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 uint8_t sm_sc_oob_random[16]; 197 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 198 static sm_sc_oob_state_t sm_sc_oob_state; 199 #endif 200 201 202 static uint8_t sm_persistent_keys_random_active; 203 static const btstack_tlv_t * sm_tlv_impl; 204 static void * sm_tlv_context; 205 206 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 207 static sm_key_t sm_persistent_er; 208 static sm_key_t sm_persistent_ir; 209 210 // derived from sm_persistent_ir 211 static sm_key_t sm_persistent_dhk; 212 static sm_key_t sm_persistent_irk; 213 static derived_key_generation_t dkg_state; 214 215 // derived from sm_persistent_er 216 // .. 217 218 // random address update 219 static random_address_update_t rau_state; 220 static bd_addr_t sm_random_address; 221 222 #ifdef USE_CMAC_ENGINE 223 // CMAC Calculation: General 224 static btstack_crypto_aes128_cmac_t sm_cmac_request; 225 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 226 static uint8_t sm_cmac_active; 227 static uint8_t sm_cmac_hash[16]; 228 #endif 229 230 // CMAC for ATT Signed Writes 231 #ifdef ENABLE_LE_SIGNED_WRITE 232 static uint16_t sm_cmac_signed_write_message_len; 233 static uint8_t sm_cmac_signed_write_header[3]; 234 static const uint8_t * sm_cmac_signed_write_message; 235 static uint8_t sm_cmac_signed_write_sign_counter[4]; 236 #endif 237 238 // CMAC for Secure Connection functions 239 #ifdef ENABLE_LE_SECURE_CONNECTIONS 240 static sm_connection_t * sm_cmac_connection; 241 static uint8_t sm_cmac_sc_buffer[80]; 242 #endif 243 244 // resolvable private address lookup / CSRK calculation 245 static int sm_address_resolution_test; 246 static int sm_address_resolution_ah_calculation_active; 247 static uint8_t sm_address_resolution_addr_type; 248 static bd_addr_t sm_address_resolution_address; 249 static void * sm_address_resolution_context; 250 static address_resolution_mode_t sm_address_resolution_mode; 251 static btstack_linked_list_t sm_address_resolution_general_queue; 252 253 // aes128 crypto engine. 254 static sm_aes128_state_t sm_aes128_state; 255 256 // crypto 257 static btstack_crypto_random_t sm_crypto_random_request; 258 static btstack_crypto_aes128_t sm_crypto_aes128_request; 259 #ifdef ENABLE_LE_SECURE_CONNECTIONS 260 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 261 #endif 262 263 // temp storage for random data 264 static uint8_t sm_random_data[8]; 265 static uint8_t sm_aes128_key[16]; 266 static uint8_t sm_aes128_plaintext[16]; 267 static uint8_t sm_aes128_ciphertext[16]; 268 269 // to receive hci events 270 static btstack_packet_callback_registration_t hci_event_callback_registration; 271 272 /* to dispatch sm event */ 273 static btstack_linked_list_t sm_event_handlers; 274 275 // LE Secure Connections 276 #ifdef ENABLE_LE_SECURE_CONNECTIONS 277 static ec_key_generation_state_t ec_key_generation_state; 278 static uint8_t ec_q[64]; 279 #endif 280 281 // 282 // Volume 3, Part H, Chapter 24 283 // "Security shall be initiated by the Security Manager in the device in the master role. 284 // The device in the slave role shall be the responding device." 285 // -> master := initiator, slave := responder 286 // 287 288 // data needed for security setup 289 typedef struct sm_setup_context { 290 291 btstack_timer_source_t sm_timeout; 292 293 // used in all phases 294 uint8_t sm_pairing_failed_reason; 295 296 // user response, (Phase 1 and/or 2) 297 uint8_t sm_user_response; 298 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 299 300 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 301 uint8_t sm_key_distribution_send_set; 302 uint8_t sm_key_distribution_sent_set; 303 uint8_t sm_key_distribution_received_set; 304 305 // Phase 2 (Pairing over SMP) 306 stk_generation_method_t sm_stk_generation_method; 307 sm_key_t sm_tk; 308 uint8_t sm_have_oob_data; 309 uint8_t sm_use_secure_connections; 310 311 sm_key_t sm_c1_t3_value; // c1 calculation 312 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 313 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 314 sm_key_t sm_local_random; 315 sm_key_t sm_local_confirm; 316 sm_key_t sm_peer_random; 317 sm_key_t sm_peer_confirm; 318 uint8_t sm_m_addr_type; // address and type can be removed 319 uint8_t sm_s_addr_type; // '' 320 bd_addr_t sm_m_address; // '' 321 bd_addr_t sm_s_address; // '' 322 sm_key_t sm_ltk; 323 324 uint8_t sm_state_vars; 325 #ifdef ENABLE_LE_SECURE_CONNECTIONS 326 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 327 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 328 sm_key_t sm_local_nonce; // might be combined with sm_local_random 329 uint8_t sm_dhkey[32]; 330 sm_key_t sm_peer_dhkey_check; 331 sm_key_t sm_local_dhkey_check; 332 sm_key_t sm_ra; 333 sm_key_t sm_rb; 334 sm_key_t sm_t; // used for f5 and h6 335 sm_key_t sm_mackey; 336 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 337 #endif 338 339 // Phase 3 340 341 // key distribution, we generate 342 uint16_t sm_local_y; 343 uint16_t sm_local_div; 344 uint16_t sm_local_ediv; 345 uint8_t sm_local_rand[8]; 346 sm_key_t sm_local_ltk; 347 sm_key_t sm_local_csrk; 348 sm_key_t sm_local_irk; 349 // sm_local_address/addr_type not needed 350 351 // key distribution, received from peer 352 uint16_t sm_peer_y; 353 uint16_t sm_peer_div; 354 uint16_t sm_peer_ediv; 355 uint8_t sm_peer_rand[8]; 356 sm_key_t sm_peer_ltk; 357 sm_key_t sm_peer_irk; 358 sm_key_t sm_peer_csrk; 359 uint8_t sm_peer_addr_type; 360 bd_addr_t sm_peer_address; 361 #ifdef ENABLE_LE_SIGNED_WRITE 362 int sm_le_device_index; 363 #endif 364 365 } sm_setup_context_t; 366 367 // 368 static sm_setup_context_t the_setup; 369 static sm_setup_context_t * setup = &the_setup; 370 371 // active connection - the one for which the_setup is used for 372 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 373 374 // @returns 1 if oob data is available 375 // stores oob data in provided 16 byte buffer if not null 376 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 377 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); 378 379 static void sm_run(void); 380 static void sm_done_for_handle(hci_con_handle_t con_handle); 381 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 382 static inline int sm_calc_actual_encryption_key_size(int other); 383 static int sm_validate_stk_generation_method(void); 384 static void sm_handle_encryption_result_address_resolution(void *arg); 385 static void sm_handle_encryption_result_dkg_dhk(void *arg); 386 static void sm_handle_encryption_result_dkg_irk(void *arg); 387 static void sm_handle_encryption_result_enc_a(void *arg); 388 static void sm_handle_encryption_result_enc_b(void *arg); 389 static void sm_handle_encryption_result_enc_c(void *arg); 390 static void sm_handle_encryption_result_enc_csrk(void *arg); 391 static void sm_handle_encryption_result_enc_d(void * arg); 392 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 393 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 394 #ifdef ENABLE_LE_PERIPHERAL 395 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 396 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 397 #endif 398 static void sm_handle_encryption_result_enc_stk(void *arg); 399 static void sm_handle_encryption_result_rau(void *arg); 400 static void sm_handle_random_result_ph2_tk(void * arg); 401 static void sm_handle_random_result_rau(void * arg); 402 #ifdef ENABLE_LE_SECURE_CONNECTIONS 403 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)); 404 static void sm_ec_generate_new_key(void); 405 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 406 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 407 static int sm_passkey_entry(stk_generation_method_t method); 408 #endif 409 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 410 411 static void log_info_hex16(const char * name, uint16_t value){ 412 log_info("%-6s 0x%04x", name, value); 413 } 414 415 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 416 // return packet[0]; 417 // } 418 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 419 return packet[1]; 420 } 421 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 422 return packet[2]; 423 } 424 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 425 return packet[3]; 426 } 427 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 428 return packet[4]; 429 } 430 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 431 return packet[5]; 432 } 433 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 434 return packet[6]; 435 } 436 437 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 438 packet[0] = code; 439 } 440 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 441 packet[1] = io_capability; 442 } 443 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 444 packet[2] = oob_data_flag; 445 } 446 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 447 packet[3] = auth_req; 448 } 449 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 450 packet[4] = max_encryption_key_size; 451 } 452 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 453 packet[5] = initiator_key_distribution; 454 } 455 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 456 packet[6] = responder_key_distribution; 457 } 458 459 // @returns 1 if all bytes are 0 460 static int sm_is_null(uint8_t * data, int size){ 461 int i; 462 for (i=0; i < size ; i++){ 463 if (data[i]) return 0; 464 } 465 return 1; 466 } 467 468 static int sm_is_null_random(uint8_t random[8]){ 469 return sm_is_null(random, 8); 470 } 471 472 static int sm_is_null_key(uint8_t * key){ 473 return sm_is_null(key, 16); 474 } 475 476 // Key utils 477 static void sm_reset_tk(void){ 478 int i; 479 for (i=0;i<16;i++){ 480 setup->sm_tk[i] = 0; 481 } 482 } 483 484 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 485 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 486 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 487 int i; 488 for (i = max_encryption_size ; i < 16 ; i++){ 489 key[15-i] = 0; 490 } 491 } 492 493 // ER / IR checks 494 static void sm_er_ir_set_default(void){ 495 int i; 496 for (i=0;i<16;i++){ 497 sm_persistent_er[i] = 0x30 + i; 498 sm_persistent_ir[i] = 0x90 + i; 499 } 500 } 501 502 static int sm_er_is_default(void){ 503 int i; 504 for (i=0;i<16;i++){ 505 if (sm_persistent_er[i] != (0x30+i)) return 0; 506 } 507 return 1; 508 } 509 510 static int sm_ir_is_default(void){ 511 int i; 512 for (i=0;i<16;i++){ 513 if (sm_persistent_ir[i] != (0x90+i)) return 0; 514 } 515 return 1; 516 } 517 518 // SMP Timeout implementation 519 520 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 521 // the Security Manager Timer shall be reset and started. 522 // 523 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 524 // 525 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 526 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 527 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 528 // established. 529 530 static void sm_timeout_handler(btstack_timer_source_t * timer){ 531 log_info("SM timeout"); 532 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 533 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 534 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 535 sm_done_for_handle(sm_conn->sm_handle); 536 537 // trigger handling of next ready connection 538 sm_run(); 539 } 540 static void sm_timeout_start(sm_connection_t * sm_conn){ 541 btstack_run_loop_remove_timer(&setup->sm_timeout); 542 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 543 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 544 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 545 btstack_run_loop_add_timer(&setup->sm_timeout); 546 } 547 static void sm_timeout_stop(void){ 548 btstack_run_loop_remove_timer(&setup->sm_timeout); 549 } 550 static void sm_timeout_reset(sm_connection_t * sm_conn){ 551 sm_timeout_stop(); 552 sm_timeout_start(sm_conn); 553 } 554 555 // end of sm timeout 556 557 // GAP Random Address updates 558 static gap_random_address_type_t gap_random_adress_type; 559 static btstack_timer_source_t gap_random_address_update_timer; 560 static uint32_t gap_random_adress_update_period; 561 562 static void gap_random_address_trigger(void){ 563 log_info("gap_random_address_trigger, state %u", rau_state); 564 if (rau_state != RAU_IDLE) return; 565 rau_state = RAU_GET_RANDOM; 566 sm_run(); 567 } 568 569 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 570 UNUSED(timer); 571 572 log_info("GAP Random Address Update due"); 573 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 574 btstack_run_loop_add_timer(&gap_random_address_update_timer); 575 gap_random_address_trigger(); 576 } 577 578 static void gap_random_address_update_start(void){ 579 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 580 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 581 btstack_run_loop_add_timer(&gap_random_address_update_timer); 582 } 583 584 static void gap_random_address_update_stop(void){ 585 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 586 } 587 588 // ah(k,r) helper 589 // r = padding || r 590 // r - 24 bit value 591 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 592 // r'= padding || r 593 memset(r_prime, 0, 16); 594 (void)memcpy(&r_prime[13], r, 3); 595 } 596 597 // d1 helper 598 // d' = padding || r || d 599 // d,r - 16 bit values 600 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 601 // d'= padding || r || d 602 memset(d1_prime, 0, 16); 603 big_endian_store_16(d1_prime, 12, r); 604 big_endian_store_16(d1_prime, 14, d); 605 } 606 607 // calculate arguments for first AES128 operation in C1 function 608 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){ 609 610 // p1 = pres || preq || rat’ || iat’ 611 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 612 // cant octet of pres becomes the most significant octet of p1. 613 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 614 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 615 // p1 is 0x05000800000302070710000001010001." 616 617 sm_key_t p1; 618 reverse_56(pres, &p1[0]); 619 reverse_56(preq, &p1[7]); 620 p1[14] = rat; 621 p1[15] = iat; 622 log_info_key("p1", p1); 623 log_info_key("r", r); 624 625 // t1 = r xor p1 626 int i; 627 for (i=0;i<16;i++){ 628 t1[i] = r[i] ^ p1[i]; 629 } 630 log_info_key("t1", t1); 631 } 632 633 // calculate arguments for second AES128 operation in C1 function 634 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 635 // p2 = padding || ia || ra 636 // "The least significant octet of ra becomes the least significant octet of p2 and 637 // the most significant octet of padding becomes the most significant octet of p2. 638 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 639 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 640 641 sm_key_t p2; 642 memset(p2, 0, 16); 643 (void)memcpy(&p2[4], ia, 6); 644 (void)memcpy(&p2[10], ra, 6); 645 log_info_key("p2", p2); 646 647 // c1 = e(k, t2_xor_p2) 648 int i; 649 for (i=0;i<16;i++){ 650 t3[i] = t2[i] ^ p2[i]; 651 } 652 log_info_key("t3", t3); 653 } 654 655 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 656 log_info_key("r1", r1); 657 log_info_key("r2", r2); 658 (void)memcpy(&r_prime[8], &r2[8], 8); 659 (void)memcpy(&r_prime[0], &r1[8], 8); 660 } 661 662 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 663 UNUSED(channel); 664 665 // log event 666 hci_dump_packet(packet_type, 1, packet, size); 667 // dispatch to all event handlers 668 btstack_linked_list_iterator_t it; 669 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 670 while (btstack_linked_list_iterator_has_next(&it)){ 671 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 672 entry->callback(packet_type, 0, packet, size); 673 } 674 } 675 676 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){ 677 event[0] = type; 678 event[1] = event_size - 2; 679 little_endian_store_16(event, 2, con_handle); 680 event[4] = addr_type; 681 reverse_bd_addr(address, &event[5]); 682 } 683 684 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 685 uint8_t event[11]; 686 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 687 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 688 } 689 690 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){ 691 uint8_t event[15]; 692 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 693 little_endian_store_32(event, 11, passkey); 694 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 695 } 696 697 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){ 698 // fetch addr and addr type from db, only called for valid entries 699 bd_addr_t identity_address; 700 int identity_address_type; 701 le_device_db_info(index, &identity_address_type, identity_address, NULL); 702 703 uint8_t event[20]; 704 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 705 event[11] = identity_address_type; 706 reverse_bd_addr(identity_address, &event[12]); 707 little_endian_store_16(event, 18, index); 708 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 709 } 710 711 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){ 712 uint8_t event[12]; 713 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 714 event[11] = status; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 719 uint8_t event[13]; 720 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 721 event[11] = status; 722 event[12] = reason; 723 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 724 } 725 726 // decide on stk generation based on 727 // - pairing request 728 // - io capabilities 729 // - OOB data availability 730 static void sm_setup_tk(void){ 731 732 // horizontal: initiator capabilities 733 // vertial: responder capabilities 734 static const stk_generation_method_t stk_generation_method [5] [5] = { 735 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 736 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 737 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 738 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 739 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 740 }; 741 742 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 743 #ifdef ENABLE_LE_SECURE_CONNECTIONS 744 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 745 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 746 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 747 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 748 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 749 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 750 }; 751 #endif 752 753 // default: just works 754 setup->sm_stk_generation_method = JUST_WORKS; 755 756 #ifdef ENABLE_LE_SECURE_CONNECTIONS 757 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 758 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 759 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 760 #else 761 setup->sm_use_secure_connections = 0; 762 #endif 763 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 764 765 766 // decide if OOB will be used based on SC vs. Legacy and oob flags 767 int use_oob = 0; 768 if (setup->sm_use_secure_connections){ 769 // In LE Secure Connections pairing, the out of band method is used if at least 770 // one device has the peer device's out of band authentication data available. 771 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 772 } else { 773 // In LE legacy pairing, the out of band method is used if both the devices have 774 // the other device's out of band authentication data available. 775 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 776 } 777 if (use_oob){ 778 log_info("SM: have OOB data"); 779 log_info_key("OOB", setup->sm_tk); 780 setup->sm_stk_generation_method = OOB; 781 return; 782 } 783 784 // If both devices have not set the MITM option in the Authentication Requirements 785 // Flags, then the IO capabilities shall be ignored and the Just Works association 786 // model shall be used. 787 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 788 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 789 log_info("SM: MITM not required by both -> JUST WORKS"); 790 return; 791 } 792 793 // Reset TK as it has been setup in sm_init_setup 794 sm_reset_tk(); 795 796 // Also use just works if unknown io capabilites 797 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)){ 798 return; 799 } 800 801 // Otherwise the IO capabilities of the devices shall be used to determine the 802 // pairing method as defined in Table 2.4. 803 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 804 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 805 806 #ifdef ENABLE_LE_SECURE_CONNECTIONS 807 // table not define by default 808 if (setup->sm_use_secure_connections){ 809 generation_method = stk_generation_method_with_secure_connection; 810 } 811 #endif 812 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)]; 813 814 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 815 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); 816 } 817 818 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 819 int flags = 0; 820 if (key_set & SM_KEYDIST_ENC_KEY){ 821 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 822 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 823 } 824 if (key_set & SM_KEYDIST_ID_KEY){ 825 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 826 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 827 } 828 if (key_set & SM_KEYDIST_SIGN){ 829 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 830 } 831 return flags; 832 } 833 834 static void sm_setup_key_distribution(uint8_t key_set){ 835 setup->sm_key_distribution_received_set = 0; 836 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 837 setup->sm_key_distribution_sent_set = 0; 838 #ifdef ENABLE_LE_SIGNED_WRITE 839 setup->sm_le_device_index = -1; 840 #endif 841 } 842 843 // CSRK Key Lookup 844 845 846 static int sm_address_resolution_idle(void){ 847 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 848 } 849 850 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){ 851 (void)memcpy(sm_address_resolution_address, addr, 6); 852 sm_address_resolution_addr_type = addr_type; 853 sm_address_resolution_test = 0; 854 sm_address_resolution_mode = mode; 855 sm_address_resolution_context = context; 856 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 857 } 858 859 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 860 // check if already in list 861 btstack_linked_list_iterator_t it; 862 sm_lookup_entry_t * entry; 863 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 864 while(btstack_linked_list_iterator_has_next(&it)){ 865 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 866 if (entry->address_type != address_type) continue; 867 if (memcmp(entry->address, address, 6)) continue; 868 // already in list 869 return BTSTACK_BUSY; 870 } 871 entry = btstack_memory_sm_lookup_entry_get(); 872 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 873 entry->address_type = (bd_addr_type_t) address_type; 874 (void)memcpy(entry->address, address, 6); 875 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 876 sm_run(); 877 return 0; 878 } 879 880 // CMAC calculation using AES Engineq 881 #ifdef USE_CMAC_ENGINE 882 883 static void sm_cmac_done_trampoline(void * arg){ 884 UNUSED(arg); 885 sm_cmac_active = 0; 886 (*sm_cmac_done_callback)(sm_cmac_hash); 887 sm_run(); 888 } 889 890 int sm_cmac_ready(void){ 891 return sm_cmac_active == 0; 892 } 893 #endif 894 895 #ifdef ENABLE_LE_SECURE_CONNECTIONS 896 // generic cmac calculation 897 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)){ 898 sm_cmac_active = 1; 899 sm_cmac_done_callback = done_callback; 900 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 901 } 902 #endif 903 904 // cmac for ATT Message signing 905 #ifdef ENABLE_LE_SIGNED_WRITE 906 907 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)){ 908 sm_cmac_active = 1; 909 sm_cmac_done_callback = done_callback; 910 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 911 } 912 913 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 914 if (offset >= sm_cmac_signed_write_message_len) { 915 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 916 return 0; 917 } 918 919 offset = sm_cmac_signed_write_message_len - 1 - offset; 920 921 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 922 if (offset < 3){ 923 return sm_cmac_signed_write_header[offset]; 924 } 925 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 926 if (offset < actual_message_len_incl_header){ 927 return sm_cmac_signed_write_message[offset - 3]; 928 } 929 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 930 } 931 932 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)){ 933 // ATT Message Signing 934 sm_cmac_signed_write_header[0] = opcode; 935 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 936 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 937 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 938 sm_cmac_signed_write_message = message; 939 sm_cmac_signed_write_message_len = total_message_len; 940 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 941 } 942 #endif 943 944 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 945 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 946 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 947 switch (setup->sm_stk_generation_method){ 948 case PK_RESP_INPUT: 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 951 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 952 } else { 953 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)); 954 } 955 break; 956 case PK_INIT_INPUT: 957 if (IS_RESPONDER(sm_conn->sm_role)){ 958 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)); 959 } else { 960 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 961 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 962 } 963 break; 964 case PK_BOTH_INPUT: 965 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 966 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 967 break; 968 case NUMERIC_COMPARISON: 969 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 970 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)); 971 break; 972 case JUST_WORKS: 973 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 974 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 975 break; 976 case OOB: 977 // client already provided OOB data, let's skip notification. 978 break; 979 } 980 } 981 982 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 983 int recv_flags; 984 if (IS_RESPONDER(sm_conn->sm_role)){ 985 // slave / responder 986 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 987 } else { 988 // master / initiator 989 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 990 } 991 992 #ifdef ENABLE_LE_SECURE_CONNECTIONS 993 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 994 if (setup->sm_use_secure_connections){ 995 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 996 } 997 #endif 998 999 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1000 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 1001 } 1002 1003 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1004 if (sm_active_connection_handle == con_handle){ 1005 sm_timeout_stop(); 1006 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1007 log_info("sm: connection 0x%x released setup context", con_handle); 1008 1009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1010 // generate new ec key after each pairing (that used it) 1011 if (setup->sm_use_secure_connections){ 1012 sm_ec_generate_new_key(); 1013 } 1014 #endif 1015 } 1016 } 1017 1018 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1019 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1020 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 1021 sm_done_for_handle(connection->sm_handle); 1022 } 1023 1024 static int sm_key_distribution_flags_for_auth_req(void){ 1025 1026 int flags = SM_KEYDIST_ID_KEY; 1027 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1028 // encryption and signing information only if bonding requested 1029 flags |= SM_KEYDIST_ENC_KEY; 1030 #ifdef ENABLE_LE_SIGNED_WRITE 1031 flags |= SM_KEYDIST_SIGN; 1032 #endif 1033 } 1034 return flags; 1035 } 1036 1037 static void sm_reset_setup(void){ 1038 // fill in sm setup 1039 setup->sm_state_vars = 0; 1040 setup->sm_keypress_notification = 0; 1041 sm_reset_tk(); 1042 } 1043 1044 static void sm_init_setup(sm_connection_t * sm_conn){ 1045 1046 // fill in sm setup 1047 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1048 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1049 1050 // query client for Legacy Pairing OOB data 1051 setup->sm_have_oob_data = 0; 1052 if (sm_get_oob_data) { 1053 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1054 } 1055 1056 // if available and SC supported, also ask for SC OOB Data 1057 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1058 memset(setup->sm_ra, 0, 16); 1059 memset(setup->sm_rb, 0, 16); 1060 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1061 if (sm_get_sc_oob_data){ 1062 if (IS_RESPONDER(sm_conn->sm_role)){ 1063 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1064 sm_conn->sm_peer_addr_type, 1065 sm_conn->sm_peer_address, 1066 setup->sm_peer_confirm, 1067 setup->sm_ra); 1068 } else { 1069 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1070 sm_conn->sm_peer_addr_type, 1071 sm_conn->sm_peer_address, 1072 setup->sm_peer_confirm, 1073 setup->sm_rb); 1074 } 1075 } else { 1076 setup->sm_have_oob_data = 0; 1077 } 1078 } 1079 #endif 1080 1081 sm_pairing_packet_t * local_packet; 1082 if (IS_RESPONDER(sm_conn->sm_role)){ 1083 // slave 1084 local_packet = &setup->sm_s_pres; 1085 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1086 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1087 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1088 } else { 1089 // master 1090 local_packet = &setup->sm_m_preq; 1091 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1092 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1093 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1094 1095 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1096 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1097 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1098 } 1099 1100 uint8_t auth_req = sm_auth_req; 1101 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1102 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1103 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1104 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1105 } 1106 1107 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1108 1109 sm_pairing_packet_t * remote_packet; 1110 int remote_key_request; 1111 if (IS_RESPONDER(sm_conn->sm_role)){ 1112 // slave / responder 1113 remote_packet = &setup->sm_m_preq; 1114 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1115 } else { 1116 // master / initiator 1117 remote_packet = &setup->sm_s_pres; 1118 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1119 } 1120 1121 // check key size 1122 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1123 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1124 1125 // decide on STK generation method / SC 1126 sm_setup_tk(); 1127 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1128 1129 // check if STK generation method is acceptable by client 1130 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1131 1132 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1133 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1134 if (setup->sm_use_secure_connections){ 1135 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1136 } 1137 #endif 1138 1139 // identical to responder 1140 sm_setup_key_distribution(remote_key_request); 1141 1142 // JUST WORKS doens't provide authentication 1143 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1144 1145 return 0; 1146 } 1147 1148 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1149 1150 // cache and reset context 1151 int matched_device_id = sm_address_resolution_test; 1152 address_resolution_mode_t mode = sm_address_resolution_mode; 1153 void * context = sm_address_resolution_context; 1154 1155 // reset context 1156 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1157 sm_address_resolution_context = NULL; 1158 sm_address_resolution_test = -1; 1159 hci_con_handle_t con_handle = 0; 1160 1161 sm_connection_t * sm_connection; 1162 #ifdef ENABLE_LE_CENTRAL 1163 sm_key_t ltk; 1164 int have_ltk; 1165 int pairing_need; 1166 #endif 1167 switch (mode){ 1168 case ADDRESS_RESOLUTION_GENERAL: 1169 break; 1170 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1171 sm_connection = (sm_connection_t *) context; 1172 con_handle = sm_connection->sm_handle; 1173 switch (event){ 1174 case ADDRESS_RESOLUTION_SUCEEDED: 1175 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1176 sm_connection->sm_le_db_index = matched_device_id; 1177 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1178 if (sm_connection->sm_role) { 1179 // LTK request received before, IRK required -> start LTK calculation 1180 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1181 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1182 } 1183 break; 1184 } 1185 #ifdef ENABLE_LE_CENTRAL 1186 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 1187 have_ltk = !sm_is_null_key(ltk); 1188 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1189 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1190 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1191 // reset requests 1192 sm_connection->sm_security_request_received = 0; 1193 sm_connection->sm_pairing_requested = 0; 1194 1195 // have ltk -> start encryption 1196 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1197 // "When a bond has been created between two devices, any reconnection should result in the local device 1198 // enabling or requesting encryption with the remote device before initiating any service request." 1199 if (have_ltk){ 1200 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1201 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1202 break; 1203 #else 1204 log_info("central: defer enabling encryption for bonded device"); 1205 #endif 1206 } 1207 // pairint_request -> send pairing request 1208 if (pairing_need){ 1209 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1210 break; 1211 } 1212 #endif 1213 break; 1214 case ADDRESS_RESOLUTION_FAILED: 1215 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1216 if (sm_connection->sm_role) { 1217 // LTK request received before, IRK required -> negative LTK reply 1218 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1219 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1220 } 1221 break; 1222 } 1223 #ifdef ENABLE_LE_CENTRAL 1224 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1225 sm_connection->sm_security_request_received = 0; 1226 sm_connection->sm_pairing_requested = 0; 1227 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1228 #endif 1229 break; 1230 } 1231 break; 1232 default: 1233 break; 1234 } 1235 1236 switch (event){ 1237 case ADDRESS_RESOLUTION_SUCEEDED: 1238 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1239 break; 1240 case ADDRESS_RESOLUTION_FAILED: 1241 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1242 break; 1243 } 1244 } 1245 1246 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1247 1248 int le_db_index = -1; 1249 1250 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1251 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1252 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1253 & SM_AUTHREQ_BONDING ) != 0; 1254 1255 if (bonding_enabed){ 1256 1257 // lookup device based on IRK 1258 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1259 int i; 1260 for (i=0; i < le_device_db_max_count(); i++){ 1261 sm_key_t irk; 1262 bd_addr_t address; 1263 int address_type = BD_ADDR_TYPE_UNKNOWN; 1264 le_device_db_info(i, &address_type, address, irk); 1265 // skip unused entries 1266 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1267 // compare IRK 1268 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1269 1270 log_info("sm: device found for IRK, updating"); 1271 le_db_index = i; 1272 break; 1273 } 1274 } else { 1275 // assert IRK is set to zero 1276 memset(setup->sm_peer_irk, 0, 16); 1277 } 1278 1279 // if not found, lookup via public address if possible 1280 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1281 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1282 int i; 1283 for (i=0; i < le_device_db_max_count(); i++){ 1284 bd_addr_t address; 1285 int address_type = BD_ADDR_TYPE_UNKNOWN; 1286 le_device_db_info(i, &address_type, address, NULL); 1287 // skip unused entries 1288 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1289 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1290 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1291 log_info("sm: device found for public address, updating"); 1292 le_db_index = i; 1293 break; 1294 } 1295 } 1296 } 1297 1298 // if not found, add to db 1299 if (le_db_index < 0) { 1300 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1301 } 1302 1303 if (le_db_index >= 0){ 1304 1305 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1306 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1307 1308 #ifdef ENABLE_LE_SIGNED_WRITE 1309 // store local CSRK 1310 setup->sm_le_device_index = le_db_index; 1311 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1312 log_info("sm: store local CSRK"); 1313 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1314 le_device_db_local_counter_set(le_db_index, 0); 1315 } 1316 1317 // store remote CSRK 1318 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1319 log_info("sm: store remote CSRK"); 1320 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1321 le_device_db_remote_counter_set(le_db_index, 0); 1322 } 1323 #endif 1324 // store encryption information for secure connections: LTK generated by ECDH 1325 if (setup->sm_use_secure_connections){ 1326 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1327 uint8_t zero_rand[8]; 1328 memset(zero_rand, 0, 8); 1329 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1330 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1331 } 1332 1333 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1334 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1335 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1336 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1337 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1338 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1339 1340 } 1341 } 1342 } else { 1343 log_info("Ignoring received keys, bonding not enabled"); 1344 } 1345 1346 // keep le_db_index 1347 sm_conn->sm_le_db_index = le_db_index; 1348 } 1349 1350 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1351 setup->sm_pairing_failed_reason = reason; 1352 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1353 } 1354 1355 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1356 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1357 } 1358 1359 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1360 1361 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1362 static int sm_passkey_used(stk_generation_method_t method); 1363 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1364 1365 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1366 if (setup->sm_stk_generation_method == OOB){ 1367 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1368 } else { 1369 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); 1370 } 1371 } 1372 1373 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1374 if (IS_RESPONDER(sm_conn->sm_role)){ 1375 // Responder 1376 if (setup->sm_stk_generation_method == OOB){ 1377 // generate Nb 1378 log_info("Generate Nb"); 1379 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); 1380 } else { 1381 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1382 } 1383 } else { 1384 // Initiator role 1385 switch (setup->sm_stk_generation_method){ 1386 case JUST_WORKS: 1387 sm_sc_prepare_dhkey_check(sm_conn); 1388 break; 1389 1390 case NUMERIC_COMPARISON: 1391 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1392 break; 1393 case PK_INIT_INPUT: 1394 case PK_RESP_INPUT: 1395 case PK_BOTH_INPUT: 1396 if (setup->sm_passkey_bit < 20) { 1397 sm_sc_start_calculating_local_confirm(sm_conn); 1398 } else { 1399 sm_sc_prepare_dhkey_check(sm_conn); 1400 } 1401 break; 1402 case OOB: 1403 sm_sc_prepare_dhkey_check(sm_conn); 1404 break; 1405 } 1406 } 1407 } 1408 1409 static void sm_sc_cmac_done(uint8_t * hash){ 1410 log_info("sm_sc_cmac_done: "); 1411 log_info_hexdump(hash, 16); 1412 1413 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1414 sm_sc_oob_state = SM_SC_OOB_IDLE; 1415 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1416 return; 1417 } 1418 1419 sm_connection_t * sm_conn = sm_cmac_connection; 1420 sm_cmac_connection = NULL; 1421 #ifdef ENABLE_CLASSIC 1422 link_key_type_t link_key_type; 1423 #endif 1424 1425 switch (sm_conn->sm_engine_state){ 1426 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1427 (void)memcpy(setup->sm_local_confirm, hash, 16); 1428 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1429 break; 1430 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1431 // check 1432 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1433 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1434 break; 1435 } 1436 sm_sc_state_after_receiving_random(sm_conn); 1437 break; 1438 case SM_SC_W4_CALCULATE_G2: { 1439 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1440 big_endian_store_32(setup->sm_tk, 12, vab); 1441 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1442 sm_trigger_user_response(sm_conn); 1443 break; 1444 } 1445 case SM_SC_W4_CALCULATE_F5_SALT: 1446 (void)memcpy(setup->sm_t, hash, 16); 1447 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1448 break; 1449 case SM_SC_W4_CALCULATE_F5_MACKEY: 1450 (void)memcpy(setup->sm_mackey, hash, 16); 1451 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1452 break; 1453 case SM_SC_W4_CALCULATE_F5_LTK: 1454 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1455 // Errata Service Release to the Bluetooth Specification: ESR09 1456 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1457 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1458 (void)memcpy(setup->sm_ltk, hash, 16); 1459 (void)memcpy(setup->sm_local_ltk, hash, 16); 1460 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1461 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1462 break; 1463 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1464 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1465 if (IS_RESPONDER(sm_conn->sm_role)){ 1466 // responder 1467 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1468 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1469 } else { 1470 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1471 } 1472 } else { 1473 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1474 } 1475 break; 1476 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1477 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1478 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1479 break; 1480 } 1481 if (IS_RESPONDER(sm_conn->sm_role)){ 1482 // responder 1483 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1484 } else { 1485 // initiator 1486 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1487 } 1488 break; 1489 case SM_SC_W4_CALCULATE_H6_ILK: 1490 (void)memcpy(setup->sm_t, hash, 16); 1491 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1492 break; 1493 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1494 #ifdef ENABLE_CLASSIC 1495 reverse_128(hash, setup->sm_t); 1496 link_key_type = sm_conn->sm_connection_authenticated ? 1497 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1498 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1499 if (IS_RESPONDER(sm_conn->sm_role)){ 1500 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1501 } else { 1502 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1503 } 1504 #endif 1505 if (IS_RESPONDER(sm_conn->sm_role)){ 1506 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1507 } else { 1508 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1509 } 1510 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1511 sm_done_for_handle(sm_conn->sm_handle); 1512 break; 1513 default: 1514 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1515 break; 1516 } 1517 sm_run(); 1518 } 1519 1520 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){ 1521 const uint16_t message_len = 65; 1522 sm_cmac_connection = sm_conn; 1523 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1524 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1525 sm_cmac_sc_buffer[64] = z; 1526 log_info("f4 key"); 1527 log_info_hexdump(x, 16); 1528 log_info("f4 message"); 1529 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1530 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1531 } 1532 1533 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1534 static const uint8_t f5_length[] = { 0x01, 0x00}; 1535 1536 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1537 1538 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1539 1540 log_info("f5_calculate_salt"); 1541 // calculate salt for f5 1542 const uint16_t message_len = 32; 1543 sm_cmac_connection = sm_conn; 1544 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1545 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1546 } 1547 1548 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){ 1549 const uint16_t message_len = 53; 1550 sm_cmac_connection = sm_conn; 1551 1552 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1553 sm_cmac_sc_buffer[0] = 0; 1554 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1555 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1556 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1557 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1558 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1559 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1560 log_info("f5 key"); 1561 log_info_hexdump(t, 16); 1562 log_info("f5 message for MacKey"); 1563 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1564 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1565 } 1566 1567 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1568 sm_key56_t bd_addr_master, bd_addr_slave; 1569 bd_addr_master[0] = setup->sm_m_addr_type; 1570 bd_addr_slave[0] = setup->sm_s_addr_type; 1571 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1572 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1573 if (IS_RESPONDER(sm_conn->sm_role)){ 1574 // responder 1575 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1576 } else { 1577 // initiator 1578 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1579 } 1580 } 1581 1582 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1583 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1584 const uint16_t message_len = 53; 1585 sm_cmac_connection = sm_conn; 1586 sm_cmac_sc_buffer[0] = 1; 1587 // 1..52 setup before 1588 log_info("f5 key"); 1589 log_info_hexdump(t, 16); 1590 log_info("f5 message for LTK"); 1591 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1592 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1593 } 1594 1595 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1596 f5_ltk(sm_conn, setup->sm_t); 1597 } 1598 1599 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){ 1600 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1601 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1602 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1603 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1604 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1605 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1606 } 1607 1608 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1609 const uint16_t message_len = 65; 1610 sm_cmac_connection = sm_conn; 1611 log_info("f6 key"); 1612 log_info_hexdump(w, 16); 1613 log_info("f6 message"); 1614 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1615 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1616 } 1617 1618 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1619 // - U is 256 bits 1620 // - V is 256 bits 1621 // - X is 128 bits 1622 // - Y is 128 bits 1623 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){ 1624 const uint16_t message_len = 80; 1625 sm_cmac_connection = sm_conn; 1626 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1627 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1628 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1629 log_info("g2 key"); 1630 log_info_hexdump(x, 16); 1631 log_info("g2 message"); 1632 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1633 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1634 } 1635 1636 static void g2_calculate(sm_connection_t * sm_conn) { 1637 // calc Va if numeric comparison 1638 if (IS_RESPONDER(sm_conn->sm_role)){ 1639 // responder 1640 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1641 } else { 1642 // initiator 1643 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1644 } 1645 } 1646 1647 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1648 uint8_t z = 0; 1649 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1650 // some form of passkey 1651 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1652 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1653 setup->sm_passkey_bit++; 1654 } 1655 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1656 } 1657 1658 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1659 // OOB 1660 if (setup->sm_stk_generation_method == OOB){ 1661 if (IS_RESPONDER(sm_conn->sm_role)){ 1662 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1663 } else { 1664 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1665 } 1666 return; 1667 } 1668 1669 uint8_t z = 0; 1670 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1671 // some form of passkey 1672 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1673 // sm_passkey_bit was increased before sending confirm value 1674 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1675 } 1676 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1677 } 1678 1679 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1680 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1681 1682 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1683 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1684 return; 1685 } else { 1686 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1687 } 1688 } 1689 1690 static void sm_sc_dhkey_calculated(void * arg){ 1691 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1692 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1693 if (sm_conn == NULL) return; 1694 1695 log_info("dhkey"); 1696 log_info_hexdump(&setup->sm_dhkey[0], 32); 1697 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1698 // trigger next step 1699 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1700 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1701 } 1702 sm_run(); 1703 } 1704 1705 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1706 // calculate DHKCheck 1707 sm_key56_t bd_addr_master, bd_addr_slave; 1708 bd_addr_master[0] = setup->sm_m_addr_type; 1709 bd_addr_slave[0] = setup->sm_s_addr_type; 1710 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1711 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1712 uint8_t iocap_a[3]; 1713 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1714 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1715 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1716 uint8_t iocap_b[3]; 1717 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1718 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1719 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1720 if (IS_RESPONDER(sm_conn->sm_role)){ 1721 // responder 1722 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1723 f6_engine(sm_conn, setup->sm_mackey); 1724 } else { 1725 // initiator 1726 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1727 f6_engine(sm_conn, setup->sm_mackey); 1728 } 1729 } 1730 1731 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1732 // validate E = f6() 1733 sm_key56_t bd_addr_master, bd_addr_slave; 1734 bd_addr_master[0] = setup->sm_m_addr_type; 1735 bd_addr_slave[0] = setup->sm_s_addr_type; 1736 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1737 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1738 1739 uint8_t iocap_a[3]; 1740 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1741 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1742 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1743 uint8_t iocap_b[3]; 1744 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1745 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1746 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1747 if (IS_RESPONDER(sm_conn->sm_role)){ 1748 // responder 1749 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1750 f6_engine(sm_conn, setup->sm_mackey); 1751 } else { 1752 // initiator 1753 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1754 f6_engine(sm_conn, setup->sm_mackey); 1755 } 1756 } 1757 1758 1759 // 1760 // Link Key Conversion Function h6 1761 // 1762 // h6(W, keyID) = AES-CMACW(keyID) 1763 // - W is 128 bits 1764 // - keyID is 32 bits 1765 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1766 const uint16_t message_len = 4; 1767 sm_cmac_connection = sm_conn; 1768 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1769 log_info("h6 key"); 1770 log_info_hexdump(w, 16); 1771 log_info("h6 message"); 1772 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1773 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1774 } 1775 1776 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1777 // Errata Service Release to the Bluetooth Specification: ESR09 1778 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1779 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1780 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1781 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1782 } 1783 1784 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1785 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1786 } 1787 1788 #endif 1789 1790 // key management legacy connections: 1791 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1792 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1793 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1794 // - responder reconnects: responder uses LTK receveived from master 1795 1796 // key management secure connections: 1797 // - both devices store same LTK from ECDH key exchange. 1798 1799 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1800 static void sm_load_security_info(sm_connection_t * sm_connection){ 1801 int encryption_key_size; 1802 int authenticated; 1803 int authorized; 1804 int secure_connection; 1805 1806 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1807 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1808 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1809 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); 1810 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1811 sm_connection->sm_connection_authenticated = authenticated; 1812 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1813 sm_connection->sm_connection_sc = secure_connection; 1814 } 1815 #endif 1816 1817 #ifdef ENABLE_LE_PERIPHERAL 1818 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1819 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1820 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1821 // re-establish used key encryption size 1822 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1823 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1824 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1825 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1826 // Legacy paring -> not SC 1827 sm_connection->sm_connection_sc = 0; 1828 log_info("sm: received ltk request with key size %u, authenticated %u", 1829 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1830 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1831 sm_run(); 1832 } 1833 #endif 1834 1835 // distributed key generation 1836 static bool sm_run_dpkg(void){ 1837 switch (dkg_state){ 1838 case DKG_CALC_IRK: 1839 // already busy? 1840 if (sm_aes128_state == SM_AES128_IDLE) { 1841 log_info("DKG_CALC_IRK started"); 1842 // IRK = d1(IR, 1, 0) 1843 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1844 sm_aes128_state = SM_AES128_ACTIVE; 1845 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1846 return true; 1847 } 1848 break; 1849 case DKG_CALC_DHK: 1850 // already busy? 1851 if (sm_aes128_state == SM_AES128_IDLE) { 1852 log_info("DKG_CALC_DHK started"); 1853 // DHK = d1(IR, 3, 0) 1854 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1855 sm_aes128_state = SM_AES128_ACTIVE; 1856 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1857 return true; 1858 } 1859 break; 1860 default: 1861 break; 1862 } 1863 return false; 1864 } 1865 1866 // random address updates 1867 static bool sm_run_rau(void){ 1868 switch (rau_state){ 1869 case RAU_GET_RANDOM: 1870 rau_state = RAU_W4_RANDOM; 1871 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1872 return true; 1873 case RAU_GET_ENC: 1874 // already busy? 1875 if (sm_aes128_state == SM_AES128_IDLE) { 1876 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1877 sm_aes128_state = SM_AES128_ACTIVE; 1878 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1879 return true; 1880 } 1881 break; 1882 case RAU_SET_ADDRESS: 1883 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1884 rau_state = RAU_IDLE; 1885 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1886 return true; 1887 default: 1888 break; 1889 } 1890 return false; 1891 } 1892 1893 // CSRK Lookup 1894 static bool sm_run_csrk(void){ 1895 btstack_linked_list_iterator_t it; 1896 1897 // -- if csrk lookup ready, find connection that require csrk lookup 1898 if (sm_address_resolution_idle()){ 1899 hci_connections_get_iterator(&it); 1900 while(btstack_linked_list_iterator_has_next(&it)){ 1901 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1902 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1903 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1904 // and start lookup 1905 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); 1906 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1907 break; 1908 } 1909 } 1910 } 1911 1912 // -- if csrk lookup ready, resolved addresses for received addresses 1913 if (sm_address_resolution_idle()) { 1914 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1915 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1916 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1917 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1918 btstack_memory_sm_lookup_entry_free(entry); 1919 } 1920 } 1921 1922 // -- Continue with CSRK device lookup by public or resolvable private address 1923 if (!sm_address_resolution_idle()){ 1924 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1925 while (sm_address_resolution_test < le_device_db_max_count()){ 1926 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1927 bd_addr_t addr; 1928 sm_key_t irk; 1929 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1930 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1931 1932 // skip unused entries 1933 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1934 sm_address_resolution_test++; 1935 continue; 1936 } 1937 1938 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1939 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1940 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1941 break; 1942 } 1943 1944 // if connection type is public, it must be a different one 1945 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1946 sm_address_resolution_test++; 1947 continue; 1948 } 1949 1950 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1951 1952 log_info("LE Device Lookup: calculate AH"); 1953 log_info_key("IRK", irk); 1954 1955 (void)memcpy(sm_aes128_key, irk, 16); 1956 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1957 sm_address_resolution_ah_calculation_active = 1; 1958 sm_aes128_state = SM_AES128_ACTIVE; 1959 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1960 return true; 1961 } 1962 1963 if (sm_address_resolution_test >= le_device_db_max_count()){ 1964 log_info("LE Device Lookup: not found"); 1965 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1966 } 1967 } 1968 return false; 1969 } 1970 1971 // SC OOB 1972 static bool sm_run_oob(void){ 1973 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1974 switch (sm_sc_oob_state){ 1975 case SM_SC_OOB_W2_CALC_CONFIRM: 1976 if (!sm_cmac_ready()) break; 1977 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1978 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1979 return true; 1980 default: 1981 break; 1982 } 1983 #endif 1984 return false; 1985 } 1986 1987 // handle basic actions that don't requires the full context 1988 static bool sm_run_basic(void){ 1989 btstack_linked_list_iterator_t it; 1990 hci_connections_get_iterator(&it); 1991 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1992 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1993 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1994 switch(sm_connection->sm_engine_state){ 1995 // responder side 1996 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1997 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1998 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1999 return true; 2000 2001 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2002 case SM_SC_RECEIVED_LTK_REQUEST: 2003 switch (sm_connection->sm_irk_lookup_state){ 2004 case IRK_LOOKUP_FAILED: 2005 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2006 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2007 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2008 return true; 2009 default: 2010 break; 2011 } 2012 break; 2013 #endif 2014 default: 2015 break; 2016 } 2017 } 2018 return false; 2019 } 2020 2021 static void sm_run_activate_connection(void){ 2022 // Find connections that requires setup context and make active if no other is locked 2023 btstack_linked_list_iterator_t it; 2024 hci_connections_get_iterator(&it); 2025 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2026 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2027 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2028 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2029 int done = 1; 2030 int err; 2031 UNUSED(err); 2032 2033 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2034 // assert ec key is ready 2035 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2036 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2037 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2038 sm_ec_generate_new_key(); 2039 } 2040 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2041 continue; 2042 } 2043 } 2044 #endif 2045 2046 switch (sm_connection->sm_engine_state) { 2047 #ifdef ENABLE_LE_PERIPHERAL 2048 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2049 // send packet if possible, 2050 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2051 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2052 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2053 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2054 } else { 2055 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2056 } 2057 // don't lock sxetup context yet 2058 done = 0; 2059 break; 2060 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2061 sm_reset_setup(); 2062 sm_init_setup(sm_connection); 2063 // recover pairing request 2064 (void)memcpy(&setup->sm_m_preq, 2065 &sm_connection->sm_m_preq, 2066 sizeof(sm_pairing_packet_t)); 2067 err = sm_stk_generation_init(sm_connection); 2068 2069 #ifdef ENABLE_TESTING_SUPPORT 2070 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2071 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2072 err = test_pairing_failure; 2073 } 2074 #endif 2075 if (err){ 2076 setup->sm_pairing_failed_reason = err; 2077 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2078 break; 2079 } 2080 sm_timeout_start(sm_connection); 2081 // generate random number first, if we need to show passkey 2082 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2083 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); 2084 break; 2085 } 2086 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2087 break; 2088 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2089 sm_reset_setup(); 2090 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2091 break; 2092 2093 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2094 case SM_SC_RECEIVED_LTK_REQUEST: 2095 switch (sm_connection->sm_irk_lookup_state){ 2096 case IRK_LOOKUP_SUCCEEDED: 2097 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2098 // start using context by loading security info 2099 sm_reset_setup(); 2100 sm_load_security_info(sm_connection); 2101 if ((setup->sm_peer_ediv == 0) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2102 (void)memcpy(setup->sm_ltk, 2103 setup->sm_peer_ltk, 16); 2104 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2105 break; 2106 } 2107 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2108 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2109 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2110 // don't lock setup context yet 2111 return; 2112 default: 2113 // just wait until IRK lookup is completed 2114 // don't lock setup context yet 2115 done = 0; 2116 break; 2117 } 2118 break; 2119 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2120 #endif /* ENABLE_LE_PERIPHERAL */ 2121 2122 #ifdef ENABLE_LE_CENTRAL 2123 case SM_INITIATOR_PH0_HAS_LTK: 2124 sm_reset_setup(); 2125 sm_load_security_info(sm_connection); 2126 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2127 break; 2128 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2129 sm_reset_setup(); 2130 sm_init_setup(sm_connection); 2131 sm_timeout_start(sm_connection); 2132 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2133 break; 2134 #endif 2135 2136 default: 2137 done = 0; 2138 break; 2139 } 2140 if (done){ 2141 sm_active_connection_handle = sm_connection->sm_handle; 2142 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); 2143 } 2144 } 2145 } 2146 2147 static void sm_run(void){ 2148 2149 // assert that stack has already bootet 2150 if (hci_get_state() != HCI_STATE_WORKING) return; 2151 2152 // assert that we can send at least commands 2153 if (!hci_can_send_command_packet_now()) return; 2154 2155 // pause until IR/ER are ready 2156 if (sm_persistent_keys_random_active) return; 2157 2158 bool done; 2159 2160 // 2161 // non-connection related behaviour 2162 // 2163 2164 done = sm_run_dpkg(); 2165 if (done) return; 2166 2167 done = sm_run_rau(); 2168 if (done) return; 2169 2170 done = sm_run_csrk(); 2171 if (done) return; 2172 2173 done = sm_run_oob(); 2174 if (done) return; 2175 2176 // assert that we can send at least commands - cmd might have been sent by crypto engine 2177 if (!hci_can_send_command_packet_now()) return; 2178 2179 // handle basic actions that don't requires the full context 2180 done = sm_run_basic(); 2181 if (done) return; 2182 2183 // 2184 // active connection handling 2185 // -- use loop to handle next connection if lock on setup context is released 2186 2187 while (true) { 2188 2189 sm_run_activate_connection(); 2190 2191 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2192 2193 // 2194 // active connection handling 2195 // 2196 2197 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2198 if (!connection) { 2199 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2200 return; 2201 } 2202 2203 // assert that we could send a SM PDU - not needed for all of the following 2204 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2205 log_info("cannot send now, requesting can send now event"); 2206 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2207 return; 2208 } 2209 2210 // send keypress notifications 2211 if (setup->sm_keypress_notification){ 2212 int i; 2213 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2214 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2215 uint8_t action = 0; 2216 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2217 if (flags & (1<<i)){ 2218 int clear_flag = 1; 2219 switch (i){ 2220 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2221 case SM_KEYPRESS_PASSKEY_CLEARED: 2222 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2223 default: 2224 break; 2225 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2226 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2227 num_actions--; 2228 clear_flag = num_actions == 0; 2229 break; 2230 } 2231 if (clear_flag){ 2232 flags &= ~(1<<i); 2233 } 2234 action = i; 2235 break; 2236 } 2237 } 2238 setup->sm_keypress_notification = (num_actions << 5) | flags; 2239 2240 // send keypress notification 2241 uint8_t buffer[2]; 2242 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2243 buffer[1] = action; 2244 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2245 2246 // try 2247 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2248 return; 2249 } 2250 2251 int key_distribution_flags; 2252 UNUSED(key_distribution_flags); 2253 2254 log_info("sm_run: state %u", connection->sm_engine_state); 2255 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2256 log_info("sm_run // cannot send"); 2257 } 2258 switch (connection->sm_engine_state){ 2259 2260 // general 2261 case SM_GENERAL_SEND_PAIRING_FAILED: { 2262 uint8_t buffer[2]; 2263 buffer[0] = SM_CODE_PAIRING_FAILED; 2264 buffer[1] = setup->sm_pairing_failed_reason; 2265 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2266 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2267 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2268 sm_done_for_handle(connection->sm_handle); 2269 break; 2270 } 2271 2272 // responding state 2273 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2274 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2275 if (!sm_cmac_ready()) break; 2276 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2277 sm_sc_calculate_local_confirm(connection); 2278 break; 2279 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2280 if (!sm_cmac_ready()) break; 2281 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2282 sm_sc_calculate_remote_confirm(connection); 2283 break; 2284 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2285 if (!sm_cmac_ready()) break; 2286 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2287 sm_sc_calculate_f6_for_dhkey_check(connection); 2288 break; 2289 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2290 if (!sm_cmac_ready()) break; 2291 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2292 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2293 break; 2294 case SM_SC_W2_CALCULATE_F5_SALT: 2295 if (!sm_cmac_ready()) break; 2296 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2297 f5_calculate_salt(connection); 2298 break; 2299 case SM_SC_W2_CALCULATE_F5_MACKEY: 2300 if (!sm_cmac_ready()) break; 2301 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2302 f5_calculate_mackey(connection); 2303 break; 2304 case SM_SC_W2_CALCULATE_F5_LTK: 2305 if (!sm_cmac_ready()) break; 2306 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2307 f5_calculate_ltk(connection); 2308 break; 2309 case SM_SC_W2_CALCULATE_G2: 2310 if (!sm_cmac_ready()) break; 2311 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2312 g2_calculate(connection); 2313 break; 2314 case SM_SC_W2_CALCULATE_H6_ILK: 2315 if (!sm_cmac_ready()) break; 2316 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2317 h6_calculate_ilk(connection); 2318 break; 2319 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2320 if (!sm_cmac_ready()) break; 2321 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2322 h6_calculate_br_edr_link_key(connection); 2323 break; 2324 #endif 2325 2326 #ifdef ENABLE_LE_CENTRAL 2327 // initiator side 2328 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2329 sm_key_t peer_ltk_flipped; 2330 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2331 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2332 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2333 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2334 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2335 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2336 return; 2337 } 2338 2339 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2340 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2341 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2342 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2343 sm_timeout_reset(connection); 2344 break; 2345 #endif 2346 2347 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2348 2349 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2350 int trigger_user_response = 0; 2351 int trigger_start_calculating_local_confirm = 0; 2352 uint8_t buffer[65]; 2353 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2354 // 2355 reverse_256(&ec_q[0], &buffer[1]); 2356 reverse_256(&ec_q[32], &buffer[33]); 2357 2358 #ifdef ENABLE_TESTING_SUPPORT 2359 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2360 log_info("testing_support: invalidating public key"); 2361 // flip single bit of public key coordinate 2362 buffer[1] ^= 1; 2363 } 2364 #endif 2365 2366 // stk generation method 2367 // passkey entry: notify app to show passkey or to request passkey 2368 switch (setup->sm_stk_generation_method){ 2369 case JUST_WORKS: 2370 case NUMERIC_COMPARISON: 2371 if (IS_RESPONDER(connection->sm_role)){ 2372 // responder 2373 trigger_start_calculating_local_confirm = 1; 2374 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2375 } else { 2376 // initiator 2377 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2378 } 2379 break; 2380 case PK_INIT_INPUT: 2381 case PK_RESP_INPUT: 2382 case PK_BOTH_INPUT: 2383 // use random TK for display 2384 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2385 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2386 setup->sm_passkey_bit = 0; 2387 2388 if (IS_RESPONDER(connection->sm_role)){ 2389 // responder 2390 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2391 } else { 2392 // initiator 2393 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2394 } 2395 trigger_user_response = 1; 2396 break; 2397 case OOB: 2398 if (IS_RESPONDER(connection->sm_role)){ 2399 // responder 2400 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2401 } else { 2402 // initiator 2403 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2404 } 2405 break; 2406 } 2407 2408 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2409 sm_timeout_reset(connection); 2410 2411 // trigger user response and calc confirm after sending pdu 2412 if (trigger_user_response){ 2413 sm_trigger_user_response(connection); 2414 } 2415 if (trigger_start_calculating_local_confirm){ 2416 sm_sc_start_calculating_local_confirm(connection); 2417 } 2418 break; 2419 } 2420 case SM_SC_SEND_CONFIRMATION: { 2421 uint8_t buffer[17]; 2422 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2423 reverse_128(setup->sm_local_confirm, &buffer[1]); 2424 if (IS_RESPONDER(connection->sm_role)){ 2425 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2426 } else { 2427 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2428 } 2429 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2430 sm_timeout_reset(connection); 2431 break; 2432 } 2433 case SM_SC_SEND_PAIRING_RANDOM: { 2434 uint8_t buffer[17]; 2435 buffer[0] = SM_CODE_PAIRING_RANDOM; 2436 reverse_128(setup->sm_local_nonce, &buffer[1]); 2437 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2438 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20)){ 2439 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2440 if (IS_RESPONDER(connection->sm_role)){ 2441 // responder 2442 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2443 } else { 2444 // initiator 2445 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2446 } 2447 } else { 2448 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2449 if (IS_RESPONDER(connection->sm_role)){ 2450 // responder 2451 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2452 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2453 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2454 } else { 2455 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2456 sm_sc_prepare_dhkey_check(connection); 2457 } 2458 } else { 2459 // initiator 2460 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2461 } 2462 } 2463 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2464 sm_timeout_reset(connection); 2465 break; 2466 } 2467 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2468 uint8_t buffer[17]; 2469 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2470 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2471 2472 if (IS_RESPONDER(connection->sm_role)){ 2473 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2474 } else { 2475 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2476 } 2477 2478 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2479 sm_timeout_reset(connection); 2480 break; 2481 } 2482 2483 #endif 2484 2485 #ifdef ENABLE_LE_PERIPHERAL 2486 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2487 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2488 2489 // start with initiator key dist flags 2490 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2491 2492 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2493 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2494 if (setup->sm_use_secure_connections){ 2495 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2496 } 2497 #endif 2498 // setup in response 2499 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); 2500 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); 2501 2502 // update key distribution after ENC was dropped 2503 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2504 2505 if (setup->sm_use_secure_connections){ 2506 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2507 } else { 2508 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2509 } 2510 2511 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2512 sm_timeout_reset(connection); 2513 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2514 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2515 sm_trigger_user_response(connection); 2516 } 2517 return; 2518 #endif 2519 2520 case SM_PH2_SEND_PAIRING_RANDOM: { 2521 uint8_t buffer[17]; 2522 buffer[0] = SM_CODE_PAIRING_RANDOM; 2523 reverse_128(setup->sm_local_random, &buffer[1]); 2524 if (IS_RESPONDER(connection->sm_role)){ 2525 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2526 } else { 2527 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2528 } 2529 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2530 sm_timeout_reset(connection); 2531 break; 2532 } 2533 2534 case SM_PH2_C1_GET_ENC_A: 2535 // already busy? 2536 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2537 // calculate confirm using aes128 engine - step 1 2538 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); 2539 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2540 sm_aes128_state = SM_AES128_ACTIVE; 2541 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); 2542 break; 2543 2544 case SM_PH2_C1_GET_ENC_C: 2545 // already busy? 2546 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2547 // calculate m_confirm using aes128 engine - step 1 2548 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); 2549 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2550 sm_aes128_state = SM_AES128_ACTIVE; 2551 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); 2552 break; 2553 2554 case SM_PH2_CALC_STK: 2555 // already busy? 2556 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2557 // calculate STK 2558 if (IS_RESPONDER(connection->sm_role)){ 2559 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2560 } else { 2561 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2562 } 2563 connection->sm_engine_state = SM_PH2_W4_STK; 2564 sm_aes128_state = SM_AES128_ACTIVE; 2565 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); 2566 break; 2567 2568 case SM_PH3_Y_GET_ENC: 2569 // already busy? 2570 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2571 // PH3B2 - calculate Y from - enc 2572 2573 // dm helper (was sm_dm_r_prime) 2574 // r' = padding || r 2575 // r - 64 bit value 2576 memset(&sm_aes128_plaintext[0], 0, 8); 2577 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2578 2579 // Y = dm(DHK, Rand) 2580 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2581 sm_aes128_state = SM_AES128_ACTIVE; 2582 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); 2583 break; 2584 2585 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2586 uint8_t buffer[17]; 2587 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2588 reverse_128(setup->sm_local_confirm, &buffer[1]); 2589 if (IS_RESPONDER(connection->sm_role)){ 2590 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2591 } else { 2592 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2593 } 2594 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2595 sm_timeout_reset(connection); 2596 return; 2597 } 2598 #ifdef ENABLE_LE_PERIPHERAL 2599 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2600 sm_key_t stk_flipped; 2601 reverse_128(setup->sm_ltk, stk_flipped); 2602 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2603 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2604 return; 2605 } 2606 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2607 sm_key_t ltk_flipped; 2608 reverse_128(setup->sm_ltk, ltk_flipped); 2609 connection->sm_engine_state = SM_RESPONDER_IDLE; 2610 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2611 sm_done_for_handle(connection->sm_handle); 2612 return; 2613 } 2614 case SM_RESPONDER_PH4_Y_GET_ENC: 2615 // already busy? 2616 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2617 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2618 2619 // dm helper (was sm_dm_r_prime) 2620 // r' = padding || r 2621 // r - 64 bit value 2622 memset(&sm_aes128_plaintext[0], 0, 8); 2623 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2624 2625 // Y = dm(DHK, Rand) 2626 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2627 sm_aes128_state = SM_AES128_ACTIVE; 2628 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); 2629 return; 2630 #endif 2631 #ifdef ENABLE_LE_CENTRAL 2632 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2633 sm_key_t stk_flipped; 2634 reverse_128(setup->sm_ltk, stk_flipped); 2635 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2636 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2637 return; 2638 } 2639 #endif 2640 2641 case SM_PH3_DISTRIBUTE_KEYS: 2642 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2643 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2644 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2645 uint8_t buffer[17]; 2646 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2647 reverse_128(setup->sm_ltk, &buffer[1]); 2648 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2649 sm_timeout_reset(connection); 2650 return; 2651 } 2652 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2653 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2654 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2655 uint8_t buffer[11]; 2656 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2657 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2658 reverse_64(setup->sm_local_rand, &buffer[3]); 2659 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2660 sm_timeout_reset(connection); 2661 return; 2662 } 2663 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2664 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2665 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2666 uint8_t buffer[17]; 2667 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2668 reverse_128(sm_persistent_irk, &buffer[1]); 2669 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2670 sm_timeout_reset(connection); 2671 return; 2672 } 2673 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2674 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2675 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2676 bd_addr_t local_address; 2677 uint8_t buffer[8]; 2678 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2679 switch (gap_random_address_get_mode()){ 2680 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2681 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2682 // public or static random 2683 gap_le_get_own_address(&buffer[1], local_address); 2684 break; 2685 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2686 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2687 // fallback to public 2688 gap_local_bd_addr(local_address); 2689 buffer[1] = 0; 2690 break; 2691 } 2692 reverse_bd_addr(local_address, &buffer[2]); 2693 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2694 sm_timeout_reset(connection); 2695 return; 2696 } 2697 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2698 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2699 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2700 2701 #ifdef ENABLE_LE_SIGNED_WRITE 2702 // hack to reproduce test runs 2703 if (test_use_fixed_local_csrk){ 2704 memset(setup->sm_local_csrk, 0xcc, 16); 2705 } 2706 2707 // store local CSRK 2708 if (setup->sm_le_device_index >= 0){ 2709 log_info("sm: store local CSRK"); 2710 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2711 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2712 } 2713 #endif 2714 2715 uint8_t buffer[17]; 2716 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2717 reverse_128(setup->sm_local_csrk, &buffer[1]); 2718 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2719 sm_timeout_reset(connection); 2720 return; 2721 } 2722 2723 // keys are sent 2724 if (IS_RESPONDER(connection->sm_role)){ 2725 // slave -> receive master keys if any 2726 if (sm_key_distribution_all_received(connection)){ 2727 sm_key_distribution_handle_all_received(connection); 2728 connection->sm_engine_state = SM_RESPONDER_IDLE; 2729 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2730 sm_done_for_handle(connection->sm_handle); 2731 } else { 2732 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2733 } 2734 } else { 2735 sm_master_pairing_success(connection); 2736 } 2737 break; 2738 2739 default: 2740 break; 2741 } 2742 2743 // check again if active connection was released 2744 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2745 } 2746 } 2747 2748 // sm_aes128_state stays active 2749 static void sm_handle_encryption_result_enc_a(void *arg){ 2750 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2751 sm_aes128_state = SM_AES128_IDLE; 2752 2753 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2754 if (connection == NULL) return; 2755 2756 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2757 sm_aes128_state = SM_AES128_ACTIVE; 2758 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); 2759 } 2760 2761 static void sm_handle_encryption_result_enc_b(void *arg){ 2762 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2763 sm_aes128_state = SM_AES128_IDLE; 2764 2765 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2766 if (connection == NULL) return; 2767 2768 log_info_key("c1!", setup->sm_local_confirm); 2769 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2770 sm_run(); 2771 } 2772 2773 // sm_aes128_state stays active 2774 static void sm_handle_encryption_result_enc_c(void *arg){ 2775 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2776 sm_aes128_state = SM_AES128_IDLE; 2777 2778 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2779 if (connection == NULL) return; 2780 2781 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2782 sm_aes128_state = SM_AES128_ACTIVE; 2783 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); 2784 } 2785 2786 static void sm_handle_encryption_result_enc_d(void * arg){ 2787 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2788 sm_aes128_state = SM_AES128_IDLE; 2789 2790 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2791 if (connection == NULL) return; 2792 2793 log_info_key("c1!", sm_aes128_ciphertext); 2794 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2795 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2796 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2797 sm_run(); 2798 return; 2799 } 2800 if (IS_RESPONDER(connection->sm_role)){ 2801 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2802 sm_run(); 2803 } else { 2804 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2805 sm_aes128_state = SM_AES128_ACTIVE; 2806 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); 2807 } 2808 } 2809 2810 static void sm_handle_encryption_result_enc_stk(void *arg){ 2811 sm_aes128_state = SM_AES128_IDLE; 2812 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2813 2814 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2815 if (connection == NULL) return; 2816 2817 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2818 log_info_key("stk", setup->sm_ltk); 2819 if (IS_RESPONDER(connection->sm_role)){ 2820 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2821 } else { 2822 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2823 } 2824 sm_run(); 2825 } 2826 2827 // sm_aes128_state stays active 2828 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2829 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2830 sm_aes128_state = SM_AES128_IDLE; 2831 2832 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2833 if (connection == NULL) return; 2834 2835 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2836 log_info_hex16("y", setup->sm_local_y); 2837 // PH3B3 - calculate EDIV 2838 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2839 log_info_hex16("ediv", setup->sm_local_ediv); 2840 // PH3B4 - calculate LTK - enc 2841 // LTK = d1(ER, DIV, 0)) 2842 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2843 sm_aes128_state = SM_AES128_ACTIVE; 2844 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); 2845 } 2846 2847 #ifdef ENABLE_LE_PERIPHERAL 2848 // sm_aes128_state stays active 2849 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2850 sm_aes128_state = SM_AES128_IDLE; 2851 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2852 2853 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2854 if (connection == NULL) return; 2855 2856 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2857 log_info_hex16("y", setup->sm_local_y); 2858 2859 // PH3B3 - calculate DIV 2860 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2861 log_info_hex16("ediv", setup->sm_local_ediv); 2862 // PH3B4 - calculate LTK - enc 2863 // LTK = d1(ER, DIV, 0)) 2864 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2865 sm_aes128_state = SM_AES128_ACTIVE; 2866 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); 2867 } 2868 #endif 2869 2870 // sm_aes128_state stays active 2871 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2872 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2873 sm_aes128_state = SM_AES128_IDLE; 2874 2875 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2876 if (connection == NULL) return; 2877 2878 log_info_key("ltk", setup->sm_ltk); 2879 // calc CSRK next 2880 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2881 sm_aes128_state = SM_AES128_ACTIVE; 2882 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); 2883 } 2884 2885 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2886 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2887 sm_aes128_state = SM_AES128_IDLE; 2888 2889 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2890 if (connection == NULL) return; 2891 2892 sm_aes128_state = SM_AES128_IDLE; 2893 log_info_key("csrk", setup->sm_local_csrk); 2894 if (setup->sm_key_distribution_send_set){ 2895 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2896 } else { 2897 // no keys to send, just continue 2898 if (IS_RESPONDER(connection->sm_role)){ 2899 // slave -> receive master keys 2900 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2901 } else { 2902 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2903 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2904 } else { 2905 sm_master_pairing_success(connection); 2906 } 2907 } 2908 } 2909 sm_run(); 2910 } 2911 2912 #ifdef ENABLE_LE_PERIPHERAL 2913 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2914 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2915 sm_aes128_state = SM_AES128_IDLE; 2916 2917 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2918 if (connection == NULL) return; 2919 2920 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2921 log_info_key("ltk", setup->sm_ltk); 2922 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2923 sm_run(); 2924 } 2925 #endif 2926 2927 static void sm_handle_encryption_result_address_resolution(void *arg){ 2928 UNUSED(arg); 2929 sm_aes128_state = SM_AES128_IDLE; 2930 2931 sm_address_resolution_ah_calculation_active = 0; 2932 // compare calulated address against connecting device 2933 uint8_t * hash = &sm_aes128_ciphertext[13]; 2934 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2935 log_info("LE Device Lookup: matched resolvable private address"); 2936 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2937 sm_run(); 2938 return; 2939 } 2940 // no match, try next 2941 sm_address_resolution_test++; 2942 sm_run(); 2943 } 2944 2945 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2946 UNUSED(arg); 2947 sm_aes128_state = SM_AES128_IDLE; 2948 2949 log_info_key("irk", sm_persistent_irk); 2950 dkg_state = DKG_CALC_DHK; 2951 sm_run(); 2952 } 2953 2954 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2955 UNUSED(arg); 2956 sm_aes128_state = SM_AES128_IDLE; 2957 2958 log_info_key("dhk", sm_persistent_dhk); 2959 dkg_state = DKG_READY; 2960 sm_run(); 2961 } 2962 2963 static void sm_handle_encryption_result_rau(void *arg){ 2964 UNUSED(arg); 2965 sm_aes128_state = SM_AES128_IDLE; 2966 2967 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2968 rau_state = RAU_SET_ADDRESS; 2969 sm_run(); 2970 } 2971 2972 static void sm_handle_random_result_rau(void * arg){ 2973 UNUSED(arg); 2974 // non-resolvable vs. resolvable 2975 switch (gap_random_adress_type){ 2976 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2977 // resolvable: use random as prand and calc address hash 2978 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2979 sm_random_address[0] &= 0x3f; 2980 sm_random_address[0] |= 0x40; 2981 rau_state = RAU_GET_ENC; 2982 break; 2983 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2984 default: 2985 // "The two most significant bits of the address shall be equal to ‘0’"" 2986 sm_random_address[0] &= 0x3f; 2987 rau_state = RAU_SET_ADDRESS; 2988 break; 2989 } 2990 sm_run(); 2991 } 2992 2993 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2994 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 2995 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2996 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2997 if (connection == NULL) return; 2998 2999 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3000 sm_run(); 3001 } 3002 3003 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3004 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3005 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3006 if (connection == NULL) return; 3007 3008 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3009 sm_run(); 3010 } 3011 #endif 3012 3013 static void sm_handle_random_result_ph2_random(void * arg){ 3014 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3015 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3016 if (connection == NULL) return; 3017 3018 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3019 sm_run(); 3020 } 3021 3022 static void sm_handle_random_result_ph2_tk(void * arg){ 3023 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3024 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3025 if (connection == NULL) return; 3026 3027 sm_reset_tk(); 3028 uint32_t tk; 3029 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3030 // map random to 0-999999 without speding much cycles on a modulus operation 3031 tk = little_endian_read_32(sm_random_data,0); 3032 tk = tk & 0xfffff; // 1048575 3033 if (tk >= 999999){ 3034 tk = tk - 999999; 3035 } 3036 } else { 3037 // override with pre-defined passkey 3038 tk = sm_fixed_passkey_in_display_role; 3039 } 3040 big_endian_store_32(setup->sm_tk, 12, tk); 3041 if (IS_RESPONDER(connection->sm_role)){ 3042 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3043 } else { 3044 if (setup->sm_use_secure_connections){ 3045 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3046 } else { 3047 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3048 sm_trigger_user_response(connection); 3049 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3050 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3051 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); 3052 } 3053 } 3054 } 3055 sm_run(); 3056 } 3057 3058 static void sm_handle_random_result_ph3_div(void * arg){ 3059 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3060 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3061 if (connection == NULL) return; 3062 3063 // use 16 bit from random value as div 3064 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3065 log_info_hex16("div", setup->sm_local_div); 3066 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3067 sm_run(); 3068 } 3069 3070 static void sm_handle_random_result_ph3_random(void * arg){ 3071 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3072 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3073 if (connection == NULL) return; 3074 3075 reverse_64(sm_random_data, setup->sm_local_rand); 3076 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3077 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3078 // no db for authenticated flag hack: store flag in bit 4 of LSB 3079 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3080 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3081 } 3082 static void sm_validate_er_ir(void){ 3083 // warn about default ER/IR 3084 int warning = 0; 3085 if (sm_ir_is_default()){ 3086 warning = 1; 3087 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3088 } 3089 if (sm_er_is_default()){ 3090 warning = 1; 3091 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3092 } 3093 if (warning) { 3094 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3095 } 3096 } 3097 3098 static void sm_handle_random_result_ir(void *arg){ 3099 sm_persistent_keys_random_active = 0; 3100 if (arg){ 3101 // key generated, store in tlv 3102 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16); 3103 log_info("Generated IR key. Store in TLV status: %d", status); 3104 } 3105 log_info_key("IR", sm_persistent_ir); 3106 dkg_state = DKG_CALC_IRK; 3107 3108 if (test_use_fixed_local_irk){ 3109 log_info_key("IRK", sm_persistent_irk); 3110 dkg_state = DKG_CALC_DHK; 3111 } 3112 3113 sm_run(); 3114 } 3115 3116 static void sm_handle_random_result_er(void *arg){ 3117 sm_persistent_keys_random_active = 0; 3118 if (arg){ 3119 // key generated, store in tlv 3120 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16); 3121 log_info("Generated ER key. Store in TLV status: %d", status); 3122 } 3123 log_info_key("ER", sm_persistent_er); 3124 3125 // try load ir 3126 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16); 3127 if (key_size == 16){ 3128 // ok, let's continue 3129 log_info("IR from TLV"); 3130 sm_handle_random_result_ir( NULL ); 3131 } else { 3132 // invalid, generate new random one 3133 sm_persistent_keys_random_active = 1; 3134 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3135 } 3136 } 3137 3138 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3139 3140 UNUSED(channel); // ok: there is no channel 3141 UNUSED(size); // ok: fixed format HCI events 3142 3143 sm_connection_t * sm_conn; 3144 hci_con_handle_t con_handle; 3145 3146 switch (packet_type) { 3147 3148 case HCI_EVENT_PACKET: 3149 switch (hci_event_packet_get_type(packet)) { 3150 3151 case BTSTACK_EVENT_STATE: 3152 // bt stack activated, get started 3153 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3154 log_info("HCI Working!"); 3155 3156 // setup IR/ER with TLV 3157 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3158 if (sm_tlv_impl){ 3159 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16); 3160 if (key_size == 16){ 3161 // ok, let's continue 3162 log_info("ER from TLV"); 3163 sm_handle_random_result_er( NULL ); 3164 } else { 3165 // invalid, generate random one 3166 sm_persistent_keys_random_active = 1; 3167 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3168 } 3169 } else { 3170 sm_validate_er_ir(); 3171 dkg_state = DKG_CALC_IRK; 3172 3173 if (test_use_fixed_local_irk){ 3174 log_info_key("IRK", sm_persistent_irk); 3175 dkg_state = DKG_CALC_DHK; 3176 } 3177 } 3178 3179 // restart random address updates after power cycle 3180 gap_random_address_set_mode(gap_random_adress_type); 3181 } 3182 break; 3183 3184 case HCI_EVENT_LE_META: 3185 switch (packet[2]) { 3186 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3187 3188 log_info("sm: connected"); 3189 3190 if (packet[3]) return; // connection failed 3191 3192 con_handle = little_endian_read_16(packet, 4); 3193 sm_conn = sm_get_connection_for_handle(con_handle); 3194 if (!sm_conn) break; 3195 3196 sm_conn->sm_handle = con_handle; 3197 sm_conn->sm_role = packet[6]; 3198 sm_conn->sm_peer_addr_type = packet[7]; 3199 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3200 3201 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3202 3203 // reset security properties 3204 sm_conn->sm_connection_encrypted = 0; 3205 sm_conn->sm_connection_authenticated = 0; 3206 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3207 sm_conn->sm_le_db_index = -1; 3208 3209 // prepare CSRK lookup (does not involve setup) 3210 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3211 3212 // just connected -> everything else happens in sm_run() 3213 if (IS_RESPONDER(sm_conn->sm_role)){ 3214 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3215 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3216 if (sm_slave_request_security) { 3217 // request security if requested by app 3218 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3219 } else { 3220 // otherwise, wait for pairing request 3221 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3222 } 3223 } 3224 break; 3225 } else { 3226 // master 3227 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3228 } 3229 break; 3230 3231 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3232 con_handle = little_endian_read_16(packet, 3); 3233 sm_conn = sm_get_connection_for_handle(con_handle); 3234 if (!sm_conn) break; 3235 3236 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3237 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3238 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3239 break; 3240 } 3241 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3242 // PH2 SEND LTK as we need to exchange keys in PH3 3243 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3244 break; 3245 } 3246 3247 // store rand and ediv 3248 reverse_64(&packet[5], sm_conn->sm_local_rand); 3249 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3250 3251 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3252 // potentially stored LTK is from the master 3253 if ((sm_conn->sm_local_ediv != 0) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3254 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3255 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3256 break; 3257 } 3258 // additionally check if remote is in LE Device DB if requested 3259 switch(sm_conn->sm_irk_lookup_state){ 3260 case IRK_LOOKUP_FAILED: 3261 log_info("LTK Request: device not in device db"); 3262 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3263 break; 3264 case IRK_LOOKUP_SUCCEEDED: 3265 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3266 break; 3267 default: 3268 // wait for irk look doen 3269 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3270 break; 3271 } 3272 break; 3273 } 3274 3275 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3276 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3277 #else 3278 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3279 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3280 #endif 3281 break; 3282 3283 default: 3284 break; 3285 } 3286 break; 3287 3288 case HCI_EVENT_ENCRYPTION_CHANGE: 3289 con_handle = little_endian_read_16(packet, 3); 3290 sm_conn = sm_get_connection_for_handle(con_handle); 3291 if (!sm_conn) break; 3292 3293 sm_conn->sm_connection_encrypted = packet[5]; 3294 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3295 sm_conn->sm_actual_encryption_key_size); 3296 log_info("event handler, state %u", sm_conn->sm_engine_state); 3297 3298 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3299 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3300 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3301 // notify client, if pairing was requested before 3302 if (sm_conn->sm_pairing_requested){ 3303 sm_conn->sm_pairing_requested = 0; 3304 if (sm_conn->sm_connection_encrypted){ 3305 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3306 } else { 3307 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3308 } 3309 } 3310 sm_done_for_handle(sm_conn->sm_handle); 3311 break; 3312 } 3313 3314 if (!sm_conn->sm_connection_encrypted) break; 3315 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3316 3317 // continue pairing 3318 switch (sm_conn->sm_engine_state){ 3319 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3320 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3321 sm_done_for_handle(sm_conn->sm_handle); 3322 break; 3323 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3324 if (IS_RESPONDER(sm_conn->sm_role)){ 3325 // slave 3326 if (setup->sm_use_secure_connections){ 3327 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3328 } else { 3329 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); 3330 } 3331 } else { 3332 // master 3333 if (sm_key_distribution_all_received(sm_conn)){ 3334 // skip receiving keys as there are none 3335 sm_key_distribution_handle_all_received(sm_conn); 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 } else { 3338 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3339 } 3340 } 3341 break; 3342 default: 3343 break; 3344 } 3345 break; 3346 3347 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3348 con_handle = little_endian_read_16(packet, 3); 3349 sm_conn = sm_get_connection_for_handle(con_handle); 3350 if (!sm_conn) break; 3351 3352 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3353 log_info("event handler, state %u", sm_conn->sm_engine_state); 3354 // continue if part of initial pairing 3355 switch (sm_conn->sm_engine_state){ 3356 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3357 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3358 sm_done_for_handle(sm_conn->sm_handle); 3359 break; 3360 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3361 if (IS_RESPONDER(sm_conn->sm_role)){ 3362 // slave 3363 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); 3364 } else { 3365 // master 3366 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3367 } 3368 break; 3369 default: 3370 break; 3371 } 3372 break; 3373 3374 3375 case HCI_EVENT_DISCONNECTION_COMPLETE: 3376 con_handle = little_endian_read_16(packet, 3); 3377 sm_done_for_handle(con_handle); 3378 sm_conn = sm_get_connection_for_handle(con_handle); 3379 if (!sm_conn) break; 3380 3381 // delete stored bonding on disconnect with authentication failure in ph0 3382 if ((sm_conn->sm_role == 0) 3383 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3384 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3385 le_device_db_remove(sm_conn->sm_le_db_index); 3386 } 3387 3388 // pairing failed, if it was ongoing 3389 switch (sm_conn->sm_engine_state){ 3390 case SM_GENERAL_IDLE: 3391 case SM_INITIATOR_CONNECTED: 3392 case SM_RESPONDER_IDLE: 3393 break; 3394 default: 3395 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3396 break; 3397 } 3398 3399 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3400 sm_conn->sm_handle = 0; 3401 break; 3402 3403 case HCI_EVENT_COMMAND_COMPLETE: 3404 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3405 // set local addr for le device db 3406 bd_addr_t addr; 3407 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3408 le_device_db_set_local_bd_addr(addr); 3409 } 3410 break; 3411 default: 3412 break; 3413 } 3414 break; 3415 default: 3416 break; 3417 } 3418 3419 sm_run(); 3420 } 3421 3422 static inline int sm_calc_actual_encryption_key_size(int other){ 3423 if (other < sm_min_encryption_key_size) return 0; 3424 if (other < sm_max_encryption_key_size) return other; 3425 return sm_max_encryption_key_size; 3426 } 3427 3428 3429 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3430 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3431 switch (method){ 3432 case JUST_WORKS: 3433 case NUMERIC_COMPARISON: 3434 return 1; 3435 default: 3436 return 0; 3437 } 3438 } 3439 // responder 3440 3441 static int sm_passkey_used(stk_generation_method_t method){ 3442 switch (method){ 3443 case PK_RESP_INPUT: 3444 return 1; 3445 default: 3446 return 0; 3447 } 3448 } 3449 3450 static int sm_passkey_entry(stk_generation_method_t method){ 3451 switch (method){ 3452 case PK_RESP_INPUT: 3453 case PK_INIT_INPUT: 3454 case PK_BOTH_INPUT: 3455 return 1; 3456 default: 3457 return 0; 3458 } 3459 } 3460 3461 #endif 3462 3463 /** 3464 * @return ok 3465 */ 3466 static int sm_validate_stk_generation_method(void){ 3467 // check if STK generation method is acceptable by client 3468 switch (setup->sm_stk_generation_method){ 3469 case JUST_WORKS: 3470 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3471 case PK_RESP_INPUT: 3472 case PK_INIT_INPUT: 3473 case PK_BOTH_INPUT: 3474 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3475 case OOB: 3476 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3477 case NUMERIC_COMPARISON: 3478 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3479 default: 3480 return 0; 3481 } 3482 } 3483 3484 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3485 3486 // size of complete sm_pdu used to validate input 3487 static const uint8_t sm_pdu_size[] = { 3488 0, // 0x00 invalid opcode 3489 7, // 0x01 pairing request 3490 7, // 0x02 pairing response 3491 17, // 0x03 pairing confirm 3492 17, // 0x04 pairing random 3493 2, // 0x05 pairing failed 3494 17, // 0x06 encryption information 3495 11, // 0x07 master identification 3496 17, // 0x08 identification information 3497 8, // 0x09 identify address information 3498 17, // 0x0a signing information 3499 2, // 0x0b security request 3500 65, // 0x0c pairing public key 3501 17, // 0x0d pairing dhk check 3502 2, // 0x0e keypress notification 3503 }; 3504 3505 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3506 sm_run(); 3507 } 3508 3509 if (packet_type != SM_DATA_PACKET) return; 3510 if (size == 0) return; 3511 3512 uint8_t sm_pdu_code = packet[0]; 3513 3514 // validate pdu size 3515 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3516 if (sm_pdu_size[sm_pdu_code] != size) return; 3517 3518 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3519 if (!sm_conn) return; 3520 3521 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3522 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3523 sm_done_for_handle(con_handle); 3524 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3525 return; 3526 } 3527 3528 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3529 3530 int err; 3531 UNUSED(err); 3532 3533 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3534 uint8_t buffer[5]; 3535 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3536 buffer[1] = 3; 3537 little_endian_store_16(buffer, 2, con_handle); 3538 buffer[4] = packet[1]; 3539 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3540 return; 3541 } 3542 3543 switch (sm_conn->sm_engine_state){ 3544 3545 // a sm timeout requries a new physical connection 3546 case SM_GENERAL_TIMEOUT: 3547 return; 3548 3549 #ifdef ENABLE_LE_CENTRAL 3550 3551 // Initiator 3552 case SM_INITIATOR_CONNECTED: 3553 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3554 sm_pdu_received_in_wrong_state(sm_conn); 3555 break; 3556 } 3557 3558 // IRK complete? 3559 int have_ltk; 3560 uint8_t ltk[16]; 3561 switch (sm_conn->sm_irk_lookup_state){ 3562 case IRK_LOOKUP_FAILED: 3563 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3564 break; 3565 case IRK_LOOKUP_SUCCEEDED: 3566 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3567 have_ltk = !sm_is_null_key(ltk); 3568 log_info("central: security request - have_ltk %u", have_ltk); 3569 if (have_ltk){ 3570 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3571 } else { 3572 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3573 } 3574 break; 3575 default: 3576 break; 3577 } 3578 3579 // otherwise, store security request 3580 sm_conn->sm_security_request_received = 1; 3581 break; 3582 3583 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3584 // Core 5, Vol 3, Part H, 2.4.6: 3585 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3586 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3587 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3588 log_info("Ignoring Security Request"); 3589 break; 3590 } 3591 3592 // all other pdus are incorrect 3593 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3594 sm_pdu_received_in_wrong_state(sm_conn); 3595 break; 3596 } 3597 3598 // store pairing request 3599 (void)memcpy(&setup->sm_s_pres, packet, 3600 sizeof(sm_pairing_packet_t)); 3601 err = sm_stk_generation_init(sm_conn); 3602 3603 #ifdef ENABLE_TESTING_SUPPORT 3604 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3605 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3606 err = test_pairing_failure; 3607 } 3608 #endif 3609 3610 if (err){ 3611 setup->sm_pairing_failed_reason = err; 3612 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3613 break; 3614 } 3615 3616 // generate random number first, if we need to show passkey 3617 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3618 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); 3619 break; 3620 } 3621 3622 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3623 if (setup->sm_use_secure_connections){ 3624 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3625 if (setup->sm_stk_generation_method == JUST_WORKS){ 3626 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3627 sm_trigger_user_response(sm_conn); 3628 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3629 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3630 } 3631 } else { 3632 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3633 } 3634 break; 3635 } 3636 #endif 3637 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3638 sm_trigger_user_response(sm_conn); 3639 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3640 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3641 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); 3642 } 3643 break; 3644 3645 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3646 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3647 sm_pdu_received_in_wrong_state(sm_conn); 3648 break; 3649 } 3650 3651 // store s_confirm 3652 reverse_128(&packet[1], setup->sm_peer_confirm); 3653 3654 #ifdef ENABLE_TESTING_SUPPORT 3655 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3656 log_info("testing_support: reset confirm value"); 3657 memset(setup->sm_peer_confirm, 0, 16); 3658 } 3659 #endif 3660 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3661 break; 3662 3663 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3664 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3665 sm_pdu_received_in_wrong_state(sm_conn); 3666 break;; 3667 } 3668 3669 // received random value 3670 reverse_128(&packet[1], setup->sm_peer_random); 3671 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3672 break; 3673 #endif 3674 3675 #ifdef ENABLE_LE_PERIPHERAL 3676 // Responder 3677 case SM_RESPONDER_IDLE: 3678 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3679 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3680 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3681 sm_pdu_received_in_wrong_state(sm_conn); 3682 break;; 3683 } 3684 3685 // store pairing request 3686 (void)memcpy(&sm_conn->sm_m_preq, packet, 3687 sizeof(sm_pairing_packet_t)); 3688 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3689 break; 3690 #endif 3691 3692 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3693 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3694 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3695 sm_pdu_received_in_wrong_state(sm_conn); 3696 break; 3697 } 3698 3699 // store public key for DH Key calculation 3700 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3701 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3702 3703 // validate public key 3704 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3705 if (err){ 3706 log_error("sm: peer public key invalid %x", err); 3707 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3708 break; 3709 } 3710 3711 // start calculating dhkey 3712 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); 3713 3714 3715 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3716 if (IS_RESPONDER(sm_conn->sm_role)){ 3717 // responder 3718 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3719 } else { 3720 // initiator 3721 // stk generation method 3722 // passkey entry: notify app to show passkey or to request passkey 3723 switch (setup->sm_stk_generation_method){ 3724 case JUST_WORKS: 3725 case NUMERIC_COMPARISON: 3726 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3727 break; 3728 case PK_RESP_INPUT: 3729 sm_sc_start_calculating_local_confirm(sm_conn); 3730 break; 3731 case PK_INIT_INPUT: 3732 case PK_BOTH_INPUT: 3733 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3734 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3735 break; 3736 } 3737 sm_sc_start_calculating_local_confirm(sm_conn); 3738 break; 3739 case OOB: 3740 // generate Nx 3741 log_info("Generate Na"); 3742 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); 3743 break; 3744 } 3745 } 3746 break; 3747 3748 case SM_SC_W4_CONFIRMATION: 3749 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3750 sm_pdu_received_in_wrong_state(sm_conn); 3751 break; 3752 } 3753 // received confirm value 3754 reverse_128(&packet[1], setup->sm_peer_confirm); 3755 3756 #ifdef ENABLE_TESTING_SUPPORT 3757 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3758 log_info("testing_support: reset confirm value"); 3759 memset(setup->sm_peer_confirm, 0, 16); 3760 } 3761 #endif 3762 if (IS_RESPONDER(sm_conn->sm_role)){ 3763 // responder 3764 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3765 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3766 // still waiting for passkey 3767 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3768 break; 3769 } 3770 } 3771 sm_sc_start_calculating_local_confirm(sm_conn); 3772 } else { 3773 // initiator 3774 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3775 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); 3776 } else { 3777 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3778 } 3779 } 3780 break; 3781 3782 case SM_SC_W4_PAIRING_RANDOM: 3783 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3784 sm_pdu_received_in_wrong_state(sm_conn); 3785 break; 3786 } 3787 3788 // received random value 3789 reverse_128(&packet[1], setup->sm_peer_nonce); 3790 3791 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3792 // only check for JUST WORK/NC in initiator role OR passkey entry 3793 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3794 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3795 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3796 break; 3797 } 3798 3799 // OOB 3800 if (setup->sm_stk_generation_method == OOB){ 3801 3802 // setup local random, set to zero if remote did not receive our data 3803 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3804 if (IS_RESPONDER(sm_conn->sm_role)){ 3805 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3806 log_info("Reset rb as A does not have OOB data"); 3807 memset(setup->sm_rb, 0, 16); 3808 } else { 3809 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3810 log_info("Use stored rb"); 3811 log_info_hexdump(setup->sm_rb, 16); 3812 } 3813 } else { 3814 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3815 log_info("Reset ra as B does not have OOB data"); 3816 memset(setup->sm_ra, 0, 16); 3817 } else { 3818 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3819 log_info("Use stored ra"); 3820 log_info_hexdump(setup->sm_ra, 16); 3821 } 3822 } 3823 3824 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3825 if (setup->sm_have_oob_data){ 3826 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3827 break; 3828 } 3829 } 3830 3831 // TODO: we only get here for Responder role with JW/NC 3832 sm_sc_state_after_receiving_random(sm_conn); 3833 break; 3834 3835 case SM_SC_W2_CALCULATE_G2: 3836 case SM_SC_W4_CALCULATE_G2: 3837 case SM_SC_W4_CALCULATE_DHKEY: 3838 case SM_SC_W2_CALCULATE_F5_SALT: 3839 case SM_SC_W4_CALCULATE_F5_SALT: 3840 case SM_SC_W2_CALCULATE_F5_MACKEY: 3841 case SM_SC_W4_CALCULATE_F5_MACKEY: 3842 case SM_SC_W2_CALCULATE_F5_LTK: 3843 case SM_SC_W4_CALCULATE_F5_LTK: 3844 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3845 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3846 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3847 case SM_SC_W4_USER_RESPONSE: 3848 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3849 sm_pdu_received_in_wrong_state(sm_conn); 3850 break; 3851 } 3852 // store DHKey Check 3853 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3854 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3855 3856 // have we been only waiting for dhkey check command? 3857 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3858 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3859 } 3860 break; 3861 #endif 3862 3863 #ifdef ENABLE_LE_PERIPHERAL 3864 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3865 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3866 sm_pdu_received_in_wrong_state(sm_conn); 3867 break; 3868 } 3869 3870 // received confirm value 3871 reverse_128(&packet[1], setup->sm_peer_confirm); 3872 3873 #ifdef ENABLE_TESTING_SUPPORT 3874 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3875 log_info("testing_support: reset confirm value"); 3876 memset(setup->sm_peer_confirm, 0, 16); 3877 } 3878 #endif 3879 // notify client to hide shown passkey 3880 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3881 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3882 } 3883 3884 // handle user cancel pairing? 3885 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3886 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3887 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3888 break; 3889 } 3890 3891 // wait for user action? 3892 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3893 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3894 break; 3895 } 3896 3897 // calculate and send local_confirm 3898 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); 3899 break; 3900 3901 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3902 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3903 sm_pdu_received_in_wrong_state(sm_conn); 3904 break;; 3905 } 3906 3907 // received random value 3908 reverse_128(&packet[1], setup->sm_peer_random); 3909 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3910 break; 3911 #endif 3912 3913 case SM_PH3_RECEIVE_KEYS: 3914 switch(sm_pdu_code){ 3915 case SM_CODE_ENCRYPTION_INFORMATION: 3916 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3917 reverse_128(&packet[1], setup->sm_peer_ltk); 3918 break; 3919 3920 case SM_CODE_MASTER_IDENTIFICATION: 3921 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3922 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3923 reverse_64(&packet[3], setup->sm_peer_rand); 3924 break; 3925 3926 case SM_CODE_IDENTITY_INFORMATION: 3927 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3928 reverse_128(&packet[1], setup->sm_peer_irk); 3929 break; 3930 3931 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3932 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3933 setup->sm_peer_addr_type = packet[1]; 3934 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3935 break; 3936 3937 case SM_CODE_SIGNING_INFORMATION: 3938 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3939 reverse_128(&packet[1], setup->sm_peer_csrk); 3940 break; 3941 default: 3942 // Unexpected PDU 3943 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3944 break; 3945 } 3946 // done with key distribution? 3947 if (sm_key_distribution_all_received(sm_conn)){ 3948 3949 sm_key_distribution_handle_all_received(sm_conn); 3950 3951 if (IS_RESPONDER(sm_conn->sm_role)){ 3952 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3953 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3954 } else { 3955 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3956 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3957 sm_done_for_handle(sm_conn->sm_handle); 3958 } 3959 } else { 3960 if (setup->sm_use_secure_connections){ 3961 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3962 } else { 3963 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); 3964 } 3965 } 3966 } 3967 break; 3968 default: 3969 // Unexpected PDU 3970 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3971 break; 3972 } 3973 3974 // try to send preparared packet 3975 sm_run(); 3976 } 3977 3978 // Security Manager Client API 3979 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3980 sm_get_oob_data = get_oob_data_callback; 3981 } 3982 3983 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)){ 3984 sm_get_sc_oob_data = get_sc_oob_data_callback; 3985 } 3986 3987 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3988 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3989 } 3990 3991 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3992 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3993 } 3994 3995 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3996 sm_min_encryption_key_size = min_size; 3997 sm_max_encryption_key_size = max_size; 3998 } 3999 4000 void sm_set_authentication_requirements(uint8_t auth_req){ 4001 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4002 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4003 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4004 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4005 } 4006 #endif 4007 sm_auth_req = auth_req; 4008 } 4009 4010 void sm_set_io_capabilities(io_capability_t io_capability){ 4011 sm_io_capabilities = io_capability; 4012 } 4013 4014 #ifdef ENABLE_LE_PERIPHERAL 4015 void sm_set_request_security(int enable){ 4016 sm_slave_request_security = enable; 4017 } 4018 #endif 4019 4020 void sm_set_er(sm_key_t er){ 4021 (void)memcpy(sm_persistent_er, er, 16); 4022 } 4023 4024 void sm_set_ir(sm_key_t ir){ 4025 (void)memcpy(sm_persistent_ir, ir, 16); 4026 } 4027 4028 // Testing support only 4029 void sm_test_set_irk(sm_key_t irk){ 4030 (void)memcpy(sm_persistent_irk, irk, 16); 4031 dkg_state = DKG_CALC_DHK; 4032 test_use_fixed_local_irk = true; 4033 } 4034 4035 void sm_test_use_fixed_local_csrk(void){ 4036 test_use_fixed_local_csrk = true; 4037 } 4038 4039 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4040 static void sm_ec_generated(void * arg){ 4041 UNUSED(arg); 4042 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4043 // trigger pairing if pending for ec key 4044 sm_run(); 4045 } 4046 static void sm_ec_generate_new_key(void){ 4047 log_info("sm: generate new ec key"); 4048 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4049 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4050 } 4051 #endif 4052 4053 #ifdef ENABLE_TESTING_SUPPORT 4054 void sm_test_set_pairing_failure(int reason){ 4055 test_pairing_failure = reason; 4056 } 4057 #endif 4058 4059 void sm_init(void){ 4060 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4061 sm_er_ir_set_default(); 4062 4063 // defaults 4064 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4065 | SM_STK_GENERATION_METHOD_OOB 4066 | SM_STK_GENERATION_METHOD_PASSKEY 4067 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4068 4069 sm_max_encryption_key_size = 16; 4070 sm_min_encryption_key_size = 7; 4071 4072 sm_fixed_passkey_in_display_role = 0xffffffff; 4073 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4074 4075 #ifdef USE_CMAC_ENGINE 4076 sm_cmac_active = 0; 4077 #endif 4078 dkg_state = DKG_W4_WORKING; 4079 rau_state = RAU_IDLE; 4080 sm_aes128_state = SM_AES128_IDLE; 4081 sm_address_resolution_test = -1; // no private address to resolve yet 4082 sm_address_resolution_ah_calculation_active = 0; 4083 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4084 sm_address_resolution_general_queue = NULL; 4085 4086 gap_random_adress_update_period = 15 * 60 * 1000L; 4087 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4088 4089 test_use_fixed_local_csrk = false; 4090 4091 // register for HCI Events from HCI 4092 hci_event_callback_registration.callback = &sm_event_packet_handler; 4093 hci_add_event_handler(&hci_event_callback_registration); 4094 4095 // 4096 btstack_crypto_init(); 4097 4098 // init le_device_db 4099 le_device_db_init(); 4100 4101 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4102 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4103 4104 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4105 sm_ec_generate_new_key(); 4106 #endif 4107 } 4108 4109 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4110 sm_fixed_passkey_in_display_role = passkey; 4111 } 4112 4113 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4114 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4115 } 4116 4117 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4118 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4119 if (!hci_con) return NULL; 4120 return &hci_con->sm_connection; 4121 } 4122 4123 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4124 switch (sm_conn->sm_engine_state){ 4125 case SM_GENERAL_IDLE: 4126 case SM_RESPONDER_IDLE: 4127 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4128 sm_run(); 4129 break; 4130 default: 4131 break; 4132 } 4133 } 4134 4135 /** 4136 * @brief Trigger Security Request 4137 */ 4138 void sm_send_security_request(hci_con_handle_t con_handle){ 4139 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4140 if (!sm_conn) return; 4141 sm_send_security_request_for_connection(sm_conn); 4142 } 4143 4144 // request pairing 4145 void sm_request_pairing(hci_con_handle_t con_handle){ 4146 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4147 if (!sm_conn) return; // wrong connection 4148 4149 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4150 if (IS_RESPONDER(sm_conn->sm_role)){ 4151 sm_send_security_request_for_connection(sm_conn); 4152 } else { 4153 // used as a trigger to start central/master/initiator security procedures 4154 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4155 uint8_t ltk[16]; 4156 bool have_ltk; 4157 switch (sm_conn->sm_irk_lookup_state){ 4158 case IRK_LOOKUP_SUCCEEDED: 4159 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4160 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4161 have_ltk = !sm_is_null_key(ltk); 4162 log_info("have ltk %u", have_ltk); 4163 if (have_ltk){ 4164 sm_conn->sm_pairing_requested = 1; 4165 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4166 break; 4167 } 4168 #endif 4169 /* fall through */ 4170 4171 case IRK_LOOKUP_FAILED: 4172 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4173 break; 4174 default: 4175 log_info("irk lookup pending"); 4176 sm_conn->sm_pairing_requested = 1; 4177 break; 4178 } 4179 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4180 sm_conn->sm_pairing_requested = 1; 4181 } 4182 } 4183 sm_run(); 4184 } 4185 4186 // called by client app on authorization request 4187 void sm_authorization_decline(hci_con_handle_t con_handle){ 4188 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4189 if (!sm_conn) return; // wrong connection 4190 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4191 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4192 } 4193 4194 void sm_authorization_grant(hci_con_handle_t con_handle){ 4195 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4196 if (!sm_conn) return; // wrong connection 4197 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4198 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4199 } 4200 4201 // GAP Bonding API 4202 4203 void sm_bonding_decline(hci_con_handle_t con_handle){ 4204 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4205 if (!sm_conn) return; // wrong connection 4206 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4207 log_info("decline, state %u", sm_conn->sm_engine_state); 4208 switch(sm_conn->sm_engine_state){ 4209 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4210 case SM_SC_W4_USER_RESPONSE: 4211 case SM_SC_W4_CONFIRMATION: 4212 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4213 #endif 4214 case SM_PH1_W4_USER_RESPONSE: 4215 switch (setup->sm_stk_generation_method){ 4216 case PK_RESP_INPUT: 4217 case PK_INIT_INPUT: 4218 case PK_BOTH_INPUT: 4219 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4220 break; 4221 case NUMERIC_COMPARISON: 4222 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4223 break; 4224 case JUST_WORKS: 4225 case OOB: 4226 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4227 break; 4228 } 4229 break; 4230 default: 4231 break; 4232 } 4233 sm_run(); 4234 } 4235 4236 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4237 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4238 if (!sm_conn) return; // wrong connection 4239 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4240 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4241 if (setup->sm_use_secure_connections){ 4242 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4243 } else { 4244 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); 4245 } 4246 } 4247 4248 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4249 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4250 sm_sc_prepare_dhkey_check(sm_conn); 4251 } 4252 #endif 4253 4254 sm_run(); 4255 } 4256 4257 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4258 // for now, it's the same 4259 sm_just_works_confirm(con_handle); 4260 } 4261 4262 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4263 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4264 if (!sm_conn) return; // wrong connection 4265 sm_reset_tk(); 4266 big_endian_store_32(setup->sm_tk, 12, passkey); 4267 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4268 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4269 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); 4270 } 4271 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4272 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4273 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4274 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4275 sm_sc_start_calculating_local_confirm(sm_conn); 4276 } 4277 #endif 4278 sm_run(); 4279 } 4280 4281 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4282 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4283 if (!sm_conn) return; // wrong connection 4284 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4285 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4286 uint8_t flags = setup->sm_keypress_notification & 0x1f; 4287 switch (action){ 4288 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4289 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4290 flags |= (1 << action); 4291 break; 4292 case SM_KEYPRESS_PASSKEY_CLEARED: 4293 // clear counter, keypress & erased flags + set passkey cleared 4294 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 4295 break; 4296 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4297 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4298 // erase actions queued 4299 num_actions--; 4300 if (num_actions == 0){ 4301 // clear counter, keypress & erased flags 4302 flags &= 0x19; 4303 } 4304 break; 4305 } 4306 num_actions++; 4307 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4308 break; 4309 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4310 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4311 // enter actions queued 4312 num_actions--; 4313 if (num_actions == 0){ 4314 // clear counter, keypress & erased flags 4315 flags &= 0x19; 4316 } 4317 break; 4318 } 4319 num_actions++; 4320 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4321 break; 4322 default: 4323 break; 4324 } 4325 setup->sm_keypress_notification = (num_actions << 5) | flags; 4326 sm_run(); 4327 } 4328 4329 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4330 static void sm_handle_random_result_oob(void * arg){ 4331 UNUSED(arg); 4332 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4333 sm_run(); 4334 } 4335 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4336 4337 static btstack_crypto_random_t sm_crypto_random_oob_request; 4338 4339 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4340 sm_sc_oob_callback = callback; 4341 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4342 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4343 return 0; 4344 } 4345 #endif 4346 4347 /** 4348 * @brief Get Identity Resolving state 4349 * @param con_handle 4350 * @return irk_lookup_state_t 4351 */ 4352 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4353 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4354 if (!sm_conn) return IRK_LOOKUP_IDLE; 4355 return sm_conn->sm_irk_lookup_state; 4356 } 4357 4358 /** 4359 * @brief Identify device in LE Device DB 4360 * @param handle 4361 * @returns index from le_device_db or -1 if not found/identified 4362 */ 4363 int sm_le_device_index(hci_con_handle_t con_handle ){ 4364 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4365 if (!sm_conn) return -1; 4366 return sm_conn->sm_le_db_index; 4367 } 4368 4369 static int gap_random_address_type_requires_updates(void){ 4370 switch (gap_random_adress_type){ 4371 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4372 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4373 return 0; 4374 default: 4375 return 1; 4376 } 4377 } 4378 4379 static uint8_t own_address_type(void){ 4380 switch (gap_random_adress_type){ 4381 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4382 return BD_ADDR_TYPE_LE_PUBLIC; 4383 default: 4384 return BD_ADDR_TYPE_LE_RANDOM; 4385 } 4386 } 4387 4388 // GAP LE API 4389 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4390 gap_random_address_update_stop(); 4391 gap_random_adress_type = random_address_type; 4392 hci_le_set_own_address_type(own_address_type()); 4393 if (!gap_random_address_type_requires_updates()) return; 4394 gap_random_address_update_start(); 4395 gap_random_address_trigger(); 4396 } 4397 4398 gap_random_address_type_t gap_random_address_get_mode(void){ 4399 return gap_random_adress_type; 4400 } 4401 4402 void gap_random_address_set_update_period(int period_ms){ 4403 gap_random_adress_update_period = period_ms; 4404 if (!gap_random_address_type_requires_updates()) return; 4405 gap_random_address_update_stop(); 4406 gap_random_address_update_start(); 4407 } 4408 4409 void gap_random_address_set(bd_addr_t addr){ 4410 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4411 (void)memcpy(sm_random_address, addr, 6); 4412 rau_state = RAU_SET_ADDRESS; 4413 sm_run(); 4414 } 4415 4416 #ifdef ENABLE_LE_PERIPHERAL 4417 /* 4418 * @brief Set Advertisement Paramters 4419 * @param adv_int_min 4420 * @param adv_int_max 4421 * @param adv_type 4422 * @param direct_address_type 4423 * @param direct_address 4424 * @param channel_map 4425 * @param filter_policy 4426 * 4427 * @note own_address_type is used from gap_random_address_set_mode 4428 */ 4429 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4430 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4431 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4432 direct_address_typ, direct_address, channel_map, filter_policy); 4433 } 4434 #endif 4435 4436 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4437 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4438 // wrong connection 4439 if (!sm_conn) return 0; 4440 // already encrypted 4441 if (sm_conn->sm_connection_encrypted) return 0; 4442 // only central can re-encrypt 4443 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4444 // irk status? 4445 switch(sm_conn->sm_irk_lookup_state){ 4446 case IRK_LOOKUP_FAILED: 4447 // done, cannot setup encryption 4448 return 0; 4449 case IRK_LOOKUP_SUCCEEDED: 4450 break; 4451 default: 4452 // IR Lookup pending 4453 return 1; 4454 } 4455 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4456 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4457 } 4458