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 // sm_trigger_run allows to schedule callback from main run loop // reduces stack depth 490 static void sm_run_timer_handler(btstack_timer_source_t * ts){ 491 UNUSED(ts); 492 sm_run(); 493 } 494 static void sm_trigger_run(void){ 495 if (!sm_initialized) return; 496 (void)btstack_run_loop_remove_timer(&sm_run_timer); 497 btstack_run_loop_set_timer(&sm_run_timer, 0); 498 btstack_run_loop_add_timer(&sm_run_timer); 499 } 500 501 // Key utils 502 static void sm_reset_tk(void){ 503 int i; 504 for (i=0;i<16;i++){ 505 setup->sm_tk[i] = 0; 506 } 507 } 508 509 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 510 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 511 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 512 int i; 513 for (i = max_encryption_size ; i < 16 ; i++){ 514 key[15-i] = 0; 515 } 516 } 517 518 // ER / IR checks 519 static void sm_er_ir_set_default(void){ 520 int i; 521 for (i=0;i<16;i++){ 522 sm_persistent_er[i] = 0x30 + i; 523 sm_persistent_ir[i] = 0x90 + i; 524 } 525 } 526 527 static int sm_er_is_default(void){ 528 int i; 529 for (i=0;i<16;i++){ 530 if (sm_persistent_er[i] != (0x30+i)) return 0; 531 } 532 return 1; 533 } 534 535 static int sm_ir_is_default(void){ 536 int i; 537 for (i=0;i<16;i++){ 538 if (sm_persistent_ir[i] != (0x90+i)) return 0; 539 } 540 return 1; 541 } 542 543 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 544 UNUSED(channel); 545 546 // log event 547 hci_dump_packet(packet_type, 1, packet, size); 548 // dispatch to all event handlers 549 btstack_linked_list_iterator_t it; 550 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 551 while (btstack_linked_list_iterator_has_next(&it)){ 552 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 553 entry->callback(packet_type, 0, packet, size); 554 } 555 } 556 557 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){ 558 event[0] = type; 559 event[1] = event_size - 2; 560 little_endian_store_16(event, 2, con_handle); 561 event[4] = addr_type; 562 reverse_bd_addr(address, &event[5]); 563 } 564 565 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 566 uint8_t event[11]; 567 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 568 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 569 } 570 571 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){ 572 // fetch addr and addr type from db, only called for valid entries 573 bd_addr_t identity_address; 574 int identity_address_type; 575 le_device_db_info(index, &identity_address_type, identity_address, NULL); 576 577 uint8_t event[20]; 578 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 579 event[11] = identity_address_type; 580 reverse_bd_addr(identity_address, &event[12]); 581 little_endian_store_16(event, 18, index); 582 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 583 } 584 585 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){ 586 uint8_t event[12]; 587 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 588 event[11] = status; 589 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 590 } 591 592 593 static void sm_reencryption_started(sm_connection_t * sm_conn){ 594 595 if (sm_conn->sm_reencryption_active) return; 596 597 sm_conn->sm_reencryption_active = true; 598 599 int identity_addr_type; 600 bd_addr_t identity_addr; 601 if (sm_conn->sm_le_db_index >= 0){ 602 // fetch addr and addr type from db, only called for valid entries 603 le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); 604 } else { 605 // for legacy pairing with LTK re-construction, use current peer addr 606 identity_addr_type = sm_conn->sm_peer_addr_type; 607 // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy 608 memcpy(identity_addr, sm_conn->sm_peer_address, 6); 609 } 610 611 sm_notify_client_base(SM_EVENT_REENCRYPTION_STARTED, sm_conn->sm_handle, identity_addr_type, identity_addr); 612 } 613 614 static void sm_reencryption_complete(sm_connection_t * sm_conn, uint8_t status){ 615 616 if (!sm_conn->sm_reencryption_active) return; 617 618 sm_conn->sm_reencryption_active = false; 619 620 int identity_addr_type; 621 bd_addr_t identity_addr; 622 if (sm_conn->sm_le_db_index >= 0){ 623 // fetch addr and addr type from db, only called for valid entries 624 le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); 625 } else { 626 // for legacy pairing with LTK re-construction, use current peer addr 627 identity_addr_type = sm_conn->sm_peer_addr_type; 628 // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy 629 memcpy(identity_addr, sm_conn->sm_peer_address, 6); 630 } 631 632 sm_notify_client_status(SM_EVENT_REENCRYPTION_COMPLETE, sm_conn->sm_handle, identity_addr_type, identity_addr, status); 633 } 634 635 static void sm_pairing_started(sm_connection_t * sm_conn){ 636 637 if (sm_conn->sm_pairing_active) return; 638 639 sm_conn->sm_pairing_active = true; 640 641 uint8_t event[11]; 642 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_STARTED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 643 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 644 } 645 646 static void sm_pairing_complete(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 647 648 if (!sm_conn->sm_pairing_active) return; 649 650 sm_conn->sm_pairing_active = false; 651 652 uint8_t event[13]; 653 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 654 event[11] = status; 655 event[12] = reason; 656 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 657 } 658 659 // SMP Timeout implementation 660 661 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 662 // the Security Manager Timer shall be reset and started. 663 // 664 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 665 // 666 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 667 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 668 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 669 // established. 670 671 static void sm_timeout_handler(btstack_timer_source_t * timer){ 672 log_info("SM timeout"); 673 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 674 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 675 sm_reencryption_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT); 676 sm_pairing_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 677 sm_done_for_handle(sm_conn->sm_handle); 678 679 // trigger handling of next ready connection 680 sm_run(); 681 } 682 static void sm_timeout_start(sm_connection_t * sm_conn){ 683 btstack_run_loop_remove_timer(&setup->sm_timeout); 684 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 685 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 686 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 687 btstack_run_loop_add_timer(&setup->sm_timeout); 688 } 689 static void sm_timeout_stop(void){ 690 btstack_run_loop_remove_timer(&setup->sm_timeout); 691 } 692 static void sm_timeout_reset(sm_connection_t * sm_conn){ 693 sm_timeout_stop(); 694 sm_timeout_start(sm_conn); 695 } 696 697 // end of sm timeout 698 699 // GAP Random Address updates 700 static gap_random_address_type_t gap_random_adress_type; 701 static btstack_timer_source_t gap_random_address_update_timer; 702 static uint32_t gap_random_adress_update_period; 703 704 static void gap_random_address_trigger(void){ 705 log_info("gap_random_address_trigger, state %u", rau_state); 706 if (rau_state != RAU_IDLE) return; 707 rau_state = RAU_GET_RANDOM; 708 sm_trigger_run(); 709 } 710 711 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 712 UNUSED(timer); 713 714 log_info("GAP Random Address Update due"); 715 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 716 btstack_run_loop_add_timer(&gap_random_address_update_timer); 717 gap_random_address_trigger(); 718 } 719 720 static void gap_random_address_update_start(void){ 721 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 722 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 723 btstack_run_loop_add_timer(&gap_random_address_update_timer); 724 } 725 726 static void gap_random_address_update_stop(void){ 727 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 728 } 729 730 // ah(k,r) helper 731 // r = padding || r 732 // r - 24 bit value 733 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 734 // r'= padding || r 735 memset(r_prime, 0, 16); 736 (void)memcpy(&r_prime[13], r, 3); 737 } 738 739 // d1 helper 740 // d' = padding || r || d 741 // d,r - 16 bit values 742 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 743 // d'= padding || r || d 744 memset(d1_prime, 0, 16); 745 big_endian_store_16(d1_prime, 12, r); 746 big_endian_store_16(d1_prime, 14, d); 747 } 748 749 // calculate arguments for first AES128 operation in C1 function 750 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){ 751 752 // p1 = pres || preq || rat’ || iat’ 753 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 754 // cant octet of pres becomes the most significant octet of p1. 755 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 756 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 757 // p1 is 0x05000800000302070710000001010001." 758 759 sm_key_t p1; 760 reverse_56(pres, &p1[0]); 761 reverse_56(preq, &p1[7]); 762 p1[14] = rat; 763 p1[15] = iat; 764 log_info_key("p1", p1); 765 log_info_key("r", r); 766 767 // t1 = r xor p1 768 int i; 769 for (i=0;i<16;i++){ 770 t1[i] = r[i] ^ p1[i]; 771 } 772 log_info_key("t1", t1); 773 } 774 775 // calculate arguments for second AES128 operation in C1 function 776 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 777 // p2 = padding || ia || ra 778 // "The least significant octet of ra becomes the least significant octet of p2 and 779 // the most significant octet of padding becomes the most significant octet of p2. 780 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 781 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 782 783 sm_key_t p2; 784 // cppcheck-suppress uninitvar ; p2 is reported as uninitialized 785 memset(p2, 0, 16); 786 (void)memcpy(&p2[4], ia, 6); 787 (void)memcpy(&p2[10], ra, 6); 788 log_info_key("p2", p2); 789 790 // c1 = e(k, t2_xor_p2) 791 int i; 792 for (i=0;i<16;i++){ 793 t3[i] = t2[i] ^ p2[i]; 794 } 795 log_info_key("t3", t3); 796 } 797 798 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 799 log_info_key("r1", r1); 800 log_info_key("r2", r2); 801 (void)memcpy(&r_prime[8], &r2[8], 8); 802 (void)memcpy(&r_prime[0], &r1[8], 8); 803 } 804 805 806 // decide on stk generation based on 807 // - pairing request 808 // - io capabilities 809 // - OOB data availability 810 static void sm_setup_tk(void){ 811 812 // horizontal: initiator capabilities 813 // vertial: responder capabilities 814 static const stk_generation_method_t stk_generation_method [5] [5] = { 815 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 816 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 817 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 818 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 819 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 820 }; 821 822 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 823 #ifdef ENABLE_LE_SECURE_CONNECTIONS 824 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 825 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 826 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 827 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 828 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 829 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 830 }; 831 #endif 832 833 // default: just works 834 setup->sm_stk_generation_method = JUST_WORKS; 835 836 #ifdef ENABLE_LE_SECURE_CONNECTIONS 837 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 838 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 839 & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; 840 #else 841 setup->sm_use_secure_connections = 0; 842 #endif 843 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 844 845 846 // decide if OOB will be used based on SC vs. Legacy and oob flags 847 bool use_oob; 848 if (setup->sm_use_secure_connections){ 849 // In LE Secure Connections pairing, the out of band method is used if at least 850 // one device has the peer device's out of band authentication data available. 851 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; 852 } else { 853 // In LE legacy pairing, the out of band method is used if both the devices have 854 // the other device's out of band authentication data available. 855 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; 856 } 857 if (use_oob){ 858 log_info("SM: have OOB data"); 859 log_info_key("OOB", setup->sm_tk); 860 setup->sm_stk_generation_method = OOB; 861 return; 862 } 863 864 // If both devices have not set the MITM option in the Authentication Requirements 865 // Flags, then the IO capabilities shall be ignored and the Just Works association 866 // model shall be used. 867 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) 868 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ 869 log_info("SM: MITM not required by both -> JUST WORKS"); 870 return; 871 } 872 873 // Reset TK as it has been setup in sm_init_setup 874 sm_reset_tk(); 875 876 // Also use just works if unknown io capabilites 877 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)){ 878 return; 879 } 880 881 // Otherwise the IO capabilities of the devices shall be used to determine the 882 // pairing method as defined in Table 2.4. 883 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 884 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 885 886 #ifdef ENABLE_LE_SECURE_CONNECTIONS 887 // table not define by default 888 if (setup->sm_use_secure_connections){ 889 generation_method = stk_generation_method_with_secure_connection; 890 } 891 #endif 892 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)]; 893 894 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 895 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); 896 } 897 898 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 899 int flags = 0; 900 if (key_set & SM_KEYDIST_ENC_KEY){ 901 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 902 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 903 } 904 if (key_set & SM_KEYDIST_ID_KEY){ 905 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 906 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 907 } 908 if (key_set & SM_KEYDIST_SIGN){ 909 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 910 } 911 return flags; 912 } 913 914 static void sm_setup_key_distribution(uint8_t keys_to_send, uint8_t keys_to_receive){ 915 setup->sm_key_distribution_received_set = 0; 916 setup->sm_key_distribution_expected_set = sm_key_distribution_flags_for_set(keys_to_receive); 917 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(keys_to_send); 918 setup->sm_key_distribution_sent_set = 0; 919 #ifdef ENABLE_LE_SIGNED_WRITE 920 setup->sm_le_device_index = -1; 921 #endif 922 } 923 924 // CSRK Key Lookup 925 926 927 static int sm_address_resolution_idle(void){ 928 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 929 } 930 931 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){ 932 (void)memcpy(sm_address_resolution_address, addr, 6); 933 sm_address_resolution_addr_type = addr_type; 934 sm_address_resolution_test = 0; 935 sm_address_resolution_mode = mode; 936 sm_address_resolution_context = context; 937 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 938 } 939 940 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 941 // check if already in list 942 btstack_linked_list_iterator_t it; 943 sm_lookup_entry_t * entry; 944 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 945 while(btstack_linked_list_iterator_has_next(&it)){ 946 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 947 if (entry->address_type != address_type) continue; 948 if (memcmp(entry->address, address, 6)) continue; 949 // already in list 950 return BTSTACK_BUSY; 951 } 952 entry = btstack_memory_sm_lookup_entry_get(); 953 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 954 entry->address_type = (bd_addr_type_t) address_type; 955 (void)memcpy(entry->address, address, 6); 956 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 957 sm_trigger_run(); 958 return 0; 959 } 960 961 // CMAC calculation using AES Engineq 962 #ifdef USE_CMAC_ENGINE 963 964 static void sm_cmac_done_trampoline(void * arg){ 965 UNUSED(arg); 966 sm_cmac_active = 0; 967 (*sm_cmac_done_callback)(sm_cmac_hash); 968 sm_trigger_run(); 969 } 970 971 int sm_cmac_ready(void){ 972 return sm_cmac_active == 0u; 973 } 974 #endif 975 976 #ifdef ENABLE_LE_SECURE_CONNECTIONS 977 // generic cmac calculation 978 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)){ 979 sm_cmac_active = 1; 980 sm_cmac_done_callback = done_callback; 981 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 982 } 983 #endif 984 985 // cmac for ATT Message signing 986 #ifdef ENABLE_LE_SIGNED_WRITE 987 988 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)){ 989 sm_cmac_active = 1; 990 sm_cmac_done_callback = done_callback; 991 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 992 } 993 994 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 995 if (offset >= sm_cmac_signed_write_message_len) { 996 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 997 return 0; 998 } 999 1000 offset = sm_cmac_signed_write_message_len - 1 - offset; 1001 1002 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 1003 if (offset < 3){ 1004 return sm_cmac_signed_write_header[offset]; 1005 } 1006 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 1007 if (offset < actual_message_len_incl_header){ 1008 return sm_cmac_signed_write_message[offset - 3]; 1009 } 1010 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 1011 } 1012 1013 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)){ 1014 // ATT Message Signing 1015 sm_cmac_signed_write_header[0] = opcode; 1016 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 1017 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 1018 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 1019 sm_cmac_signed_write_message = message; 1020 sm_cmac_signed_write_message_len = total_message_len; 1021 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 1022 } 1023 #endif 1024 1025 static void sm_trigger_user_response_basic(sm_connection_t * sm_conn, uint8_t event_type){ 1026 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1027 uint8_t event[12]; 1028 sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1029 event[11] = setup->sm_use_secure_connections ? 1 : 0; 1030 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1031 } 1032 1033 static void sm_trigger_user_response_passkey(sm_connection_t * sm_conn, uint8_t event_type){ 1034 uint8_t event[16]; 1035 uint32_t passkey = big_endian_read_32(setup->sm_tk, 12); 1036 sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, 1037 sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1038 event[11] = setup->sm_use_secure_connections ? 1 : 0; 1039 little_endian_store_32(event, 12, passkey); 1040 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1041 } 1042 1043 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1044 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1045 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1046 sm_conn->sm_pairing_active = true; 1047 switch (setup->sm_stk_generation_method){ 1048 case PK_RESP_INPUT: 1049 if (IS_RESPONDER(sm_conn->sm_role)){ 1050 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1051 } else { 1052 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); 1053 } 1054 break; 1055 case PK_INIT_INPUT: 1056 if (IS_RESPONDER(sm_conn->sm_role)){ 1057 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); 1058 } else { 1059 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1060 } 1061 break; 1062 case PK_BOTH_INPUT: 1063 sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); 1064 break; 1065 case NUMERIC_COMPARISON: 1066 sm_trigger_user_response_passkey(sm_conn, SM_EVENT_NUMERIC_COMPARISON_REQUEST); 1067 break; 1068 case JUST_WORKS: 1069 sm_trigger_user_response_basic(sm_conn, SM_EVENT_JUST_WORKS_REQUEST); 1070 break; 1071 case OOB: 1072 // client already provided OOB data, let's skip notification. 1073 break; 1074 default: 1075 btstack_assert(false); 1076 break; 1077 } 1078 } 1079 1080 static bool sm_key_distribution_all_received(void) { 1081 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); 1082 return (setup->sm_key_distribution_expected_set & setup->sm_key_distribution_received_set) == setup->sm_key_distribution_expected_set; 1083 } 1084 1085 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1086 if (sm_active_connection_handle == con_handle){ 1087 sm_timeout_stop(); 1088 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1089 log_info("sm: connection 0x%x released setup context", con_handle); 1090 1091 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1092 // generate new ec key after each pairing (that used it) 1093 if (setup->sm_use_secure_connections){ 1094 sm_ec_generate_new_key(); 1095 } 1096 #endif 1097 } 1098 } 1099 1100 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1101 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1102 sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); 1103 sm_done_for_handle(connection->sm_handle); 1104 } 1105 1106 static int sm_key_distribution_flags_for_auth_req(void){ 1107 1108 int flags = SM_KEYDIST_ID_KEY; 1109 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1110 // encryption and signing information only if bonding requested 1111 flags |= SM_KEYDIST_ENC_KEY; 1112 #ifdef ENABLE_LE_SIGNED_WRITE 1113 flags |= SM_KEYDIST_SIGN; 1114 #endif 1115 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1116 // LinkKey for CTKD requires SC 1117 if (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 1118 flags |= SM_KEYDIST_LINK_KEY; 1119 } 1120 #endif 1121 } 1122 return flags; 1123 } 1124 1125 static void sm_reset_setup(void){ 1126 // fill in sm setup 1127 setup->sm_state_vars = 0; 1128 setup->sm_keypress_notification = 0; 1129 setup->sm_have_oob_data = 0; 1130 sm_reset_tk(); 1131 } 1132 1133 static void sm_init_setup(sm_connection_t * sm_conn){ 1134 // fill in sm setup 1135 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1136 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1137 1138 // query client for Legacy Pairing OOB data 1139 if (sm_get_oob_data != NULL) { 1140 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1141 } 1142 1143 // if available and SC supported, also ask for SC OOB Data 1144 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1145 memset(setup->sm_ra, 0, 16); 1146 memset(setup->sm_rb, 0, 16); 1147 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1148 if (sm_get_sc_oob_data != NULL){ 1149 if (IS_RESPONDER(sm_conn->sm_role)){ 1150 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1151 sm_conn->sm_peer_addr_type, 1152 sm_conn->sm_peer_address, 1153 setup->sm_peer_confirm, 1154 setup->sm_ra); 1155 } else { 1156 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1157 sm_conn->sm_peer_addr_type, 1158 sm_conn->sm_peer_address, 1159 setup->sm_peer_confirm, 1160 setup->sm_rb); 1161 } 1162 } else { 1163 setup->sm_have_oob_data = 0; 1164 } 1165 } 1166 #endif 1167 1168 sm_pairing_packet_t * local_packet; 1169 if (IS_RESPONDER(sm_conn->sm_role)){ 1170 // slave 1171 local_packet = &setup->sm_s_pres; 1172 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1173 setup->sm_s_addr_type = sm_conn->sm_own_addr_type; 1174 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1175 (void)memcpy(setup->sm_s_address, sm_conn->sm_own_address, 6); 1176 } else { 1177 // master 1178 local_packet = &setup->sm_m_preq; 1179 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1180 setup->sm_m_addr_type = sm_conn->sm_own_addr_type; 1181 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1182 (void)memcpy(setup->sm_m_address, sm_conn->sm_own_address, 6); 1183 1184 uint8_t key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1185 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1186 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1187 } 1188 1189 uint8_t auth_req = sm_auth_req & ~SM_AUTHREQ_CT2; 1190 uint8_t max_encryption_key_size = sm_max_encryption_key_size; 1191 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1192 // enable SC for SC only mode 1193 if (sm_sc_only_mode){ 1194 auth_req |= SM_AUTHREQ_SECURE_CONNECTION; 1195 max_encryption_key_size = 16; 1196 } 1197 #endif 1198 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1199 // set CT2 if SC + Bonding + CTKD 1200 const uint8_t auth_req_for_ct2 = SM_AUTHREQ_SECURE_CONNECTION | SM_AUTHREQ_BONDING; 1201 if ((auth_req & auth_req_for_ct2) == auth_req_for_ct2){ 1202 auth_req |= SM_AUTHREQ_CT2; 1203 } 1204 #endif 1205 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1206 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1207 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1208 sm_pairing_packet_set_max_encryption_key_size(*local_packet, max_encryption_key_size); 1209 } 1210 1211 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1212 1213 sm_pairing_packet_t * remote_packet; 1214 uint8_t keys_to_send; 1215 uint8_t keys_to_receive; 1216 if (IS_RESPONDER(sm_conn->sm_role)){ 1217 // slave / responder 1218 remote_packet = &setup->sm_m_preq; 1219 keys_to_send = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1220 keys_to_receive = sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq); 1221 } else { 1222 // master / initiator 1223 remote_packet = &setup->sm_s_pres; 1224 keys_to_send = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1225 keys_to_receive = sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres); 1226 } 1227 1228 // check key size 1229 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1230 // SC Only mandates 128 bit key size 1231 if (sm_sc_only_mode && (sm_pairing_packet_get_max_encryption_key_size(*remote_packet) < 16)) { 1232 return SM_REASON_ENCRYPTION_KEY_SIZE; 1233 } 1234 #endif 1235 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1236 if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; 1237 1238 // decide on STK generation method / SC 1239 sm_setup_tk(); 1240 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1241 1242 // check if STK generation method is acceptable by client 1243 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1244 1245 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1246 // Check LE SC Only mode 1247 if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ 1248 log_info("SC Only mode active but SC not possible"); 1249 return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1250 } 1251 1252 // LTK (= encryption information & master identification) only used exchanged for LE Legacy Connection 1253 if (setup->sm_use_secure_connections){ 1254 keys_to_send &= ~SM_KEYDIST_ENC_KEY; 1255 keys_to_receive &= ~SM_KEYDIST_ENC_KEY; 1256 } 1257 #endif 1258 1259 // identical to responder 1260 sm_setup_key_distribution(keys_to_send, keys_to_receive); 1261 1262 // JUST WORKS doens't provide authentication 1263 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1264 1265 return 0; 1266 } 1267 1268 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1269 1270 // cache and reset context 1271 int matched_device_id = sm_address_resolution_test; 1272 address_resolution_mode_t mode = sm_address_resolution_mode; 1273 void * context = sm_address_resolution_context; 1274 1275 // reset context 1276 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1277 sm_address_resolution_context = NULL; 1278 sm_address_resolution_test = -1; 1279 hci_con_handle_t con_handle = 0; 1280 1281 sm_connection_t * sm_connection; 1282 sm_key_t ltk; 1283 bool have_ltk; 1284 #ifdef ENABLE_LE_CENTRAL 1285 bool trigger_pairing; 1286 int authenticated; 1287 #endif 1288 switch (mode){ 1289 case ADDRESS_RESOLUTION_GENERAL: 1290 break; 1291 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1292 sm_connection = (sm_connection_t *) context; 1293 con_handle = sm_connection->sm_handle; 1294 1295 // have ltk -> start encryption / send security request 1296 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1297 // "When a bond has been created between two devices, any reconnection should result in the local device 1298 // enabling or requesting encryption with the remote device before initiating any service request." 1299 1300 switch (event){ 1301 case ADDRESS_RESOLUTION_SUCCEEDED: 1302 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1303 sm_connection->sm_le_db_index = matched_device_id; 1304 log_info("ADDRESS_RESOLUTION_SUCCEEDED, index %d", sm_connection->sm_le_db_index); 1305 1306 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); 1307 have_ltk = !sm_is_null_key(ltk); 1308 1309 if (sm_connection->sm_role) { 1310 #ifdef ENABLE_LE_PERIPHERAL 1311 // IRK required before, continue 1312 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1313 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1314 break; 1315 } 1316 if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK){ 1317 sm_connection->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 1318 break; 1319 } 1320 bool trigger_security_request = (sm_connection->sm_pairing_requested != 0) || (sm_slave_request_security != 0); 1321 sm_connection->sm_pairing_requested = 0; 1322 #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION 1323 // trigger security request for Proactive Authentication if LTK available 1324 trigger_security_request = trigger_security_request || have_ltk; 1325 #endif 1326 1327 log_info("peripheral: pairing request local %u, have_ltk %u => trigger_security_request %u", 1328 sm_connection->sm_pairing_requested, (int) have_ltk, trigger_security_request); 1329 1330 if (trigger_security_request){ 1331 sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 1332 if (have_ltk){ 1333 sm_reencryption_started(sm_connection); 1334 } else { 1335 sm_pairing_started(sm_connection); 1336 } 1337 sm_trigger_run(); 1338 } 1339 #endif 1340 } else { 1341 1342 #ifdef ENABLE_LE_CENTRAL 1343 // check if pairing already requested and reset requests 1344 trigger_pairing = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1345 bool auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; 1346 1347 log_info("central: pairing request local %u, remote %u => trigger_pairing %u. have_ltk %u", 1348 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, (int) trigger_pairing, (int) have_ltk); 1349 sm_connection->sm_security_request_received = 0; 1350 sm_connection->sm_pairing_requested = 0; 1351 bool trigger_reencryption = false; 1352 1353 if (have_ltk){ 1354 if (trigger_pairing){ 1355 // if pairing is requested, re-encryption is sufficient, if ltk is already authenticated or we don't require authentication 1356 trigger_reencryption = (authenticated != 0) || (auth_required == false); 1357 } else { 1358 #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION 1359 trigger_reencryption = true; 1360 #else 1361 log_info("central: defer enabling encryption for bonded device"); 1362 #endif 1363 } 1364 } 1365 1366 if (trigger_reencryption){ 1367 log_info("central: enable encryption for bonded device"); 1368 sm_connection->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 1369 break; 1370 } 1371 1372 // pairing_request -> send pairing request 1373 if (trigger_pairing){ 1374 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1375 break; 1376 } 1377 #endif 1378 } 1379 break; 1380 case ADDRESS_RESOLUTION_FAILED: 1381 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1382 if (sm_connection->sm_role) { 1383 #ifdef ENABLE_LE_PERIPHERAL 1384 // LTK request received before, IRK required -> negative LTK reply 1385 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1386 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1387 } 1388 // send security request if requested 1389 bool trigger_security_request = (sm_connection->sm_pairing_requested != 0) || (sm_slave_request_security != 0); 1390 sm_connection->sm_pairing_requested = 0; 1391 if (trigger_security_request){ 1392 sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 1393 sm_pairing_started(sm_connection); 1394 } 1395 break; 1396 #endif 1397 } 1398 #ifdef ENABLE_LE_CENTRAL 1399 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1400 sm_connection->sm_security_request_received = 0; 1401 sm_connection->sm_pairing_requested = 0; 1402 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1403 #endif 1404 break; 1405 1406 default: 1407 btstack_assert(false); 1408 break; 1409 } 1410 break; 1411 default: 1412 break; 1413 } 1414 1415 switch (event){ 1416 case ADDRESS_RESOLUTION_SUCCEEDED: 1417 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1418 break; 1419 case ADDRESS_RESOLUTION_FAILED: 1420 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1421 break; 1422 default: 1423 btstack_assert(false); 1424 break; 1425 } 1426 } 1427 1428 static void sm_store_bonding_information(sm_connection_t * sm_conn){ 1429 int le_db_index = -1; 1430 1431 // lookup device based on IRK 1432 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1433 int i; 1434 for (i=0; i < le_device_db_max_count(); i++){ 1435 sm_key_t irk; 1436 bd_addr_t address; 1437 int address_type = BD_ADDR_TYPE_UNKNOWN; 1438 le_device_db_info(i, &address_type, address, irk); 1439 // skip unused entries 1440 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1441 // compare Identity Address 1442 if (memcmp(address, setup->sm_peer_address, 6) != 0) continue; 1443 // compare Identity Resolving Key 1444 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1445 1446 log_info("sm: device found for IRK, updating"); 1447 le_db_index = i; 1448 break; 1449 } 1450 } else { 1451 // assert IRK is set to zero 1452 memset(setup->sm_peer_irk, 0, 16); 1453 } 1454 1455 // if not found, lookup via public address if possible 1456 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1457 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1458 int i; 1459 for (i=0; i < le_device_db_max_count(); i++){ 1460 bd_addr_t address; 1461 int address_type = BD_ADDR_TYPE_UNKNOWN; 1462 le_device_db_info(i, &address_type, address, NULL); 1463 // skip unused entries 1464 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1465 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1466 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1467 log_info("sm: device found for public address, updating"); 1468 le_db_index = i; 1469 break; 1470 } 1471 } 1472 } 1473 1474 // if not found, add to db 1475 bool new_to_le_device_db = false; 1476 if (le_db_index < 0) { 1477 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1478 new_to_le_device_db = true; 1479 } 1480 1481 if (le_db_index >= 0){ 1482 1483 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1484 if (!new_to_le_device_db){ 1485 hci_remove_le_device_db_entry_from_resolving_list(le_db_index); 1486 } 1487 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1488 #else 1489 UNUSED(new_to_le_device_db); 1490 #endif 1491 1492 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1493 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1494 sm_conn->sm_le_db_index = le_db_index; 1495 1496 #ifdef ENABLE_LE_SIGNED_WRITE 1497 // store local CSRK 1498 setup->sm_le_device_index = le_db_index; 1499 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1500 log_info("sm: store local CSRK"); 1501 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1502 le_device_db_local_counter_set(le_db_index, 0); 1503 } 1504 1505 // store remote CSRK 1506 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1507 log_info("sm: store remote CSRK"); 1508 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1509 le_device_db_remote_counter_set(le_db_index, 0); 1510 } 1511 #endif 1512 // store encryption information for secure connections: LTK generated by ECDH 1513 if (setup->sm_use_secure_connections){ 1514 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1515 uint8_t zero_rand[8]; 1516 memset(zero_rand, 0, 8); 1517 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1518 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1519 } 1520 1521 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1522 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1523 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1524 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1525 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1526 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1527 1528 } 1529 } 1530 } 1531 1532 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1533 sm_conn->sm_pairing_failed_reason = reason; 1534 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1535 } 1536 1537 static int sm_le_device_db_index_lookup(bd_addr_type_t address_type, bd_addr_t address){ 1538 int i; 1539 for (i=0; i < le_device_db_max_count(); i++){ 1540 bd_addr_t db_address; 1541 int db_address_type = BD_ADDR_TYPE_UNKNOWN; 1542 le_device_db_info(i, &db_address_type, db_address, NULL); 1543 // skip unused entries 1544 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1545 if ((address_type == db_address_type) && (memcmp(address, db_address, 6) == 0)){ 1546 return i; 1547 } 1548 } 1549 return -1; 1550 } 1551 1552 static void sm_remove_le_device_db_entry(uint16_t i) { 1553 le_device_db_remove(i); 1554 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1555 // to remove an entry from the resolving list requires its identity address, which was already deleted 1556 // fully reload resolving list instead 1557 gap_load_resolving_list_from_le_device_db(); 1558 #endif 1559 } 1560 1561 static uint8_t sm_key_distribution_validate_received(sm_connection_t * sm_conn){ 1562 // if identity is provided, abort if we have bonding with same address but different irk 1563 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1564 int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, setup->sm_peer_address); 1565 if (index >= 0){ 1566 sm_key_t irk; 1567 le_device_db_info(index, NULL, NULL, irk); 1568 if (memcmp(irk, setup->sm_peer_irk, 16) != 0){ 1569 // IRK doesn't match, delete bonding information 1570 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); 1571 sm_remove_le_device_db_entry(index); 1572 } 1573 } 1574 } 1575 return 0; 1576 } 1577 1578 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1579 1580 // abort pairing if received keys are not valid 1581 uint8_t reason = sm_key_distribution_validate_received(sm_conn); 1582 if (reason != 0){ 1583 sm_pairing_error(sm_conn, reason); 1584 return; 1585 } 1586 1587 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1588 bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1589 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1590 & SM_AUTHREQ_BONDING ) != 0u; 1591 1592 if (bonding_enabled){ 1593 sm_store_bonding_information(sm_conn); 1594 } else { 1595 log_info("Ignoring received keys, bonding not enabled"); 1596 } 1597 } 1598 1599 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1600 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1601 } 1602 1603 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1604 1605 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1606 static int sm_passkey_used(stk_generation_method_t method); 1607 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1608 1609 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1610 if (setup->sm_stk_generation_method == OOB){ 1611 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1612 } else { 1613 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); 1614 } 1615 } 1616 1617 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1618 if (IS_RESPONDER(sm_conn->sm_role)){ 1619 // Responder 1620 if (setup->sm_stk_generation_method == OOB){ 1621 // generate Nb 1622 log_info("Generate Nb"); 1623 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); 1624 } else { 1625 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1626 } 1627 } else { 1628 // Initiator role 1629 switch (setup->sm_stk_generation_method){ 1630 case JUST_WORKS: 1631 sm_sc_prepare_dhkey_check(sm_conn); 1632 break; 1633 1634 case NUMERIC_COMPARISON: 1635 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1636 break; 1637 case PK_INIT_INPUT: 1638 case PK_RESP_INPUT: 1639 case PK_BOTH_INPUT: 1640 if (setup->sm_passkey_bit < 20u) { 1641 sm_sc_start_calculating_local_confirm(sm_conn); 1642 } else { 1643 sm_sc_prepare_dhkey_check(sm_conn); 1644 } 1645 break; 1646 case OOB: 1647 sm_sc_prepare_dhkey_check(sm_conn); 1648 break; 1649 default: 1650 btstack_assert(false); 1651 break; 1652 } 1653 } 1654 } 1655 1656 static void sm_sc_cmac_done(uint8_t * hash){ 1657 log_info("sm_sc_cmac_done: "); 1658 log_info_hexdump(hash, 16); 1659 1660 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1661 sm_sc_oob_state = SM_SC_OOB_IDLE; 1662 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1663 return; 1664 } 1665 1666 sm_connection_t * sm_conn = sm_cmac_connection; 1667 sm_cmac_connection = NULL; 1668 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1669 link_key_type_t link_key_type; 1670 #endif 1671 1672 switch (sm_conn->sm_engine_state){ 1673 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1674 (void)memcpy(setup->sm_local_confirm, hash, 16); 1675 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1676 break; 1677 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1678 // check 1679 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1680 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1681 break; 1682 } 1683 sm_sc_state_after_receiving_random(sm_conn); 1684 break; 1685 case SM_SC_W4_CALCULATE_G2: { 1686 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1687 big_endian_store_32(setup->sm_tk, 12, vab); 1688 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1689 sm_trigger_user_response(sm_conn); 1690 break; 1691 } 1692 case SM_SC_W4_CALCULATE_F5_SALT: 1693 (void)memcpy(setup->sm_t, hash, 16); 1694 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1695 break; 1696 case SM_SC_W4_CALCULATE_F5_MACKEY: 1697 (void)memcpy(setup->sm_mackey, hash, 16); 1698 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1699 break; 1700 case SM_SC_W4_CALCULATE_F5_LTK: 1701 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1702 // Errata Service Release to the Bluetooth Specification: ESR09 1703 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1704 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1705 (void)memcpy(setup->sm_ltk, hash, 16); 1706 (void)memcpy(setup->sm_local_ltk, hash, 16); 1707 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1708 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1709 break; 1710 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1711 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1712 if (IS_RESPONDER(sm_conn->sm_role)){ 1713 // responder 1714 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1715 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1716 } else { 1717 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1718 } 1719 } else { 1720 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1721 } 1722 break; 1723 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1724 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1725 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1726 break; 1727 } 1728 if (IS_RESPONDER(sm_conn->sm_role)){ 1729 // responder 1730 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1731 } else { 1732 // initiator 1733 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1734 } 1735 break; 1736 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 1737 case SM_SC_W4_CALCULATE_ILK: 1738 (void)memcpy(setup->sm_t, hash, 16); 1739 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY; 1740 break; 1741 case SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY: 1742 reverse_128(hash, setup->sm_t); 1743 link_key_type = sm_conn->sm_connection_authenticated ? 1744 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1745 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1746 gap_store_link_key_for_bd_addr(setup->sm_peer_address, setup->sm_t, link_key_type); 1747 if (IS_RESPONDER(sm_conn->sm_role)){ 1748 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1749 } else { 1750 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1751 } 1752 sm_pairing_complete(sm_conn, ERROR_CODE_SUCCESS, 0); 1753 sm_done_for_handle(sm_conn->sm_handle); 1754 break; 1755 case SM_BR_EDR_W4_CALCULATE_ILK: 1756 (void)memcpy(setup->sm_t, hash, 16); 1757 sm_conn->sm_engine_state = SM_BR_EDR_W2_CALCULATE_LE_LTK; 1758 break; 1759 case SM_BR_EDR_W4_CALCULATE_LE_LTK: 1760 log_info("Derived LE LTK from BR/EDR Link Key"); 1761 log_info_key("Link Key", hash); 1762 (void)memcpy(setup->sm_ltk, hash, 16); 1763 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1764 sm_conn->sm_connection_authenticated = setup->sm_link_key_type == AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1765 sm_store_bonding_information(sm_conn); 1766 sm_done_for_handle(sm_conn->sm_handle); 1767 break; 1768 #endif 1769 default: 1770 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1771 break; 1772 } 1773 sm_trigger_run(); 1774 } 1775 1776 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){ 1777 const uint16_t message_len = 65; 1778 sm_cmac_connection = sm_conn; 1779 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1780 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1781 sm_cmac_sc_buffer[64] = z; 1782 log_info("f4 key"); 1783 log_info_hexdump(x, 16); 1784 log_info("f4 message"); 1785 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1786 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1787 } 1788 1789 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1790 static const uint8_t f5_length[] = { 0x01, 0x00}; 1791 1792 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1793 1794 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1795 1796 log_info("f5_calculate_salt"); 1797 // calculate salt for f5 1798 const uint16_t message_len = 32; 1799 sm_cmac_connection = sm_conn; 1800 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1801 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1802 } 1803 1804 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){ 1805 const uint16_t message_len = 53; 1806 sm_cmac_connection = sm_conn; 1807 1808 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1809 sm_cmac_sc_buffer[0] = 0; 1810 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1811 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1812 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1813 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1814 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1815 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1816 log_info("f5 key"); 1817 log_info_hexdump(t, 16); 1818 log_info("f5 message for MacKey"); 1819 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1820 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1821 } 1822 1823 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1824 sm_key56_t bd_addr_master, bd_addr_slave; 1825 bd_addr_master[0] = setup->sm_m_addr_type; 1826 bd_addr_slave[0] = setup->sm_s_addr_type; 1827 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1828 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1829 if (IS_RESPONDER(sm_conn->sm_role)){ 1830 // responder 1831 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1832 } else { 1833 // initiator 1834 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1835 } 1836 } 1837 1838 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1839 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1840 const uint16_t message_len = 53; 1841 sm_cmac_connection = sm_conn; 1842 sm_cmac_sc_buffer[0] = 1; 1843 // 1..52 setup before 1844 log_info("f5 key"); 1845 log_info_hexdump(t, 16); 1846 log_info("f5 message for LTK"); 1847 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1848 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1849 } 1850 1851 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1852 f5_ltk(sm_conn, setup->sm_t); 1853 } 1854 1855 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){ 1856 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1857 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1858 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1859 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1860 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1861 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1862 } 1863 1864 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1865 const uint16_t message_len = 65; 1866 sm_cmac_connection = sm_conn; 1867 log_info("f6 key"); 1868 log_info_hexdump(w, 16); 1869 log_info("f6 message"); 1870 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1871 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1872 } 1873 1874 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1875 // - U is 256 bits 1876 // - V is 256 bits 1877 // - X is 128 bits 1878 // - Y is 128 bits 1879 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){ 1880 const uint16_t message_len = 80; 1881 sm_cmac_connection = sm_conn; 1882 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1883 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1884 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1885 log_info("g2 key"); 1886 log_info_hexdump(x, 16); 1887 log_info("g2 message"); 1888 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1889 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1890 } 1891 1892 static void g2_calculate(sm_connection_t * sm_conn) { 1893 // calc Va if numeric comparison 1894 if (IS_RESPONDER(sm_conn->sm_role)){ 1895 // responder 1896 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1897 } else { 1898 // initiator 1899 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1900 } 1901 } 1902 1903 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1904 uint8_t z = 0; 1905 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1906 // some form of passkey 1907 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1908 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1909 setup->sm_passkey_bit++; 1910 } 1911 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1912 } 1913 1914 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1915 // OOB 1916 if (setup->sm_stk_generation_method == OOB){ 1917 if (IS_RESPONDER(sm_conn->sm_role)){ 1918 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1919 } else { 1920 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1921 } 1922 return; 1923 } 1924 1925 uint8_t z = 0; 1926 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1927 // some form of passkey 1928 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1929 // sm_passkey_bit was increased before sending confirm value 1930 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1931 } 1932 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1933 } 1934 1935 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1936 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1937 1938 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1939 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1940 return; 1941 } else { 1942 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1943 } 1944 } 1945 1946 static void sm_sc_dhkey_calculated(void * arg){ 1947 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1948 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1949 if (sm_conn == NULL) return; 1950 1951 log_info("dhkey"); 1952 log_info_hexdump(&setup->sm_dhkey[0], 32); 1953 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1954 // trigger next step 1955 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1956 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1957 } 1958 sm_trigger_run(); 1959 } 1960 1961 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1962 // calculate DHKCheck 1963 sm_key56_t bd_addr_master, bd_addr_slave; 1964 bd_addr_master[0] = setup->sm_m_addr_type; 1965 bd_addr_slave[0] = setup->sm_s_addr_type; 1966 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1967 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1968 uint8_t iocap_a[3]; 1969 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1970 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1971 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1972 uint8_t iocap_b[3]; 1973 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1974 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1975 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1976 if (IS_RESPONDER(sm_conn->sm_role)){ 1977 // responder 1978 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1979 f6_engine(sm_conn, setup->sm_mackey); 1980 } else { 1981 // initiator 1982 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1983 f6_engine(sm_conn, setup->sm_mackey); 1984 } 1985 } 1986 1987 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1988 // validate E = f6() 1989 sm_key56_t bd_addr_master, bd_addr_slave; 1990 bd_addr_master[0] = setup->sm_m_addr_type; 1991 bd_addr_slave[0] = setup->sm_s_addr_type; 1992 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1993 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1994 1995 uint8_t iocap_a[3]; 1996 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1997 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1998 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1999 uint8_t iocap_b[3]; 2000 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 2001 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 2002 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 2003 if (IS_RESPONDER(sm_conn->sm_role)){ 2004 // responder 2005 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 2006 f6_engine(sm_conn, setup->sm_mackey); 2007 } else { 2008 // initiator 2009 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 2010 f6_engine(sm_conn, setup->sm_mackey); 2011 } 2012 } 2013 2014 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2015 2016 // 2017 // Link Key Conversion Function h6 2018 // 2019 // h6(W, keyID) = AES-CMAC_W(keyID) 2020 // - W is 128 bits 2021 // - keyID is 32 bits 2022 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 2023 const uint16_t message_len = 4; 2024 sm_cmac_connection = sm_conn; 2025 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 2026 log_info("h6 key"); 2027 log_info_hexdump(w, 16); 2028 log_info("h6 message"); 2029 log_info_hexdump(sm_cmac_sc_buffer, message_len); 2030 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 2031 } 2032 // 2033 // Link Key Conversion Function h7 2034 // 2035 // h7(SALT, W) = AES-CMAC_SALT(W) 2036 // - SALT is 128 bits 2037 // - W is 128 bits 2038 static void h7_engine(sm_connection_t * sm_conn, const sm_key_t salt, const sm_key_t w) { 2039 const uint16_t message_len = 16; 2040 sm_cmac_connection = sm_conn; 2041 log_info("h7 key"); 2042 log_info_hexdump(salt, 16); 2043 log_info("h7 message"); 2044 log_info_hexdump(w, 16); 2045 sm_cmac_message_start(salt, message_len, w, &sm_sc_cmac_done); 2046 } 2047 2048 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 2049 // Errata Service Release to the Bluetooth Specification: ESR09 2050 // E6405 – Cross transport key derivation from a key of size less than 128 bits 2051 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 2052 2053 static void h6_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ 2054 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 2055 } 2056 2057 static void h6_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ 2058 h6_engine(sm_conn, setup->sm_link_key, 0x746D7032); // "tmp2" 2059 } 2060 2061 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 2062 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 2063 } 2064 2065 static void h6_calculate_le_ltk(sm_connection_t * sm_conn){ 2066 h6_engine(sm_conn, setup->sm_t, 0x62726C65); // "brle" 2067 } 2068 2069 static void h7_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ 2070 const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x31}; // "tmp1" 2071 h7_engine(sm_conn, salt, setup->sm_local_ltk); 2072 } 2073 2074 static void h7_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ 2075 const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x32}; // "tmp2" 2076 h7_engine(sm_conn, salt, setup->sm_link_key); 2077 } 2078 2079 static void sm_ctkd_fetch_br_edr_link_key(sm_connection_t * sm_conn){ 2080 hci_connection_t * hci_connection = hci_connection_for_handle(sm_conn->sm_handle); 2081 btstack_assert(hci_connection != NULL); 2082 reverse_128(hci_connection->link_key, setup->sm_link_key); 2083 setup->sm_link_key_type = hci_connection->link_key_type; 2084 } 2085 2086 static void sm_ctkd_start_from_br_edr(sm_connection_t * sm_conn){ 2087 // only derive LTK if EncKey is set by both 2088 bool derive_ltk = (sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & 2089 sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & SM_KEYDIST_ENC_KEY) != 0; 2090 if (derive_ltk){ 2091 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; 2092 sm_conn->sm_engine_state = use_h7 ? SM_BR_EDR_W2_CALCULATE_ILK_USING_H7 : SM_BR_EDR_W2_CALCULATE_ILK_USING_H6; 2093 } else { 2094 sm_done_for_handle(sm_conn->sm_handle); 2095 } 2096 } 2097 2098 #endif 2099 2100 #endif 2101 2102 // key management legacy connections: 2103 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 2104 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 2105 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 2106 // - responder reconnects: responder uses LTK receveived from master 2107 2108 // key management secure connections: 2109 // - both devices store same LTK from ECDH key exchange. 2110 2111 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 2112 static void sm_load_security_info(sm_connection_t * sm_connection){ 2113 int encryption_key_size; 2114 int authenticated; 2115 int authorized; 2116 int secure_connection; 2117 2118 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 2119 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 2120 &encryption_key_size, &authenticated, &authorized, &secure_connection); 2121 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); 2122 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 2123 sm_connection->sm_connection_authenticated = authenticated; 2124 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 2125 sm_connection->sm_connection_sc = secure_connection; 2126 } 2127 #endif 2128 2129 #ifdef ENABLE_LE_PERIPHERAL 2130 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 2131 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 2132 setup->sm_local_ediv = sm_connection->sm_local_ediv; 2133 // re-establish used key encryption size 2134 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2135 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 2136 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 2137 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 2138 // Legacy paring -> not SC 2139 sm_connection->sm_connection_sc = 0; 2140 log_info("sm: received ltk request with key size %u, authenticated %u", 2141 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 2142 } 2143 #endif 2144 2145 // distributed key generation 2146 static bool sm_run_dpkg(void){ 2147 switch (dkg_state){ 2148 case DKG_CALC_IRK: 2149 // already busy? 2150 if (sm_aes128_state == SM_AES128_IDLE) { 2151 log_info("DKG_CALC_IRK started"); 2152 // IRK = d1(IR, 1, 0) 2153 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 2154 sm_aes128_state = SM_AES128_ACTIVE; 2155 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 2156 return true; 2157 } 2158 break; 2159 case DKG_CALC_DHK: 2160 // already busy? 2161 if (sm_aes128_state == SM_AES128_IDLE) { 2162 log_info("DKG_CALC_DHK started"); 2163 // DHK = d1(IR, 3, 0) 2164 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 2165 sm_aes128_state = SM_AES128_ACTIVE; 2166 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 2167 return true; 2168 } 2169 break; 2170 default: 2171 break; 2172 } 2173 return false; 2174 } 2175 2176 // random address updates 2177 static bool sm_run_rau(void){ 2178 switch (rau_state){ 2179 case RAU_GET_RANDOM: 2180 rau_state = RAU_W4_RANDOM; 2181 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 2182 return true; 2183 case RAU_GET_ENC: 2184 // already busy? 2185 if (sm_aes128_state == SM_AES128_IDLE) { 2186 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 2187 sm_aes128_state = SM_AES128_ACTIVE; 2188 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 2189 return true; 2190 } 2191 break; 2192 default: 2193 break; 2194 } 2195 return false; 2196 } 2197 2198 // CSRK Lookup 2199 static bool sm_run_csrk(void){ 2200 btstack_linked_list_iterator_t it; 2201 2202 // -- if csrk lookup ready, find connection that require csrk lookup 2203 if (sm_address_resolution_idle()){ 2204 hci_connections_get_iterator(&it); 2205 while(btstack_linked_list_iterator_has_next(&it)){ 2206 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2207 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2208 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 2209 // and start lookup 2210 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); 2211 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 2212 break; 2213 } 2214 } 2215 } 2216 2217 // -- if csrk lookup ready, resolved addresses for received addresses 2218 if (sm_address_resolution_idle()) { 2219 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 2220 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 2221 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 2222 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 2223 btstack_memory_sm_lookup_entry_free(entry); 2224 } 2225 } 2226 2227 // -- Continue with device lookup by public or resolvable private address 2228 if (!sm_address_resolution_idle()){ 2229 while (sm_address_resolution_test < le_device_db_max_count()){ 2230 int addr_type = BD_ADDR_TYPE_UNKNOWN; 2231 bd_addr_t addr; 2232 sm_key_t irk; 2233 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2234 2235 // skip unused entries 2236 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 2237 sm_address_resolution_test++; 2238 continue; 2239 } 2240 2241 log_info("LE Device Lookup: device %u of %u", sm_address_resolution_test, le_device_db_max_count()); 2242 2243 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 2244 log_info("LE Device Lookup: found by { addr_type, address} "); 2245 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); 2246 break; 2247 } 2248 2249 // if connection type is public, it must be a different one 2250 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 2251 sm_address_resolution_test++; 2252 continue; 2253 } 2254 2255 // skip AH if no IRK 2256 if (sm_is_null_key(irk)){ 2257 sm_address_resolution_test++; 2258 continue; 2259 } 2260 2261 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2262 2263 log_info("LE Device Lookup: calculate AH"); 2264 log_info_key("IRK", irk); 2265 2266 (void)memcpy(sm_aes128_key, irk, 16); 2267 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 2268 sm_aes128_state = SM_AES128_ACTIVE; 2269 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 2270 return true; 2271 } 2272 2273 if (sm_address_resolution_test >= le_device_db_max_count()){ 2274 log_info("LE Device Lookup: not found"); 2275 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2276 } 2277 } 2278 return false; 2279 } 2280 2281 // SC OOB 2282 static bool sm_run_oob(void){ 2283 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2284 switch (sm_sc_oob_state){ 2285 case SM_SC_OOB_W2_CALC_CONFIRM: 2286 if (!sm_cmac_ready()) break; 2287 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 2288 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 2289 return true; 2290 default: 2291 break; 2292 } 2293 #endif 2294 return false; 2295 } 2296 2297 static void sm_send_connectionless(sm_connection_t * sm_connection, const uint8_t * buffer, uint16_t size){ 2298 l2cap_send_connectionless(sm_connection->sm_handle, sm_connection->sm_cid, (uint8_t*) buffer, size); 2299 } 2300 2301 // handle basic actions that don't requires the full context 2302 static bool sm_run_basic(void){ 2303 btstack_linked_list_iterator_t it; 2304 hci_connections_get_iterator(&it); 2305 while(btstack_linked_list_iterator_has_next(&it)){ 2306 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2307 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2308 switch(sm_connection->sm_engine_state){ 2309 2310 // general 2311 case SM_GENERAL_SEND_PAIRING_FAILED: { 2312 uint8_t buffer[2]; 2313 buffer[0] = SM_CODE_PAIRING_FAILED; 2314 buffer[1] = sm_connection->sm_pairing_failed_reason; 2315 sm_connection->sm_engine_state = sm_connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2316 sm_send_connectionless(sm_connection, (uint8_t*) buffer, sizeof(buffer)); 2317 sm_pairing_complete(sm_connection, ERROR_CODE_AUTHENTICATION_FAILURE, sm_connection->sm_pairing_failed_reason); 2318 sm_done_for_handle(sm_connection->sm_handle); 2319 break; 2320 } 2321 2322 // responder side 2323 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2324 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2325 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2326 return true; 2327 2328 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2329 case SM_SC_RECEIVED_LTK_REQUEST: 2330 switch (sm_connection->sm_irk_lookup_state){ 2331 case IRK_LOOKUP_FAILED: 2332 log_info("LTK Request: IRK Lookup Failed)"); 2333 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2334 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2335 return true; 2336 default: 2337 break; 2338 } 2339 break; 2340 #endif 2341 default: 2342 break; 2343 } 2344 } 2345 return false; 2346 } 2347 2348 static void sm_run_activate_connection(void){ 2349 // Find connections that requires setup context and make active if no other is locked 2350 btstack_linked_list_iterator_t it; 2351 hci_connections_get_iterator(&it); 2352 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2353 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2354 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2355 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2356 bool done = true; 2357 int err; 2358 UNUSED(err); 2359 2360 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2361 // assert ec key is ready 2362 if ( (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2363 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST) 2364 || (sm_connection->sm_engine_state == SM_RESPONDER_SEND_SECURITY_REQUEST)){ 2365 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2366 sm_ec_generate_new_key(); 2367 } 2368 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2369 continue; 2370 } 2371 } 2372 #endif 2373 2374 switch (sm_connection->sm_engine_state) { 2375 #ifdef ENABLE_LE_PERIPHERAL 2376 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2377 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2378 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2379 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2380 case SM_SC_RECEIVED_LTK_REQUEST: 2381 #endif 2382 #endif 2383 #ifdef ENABLE_LE_CENTRAL 2384 case SM_INITIATOR_PH4_HAS_LTK: 2385 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2386 #endif 2387 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2388 case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: 2389 case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: 2390 #endif 2391 // just lock context 2392 break; 2393 default: 2394 done = false; 2395 break; 2396 } 2397 if (done){ 2398 sm_active_connection_handle = sm_connection->sm_handle; 2399 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); 2400 } 2401 } 2402 } 2403 2404 static void sm_run_send_keypress_notification(sm_connection_t * connection){ 2405 int i; 2406 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2407 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2408 uint8_t action = 0; 2409 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2410 if (flags & (1u<<i)){ 2411 bool clear_flag = true; 2412 switch (i){ 2413 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2414 case SM_KEYPRESS_PASSKEY_CLEARED: 2415 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2416 default: 2417 break; 2418 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2419 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2420 num_actions--; 2421 clear_flag = num_actions == 0u; 2422 break; 2423 } 2424 if (clear_flag){ 2425 flags &= ~(1<<i); 2426 } 2427 action = i; 2428 break; 2429 } 2430 } 2431 setup->sm_keypress_notification = (num_actions << 5) | flags; 2432 2433 // send keypress notification 2434 uint8_t buffer[2]; 2435 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2436 buffer[1] = action; 2437 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2438 2439 // try 2440 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); 2441 } 2442 2443 static void sm_run_distribute_keys(sm_connection_t * connection){ 2444 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2445 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2446 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2447 uint8_t buffer[17]; 2448 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2449 reverse_128(setup->sm_ltk, &buffer[1]); 2450 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2451 sm_timeout_reset(connection); 2452 return; 2453 } 2454 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2455 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2456 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2457 uint8_t buffer[11]; 2458 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2459 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2460 reverse_64(setup->sm_local_rand, &buffer[3]); 2461 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2462 sm_timeout_reset(connection); 2463 return; 2464 } 2465 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2466 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2467 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2468 uint8_t buffer[17]; 2469 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2470 reverse_128(sm_persistent_irk, &buffer[1]); 2471 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2472 sm_timeout_reset(connection); 2473 return; 2474 } 2475 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2476 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2477 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2478 bd_addr_t local_address; 2479 uint8_t buffer[8]; 2480 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2481 switch (gap_random_address_get_mode()){ 2482 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2483 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2484 // public or static random 2485 gap_le_get_own_address(&buffer[1], local_address); 2486 break; 2487 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2488 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2489 // fallback to public 2490 gap_local_bd_addr(local_address); 2491 buffer[1] = 0; 2492 break; 2493 default: 2494 btstack_assert(false); 2495 break; 2496 } 2497 reverse_bd_addr(local_address, &buffer[2]); 2498 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2499 sm_timeout_reset(connection); 2500 return; 2501 } 2502 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2503 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2504 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2505 2506 #ifdef ENABLE_LE_SIGNED_WRITE 2507 // hack to reproduce test runs 2508 if (test_use_fixed_local_csrk){ 2509 memset(setup->sm_local_csrk, 0xcc, 16); 2510 } 2511 2512 // store local CSRK 2513 if (setup->sm_le_device_index >= 0){ 2514 log_info("sm: store local CSRK"); 2515 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2516 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2517 } 2518 #endif 2519 2520 uint8_t buffer[17]; 2521 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2522 reverse_128(setup->sm_local_csrk, &buffer[1]); 2523 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2524 sm_timeout_reset(connection); 2525 return; 2526 } 2527 btstack_assert(false); 2528 } 2529 2530 static bool sm_ctkd_from_le(sm_connection_t *sm_connection) { 2531 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2532 // requirements to derive link key from LE: 2533 // - use secure connections 2534 if (setup->sm_use_secure_connections == 0) return false; 2535 // - bonding needs to be enabled: 2536 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; 2537 if (!bonding_enabled) return false; 2538 // - need identity address / public addr 2539 bool have_identity_address_info = ((setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION) != 0) || (setup->sm_peer_addr_type == 0); 2540 if (!have_identity_address_info) return false; 2541 // - 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) 2542 // this requirement is motivated by BLURtooth paper. The paper recommends to not overwrite keys at all. 2543 // If SC is authenticated, we consider it safe to overwrite a stored key. 2544 // 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. 2545 uint8_t link_key[16]; 2546 link_key_type_t link_key_type; 2547 bool have_link_key = gap_get_link_key_for_bd_addr(setup->sm_peer_address, link_key, &link_key_type); 2548 bool link_key_authenticated = gap_authenticated_for_link_key_type(link_key_type); 2549 bool derived_key_authenticated = sm_connection->sm_connection_authenticated != 0; 2550 if (have_link_key && link_key_authenticated && !derived_key_authenticated) { 2551 return false; 2552 } 2553 // get started (all of the above are true) 2554 return true; 2555 #else 2556 UNUSED(sm_connection); 2557 return false; 2558 #endif 2559 } 2560 2561 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 2562 static bool sm_ctkd_from_classic(sm_connection_t * sm_connection){ 2563 hci_connection_t * hci_connection = hci_connection_for_handle(sm_connection->sm_handle); 2564 btstack_assert(hci_connection != NULL); 2565 // requirements to derive ltk from BR/EDR: 2566 // - BR/EDR uses secure connections 2567 if (gap_secure_connection_for_link_key_type(hci_connection->link_key_type) == false) return false; 2568 // - bonding needs to be enabled: 2569 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; 2570 if (!bonding_enabled) return false; 2571 // - 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) 2572 bool link_key_authenticated = gap_authenticated_for_link_key_type(hci_connection->link_key_type); 2573 if (link_key_authenticated) return true; 2574 int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, hci_connection->address); 2575 if (index >= 0){ 2576 int ltk_authenticated; 2577 sm_key_t ltk; 2578 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, <k_authenticated, NULL, NULL); 2579 bool have_ltk = !sm_is_null_key(ltk); 2580 if (have_ltk && ltk_authenticated) return false; 2581 } 2582 return true; 2583 } 2584 #endif 2585 2586 static void sm_key_distribution_complete_responder(sm_connection_t * connection){ 2587 if (sm_ctkd_from_le(connection)){ 2588 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; 2589 connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; 2590 } else { 2591 connection->sm_engine_state = SM_RESPONDER_IDLE; 2592 sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); 2593 sm_done_for_handle(connection->sm_handle); 2594 } 2595 } 2596 2597 static void sm_key_distribution_complete_initiator(sm_connection_t * connection){ 2598 if (sm_ctkd_from_le(connection)){ 2599 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; 2600 connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; 2601 } else { 2602 sm_master_pairing_success(connection); 2603 } 2604 } 2605 2606 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2607 static void sm_run_state_sc_send_confirmation(sm_connection_t *connection) { 2608 uint8_t buffer[17]; 2609 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2610 reverse_128(setup->sm_local_confirm, &buffer[1]); 2611 if (IS_RESPONDER(connection->sm_role)){ 2612 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2613 } else { 2614 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2615 } 2616 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2617 sm_timeout_reset(connection); 2618 } 2619 2620 static void sm_run_state_sc_send_pairing_random(sm_connection_t *connection) { 2621 uint8_t buffer[17]; 2622 buffer[0] = SM_CODE_PAIRING_RANDOM; 2623 reverse_128(setup->sm_local_nonce, &buffer[1]); 2624 log_info("stk method %u, bit num: %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2625 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2626 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2627 if (IS_RESPONDER(connection->sm_role)){ 2628 // responder 2629 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2630 } else { 2631 // initiator 2632 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2633 } 2634 } else { 2635 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2636 if (IS_RESPONDER(connection->sm_role)){ 2637 // responder 2638 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2639 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2640 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2641 } else { 2642 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2643 sm_sc_prepare_dhkey_check(connection); 2644 } 2645 } else { 2646 // initiator 2647 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2648 } 2649 } 2650 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2651 sm_timeout_reset(connection); 2652 } 2653 2654 static void sm_run_state_sc_send_dhkey_check_command(sm_connection_t *connection) { 2655 uint8_t buffer[17]; 2656 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2657 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2658 2659 if (IS_RESPONDER(connection->sm_role)){ 2660 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2661 } else { 2662 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2663 } 2664 2665 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2666 sm_timeout_reset(connection); 2667 } 2668 2669 static void sm_run_state_sc_send_public_key_command(sm_connection_t *connection) { 2670 bool trigger_user_response = false; 2671 bool trigger_start_calculating_local_confirm = false; 2672 uint8_t buffer[65]; 2673 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2674 // 2675 reverse_256(&ec_q[0], &buffer[1]); 2676 reverse_256(&ec_q[32], &buffer[33]); 2677 2678 #ifdef ENABLE_TESTING_SUPPORT 2679 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2680 log_info("testing_support: invalidating public key"); 2681 // flip single bit of public key coordinate 2682 buffer[1] ^= 1; 2683 } 2684 #endif 2685 2686 // stk generation method 2687 // passkey entry: notify app to show passkey or to request passkey 2688 switch (setup->sm_stk_generation_method){ 2689 case JUST_WORKS: 2690 case NUMERIC_COMPARISON: 2691 if (IS_RESPONDER(connection->sm_role)){ 2692 // responder 2693 trigger_start_calculating_local_confirm = true; 2694 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2695 } else { 2696 // initiator 2697 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2698 } 2699 break; 2700 case PK_INIT_INPUT: 2701 case PK_RESP_INPUT: 2702 case PK_BOTH_INPUT: 2703 // use random TK for display 2704 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2705 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2706 setup->sm_passkey_bit = 0; 2707 2708 if (IS_RESPONDER(connection->sm_role)){ 2709 // responder 2710 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2711 } else { 2712 // initiator 2713 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2714 } 2715 trigger_user_response = true; 2716 break; 2717 case OOB: 2718 if (IS_RESPONDER(connection->sm_role)){ 2719 // responder 2720 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2721 } else { 2722 // initiator 2723 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2724 } 2725 break; 2726 default: 2727 btstack_assert(false); 2728 break; 2729 } 2730 2731 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 2732 sm_timeout_reset(connection); 2733 2734 // trigger user response and calc confirm after sending pdu 2735 if (trigger_user_response){ 2736 sm_trigger_user_response(connection); 2737 } 2738 if (trigger_start_calculating_local_confirm){ 2739 sm_sc_start_calculating_local_confirm(connection); 2740 } 2741 } 2742 #endif 2743 2744 static bool sm_run_non_connection_logic(void){ 2745 bool done;; 2746 2747 done = sm_run_dpkg(); 2748 if (done) return true; 2749 2750 done = sm_run_rau(); 2751 if (done) return true; 2752 2753 done = sm_run_csrk(); 2754 if (done) return true; 2755 2756 done = sm_run_oob(); 2757 return done; 2758 } 2759 2760 static void sm_run(void){ 2761 2762 // assert that stack has already bootet 2763 if (hci_get_state() != HCI_STATE_WORKING) return; 2764 2765 // assert that we can send at least commands 2766 if (!hci_can_send_command_packet_now()) return; 2767 2768 // pause until IR/ER are ready 2769 if (sm_persistent_keys_random_active) return; 2770 2771 // non-connection related behaviour 2772 bool done = sm_run_non_connection_logic(); 2773 if (done) return; 2774 2775 // assert that we can send at least commands - cmd might have been sent by crypto engine 2776 if (!hci_can_send_command_packet_now()) return; 2777 2778 // handle basic actions that don't requires the full context 2779 done = sm_run_basic(); 2780 if (done) return; 2781 2782 // 2783 // active connection handling 2784 // -- use loop to handle next connection if lock on setup context is released 2785 2786 while (true) { 2787 2788 sm_run_activate_connection(); 2789 2790 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2791 2792 // 2793 // active connection handling 2794 // 2795 2796 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2797 if (!connection) { 2798 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2799 return; 2800 } 2801 2802 // assert that we could send a SM PDU - not needed for all of the following 2803 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, connection->sm_cid)) { 2804 log_info("cannot send now, requesting can send now event"); 2805 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); 2806 return; 2807 } 2808 2809 // send keypress notifications 2810 if (setup->sm_keypress_notification){ 2811 sm_run_send_keypress_notification(connection); 2812 return; 2813 } 2814 2815 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2816 // assert that sm cmac engine is ready 2817 if (sm_cmac_ready() == false){ 2818 break; 2819 } 2820 #endif 2821 2822 int key_distribution_flags; 2823 UNUSED(key_distribution_flags); 2824 #ifdef ENABLE_LE_PERIPHERAL 2825 int err; 2826 bool have_ltk; 2827 uint8_t ltk[16]; 2828 #endif 2829 2830 log_info("sm_run: state %u", connection->sm_engine_state); 2831 switch (connection->sm_engine_state){ 2832 2833 // secure connections, initiator + responding states 2834 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2835 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2836 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2837 sm_sc_calculate_local_confirm(connection); 2838 break; 2839 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2840 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2841 sm_sc_calculate_remote_confirm(connection); 2842 break; 2843 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2844 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2845 sm_sc_calculate_f6_for_dhkey_check(connection); 2846 break; 2847 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2848 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2849 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2850 break; 2851 case SM_SC_W2_CALCULATE_F5_SALT: 2852 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2853 f5_calculate_salt(connection); 2854 break; 2855 case SM_SC_W2_CALCULATE_F5_MACKEY: 2856 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2857 f5_calculate_mackey(connection); 2858 break; 2859 case SM_SC_W2_CALCULATE_F5_LTK: 2860 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2861 f5_calculate_ltk(connection); 2862 break; 2863 case SM_SC_W2_CALCULATE_G2: 2864 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2865 g2_calculate(connection); 2866 break; 2867 #endif 2868 2869 #ifdef ENABLE_LE_CENTRAL 2870 // initiator side 2871 2872 case SM_INITIATOR_PH4_HAS_LTK: { 2873 sm_reset_setup(); 2874 sm_load_security_info(connection); 2875 2876 sm_key_t peer_ltk_flipped; 2877 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2878 connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; 2879 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2880 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2881 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2882 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2883 2884 // notify after sending 2885 sm_reencryption_started(connection); 2886 return; 2887 } 2888 2889 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2890 sm_reset_setup(); 2891 sm_init_setup(connection); 2892 2893 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2894 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2895 sm_send_connectionless(connection, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2896 sm_timeout_reset(connection); 2897 2898 // notify after sending 2899 sm_pairing_started(connection); 2900 break; 2901 #endif 2902 2903 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2904 case SM_SC_SEND_PUBLIC_KEY_COMMAND: 2905 sm_run_state_sc_send_public_key_command(connection); 2906 break; 2907 case SM_SC_SEND_CONFIRMATION: 2908 sm_run_state_sc_send_confirmation(connection); 2909 break; 2910 case SM_SC_SEND_PAIRING_RANDOM: 2911 sm_run_state_sc_send_pairing_random(connection); 2912 break; 2913 case SM_SC_SEND_DHKEY_CHECK_COMMAND: 2914 sm_run_state_sc_send_dhkey_check_command(connection); 2915 break; 2916 #endif 2917 2918 #ifdef ENABLE_LE_PERIPHERAL 2919 2920 case SM_RESPONDER_SEND_SECURITY_REQUEST: { 2921 const uint8_t buffer[2] = {SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2922 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2923 sm_send_connectionless(connection, (uint8_t *) buffer, sizeof(buffer)); 2924 sm_timeout_start(connection); 2925 break; 2926 } 2927 2928 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2929 case SM_SC_RECEIVED_LTK_REQUEST: 2930 switch (connection->sm_irk_lookup_state){ 2931 case IRK_LOOKUP_SUCCEEDED: 2932 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2933 // start using context by loading security info 2934 sm_reset_setup(); 2935 sm_load_security_info(connection); 2936 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2937 (void)memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2938 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2939 sm_reencryption_started(connection); 2940 sm_trigger_run(); 2941 break; 2942 } 2943 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2944 connection->sm_engine_state = SM_RESPONDER_IDLE; 2945 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2946 return; 2947 default: 2948 // just wait until IRK lookup is completed 2949 break; 2950 } 2951 break; 2952 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2953 2954 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2955 sm_reset_setup(); 2956 2957 // handle Pairing Request with LTK available 2958 switch (connection->sm_irk_lookup_state) { 2959 case IRK_LOOKUP_SUCCEEDED: 2960 le_device_db_encryption_get(connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 2961 have_ltk = !sm_is_null_key(ltk); 2962 if (have_ltk){ 2963 log_info("pairing request but LTK available"); 2964 // emit re-encryption start/fail sequence 2965 sm_reencryption_started(connection); 2966 sm_reencryption_complete(connection, ERROR_CODE_PIN_OR_KEY_MISSING); 2967 } 2968 break; 2969 default: 2970 break; 2971 } 2972 2973 sm_init_setup(connection); 2974 2975 // recover pairing request 2976 (void)memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2977 err = sm_stk_generation_init(connection); 2978 2979 #ifdef ENABLE_TESTING_SUPPORT 2980 if ((0 < test_pairing_failure) && (test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED)){ 2981 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2982 err = test_pairing_failure; 2983 } 2984 #endif 2985 if (err != 0){ 2986 // emit pairing started/failed sequence 2987 sm_pairing_started(connection); 2988 sm_pairing_error(connection, err); 2989 sm_trigger_run(); 2990 break; 2991 } 2992 2993 sm_timeout_start(connection); 2994 2995 // generate random number first, if we need to show passkey, otherwise send response 2996 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2997 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) connection->sm_handle); 2998 break; 2999 } 3000 3001 /* fall through */ 3002 3003 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 3004 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 3005 3006 // start with initiator key dist flags 3007 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 3008 3009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3010 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 3011 if (setup->sm_use_secure_connections){ 3012 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 3013 } 3014 #endif 3015 // setup in response 3016 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); 3017 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); 3018 3019 // update key distribution after ENC was dropped 3020 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)); 3021 3022 if (setup->sm_use_secure_connections){ 3023 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 3024 } else { 3025 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 3026 } 3027 3028 sm_send_connectionless(connection, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 3029 sm_timeout_reset(connection); 3030 3031 // notify after sending 3032 sm_pairing_started(connection); 3033 3034 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3035 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 3036 sm_trigger_user_response(connection); 3037 } 3038 return; 3039 #endif 3040 3041 case SM_PH2_SEND_PAIRING_RANDOM: { 3042 uint8_t buffer[17]; 3043 buffer[0] = SM_CODE_PAIRING_RANDOM; 3044 reverse_128(setup->sm_local_random, &buffer[1]); 3045 if (IS_RESPONDER(connection->sm_role)){ 3046 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 3047 } else { 3048 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 3049 } 3050 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 3051 sm_timeout_reset(connection); 3052 break; 3053 } 3054 3055 case SM_PH2_C1_GET_ENC_A: 3056 // already busy? 3057 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3058 // calculate confirm using aes128 engine - step 1 3059 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); 3060 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 3061 sm_aes128_state = SM_AES128_ACTIVE; 3062 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); 3063 break; 3064 3065 case SM_PH2_C1_GET_ENC_C: 3066 // already busy? 3067 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3068 // calculate m_confirm using aes128 engine - step 1 3069 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); 3070 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 3071 sm_aes128_state = SM_AES128_ACTIVE; 3072 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); 3073 break; 3074 3075 case SM_PH2_CALC_STK: 3076 // already busy? 3077 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3078 // calculate STK 3079 if (IS_RESPONDER(connection->sm_role)){ 3080 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 3081 } else { 3082 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 3083 } 3084 connection->sm_engine_state = SM_PH2_W4_STK; 3085 sm_aes128_state = SM_AES128_ACTIVE; 3086 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); 3087 break; 3088 3089 case SM_PH3_Y_GET_ENC: 3090 // already busy? 3091 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3092 // PH3B2 - calculate Y from - enc 3093 3094 // dm helper (was sm_dm_r_prime) 3095 // r' = padding || r 3096 // r - 64 bit value 3097 memset(&sm_aes128_plaintext[0], 0, 8); 3098 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 3099 3100 // Y = dm(DHK, Rand) 3101 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 3102 sm_aes128_state = SM_AES128_ACTIVE; 3103 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); 3104 break; 3105 3106 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 3107 uint8_t buffer[17]; 3108 buffer[0] = SM_CODE_PAIRING_CONFIRM; 3109 reverse_128(setup->sm_local_confirm, &buffer[1]); 3110 if (IS_RESPONDER(connection->sm_role)){ 3111 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 3112 } else { 3113 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 3114 } 3115 sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); 3116 sm_timeout_reset(connection); 3117 return; 3118 } 3119 #ifdef ENABLE_LE_PERIPHERAL 3120 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 3121 // cache key before using 3122 sm_cache_ltk(connection, setup->sm_ltk); 3123 sm_key_t stk_flipped; 3124 reverse_128(setup->sm_ltk, stk_flipped); 3125 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 3126 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 3127 return; 3128 } 3129 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 3130 // allow to override LTK 3131 if (sm_get_ltk_callback != NULL){ 3132 (void)(*sm_get_ltk_callback)(connection->sm_handle, connection->sm_peer_addr_type, connection->sm_peer_address, setup->sm_ltk); 3133 } 3134 // cache key before using 3135 sm_cache_ltk(connection, setup->sm_ltk); 3136 sm_key_t ltk_flipped; 3137 reverse_128(setup->sm_ltk, ltk_flipped); 3138 connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; 3139 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 3140 return; 3141 } 3142 3143 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 3144 // already busy? 3145 if (sm_aes128_state == SM_AES128_ACTIVE) break; 3146 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 3147 3148 sm_reset_setup(); 3149 sm_start_calculating_ltk_from_ediv_and_rand(connection); 3150 3151 sm_reencryption_started(connection); 3152 3153 // dm helper (was sm_dm_r_prime) 3154 // r' = padding || r 3155 // r - 64 bit value 3156 memset(&sm_aes128_plaintext[0], 0, 8); 3157 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 3158 3159 // Y = dm(DHK, Rand) 3160 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 3161 sm_aes128_state = SM_AES128_ACTIVE; 3162 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); 3163 return; 3164 #endif 3165 #ifdef ENABLE_LE_CENTRAL 3166 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 3167 sm_key_t stk_flipped; 3168 reverse_128(setup->sm_ltk, stk_flipped); 3169 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 3170 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 3171 return; 3172 } 3173 #endif 3174 3175 case SM_PH3_DISTRIBUTE_KEYS: 3176 // send next key 3177 if (setup->sm_key_distribution_send_set != 0){ 3178 sm_run_distribute_keys(connection); 3179 } 3180 3181 // more to send? 3182 if (setup->sm_key_distribution_send_set != 0){ 3183 return; 3184 } 3185 3186 // keys are sent 3187 if (IS_RESPONDER(connection->sm_role)){ 3188 // slave -> receive master keys if any 3189 if (sm_key_distribution_all_received()){ 3190 sm_key_distribution_handle_all_received(connection); 3191 sm_key_distribution_complete_responder(connection); 3192 // start CTKD right away 3193 continue; 3194 } else { 3195 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3196 } 3197 } else { 3198 sm_master_pairing_success(connection); 3199 } 3200 break; 3201 3202 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3203 case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: 3204 // fill in sm setup (lite version of sm_init_setup) 3205 sm_reset_setup(); 3206 setup->sm_peer_addr_type = connection->sm_peer_addr_type; 3207 setup->sm_m_addr_type = connection->sm_peer_addr_type; 3208 setup->sm_s_addr_type = connection->sm_own_addr_type; 3209 (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); 3210 (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); 3211 (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); 3212 setup->sm_use_secure_connections = true; 3213 sm_ctkd_fetch_br_edr_link_key(connection); 3214 3215 // Enc Key and IRK if requested 3216 key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; 3217 #ifdef ENABLE_LE_SIGNED_WRITE 3218 // Plus signing key if supported 3219 key_distribution_flags |= SM_KEYDIST_ID_KEY; 3220 #endif 3221 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 3222 sm_pairing_packet_set_io_capability(setup->sm_m_preq, 0); 3223 sm_pairing_packet_set_oob_data_flag(setup->sm_m_preq, 0); 3224 sm_pairing_packet_set_auth_req(setup->sm_m_preq, SM_AUTHREQ_CT2); 3225 sm_pairing_packet_set_max_encryption_key_size(setup->sm_m_preq, sm_max_encryption_key_size); 3226 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 3227 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 3228 3229 // set state and send pairing response 3230 sm_timeout_start(connection); 3231 connection->sm_engine_state = SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE; 3232 sm_send_connectionless(connection, (uint8_t *) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 3233 break; 3234 3235 case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: 3236 // fill in sm setup (lite version of sm_init_setup) 3237 sm_reset_setup(); 3238 setup->sm_peer_addr_type = connection->sm_peer_addr_type; 3239 setup->sm_m_addr_type = connection->sm_peer_addr_type; 3240 setup->sm_s_addr_type = connection->sm_own_addr_type; 3241 (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); 3242 (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); 3243 (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); 3244 setup->sm_use_secure_connections = true; 3245 sm_ctkd_fetch_br_edr_link_key(connection); 3246 (void) memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 3247 3248 // Enc Key and IRK if requested 3249 key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; 3250 #ifdef ENABLE_LE_SIGNED_WRITE 3251 // Plus signing key if supported 3252 key_distribution_flags |= SM_KEYDIST_ID_KEY; 3253 #endif 3254 // drop flags not requested by initiator 3255 key_distribution_flags &= sm_pairing_packet_get_initiator_key_distribution(connection->sm_m_preq); 3256 3257 // If Secure Connections pairing has been initiated over BR/EDR, the following fields of the SM Pairing Request PDU are reserved for future use: 3258 // - the IO Capability field, 3259 // - the OOB data flag field, and 3260 // - all bits in the Auth Req field except the CT2 bit. 3261 sm_pairing_packet_set_code(setup->sm_s_pres, SM_CODE_PAIRING_RESPONSE); 3262 sm_pairing_packet_set_io_capability(setup->sm_s_pres, 0); 3263 sm_pairing_packet_set_oob_data_flag(setup->sm_s_pres, 0); 3264 sm_pairing_packet_set_auth_req(setup->sm_s_pres, SM_AUTHREQ_CT2); 3265 sm_pairing_packet_set_max_encryption_key_size(setup->sm_s_pres, connection->sm_actual_encryption_key_size); 3266 sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, key_distribution_flags); 3267 sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, key_distribution_flags); 3268 3269 // configure key distribution, LTK is derived locally 3270 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 3271 sm_setup_key_distribution(key_distribution_flags, key_distribution_flags); 3272 3273 // set state and send pairing response 3274 sm_timeout_start(connection); 3275 connection->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 3276 sm_send_connectionless(connection, (uint8_t *) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 3277 break; 3278 case SM_BR_EDR_DISTRIBUTE_KEYS: 3279 if (setup->sm_key_distribution_send_set != 0) { 3280 sm_run_distribute_keys(connection); 3281 return; 3282 } 3283 // keys are sent 3284 if (IS_RESPONDER(connection->sm_role)) { 3285 // responder -> receive master keys if there are any 3286 if (!sm_key_distribution_all_received()){ 3287 connection->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; 3288 break; 3289 } 3290 } 3291 // otherwise start CTKD right away (responder and no keys to receive / initiator) 3292 sm_ctkd_start_from_br_edr(connection); 3293 continue; 3294 case SM_SC_W2_CALCULATE_ILK_USING_H6: 3295 connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; 3296 h6_calculate_ilk_from_le_ltk(connection); 3297 break; 3298 case SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY: 3299 connection->sm_engine_state = SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY; 3300 h6_calculate_br_edr_link_key(connection); 3301 break; 3302 case SM_SC_W2_CALCULATE_ILK_USING_H7: 3303 connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; 3304 h7_calculate_ilk_from_le_ltk(connection); 3305 break; 3306 case SM_BR_EDR_W2_CALCULATE_ILK_USING_H6: 3307 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; 3308 h6_calculate_ilk_from_br_edr(connection); 3309 break; 3310 case SM_BR_EDR_W2_CALCULATE_LE_LTK: 3311 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_LE_LTK; 3312 h6_calculate_le_ltk(connection); 3313 break; 3314 case SM_BR_EDR_W2_CALCULATE_ILK_USING_H7: 3315 connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; 3316 h7_calculate_ilk_from_br_edr(connection); 3317 break; 3318 #endif 3319 3320 default: 3321 break; 3322 } 3323 3324 // check again if active connection was released 3325 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 3326 } 3327 } 3328 3329 // sm_aes128_state stays active 3330 static void sm_handle_encryption_result_enc_a(void *arg){ 3331 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3332 sm_aes128_state = SM_AES128_IDLE; 3333 3334 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3335 if (connection == NULL) return; 3336 3337 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 3338 sm_aes128_state = SM_AES128_ACTIVE; 3339 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); 3340 } 3341 3342 static void sm_handle_encryption_result_enc_b(void *arg){ 3343 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3344 sm_aes128_state = SM_AES128_IDLE; 3345 3346 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3347 if (connection == NULL) return; 3348 3349 log_info_key("c1!", setup->sm_local_confirm); 3350 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 3351 sm_trigger_run(); 3352 } 3353 3354 // sm_aes128_state stays active 3355 static void sm_handle_encryption_result_enc_c(void *arg){ 3356 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3357 sm_aes128_state = SM_AES128_IDLE; 3358 3359 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3360 if (connection == NULL) return; 3361 3362 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 3363 sm_aes128_state = SM_AES128_ACTIVE; 3364 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); 3365 } 3366 3367 static void sm_handle_encryption_result_enc_d(void * arg){ 3368 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3369 sm_aes128_state = SM_AES128_IDLE; 3370 3371 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3372 if (connection == NULL) return; 3373 3374 log_info_key("c1!", sm_aes128_ciphertext); 3375 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 3376 sm_pairing_error(connection, SM_REASON_CONFIRM_VALUE_FAILED); 3377 sm_trigger_run(); 3378 return; 3379 } 3380 if (IS_RESPONDER(connection->sm_role)){ 3381 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3382 sm_trigger_run(); 3383 } else { 3384 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 3385 sm_aes128_state = SM_AES128_ACTIVE; 3386 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); 3387 } 3388 } 3389 3390 static void sm_handle_encryption_result_enc_stk(void *arg){ 3391 sm_aes128_state = SM_AES128_IDLE; 3392 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3393 3394 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3395 if (connection == NULL) return; 3396 3397 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 3398 log_info_key("stk", setup->sm_ltk); 3399 if (IS_RESPONDER(connection->sm_role)){ 3400 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3401 } else { 3402 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 3403 } 3404 sm_trigger_run(); 3405 } 3406 3407 // sm_aes128_state stays active 3408 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 3409 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3410 sm_aes128_state = SM_AES128_IDLE; 3411 3412 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3413 if (connection == NULL) return; 3414 3415 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 3416 log_info_hex16("y", setup->sm_local_y); 3417 // PH3B3 - calculate EDIV 3418 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 3419 log_info_hex16("ediv", setup->sm_local_ediv); 3420 // PH3B4 - calculate LTK - enc 3421 // LTK = d1(ER, DIV, 0)) 3422 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 3423 sm_aes128_state = SM_AES128_ACTIVE; 3424 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); 3425 } 3426 3427 #ifdef ENABLE_LE_PERIPHERAL 3428 // sm_aes128_state stays active 3429 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 3430 sm_aes128_state = SM_AES128_IDLE; 3431 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3432 3433 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3434 if (connection == NULL) return; 3435 3436 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 3437 log_info_hex16("y", setup->sm_local_y); 3438 3439 // PH3B3 - calculate DIV 3440 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 3441 log_info_hex16("ediv", setup->sm_local_ediv); 3442 // PH3B4 - calculate LTK - enc 3443 // LTK = d1(ER, DIV, 0)) 3444 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 3445 sm_aes128_state = SM_AES128_ACTIVE; 3446 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); 3447 } 3448 #endif 3449 3450 // sm_aes128_state stays active 3451 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 3452 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3453 sm_aes128_state = SM_AES128_IDLE; 3454 3455 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3456 if (connection == NULL) return; 3457 3458 log_info_key("ltk", setup->sm_ltk); 3459 // calc CSRK next 3460 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 3461 sm_aes128_state = SM_AES128_ACTIVE; 3462 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); 3463 } 3464 3465 static void sm_handle_encryption_result_enc_csrk(void *arg){ 3466 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3467 sm_aes128_state = SM_AES128_IDLE; 3468 3469 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3470 if (connection == NULL) return; 3471 3472 sm_aes128_state = SM_AES128_IDLE; 3473 log_info_key("csrk", setup->sm_local_csrk); 3474 if (setup->sm_key_distribution_send_set){ 3475 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3476 } else { 3477 // no keys to send, just continue 3478 if (IS_RESPONDER(connection->sm_role)){ 3479 if (sm_key_distribution_all_received()){ 3480 sm_key_distribution_handle_all_received(connection); 3481 sm_key_distribution_complete_responder(connection); 3482 } else { 3483 // slave -> receive master keys 3484 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3485 } 3486 } else { 3487 sm_key_distribution_complete_initiator(connection); 3488 } 3489 } 3490 sm_trigger_run(); 3491 } 3492 3493 #ifdef ENABLE_LE_PERIPHERAL 3494 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 3495 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3496 sm_aes128_state = SM_AES128_IDLE; 3497 3498 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3499 if (connection == NULL) return; 3500 3501 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 3502 log_info_key("ltk", setup->sm_ltk); 3503 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 3504 sm_trigger_run(); 3505 } 3506 #endif 3507 3508 static void sm_handle_encryption_result_address_resolution(void *arg){ 3509 UNUSED(arg); 3510 sm_aes128_state = SM_AES128_IDLE; 3511 3512 // compare calulated address against connecting device 3513 uint8_t * hash = &sm_aes128_ciphertext[13]; 3514 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 3515 log_info("LE Device Lookup: matched resolvable private address"); 3516 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); 3517 sm_trigger_run(); 3518 return; 3519 } 3520 // no match, try next 3521 sm_address_resolution_test++; 3522 sm_trigger_run(); 3523 } 3524 3525 static void sm_handle_encryption_result_dkg_irk(void *arg){ 3526 UNUSED(arg); 3527 sm_aes128_state = SM_AES128_IDLE; 3528 3529 log_info_key("irk", sm_persistent_irk); 3530 dkg_state = DKG_CALC_DHK; 3531 sm_trigger_run(); 3532 } 3533 3534 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 3535 UNUSED(arg); 3536 sm_aes128_state = SM_AES128_IDLE; 3537 3538 log_info_key("dhk", sm_persistent_dhk); 3539 dkg_state = DKG_READY; 3540 sm_trigger_run(); 3541 } 3542 3543 static void sm_handle_encryption_result_rau(void *arg){ 3544 UNUSED(arg); 3545 sm_aes128_state = SM_AES128_IDLE; 3546 3547 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 3548 rau_state = RAU_IDLE; 3549 hci_le_random_address_set(sm_random_address); 3550 3551 sm_trigger_run(); 3552 } 3553 3554 static void sm_handle_random_result_rau(void * arg){ 3555 UNUSED(arg); 3556 // non-resolvable vs. resolvable 3557 switch (gap_random_adress_type){ 3558 case GAP_RANDOM_ADDRESS_RESOLVABLE: 3559 // resolvable: use random as prand and calc address hash 3560 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 3561 sm_random_address[0u] &= 0x3fu; 3562 sm_random_address[0u] |= 0x40u; 3563 rau_state = RAU_GET_ENC; 3564 break; 3565 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 3566 default: 3567 // "The two most significant bits of the address shall be equal to ‘0’"" 3568 sm_random_address[0u] &= 0x3fu; 3569 rau_state = RAU_IDLE; 3570 hci_le_random_address_set(sm_random_address); 3571 break; 3572 } 3573 sm_trigger_run(); 3574 } 3575 3576 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3577 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3578 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3579 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3580 if (connection == NULL) return; 3581 3582 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3583 sm_trigger_run(); 3584 } 3585 3586 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3587 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3588 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3589 if (connection == NULL) return; 3590 3591 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3592 sm_trigger_run(); 3593 } 3594 #endif 3595 3596 static void sm_handle_random_result_ph2_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_PH2_C1_GET_ENC_A; 3602 sm_trigger_run(); 3603 } 3604 3605 static void sm_handle_random_result_ph2_tk(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 sm_reset_tk(); 3611 uint32_t tk; 3612 if (sm_fixed_passkey_in_display_role == 0xffffffffU){ 3613 // map random to 0-999999 without speding much cycles on a modulus operation 3614 tk = little_endian_read_32(sm_random_data,0); 3615 tk = tk & 0xfffff; // 1048575 3616 if (tk >= 999999u){ 3617 tk = tk - 999999u; 3618 } 3619 } else { 3620 // override with pre-defined passkey 3621 tk = sm_fixed_passkey_in_display_role; 3622 } 3623 big_endian_store_32(setup->sm_tk, 12, tk); 3624 if (IS_RESPONDER(connection->sm_role)){ 3625 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3626 } else { 3627 if (setup->sm_use_secure_connections){ 3628 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3629 } else { 3630 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3631 sm_trigger_user_response(connection); 3632 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3633 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3634 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); 3635 } 3636 } 3637 } 3638 sm_trigger_run(); 3639 } 3640 3641 static void sm_handle_random_result_ph3_div(void * arg){ 3642 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3643 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3644 if (connection == NULL) return; 3645 3646 // use 16 bit from random value as div 3647 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3648 log_info_hex16("div", setup->sm_local_div); 3649 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3650 sm_trigger_run(); 3651 } 3652 3653 static void sm_handle_random_result_ph3_random(void * arg){ 3654 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3655 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3656 if (connection == NULL) return; 3657 3658 reverse_64(sm_random_data, setup->sm_local_rand); 3659 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3660 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3661 // no db for authenticated flag hack: store flag in bit 4 of LSB 3662 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3663 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3664 } 3665 static void sm_validate_er_ir(void){ 3666 // warn about default ER/IR 3667 bool warning = false; 3668 if (sm_ir_is_default()){ 3669 warning = true; 3670 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3671 } 3672 if (sm_er_is_default()){ 3673 warning = true; 3674 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3675 } 3676 if (warning) { 3677 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3678 } 3679 } 3680 3681 static void sm_handle_random_result_ir(void *arg){ 3682 sm_persistent_keys_random_active = false; 3683 if (arg != NULL){ 3684 // key generated, store in tlv 3685 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3686 log_info("Generated IR key. Store in TLV status: %d", status); 3687 UNUSED(status); 3688 } 3689 log_info_key("IR", sm_persistent_ir); 3690 dkg_state = DKG_CALC_IRK; 3691 3692 if (test_use_fixed_local_irk){ 3693 log_info_key("IRK", sm_persistent_irk); 3694 dkg_state = DKG_CALC_DHK; 3695 } 3696 3697 sm_trigger_run(); 3698 } 3699 3700 static void sm_handle_random_result_er(void *arg){ 3701 sm_persistent_keys_random_active = false; 3702 if (arg != 0){ 3703 // key generated, store in tlv 3704 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3705 log_info("Generated ER key. Store in TLV status: %d", status); 3706 UNUSED(status); 3707 } 3708 log_info_key("ER", sm_persistent_er); 3709 3710 // try load ir 3711 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3712 if (key_size == 16){ 3713 // ok, let's continue 3714 log_info("IR from TLV"); 3715 sm_handle_random_result_ir( NULL ); 3716 } else { 3717 // invalid, generate new random one 3718 sm_persistent_keys_random_active = true; 3719 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3720 } 3721 } 3722 3723 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){ 3724 3725 // connection info 3726 sm_conn->sm_handle = con_handle; 3727 sm_conn->sm_role = role; 3728 sm_conn->sm_peer_addr_type = addr_type; 3729 memcpy(sm_conn->sm_peer_address, address, 6); 3730 3731 // security properties 3732 sm_conn->sm_connection_encrypted = 0; 3733 sm_conn->sm_connection_authenticated = 0; 3734 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3735 sm_conn->sm_le_db_index = -1; 3736 sm_conn->sm_reencryption_active = false; 3737 3738 // prepare CSRK lookup (does not involve setup) 3739 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3740 3741 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3742 } 3743 3744 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3745 static void sm_event_handle_classic_encryption_event(sm_connection_t * sm_conn, hci_con_handle_t con_handle){ 3746 // CTKD requires BR/EDR Secure Connection 3747 if (sm_conn->sm_connection_encrypted != 2) return; 3748 // prepare for pairing request 3749 if (IS_RESPONDER(sm_conn->sm_role)){ 3750 sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST; 3751 } else if (sm_conn->sm_pairing_requested){ 3752 // check if remote supports fixed channels 3753 bool defer = true; 3754 const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 3755 if (hci_connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE){ 3756 // check if remote supports SMP over BR/EDR 3757 if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ 3758 log_info("CTKD: SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST"); 3759 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; 3760 } else { 3761 defer = false; 3762 } 3763 } else { 3764 // wait for fixed channel info 3765 log_info("CTKD: SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK"); 3766 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK; 3767 } 3768 if (defer){ 3769 hci_dedicated_bonding_defer_disconnect(con_handle, true); 3770 } 3771 } 3772 } 3773 #endif 3774 3775 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3776 3777 UNUSED(channel); // ok: there is no channel 3778 UNUSED(size); // ok: fixed format HCI events 3779 3780 sm_connection_t * sm_conn; 3781 hci_con_handle_t con_handle; 3782 uint8_t status; 3783 bd_addr_t addr; 3784 3785 switch (packet_type) { 3786 3787 case HCI_EVENT_PACKET: 3788 switch (hci_event_packet_get_type(packet)) { 3789 3790 case BTSTACK_EVENT_STATE: 3791 switch (btstack_event_state_get_state(packet)){ 3792 case HCI_STATE_WORKING: 3793 log_info("HCI Working!"); 3794 // setup IR/ER with TLV 3795 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3796 if (sm_tlv_impl != NULL){ 3797 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3798 if (key_size == 16){ 3799 // ok, let's continue 3800 log_info("ER from TLV"); 3801 sm_handle_random_result_er( NULL ); 3802 } else { 3803 // invalid, generate random one 3804 sm_persistent_keys_random_active = true; 3805 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3806 } 3807 } else { 3808 sm_validate_er_ir(); 3809 dkg_state = DKG_CALC_IRK; 3810 3811 if (test_use_fixed_local_irk){ 3812 log_info_key("IRK", sm_persistent_irk); 3813 dkg_state = DKG_CALC_DHK; 3814 } 3815 } 3816 3817 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3818 // trigger ECC key generation 3819 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 3820 sm_ec_generate_new_key(); 3821 } 3822 #endif 3823 3824 // restart random address updates after power cycle 3825 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_STATIC){ 3826 gap_random_address_set(sm_random_address); 3827 } else { 3828 gap_random_address_set_mode(gap_random_adress_type); 3829 } 3830 break; 3831 3832 case HCI_STATE_OFF: 3833 case HCI_STATE_HALTING: 3834 log_info("SM: reset state"); 3835 // stop random address update 3836 gap_random_address_update_stop(); 3837 // reset state 3838 sm_state_reset(); 3839 break; 3840 3841 default: 3842 break; 3843 } 3844 break; 3845 3846 #ifdef ENABLE_CLASSIC 3847 case HCI_EVENT_CONNECTION_COMPLETE: 3848 // ignore if connection failed 3849 if (hci_event_connection_complete_get_status(packet)) return; 3850 3851 con_handle = hci_event_connection_complete_get_connection_handle(packet); 3852 sm_conn = sm_get_connection_for_handle(con_handle); 3853 if (!sm_conn) break; 3854 3855 hci_event_connection_complete_get_bd_addr(packet, addr); 3856 sm_connection_init(sm_conn, 3857 con_handle, 3858 (uint8_t) gap_get_role(con_handle), 3859 BD_ADDR_TYPE_LE_PUBLIC, 3860 addr); 3861 // classic connection corresponds to public le address 3862 sm_conn->sm_own_addr_type = BD_ADDR_TYPE_LE_PUBLIC; 3863 gap_local_bd_addr(sm_conn->sm_own_address); 3864 sm_conn->sm_cid = L2CAP_CID_BR_EDR_SECURITY_MANAGER; 3865 sm_conn->sm_engine_state = SM_BR_EDR_W4_ENCRYPTION_COMPLETE; 3866 break; 3867 #endif 3868 3869 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 3870 case HCI_EVENT_SIMPLE_PAIRING_COMPLETE: 3871 if (hci_event_simple_pairing_complete_get_status(packet) != ERROR_CODE_SUCCESS) break; 3872 hci_event_simple_pairing_complete_get_bd_addr(packet, addr); 3873 sm_conn = sm_get_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL); 3874 if (sm_conn == NULL) break; 3875 sm_conn->sm_pairing_requested = 1; 3876 break; 3877 #endif 3878 3879 case HCI_EVENT_LE_META: 3880 switch (packet[2]) { 3881 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3882 // ignore if connection failed 3883 if (packet[3]) return; 3884 3885 con_handle = little_endian_read_16(packet, 4); 3886 sm_conn = sm_get_connection_for_handle(con_handle); 3887 if (!sm_conn) break; 3888 3889 hci_subevent_le_connection_complete_get_peer_address(packet, addr); 3890 sm_connection_init(sm_conn, 3891 con_handle, 3892 hci_subevent_le_connection_complete_get_role(packet), 3893 hci_subevent_le_connection_complete_get_peer_address_type(packet), 3894 addr); 3895 sm_conn->sm_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 3896 3897 // track our addr used for this connection and set state 3898 #ifdef ENABLE_LE_PERIPHERAL 3899 if (hci_subevent_le_connection_complete_get_role(packet) != 0){ 3900 // responder - use own address from advertisements 3901 gap_le_get_own_advertisements_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); 3902 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3903 } 3904 #endif 3905 #ifdef ENABLE_LE_CENTRAL 3906 if (hci_subevent_le_connection_complete_get_role(packet) == 0){ 3907 // initiator - use own address from create connection 3908 gap_le_get_own_connection_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); 3909 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3910 } 3911 #endif 3912 break; 3913 3914 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3915 con_handle = little_endian_read_16(packet, 3); 3916 sm_conn = sm_get_connection_for_handle(con_handle); 3917 if (!sm_conn) break; 3918 3919 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3920 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3921 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3922 break; 3923 } 3924 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3925 // PH2 SEND LTK as we need to exchange keys in PH3 3926 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3927 break; 3928 } 3929 3930 // store rand and ediv 3931 reverse_64(&packet[5], sm_conn->sm_local_rand); 3932 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3933 3934 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3935 // potentially stored LTK is from the master 3936 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3937 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3938 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3939 break; 3940 } 3941 // additionally check if remote is in LE Device DB if requested 3942 switch(sm_conn->sm_irk_lookup_state){ 3943 case IRK_LOOKUP_FAILED: 3944 log_info("LTK Request: device not in device db"); 3945 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3946 break; 3947 case IRK_LOOKUP_SUCCEEDED: 3948 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3949 break; 3950 default: 3951 // wait for irk look doen 3952 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3953 break; 3954 } 3955 break; 3956 } 3957 3958 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3959 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3960 #else 3961 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3962 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3963 #endif 3964 break; 3965 3966 default: 3967 break; 3968 } 3969 break; 3970 3971 case HCI_EVENT_ENCRYPTION_CHANGE: 3972 case HCI_EVENT_ENCRYPTION_CHANGE_V2: 3973 con_handle = hci_event_encryption_change_get_connection_handle(packet); 3974 sm_conn = sm_get_connection_for_handle(con_handle); 3975 if (!sm_conn) break; 3976 3977 sm_conn->sm_connection_encrypted = hci_event_encryption_change_get_encryption_enabled(packet); 3978 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3979 sm_conn->sm_actual_encryption_key_size); 3980 log_info("event handler, state %u", sm_conn->sm_engine_state); 3981 3982 switch (sm_conn->sm_engine_state){ 3983 3984 case SM_PH4_W4_CONNECTION_ENCRYPTED: 3985 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3986 if (sm_conn->sm_connection_encrypted) { 3987 status = ERROR_CODE_SUCCESS; 3988 if (sm_conn->sm_role){ 3989 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3990 } else { 3991 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3992 } 3993 } else { 3994 status = hci_event_encryption_change_get_status(packet); 3995 // set state to 'RE-ENCRYPTION FAILED' to allow pairing but prevent other interactions 3996 // also, gap_reconnect_security_setup_active will return true 3997 sm_conn->sm_engine_state = SM_GENERAL_REENCRYPTION_FAILED; 3998 } 3999 4000 // emit re-encryption complete 4001 sm_reencryption_complete(sm_conn, status); 4002 4003 // notify client, if pairing was requested before 4004 if (sm_conn->sm_pairing_requested){ 4005 sm_conn->sm_pairing_requested = 0; 4006 sm_pairing_complete(sm_conn, status, 0); 4007 } 4008 4009 sm_done_for_handle(sm_conn->sm_handle); 4010 break; 4011 4012 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4013 if (!sm_conn->sm_connection_encrypted) break; 4014 // handler for HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE 4015 // contains the same code for this state 4016 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 4017 if (IS_RESPONDER(sm_conn->sm_role)){ 4018 // slave 4019 if (sm_conn->sm_connection_sc){ 4020 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4021 } else { 4022 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); 4023 } 4024 } else { 4025 // master 4026 if (sm_key_distribution_all_received()){ 4027 // skip receiving keys as there are none 4028 sm_key_distribution_handle_all_received(sm_conn); 4029 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); 4030 } else { 4031 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 4032 } 4033 } 4034 break; 4035 4036 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4037 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4038 sm_event_handle_classic_encryption_event(sm_conn, con_handle); 4039 break; 4040 #endif 4041 default: 4042 break; 4043 } 4044 break; 4045 4046 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 4047 con_handle = little_endian_read_16(packet, 3); 4048 sm_conn = sm_get_connection_for_handle(con_handle); 4049 if (!sm_conn) break; 4050 4051 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 4052 log_info("event handler, state %u", sm_conn->sm_engine_state); 4053 // continue if part of initial pairing 4054 switch (sm_conn->sm_engine_state){ 4055 case SM_PH4_W4_CONNECTION_ENCRYPTED: 4056 if (sm_conn->sm_role){ 4057 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 4058 } else { 4059 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 4060 } 4061 sm_done_for_handle(sm_conn->sm_handle); 4062 break; 4063 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4064 // handler for HCI_EVENT_ENCRYPTION_CHANGE 4065 // contains the same code for this state 4066 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 4067 if (IS_RESPONDER(sm_conn->sm_role)){ 4068 // slave 4069 if (sm_conn->sm_connection_sc){ 4070 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4071 } else { 4072 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); 4073 } 4074 } else { 4075 // master 4076 if (sm_key_distribution_all_received()){ 4077 // skip receiving keys as there are none 4078 sm_key_distribution_handle_all_received(sm_conn); 4079 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); 4080 } else { 4081 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 4082 } 4083 } 4084 break; 4085 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4086 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4087 sm_event_handle_classic_encryption_event(sm_conn, con_handle); 4088 break; 4089 #endif 4090 default: 4091 break; 4092 } 4093 break; 4094 4095 4096 case HCI_EVENT_DISCONNECTION_COMPLETE: 4097 con_handle = little_endian_read_16(packet, 3); 4098 sm_done_for_handle(con_handle); 4099 sm_conn = sm_get_connection_for_handle(con_handle); 4100 if (!sm_conn) break; 4101 4102 // pairing failed, if it was ongoing 4103 switch (sm_conn->sm_engine_state){ 4104 case SM_GENERAL_IDLE: 4105 case SM_INITIATOR_CONNECTED: 4106 case SM_RESPONDER_IDLE: 4107 break; 4108 default: 4109 sm_reencryption_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION); 4110 sm_pairing_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 4111 break; 4112 } 4113 4114 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 4115 sm_conn->sm_handle = 0; 4116 break; 4117 4118 case HCI_EVENT_COMMAND_COMPLETE: 4119 if (hci_event_command_complete_get_command_opcode(packet) == HCI_OPCODE_HCI_READ_BD_ADDR) { 4120 // set local addr for le device db 4121 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 4122 le_device_db_set_local_bd_addr(addr); 4123 } 4124 break; 4125 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4126 case L2CAP_EVENT_INFORMATION_RESPONSE: 4127 con_handle = l2cap_event_information_response_get_con_handle(packet); 4128 sm_conn = sm_get_connection_for_handle(con_handle); 4129 if (!sm_conn) break; 4130 if (sm_conn->sm_engine_state == SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK){ 4131 // check if remote supports SMP over BR/EDR 4132 const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 4133 if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ 4134 sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; 4135 } else { 4136 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 4137 hci_dedicated_bonding_defer_disconnect(con_handle, false); 4138 } 4139 } 4140 break; 4141 #endif 4142 default: 4143 break; 4144 } 4145 break; 4146 default: 4147 break; 4148 } 4149 4150 sm_run(); 4151 } 4152 4153 static inline int sm_calc_actual_encryption_key_size(int other){ 4154 if (other < sm_min_encryption_key_size) return 0; 4155 if (other < sm_max_encryption_key_size) return other; 4156 return sm_max_encryption_key_size; 4157 } 4158 4159 4160 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4161 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 4162 switch (method){ 4163 case JUST_WORKS: 4164 case NUMERIC_COMPARISON: 4165 return 1; 4166 default: 4167 return 0; 4168 } 4169 } 4170 // responder 4171 4172 static int sm_passkey_used(stk_generation_method_t method){ 4173 switch (method){ 4174 case PK_RESP_INPUT: 4175 return 1; 4176 default: 4177 return 0; 4178 } 4179 } 4180 4181 static int sm_passkey_entry(stk_generation_method_t method){ 4182 switch (method){ 4183 case PK_RESP_INPUT: 4184 case PK_INIT_INPUT: 4185 case PK_BOTH_INPUT: 4186 return 1; 4187 default: 4188 return 0; 4189 } 4190 } 4191 4192 #endif 4193 4194 /** 4195 * @return ok 4196 */ 4197 static int sm_validate_stk_generation_method(void){ 4198 // check if STK generation method is acceptable by client 4199 switch (setup->sm_stk_generation_method){ 4200 case JUST_WORKS: 4201 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 4202 case PK_RESP_INPUT: 4203 case PK_INIT_INPUT: 4204 case PK_BOTH_INPUT: 4205 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 4206 case OOB: 4207 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 4208 case NUMERIC_COMPARISON: 4209 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 4210 default: 4211 return 0; 4212 } 4213 } 4214 4215 #ifdef ENABLE_LE_CENTRAL 4216 static void sm_initiator_connected_handle_security_request(sm_connection_t * sm_conn, const uint8_t *packet){ 4217 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4218 if (sm_sc_only_mode){ 4219 uint8_t auth_req = packet[1]; 4220 if ((auth_req & SM_AUTHREQ_SECURE_CONNECTION) == 0){ 4221 sm_pairing_error(sm_conn, SM_REASON_AUTHENTHICATION_REQUIREMENTS); 4222 return; 4223 } 4224 } 4225 #else 4226 UNUSED(packet); 4227 #endif 4228 4229 int have_ltk; 4230 uint8_t ltk[16]; 4231 4232 // IRK complete? 4233 switch (sm_conn->sm_irk_lookup_state){ 4234 case IRK_LOOKUP_FAILED: 4235 // start pairing 4236 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4237 break; 4238 case IRK_LOOKUP_SUCCEEDED: 4239 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4240 have_ltk = !sm_is_null_key(ltk); 4241 log_info("central: security request - have_ltk %u, encryption %u", have_ltk, sm_conn->sm_connection_encrypted); 4242 if (have_ltk && (sm_conn->sm_connection_encrypted == 0)){ 4243 // start re-encrypt if we have LTK and the connection is not already encrypted 4244 sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 4245 } else { 4246 // start pairing 4247 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4248 } 4249 break; 4250 default: 4251 // otherwise, store security request 4252 sm_conn->sm_security_request_received = 1; 4253 break; 4254 } 4255 } 4256 #endif 4257 4258 static uint8_t sm_pdu_validate_and_get_opcode(uint8_t packet_type, const uint8_t *packet, uint16_t size){ 4259 4260 // size of complete sm_pdu used to validate input 4261 static const uint8_t sm_pdu_size[] = { 4262 0, // 0x00 invalid opcode 4263 7, // 0x01 pairing request 4264 7, // 0x02 pairing response 4265 17, // 0x03 pairing confirm 4266 17, // 0x04 pairing random 4267 2, // 0x05 pairing failed 4268 17, // 0x06 encryption information 4269 11, // 0x07 master identification 4270 17, // 0x08 identification information 4271 8, // 0x09 identify address information 4272 17, // 0x0a signing information 4273 2, // 0x0b security request 4274 65, // 0x0c pairing public key 4275 17, // 0x0d pairing dhk check 4276 2, // 0x0e keypress notification 4277 }; 4278 4279 if (packet_type != SM_DATA_PACKET) return 0; 4280 if (size == 0u) return 0; 4281 4282 uint8_t sm_pdu_code = packet[0]; 4283 4284 // validate pdu size 4285 if (sm_pdu_code >= sizeof(sm_pdu_size)) return 0; 4286 if (sm_pdu_size[sm_pdu_code] != size) return 0; 4287 4288 return sm_pdu_code; 4289 } 4290 4291 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 4292 4293 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 4294 sm_run(); 4295 } 4296 4297 uint8_t sm_pdu_code = sm_pdu_validate_and_get_opcode(packet_type, packet, size); 4298 if (sm_pdu_code == 0) return; 4299 4300 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4301 if (!sm_conn) return; 4302 4303 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 4304 sm_reencryption_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE); 4305 sm_pairing_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 4306 sm_done_for_handle(con_handle); 4307 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 4308 return; 4309 } 4310 4311 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 4312 4313 int err; 4314 UNUSED(err); 4315 4316 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 4317 uint8_t buffer[5]; 4318 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 4319 buffer[1] = 3; 4320 little_endian_store_16(buffer, 2, con_handle); 4321 buffer[4] = packet[1]; 4322 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 4323 return; 4324 } 4325 4326 switch (sm_conn->sm_engine_state){ 4327 4328 // a sm timeout requires a new physical connection 4329 case SM_GENERAL_TIMEOUT: 4330 return; 4331 4332 #ifdef ENABLE_LE_CENTRAL 4333 4334 // Initiator 4335 case SM_INITIATOR_CONNECTED: 4336 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 4337 sm_pdu_received_in_wrong_state(sm_conn); 4338 break; 4339 } 4340 sm_initiator_connected_handle_security_request(sm_conn, packet); 4341 break; 4342 4343 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 4344 // Core 5, Vol 3, Part H, 2.4.6: 4345 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 4346 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 4347 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 4348 log_info("Ignoring Security Request"); 4349 break; 4350 } 4351 4352 // all other pdus are incorrect 4353 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 4354 sm_pdu_received_in_wrong_state(sm_conn); 4355 break; 4356 } 4357 4358 // store pairing request 4359 (void)memcpy(&setup->sm_s_pres, packet, 4360 sizeof(sm_pairing_packet_t)); 4361 err = sm_stk_generation_init(sm_conn); 4362 4363 #ifdef ENABLE_TESTING_SUPPORT 4364 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 4365 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 4366 err = test_pairing_failure; 4367 } 4368 #endif 4369 4370 if (err != 0){ 4371 sm_pairing_error(sm_conn, err); 4372 break; 4373 } 4374 4375 // generate random number first, if we need to show passkey 4376 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 4377 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); 4378 break; 4379 } 4380 4381 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4382 if (setup->sm_use_secure_connections){ 4383 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 4384 if (setup->sm_stk_generation_method == JUST_WORKS){ 4385 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4386 sm_trigger_user_response(sm_conn); 4387 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 4388 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4389 } 4390 } else { 4391 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4392 } 4393 break; 4394 } 4395 #endif 4396 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4397 sm_trigger_user_response(sm_conn); 4398 // response_idle == nothing <--> sm_trigger_user_response() did not require response 4399 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 4400 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); 4401 } 4402 break; 4403 4404 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 4405 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4406 sm_pdu_received_in_wrong_state(sm_conn); 4407 break; 4408 } 4409 4410 // store s_confirm 4411 reverse_128(&packet[1], setup->sm_peer_confirm); 4412 4413 // abort if s_confirm matches m_confirm 4414 if (memcmp(setup->sm_local_confirm, setup->sm_peer_confirm, 16) == 0){ 4415 sm_pdu_received_in_wrong_state(sm_conn); 4416 break; 4417 } 4418 4419 #ifdef ENABLE_TESTING_SUPPORT 4420 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4421 log_info("testing_support: reset confirm value"); 4422 memset(setup->sm_peer_confirm, 0, 16); 4423 } 4424 #endif 4425 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 4426 break; 4427 4428 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 4429 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4430 sm_pdu_received_in_wrong_state(sm_conn); 4431 break;; 4432 } 4433 4434 // received random value 4435 reverse_128(&packet[1], setup->sm_peer_random); 4436 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 4437 break; 4438 4439 case SM_PH4_W4_CONNECTION_ENCRYPTED: 4440 // ignore Security Request, see SM_INITIATOR_PH1_W4_PAIRING_RESPONSE above 4441 if (sm_pdu_code != SM_CODE_SECURITY_REQUEST){ 4442 sm_pdu_received_in_wrong_state(sm_conn); 4443 } 4444 break; 4445 #endif 4446 4447 #ifdef ENABLE_LE_PERIPHERAL 4448 // Responder 4449 case SM_RESPONDER_IDLE: 4450 case SM_RESPONDER_SEND_SECURITY_REQUEST: 4451 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 4452 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 4453 sm_pdu_received_in_wrong_state(sm_conn); 4454 break;; 4455 } 4456 4457 // store pairing request 4458 (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 4459 4460 // check if IRK completed 4461 switch (sm_conn->sm_irk_lookup_state){ 4462 case IRK_LOOKUP_SUCCEEDED: 4463 case IRK_LOOKUP_FAILED: 4464 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 4465 break; 4466 default: 4467 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK; 4468 break; 4469 } 4470 break; 4471 #endif 4472 4473 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4474 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4475 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 4476 sm_pdu_received_in_wrong_state(sm_conn); 4477 break; 4478 } 4479 4480 // store public key for DH Key calculation 4481 reverse_256(&packet[01], &setup->sm_peer_q[0]); 4482 reverse_256(&packet[33], &setup->sm_peer_q[32]); 4483 4484 // CVE-2020-26558: abort pairing if remote uses the same public key 4485 if (memcmp(&setup->sm_peer_q, ec_q, 64) == 0){ 4486 log_info("Remote PK matches ours"); 4487 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 4488 break; 4489 } 4490 4491 // validate public key 4492 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 4493 if (err != 0){ 4494 log_info("sm: peer public key invalid %x", err); 4495 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 4496 break; 4497 } 4498 4499 // start calculating dhkey 4500 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); 4501 4502 4503 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 4504 if (IS_RESPONDER(sm_conn->sm_role)){ 4505 // responder 4506 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4507 } else { 4508 // initiator 4509 // stk generation method 4510 // passkey entry: notify app to show passkey or to request passkey 4511 switch (setup->sm_stk_generation_method){ 4512 case JUST_WORKS: 4513 case NUMERIC_COMPARISON: 4514 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 4515 break; 4516 case PK_RESP_INPUT: 4517 sm_sc_start_calculating_local_confirm(sm_conn); 4518 break; 4519 case PK_INIT_INPUT: 4520 case PK_BOTH_INPUT: 4521 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 4522 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 4523 break; 4524 } 4525 sm_sc_start_calculating_local_confirm(sm_conn); 4526 break; 4527 case OOB: 4528 // generate Nx 4529 log_info("Generate Na"); 4530 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); 4531 break; 4532 default: 4533 btstack_assert(false); 4534 break; 4535 } 4536 } 4537 break; 4538 4539 case SM_SC_W4_CONFIRMATION: 4540 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4541 sm_pdu_received_in_wrong_state(sm_conn); 4542 break; 4543 } 4544 // received confirm value 4545 reverse_128(&packet[1], setup->sm_peer_confirm); 4546 4547 #ifdef ENABLE_TESTING_SUPPORT 4548 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4549 log_info("testing_support: reset confirm value"); 4550 memset(setup->sm_peer_confirm, 0, 16); 4551 } 4552 #endif 4553 if (IS_RESPONDER(sm_conn->sm_role)){ 4554 // responder 4555 if (sm_passkey_used(setup->sm_stk_generation_method)){ 4556 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 4557 // still waiting for passkey 4558 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 4559 break; 4560 } 4561 } 4562 sm_sc_start_calculating_local_confirm(sm_conn); 4563 } else { 4564 // initiator 4565 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 4566 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); 4567 } else { 4568 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 4569 } 4570 } 4571 break; 4572 4573 case SM_SC_W4_PAIRING_RANDOM: 4574 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4575 sm_pdu_received_in_wrong_state(sm_conn); 4576 break; 4577 } 4578 4579 // received random value 4580 reverse_128(&packet[1], setup->sm_peer_nonce); 4581 4582 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 4583 // only check for JUST WORK/NC in initiator role OR passkey entry 4584 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 4585 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 4586 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 4587 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 4588 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 4589 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 4590 break; 4591 } 4592 4593 // OOB 4594 if (setup->sm_stk_generation_method == OOB){ 4595 4596 // setup local random, set to zero if remote did not receive our data 4597 log_info("Received nonce, setup local random ra/rb for dhkey check"); 4598 if (IS_RESPONDER(sm_conn->sm_role)){ 4599 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 4600 log_info("Reset rb as A does not have OOB data"); 4601 memset(setup->sm_rb, 0, 16); 4602 } else { 4603 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 4604 log_info("Use stored rb"); 4605 log_info_hexdump(setup->sm_rb, 16); 4606 } 4607 } else { 4608 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 4609 log_info("Reset ra as B does not have OOB data"); 4610 memset(setup->sm_ra, 0, 16); 4611 } else { 4612 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 4613 log_info("Use stored ra"); 4614 log_info_hexdump(setup->sm_ra, 16); 4615 } 4616 } 4617 4618 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 4619 if (setup->sm_have_oob_data){ 4620 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 4621 break; 4622 } 4623 } 4624 4625 // TODO: we only get here for Responder role with JW/NC 4626 sm_sc_state_after_receiving_random(sm_conn); 4627 break; 4628 4629 case SM_SC_W2_CALCULATE_G2: 4630 case SM_SC_W4_CALCULATE_G2: 4631 case SM_SC_W4_CALCULATE_DHKEY: 4632 case SM_SC_W2_CALCULATE_F5_SALT: 4633 case SM_SC_W4_CALCULATE_F5_SALT: 4634 case SM_SC_W2_CALCULATE_F5_MACKEY: 4635 case SM_SC_W4_CALCULATE_F5_MACKEY: 4636 case SM_SC_W2_CALCULATE_F5_LTK: 4637 case SM_SC_W4_CALCULATE_F5_LTK: 4638 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 4639 case SM_SC_W4_DHKEY_CHECK_COMMAND: 4640 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 4641 case SM_SC_W4_USER_RESPONSE: 4642 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 4643 sm_pdu_received_in_wrong_state(sm_conn); 4644 break; 4645 } 4646 // store DHKey Check 4647 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 4648 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 4649 4650 // have we been only waiting for dhkey check command? 4651 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 4652 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 4653 } 4654 break; 4655 #endif 4656 4657 #ifdef ENABLE_LE_PERIPHERAL 4658 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 4659 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 4660 sm_pdu_received_in_wrong_state(sm_conn); 4661 break; 4662 } 4663 4664 // received confirm value 4665 reverse_128(&packet[1], setup->sm_peer_confirm); 4666 4667 #ifdef ENABLE_TESTING_SUPPORT 4668 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 4669 log_info("testing_support: reset confirm value"); 4670 memset(setup->sm_peer_confirm, 0, 16); 4671 } 4672 #endif 4673 // notify client to hide shown passkey 4674 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 4675 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 4676 } 4677 4678 // handle user cancel pairing? 4679 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 4680 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4681 break; 4682 } 4683 4684 // wait for user action? 4685 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 4686 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 4687 break; 4688 } 4689 4690 // calculate and send local_confirm 4691 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); 4692 break; 4693 4694 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 4695 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 4696 sm_pdu_received_in_wrong_state(sm_conn); 4697 break;; 4698 } 4699 4700 // received random value 4701 reverse_128(&packet[1], setup->sm_peer_random); 4702 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 4703 break; 4704 #endif 4705 4706 case SM_PH2_W4_CONNECTION_ENCRYPTED: 4707 case SM_PH3_RECEIVE_KEYS: 4708 switch(sm_pdu_code){ 4709 case SM_CODE_ENCRYPTION_INFORMATION: 4710 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 4711 reverse_128(&packet[1], setup->sm_peer_ltk); 4712 break; 4713 4714 case SM_CODE_MASTER_IDENTIFICATION: 4715 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 4716 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 4717 reverse_64(&packet[3], setup->sm_peer_rand); 4718 break; 4719 4720 case SM_CODE_IDENTITY_INFORMATION: 4721 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 4722 reverse_128(&packet[1], setup->sm_peer_irk); 4723 break; 4724 4725 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 4726 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 4727 setup->sm_peer_addr_type = packet[1]; 4728 reverse_bd_addr(&packet[2], setup->sm_peer_address); 4729 break; 4730 4731 case SM_CODE_SIGNING_INFORMATION: 4732 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 4733 reverse_128(&packet[1], setup->sm_peer_csrk); 4734 break; 4735 default: 4736 // Unexpected PDU 4737 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 4738 break; 4739 } 4740 // done with key distribution? 4741 if (sm_key_distribution_all_received()){ 4742 4743 sm_key_distribution_handle_all_received(sm_conn); 4744 4745 if (IS_RESPONDER(sm_conn->sm_role)){ 4746 sm_key_distribution_complete_responder(sm_conn); 4747 } else { 4748 if (setup->sm_use_secure_connections){ 4749 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 4750 } else { 4751 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); 4752 } 4753 } 4754 } 4755 break; 4756 4757 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 4758 4759 case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: 4760 // GAP/DM/LEP/BI-02-C - reject CTKD if P-192 encryption is used 4761 if (sm_pdu_code == SM_CODE_PAIRING_REQUEST){ 4762 sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); 4763 } 4764 break; 4765 4766 case SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE: 4767 4768 // dedicated bonding complete 4769 hci_dedicated_bonding_defer_disconnect(sm_conn->sm_handle, false); 4770 4771 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 4772 sm_pdu_received_in_wrong_state(sm_conn); 4773 break; 4774 } 4775 // store pairing response 4776 (void)memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 4777 4778 // validate encryption key size 4779 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)); 4780 // SC Only mandates 128 bit key size 4781 if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { 4782 sm_conn->sm_actual_encryption_key_size = 0; 4783 } 4784 if (sm_conn->sm_actual_encryption_key_size == 0){ 4785 sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); 4786 break; 4787 } 4788 4789 // prepare key exchange, LTK is derived locally 4790 sm_setup_key_distribution(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY, 4791 sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY); 4792 4793 // skip receive if there are none 4794 if (sm_key_distribution_all_received()){ 4795 // distribute keys in run handles 'no keys to send' 4796 sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 4797 } else { 4798 sm_conn->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; 4799 } 4800 break; 4801 4802 case SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST: 4803 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 4804 sm_pdu_received_in_wrong_state(sm_conn); 4805 break; 4806 } 4807 // store pairing request 4808 (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 4809 // validate encryption key size 4810 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)); 4811 // SC Only mandates 128 bit key size 4812 if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { 4813 sm_conn->sm_actual_encryption_key_size = 0; 4814 } 4815 if (sm_conn->sm_actual_encryption_key_size == 0){ 4816 sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); 4817 break; 4818 } 4819 // trigger response 4820 if (sm_ctkd_from_classic(sm_conn)){ 4821 sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED; 4822 } else { 4823 sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); 4824 } 4825 break; 4826 4827 case SM_BR_EDR_RECEIVE_KEYS: 4828 switch(sm_pdu_code){ 4829 case SM_CODE_IDENTITY_INFORMATION: 4830 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 4831 reverse_128(&packet[1], setup->sm_peer_irk); 4832 break; 4833 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 4834 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 4835 setup->sm_peer_addr_type = packet[1]; 4836 reverse_bd_addr(&packet[2], setup->sm_peer_address); 4837 break; 4838 case SM_CODE_SIGNING_INFORMATION: 4839 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 4840 reverse_128(&packet[1], setup->sm_peer_csrk); 4841 break; 4842 default: 4843 // Unexpected PDU 4844 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 4845 break; 4846 } 4847 4848 // all keys received 4849 if (sm_key_distribution_all_received()){ 4850 if (IS_RESPONDER(sm_conn->sm_role)){ 4851 // responder -> keys exchanged, derive LE LTK 4852 sm_ctkd_start_from_br_edr(sm_conn); 4853 } else { 4854 // initiator -> send our keys if any 4855 sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; 4856 } 4857 } 4858 break; 4859 #endif 4860 4861 default: 4862 // Unexpected PDU 4863 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 4864 sm_pdu_received_in_wrong_state(sm_conn); 4865 break; 4866 } 4867 4868 // try to send next pdu 4869 sm_trigger_run(); 4870 } 4871 4872 // Security Manager Client API 4873 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 4874 sm_get_oob_data = get_oob_data_callback; 4875 } 4876 4877 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)){ 4878 sm_get_sc_oob_data = get_sc_oob_data_callback; 4879 } 4880 4881 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)){ 4882 sm_get_ltk_callback = get_ltk_callback; 4883 } 4884 4885 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4886 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4887 } 4888 4889 void sm_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4890 btstack_linked_list_remove(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4891 } 4892 4893 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4894 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4895 } 4896 4897 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4898 sm_min_encryption_key_size = min_size; 4899 sm_max_encryption_key_size = max_size; 4900 } 4901 4902 void sm_set_authentication_requirements(uint8_t auth_req){ 4903 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4904 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4905 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4906 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4907 } 4908 #endif 4909 sm_auth_req = auth_req; 4910 } 4911 4912 void sm_set_io_capabilities(io_capability_t io_capability){ 4913 sm_io_capabilities = io_capability; 4914 } 4915 4916 #ifdef ENABLE_LE_PERIPHERAL 4917 void sm_set_request_security(int enable){ 4918 sm_slave_request_security = enable; 4919 } 4920 #endif 4921 4922 void sm_set_er(sm_key_t er){ 4923 (void)memcpy(sm_persistent_er, er, 16); 4924 } 4925 4926 void sm_set_ir(sm_key_t ir){ 4927 (void)memcpy(sm_persistent_ir, ir, 16); 4928 } 4929 4930 // Testing support only 4931 void sm_test_set_irk(sm_key_t irk){ 4932 (void)memcpy(sm_persistent_irk, irk, 16); 4933 dkg_state = DKG_CALC_DHK; 4934 test_use_fixed_local_irk = true; 4935 } 4936 4937 void sm_test_use_fixed_local_csrk(void){ 4938 test_use_fixed_local_csrk = true; 4939 } 4940 4941 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4942 static void sm_ec_generated(void * arg){ 4943 UNUSED(arg); 4944 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4945 // trigger pairing if pending for ec key 4946 sm_trigger_run(); 4947 } 4948 static void sm_ec_generate_new_key(void){ 4949 log_info("sm: generate new ec key"); 4950 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4951 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4952 } 4953 #endif 4954 4955 #ifdef ENABLE_TESTING_SUPPORT 4956 void sm_test_set_pairing_failure(int reason){ 4957 test_pairing_failure = reason; 4958 } 4959 #endif 4960 4961 static void sm_state_reset(void) { 4962 #ifdef USE_CMAC_ENGINE 4963 sm_cmac_active = 0; 4964 #endif 4965 dkg_state = DKG_W4_WORKING; 4966 rau_state = RAU_IDLE; 4967 sm_aes128_state = SM_AES128_IDLE; 4968 sm_address_resolution_test = -1; // no private address to resolve yet 4969 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4970 sm_address_resolution_general_queue = NULL; 4971 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4972 sm_persistent_keys_random_active = false; 4973 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4974 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 4975 #endif 4976 } 4977 4978 void sm_init(void){ 4979 4980 if (sm_initialized) return; 4981 4982 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4983 sm_er_ir_set_default(); 4984 4985 // defaults 4986 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4987 | SM_STK_GENERATION_METHOD_OOB 4988 | SM_STK_GENERATION_METHOD_PASSKEY 4989 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4990 4991 sm_max_encryption_key_size = 16; 4992 sm_min_encryption_key_size = 7; 4993 4994 sm_fixed_passkey_in_display_role = 0xffffffffU; 4995 sm_reconstruct_ltk_without_le_device_db_entry = true; 4996 4997 gap_random_adress_update_period = 15 * 60 * 1000L; 4998 4999 test_use_fixed_local_csrk = false; 5000 5001 // other 5002 btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); 5003 5004 // register for HCI Events 5005 hci_event_callback_registration.callback = &sm_event_packet_handler; 5006 hci_add_event_handler(&hci_event_callback_registration); 5007 5008 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 5009 // register for L2CAP events 5010 l2cap_event_callback_registration.callback = &sm_event_packet_handler; 5011 l2cap_add_event_handler(&l2cap_event_callback_registration); 5012 #endif 5013 5014 // 5015 btstack_crypto_init(); 5016 5017 // init le_device_db 5018 le_device_db_init(); 5019 5020 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 5021 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 5022 #ifdef ENABLE_CLASSIC 5023 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_BR_EDR_SECURITY_MANAGER); 5024 #endif 5025 5026 // state 5027 sm_state_reset(); 5028 5029 sm_initialized = true; 5030 } 5031 5032 void sm_deinit(void){ 5033 sm_initialized = false; 5034 btstack_run_loop_remove_timer(&sm_run_timer); 5035 } 5036 5037 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 5038 sm_fixed_passkey_in_display_role = passkey; 5039 } 5040 5041 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 5042 sm_reconstruct_ltk_without_le_device_db_entry = allow != 0; 5043 } 5044 5045 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 5046 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 5047 if (!hci_con) return NULL; 5048 return &hci_con->sm_connection; 5049 } 5050 5051 static void sm_cache_ltk(sm_connection_t * connection, const sm_key_t ltk){ 5052 hci_connection_t * hci_con = hci_connection_for_handle(connection->sm_handle); 5053 btstack_assert(hci_con != NULL); 5054 memcpy(hci_con->link_key, ltk, 16); 5055 hci_con->link_key_type = 1; 5056 } 5057 5058 #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION 5059 static sm_connection_t * sm_get_connection_for_bd_addr_and_type(bd_addr_t address, bd_addr_type_t addr_type){ 5060 hci_connection_t * hci_con = hci_connection_for_bd_addr_and_type(address, addr_type); 5061 if (!hci_con) return NULL; 5062 return &hci_con->sm_connection; 5063 } 5064 #endif 5065 5066 // @deprecated: map onto sm_request_pairing 5067 void sm_send_security_request(hci_con_handle_t con_handle){ 5068 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5069 if (!sm_conn) return; 5070 if (!IS_RESPONDER(sm_conn->sm_role)) return; 5071 sm_request_pairing(con_handle); 5072 } 5073 5074 // request pairing 5075 void sm_request_pairing(hci_con_handle_t con_handle){ 5076 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5077 if (!sm_conn) return; // wrong connection 5078 5079 bool have_ltk; 5080 uint8_t ltk[16]; 5081 bool auth_required; 5082 int authenticated; 5083 bool trigger_reencryption; 5084 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 5085 if (IS_RESPONDER(sm_conn->sm_role)){ 5086 switch (sm_conn->sm_engine_state){ 5087 case SM_GENERAL_IDLE: 5088 case SM_RESPONDER_IDLE: 5089 switch (sm_conn->sm_irk_lookup_state){ 5090 case IRK_LOOKUP_SUCCEEDED: 5091 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 5092 have_ltk = !sm_is_null_key(ltk); 5093 log_info("have ltk %u", have_ltk); 5094 if (have_ltk){ 5095 sm_conn->sm_pairing_requested = 1; 5096 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 5097 sm_reencryption_started(sm_conn); 5098 break; 5099 } 5100 /* fall through */ 5101 5102 case IRK_LOOKUP_FAILED: 5103 sm_conn->sm_pairing_requested = 1; 5104 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 5105 sm_pairing_started(sm_conn); 5106 break; 5107 default: 5108 log_info("irk lookup pending"); 5109 sm_conn->sm_pairing_requested = 1; 5110 break; 5111 } 5112 break; 5113 default: 5114 break; 5115 } 5116 } else { 5117 // used as a trigger to start central/master/initiator security procedures 5118 switch (sm_conn->sm_engine_state){ 5119 case SM_INITIATOR_CONNECTED: 5120 switch (sm_conn->sm_irk_lookup_state){ 5121 case IRK_LOOKUP_SUCCEEDED: 5122 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); 5123 have_ltk = !sm_is_null_key(ltk); 5124 auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; 5125 // re-encrypt is sufficient if we have ltk and that is either already authenticated or we don't require authentication 5126 trigger_reencryption = have_ltk && ((authenticated != 0) || (auth_required == false)); 5127 log_info("have ltk %u, authenticated %u, auth required %u => reencrypt %u", have_ltk, authenticated, auth_required, trigger_reencryption); 5128 if (trigger_reencryption){ 5129 sm_conn->sm_pairing_requested = 1; 5130 sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; 5131 break; 5132 } 5133 /* fall through */ 5134 5135 case IRK_LOOKUP_FAILED: 5136 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 5137 break; 5138 default: 5139 log_info("irk lookup pending"); 5140 sm_conn->sm_pairing_requested = 1; 5141 break; 5142 } 5143 break; 5144 case SM_GENERAL_REENCRYPTION_FAILED: 5145 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 5146 break; 5147 case SM_GENERAL_IDLE: 5148 sm_conn->sm_pairing_requested = 1; 5149 break; 5150 default: 5151 break; 5152 } 5153 } 5154 sm_trigger_run(); 5155 } 5156 5157 // called by client app on authorization request 5158 void sm_authorization_decline(hci_con_handle_t con_handle){ 5159 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5160 if (!sm_conn) return; // wrong connection 5161 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 5162 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 5163 } 5164 5165 void sm_authorization_grant(hci_con_handle_t con_handle){ 5166 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5167 if (!sm_conn) return; // wrong connection 5168 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 5169 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 5170 } 5171 5172 // GAP Bonding API 5173 5174 void sm_bonding_decline(hci_con_handle_t con_handle){ 5175 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5176 if (!sm_conn) return; // wrong connection 5177 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 5178 log_info("decline, state %u", sm_conn->sm_engine_state); 5179 switch(sm_conn->sm_engine_state){ 5180 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5181 case SM_SC_W4_USER_RESPONSE: 5182 case SM_SC_W4_CONFIRMATION: 5183 case SM_SC_W4_PUBLIC_KEY_COMMAND: 5184 #endif 5185 case SM_PH1_W4_USER_RESPONSE: 5186 switch (setup->sm_stk_generation_method){ 5187 case PK_RESP_INPUT: 5188 case PK_INIT_INPUT: 5189 case PK_BOTH_INPUT: 5190 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 5191 break; 5192 case NUMERIC_COMPARISON: 5193 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 5194 break; 5195 case JUST_WORKS: 5196 case OOB: 5197 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 5198 break; 5199 default: 5200 btstack_assert(false); 5201 break; 5202 } 5203 break; 5204 default: 5205 break; 5206 } 5207 sm_trigger_run(); 5208 } 5209 5210 void sm_just_works_confirm(hci_con_handle_t con_handle){ 5211 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5212 if (!sm_conn) return; // wrong connection 5213 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 5214 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 5215 if (setup->sm_use_secure_connections){ 5216 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 5217 } else { 5218 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); 5219 } 5220 } 5221 5222 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5223 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 5224 sm_sc_prepare_dhkey_check(sm_conn); 5225 } 5226 #endif 5227 5228 sm_trigger_run(); 5229 } 5230 5231 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 5232 // for now, it's the same 5233 sm_just_works_confirm(con_handle); 5234 } 5235 5236 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 5237 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5238 if (!sm_conn) return; // wrong connection 5239 sm_reset_tk(); 5240 big_endian_store_32(setup->sm_tk, 12, passkey); 5241 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 5242 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 5243 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); 5244 } 5245 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5246 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 5247 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 5248 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 5249 sm_sc_start_calculating_local_confirm(sm_conn); 5250 } 5251 #endif 5252 sm_trigger_run(); 5253 } 5254 5255 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 5256 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5257 if (!sm_conn) return; // wrong connection 5258 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 5259 uint8_t num_actions = setup->sm_keypress_notification >> 5; 5260 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 5261 switch (action){ 5262 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 5263 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 5264 flags |= (1u << action); 5265 break; 5266 case SM_KEYPRESS_PASSKEY_CLEARED: 5267 // clear counter, keypress & erased flags + set passkey cleared 5268 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 5269 break; 5270 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 5271 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 5272 // erase actions queued 5273 num_actions--; 5274 if (num_actions == 0u){ 5275 // clear counter, keypress & erased flags 5276 flags &= 0x19u; 5277 } 5278 break; 5279 } 5280 num_actions++; 5281 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 5282 break; 5283 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 5284 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 5285 // enter actions queued 5286 num_actions--; 5287 if (num_actions == 0u){ 5288 // clear counter, keypress & erased flags 5289 flags &= 0x19u; 5290 } 5291 break; 5292 } 5293 num_actions++; 5294 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 5295 break; 5296 default: 5297 break; 5298 } 5299 setup->sm_keypress_notification = (num_actions << 5) | flags; 5300 sm_trigger_run(); 5301 } 5302 5303 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5304 static void sm_handle_random_result_oob(void * arg){ 5305 UNUSED(arg); 5306 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 5307 sm_trigger_run(); 5308 } 5309 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 5310 5311 static btstack_crypto_random_t sm_crypto_random_oob_request; 5312 5313 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 5314 sm_sc_oob_callback = callback; 5315 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 5316 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 5317 return 0; 5318 } 5319 #endif 5320 5321 /** 5322 * @brief Get Identity Resolving state 5323 * @param con_handle 5324 * @return irk_lookup_state_t 5325 */ 5326 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 5327 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5328 if (!sm_conn) return IRK_LOOKUP_IDLE; 5329 return sm_conn->sm_irk_lookup_state; 5330 } 5331 5332 /** 5333 * @brief Identify device in LE Device DB 5334 * @param handle 5335 * @return index from le_device_db or -1 if not found/identified 5336 */ 5337 int sm_le_device_index(hci_con_handle_t con_handle ){ 5338 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5339 if (!sm_conn) return -1; 5340 return sm_conn->sm_le_db_index; 5341 } 5342 5343 uint8_t sm_get_ltk(hci_con_handle_t con_handle, sm_key_t ltk){ 5344 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 5345 if (hci_connection == NULL){ 5346 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 5347 } 5348 if (hci_connection->link_key_type == 0){ 5349 return ERROR_CODE_PIN_OR_KEY_MISSING; 5350 } 5351 memcpy(ltk, hci_connection->link_key, 16); 5352 return ERROR_CODE_SUCCESS; 5353 } 5354 5355 static int gap_random_address_type_requires_updates(void){ 5356 switch (gap_random_adress_type){ 5357 case GAP_RANDOM_ADDRESS_TYPE_OFF: 5358 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 5359 return 0; 5360 default: 5361 return 1; 5362 } 5363 } 5364 5365 static uint8_t own_address_type(void){ 5366 switch (gap_random_adress_type){ 5367 case GAP_RANDOM_ADDRESS_TYPE_OFF: 5368 return BD_ADDR_TYPE_LE_PUBLIC; 5369 default: 5370 return BD_ADDR_TYPE_LE_RANDOM; 5371 } 5372 } 5373 5374 // GAP LE API 5375 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 5376 gap_random_address_update_stop(); 5377 gap_random_adress_type = random_address_type; 5378 hci_le_set_own_address_type(own_address_type()); 5379 if (!gap_random_address_type_requires_updates()) return; 5380 gap_random_address_update_start(); 5381 gap_random_address_trigger(); 5382 } 5383 5384 gap_random_address_type_t gap_random_address_get_mode(void){ 5385 return gap_random_adress_type; 5386 } 5387 5388 void gap_random_address_set_update_period(int period_ms){ 5389 gap_random_adress_update_period = period_ms; 5390 if (!gap_random_address_type_requires_updates()) return; 5391 gap_random_address_update_stop(); 5392 gap_random_address_update_start(); 5393 } 5394 5395 void gap_random_address_set(const bd_addr_t addr){ 5396 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 5397 (void)memcpy(sm_random_address, addr, 6); 5398 // assert msb bits are set to '11' 5399 sm_random_address[0] |= 0xc0; 5400 hci_le_random_address_set(sm_random_address); 5401 } 5402 5403 #ifdef ENABLE_LE_PERIPHERAL 5404 /* 5405 * @brief Set Advertisement Paramters 5406 * @param adv_int_min 5407 * @param adv_int_max 5408 * @param adv_type 5409 * @param direct_address_type 5410 * @param direct_address 5411 * @param channel_map 5412 * @param filter_policy 5413 * 5414 * @note own_address_type is used from gap_random_address_set_mode 5415 */ 5416 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 5417 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 5418 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 5419 direct_address_typ, direct_address, channel_map, filter_policy); 5420 } 5421 #endif 5422 5423 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 5424 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 5425 // wrong connection 5426 if (!sm_conn) return 0; 5427 // already encrypted 5428 if (sm_conn->sm_connection_encrypted) return 0; 5429 // irk status? 5430 switch(sm_conn->sm_irk_lookup_state){ 5431 case IRK_LOOKUP_FAILED: 5432 // done, cannot setup encryption 5433 return 0; 5434 case IRK_LOOKUP_SUCCEEDED: 5435 break; 5436 default: 5437 // IR Lookup pending 5438 return 1; 5439 } 5440 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset or indicates failure 5441 if (sm_conn->sm_engine_state == SM_GENERAL_REENCRYPTION_FAILED) return 0; 5442 if (sm_conn->sm_role){ 5443 return sm_conn->sm_engine_state != SM_RESPONDER_IDLE; 5444 } else { 5445 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 5446 } 5447 } 5448 5449 void sm_set_secure_connections_only_mode(bool enable){ 5450 #ifdef ENABLE_LE_SECURE_CONNECTIONS 5451 sm_sc_only_mode = enable; 5452 #else 5453 // SC Only mode not possible without support for SC 5454 btstack_assert(enable == false); 5455 #endif 5456 } 5457 5458 const uint8_t * gap_get_persistent_irk(void){ 5459 return sm_persistent_irk; 5460 } 5461 5462 void gap_delete_bonding(bd_addr_type_t address_type, bd_addr_t address){ 5463 int index = sm_le_device_db_index_lookup(address_type, address); 5464 if (index >= 0){ 5465 sm_remove_le_device_db_entry(index); 5466 } 5467 } 5468