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 } 1309 1310 if (le_db_index >= 0){ 1311 1312 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1313 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1314 1315 #ifdef ENABLE_LE_SIGNED_WRITE 1316 // store local CSRK 1317 setup->sm_le_device_index = le_db_index; 1318 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1319 log_info("sm: store local CSRK"); 1320 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1321 le_device_db_local_counter_set(le_db_index, 0); 1322 } 1323 1324 // store remote CSRK 1325 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1326 log_info("sm: store remote CSRK"); 1327 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1328 le_device_db_remote_counter_set(le_db_index, 0); 1329 } 1330 #endif 1331 // store encryption information for secure connections: LTK generated by ECDH 1332 if (setup->sm_use_secure_connections){ 1333 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1334 uint8_t zero_rand[8]; 1335 memset(zero_rand, 0, 8); 1336 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1337 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1338 } 1339 1340 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1341 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1342 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1343 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1344 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1345 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1346 1347 } 1348 } 1349 } else { 1350 log_info("Ignoring received keys, bonding not enabled"); 1351 } 1352 1353 // keep le_db_index 1354 sm_conn->sm_le_db_index = le_db_index; 1355 } 1356 1357 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1358 setup->sm_pairing_failed_reason = reason; 1359 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1360 } 1361 1362 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1363 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1364 } 1365 1366 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1367 1368 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1369 static int sm_passkey_used(stk_generation_method_t method); 1370 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1371 1372 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1373 if (setup->sm_stk_generation_method == OOB){ 1374 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1375 } else { 1376 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); 1377 } 1378 } 1379 1380 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1381 if (IS_RESPONDER(sm_conn->sm_role)){ 1382 // Responder 1383 if (setup->sm_stk_generation_method == OOB){ 1384 // generate Nb 1385 log_info("Generate Nb"); 1386 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); 1387 } else { 1388 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1389 } 1390 } else { 1391 // Initiator role 1392 switch (setup->sm_stk_generation_method){ 1393 case JUST_WORKS: 1394 sm_sc_prepare_dhkey_check(sm_conn); 1395 break; 1396 1397 case NUMERIC_COMPARISON: 1398 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1399 break; 1400 case PK_INIT_INPUT: 1401 case PK_RESP_INPUT: 1402 case PK_BOTH_INPUT: 1403 if (setup->sm_passkey_bit < 20u) { 1404 sm_sc_start_calculating_local_confirm(sm_conn); 1405 } else { 1406 sm_sc_prepare_dhkey_check(sm_conn); 1407 } 1408 break; 1409 case OOB: 1410 sm_sc_prepare_dhkey_check(sm_conn); 1411 break; 1412 } 1413 } 1414 } 1415 1416 static void sm_sc_cmac_done(uint8_t * hash){ 1417 log_info("sm_sc_cmac_done: "); 1418 log_info_hexdump(hash, 16); 1419 1420 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1421 sm_sc_oob_state = SM_SC_OOB_IDLE; 1422 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1423 return; 1424 } 1425 1426 sm_connection_t * sm_conn = sm_cmac_connection; 1427 sm_cmac_connection = NULL; 1428 #ifdef ENABLE_CLASSIC 1429 link_key_type_t link_key_type; 1430 #endif 1431 1432 switch (sm_conn->sm_engine_state){ 1433 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1434 (void)memcpy(setup->sm_local_confirm, hash, 16); 1435 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1436 break; 1437 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1438 // check 1439 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1440 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1441 break; 1442 } 1443 sm_sc_state_after_receiving_random(sm_conn); 1444 break; 1445 case SM_SC_W4_CALCULATE_G2: { 1446 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1447 big_endian_store_32(setup->sm_tk, 12, vab); 1448 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1449 sm_trigger_user_response(sm_conn); 1450 break; 1451 } 1452 case SM_SC_W4_CALCULATE_F5_SALT: 1453 (void)memcpy(setup->sm_t, hash, 16); 1454 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1455 break; 1456 case SM_SC_W4_CALCULATE_F5_MACKEY: 1457 (void)memcpy(setup->sm_mackey, hash, 16); 1458 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1459 break; 1460 case SM_SC_W4_CALCULATE_F5_LTK: 1461 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1462 // Errata Service Release to the Bluetooth Specification: ESR09 1463 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1464 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1465 (void)memcpy(setup->sm_ltk, hash, 16); 1466 (void)memcpy(setup->sm_local_ltk, hash, 16); 1467 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1468 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1469 break; 1470 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1471 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1472 if (IS_RESPONDER(sm_conn->sm_role)){ 1473 // responder 1474 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1475 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1476 } else { 1477 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1478 } 1479 } else { 1480 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1481 } 1482 break; 1483 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1484 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1485 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1486 break; 1487 } 1488 if (IS_RESPONDER(sm_conn->sm_role)){ 1489 // responder 1490 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1491 } else { 1492 // initiator 1493 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1494 } 1495 break; 1496 case SM_SC_W4_CALCULATE_H6_ILK: 1497 (void)memcpy(setup->sm_t, hash, 16); 1498 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1499 break; 1500 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1501 #ifdef ENABLE_CLASSIC 1502 reverse_128(hash, setup->sm_t); 1503 link_key_type = sm_conn->sm_connection_authenticated ? 1504 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1505 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1506 if (IS_RESPONDER(sm_conn->sm_role)){ 1507 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1508 } else { 1509 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1510 } 1511 #endif 1512 if (IS_RESPONDER(sm_conn->sm_role)){ 1513 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1514 } else { 1515 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1516 } 1517 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1518 sm_done_for_handle(sm_conn->sm_handle); 1519 break; 1520 default: 1521 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1522 break; 1523 } 1524 sm_run(); 1525 } 1526 1527 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){ 1528 const uint16_t message_len = 65; 1529 sm_cmac_connection = sm_conn; 1530 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1531 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1532 sm_cmac_sc_buffer[64] = z; 1533 log_info("f4 key"); 1534 log_info_hexdump(x, 16); 1535 log_info("f4 message"); 1536 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1537 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1538 } 1539 1540 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1541 static const uint8_t f5_length[] = { 0x01, 0x00}; 1542 1543 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1544 1545 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1546 1547 log_info("f5_calculate_salt"); 1548 // calculate salt for f5 1549 const uint16_t message_len = 32; 1550 sm_cmac_connection = sm_conn; 1551 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1552 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1553 } 1554 1555 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){ 1556 const uint16_t message_len = 53; 1557 sm_cmac_connection = sm_conn; 1558 1559 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1560 sm_cmac_sc_buffer[0] = 0; 1561 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1562 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1563 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1564 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1565 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1566 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1567 log_info("f5 key"); 1568 log_info_hexdump(t, 16); 1569 log_info("f5 message for MacKey"); 1570 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1571 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1572 } 1573 1574 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1575 sm_key56_t bd_addr_master, bd_addr_slave; 1576 bd_addr_master[0] = setup->sm_m_addr_type; 1577 bd_addr_slave[0] = setup->sm_s_addr_type; 1578 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1579 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1580 if (IS_RESPONDER(sm_conn->sm_role)){ 1581 // responder 1582 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1583 } else { 1584 // initiator 1585 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1586 } 1587 } 1588 1589 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1590 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1591 const uint16_t message_len = 53; 1592 sm_cmac_connection = sm_conn; 1593 sm_cmac_sc_buffer[0] = 1; 1594 // 1..52 setup before 1595 log_info("f5 key"); 1596 log_info_hexdump(t, 16); 1597 log_info("f5 message for LTK"); 1598 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1599 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1600 } 1601 1602 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1603 f5_ltk(sm_conn, setup->sm_t); 1604 } 1605 1606 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){ 1607 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1608 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1609 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1610 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1611 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1612 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1613 } 1614 1615 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1616 const uint16_t message_len = 65; 1617 sm_cmac_connection = sm_conn; 1618 log_info("f6 key"); 1619 log_info_hexdump(w, 16); 1620 log_info("f6 message"); 1621 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1622 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1623 } 1624 1625 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1626 // - U is 256 bits 1627 // - V is 256 bits 1628 // - X is 128 bits 1629 // - Y is 128 bits 1630 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){ 1631 const uint16_t message_len = 80; 1632 sm_cmac_connection = sm_conn; 1633 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1634 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1635 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1636 log_info("g2 key"); 1637 log_info_hexdump(x, 16); 1638 log_info("g2 message"); 1639 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1640 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1641 } 1642 1643 static void g2_calculate(sm_connection_t * sm_conn) { 1644 // calc Va if numeric comparison 1645 if (IS_RESPONDER(sm_conn->sm_role)){ 1646 // responder 1647 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1648 } else { 1649 // initiator 1650 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1651 } 1652 } 1653 1654 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1655 uint8_t z = 0; 1656 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1657 // some form of passkey 1658 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1659 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1660 setup->sm_passkey_bit++; 1661 } 1662 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1663 } 1664 1665 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1666 // OOB 1667 if (setup->sm_stk_generation_method == OOB){ 1668 if (IS_RESPONDER(sm_conn->sm_role)){ 1669 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1670 } else { 1671 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1672 } 1673 return; 1674 } 1675 1676 uint8_t z = 0; 1677 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1678 // some form of passkey 1679 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1680 // sm_passkey_bit was increased before sending confirm value 1681 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1682 } 1683 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1684 } 1685 1686 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1687 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1688 1689 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1690 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1691 return; 1692 } else { 1693 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1694 } 1695 } 1696 1697 static void sm_sc_dhkey_calculated(void * arg){ 1698 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1699 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1700 if (sm_conn == NULL) return; 1701 1702 log_info("dhkey"); 1703 log_info_hexdump(&setup->sm_dhkey[0], 32); 1704 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1705 // trigger next step 1706 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1707 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1708 } 1709 sm_run(); 1710 } 1711 1712 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1713 // calculate DHKCheck 1714 sm_key56_t bd_addr_master, bd_addr_slave; 1715 bd_addr_master[0] = setup->sm_m_addr_type; 1716 bd_addr_slave[0] = setup->sm_s_addr_type; 1717 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1718 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1719 uint8_t iocap_a[3]; 1720 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1721 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1722 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1723 uint8_t iocap_b[3]; 1724 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1725 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1726 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1727 if (IS_RESPONDER(sm_conn->sm_role)){ 1728 // responder 1729 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1730 f6_engine(sm_conn, setup->sm_mackey); 1731 } else { 1732 // initiator 1733 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1734 f6_engine(sm_conn, setup->sm_mackey); 1735 } 1736 } 1737 1738 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1739 // validate E = f6() 1740 sm_key56_t bd_addr_master, bd_addr_slave; 1741 bd_addr_master[0] = setup->sm_m_addr_type; 1742 bd_addr_slave[0] = setup->sm_s_addr_type; 1743 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1744 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1745 1746 uint8_t iocap_a[3]; 1747 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1748 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1749 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1750 uint8_t iocap_b[3]; 1751 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1752 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1753 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1754 if (IS_RESPONDER(sm_conn->sm_role)){ 1755 // responder 1756 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1757 f6_engine(sm_conn, setup->sm_mackey); 1758 } else { 1759 // initiator 1760 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1761 f6_engine(sm_conn, setup->sm_mackey); 1762 } 1763 } 1764 1765 1766 // 1767 // Link Key Conversion Function h6 1768 // 1769 // h6(W, keyID) = AES-CMACW(keyID) 1770 // - W is 128 bits 1771 // - keyID is 32 bits 1772 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1773 const uint16_t message_len = 4; 1774 sm_cmac_connection = sm_conn; 1775 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1776 log_info("h6 key"); 1777 log_info_hexdump(w, 16); 1778 log_info("h6 message"); 1779 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1780 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1781 } 1782 1783 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1784 // Errata Service Release to the Bluetooth Specification: ESR09 1785 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1786 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1787 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1788 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1789 } 1790 1791 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1792 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1793 } 1794 1795 #endif 1796 1797 // key management legacy connections: 1798 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1799 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1800 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1801 // - responder reconnects: responder uses LTK receveived from master 1802 1803 // key management secure connections: 1804 // - both devices store same LTK from ECDH key exchange. 1805 1806 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1807 static void sm_load_security_info(sm_connection_t * sm_connection){ 1808 int encryption_key_size; 1809 int authenticated; 1810 int authorized; 1811 int secure_connection; 1812 1813 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1814 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1815 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1816 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); 1817 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1818 sm_connection->sm_connection_authenticated = authenticated; 1819 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1820 sm_connection->sm_connection_sc = secure_connection; 1821 } 1822 #endif 1823 1824 #ifdef ENABLE_LE_PERIPHERAL 1825 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1826 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1827 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1828 // re-establish used key encryption size 1829 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1830 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 1831 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1832 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 1833 // Legacy paring -> not SC 1834 sm_connection->sm_connection_sc = 0; 1835 log_info("sm: received ltk request with key size %u, authenticated %u", 1836 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1837 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1838 sm_run(); 1839 } 1840 #endif 1841 1842 // distributed key generation 1843 static bool sm_run_dpkg(void){ 1844 switch (dkg_state){ 1845 case DKG_CALC_IRK: 1846 // already busy? 1847 if (sm_aes128_state == SM_AES128_IDLE) { 1848 log_info("DKG_CALC_IRK started"); 1849 // IRK = d1(IR, 1, 0) 1850 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1851 sm_aes128_state = SM_AES128_ACTIVE; 1852 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1853 return true; 1854 } 1855 break; 1856 case DKG_CALC_DHK: 1857 // already busy? 1858 if (sm_aes128_state == SM_AES128_IDLE) { 1859 log_info("DKG_CALC_DHK started"); 1860 // DHK = d1(IR, 3, 0) 1861 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1862 sm_aes128_state = SM_AES128_ACTIVE; 1863 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1864 return true; 1865 } 1866 break; 1867 default: 1868 break; 1869 } 1870 return false; 1871 } 1872 1873 // random address updates 1874 static bool sm_run_rau(void){ 1875 switch (rau_state){ 1876 case RAU_GET_RANDOM: 1877 rau_state = RAU_W4_RANDOM; 1878 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1879 return true; 1880 case RAU_GET_ENC: 1881 // already busy? 1882 if (sm_aes128_state == SM_AES128_IDLE) { 1883 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1884 sm_aes128_state = SM_AES128_ACTIVE; 1885 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1886 return true; 1887 } 1888 break; 1889 case RAU_SET_ADDRESS: 1890 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1891 rau_state = RAU_IDLE; 1892 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1893 return true; 1894 default: 1895 break; 1896 } 1897 return false; 1898 } 1899 1900 // CSRK Lookup 1901 static bool sm_run_csrk(void){ 1902 btstack_linked_list_iterator_t it; 1903 1904 // -- if csrk lookup ready, find connection that require csrk lookup 1905 if (sm_address_resolution_idle()){ 1906 hci_connections_get_iterator(&it); 1907 while(btstack_linked_list_iterator_has_next(&it)){ 1908 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1909 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1910 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1911 // and start lookup 1912 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); 1913 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1914 break; 1915 } 1916 } 1917 } 1918 1919 // -- if csrk lookup ready, resolved addresses for received addresses 1920 if (sm_address_resolution_idle()) { 1921 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1922 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1923 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1924 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1925 btstack_memory_sm_lookup_entry_free(entry); 1926 } 1927 } 1928 1929 // -- Continue with CSRK device lookup by public or resolvable private address 1930 if (!sm_address_resolution_idle()){ 1931 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1932 while (sm_address_resolution_test < le_device_db_max_count()){ 1933 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1934 bd_addr_t addr; 1935 sm_key_t irk; 1936 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1937 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1938 1939 // skip unused entries 1940 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1941 sm_address_resolution_test++; 1942 continue; 1943 } 1944 1945 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1946 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1947 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1948 break; 1949 } 1950 1951 // if connection type is public, it must be a different one 1952 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1953 sm_address_resolution_test++; 1954 continue; 1955 } 1956 1957 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1958 1959 log_info("LE Device Lookup: calculate AH"); 1960 log_info_key("IRK", irk); 1961 1962 (void)memcpy(sm_aes128_key, irk, 16); 1963 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1964 sm_address_resolution_ah_calculation_active = 1; 1965 sm_aes128_state = SM_AES128_ACTIVE; 1966 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1967 return true; 1968 } 1969 1970 if (sm_address_resolution_test >= le_device_db_max_count()){ 1971 log_info("LE Device Lookup: not found"); 1972 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1973 } 1974 } 1975 return false; 1976 } 1977 1978 // SC OOB 1979 static bool sm_run_oob(void){ 1980 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1981 switch (sm_sc_oob_state){ 1982 case SM_SC_OOB_W2_CALC_CONFIRM: 1983 if (!sm_cmac_ready()) break; 1984 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1985 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1986 return true; 1987 default: 1988 break; 1989 } 1990 #endif 1991 return false; 1992 } 1993 1994 // handle basic actions that don't requires the full context 1995 static bool sm_run_basic(void){ 1996 btstack_linked_list_iterator_t it; 1997 hci_connections_get_iterator(&it); 1998 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1999 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2000 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2001 switch(sm_connection->sm_engine_state){ 2002 // responder side 2003 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2004 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2005 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2006 return true; 2007 2008 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2009 case SM_SC_RECEIVED_LTK_REQUEST: 2010 switch (sm_connection->sm_irk_lookup_state){ 2011 case IRK_LOOKUP_FAILED: 2012 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2013 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2014 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2015 return true; 2016 default: 2017 break; 2018 } 2019 break; 2020 #endif 2021 default: 2022 break; 2023 } 2024 } 2025 return false; 2026 } 2027 2028 static void sm_run_activate_connection(void){ 2029 // Find connections that requires setup context and make active if no other is locked 2030 btstack_linked_list_iterator_t it; 2031 hci_connections_get_iterator(&it); 2032 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2033 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2034 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2035 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2036 int done = 1; 2037 int err; 2038 UNUSED(err); 2039 2040 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2041 // assert ec key is ready 2042 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2043 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2044 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2045 sm_ec_generate_new_key(); 2046 } 2047 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2048 continue; 2049 } 2050 } 2051 #endif 2052 2053 switch (sm_connection->sm_engine_state) { 2054 #ifdef ENABLE_LE_PERIPHERAL 2055 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2056 // send packet if possible, 2057 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2058 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2059 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2060 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2061 } else { 2062 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2063 } 2064 // don't lock sxetup context yet 2065 done = 0; 2066 break; 2067 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2068 sm_reset_setup(); 2069 sm_init_setup(sm_connection); 2070 // recover pairing request 2071 (void)memcpy(&setup->sm_m_preq, 2072 &sm_connection->sm_m_preq, 2073 sizeof(sm_pairing_packet_t)); 2074 err = sm_stk_generation_init(sm_connection); 2075 2076 #ifdef ENABLE_TESTING_SUPPORT 2077 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2078 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2079 err = test_pairing_failure; 2080 } 2081 #endif 2082 if (err){ 2083 setup->sm_pairing_failed_reason = err; 2084 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2085 break; 2086 } 2087 sm_timeout_start(sm_connection); 2088 // generate random number first, if we need to show passkey 2089 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2090 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); 2091 break; 2092 } 2093 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2094 break; 2095 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2096 sm_reset_setup(); 2097 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2098 break; 2099 2100 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2101 case SM_SC_RECEIVED_LTK_REQUEST: 2102 switch (sm_connection->sm_irk_lookup_state){ 2103 case IRK_LOOKUP_SUCCEEDED: 2104 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2105 // start using context by loading security info 2106 sm_reset_setup(); 2107 sm_load_security_info(sm_connection); 2108 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2109 (void)memcpy(setup->sm_ltk, 2110 setup->sm_peer_ltk, 16); 2111 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2112 break; 2113 } 2114 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2115 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2116 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2117 // don't lock setup context yet 2118 return; 2119 default: 2120 // just wait until IRK lookup is completed 2121 // don't lock setup context yet 2122 done = 0; 2123 break; 2124 } 2125 break; 2126 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2127 #endif /* ENABLE_LE_PERIPHERAL */ 2128 2129 #ifdef ENABLE_LE_CENTRAL 2130 case SM_INITIATOR_PH0_HAS_LTK: 2131 sm_reset_setup(); 2132 sm_load_security_info(sm_connection); 2133 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2134 break; 2135 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2136 sm_reset_setup(); 2137 sm_init_setup(sm_connection); 2138 sm_timeout_start(sm_connection); 2139 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2140 break; 2141 #endif 2142 2143 default: 2144 done = 0; 2145 break; 2146 } 2147 if (done){ 2148 sm_active_connection_handle = sm_connection->sm_handle; 2149 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); 2150 } 2151 } 2152 } 2153 2154 static void sm_run(void){ 2155 2156 // assert that stack has already bootet 2157 if (hci_get_state() != HCI_STATE_WORKING) return; 2158 2159 // assert that we can send at least commands 2160 if (!hci_can_send_command_packet_now()) return; 2161 2162 // pause until IR/ER are ready 2163 if (sm_persistent_keys_random_active) return; 2164 2165 bool done; 2166 2167 // 2168 // non-connection related behaviour 2169 // 2170 2171 done = sm_run_dpkg(); 2172 if (done) return; 2173 2174 done = sm_run_rau(); 2175 if (done) return; 2176 2177 done = sm_run_csrk(); 2178 if (done) return; 2179 2180 done = sm_run_oob(); 2181 if (done) return; 2182 2183 // assert that we can send at least commands - cmd might have been sent by crypto engine 2184 if (!hci_can_send_command_packet_now()) return; 2185 2186 // handle basic actions that don't requires the full context 2187 done = sm_run_basic(); 2188 if (done) return; 2189 2190 // 2191 // active connection handling 2192 // -- use loop to handle next connection if lock on setup context is released 2193 2194 while (true) { 2195 2196 sm_run_activate_connection(); 2197 2198 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2199 2200 // 2201 // active connection handling 2202 // 2203 2204 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2205 if (!connection) { 2206 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2207 return; 2208 } 2209 2210 // assert that we could send a SM PDU - not needed for all of the following 2211 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2212 log_info("cannot send now, requesting can send now event"); 2213 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2214 return; 2215 } 2216 2217 // send keypress notifications 2218 if (setup->sm_keypress_notification){ 2219 int i; 2220 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2221 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2222 uint8_t action = 0; 2223 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2224 if (flags & (1u<<i)){ 2225 int clear_flag = 1; 2226 switch (i){ 2227 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2228 case SM_KEYPRESS_PASSKEY_CLEARED: 2229 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2230 default: 2231 break; 2232 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2233 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2234 num_actions--; 2235 clear_flag = num_actions == 0u; 2236 break; 2237 } 2238 if (clear_flag){ 2239 flags &= ~(1<<i); 2240 } 2241 action = i; 2242 break; 2243 } 2244 } 2245 setup->sm_keypress_notification = (num_actions << 5) | flags; 2246 2247 // send keypress notification 2248 uint8_t buffer[2]; 2249 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2250 buffer[1] = action; 2251 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2252 2253 // try 2254 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2255 return; 2256 } 2257 2258 int key_distribution_flags; 2259 UNUSED(key_distribution_flags); 2260 2261 log_info("sm_run: state %u", connection->sm_engine_state); 2262 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2263 log_info("sm_run // cannot send"); 2264 } 2265 switch (connection->sm_engine_state){ 2266 2267 // general 2268 case SM_GENERAL_SEND_PAIRING_FAILED: { 2269 uint8_t buffer[2]; 2270 buffer[0] = SM_CODE_PAIRING_FAILED; 2271 buffer[1] = setup->sm_pairing_failed_reason; 2272 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2273 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2274 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2275 sm_done_for_handle(connection->sm_handle); 2276 break; 2277 } 2278 2279 // responding state 2280 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2281 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2282 if (!sm_cmac_ready()) break; 2283 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2284 sm_sc_calculate_local_confirm(connection); 2285 break; 2286 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2287 if (!sm_cmac_ready()) break; 2288 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2289 sm_sc_calculate_remote_confirm(connection); 2290 break; 2291 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2292 if (!sm_cmac_ready()) break; 2293 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2294 sm_sc_calculate_f6_for_dhkey_check(connection); 2295 break; 2296 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2297 if (!sm_cmac_ready()) break; 2298 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2299 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2300 break; 2301 case SM_SC_W2_CALCULATE_F5_SALT: 2302 if (!sm_cmac_ready()) break; 2303 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2304 f5_calculate_salt(connection); 2305 break; 2306 case SM_SC_W2_CALCULATE_F5_MACKEY: 2307 if (!sm_cmac_ready()) break; 2308 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2309 f5_calculate_mackey(connection); 2310 break; 2311 case SM_SC_W2_CALCULATE_F5_LTK: 2312 if (!sm_cmac_ready()) break; 2313 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2314 f5_calculate_ltk(connection); 2315 break; 2316 case SM_SC_W2_CALCULATE_G2: 2317 if (!sm_cmac_ready()) break; 2318 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2319 g2_calculate(connection); 2320 break; 2321 case SM_SC_W2_CALCULATE_H6_ILK: 2322 if (!sm_cmac_ready()) break; 2323 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2324 h6_calculate_ilk(connection); 2325 break; 2326 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2327 if (!sm_cmac_ready()) break; 2328 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2329 h6_calculate_br_edr_link_key(connection); 2330 break; 2331 #endif 2332 2333 #ifdef ENABLE_LE_CENTRAL 2334 // initiator side 2335 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2336 sm_key_t peer_ltk_flipped; 2337 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2338 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2339 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2340 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2341 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2342 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2343 return; 2344 } 2345 2346 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2347 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2348 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2349 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2350 sm_timeout_reset(connection); 2351 break; 2352 #endif 2353 2354 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2355 2356 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2357 int trigger_user_response = 0; 2358 int trigger_start_calculating_local_confirm = 0; 2359 uint8_t buffer[65]; 2360 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2361 // 2362 reverse_256(&ec_q[0], &buffer[1]); 2363 reverse_256(&ec_q[32], &buffer[33]); 2364 2365 #ifdef ENABLE_TESTING_SUPPORT 2366 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2367 log_info("testing_support: invalidating public key"); 2368 // flip single bit of public key coordinate 2369 buffer[1] ^= 1; 2370 } 2371 #endif 2372 2373 // stk generation method 2374 // passkey entry: notify app to show passkey or to request passkey 2375 switch (setup->sm_stk_generation_method){ 2376 case JUST_WORKS: 2377 case NUMERIC_COMPARISON: 2378 if (IS_RESPONDER(connection->sm_role)){ 2379 // responder 2380 trigger_start_calculating_local_confirm = 1; 2381 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2382 } else { 2383 // initiator 2384 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2385 } 2386 break; 2387 case PK_INIT_INPUT: 2388 case PK_RESP_INPUT: 2389 case PK_BOTH_INPUT: 2390 // use random TK for display 2391 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2392 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2393 setup->sm_passkey_bit = 0; 2394 2395 if (IS_RESPONDER(connection->sm_role)){ 2396 // responder 2397 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2398 } else { 2399 // initiator 2400 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2401 } 2402 trigger_user_response = 1; 2403 break; 2404 case OOB: 2405 if (IS_RESPONDER(connection->sm_role)){ 2406 // responder 2407 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2408 } else { 2409 // initiator 2410 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2411 } 2412 break; 2413 } 2414 2415 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2416 sm_timeout_reset(connection); 2417 2418 // trigger user response and calc confirm after sending pdu 2419 if (trigger_user_response){ 2420 sm_trigger_user_response(connection); 2421 } 2422 if (trigger_start_calculating_local_confirm){ 2423 sm_sc_start_calculating_local_confirm(connection); 2424 } 2425 break; 2426 } 2427 case SM_SC_SEND_CONFIRMATION: { 2428 uint8_t buffer[17]; 2429 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2430 reverse_128(setup->sm_local_confirm, &buffer[1]); 2431 if (IS_RESPONDER(connection->sm_role)){ 2432 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2433 } else { 2434 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2435 } 2436 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2437 sm_timeout_reset(connection); 2438 break; 2439 } 2440 case SM_SC_SEND_PAIRING_RANDOM: { 2441 uint8_t buffer[17]; 2442 buffer[0] = SM_CODE_PAIRING_RANDOM; 2443 reverse_128(setup->sm_local_nonce, &buffer[1]); 2444 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2445 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2446 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2447 if (IS_RESPONDER(connection->sm_role)){ 2448 // responder 2449 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2450 } else { 2451 // initiator 2452 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2453 } 2454 } else { 2455 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2456 if (IS_RESPONDER(connection->sm_role)){ 2457 // responder 2458 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2459 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2460 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2461 } else { 2462 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2463 sm_sc_prepare_dhkey_check(connection); 2464 } 2465 } else { 2466 // initiator 2467 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2468 } 2469 } 2470 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2471 sm_timeout_reset(connection); 2472 break; 2473 } 2474 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2475 uint8_t buffer[17]; 2476 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2477 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2478 2479 if (IS_RESPONDER(connection->sm_role)){ 2480 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2481 } else { 2482 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2483 } 2484 2485 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2486 sm_timeout_reset(connection); 2487 break; 2488 } 2489 2490 #endif 2491 2492 #ifdef ENABLE_LE_PERIPHERAL 2493 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2494 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2495 2496 // start with initiator key dist flags 2497 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2498 2499 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2500 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2501 if (setup->sm_use_secure_connections){ 2502 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2503 } 2504 #endif 2505 // setup in response 2506 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); 2507 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); 2508 2509 // update key distribution after ENC was dropped 2510 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2511 2512 if (setup->sm_use_secure_connections){ 2513 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2514 } else { 2515 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2516 } 2517 2518 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2519 sm_timeout_reset(connection); 2520 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2521 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2522 sm_trigger_user_response(connection); 2523 } 2524 return; 2525 #endif 2526 2527 case SM_PH2_SEND_PAIRING_RANDOM: { 2528 uint8_t buffer[17]; 2529 buffer[0] = SM_CODE_PAIRING_RANDOM; 2530 reverse_128(setup->sm_local_random, &buffer[1]); 2531 if (IS_RESPONDER(connection->sm_role)){ 2532 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2533 } else { 2534 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2535 } 2536 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2537 sm_timeout_reset(connection); 2538 break; 2539 } 2540 2541 case SM_PH2_C1_GET_ENC_A: 2542 // already busy? 2543 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2544 // calculate confirm using aes128 engine - step 1 2545 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); 2546 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2547 sm_aes128_state = SM_AES128_ACTIVE; 2548 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); 2549 break; 2550 2551 case SM_PH2_C1_GET_ENC_C: 2552 // already busy? 2553 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2554 // calculate m_confirm using aes128 engine - step 1 2555 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); 2556 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2557 sm_aes128_state = SM_AES128_ACTIVE; 2558 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); 2559 break; 2560 2561 case SM_PH2_CALC_STK: 2562 // already busy? 2563 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2564 // calculate STK 2565 if (IS_RESPONDER(connection->sm_role)){ 2566 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2567 } else { 2568 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2569 } 2570 connection->sm_engine_state = SM_PH2_W4_STK; 2571 sm_aes128_state = SM_AES128_ACTIVE; 2572 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); 2573 break; 2574 2575 case SM_PH3_Y_GET_ENC: 2576 // already busy? 2577 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2578 // PH3B2 - calculate Y from - enc 2579 2580 // dm helper (was sm_dm_r_prime) 2581 // r' = padding || r 2582 // r - 64 bit value 2583 memset(&sm_aes128_plaintext[0], 0, 8); 2584 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2585 2586 // Y = dm(DHK, Rand) 2587 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2588 sm_aes128_state = SM_AES128_ACTIVE; 2589 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); 2590 break; 2591 2592 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2593 uint8_t buffer[17]; 2594 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2595 reverse_128(setup->sm_local_confirm, &buffer[1]); 2596 if (IS_RESPONDER(connection->sm_role)){ 2597 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2598 } else { 2599 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2600 } 2601 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2602 sm_timeout_reset(connection); 2603 return; 2604 } 2605 #ifdef ENABLE_LE_PERIPHERAL 2606 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2607 sm_key_t stk_flipped; 2608 reverse_128(setup->sm_ltk, stk_flipped); 2609 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2610 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2611 return; 2612 } 2613 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2614 sm_key_t ltk_flipped; 2615 reverse_128(setup->sm_ltk, ltk_flipped); 2616 connection->sm_engine_state = SM_RESPONDER_IDLE; 2617 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2618 sm_done_for_handle(connection->sm_handle); 2619 return; 2620 } 2621 case SM_RESPONDER_PH4_Y_GET_ENC: 2622 // already busy? 2623 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2624 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2625 2626 // dm helper (was sm_dm_r_prime) 2627 // r' = padding || r 2628 // r - 64 bit value 2629 memset(&sm_aes128_plaintext[0], 0, 8); 2630 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2631 2632 // Y = dm(DHK, Rand) 2633 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2634 sm_aes128_state = SM_AES128_ACTIVE; 2635 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); 2636 return; 2637 #endif 2638 #ifdef ENABLE_LE_CENTRAL 2639 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2640 sm_key_t stk_flipped; 2641 reverse_128(setup->sm_ltk, stk_flipped); 2642 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2643 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2644 return; 2645 } 2646 #endif 2647 2648 case SM_PH3_DISTRIBUTE_KEYS: 2649 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2650 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2651 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2652 uint8_t buffer[17]; 2653 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2654 reverse_128(setup->sm_ltk, &buffer[1]); 2655 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2656 sm_timeout_reset(connection); 2657 return; 2658 } 2659 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2660 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2661 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2662 uint8_t buffer[11]; 2663 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2664 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2665 reverse_64(setup->sm_local_rand, &buffer[3]); 2666 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2667 sm_timeout_reset(connection); 2668 return; 2669 } 2670 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2671 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2672 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2673 uint8_t buffer[17]; 2674 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2675 reverse_128(sm_persistent_irk, &buffer[1]); 2676 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2677 sm_timeout_reset(connection); 2678 return; 2679 } 2680 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2681 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2682 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2683 bd_addr_t local_address; 2684 uint8_t buffer[8]; 2685 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2686 switch (gap_random_address_get_mode()){ 2687 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2688 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2689 // public or static random 2690 gap_le_get_own_address(&buffer[1], local_address); 2691 break; 2692 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2693 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2694 // fallback to public 2695 gap_local_bd_addr(local_address); 2696 buffer[1] = 0; 2697 break; 2698 } 2699 reverse_bd_addr(local_address, &buffer[2]); 2700 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2701 sm_timeout_reset(connection); 2702 return; 2703 } 2704 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2705 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2706 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2707 2708 #ifdef ENABLE_LE_SIGNED_WRITE 2709 // hack to reproduce test runs 2710 if (test_use_fixed_local_csrk){ 2711 memset(setup->sm_local_csrk, 0xcc, 16); 2712 } 2713 2714 // store local CSRK 2715 if (setup->sm_le_device_index >= 0){ 2716 log_info("sm: store local CSRK"); 2717 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2718 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2719 } 2720 #endif 2721 2722 uint8_t buffer[17]; 2723 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2724 reverse_128(setup->sm_local_csrk, &buffer[1]); 2725 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2726 sm_timeout_reset(connection); 2727 return; 2728 } 2729 2730 // keys are sent 2731 if (IS_RESPONDER(connection->sm_role)){ 2732 // slave -> receive master keys if any 2733 if (sm_key_distribution_all_received(connection)){ 2734 sm_key_distribution_handle_all_received(connection); 2735 connection->sm_engine_state = SM_RESPONDER_IDLE; 2736 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2737 sm_done_for_handle(connection->sm_handle); 2738 } else { 2739 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2740 } 2741 } else { 2742 sm_master_pairing_success(connection); 2743 } 2744 break; 2745 2746 default: 2747 break; 2748 } 2749 2750 // check again if active connection was released 2751 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2752 } 2753 } 2754 2755 // sm_aes128_state stays active 2756 static void sm_handle_encryption_result_enc_a(void *arg){ 2757 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2758 sm_aes128_state = SM_AES128_IDLE; 2759 2760 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2761 if (connection == NULL) return; 2762 2763 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2764 sm_aes128_state = SM_AES128_ACTIVE; 2765 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); 2766 } 2767 2768 static void sm_handle_encryption_result_enc_b(void *arg){ 2769 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2770 sm_aes128_state = SM_AES128_IDLE; 2771 2772 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2773 if (connection == NULL) return; 2774 2775 log_info_key("c1!", setup->sm_local_confirm); 2776 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2777 sm_run(); 2778 } 2779 2780 // sm_aes128_state stays active 2781 static void sm_handle_encryption_result_enc_c(void *arg){ 2782 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2783 sm_aes128_state = SM_AES128_IDLE; 2784 2785 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2786 if (connection == NULL) return; 2787 2788 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2789 sm_aes128_state = SM_AES128_ACTIVE; 2790 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); 2791 } 2792 2793 static void sm_handle_encryption_result_enc_d(void * arg){ 2794 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2795 sm_aes128_state = SM_AES128_IDLE; 2796 2797 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2798 if (connection == NULL) return; 2799 2800 log_info_key("c1!", sm_aes128_ciphertext); 2801 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2802 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2803 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2804 sm_run(); 2805 return; 2806 } 2807 if (IS_RESPONDER(connection->sm_role)){ 2808 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2809 sm_run(); 2810 } else { 2811 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2812 sm_aes128_state = SM_AES128_ACTIVE; 2813 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); 2814 } 2815 } 2816 2817 static void sm_handle_encryption_result_enc_stk(void *arg){ 2818 sm_aes128_state = SM_AES128_IDLE; 2819 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2820 2821 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2822 if (connection == NULL) return; 2823 2824 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2825 log_info_key("stk", setup->sm_ltk); 2826 if (IS_RESPONDER(connection->sm_role)){ 2827 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2828 } else { 2829 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2830 } 2831 sm_run(); 2832 } 2833 2834 // sm_aes128_state stays active 2835 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2836 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2837 sm_aes128_state = SM_AES128_IDLE; 2838 2839 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2840 if (connection == NULL) return; 2841 2842 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2843 log_info_hex16("y", setup->sm_local_y); 2844 // PH3B3 - calculate EDIV 2845 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2846 log_info_hex16("ediv", setup->sm_local_ediv); 2847 // PH3B4 - calculate LTK - enc 2848 // LTK = d1(ER, DIV, 0)) 2849 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2850 sm_aes128_state = SM_AES128_ACTIVE; 2851 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); 2852 } 2853 2854 #ifdef ENABLE_LE_PERIPHERAL 2855 // sm_aes128_state stays active 2856 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2857 sm_aes128_state = SM_AES128_IDLE; 2858 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2859 2860 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2861 if (connection == NULL) return; 2862 2863 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2864 log_info_hex16("y", setup->sm_local_y); 2865 2866 // PH3B3 - calculate DIV 2867 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2868 log_info_hex16("ediv", setup->sm_local_ediv); 2869 // PH3B4 - calculate LTK - enc 2870 // LTK = d1(ER, DIV, 0)) 2871 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2872 sm_aes128_state = SM_AES128_ACTIVE; 2873 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); 2874 } 2875 #endif 2876 2877 // sm_aes128_state stays active 2878 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2879 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2880 sm_aes128_state = SM_AES128_IDLE; 2881 2882 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2883 if (connection == NULL) return; 2884 2885 log_info_key("ltk", setup->sm_ltk); 2886 // calc CSRK next 2887 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2888 sm_aes128_state = SM_AES128_ACTIVE; 2889 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_local_csrk, sm_handle_encryption_result_enc_csrk, (void *)(uintptr_t) connection->sm_handle); 2890 } 2891 2892 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2893 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2894 sm_aes128_state = SM_AES128_IDLE; 2895 2896 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2897 if (connection == NULL) return; 2898 2899 sm_aes128_state = SM_AES128_IDLE; 2900 log_info_key("csrk", setup->sm_local_csrk); 2901 if (setup->sm_key_distribution_send_set){ 2902 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2903 } else { 2904 // no keys to send, just continue 2905 if (IS_RESPONDER(connection->sm_role)){ 2906 // slave -> receive master keys 2907 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2908 } else { 2909 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2910 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2911 } else { 2912 sm_master_pairing_success(connection); 2913 } 2914 } 2915 } 2916 sm_run(); 2917 } 2918 2919 #ifdef ENABLE_LE_PERIPHERAL 2920 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2921 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2922 sm_aes128_state = SM_AES128_IDLE; 2923 2924 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2925 if (connection == NULL) return; 2926 2927 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2928 log_info_key("ltk", setup->sm_ltk); 2929 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2930 sm_run(); 2931 } 2932 #endif 2933 2934 static void sm_handle_encryption_result_address_resolution(void *arg){ 2935 UNUSED(arg); 2936 sm_aes128_state = SM_AES128_IDLE; 2937 2938 sm_address_resolution_ah_calculation_active = 0; 2939 // compare calulated address against connecting device 2940 uint8_t * hash = &sm_aes128_ciphertext[13]; 2941 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2942 log_info("LE Device Lookup: matched resolvable private address"); 2943 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2944 sm_run(); 2945 return; 2946 } 2947 // no match, try next 2948 sm_address_resolution_test++; 2949 sm_run(); 2950 } 2951 2952 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2953 UNUSED(arg); 2954 sm_aes128_state = SM_AES128_IDLE; 2955 2956 log_info_key("irk", sm_persistent_irk); 2957 dkg_state = DKG_CALC_DHK; 2958 sm_run(); 2959 } 2960 2961 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2962 UNUSED(arg); 2963 sm_aes128_state = SM_AES128_IDLE; 2964 2965 log_info_key("dhk", sm_persistent_dhk); 2966 dkg_state = DKG_READY; 2967 sm_run(); 2968 } 2969 2970 static void sm_handle_encryption_result_rau(void *arg){ 2971 UNUSED(arg); 2972 sm_aes128_state = SM_AES128_IDLE; 2973 2974 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2975 rau_state = RAU_SET_ADDRESS; 2976 sm_run(); 2977 } 2978 2979 static void sm_handle_random_result_rau(void * arg){ 2980 UNUSED(arg); 2981 // non-resolvable vs. resolvable 2982 switch (gap_random_adress_type){ 2983 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2984 // resolvable: use random as prand and calc address hash 2985 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2986 sm_random_address[0u] &= 0x3fu; 2987 sm_random_address[0u] |= 0x40u; 2988 rau_state = RAU_GET_ENC; 2989 break; 2990 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2991 default: 2992 // "The two most significant bits of the address shall be equal to ‘0’"" 2993 sm_random_address[0u] &= 0x3fu; 2994 rau_state = RAU_SET_ADDRESS; 2995 break; 2996 } 2997 sm_run(); 2998 } 2999 3000 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3001 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3002 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3003 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3004 if (connection == NULL) return; 3005 3006 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3007 sm_run(); 3008 } 3009 3010 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3011 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3012 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3013 if (connection == NULL) return; 3014 3015 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3016 sm_run(); 3017 } 3018 #endif 3019 3020 static void sm_handle_random_result_ph2_random(void * arg){ 3021 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3022 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3023 if (connection == NULL) return; 3024 3025 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3026 sm_run(); 3027 } 3028 3029 static void sm_handle_random_result_ph2_tk(void * arg){ 3030 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3031 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3032 if (connection == NULL) return; 3033 3034 sm_reset_tk(); 3035 uint32_t tk; 3036 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3037 // map random to 0-999999 without speding much cycles on a modulus operation 3038 tk = little_endian_read_32(sm_random_data,0); 3039 tk = tk & 0xfffff; // 1048575 3040 if (tk >= 999999u){ 3041 tk = tk - 999999u; 3042 } 3043 } else { 3044 // override with pre-defined passkey 3045 tk = sm_fixed_passkey_in_display_role; 3046 } 3047 big_endian_store_32(setup->sm_tk, 12, tk); 3048 if (IS_RESPONDER(connection->sm_role)){ 3049 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3050 } else { 3051 if (setup->sm_use_secure_connections){ 3052 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3053 } else { 3054 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3055 sm_trigger_user_response(connection); 3056 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3057 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3058 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); 3059 } 3060 } 3061 } 3062 sm_run(); 3063 } 3064 3065 static void sm_handle_random_result_ph3_div(void * arg){ 3066 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3067 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3068 if (connection == NULL) return; 3069 3070 // use 16 bit from random value as div 3071 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3072 log_info_hex16("div", setup->sm_local_div); 3073 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3074 sm_run(); 3075 } 3076 3077 static void sm_handle_random_result_ph3_random(void * arg){ 3078 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3079 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3080 if (connection == NULL) return; 3081 3082 reverse_64(sm_random_data, setup->sm_local_rand); 3083 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3084 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3085 // no db for authenticated flag hack: store flag in bit 4 of LSB 3086 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3087 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3088 } 3089 static void sm_validate_er_ir(void){ 3090 // warn about default ER/IR 3091 int warning = 0; 3092 if (sm_ir_is_default()){ 3093 warning = 1; 3094 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3095 } 3096 if (sm_er_is_default()){ 3097 warning = 1; 3098 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3099 } 3100 if (warning) { 3101 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3102 } 3103 } 3104 3105 static void sm_handle_random_result_ir(void *arg){ 3106 sm_persistent_keys_random_active = 0; 3107 if (arg){ 3108 // key generated, store in tlv 3109 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3110 log_info("Generated IR key. Store in TLV status: %d", status); 3111 } 3112 log_info_key("IR", sm_persistent_ir); 3113 dkg_state = DKG_CALC_IRK; 3114 3115 if (test_use_fixed_local_irk){ 3116 log_info_key("IRK", sm_persistent_irk); 3117 dkg_state = DKG_CALC_DHK; 3118 } 3119 3120 sm_run(); 3121 } 3122 3123 static void sm_handle_random_result_er(void *arg){ 3124 sm_persistent_keys_random_active = 0; 3125 if (arg){ 3126 // key generated, store in tlv 3127 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3128 log_info("Generated ER key. Store in TLV status: %d", status); 3129 } 3130 log_info_key("ER", sm_persistent_er); 3131 3132 // try load ir 3133 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3134 if (key_size == 16){ 3135 // ok, let's continue 3136 log_info("IR from TLV"); 3137 sm_handle_random_result_ir( NULL ); 3138 } else { 3139 // invalid, generate new random one 3140 sm_persistent_keys_random_active = 1; 3141 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3142 } 3143 } 3144 3145 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3146 3147 UNUSED(channel); // ok: there is no channel 3148 UNUSED(size); // ok: fixed format HCI events 3149 3150 sm_connection_t * sm_conn; 3151 hci_con_handle_t con_handle; 3152 3153 switch (packet_type) { 3154 3155 case HCI_EVENT_PACKET: 3156 switch (hci_event_packet_get_type(packet)) { 3157 3158 case BTSTACK_EVENT_STATE: 3159 // bt stack activated, get started 3160 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3161 log_info("HCI Working!"); 3162 3163 // setup IR/ER with TLV 3164 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3165 if (sm_tlv_impl){ 3166 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3167 if (key_size == 16){ 3168 // ok, let's continue 3169 log_info("ER from TLV"); 3170 sm_handle_random_result_er( NULL ); 3171 } else { 3172 // invalid, generate random one 3173 sm_persistent_keys_random_active = 1; 3174 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3175 } 3176 } else { 3177 sm_validate_er_ir(); 3178 dkg_state = DKG_CALC_IRK; 3179 3180 if (test_use_fixed_local_irk){ 3181 log_info_key("IRK", sm_persistent_irk); 3182 dkg_state = DKG_CALC_DHK; 3183 } 3184 } 3185 3186 // restart random address updates after power cycle 3187 gap_random_address_set_mode(gap_random_adress_type); 3188 } 3189 break; 3190 3191 case HCI_EVENT_LE_META: 3192 switch (packet[2]) { 3193 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3194 3195 log_info("sm: connected"); 3196 3197 if (packet[3]) return; // connection failed 3198 3199 con_handle = little_endian_read_16(packet, 4); 3200 sm_conn = sm_get_connection_for_handle(con_handle); 3201 if (!sm_conn) break; 3202 3203 sm_conn->sm_handle = con_handle; 3204 sm_conn->sm_role = packet[6]; 3205 sm_conn->sm_peer_addr_type = packet[7]; 3206 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3207 3208 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3209 3210 // reset security properties 3211 sm_conn->sm_connection_encrypted = 0; 3212 sm_conn->sm_connection_authenticated = 0; 3213 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3214 sm_conn->sm_le_db_index = -1; 3215 3216 // prepare CSRK lookup (does not involve setup) 3217 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3218 3219 // just connected -> everything else happens in sm_run() 3220 if (IS_RESPONDER(sm_conn->sm_role)){ 3221 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3222 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3223 if (sm_slave_request_security) { 3224 // request security if requested by app 3225 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3226 } else { 3227 // otherwise, wait for pairing request 3228 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3229 } 3230 } 3231 break; 3232 } else { 3233 // master 3234 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3235 } 3236 break; 3237 3238 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3239 con_handle = little_endian_read_16(packet, 3); 3240 sm_conn = sm_get_connection_for_handle(con_handle); 3241 if (!sm_conn) break; 3242 3243 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3244 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3245 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3246 break; 3247 } 3248 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3249 // PH2 SEND LTK as we need to exchange keys in PH3 3250 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3251 break; 3252 } 3253 3254 // store rand and ediv 3255 reverse_64(&packet[5], sm_conn->sm_local_rand); 3256 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3257 3258 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3259 // potentially stored LTK is from the master 3260 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3261 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3262 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3263 break; 3264 } 3265 // additionally check if remote is in LE Device DB if requested 3266 switch(sm_conn->sm_irk_lookup_state){ 3267 case IRK_LOOKUP_FAILED: 3268 log_info("LTK Request: device not in device db"); 3269 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3270 break; 3271 case IRK_LOOKUP_SUCCEEDED: 3272 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3273 break; 3274 default: 3275 // wait for irk look doen 3276 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3277 break; 3278 } 3279 break; 3280 } 3281 3282 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3283 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3284 #else 3285 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3286 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3287 #endif 3288 break; 3289 3290 default: 3291 break; 3292 } 3293 break; 3294 3295 case HCI_EVENT_ENCRYPTION_CHANGE: 3296 con_handle = little_endian_read_16(packet, 3); 3297 sm_conn = sm_get_connection_for_handle(con_handle); 3298 if (!sm_conn) break; 3299 3300 sm_conn->sm_connection_encrypted = packet[5]; 3301 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3302 sm_conn->sm_actual_encryption_key_size); 3303 log_info("event handler, state %u", sm_conn->sm_engine_state); 3304 3305 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3306 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3307 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3308 // notify client, if pairing was requested before 3309 if (sm_conn->sm_pairing_requested){ 3310 sm_conn->sm_pairing_requested = 0; 3311 if (sm_conn->sm_connection_encrypted){ 3312 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3313 } else { 3314 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3315 } 3316 } 3317 sm_done_for_handle(sm_conn->sm_handle); 3318 break; 3319 } 3320 3321 if (!sm_conn->sm_connection_encrypted) break; 3322 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3323 3324 // continue pairing 3325 switch (sm_conn->sm_engine_state){ 3326 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3327 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3328 sm_done_for_handle(sm_conn->sm_handle); 3329 break; 3330 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3331 if (IS_RESPONDER(sm_conn->sm_role)){ 3332 // slave 3333 if (setup->sm_use_secure_connections){ 3334 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3335 } else { 3336 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); 3337 } 3338 } else { 3339 // master 3340 if (sm_key_distribution_all_received(sm_conn)){ 3341 // skip receiving keys as there are none 3342 sm_key_distribution_handle_all_received(sm_conn); 3343 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); 3344 } else { 3345 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3346 } 3347 } 3348 break; 3349 default: 3350 break; 3351 } 3352 break; 3353 3354 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3355 con_handle = little_endian_read_16(packet, 3); 3356 sm_conn = sm_get_connection_for_handle(con_handle); 3357 if (!sm_conn) break; 3358 3359 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3360 log_info("event handler, state %u", sm_conn->sm_engine_state); 3361 // continue if part of initial pairing 3362 switch (sm_conn->sm_engine_state){ 3363 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3364 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3365 sm_done_for_handle(sm_conn->sm_handle); 3366 break; 3367 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3368 if (IS_RESPONDER(sm_conn->sm_role)){ 3369 // slave 3370 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); 3371 } else { 3372 // master 3373 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3374 } 3375 break; 3376 default: 3377 break; 3378 } 3379 break; 3380 3381 3382 case HCI_EVENT_DISCONNECTION_COMPLETE: 3383 con_handle = little_endian_read_16(packet, 3); 3384 sm_done_for_handle(con_handle); 3385 sm_conn = sm_get_connection_for_handle(con_handle); 3386 if (!sm_conn) break; 3387 3388 // delete stored bonding on disconnect with authentication failure in ph0 3389 if ((sm_conn->sm_role == 0u) 3390 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3391 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3392 le_device_db_remove(sm_conn->sm_le_db_index); 3393 } 3394 3395 // pairing failed, if it was ongoing 3396 switch (sm_conn->sm_engine_state){ 3397 case SM_GENERAL_IDLE: 3398 case SM_INITIATOR_CONNECTED: 3399 case SM_RESPONDER_IDLE: 3400 break; 3401 default: 3402 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3403 break; 3404 } 3405 3406 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3407 sm_conn->sm_handle = 0; 3408 break; 3409 3410 case HCI_EVENT_COMMAND_COMPLETE: 3411 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3412 // set local addr for le device db 3413 bd_addr_t addr; 3414 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3415 le_device_db_set_local_bd_addr(addr); 3416 } 3417 break; 3418 default: 3419 break; 3420 } 3421 break; 3422 default: 3423 break; 3424 } 3425 3426 sm_run(); 3427 } 3428 3429 static inline int sm_calc_actual_encryption_key_size(int other){ 3430 if (other < sm_min_encryption_key_size) return 0; 3431 if (other < sm_max_encryption_key_size) return other; 3432 return sm_max_encryption_key_size; 3433 } 3434 3435 3436 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3437 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3438 switch (method){ 3439 case JUST_WORKS: 3440 case NUMERIC_COMPARISON: 3441 return 1; 3442 default: 3443 return 0; 3444 } 3445 } 3446 // responder 3447 3448 static int sm_passkey_used(stk_generation_method_t method){ 3449 switch (method){ 3450 case PK_RESP_INPUT: 3451 return 1; 3452 default: 3453 return 0; 3454 } 3455 } 3456 3457 static int sm_passkey_entry(stk_generation_method_t method){ 3458 switch (method){ 3459 case PK_RESP_INPUT: 3460 case PK_INIT_INPUT: 3461 case PK_BOTH_INPUT: 3462 return 1; 3463 default: 3464 return 0; 3465 } 3466 } 3467 3468 #endif 3469 3470 /** 3471 * @return ok 3472 */ 3473 static int sm_validate_stk_generation_method(void){ 3474 // check if STK generation method is acceptable by client 3475 switch (setup->sm_stk_generation_method){ 3476 case JUST_WORKS: 3477 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 3478 case PK_RESP_INPUT: 3479 case PK_INIT_INPUT: 3480 case PK_BOTH_INPUT: 3481 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 3482 case OOB: 3483 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 3484 case NUMERIC_COMPARISON: 3485 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 3486 default: 3487 return 0; 3488 } 3489 } 3490 3491 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3492 3493 // size of complete sm_pdu used to validate input 3494 static const uint8_t sm_pdu_size[] = { 3495 0, // 0x00 invalid opcode 3496 7, // 0x01 pairing request 3497 7, // 0x02 pairing response 3498 17, // 0x03 pairing confirm 3499 17, // 0x04 pairing random 3500 2, // 0x05 pairing failed 3501 17, // 0x06 encryption information 3502 11, // 0x07 master identification 3503 17, // 0x08 identification information 3504 8, // 0x09 identify address information 3505 17, // 0x0a signing information 3506 2, // 0x0b security request 3507 65, // 0x0c pairing public key 3508 17, // 0x0d pairing dhk check 3509 2, // 0x0e keypress notification 3510 }; 3511 3512 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3513 sm_run(); 3514 } 3515 3516 if (packet_type != SM_DATA_PACKET) return; 3517 if (size == 0u) return; 3518 3519 uint8_t sm_pdu_code = packet[0]; 3520 3521 // validate pdu size 3522 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3523 if (sm_pdu_size[sm_pdu_code] != size) return; 3524 3525 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3526 if (!sm_conn) return; 3527 3528 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3529 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3530 sm_done_for_handle(con_handle); 3531 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3532 return; 3533 } 3534 3535 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3536 3537 int err; 3538 UNUSED(err); 3539 3540 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3541 uint8_t buffer[5]; 3542 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3543 buffer[1] = 3; 3544 little_endian_store_16(buffer, 2, con_handle); 3545 buffer[4] = packet[1]; 3546 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3547 return; 3548 } 3549 3550 switch (sm_conn->sm_engine_state){ 3551 3552 // a sm timeout requries a new physical connection 3553 case SM_GENERAL_TIMEOUT: 3554 return; 3555 3556 #ifdef ENABLE_LE_CENTRAL 3557 3558 // Initiator 3559 case SM_INITIATOR_CONNECTED: 3560 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3561 sm_pdu_received_in_wrong_state(sm_conn); 3562 break; 3563 } 3564 3565 // IRK complete? 3566 int have_ltk; 3567 uint8_t ltk[16]; 3568 switch (sm_conn->sm_irk_lookup_state){ 3569 case IRK_LOOKUP_FAILED: 3570 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3571 break; 3572 case IRK_LOOKUP_SUCCEEDED: 3573 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3574 have_ltk = !sm_is_null_key(ltk); 3575 log_info("central: security request - have_ltk %u", have_ltk); 3576 if (have_ltk){ 3577 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3578 } else { 3579 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3580 } 3581 break; 3582 default: 3583 break; 3584 } 3585 3586 // otherwise, store security request 3587 sm_conn->sm_security_request_received = 1; 3588 break; 3589 3590 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3591 // Core 5, Vol 3, Part H, 2.4.6: 3592 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3593 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3594 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3595 log_info("Ignoring Security Request"); 3596 break; 3597 } 3598 3599 // all other pdus are incorrect 3600 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3601 sm_pdu_received_in_wrong_state(sm_conn); 3602 break; 3603 } 3604 3605 // store pairing request 3606 (void)memcpy(&setup->sm_s_pres, packet, 3607 sizeof(sm_pairing_packet_t)); 3608 err = sm_stk_generation_init(sm_conn); 3609 3610 #ifdef ENABLE_TESTING_SUPPORT 3611 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3612 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3613 err = test_pairing_failure; 3614 } 3615 #endif 3616 3617 if (err){ 3618 setup->sm_pairing_failed_reason = err; 3619 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3620 break; 3621 } 3622 3623 // generate random number first, if we need to show passkey 3624 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3625 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); 3626 break; 3627 } 3628 3629 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3630 if (setup->sm_use_secure_connections){ 3631 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3632 if (setup->sm_stk_generation_method == JUST_WORKS){ 3633 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3634 sm_trigger_user_response(sm_conn); 3635 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3636 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3637 } 3638 } else { 3639 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3640 } 3641 break; 3642 } 3643 #endif 3644 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3645 sm_trigger_user_response(sm_conn); 3646 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3647 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3648 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); 3649 } 3650 break; 3651 3652 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3653 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3654 sm_pdu_received_in_wrong_state(sm_conn); 3655 break; 3656 } 3657 3658 // store s_confirm 3659 reverse_128(&packet[1], setup->sm_peer_confirm); 3660 3661 #ifdef ENABLE_TESTING_SUPPORT 3662 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3663 log_info("testing_support: reset confirm value"); 3664 memset(setup->sm_peer_confirm, 0, 16); 3665 } 3666 #endif 3667 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3668 break; 3669 3670 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3671 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3672 sm_pdu_received_in_wrong_state(sm_conn); 3673 break;; 3674 } 3675 3676 // received random value 3677 reverse_128(&packet[1], setup->sm_peer_random); 3678 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3679 break; 3680 #endif 3681 3682 #ifdef ENABLE_LE_PERIPHERAL 3683 // Responder 3684 case SM_RESPONDER_IDLE: 3685 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3686 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3687 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3688 sm_pdu_received_in_wrong_state(sm_conn); 3689 break;; 3690 } 3691 3692 // store pairing request 3693 (void)memcpy(&sm_conn->sm_m_preq, packet, 3694 sizeof(sm_pairing_packet_t)); 3695 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3696 break; 3697 #endif 3698 3699 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3700 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3701 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3702 sm_pdu_received_in_wrong_state(sm_conn); 3703 break; 3704 } 3705 3706 // store public key for DH Key calculation 3707 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3708 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3709 3710 // validate public key 3711 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3712 if (err){ 3713 log_error("sm: peer public key invalid %x", err); 3714 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3715 break; 3716 } 3717 3718 // start calculating dhkey 3719 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); 3720 3721 3722 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3723 if (IS_RESPONDER(sm_conn->sm_role)){ 3724 // responder 3725 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3726 } else { 3727 // initiator 3728 // stk generation method 3729 // passkey entry: notify app to show passkey or to request passkey 3730 switch (setup->sm_stk_generation_method){ 3731 case JUST_WORKS: 3732 case NUMERIC_COMPARISON: 3733 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3734 break; 3735 case PK_RESP_INPUT: 3736 sm_sc_start_calculating_local_confirm(sm_conn); 3737 break; 3738 case PK_INIT_INPUT: 3739 case PK_BOTH_INPUT: 3740 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3741 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3742 break; 3743 } 3744 sm_sc_start_calculating_local_confirm(sm_conn); 3745 break; 3746 case OOB: 3747 // generate Nx 3748 log_info("Generate Na"); 3749 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); 3750 break; 3751 } 3752 } 3753 break; 3754 3755 case SM_SC_W4_CONFIRMATION: 3756 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3757 sm_pdu_received_in_wrong_state(sm_conn); 3758 break; 3759 } 3760 // received confirm value 3761 reverse_128(&packet[1], setup->sm_peer_confirm); 3762 3763 #ifdef ENABLE_TESTING_SUPPORT 3764 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3765 log_info("testing_support: reset confirm value"); 3766 memset(setup->sm_peer_confirm, 0, 16); 3767 } 3768 #endif 3769 if (IS_RESPONDER(sm_conn->sm_role)){ 3770 // responder 3771 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3772 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3773 // still waiting for passkey 3774 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3775 break; 3776 } 3777 } 3778 sm_sc_start_calculating_local_confirm(sm_conn); 3779 } else { 3780 // initiator 3781 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3782 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); 3783 } else { 3784 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3785 } 3786 } 3787 break; 3788 3789 case SM_SC_W4_PAIRING_RANDOM: 3790 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3791 sm_pdu_received_in_wrong_state(sm_conn); 3792 break; 3793 } 3794 3795 // received random value 3796 reverse_128(&packet[1], setup->sm_peer_nonce); 3797 3798 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3799 // only check for JUST WORK/NC in initiator role OR passkey entry 3800 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 3801 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 3802 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 3803 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3804 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 3805 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3806 break; 3807 } 3808 3809 // OOB 3810 if (setup->sm_stk_generation_method == OOB){ 3811 3812 // setup local random, set to zero if remote did not receive our data 3813 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3814 if (IS_RESPONDER(sm_conn->sm_role)){ 3815 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 3816 log_info("Reset rb as A does not have OOB data"); 3817 memset(setup->sm_rb, 0, 16); 3818 } else { 3819 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3820 log_info("Use stored rb"); 3821 log_info_hexdump(setup->sm_rb, 16); 3822 } 3823 } else { 3824 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 3825 log_info("Reset ra as B does not have OOB data"); 3826 memset(setup->sm_ra, 0, 16); 3827 } else { 3828 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3829 log_info("Use stored ra"); 3830 log_info_hexdump(setup->sm_ra, 16); 3831 } 3832 } 3833 3834 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3835 if (setup->sm_have_oob_data){ 3836 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3837 break; 3838 } 3839 } 3840 3841 // TODO: we only get here for Responder role with JW/NC 3842 sm_sc_state_after_receiving_random(sm_conn); 3843 break; 3844 3845 case SM_SC_W2_CALCULATE_G2: 3846 case SM_SC_W4_CALCULATE_G2: 3847 case SM_SC_W4_CALCULATE_DHKEY: 3848 case SM_SC_W2_CALCULATE_F5_SALT: 3849 case SM_SC_W4_CALCULATE_F5_SALT: 3850 case SM_SC_W2_CALCULATE_F5_MACKEY: 3851 case SM_SC_W4_CALCULATE_F5_MACKEY: 3852 case SM_SC_W2_CALCULATE_F5_LTK: 3853 case SM_SC_W4_CALCULATE_F5_LTK: 3854 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3855 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3856 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3857 case SM_SC_W4_USER_RESPONSE: 3858 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3859 sm_pdu_received_in_wrong_state(sm_conn); 3860 break; 3861 } 3862 // store DHKey Check 3863 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3864 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3865 3866 // have we been only waiting for dhkey check command? 3867 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3868 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3869 } 3870 break; 3871 #endif 3872 3873 #ifdef ENABLE_LE_PERIPHERAL 3874 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3875 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3876 sm_pdu_received_in_wrong_state(sm_conn); 3877 break; 3878 } 3879 3880 // received confirm value 3881 reverse_128(&packet[1], setup->sm_peer_confirm); 3882 3883 #ifdef ENABLE_TESTING_SUPPORT 3884 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3885 log_info("testing_support: reset confirm value"); 3886 memset(setup->sm_peer_confirm, 0, 16); 3887 } 3888 #endif 3889 // notify client to hide shown passkey 3890 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3891 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3892 } 3893 3894 // handle user cancel pairing? 3895 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3896 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3897 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3898 break; 3899 } 3900 3901 // wait for user action? 3902 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3903 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3904 break; 3905 } 3906 3907 // calculate and send local_confirm 3908 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); 3909 break; 3910 3911 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3912 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3913 sm_pdu_received_in_wrong_state(sm_conn); 3914 break;; 3915 } 3916 3917 // received random value 3918 reverse_128(&packet[1], setup->sm_peer_random); 3919 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3920 break; 3921 #endif 3922 3923 case SM_PH3_RECEIVE_KEYS: 3924 switch(sm_pdu_code){ 3925 case SM_CODE_ENCRYPTION_INFORMATION: 3926 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3927 reverse_128(&packet[1], setup->sm_peer_ltk); 3928 break; 3929 3930 case SM_CODE_MASTER_IDENTIFICATION: 3931 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3932 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3933 reverse_64(&packet[3], setup->sm_peer_rand); 3934 break; 3935 3936 case SM_CODE_IDENTITY_INFORMATION: 3937 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3938 reverse_128(&packet[1], setup->sm_peer_irk); 3939 break; 3940 3941 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3942 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3943 setup->sm_peer_addr_type = packet[1]; 3944 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3945 break; 3946 3947 case SM_CODE_SIGNING_INFORMATION: 3948 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3949 reverse_128(&packet[1], setup->sm_peer_csrk); 3950 break; 3951 default: 3952 // Unexpected PDU 3953 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3954 break; 3955 } 3956 // done with key distribution? 3957 if (sm_key_distribution_all_received(sm_conn)){ 3958 3959 sm_key_distribution_handle_all_received(sm_conn); 3960 3961 if (IS_RESPONDER(sm_conn->sm_role)){ 3962 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3963 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3964 } else { 3965 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3966 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3967 sm_done_for_handle(sm_conn->sm_handle); 3968 } 3969 } else { 3970 if (setup->sm_use_secure_connections){ 3971 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3972 } else { 3973 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); 3974 } 3975 } 3976 } 3977 break; 3978 default: 3979 // Unexpected PDU 3980 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3981 break; 3982 } 3983 3984 // try to send preparared packet 3985 sm_run(); 3986 } 3987 3988 // Security Manager Client API 3989 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3990 sm_get_oob_data = get_oob_data_callback; 3991 } 3992 3993 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)){ 3994 sm_get_sc_oob_data = get_sc_oob_data_callback; 3995 } 3996 3997 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3998 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3999 } 4000 4001 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4002 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4003 } 4004 4005 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4006 sm_min_encryption_key_size = min_size; 4007 sm_max_encryption_key_size = max_size; 4008 } 4009 4010 void sm_set_authentication_requirements(uint8_t auth_req){ 4011 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4012 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4013 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4014 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4015 } 4016 #endif 4017 sm_auth_req = auth_req; 4018 } 4019 4020 void sm_set_io_capabilities(io_capability_t io_capability){ 4021 sm_io_capabilities = io_capability; 4022 } 4023 4024 #ifdef ENABLE_LE_PERIPHERAL 4025 void sm_set_request_security(int enable){ 4026 sm_slave_request_security = enable; 4027 } 4028 #endif 4029 4030 void sm_set_er(sm_key_t er){ 4031 (void)memcpy(sm_persistent_er, er, 16); 4032 } 4033 4034 void sm_set_ir(sm_key_t ir){ 4035 (void)memcpy(sm_persistent_ir, ir, 16); 4036 } 4037 4038 // Testing support only 4039 void sm_test_set_irk(sm_key_t irk){ 4040 (void)memcpy(sm_persistent_irk, irk, 16); 4041 dkg_state = DKG_CALC_DHK; 4042 test_use_fixed_local_irk = true; 4043 } 4044 4045 void sm_test_use_fixed_local_csrk(void){ 4046 test_use_fixed_local_csrk = true; 4047 } 4048 4049 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4050 static void sm_ec_generated(void * arg){ 4051 UNUSED(arg); 4052 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4053 // trigger pairing if pending for ec key 4054 sm_run(); 4055 } 4056 static void sm_ec_generate_new_key(void){ 4057 log_info("sm: generate new ec key"); 4058 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4059 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4060 } 4061 #endif 4062 4063 #ifdef ENABLE_TESTING_SUPPORT 4064 void sm_test_set_pairing_failure(int reason){ 4065 test_pairing_failure = reason; 4066 } 4067 #endif 4068 4069 void sm_init(void){ 4070 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4071 sm_er_ir_set_default(); 4072 4073 // defaults 4074 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4075 | SM_STK_GENERATION_METHOD_OOB 4076 | SM_STK_GENERATION_METHOD_PASSKEY 4077 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4078 4079 sm_max_encryption_key_size = 16; 4080 sm_min_encryption_key_size = 7; 4081 4082 sm_fixed_passkey_in_display_role = 0xffffffff; 4083 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4084 4085 #ifdef USE_CMAC_ENGINE 4086 sm_cmac_active = 0; 4087 #endif 4088 dkg_state = DKG_W4_WORKING; 4089 rau_state = RAU_IDLE; 4090 sm_aes128_state = SM_AES128_IDLE; 4091 sm_address_resolution_test = -1; // no private address to resolve yet 4092 sm_address_resolution_ah_calculation_active = 0; 4093 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4094 sm_address_resolution_general_queue = NULL; 4095 4096 gap_random_adress_update_period = 15 * 60 * 1000L; 4097 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4098 4099 test_use_fixed_local_csrk = false; 4100 4101 // register for HCI Events from HCI 4102 hci_event_callback_registration.callback = &sm_event_packet_handler; 4103 hci_add_event_handler(&hci_event_callback_registration); 4104 4105 // 4106 btstack_crypto_init(); 4107 4108 // init le_device_db 4109 le_device_db_init(); 4110 4111 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4112 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4113 4114 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4115 sm_ec_generate_new_key(); 4116 #endif 4117 } 4118 4119 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4120 sm_fixed_passkey_in_display_role = passkey; 4121 } 4122 4123 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4124 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4125 } 4126 4127 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4128 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4129 if (!hci_con) return NULL; 4130 return &hci_con->sm_connection; 4131 } 4132 4133 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4134 switch (sm_conn->sm_engine_state){ 4135 case SM_GENERAL_IDLE: 4136 case SM_RESPONDER_IDLE: 4137 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4138 sm_run(); 4139 break; 4140 default: 4141 break; 4142 } 4143 } 4144 4145 /** 4146 * @brief Trigger Security Request 4147 */ 4148 void sm_send_security_request(hci_con_handle_t con_handle){ 4149 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4150 if (!sm_conn) return; 4151 sm_send_security_request_for_connection(sm_conn); 4152 } 4153 4154 // request pairing 4155 void sm_request_pairing(hci_con_handle_t con_handle){ 4156 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4157 if (!sm_conn) return; // wrong connection 4158 4159 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4160 if (IS_RESPONDER(sm_conn->sm_role)){ 4161 sm_send_security_request_for_connection(sm_conn); 4162 } else { 4163 // used as a trigger to start central/master/initiator security procedures 4164 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4165 uint8_t ltk[16]; 4166 bool have_ltk; 4167 switch (sm_conn->sm_irk_lookup_state){ 4168 case IRK_LOOKUP_SUCCEEDED: 4169 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4170 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4171 have_ltk = !sm_is_null_key(ltk); 4172 log_info("have ltk %u", have_ltk); 4173 if (have_ltk){ 4174 sm_conn->sm_pairing_requested = 1; 4175 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4176 break; 4177 } 4178 #endif 4179 /* fall through */ 4180 4181 case IRK_LOOKUP_FAILED: 4182 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4183 break; 4184 default: 4185 log_info("irk lookup pending"); 4186 sm_conn->sm_pairing_requested = 1; 4187 break; 4188 } 4189 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4190 sm_conn->sm_pairing_requested = 1; 4191 } 4192 } 4193 sm_run(); 4194 } 4195 4196 // called by client app on authorization request 4197 void sm_authorization_decline(hci_con_handle_t con_handle){ 4198 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4199 if (!sm_conn) return; // wrong connection 4200 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4201 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4202 } 4203 4204 void sm_authorization_grant(hci_con_handle_t con_handle){ 4205 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4206 if (!sm_conn) return; // wrong connection 4207 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4208 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4209 } 4210 4211 // GAP Bonding API 4212 4213 void sm_bonding_decline(hci_con_handle_t con_handle){ 4214 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4215 if (!sm_conn) return; // wrong connection 4216 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4217 log_info("decline, state %u", sm_conn->sm_engine_state); 4218 switch(sm_conn->sm_engine_state){ 4219 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4220 case SM_SC_W4_USER_RESPONSE: 4221 case SM_SC_W4_CONFIRMATION: 4222 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4223 #endif 4224 case SM_PH1_W4_USER_RESPONSE: 4225 switch (setup->sm_stk_generation_method){ 4226 case PK_RESP_INPUT: 4227 case PK_INIT_INPUT: 4228 case PK_BOTH_INPUT: 4229 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4230 break; 4231 case NUMERIC_COMPARISON: 4232 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4233 break; 4234 case JUST_WORKS: 4235 case OOB: 4236 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4237 break; 4238 } 4239 break; 4240 default: 4241 break; 4242 } 4243 sm_run(); 4244 } 4245 4246 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4247 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4248 if (!sm_conn) return; // wrong connection 4249 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4250 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4251 if (setup->sm_use_secure_connections){ 4252 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4253 } else { 4254 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); 4255 } 4256 } 4257 4258 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4259 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4260 sm_sc_prepare_dhkey_check(sm_conn); 4261 } 4262 #endif 4263 4264 sm_run(); 4265 } 4266 4267 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4268 // for now, it's the same 4269 sm_just_works_confirm(con_handle); 4270 } 4271 4272 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4273 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4274 if (!sm_conn) return; // wrong connection 4275 sm_reset_tk(); 4276 big_endian_store_32(setup->sm_tk, 12, passkey); 4277 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4278 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4279 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); 4280 } 4281 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4282 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4283 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4284 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4285 sm_sc_start_calculating_local_confirm(sm_conn); 4286 } 4287 #endif 4288 sm_run(); 4289 } 4290 4291 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4292 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4293 if (!sm_conn) return; // wrong connection 4294 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4295 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4296 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 4297 switch (action){ 4298 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4299 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4300 flags |= (1u << action); 4301 break; 4302 case SM_KEYPRESS_PASSKEY_CLEARED: 4303 // clear counter, keypress & erased flags + set passkey cleared 4304 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 4305 break; 4306 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4307 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4308 // erase actions queued 4309 num_actions--; 4310 if (num_actions == 0u){ 4311 // clear counter, keypress & erased flags 4312 flags &= 0x19u; 4313 } 4314 break; 4315 } 4316 num_actions++; 4317 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4318 break; 4319 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4320 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4321 // enter actions queued 4322 num_actions--; 4323 if (num_actions == 0u){ 4324 // clear counter, keypress & erased flags 4325 flags &= 0x19u; 4326 } 4327 break; 4328 } 4329 num_actions++; 4330 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4331 break; 4332 default: 4333 break; 4334 } 4335 setup->sm_keypress_notification = (num_actions << 5) | flags; 4336 sm_run(); 4337 } 4338 4339 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4340 static void sm_handle_random_result_oob(void * arg){ 4341 UNUSED(arg); 4342 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4343 sm_run(); 4344 } 4345 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4346 4347 static btstack_crypto_random_t sm_crypto_random_oob_request; 4348 4349 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4350 sm_sc_oob_callback = callback; 4351 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4352 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4353 return 0; 4354 } 4355 #endif 4356 4357 /** 4358 * @brief Get Identity Resolving state 4359 * @param con_handle 4360 * @return irk_lookup_state_t 4361 */ 4362 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4363 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4364 if (!sm_conn) return IRK_LOOKUP_IDLE; 4365 return sm_conn->sm_irk_lookup_state; 4366 } 4367 4368 /** 4369 * @brief Identify device in LE Device DB 4370 * @param handle 4371 * @returns index from le_device_db or -1 if not found/identified 4372 */ 4373 int sm_le_device_index(hci_con_handle_t con_handle ){ 4374 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4375 if (!sm_conn) return -1; 4376 return sm_conn->sm_le_db_index; 4377 } 4378 4379 static int gap_random_address_type_requires_updates(void){ 4380 switch (gap_random_adress_type){ 4381 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4382 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4383 return 0; 4384 default: 4385 return 1; 4386 } 4387 } 4388 4389 static uint8_t own_address_type(void){ 4390 switch (gap_random_adress_type){ 4391 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4392 return BD_ADDR_TYPE_LE_PUBLIC; 4393 default: 4394 return BD_ADDR_TYPE_LE_RANDOM; 4395 } 4396 } 4397 4398 // GAP LE API 4399 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4400 gap_random_address_update_stop(); 4401 gap_random_adress_type = random_address_type; 4402 hci_le_set_own_address_type(own_address_type()); 4403 if (!gap_random_address_type_requires_updates()) return; 4404 gap_random_address_update_start(); 4405 gap_random_address_trigger(); 4406 } 4407 4408 gap_random_address_type_t gap_random_address_get_mode(void){ 4409 return gap_random_adress_type; 4410 } 4411 4412 void gap_random_address_set_update_period(int period_ms){ 4413 gap_random_adress_update_period = period_ms; 4414 if (!gap_random_address_type_requires_updates()) return; 4415 gap_random_address_update_stop(); 4416 gap_random_address_update_start(); 4417 } 4418 4419 void gap_random_address_set(bd_addr_t addr){ 4420 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4421 (void)memcpy(sm_random_address, addr, 6); 4422 rau_state = RAU_SET_ADDRESS; 4423 sm_run(); 4424 } 4425 4426 #ifdef ENABLE_LE_PERIPHERAL 4427 /* 4428 * @brief Set Advertisement Paramters 4429 * @param adv_int_min 4430 * @param adv_int_max 4431 * @param adv_type 4432 * @param direct_address_type 4433 * @param direct_address 4434 * @param channel_map 4435 * @param filter_policy 4436 * 4437 * @note own_address_type is used from gap_random_address_set_mode 4438 */ 4439 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4440 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4441 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4442 direct_address_typ, direct_address, channel_map, filter_policy); 4443 } 4444 #endif 4445 4446 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4447 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4448 // wrong connection 4449 if (!sm_conn) return 0; 4450 // already encrypted 4451 if (sm_conn->sm_connection_encrypted) return 0; 4452 // only central can re-encrypt 4453 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4454 // irk status? 4455 switch(sm_conn->sm_irk_lookup_state){ 4456 case IRK_LOOKUP_FAILED: 4457 // done, cannot setup encryption 4458 return 0; 4459 case IRK_LOOKUP_SUCCEEDED: 4460 break; 4461 default: 4462 // IR Lookup pending 4463 return 1; 4464 } 4465 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4466 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4467 } 4468 4469 void sm_set_secure_connections_only_mode(bool enable){ 4470 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4471 sm_sc_only_mode = enable; 4472 #else 4473 // SC Only mode not possible without support for SC 4474 btstack_assert(enable == false); 4475 #endif 4476 } 4477