xref: /btstack/src/mesh/mesh_upper_transport.c (revision a6fcac7c46d75d9a688bbacc6668e6f0263745b2)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define __BTSTACK_FILE__ "mesh_transport.c"
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include "mesh/beacon.h"
44 #include "mesh/mesh_lower_transport.h"
45 #include "mesh/mesh_upper_transport.h"
46 #include "btstack_util.h"
47 #include "btstack_memory.h"
48 #include "mesh_peer.h"
49 #include "mesh_keys.h"
50 #include "mesh_virtual_addresses.h"
51 #include "mesh_iv_index_seq_number.h"
52 
53 static void (*higher_layer_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu);
54 
55 static void mesh_print_hex(const char * name, const uint8_t * data, uint16_t len){
56     printf("%-20s ", name);
57     printf_hexdump(data, len);
58 }
59 // static void mesh_print_x(const char * name, uint32_t value){
60 //     printf("%20s: 0x%x", name, (int) value);
61 // }
62 
63 
64 // combined key x address iterator for upper transport decryption
65 
66 typedef struct {
67     // state
68     mesh_transport_key_iterator_t  key_it;
69     mesh_virtual_address_iterator_t address_it;
70     // elements
71     const mesh_transport_key_t *   key;
72     const mesh_virtual_address_t * address;
73     // address - might be virtual
74     uint16_t dst;
75     // key info
76 } mesh_transport_key_and_virtual_address_iterator_t;
77 
78 static void mesh_transport_key_and_virtual_address_iterator_init(mesh_transport_key_and_virtual_address_iterator_t *it,
79                                                                  uint16_t dst, uint16_t netkey_index, uint8_t akf,
80                                                                  uint8_t aid) {
81     printf("KEY_INIT: dst %04x, akf %x, aid %x\n", dst, akf, aid);
82     // config
83     it->dst   = dst;
84     // init elements
85     it->key     = NULL;
86     it->address = NULL;
87     // init element iterators
88     mesh_transport_key_aid_iterator_init(&it->key_it, netkey_index, akf, aid);
89     // init address iterator
90     if (mesh_network_address_virtual(it->dst)){
91         mesh_virtual_address_iterator_init(&it->address_it, dst);
92         // get first key
93         if (mesh_transport_key_aid_iterator_has_more(&it->key_it)) {
94             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
95         }
96     }
97 }
98 
99 // cartesian product: keys x addressses
100 static int mesh_transport_key_and_virtual_address_iterator_has_more(mesh_transport_key_and_virtual_address_iterator_t * it){
101     if (mesh_network_address_virtual(it->dst)) {
102         // find next valid entry
103         while (1){
104             if (mesh_virtual_address_iterator_has_more(&it->address_it)) return 1;
105             if (!mesh_transport_key_aid_iterator_has_more(&it->key_it)) return 0;
106             // get next key
107             it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
108             mesh_virtual_address_iterator_init(&it->address_it, it->dst);
109         }
110     } else {
111         return mesh_transport_key_aid_iterator_has_more(&it->key_it);
112     }
113 }
114 
115 static void mesh_transport_key_and_virtual_address_iterator_next(mesh_transport_key_and_virtual_address_iterator_t * it){
116     if (mesh_network_address_virtual(it->dst)) {
117         it->address = mesh_virtual_address_iterator_get_next(&it->address_it);
118     } else {
119         it->key = mesh_transport_key_aid_iterator_get_next(&it->key_it);
120     }
121 }
122 
123 // UPPER TRANSPORT
124 
125 // stub lower transport
126 
127 static void mesh_upper_transport_validate_unsegmented_message(mesh_network_pdu_t * network_pdu);
128 static void mesh_upper_transport_validate_segmented_message(mesh_transport_pdu_t * transport_pdu);
129 
130 static void mesh_transport_run(void);
131 
132 static int crypto_active;
133 static mesh_network_pdu_t   * network_pdu_in_validation;
134 static mesh_transport_pdu_t * transport_pdu_in_validation;
135 static uint8_t application_nonce[13];
136 static btstack_crypto_ccm_t ccm;
137 static mesh_transport_key_and_virtual_address_iterator_t mesh_transport_key_it;
138 
139 // upper transport callbacks - in access layer
140 static void (*mesh_access_message_handler)(mesh_pdu_t * pdu);
141 static void (*mesh_control_message_handler)(mesh_pdu_t * pdu);
142 
143 // unsegmented (network) and segmented (transport) control and access messages
144 static btstack_linked_list_t upper_transport_incoming;
145 
146 
147 void mesh_upper_unsegmented_control_message_received(mesh_network_pdu_t * network_pdu){
148     uint8_t * lower_transport_pdu     = mesh_network_pdu_data(network_pdu);
149     uint8_t  opcode = lower_transport_pdu[0];
150     if (mesh_control_message_handler){
151         mesh_control_message_handler((mesh_pdu_t*) network_pdu);
152     } else {
153         printf("[!] Unhandled Control message with opcode %02x\n", opcode);
154         // done
155         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) network_pdu);
156     }
157 }
158 
159 static void mesh_upper_transport_process_unsegmented_message_done(mesh_network_pdu_t *network_pdu){
160     crypto_active = 0;
161     if (mesh_network_control(network_pdu)) {
162         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) network_pdu);
163     } else {
164         mesh_network_pdu_free(network_pdu);
165         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) network_pdu_in_validation);
166         network_pdu_in_validation = NULL;
167     }
168     mesh_transport_run();
169 }
170 
171 static void mesh_upper_transport_process_segmented_message_done(mesh_transport_pdu_t *transport_pdu){
172     crypto_active = 0;
173     if (mesh_transport_ctl(transport_pdu)) {
174         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)transport_pdu);
175     } else {
176         mesh_transport_pdu_free(transport_pdu);
177         mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *)transport_pdu_in_validation);
178         transport_pdu_in_validation = NULL;
179     }
180     mesh_transport_run();
181 }
182 
183 static uint32_t iv_index_for_ivi_nid(uint8_t ivi_nid){
184     // get IV Index and IVI
185     uint32_t iv_index = mesh_get_iv_index();
186     int ivi = ivi_nid >> 7;
187 
188     // if least significant bit differs, use previous IV Index
189     if ((iv_index & 1 ) ^ ivi){
190         iv_index--;
191     }
192     return iv_index;
193 }
194 
195 static void transport_unsegmented_setup_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
196     nonce[1] = 0x00;    // SZMIC if a Segmented Access message or 0 for all other message formats
197     memcpy(&nonce[2], &network_pdu->data[2], 7);
198     big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(network_pdu->data[0]));
199 }
200 
201 static void transport_segmented_setup_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
202     nonce[1] = transport_pdu->transmic_len == 8 ? 0x80 : 0x00;
203     memcpy(&nonce[2], &transport_pdu->network_header[2], 7);
204     big_endian_store_32(nonce, 9, iv_index_for_ivi_nid(transport_pdu->network_header[0]));
205 }
206 
207 static void transport_unsegmented_setup_application_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
208     nonce[0] = 0x01;
209     transport_unsegmented_setup_nonce(nonce, network_pdu);
210     mesh_print_hex("AppNonce", nonce, 13);
211 }
212 
213 static void transport_unsegmented_setup_device_nonce(uint8_t * nonce, const mesh_network_pdu_t * network_pdu){
214     nonce[0] = 0x02;
215     transport_unsegmented_setup_nonce(nonce, network_pdu);
216     mesh_print_hex("DeviceNonce", nonce, 13);
217 }
218 
219 static void transport_segmented_setup_application_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
220     nonce[0] = 0x01;
221     transport_segmented_setup_nonce(nonce, transport_pdu);
222     mesh_print_hex("AppNonce", nonce, 13);
223 }
224 
225 static void transport_segmented_setup_device_nonce(uint8_t * nonce, const mesh_transport_pdu_t * transport_pdu){
226     nonce[0] = 0x02;
227     transport_segmented_setup_nonce(nonce, transport_pdu);
228     mesh_print_hex("DeviceNonce", nonce, 13);
229 }
230 
231 static void mesh_upper_transport_validate_unsegmented_message_ccm(void * arg){
232     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
233 
234     uint8_t * lower_transport_pdu     = mesh_network_pdu_data(network_pdu);
235     uint8_t trans_mic_len = 4;
236 
237     // store TransMIC
238     uint8_t trans_mic[8];
239     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
240     mesh_print_hex("TransMIC", trans_mic, trans_mic_len);
241 
242     uint8_t * upper_transport_pdu     = mesh_network_pdu_data(network_pdu) + 1;
243     uint8_t   upper_transport_pdu_len = mesh_network_pdu_len(network_pdu)  - 1;
244 
245     mesh_print_hex("Decryted PDU", upper_transport_pdu, upper_transport_pdu_len - trans_mic_len);
246 
247     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len - trans_mic_len], trans_mic_len) == 0){
248         printf("TransMIC matches\n");
249 
250         // remove TransMIC from payload
251         network_pdu->len -= trans_mic_len;
252 
253         // if virtual address, update dst to pseudo_dst
254         if (mesh_network_address_virtual(mesh_network_dst(network_pdu))){
255             big_endian_store_16(network_pdu->data, 7, mesh_transport_key_it.address->pseudo_dst);
256         }
257 
258         // pass to upper layer
259         if (mesh_access_message_handler){
260             mesh_access_message_handler((mesh_pdu_t*) network_pdu);
261         } else {
262             printf("[!] Unhandled Unsegmented Access message\n");
263             // done
264             mesh_upper_transport_process_unsegmented_message_done(network_pdu);
265         }
266 
267         printf("\n");
268     } else {
269         uint8_t afk = lower_transport_pdu[0] & 0x40;
270         if (afk){
271             printf("TransMIC does not match, try next key\n");
272             mesh_upper_transport_validate_unsegmented_message(network_pdu);
273         } else {
274             printf("TransMIC does not match device key, done\n");
275             // done
276             mesh_upper_transport_process_unsegmented_message_done(network_pdu);
277         }
278     }
279 }
280 
281 static void mesh_upper_transport_validate_segmented_message_ccm(void * arg){
282     mesh_transport_pdu_t * transport_pdu = (mesh_transport_pdu_t *) arg;
283 
284     uint8_t * upper_transport_pdu     =  transport_pdu->data;
285     uint8_t   upper_transport_pdu_len =  transport_pdu->len - transport_pdu->transmic_len;
286 
287     mesh_print_hex("Decrypted PDU", upper_transport_pdu, upper_transport_pdu_len);
288 
289     // store TransMIC
290     uint8_t trans_mic[8];
291     btstack_crypto_ccm_get_authentication_value(&ccm, trans_mic);
292     mesh_print_hex("TransMIC", trans_mic, transport_pdu->transmic_len);
293 
294     if (memcmp(trans_mic, &upper_transport_pdu[upper_transport_pdu_len], transport_pdu->transmic_len) == 0){
295         printf("TransMIC matches\n");
296 
297         // remove TransMIC from payload
298         transport_pdu->len -= transport_pdu->transmic_len;
299 
300         // if virtual address, update dst to pseudo_dst
301         if (mesh_network_address_virtual(mesh_transport_dst(transport_pdu))){
302             big_endian_store_16(transport_pdu->network_header, 7, mesh_transport_key_it.address->pseudo_dst);
303         }
304 
305         // pass to upper layer
306         if (mesh_access_message_handler){
307             mesh_access_message_handler((mesh_pdu_t*) transport_pdu);
308         } else {
309             printf("[!] Unhandled Segmented Access/Control message\n");
310             // done
311             mesh_upper_transport_process_segmented_message_done(transport_pdu);
312         }
313 
314         printf("\n");
315 
316     } else {
317         uint8_t akf = transport_pdu->akf_aid & 0x40;
318         if (akf){
319             printf("TransMIC does not match, try next key\n");
320             mesh_upper_transport_validate_segmented_message(transport_pdu);
321         } else {
322             printf("TransMIC does not match device key, done\n");
323             // done
324             mesh_upper_transport_process_segmented_message_done(transport_pdu);
325         }
326     }
327 }
328 
329 void mesh_upper_transport_message_processed_by_higher_layer(mesh_pdu_t * pdu){
330     crypto_active = 0;
331     switch (pdu->pdu_type){
332         case MESH_PDU_TYPE_NETWORK:
333             mesh_upper_transport_process_unsegmented_message_done((mesh_network_pdu_t *) pdu);
334             break;
335         case MESH_PDU_TYPE_TRANSPORT:
336             mesh_upper_transport_process_segmented_message_done((mesh_transport_pdu_t *) pdu);
337             break;
338         default:
339             break;
340     }
341 }
342 
343 static void mesh_upper_transport_validate_segmented_message_digest(void * arg){
344     mesh_transport_pdu_t * transport_pdu   = (mesh_transport_pdu_t*) arg;
345     uint8_t   upper_transport_pdu_len      = transport_pdu_in_validation->len - transport_pdu_in_validation->transmic_len;
346     uint8_t * upper_transport_pdu_data_in  = transport_pdu_in_validation->data;
347     uint8_t * upper_transport_pdu_data_out = transport_pdu->data;
348     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_segmented_message_ccm, transport_pdu);
349 }
350 
351 static void mesh_upper_transport_validate_unsegmented_message_digest(void * arg){
352     mesh_network_pdu_t * network_pdu       = (mesh_network_pdu_t *) arg;
353     uint8_t   trans_mic_len = 4;
354     uint8_t   lower_transport_pdu_len      = network_pdu_in_validation->len - 9;
355     uint8_t * upper_transport_pdu_data_in  = &network_pdu_in_validation->data[10];
356     uint8_t * upper_transport_pdu_data_out = &network_pdu->data[10];
357     uint8_t   upper_transport_pdu_len      = lower_transport_pdu_len - 1 - trans_mic_len;
358     btstack_crypto_ccm_decrypt_block(&ccm, upper_transport_pdu_len, upper_transport_pdu_data_in, upper_transport_pdu_data_out, &mesh_upper_transport_validate_unsegmented_message_ccm, network_pdu);
359 }
360 
361 static void mesh_upper_transport_validate_unsegmented_message(mesh_network_pdu_t * network_pdu){
362 
363     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
364         printf("No valid transport key found\n");
365         mesh_upper_transport_process_unsegmented_message_done(network_pdu);
366         return;
367     }
368     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
369     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
370 
371     if (message_key->akf){
372         transport_unsegmented_setup_application_nonce(application_nonce, network_pdu_in_validation);
373     } else {
374         transport_unsegmented_setup_device_nonce(application_nonce, network_pdu_in_validation);
375     }
376 
377     // store application / device key index
378     mesh_print_hex("AppOrDevKey", message_key->key, 16);
379     network_pdu->appkey_index = message_key->appkey_index;
380 
381     // unsegmented message have TransMIC of 32 bit
382     uint8_t trans_mic_len = 4;
383     printf("Unsegmented Access message with TransMIC len 4\n");
384 
385     uint8_t   lower_transport_pdu_len = network_pdu_in_validation->len - 9;
386     uint8_t * upper_transport_pdu_data = &network_pdu_in_validation->data[10];
387     uint8_t   upper_transport_pdu_len  = lower_transport_pdu_len - 1 - trans_mic_len;
388 
389     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
390 
391     // decrypt ccm
392     crypto_active = 1;
393     uint16_t aad_len  = 0;
394     if (mesh_network_address_virtual(mesh_network_dst(network_pdu))){
395         aad_len  = 16;
396     }
397     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, trans_mic_len);
398     if (aad_len){
399         btstack_crypto_ccm_digest(&ccm, (uint8_t*) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_unsegmented_message_digest, network_pdu);
400     } else {
401         mesh_upper_transport_validate_unsegmented_message_digest(network_pdu);
402     }
403 }
404 
405 static void mesh_upper_transport_validate_segmented_message(mesh_transport_pdu_t * transport_pdu){
406     uint8_t * upper_transport_pdu_data =  transport_pdu->data;
407     uint8_t   upper_transport_pdu_len  =  transport_pdu->len - transport_pdu->transmic_len;
408 
409     if (!mesh_transport_key_and_virtual_address_iterator_has_more(&mesh_transport_key_it)){
410         printf("No valid transport key found\n");
411         mesh_upper_transport_process_segmented_message_done(transport_pdu);
412         return;
413     }
414     mesh_transport_key_and_virtual_address_iterator_next(&mesh_transport_key_it);
415     const mesh_transport_key_t * message_key = mesh_transport_key_it.key;
416 
417     if (message_key->akf){
418         transport_segmented_setup_application_nonce(application_nonce, transport_pdu_in_validation);
419     } else {
420         transport_segmented_setup_device_nonce(application_nonce, transport_pdu_in_validation);
421     }
422 
423     // store application / device key index
424     mesh_print_hex("AppOrDevKey", message_key->key, 16);
425     transport_pdu->appkey_index = message_key->appkey_index;
426 
427     mesh_print_hex("EncAccessPayload", upper_transport_pdu_data, upper_transport_pdu_len);
428 
429     // decrypt ccm
430     crypto_active = 1;
431     uint16_t aad_len  = 0;
432     if (mesh_network_address_virtual(mesh_transport_dst(transport_pdu))){
433         aad_len  = 16;
434     }
435     btstack_crypto_ccm_init(&ccm, message_key->key, application_nonce, upper_transport_pdu_len, aad_len, transport_pdu->transmic_len);
436 
437     if (aad_len){
438         btstack_crypto_ccm_digest(&ccm, (uint8_t *) mesh_transport_key_it.address->label_uuid, aad_len, &mesh_upper_transport_validate_segmented_message_digest, transport_pdu);
439     } else {
440         mesh_upper_transport_validate_segmented_message_digest(transport_pdu);
441     }
442 }
443 
444 static void mesh_upper_transport_process_unsegmented_access_message(mesh_network_pdu_t *network_pdu){
445     // copy original pdu
446     network_pdu->len = network_pdu_in_validation->len;
447     memcpy(network_pdu->data, network_pdu_in_validation->data, network_pdu->len);
448 
449     //
450     uint8_t * lower_transport_pdu     = &network_pdu_in_validation->data[9];
451     uint8_t   lower_transport_pdu_len = network_pdu_in_validation->len - 9;
452 
453     mesh_print_hex("Lower Transport network pdu", &network_pdu_in_validation->data[9], lower_transport_pdu_len);
454 
455     uint8_t aid =  lower_transport_pdu[0] & 0x3f;
456     uint8_t akf = (lower_transport_pdu[0] & 0x40) >> 6;
457     printf("AKF: %u\n",   akf);
458     printf("AID: %02x\n", aid);
459 
460     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_network_dst(network_pdu),
461             network_pdu->netkey_index, akf, aid);
462     mesh_upper_transport_validate_unsegmented_message(network_pdu);
463 }
464 
465 static void mesh_upper_transport_process_message(mesh_transport_pdu_t * transport_pdu){
466     // copy original pdu
467     transport_pdu->len = transport_pdu_in_validation->len;
468     memcpy(transport_pdu, transport_pdu_in_validation, sizeof(mesh_transport_pdu_t));
469 
470     //
471     uint8_t * upper_transport_pdu     =  transport_pdu->data;
472     uint8_t   upper_transport_pdu_len =  transport_pdu->len - transport_pdu->transmic_len;
473     mesh_print_hex("Upper Transport pdu", upper_transport_pdu, upper_transport_pdu_len);
474 
475     uint8_t aid =  transport_pdu->akf_aid & 0x3f;
476     uint8_t akf = (transport_pdu->akf_aid & 0x40) >> 6;
477 
478     printf("AKF: %u\n",   akf);
479     printf("AID: %02x\n", aid);
480 
481     mesh_transport_key_and_virtual_address_iterator_init(&mesh_transport_key_it, mesh_transport_dst(transport_pdu),
482             transport_pdu->netkey_index, akf, aid);
483     mesh_upper_transport_validate_segmented_message(transport_pdu);
484 }
485 
486 void mesh_upper_transport_message_received(mesh_pdu_t * pdu){
487     btstack_linked_list_add_tail(&upper_transport_incoming, (btstack_linked_item_t*) pdu);
488     mesh_transport_run();
489 }
490 
491 void mesh_upper_transport_pdu_free(mesh_pdu_t * pdu){
492     mesh_network_pdu_t * network_pdu;
493     mesh_transport_pdu_t * transport_pdu;
494     switch (pdu->pdu_type) {
495         case MESH_PDU_TYPE_NETWORK:
496             network_pdu = (mesh_network_pdu_t *) pdu;
497             mesh_network_pdu_free(network_pdu);
498             break;
499         case MESH_PDU_TYPE_TRANSPORT:
500             transport_pdu = (mesh_transport_pdu_t *) pdu;
501             mesh_transport_pdu_free(transport_pdu);
502             break;
503         default:
504             break;
505     }
506 }
507 
508 void mesh_upper_transport_pdu_handler(mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu){
509     switch (callback_type){
510         case MESH_TRANSPORT_PDU_RECEIVED:
511             mesh_upper_transport_message_received(pdu);
512             break;
513         case MESH_TRANSPORT_PDU_SENT:
514             // notify upper layer (or just free pdu)
515             if (higher_layer_handler){
516                 higher_layer_handler(callback_type, status, pdu);
517             } else {
518                 mesh_upper_transport_pdu_free(pdu);
519             }
520             break;
521         default:
522             break;
523     }
524 }
525 static void mesh_upper_transport_send_unsegmented_access_pdu_ccm(void * arg){
526     crypto_active = 0;
527 
528     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
529     uint8_t * upper_transport_pdu     = mesh_network_pdu_data(network_pdu) + 1;
530     uint8_t   upper_transport_pdu_len = mesh_network_pdu_len(network_pdu)  - 1;
531     mesh_print_hex("EncAccessPayload", upper_transport_pdu, upper_transport_pdu_len);
532     // store TransMIC
533     btstack_crypto_ccm_get_authentication_value(&ccm, &upper_transport_pdu[upper_transport_pdu_len]);
534     mesh_print_hex("TransMIC", &upper_transport_pdu[upper_transport_pdu_len], 4);
535     network_pdu->len += 4;
536     // send network pdu
537     mesh_lower_transport_send_pdu((mesh_pdu_t*) network_pdu);
538 }
539 
540 static void mesh_upper_transport_send_segmented_access_pdu_ccm(void * arg){
541     crypto_active = 0;
542 
543     mesh_transport_pdu_t * transport_pdu = (mesh_transport_pdu_t *) arg;
544     mesh_print_hex("EncAccessPayload", transport_pdu->data, transport_pdu->len);
545     // store TransMIC
546     btstack_crypto_ccm_get_authentication_value(&ccm, &transport_pdu->data[transport_pdu->len]);
547     mesh_print_hex("TransMIC", &transport_pdu->data[transport_pdu->len], transport_pdu->transmic_len);
548     transport_pdu->len += transport_pdu->transmic_len;
549     mesh_lower_transport_send_pdu((mesh_pdu_t*) transport_pdu);
550 }
551 
552 static uint8_t mesh_upper_transport_setup_unsegmented_control_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
553                           const uint8_t * control_pdu_data, uint16_t control_pdu_len){
554 
555     printf("[+] Upper transport, setup unsegmented Control PDU (opcode %02x): \n", opcode);
556     printf_hexdump(control_pdu_data, control_pdu_len);
557 
558     if (control_pdu_len > 11) return 1;
559 
560     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
561     if (!network_key) return 1;
562 
563     uint8_t transport_pdu_data[12];
564     transport_pdu_data[0] = opcode;
565     memcpy(&transport_pdu_data[1], control_pdu_data, control_pdu_len);
566     uint16_t transport_pdu_len = control_pdu_len + 1;
567 
568     mesh_print_hex("LowerTransportPDU", transport_pdu_data, transport_pdu_len);
569     // setup network_pdu
570     mesh_network_setup_pdu(network_pdu, netkey_index, network_key->nid, 1, ttl, mesh_sequence_number_next(), src, dest, transport_pdu_data, transport_pdu_len);
571 
572     return 0;
573 }
574 
575 static uint8_t mesh_upper_transport_setup_segmented_control_pdu(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index, uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode,
576                           const uint8_t * control_pdu_data, uint16_t control_pdu_len){
577 
578     printf("[+] Upper transport, setup segmented Control PDU (opcode %02x): \n", opcode);
579     printf_hexdump(control_pdu_data, control_pdu_len);
580 
581     if (control_pdu_len > 256) return 1;
582 
583     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
584     if (!network_key) return 1;
585 
586     uint32_t seq = mesh_sequence_number_peek();
587 
588     memcpy(transport_pdu->data, control_pdu_data, control_pdu_len);
589     transport_pdu->len = control_pdu_len;
590     transport_pdu->netkey_index = netkey_index;
591     transport_pdu->akf_aid = opcode;
592     transport_pdu->transmic_len = 0;    // no TransMIC for control
593     mesh_transport_set_nid_ivi(transport_pdu, network_key->nid);
594     mesh_transport_set_seq(transport_pdu, seq);
595     mesh_transport_set_src(transport_pdu, src);
596     mesh_transport_set_dest(transport_pdu, dest);
597     mesh_transport_set_ctl_ttl(transport_pdu, 0x80 | ttl);
598 
599     return 0;
600 }
601 
602 uint8_t mesh_upper_transport_setup_control_pdu(mesh_pdu_t * pdu, uint16_t netkey_index,
603                                                uint8_t ttl, uint16_t src, uint16_t dest, uint8_t opcode, const uint8_t * control_pdu_data, uint16_t control_pdu_len){
604     switch (pdu->pdu_type){
605         case MESH_PDU_TYPE_NETWORK:
606             return mesh_upper_transport_setup_unsegmented_control_pdu((mesh_network_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
607         case MESH_PDU_TYPE_TRANSPORT:
608             return mesh_upper_transport_setup_segmented_control_pdu((mesh_transport_pdu_t *) pdu, netkey_index, ttl, src, dest, opcode, control_pdu_data, control_pdu_len);
609         default:
610             return 1;
611     }
612 }
613 
614 static uint8_t mesh_upper_transport_setup_unsegmented_access_pdu_header(mesh_network_pdu_t * network_pdu, uint16_t netkey_index,
615         uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest){
616 
617     // get app or device key
618     const mesh_transport_key_t * appkey;
619     appkey = mesh_transport_key_get(appkey_index);
620     if (appkey == NULL){
621         printf("appkey_index %x unknown\n", appkey_index);
622         return 1;
623     }
624     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
625 
626     // lookup network by netkey_index
627     const mesh_network_key_t * network_key = mesh_network_key_list_get(netkey_index);
628     if (!network_key) return 1;
629 
630     network_pdu->data[9] = akf_aid;
631     // setup network_pdu
632     mesh_network_setup_pdu_header(network_pdu, netkey_index, network_key->nid, 0, ttl, mesh_sequence_number_next(), src, dest);
633     network_pdu->appkey_index = appkey_index;
634     return 0;
635 }
636 
637 static uint8_t mesh_upper_transport_setup_unsegmented_access_pdu(mesh_network_pdu_t * network_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
638                                                        const uint8_t * access_pdu_data, uint8_t access_pdu_len){
639 
640     int status = mesh_upper_transport_setup_unsegmented_access_pdu_header(network_pdu, netkey_index, appkey_index, ttl, src, dest);
641     if (status) return status;
642 
643     printf("[+] Upper transport, setup unsegmented Access PDU - seq %06x\n", mesh_network_seq(network_pdu));
644     mesh_print_hex("Access Payload", access_pdu_data, access_pdu_len);
645 
646     // store in transport pdu
647     memcpy(&network_pdu->data[10], access_pdu_data, access_pdu_len);
648     network_pdu->len = 10 + access_pdu_len;
649     return 0;
650 }
651 
652 static uint8_t mesh_upper_transport_setup_segmented_access_pdu_header(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
653                                                         uint8_t szmic){
654     uint32_t seq = mesh_sequence_number_peek();
655 
656     printf("[+] Upper transport, setup segmented Access PDU - seq %06x, szmic %u, iv_index %08x\n", seq, szmic,
657            mesh_get_iv_index_for_tx());
658     mesh_print_hex("Access Payload", transport_pdu->data, transport_pdu->len);
659 
660     // get app or device key
661     const mesh_transport_key_t *appkey;
662     appkey = mesh_transport_key_get(appkey_index);
663     if (appkey == NULL) {
664         printf("appkey_index %x unknown\n", appkey_index);
665         return 1;
666     }
667     uint8_t akf_aid = (appkey->akf << 6) | appkey->aid;
668 
669     // lookup network by netkey_index
670     const mesh_network_key_t *network_key = mesh_network_key_list_get(netkey_index);
671     if (!network_key) return 1;
672 
673     const uint8_t trans_mic_len = szmic ? 8 : 4;
674 
675     // store in transport pdu
676     transport_pdu->transmic_len = trans_mic_len;
677     transport_pdu->netkey_index = netkey_index;
678     transport_pdu->appkey_index = appkey_index;
679     transport_pdu->akf_aid = akf_aid;
680     mesh_transport_set_nid_ivi(transport_pdu, network_key->nid | ((mesh_get_iv_index_for_tx() & 1) << 7));
681     mesh_transport_set_seq(transport_pdu, seq);
682     mesh_transport_set_src(transport_pdu, src);
683     mesh_transport_set_dest(transport_pdu, dest);
684     mesh_transport_set_ctl_ttl(transport_pdu, ttl);
685     return 0;
686 }
687 
688 
689 static uint8_t mesh_upper_transport_setup_segmented_access_pdu(mesh_transport_pdu_t * transport_pdu, uint16_t netkey_index, uint16_t appkey_index, uint8_t ttl, uint16_t src, uint16_t dest,
690                           uint8_t szmic, const uint8_t * access_pdu_data, uint8_t access_pdu_len){
691     int status = mesh_upper_transport_setup_segmented_access_pdu_header(transport_pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
692     if (status) return status;
693 
694     // store in transport pdu
695     memcpy(transport_pdu->data, access_pdu_data, access_pdu_len);
696     transport_pdu->len = access_pdu_len;
697     return 0;
698 }
699 uint8_t mesh_upper_transport_setup_access_pdu_header(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
700                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic){
701     switch (pdu->pdu_type){
702         case MESH_PDU_TYPE_NETWORK:
703             return mesh_upper_transport_setup_unsegmented_access_pdu_header((mesh_network_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest);
704         case MESH_PDU_TYPE_TRANSPORT:
705             return mesh_upper_transport_setup_segmented_access_pdu_header((mesh_transport_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic);
706         default:
707             return 1;
708     }
709 }
710 
711 uint8_t mesh_upper_transport_setup_access_pdu(mesh_pdu_t * pdu, uint16_t netkey_index, uint16_t appkey_index,
712                                               uint8_t ttl, uint16_t src, uint16_t dest, uint8_t szmic,
713                                               const uint8_t * access_pdu_data, uint8_t access_pdu_len){
714     switch (pdu->pdu_type){
715         case MESH_PDU_TYPE_NETWORK:
716             return mesh_upper_transport_setup_unsegmented_access_pdu((mesh_network_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, access_pdu_data, access_pdu_len);
717         case MESH_PDU_TYPE_TRANSPORT:
718             return mesh_upper_transport_setup_segmented_access_pdu((mesh_transport_pdu_t *) pdu, netkey_index, appkey_index, ttl, src, dest, szmic, access_pdu_data, access_pdu_len);
719         default:
720             return 1;
721     }
722 }
723 
724 void mesh_upper_transport_send_control_pdu(mesh_pdu_t * pdu){
725     mesh_lower_transport_send_pdu((mesh_pdu_t*) pdu);
726 }
727 
728 static void mesh_upper_transport_send_unsegmented_access_pdu_digest(void * arg){
729     mesh_network_pdu_t * network_pdu = (mesh_network_pdu_t *) arg;
730     uint8_t * access_pdu_data = mesh_network_pdu_data(network_pdu) + 1;
731     uint16_t  access_pdu_len  = mesh_network_pdu_len(network_pdu)  - 1;
732     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len, access_pdu_data, access_pdu_data, &mesh_upper_transport_send_unsegmented_access_pdu_ccm, network_pdu);
733 }
734 
735 static mesh_transport_key_t * mesh_upper_transport_get_outgoing_appkey(uint16_t netkey_index, uint16_t appkey_index){
736     // Device Key is fixed
737     if (appkey_index == MESH_DEVICE_KEY_INDEX) {
738         return mesh_transport_key_get(appkey_index);
739     }
740 
741     // Get key refresh state from subnet
742     mesh_subnet_t * subnet = mesh_subnet_get_by_netkey_index(netkey_index);
743     if (subnet == NULL) return NULL;
744 
745     // identify old and new app keys for given appkey_index
746     mesh_transport_key_t * old_key = NULL;
747     mesh_transport_key_t * new_key = NULL;
748     mesh_transport_key_iterator_t it;
749     mesh_transport_key_iterator_init(&it, netkey_index);
750     while (mesh_transport_key_iterator_has_more(&it)){
751         mesh_transport_key_t * transport_key = mesh_transport_key_iterator_get_next(&it);
752         if (transport_key->appkey_index != appkey_index) continue;
753         if (transport_key->old_key == 0) {
754             new_key = transport_key;
755         } else {
756             old_key = transport_key;
757         }
758     }
759 
760     // if no key is marked as old, just use the current one
761     if (old_key == NULL) return new_key;
762 
763     // use new key if it exists in phase two
764     if ((subnet->key_refresh == MESH_KEY_REFRESH_SECOND_PHASE) && (new_key != NULL)){
765         return new_key;
766     } else {
767         return old_key;
768     }
769 }
770 
771 static void mesh_upper_transport_send_unsegmented_access_pdu(mesh_network_pdu_t * network_pdu){
772 
773     // if dst is virtual address, lookup label uuid and hash
774     uint16_t aad_len = 0;
775     mesh_virtual_address_t * virtual_address = NULL;
776     uint16_t dst = mesh_network_dst(network_pdu);
777     if (mesh_network_address_virtual(dst)){
778         virtual_address = mesh_virtual_address_for_pseudo_dst(dst);
779         if (!virtual_address){
780             printf("No virtual address register for pseudo dst %4x\n", dst);
781             btstack_memory_mesh_network_pdu_free(network_pdu);
782             return;
783         }
784         aad_len = 16;
785         big_endian_store_16(network_pdu->data, 7, virtual_address->hash);
786     }
787 
788     // setup nonce
789     uint16_t appkey_index = network_pdu->appkey_index;
790     if (appkey_index == MESH_DEVICE_KEY_INDEX){
791         transport_unsegmented_setup_device_nonce(application_nonce, network_pdu);
792     } else {
793         transport_unsegmented_setup_application_nonce(application_nonce, network_pdu);
794     }
795 
796     // get app or device key
797     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(network_pdu->netkey_index, appkey_index);
798     mesh_print_hex("AppOrDevKey", appkey->key, 16);
799 
800     // encrypt ccm
801     uint8_t   trans_mic_len = 4;
802     uint16_t  access_pdu_len  = mesh_network_pdu_len(network_pdu)  - 1;
803     crypto_active = 1;
804 
805     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, trans_mic_len);
806     if (virtual_address){
807         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
808         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16, &mesh_upper_transport_send_unsegmented_access_pdu_digest, network_pdu);
809     } else {
810         mesh_upper_transport_send_unsegmented_access_pdu_digest(network_pdu);
811     }
812 }
813 
814 static void mesh_upper_transport_send_segmented_access_pdu_digest(void *arg){
815     mesh_transport_pdu_t * transport_pdu = (mesh_transport_pdu_t *) arg;
816     uint16_t  access_pdu_len  = transport_pdu->len;
817     uint8_t * access_pdu_data = transport_pdu->data;
818     btstack_crypto_ccm_encrypt_block(&ccm, access_pdu_len,access_pdu_data, access_pdu_data, &mesh_upper_transport_send_segmented_access_pdu_ccm, transport_pdu);
819 }
820 
821 static void mesh_upper_transport_send_segmented_access_pdu(mesh_transport_pdu_t * transport_pdu){
822 
823     // if dst is virtual address, lookup label uuid and hash
824     uint16_t aad_len = 0;
825     mesh_virtual_address_t * virtual_address = NULL;
826     uint16_t dst = mesh_transport_dst(transport_pdu);
827     if (mesh_network_address_virtual(dst)){
828         virtual_address = mesh_virtual_address_for_pseudo_dst(dst);
829         if (!virtual_address){
830             printf("No virtual address register for pseudo dst %4x\n", dst);
831             btstack_memory_mesh_transport_pdu_free(transport_pdu);
832             return;
833         }
834         // printf("Using hash %4x with LabelUUID: ", virtual_address->hash);
835         // printf_hexdump(virtual_address->label_uuid, 16);
836         aad_len = 16;
837         big_endian_store_16(transport_pdu->network_header, 7, virtual_address->hash);
838     }
839 
840     // setup nonce - uses dst, so after pseudo address translation
841     uint16_t appkey_index = transport_pdu->appkey_index;
842     if (appkey_index == MESH_DEVICE_KEY_INDEX){
843         transport_segmented_setup_device_nonce(application_nonce, transport_pdu);
844     } else {
845         transport_segmented_setup_application_nonce(application_nonce, transport_pdu);
846     }
847 
848     // get app or device key
849     const mesh_transport_key_t * appkey = mesh_upper_transport_get_outgoing_appkey(transport_pdu->netkey_index, appkey_index);
850     mesh_print_hex("AppOrDevKey", appkey->key, 16);
851 
852     // encrypt ccm
853     uint8_t   transmic_len    = transport_pdu->transmic_len;
854     uint16_t  access_pdu_len  = transport_pdu->len;
855     crypto_active = 1;
856     btstack_crypto_ccm_init(&ccm, appkey->key, application_nonce, access_pdu_len, aad_len, transmic_len);
857     if (virtual_address){
858         mesh_print_hex("LabelUUID", virtual_address->label_uuid, 16);
859         btstack_crypto_ccm_digest(&ccm, virtual_address->label_uuid, 16, &mesh_upper_transport_send_segmented_access_pdu_digest, transport_pdu);
860     } else {
861         mesh_upper_transport_send_segmented_access_pdu_digest(transport_pdu);
862     }
863 }
864 
865 void mesh_upper_transport_send_access_pdu(mesh_pdu_t * pdu){
866     switch (pdu->pdu_type){
867         case MESH_PDU_TYPE_NETWORK:
868             mesh_upper_transport_send_unsegmented_access_pdu((mesh_network_pdu_t *) pdu);
869             break;
870         case MESH_PDU_TYPE_TRANSPORT:
871             mesh_upper_transport_send_segmented_access_pdu((mesh_transport_pdu_t *) pdu);
872             break;
873         default:
874             break;
875     }
876 }
877 
878 void mesh_upper_transport_register_access_message_handler(void (*callback)(mesh_pdu_t *pdu)){
879     mesh_access_message_handler = callback;
880 }
881 
882 void mesh_upper_transport_register_control_message_handler(void (*callback)(mesh_pdu_t *pdu)){
883     mesh_control_message_handler = callback;
884 }
885 
886 void mesh_upper_transport_set_higher_layer_handler(void (*pdu_handler)( mesh_transport_callback_type_t callback_type, mesh_transport_status_t status, mesh_pdu_t * pdu)){
887     higher_layer_handler = pdu_handler;
888 }
889 
890 void mesh_upper_transport_init(){
891     mesh_lower_transport_init();
892     mesh_lower_transport_set_higher_layer_handler(&mesh_upper_transport_pdu_handler);
893 }
894 
895 static void mesh_transport_run(void){
896     while(!btstack_linked_list_empty(&upper_transport_incoming)){
897 
898         if (crypto_active) return;
899 
900         // peek at next message
901         mesh_pdu_t * pdu =  (mesh_pdu_t *) btstack_linked_list_get_first_item(&upper_transport_incoming);
902         mesh_transport_pdu_t * transport_pdu;
903         mesh_network_pdu_t   * network_pdu;
904         switch (pdu->pdu_type){
905             case MESH_PDU_TYPE_NETWORK:
906                 network_pdu = (mesh_network_pdu_t *) pdu;
907                 // control?
908                 if (mesh_network_control(network_pdu)) {
909                     (void) btstack_linked_list_pop(&upper_transport_incoming);
910                     mesh_upper_unsegmented_control_message_received(network_pdu);
911                 } else {
912                     mesh_network_pdu_t * decode_pdu = mesh_network_pdu_get();
913                     if (!decode_pdu) return;
914                     // get encoded network pdu and start processing
915                     network_pdu_in_validation = network_pdu;
916                     (void) btstack_linked_list_pop(&upper_transport_incoming);
917                     mesh_upper_transport_process_unsegmented_access_message(decode_pdu);
918                 }
919                 break;
920             case MESH_PDU_TYPE_TRANSPORT:
921                 transport_pdu = (mesh_transport_pdu_t *) pdu;
922                 uint8_t ctl = mesh_transport_ctl(transport_pdu);
923                 if (ctl){
924                     printf("Ignoring Segmented Control Message\n");
925                     (void) btstack_linked_list_pop(&upper_transport_incoming);
926                     mesh_lower_transport_message_processed_by_higher_layer((mesh_pdu_t *) transport_pdu);
927                 } else {
928                     mesh_transport_pdu_t * decode_pdu = mesh_transport_pdu_get();
929                     if (!decode_pdu) return;
930                     // get encoded transport pdu and start processing
931                     transport_pdu_in_validation = transport_pdu;
932                     (void) btstack_linked_list_pop(&upper_transport_incoming);
933                     mesh_upper_transport_process_message(decode_pdu);
934                 }
935                 break;
936             default:
937                 break;
938         }
939     }
940 }
941 
942 // buffer pool
943 mesh_transport_pdu_t * mesh_transport_pdu_get(void){
944     mesh_transport_pdu_t * transport_pdu = btstack_memory_mesh_transport_pdu_get();
945     if (transport_pdu) {
946         memset(transport_pdu, 0, sizeof(mesh_transport_pdu_t));
947         transport_pdu->pdu_header.pdu_type = MESH_PDU_TYPE_TRANSPORT;
948     }
949     return transport_pdu;
950 }
951 
952 void mesh_transport_pdu_free(mesh_transport_pdu_t * transport_pdu){
953     btstack_memory_mesh_transport_pdu_free(transport_pdu);
954 }
955