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