "Number of OCF encryption operation retries");
123 
124 static int
125 ktls_ocf_callback_sync(struct cryptop *crp __unused)
126 {
127 	return (0);
128 }
129 
130 static int
131 ktls_ocf_callback_async(struct cryptop *crp)
132 {
133 	struct ocf_operation *oo;
134 
135 	oo = crp->crp_opaque;
136 	mtx_lock(&oo->os->lock);
137 	oo->done = true;
138 	mtx_unlock(&oo->os->lock);
139 	wakeup(oo);
140 	return (0);
141 }
142 
143 static int
144 ktls_ocf_dispatch(struct ocf_session *os, struct cryptop *crp)
145 {
146 	struct ocf_operation oo;
147 	int error;
148 	bool async;
149 
150 	oo.os = os;
151 	oo.done = false;
152 
153 	crp->crp_opaque = &oo;
154 	for (;;) {
155 		async = !CRYPTO_SESS_SYNC(crp->crp_session);
156 		crp->crp_callback = async ? ktls_ocf_callback_async :
157 		    ktls_ocf_callback_sync;
158 
159 		error = crypto_dispatch(crp);
160 		if (error)
161 			break;
162 		if (async) {
163 			mtx_lock(&os->lock);
164 			while (!oo.done)
165 				mtx_sleep(&oo, &os->lock, 0, "ocfktls", 0);
166 			mtx_unlock(&os->lock);
167 		}
168 
169 		if (crp->crp_etype != EAGAIN) {
170 			error = crp->crp_etype;
171 			break;
172 		}
173 
174 		crp->crp_etype = 0;
175 		crp->crp_flags &= ~CRYPTO_F_DONE;
176 		oo.done = false;
177 		counter_u64_add(ocf_retries, 1);
178 	}
179 	return (error);
180 }
181 
182 static int
183 ktls_ocf_tls_cbc_encrypt(struct ktls_session *tls, struct mbuf *m,
184     struct iovec *outiov, int outiovcnt)
185 {
186 	const struct tls_record_layer *hdr;
187 	struct uio uio;
188 	struct tls_mac_data ad;
189 	struct cryptop crp;
190 	struct ocf_session *os;
191 	struct iovec iov[m->m_epg_npgs + 2];
192 	u_int pgoff;
193 	int i, error;
194 	uint16_t tls_comp_len;
195 	uint8_t pad;
196 
197 	MPASS(outiovcnt + 1 <= nitems(iov));
198 
199 	os = tls->cipher;
200 	hdr = (const struct tls_record_layer *)m->m_epg_hdr;
201 
202 #ifdef INVARIANTS
203 	if (os->implicit_iv) {
204 		mtx_lock(&os->lock);
205 		KASSERT(!os->in_progress,
206 		    ("concurrent implicit IV encryptions"));
207 		if (os->next_seqno != m->m_epg_seqno) {
208 			printf("KTLS CBC: TLS records out of order.  "
209 			    "Expected %ju, got %ju\n",
210 			    (uintmax_t)os->next_seqno,
211 			    (uintmax_t)m->m_epg_seqno);
212 			mtx_unlock(&os->lock);
213 			return (EINVAL);
214 		}
215 		os->in_progress = true;
216 		mtx_unlock(&os->lock);
217 	}
218 #endif
219 
220 	/* Payload length. */
221 	tls_comp_len = m->m_len - (m->m_epg_hdrlen + m->m_epg_trllen);
222 
223 	/* Initialize the AAD. */
224 	ad.seq = htobe64(m->m_epg_seqno);
225 	ad.type = hdr->tls_type;
226 	ad.tls_vmajor = hdr->tls_vmajor;
227 	ad.tls_vminor = hdr->tls_vminor;
228 	ad.tls_length = htons(tls_comp_len);
229 
230 	/* First, compute the MAC. */
231 	iov[0].iov_base = &ad;
232 	iov[0].iov_len = sizeof(ad);
233 	pgoff = m->m_epg_1st_off;
234 	for (i = 0; i < m->m_epg_npgs; i++, pgoff = 0) {
235 		iov[i + 1].iov_base = (void *)PHYS_TO_DMAP(m->m_epg_pa[i] +
236 		    pgoff);
237 		iov[i + 1].iov_len = m_epg_pagelen(m, i, pgoff);
238 	}
239 	iov[m->m_epg_npgs + 1].iov_base = m->m_epg_trail;
240 	iov[m->m_epg_npgs + 1].iov_len = os->mac_len;
241 	uio.uio_iov = iov;
242 	uio.uio_iovcnt = m->m_epg_npgs + 2;
243 	uio.uio_offset = 0;
244 	uio.uio_segflg = UIO_SYSSPACE;
245 	uio.uio_td = curthread;
246 	uio.uio_resid = sizeof(ad) + tls_comp_len + os->mac_len;
247 
248 	crypto_initreq(&crp, os->mac_sid);
249 	crp.crp_payload_start = 0;
250 	crp.crp_payload_length = sizeof(ad) + tls_comp_len;
251 	crp.crp_digest_start = crp.crp_payload_length;
252 	crp.crp_op = CRYPTO_OP_COMPUTE_DIGEST;
253 	crp.crp_flags = CRYPTO_F_CBIMM;
254 	crypto_use_uio(&crp, &uio);
255 	error = ktls_ocf_dispatch(os, &crp);
256 
257 	crypto_destroyreq(&crp);
258 	if (error) {
259 #ifdef INVARIANTS
260 		if (os->implicit_iv) {
261 			mtx_lock(&os->lock);
262 			os->in_progress = false;
263 			mtx_unlock(&os->lock);
264 		}
265 #endif
266 		return (error);
267 	}
268 
269 	/* Second, add the padding. */
270 	pad = m->m_epg_trllen - os->mac_len - 1;
271 	for (i = 0; i < pad + 1; i++)
272 		m->m_epg_trail[os->mac_len + i] = pad;
273 
274 	/* Finally, encrypt the record. */
275 	crypto_initreq(&crp, os->sid);
276 	crp.crp_payload_start = m->m_epg_hdrlen;
277 	crp.crp_payload_length = tls_comp_len + m->m_epg_trllen;
278 	KASSERT(crp.crp_payload_length % AES_BLOCK_LEN == 0,
279 	    ("invalid encryption size"));
280 	crypto_use_single_mbuf(&crp, m);
281 	crp.crp_op = CRYPTO_OP_ENCRYPT;
282 	crp.crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
283 	if (os->implicit_iv)
284 		memcpy(crp.crp_iv, os->iv, AES_BLOCK_LEN);
285 	else
286 		memcpy(crp.crp_iv, hdr + 1, AES_BLOCK_LEN);
287 
288 	if (outiov != NULL) {
289 		uio.uio_iov = outiov;
290 		uio.uio_iovcnt = outiovcnt;
291 		uio.uio_offset = 0;
292 		uio.uio_segflg = UIO_SYSSPACE;
293 		uio.uio_td = curthread;
294 		uio.uio_resid = crp.crp_payload_length;
295 		crypto_use_output_uio(&crp, &uio);
296 	}
297 
298 	if (os->implicit_iv)
299 		counter_u64_add(ocf_tls10_cbc_crypts, 1);
300 	else
301 		counter_u64_add(ocf_tls11_cbc_crypts, 1);
302 	if (outiov != NULL)
303 		counter_u64_add(ocf_separate_output, 1);
304 	else
305 		counter_u64_add(ocf_inplace, 1);
306 	error = ktls_ocf_dispatch(os, &crp);
307 
308 	crypto_destroyreq(&crp);
309 
310 	if (os->implicit_iv) {
311 		KASSERT(os->mac_len + pad + 1 >= AES_BLOCK_LEN,
312 		    ("trailer too short to read IV"));
313 		memcpy(os->iv, m->m_epg_trail + m->m_epg_trllen - AES_BLOCK_LEN,
314 		    AES_BLOCK_LEN);
315 #ifdef INVARIANTS
316 		mtx_lock(&os->lock);
317 		os->next_seqno = m->m_epg_seqno + 1;
318 		os->in_progress = false;
319 		mtx_unlock(&os->lock);
320 #endif
321 	}
322 	return (error);
323 }
324 
325 static int
326 ktls_ocf_tls12_aead_encrypt(struct ktls_session *tls, struct mbuf *m,
327     struct iovec *outiov, int outiovcnt)
328 {
329 	const struct tls_record_layer *hdr;
330 	struct uio uio;
331 	struct tls_aead_data ad;
332 	struct cryptop crp;
333 	struct ocf_session *os;
334 	int error;
335 	uint16_t tls_comp_len;
336 
337 	os = tls->cipher;
338 	hdr = (const struct tls_record_layer *)m->m_epg_hdr;
339 
340 	crypto_initreq(&crp, os->sid);
341 
342 	/* Setup the IV. */
343 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16) {
344 		memcpy(crp.crp_iv, tls->params.iv, TLS_AEAD_GCM_LEN);
345 		memcpy(crp.crp_iv + TLS_AEAD_GCM_LEN, hdr + 1,
346 		    sizeof(uint64_t));
347 	} else {
348 		/*
349 		 * Chacha20-Poly1305 constructs the IV for TLS 1.2
350 		 * identically to constructing the IV for AEAD in TLS
351 		 * 1.3.
352 		 */
353 		memcpy(crp.crp_iv, tls->params.iv, tls->params.iv_len);
354 		*(uint64_t *)(crp.crp_iv + 4) ^= htobe64(m->m_epg_seqno);
355 	}
356 
357 	/* Setup the AAD. */
358 	tls_comp_len = m->m_len - (m->m_epg_hdrlen + m->m_epg_trllen);
359 	ad.seq = htobe64(m->m_epg_seqno);
360 	ad.type = hdr->tls_type;
361 	ad.tls_vmajor = hdr->tls_vmajor;
362 	ad.tls_vminor = hdr->tls_vminor;
363 	ad.tls_length = htons(tls_comp_len);
364 	crp.crp_aad = &ad;
365 	crp.crp_aad_length = sizeof(ad);
366 
367 	/* Set fields for input payload. */
368 	crypto_use_single_mbuf(&crp, m);
369 	crp.crp_payload_start = m->m_epg_hdrlen;
370 	crp.crp_payload_length = tls_comp_len;
371 
372 	if (outiov != NULL) {
373 		crp.crp_digest_start = crp.crp_payload_length;
374 
375 		uio.uio_iov = outiov;
376 		uio.uio_iovcnt = outiovcnt;
377 		uio.uio_offset = 0;
378 		uio.uio_segflg = UIO_SYSSPACE;
379 		uio.uio_td = curthread;
380 		uio.uio_resid = crp.crp_payload_length + tls->params.tls_tlen;
381 		crypto_use_output_uio(&crp, &uio);
382 	} else
383 		crp.crp_digest_start = crp.crp_payload_start +
384 		    crp.crp_payload_length;
385 
386 	crp.crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
387 	crp.crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
388 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16)
389 		counter_u64_add(ocf_tls12_gcm_crypts, 1);
390 	else
391 		counter_u64_add(ocf_tls12_chacha20_crypts, 1);
392 	if (outiov != NULL)
393 		counter_u64_add(ocf_separate_output, 1);
394 	else
395 		counter_u64_add(ocf_inplace, 1);
396 	error = ktls_ocf_dispatch(os, &crp);
397 
398 	crypto_destroyreq(&crp);
399 	return (error);
400 }
401 
402 static int
403 ktls_ocf_tls12_aead_decrypt(struct ktls_session *tls,
404     const struct tls_record_layer *hdr, struct mbuf *m, uint64_t seqno,
405     int *trailer_len)
406 {
407 	struct tls_aead_data ad;
408 	struct cryptop crp;
409 	struct ocf_session *os;
410 	struct ocf_operation oo;
411 	int error;
412 	uint16_t tls_comp_len;
413 
414 	os = tls->cipher;
415 
416 	oo.os = os;
417 	oo.done = false;
418 
419 	crypto_initreq(&crp, os->sid);
420 
421 	/* Setup the IV. */
422 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16) {
423 		memcpy(crp.crp_iv, tls->params.iv, TLS_AEAD_GCM_LEN);
424 		memcpy(crp.crp_iv + TLS_AEAD_GCM_LEN, hdr + 1,
425 		    sizeof(uint64_t));
426 	} else {
427 		/*
428 		 * Chacha20-Poly1305 constructs the IV for TLS 1.2
429 		 * identically to constructing the IV for AEAD in TLS
430 		 * 1.3.
431 		 */
432 		memcpy(crp.crp_iv, tls->params.iv, tls->params.iv_len);
433 		*(uint64_t *)(crp.crp_iv + 4) ^= htobe64(seqno);
434 	}
435 
436 	/* Setup the AAD. */
437 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16)
438 		tls_comp_len = ntohs(hdr->tls_length) -
439 		    (AES_GMAC_HASH_LEN + sizeof(uint64_t));
440 	else
441 		tls_comp_len = ntohs(hdr->tls_length) - POLY1305_HASH_LEN;
442 	ad.seq = htobe64(seqno);
443 	ad.type = hdr->tls_type;
444 	ad.tls_vmajor = hdr->tls_vmajor;
445 	ad.tls_vminor = hdr->tls_vminor;
446 	ad.tls_length = htons(tls_comp_len);
447 	crp.crp_aad = &ad;
448 	crp.crp_aad_length = sizeof(ad);
449 
450 	crp.crp_payload_start = tls->params.tls_hlen;
451 	crp.crp_payload_length = tls_comp_len;
452 	crp.crp_digest_start = crp.crp_payload_start + crp.crp_payload_length;
453 
454 	crp.crp_op = CRYPTO_OP_DECRYPT | CRYPTO_OP_VERIFY_DIGEST;
455 	crp.crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
456 	crypto_use_mbuf(&crp, m);
457 
458 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16)
459 		counter_u64_add(ocf_tls12_gcm_crypts, 1);
460 	else
461 		counter_u64_add(ocf_tls12_chacha20_crypts, 1);
462 	error = ktls_ocf_dispatch(os, &crp);
463 
464 	crypto_destroyreq(&crp);
465 	*trailer_len = tls->params.tls_tlen;
466 	return (error);
467 }
468 
469 static int
470 ktls_ocf_tls13_aead_encrypt(struct ktls_session *tls, struct mbuf *m,
471     struct iovec *outiov, int outiovcnt)
472 {
473 	const struct tls_record_layer *hdr;
474 	struct uio uio;
475 	struct tls_aead_data_13 ad;
476 	char nonce[12];
477 	struct cryptop crp;
478 	struct ocf_session *os;
479 	int error;
480 
481 	os = tls->cipher;
482 	hdr = (const struct tls_record_layer *)m->m_epg_hdr;
483 
484 	crypto_initreq(&crp, os->sid);
485 
486 	/* Setup the nonce. */
487 	memcpy(nonce, tls->params.iv, tls->params.iv_len);
488 	*(uint64_t *)(nonce + 4) ^= htobe64(m->m_epg_seqno);
489 
490 	/* Setup the AAD. */
491 	ad.type = hdr->tls_type;
492 	ad.tls_vmajor = hdr->tls_vmajor;
493 	ad.tls_vminor = hdr->tls_vminor;
494 	ad.tls_length = hdr->tls_length;
495 	crp.crp_aad = &ad;
496 	crp.crp_aad_length = sizeof(ad);
497 
498 	/* Set fields for input payload. */
499 	crypto_use_single_mbuf(&crp, m);
500 	crp.crp_payload_start = m->m_epg_hdrlen;
501 	crp.crp_payload_length = m->m_len - (m->m_epg_hdrlen + m->m_epg_trllen);
502 
503 	/* Store the record type as the first byte of the trailer. */
504 	m->m_epg_trail[0] = m->m_epg_record_type;
505 	crp.crp_payload_length++;
506 
507 	if (outiov != NULL) {
508 		crp.crp_digest_start = crp.crp_payload_length;
509 
510 		uio.uio_iov = outiov;
511 		uio.uio_iovcnt = outiovcnt;
512 		uio.uio_offset = 0;
513 		uio.uio_segflg = UIO_SYSSPACE;
514 		uio.uio_td = curthread;
515 		uio.uio_resid = m->m_len - m->m_epg_hdrlen;
516 		crypto_use_output_uio(&crp, &uio);
517 	} else
518 		crp.crp_digest_start = crp.crp_payload_start +
519 		    crp.crp_payload_length;
520 
521 	crp.crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
522 	crp.crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
523 
524 	memcpy(crp.crp_iv, nonce, sizeof(nonce));
525 
526 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16)
527 		counter_u64_add(ocf_tls13_gcm_crypts, 1);
528 	else
529 		counter_u64_add(ocf_tls13_chacha20_crypts, 1);
530 	if (outiov != NULL)
531 		counter_u64_add(ocf_separate_output, 1);
532 	else
533 		counter_u64_add(ocf_inplace, 1);
534 	error = ktls_ocf_dispatch(os, &crp);
535 
536 	crypto_destroyreq(&crp);
537 	return (error);
538 }
539 
540 void
541 ktls_ocf_free(struct ktls_session *tls)
542 {
543 	struct ocf_session *os;
544 
545 	os = tls->cipher;
546 	crypto_freesession(os->sid);
547 	mtx_destroy(&os->lock);
548 	zfree(os, M_KTLS_OCF);
549 }
550 
551 int
552 ktls_ocf_try(struct socket *so, struct ktls_session *tls, int direction)
553 {
554 	struct crypto_session_params csp, mac_csp;
555 	struct ocf_session *os;
556 	int error, mac_len;
557 
558 	memset(&csp, 0, sizeof(csp));
559 	memset(&mac_csp, 0, sizeof(mac_csp));
560 	mac_csp.csp_mode = CSP_MODE_NONE;
561 	mac_len = 0;
562 
563 	switch (tls->params.cipher_algorithm) {
564 	case CRYPTO_AES_NIST_GCM_16:
565 		switch (tls->params.cipher_key_len) {
566 		case 128 / 8:
567 		case 256 / 8:
568 			break;
569 		default:
570 			return (EINVAL);
571 		}
572 
573 		/* Only TLS 1.2 and 1.3 are supported. */
574 		if (tls->params.tls_vmajor != TLS_MAJOR_VER_ONE ||
575 		    tls->params.tls_vminor < TLS_MINOR_VER_TWO ||
576 		    tls->params.tls_vminor > TLS_MINOR_VER_THREE)
577 			return (EPROTONOSUPPORT);
578 
579 		/* TLS 1.3 is not yet supported for receive. */
580 		if (direction == KTLS_RX &&
581 		    tls->params.tls_vminor == TLS_MINOR_VER_THREE)
582 			return (EPROTONOSUPPORT);
583 
584 		csp.csp_flags |= CSP_F_SEPARATE_OUTPUT | CSP_F_SEPARATE_AAD;
585 		csp.csp_mode = CSP_MODE_AEAD;
586 		csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
587 		csp.csp_cipher_key = tls->params.cipher_key;
588 		csp.csp_cipher_klen = tls->params.cipher_key_len;
589 		csp.csp_ivlen = AES_GCM_IV_LEN;
590 		break;
591 	case CRYPTO_AES_CBC:
592 		switch (tls->params.cipher_key_len) {
593 		case 128 / 8:
594 		case 256 / 8:
595 			break;
596 		default:
597 			return (EINVAL);
598 		}
599 
600 		switch (tls->params.auth_algorithm) {
601 		case CRYPTO_SHA1_HMAC:
602 			mac_len = SHA1_HASH_LEN;
603 			break;
604 		case CRYPTO_SHA2_256_HMAC:
605 			mac_len = SHA2_256_HASH_LEN;
606 			break;
607 		case CRYPTO_SHA2_384_HMAC:
608 			mac_len = SHA2_384_HASH_LEN;
609 			break;
610 		default:
611 			return (EINVAL);
612 		}
613 
614 		/* Only TLS 1.0-1.2 are supported. */
615 		if (tls->params.tls_vmajor != TLS_MAJOR_VER_ONE ||
616 		    tls->params.tls_vminor < TLS_MINOR_VER_ZERO ||
617 		    tls->params.tls_vminor > TLS_MINOR_VER_TWO)
618 			return (EPROTONOSUPPORT);
619 
620 		/* AES-CBC is not supported for receive. */
621 		if (direction == KTLS_RX)
622 			return (EPROTONOSUPPORT);
623 
624 		csp.csp_flags |= CSP_F_SEPARATE_OUTPUT;
625 		csp.csp_mode = CSP_MODE_CIPHER;
626 		csp.csp_cipher_alg = CRYPTO_AES_CBC;
627 		csp.csp_cipher_key = tls->params.cipher_key;
628 		csp.csp_cipher_klen = tls->params.cipher_key_len;
629 		csp.csp_ivlen = AES_BLOCK_LEN;
630 
631 		mac_csp.csp_flags |= CSP_F_SEPARATE_OUTPUT;
632 		mac_csp.csp_mode = CSP_MODE_DIGEST;
633 		mac_csp.csp_auth_alg = tls->params.auth_algorithm;
634 		mac_csp.csp_auth_key = tls->params.auth_key;
635 		mac_csp.csp_auth_klen = tls->params.auth_key_len;
636 		break;
637 	case CRYPTO_CHACHA20_POLY1305:
638 		switch (tls->params.cipher_key_len) {
639 		case 256 / 8:
640 			break;
641 		default:
642 			return (EINVAL);
643 		}
644 
645 		/* Only TLS 1.2 and 1.3 are supported. */
646 		if (tls->params.tls_vmajor != TLS_MAJOR_VER_ONE ||
647 		    tls->params.tls_vminor < TLS_MINOR_VER_TWO ||
648 		    tls->params.tls_vminor > TLS_MINOR_VER_THREE)
649 			return (EPROTONOSUPPORT);
650 
651 		/* TLS 1.3 is not yet supported for receive. */
652 		if (direction == KTLS_RX &&
653 		    tls->params.tls_vminor == TLS_MINOR_VER_THREE)
654 			return (EPROTONOSUPPORT);
655 
656 		csp.csp_flags |= CSP_F_SEPARATE_OUTPUT | CSP_F_SEPARATE_AAD;
657 		csp.csp_mode = CSP_MODE_AEAD;
658 		csp.csp_cipher_alg = CRYPTO_CHACHA20_POLY1305;
659 		csp.csp_cipher_key = tls->params.cipher_key;
660 		csp.csp_cipher_klen = tls->params.cipher_key_len;
661 		csp.csp_ivlen = CHACHA20_POLY1305_IV_LEN;
662 		break;
663 	default:
664 		return (EPROTONOSUPPORT);
665 	}
666 
667 	os = malloc(sizeof(*os), M_KTLS_OCF, M_NOWAIT | M_ZERO);
668 	if (os == NULL)
669 		return (ENOMEM);
670 
671 	error = crypto_newsession(&os->sid, &csp,
672 	    CRYPTO_FLAG_HARDWARE | CRYPTO_FLAG_SOFTWARE);
673 	if (error) {
674 		free(os, M_KTLS_OCF);
675 		return (error);
676 	}
677 
678 	if (mac_csp.csp_mode != CSP_MODE_NONE) {
679 		error = crypto_newsession(&os->mac_sid, &mac_csp,
680 		    CRYPTO_FLAG_HARDWARE | CRYPTO_FLAG_SOFTWARE);
681 		if (error) {
682 			crypto_freesession(os->sid);
683 			free(os, M_KTLS_OCF);
684 			return (error);
685 		}
686 		os->mac_len = mac_len;
687 	}
688 
689 	mtx_init(&os->lock, "ktls_ocf", NULL, MTX_DEF);
690 	tls->cipher = os;
691 	if (tls->params.cipher_algorithm == CRYPTO_AES_NIST_GCM_16 ||
692 	    tls->params.cipher_algorithm == CRYPTO_CHACHA20_POLY1305) {
693 		if (direction == KTLS_TX) {
694 			if (tls->params.tls_vminor == TLS_MINOR_VER_THREE)
695 				tls->sw_encrypt = ktls_ocf_tls13_aead_encrypt;
696 			else
697 				tls->sw_encrypt = ktls_ocf_tls12_aead_encrypt;
698 		} else {
699 			tls->sw_decrypt = ktls_ocf_tls12_aead_decrypt;
700 		}
701 	} else {
702 		tls->sw_encrypt = ktls_ocf_tls_cbc_encrypt;
703 		if (tls->params.tls_vminor == TLS_MINOR_VER_ZERO) {
704 			os->implicit_iv = true;
705 			memcpy(os->iv, tls->params.iv, AES_BLOCK_LEN);
706 		}
707 	}
708 	return (0);
709 }
710