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 BLUEKITCHEN 24 * GMBH 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__ "sm.c" 39 40 #include <string.h> 41 #include <inttypes.h> 42 43 #include "ble/le_device_db.h" 44 #include "ble/core.h" 45 #include "ble/sm.h" 46 #include "bluetooth_company_id.h" 47 #include "btstack_bool.h" 48 #include "btstack_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "btstack_tlv.h" 54 #include "gap.h" 55 #include "hci.h" 56 #include "hci_dump.h" 57 #include "l2cap.h" 58 59 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 60 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 61 #endif 62 63 #if defined(ENABLE_CROSS_TRANSPORT_KEY_DERIVATION) && (!defined(ENABLE_CLASSIC) || !defined(ENABLE_LE_SECURE_CONNECTIONS)) 64 #error "Cross Transport Key Derivation requires support for LE Secure Connections and BR/EDR (Classic)" 65 #endif 66 67 // assert SM Public Key can be sent/received 68 #ifdef ENABLE_LE_SECURE_CONNECTIONS 69 #if HCI_ACL_PAYLOAD_SIZE < 69 70 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 71 #endif 72 #endif 73 74 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 75 #define IS_RESPONDER(role) (role) 76 #else 77 #ifdef ENABLE_LE_CENTRAL 78 // only central - never responder (avoid 'unused variable' warnings) 79 #define IS_RESPONDER(role) (0 && role) 80 #else 81 // only peripheral - always responder (avoid 'unused variable' warnings) 82 #define IS_RESPONDER(role) (1 || role) 83 #endif 84 #endif 85 86 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 87 #define USE_CMAC_ENGINE 88 #endif 89 90 91 #define BTSTACK_TAG32(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) 92 93 // 94 // SM internal types and globals 95 // 96 97 typedef enum { 98 DKG_W4_WORKING, 99 DKG_CALC_IRK, 100 DKG_CALC_DHK, 101 DKG_READY 102 } derived_key_generation_t; 103 104 typedef enum { 105 RAU_IDLE, 106 RAU_GET_RANDOM, 107 RAU_W4_RANDOM, 108 RAU_GET_ENC, 109 RAU_W4_ENC, 110 } random_address_update_t; 111 112 typedef enum { 113 CMAC_IDLE, 114 CMAC_CALC_SUBKEYS, 115 CMAC_W4_SUBKEYS, 116 CMAC_CALC_MI, 117 CMAC_W4_MI, 118 CMAC_CALC_MLAST, 119 CMAC_W4_MLAST 120 } cmac_state_t; 121 122 typedef enum { 123 JUST_WORKS, 124 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 125 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 126 PK_BOTH_INPUT, // Only input on both, both input PK 127 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 128 OOB // OOB available on one (SC) or both sides (legacy) 129 } stk_generation_method_t; 130 131 typedef enum { 132 SM_USER_RESPONSE_IDLE, 133 SM_USER_RESPONSE_PENDING, 134 SM_USER_RESPONSE_CONFIRM, 135 SM_USER_RESPONSE_PASSKEY, 136 SM_USER_RESPONSE_DECLINE 137 } sm_user_response_t; 138 139 typedef enum { 140 SM_AES128_IDLE, 141 SM_AES128_ACTIVE 142 } sm_aes128_state_t; 143 144 typedef enum { 145 ADDRESS_RESOLUTION_IDLE, 146 ADDRESS_RESOLUTION_GENERAL, 147 ADDRESS_RESOLUTION_FOR_CONNECTION, 148 } address_resolution_mode_t; 149 150 typedef enum { 151 ADDRESS_RESOLUTION_SUCCEEDED, 152 ADDRESS_RESOLUTION_FAILED, 153 } address_resolution_event_t; 154 155 typedef enum { 156 EC_KEY_GENERATION_IDLE, 157 EC_KEY_GENERATION_ACTIVE, 158 EC_KEY_GENERATION_DONE, 159 } ec_key_generation_state_t; 160 161 typedef enum { 162 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 163 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 164 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 165 } sm_state_var_t; 166 167 typedef enum { 168 SM_SC_OOB_IDLE, 169 SM_SC_OOB_W4_RANDOM, 170 SM_SC_OOB_W2_CALC_CONFIRM, 171 SM_SC_OOB_W4_CONFIRM, 172 } sm_sc_oob_state_t; 173 174 typedef uint8_t sm_key24_t[3]; 175 typedef uint8_t sm_key56_t[7]; 176 typedef uint8_t sm_key256_t[32]; 177 178 // 179 // GLOBAL DATA 180 // 181 182 static bool sm_initialized; 183 184 static bool test_use_fixed_local_csrk; 185 static bool test_use_fixed_local_irk; 186 187 #ifdef ENABLE_TESTING_SUPPORT 188 static uint8_t test_pairing_failure; 189 #endif 190 191 // configuration 192 static uint8_t sm_accepted_stk_generation_methods; 193 static uint8_t sm_max_encryption_key_size; 194 static uint8_t sm_min_encryption_key_size; 195 static uint8_t sm_auth_req = 0; 196 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 197 static uint32_t sm_fixed_passkey_in_display_role; 198 static bool sm_reconstruct_ltk_without_le_device_db_entry; 199 200 #ifdef ENABLE_LE_PERIPHERAL 201 static uint8_t sm_slave_request_security; 202 #endif 203 204 #ifdef ENABLE_LE_SECURE_CONNECTIONS 205 static bool sm_sc_only_mode; 206 static uint8_t sm_sc_oob_random[16]; 207 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 208 static sm_sc_oob_state_t sm_sc_oob_state; 209 #endif 210 211 212 static bool sm_persistent_keys_random_active; 213 static const btstack_tlv_t * sm_tlv_impl; 214 static void * sm_tlv_context; 215 216 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 217 static sm_key_t sm_persistent_er; 218 static sm_key_t sm_persistent_ir; 219 220 // derived from sm_persistent_ir 221 static sm_key_t sm_persistent_dhk; 222 static sm_key_t sm_persistent_irk; 223 static derived_key_generation_t dkg_state; 224 225 // derived from sm_persistent_er 226 // .. 227 228 // random address update 229 static random_address_update_t rau_state; 230 static bd_addr_t sm_random_address; 231 232 #ifdef USE_CMAC_ENGINE 233 // CMAC Calculation: General 234 static btstack_crypto_aes128_cmac_t sm_cmac_request; 235 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 236 static uint8_t sm_cmac_active; 237 static uint8_t sm_cmac_hash[16]; 238 #endif 239 240 // CMAC for ATT Signed Writes 241 #ifdef ENABLE_LE_SIGNED_WRITE 242 static uint16_t sm_cmac_signed_write_message_len; 243 static uint8_t sm_cmac_signed_write_header[3]; 244 static const uint8_t * sm_cmac_signed_write_message; 245 static uint8_t sm_cmac_signed_write_sign_counter[4]; 246 #endif 247 248 // CMAC for Secure Connection functions 249 #ifdef ENABLE_LE_SECURE_CONNECTIONS 250 static sm_connection_t * sm_cmac_connection; 251 static uint8_t sm_cmac_sc_buffer[80]; 252 #endif 253 254 // resolvable private address lookup / CSRK calculation 255 static int sm_address_resolution_test; 256 static uint8_t sm_address_resolution_addr_type; 257 static bd_addr_t sm_address_resolution_address; 258 static void * sm_address_resolution_context; 259 static address_resolution_mode_t sm_address_resolution_mode; 260 static btstack_linked_list_t sm_address_resolution_general_queue; 261 262 // aes128 crypto engine. 263 static sm_aes128_state_t sm_aes128_state; 264 265 // crypto 266 static btstack_crypto_random_t sm_crypto_random_request; 267 static btstack_crypto_aes128_t sm_crypto_aes128_request; 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 270 #endif 271 272 // temp storage for random data 273 static uint8_t sm_random_data[8]; 274 static uint8_t sm_aes128_key[16]; 275 static uint8_t sm_aes128_plaintext[16]; 276 static uint8_t sm_aes128_ciphertext[16]; 277 278 // to receive events 279 static btstack_packet_callback_registration_t hci_event_callback_registration; 280 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 281 static btstack_packet_callback_registration_t l2cap_event_callback_registration; 282 #endif 283 284 /* to dispatch sm event */ 285 static btstack_linked_list_t sm_event_handlers; 286 287 /* to schedule calls to sm_run */ 288 static btstack_timer_source_t sm_run_timer; 289 290 // LE Secure Connections 291 #ifdef ENABLE_LE_SECURE_CONNECTIONS 292 static ec_key_generation_state_t ec_key_generation_state; 293 static uint8_t ec_q[64]; 294 #endif 295 296 // 297 // Volume 3, Part H, Chapter 24 298 // "Security shall be initiated by the Security Manager in the device in the master role. 299 // The device in the slave role shall be the responding device." 300 // -> master := initiator, slave := responder 301 // 302 303 // data needed for security setup 304 typedef struct sm_setup_context { 305 306 btstack_timer_source_t sm_timeout; 307 308 // user response, (Phase 1 and/or 2) 309 uint8_t sm_user_response; 310 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 311 312 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 313 uint8_t sm_key_distribution_send_set; 314 uint8_t sm_key_distribution_sent_set; 315 uint8_t sm_key_distribution_expected_set; 316 uint8_t sm_key_distribution_received_set; 317 318 // Phase 2 (Pairing over SMP) 319 stk_generation_method_t sm_stk_generation_method; 320 sm_key_t sm_tk; 321 uint8_t sm_have_oob_data; 322 uint8_t sm_use_secure_connections; 323 324 sm_key_t sm_c1_t3_value; // c1 calculation 325 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 326 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 327 sm_key_t sm_local_random; 328 sm_key_t sm_local_confirm; 329 sm_key_t sm_peer_random; 330 sm_key_t sm_peer_confirm; 331 uint8_t sm_m_addr_type; // address and type can be removed 332 uint8_t sm_s_addr_type; // '' 333 bd_addr_t sm_m_address; // '' 334 bd_addr_t sm_s_address; // '' 335 sm_key_t sm_ltk; 336 337 uint8_t sm_state_vars; 338 #ifdef ENABLE_LE_SECURE_CONNECTIONS 339 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 340 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 341 sm_key_t sm_local_nonce; // might be combined with sm_local_random 342 uint8_t sm_dhkey[32]; 343 sm_key_t sm_peer_dhkey_check; 344 sm_key_t sm_local_dhkey_check; 345 sm_key_t sm_ra; 346 sm_key_t sm_rb; 347 sm_key_t sm_t; // used for f5 and h6 348 sm_key_t sm_mackey; 349 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 350 #endif 351 352 // Phase 3 353 354 // key distribution, we generate 355 uint16_t sm_local_y; 356 uint16_t sm_local_div; 357 uint16_t sm_local_ediv; 358 uint8_t sm_local_rand[8]; 359 sm_key_t sm_local_ltk; 360 sm_key_t sm_local_csrk; 361 sm_key_t sm_local_irk; 362 // sm_local_address/addr_type not needed 363 364 // key distribution, received from peer 365 uint16_t sm_peer_y; 366 uint16_t sm_peer_div; 367 uint16_t sm_peer_ediv; 368 uint8_t sm_peer_rand[8]; 369 sm_key_t sm_peer_ltk; 370 sm_key_t sm_peer_irk; 371 sm_key_t sm_peer_csrk; 372 uint8_t sm_peer_addr_type; 373 bd_addr_t sm_peer_address; 374 #ifdef ENABLE_LE_SIGNED_WRITE 375 int sm_le_device_index; 376 #endif 377 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 378 link_key_t sm_link_key; 379 link_key_type_t sm_link_key_type; 380 #endif 381 } sm_setup_context_t; 382 383 // 384 static sm_setup_context_t the_setup; 385 static sm_setup_context_t * setup = &the_setup; 386 387 // active connection - the one for which the_setup is used for 388 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 389 390 // @return 1 if oob data is available 391 // stores oob data in provided 16 byte buffer if not null 392 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 393 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 394 static bool (*sm_get_ltk_callback)(hci_con_handle_t con_handle, uint8_t addres_type, bd_addr_t addr, uint8_t * ltk); 395 396 static void sm_run(void); 397 static void sm_state_reset(void); 398 static void sm_done_for_handle(hci_con_handle_t con_handle); 399 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 400 static void sm_cache_ltk(sm_connection_t * connection, const sm_key_t ltk); 401 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 402 static sm_connection_t * sm_get_connection_for_bd_addr_and_type(bd_addr_t address, bd_addr_type_t addr_type); 403 #endif 404 static inline int sm_calc_actual_encryption_key_size(int other); 405 static int sm_validate_stk_generation_method(void); 406 static void sm_handle_encryption_result_address_resolution(void *arg); 407 static void sm_handle_encryption_result_dkg_dhk(void *arg); 408 static void sm_handle_encryption_result_dkg_irk(void *arg); 409 static void sm_handle_encryption_result_enc_a(void *arg); 410 static void sm_handle_encryption_result_enc_b(void *arg); 411 static void sm_handle_encryption_result_enc_c(void *arg); 412 static void sm_handle_encryption_result_enc_csrk(void *arg); 413 static void sm_handle_encryption_result_enc_d(void * arg); 414 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 415 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 416 #ifdef ENABLE_LE_PERIPHERAL 417 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 418 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 419 #endif 420 static void sm_handle_encryption_result_enc_stk(void *arg); 421 static void sm_handle_encryption_result_rau(void *arg); 422 static void sm_handle_random_result_ph2_tk(void * arg); 423 static void sm_handle_random_result_rau(void * arg); 424 #ifdef ENABLE_LE_SECURE_CONNECTIONS 425 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 426 static void sm_ec_generate_new_key(void); 427 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 428 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 429 static int sm_passkey_entry(stk_generation_method_t method); 430 #endif 431 static void sm_pairing_complete(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 432 433 static void log_info_hex16(const char * name, uint16_t value){ 434 log_info("%-6s 0x%04x", name, value); 435 } 436 437 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 438 // return packet[0]; 439 // } 440 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 441 return packet[1]; 442 } 443 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 444 return packet[2]; 445 } 446 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 447 return packet[3]; 448 } 449 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 450 return packet[4]; 451 } 452 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 453 return packet[5]; 454 } 455 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 456 return packet[6]; 457 } 458 459 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 460 packet[0] = code; 461 } 462 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 463 packet[1] = io_capability; 464 } 465 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 466 packet[2] = oob_data_flag; 467 } 468 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 469 packet[3] = auth_req; 470 } 471 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 472 packet[4] = max_encryption_key_size; 473 } 474 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 475 packet[5] = initiator_key_distribution; 476 } 477 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 478 packet[6] = responder_key_distribution; 479 } 480 481 static bool sm_is_null_random(uint8_t random[8]){ 482 return btstack_is_null(random, 8); 483 } 484 485 static bool sm_is_null_key(uint8_t * key){ 486 return btstack_is_null(key, 16); 487 } 488 489 #ifdef ENABLE_LE_SECURE_CONNECTIONS 490 static bool sm_is_ff(const uint8_t * buffer, uint16_t size){ 491 uint16_t i; 492 for (i=0; i < size ; i++){ 493 if (buffer[i] != 0xff) { 494 return false; 495 } 496 } 497 return true; 498 } 499 #endif 500 501 // sm_trigger_run allows to schedule callback from main run loop // reduces stack depth 502 static void sm_run_timer_handler(btstack_timer_source_t * ts){ 503 UNUSED(ts); 504 sm_run(); 505 } 506 static void sm_trigger_run(void){ 507 if (!sm_initialized) return; 508 (void)btstack_run_loop_remove_timer(&sm_run_timer); 509 btstack_run_loop_set_timer(&sm_run_timer, 0); 510 btstack_run_loop_add_timer(&sm_run_timer); 511 } 512 513 // Key utils 514 static void sm_reset_tk(void){ 515 int i; 516 for (i=0;i<16;i++){ 517 setup->sm_tk[i] = 0; 518 } 519 } 520 521 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 522 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 523 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 524 int i; 525 for (i = max_encryption_size ; i < 16 ; i++){ 526 key[15-i] = 0; 527 } 528 } 529 530 // ER / IR checks 531 static void sm_er_ir_set_default(void){ 532 int i; 533 for (i=0;i<16;i++){ 534 sm_persistent_er[i] = 0x30 + i; 535 sm_persistent_ir[i] = 0x90 + i; 536 } 537 } 538 539 static int sm_er_is_default(void){ 540 int i; 541 for (i=0;i<16;i++){ 542 if (sm_persistent_er[i] != (0x30+i)) return 0; 543 } 544 return 1; 545 } 546 547 static int sm_ir_is_default(void){ 548 int i; 549 for (i=0;i<16;i++){ 550 if (sm_persistent_ir[i] != (0x90+i)) return 0; 551 } 552 return 1; 553 } 554 555 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 556 UNUSED(channel); 557 558 // log event 559 hci_dump_packet(packet_type, 1, packet, size); 560 // dispatch to all event handlers 561 btstack_linked_list_iterator_t it; 562 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 563 while (btstack_linked_list_iterator_has_next(&it)){ 564 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 565 entry->callback(packet_type, 0, packet, size); 566 } 567 } 568 569 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 570 event[0] = type; 571 event[1] = event_size - 2; 572 little_endian_store_16(event, 2, con_handle); 573 event[4] = addr_type; 574 reverse_bd_addr(address, &event[5]); 575 } 576 577 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 578 uint8_t event[11]; 579 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 580 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 581 } 582 583 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 584 // fetch addr and addr type from db, only called for valid entries 585 bd_addr_t identity_address; 586 int identity_address_type; 587 le_device_db_info(index, &identity_address_type, identity_address, NULL); 588 589 uint8_t event[20]; 590 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 591 event[11] = identity_address_type; 592 reverse_bd_addr(identity_address, &event[12]); 593 little_endian_store_16(event, 18, index); 594 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 595 } 596 597 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 598 uint8_t event[12]; 599 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 600 event[11] = status; 601 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 602 } 603 604 605 static void sm_reencryption_started(sm_connection_t * sm_conn){ 606 607 if (sm_conn->sm_reencryption_active) return; 608 609 sm_conn->sm_reencryption_active = true; 610 611 int identity_addr_type; 612 bd_addr_t identity_addr; 613 if (sm_conn->sm_le_db_index >= 0){ 614 // fetch addr and addr type from db, only called for valid entries 615 le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); 616 } else { 617 // for legacy pairing with LTK re-construction, use current peer addr 618 identity_addr_type = sm_conn->sm_peer_addr_type; 619 // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy 620 memcpy(identity_addr, sm_conn->sm_peer_address, 6); 621 } 622 623 sm_notify_client_base(SM_EVENT_REENCRYPTION_STARTED, sm_conn->sm_handle, identity_addr_type, identity_addr); 624 } 625 626 static void sm_reencryption_complete(sm_connection_t * sm_conn, uint8_t status){ 627 628 if (!sm_conn->sm_reencryption_active) return; 629 630 sm_conn->sm_reencryption_active = false; 631 632 int identity_addr_type; 633 bd_addr_t identity_addr; 634 if (sm_conn->sm_le_db_index >= 0){ 635 // fetch addr and addr type from db, only called for valid entries 636 le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); 637 } else { 638 // for legacy pairing with LTK re-construction, use current peer addr 639 identity_addr_type = sm_conn->sm_peer_addr_type; 640 // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy 641 memcpy(identity_addr, sm_conn->sm_peer_address, 6); 642 } 643 644 sm_notify_client_status(SM_EVENT_REENCRYPTION_COMPLETE, sm_conn->sm_handle, identity_addr_type, identity_addr, status); 645 } 646 647 static void sm_pairing_started(sm_connection_t * sm_conn){ 648 649 if (sm_conn->sm_pairing_active) return; 650 651 sm_conn->sm_pairing_active = true; 652 653 uint8_t event[11]; 654 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_STARTED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 655 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 656 } 657 658 static void sm_pairing_complete(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 659 660 if (!sm_conn->sm_pairing_active) return; 661 662 sm_conn->sm_pairing_active = false; 663 664 uint8_t event[13]; 665 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 666 event[11] = status; 667 event[12] = reason; 668 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 669 } 670 671 // SMP Timeout implementation 672 673 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 674 // the Security Manager Timer shall be reset and started. 675 // 676 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 677 // 678 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 679 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 680 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 681 // established. 682 683 static void sm_timeout_handler(btstack_timer_source_t * timer){ 684 log_info("SM timeout"); 685 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 686 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 687 sm_reencryption_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT); 688 sm_pairing_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 689 sm_done_for_handle(sm_conn->sm_handle); 690 691 // trigger handling of next ready connection 692 sm_run(); 693 } 694 static void sm_timeout_start(sm_connection_t * sm_conn){ 695 btstack_run_loop_remove_timer(&setup->sm_timeout); 696 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 697 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 698 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 699 btstack_run_loop_add_timer(&setup->sm_timeout); 700 } 701 static void sm_timeout_stop(void){ 702 btstack_run_loop_remove_timer(&setup->sm_timeout); 703 } 704 static void sm_timeout_reset(sm_connection_t * sm_conn){ 705 sm_timeout_stop(); 706 sm_timeout_start(sm_conn); 707 } 708 709 // end of sm timeout 710 711 // GAP Random Address updates 712 static gap_random_address_type_t gap_random_adress_type; 713 static btstack_timer_source_t gap_random_address_update_timer; 714 static uint32_t gap_random_adress_update_period; 715 716 static void gap_random_address_trigger(void){ 717 log_info("gap_random_address_trigger, state %u", rau_state); 718 if (rau_state != RAU_IDLE) return; 719 rau_state = RAU_GET_RANDOM; 720 sm_trigger_run(); 721 } 722 723 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 724 UNUSED(timer); 725 726 log_info("GAP Random Address Update due"); 727 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 728 btstack_run_loop_add_timer(&gap_random_address_update_timer); 729 gap_random_address_trigger(); 730 } 731 732 static void gap_random_address_update_start(void){ 733 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 734 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 735 btstack_run_loop_add_timer(&gap_random_address_update_timer); 736 } 737 738 static void gap_random_address_update_stop(void){ 739 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 740 } 741 742 // ah(k,r) helper 743 // r = padding || r 744 // r - 24 bit value 745 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 746 // r'= padding || r 747 memset(r_prime, 0, 16); 748 (void)memcpy(&r_prime[13], r, 3); 749 } 750 751 // d1 helper 752 // d' = padding || r || d 753 // d,r - 16 bit values 754 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 755 // d'= padding || r || d 756 memset(d1_prime, 0, 16); 757 big_endian_store_16(d1_prime, 12, r); 758 big_endian_store_16(d1_prime, 14, d); 759 } 760 761 // calculate arguments for first AES128 operation in C1 function 762 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 763 764 // p1 = pres || preq || rat’ || iat’ 765 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 766 // cant octet of pres becomes the most significant octet of p1. 767 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 768 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 769 // p1 is 0x05000800000302070710000001010001." 770 771 sm_key_t p1; 772 reverse_56(pres, &p1[0]); 773 reverse_56(preq, &p1[7]); 774 p1[14] = rat; 775 p1[15] = iat; 776 log_info_key("p1", p1); 777 log_info_key("r", r); 778 779 // t1 = r xor p1 780 int i; 781 for (i=0;i<16;i++){ 782 t1[i] = r[i] ^ p1[i]; 783 } 784 log_info_key("t1", t1); 785 } 786 787 // calculate arguments for second AES128 operation in C1 function 788 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 789 // p2 = padding || ia || ra 790 // "The least significant octet of ra becomes the least significant octet of p2 and 791 // the most significant octet of padding becomes the most significant octet of p2. 792 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 793 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 794 795 sm_key_t p2; 796 // cppcheck-suppress uninitvar ; p2 is reported as uninitialized 797 memset(p2, 0, 16); 798 (void)memcpy(&p2[4], ia, 6); 799 (void)memcpy(&p2[10], ra, 6); 800 log_info_key("p2", p2); 801 802 // c1 = e(k, t2_xor_p2) 803 int i; 804 for (i=0;i<16;i++){ 805 t3[i] = t2[i] ^ p2[i]; 806 } 807 log_info_key("t3", t3); 808 } 809 810 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 811 log_info_key("r1", r1); 812 log_info_key("r2", r2); 813 (void)memcpy(&r_prime[8], &r2[8], 8); 814 (void)memcpy(&r_prime[0], &r1[8], 8); 815 } 816 817 818 // decide on stk generation based on 819 // - pairing request 820 // - io capabilities 821 // - OOB data availability 822 static void sm_setup_tk(void){ 823 824 // horizontal: initiator capabilities 825 // vertial: responder capabilities 826 static const stk_generation_method_t stk_generation_method [5] [5] = { 827 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 828 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 829 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 830 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 831 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 832 }; 833 834 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 835 #ifdef ENABLE_LE_SECURE_CONNECTIONS 836 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 837 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 838 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 839 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 840 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 841 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 842 }; 843 #endif 844 845 // default: just works 846 setup->sm_stk_generation_method = JUST_WORKS; 847 848 #ifdef ENABLE_LE_SECURE_CONNECTIONS 849 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 850 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 851 & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; 852 #else 853 setup->sm_use_secure_connections = 0; 854 #endif 855 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 856 857 858 // decide if OOB will be used based on SC vs. Legacy and oob flags 859 bool use_oob; 860 if (setup->sm_use_secure_connections){ 861 // In LE Secure Connections pairing, the out of band method is used if at least 862 // one device has the peer device's out of band authentication data available. 863 use_oob = (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)) != 0; 864 } else { 865 // In LE legacy pairing, the out of band method is used if both the devices have 866 // the other device's out of band authentication data available. 867 use_oob = (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)) != 0; 868 } 869 if (use_oob){ 870 log_info("SM: have OOB data"); 871 log_info_key("OOB", setup->sm_tk); 872 setup->sm_stk_generation_method = OOB; 873 return; 874 } 875 876 // If both devices have not set the MITM option in the Authentication Requirements 877 // Flags, then the IO capabilities shall be ignored and the Just Works association 878 // model shall be used. 879 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) 880 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ 881 log_info("SM: MITM not required by both -> JUST WORKS"); 882 return; 883 } 884 885 // Reset TK as it has been setup in sm_init_setup 886 sm_reset_tk(); 887 888 // Also use just works if unknown io capabilites 889 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 890 return; 891 } 892 893 // Otherwise the IO capabilities of the devices shall be used to determine the 894 // pairing method as defined in Table 2.4. 895 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 896 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 897 898 #ifdef ENABLE_LE_SECURE_CONNECTIONS 899 // table not define by default 900 if (setup->sm_use_secure_connections){ 901 generation_method = stk_generation_method_with_secure_connection; 902 } 903 #endif 904 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 905 906 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 907 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 908 } 909 910 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 911 int flags = 0; 912 if (key_set & SM_KEYDIST_ENC_KEY){ 913 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 914 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 915 } 916 if (key_set & SM_KEYDIST_ID_KEY){ 917 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 918 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 919 } 920 if (key_set & SM_KEYDIST_SIGN){ 921 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 922 } 923 return flags; 924 } 925 926 static void sm_setup_key_distribution(uint8_t keys_to_send, uint8_t keys_to_receive){ 927 setup->sm_key_distribution_received_set = 0; 928 setup->sm_key_distribution_expected_set = sm_key_distribution_flags_for_set(keys_to_receive); 929 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(keys_to_send); 930 setup->sm_key_distribution_sent_set = 0; 931 #ifdef ENABLE_LE_SIGNED_WRITE 932 setup->sm_le_device_index = -1; 933 #endif 934 } 935 936 // CSRK Key Lookup 937 938 939 static int sm_address_resolution_idle(void){ 940 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 941 } 942 943 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 944 (void)memcpy(sm_address_resolution_address, addr, 6); 945 sm_address_resolution_addr_type = addr_type; 946 sm_address_resolution_test = 0; 947 sm_address_resolution_mode = mode; 948 sm_address_resolution_context = context; 949 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 950 } 951 952 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 953 // check if already in list 954 btstack_linked_list_iterator_t it; 955 sm_lookup_entry_t * entry; 956 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 957 while(btstack_linked_list_iterator_has_next(&it)){ 958 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 959 if (entry->address_type != address_type) continue; 960 if (memcmp(entry->address, address, 6)) continue; 961 // already in list 962 return BTSTACK_BUSY; 963 } 964 entry = btstack_memory_sm_lookup_entry_get(); 965 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 966 entry->address_type = (bd_addr_type_t) address_type; 967 (void)memcpy(entry->address, address, 6); 968 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 969 sm_trigger_run(); 970 return 0; 971 } 972 973 // CMAC calculation using AES Engineq 974 #ifdef USE_CMAC_ENGINE 975 976 static void sm_cmac_done_trampoline(void * arg){ 977 UNUSED(arg); 978 sm_cmac_active = 0; 979 (*sm_cmac_done_callback)(sm_cmac_hash); 980 sm_trigger_run(); 981 } 982 983 int sm_cmac_ready(void){ 984 return sm_cmac_active == 0u; 985 } 986 #endif 987 988 #ifdef ENABLE_LE_SECURE_CONNECTIONS 989 // generic cmac calculation 990 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 991 sm_cmac_active = 1; 992 sm_cmac_done_callback = done_callback; 993 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 994 } 995 #endif 996 997 // cmac for ATT Message signing 998 #ifdef ENABLE_LE_SIGNED_WRITE 999 1000 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 1001 sm_cmac_active = 1; 1002 sm_cmac_done_callback = done_callback; 1003 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 1004 } 1005 1006 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 1007 if (offset >= sm_cmac_signed_write_message_len) { 1008 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 1009 return 0; 1010 } 1011 1012 offset = sm_cmac_signed_write_message_len - 1 - offset; 1013 1014 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 1015 if (offset < 3){ 1016 return sm_cmac_signed_write_header[offset]; 1017 } 1018 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 1019 if (offset < actual_message_len_incl_header){ 1020 return sm_cmac_signed_write_message[offset - 3]; 1021 } 1022 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 1023 } 1024 1025 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 1026 // ATT Message Signing 1027 sm_cmac_signed_write_header[0] = opcode; 1028 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 1029 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 1030 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 1031 sm_cmac_signed_write_message = message; 1032 sm_cmac_signed_write_message_len = total_message_len; 1033 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 1034 } 1035 #endif 1036 1037 static void sm_trigger_user_response_basic(sm_connection_t * sm_conn, uint8_t event_type){ 1038 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1039 uint8_t event[12]; 1040 sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1041 event[11] = setup->sm_use_secure_connections ? 1 : 0; 1042 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1043 } 1044 1045 static void sm_trigger_user_response_passkey(sm_connection_t * sm_conn, uint8_t event_type){ 1046 uint8_t event[16]; 1047 uint32_t passkey = big_endian_read_32(setup->sm_tk, 12); 1048 sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, 1049 sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1050 event[11] = setup->sm_use_secure_connections ? 1 : 0; 1051 little_endian_store_32(event, 12, passkey); 1052 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1053 } 1054 1055 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1056 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1057 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1058 sm_conn->sm_pairing_active = true; 1059 switch (setup->sm_stk_generation_method){ 1060 case PK_RESP_INPUT: 1061 if (IS_RESPONDER(sm_conn->sm_role)){ 1062 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1063 } else { 1064 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); 1065 } 1066 break; 1067 case PK_INIT_INPUT: 1068 if (IS_RESPONDER(sm_conn->sm_role)){ 1069 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); 1070 } else { 1071 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1072 } 1073 break; 1074 case PK_BOTH_INPUT: 1075 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1076 break; 1077 case NUMERIC_COMPARISON: 1078 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_NUMERIC_COMPARISON_REQUEST); 1079 break; 1080 case JUST_WORKS: 1081 sm_trigger_user_response_basic(sm_conn, SM_EVENT_JUST_WORKS_REQUEST); 1082 break; 1083 case OOB: 1084 // client already provided OOB data, let's skip notification. 1085 break; 1086 default: 1087 btstack_assert(false); 1088 break; 1089 } 1090 } 1091 1092 static bool sm_key_distribution_all_received(void) { 1093 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, setup->sm_key_distribution_expected_set); 1094 return (setup->sm_key_distribution_expected_set & setup->sm_key_distribution_received_set) == setup->sm_key_distribution_expected_set; 1095 } 1096 1097 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1098 if (sm_active_connection_handle == con_handle){ 1099 sm_timeout_stop(); 1100 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1101 log_info("sm: connection 0x%x released setup context", con_handle); 1102 1103 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1104 // generate new ec key after each pairing (that used it) 1105 if (setup->sm_use_secure_connections){ 1106 sm_ec_generate_new_key(); 1107 } 1108 #endif 1109 } 1110 } 1111 1112 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1113 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1114 sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); 1115 sm_done_for_handle(connection->sm_handle); 1116 } 1117 1118 static int sm_key_distribution_flags_for_auth_req(void){ 1119 1120 int flags = SM_KEYDIST_ID_KEY; 1121 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1122 // encryption and signing information only if bonding requested 1123 flags |= SM_KEYDIST_ENC_KEY; 1124 #ifdef ENABLE_LE_SIGNED_WRITE 1125 flags |= SM_KEYDIST_SIGN; 1126 #endif 1127 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1128 // LinkKey for CTKD requires SC 1129 if (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 1130 flags |= SM_KEYDIST_LINK_KEY; 1131 } 1132 #endif 1133 } 1134 return flags; 1135 } 1136 1137 static void sm_reset_setup(void){ 1138 // fill in sm setup 1139 setup->sm_state_vars = 0; 1140 setup->sm_keypress_notification = 0; 1141 setup->sm_have_oob_data = 0; 1142 sm_reset_tk(); 1143 } 1144 1145 static void sm_init_setup(sm_connection_t * sm_conn){ 1146 // fill in sm setup 1147 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1148 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1149 1150 // query client for Legacy Pairing OOB data 1151 if (sm_get_oob_data != NULL) { 1152 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1153 } 1154 1155 // if available and SC supported, also ask for SC OOB Data 1156 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1157 memset(setup->sm_ra, 0, 16); 1158 memset(setup->sm_rb, 0, 16); 1159 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1160 if (sm_get_sc_oob_data != NULL){ 1161 if (IS_RESPONDER(sm_conn->sm_role)){ 1162 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1163 sm_conn->sm_peer_addr_type, 1164 sm_conn->sm_peer_address, 1165 setup->sm_peer_confirm, 1166 setup->sm_ra); 1167 } else { 1168 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1169 sm_conn->sm_peer_addr_type, 1170 sm_conn->sm_peer_address, 1171 setup->sm_peer_confirm, 1172 setup->sm_rb); 1173 } 1174 } else { 1175 setup->sm_have_oob_data = 0; 1176 } 1177 } 1178 #endif 1179 1180 sm_pairing_packet_t * local_packet; 1181 if (IS_RESPONDER(sm_conn->sm_role)){ 1182 // slave 1183 local_packet = &setup->sm_s_pres; 1184 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1185 setup->sm_s_addr_type = sm_conn->sm_own_addr_type; 1186 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1187 (void)memcpy(setup->sm_s_address, sm_conn->sm_own_address, 6); 1188 } else { 1189 // master 1190 local_packet = &setup->sm_m_preq; 1191 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1192 setup->sm_m_addr_type = sm_conn->sm_own_addr_type; 1193 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1194 (void)memcpy(setup->sm_m_address, sm_conn->sm_own_address, 6); 1195 1196 uint8_t key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1197 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1198 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1199 } 1200 1201 uint8_t auth_req = sm_auth_req & ~SM_AUTHREQ_CT2; 1202 uint8_t max_encryption_key_size = sm_max_encryption_key_size; 1203 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1204 // enable SC for SC only mode 1205 if (sm_sc_only_mode){ 1206 auth_req |= SM_AUTHREQ_SECURE_CONNECTION; 1207 max_encryption_key_size = 16; 1208 } 1209 #endif 1210 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1211 // set CT2 if SC + Bonding + CTKD 1212 const uint8_t auth_req_for_ct2 = SM_AUTHREQ_SECURE_CONNECTION | SM_AUTHREQ_BONDING; 1213 if ((auth_req & auth_req_for_ct2) == auth_req_for_ct2){ 1214 auth_req |= SM_AUTHREQ_CT2; 1215 } 1216 #endif 1217 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1218 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1219 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1220 sm_pairing_packet_set_max_encryption_key_size(*local_packet, max_encryption_key_size); 1221 } 1222 1223 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1224 1225 sm_pairing_packet_t * remote_packet; 1226 uint8_t keys_to_send; 1227 uint8_t keys_to_receive; 1228 if (IS_RESPONDER(sm_conn->sm_role)){ 1229 // slave / responder 1230 remote_packet = &setup->sm_m_preq; 1231 keys_to_send = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1232 keys_to_receive = sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq); 1233 } else { 1234 // master / initiator 1235 remote_packet = &setup->sm_s_pres; 1236 keys_to_send = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1237 keys_to_receive = sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres); 1238 } 1239 1240 // check key size 1241 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1242 // SC Only mandates 128 bit key size 1243 if (sm_sc_only_mode && (sm_pairing_packet_get_max_encryption_key_size(*remote_packet) < 16)) { 1244 return SM_REASON_ENCRYPTION_KEY_SIZE; 1245 } 1246 #endif 1247 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1248 if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; 1249 1250 // decide on STK generation method / SC 1251 sm_setup_tk(); 1252 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1253 1254 // check if STK generation method is acceptable by client 1255 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1256 1257 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1258 // Check LE SC Only mode 1259 if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ 1260 log_info("SC Only mode active but SC not possible"); 1261 return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1262 } 1263 1264 // LTK (= encryption information & master identification) only used exchanged for LE Legacy Connection 1265 if (setup->sm_use_secure_connections){ 1266 keys_to_send &= ~SM_KEYDIST_ENC_KEY; 1267 keys_to_receive &= ~SM_KEYDIST_ENC_KEY; 1268 } 1269 #endif 1270 1271 // identical to responder 1272 sm_setup_key_distribution(keys_to_send, keys_to_receive); 1273 1274 // JUST WORKS doens't provide authentication 1275 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1276 1277 return 0; 1278 } 1279 1280 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1281 1282 // cache and reset context 1283 int matched_device_id = sm_address_resolution_test; 1284 address_resolution_mode_t mode = sm_address_resolution_mode; 1285 void * context = sm_address_resolution_context; 1286 1287 // reset context 1288 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1289 sm_address_resolution_context = NULL; 1290 sm_address_resolution_test = -1; 1291 hci_con_handle_t con_handle = 0; 1292 1293 sm_connection_t * sm_connection; 1294 sm_key_t ltk; 1295 bool have_ltk; 1296 #ifdef ENABLE_LE_CENTRAL 1297 bool trigger_pairing; 1298 int authenticated; 1299 #endif 1300 switch (mode){ 1301 case ADDRESS_RESOLUTION_GENERAL: 1302 break; 1303 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1304 sm_connection = (sm_connection_t *) context; 1305 con_handle = sm_connection->sm_handle; 1306 1307 // have ltk -> start encryption / send security request 1308 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1309 // "When a bond has been created between two devices, any reconnection should result in the local device 1310 // enabling or requesting encryption with the remote device before initiating any service request." 1311 1312 switch (event){ 1313 case ADDRESS_RESOLUTION_SUCCEEDED: 1314 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1315 sm_connection->sm_le_db_index = matched_device_id; 1316 log_info("ADDRESS_RESOLUTION_SUCCEEDED, index %d", sm_connection->sm_le_db_index); 1317 1318 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); 1319 have_ltk = !sm_is_null_key(ltk); 1320 1321 if (sm_connection->sm_role) { 1322 #ifdef ENABLE_LE_PERIPHERAL 1323 // IRK required before, continue 1324 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1325 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1326 break; 1327 } 1328 if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK){ 1329 sm_connection->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 1330 break; 1331 } 1332 bool trigger_security_request = (sm_connection->sm_pairing_requested != 0) || (sm_slave_request_security != 0); 1333 sm_connection->sm_pairing_requested = 0; 1334 #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION 1335 // trigger security request for Proactive Authentication if LTK available 1336 trigger_security_request = trigger_security_request || have_ltk; 1337 #endif 1338 1339 log_info("peripheral: pairing request local %u, have_ltk %u => trigger_security_request %u", 1340 sm_connection->sm_pairing_requested, (int) have_ltk, trigger_security_request); 1341 1342 if (trigger_security_request){ 1343 sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 1344 if (have_ltk){ 1345 sm_reencryption_started(sm_connection); 1346 } else { 1347 sm_pairing_started(sm_connection); 1348 } 1349 sm_trigger_run(); 1350 } 1351 #endif 1352 } else { 1353 1354 #ifdef ENABLE_LE_CENTRAL 1355 // check if pairing already requested and reset requests 1356 trigger_pairing = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1357 bool auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; 1358 1359 log_info("central: pairing request local %u, remote %u => trigger_pairing %u. have_ltk %u", 1360 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, (int) trigger_pairing, (int) have_ltk); 1361 sm_connection->sm_security_request_received = 0; 1362 sm_connection->sm_pairing_requested = 0; 1363 bool trigger_reencryption = false; 1364 1365 if (have_ltk){ 1366 if (trigger_pairing){ 1367 // if pairing is requested, re-encryption is sufficient, if ltk is already authenticated or we don't require authentication 1368 trigger_reencryption = (authenticated != 0) || (auth_required == false); 1369 } else { 1370 #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION 1371 trigger_reencryption = true; 1372 #else 1373 log_info("central: defer enabling encryption for bonded device"); 1374 #endif 1375 } 1376 } 1377 1378 if (trigger_reencryption){ 1379 log_info("central: enable encryption for bonded device"); 1380 sm_connection->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 1381 break; 1382 } 1383 1384 // pairing_request -> send pairing request 1385 if (trigger_pairing){ 1386 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1387 break; 1388 } 1389 #endif 1390 } 1391 break; 1392 case ADDRESS_RESOLUTION_FAILED: 1393 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1394 if (sm_connection->sm_role) { 1395 #ifdef ENABLE_LE_PERIPHERAL 1396 // LTK request received before, IRK required -> negative LTK reply 1397 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1398 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1399 } 1400 // send security request if requested 1401 bool trigger_security_request = (sm_connection->sm_pairing_requested != 0) || (sm_slave_request_security != 0); 1402 sm_connection->sm_pairing_requested = 0; 1403 if (trigger_security_request){ 1404 sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 1405 sm_pairing_started(sm_connection); 1406 } 1407 break; 1408 #endif 1409 } 1410 #ifdef ENABLE_LE_CENTRAL 1411 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1412 sm_connection->sm_security_request_received = 0; 1413 sm_connection->sm_pairing_requested = 0; 1414 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1415 #endif 1416 break; 1417 1418 default: 1419 btstack_assert(false); 1420 break; 1421 } 1422 break; 1423 default: 1424 break; 1425 } 1426 1427 switch (event){ 1428 case ADDRESS_RESOLUTION_SUCCEEDED: 1429 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1430 break; 1431 case ADDRESS_RESOLUTION_FAILED: 1432 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1433 break; 1434 default: 1435 btstack_assert(false); 1436 break; 1437 } 1438 } 1439 1440 static void sm_store_bonding_information(sm_connection_t * sm_conn){ 1441 int le_db_index = -1; 1442 1443 // lookup device based on IRK 1444 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1445 int i; 1446 for (i=0; i < le_device_db_max_count(); i++){ 1447 sm_key_t irk; 1448 bd_addr_t address; 1449 int address_type = BD_ADDR_TYPE_UNKNOWN; 1450 le_device_db_info(i, &address_type, address, irk); 1451 // skip unused entries 1452 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1453 // compare Identity Address 1454 if (memcmp(address, setup->sm_peer_address, 6) != 0) continue; 1455 // compare Identity Resolving Key 1456 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1457 1458 log_info("sm: device found for IRK, updating"); 1459 le_db_index = i; 1460 break; 1461 } 1462 } else { 1463 // assert IRK is set to zero 1464 memset(setup->sm_peer_irk, 0, 16); 1465 } 1466 1467 // if not found, lookup via public address if possible 1468 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1469 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1470 int i; 1471 for (i=0; i < le_device_db_max_count(); i++){ 1472 bd_addr_t address; 1473 int address_type = BD_ADDR_TYPE_UNKNOWN; 1474 le_device_db_info(i, &address_type, address, NULL); 1475 // skip unused entries 1476 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1477 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1478 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1479 log_info("sm: device found for public address, updating"); 1480 le_db_index = i; 1481 break; 1482 } 1483 } 1484 } 1485 1486 // if not found, add to db 1487 bool new_to_le_device_db = false; 1488 if (le_db_index < 0) { 1489 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1490 new_to_le_device_db = true; 1491 } 1492 1493 if (le_db_index >= 0){ 1494 1495 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1496 if (!new_to_le_device_db){ 1497 hci_remove_le_device_db_entry_from_resolving_list(le_db_index); 1498 } 1499 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1500 #else 1501 UNUSED(new_to_le_device_db); 1502 #endif 1503 1504 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1505 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1506 sm_conn->sm_le_db_index = le_db_index; 1507 1508 #ifdef ENABLE_LE_SIGNED_WRITE 1509 // store local CSRK 1510 setup->sm_le_device_index = le_db_index; 1511 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1512 log_info("sm: store local CSRK"); 1513 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1514 le_device_db_local_counter_set(le_db_index, 0); 1515 } 1516 1517 // store remote CSRK 1518 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1519 log_info("sm: store remote CSRK"); 1520 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1521 le_device_db_remote_counter_set(le_db_index, 0); 1522 } 1523 #endif 1524 // store encryption information for secure connections: LTK generated by ECDH 1525 if (setup->sm_use_secure_connections){ 1526 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1527 uint8_t zero_rand[8]; 1528 memset(zero_rand, 0, 8); 1529 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1530 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1531 } 1532 1533 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1534 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1535 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1536 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1537 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1538 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1539 1540 } 1541 } 1542 } 1543 1544 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1545 sm_conn->sm_pairing_failed_reason = reason; 1546 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1547 } 1548 1549 static int sm_le_device_db_index_lookup(bd_addr_type_t address_type, bd_addr_t address){ 1550 int i; 1551 for (i=0; i < le_device_db_max_count(); i++){ 1552 bd_addr_t db_address; 1553 int db_address_type = BD_ADDR_TYPE_UNKNOWN; 1554 le_device_db_info(i, &db_address_type, db_address, NULL); 1555 // skip unused entries 1556 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1557 if ((address_type == db_address_type) && (memcmp(address, db_address, 6) == 0)){ 1558 return i; 1559 } 1560 } 1561 return -1; 1562 } 1563 1564 static void sm_remove_le_device_db_entry(uint16_t i) { 1565 le_device_db_remove(i); 1566 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1567 // to remove an entry from the resolving list requires its identity address, which was already deleted 1568 // fully reload resolving list instead 1569 gap_load_resolving_list_from_le_device_db(); 1570 #endif 1571 } 1572 1573 static uint8_t sm_key_distribution_validate_received(sm_connection_t * sm_conn){ 1574 // if identity is provided, abort if we have bonding with same address but different irk 1575 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1576 int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, setup->sm_peer_address); 1577 if (index >= 0){ 1578 sm_key_t irk; 1579 le_device_db_info(index, NULL, NULL, irk); 1580 if (memcmp(irk, setup->sm_peer_irk, 16) != 0){ 1581 // IRK doesn't match, delete bonding information 1582 log_info("New IRK for %s (type %u) does not match stored IRK -> delete bonding information", bd_addr_to_str(sm_conn->sm_peer_address), sm_conn->sm_peer_addr_type); 1583 sm_remove_le_device_db_entry(index); 1584 } 1585 } 1586 } 1587 return 0; 1588 } 1589 1590 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1591 1592 // abort pairing if received keys are not valid 1593 uint8_t reason = sm_key_distribution_validate_received(sm_conn); 1594 if (reason != 0){ 1595 sm_pairing_error(sm_conn, reason); 1596 return; 1597 } 1598 1599 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1600 bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1601 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1602 & SM_AUTHREQ_BONDING ) != 0u; 1603 1604 if (bonding_enabled){ 1605 sm_store_bonding_information(sm_conn); 1606 } else { 1607 log_info("Ignoring received keys, bonding not enabled"); 1608 } 1609 } 1610 1611 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1612 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1613 } 1614 1615 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1616 1617 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1618 static int sm_passkey_used(stk_generation_method_t method); 1619 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1620 1621 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1622 if (setup->sm_stk_generation_method == OOB){ 1623 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1624 } else { 1625 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_w2_cmac_for_confirmation, (void *)(uintptr_t) sm_conn->sm_handle); 1626 } 1627 } 1628 1629 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1630 if (IS_RESPONDER(sm_conn->sm_role)){ 1631 // Responder 1632 if (setup->sm_stk_generation_method == OOB){ 1633 // generate Nb 1634 log_info("Generate Nb"); 1635 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void *)(uintptr_t) sm_conn->sm_handle); 1636 } else { 1637 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1638 } 1639 } else { 1640 // Initiator role 1641 switch (setup->sm_stk_generation_method){ 1642 case JUST_WORKS: 1643 sm_sc_prepare_dhkey_check(sm_conn); 1644 break; 1645 1646 case NUMERIC_COMPARISON: 1647 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1648 break; 1649 case PK_INIT_INPUT: 1650 case PK_RESP_INPUT: 1651 case PK_BOTH_INPUT: 1652 if (setup->sm_passkey_bit < 20u) { 1653 sm_sc_start_calculating_local_confirm(sm_conn); 1654 } else { 1655 sm_sc_prepare_dhkey_check(sm_conn); 1656 } 1657 break; 1658 case OOB: 1659 sm_sc_prepare_dhkey_check(sm_conn); 1660 break; 1661 default: 1662 btstack_assert(false); 1663 break; 1664 } 1665 } 1666 } 1667 1668 static void sm_sc_cmac_done(uint8_t * hash){ 1669 log_info("sm_sc_cmac_done: "); 1670 log_info_hexdump(hash, 16); 1671 1672 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1673 sm_sc_oob_state = SM_SC_OOB_IDLE; 1674 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1675 return; 1676 } 1677 1678 sm_connection_t * sm_conn = sm_cmac_connection; 1679 sm_cmac_connection = NULL; 1680 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1681 link_key_type_t link_key_type; 1682 #endif 1683 1684 switch (sm_conn->sm_engine_state){ 1685 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1686 (void)memcpy(setup->sm_local_confirm, hash, 16); 1687 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1688 break; 1689 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1690 // check 1691 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1692 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1693 break; 1694 } 1695 sm_sc_state_after_receiving_random(sm_conn); 1696 break; 1697 case SM_SC_W4_CALCULATE_G2: { 1698 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1699 big_endian_store_32(setup->sm_tk, 12, vab); 1700 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1701 sm_trigger_user_response(sm_conn); 1702 break; 1703 } 1704 case SM_SC_W4_CALCULATE_F5_SALT: 1705 (void)memcpy(setup->sm_t, hash, 16); 1706 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1707 break; 1708 case SM_SC_W4_CALCULATE_F5_MACKEY: 1709 (void)memcpy(setup->sm_mackey, hash, 16); 1710 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1711 break; 1712 case SM_SC_W4_CALCULATE_F5_LTK: 1713 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1714 // Errata Service Release to the Bluetooth Specification: ESR09 1715 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1716 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1717 (void)memcpy(setup->sm_ltk, hash, 16); 1718 (void)memcpy(setup->sm_local_ltk, hash, 16); 1719 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1720 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1721 break; 1722 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1723 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1724 if (IS_RESPONDER(sm_conn->sm_role)){ 1725 // responder 1726 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1727 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1728 } else { 1729 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1730 } 1731 } else { 1732 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1733 } 1734 break; 1735 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1736 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1737 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1738 break; 1739 } 1740 if (IS_RESPONDER(sm_conn->sm_role)){ 1741 // responder 1742 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1743 } else { 1744 // initiator 1745 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1746 } 1747 break; 1748 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1749 case SM_SC_W4_CALCULATE_ILK: 1750 (void)memcpy(setup->sm_t, hash, 16); 1751 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY; 1752 break; 1753 case SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY: 1754 reverse_128(hash, setup->sm_t); 1755 link_key_type = sm_conn->sm_connection_authenticated ? 1756 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1757 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1758 gap_store_link_key_for_bd_addr(setup->sm_peer_address, setup->sm_t, link_key_type); 1759 if (IS_RESPONDER(sm_conn->sm_role)){ 1760 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1761 } else { 1762 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1763 } 1764 sm_pairing_complete(sm_conn, ERROR_CODE_SUCCESS, 0); 1765 sm_done_for_handle(sm_conn->sm_handle); 1766 break; 1767 case SM_BR_EDR_W4_CALCULATE_ILK: 1768 (void)memcpy(setup->sm_t, hash, 16); 1769 sm_conn->sm_engine_state = SM_BR_EDR_W2_CALCULATE_LE_LTK; 1770 break; 1771 case SM_BR_EDR_W4_CALCULATE_LE_LTK: 1772 log_info("Derived LE LTK from BR/EDR Link Key"); 1773 log_info_key("Link Key", hash); 1774 (void)memcpy(setup->sm_ltk, hash, 16); 1775 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1776 sm_conn->sm_connection_authenticated = setup->sm_link_key_type == AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1777 sm_store_bonding_information(sm_conn); 1778 sm_done_for_handle(sm_conn->sm_handle); 1779 break; 1780 #endif 1781 default: 1782 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1783 break; 1784 } 1785 sm_trigger_run(); 1786 } 1787 1788 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1789 const uint16_t message_len = 65; 1790 sm_cmac_connection = sm_conn; 1791 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1792 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1793 sm_cmac_sc_buffer[64] = z; 1794 log_info("f4 key"); 1795 log_info_hexdump(x, 16); 1796 log_info("f4 message"); 1797 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1798 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1799 } 1800 1801 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1802 static const uint8_t f5_length[] = { 0x01, 0x00}; 1803 1804 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1805 1806 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1807 1808 log_info("f5_calculate_salt"); 1809 // calculate salt for f5 1810 const uint16_t message_len = 32; 1811 sm_cmac_connection = sm_conn; 1812 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1813 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1814 } 1815 1816 static inline void f5_mackkey(sm_connection_t * sm_conn, sm_key_t t, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ 1817 const uint16_t message_len = 53; 1818 sm_cmac_connection = sm_conn; 1819 1820 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1821 sm_cmac_sc_buffer[0] = 0; 1822 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1823 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1824 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1825 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1826 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1827 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1828 log_info("f5 key"); 1829 log_info_hexdump(t, 16); 1830 log_info("f5 message for MacKey"); 1831 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1832 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1833 } 1834 1835 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1836 sm_key56_t bd_addr_master, bd_addr_slave; 1837 bd_addr_master[0] = setup->sm_m_addr_type; 1838 bd_addr_slave[0] = setup->sm_s_addr_type; 1839 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1840 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1841 if (IS_RESPONDER(sm_conn->sm_role)){ 1842 // responder 1843 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1844 } else { 1845 // initiator 1846 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1847 } 1848 } 1849 1850 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1851 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1852 const uint16_t message_len = 53; 1853 sm_cmac_connection = sm_conn; 1854 sm_cmac_sc_buffer[0] = 1; 1855 // 1..52 setup before 1856 log_info("f5 key"); 1857 log_info_hexdump(t, 16); 1858 log_info("f5 message for LTK"); 1859 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1860 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1861 } 1862 1863 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1864 f5_ltk(sm_conn, setup->sm_t); 1865 } 1866 1867 static void f6_setup(const sm_key_t n1, const sm_key_t n2, const sm_key_t r, const sm_key24_t io_cap, const sm_key56_t a1, const sm_key56_t a2){ 1868 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1869 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1870 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1871 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1872 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1873 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1874 } 1875 1876 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1877 const uint16_t message_len = 65; 1878 sm_cmac_connection = sm_conn; 1879 log_info("f6 key"); 1880 log_info_hexdump(w, 16); 1881 log_info("f6 message"); 1882 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1883 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1884 } 1885 1886 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1887 // - U is 256 bits 1888 // - V is 256 bits 1889 // - X is 128 bits 1890 // - Y is 128 bits 1891 static void g2_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ 1892 const uint16_t message_len = 80; 1893 sm_cmac_connection = sm_conn; 1894 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1895 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1896 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1897 log_info("g2 key"); 1898 log_info_hexdump(x, 16); 1899 log_info("g2 message"); 1900 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1901 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1902 } 1903 1904 static void g2_calculate(sm_connection_t * sm_conn) { 1905 // calc Va if numeric comparison 1906 if (IS_RESPONDER(sm_conn->sm_role)){ 1907 // responder 1908 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1909 } else { 1910 // initiator 1911 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1912 } 1913 } 1914 1915 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1916 uint8_t z = 0; 1917 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1918 // some form of passkey 1919 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1920 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1921 setup->sm_passkey_bit++; 1922 } 1923 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1924 } 1925 1926 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1927 // OOB 1928 if (setup->sm_stk_generation_method == OOB){ 1929 if (IS_RESPONDER(sm_conn->sm_role)){ 1930 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1931 } else { 1932 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1933 } 1934 return; 1935 } 1936 1937 uint8_t z = 0; 1938 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1939 // some form of passkey 1940 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1941 // sm_passkey_bit was increased before sending confirm value 1942 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1943 } 1944 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1945 } 1946 1947 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1948 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1949 1950 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1951 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1952 return; 1953 } else { 1954 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1955 } 1956 } 1957 1958 static void sm_sc_dhkey_calculated(void * arg){ 1959 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1960 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1961 if (sm_conn == NULL) return; 1962 1963 // check for invalid public key detected by Controller 1964 if (sm_is_ff(setup->sm_dhkey, 32)){ 1965 log_info("sm: peer public key invalid"); 1966 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1967 return; 1968 } 1969 1970 log_info("dhkey"); 1971 log_info_hexdump(&setup->sm_dhkey[0], 32); 1972 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1973 // trigger next step 1974 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1975 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1976 } 1977 sm_trigger_run(); 1978 } 1979 1980 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1981 // calculate DHKCheck 1982 sm_key56_t bd_addr_master, bd_addr_slave; 1983 bd_addr_master[0] = setup->sm_m_addr_type; 1984 bd_addr_slave[0] = setup->sm_s_addr_type; 1985 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1986 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1987 uint8_t iocap_a[3]; 1988 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1989 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1990 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1991 uint8_t iocap_b[3]; 1992 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1993 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1994 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1995 if (IS_RESPONDER(sm_conn->sm_role)){ 1996 // responder 1997 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1998 f6_engine(sm_conn, setup->sm_mackey); 1999 } else { 2000 // initiator 2001 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 2002 f6_engine(sm_conn, setup->sm_mackey); 2003 } 2004 } 2005 2006 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 2007 // validate E = f6() 2008 sm_key56_t bd_addr_master, bd_addr_slave; 2009 bd_addr_master[0] = setup->sm_m_addr_type; 2010 bd_addr_slave[0] = setup->sm_s_addr_type; 2011 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 2012 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 2013 2014 uint8_t iocap_a[3]; 2015 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 2016 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 2017 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 2018 uint8_t iocap_b[3]; 2019 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 2020 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 2021 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 2022 if (IS_RESPONDER(sm_conn->sm_role)){ 2023 // responder 2024 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 2025 f6_engine(sm_conn, setup->sm_mackey); 2026 } else { 2027 // initiator 2028 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 2029 f6_engine(sm_conn, setup->sm_mackey); 2030 } 2031 } 2032 2033 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2034 2035 // 2036 // Link Key Conversion Function h6 2037 // 2038 // h6(W, keyID) = AES-CMAC_W(keyID) 2039 // - W is 128 bits 2040 // - keyID is 32 bits 2041 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 2042 const uint16_t message_len = 4; 2043 sm_cmac_connection = sm_conn; 2044 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 2045 log_info("h6 key"); 2046 log_info_hexdump(w, 16); 2047 log_info("h6 message"); 2048 log_info_hexdump(sm_cmac_sc_buffer, message_len); 2049 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 2050 } 2051 // 2052 // Link Key Conversion Function h7 2053 // 2054 // h7(SALT, W) = AES-CMAC_SALT(W) 2055 // - SALT is 128 bits 2056 // - W is 128 bits 2057 static void h7_engine(sm_connection_t * sm_conn, const sm_key_t salt, const sm_key_t w) { 2058 const uint16_t message_len = 16; 2059 sm_cmac_connection = sm_conn; 2060 log_info("h7 key"); 2061 log_info_hexdump(salt, 16); 2062 log_info("h7 message"); 2063 log_info_hexdump(w, 16); 2064 sm_cmac_message_start(salt, message_len, w, &sm_sc_cmac_done); 2065 } 2066 2067 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 2068 // Errata Service Release to the Bluetooth Specification: ESR09 2069 // E6405 – Cross transport key derivation from a key of size less than 128 bits 2070 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 2071 2072 static void h6_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ 2073 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 2074 } 2075 2076 static void h6_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ 2077 h6_engine(sm_conn, setup->sm_link_key, 0x746D7032); // "tmp2" 2078 } 2079 2080 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 2081 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 2082 } 2083 2084 static void h6_calculate_le_ltk(sm_connection_t * sm_conn){ 2085 h6_engine(sm_conn, setup->sm_t, 0x62726C65); // "brle" 2086 } 2087 2088 static void h7_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ 2089 const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x31}; // "tmp1" 2090 h7_engine(sm_conn, salt, setup->sm_local_ltk); 2091 } 2092 2093 static void h7_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ 2094 const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x32}; // "tmp2" 2095 h7_engine(sm_conn, salt, setup->sm_link_key); 2096 } 2097 2098 static void sm_ctkd_fetch_br_edr_link_key(sm_connection_t * sm_conn){ 2099 hci_connection_t * hci_connection = hci_connection_for_handle(sm_conn->sm_handle); 2100 btstack_assert(hci_connection != NULL); 2101 reverse_128(hci_connection->link_key, setup->sm_link_key); 2102 setup->sm_link_key_type = hci_connection->link_key_type; 2103 } 2104 2105 static void sm_ctkd_start_from_br_edr(sm_connection_t * sm_conn){ 2106 // only derive LTK if EncKey is set by both 2107 bool derive_ltk = (sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & 2108 sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & SM_KEYDIST_ENC_KEY) != 0; 2109 if (derive_ltk){ 2110 bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; 2111 sm_conn->sm_engine_state = use_h7 ? SM_BR_EDR_W2_CALCULATE_ILK_USING_H7 : SM_BR_EDR_W2_CALCULATE_ILK_USING_H6; 2112 } else { 2113 sm_done_for_handle(sm_conn->sm_handle); 2114 } 2115 } 2116 2117 #endif 2118 2119 #endif 2120 2121 // key management legacy connections: 2122 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 2123 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 2124 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 2125 // - responder reconnects: responder uses LTK receveived from master 2126 2127 // key management secure connections: 2128 // - both devices store same LTK from ECDH key exchange. 2129 2130 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 2131 static void sm_load_security_info(sm_connection_t * sm_connection){ 2132 int encryption_key_size; 2133 int authenticated; 2134 int authorized; 2135 int secure_connection; 2136 2137 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 2138 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 2139 &encryption_key_size, &authenticated, &authorized, &secure_connection); 2140 log_info("db index %u, key size %u, authenticated %u, authorized %u, secure connetion %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized, secure_connection); 2141 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 2142 sm_connection->sm_connection_authenticated = authenticated; 2143 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 2144 sm_connection->sm_connection_sc = secure_connection; 2145 } 2146 #endif 2147 2148 #ifdef ENABLE_LE_PERIPHERAL 2149 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 2150 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 2151 setup->sm_local_ediv = sm_connection->sm_local_ediv; 2152 // re-establish used key encryption size 2153 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2154 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 2155 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 2156 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 2157 // Legacy paring -> not SC 2158 sm_connection->sm_connection_sc = 0; 2159 log_info("sm: received ltk request with key size %u, authenticated %u", 2160 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 2161 } 2162 #endif 2163 2164 // distributed key generation 2165 static bool sm_run_dpkg(void){ 2166 switch (dkg_state){ 2167 case DKG_CALC_IRK: 2168 // already busy? 2169 if (sm_aes128_state == SM_AES128_IDLE) { 2170 log_info("DKG_CALC_IRK started"); 2171 // IRK = d1(IR, 1, 0) 2172 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 2173 sm_aes128_state = SM_AES128_ACTIVE; 2174 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 2175 return true; 2176 } 2177 break; 2178 case DKG_CALC_DHK: 2179 // already busy? 2180 if (sm_aes128_state == SM_AES128_IDLE) { 2181 log_info("DKG_CALC_DHK started"); 2182 // DHK = d1(IR, 3, 0) 2183 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 2184 sm_aes128_state = SM_AES128_ACTIVE; 2185 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 2186 return true; 2187 } 2188 break; 2189 default: 2190 break; 2191 } 2192 return false; 2193 } 2194 2195 // random address updates 2196 static bool sm_run_rau(void){ 2197 switch (rau_state){ 2198 case RAU_GET_RANDOM: 2199 rau_state = RAU_W4_RANDOM; 2200 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 2201 return true; 2202 case RAU_GET_ENC: 2203 // already busy? 2204 if (sm_aes128_state == SM_AES128_IDLE) { 2205 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 2206 sm_aes128_state = SM_AES128_ACTIVE; 2207 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 2208 return true; 2209 } 2210 break; 2211 default: 2212 break; 2213 } 2214 return false; 2215 } 2216 2217 // CSRK Lookup 2218 static bool sm_run_csrk(void){ 2219 btstack_linked_list_iterator_t it; 2220 2221 // -- if csrk lookup ready, find connection that require csrk lookup 2222 if (sm_address_resolution_idle()){ 2223 hci_connections_get_iterator(&it); 2224 while(btstack_linked_list_iterator_has_next(&it)){ 2225 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2226 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2227 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 2228 // and start lookup 2229 sm_address_resolution_start_lookup(sm_connection->sm_peer_addr_type, sm_connection->sm_handle, sm_connection->sm_peer_address, ADDRESS_RESOLUTION_FOR_CONNECTION, sm_connection); 2230 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 2231 break; 2232 } 2233 } 2234 } 2235 2236 // -- if csrk lookup ready, resolved addresses for received addresses 2237 if (sm_address_resolution_idle()) { 2238 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 2239 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 2240 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 2241 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 2242 btstack_memory_sm_lookup_entry_free(entry); 2243 } 2244 } 2245 2246 // -- Continue with device lookup by public or resolvable private address 2247 if (!sm_address_resolution_idle()){ 2248 while (sm_address_resolution_test < le_device_db_max_count()){ 2249 int addr_type = BD_ADDR_TYPE_UNKNOWN; 2250 bd_addr_t addr; 2251 sm_key_t irk; 2252 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2253 2254 // skip unused entries 2255 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 2256 sm_address_resolution_test++; 2257 continue; 2258 } 2259 2260 log_info("LE Device Lookup: device %u of %u", sm_address_resolution_test, le_device_db_max_count()); 2261 2262 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 2263 log_info("LE Device Lookup: found by { addr_type, address} "); 2264 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); 2265 break; 2266 } 2267 2268 // if connection type is public, it must be a different one 2269 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 2270 sm_address_resolution_test++; 2271 continue; 2272 } 2273 2274 // skip AH if no IRK 2275 if (sm_is_null_key(irk)){ 2276 sm_address_resolution_test++; 2277 continue; 2278 } 2279 2280 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2281 2282 log_info("LE Device Lookup: calculate AH"); 2283 log_info_key("IRK", irk); 2284 2285 (void)memcpy(sm_aes128_key, irk, 16); 2286 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 2287 sm_aes128_state = SM_AES128_ACTIVE; 2288 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 2289 return true; 2290 } 2291 2292 if (sm_address_resolution_test >= le_device_db_max_count()){ 2293 log_info("LE Device Lookup: not found"); 2294 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2295 } 2296 } 2297 return false; 2298 } 2299 2300 // SC OOB 2301 static bool sm_run_oob(void){ 2302 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2303 switch (sm_sc_oob_state){ 2304 case SM_SC_OOB_W2_CALC_CONFIRM: 2305 if (!sm_cmac_ready()) break; 2306 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 2307 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 2308 return true; 2309 default: 2310 break; 2311 } 2312 #endif 2313 return false; 2314 } 2315 2316 static void sm_send_connectionless(sm_connection_t * sm_connection, const uint8_t * buffer, uint16_t size){ 2317 l2cap_send_connectionless(sm_connection->sm_handle, sm_connection->sm_cid, (uint8_t*) buffer, size); 2318 } 2319 2320 // handle basic actions that don't requires the full context 2321 static bool sm_run_basic(void){ 2322 btstack_linked_list_iterator_t it; 2323 hci_connections_get_iterator(&it); 2324 while(btstack_linked_list_iterator_has_next(&it)){ 2325 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2326 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2327 switch(sm_connection->sm_engine_state){ 2328 2329 // general 2330 case SM_GENERAL_SEND_PAIRING_FAILED: { 2331 uint8_t buffer[2]; 2332 buffer[0] = SM_CODE_PAIRING_FAILED; 2333 buffer[1] = sm_connection->sm_pairing_failed_reason; 2334 sm_connection->sm_engine_state = sm_connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2335 sm_send_connectionless(sm_connection, (uint8_t*) buffer, sizeof(buffer)); 2336 sm_pairing_complete(sm_connection, ERROR_CODE_AUTHENTICATION_FAILURE, sm_connection->sm_pairing_failed_reason); 2337 sm_done_for_handle(sm_connection->sm_handle); 2338 break; 2339 } 2340 2341 // responder side 2342 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2343 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2344 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2345 return true; 2346 2347 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2348 case SM_SC_RECEIVED_LTK_REQUEST: 2349 switch (sm_connection->sm_irk_lookup_state){ 2350 case IRK_LOOKUP_FAILED: 2351 log_info("LTK Request: IRK Lookup Failed)"); 2352 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2353 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2354 return true; 2355 default: 2356 break; 2357 } 2358 break; 2359 #endif 2360 default: 2361 break; 2362 } 2363 } 2364 return false; 2365 } 2366 2367 static void sm_run_activate_connection(void){ 2368 // Find connections that requires setup context and make active if no other is locked 2369 btstack_linked_list_iterator_t it; 2370 hci_connections_get_iterator(&it); 2371 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2372 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2373 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2374 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2375 bool done = true; 2376 int err; 2377 UNUSED(err); 2378 2379 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2380 // assert ec key is ready 2381 if ( (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2382 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST) 2383 || (sm_connection->sm_engine_state == SM_RESPONDER_SEND_SECURITY_REQUEST)){ 2384 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2385 sm_ec_generate_new_key(); 2386 } 2387 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2388 continue; 2389 } 2390 } 2391 #endif 2392 2393 switch (sm_connection->sm_engine_state) { 2394 #ifdef ENABLE_LE_PERIPHERAL 2395 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2396 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2397 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2398 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2399 case SM_SC_RECEIVED_LTK_REQUEST: 2400 #endif 2401 #endif 2402 #ifdef ENABLE_LE_CENTRAL 2403 case SM_INITIATOR_PH4_HAS_LTK: 2404 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2405 #endif 2406 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2407 case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: 2408 case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: 2409 #endif 2410 // just lock context 2411 break; 2412 default: 2413 done = false; 2414 break; 2415 } 2416 if (done){ 2417 sm_active_connection_handle = sm_connection->sm_handle; 2418 log_info("sm: connection 0x%04x locked setup context as %s, state %u", sm_active_connection_handle, sm_connection->sm_role ? "responder" : "initiator", sm_connection->sm_engine_state); 2419 } 2420 } 2421 } 2422 2423 static void sm_run_send_keypress_notification(sm_connection_t * connection){ 2424 int i; 2425 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2426 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2427 uint8_t action = 0; 2428 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2429 if (flags & (1u<<i)){ 2430 bool clear_flag = true; 2431 switch (i){ 2432 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2433 case SM_KEYPRESS_PASSKEY_CLEARED: 2434 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2435 default: 2436 break; 2437 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2438 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2439 num_actions--; 2440 clear_flag = num_actions == 0u; 2441 break; 2442 } 2443 if (clear_flag){ 2444 flags &= ~(1<<i); 2445 } 2446 action = i; 2447 break; 2448 } 2449 } 2450 setup->sm_keypress_notification = (num_actions << 5) | flags; 2451 2452 // send keypress notification 2453 uint8_t buffer[2]; 2454 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2455 buffer[1] = action; 2456 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2457 2458 // try 2459 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); 2460 } 2461 2462 static void sm_run_distribute_keys(sm_connection_t * connection){ 2463 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2464 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2465 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2466 uint8_t buffer[17]; 2467 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2468 reverse_128(setup->sm_ltk, &buffer[1]); 2469 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2470 sm_timeout_reset(connection); 2471 return; 2472 } 2473 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2474 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2475 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2476 uint8_t buffer[11]; 2477 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2478 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2479 reverse_64(setup->sm_local_rand, &buffer[3]); 2480 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2481 sm_timeout_reset(connection); 2482 return; 2483 } 2484 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2485 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2486 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2487 uint8_t buffer[17]; 2488 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2489 reverse_128(sm_persistent_irk, &buffer[1]); 2490 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2491 sm_timeout_reset(connection); 2492 return; 2493 } 2494 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2495 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2496 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2497 bd_addr_t local_address; 2498 uint8_t buffer[8]; 2499 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2500 switch (gap_random_address_get_mode()){ 2501 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2502 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2503 // public or static random 2504 gap_le_get_own_address(&buffer[1], local_address); 2505 break; 2506 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2507 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2508 // fallback to public 2509 gap_local_bd_addr(local_address); 2510 buffer[1] = 0; 2511 break; 2512 default: 2513 btstack_assert(false); 2514 break; 2515 } 2516 reverse_bd_addr(local_address, &buffer[2]); 2517 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2518 sm_timeout_reset(connection); 2519 return; 2520 } 2521 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2522 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2523 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2524 2525 #ifdef ENABLE_LE_SIGNED_WRITE 2526 // hack to reproduce test runs 2527 if (test_use_fixed_local_csrk){ 2528 memset(setup->sm_local_csrk, 0xcc, 16); 2529 } 2530 2531 // store local CSRK 2532 if (setup->sm_le_device_index >= 0){ 2533 log_info("sm: store local CSRK"); 2534 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2535 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2536 } 2537 #endif 2538 2539 uint8_t buffer[17]; 2540 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2541 reverse_128(setup->sm_local_csrk, &buffer[1]); 2542 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2543 sm_timeout_reset(connection); 2544 return; 2545 } 2546 btstack_assert(false); 2547 } 2548 2549 static bool sm_ctkd_from_le(sm_connection_t *sm_connection) { 2550 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2551 // requirements to derive link key from LE: 2552 // - use secure connections 2553 if (setup->sm_use_secure_connections == 0) return false; 2554 // - bonding needs to be enabled: 2555 bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_BONDING ) != 0u; 2556 if (!bonding_enabled) return false; 2557 // - need identity address / public addr 2558 bool have_identity_address_info = ((setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION) != 0) || (setup->sm_peer_addr_type == 0); 2559 if (!have_identity_address_info) return false; 2560 // - there is no stored BR/EDR link key or the derived key has at least the same level of authentication (bail if stored key has higher authentication) 2561 // this requirement is motivated by BLURtooth paper. The paper recommends to not overwrite keys at all. 2562 // If SC is authenticated, we consider it safe to overwrite a stored key. 2563 // If stored link key is not authenticated, it could already be compromised by a MITM attack. Allowing overwrite by unauthenticated derived key does not make it worse. 2564 uint8_t link_key[16]; 2565 link_key_type_t link_key_type; 2566 bool have_link_key = gap_get_link_key_for_bd_addr(setup->sm_peer_address, link_key, &link_key_type); 2567 bool link_key_authenticated = gap_authenticated_for_link_key_type(link_key_type); 2568 bool derived_key_authenticated = sm_connection->sm_connection_authenticated != 0; 2569 if (have_link_key && link_key_authenticated && !derived_key_authenticated) { 2570 return false; 2571 } 2572 // get started (all of the above are true) 2573 return true; 2574 #else 2575 UNUSED(sm_connection); 2576 return false; 2577 #endif 2578 } 2579 2580 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2581 static bool sm_ctkd_from_classic(sm_connection_t * sm_connection){ 2582 hci_connection_t * hci_connection = hci_connection_for_handle(sm_connection->sm_handle); 2583 btstack_assert(hci_connection != NULL); 2584 // requirements to derive ltk from BR/EDR: 2585 // - BR/EDR uses secure connections 2586 if (gap_secure_connection_for_link_key_type(hci_connection->link_key_type) == false) return false; 2587 // - bonding needs to be enabled: 2588 bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_BONDING ) != 0u; 2589 if (!bonding_enabled) return false; 2590 // - there is no stored LTK or the derived key has at least the same level of authentication (bail if LTK is authenticated but Link Key isn't) 2591 bool link_key_authenticated = gap_authenticated_for_link_key_type(hci_connection->link_key_type); 2592 if (link_key_authenticated) return true; 2593 int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, hci_connection->address); 2594 if (index >= 0){ 2595 int ltk_authenticated; 2596 sm_key_t ltk; 2597 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, <k_authenticated, NULL, NULL); 2598 bool have_ltk = !sm_is_null_key(ltk); 2599 if (have_ltk && ltk_authenticated) return false; 2600 } 2601 return true; 2602 } 2603 #endif 2604 2605 static void sm_key_distribution_complete_responder(sm_connection_t * connection){ 2606 if (sm_ctkd_from_le(connection)){ 2607 bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; 2608 connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; 2609 } else { 2610 connection->sm_engine_state = SM_RESPONDER_IDLE; 2611 sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); 2612 sm_done_for_handle(connection->sm_handle); 2613 } 2614 } 2615 2616 static void sm_key_distribution_complete_initiator(sm_connection_t * connection){ 2617 if (sm_ctkd_from_le(connection)){ 2618 bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; 2619 connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; 2620 } else { 2621 sm_master_pairing_success(connection); 2622 } 2623 } 2624 2625 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2626 static void sm_run_state_sc_send_confirmation(sm_connection_t *connection) { 2627 uint8_t buffer[17]; 2628 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2629 reverse_128(setup->sm_local_confirm, &buffer[1]); 2630 if (IS_RESPONDER(connection->sm_role)){ 2631 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2632 } else { 2633 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2634 } 2635 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2636 sm_timeout_reset(connection); 2637 } 2638 2639 static void sm_run_state_sc_send_pairing_random(sm_connection_t *connection) { 2640 uint8_t buffer[17]; 2641 buffer[0] = SM_CODE_PAIRING_RANDOM; 2642 reverse_128(setup->sm_local_nonce, &buffer[1]); 2643 log_info("stk method %u, bit num: %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2644 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2645 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2646 if (IS_RESPONDER(connection->sm_role)){ 2647 // responder 2648 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2649 } else { 2650 // initiator 2651 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2652 } 2653 } else { 2654 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2655 if (IS_RESPONDER(connection->sm_role)){ 2656 // responder 2657 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2658 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2659 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2660 } else { 2661 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2662 sm_sc_prepare_dhkey_check(connection); 2663 } 2664 } else { 2665 // initiator 2666 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2667 } 2668 } 2669 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2670 sm_timeout_reset(connection); 2671 } 2672 2673 static void sm_run_state_sc_send_dhkey_check_command(sm_connection_t *connection) { 2674 uint8_t buffer[17]; 2675 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2676 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2677 2678 if (IS_RESPONDER(connection->sm_role)){ 2679 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2680 } else { 2681 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2682 } 2683 2684 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2685 sm_timeout_reset(connection); 2686 } 2687 2688 static void sm_run_state_sc_send_public_key_command(sm_connection_t *connection) { 2689 bool trigger_user_response = false; 2690 bool trigger_start_calculating_local_confirm = false; 2691 uint8_t buffer[65]; 2692 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2693 // 2694 reverse_256(&ec_q[0], &buffer[1]); 2695 reverse_256(&ec_q[32], &buffer[33]); 2696 2697 #ifdef ENABLE_TESTING_SUPPORT 2698 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2699 log_info("testing_support: invalidating public key"); 2700 // flip single bit of public key coordinate 2701 buffer[1] ^= 1; 2702 } 2703 #endif 2704 2705 // stk generation method 2706 // passkey entry: notify app to show passkey or to request passkey 2707 switch (setup->sm_stk_generation_method){ 2708 case JUST_WORKS: 2709 case NUMERIC_COMPARISON: 2710 if (IS_RESPONDER(connection->sm_role)){ 2711 // responder 2712 trigger_start_calculating_local_confirm = true; 2713 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2714 } else { 2715 // initiator 2716 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2717 } 2718 break; 2719 case PK_INIT_INPUT: 2720 case PK_RESP_INPUT: 2721 case PK_BOTH_INPUT: 2722 // use random TK for display 2723 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2724 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2725 setup->sm_passkey_bit = 0; 2726 2727 if (IS_RESPONDER(connection->sm_role)){ 2728 // responder 2729 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2730 } else { 2731 // initiator 2732 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2733 } 2734 trigger_user_response = true; 2735 break; 2736 case OOB: 2737 if (IS_RESPONDER(connection->sm_role)){ 2738 // responder 2739 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2740 } else { 2741 // initiator 2742 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2743 } 2744 break; 2745 default: 2746 btstack_assert(false); 2747 break; 2748 } 2749 2750 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2751 sm_timeout_reset(connection); 2752 2753 // trigger user response and calc confirm after sending pdu 2754 if (trigger_user_response){ 2755 sm_trigger_user_response(connection); 2756 } 2757 if (trigger_start_calculating_local_confirm){ 2758 sm_sc_start_calculating_local_confirm(connection); 2759 } 2760 } 2761 #endif 2762 2763 static bool sm_run_non_connection_logic(void){ 2764 bool done;; 2765 2766 done = sm_run_dpkg(); 2767 if (done) return true; 2768 2769 done = sm_run_rau(); 2770 if (done) return true; 2771 2772 done = sm_run_csrk(); 2773 if (done) return true; 2774 2775 done = sm_run_oob(); 2776 return done; 2777 } 2778 2779 static void sm_run(void){ 2780 2781 // assert that stack has already bootet 2782 if (hci_get_state() != HCI_STATE_WORKING) return; 2783 2784 // assert that we can send at least commands 2785 if (!hci_can_send_command_packet_now()) return; 2786 2787 // pause until IR/ER are ready 2788 if (sm_persistent_keys_random_active) return; 2789 2790 // non-connection related behaviour 2791 bool done = sm_run_non_connection_logic(); 2792 if (done) return; 2793 2794 // assert that we can send at least commands - cmd might have been sent by crypto engine 2795 if (!hci_can_send_command_packet_now()) return; 2796 2797 // handle basic actions that don't requires the full context 2798 done = sm_run_basic(); 2799 if (done) return; 2800 2801 // 2802 // active connection handling 2803 // -- use loop to handle next connection if lock on setup context is released 2804 2805 while (true) { 2806 2807 sm_run_activate_connection(); 2808 2809 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2810 2811 // 2812 // active connection handling 2813 // 2814 2815 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2816 if (!connection) { 2817 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2818 return; 2819 } 2820 2821 // assert that we could send a SM PDU - not needed for all of the following 2822 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, connection->sm_cid)) { 2823 log_info("cannot send now, requesting can send now event"); 2824 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); 2825 return; 2826 } 2827 2828 // send keypress notifications 2829 if (setup->sm_keypress_notification){ 2830 sm_run_send_keypress_notification(connection); 2831 return; 2832 } 2833 2834 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2835 // assert that sm cmac engine is ready 2836 if (sm_cmac_ready() == false){ 2837 break; 2838 } 2839 #endif 2840 2841 int key_distribution_flags; 2842 UNUSED(key_distribution_flags); 2843 #ifdef ENABLE_LE_PERIPHERAL 2844 int err; 2845 bool have_ltk; 2846 uint8_t ltk[16]; 2847 #endif 2848 2849 log_info("sm_run: state %u", connection->sm_engine_state); 2850 switch (connection->sm_engine_state){ 2851 2852 // secure connections, initiator + responding states 2853 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2854 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2855 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2856 sm_sc_calculate_local_confirm(connection); 2857 break; 2858 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2859 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2860 sm_sc_calculate_remote_confirm(connection); 2861 break; 2862 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2863 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2864 sm_sc_calculate_f6_for_dhkey_check(connection); 2865 break; 2866 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2867 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2868 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2869 break; 2870 case SM_SC_W2_CALCULATE_F5_SALT: 2871 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2872 f5_calculate_salt(connection); 2873 break; 2874 case SM_SC_W2_CALCULATE_F5_MACKEY: 2875 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2876 f5_calculate_mackey(connection); 2877 break; 2878 case SM_SC_W2_CALCULATE_F5_LTK: 2879 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2880 f5_calculate_ltk(connection); 2881 break; 2882 case SM_SC_W2_CALCULATE_G2: 2883 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2884 g2_calculate(connection); 2885 break; 2886 #endif 2887 2888 #ifdef ENABLE_LE_CENTRAL 2889 // initiator side 2890 2891 case SM_INITIATOR_PH4_HAS_LTK: { 2892 sm_reset_setup(); 2893 sm_load_security_info(connection); 2894 2895 sm_key_t peer_ltk_flipped; 2896 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2897 connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; 2898 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2899 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2900 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2901 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2902 2903 // notify after sending 2904 sm_reencryption_started(connection); 2905 return; 2906 } 2907 2908 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2909 sm_reset_setup(); 2910 sm_init_setup(connection); 2911 2912 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2913 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2914 sm_send_connectionless(connection, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2915 sm_timeout_reset(connection); 2916 2917 // notify after sending 2918 sm_pairing_started(connection); 2919 break; 2920 #endif 2921 2922 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2923 case SM_SC_SEND_PUBLIC_KEY_COMMAND: 2924 sm_run_state_sc_send_public_key_command(connection); 2925 break; 2926 case SM_SC_SEND_CONFIRMATION: 2927 sm_run_state_sc_send_confirmation(connection); 2928 break; 2929 case SM_SC_SEND_PAIRING_RANDOM: 2930 sm_run_state_sc_send_pairing_random(connection); 2931 break; 2932 case SM_SC_SEND_DHKEY_CHECK_COMMAND: 2933 sm_run_state_sc_send_dhkey_check_command(connection); 2934 break; 2935 #endif 2936 2937 #ifdef ENABLE_LE_PERIPHERAL 2938 2939 case SM_RESPONDER_SEND_SECURITY_REQUEST: { 2940 const uint8_t buffer[2] = {SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2941 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2942 sm_send_connectionless(connection, (uint8_t *) buffer, sizeof(buffer)); 2943 sm_timeout_start(connection); 2944 break; 2945 } 2946 2947 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2948 case SM_SC_RECEIVED_LTK_REQUEST: 2949 switch (connection->sm_irk_lookup_state){ 2950 case IRK_LOOKUP_SUCCEEDED: 2951 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2952 // start using context by loading security info 2953 sm_reset_setup(); 2954 sm_load_security_info(connection); 2955 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2956 (void)memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2957 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2958 sm_reencryption_started(connection); 2959 sm_trigger_run(); 2960 break; 2961 } 2962 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2963 connection->sm_engine_state = SM_RESPONDER_IDLE; 2964 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2965 return; 2966 default: 2967 // just wait until IRK lookup is completed 2968 break; 2969 } 2970 break; 2971 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2972 2973 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2974 sm_reset_setup(); 2975 2976 // handle Pairing Request with LTK available 2977 switch (connection->sm_irk_lookup_state) { 2978 case IRK_LOOKUP_SUCCEEDED: 2979 le_device_db_encryption_get(connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 2980 have_ltk = !sm_is_null_key(ltk); 2981 if (have_ltk){ 2982 log_info("pairing request but LTK available"); 2983 // emit re-encryption start/fail sequence 2984 sm_reencryption_started(connection); 2985 sm_reencryption_complete(connection, ERROR_CODE_PIN_OR_KEY_MISSING); 2986 } 2987 break; 2988 default: 2989 break; 2990 } 2991 2992 sm_init_setup(connection); 2993 2994 // recover pairing request 2995 (void)memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2996 err = sm_stk_generation_init(connection); 2997 2998 #ifdef ENABLE_TESTING_SUPPORT 2999 if ((0 < test_pairing_failure) && (test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED)){ 3000 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 3001 err = test_pairing_failure; 3002 } 3003 #endif 3004 if (err != 0){ 3005 // emit pairing started/failed sequence 3006 sm_pairing_started(connection); 3007 sm_pairing_error(connection, err); 3008 sm_trigger_run(); 3009 break; 3010 } 3011 3012 sm_timeout_start(connection); 3013 3014 // generate random number first, if we need to show passkey, otherwise send response 3015 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3016 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) connection->sm_handle); 3017 break; 3018 } 3019 3020 /* fall through */ 3021 3022 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 3023 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 3024 3025 // start with initiator key dist flags 3026 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 3027 3028 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3029 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 3030 if (setup->sm_use_secure_connections){ 3031 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 3032 } 3033 #endif 3034 // setup in response 3035 sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq) & key_distribution_flags); 3036 sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq) & key_distribution_flags); 3037 3038 // update key distribution after ENC was dropped 3039 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres), sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 3040 3041 if (setup->sm_use_secure_connections){ 3042 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 3043 } else { 3044 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 3045 } 3046 3047 sm_send_connectionless(connection, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 3048 sm_timeout_reset(connection); 3049 3050 // notify after sending 3051 sm_pairing_started(connection); 3052 3053 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3054 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 3055 sm_trigger_user_response(connection); 3056 } 3057 return; 3058 #endif 3059 3060 case SM_PH2_SEND_PAIRING_RANDOM: { 3061 uint8_t buffer[17]; 3062 buffer[0] = SM_CODE_PAIRING_RANDOM; 3063 reverse_128(setup->sm_local_random, &buffer[1]); 3064 if (IS_RESPONDER(connection->sm_role)){ 3065 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 3066 } else { 3067 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 3068 } 3069 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 3070 sm_timeout_reset(connection); 3071 break; 3072 } 3073 3074 case SM_PH2_C1_GET_ENC_A: 3075 // already busy? 3076 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3077 // calculate confirm using aes128 engine - step 1 3078 sm_c1_t1(setup->sm_local_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, sm_aes128_plaintext); 3079 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 3080 sm_aes128_state = SM_AES128_ACTIVE; 3081 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, (void *)(uintptr_t) connection->sm_handle); 3082 break; 3083 3084 case SM_PH2_C1_GET_ENC_C: 3085 // already busy? 3086 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3087 // calculate m_confirm using aes128 engine - step 1 3088 sm_c1_t1(setup->sm_peer_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, sm_aes128_plaintext); 3089 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 3090 sm_aes128_state = SM_AES128_ACTIVE; 3091 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, (void *)(uintptr_t) connection->sm_handle); 3092 break; 3093 3094 case SM_PH2_CALC_STK: 3095 // already busy? 3096 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3097 // calculate STK 3098 if (IS_RESPONDER(connection->sm_role)){ 3099 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 3100 } else { 3101 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 3102 } 3103 connection->sm_engine_state = SM_PH2_W4_STK; 3104 sm_aes128_state = SM_AES128_ACTIVE; 3105 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, (void *)(uintptr_t) connection->sm_handle); 3106 break; 3107 3108 case SM_PH3_Y_GET_ENC: 3109 // already busy? 3110 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3111 // PH3B2 - calculate Y from - enc 3112 3113 // dm helper (was sm_dm_r_prime) 3114 // r' = padding || r 3115 // r - 64 bit value 3116 memset(&sm_aes128_plaintext[0], 0, 8); 3117 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 3118 3119 // Y = dm(DHK, Rand) 3120 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 3121 sm_aes128_state = SM_AES128_ACTIVE; 3122 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph3_y, (void *)(uintptr_t) connection->sm_handle); 3123 break; 3124 3125 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 3126 uint8_t buffer[17]; 3127 buffer[0] = SM_CODE_PAIRING_CONFIRM; 3128 reverse_128(setup->sm_local_confirm, &buffer[1]); 3129 if (IS_RESPONDER(connection->sm_role)){ 3130 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 3131 } else { 3132 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 3133 } 3134 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 3135 sm_timeout_reset(connection); 3136 return; 3137 } 3138 #ifdef ENABLE_LE_PERIPHERAL 3139 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 3140 // cache key before using 3141 sm_cache_ltk(connection, setup->sm_ltk); 3142 sm_key_t stk_flipped; 3143 reverse_128(setup->sm_ltk, stk_flipped); 3144 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 3145 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 3146 return; 3147 } 3148 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 3149 // allow to override LTK 3150 if (sm_get_ltk_callback != NULL){ 3151 (void)(*sm_get_ltk_callback)(connection->sm_handle, connection->sm_peer_addr_type, connection->sm_peer_address, setup->sm_ltk); 3152 } 3153 // cache key before using 3154 sm_cache_ltk(connection, setup->sm_ltk); 3155 sm_key_t ltk_flipped; 3156 reverse_128(setup->sm_ltk, ltk_flipped); 3157 connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; 3158 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 3159 return; 3160 } 3161 3162 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 3163 // already busy? 3164 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3165 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 3166 3167 sm_reset_setup(); 3168 sm_start_calculating_ltk_from_ediv_and_rand(connection); 3169 3170 sm_reencryption_started(connection); 3171 3172 // dm helper (was sm_dm_r_prime) 3173 // r' = padding || r 3174 // r - 64 bit value 3175 memset(&sm_aes128_plaintext[0], 0, 8); 3176 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 3177 3178 // Y = dm(DHK, Rand) 3179 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 3180 sm_aes128_state = SM_AES128_ACTIVE; 3181 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph4_y, (void *)(uintptr_t) connection->sm_handle); 3182 return; 3183 #endif 3184 #ifdef ENABLE_LE_CENTRAL 3185 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 3186 sm_key_t stk_flipped; 3187 reverse_128(setup->sm_ltk, stk_flipped); 3188 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 3189 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 3190 return; 3191 } 3192 #endif 3193 3194 case SM_PH3_DISTRIBUTE_KEYS: 3195 // send next key 3196 if (setup->sm_key_distribution_send_set != 0){ 3197 sm_run_distribute_keys(connection); 3198 } 3199 3200 // more to send? 3201 if (setup->sm_key_distribution_send_set != 0){ 3202 return; 3203 } 3204 3205 // keys are sent 3206 if (IS_RESPONDER(connection->sm_role)){ 3207 // slave -> receive master keys if any 3208 if (sm_key_distribution_all_received()){ 3209 sm_key_distribution_handle_all_received(connection); 3210 sm_key_distribution_complete_responder(connection); 3211 // start CTKD right away 3212 continue; 3213 } else { 3214 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3215 } 3216 } else { 3217 sm_master_pairing_success(connection); 3218 } 3219 break; 3220 3221 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3222 case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: 3223 // fill in sm setup (lite version of sm_init_setup) 3224 sm_reset_setup(); 3225 setup->sm_peer_addr_type = connection->sm_peer_addr_type; 3226 setup->sm_m_addr_type = connection->sm_peer_addr_type; 3227 setup->sm_s_addr_type = connection->sm_own_addr_type; 3228 (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); 3229 (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); 3230 (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); 3231 setup->sm_use_secure_connections = true; 3232 sm_ctkd_fetch_br_edr_link_key(connection); 3233 3234 // Enc Key and IRK if requested 3235 key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; 3236 #ifdef ENABLE_LE_SIGNED_WRITE 3237 // Plus signing key if supported 3238 key_distribution_flags |= SM_KEYDIST_ID_KEY; 3239 #endif 3240 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 3241 sm_pairing_packet_set_io_capability(setup->sm_m_preq, 0); 3242 sm_pairing_packet_set_oob_data_flag(setup->sm_m_preq, 0); 3243 sm_pairing_packet_set_auth_req(setup->sm_m_preq, SM_AUTHREQ_CT2); 3244 sm_pairing_packet_set_max_encryption_key_size(setup->sm_m_preq, sm_max_encryption_key_size); 3245 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 3246 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 3247 3248 // set state and send pairing response 3249 sm_timeout_start(connection); 3250 connection->sm_engine_state = SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE; 3251 sm_send_connectionless(connection, (uint8_t *) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 3252 break; 3253 3254 case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: 3255 // fill in sm setup (lite version of sm_init_setup) 3256 sm_reset_setup(); 3257 setup->sm_peer_addr_type = connection->sm_peer_addr_type; 3258 setup->sm_m_addr_type = connection->sm_peer_addr_type; 3259 setup->sm_s_addr_type = connection->sm_own_addr_type; 3260 (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); 3261 (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); 3262 (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); 3263 setup->sm_use_secure_connections = true; 3264 sm_ctkd_fetch_br_edr_link_key(connection); 3265 (void) memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 3266 3267 // Enc Key and IRK if requested 3268 key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; 3269 #ifdef ENABLE_LE_SIGNED_WRITE 3270 // Plus signing key if supported 3271 key_distribution_flags |= SM_KEYDIST_ID_KEY; 3272 #endif 3273 // drop flags not requested by initiator 3274 key_distribution_flags &= sm_pairing_packet_get_initiator_key_distribution(connection->sm_m_preq); 3275 3276 // If Secure Connections pairing has been initiated over BR/EDR, the following fields of the SM Pairing Request PDU are reserved for future use: 3277 // - the IO Capability field, 3278 // - the OOB data flag field, and 3279 // - all bits in the Auth Req field except the CT2 bit. 3280 sm_pairing_packet_set_code(setup->sm_s_pres, SM_CODE_PAIRING_RESPONSE); 3281 sm_pairing_packet_set_io_capability(setup->sm_s_pres, 0); 3282 sm_pairing_packet_set_oob_data_flag(setup->sm_s_pres, 0); 3283 sm_pairing_packet_set_auth_req(setup->sm_s_pres, SM_AUTHREQ_CT2); 3284 sm_pairing_packet_set_max_encryption_key_size(setup->sm_s_pres, connection->sm_actual_encryption_key_size); 3285 sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, key_distribution_flags); 3286 sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, key_distribution_flags); 3287 3288 // configure key distribution, LTK is derived locally 3289 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 3290 sm_setup_key_distribution(key_distribution_flags, key_distribution_flags); 3291 3292 // set state and send pairing response 3293 sm_timeout_start(connection); 3294 connection->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 3295 sm_send_connectionless(connection, (uint8_t *) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 3296 break; 3297 case SM_BR_EDR_DISTRIBUTE_KEYS: 3298 if (setup->sm_key_distribution_send_set != 0) { 3299 sm_run_distribute_keys(connection); 3300 return; 3301 } 3302 // keys are sent 3303 if (IS_RESPONDER(connection->sm_role)) { 3304 // responder -> receive master keys if there are any 3305 if (!sm_key_distribution_all_received()){ 3306 connection->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; 3307 break; 3308 } 3309 } 3310 // otherwise start CTKD right away (responder and no keys to receive / initiator) 3311 sm_ctkd_start_from_br_edr(connection); 3312 continue; 3313 case SM_SC_W2_CALCULATE_ILK_USING_H6: 3314 connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; 3315 h6_calculate_ilk_from_le_ltk(connection); 3316 break; 3317 case SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY: 3318 connection->sm_engine_state = SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY; 3319 h6_calculate_br_edr_link_key(connection); 3320 break; 3321 case SM_SC_W2_CALCULATE_ILK_USING_H7: 3322 connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; 3323 h7_calculate_ilk_from_le_ltk(connection); 3324 break; 3325 case SM_BR_EDR_W2_CALCULATE_ILK_USING_H6: 3326 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; 3327 h6_calculate_ilk_from_br_edr(connection); 3328 break; 3329 case SM_BR_EDR_W2_CALCULATE_LE_LTK: 3330 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_LE_LTK; 3331 h6_calculate_le_ltk(connection); 3332 break; 3333 case SM_BR_EDR_W2_CALCULATE_ILK_USING_H7: 3334 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; 3335 h7_calculate_ilk_from_br_edr(connection); 3336 break; 3337 #endif 3338 3339 default: 3340 break; 3341 } 3342 3343 // check again if active connection was released 3344 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 3345 } 3346 } 3347 3348 // sm_aes128_state stays active 3349 static void sm_handle_encryption_result_enc_a(void *arg){ 3350 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3351 sm_aes128_state = SM_AES128_IDLE; 3352 3353 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3354 if (connection == NULL) return; 3355 3356 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 3357 sm_aes128_state = SM_AES128_ACTIVE; 3358 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, setup->sm_local_confirm, sm_handle_encryption_result_enc_b, (void *)(uintptr_t) connection->sm_handle); 3359 } 3360 3361 static void sm_handle_encryption_result_enc_b(void *arg){ 3362 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3363 sm_aes128_state = SM_AES128_IDLE; 3364 3365 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3366 if (connection == NULL) return; 3367 3368 log_info_key("c1!", setup->sm_local_confirm); 3369 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 3370 sm_trigger_run(); 3371 } 3372 3373 // sm_aes128_state stays active 3374 static void sm_handle_encryption_result_enc_c(void *arg){ 3375 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3376 sm_aes128_state = SM_AES128_IDLE; 3377 3378 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3379 if (connection == NULL) return; 3380 3381 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 3382 sm_aes128_state = SM_AES128_ACTIVE; 3383 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, sm_aes128_ciphertext, sm_handle_encryption_result_enc_d, (void *)(uintptr_t) connection->sm_handle); 3384 } 3385 3386 static void sm_handle_encryption_result_enc_d(void * arg){ 3387 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3388 sm_aes128_state = SM_AES128_IDLE; 3389 3390 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3391 if (connection == NULL) return; 3392 3393 log_info_key("c1!", sm_aes128_ciphertext); 3394 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 3395 sm_pairing_error(connection, SM_REASON_CONFIRM_VALUE_FAILED); 3396 sm_trigger_run(); 3397 return; 3398 } 3399 if (IS_RESPONDER(connection->sm_role)){ 3400 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3401 sm_trigger_run(); 3402 } else { 3403 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 3404 sm_aes128_state = SM_AES128_ACTIVE; 3405 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, (void *)(uintptr_t) connection->sm_handle); 3406 } 3407 } 3408 3409 static void sm_handle_encryption_result_enc_stk(void *arg){ 3410 sm_aes128_state = SM_AES128_IDLE; 3411 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3412 3413 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3414 if (connection == NULL) return; 3415 3416 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 3417 log_info_key("stk", setup->sm_ltk); 3418 if (IS_RESPONDER(connection->sm_role)){ 3419 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3420 } else { 3421 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 3422 } 3423 sm_trigger_run(); 3424 } 3425 3426 // sm_aes128_state stays active 3427 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 3428 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3429 sm_aes128_state = SM_AES128_IDLE; 3430 3431 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3432 if (connection == NULL) return; 3433 3434 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 3435 log_info_hex16("y", setup->sm_local_y); 3436 // PH3B3 - calculate EDIV 3437 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 3438 log_info_hex16("ediv", setup->sm_local_ediv); 3439 // PH3B4 - calculate LTK - enc 3440 // LTK = d1(ER, DIV, 0)) 3441 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 3442 sm_aes128_state = SM_AES128_ACTIVE; 3443 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph3_ltk, (void *)(uintptr_t) connection->sm_handle); 3444 } 3445 3446 #ifdef ENABLE_LE_PERIPHERAL 3447 // sm_aes128_state stays active 3448 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 3449 sm_aes128_state = SM_AES128_IDLE; 3450 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3451 3452 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3453 if (connection == NULL) return; 3454 3455 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 3456 log_info_hex16("y", setup->sm_local_y); 3457 3458 // PH3B3 - calculate DIV 3459 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 3460 log_info_hex16("ediv", setup->sm_local_ediv); 3461 // PH3B4 - calculate LTK - enc 3462 // LTK = d1(ER, DIV, 0)) 3463 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 3464 sm_aes128_state = SM_AES128_ACTIVE; 3465 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph4_ltk, (void *)(uintptr_t) connection->sm_handle); 3466 } 3467 #endif 3468 3469 // sm_aes128_state stays active 3470 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 3471 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3472 sm_aes128_state = SM_AES128_IDLE; 3473 3474 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3475 if (connection == NULL) return; 3476 3477 log_info_key("ltk", setup->sm_ltk); 3478 // calc CSRK next 3479 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 3480 sm_aes128_state = SM_AES128_ACTIVE; 3481 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_local_csrk, sm_handle_encryption_result_enc_csrk, (void *)(uintptr_t) connection->sm_handle); 3482 } 3483 3484 static void sm_handle_encryption_result_enc_csrk(void *arg){ 3485 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3486 sm_aes128_state = SM_AES128_IDLE; 3487 3488 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3489 if (connection == NULL) return; 3490 3491 sm_aes128_state = SM_AES128_IDLE; 3492 log_info_key("csrk", setup->sm_local_csrk); 3493 if (setup->sm_key_distribution_send_set){ 3494 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3495 } else { 3496 // no keys to send, just continue 3497 if (IS_RESPONDER(connection->sm_role)){ 3498 if (sm_key_distribution_all_received()){ 3499 sm_key_distribution_handle_all_received(connection); 3500 sm_key_distribution_complete_responder(connection); 3501 } else { 3502 // slave -> receive master keys 3503 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3504 } 3505 } else { 3506 sm_key_distribution_complete_initiator(connection); 3507 } 3508 } 3509 sm_trigger_run(); 3510 } 3511 3512 #ifdef ENABLE_LE_PERIPHERAL 3513 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 3514 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3515 sm_aes128_state = SM_AES128_IDLE; 3516 3517 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3518 if (connection == NULL) return; 3519 3520 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 3521 log_info_key("ltk", setup->sm_ltk); 3522 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 3523 sm_trigger_run(); 3524 } 3525 #endif 3526 3527 static void sm_handle_encryption_result_address_resolution(void *arg){ 3528 UNUSED(arg); 3529 sm_aes128_state = SM_AES128_IDLE; 3530 3531 // compare calulated address against connecting device 3532 uint8_t * hash = &sm_aes128_ciphertext[13]; 3533 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 3534 log_info("LE Device Lookup: matched resolvable private address"); 3535 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); 3536 sm_trigger_run(); 3537 return; 3538 } 3539 // no match, try next 3540 sm_address_resolution_test++; 3541 sm_trigger_run(); 3542 } 3543 3544 static void sm_handle_encryption_result_dkg_irk(void *arg){ 3545 UNUSED(arg); 3546 sm_aes128_state = SM_AES128_IDLE; 3547 3548 log_info_key("irk", sm_persistent_irk); 3549 dkg_state = DKG_CALC_DHK; 3550 sm_trigger_run(); 3551 } 3552 3553 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 3554 UNUSED(arg); 3555 sm_aes128_state = SM_AES128_IDLE; 3556 3557 log_info_key("dhk", sm_persistent_dhk); 3558 dkg_state = DKG_READY; 3559 sm_trigger_run(); 3560 } 3561 3562 static void sm_handle_encryption_result_rau(void *arg){ 3563 UNUSED(arg); 3564 sm_aes128_state = SM_AES128_IDLE; 3565 3566 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 3567 rau_state = RAU_IDLE; 3568 hci_le_random_address_set(sm_random_address); 3569 3570 sm_trigger_run(); 3571 } 3572 3573 static void sm_handle_random_result_rau(void * arg){ 3574 UNUSED(arg); 3575 // non-resolvable vs. resolvable 3576 switch (gap_random_adress_type){ 3577 case GAP_RANDOM_ADDRESS_RESOLVABLE: 3578 // resolvable: use random as prand and calc address hash 3579 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 3580 sm_random_address[0u] &= 0x3fu; 3581 sm_random_address[0u] |= 0x40u; 3582 rau_state = RAU_GET_ENC; 3583 break; 3584 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 3585 default: 3586 // "The two most significant bits of the address shall be equal to ‘0’"" 3587 sm_random_address[0u] &= 0x3fu; 3588 rau_state = RAU_IDLE; 3589 hci_le_random_address_set(sm_random_address); 3590 break; 3591 } 3592 sm_trigger_run(); 3593 } 3594 3595 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3596 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3597 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3598 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3599 if (connection == NULL) return; 3600 3601 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3602 sm_trigger_run(); 3603 } 3604 3605 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3606 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3607 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3608 if (connection == NULL) return; 3609 3610 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3611 sm_trigger_run(); 3612 } 3613 #endif 3614 3615 static void sm_handle_random_result_ph2_random(void * arg){ 3616 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3617 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3618 if (connection == NULL) return; 3619 3620 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3621 sm_trigger_run(); 3622 } 3623 3624 static void sm_handle_random_result_ph2_tk(void * arg){ 3625 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3626 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3627 if (connection == NULL) return; 3628 3629 sm_reset_tk(); 3630 uint32_t tk; 3631 if (sm_fixed_passkey_in_display_role == 0xffffffffU){ 3632 // map random to 0-999999 without speding much cycles on a modulus operation 3633 tk = little_endian_read_32(sm_random_data,0); 3634 tk = tk & 0xfffff; // 1048575 3635 if (tk >= 999999u){ 3636 tk = tk - 999999u; 3637 } 3638 } else { 3639 // override with pre-defined passkey 3640 tk = sm_fixed_passkey_in_display_role; 3641 } 3642 big_endian_store_32(setup->sm_tk, 12, tk); 3643 if (IS_RESPONDER(connection->sm_role)){ 3644 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3645 } else { 3646 if (setup->sm_use_secure_connections){ 3647 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3648 } else { 3649 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3650 sm_trigger_user_response(connection); 3651 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3652 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3653 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) connection->sm_handle); 3654 } 3655 } 3656 } 3657 sm_trigger_run(); 3658 } 3659 3660 static void sm_handle_random_result_ph3_div(void * arg){ 3661 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3662 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3663 if (connection == NULL) return; 3664 3665 // use 16 bit from random value as div 3666 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3667 log_info_hex16("div", setup->sm_local_div); 3668 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3669 sm_trigger_run(); 3670 } 3671 3672 static void sm_handle_random_result_ph3_random(void * arg){ 3673 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3674 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3675 if (connection == NULL) return; 3676 3677 reverse_64(sm_random_data, setup->sm_local_rand); 3678 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3679 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3680 // no db for authenticated flag hack: store flag in bit 4 of LSB 3681 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3682 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3683 } 3684 static void sm_validate_er_ir(void){ 3685 // warn about default ER/IR 3686 bool warning = false; 3687 if (sm_ir_is_default()){ 3688 warning = true; 3689 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3690 } 3691 if (sm_er_is_default()){ 3692 warning = true; 3693 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3694 } 3695 if (warning) { 3696 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3697 } 3698 } 3699 3700 static void sm_handle_random_result_ir(void *arg){ 3701 sm_persistent_keys_random_active = false; 3702 if (arg != NULL){ 3703 // key generated, store in tlv 3704 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3705 log_info("Generated IR key. Store in TLV status: %d", status); 3706 UNUSED(status); 3707 } 3708 log_info_key("IR", sm_persistent_ir); 3709 dkg_state = DKG_CALC_IRK; 3710 3711 if (test_use_fixed_local_irk){ 3712 log_info_key("IRK", sm_persistent_irk); 3713 dkg_state = DKG_CALC_DHK; 3714 } 3715 3716 sm_trigger_run(); 3717 } 3718 3719 static void sm_handle_random_result_er(void *arg){ 3720 sm_persistent_keys_random_active = false; 3721 if (arg != 0){ 3722 // key generated, store in tlv 3723 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3724 log_info("Generated ER key. Store in TLV status: %d", status); 3725 UNUSED(status); 3726 } 3727 log_info_key("ER", sm_persistent_er); 3728 3729 // try load ir 3730 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3731 if (key_size == 16){ 3732 // ok, let's continue 3733 log_info("IR from TLV"); 3734 sm_handle_random_result_ir( NULL ); 3735 } else { 3736 // invalid, generate new random one 3737 sm_persistent_keys_random_active = true; 3738 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3739 } 3740 } 3741 3742 static void sm_connection_init(sm_connection_t * sm_conn, hci_con_handle_t con_handle, uint8_t role, uint8_t addr_type, bd_addr_t address){ 3743 3744 // connection info 3745 sm_conn->sm_handle = con_handle; 3746 sm_conn->sm_role = role; 3747 sm_conn->sm_peer_addr_type = addr_type; 3748 memcpy(sm_conn->sm_peer_address, address, 6); 3749 3750 // security properties 3751 sm_conn->sm_connection_encrypted = 0; 3752 sm_conn->sm_connection_authenticated = 0; 3753 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3754 sm_conn->sm_le_db_index = -1; 3755 sm_conn->sm_reencryption_active = false; 3756 3757 // prepare CSRK lookup (does not involve setup) 3758 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3759 3760 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3761 } 3762 3763 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3764 static void sm_event_handle_classic_encryption_event(sm_connection_t * sm_conn, hci_con_handle_t con_handle){ 3765 // CTKD requires BR/EDR Secure Connection 3766 if (sm_conn->sm_connection_encrypted != 2) return; 3767 // prepare for pairing request 3768 if (IS_RESPONDER(sm_conn->sm_role)){ 3769 sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST; 3770 } else if (sm_conn->sm_pairing_requested){ 3771 // check if remote supports fixed channels 3772 bool defer = true; 3773 const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 3774 if (hci_connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE){ 3775 // check if remote supports SMP over BR/EDR 3776 if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ 3777 log_info("CTKD: SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST"); 3778 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; 3779 } else { 3780 defer = false; 3781 } 3782 } else { 3783 // wait for fixed channel info 3784 log_info("CTKD: SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK"); 3785 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK; 3786 } 3787 if (defer){ 3788 hci_dedicated_bonding_defer_disconnect(con_handle, true); 3789 } 3790 } 3791 } 3792 #endif 3793 3794 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3795 3796 UNUSED(channel); // ok: there is no channel 3797 UNUSED(size); // ok: fixed format HCI events 3798 3799 sm_connection_t * sm_conn; 3800 hci_con_handle_t con_handle; 3801 uint8_t status; 3802 bd_addr_t addr; 3803 3804 switch (packet_type) { 3805 3806 case HCI_EVENT_PACKET: 3807 switch (hci_event_packet_get_type(packet)) { 3808 3809 case BTSTACK_EVENT_STATE: 3810 switch (btstack_event_state_get_state(packet)){ 3811 case HCI_STATE_WORKING: 3812 log_info("HCI Working!"); 3813 // setup IR/ER with TLV 3814 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3815 if (sm_tlv_impl != NULL){ 3816 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3817 if (key_size == 16){ 3818 // ok, let's continue 3819 log_info("ER from TLV"); 3820 sm_handle_random_result_er( NULL ); 3821 } else { 3822 // invalid, generate random one 3823 sm_persistent_keys_random_active = true; 3824 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3825 } 3826 } else { 3827 sm_validate_er_ir(); 3828 dkg_state = DKG_CALC_IRK; 3829 3830 if (test_use_fixed_local_irk){ 3831 log_info_key("IRK", sm_persistent_irk); 3832 dkg_state = DKG_CALC_DHK; 3833 } 3834 } 3835 3836 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3837 // trigger ECC key generation 3838 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 3839 sm_ec_generate_new_key(); 3840 } 3841 #endif 3842 3843 // restart random address updates after power cycle 3844 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_STATIC){ 3845 gap_random_address_set(sm_random_address); 3846 } else { 3847 gap_random_address_set_mode(gap_random_adress_type); 3848 } 3849 break; 3850 3851 case HCI_STATE_OFF: 3852 case HCI_STATE_HALTING: 3853 log_info("SM: reset state"); 3854 // stop random address update 3855 gap_random_address_update_stop(); 3856 // reset state 3857 sm_state_reset(); 3858 break; 3859 3860 default: 3861 break; 3862 } 3863 break; 3864 3865 #ifdef ENABLE_CLASSIC 3866 case HCI_EVENT_CONNECTION_COMPLETE: 3867 // ignore if connection failed 3868 if (hci_event_connection_complete_get_status(packet)) return; 3869 3870 con_handle = hci_event_connection_complete_get_connection_handle(packet); 3871 sm_conn = sm_get_connection_for_handle(con_handle); 3872 if (!sm_conn) break; 3873 3874 hci_event_connection_complete_get_bd_addr(packet, addr); 3875 sm_connection_init(sm_conn, 3876 con_handle, 3877 (uint8_t) gap_get_role(con_handle), 3878 BD_ADDR_TYPE_LE_PUBLIC, 3879 addr); 3880 // classic connection corresponds to public le address 3881 sm_conn->sm_own_addr_type = BD_ADDR_TYPE_LE_PUBLIC; 3882 gap_local_bd_addr(sm_conn->sm_own_address); 3883 sm_conn->sm_cid = L2CAP_CID_BR_EDR_SECURITY_MANAGER; 3884 sm_conn->sm_engine_state = SM_BR_EDR_W4_ENCRYPTION_COMPLETE; 3885 break; 3886 #endif 3887 3888 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3889 case HCI_EVENT_SIMPLE_PAIRING_COMPLETE: 3890 if (hci_event_simple_pairing_complete_get_status(packet) != ERROR_CODE_SUCCESS) break; 3891 hci_event_simple_pairing_complete_get_bd_addr(packet, addr); 3892 sm_conn = sm_get_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL); 3893 if (sm_conn == NULL) break; 3894 sm_conn->sm_pairing_requested = 1; 3895 break; 3896 #endif 3897 3898 case HCI_EVENT_LE_META: 3899 switch (packet[2]) { 3900 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3901 // ignore if connection failed 3902 if (packet[3]) return; 3903 3904 con_handle = little_endian_read_16(packet, 4); 3905 sm_conn = sm_get_connection_for_handle(con_handle); 3906 if (!sm_conn) break; 3907 3908 hci_subevent_le_connection_complete_get_peer_address(packet, addr); 3909 sm_connection_init(sm_conn, 3910 con_handle, 3911 hci_subevent_le_connection_complete_get_role(packet), 3912 hci_subevent_le_connection_complete_get_peer_address_type(packet), 3913 addr); 3914 sm_conn->sm_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 3915 3916 // track our addr used for this connection and set state 3917 #ifdef ENABLE_LE_PERIPHERAL 3918 if (hci_subevent_le_connection_complete_get_role(packet) != 0){ 3919 // responder - use own address from advertisements 3920 gap_le_get_own_advertisements_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); 3921 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3922 } 3923 #endif 3924 #ifdef ENABLE_LE_CENTRAL 3925 if (hci_subevent_le_connection_complete_get_role(packet) == 0){ 3926 // initiator - use own address from create connection 3927 gap_le_get_own_connection_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); 3928 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3929 } 3930 #endif 3931 break; 3932 3933 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3934 con_handle = little_endian_read_16(packet, 3); 3935 sm_conn = sm_get_connection_for_handle(con_handle); 3936 if (!sm_conn) break; 3937 3938 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3939 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3940 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3941 break; 3942 } 3943 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3944 // PH2 SEND LTK as we need to exchange keys in PH3 3945 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3946 break; 3947 } 3948 3949 // store rand and ediv 3950 reverse_64(&packet[5], sm_conn->sm_local_rand); 3951 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3952 3953 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3954 // potentially stored LTK is from the master 3955 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3956 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3957 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3958 break; 3959 } 3960 // additionally check if remote is in LE Device DB if requested 3961 switch(sm_conn->sm_irk_lookup_state){ 3962 case IRK_LOOKUP_FAILED: 3963 log_info("LTK Request: device not in device db"); 3964 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3965 break; 3966 case IRK_LOOKUP_SUCCEEDED: 3967 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3968 break; 3969 default: 3970 // wait for irk look doen 3971 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3972 break; 3973 } 3974 break; 3975 } 3976 3977 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3978 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3979 #else 3980 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3981 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3982 #endif 3983 break; 3984 3985 default: 3986 break; 3987 } 3988 break; 3989 3990 case HCI_EVENT_ENCRYPTION_CHANGE: 3991 case HCI_EVENT_ENCRYPTION_CHANGE_V2: 3992 con_handle = hci_event_encryption_change_get_connection_handle(packet); 3993 sm_conn = sm_get_connection_for_handle(con_handle); 3994 if (!sm_conn) break; 3995 3996 sm_conn->sm_connection_encrypted = hci_event_encryption_change_get_encryption_enabled(packet); 3997 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3998 sm_conn->sm_actual_encryption_key_size); 3999 log_info("event handler, state %u", sm_conn->sm_engine_state); 4000 4001 switch (sm_conn->sm_engine_state){ 4002 4003 case SM_PH4_W4_CONNECTION_ENCRYPTED: 4004 // encryption change event concludes re-encryption for bonded devices (even if it fails) 4005 if (sm_conn->sm_connection_encrypted) { 4006 status = ERROR_CODE_SUCCESS; 4007 if (sm_conn->sm_role){ 4008 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 4009 } else { 4010 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 4011 } 4012 } else { 4013 status = hci_event_encryption_change_get_status(packet); 4014 // set state to 'RE-ENCRYPTION FAILED' to allow pairing but prevent other interactions 4015 // also, gap_reconnect_security_setup_active will return true 4016 sm_conn->sm_engine_state = SM_GENERAL_REENCRYPTION_FAILED; 4017 } 4018 4019 // emit re-encryption complete 4020 sm_reencryption_complete(sm_conn, status); 4021 4022 // notify client, if pairing was requested before 4023 if (sm_conn->sm_pairing_requested){ 4024 sm_conn->sm_pairing_requested = 0; 4025 sm_pairing_complete(sm_conn, status, 0); 4026 } 4027 4028 sm_done_for_handle(sm_conn->sm_handle); 4029 break; 4030 4031 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4032 if (!sm_conn->sm_connection_encrypted) break; 4033 // handler for HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE 4034 // contains the same code for this state 4035 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 4036 if (IS_RESPONDER(sm_conn->sm_role)){ 4037 // slave 4038 if (sm_conn->sm_connection_sc){ 4039 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4040 } else { 4041 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 4042 } 4043 } else { 4044 // master 4045 if (sm_key_distribution_all_received()){ 4046 // skip receiving keys as there are none 4047 sm_key_distribution_handle_all_received(sm_conn); 4048 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 4049 } else { 4050 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 4051 } 4052 } 4053 break; 4054 4055 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4056 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4057 sm_event_handle_classic_encryption_event(sm_conn, con_handle); 4058 break; 4059 #endif 4060 default: 4061 break; 4062 } 4063 break; 4064 4065 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 4066 con_handle = little_endian_read_16(packet, 3); 4067 sm_conn = sm_get_connection_for_handle(con_handle); 4068 if (!sm_conn) break; 4069 4070 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 4071 log_info("event handler, state %u", sm_conn->sm_engine_state); 4072 // continue if part of initial pairing 4073 switch (sm_conn->sm_engine_state){ 4074 case SM_PH4_W4_CONNECTION_ENCRYPTED: 4075 if (sm_conn->sm_role){ 4076 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 4077 } else { 4078 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 4079 } 4080 sm_done_for_handle(sm_conn->sm_handle); 4081 break; 4082 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4083 // handler for HCI_EVENT_ENCRYPTION_CHANGE 4084 // contains the same code for this state 4085 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 4086 if (IS_RESPONDER(sm_conn->sm_role)){ 4087 // slave 4088 if (sm_conn->sm_connection_sc){ 4089 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4090 } else { 4091 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 4092 } 4093 } else { 4094 // master 4095 if (sm_key_distribution_all_received()){ 4096 // skip receiving keys as there are none 4097 sm_key_distribution_handle_all_received(sm_conn); 4098 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 4099 } else { 4100 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 4101 } 4102 } 4103 break; 4104 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4105 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4106 sm_event_handle_classic_encryption_event(sm_conn, con_handle); 4107 break; 4108 #endif 4109 default: 4110 break; 4111 } 4112 break; 4113 4114 4115 case HCI_EVENT_DISCONNECTION_COMPLETE: 4116 con_handle = little_endian_read_16(packet, 3); 4117 sm_done_for_handle(con_handle); 4118 sm_conn = sm_get_connection_for_handle(con_handle); 4119 if (!sm_conn) break; 4120 4121 // pairing failed, if it was ongoing 4122 switch (sm_conn->sm_engine_state){ 4123 case SM_GENERAL_IDLE: 4124 case SM_INITIATOR_CONNECTED: 4125 case SM_RESPONDER_IDLE: 4126 break; 4127 default: 4128 sm_reencryption_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION); 4129 sm_pairing_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 4130 break; 4131 } 4132 4133 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 4134 sm_conn->sm_handle = 0; 4135 break; 4136 4137 case HCI_EVENT_COMMAND_COMPLETE: 4138 if (hci_event_command_complete_get_command_opcode(packet) == HCI_OPCODE_HCI_READ_BD_ADDR) { 4139 // set local addr for le device db 4140 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 4141 le_device_db_set_local_bd_addr(addr); 4142 } 4143 break; 4144 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4145 case L2CAP_EVENT_INFORMATION_RESPONSE: 4146 con_handle = l2cap_event_information_response_get_con_handle(packet); 4147 sm_conn = sm_get_connection_for_handle(con_handle); 4148 if (!sm_conn) break; 4149 if (sm_conn->sm_engine_state == SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK){ 4150 // check if remote supports SMP over BR/EDR 4151 const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 4152 if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ 4153 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; 4154 } else { 4155 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 4156 hci_dedicated_bonding_defer_disconnect(con_handle, false); 4157 } 4158 } 4159 break; 4160 #endif 4161 default: 4162 break; 4163 } 4164 break; 4165 default: 4166 break; 4167 } 4168 4169 sm_run(); 4170 } 4171 4172 static inline int sm_calc_actual_encryption_key_size(int other){ 4173 if (other < sm_min_encryption_key_size) return 0; 4174 if (other < sm_max_encryption_key_size) return other; 4175 return sm_max_encryption_key_size; 4176 } 4177 4178 4179 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4180 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 4181 switch (method){ 4182 case JUST_WORKS: 4183 case NUMERIC_COMPARISON: 4184 return 1; 4185 default: 4186 return 0; 4187 } 4188 } 4189 // responder 4190 4191 static int sm_passkey_used(stk_generation_method_t method){ 4192 switch (method){ 4193 case PK_RESP_INPUT: 4194 return 1; 4195 default: 4196 return 0; 4197 } 4198 } 4199 4200 static int sm_passkey_entry(stk_generation_method_t method){ 4201 switch (method){ 4202 case PK_RESP_INPUT: 4203 case PK_INIT_INPUT: 4204 case PK_BOTH_INPUT: 4205 return 1; 4206 default: 4207 return 0; 4208 } 4209 } 4210 4211 #endif 4212 4213 /** 4214 * @return ok 4215 */ 4216 static int sm_validate_stk_generation_method(void){ 4217 // check if STK generation method is acceptable by client 4218 switch (setup->sm_stk_generation_method){ 4219 case JUST_WORKS: 4220 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 4221 case PK_RESP_INPUT: 4222 case PK_INIT_INPUT: 4223 case PK_BOTH_INPUT: 4224 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 4225 case OOB: 4226 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 4227 case NUMERIC_COMPARISON: 4228 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 4229 default: 4230 return 0; 4231 } 4232 } 4233 4234 #ifdef ENABLE_LE_CENTRAL 4235 static void sm_initiator_connected_handle_security_request(sm_connection_t * sm_conn, const uint8_t *packet){ 4236 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4237 if (sm_sc_only_mode){ 4238 uint8_t auth_req = packet[1]; 4239 if ((auth_req & SM_AUTHREQ_SECURE_CONNECTION) == 0){ 4240 sm_pairing_error(sm_conn, SM_REASON_AUTHENTHICATION_REQUIREMENTS); 4241 return; 4242 } 4243 } 4244 #else 4245 UNUSED(packet); 4246 #endif 4247 4248 int have_ltk; 4249 uint8_t ltk[16]; 4250 4251 // IRK complete? 4252 switch (sm_conn->sm_irk_lookup_state){ 4253 case IRK_LOOKUP_FAILED: 4254 // start pairing 4255 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4256 break; 4257 case IRK_LOOKUP_SUCCEEDED: 4258 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4259 have_ltk = !sm_is_null_key(ltk); 4260 log_info("central: security request - have_ltk %u, encryption %u", have_ltk, sm_conn->sm_connection_encrypted); 4261 if (have_ltk && (sm_conn->sm_connection_encrypted == 0)){ 4262 // start re-encrypt if we have LTK and the connection is not already encrypted 4263 sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 4264 } else { 4265 // start pairing 4266 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4267 } 4268 break; 4269 default: 4270 // otherwise, store security request 4271 sm_conn->sm_security_request_received = 1; 4272 break; 4273 } 4274 } 4275 #endif 4276 4277 static uint8_t sm_pdu_validate_and_get_opcode(uint8_t packet_type, const uint8_t *packet, uint16_t size){ 4278 4279 // size of complete sm_pdu used to validate input 4280 static const uint8_t sm_pdu_size[] = { 4281 0, // 0x00 invalid opcode 4282 7, // 0x01 pairing request 4283 7, // 0x02 pairing response 4284 17, // 0x03 pairing confirm 4285 17, // 0x04 pairing random 4286 2, // 0x05 pairing failed 4287 17, // 0x06 encryption information 4288 11, // 0x07 master identification 4289 17, // 0x08 identification information 4290 8, // 0x09 identify address information 4291 17, // 0x0a signing information 4292 2, // 0x0b security request 4293 65, // 0x0c pairing public key 4294 17, // 0x0d pairing dhk check 4295 2, // 0x0e keypress notification 4296 }; 4297 4298 if (packet_type != SM_DATA_PACKET) return 0; 4299 if (size == 0u) return 0; 4300 4301 uint8_t sm_pdu_code = packet[0]; 4302 4303 // validate pdu size 4304 if (sm_pdu_code >= sizeof(sm_pdu_size)) return 0; 4305 if (sm_pdu_size[sm_pdu_code] != size) return 0; 4306 4307 return sm_pdu_code; 4308 } 4309 4310 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 4311 4312 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 4313 sm_run(); 4314 } 4315 4316 uint8_t sm_pdu_code = sm_pdu_validate_and_get_opcode(packet_type, packet, size); 4317 if (sm_pdu_code == 0) return; 4318 4319 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4320 if (!sm_conn) return; 4321 4322 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 4323 sm_reencryption_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE); 4324 sm_pairing_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 4325 sm_done_for_handle(con_handle); 4326 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 4327 return; 4328 } 4329 4330 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 4331 4332 int err; 4333 UNUSED(err); 4334 4335 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 4336 uint8_t buffer[5]; 4337 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 4338 buffer[1] = 3; 4339 little_endian_store_16(buffer, 2, con_handle); 4340 buffer[4] = packet[1]; 4341 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 4342 return; 4343 } 4344 4345 switch (sm_conn->sm_engine_state){ 4346 4347 // a sm timeout requires a new physical connection 4348 case SM_GENERAL_TIMEOUT: 4349 return; 4350 4351 #ifdef ENABLE_LE_CENTRAL 4352 4353 // Initiator 4354 case SM_INITIATOR_CONNECTED: 4355 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 4356 sm_pdu_received_in_wrong_state(sm_conn); 4357 break; 4358 } 4359 sm_initiator_connected_handle_security_request(sm_conn, packet); 4360 break; 4361 4362 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 4363 // Core 5, Vol 3, Part H, 2.4.6: 4364 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 4365 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 4366 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 4367 log_info("Ignoring Security Request"); 4368 break; 4369 } 4370 4371 // all other pdus are incorrect 4372 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 4373 sm_pdu_received_in_wrong_state(sm_conn); 4374 break; 4375 } 4376 4377 // store pairing request 4378 (void)memcpy(&setup->sm_s_pres, packet, 4379 sizeof(sm_pairing_packet_t)); 4380 err = sm_stk_generation_init(sm_conn); 4381 4382 #ifdef ENABLE_TESTING_SUPPORT 4383 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 4384 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 4385 err = test_pairing_failure; 4386 } 4387 #endif 4388 4389 if (err != 0){ 4390 sm_pairing_error(sm_conn, err); 4391 break; 4392 } 4393 4394 // generate random number first, if we need to show passkey 4395 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 4396 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) sm_conn->sm_handle); 4397 break; 4398 } 4399 4400 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4401 if (setup->sm_use_secure_connections){ 4402 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 4403 if (setup->sm_stk_generation_method == JUST_WORKS){ 4404 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4405 sm_trigger_user_response(sm_conn); 4406 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 4407 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4408 } 4409 } else { 4410 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4411 } 4412 break; 4413 } 4414 #endif 4415 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4416 sm_trigger_user_response(sm_conn); 4417 // response_idle == nothing <--> sm_trigger_user_response() did not require response 4418 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 4419 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); 4420 } 4421 break; 4422 4423 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 4424 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4425 sm_pdu_received_in_wrong_state(sm_conn); 4426 break; 4427 } 4428 4429 // store s_confirm 4430 reverse_128(&packet[1], setup->sm_peer_confirm); 4431 4432 // abort if s_confirm matches m_confirm 4433 if (memcmp(setup->sm_local_confirm, setup->sm_peer_confirm, 16) == 0){ 4434 sm_pdu_received_in_wrong_state(sm_conn); 4435 break; 4436 } 4437 4438 #ifdef ENABLE_TESTING_SUPPORT 4439 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4440 log_info("testing_support: reset confirm value"); 4441 memset(setup->sm_peer_confirm, 0, 16); 4442 } 4443 #endif 4444 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 4445 break; 4446 4447 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 4448 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4449 sm_pdu_received_in_wrong_state(sm_conn); 4450 break;; 4451 } 4452 4453 // received random value 4454 reverse_128(&packet[1], setup->sm_peer_random); 4455 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 4456 break; 4457 4458 case SM_PH4_W4_CONNECTION_ENCRYPTED: 4459 // ignore Security Request, see SM_INITIATOR_PH1_W4_PAIRING_RESPONSE above 4460 if (sm_pdu_code != SM_CODE_SECURITY_REQUEST){ 4461 sm_pdu_received_in_wrong_state(sm_conn); 4462 } 4463 break; 4464 #endif 4465 4466 #ifdef ENABLE_LE_PERIPHERAL 4467 // Responder 4468 case SM_RESPONDER_IDLE: 4469 case SM_RESPONDER_SEND_SECURITY_REQUEST: 4470 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 4471 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 4472 sm_pdu_received_in_wrong_state(sm_conn); 4473 break;; 4474 } 4475 4476 // store pairing request 4477 (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 4478 4479 // check if IRK completed 4480 switch (sm_conn->sm_irk_lookup_state){ 4481 case IRK_LOOKUP_SUCCEEDED: 4482 case IRK_LOOKUP_FAILED: 4483 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 4484 break; 4485 default: 4486 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK; 4487 break; 4488 } 4489 break; 4490 #endif 4491 4492 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4493 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4494 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 4495 sm_pdu_received_in_wrong_state(sm_conn); 4496 break; 4497 } 4498 4499 // store public key for DH Key calculation 4500 reverse_256(&packet[01], &setup->sm_peer_q[0]); 4501 reverse_256(&packet[33], &setup->sm_peer_q[32]); 4502 4503 // CVE-2020-26558: abort pairing if remote uses the same public key 4504 if (memcmp(&setup->sm_peer_q, ec_q, 64) == 0){ 4505 log_info("Remote PK matches ours"); 4506 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 4507 break; 4508 } 4509 4510 // validate public key 4511 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 4512 if (err != 0){ 4513 log_info("sm: peer public key invalid %x", err); 4514 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 4515 break; 4516 } 4517 4518 // start calculating dhkey 4519 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, (void*)(uintptr_t) sm_conn->sm_handle); 4520 4521 4522 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 4523 if (IS_RESPONDER(sm_conn->sm_role)){ 4524 // responder 4525 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4526 } else { 4527 // initiator 4528 // stk generation method 4529 // passkey entry: notify app to show passkey or to request passkey 4530 switch (setup->sm_stk_generation_method){ 4531 case JUST_WORKS: 4532 case NUMERIC_COMPARISON: 4533 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 4534 break; 4535 case PK_RESP_INPUT: 4536 sm_sc_start_calculating_local_confirm(sm_conn); 4537 break; 4538 case PK_INIT_INPUT: 4539 case PK_BOTH_INPUT: 4540 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 4541 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 4542 break; 4543 } 4544 sm_sc_start_calculating_local_confirm(sm_conn); 4545 break; 4546 case OOB: 4547 // generate Nx 4548 log_info("Generate Na"); 4549 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void*)(uintptr_t) sm_conn->sm_handle); 4550 break; 4551 default: 4552 btstack_assert(false); 4553 break; 4554 } 4555 } 4556 break; 4557 4558 case SM_SC_W4_CONFIRMATION: 4559 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4560 sm_pdu_received_in_wrong_state(sm_conn); 4561 break; 4562 } 4563 // received confirm value 4564 reverse_128(&packet[1], setup->sm_peer_confirm); 4565 4566 #ifdef ENABLE_TESTING_SUPPORT 4567 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4568 log_info("testing_support: reset confirm value"); 4569 memset(setup->sm_peer_confirm, 0, 16); 4570 } 4571 #endif 4572 if (IS_RESPONDER(sm_conn->sm_role)){ 4573 // responder 4574 if (sm_passkey_used(setup->sm_stk_generation_method)){ 4575 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 4576 // still waiting for passkey 4577 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 4578 break; 4579 } 4580 } 4581 sm_sc_start_calculating_local_confirm(sm_conn); 4582 } else { 4583 // initiator 4584 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 4585 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void*)(uintptr_t) sm_conn->sm_handle); 4586 } else { 4587 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 4588 } 4589 } 4590 break; 4591 4592 case SM_SC_W4_PAIRING_RANDOM: 4593 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4594 sm_pdu_received_in_wrong_state(sm_conn); 4595 break; 4596 } 4597 4598 // received random value 4599 reverse_128(&packet[1], setup->sm_peer_nonce); 4600 4601 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 4602 // only check for JUST WORK/NC in initiator role OR passkey entry 4603 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 4604 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 4605 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 4606 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 4607 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 4608 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 4609 break; 4610 } 4611 4612 // OOB 4613 if (setup->sm_stk_generation_method == OOB){ 4614 4615 // setup local random, set to zero if remote did not receive our data 4616 log_info("Received nonce, setup local random ra/rb for dhkey check"); 4617 if (IS_RESPONDER(sm_conn->sm_role)){ 4618 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 4619 log_info("Reset rb as A does not have OOB data"); 4620 memset(setup->sm_rb, 0, 16); 4621 } else { 4622 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 4623 log_info("Use stored rb"); 4624 log_info_hexdump(setup->sm_rb, 16); 4625 } 4626 } else { 4627 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 4628 log_info("Reset ra as B does not have OOB data"); 4629 memset(setup->sm_ra, 0, 16); 4630 } else { 4631 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 4632 log_info("Use stored ra"); 4633 log_info_hexdump(setup->sm_ra, 16); 4634 } 4635 } 4636 4637 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 4638 if (setup->sm_have_oob_data){ 4639 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 4640 break; 4641 } 4642 } 4643 4644 // TODO: we only get here for Responder role with JW/NC 4645 sm_sc_state_after_receiving_random(sm_conn); 4646 break; 4647 4648 case SM_SC_W2_CALCULATE_G2: 4649 case SM_SC_W4_CALCULATE_G2: 4650 case SM_SC_W4_CALCULATE_DHKEY: 4651 case SM_SC_W2_CALCULATE_F5_SALT: 4652 case SM_SC_W4_CALCULATE_F5_SALT: 4653 case SM_SC_W2_CALCULATE_F5_MACKEY: 4654 case SM_SC_W4_CALCULATE_F5_MACKEY: 4655 case SM_SC_W2_CALCULATE_F5_LTK: 4656 case SM_SC_W4_CALCULATE_F5_LTK: 4657 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 4658 case SM_SC_W4_DHKEY_CHECK_COMMAND: 4659 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 4660 case SM_SC_W4_USER_RESPONSE: 4661 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 4662 sm_pdu_received_in_wrong_state(sm_conn); 4663 break; 4664 } 4665 // store DHKey Check 4666 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 4667 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 4668 4669 // have we been only waiting for dhkey check command? 4670 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 4671 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 4672 } 4673 break; 4674 #endif 4675 4676 #ifdef ENABLE_LE_PERIPHERAL 4677 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 4678 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4679 sm_pdu_received_in_wrong_state(sm_conn); 4680 break; 4681 } 4682 4683 // received confirm value 4684 reverse_128(&packet[1], setup->sm_peer_confirm); 4685 4686 #ifdef ENABLE_TESTING_SUPPORT 4687 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4688 log_info("testing_support: reset confirm value"); 4689 memset(setup->sm_peer_confirm, 0, 16); 4690 } 4691 #endif 4692 // notify client to hide shown passkey 4693 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 4694 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 4695 } 4696 4697 // handle user cancel pairing? 4698 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 4699 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4700 break; 4701 } 4702 4703 // wait for user action? 4704 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 4705 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4706 break; 4707 } 4708 4709 // calculate and send local_confirm 4710 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); 4711 break; 4712 4713 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 4714 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4715 sm_pdu_received_in_wrong_state(sm_conn); 4716 break;; 4717 } 4718 4719 // received random value 4720 reverse_128(&packet[1], setup->sm_peer_random); 4721 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 4722 break; 4723 #endif 4724 4725 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4726 case SM_PH3_RECEIVE_KEYS: 4727 switch(sm_pdu_code){ 4728 case SM_CODE_ENCRYPTION_INFORMATION: 4729 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 4730 reverse_128(&packet[1], setup->sm_peer_ltk); 4731 break; 4732 4733 case SM_CODE_MASTER_IDENTIFICATION: 4734 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 4735 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 4736 reverse_64(&packet[3], setup->sm_peer_rand); 4737 break; 4738 4739 case SM_CODE_IDENTITY_INFORMATION: 4740 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 4741 reverse_128(&packet[1], setup->sm_peer_irk); 4742 break; 4743 4744 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 4745 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 4746 setup->sm_peer_addr_type = packet[1]; 4747 reverse_bd_addr(&packet[2], setup->sm_peer_address); 4748 break; 4749 4750 case SM_CODE_SIGNING_INFORMATION: 4751 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 4752 reverse_128(&packet[1], setup->sm_peer_csrk); 4753 break; 4754 default: 4755 // Unexpected PDU 4756 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 4757 break; 4758 } 4759 // done with key distribution? 4760 if (sm_key_distribution_all_received()){ 4761 4762 sm_key_distribution_handle_all_received(sm_conn); 4763 4764 if (IS_RESPONDER(sm_conn->sm_role)){ 4765 sm_key_distribution_complete_responder(sm_conn); 4766 } else { 4767 if (setup->sm_use_secure_connections){ 4768 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4769 } else { 4770 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 4771 } 4772 } 4773 } 4774 break; 4775 4776 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4777 4778 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4779 // GAP/DM/LEP/BI-02-C - reject CTKD if P-192 encryption is used 4780 if (sm_pdu_code == SM_CODE_PAIRING_REQUEST){ 4781 sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); 4782 } 4783 break; 4784 4785 case SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE: 4786 4787 // dedicated bonding complete 4788 hci_dedicated_bonding_defer_disconnect(sm_conn->sm_handle, false); 4789 4790 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 4791 sm_pdu_received_in_wrong_state(sm_conn); 4792 break; 4793 } 4794 // store pairing response 4795 (void)memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 4796 4797 // validate encryption key size 4798 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(setup->sm_s_pres)); 4799 // SC Only mandates 128 bit key size 4800 if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { 4801 sm_conn->sm_actual_encryption_key_size = 0; 4802 } 4803 if (sm_conn->sm_actual_encryption_key_size == 0){ 4804 sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); 4805 break; 4806 } 4807 4808 // prepare key exchange, LTK is derived locally 4809 sm_setup_key_distribution(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY, 4810 sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY); 4811 4812 // skip receive if there are none 4813 if (sm_key_distribution_all_received()){ 4814 // distribute keys in run handles 'no keys to send' 4815 sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 4816 } else { 4817 sm_conn->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; 4818 } 4819 break; 4820 4821 case SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST: 4822 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 4823 sm_pdu_received_in_wrong_state(sm_conn); 4824 break; 4825 } 4826 // store pairing request 4827 (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 4828 // validate encryption key size 4829 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(sm_conn->sm_m_preq)); 4830 // SC Only mandates 128 bit key size 4831 if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { 4832 sm_conn->sm_actual_encryption_key_size = 0; 4833 } 4834 if (sm_conn->sm_actual_encryption_key_size == 0){ 4835 sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); 4836 break; 4837 } 4838 // trigger response 4839 if (sm_ctkd_from_classic(sm_conn)){ 4840 sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED; 4841 } else { 4842 sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); 4843 } 4844 break; 4845 4846 case SM_BR_EDR_RECEIVE_KEYS: 4847 switch(sm_pdu_code){ 4848 case SM_CODE_IDENTITY_INFORMATION: 4849 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 4850 reverse_128(&packet[1], setup->sm_peer_irk); 4851 break; 4852 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 4853 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 4854 setup->sm_peer_addr_type = packet[1]; 4855 reverse_bd_addr(&packet[2], setup->sm_peer_address); 4856 break; 4857 case SM_CODE_SIGNING_INFORMATION: 4858 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 4859 reverse_128(&packet[1], setup->sm_peer_csrk); 4860 break; 4861 default: 4862 // Unexpected PDU 4863 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 4864 break; 4865 } 4866 4867 // all keys received 4868 if (sm_key_distribution_all_received()){ 4869 if (IS_RESPONDER(sm_conn->sm_role)){ 4870 // responder -> keys exchanged, derive LE LTK 4871 sm_ctkd_start_from_br_edr(sm_conn); 4872 } else { 4873 // initiator -> send our keys if any 4874 sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 4875 } 4876 } 4877 break; 4878 #endif 4879 4880 default: 4881 // Unexpected PDU 4882 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 4883 sm_pdu_received_in_wrong_state(sm_conn); 4884 break; 4885 } 4886 4887 // try to send next pdu 4888 sm_trigger_run(); 4889 } 4890 4891 // Security Manager Client API 4892 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 4893 sm_get_oob_data = get_oob_data_callback; 4894 } 4895 4896 void sm_register_sc_oob_data_callback( int (*get_sc_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random)){ 4897 sm_get_sc_oob_data = get_sc_oob_data_callback; 4898 } 4899 4900 void sm_register_ltk_callback( bool (*get_ltk_callback)(hci_con_handle_t con_handle, uint8_t address_type, bd_addr_t addr, uint8_t * ltk)){ 4901 sm_get_ltk_callback = get_ltk_callback; 4902 } 4903 4904 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4905 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4906 } 4907 4908 void sm_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4909 btstack_linked_list_remove(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4910 } 4911 4912 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4913 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4914 } 4915 4916 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4917 sm_min_encryption_key_size = min_size; 4918 sm_max_encryption_key_size = max_size; 4919 } 4920 4921 void sm_set_authentication_requirements(uint8_t auth_req){ 4922 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4923 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4924 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4925 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4926 } 4927 #endif 4928 sm_auth_req = auth_req; 4929 } 4930 4931 void sm_set_io_capabilities(io_capability_t io_capability){ 4932 sm_io_capabilities = io_capability; 4933 } 4934 4935 #ifdef ENABLE_LE_PERIPHERAL 4936 void sm_set_request_security(int enable){ 4937 sm_slave_request_security = enable; 4938 } 4939 #endif 4940 4941 void sm_set_er(sm_key_t er){ 4942 (void)memcpy(sm_persistent_er, er, 16); 4943 } 4944 4945 void sm_set_ir(sm_key_t ir){ 4946 (void)memcpy(sm_persistent_ir, ir, 16); 4947 } 4948 4949 // Testing support only 4950 void sm_test_set_irk(sm_key_t irk){ 4951 (void)memcpy(sm_persistent_irk, irk, 16); 4952 dkg_state = DKG_CALC_DHK; 4953 test_use_fixed_local_irk = true; 4954 } 4955 4956 void sm_test_use_fixed_local_csrk(void){ 4957 test_use_fixed_local_csrk = true; 4958 } 4959 4960 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4961 static void sm_ec_generated(void * arg){ 4962 UNUSED(arg); 4963 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4964 // trigger pairing if pending for ec key 4965 sm_trigger_run(); 4966 } 4967 static void sm_ec_generate_new_key(void){ 4968 log_info("sm: generate new ec key"); 4969 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4970 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4971 } 4972 #endif 4973 4974 #ifdef ENABLE_TESTING_SUPPORT 4975 void sm_test_set_pairing_failure(int reason){ 4976 test_pairing_failure = reason; 4977 } 4978 #endif 4979 4980 static void sm_state_reset(void) { 4981 #ifdef USE_CMAC_ENGINE 4982 sm_cmac_active = 0; 4983 #endif 4984 dkg_state = DKG_W4_WORKING; 4985 rau_state = RAU_IDLE; 4986 sm_aes128_state = SM_AES128_IDLE; 4987 sm_address_resolution_test = -1; // no private address to resolve yet 4988 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4989 sm_address_resolution_general_queue = NULL; 4990 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4991 sm_persistent_keys_random_active = false; 4992 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4993 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 4994 #endif 4995 } 4996 4997 void sm_init(void){ 4998 4999 if (sm_initialized) return; 5000 5001 // set default ER and IR values (should be unique - set by app or sm later using TLV) 5002 sm_er_ir_set_default(); 5003 5004 // defaults 5005 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 5006 | SM_STK_GENERATION_METHOD_OOB 5007 | SM_STK_GENERATION_METHOD_PASSKEY 5008 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 5009 5010 sm_max_encryption_key_size = 16; 5011 sm_min_encryption_key_size = 7; 5012 5013 sm_fixed_passkey_in_display_role = 0xffffffffU; 5014 sm_reconstruct_ltk_without_le_device_db_entry = true; 5015 5016 gap_random_adress_update_period = 15 * 60 * 1000L; 5017 5018 test_use_fixed_local_csrk = false; 5019 5020 // other 5021 btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); 5022 5023 // register for HCI Events 5024 hci_event_callback_registration.callback = &sm_event_packet_handler; 5025 hci_add_event_handler(&hci_event_callback_registration); 5026 5027 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 5028 // register for L2CAP events 5029 l2cap_event_callback_registration.callback = &sm_event_packet_handler; 5030 l2cap_add_event_handler(&l2cap_event_callback_registration); 5031 #endif 5032 5033 // 5034 btstack_crypto_init(); 5035 5036 // init le_device_db 5037 le_device_db_init(); 5038 5039 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 5040 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 5041 #ifdef ENABLE_CLASSIC 5042 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_BR_EDR_SECURITY_MANAGER); 5043 #endif 5044 5045 // state 5046 sm_state_reset(); 5047 5048 sm_initialized = true; 5049 } 5050 5051 void sm_deinit(void){ 5052 sm_initialized = false; 5053 btstack_run_loop_remove_timer(&sm_run_timer); 5054 } 5055 5056 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 5057 sm_fixed_passkey_in_display_role = passkey; 5058 } 5059 5060 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 5061 sm_reconstruct_ltk_without_le_device_db_entry = allow != 0; 5062 } 5063 5064 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 5065 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 5066 if (!hci_con) return NULL; 5067 return &hci_con->sm_connection; 5068 } 5069 5070 static void sm_cache_ltk(sm_connection_t * connection, const sm_key_t ltk){ 5071 hci_connection_t * hci_con = hci_connection_for_handle(connection->sm_handle); 5072 btstack_assert(hci_con != NULL); 5073 memcpy(hci_con->link_key, ltk, 16); 5074 hci_con->link_key_type = 1; 5075 } 5076 5077 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 5078 static sm_connection_t * sm_get_connection_for_bd_addr_and_type(bd_addr_t address, bd_addr_type_t addr_type){ 5079 hci_connection_t * hci_con = hci_connection_for_bd_addr_and_type(address, addr_type); 5080 if (!hci_con) return NULL; 5081 return &hci_con->sm_connection; 5082 } 5083 #endif 5084 5085 // @deprecated: map onto sm_request_pairing 5086 void sm_send_security_request(hci_con_handle_t con_handle){ 5087 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5088 if (!sm_conn) return; 5089 if (!IS_RESPONDER(sm_conn->sm_role)) return; 5090 sm_request_pairing(con_handle); 5091 } 5092 5093 // request pairing 5094 void sm_request_pairing(hci_con_handle_t con_handle){ 5095 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5096 if (!sm_conn) return; // wrong connection 5097 5098 bool have_ltk; 5099 uint8_t ltk[16]; 5100 bool auth_required; 5101 int authenticated; 5102 bool trigger_reencryption; 5103 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 5104 if (IS_RESPONDER(sm_conn->sm_role)){ 5105 switch (sm_conn->sm_engine_state){ 5106 case SM_GENERAL_IDLE: 5107 case SM_RESPONDER_IDLE: 5108 switch (sm_conn->sm_irk_lookup_state){ 5109 case IRK_LOOKUP_SUCCEEDED: 5110 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 5111 have_ltk = !sm_is_null_key(ltk); 5112 log_info("have ltk %u", have_ltk); 5113 if (have_ltk){ 5114 sm_conn->sm_pairing_requested = 1; 5115 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 5116 sm_reencryption_started(sm_conn); 5117 break; 5118 } 5119 /* fall through */ 5120 5121 case IRK_LOOKUP_FAILED: 5122 sm_conn->sm_pairing_requested = 1; 5123 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 5124 sm_pairing_started(sm_conn); 5125 break; 5126 default: 5127 log_info("irk lookup pending"); 5128 sm_conn->sm_pairing_requested = 1; 5129 break; 5130 } 5131 break; 5132 default: 5133 break; 5134 } 5135 } else { 5136 // used as a trigger to start central/master/initiator security procedures 5137 switch (sm_conn->sm_engine_state){ 5138 case SM_INITIATOR_CONNECTED: 5139 switch (sm_conn->sm_irk_lookup_state){ 5140 case IRK_LOOKUP_SUCCEEDED: 5141 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); 5142 have_ltk = !sm_is_null_key(ltk); 5143 auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; 5144 // re-encrypt is sufficient if we have ltk and that is either already authenticated or we don't require authentication 5145 trigger_reencryption = have_ltk && ((authenticated != 0) || (auth_required == false)); 5146 log_info("have ltk %u, authenticated %u, auth required %u => reencrypt %u", have_ltk, authenticated, auth_required, trigger_reencryption); 5147 if (trigger_reencryption){ 5148 sm_conn->sm_pairing_requested = 1; 5149 sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 5150 break; 5151 } 5152 /* fall through */ 5153 5154 case IRK_LOOKUP_FAILED: 5155 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 5156 break; 5157 default: 5158 log_info("irk lookup pending"); 5159 sm_conn->sm_pairing_requested = 1; 5160 break; 5161 } 5162 break; 5163 case SM_GENERAL_REENCRYPTION_FAILED: 5164 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 5165 break; 5166 case SM_GENERAL_IDLE: 5167 sm_conn->sm_pairing_requested = 1; 5168 break; 5169 default: 5170 break; 5171 } 5172 } 5173 sm_trigger_run(); 5174 } 5175 5176 // called by client app on authorization request 5177 void sm_authorization_decline(hci_con_handle_t con_handle){ 5178 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5179 if (!sm_conn) return; // wrong connection 5180 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 5181 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 5182 } 5183 5184 void sm_authorization_grant(hci_con_handle_t con_handle){ 5185 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5186 if (!sm_conn) return; // wrong connection 5187 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 5188 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 5189 } 5190 5191 // GAP Bonding API 5192 5193 void sm_bonding_decline(hci_con_handle_t con_handle){ 5194 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5195 if (!sm_conn) return; // wrong connection 5196 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 5197 log_info("decline, state %u", sm_conn->sm_engine_state); 5198 switch(sm_conn->sm_engine_state){ 5199 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5200 case SM_SC_W4_USER_RESPONSE: 5201 case SM_SC_W4_CONFIRMATION: 5202 case SM_SC_W4_PUBLIC_KEY_COMMAND: 5203 #endif 5204 case SM_PH1_W4_USER_RESPONSE: 5205 switch (setup->sm_stk_generation_method){ 5206 case PK_RESP_INPUT: 5207 case PK_INIT_INPUT: 5208 case PK_BOTH_INPUT: 5209 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 5210 break; 5211 case NUMERIC_COMPARISON: 5212 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 5213 break; 5214 case JUST_WORKS: 5215 case OOB: 5216 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 5217 break; 5218 default: 5219 btstack_assert(false); 5220 break; 5221 } 5222 break; 5223 default: 5224 break; 5225 } 5226 sm_trigger_run(); 5227 } 5228 5229 void sm_just_works_confirm(hci_con_handle_t con_handle){ 5230 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5231 if (!sm_conn) return; // wrong connection 5232 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 5233 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 5234 if (setup->sm_use_secure_connections){ 5235 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 5236 } else { 5237 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); 5238 } 5239 } 5240 5241 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5242 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 5243 sm_sc_prepare_dhkey_check(sm_conn); 5244 } 5245 #endif 5246 5247 sm_trigger_run(); 5248 } 5249 5250 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 5251 // for now, it's the same 5252 sm_just_works_confirm(con_handle); 5253 } 5254 5255 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 5256 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5257 if (!sm_conn) return; // wrong connection 5258 sm_reset_tk(); 5259 big_endian_store_32(setup->sm_tk, 12, passkey); 5260 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 5261 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 5262 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); 5263 } 5264 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5265 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 5266 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 5267 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 5268 sm_sc_start_calculating_local_confirm(sm_conn); 5269 } 5270 #endif 5271 sm_trigger_run(); 5272 } 5273 5274 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 5275 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5276 if (!sm_conn) return; // wrong connection 5277 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 5278 uint8_t num_actions = setup->sm_keypress_notification >> 5; 5279 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 5280 switch (action){ 5281 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 5282 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 5283 flags |= (1u << action); 5284 break; 5285 case SM_KEYPRESS_PASSKEY_CLEARED: 5286 // clear counter, keypress & erased flags + set passkey cleared 5287 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 5288 break; 5289 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 5290 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 5291 // erase actions queued 5292 num_actions--; 5293 if (num_actions == 0u){ 5294 // clear counter, keypress & erased flags 5295 flags &= 0x19u; 5296 } 5297 break; 5298 } 5299 num_actions++; 5300 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 5301 break; 5302 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 5303 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 5304 // enter actions queued 5305 num_actions--; 5306 if (num_actions == 0u){ 5307 // clear counter, keypress & erased flags 5308 flags &= 0x19u; 5309 } 5310 break; 5311 } 5312 num_actions++; 5313 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 5314 break; 5315 default: 5316 break; 5317 } 5318 setup->sm_keypress_notification = (num_actions << 5) | flags; 5319 sm_trigger_run(); 5320 } 5321 5322 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5323 static void sm_handle_random_result_oob(void * arg){ 5324 UNUSED(arg); 5325 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 5326 sm_trigger_run(); 5327 } 5328 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 5329 5330 static btstack_crypto_random_t sm_crypto_random_oob_request; 5331 5332 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 5333 sm_sc_oob_callback = callback; 5334 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 5335 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 5336 return 0; 5337 } 5338 #endif 5339 5340 /** 5341 * @brief Get Identity Resolving state 5342 * @param con_handle 5343 * @return irk_lookup_state_t 5344 */ 5345 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 5346 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5347 if (!sm_conn) return IRK_LOOKUP_IDLE; 5348 return sm_conn->sm_irk_lookup_state; 5349 } 5350 5351 /** 5352 * @brief Identify device in LE Device DB 5353 * @param handle 5354 * @return index from le_device_db or -1 if not found/identified 5355 */ 5356 int sm_le_device_index(hci_con_handle_t con_handle ){ 5357 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5358 if (!sm_conn) return -1; 5359 return sm_conn->sm_le_db_index; 5360 } 5361 5362 uint8_t sm_get_ltk(hci_con_handle_t con_handle, sm_key_t ltk){ 5363 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 5364 if (hci_connection == NULL){ 5365 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 5366 } 5367 if (hci_connection->link_key_type == 0){ 5368 return ERROR_CODE_PIN_OR_KEY_MISSING; 5369 } 5370 memcpy(ltk, hci_connection->link_key, 16); 5371 return ERROR_CODE_SUCCESS; 5372 } 5373 5374 static int gap_random_address_type_requires_updates(void){ 5375 switch (gap_random_adress_type){ 5376 case GAP_RANDOM_ADDRESS_TYPE_OFF: 5377 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 5378 return 0; 5379 default: 5380 return 1; 5381 } 5382 } 5383 5384 static uint8_t own_address_type(void){ 5385 switch (gap_random_adress_type){ 5386 case GAP_RANDOM_ADDRESS_TYPE_OFF: 5387 return BD_ADDR_TYPE_LE_PUBLIC; 5388 default: 5389 return BD_ADDR_TYPE_LE_RANDOM; 5390 } 5391 } 5392 5393 // GAP LE API 5394 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 5395 gap_random_address_update_stop(); 5396 gap_random_adress_type = random_address_type; 5397 hci_le_set_own_address_type(own_address_type()); 5398 if (!gap_random_address_type_requires_updates()) return; 5399 gap_random_address_update_start(); 5400 gap_random_address_trigger(); 5401 } 5402 5403 gap_random_address_type_t gap_random_address_get_mode(void){ 5404 return gap_random_adress_type; 5405 } 5406 5407 void gap_random_address_set_update_period(int period_ms){ 5408 gap_random_adress_update_period = period_ms; 5409 if (!gap_random_address_type_requires_updates()) return; 5410 gap_random_address_update_stop(); 5411 gap_random_address_update_start(); 5412 } 5413 5414 void gap_random_address_set(const bd_addr_t addr){ 5415 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 5416 (void)memcpy(sm_random_address, addr, 6); 5417 // assert msb bits are set to '11' 5418 sm_random_address[0] |= 0xc0; 5419 hci_le_random_address_set(sm_random_address); 5420 } 5421 5422 #ifdef ENABLE_LE_PERIPHERAL 5423 /* 5424 * @brief Set Advertisement Paramters 5425 * @param adv_int_min 5426 * @param adv_int_max 5427 * @param adv_type 5428 * @param direct_address_type 5429 * @param direct_address 5430 * @param channel_map 5431 * @param filter_policy 5432 * 5433 * @note own_address_type is used from gap_random_address_set_mode 5434 */ 5435 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 5436 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 5437 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 5438 direct_address_typ, direct_address, channel_map, filter_policy); 5439 } 5440 #endif 5441 5442 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 5443 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5444 // wrong connection 5445 if (!sm_conn) return 0; 5446 // already encrypted 5447 if (sm_conn->sm_connection_encrypted) return 0; 5448 // irk status? 5449 switch(sm_conn->sm_irk_lookup_state){ 5450 case IRK_LOOKUP_FAILED: 5451 // done, cannot setup encryption 5452 return 0; 5453 case IRK_LOOKUP_SUCCEEDED: 5454 break; 5455 default: 5456 // IR Lookup pending 5457 return 1; 5458 } 5459 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset or indicates failure 5460 if (sm_conn->sm_engine_state == SM_GENERAL_REENCRYPTION_FAILED) return 0; 5461 if (sm_conn->sm_role){ 5462 return sm_conn->sm_engine_state != SM_RESPONDER_IDLE; 5463 } else { 5464 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 5465 } 5466 } 5467 5468 void sm_set_secure_connections_only_mode(bool enable){ 5469 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5470 sm_sc_only_mode = enable; 5471 #else 5472 // SC Only mode not possible without support for SC 5473 btstack_assert(enable == false); 5474 #endif 5475 } 5476 5477 const uint8_t * gap_get_persistent_irk(void){ 5478 return sm_persistent_irk; 5479 } 5480 5481 void gap_delete_bonding(bd_addr_type_t address_type, bd_addr_t address){ 5482 int index = sm_le_device_db_index_lookup(address_type, address); 5483 if (index >= 0){ 5484 sm_remove_le_device_db_entry(index); 5485 } 5486 } 5487