2 * esp_decrypt.c : IPSec ESP Decrypt node using DPDK Cryptodev
4 * Copyright (c) 2017 Intel and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a opy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include <vnet/vnet.h>
19 #include <vnet/api_errno.h>
20 #include <vnet/ip/ip.h>
22 #include <vnet/ipsec/ipsec.h>
23 #include <vnet/ipsec/esp.h>
24 #include <dpdk/buffer.h>
25 #include <dpdk/ipsec/ipsec.h>
26 #include <dpdk/device/dpdk.h>
27 #include <dpdk/device/dpdk_priv.h>
29 #define foreach_esp_decrypt_next \
30 _(DROP, "error-drop") \
31 _(IP4_INPUT, "ip4-input-no-checksum") \
32 _(IP6_INPUT, "ip6-input")
34 #define _(v, s) ESP_DECRYPT_NEXT_##v,
37 foreach_esp_decrypt_next
42 #define foreach_esp_decrypt_error \
43 _(RX_PKTS, "ESP pkts received") \
44 _(DECRYPTION_FAILED, "ESP decryption failed") \
45 _(REPLAY, "SA replayed packet") \
46 _(NOT_IP, "Not IP packet (dropped)") \
47 _(ENQ_FAIL, "Enqueue failed (buffer full)") \
48 _(DISCARD, "Not enough crypto operations, discarding frame") \
49 _(BAD_LEN, "Invalid ciphertext length") \
50 _(SESSION, "Failed to get crypto session") \
51 _(NOSUP, "Cipher/Auth not supported")
56 #define _(sym,str) ESP_DECRYPT_ERROR_##sym,
57 foreach_esp_decrypt_error
60 } esp_decrypt_error_t;
62 static char *esp_decrypt_error_strings[] = {
63 #define _(sym,string) string,
64 foreach_esp_decrypt_error
68 extern vlib_node_registration_t dpdk_esp4_decrypt_node;
69 extern vlib_node_registration_t dpdk_esp6_decrypt_node;
73 ipsec_crypto_alg_t crypto_alg;
74 ipsec_integ_alg_t integ_alg;
76 } esp_decrypt_trace_t;
78 /* packet trace format function */
80 format_esp_decrypt_trace (u8 * s, va_list * args)
82 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
83 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
84 esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *);
85 u32 indent = format_get_indent (s);
87 s = format (s, "cipher %U auth %U\n",
88 format_ipsec_crypto_alg, t->crypto_alg,
89 format_ipsec_integ_alg, t->integ_alg);
90 s = format (s, "%U%U",
91 format_white_space, indent, format_esp_header, t->packet_data);
96 dpdk_esp_decrypt_inline (vlib_main_t * vm,
97 vlib_node_runtime_t * node,
98 vlib_frame_t * from_frame, int is_ip6)
100 u32 n_left_from, *from, *to_next, next_index, thread_index;
101 ipsec_main_t *im = &ipsec_main;
102 u32 thread_idx = vlib_get_thread_index ();
103 dpdk_crypto_main_t *dcm = &dpdk_crypto_main;
104 crypto_resource_t *res = 0;
106 crypto_alg_t *cipher_alg = 0, *auth_alg = 0;
107 struct rte_cryptodev_sym_session *session = 0;
108 u32 ret, last_sa_index = ~0;
109 u8 numa = rte_socket_id ();
111 crypto_worker_main_t *cwm =
112 vec_elt_at_index (dcm->workers_main, thread_idx);
113 struct rte_crypto_op **ops = cwm->ops;
115 from = vlib_frame_vector_args (from_frame);
116 n_left_from = from_frame->n_vectors;
117 thread_index = vm->thread_index;
119 ret = crypto_alloc_ops (numa, ops, n_left_from);
123 vlib_node_increment_counter (vm, dpdk_esp6_decrypt_node.index,
124 ESP_DECRYPT_ERROR_DISCARD, 1);
126 vlib_node_increment_counter (vm, dpdk_esp4_decrypt_node.index,
127 ESP_DECRYPT_ERROR_DISCARD, 1);
128 /* Discard whole frame */
132 next_index = ESP_DECRYPT_NEXT_DROP;
134 while (n_left_from > 0)
138 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
140 while (n_left_from > 0 && n_left_to_next > 0)
143 u32 bi0, sa_index0, iv_size;
147 struct rte_mbuf *mb0;
148 struct rte_crypto_op *op;
155 b0 = vlib_get_buffer (vm, bi0);
156 mb0 = rte_mbuf_from_vlib_buffer (b0);
157 esp0 = vlib_buffer_get_current (b0);
160 CLIB_PREFETCH (esp0, sizeof (esp0[0]) + 16, LOAD);
162 CLIB_PREFETCH (mb0, CLIB_CACHE_LINE_BYTES, STORE);
166 ASSERT (op->status == RTE_CRYPTO_OP_STATUS_NOT_PROCESSED);
168 dpdk_op_priv_t *priv = crypto_op_get_priv (op);
169 /* store bi in op private */
174 sizeof (op[0]) + sizeof (op[0].sym[0]) + sizeof (priv[0]);
175 CLIB_PREFETCH (op, op_len, STORE);
177 sa_index0 = vnet_buffer (b0)->ipsec.sad_index;
178 vlib_prefetch_combined_counter (&ipsec_sa_counters,
179 thread_index, sa_index0);
181 if (sa_index0 != last_sa_index)
183 sa0 = pool_elt_at_index (im->sad, sa_index0);
186 vec_elt_at_index (dcm->cipher_algs, sa0->crypto_alg);
187 auth_alg = vec_elt_at_index (dcm->auth_algs, sa0->integ_alg);
189 is_aead = (cipher_alg->type == RTE_CRYPTO_SYM_XFORM_AEAD);
191 auth_alg = cipher_alg;
193 res_idx = get_resource (cwm, sa0);
195 if (PREDICT_FALSE (res_idx == (u16) ~ 0))
197 clib_warning ("unsupported SA by thread index %u",
200 vlib_node_increment_counter (vm,
201 dpdk_esp6_decrypt_node.index,
202 ESP_DECRYPT_ERROR_NOSUP, 1);
204 vlib_node_increment_counter (vm,
205 dpdk_esp4_decrypt_node.index,
206 ESP_DECRYPT_ERROR_NOSUP, 1);
212 res = vec_elt_at_index (dcm->resource, res_idx);
214 error = crypto_get_session (&session, sa_index0, res, cwm, 0);
215 if (PREDICT_FALSE (error || !session))
217 clib_warning ("failed to get crypto session");
219 vlib_node_increment_counter (vm,
220 dpdk_esp6_decrypt_node.index,
221 ESP_DECRYPT_ERROR_SESSION,
224 vlib_node_increment_counter (vm,
225 dpdk_esp4_decrypt_node.index,
226 ESP_DECRYPT_ERROR_SESSION,
234 last_sa_index = sa_index0;
237 /* anti-replay check */
238 if (ipsec_sa_anti_replay_check (sa0, &esp0->seq))
240 clib_warning ("failed anti-replay check");
242 vlib_node_increment_counter (vm,
243 dpdk_esp6_decrypt_node.index,
244 ESP_DECRYPT_ERROR_REPLAY, 1);
246 vlib_node_increment_counter (vm,
247 dpdk_esp4_decrypt_node.index,
248 ESP_DECRYPT_ERROR_REPLAY, 1);
256 priv->next = DPDK_CRYPTO_INPUT_NEXT_DECRYPT6_POST;
258 priv->next = DPDK_CRYPTO_INPUT_NEXT_DECRYPT4_POST;
260 /* FIXME multi-seg */
261 vlib_increment_combined_counter
262 (&ipsec_sa_counters, thread_index, sa_index0,
263 1, b0->current_length);
265 res->ops[res->n_ops] = op;
266 res->bi[res->n_ops] = bi0;
269 /* Convert vlib buffer to mbuf */
270 mb0->data_len = b0->current_length;
271 mb0->pkt_len = b0->current_length;
272 mb0->data_off = RTE_PKTMBUF_HEADROOM + b0->current_data;
274 trunc_size = auth_alg->trunc_size;
275 iv_size = cipher_alg->iv_len;
277 /* Outer IP header has already been stripped */
279 b0->current_length - sizeof (esp_header_t) - iv_size - trunc_size;
281 ASSERT (payload_len >= 4);
283 if (payload_len & (cipher_alg->boundary - 1))
285 clib_warning ("payload %u not multiple of %d\n",
286 payload_len, cipher_alg->boundary);
288 vlib_node_increment_counter (vm, dpdk_esp6_decrypt_node.index,
289 ESP_DECRYPT_ERROR_BAD_LEN, 1);
291 vlib_node_increment_counter (vm, dpdk_esp4_decrypt_node.index,
292 ESP_DECRYPT_ERROR_BAD_LEN, 1);
300 u32 cipher_off, cipher_len;
304 u8 *iv = (u8 *) (esp0 + 1);
306 dpdk_gcm_cnt_blk *icb = &priv->cb;
308 cipher_off = sizeof (esp_header_t) + iv_size;
309 cipher_len = payload_len;
311 u8 *digest = vlib_buffer_get_tail (b0) - trunc_size;
313 mb0->buf_physaddr + digest - ((u8 *) mb0->buf_addr);
315 if (!is_aead && cipher_alg->alg == RTE_CRYPTO_CIPHER_AES_CBC)
316 clib_memcpy_fast (icb, iv, 16);
319 u32 *_iv = (u32 *) iv;
321 crypto_set_icb (icb, sa0->salt, _iv[0], _iv[1]);
327 u32 *_aad = (u32 *) aad;
328 clib_memcpy_fast (aad, esp0, 8);
330 /* _aad[3] should always be 0 */
331 if (PREDICT_FALSE (ipsec_sa_is_set_USE_ESN (sa0)))
332 _aad[2] = clib_host_to_net_u32 (sa0->seq_hi);
338 auth_len = sizeof (esp_header_t) + iv_size + payload_len;
340 if (ipsec_sa_is_set_USE_ESN (sa0))
342 clib_memcpy_fast (priv->icv, digest, trunc_size);
343 u32 *_digest = (u32 *) digest;
344 _digest[0] = clib_host_to_net_u32 (sa0->seq_hi);
345 auth_len += sizeof (sa0->seq_hi);
349 op->phys_addr + (uintptr_t) priv->icv - (uintptr_t) op;
353 crypto_op_setup (is_aead, mb0, op, session, cipher_off, cipher_len,
354 0, auth_len, aad, digest, digest_paddr);
356 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
358 esp_decrypt_trace_t *tr =
359 vlib_add_trace (vm, node, b0, sizeof (*tr));
360 tr->crypto_alg = sa0->crypto_alg;
361 tr->integ_alg = sa0->integ_alg;
362 clib_memcpy_fast (tr->packet_data, vlib_buffer_get_current (b0),
363 sizeof (esp_header_t));
366 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
371 vlib_node_increment_counter (vm, dpdk_esp6_decrypt_node.index,
372 ESP_DECRYPT_ERROR_RX_PKTS,
373 from_frame->n_vectors);
375 crypto_enqueue_ops (vm, cwm, dpdk_esp6_decrypt_node.index,
376 ESP_DECRYPT_ERROR_ENQ_FAIL, numa, 0 /* encrypt */ );
380 vlib_node_increment_counter (vm, dpdk_esp4_decrypt_node.index,
381 ESP_DECRYPT_ERROR_RX_PKTS,
382 from_frame->n_vectors);
384 crypto_enqueue_ops (vm, cwm, dpdk_esp4_decrypt_node.index,
385 ESP_DECRYPT_ERROR_ENQ_FAIL, numa, 0 /* encrypt */ );
388 crypto_free_ops (numa, ops, cwm->ops + from_frame->n_vectors - ops);
390 return from_frame->n_vectors;
393 VLIB_NODE_FN (dpdk_esp4_decrypt_node) (vlib_main_t * vm,
394 vlib_node_runtime_t * node,
395 vlib_frame_t * from_frame)
397 return dpdk_esp_decrypt_inline (vm, node, from_frame, 0 /*is_ip6 */ );
401 VLIB_REGISTER_NODE (dpdk_esp4_decrypt_node) = {
402 .name = "dpdk-esp4-decrypt",
403 .vector_size = sizeof (u32),
404 .format_trace = format_esp_decrypt_trace,
405 .type = VLIB_NODE_TYPE_INTERNAL,
407 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
408 .error_strings = esp_decrypt_error_strings,
410 .n_next_nodes = ESP_DECRYPT_N_NEXT,
412 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
413 foreach_esp_decrypt_next
419 VLIB_NODE_FN (dpdk_esp6_decrypt_node) (vlib_main_t * vm,
420 vlib_node_runtime_t * node,
421 vlib_frame_t * from_frame)
423 return dpdk_esp_decrypt_inline (vm, node, from_frame, 1 /*is_ip6 */ );
427 VLIB_REGISTER_NODE (dpdk_esp6_decrypt_node) = {
428 .name = "dpdk-esp6-decrypt",
429 .vector_size = sizeof (u32),
430 .format_trace = format_esp_decrypt_trace,
431 .type = VLIB_NODE_TYPE_INTERNAL,
433 .n_errors = ARRAY_LEN(esp_decrypt_error_strings),
434 .error_strings = esp_decrypt_error_strings,
436 .n_next_nodes = ESP_DECRYPT_N_NEXT,
438 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
439 foreach_esp_decrypt_next
449 #define foreach_esp_decrypt_post_error \
450 _(PKTS, "ESP post pkts")
454 #define _(sym,str) ESP_DECRYPT_POST_ERROR_##sym,
455 foreach_esp_decrypt_post_error
457 ESP_DECRYPT_POST_N_ERROR,
458 } esp_decrypt_post_error_t;
460 static char *esp_decrypt_post_error_strings[] = {
461 #define _(sym,string) string,
462 foreach_esp_decrypt_post_error
466 extern vlib_node_registration_t dpdk_esp4_decrypt_post_node;
467 extern vlib_node_registration_t dpdk_esp6_decrypt_post_node;
470 format_esp_decrypt_post_trace (u8 * s, va_list * args)
472 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
473 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
474 esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *);
475 u32 indent = format_get_indent (s);
477 s = format (s, "cipher %U auth %U\n",
478 format_ipsec_crypto_alg, t->crypto_alg,
479 format_ipsec_integ_alg, t->integ_alg);
481 ip4_header_t *ih4 = (ip4_header_t *) t->packet_data;
482 if ((ih4->ip_version_and_header_length & 0xF0) == 0x60)
484 format (s, "%U%U", format_white_space, indent, format_ip6_header, ih4);
487 format (s, "%U%U", format_white_space, indent, format_ip4_header, ih4);
493 dpdk_esp_decrypt_post_inline (vlib_main_t * vm,
494 vlib_node_runtime_t * node,
495 vlib_frame_t * from_frame, int is_ip6)
497 u32 n_left_from, *from, *to_next = 0, next_index;
500 ipsec_main_t *im = &ipsec_main;
501 dpdk_crypto_main_t *dcm = &dpdk_crypto_main;
503 from = vlib_frame_vector_args (from_frame);
504 n_left_from = from_frame->n_vectors;
506 next_index = node->cached_next_index;
508 while (n_left_from > 0)
512 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
514 while (n_left_from > 0 && n_left_to_next > 0)
517 u32 bi0, iv_size, next0;
518 vlib_buffer_t *b0 = 0;
519 ip4_header_t *ih4 = 0, *oh4 = 0;
520 ip6_header_t *ih6 = 0, *oh6 = 0;
521 crypto_alg_t *cipher_alg, *auth_alg;
523 u8 trunc_size, is_aead;
524 u16 udp_encap_adv = 0;
526 next0 = ESP_DECRYPT_NEXT_DROP;
533 b0 = vlib_get_buffer (vm, bi0);
534 esp0 = vlib_buffer_get_current (b0);
536 sa_index0 = vnet_buffer (b0)->ipsec.sad_index;
537 sa0 = pool_elt_at_index (im->sad, sa_index0);
542 cipher_alg = vec_elt_at_index (dcm->cipher_algs, sa0->crypto_alg);
543 auth_alg = vec_elt_at_index (dcm->auth_algs, sa0->integ_alg);
544 is_aead = cipher_alg->type == RTE_CRYPTO_SYM_XFORM_AEAD;
546 auth_alg = cipher_alg;
548 trunc_size = auth_alg->trunc_size;
550 iv_size = cipher_alg->iv_len;
552 ipsec_sa_anti_replay_advance (sa0, esp0->seq);
554 /* if UDP encapsulation is used adjust the address of the IP header */
555 if (ipsec_sa_is_set_UDP_ENCAP (sa0)
556 && (b0->flags & VNET_BUFFER_F_IS_IP4))
558 udp_encap_adv = sizeof (udp_header_t);
561 if (b0->flags & VNET_BUFFER_F_IS_IP4)
562 ih4 = (ip4_header_t *)
563 ((u8 *) esp0 - udp_encap_adv - sizeof (ip4_header_t));
565 ih4 = (ip4_header_t *) ((u8 *) esp0 - sizeof (ip6_header_t));
567 vlib_buffer_advance (b0, sizeof (esp_header_t) + iv_size);
569 b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
570 f0 = (esp_footer_t *) (vlib_buffer_get_tail (b0) - trunc_size - 2);
571 b0->current_length -= (f0->pad_length + trunc_size + 2);
574 const u8 *padding = vlib_buffer_get_tail (b0);
575 if (PREDICT_FALSE (memcmp (padding, pad_data, f0->pad_length)))
577 clib_warning ("bad padding");
578 vlib_node_increment_counter (vm, dpdk_esp_decrypt_node.index,
579 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
584 if (ipsec_sa_is_set_IS_TUNNEL (sa0))
586 if (f0->next_header == IP_PROTOCOL_IP_IN_IP)
587 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
588 else if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa0)
589 && f0->next_header == IP_PROTOCOL_IPV6)
590 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
593 clib_warning ("next header: 0x%x", f0->next_header);
595 vlib_node_increment_counter (vm,
596 dpdk_esp6_decrypt_node.index,
597 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
600 vlib_node_increment_counter (vm,
601 dpdk_esp4_decrypt_node.index,
602 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
607 else /* transport mode */
609 if ((ih4->ip_version_and_header_length & 0xF0) == 0x40)
611 u16 ih4_len = ip4_header_bytes (ih4);
612 vlib_buffer_advance (b0, -ih4_len - udp_encap_adv);
613 next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
614 if (!ipsec_sa_is_set_UDP_ENCAP (sa0))
616 oh4 = vlib_buffer_get_current (b0);
617 memmove (oh4, ih4, ih4_len);
618 oh4->protocol = f0->next_header;
619 oh4->length = clib_host_to_net_u16 (b0->current_length);
620 oh4->checksum = ip4_header_checksum (oh4);
623 else if ((ih4->ip_version_and_header_length & 0xF0) == 0x60)
625 ih6 = (ip6_header_t *) ih4;
626 vlib_buffer_advance (b0, -sizeof (ip6_header_t));
627 oh6 = vlib_buffer_get_current (b0);
628 memmove (oh6, ih6, sizeof (ip6_header_t));
630 next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
631 oh6->protocol = f0->next_header;
632 u16 len = b0->current_length - sizeof (ip6_header_t);
633 oh6->payload_length = clib_host_to_net_u16 (len);
637 clib_warning ("next header: 0x%x", f0->next_header);
639 vlib_node_increment_counter (vm,
640 dpdk_esp6_decrypt_node.index,
641 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
644 vlib_node_increment_counter (vm,
645 dpdk_esp4_decrypt_node.index,
646 ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
652 vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
655 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
657 esp_decrypt_trace_t *tr =
658 vlib_add_trace (vm, node, b0, sizeof (*tr));
659 tr->crypto_alg = sa0->crypto_alg;
660 tr->integ_alg = sa0->integ_alg;
661 ih4 = vlib_buffer_get_current (b0);
662 clib_memcpy_fast (tr->packet_data, ih4, sizeof (ip6_header_t));
665 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
666 to_next, n_left_to_next, bi0,
669 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
673 vlib_node_increment_counter (vm, dpdk_esp6_decrypt_post_node.index,
674 ESP_DECRYPT_POST_ERROR_PKTS,
675 from_frame->n_vectors);
677 vlib_node_increment_counter (vm, dpdk_esp4_decrypt_post_node.index,
678 ESP_DECRYPT_POST_ERROR_PKTS,
679 from_frame->n_vectors);
681 return from_frame->n_vectors;
684 VLIB_NODE_FN (dpdk_esp4_decrypt_post_node) (vlib_main_t * vm,
685 vlib_node_runtime_t * node,
686 vlib_frame_t * from_frame)
688 return dpdk_esp_decrypt_post_inline (vm, node, from_frame, 0 /*is_ip6 */ );
692 VLIB_REGISTER_NODE (dpdk_esp4_decrypt_post_node) = {
693 .name = "dpdk-esp4-decrypt-post",
694 .vector_size = sizeof (u32),
695 .format_trace = format_esp_decrypt_post_trace,
696 .type = VLIB_NODE_TYPE_INTERNAL,
698 .n_errors = ARRAY_LEN(esp_decrypt_post_error_strings),
699 .error_strings = esp_decrypt_post_error_strings,
701 .n_next_nodes = ESP_DECRYPT_N_NEXT,
703 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
704 foreach_esp_decrypt_next
710 VLIB_NODE_FN (dpdk_esp6_decrypt_post_node) (vlib_main_t * vm,
711 vlib_node_runtime_t * node,
712 vlib_frame_t * from_frame)
714 return dpdk_esp_decrypt_post_inline (vm, node, from_frame, 0 /*is_ip6 */ );
718 VLIB_REGISTER_NODE (dpdk_esp6_decrypt_post_node) = {
719 .name = "dpdk-esp6-decrypt-post",
720 .vector_size = sizeof (u32),
721 .format_trace = format_esp_decrypt_post_trace,
722 .type = VLIB_NODE_TYPE_INTERNAL,
724 .n_errors = ARRAY_LEN(esp_decrypt_post_error_strings),
725 .error_strings = esp_decrypt_post_error_strings,
727 .n_next_nodes = ESP_DECRYPT_N_NEXT,
729 #define _(s,n) [ESP_DECRYPT_NEXT_##s] = n,
730 foreach_esp_decrypt_next
737 * fd.io coding-style-patch-verification: ON
740 * eval: (c-set-style "gnu")