1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "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 // assert SM Public Key can be sent/received 64 #ifdef ENABLE_LE_SECURE_CONNECTIONS 65 #if HCI_ACL_PAYLOAD_SIZE < 69 66 #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" 67 #endif 68 #endif 69 70 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 71 #define IS_RESPONDER(role) (role) 72 #else 73 #ifdef ENABLE_LE_CENTRAL 74 // only central - never responder (avoid 'unused variable' warnings) 75 #define IS_RESPONDER(role) (0 && role) 76 #else 77 // only peripheral - always responder (avoid 'unused variable' warnings) 78 #define IS_RESPONDER(role) (1 || role) 79 #endif 80 #endif 81 82 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 83 #define USE_CMAC_ENGINE 84 #endif 85 86 #define BTSTACK_TAG32(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) 87 88 // 89 // SM internal types and globals 90 // 91 92 typedef enum { 93 DKG_W4_WORKING, 94 DKG_CALC_IRK, 95 DKG_CALC_DHK, 96 DKG_READY 97 } derived_key_generation_t; 98 99 typedef enum { 100 RAU_IDLE, 101 RAU_GET_RANDOM, 102 RAU_W4_RANDOM, 103 RAU_GET_ENC, 104 RAU_W4_ENC, 105 RAU_SET_ADDRESS, 106 } random_address_update_t; 107 108 typedef enum { 109 CMAC_IDLE, 110 CMAC_CALC_SUBKEYS, 111 CMAC_W4_SUBKEYS, 112 CMAC_CALC_MI, 113 CMAC_W4_MI, 114 CMAC_CALC_MLAST, 115 CMAC_W4_MLAST 116 } cmac_state_t; 117 118 typedef enum { 119 JUST_WORKS, 120 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 121 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 122 PK_BOTH_INPUT, // Only input on both, both input PK 123 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 124 OOB // OOB available on one (SC) or both sides (legacy) 125 } stk_generation_method_t; 126 127 typedef enum { 128 SM_USER_RESPONSE_IDLE, 129 SM_USER_RESPONSE_PENDING, 130 SM_USER_RESPONSE_CONFIRM, 131 SM_USER_RESPONSE_PASSKEY, 132 SM_USER_RESPONSE_DECLINE 133 } sm_user_response_t; 134 135 typedef enum { 136 SM_AES128_IDLE, 137 SM_AES128_ACTIVE 138 } sm_aes128_state_t; 139 140 typedef enum { 141 ADDRESS_RESOLUTION_IDLE, 142 ADDRESS_RESOLUTION_GENERAL, 143 ADDRESS_RESOLUTION_FOR_CONNECTION, 144 } address_resolution_mode_t; 145 146 typedef enum { 147 ADDRESS_RESOLUTION_SUCEEDED, 148 ADDRESS_RESOLUTION_FAILED, 149 } address_resolution_event_t; 150 151 typedef enum { 152 EC_KEY_GENERATION_IDLE, 153 EC_KEY_GENERATION_ACTIVE, 154 EC_KEY_GENERATION_DONE, 155 } ec_key_generation_state_t; 156 157 typedef enum { 158 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 159 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 160 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 161 } sm_state_var_t; 162 163 typedef enum { 164 SM_SC_OOB_IDLE, 165 SM_SC_OOB_W4_RANDOM, 166 SM_SC_OOB_W2_CALC_CONFIRM, 167 SM_SC_OOB_W4_CONFIRM, 168 } sm_sc_oob_state_t; 169 170 typedef uint8_t sm_key24_t[3]; 171 typedef uint8_t sm_key56_t[7]; 172 typedef uint8_t sm_key256_t[32]; 173 174 // 175 // GLOBAL DATA 176 // 177 178 static bool test_use_fixed_local_csrk; 179 static bool test_use_fixed_local_irk; 180 181 #ifdef ENABLE_TESTING_SUPPORT 182 static uint8_t test_pairing_failure; 183 #endif 184 185 // configuration 186 static uint8_t sm_accepted_stk_generation_methods; 187 static uint8_t sm_max_encryption_key_size; 188 static uint8_t sm_min_encryption_key_size; 189 static uint8_t sm_auth_req = 0; 190 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 191 static uint8_t sm_slave_request_security; 192 static uint32_t sm_fixed_passkey_in_display_role; 193 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 194 195 #ifdef ENABLE_LE_SECURE_CONNECTIONS 196 static bool sm_sc_only_mode; 197 static uint8_t sm_sc_oob_random[16]; 198 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 199 static sm_sc_oob_state_t sm_sc_oob_state; 200 #endif 201 202 203 static uint8_t sm_persistent_keys_random_active; 204 static const btstack_tlv_t * sm_tlv_impl; 205 static void * sm_tlv_context; 206 207 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 208 static sm_key_t sm_persistent_er; 209 static sm_key_t sm_persistent_ir; 210 211 // derived from sm_persistent_ir 212 static sm_key_t sm_persistent_dhk; 213 static sm_key_t sm_persistent_irk; 214 static derived_key_generation_t dkg_state; 215 216 // derived from sm_persistent_er 217 // .. 218 219 // random address update 220 static random_address_update_t rau_state; 221 static bd_addr_t sm_random_address; 222 223 #ifdef USE_CMAC_ENGINE 224 // CMAC Calculation: General 225 static btstack_crypto_aes128_cmac_t sm_cmac_request; 226 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 227 static uint8_t sm_cmac_active; 228 static uint8_t sm_cmac_hash[16]; 229 #endif 230 231 // CMAC for ATT Signed Writes 232 #ifdef ENABLE_LE_SIGNED_WRITE 233 static uint16_t sm_cmac_signed_write_message_len; 234 static uint8_t sm_cmac_signed_write_header[3]; 235 static const uint8_t * sm_cmac_signed_write_message; 236 static uint8_t sm_cmac_signed_write_sign_counter[4]; 237 #endif 238 239 // CMAC for Secure Connection functions 240 #ifdef ENABLE_LE_SECURE_CONNECTIONS 241 static sm_connection_t * sm_cmac_connection; 242 static uint8_t sm_cmac_sc_buffer[80]; 243 #endif 244 245 // resolvable private address lookup / CSRK calculation 246 static int sm_address_resolution_test; 247 static int sm_address_resolution_ah_calculation_active; 248 static uint8_t sm_address_resolution_addr_type; 249 static bd_addr_t sm_address_resolution_address; 250 static void * sm_address_resolution_context; 251 static address_resolution_mode_t sm_address_resolution_mode; 252 static btstack_linked_list_t sm_address_resolution_general_queue; 253 254 // aes128 crypto engine. 255 static sm_aes128_state_t sm_aes128_state; 256 257 // crypto 258 static btstack_crypto_random_t sm_crypto_random_request; 259 static btstack_crypto_aes128_t sm_crypto_aes128_request; 260 #ifdef ENABLE_LE_SECURE_CONNECTIONS 261 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 262 #endif 263 264 // temp storage for random data 265 static uint8_t sm_random_data[8]; 266 static uint8_t sm_aes128_key[16]; 267 static uint8_t sm_aes128_plaintext[16]; 268 static uint8_t sm_aes128_ciphertext[16]; 269 270 // to receive hci events 271 static btstack_packet_callback_registration_t hci_event_callback_registration; 272 273 /* to dispatch sm event */ 274 static btstack_linked_list_t sm_event_handlers; 275 276 // LE Secure Connections 277 #ifdef ENABLE_LE_SECURE_CONNECTIONS 278 static ec_key_generation_state_t ec_key_generation_state; 279 static uint8_t ec_q[64]; 280 #endif 281 282 // 283 // Volume 3, Part H, Chapter 24 284 // "Security shall be initiated by the Security Manager in the device in the master role. 285 // The device in the slave role shall be the responding device." 286 // -> master := initiator, slave := responder 287 // 288 289 // data needed for security setup 290 typedef struct sm_setup_context { 291 292 btstack_timer_source_t sm_timeout; 293 294 // used in all phases 295 uint8_t sm_pairing_failed_reason; 296 297 // user response, (Phase 1 and/or 2) 298 uint8_t sm_user_response; 299 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 300 301 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 302 uint8_t sm_key_distribution_send_set; 303 uint8_t sm_key_distribution_sent_set; 304 uint8_t sm_key_distribution_received_set; 305 306 // Phase 2 (Pairing over SMP) 307 stk_generation_method_t sm_stk_generation_method; 308 sm_key_t sm_tk; 309 uint8_t sm_have_oob_data; 310 uint8_t sm_use_secure_connections; 311 312 sm_key_t sm_c1_t3_value; // c1 calculation 313 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 314 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 315 sm_key_t sm_local_random; 316 sm_key_t sm_local_confirm; 317 sm_key_t sm_peer_random; 318 sm_key_t sm_peer_confirm; 319 uint8_t sm_m_addr_type; // address and type can be removed 320 uint8_t sm_s_addr_type; // '' 321 bd_addr_t sm_m_address; // '' 322 bd_addr_t sm_s_address; // '' 323 sm_key_t sm_ltk; 324 325 uint8_t sm_state_vars; 326 #ifdef ENABLE_LE_SECURE_CONNECTIONS 327 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 328 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 329 sm_key_t sm_local_nonce; // might be combined with sm_local_random 330 uint8_t sm_dhkey[32]; 331 sm_key_t sm_peer_dhkey_check; 332 sm_key_t sm_local_dhkey_check; 333 sm_key_t sm_ra; 334 sm_key_t sm_rb; 335 sm_key_t sm_t; // used for f5 and h6 336 sm_key_t sm_mackey; 337 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 338 #endif 339 340 // Phase 3 341 342 // key distribution, we generate 343 uint16_t sm_local_y; 344 uint16_t sm_local_div; 345 uint16_t sm_local_ediv; 346 uint8_t sm_local_rand[8]; 347 sm_key_t sm_local_ltk; 348 sm_key_t sm_local_csrk; 349 sm_key_t sm_local_irk; 350 // sm_local_address/addr_type not needed 351 352 // key distribution, received from peer 353 uint16_t sm_peer_y; 354 uint16_t sm_peer_div; 355 uint16_t sm_peer_ediv; 356 uint8_t sm_peer_rand[8]; 357 sm_key_t sm_peer_ltk; 358 sm_key_t sm_peer_irk; 359 sm_key_t sm_peer_csrk; 360 uint8_t sm_peer_addr_type; 361 bd_addr_t sm_peer_address; 362 #ifdef ENABLE_LE_SIGNED_WRITE 363 int sm_le_device_index; 364 #endif 365 366 } sm_setup_context_t; 367 368 // 369 static sm_setup_context_t the_setup; 370 static sm_setup_context_t * setup = &the_setup; 371 372 // active connection - the one for which the_setup is used for 373 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 374 375 // @returns 1 if oob data is available 376 // stores oob data in provided 16 byte buffer if not null 377 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 378 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); 379 380 static void sm_run(void); 381 static void sm_done_for_handle(hci_con_handle_t con_handle); 382 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 383 static inline int sm_calc_actual_encryption_key_size(int other); 384 static int sm_validate_stk_generation_method(void); 385 static void sm_handle_encryption_result_address_resolution(void *arg); 386 static void sm_handle_encryption_result_dkg_dhk(void *arg); 387 static void sm_handle_encryption_result_dkg_irk(void *arg); 388 static void sm_handle_encryption_result_enc_a(void *arg); 389 static void sm_handle_encryption_result_enc_b(void *arg); 390 static void sm_handle_encryption_result_enc_c(void *arg); 391 static void sm_handle_encryption_result_enc_csrk(void *arg); 392 static void sm_handle_encryption_result_enc_d(void * arg); 393 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 394 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 395 #ifdef ENABLE_LE_PERIPHERAL 396 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 397 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 398 #endif 399 static void sm_handle_encryption_result_enc_stk(void *arg); 400 static void sm_handle_encryption_result_rau(void *arg); 401 static void sm_handle_random_result_ph2_tk(void * arg); 402 static void sm_handle_random_result_rau(void * arg); 403 #ifdef ENABLE_LE_SECURE_CONNECTIONS 404 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)); 405 static void sm_ec_generate_new_key(void); 406 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 407 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 408 static int sm_passkey_entry(stk_generation_method_t method); 409 #endif 410 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 411 412 static void log_info_hex16(const char * name, uint16_t value){ 413 log_info("%-6s 0x%04x", name, value); 414 } 415 416 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 417 // return packet[0]; 418 // } 419 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 420 return packet[1]; 421 } 422 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 423 return packet[2]; 424 } 425 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 426 return packet[3]; 427 } 428 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 429 return packet[4]; 430 } 431 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 432 return packet[5]; 433 } 434 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 435 return packet[6]; 436 } 437 438 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 439 packet[0] = code; 440 } 441 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 442 packet[1] = io_capability; 443 } 444 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 445 packet[2] = oob_data_flag; 446 } 447 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 448 packet[3] = auth_req; 449 } 450 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 451 packet[4] = max_encryption_key_size; 452 } 453 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 454 packet[5] = initiator_key_distribution; 455 } 456 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 457 packet[6] = responder_key_distribution; 458 } 459 460 // @returns 1 if all bytes are 0 461 static int sm_is_null(uint8_t * data, int size){ 462 int i; 463 for (i=0; i < size ; i++){ 464 if (data[i] != 0) { 465 return 0; 466 } 467 } 468 return 1; 469 } 470 471 static int sm_is_null_random(uint8_t random[8]){ 472 return sm_is_null(random, 8); 473 } 474 475 static int sm_is_null_key(uint8_t * key){ 476 return sm_is_null(key, 16); 477 } 478 479 // sm_trigger_run allows to schedule callback from main run loop // reduces stack depth 480 static void sm_run_timer_handler(btstack_timer_source_t * ts){ 481 UNUSED(ts); 482 sm_run(); 483 } 484 static void sm_trigger_run(void){ 485 static btstack_timer_source_t sm_run_timer; 486 (void)btstack_run_loop_remove_timer(&sm_run_timer); 487 btstack_run_loop_set_timer(&sm_run_timer, 0); 488 btstack_run_loop_add_timer(&sm_run_timer); 489 } 490 491 // Key utils 492 static void sm_reset_tk(void){ 493 int i; 494 for (i=0;i<16;i++){ 495 setup->sm_tk[i] = 0; 496 } 497 } 498 499 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 500 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 501 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 502 int i; 503 for (i = max_encryption_size ; i < 16 ; i++){ 504 key[15-i] = 0; 505 } 506 } 507 508 // ER / IR checks 509 static void sm_er_ir_set_default(void){ 510 int i; 511 for (i=0;i<16;i++){ 512 sm_persistent_er[i] = 0x30 + i; 513 sm_persistent_ir[i] = 0x90 + i; 514 } 515 } 516 517 static int sm_er_is_default(void){ 518 int i; 519 for (i=0;i<16;i++){ 520 if (sm_persistent_er[i] != (0x30+i)) return 0; 521 } 522 return 1; 523 } 524 525 static int sm_ir_is_default(void){ 526 int i; 527 for (i=0;i<16;i++){ 528 if (sm_persistent_ir[i] != (0x90+i)) return 0; 529 } 530 return 1; 531 } 532 533 // SMP Timeout implementation 534 535 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 536 // the Security Manager Timer shall be reset and started. 537 // 538 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 539 // 540 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 541 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 542 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 543 // established. 544 545 static void sm_timeout_handler(btstack_timer_source_t * timer){ 546 log_info("SM timeout"); 547 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 548 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 549 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 550 sm_done_for_handle(sm_conn->sm_handle); 551 552 // trigger handling of next ready connection 553 sm_run(); 554 } 555 static void sm_timeout_start(sm_connection_t * sm_conn){ 556 btstack_run_loop_remove_timer(&setup->sm_timeout); 557 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 558 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 559 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 560 btstack_run_loop_add_timer(&setup->sm_timeout); 561 } 562 static void sm_timeout_stop(void){ 563 btstack_run_loop_remove_timer(&setup->sm_timeout); 564 } 565 static void sm_timeout_reset(sm_connection_t * sm_conn){ 566 sm_timeout_stop(); 567 sm_timeout_start(sm_conn); 568 } 569 570 // end of sm timeout 571 572 // GAP Random Address updates 573 static gap_random_address_type_t gap_random_adress_type; 574 static btstack_timer_source_t gap_random_address_update_timer; 575 static uint32_t gap_random_adress_update_period; 576 577 static void gap_random_address_trigger(void){ 578 log_info("gap_random_address_trigger, state %u", rau_state); 579 if (rau_state != RAU_IDLE) return; 580 rau_state = RAU_GET_RANDOM; 581 sm_trigger_run(); 582 } 583 584 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 585 UNUSED(timer); 586 587 log_info("GAP Random Address Update due"); 588 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 589 btstack_run_loop_add_timer(&gap_random_address_update_timer); 590 gap_random_address_trigger(); 591 } 592 593 static void gap_random_address_update_start(void){ 594 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 595 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 596 btstack_run_loop_add_timer(&gap_random_address_update_timer); 597 } 598 599 static void gap_random_address_update_stop(void){ 600 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 601 } 602 603 // ah(k,r) helper 604 // r = padding || r 605 // r - 24 bit value 606 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 607 // r'= padding || r 608 memset(r_prime, 0, 16); 609 (void)memcpy(&r_prime[13], r, 3); 610 } 611 612 // d1 helper 613 // d' = padding || r || d 614 // d,r - 16 bit values 615 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 616 // d'= padding || r || d 617 memset(d1_prime, 0, 16); 618 big_endian_store_16(d1_prime, 12, r); 619 big_endian_store_16(d1_prime, 14, d); 620 } 621 622 // calculate arguments for first AES128 operation in C1 function 623 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){ 624 625 // p1 = pres || preq || rat’ || iat’ 626 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 627 // cant octet of pres becomes the most significant octet of p1. 628 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 629 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 630 // p1 is 0x05000800000302070710000001010001." 631 632 sm_key_t p1; 633 reverse_56(pres, &p1[0]); 634 reverse_56(preq, &p1[7]); 635 p1[14] = rat; 636 p1[15] = iat; 637 log_info_key("p1", p1); 638 log_info_key("r", r); 639 640 // t1 = r xor p1 641 int i; 642 for (i=0;i<16;i++){ 643 t1[i] = r[i] ^ p1[i]; 644 } 645 log_info_key("t1", t1); 646 } 647 648 // calculate arguments for second AES128 operation in C1 function 649 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 650 // p2 = padding || ia || ra 651 // "The least significant octet of ra becomes the least significant octet of p2 and 652 // the most significant octet of padding becomes the most significant octet of p2. 653 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 654 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 655 656 sm_key_t p2; 657 memset(p2, 0, 16); 658 (void)memcpy(&p2[4], ia, 6); 659 (void)memcpy(&p2[10], ra, 6); 660 log_info_key("p2", p2); 661 662 // c1 = e(k, t2_xor_p2) 663 int i; 664 for (i=0;i<16;i++){ 665 t3[i] = t2[i] ^ p2[i]; 666 } 667 log_info_key("t3", t3); 668 } 669 670 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 671 log_info_key("r1", r1); 672 log_info_key("r2", r2); 673 (void)memcpy(&r_prime[8], &r2[8], 8); 674 (void)memcpy(&r_prime[0], &r1[8], 8); 675 } 676 677 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 678 UNUSED(channel); 679 680 // log event 681 hci_dump_packet(packet_type, 1, packet, size); 682 // dispatch to all event handlers 683 btstack_linked_list_iterator_t it; 684 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 685 while (btstack_linked_list_iterator_has_next(&it)){ 686 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 687 entry->callback(packet_type, 0, packet, size); 688 } 689 } 690 691 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){ 692 event[0] = type; 693 event[1] = event_size - 2; 694 little_endian_store_16(event, 2, con_handle); 695 event[4] = addr_type; 696 reverse_bd_addr(address, &event[5]); 697 } 698 699 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 700 uint8_t event[11]; 701 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 702 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 703 } 704 705 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 706 uint8_t event[15]; 707 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 708 little_endian_store_32(event, 11, passkey); 709 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 710 } 711 712 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){ 713 // fetch addr and addr type from db, only called for valid entries 714 bd_addr_t identity_address; 715 int identity_address_type; 716 le_device_db_info(index, &identity_address_type, identity_address, NULL); 717 718 uint8_t event[20]; 719 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 720 event[11] = identity_address_type; 721 reverse_bd_addr(identity_address, &event[12]); 722 little_endian_store_16(event, 18, index); 723 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 724 } 725 726 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){ 727 uint8_t event[12]; 728 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 729 event[11] = status; 730 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 731 } 732 733 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 734 uint8_t event[13]; 735 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 736 event[11] = status; 737 event[12] = reason; 738 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 739 } 740 741 // decide on stk generation based on 742 // - pairing request 743 // - io capabilities 744 // - OOB data availability 745 static void sm_setup_tk(void){ 746 747 // horizontal: initiator capabilities 748 // vertial: responder capabilities 749 static const stk_generation_method_t stk_generation_method [5] [5] = { 750 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 751 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 752 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 753 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 754 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 755 }; 756 757 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 758 #ifdef ENABLE_LE_SECURE_CONNECTIONS 759 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 760 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 761 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 762 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 763 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 764 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 765 }; 766 #endif 767 768 // default: just works 769 setup->sm_stk_generation_method = JUST_WORKS; 770 771 #ifdef ENABLE_LE_SECURE_CONNECTIONS 772 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 773 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 774 & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; 775 #else 776 setup->sm_use_secure_connections = 0; 777 #endif 778 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 779 780 781 // decide if OOB will be used based on SC vs. Legacy and oob flags 782 int use_oob = 0; 783 if (setup->sm_use_secure_connections){ 784 // In LE Secure Connections pairing, the out of band method is used if at least 785 // one device has the peer device's out of band authentication data available. 786 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 787 } else { 788 // In LE legacy pairing, the out of band method is used if both the devices have 789 // the other device's out of band authentication data available. 790 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 791 } 792 if (use_oob){ 793 log_info("SM: have OOB data"); 794 log_info_key("OOB", setup->sm_tk); 795 setup->sm_stk_generation_method = OOB; 796 return; 797 } 798 799 // If both devices have not set the MITM option in the Authentication Requirements 800 // Flags, then the IO capabilities shall be ignored and the Just Works association 801 // model shall be used. 802 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) 803 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ 804 log_info("SM: MITM not required by both -> JUST WORKS"); 805 return; 806 } 807 808 // Reset TK as it has been setup in sm_init_setup 809 sm_reset_tk(); 810 811 // Also use just works if unknown io capabilites 812 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)){ 813 return; 814 } 815 816 // Otherwise the IO capabilities of the devices shall be used to determine the 817 // pairing method as defined in Table 2.4. 818 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 819 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 820 821 #ifdef ENABLE_LE_SECURE_CONNECTIONS 822 // table not define by default 823 if (setup->sm_use_secure_connections){ 824 generation_method = stk_generation_method_with_secure_connection; 825 } 826 #endif 827 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)]; 828 829 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 830 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); 831 } 832 833 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 834 int flags = 0; 835 if (key_set & SM_KEYDIST_ENC_KEY){ 836 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 837 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 838 } 839 if (key_set & SM_KEYDIST_ID_KEY){ 840 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 841 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 842 } 843 if (key_set & SM_KEYDIST_SIGN){ 844 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 845 } 846 return flags; 847 } 848 849 static void sm_setup_key_distribution(uint8_t key_set){ 850 setup->sm_key_distribution_received_set = 0; 851 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 852 setup->sm_key_distribution_sent_set = 0; 853 #ifdef ENABLE_LE_SIGNED_WRITE 854 setup->sm_le_device_index = -1; 855 #endif 856 } 857 858 // CSRK Key Lookup 859 860 861 static int sm_address_resolution_idle(void){ 862 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 863 } 864 865 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){ 866 (void)memcpy(sm_address_resolution_address, addr, 6); 867 sm_address_resolution_addr_type = addr_type; 868 sm_address_resolution_test = 0; 869 sm_address_resolution_mode = mode; 870 sm_address_resolution_context = context; 871 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 872 } 873 874 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 875 // check if already in list 876 btstack_linked_list_iterator_t it; 877 sm_lookup_entry_t * entry; 878 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 879 while(btstack_linked_list_iterator_has_next(&it)){ 880 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 881 if (entry->address_type != address_type) continue; 882 if (memcmp(entry->address, address, 6)) continue; 883 // already in list 884 return BTSTACK_BUSY; 885 } 886 entry = btstack_memory_sm_lookup_entry_get(); 887 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 888 entry->address_type = (bd_addr_type_t) address_type; 889 (void)memcpy(entry->address, address, 6); 890 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 891 sm_trigger_run(); 892 return 0; 893 } 894 895 // CMAC calculation using AES Engineq 896 #ifdef USE_CMAC_ENGINE 897 898 static void sm_cmac_done_trampoline(void * arg){ 899 UNUSED(arg); 900 sm_cmac_active = 0; 901 (*sm_cmac_done_callback)(sm_cmac_hash); 902 sm_trigger_run(); 903 } 904 905 int sm_cmac_ready(void){ 906 return sm_cmac_active == 0u; 907 } 908 #endif 909 910 #ifdef ENABLE_LE_SECURE_CONNECTIONS 911 // generic cmac calculation 912 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)){ 913 sm_cmac_active = 1; 914 sm_cmac_done_callback = done_callback; 915 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 916 } 917 #endif 918 919 // cmac for ATT Message signing 920 #ifdef ENABLE_LE_SIGNED_WRITE 921 922 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)){ 923 sm_cmac_active = 1; 924 sm_cmac_done_callback = done_callback; 925 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 926 } 927 928 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 929 if (offset >= sm_cmac_signed_write_message_len) { 930 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 931 return 0; 932 } 933 934 offset = sm_cmac_signed_write_message_len - 1 - offset; 935 936 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 937 if (offset < 3){ 938 return sm_cmac_signed_write_header[offset]; 939 } 940 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 941 if (offset < actual_message_len_incl_header){ 942 return sm_cmac_signed_write_message[offset - 3]; 943 } 944 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 945 } 946 947 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)){ 948 // ATT Message Signing 949 sm_cmac_signed_write_header[0] = opcode; 950 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 951 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 952 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 953 sm_cmac_signed_write_message = message; 954 sm_cmac_signed_write_message_len = total_message_len; 955 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 956 } 957 #endif 958 959 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 960 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 961 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 962 switch (setup->sm_stk_generation_method){ 963 case PK_RESP_INPUT: 964 if (IS_RESPONDER(sm_conn->sm_role)){ 965 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 966 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 967 } else { 968 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 969 } 970 break; 971 case PK_INIT_INPUT: 972 if (IS_RESPONDER(sm_conn->sm_role)){ 973 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 974 } else { 975 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 976 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 977 } 978 break; 979 case PK_BOTH_INPUT: 980 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 981 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 982 break; 983 case NUMERIC_COMPARISON: 984 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 985 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 986 break; 987 case JUST_WORKS: 988 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 989 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 990 break; 991 case OOB: 992 // client already provided OOB data, let's skip notification. 993 break; 994 } 995 } 996 997 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 998 int recv_flags; 999 if (IS_RESPONDER(sm_conn->sm_role)){ 1000 // slave / responder 1001 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1002 } else { 1003 // master / initiator 1004 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1005 } 1006 1007 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1008 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1009 if (setup->sm_use_secure_connections){ 1010 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 1011 } 1012 #endif 1013 1014 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1015 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 1016 } 1017 1018 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1019 if (sm_active_connection_handle == con_handle){ 1020 sm_timeout_stop(); 1021 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1022 log_info("sm: connection 0x%x released setup context", con_handle); 1023 1024 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1025 // generate new ec key after each pairing (that used it) 1026 if (setup->sm_use_secure_connections){ 1027 sm_ec_generate_new_key(); 1028 } 1029 #endif 1030 } 1031 } 1032 1033 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1034 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1035 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 1036 sm_done_for_handle(connection->sm_handle); 1037 } 1038 1039 static int sm_key_distribution_flags_for_auth_req(void){ 1040 1041 int flags = SM_KEYDIST_ID_KEY; 1042 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1043 // encryption and signing information only if bonding requested 1044 flags |= SM_KEYDIST_ENC_KEY; 1045 #ifdef ENABLE_LE_SIGNED_WRITE 1046 flags |= SM_KEYDIST_SIGN; 1047 #endif 1048 } 1049 return flags; 1050 } 1051 1052 static void sm_reset_setup(void){ 1053 // fill in sm setup 1054 setup->sm_state_vars = 0; 1055 setup->sm_keypress_notification = 0; 1056 sm_reset_tk(); 1057 } 1058 1059 static void sm_init_setup(sm_connection_t * sm_conn){ 1060 1061 // fill in sm setup 1062 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1063 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1064 1065 // query client for Legacy Pairing OOB data 1066 setup->sm_have_oob_data = 0; 1067 if (sm_get_oob_data) { 1068 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1069 } 1070 1071 // if available and SC supported, also ask for SC OOB Data 1072 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1073 memset(setup->sm_ra, 0, 16); 1074 memset(setup->sm_rb, 0, 16); 1075 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1076 if (sm_get_sc_oob_data){ 1077 if (IS_RESPONDER(sm_conn->sm_role)){ 1078 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1079 sm_conn->sm_peer_addr_type, 1080 sm_conn->sm_peer_address, 1081 setup->sm_peer_confirm, 1082 setup->sm_ra); 1083 } else { 1084 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1085 sm_conn->sm_peer_addr_type, 1086 sm_conn->sm_peer_address, 1087 setup->sm_peer_confirm, 1088 setup->sm_rb); 1089 } 1090 } else { 1091 setup->sm_have_oob_data = 0; 1092 } 1093 } 1094 #endif 1095 1096 sm_pairing_packet_t * local_packet; 1097 if (IS_RESPONDER(sm_conn->sm_role)){ 1098 // slave 1099 local_packet = &setup->sm_s_pres; 1100 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1101 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1102 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1103 } else { 1104 // master 1105 local_packet = &setup->sm_m_preq; 1106 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1107 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1108 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1109 1110 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1111 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1112 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1113 } 1114 1115 uint8_t auth_req = sm_auth_req; 1116 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1117 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1118 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1119 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1120 } 1121 1122 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1123 1124 sm_pairing_packet_t * remote_packet; 1125 int remote_key_request; 1126 if (IS_RESPONDER(sm_conn->sm_role)){ 1127 // slave / responder 1128 remote_packet = &setup->sm_m_preq; 1129 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1130 } else { 1131 // master / initiator 1132 remote_packet = &setup->sm_s_pres; 1133 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1134 } 1135 1136 // check key size 1137 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1138 if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; 1139 1140 // decide on STK generation method / SC 1141 sm_setup_tk(); 1142 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1143 1144 // check if STK generation method is acceptable by client 1145 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1146 1147 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1148 // check LE SC Only mode 1149 if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ 1150 log_info("SC Only mode active but SC not possible"); 1151 return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1152 } 1153 1154 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1155 if (setup->sm_use_secure_connections){ 1156 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1157 } 1158 #endif 1159 1160 // identical to responder 1161 sm_setup_key_distribution(remote_key_request); 1162 1163 // JUST WORKS doens't provide authentication 1164 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1165 1166 return 0; 1167 } 1168 1169 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1170 1171 // cache and reset context 1172 int matched_device_id = sm_address_resolution_test; 1173 address_resolution_mode_t mode = sm_address_resolution_mode; 1174 void * context = sm_address_resolution_context; 1175 1176 // reset context 1177 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1178 sm_address_resolution_context = NULL; 1179 sm_address_resolution_test = -1; 1180 hci_con_handle_t con_handle = 0; 1181 1182 sm_connection_t * sm_connection; 1183 #ifdef ENABLE_LE_CENTRAL 1184 sm_key_t ltk; 1185 int have_ltk; 1186 int pairing_need; 1187 #endif 1188 switch (mode){ 1189 case ADDRESS_RESOLUTION_GENERAL: 1190 break; 1191 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1192 sm_connection = (sm_connection_t *) context; 1193 con_handle = sm_connection->sm_handle; 1194 switch (event){ 1195 case ADDRESS_RESOLUTION_SUCEEDED: 1196 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1197 sm_connection->sm_le_db_index = matched_device_id; 1198 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1199 if (sm_connection->sm_role) { 1200 // LTK request received before, IRK required -> start LTK calculation 1201 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1202 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1203 } 1204 break; 1205 } 1206 #ifdef ENABLE_LE_CENTRAL 1207 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 1208 have_ltk = !sm_is_null_key(ltk); 1209 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1210 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1211 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1212 // reset requests 1213 sm_connection->sm_security_request_received = 0; 1214 sm_connection->sm_pairing_requested = 0; 1215 1216 // have ltk -> start encryption 1217 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1218 // "When a bond has been created between two devices, any reconnection should result in the local device 1219 // enabling or requesting encryption with the remote device before initiating any service request." 1220 if (have_ltk){ 1221 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1222 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1223 break; 1224 #else 1225 log_info("central: defer enabling encryption for bonded device"); 1226 #endif 1227 } 1228 // pairint_request -> send pairing request 1229 if (pairing_need){ 1230 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1231 break; 1232 } 1233 #endif 1234 break; 1235 case ADDRESS_RESOLUTION_FAILED: 1236 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1237 if (sm_connection->sm_role) { 1238 // LTK request received before, IRK required -> negative LTK reply 1239 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1240 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1241 } 1242 break; 1243 } 1244 #ifdef ENABLE_LE_CENTRAL 1245 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1246 sm_connection->sm_security_request_received = 0; 1247 sm_connection->sm_pairing_requested = 0; 1248 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1249 #endif 1250 break; 1251 } 1252 break; 1253 default: 1254 break; 1255 } 1256 1257 switch (event){ 1258 case ADDRESS_RESOLUTION_SUCEEDED: 1259 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1260 break; 1261 case ADDRESS_RESOLUTION_FAILED: 1262 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1263 break; 1264 } 1265 } 1266 1267 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1268 1269 int le_db_index = -1; 1270 1271 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1272 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1273 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1274 & SM_AUTHREQ_BONDING ) != 0u; 1275 1276 if (bonding_enabed){ 1277 1278 // lookup device based on IRK 1279 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1280 int i; 1281 for (i=0; i < le_device_db_max_count(); i++){ 1282 sm_key_t irk; 1283 bd_addr_t address; 1284 int address_type = BD_ADDR_TYPE_UNKNOWN; 1285 le_device_db_info(i, &address_type, address, irk); 1286 // skip unused entries 1287 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1288 // compare IRK 1289 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1290 1291 log_info("sm: device found for IRK, updating"); 1292 le_db_index = i; 1293 break; 1294 } 1295 } else { 1296 // assert IRK is set to zero 1297 memset(setup->sm_peer_irk, 0, 16); 1298 } 1299 1300 // if not found, lookup via public address if possible 1301 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1302 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1303 int i; 1304 for (i=0; i < le_device_db_max_count(); i++){ 1305 bd_addr_t address; 1306 int address_type = BD_ADDR_TYPE_UNKNOWN; 1307 le_device_db_info(i, &address_type, address, NULL); 1308 // skip unused entries 1309 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1310 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1311 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1312 log_info("sm: device found for public address, updating"); 1313 le_db_index = i; 1314 break; 1315 } 1316 } 1317 } 1318 1319 // if not found, add to db 1320 if (le_db_index < 0) { 1321 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1322 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1323 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1324 #endif 1325 } 1326 1327 if (le_db_index >= 0){ 1328 1329 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1330 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1331 1332 #ifdef ENABLE_LE_SIGNED_WRITE 1333 // store local CSRK 1334 setup->sm_le_device_index = le_db_index; 1335 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1336 log_info("sm: store local CSRK"); 1337 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1338 le_device_db_local_counter_set(le_db_index, 0); 1339 } 1340 1341 // store remote CSRK 1342 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1343 log_info("sm: store remote CSRK"); 1344 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1345 le_device_db_remote_counter_set(le_db_index, 0); 1346 } 1347 #endif 1348 // store encryption information for secure connections: LTK generated by ECDH 1349 if (setup->sm_use_secure_connections){ 1350 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1351 uint8_t zero_rand[8]; 1352 memset(zero_rand, 0, 8); 1353 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1354 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1355 } 1356 1357 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1358 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1359 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1360 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1361 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1362 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1363 1364 } 1365 } 1366 } else { 1367 log_info("Ignoring received keys, bonding not enabled"); 1368 } 1369 1370 // keep le_db_index 1371 sm_conn->sm_le_db_index = le_db_index; 1372 } 1373 1374 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1375 setup->sm_pairing_failed_reason = reason; 1376 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1377 } 1378 1379 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1380 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1381 } 1382 1383 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1384 1385 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1386 static int sm_passkey_used(stk_generation_method_t method); 1387 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1388 1389 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1390 if (setup->sm_stk_generation_method == OOB){ 1391 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1392 } else { 1393 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); 1394 } 1395 } 1396 1397 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1398 if (IS_RESPONDER(sm_conn->sm_role)){ 1399 // Responder 1400 if (setup->sm_stk_generation_method == OOB){ 1401 // generate Nb 1402 log_info("Generate Nb"); 1403 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); 1404 } else { 1405 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1406 } 1407 } else { 1408 // Initiator role 1409 switch (setup->sm_stk_generation_method){ 1410 case JUST_WORKS: 1411 sm_sc_prepare_dhkey_check(sm_conn); 1412 break; 1413 1414 case NUMERIC_COMPARISON: 1415 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1416 break; 1417 case PK_INIT_INPUT: 1418 case PK_RESP_INPUT: 1419 case PK_BOTH_INPUT: 1420 if (setup->sm_passkey_bit < 20u) { 1421 sm_sc_start_calculating_local_confirm(sm_conn); 1422 } else { 1423 sm_sc_prepare_dhkey_check(sm_conn); 1424 } 1425 break; 1426 case OOB: 1427 sm_sc_prepare_dhkey_check(sm_conn); 1428 break; 1429 } 1430 } 1431 } 1432 1433 static void sm_sc_cmac_done(uint8_t * hash){ 1434 log_info("sm_sc_cmac_done: "); 1435 log_info_hexdump(hash, 16); 1436 1437 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1438 sm_sc_oob_state = SM_SC_OOB_IDLE; 1439 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1440 return; 1441 } 1442 1443 sm_connection_t * sm_conn = sm_cmac_connection; 1444 sm_cmac_connection = NULL; 1445 #ifdef ENABLE_CLASSIC 1446 link_key_type_t link_key_type; 1447 #endif 1448 1449 switch (sm_conn->sm_engine_state){ 1450 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1451 (void)memcpy(setup->sm_local_confirm, hash, 16); 1452 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1453 break; 1454 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1455 // check 1456 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1457 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1458 break; 1459 } 1460 sm_sc_state_after_receiving_random(sm_conn); 1461 break; 1462 case SM_SC_W4_CALCULATE_G2: { 1463 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1464 big_endian_store_32(setup->sm_tk, 12, vab); 1465 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1466 sm_trigger_user_response(sm_conn); 1467 break; 1468 } 1469 case SM_SC_W4_CALCULATE_F5_SALT: 1470 (void)memcpy(setup->sm_t, hash, 16); 1471 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1472 break; 1473 case SM_SC_W4_CALCULATE_F5_MACKEY: 1474 (void)memcpy(setup->sm_mackey, hash, 16); 1475 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1476 break; 1477 case SM_SC_W4_CALCULATE_F5_LTK: 1478 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1479 // Errata Service Release to the Bluetooth Specification: ESR09 1480 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1481 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1482 (void)memcpy(setup->sm_ltk, hash, 16); 1483 (void)memcpy(setup->sm_local_ltk, hash, 16); 1484 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1485 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1486 break; 1487 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1488 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1489 if (IS_RESPONDER(sm_conn->sm_role)){ 1490 // responder 1491 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1492 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1493 } else { 1494 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1495 } 1496 } else { 1497 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1498 } 1499 break; 1500 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1501 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1502 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1503 break; 1504 } 1505 if (IS_RESPONDER(sm_conn->sm_role)){ 1506 // responder 1507 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1508 } else { 1509 // initiator 1510 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1511 } 1512 break; 1513 case SM_SC_W4_CALCULATE_H6_ILK: 1514 (void)memcpy(setup->sm_t, hash, 16); 1515 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1516 break; 1517 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1518 #ifdef ENABLE_CLASSIC 1519 reverse_128(hash, setup->sm_t); 1520 link_key_type = sm_conn->sm_connection_authenticated ? 1521 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1522 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1523 if (IS_RESPONDER(sm_conn->sm_role)){ 1524 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1525 } else { 1526 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1527 } 1528 #endif 1529 if (IS_RESPONDER(sm_conn->sm_role)){ 1530 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1531 } else { 1532 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1533 } 1534 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1535 sm_done_for_handle(sm_conn->sm_handle); 1536 break; 1537 default: 1538 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1539 break; 1540 } 1541 sm_trigger_run(); 1542 } 1543 1544 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){ 1545 const uint16_t message_len = 65; 1546 sm_cmac_connection = sm_conn; 1547 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1548 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1549 sm_cmac_sc_buffer[64] = z; 1550 log_info("f4 key"); 1551 log_info_hexdump(x, 16); 1552 log_info("f4 message"); 1553 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1554 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1555 } 1556 1557 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1558 static const uint8_t f5_length[] = { 0x01, 0x00}; 1559 1560 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1561 1562 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1563 1564 log_info("f5_calculate_salt"); 1565 // calculate salt for f5 1566 const uint16_t message_len = 32; 1567 sm_cmac_connection = sm_conn; 1568 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1569 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1570 } 1571 1572 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){ 1573 const uint16_t message_len = 53; 1574 sm_cmac_connection = sm_conn; 1575 1576 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1577 sm_cmac_sc_buffer[0] = 0; 1578 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1579 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1580 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1581 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1582 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1583 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1584 log_info("f5 key"); 1585 log_info_hexdump(t, 16); 1586 log_info("f5 message for MacKey"); 1587 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1588 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1589 } 1590 1591 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1592 sm_key56_t bd_addr_master, bd_addr_slave; 1593 bd_addr_master[0] = setup->sm_m_addr_type; 1594 bd_addr_slave[0] = setup->sm_s_addr_type; 1595 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1596 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1597 if (IS_RESPONDER(sm_conn->sm_role)){ 1598 // responder 1599 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1600 } else { 1601 // initiator 1602 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1603 } 1604 } 1605 1606 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1607 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1608 const uint16_t message_len = 53; 1609 sm_cmac_connection = sm_conn; 1610 sm_cmac_sc_buffer[0] = 1; 1611 // 1..52 setup before 1612 log_info("f5 key"); 1613 log_info_hexdump(t, 16); 1614 log_info("f5 message for LTK"); 1615 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1616 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1617 } 1618 1619 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1620 f5_ltk(sm_conn, setup->sm_t); 1621 } 1622 1623 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){ 1624 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1625 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1626 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1627 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1628 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1629 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1630 } 1631 1632 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1633 const uint16_t message_len = 65; 1634 sm_cmac_connection = sm_conn; 1635 log_info("f6 key"); 1636 log_info_hexdump(w, 16); 1637 log_info("f6 message"); 1638 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1639 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1640 } 1641 1642 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1643 // - U is 256 bits 1644 // - V is 256 bits 1645 // - X is 128 bits 1646 // - Y is 128 bits 1647 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){ 1648 const uint16_t message_len = 80; 1649 sm_cmac_connection = sm_conn; 1650 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1651 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1652 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1653 log_info("g2 key"); 1654 log_info_hexdump(x, 16); 1655 log_info("g2 message"); 1656 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1657 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1658 } 1659 1660 static void g2_calculate(sm_connection_t * sm_conn) { 1661 // calc Va if numeric comparison 1662 if (IS_RESPONDER(sm_conn->sm_role)){ 1663 // responder 1664 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1665 } else { 1666 // initiator 1667 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1668 } 1669 } 1670 1671 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1672 uint8_t z = 0; 1673 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1674 // some form of passkey 1675 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1676 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1677 setup->sm_passkey_bit++; 1678 } 1679 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1680 } 1681 1682 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1683 // OOB 1684 if (setup->sm_stk_generation_method == OOB){ 1685 if (IS_RESPONDER(sm_conn->sm_role)){ 1686 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1687 } else { 1688 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1689 } 1690 return; 1691 } 1692 1693 uint8_t z = 0; 1694 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1695 // some form of passkey 1696 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1697 // sm_passkey_bit was increased before sending confirm value 1698 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1699 } 1700 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1701 } 1702 1703 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1704 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1705 1706 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1707 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1708 return; 1709 } else { 1710 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1711 } 1712 } 1713 1714 static void sm_sc_dhkey_calculated(void * arg){ 1715 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1716 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1717 if (sm_conn == NULL) return; 1718 1719 log_info("dhkey"); 1720 log_info_hexdump(&setup->sm_dhkey[0], 32); 1721 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1722 // trigger next step 1723 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1724 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1725 } 1726 sm_trigger_run(); 1727 } 1728 1729 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1730 // calculate DHKCheck 1731 sm_key56_t bd_addr_master, bd_addr_slave; 1732 bd_addr_master[0] = setup->sm_m_addr_type; 1733 bd_addr_slave[0] = setup->sm_s_addr_type; 1734 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1735 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1736 uint8_t iocap_a[3]; 1737 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1738 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1739 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1740 uint8_t iocap_b[3]; 1741 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1742 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1743 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1744 if (IS_RESPONDER(sm_conn->sm_role)){ 1745 // responder 1746 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1747 f6_engine(sm_conn, setup->sm_mackey); 1748 } else { 1749 // initiator 1750 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1751 f6_engine(sm_conn, setup->sm_mackey); 1752 } 1753 } 1754 1755 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1756 // validate E = f6() 1757 sm_key56_t bd_addr_master, bd_addr_slave; 1758 bd_addr_master[0] = setup->sm_m_addr_type; 1759 bd_addr_slave[0] = setup->sm_s_addr_type; 1760 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1761 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1762 1763 uint8_t iocap_a[3]; 1764 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1765 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1766 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1767 uint8_t iocap_b[3]; 1768 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1769 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1770 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1771 if (IS_RESPONDER(sm_conn->sm_role)){ 1772 // responder 1773 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1774 f6_engine(sm_conn, setup->sm_mackey); 1775 } else { 1776 // initiator 1777 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1778 f6_engine(sm_conn, setup->sm_mackey); 1779 } 1780 } 1781 1782 1783 // 1784 // Link Key Conversion Function h6 1785 // 1786 // h6(W, keyID) = AES-CMACW(keyID) 1787 // - W is 128 bits 1788 // - keyID is 32 bits 1789 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1790 const uint16_t message_len = 4; 1791 sm_cmac_connection = sm_conn; 1792 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1793 log_info("h6 key"); 1794 log_info_hexdump(w, 16); 1795 log_info("h6 message"); 1796 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1797 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1798 } 1799 1800 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1801 // Errata Service Release to the Bluetooth Specification: ESR09 1802 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1803 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1804 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1805 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1806 } 1807 1808 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1809 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1810 } 1811 1812 #endif 1813 1814 // key management legacy connections: 1815 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1816 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1817 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1818 // - responder reconnects: responder uses LTK receveived from master 1819 1820 // key management secure connections: 1821 // - both devices store same LTK from ECDH key exchange. 1822 1823 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1824 static void sm_load_security_info(sm_connection_t * sm_connection){ 1825 int encryption_key_size; 1826 int authenticated; 1827 int authorized; 1828 int secure_connection; 1829 1830 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1831 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1832 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1833 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); 1834 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1835 sm_connection->sm_connection_authenticated = authenticated; 1836 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1837 sm_connection->sm_connection_sc = secure_connection; 1838 } 1839 #endif 1840 1841 #ifdef ENABLE_LE_PERIPHERAL 1842 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1843 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1844 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1845 // re-establish used key encryption size 1846 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1847 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 1848 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1849 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 1850 // Legacy paring -> not SC 1851 sm_connection->sm_connection_sc = 0; 1852 log_info("sm: received ltk request with key size %u, authenticated %u", 1853 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1854 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1855 sm_trigger_run(); 1856 } 1857 #endif 1858 1859 // distributed key generation 1860 static bool sm_run_dpkg(void){ 1861 switch (dkg_state){ 1862 case DKG_CALC_IRK: 1863 // already busy? 1864 if (sm_aes128_state == SM_AES128_IDLE) { 1865 log_info("DKG_CALC_IRK started"); 1866 // IRK = d1(IR, 1, 0) 1867 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1868 sm_aes128_state = SM_AES128_ACTIVE; 1869 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1870 return true; 1871 } 1872 break; 1873 case DKG_CALC_DHK: 1874 // already busy? 1875 if (sm_aes128_state == SM_AES128_IDLE) { 1876 log_info("DKG_CALC_DHK started"); 1877 // DHK = d1(IR, 3, 0) 1878 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1879 sm_aes128_state = SM_AES128_ACTIVE; 1880 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1881 return true; 1882 } 1883 break; 1884 default: 1885 break; 1886 } 1887 return false; 1888 } 1889 1890 // random address updates 1891 static bool sm_run_rau(void){ 1892 switch (rau_state){ 1893 case RAU_GET_RANDOM: 1894 rau_state = RAU_W4_RANDOM; 1895 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1896 return true; 1897 case RAU_GET_ENC: 1898 // already busy? 1899 if (sm_aes128_state == SM_AES128_IDLE) { 1900 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1901 sm_aes128_state = SM_AES128_ACTIVE; 1902 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1903 return true; 1904 } 1905 break; 1906 case RAU_SET_ADDRESS: 1907 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1908 rau_state = RAU_IDLE; 1909 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1910 return true; 1911 default: 1912 break; 1913 } 1914 return false; 1915 } 1916 1917 // CSRK Lookup 1918 static bool sm_run_csrk(void){ 1919 btstack_linked_list_iterator_t it; 1920 1921 // -- if csrk lookup ready, find connection that require csrk lookup 1922 if (sm_address_resolution_idle()){ 1923 hci_connections_get_iterator(&it); 1924 while(btstack_linked_list_iterator_has_next(&it)){ 1925 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1926 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1927 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1928 // and start lookup 1929 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); 1930 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1931 break; 1932 } 1933 } 1934 } 1935 1936 // -- if csrk lookup ready, resolved addresses for received addresses 1937 if (sm_address_resolution_idle()) { 1938 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1939 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1940 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1941 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1942 btstack_memory_sm_lookup_entry_free(entry); 1943 } 1944 } 1945 1946 // -- Continue with CSRK device lookup by public or resolvable private address 1947 if (!sm_address_resolution_idle()){ 1948 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1949 while (sm_address_resolution_test < le_device_db_max_count()){ 1950 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1951 bd_addr_t addr; 1952 sm_key_t irk; 1953 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1954 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1955 1956 // skip unused entries 1957 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1958 sm_address_resolution_test++; 1959 continue; 1960 } 1961 1962 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1963 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1964 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1965 break; 1966 } 1967 1968 // if connection type is public, it must be a different one 1969 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1970 sm_address_resolution_test++; 1971 continue; 1972 } 1973 1974 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1975 1976 log_info("LE Device Lookup: calculate AH"); 1977 log_info_key("IRK", irk); 1978 1979 (void)memcpy(sm_aes128_key, irk, 16); 1980 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1981 sm_address_resolution_ah_calculation_active = 1; 1982 sm_aes128_state = SM_AES128_ACTIVE; 1983 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1984 return true; 1985 } 1986 1987 if (sm_address_resolution_test >= le_device_db_max_count()){ 1988 log_info("LE Device Lookup: not found"); 1989 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1990 } 1991 } 1992 return false; 1993 } 1994 1995 // SC OOB 1996 static bool sm_run_oob(void){ 1997 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1998 switch (sm_sc_oob_state){ 1999 case SM_SC_OOB_W2_CALC_CONFIRM: 2000 if (!sm_cmac_ready()) break; 2001 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 2002 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 2003 return true; 2004 default: 2005 break; 2006 } 2007 #endif 2008 return false; 2009 } 2010 2011 // handle basic actions that don't requires the full context 2012 static bool sm_run_basic(void){ 2013 btstack_linked_list_iterator_t it; 2014 hci_connections_get_iterator(&it); 2015 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2016 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2017 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2018 switch(sm_connection->sm_engine_state){ 2019 // responder side 2020 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2021 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2022 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2023 return true; 2024 2025 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2026 case SM_SC_RECEIVED_LTK_REQUEST: 2027 switch (sm_connection->sm_irk_lookup_state){ 2028 case IRK_LOOKUP_FAILED: 2029 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2030 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2031 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2032 return true; 2033 default: 2034 break; 2035 } 2036 break; 2037 #endif 2038 default: 2039 break; 2040 } 2041 } 2042 return false; 2043 } 2044 2045 static void sm_run_activate_connection(void){ 2046 // Find connections that requires setup context and make active if no other is locked 2047 btstack_linked_list_iterator_t it; 2048 hci_connections_get_iterator(&it); 2049 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2050 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2051 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2052 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2053 int done = 1; 2054 int err; 2055 UNUSED(err); 2056 2057 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2058 // assert ec key is ready 2059 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2060 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2061 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2062 sm_ec_generate_new_key(); 2063 } 2064 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2065 continue; 2066 } 2067 } 2068 #endif 2069 2070 switch (sm_connection->sm_engine_state) { 2071 #ifdef ENABLE_LE_PERIPHERAL 2072 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2073 // send packet if possible, 2074 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2075 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2076 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2077 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2078 } else { 2079 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2080 } 2081 // don't lock sxetup context yet 2082 done = 0; 2083 break; 2084 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2085 sm_reset_setup(); 2086 sm_init_setup(sm_connection); 2087 // recover pairing request 2088 (void)memcpy(&setup->sm_m_preq, 2089 &sm_connection->sm_m_preq, 2090 sizeof(sm_pairing_packet_t)); 2091 err = sm_stk_generation_init(sm_connection); 2092 2093 #ifdef ENABLE_TESTING_SUPPORT 2094 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2095 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2096 err = test_pairing_failure; 2097 } 2098 #endif 2099 if (err){ 2100 setup->sm_pairing_failed_reason = err; 2101 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2102 break; 2103 } 2104 sm_timeout_start(sm_connection); 2105 // generate random number first, if we need to show passkey 2106 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2107 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) sm_connection->sm_handle); 2108 break; 2109 } 2110 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2111 break; 2112 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2113 sm_reset_setup(); 2114 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2115 break; 2116 2117 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2118 case SM_SC_RECEIVED_LTK_REQUEST: 2119 switch (sm_connection->sm_irk_lookup_state){ 2120 case IRK_LOOKUP_SUCCEEDED: 2121 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2122 // start using context by loading security info 2123 sm_reset_setup(); 2124 sm_load_security_info(sm_connection); 2125 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2126 (void)memcpy(setup->sm_ltk, 2127 setup->sm_peer_ltk, 16); 2128 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2129 break; 2130 } 2131 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2132 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2133 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2134 // don't lock setup context yet 2135 return; 2136 default: 2137 // just wait until IRK lookup is completed 2138 // don't lock setup context yet 2139 done = 0; 2140 break; 2141 } 2142 break; 2143 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2144 #endif /* ENABLE_LE_PERIPHERAL */ 2145 2146 #ifdef ENABLE_LE_CENTRAL 2147 case SM_INITIATOR_PH0_HAS_LTK: 2148 sm_reset_setup(); 2149 sm_load_security_info(sm_connection); 2150 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2151 break; 2152 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2153 sm_reset_setup(); 2154 sm_init_setup(sm_connection); 2155 sm_timeout_start(sm_connection); 2156 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2157 break; 2158 #endif 2159 2160 default: 2161 done = 0; 2162 break; 2163 } 2164 if (done){ 2165 sm_active_connection_handle = sm_connection->sm_handle; 2166 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); 2167 } 2168 } 2169 } 2170 2171 static void sm_run(void){ 2172 2173 // assert that stack has already bootet 2174 if (hci_get_state() != HCI_STATE_WORKING) return; 2175 2176 // assert that we can send at least commands 2177 if (!hci_can_send_command_packet_now()) return; 2178 2179 // pause until IR/ER are ready 2180 if (sm_persistent_keys_random_active) return; 2181 2182 bool done; 2183 2184 // 2185 // non-connection related behaviour 2186 // 2187 2188 done = sm_run_dpkg(); 2189 if (done) return; 2190 2191 done = sm_run_rau(); 2192 if (done) return; 2193 2194 done = sm_run_csrk(); 2195 if (done) return; 2196 2197 done = sm_run_oob(); 2198 if (done) return; 2199 2200 // assert that we can send at least commands - cmd might have been sent by crypto engine 2201 if (!hci_can_send_command_packet_now()) return; 2202 2203 // handle basic actions that don't requires the full context 2204 done = sm_run_basic(); 2205 if (done) return; 2206 2207 // 2208 // active connection handling 2209 // -- use loop to handle next connection if lock on setup context is released 2210 2211 while (true) { 2212 2213 sm_run_activate_connection(); 2214 2215 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2216 2217 // 2218 // active connection handling 2219 // 2220 2221 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2222 if (!connection) { 2223 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2224 return; 2225 } 2226 2227 // assert that we could send a SM PDU - not needed for all of the following 2228 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2229 log_info("cannot send now, requesting can send now event"); 2230 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2231 return; 2232 } 2233 2234 // send keypress notifications 2235 if (setup->sm_keypress_notification){ 2236 int i; 2237 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2238 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2239 uint8_t action = 0; 2240 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2241 if (flags & (1u<<i)){ 2242 int clear_flag = 1; 2243 switch (i){ 2244 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2245 case SM_KEYPRESS_PASSKEY_CLEARED: 2246 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2247 default: 2248 break; 2249 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2250 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2251 num_actions--; 2252 clear_flag = num_actions == 0u; 2253 break; 2254 } 2255 if (clear_flag){ 2256 flags &= ~(1<<i); 2257 } 2258 action = i; 2259 break; 2260 } 2261 } 2262 setup->sm_keypress_notification = (num_actions << 5) | flags; 2263 2264 // send keypress notification 2265 uint8_t buffer[2]; 2266 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2267 buffer[1] = action; 2268 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2269 2270 // try 2271 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2272 return; 2273 } 2274 2275 int key_distribution_flags; 2276 UNUSED(key_distribution_flags); 2277 2278 log_info("sm_run: state %u", connection->sm_engine_state); 2279 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2280 log_info("sm_run // cannot send"); 2281 } 2282 switch (connection->sm_engine_state){ 2283 2284 // general 2285 case SM_GENERAL_SEND_PAIRING_FAILED: { 2286 uint8_t buffer[2]; 2287 buffer[0] = SM_CODE_PAIRING_FAILED; 2288 buffer[1] = setup->sm_pairing_failed_reason; 2289 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2290 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2291 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2292 sm_done_for_handle(connection->sm_handle); 2293 break; 2294 } 2295 2296 // responding state 2297 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2298 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2299 if (!sm_cmac_ready()) break; 2300 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2301 sm_sc_calculate_local_confirm(connection); 2302 break; 2303 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2304 if (!sm_cmac_ready()) break; 2305 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2306 sm_sc_calculate_remote_confirm(connection); 2307 break; 2308 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2309 if (!sm_cmac_ready()) break; 2310 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2311 sm_sc_calculate_f6_for_dhkey_check(connection); 2312 break; 2313 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2314 if (!sm_cmac_ready()) break; 2315 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2316 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2317 break; 2318 case SM_SC_W2_CALCULATE_F5_SALT: 2319 if (!sm_cmac_ready()) break; 2320 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2321 f5_calculate_salt(connection); 2322 break; 2323 case SM_SC_W2_CALCULATE_F5_MACKEY: 2324 if (!sm_cmac_ready()) break; 2325 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2326 f5_calculate_mackey(connection); 2327 break; 2328 case SM_SC_W2_CALCULATE_F5_LTK: 2329 if (!sm_cmac_ready()) break; 2330 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2331 f5_calculate_ltk(connection); 2332 break; 2333 case SM_SC_W2_CALCULATE_G2: 2334 if (!sm_cmac_ready()) break; 2335 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2336 g2_calculate(connection); 2337 break; 2338 case SM_SC_W2_CALCULATE_H6_ILK: 2339 if (!sm_cmac_ready()) break; 2340 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2341 h6_calculate_ilk(connection); 2342 break; 2343 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2344 if (!sm_cmac_ready()) break; 2345 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2346 h6_calculate_br_edr_link_key(connection); 2347 break; 2348 #endif 2349 2350 #ifdef ENABLE_LE_CENTRAL 2351 // initiator side 2352 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2353 sm_key_t peer_ltk_flipped; 2354 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2355 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2356 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2357 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2358 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2359 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2360 return; 2361 } 2362 2363 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2364 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2365 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2366 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2367 sm_timeout_reset(connection); 2368 break; 2369 #endif 2370 2371 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2372 2373 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2374 int trigger_user_response = 0; 2375 int trigger_start_calculating_local_confirm = 0; 2376 uint8_t buffer[65]; 2377 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2378 // 2379 reverse_256(&ec_q[0], &buffer[1]); 2380 reverse_256(&ec_q[32], &buffer[33]); 2381 2382 #ifdef ENABLE_TESTING_SUPPORT 2383 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2384 log_info("testing_support: invalidating public key"); 2385 // flip single bit of public key coordinate 2386 buffer[1] ^= 1; 2387 } 2388 #endif 2389 2390 // stk generation method 2391 // passkey entry: notify app to show passkey or to request passkey 2392 switch (setup->sm_stk_generation_method){ 2393 case JUST_WORKS: 2394 case NUMERIC_COMPARISON: 2395 if (IS_RESPONDER(connection->sm_role)){ 2396 // responder 2397 trigger_start_calculating_local_confirm = 1; 2398 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2399 } else { 2400 // initiator 2401 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2402 } 2403 break; 2404 case PK_INIT_INPUT: 2405 case PK_RESP_INPUT: 2406 case PK_BOTH_INPUT: 2407 // use random TK for display 2408 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2409 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2410 setup->sm_passkey_bit = 0; 2411 2412 if (IS_RESPONDER(connection->sm_role)){ 2413 // responder 2414 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2415 } else { 2416 // initiator 2417 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2418 } 2419 trigger_user_response = 1; 2420 break; 2421 case OOB: 2422 if (IS_RESPONDER(connection->sm_role)){ 2423 // responder 2424 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2425 } else { 2426 // initiator 2427 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2428 } 2429 break; 2430 } 2431 2432 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2433 sm_timeout_reset(connection); 2434 2435 // trigger user response and calc confirm after sending pdu 2436 if (trigger_user_response){ 2437 sm_trigger_user_response(connection); 2438 } 2439 if (trigger_start_calculating_local_confirm){ 2440 sm_sc_start_calculating_local_confirm(connection); 2441 } 2442 break; 2443 } 2444 case SM_SC_SEND_CONFIRMATION: { 2445 uint8_t buffer[17]; 2446 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2447 reverse_128(setup->sm_local_confirm, &buffer[1]); 2448 if (IS_RESPONDER(connection->sm_role)){ 2449 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2450 } else { 2451 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2452 } 2453 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2454 sm_timeout_reset(connection); 2455 break; 2456 } 2457 case SM_SC_SEND_PAIRING_RANDOM: { 2458 uint8_t buffer[17]; 2459 buffer[0] = SM_CODE_PAIRING_RANDOM; 2460 reverse_128(setup->sm_local_nonce, &buffer[1]); 2461 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2462 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2463 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2464 if (IS_RESPONDER(connection->sm_role)){ 2465 // responder 2466 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2467 } else { 2468 // initiator 2469 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2470 } 2471 } else { 2472 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2473 if (IS_RESPONDER(connection->sm_role)){ 2474 // responder 2475 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2476 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2477 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2478 } else { 2479 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2480 sm_sc_prepare_dhkey_check(connection); 2481 } 2482 } else { 2483 // initiator 2484 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2485 } 2486 } 2487 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2488 sm_timeout_reset(connection); 2489 break; 2490 } 2491 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2492 uint8_t buffer[17]; 2493 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2494 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2495 2496 if (IS_RESPONDER(connection->sm_role)){ 2497 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2498 } else { 2499 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2500 } 2501 2502 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2503 sm_timeout_reset(connection); 2504 break; 2505 } 2506 2507 #endif 2508 2509 #ifdef ENABLE_LE_PERIPHERAL 2510 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2511 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2512 2513 // start with initiator key dist flags 2514 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2515 2516 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2517 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2518 if (setup->sm_use_secure_connections){ 2519 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2520 } 2521 #endif 2522 // setup in response 2523 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); 2524 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); 2525 2526 // update key distribution after ENC was dropped 2527 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2528 2529 if (setup->sm_use_secure_connections){ 2530 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2531 } else { 2532 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2533 } 2534 2535 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2536 sm_timeout_reset(connection); 2537 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2538 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2539 sm_trigger_user_response(connection); 2540 } 2541 return; 2542 #endif 2543 2544 case SM_PH2_SEND_PAIRING_RANDOM: { 2545 uint8_t buffer[17]; 2546 buffer[0] = SM_CODE_PAIRING_RANDOM; 2547 reverse_128(setup->sm_local_random, &buffer[1]); 2548 if (IS_RESPONDER(connection->sm_role)){ 2549 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2550 } else { 2551 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2552 } 2553 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2554 sm_timeout_reset(connection); 2555 break; 2556 } 2557 2558 case SM_PH2_C1_GET_ENC_A: 2559 // already busy? 2560 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2561 // calculate confirm using aes128 engine - step 1 2562 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); 2563 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2564 sm_aes128_state = SM_AES128_ACTIVE; 2565 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); 2566 break; 2567 2568 case SM_PH2_C1_GET_ENC_C: 2569 // already busy? 2570 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2571 // calculate m_confirm using aes128 engine - step 1 2572 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); 2573 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2574 sm_aes128_state = SM_AES128_ACTIVE; 2575 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); 2576 break; 2577 2578 case SM_PH2_CALC_STK: 2579 // already busy? 2580 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2581 // calculate STK 2582 if (IS_RESPONDER(connection->sm_role)){ 2583 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2584 } else { 2585 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2586 } 2587 connection->sm_engine_state = SM_PH2_W4_STK; 2588 sm_aes128_state = SM_AES128_ACTIVE; 2589 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); 2590 break; 2591 2592 case SM_PH3_Y_GET_ENC: 2593 // already busy? 2594 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2595 // PH3B2 - calculate Y from - enc 2596 2597 // dm helper (was sm_dm_r_prime) 2598 // r' = padding || r 2599 // r - 64 bit value 2600 memset(&sm_aes128_plaintext[0], 0, 8); 2601 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2602 2603 // Y = dm(DHK, Rand) 2604 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2605 sm_aes128_state = SM_AES128_ACTIVE; 2606 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); 2607 break; 2608 2609 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2610 uint8_t buffer[17]; 2611 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2612 reverse_128(setup->sm_local_confirm, &buffer[1]); 2613 if (IS_RESPONDER(connection->sm_role)){ 2614 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2615 } else { 2616 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2617 } 2618 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2619 sm_timeout_reset(connection); 2620 return; 2621 } 2622 #ifdef ENABLE_LE_PERIPHERAL 2623 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2624 sm_key_t stk_flipped; 2625 reverse_128(setup->sm_ltk, stk_flipped); 2626 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2627 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2628 return; 2629 } 2630 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2631 sm_key_t ltk_flipped; 2632 reverse_128(setup->sm_ltk, ltk_flipped); 2633 connection->sm_engine_state = SM_RESPONDER_IDLE; 2634 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2635 sm_done_for_handle(connection->sm_handle); 2636 return; 2637 } 2638 case SM_RESPONDER_PH4_Y_GET_ENC: 2639 // already busy? 2640 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2641 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2642 2643 // dm helper (was sm_dm_r_prime) 2644 // r' = padding || r 2645 // r - 64 bit value 2646 memset(&sm_aes128_plaintext[0], 0, 8); 2647 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2648 2649 // Y = dm(DHK, Rand) 2650 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2651 sm_aes128_state = SM_AES128_ACTIVE; 2652 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); 2653 return; 2654 #endif 2655 #ifdef ENABLE_LE_CENTRAL 2656 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2657 sm_key_t stk_flipped; 2658 reverse_128(setup->sm_ltk, stk_flipped); 2659 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2660 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2661 return; 2662 } 2663 #endif 2664 2665 case SM_PH3_DISTRIBUTE_KEYS: 2666 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2667 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2668 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2669 uint8_t buffer[17]; 2670 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2671 reverse_128(setup->sm_ltk, &buffer[1]); 2672 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2673 sm_timeout_reset(connection); 2674 return; 2675 } 2676 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2677 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2678 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2679 uint8_t buffer[11]; 2680 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2681 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2682 reverse_64(setup->sm_local_rand, &buffer[3]); 2683 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2684 sm_timeout_reset(connection); 2685 return; 2686 } 2687 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2688 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2689 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2690 uint8_t buffer[17]; 2691 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2692 reverse_128(sm_persistent_irk, &buffer[1]); 2693 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2694 sm_timeout_reset(connection); 2695 return; 2696 } 2697 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2698 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2699 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2700 bd_addr_t local_address; 2701 uint8_t buffer[8]; 2702 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2703 switch (gap_random_address_get_mode()){ 2704 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2705 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2706 // public or static random 2707 gap_le_get_own_address(&buffer[1], local_address); 2708 break; 2709 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2710 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2711 // fallback to public 2712 gap_local_bd_addr(local_address); 2713 buffer[1] = 0; 2714 break; 2715 } 2716 reverse_bd_addr(local_address, &buffer[2]); 2717 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2718 sm_timeout_reset(connection); 2719 return; 2720 } 2721 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2722 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2723 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2724 2725 #ifdef ENABLE_LE_SIGNED_WRITE 2726 // hack to reproduce test runs 2727 if (test_use_fixed_local_csrk){ 2728 memset(setup->sm_local_csrk, 0xcc, 16); 2729 } 2730 2731 // store local CSRK 2732 if (setup->sm_le_device_index >= 0){ 2733 log_info("sm: store local CSRK"); 2734 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2735 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2736 } 2737 #endif 2738 2739 uint8_t buffer[17]; 2740 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2741 reverse_128(setup->sm_local_csrk, &buffer[1]); 2742 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2743 sm_timeout_reset(connection); 2744 return; 2745 } 2746 2747 // keys are sent 2748 if (IS_RESPONDER(connection->sm_role)){ 2749 // slave -> receive master keys if any 2750 if (sm_key_distribution_all_received(connection)){ 2751 sm_key_distribution_handle_all_received(connection); 2752 connection->sm_engine_state = SM_RESPONDER_IDLE; 2753 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2754 sm_done_for_handle(connection->sm_handle); 2755 } else { 2756 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2757 } 2758 } else { 2759 sm_master_pairing_success(connection); 2760 } 2761 break; 2762 2763 default: 2764 break; 2765 } 2766 2767 // check again if active connection was released 2768 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2769 } 2770 } 2771 2772 // sm_aes128_state stays active 2773 static void sm_handle_encryption_result_enc_a(void *arg){ 2774 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2775 sm_aes128_state = SM_AES128_IDLE; 2776 2777 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2778 if (connection == NULL) return; 2779 2780 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2781 sm_aes128_state = SM_AES128_ACTIVE; 2782 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); 2783 } 2784 2785 static void sm_handle_encryption_result_enc_b(void *arg){ 2786 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2787 sm_aes128_state = SM_AES128_IDLE; 2788 2789 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2790 if (connection == NULL) return; 2791 2792 log_info_key("c1!", setup->sm_local_confirm); 2793 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2794 sm_trigger_run(); 2795 } 2796 2797 // sm_aes128_state stays active 2798 static void sm_handle_encryption_result_enc_c(void *arg){ 2799 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2800 sm_aes128_state = SM_AES128_IDLE; 2801 2802 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2803 if (connection == NULL) return; 2804 2805 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2806 sm_aes128_state = SM_AES128_ACTIVE; 2807 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); 2808 } 2809 2810 static void sm_handle_encryption_result_enc_d(void * arg){ 2811 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2812 sm_aes128_state = SM_AES128_IDLE; 2813 2814 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2815 if (connection == NULL) return; 2816 2817 log_info_key("c1!", sm_aes128_ciphertext); 2818 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2819 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2820 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2821 sm_trigger_run(); 2822 return; 2823 } 2824 if (IS_RESPONDER(connection->sm_role)){ 2825 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2826 sm_trigger_run(); 2827 } else { 2828 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2829 sm_aes128_state = SM_AES128_ACTIVE; 2830 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); 2831 } 2832 } 2833 2834 static void sm_handle_encryption_result_enc_stk(void *arg){ 2835 sm_aes128_state = SM_AES128_IDLE; 2836 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2837 2838 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2839 if (connection == NULL) return; 2840 2841 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2842 log_info_key("stk", setup->sm_ltk); 2843 if (IS_RESPONDER(connection->sm_role)){ 2844 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2845 } else { 2846 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2847 } 2848 sm_trigger_run(); 2849 } 2850 2851 // sm_aes128_state stays active 2852 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2853 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2854 sm_aes128_state = SM_AES128_IDLE; 2855 2856 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2857 if (connection == NULL) return; 2858 2859 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2860 log_info_hex16("y", setup->sm_local_y); 2861 // PH3B3 - calculate EDIV 2862 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2863 log_info_hex16("ediv", setup->sm_local_ediv); 2864 // PH3B4 - calculate LTK - enc 2865 // LTK = d1(ER, DIV, 0)) 2866 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2867 sm_aes128_state = SM_AES128_ACTIVE; 2868 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); 2869 } 2870 2871 #ifdef ENABLE_LE_PERIPHERAL 2872 // sm_aes128_state stays active 2873 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2874 sm_aes128_state = SM_AES128_IDLE; 2875 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2876 2877 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2878 if (connection == NULL) return; 2879 2880 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2881 log_info_hex16("y", setup->sm_local_y); 2882 2883 // PH3B3 - calculate DIV 2884 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2885 log_info_hex16("ediv", setup->sm_local_ediv); 2886 // PH3B4 - calculate LTK - enc 2887 // LTK = d1(ER, DIV, 0)) 2888 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2889 sm_aes128_state = SM_AES128_ACTIVE; 2890 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); 2891 } 2892 #endif 2893 2894 // sm_aes128_state stays active 2895 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2896 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2897 sm_aes128_state = SM_AES128_IDLE; 2898 2899 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2900 if (connection == NULL) return; 2901 2902 log_info_key("ltk", setup->sm_ltk); 2903 // calc CSRK next 2904 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2905 sm_aes128_state = SM_AES128_ACTIVE; 2906 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); 2907 } 2908 2909 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2910 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2911 sm_aes128_state = SM_AES128_IDLE; 2912 2913 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2914 if (connection == NULL) return; 2915 2916 sm_aes128_state = SM_AES128_IDLE; 2917 log_info_key("csrk", setup->sm_local_csrk); 2918 if (setup->sm_key_distribution_send_set){ 2919 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2920 } else { 2921 // no keys to send, just continue 2922 if (IS_RESPONDER(connection->sm_role)){ 2923 // slave -> receive master keys 2924 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2925 } else { 2926 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2927 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2928 } else { 2929 sm_master_pairing_success(connection); 2930 } 2931 } 2932 } 2933 sm_trigger_run(); 2934 } 2935 2936 #ifdef ENABLE_LE_PERIPHERAL 2937 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2938 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2939 sm_aes128_state = SM_AES128_IDLE; 2940 2941 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2942 if (connection == NULL) return; 2943 2944 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2945 log_info_key("ltk", setup->sm_ltk); 2946 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2947 sm_trigger_run(); 2948 } 2949 #endif 2950 2951 static void sm_handle_encryption_result_address_resolution(void *arg){ 2952 UNUSED(arg); 2953 sm_aes128_state = SM_AES128_IDLE; 2954 2955 sm_address_resolution_ah_calculation_active = 0; 2956 // compare calulated address against connecting device 2957 uint8_t * hash = &sm_aes128_ciphertext[13]; 2958 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2959 log_info("LE Device Lookup: matched resolvable private address"); 2960 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2961 sm_trigger_run(); 2962 return; 2963 } 2964 // no match, try next 2965 sm_address_resolution_test++; 2966 sm_trigger_run(); 2967 } 2968 2969 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2970 UNUSED(arg); 2971 sm_aes128_state = SM_AES128_IDLE; 2972 2973 log_info_key("irk", sm_persistent_irk); 2974 dkg_state = DKG_CALC_DHK; 2975 sm_trigger_run(); 2976 } 2977 2978 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2979 UNUSED(arg); 2980 sm_aes128_state = SM_AES128_IDLE; 2981 2982 log_info_key("dhk", sm_persistent_dhk); 2983 dkg_state = DKG_READY; 2984 sm_trigger_run(); 2985 } 2986 2987 static void sm_handle_encryption_result_rau(void *arg){ 2988 UNUSED(arg); 2989 sm_aes128_state = SM_AES128_IDLE; 2990 2991 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2992 rau_state = RAU_SET_ADDRESS; 2993 sm_trigger_run(); 2994 } 2995 2996 static void sm_handle_random_result_rau(void * arg){ 2997 UNUSED(arg); 2998 // non-resolvable vs. resolvable 2999 switch (gap_random_adress_type){ 3000 case GAP_RANDOM_ADDRESS_RESOLVABLE: 3001 // resolvable: use random as prand and calc address hash 3002 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 3003 sm_random_address[0u] &= 0x3fu; 3004 sm_random_address[0u] |= 0x40u; 3005 rau_state = RAU_GET_ENC; 3006 break; 3007 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 3008 default: 3009 // "The two most significant bits of the address shall be equal to ‘0’"" 3010 sm_random_address[0u] &= 0x3fu; 3011 rau_state = RAU_SET_ADDRESS; 3012 break; 3013 } 3014 sm_trigger_run(); 3015 } 3016 3017 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3018 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3019 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3020 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3021 if (connection == NULL) return; 3022 3023 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3024 sm_trigger_run(); 3025 } 3026 3027 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3028 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3029 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3030 if (connection == NULL) return; 3031 3032 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3033 sm_trigger_run(); 3034 } 3035 #endif 3036 3037 static void sm_handle_random_result_ph2_random(void * arg){ 3038 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3039 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3040 if (connection == NULL) return; 3041 3042 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3043 sm_trigger_run(); 3044 } 3045 3046 static void sm_handle_random_result_ph2_tk(void * arg){ 3047 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3048 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3049 if (connection == NULL) return; 3050 3051 sm_reset_tk(); 3052 uint32_t tk; 3053 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3054 // map random to 0-999999 without speding much cycles on a modulus operation 3055 tk = little_endian_read_32(sm_random_data,0); 3056 tk = tk & 0xfffff; // 1048575 3057 if (tk >= 999999u){ 3058 tk = tk - 999999u; 3059 } 3060 } else { 3061 // override with pre-defined passkey 3062 tk = sm_fixed_passkey_in_display_role; 3063 } 3064 big_endian_store_32(setup->sm_tk, 12, tk); 3065 if (IS_RESPONDER(connection->sm_role)){ 3066 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3067 } else { 3068 if (setup->sm_use_secure_connections){ 3069 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3070 } else { 3071 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3072 sm_trigger_user_response(connection); 3073 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3074 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3075 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); 3076 } 3077 } 3078 } 3079 sm_trigger_run(); 3080 } 3081 3082 static void sm_handle_random_result_ph3_div(void * arg){ 3083 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3084 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3085 if (connection == NULL) return; 3086 3087 // use 16 bit from random value as div 3088 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3089 log_info_hex16("div", setup->sm_local_div); 3090 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3091 sm_trigger_run(); 3092 } 3093 3094 static void sm_handle_random_result_ph3_random(void * arg){ 3095 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3096 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3097 if (connection == NULL) return; 3098 3099 reverse_64(sm_random_data, setup->sm_local_rand); 3100 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3101 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3102 // no db for authenticated flag hack: store flag in bit 4 of LSB 3103 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3104 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3105 } 3106 static void sm_validate_er_ir(void){ 3107 // warn about default ER/IR 3108 int warning = 0; 3109 if (sm_ir_is_default()){ 3110 warning = 1; 3111 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3112 } 3113 if (sm_er_is_default()){ 3114 warning = 1; 3115 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3116 } 3117 if (warning) { 3118 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3119 } 3120 } 3121 3122 static void sm_handle_random_result_ir(void *arg){ 3123 sm_persistent_keys_random_active = 0; 3124 if (arg){ 3125 // key generated, store in tlv 3126 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3127 log_info("Generated IR key. Store in TLV status: %d", status); 3128 } 3129 log_info_key("IR", sm_persistent_ir); 3130 dkg_state = DKG_CALC_IRK; 3131 3132 if (test_use_fixed_local_irk){ 3133 log_info_key("IRK", sm_persistent_irk); 3134 dkg_state = DKG_CALC_DHK; 3135 } 3136 3137 sm_trigger_run(); 3138 } 3139 3140 static void sm_handle_random_result_er(void *arg){ 3141 sm_persistent_keys_random_active = 0; 3142 if (arg){ 3143 // key generated, store in tlv 3144 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3145 log_info("Generated ER key. Store in TLV status: %d", status); 3146 } 3147 log_info_key("ER", sm_persistent_er); 3148 3149 // try load ir 3150 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3151 if (key_size == 16){ 3152 // ok, let's continue 3153 log_info("IR from TLV"); 3154 sm_handle_random_result_ir( NULL ); 3155 } else { 3156 // invalid, generate new random one 3157 sm_persistent_keys_random_active = 1; 3158 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3159 } 3160 } 3161 3162 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3163 3164 UNUSED(channel); // ok: there is no channel 3165 UNUSED(size); // ok: fixed format HCI events 3166 3167 sm_connection_t * sm_conn; 3168 hci_con_handle_t con_handle; 3169 3170 switch (packet_type) { 3171 3172 case HCI_EVENT_PACKET: 3173 switch (hci_event_packet_get_type(packet)) { 3174 3175 case BTSTACK_EVENT_STATE: 3176 // bt stack activated, get started 3177 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3178 log_info("HCI Working!"); 3179 3180 // setup IR/ER with TLV 3181 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3182 if (sm_tlv_impl){ 3183 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3184 if (key_size == 16){ 3185 // ok, let's continue 3186 log_info("ER from TLV"); 3187 sm_handle_random_result_er( NULL ); 3188 } else { 3189 // invalid, generate random one 3190 sm_persistent_keys_random_active = 1; 3191 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3192 } 3193 } else { 3194 sm_validate_er_ir(); 3195 dkg_state = DKG_CALC_IRK; 3196 3197 if (test_use_fixed_local_irk){ 3198 log_info_key("IRK", sm_persistent_irk); 3199 dkg_state = DKG_CALC_DHK; 3200 } 3201 } 3202 3203 // restart random address updates after power cycle 3204 gap_random_address_set_mode(gap_random_adress_type); 3205 } 3206 break; 3207 3208 case HCI_EVENT_LE_META: 3209 switch (packet[2]) { 3210 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3211 3212 log_info("sm: connected"); 3213 3214 if (packet[3]) return; // connection failed 3215 3216 con_handle = little_endian_read_16(packet, 4); 3217 sm_conn = sm_get_connection_for_handle(con_handle); 3218 if (!sm_conn) break; 3219 3220 sm_conn->sm_handle = con_handle; 3221 sm_conn->sm_role = packet[6]; 3222 sm_conn->sm_peer_addr_type = packet[7]; 3223 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3224 3225 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3226 3227 // reset security properties 3228 sm_conn->sm_connection_encrypted = 0; 3229 sm_conn->sm_connection_authenticated = 0; 3230 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3231 sm_conn->sm_le_db_index = -1; 3232 3233 // prepare CSRK lookup (does not involve setup) 3234 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3235 3236 // just connected -> everything else happens in sm_run() 3237 if (IS_RESPONDER(sm_conn->sm_role)){ 3238 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3239 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3240 if (sm_slave_request_security) { 3241 // request security if requested by app 3242 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3243 } else { 3244 // otherwise, wait for pairing request 3245 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3246 } 3247 } 3248 break; 3249 } else { 3250 // master 3251 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3252 } 3253 break; 3254 3255 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3256 con_handle = little_endian_read_16(packet, 3); 3257 sm_conn = sm_get_connection_for_handle(con_handle); 3258 if (!sm_conn) break; 3259 3260 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3261 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3262 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3263 break; 3264 } 3265 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3266 // PH2 SEND LTK as we need to exchange keys in PH3 3267 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3268 break; 3269 } 3270 3271 // store rand and ediv 3272 reverse_64(&packet[5], sm_conn->sm_local_rand); 3273 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3274 3275 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3276 // potentially stored LTK is from the master 3277 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3278 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3279 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3280 break; 3281 } 3282 // additionally check if remote is in LE Device DB if requested 3283 switch(sm_conn->sm_irk_lookup_state){ 3284 case IRK_LOOKUP_FAILED: 3285 log_info("LTK Request: device not in device db"); 3286 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3287 break; 3288 case IRK_LOOKUP_SUCCEEDED: 3289 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3290 break; 3291 default: 3292 // wait for irk look doen 3293 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3294 break; 3295 } 3296 break; 3297 } 3298 3299 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3300 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3301 #else 3302 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3303 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3304 #endif 3305 break; 3306 3307 default: 3308 break; 3309 } 3310 break; 3311 3312 case HCI_EVENT_ENCRYPTION_CHANGE: 3313 con_handle = little_endian_read_16(packet, 3); 3314 sm_conn = sm_get_connection_for_handle(con_handle); 3315 if (!sm_conn) break; 3316 3317 sm_conn->sm_connection_encrypted = packet[5]; 3318 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3319 sm_conn->sm_actual_encryption_key_size); 3320 log_info("event handler, state %u", sm_conn->sm_engine_state); 3321 3322 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3323 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3324 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3325 // notify client, if pairing was requested before 3326 if (sm_conn->sm_pairing_requested){ 3327 sm_conn->sm_pairing_requested = 0; 3328 if (sm_conn->sm_connection_encrypted){ 3329 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3330 } else { 3331 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3332 } 3333 } 3334 sm_done_for_handle(sm_conn->sm_handle); 3335 break; 3336 } 3337 3338 if (!sm_conn->sm_connection_encrypted) break; 3339 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3340 3341 // continue pairing 3342 switch (sm_conn->sm_engine_state){ 3343 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3344 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3345 sm_done_for_handle(sm_conn->sm_handle); 3346 break; 3347 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3348 if (IS_RESPONDER(sm_conn->sm_role)){ 3349 // slave 3350 if (setup->sm_use_secure_connections){ 3351 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3352 } else { 3353 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); 3354 } 3355 } else { 3356 // master 3357 if (sm_key_distribution_all_received(sm_conn)){ 3358 // skip receiving keys as there are none 3359 sm_key_distribution_handle_all_received(sm_conn); 3360 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); 3361 } else { 3362 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3363 } 3364 } 3365 break; 3366 default: 3367 break; 3368 } 3369 break; 3370 3371 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3372 con_handle = little_endian_read_16(packet, 3); 3373 sm_conn = sm_get_connection_for_handle(con_handle); 3374 if (!sm_conn) break; 3375 3376 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3377 log_info("event handler, state %u", sm_conn->sm_engine_state); 3378 // continue if part of initial pairing 3379 switch (sm_conn->sm_engine_state){ 3380 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3381 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3382 sm_done_for_handle(sm_conn->sm_handle); 3383 break; 3384 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3385 if (IS_RESPONDER(sm_conn->sm_role)){ 3386 // slave 3387 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); 3388 } else { 3389 // master 3390 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3391 } 3392 break; 3393 default: 3394 break; 3395 } 3396 break; 3397 3398 3399 case HCI_EVENT_DISCONNECTION_COMPLETE: 3400 con_handle = little_endian_read_16(packet, 3); 3401 sm_done_for_handle(con_handle); 3402 sm_conn = sm_get_connection_for_handle(con_handle); 3403 if (!sm_conn) break; 3404 3405 // delete stored bonding on disconnect with authentication failure in ph0 3406 if ((sm_conn->sm_role == 0u) 3407 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3408 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3409 le_device_db_remove(sm_conn->sm_le_db_index); 3410 } 3411 3412 // pairing failed, if it was ongoing 3413 switch (sm_conn->sm_engine_state){ 3414 case SM_GENERAL_IDLE: 3415 case SM_INITIATOR_CONNECTED: 3416 case SM_RESPONDER_IDLE: 3417 break; 3418 default: 3419 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3420 break; 3421 } 3422 3423 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3424 sm_conn->sm_handle = 0; 3425 break; 3426 3427 case HCI_EVENT_COMMAND_COMPLETE: 3428 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3429 // set local addr for le device db 3430 bd_addr_t addr; 3431 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3432 le_device_db_set_local_bd_addr(addr); 3433 } 3434 break; 3435 default: 3436 break; 3437 } 3438 break; 3439 default: 3440 break; 3441 } 3442 3443 sm_run(); 3444 } 3445 3446 static inline int sm_calc_actual_encryption_key_size(int other){ 3447 if (other < sm_min_encryption_key_size) return 0; 3448 if (other < sm_max_encryption_key_size) return other; 3449 return sm_max_encryption_key_size; 3450 } 3451 3452 3453 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3454 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3455 switch (method){ 3456 case JUST_WORKS: 3457 case NUMERIC_COMPARISON: 3458 return 1; 3459 default: 3460 return 0; 3461 } 3462 } 3463 // responder 3464 3465 static int sm_passkey_used(stk_generation_method_t method){ 3466 switch (method){ 3467 case PK_RESP_INPUT: 3468 return 1; 3469 default: 3470 return 0; 3471 } 3472 } 3473 3474 static int sm_passkey_entry(stk_generation_method_t method){ 3475 switch (method){ 3476 case PK_RESP_INPUT: 3477 case PK_INIT_INPUT: 3478 case PK_BOTH_INPUT: 3479 return 1; 3480 default: 3481 return 0; 3482 } 3483 } 3484 3485 #endif 3486 3487 /** 3488 * @return ok 3489 */ 3490 static int sm_validate_stk_generation_method(void){ 3491 // check if STK generation method is acceptable by client 3492 switch (setup->sm_stk_generation_method){ 3493 case JUST_WORKS: 3494 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 3495 case PK_RESP_INPUT: 3496 case PK_INIT_INPUT: 3497 case PK_BOTH_INPUT: 3498 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 3499 case OOB: 3500 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 3501 case NUMERIC_COMPARISON: 3502 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 3503 default: 3504 return 0; 3505 } 3506 } 3507 3508 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3509 3510 // size of complete sm_pdu used to validate input 3511 static const uint8_t sm_pdu_size[] = { 3512 0, // 0x00 invalid opcode 3513 7, // 0x01 pairing request 3514 7, // 0x02 pairing response 3515 17, // 0x03 pairing confirm 3516 17, // 0x04 pairing random 3517 2, // 0x05 pairing failed 3518 17, // 0x06 encryption information 3519 11, // 0x07 master identification 3520 17, // 0x08 identification information 3521 8, // 0x09 identify address information 3522 17, // 0x0a signing information 3523 2, // 0x0b security request 3524 65, // 0x0c pairing public key 3525 17, // 0x0d pairing dhk check 3526 2, // 0x0e keypress notification 3527 }; 3528 3529 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3530 sm_run(); 3531 } 3532 3533 if (packet_type != SM_DATA_PACKET) return; 3534 if (size == 0u) return; 3535 3536 uint8_t sm_pdu_code = packet[0]; 3537 3538 // validate pdu size 3539 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3540 if (sm_pdu_size[sm_pdu_code] != size) return; 3541 3542 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3543 if (!sm_conn) return; 3544 3545 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3546 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3547 sm_done_for_handle(con_handle); 3548 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3549 return; 3550 } 3551 3552 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3553 3554 int err; 3555 UNUSED(err); 3556 3557 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3558 uint8_t buffer[5]; 3559 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3560 buffer[1] = 3; 3561 little_endian_store_16(buffer, 2, con_handle); 3562 buffer[4] = packet[1]; 3563 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3564 return; 3565 } 3566 3567 switch (sm_conn->sm_engine_state){ 3568 3569 // a sm timeout requries a new physical connection 3570 case SM_GENERAL_TIMEOUT: 3571 return; 3572 3573 #ifdef ENABLE_LE_CENTRAL 3574 3575 // Initiator 3576 case SM_INITIATOR_CONNECTED: 3577 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3578 sm_pdu_received_in_wrong_state(sm_conn); 3579 break; 3580 } 3581 3582 // IRK complete? 3583 int have_ltk; 3584 uint8_t ltk[16]; 3585 switch (sm_conn->sm_irk_lookup_state){ 3586 case IRK_LOOKUP_FAILED: 3587 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3588 break; 3589 case IRK_LOOKUP_SUCCEEDED: 3590 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3591 have_ltk = !sm_is_null_key(ltk); 3592 log_info("central: security request - have_ltk %u", have_ltk); 3593 if (have_ltk){ 3594 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3595 } else { 3596 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3597 } 3598 break; 3599 default: 3600 break; 3601 } 3602 3603 // otherwise, store security request 3604 sm_conn->sm_security_request_received = 1; 3605 break; 3606 3607 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3608 // Core 5, Vol 3, Part H, 2.4.6: 3609 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3610 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3611 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3612 log_info("Ignoring Security Request"); 3613 break; 3614 } 3615 3616 // all other pdus are incorrect 3617 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3618 sm_pdu_received_in_wrong_state(sm_conn); 3619 break; 3620 } 3621 3622 // store pairing request 3623 (void)memcpy(&setup->sm_s_pres, packet, 3624 sizeof(sm_pairing_packet_t)); 3625 err = sm_stk_generation_init(sm_conn); 3626 3627 #ifdef ENABLE_TESTING_SUPPORT 3628 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3629 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3630 err = test_pairing_failure; 3631 } 3632 #endif 3633 3634 if (err){ 3635 setup->sm_pairing_failed_reason = err; 3636 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3637 break; 3638 } 3639 3640 // generate random number first, if we need to show passkey 3641 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3642 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); 3643 break; 3644 } 3645 3646 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3647 if (setup->sm_use_secure_connections){ 3648 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3649 if (setup->sm_stk_generation_method == JUST_WORKS){ 3650 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3651 sm_trigger_user_response(sm_conn); 3652 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3653 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3654 } 3655 } else { 3656 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3657 } 3658 break; 3659 } 3660 #endif 3661 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3662 sm_trigger_user_response(sm_conn); 3663 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3664 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3665 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); 3666 } 3667 break; 3668 3669 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3670 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3671 sm_pdu_received_in_wrong_state(sm_conn); 3672 break; 3673 } 3674 3675 // store s_confirm 3676 reverse_128(&packet[1], setup->sm_peer_confirm); 3677 3678 #ifdef ENABLE_TESTING_SUPPORT 3679 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3680 log_info("testing_support: reset confirm value"); 3681 memset(setup->sm_peer_confirm, 0, 16); 3682 } 3683 #endif 3684 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3685 break; 3686 3687 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3688 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3689 sm_pdu_received_in_wrong_state(sm_conn); 3690 break;; 3691 } 3692 3693 // received random value 3694 reverse_128(&packet[1], setup->sm_peer_random); 3695 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3696 break; 3697 #endif 3698 3699 #ifdef ENABLE_LE_PERIPHERAL 3700 // Responder 3701 case SM_RESPONDER_IDLE: 3702 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3703 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3704 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3705 sm_pdu_received_in_wrong_state(sm_conn); 3706 break;; 3707 } 3708 3709 // store pairing request 3710 (void)memcpy(&sm_conn->sm_m_preq, packet, 3711 sizeof(sm_pairing_packet_t)); 3712 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3713 break; 3714 #endif 3715 3716 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3717 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3718 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3719 sm_pdu_received_in_wrong_state(sm_conn); 3720 break; 3721 } 3722 3723 // store public key for DH Key calculation 3724 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3725 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3726 3727 // validate public key 3728 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3729 if (err){ 3730 log_error("sm: peer public key invalid %x", err); 3731 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3732 break; 3733 } 3734 3735 // start calculating dhkey 3736 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); 3737 3738 3739 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3740 if (IS_RESPONDER(sm_conn->sm_role)){ 3741 // responder 3742 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3743 } else { 3744 // initiator 3745 // stk generation method 3746 // passkey entry: notify app to show passkey or to request passkey 3747 switch (setup->sm_stk_generation_method){ 3748 case JUST_WORKS: 3749 case NUMERIC_COMPARISON: 3750 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3751 break; 3752 case PK_RESP_INPUT: 3753 sm_sc_start_calculating_local_confirm(sm_conn); 3754 break; 3755 case PK_INIT_INPUT: 3756 case PK_BOTH_INPUT: 3757 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3758 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3759 break; 3760 } 3761 sm_sc_start_calculating_local_confirm(sm_conn); 3762 break; 3763 case OOB: 3764 // generate Nx 3765 log_info("Generate Na"); 3766 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); 3767 break; 3768 } 3769 } 3770 break; 3771 3772 case SM_SC_W4_CONFIRMATION: 3773 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3774 sm_pdu_received_in_wrong_state(sm_conn); 3775 break; 3776 } 3777 // received confirm value 3778 reverse_128(&packet[1], setup->sm_peer_confirm); 3779 3780 #ifdef ENABLE_TESTING_SUPPORT 3781 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3782 log_info("testing_support: reset confirm value"); 3783 memset(setup->sm_peer_confirm, 0, 16); 3784 } 3785 #endif 3786 if (IS_RESPONDER(sm_conn->sm_role)){ 3787 // responder 3788 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3789 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3790 // still waiting for passkey 3791 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3792 break; 3793 } 3794 } 3795 sm_sc_start_calculating_local_confirm(sm_conn); 3796 } else { 3797 // initiator 3798 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3799 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); 3800 } else { 3801 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3802 } 3803 } 3804 break; 3805 3806 case SM_SC_W4_PAIRING_RANDOM: 3807 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3808 sm_pdu_received_in_wrong_state(sm_conn); 3809 break; 3810 } 3811 3812 // received random value 3813 reverse_128(&packet[1], setup->sm_peer_nonce); 3814 3815 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3816 // only check for JUST WORK/NC in initiator role OR passkey entry 3817 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 3818 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 3819 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 3820 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3821 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 3822 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3823 break; 3824 } 3825 3826 // OOB 3827 if (setup->sm_stk_generation_method == OOB){ 3828 3829 // setup local random, set to zero if remote did not receive our data 3830 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3831 if (IS_RESPONDER(sm_conn->sm_role)){ 3832 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 3833 log_info("Reset rb as A does not have OOB data"); 3834 memset(setup->sm_rb, 0, 16); 3835 } else { 3836 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3837 log_info("Use stored rb"); 3838 log_info_hexdump(setup->sm_rb, 16); 3839 } 3840 } else { 3841 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 3842 log_info("Reset ra as B does not have OOB data"); 3843 memset(setup->sm_ra, 0, 16); 3844 } else { 3845 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3846 log_info("Use stored ra"); 3847 log_info_hexdump(setup->sm_ra, 16); 3848 } 3849 } 3850 3851 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3852 if (setup->sm_have_oob_data){ 3853 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3854 break; 3855 } 3856 } 3857 3858 // TODO: we only get here for Responder role with JW/NC 3859 sm_sc_state_after_receiving_random(sm_conn); 3860 break; 3861 3862 case SM_SC_W2_CALCULATE_G2: 3863 case SM_SC_W4_CALCULATE_G2: 3864 case SM_SC_W4_CALCULATE_DHKEY: 3865 case SM_SC_W2_CALCULATE_F5_SALT: 3866 case SM_SC_W4_CALCULATE_F5_SALT: 3867 case SM_SC_W2_CALCULATE_F5_MACKEY: 3868 case SM_SC_W4_CALCULATE_F5_MACKEY: 3869 case SM_SC_W2_CALCULATE_F5_LTK: 3870 case SM_SC_W4_CALCULATE_F5_LTK: 3871 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3872 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3873 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3874 case SM_SC_W4_USER_RESPONSE: 3875 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3876 sm_pdu_received_in_wrong_state(sm_conn); 3877 break; 3878 } 3879 // store DHKey Check 3880 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3881 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3882 3883 // have we been only waiting for dhkey check command? 3884 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3885 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3886 } 3887 break; 3888 #endif 3889 3890 #ifdef ENABLE_LE_PERIPHERAL 3891 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3892 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3893 sm_pdu_received_in_wrong_state(sm_conn); 3894 break; 3895 } 3896 3897 // received confirm value 3898 reverse_128(&packet[1], setup->sm_peer_confirm); 3899 3900 #ifdef ENABLE_TESTING_SUPPORT 3901 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3902 log_info("testing_support: reset confirm value"); 3903 memset(setup->sm_peer_confirm, 0, 16); 3904 } 3905 #endif 3906 // notify client to hide shown passkey 3907 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3908 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3909 } 3910 3911 // handle user cancel pairing? 3912 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3913 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3914 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3915 break; 3916 } 3917 3918 // wait for user action? 3919 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3920 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3921 break; 3922 } 3923 3924 // calculate and send local_confirm 3925 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); 3926 break; 3927 3928 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3929 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3930 sm_pdu_received_in_wrong_state(sm_conn); 3931 break;; 3932 } 3933 3934 // received random value 3935 reverse_128(&packet[1], setup->sm_peer_random); 3936 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3937 break; 3938 #endif 3939 3940 case SM_PH3_RECEIVE_KEYS: 3941 switch(sm_pdu_code){ 3942 case SM_CODE_ENCRYPTION_INFORMATION: 3943 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3944 reverse_128(&packet[1], setup->sm_peer_ltk); 3945 break; 3946 3947 case SM_CODE_MASTER_IDENTIFICATION: 3948 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3949 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3950 reverse_64(&packet[3], setup->sm_peer_rand); 3951 break; 3952 3953 case SM_CODE_IDENTITY_INFORMATION: 3954 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3955 reverse_128(&packet[1], setup->sm_peer_irk); 3956 break; 3957 3958 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3959 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3960 setup->sm_peer_addr_type = packet[1]; 3961 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3962 break; 3963 3964 case SM_CODE_SIGNING_INFORMATION: 3965 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3966 reverse_128(&packet[1], setup->sm_peer_csrk); 3967 break; 3968 default: 3969 // Unexpected PDU 3970 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3971 break; 3972 } 3973 // done with key distribution? 3974 if (sm_key_distribution_all_received(sm_conn)){ 3975 3976 sm_key_distribution_handle_all_received(sm_conn); 3977 3978 if (IS_RESPONDER(sm_conn->sm_role)){ 3979 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3980 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3981 } else { 3982 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3983 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3984 sm_done_for_handle(sm_conn->sm_handle); 3985 } 3986 } else { 3987 if (setup->sm_use_secure_connections){ 3988 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3989 } else { 3990 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); 3991 } 3992 } 3993 } 3994 break; 3995 default: 3996 // Unexpected PDU 3997 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3998 break; 3999 } 4000 4001 // try to send next pdu 4002 sm_trigger_run(); 4003 } 4004 4005 // Security Manager Client API 4006 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 4007 sm_get_oob_data = get_oob_data_callback; 4008 } 4009 4010 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)){ 4011 sm_get_sc_oob_data = get_sc_oob_data_callback; 4012 } 4013 4014 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4015 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4016 } 4017 4018 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4019 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4020 } 4021 4022 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4023 sm_min_encryption_key_size = min_size; 4024 sm_max_encryption_key_size = max_size; 4025 } 4026 4027 void sm_set_authentication_requirements(uint8_t auth_req){ 4028 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4029 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4030 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4031 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4032 } 4033 #endif 4034 sm_auth_req = auth_req; 4035 } 4036 4037 void sm_set_io_capabilities(io_capability_t io_capability){ 4038 sm_io_capabilities = io_capability; 4039 } 4040 4041 #ifdef ENABLE_LE_PERIPHERAL 4042 void sm_set_request_security(int enable){ 4043 sm_slave_request_security = enable; 4044 } 4045 #endif 4046 4047 void sm_set_er(sm_key_t er){ 4048 (void)memcpy(sm_persistent_er, er, 16); 4049 } 4050 4051 void sm_set_ir(sm_key_t ir){ 4052 (void)memcpy(sm_persistent_ir, ir, 16); 4053 } 4054 4055 // Testing support only 4056 void sm_test_set_irk(sm_key_t irk){ 4057 (void)memcpy(sm_persistent_irk, irk, 16); 4058 dkg_state = DKG_CALC_DHK; 4059 test_use_fixed_local_irk = true; 4060 } 4061 4062 void sm_test_use_fixed_local_csrk(void){ 4063 test_use_fixed_local_csrk = true; 4064 } 4065 4066 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4067 static void sm_ec_generated(void * arg){ 4068 UNUSED(arg); 4069 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4070 // trigger pairing if pending for ec key 4071 sm_trigger_run(); 4072 } 4073 static void sm_ec_generate_new_key(void){ 4074 log_info("sm: generate new ec key"); 4075 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4076 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4077 } 4078 #endif 4079 4080 #ifdef ENABLE_TESTING_SUPPORT 4081 void sm_test_set_pairing_failure(int reason){ 4082 test_pairing_failure = reason; 4083 } 4084 #endif 4085 4086 void sm_init(void){ 4087 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4088 sm_er_ir_set_default(); 4089 4090 // defaults 4091 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4092 | SM_STK_GENERATION_METHOD_OOB 4093 | SM_STK_GENERATION_METHOD_PASSKEY 4094 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4095 4096 sm_max_encryption_key_size = 16; 4097 sm_min_encryption_key_size = 7; 4098 4099 sm_fixed_passkey_in_display_role = 0xffffffff; 4100 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4101 4102 #ifdef USE_CMAC_ENGINE 4103 sm_cmac_active = 0; 4104 #endif 4105 dkg_state = DKG_W4_WORKING; 4106 rau_state = RAU_IDLE; 4107 sm_aes128_state = SM_AES128_IDLE; 4108 sm_address_resolution_test = -1; // no private address to resolve yet 4109 sm_address_resolution_ah_calculation_active = 0; 4110 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4111 sm_address_resolution_general_queue = NULL; 4112 4113 gap_random_adress_update_period = 15 * 60 * 1000L; 4114 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4115 4116 test_use_fixed_local_csrk = false; 4117 4118 btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); 4119 4120 // register for HCI Events from HCI 4121 hci_event_callback_registration.callback = &sm_event_packet_handler; 4122 hci_add_event_handler(&hci_event_callback_registration); 4123 4124 // 4125 btstack_crypto_init(); 4126 4127 // init le_device_db 4128 le_device_db_init(); 4129 4130 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4131 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4132 4133 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4134 sm_ec_generate_new_key(); 4135 #endif 4136 } 4137 4138 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4139 sm_fixed_passkey_in_display_role = passkey; 4140 } 4141 4142 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4143 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4144 } 4145 4146 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4147 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4148 if (!hci_con) return NULL; 4149 return &hci_con->sm_connection; 4150 } 4151 4152 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4153 switch (sm_conn->sm_engine_state){ 4154 case SM_GENERAL_IDLE: 4155 case SM_RESPONDER_IDLE: 4156 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4157 sm_trigger_run(); 4158 break; 4159 default: 4160 break; 4161 } 4162 } 4163 4164 /** 4165 * @brief Trigger Security Request 4166 */ 4167 void sm_send_security_request(hci_con_handle_t con_handle){ 4168 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4169 if (!sm_conn) return; 4170 sm_send_security_request_for_connection(sm_conn); 4171 } 4172 4173 // request pairing 4174 void sm_request_pairing(hci_con_handle_t con_handle){ 4175 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4176 if (!sm_conn) return; // wrong connection 4177 4178 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4179 if (IS_RESPONDER(sm_conn->sm_role)){ 4180 sm_send_security_request_for_connection(sm_conn); 4181 } else { 4182 // used as a trigger to start central/master/initiator security procedures 4183 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4184 uint8_t ltk[16]; 4185 bool have_ltk; 4186 switch (sm_conn->sm_irk_lookup_state){ 4187 case IRK_LOOKUP_SUCCEEDED: 4188 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4189 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4190 have_ltk = !sm_is_null_key(ltk); 4191 log_info("have ltk %u", have_ltk); 4192 if (have_ltk){ 4193 sm_conn->sm_pairing_requested = 1; 4194 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4195 break; 4196 } 4197 #endif 4198 /* fall through */ 4199 4200 case IRK_LOOKUP_FAILED: 4201 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4202 break; 4203 default: 4204 log_info("irk lookup pending"); 4205 sm_conn->sm_pairing_requested = 1; 4206 break; 4207 } 4208 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4209 sm_conn->sm_pairing_requested = 1; 4210 } 4211 } 4212 sm_trigger_run(); 4213 } 4214 4215 // called by client app on authorization request 4216 void sm_authorization_decline(hci_con_handle_t con_handle){ 4217 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4218 if (!sm_conn) return; // wrong connection 4219 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4220 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4221 } 4222 4223 void sm_authorization_grant(hci_con_handle_t con_handle){ 4224 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4225 if (!sm_conn) return; // wrong connection 4226 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4227 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4228 } 4229 4230 // GAP Bonding API 4231 4232 void sm_bonding_decline(hci_con_handle_t con_handle){ 4233 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4234 if (!sm_conn) return; // wrong connection 4235 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4236 log_info("decline, state %u", sm_conn->sm_engine_state); 4237 switch(sm_conn->sm_engine_state){ 4238 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4239 case SM_SC_W4_USER_RESPONSE: 4240 case SM_SC_W4_CONFIRMATION: 4241 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4242 #endif 4243 case SM_PH1_W4_USER_RESPONSE: 4244 switch (setup->sm_stk_generation_method){ 4245 case PK_RESP_INPUT: 4246 case PK_INIT_INPUT: 4247 case PK_BOTH_INPUT: 4248 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4249 break; 4250 case NUMERIC_COMPARISON: 4251 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4252 break; 4253 case JUST_WORKS: 4254 case OOB: 4255 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4256 break; 4257 } 4258 break; 4259 default: 4260 break; 4261 } 4262 sm_trigger_run(); 4263 } 4264 4265 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4266 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4267 if (!sm_conn) return; // wrong connection 4268 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4269 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4270 if (setup->sm_use_secure_connections){ 4271 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4272 } else { 4273 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); 4274 } 4275 } 4276 4277 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4278 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4279 sm_sc_prepare_dhkey_check(sm_conn); 4280 } 4281 #endif 4282 4283 sm_trigger_run(); 4284 } 4285 4286 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4287 // for now, it's the same 4288 sm_just_works_confirm(con_handle); 4289 } 4290 4291 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4292 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4293 if (!sm_conn) return; // wrong connection 4294 sm_reset_tk(); 4295 big_endian_store_32(setup->sm_tk, 12, passkey); 4296 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4297 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4298 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); 4299 } 4300 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4301 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4302 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4303 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4304 sm_sc_start_calculating_local_confirm(sm_conn); 4305 } 4306 #endif 4307 sm_trigger_run(); 4308 } 4309 4310 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4311 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4312 if (!sm_conn) return; // wrong connection 4313 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4314 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4315 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 4316 switch (action){ 4317 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4318 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4319 flags |= (1u << action); 4320 break; 4321 case SM_KEYPRESS_PASSKEY_CLEARED: 4322 // clear counter, keypress & erased flags + set passkey cleared 4323 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 4324 break; 4325 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4326 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4327 // erase actions queued 4328 num_actions--; 4329 if (num_actions == 0u){ 4330 // clear counter, keypress & erased flags 4331 flags &= 0x19u; 4332 } 4333 break; 4334 } 4335 num_actions++; 4336 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4337 break; 4338 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4339 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4340 // enter actions queued 4341 num_actions--; 4342 if (num_actions == 0u){ 4343 // clear counter, keypress & erased flags 4344 flags &= 0x19u; 4345 } 4346 break; 4347 } 4348 num_actions++; 4349 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4350 break; 4351 default: 4352 break; 4353 } 4354 setup->sm_keypress_notification = (num_actions << 5) | flags; 4355 sm_trigger_run(); 4356 } 4357 4358 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4359 static void sm_handle_random_result_oob(void * arg){ 4360 UNUSED(arg); 4361 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4362 sm_trigger_run(); 4363 } 4364 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4365 4366 static btstack_crypto_random_t sm_crypto_random_oob_request; 4367 4368 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4369 sm_sc_oob_callback = callback; 4370 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4371 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4372 return 0; 4373 } 4374 #endif 4375 4376 /** 4377 * @brief Get Identity Resolving state 4378 * @param con_handle 4379 * @return irk_lookup_state_t 4380 */ 4381 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4382 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4383 if (!sm_conn) return IRK_LOOKUP_IDLE; 4384 return sm_conn->sm_irk_lookup_state; 4385 } 4386 4387 /** 4388 * @brief Identify device in LE Device DB 4389 * @param handle 4390 * @returns index from le_device_db or -1 if not found/identified 4391 */ 4392 int sm_le_device_index(hci_con_handle_t con_handle ){ 4393 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4394 if (!sm_conn) return -1; 4395 return sm_conn->sm_le_db_index; 4396 } 4397 4398 static int gap_random_address_type_requires_updates(void){ 4399 switch (gap_random_adress_type){ 4400 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4401 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4402 return 0; 4403 default: 4404 return 1; 4405 } 4406 } 4407 4408 static uint8_t own_address_type(void){ 4409 switch (gap_random_adress_type){ 4410 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4411 return BD_ADDR_TYPE_LE_PUBLIC; 4412 default: 4413 return BD_ADDR_TYPE_LE_RANDOM; 4414 } 4415 } 4416 4417 // GAP LE API 4418 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4419 gap_random_address_update_stop(); 4420 gap_random_adress_type = random_address_type; 4421 hci_le_set_own_address_type(own_address_type()); 4422 if (!gap_random_address_type_requires_updates()) return; 4423 gap_random_address_update_start(); 4424 gap_random_address_trigger(); 4425 } 4426 4427 gap_random_address_type_t gap_random_address_get_mode(void){ 4428 return gap_random_adress_type; 4429 } 4430 4431 void gap_random_address_set_update_period(int period_ms){ 4432 gap_random_adress_update_period = period_ms; 4433 if (!gap_random_address_type_requires_updates()) return; 4434 gap_random_address_update_stop(); 4435 gap_random_address_update_start(); 4436 } 4437 4438 void gap_random_address_set(const bd_addr_t addr){ 4439 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4440 (void)memcpy(sm_random_address, addr, 6); 4441 rau_state = RAU_SET_ADDRESS; 4442 sm_trigger_run(); 4443 } 4444 4445 #ifdef ENABLE_LE_PERIPHERAL 4446 /* 4447 * @brief Set Advertisement Paramters 4448 * @param adv_int_min 4449 * @param adv_int_max 4450 * @param adv_type 4451 * @param direct_address_type 4452 * @param direct_address 4453 * @param channel_map 4454 * @param filter_policy 4455 * 4456 * @note own_address_type is used from gap_random_address_set_mode 4457 */ 4458 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4459 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4460 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4461 direct_address_typ, direct_address, channel_map, filter_policy); 4462 } 4463 #endif 4464 4465 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4466 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4467 // wrong connection 4468 if (!sm_conn) return 0; 4469 // already encrypted 4470 if (sm_conn->sm_connection_encrypted) return 0; 4471 // only central can re-encrypt 4472 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4473 // irk status? 4474 switch(sm_conn->sm_irk_lookup_state){ 4475 case IRK_LOOKUP_FAILED: 4476 // done, cannot setup encryption 4477 return 0; 4478 case IRK_LOOKUP_SUCCEEDED: 4479 break; 4480 default: 4481 // IR Lookup pending 4482 return 1; 4483 } 4484 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4485 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4486 } 4487 4488 void sm_set_secure_connections_only_mode(bool enable){ 4489 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4490 sm_sc_only_mode = enable; 4491 #else 4492 // SC Only mode not possible without support for SC 4493 btstack_assert(enable == false); 4494 #endif 4495 } 4496 4497 const uint8_t * gap_get_persistent_irk(void){ 4498 return sm_persistent_irk; 4499 } 4500