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