1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "sm.c" 39 40 #include <string.h> 41 #include <inttypes.h> 42 43 #include "ble/le_device_db.h" 44 #include "ble/core.h" 45 #include "ble/sm.h" 46 #include "bluetooth_company_id.h" 47 #include "btstack_bool.h" 48 #include "btstack_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "btstack_tlv.h" 54 #include "gap.h" 55 #include "hci.h" 56 #include "hci_dump.h" 57 #include "l2cap.h" 58 59 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 60 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 61 #endif 62 63 // assert SM Public Key can be sent/received 64 #ifdef ENABLE_LE_SECURE_CONNECTIONS 65 #if HCI_ACL_PAYLOAD_SIZE < 69 66 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 67 #endif 68 #endif 69 70 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 71 #define IS_RESPONDER(role) (role) 72 #else 73 #ifdef ENABLE_LE_CENTRAL 74 // only central - never responder (avoid 'unused variable' warnings) 75 #define IS_RESPONDER(role) (0 && role) 76 #else 77 // only peripheral - always responder (avoid 'unused variable' warnings) 78 #define IS_RESPONDER(role) (1 || role) 79 #endif 80 #endif 81 82 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 83 #define USE_CMAC_ENGINE 84 #endif 85 86 #define BTSTACK_TAG32(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) 87 88 // 89 // SM internal types and globals 90 // 91 92 typedef enum { 93 DKG_W4_WORKING, 94 DKG_CALC_IRK, 95 DKG_CALC_DHK, 96 DKG_READY 97 } derived_key_generation_t; 98 99 typedef enum { 100 RAU_IDLE, 101 RAU_GET_RANDOM, 102 RAU_W4_RANDOM, 103 RAU_GET_ENC, 104 RAU_W4_ENC, 105 RAU_SET_ADDRESS, 106 } random_address_update_t; 107 108 typedef enum { 109 CMAC_IDLE, 110 CMAC_CALC_SUBKEYS, 111 CMAC_W4_SUBKEYS, 112 CMAC_CALC_MI, 113 CMAC_W4_MI, 114 CMAC_CALC_MLAST, 115 CMAC_W4_MLAST 116 } cmac_state_t; 117 118 typedef enum { 119 JUST_WORKS, 120 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 121 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 122 PK_BOTH_INPUT, // Only input on both, both input PK 123 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 124 OOB // OOB available on one (SC) or both sides (legacy) 125 } stk_generation_method_t; 126 127 typedef enum { 128 SM_USER_RESPONSE_IDLE, 129 SM_USER_RESPONSE_PENDING, 130 SM_USER_RESPONSE_CONFIRM, 131 SM_USER_RESPONSE_PASSKEY, 132 SM_USER_RESPONSE_DECLINE 133 } sm_user_response_t; 134 135 typedef enum { 136 SM_AES128_IDLE, 137 SM_AES128_ACTIVE 138 } sm_aes128_state_t; 139 140 typedef enum { 141 ADDRESS_RESOLUTION_IDLE, 142 ADDRESS_RESOLUTION_GENERAL, 143 ADDRESS_RESOLUTION_FOR_CONNECTION, 144 } address_resolution_mode_t; 145 146 typedef enum { 147 ADDRESS_RESOLUTION_SUCEEDED, 148 ADDRESS_RESOLUTION_FAILED, 149 } address_resolution_event_t; 150 151 typedef enum { 152 EC_KEY_GENERATION_IDLE, 153 EC_KEY_GENERATION_ACTIVE, 154 EC_KEY_GENERATION_DONE, 155 } ec_key_generation_state_t; 156 157 typedef enum { 158 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 159 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 160 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 161 } sm_state_var_t; 162 163 typedef enum { 164 SM_SC_OOB_IDLE, 165 SM_SC_OOB_W4_RANDOM, 166 SM_SC_OOB_W2_CALC_CONFIRM, 167 SM_SC_OOB_W4_CONFIRM, 168 } sm_sc_oob_state_t; 169 170 typedef uint8_t sm_key24_t[3]; 171 typedef uint8_t sm_key56_t[7]; 172 typedef uint8_t sm_key256_t[32]; 173 174 // 175 // GLOBAL DATA 176 // 177 178 static bool test_use_fixed_local_csrk; 179 static bool test_use_fixed_local_irk; 180 181 #ifdef ENABLE_TESTING_SUPPORT 182 static uint8_t test_pairing_failure; 183 #endif 184 185 // configuration 186 static uint8_t sm_accepted_stk_generation_methods; 187 static uint8_t sm_max_encryption_key_size; 188 static uint8_t sm_min_encryption_key_size; 189 static uint8_t sm_auth_req = 0; 190 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 191 static uint8_t sm_slave_request_security; 192 static uint32_t sm_fixed_passkey_in_display_role; 193 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 194 195 #ifdef ENABLE_LE_SECURE_CONNECTIONS 196 static bool sm_sc_only_mode; 197 static uint8_t sm_sc_oob_random[16]; 198 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 199 static sm_sc_oob_state_t sm_sc_oob_state; 200 #endif 201 202 203 static uint8_t sm_persistent_keys_random_active; 204 static const btstack_tlv_t * sm_tlv_impl; 205 static void * sm_tlv_context; 206 207 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 208 static sm_key_t sm_persistent_er; 209 static sm_key_t sm_persistent_ir; 210 211 // derived from sm_persistent_ir 212 static sm_key_t sm_persistent_dhk; 213 static sm_key_t sm_persistent_irk; 214 static derived_key_generation_t dkg_state; 215 216 // derived from sm_persistent_er 217 // .. 218 219 // random address update 220 static random_address_update_t rau_state; 221 static bd_addr_t sm_random_address; 222 223 #ifdef USE_CMAC_ENGINE 224 // CMAC Calculation: General 225 static btstack_crypto_aes128_cmac_t sm_cmac_request; 226 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 227 static uint8_t sm_cmac_active; 228 static uint8_t sm_cmac_hash[16]; 229 #endif 230 231 // CMAC for ATT Signed Writes 232 #ifdef ENABLE_LE_SIGNED_WRITE 233 static uint16_t sm_cmac_signed_write_message_len; 234 static uint8_t sm_cmac_signed_write_header[3]; 235 static const uint8_t * sm_cmac_signed_write_message; 236 static uint8_t sm_cmac_signed_write_sign_counter[4]; 237 #endif 238 239 // CMAC for Secure Connection functions 240 #ifdef ENABLE_LE_SECURE_CONNECTIONS 241 static sm_connection_t * sm_cmac_connection; 242 static uint8_t sm_cmac_sc_buffer[80]; 243 #endif 244 245 // resolvable private address lookup / CSRK calculation 246 static int sm_address_resolution_test; 247 static int sm_address_resolution_ah_calculation_active; 248 static uint8_t sm_address_resolution_addr_type; 249 static bd_addr_t sm_address_resolution_address; 250 static void * sm_address_resolution_context; 251 static address_resolution_mode_t sm_address_resolution_mode; 252 static btstack_linked_list_t sm_address_resolution_general_queue; 253 254 // aes128 crypto engine. 255 static sm_aes128_state_t sm_aes128_state; 256 257 // crypto 258 static btstack_crypto_random_t sm_crypto_random_request; 259 static btstack_crypto_aes128_t sm_crypto_aes128_request; 260 #ifdef ENABLE_LE_SECURE_CONNECTIONS 261 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 262 #endif 263 264 // temp storage for random data 265 static uint8_t sm_random_data[8]; 266 static uint8_t sm_aes128_key[16]; 267 static uint8_t sm_aes128_plaintext[16]; 268 static uint8_t sm_aes128_ciphertext[16]; 269 270 // to receive hci events 271 static btstack_packet_callback_registration_t hci_event_callback_registration; 272 273 /* to dispatch sm event */ 274 static btstack_linked_list_t sm_event_handlers; 275 276 // LE Secure Connections 277 #ifdef ENABLE_LE_SECURE_CONNECTIONS 278 static ec_key_generation_state_t ec_key_generation_state; 279 static uint8_t ec_q[64]; 280 #endif 281 282 // 283 // Volume 3, Part H, Chapter 24 284 // "Security shall be initiated by the Security Manager in the device in the master role. 285 // The device in the slave role shall be the responding device." 286 // -> master := initiator, slave := responder 287 // 288 289 // data needed for security setup 290 typedef struct sm_setup_context { 291 292 btstack_timer_source_t sm_timeout; 293 294 // used in all phases 295 uint8_t sm_pairing_failed_reason; 296 297 // user response, (Phase 1 and/or 2) 298 uint8_t sm_user_response; 299 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 300 301 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 302 uint8_t sm_key_distribution_send_set; 303 uint8_t sm_key_distribution_sent_set; 304 uint8_t sm_key_distribution_received_set; 305 306 // Phase 2 (Pairing over SMP) 307 stk_generation_method_t sm_stk_generation_method; 308 sm_key_t sm_tk; 309 uint8_t sm_have_oob_data; 310 uint8_t sm_use_secure_connections; 311 312 sm_key_t sm_c1_t3_value; // c1 calculation 313 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 314 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 315 sm_key_t sm_local_random; 316 sm_key_t sm_local_confirm; 317 sm_key_t sm_peer_random; 318 sm_key_t sm_peer_confirm; 319 uint8_t sm_m_addr_type; // address and type can be removed 320 uint8_t sm_s_addr_type; // '' 321 bd_addr_t sm_m_address; // '' 322 bd_addr_t sm_s_address; // '' 323 sm_key_t sm_ltk; 324 325 uint8_t sm_state_vars; 326 #ifdef ENABLE_LE_SECURE_CONNECTIONS 327 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 328 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 329 sm_key_t sm_local_nonce; // might be combined with sm_local_random 330 uint8_t sm_dhkey[32]; 331 sm_key_t sm_peer_dhkey_check; 332 sm_key_t sm_local_dhkey_check; 333 sm_key_t sm_ra; 334 sm_key_t sm_rb; 335 sm_key_t sm_t; // used for f5 and h6 336 sm_key_t sm_mackey; 337 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 338 #endif 339 340 // Phase 3 341 342 // key distribution, we generate 343 uint16_t sm_local_y; 344 uint16_t sm_local_div; 345 uint16_t sm_local_ediv; 346 uint8_t sm_local_rand[8]; 347 sm_key_t sm_local_ltk; 348 sm_key_t sm_local_csrk; 349 sm_key_t sm_local_irk; 350 // sm_local_address/addr_type not needed 351 352 // key distribution, received from peer 353 uint16_t sm_peer_y; 354 uint16_t sm_peer_div; 355 uint16_t sm_peer_ediv; 356 uint8_t sm_peer_rand[8]; 357 sm_key_t sm_peer_ltk; 358 sm_key_t sm_peer_irk; 359 sm_key_t sm_peer_csrk; 360 uint8_t sm_peer_addr_type; 361 bd_addr_t sm_peer_address; 362 #ifdef ENABLE_LE_SIGNED_WRITE 363 int sm_le_device_index; 364 #endif 365 366 } sm_setup_context_t; 367 368 // 369 static sm_setup_context_t the_setup; 370 static sm_setup_context_t * setup = &the_setup; 371 372 // active connection - the one for which the_setup is used for 373 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 374 375 // @returns 1 if oob data is available 376 // stores oob data in provided 16 byte buffer if not null 377 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 378 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 379 380 static void sm_run(void); 381 static void sm_done_for_handle(hci_con_handle_t con_handle); 382 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 383 static inline int sm_calc_actual_encryption_key_size(int other); 384 static int sm_validate_stk_generation_method(void); 385 static void sm_handle_encryption_result_address_resolution(void *arg); 386 static void sm_handle_encryption_result_dkg_dhk(void *arg); 387 static void sm_handle_encryption_result_dkg_irk(void *arg); 388 static void sm_handle_encryption_result_enc_a(void *arg); 389 static void sm_handle_encryption_result_enc_b(void *arg); 390 static void sm_handle_encryption_result_enc_c(void *arg); 391 static void sm_handle_encryption_result_enc_csrk(void *arg); 392 static void sm_handle_encryption_result_enc_d(void * arg); 393 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 394 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 395 #ifdef ENABLE_LE_PERIPHERAL 396 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 397 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 398 #endif 399 static void sm_handle_encryption_result_enc_stk(void *arg); 400 static void sm_handle_encryption_result_rau(void *arg); 401 static void sm_handle_random_result_ph2_tk(void * arg); 402 static void sm_handle_random_result_rau(void * arg); 403 #ifdef ENABLE_LE_SECURE_CONNECTIONS 404 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 405 static void sm_ec_generate_new_key(void); 406 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 407 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 408 static int sm_passkey_entry(stk_generation_method_t method); 409 #endif 410 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 411 412 static void log_info_hex16(const char * name, uint16_t value){ 413 log_info("%-6s 0x%04x", name, value); 414 } 415 416 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 417 // return packet[0]; 418 // } 419 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 420 return packet[1]; 421 } 422 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 423 return packet[2]; 424 } 425 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 426 return packet[3]; 427 } 428 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 429 return packet[4]; 430 } 431 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 432 return packet[5]; 433 } 434 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 435 return packet[6]; 436 } 437 438 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 439 packet[0] = code; 440 } 441 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 442 packet[1] = io_capability; 443 } 444 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 445 packet[2] = oob_data_flag; 446 } 447 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 448 packet[3] = auth_req; 449 } 450 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 451 packet[4] = max_encryption_key_size; 452 } 453 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 454 packet[5] = initiator_key_distribution; 455 } 456 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 457 packet[6] = responder_key_distribution; 458 } 459 460 // @returns 1 if all bytes are 0 461 static int sm_is_null(uint8_t * data, int size){ 462 int i; 463 for (i=0; i < size ; i++){ 464 if (data[i]) return 0; 465 } 466 return 1; 467 } 468 469 static int sm_is_null_random(uint8_t random[8]){ 470 return sm_is_null(random, 8); 471 } 472 473 static int sm_is_null_key(uint8_t * key){ 474 return sm_is_null(key, 16); 475 } 476 477 // Key utils 478 static void sm_reset_tk(void){ 479 int i; 480 for (i=0;i<16;i++){ 481 setup->sm_tk[i] = 0; 482 } 483 } 484 485 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 486 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 487 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 488 int i; 489 for (i = max_encryption_size ; i < 16 ; i++){ 490 key[15-i] = 0; 491 } 492 } 493 494 // ER / IR checks 495 static void sm_er_ir_set_default(void){ 496 int i; 497 for (i=0;i<16;i++){ 498 sm_persistent_er[i] = 0x30 + i; 499 sm_persistent_ir[i] = 0x90 + i; 500 } 501 } 502 503 static int sm_er_is_default(void){ 504 int i; 505 for (i=0;i<16;i++){ 506 if (sm_persistent_er[i] != (0x30+i)) return 0; 507 } 508 return 1; 509 } 510 511 static int sm_ir_is_default(void){ 512 int i; 513 for (i=0;i<16;i++){ 514 if (sm_persistent_ir[i] != (0x90+i)) return 0; 515 } 516 return 1; 517 } 518 519 // SMP Timeout implementation 520 521 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 522 // the Security Manager Timer shall be reset and started. 523 // 524 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 525 // 526 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 527 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 528 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 529 // established. 530 531 static void sm_timeout_handler(btstack_timer_source_t * timer){ 532 log_info("SM timeout"); 533 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 534 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 535 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 536 sm_done_for_handle(sm_conn->sm_handle); 537 538 // trigger handling of next ready connection 539 sm_run(); 540 } 541 static void sm_timeout_start(sm_connection_t * sm_conn){ 542 btstack_run_loop_remove_timer(&setup->sm_timeout); 543 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 544 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 545 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 546 btstack_run_loop_add_timer(&setup->sm_timeout); 547 } 548 static void sm_timeout_stop(void){ 549 btstack_run_loop_remove_timer(&setup->sm_timeout); 550 } 551 static void sm_timeout_reset(sm_connection_t * sm_conn){ 552 sm_timeout_stop(); 553 sm_timeout_start(sm_conn); 554 } 555 556 // end of sm timeout 557 558 // GAP Random Address updates 559 static gap_random_address_type_t gap_random_adress_type; 560 static btstack_timer_source_t gap_random_address_update_timer; 561 static uint32_t gap_random_adress_update_period; 562 563 static void gap_random_address_trigger(void){ 564 log_info("gap_random_address_trigger, state %u", rau_state); 565 if (rau_state != RAU_IDLE) return; 566 rau_state = RAU_GET_RANDOM; 567 sm_run(); 568 } 569 570 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 571 UNUSED(timer); 572 573 log_info("GAP Random Address Update due"); 574 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 575 btstack_run_loop_add_timer(&gap_random_address_update_timer); 576 gap_random_address_trigger(); 577 } 578 579 static void gap_random_address_update_start(void){ 580 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 581 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 582 btstack_run_loop_add_timer(&gap_random_address_update_timer); 583 } 584 585 static void gap_random_address_update_stop(void){ 586 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 587 } 588 589 // ah(k,r) helper 590 // r = padding || r 591 // r - 24 bit value 592 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 593 // r'= padding || r 594 memset(r_prime, 0, 16); 595 (void)memcpy(&r_prime[13], r, 3); 596 } 597 598 // d1 helper 599 // d' = padding || r || d 600 // d,r - 16 bit values 601 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 602 // d'= padding || r || d 603 memset(d1_prime, 0, 16); 604 big_endian_store_16(d1_prime, 12, r); 605 big_endian_store_16(d1_prime, 14, d); 606 } 607 608 // calculate arguments for first AES128 operation in C1 function 609 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 610 611 // p1 = pres || preq || rat’ || iat’ 612 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 613 // cant octet of pres becomes the most significant octet of p1. 614 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 615 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 616 // p1 is 0x05000800000302070710000001010001." 617 618 sm_key_t p1; 619 reverse_56(pres, &p1[0]); 620 reverse_56(preq, &p1[7]); 621 p1[14] = rat; 622 p1[15] = iat; 623 log_info_key("p1", p1); 624 log_info_key("r", r); 625 626 // t1 = r xor p1 627 int i; 628 for (i=0;i<16;i++){ 629 t1[i] = r[i] ^ p1[i]; 630 } 631 log_info_key("t1", t1); 632 } 633 634 // calculate arguments for second AES128 operation in C1 function 635 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 636 // p2 = padding || ia || ra 637 // "The least significant octet of ra becomes the least significant octet of p2 and 638 // the most significant octet of padding becomes the most significant octet of p2. 639 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 640 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 641 642 sm_key_t p2; 643 memset(p2, 0, 16); 644 (void)memcpy(&p2[4], ia, 6); 645 (void)memcpy(&p2[10], ra, 6); 646 log_info_key("p2", p2); 647 648 // c1 = e(k, t2_xor_p2) 649 int i; 650 for (i=0;i<16;i++){ 651 t3[i] = t2[i] ^ p2[i]; 652 } 653 log_info_key("t3", t3); 654 } 655 656 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 657 log_info_key("r1", r1); 658 log_info_key("r2", r2); 659 (void)memcpy(&r_prime[8], &r2[8], 8); 660 (void)memcpy(&r_prime[0], &r1[8], 8); 661 } 662 663 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 664 UNUSED(channel); 665 666 // log event 667 hci_dump_packet(packet_type, 1, packet, size); 668 // dispatch to all event handlers 669 btstack_linked_list_iterator_t it; 670 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 671 while (btstack_linked_list_iterator_has_next(&it)){ 672 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 673 entry->callback(packet_type, 0, packet, size); 674 } 675 } 676 677 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 678 event[0] = type; 679 event[1] = event_size - 2; 680 little_endian_store_16(event, 2, con_handle); 681 event[4] = addr_type; 682 reverse_bd_addr(address, &event[5]); 683 } 684 685 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 686 uint8_t event[11]; 687 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 688 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 689 } 690 691 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 692 uint8_t event[15]; 693 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 694 little_endian_store_32(event, 11, passkey); 695 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 696 } 697 698 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 699 // fetch addr and addr type from db, only called for valid entries 700 bd_addr_t identity_address; 701 int identity_address_type; 702 le_device_db_info(index, &identity_address_type, identity_address, NULL); 703 704 uint8_t event[20]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = identity_address_type; 707 reverse_bd_addr(identity_address, &event[12]); 708 little_endian_store_16(event, 18, index); 709 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 710 } 711 712 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 713 uint8_t event[12]; 714 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 715 event[11] = status; 716 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 717 } 718 719 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 720 uint8_t event[13]; 721 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 722 event[11] = status; 723 event[12] = reason; 724 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 725 } 726 727 // decide on stk generation based on 728 // - pairing request 729 // - io capabilities 730 // - OOB data availability 731 static void sm_setup_tk(void){ 732 733 // horizontal: initiator capabilities 734 // vertial: responder capabilities 735 static const stk_generation_method_t stk_generation_method [5] [5] = { 736 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 737 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 738 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 739 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 740 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 741 }; 742 743 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 744 #ifdef ENABLE_LE_SECURE_CONNECTIONS 745 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 746 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 747 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 748 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 749 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 750 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 751 }; 752 #endif 753 754 // default: just works 755 setup->sm_stk_generation_method = JUST_WORKS; 756 757 #ifdef ENABLE_LE_SECURE_CONNECTIONS 758 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 759 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 760 & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; 761 #else 762 setup->sm_use_secure_connections = 0; 763 #endif 764 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 765 766 767 // decide if OOB will be used based on SC vs. Legacy and oob flags 768 int use_oob = 0; 769 if (setup->sm_use_secure_connections){ 770 // In LE Secure Connections pairing, the out of band method is used if at least 771 // one device has the peer device's out of band authentication data available. 772 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 773 } else { 774 // In LE legacy pairing, the out of band method is used if both the devices have 775 // the other device's out of band authentication data available. 776 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 777 } 778 if (use_oob){ 779 log_info("SM: have OOB data"); 780 log_info_key("OOB", setup->sm_tk); 781 setup->sm_stk_generation_method = OOB; 782 return; 783 } 784 785 // If both devices have not set the MITM option in the Authentication Requirements 786 // Flags, then the IO capabilities shall be ignored and the Just Works association 787 // model shall be used. 788 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) 789 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ 790 log_info("SM: MITM not required by both -> JUST WORKS"); 791 return; 792 } 793 794 // Reset TK as it has been setup in sm_init_setup 795 sm_reset_tk(); 796 797 // Also use just works if unknown io capabilites 798 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 799 return; 800 } 801 802 // Otherwise the IO capabilities of the devices shall be used to determine the 803 // pairing method as defined in Table 2.4. 804 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 805 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 806 807 #ifdef ENABLE_LE_SECURE_CONNECTIONS 808 // table not define by default 809 if (setup->sm_use_secure_connections){ 810 generation_method = stk_generation_method_with_secure_connection; 811 } 812 #endif 813 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 814 815 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 816 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 817 } 818 819 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 820 int flags = 0; 821 if (key_set & SM_KEYDIST_ENC_KEY){ 822 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 823 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 824 } 825 if (key_set & SM_KEYDIST_ID_KEY){ 826 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 827 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 828 } 829 if (key_set & SM_KEYDIST_SIGN){ 830 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 831 } 832 return flags; 833 } 834 835 static void sm_setup_key_distribution(uint8_t key_set){ 836 setup->sm_key_distribution_received_set = 0; 837 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 838 setup->sm_key_distribution_sent_set = 0; 839 #ifdef ENABLE_LE_SIGNED_WRITE 840 setup->sm_le_device_index = -1; 841 #endif 842 } 843 844 // CSRK Key Lookup 845 846 847 static int sm_address_resolution_idle(void){ 848 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 849 } 850 851 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 852 (void)memcpy(sm_address_resolution_address, addr, 6); 853 sm_address_resolution_addr_type = addr_type; 854 sm_address_resolution_test = 0; 855 sm_address_resolution_mode = mode; 856 sm_address_resolution_context = context; 857 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 858 } 859 860 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 861 // check if already in list 862 btstack_linked_list_iterator_t it; 863 sm_lookup_entry_t * entry; 864 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 865 while(btstack_linked_list_iterator_has_next(&it)){ 866 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 867 if (entry->address_type != address_type) continue; 868 if (memcmp(entry->address, address, 6)) continue; 869 // already in list 870 return BTSTACK_BUSY; 871 } 872 entry = btstack_memory_sm_lookup_entry_get(); 873 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 874 entry->address_type = (bd_addr_type_t) address_type; 875 (void)memcpy(entry->address, address, 6); 876 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 877 sm_run(); 878 return 0; 879 } 880 881 // CMAC calculation using AES Engineq 882 #ifdef USE_CMAC_ENGINE 883 884 static void sm_cmac_done_trampoline(void * arg){ 885 UNUSED(arg); 886 sm_cmac_active = 0; 887 (*sm_cmac_done_callback)(sm_cmac_hash); 888 sm_run(); 889 } 890 891 int sm_cmac_ready(void){ 892 return sm_cmac_active == 0u; 893 } 894 #endif 895 896 #ifdef ENABLE_LE_SECURE_CONNECTIONS 897 // generic cmac calculation 898 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 899 sm_cmac_active = 1; 900 sm_cmac_done_callback = done_callback; 901 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 902 } 903 #endif 904 905 // cmac for ATT Message signing 906 #ifdef ENABLE_LE_SIGNED_WRITE 907 908 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 909 sm_cmac_active = 1; 910 sm_cmac_done_callback = done_callback; 911 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 912 } 913 914 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 915 if (offset >= sm_cmac_signed_write_message_len) { 916 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 917 return 0; 918 } 919 920 offset = sm_cmac_signed_write_message_len - 1 - offset; 921 922 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 923 if (offset < 3){ 924 return sm_cmac_signed_write_header[offset]; 925 } 926 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 927 if (offset < actual_message_len_incl_header){ 928 return sm_cmac_signed_write_message[offset - 3]; 929 } 930 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 931 } 932 933 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 934 // ATT Message Signing 935 sm_cmac_signed_write_header[0] = opcode; 936 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 937 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 938 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 939 sm_cmac_signed_write_message = message; 940 sm_cmac_signed_write_message_len = total_message_len; 941 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 942 } 943 #endif 944 945 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 946 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 947 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 948 switch (setup->sm_stk_generation_method){ 949 case PK_RESP_INPUT: 950 if (IS_RESPONDER(sm_conn->sm_role)){ 951 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 952 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 953 } else { 954 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 955 } 956 break; 957 case PK_INIT_INPUT: 958 if (IS_RESPONDER(sm_conn->sm_role)){ 959 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 960 } else { 961 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 962 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 963 } 964 break; 965 case PK_BOTH_INPUT: 966 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 967 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 968 break; 969 case NUMERIC_COMPARISON: 970 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 971 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 972 break; 973 case JUST_WORKS: 974 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 975 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 976 break; 977 case OOB: 978 // client already provided OOB data, let's skip notification. 979 break; 980 } 981 } 982 983 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 984 int recv_flags; 985 if (IS_RESPONDER(sm_conn->sm_role)){ 986 // slave / responder 987 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 988 } else { 989 // master / initiator 990 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 991 } 992 993 #ifdef ENABLE_LE_SECURE_CONNECTIONS 994 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 995 if (setup->sm_use_secure_connections){ 996 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 997 } 998 #endif 999 1000 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1001 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 1002 } 1003 1004 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1005 if (sm_active_connection_handle == con_handle){ 1006 sm_timeout_stop(); 1007 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1008 log_info("sm: connection 0x%x released setup context", con_handle); 1009 1010 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1011 // generate new ec key after each pairing (that used it) 1012 if (setup->sm_use_secure_connections){ 1013 sm_ec_generate_new_key(); 1014 } 1015 #endif 1016 } 1017 } 1018 1019 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1020 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1021 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 1022 sm_done_for_handle(connection->sm_handle); 1023 } 1024 1025 static int sm_key_distribution_flags_for_auth_req(void){ 1026 1027 int flags = SM_KEYDIST_ID_KEY; 1028 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1029 // encryption and signing information only if bonding requested 1030 flags |= SM_KEYDIST_ENC_KEY; 1031 #ifdef ENABLE_LE_SIGNED_WRITE 1032 flags |= SM_KEYDIST_SIGN; 1033 #endif 1034 } 1035 return flags; 1036 } 1037 1038 static void sm_reset_setup(void){ 1039 // fill in sm setup 1040 setup->sm_state_vars = 0; 1041 setup->sm_keypress_notification = 0; 1042 sm_reset_tk(); 1043 } 1044 1045 static void sm_init_setup(sm_connection_t * sm_conn){ 1046 1047 // fill in sm setup 1048 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1049 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1050 1051 // query client for Legacy Pairing OOB data 1052 setup->sm_have_oob_data = 0; 1053 if (sm_get_oob_data) { 1054 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1055 } 1056 1057 // if available and SC supported, also ask for SC OOB Data 1058 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1059 memset(setup->sm_ra, 0, 16); 1060 memset(setup->sm_rb, 0, 16); 1061 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1062 if (sm_get_sc_oob_data){ 1063 if (IS_RESPONDER(sm_conn->sm_role)){ 1064 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1065 sm_conn->sm_peer_addr_type, 1066 sm_conn->sm_peer_address, 1067 setup->sm_peer_confirm, 1068 setup->sm_ra); 1069 } else { 1070 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1071 sm_conn->sm_peer_addr_type, 1072 sm_conn->sm_peer_address, 1073 setup->sm_peer_confirm, 1074 setup->sm_rb); 1075 } 1076 } else { 1077 setup->sm_have_oob_data = 0; 1078 } 1079 } 1080 #endif 1081 1082 sm_pairing_packet_t * local_packet; 1083 if (IS_RESPONDER(sm_conn->sm_role)){ 1084 // slave 1085 local_packet = &setup->sm_s_pres; 1086 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1087 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1088 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1089 } else { 1090 // master 1091 local_packet = &setup->sm_m_preq; 1092 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1093 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1094 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1095 1096 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1097 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1098 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1099 } 1100 1101 uint8_t auth_req = sm_auth_req; 1102 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1103 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1104 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1105 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1106 } 1107 1108 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1109 1110 sm_pairing_packet_t * remote_packet; 1111 int remote_key_request; 1112 if (IS_RESPONDER(sm_conn->sm_role)){ 1113 // slave / responder 1114 remote_packet = &setup->sm_m_preq; 1115 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1116 } else { 1117 // master / initiator 1118 remote_packet = &setup->sm_s_pres; 1119 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1120 } 1121 1122 // check key size 1123 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1124 if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; 1125 1126 // decide on STK generation method / SC 1127 sm_setup_tk(); 1128 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1129 1130 // check if STK generation method is acceptable by client 1131 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1132 1133 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1134 // check LE SC Only mode 1135 if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ 1136 log_info("SC Only mode active but SC not possible"); 1137 return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1138 } 1139 1140 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1141 if (setup->sm_use_secure_connections){ 1142 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1143 } 1144 #endif 1145 1146 // identical to responder 1147 sm_setup_key_distribution(remote_key_request); 1148 1149 // JUST WORKS doens't provide authentication 1150 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1151 1152 return 0; 1153 } 1154 1155 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1156 1157 // cache and reset context 1158 int matched_device_id = sm_address_resolution_test; 1159 address_resolution_mode_t mode = sm_address_resolution_mode; 1160 void * context = sm_address_resolution_context; 1161 1162 // reset context 1163 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1164 sm_address_resolution_context = NULL; 1165 sm_address_resolution_test = -1; 1166 hci_con_handle_t con_handle = 0; 1167 1168 sm_connection_t * sm_connection; 1169 #ifdef ENABLE_LE_CENTRAL 1170 sm_key_t ltk; 1171 int have_ltk; 1172 int pairing_need; 1173 #endif 1174 switch (mode){ 1175 case ADDRESS_RESOLUTION_GENERAL: 1176 break; 1177 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1178 sm_connection = (sm_connection_t *) context; 1179 con_handle = sm_connection->sm_handle; 1180 switch (event){ 1181 case ADDRESS_RESOLUTION_SUCEEDED: 1182 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1183 sm_connection->sm_le_db_index = matched_device_id; 1184 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1185 if (sm_connection->sm_role) { 1186 // LTK request received before, IRK required -> start LTK calculation 1187 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1188 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1189 } 1190 break; 1191 } 1192 #ifdef ENABLE_LE_CENTRAL 1193 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 1194 have_ltk = !sm_is_null_key(ltk); 1195 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1196 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1197 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1198 // reset requests 1199 sm_connection->sm_security_request_received = 0; 1200 sm_connection->sm_pairing_requested = 0; 1201 1202 // have ltk -> start encryption 1203 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1204 // "When a bond has been created between two devices, any reconnection should result in the local device 1205 // enabling or requesting encryption with the remote device before initiating any service request." 1206 if (have_ltk){ 1207 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1208 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1209 break; 1210 #else 1211 log_info("central: defer enabling encryption for bonded device"); 1212 #endif 1213 } 1214 // pairint_request -> send pairing request 1215 if (pairing_need){ 1216 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1217 break; 1218 } 1219 #endif 1220 break; 1221 case ADDRESS_RESOLUTION_FAILED: 1222 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1223 if (sm_connection->sm_role) { 1224 // LTK request received before, IRK required -> negative LTK reply 1225 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1226 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1227 } 1228 break; 1229 } 1230 #ifdef ENABLE_LE_CENTRAL 1231 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1232 sm_connection->sm_security_request_received = 0; 1233 sm_connection->sm_pairing_requested = 0; 1234 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1235 #endif 1236 break; 1237 } 1238 break; 1239 default: 1240 break; 1241 } 1242 1243 switch (event){ 1244 case ADDRESS_RESOLUTION_SUCEEDED: 1245 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1246 break; 1247 case ADDRESS_RESOLUTION_FAILED: 1248 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1249 break; 1250 } 1251 } 1252 1253 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1254 1255 int le_db_index = -1; 1256 1257 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1258 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1259 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1260 & SM_AUTHREQ_BONDING ) != 0u; 1261 1262 if (bonding_enabed){ 1263 1264 // lookup device based on IRK 1265 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1266 int i; 1267 for (i=0; i < le_device_db_max_count(); i++){ 1268 sm_key_t irk; 1269 bd_addr_t address; 1270 int address_type = BD_ADDR_TYPE_UNKNOWN; 1271 le_device_db_info(i, &address_type, address, irk); 1272 // skip unused entries 1273 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1274 // compare IRK 1275 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1276 1277 log_info("sm: device found for IRK, updating"); 1278 le_db_index = i; 1279 break; 1280 } 1281 } else { 1282 // assert IRK is set to zero 1283 memset(setup->sm_peer_irk, 0, 16); 1284 } 1285 1286 // if not found, lookup via public address if possible 1287 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1288 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1289 int i; 1290 for (i=0; i < le_device_db_max_count(); i++){ 1291 bd_addr_t address; 1292 int address_type = BD_ADDR_TYPE_UNKNOWN; 1293 le_device_db_info(i, &address_type, address, NULL); 1294 // skip unused entries 1295 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1296 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1297 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1298 log_info("sm: device found for public address, updating"); 1299 le_db_index = i; 1300 break; 1301 } 1302 } 1303 } 1304 1305 // if not found, add to db 1306 if (le_db_index < 0) { 1307 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1308 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1309 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1310 #endif 1311 } 1312 1313 if (le_db_index >= 0){ 1314 1315 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1316 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1317 1318 #ifdef ENABLE_LE_SIGNED_WRITE 1319 // store local CSRK 1320 setup->sm_le_device_index = le_db_index; 1321 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1322 log_info("sm: store local CSRK"); 1323 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1324 le_device_db_local_counter_set(le_db_index, 0); 1325 } 1326 1327 // store remote CSRK 1328 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1329 log_info("sm: store remote CSRK"); 1330 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1331 le_device_db_remote_counter_set(le_db_index, 0); 1332 } 1333 #endif 1334 // store encryption information for secure connections: LTK generated by ECDH 1335 if (setup->sm_use_secure_connections){ 1336 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1337 uint8_t zero_rand[8]; 1338 memset(zero_rand, 0, 8); 1339 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1340 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1341 } 1342 1343 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1344 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1345 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1346 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1347 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1348 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1349 1350 } 1351 } 1352 } else { 1353 log_info("Ignoring received keys, bonding not enabled"); 1354 } 1355 1356 // keep le_db_index 1357 sm_conn->sm_le_db_index = le_db_index; 1358 } 1359 1360 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1361 setup->sm_pairing_failed_reason = reason; 1362 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1363 } 1364 1365 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1366 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1367 } 1368 1369 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1370 1371 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1372 static int sm_passkey_used(stk_generation_method_t method); 1373 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1374 1375 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1376 if (setup->sm_stk_generation_method == OOB){ 1377 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1378 } else { 1379 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); 1380 } 1381 } 1382 1383 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1384 if (IS_RESPONDER(sm_conn->sm_role)){ 1385 // Responder 1386 if (setup->sm_stk_generation_method == OOB){ 1387 // generate Nb 1388 log_info("Generate Nb"); 1389 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); 1390 } else { 1391 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1392 } 1393 } else { 1394 // Initiator role 1395 switch (setup->sm_stk_generation_method){ 1396 case JUST_WORKS: 1397 sm_sc_prepare_dhkey_check(sm_conn); 1398 break; 1399 1400 case NUMERIC_COMPARISON: 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1402 break; 1403 case PK_INIT_INPUT: 1404 case PK_RESP_INPUT: 1405 case PK_BOTH_INPUT: 1406 if (setup->sm_passkey_bit < 20u) { 1407 sm_sc_start_calculating_local_confirm(sm_conn); 1408 } else { 1409 sm_sc_prepare_dhkey_check(sm_conn); 1410 } 1411 break; 1412 case OOB: 1413 sm_sc_prepare_dhkey_check(sm_conn); 1414 break; 1415 } 1416 } 1417 } 1418 1419 static void sm_sc_cmac_done(uint8_t * hash){ 1420 log_info("sm_sc_cmac_done: "); 1421 log_info_hexdump(hash, 16); 1422 1423 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1424 sm_sc_oob_state = SM_SC_OOB_IDLE; 1425 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1426 return; 1427 } 1428 1429 sm_connection_t * sm_conn = sm_cmac_connection; 1430 sm_cmac_connection = NULL; 1431 #ifdef ENABLE_CLASSIC 1432 link_key_type_t link_key_type; 1433 #endif 1434 1435 switch (sm_conn->sm_engine_state){ 1436 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1437 (void)memcpy(setup->sm_local_confirm, hash, 16); 1438 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1439 break; 1440 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1441 // check 1442 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1443 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1444 break; 1445 } 1446 sm_sc_state_after_receiving_random(sm_conn); 1447 break; 1448 case SM_SC_W4_CALCULATE_G2: { 1449 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1450 big_endian_store_32(setup->sm_tk, 12, vab); 1451 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1452 sm_trigger_user_response(sm_conn); 1453 break; 1454 } 1455 case SM_SC_W4_CALCULATE_F5_SALT: 1456 (void)memcpy(setup->sm_t, hash, 16); 1457 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1458 break; 1459 case SM_SC_W4_CALCULATE_F5_MACKEY: 1460 (void)memcpy(setup->sm_mackey, hash, 16); 1461 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1462 break; 1463 case SM_SC_W4_CALCULATE_F5_LTK: 1464 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1465 // Errata Service Release to the Bluetooth Specification: ESR09 1466 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1467 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1468 (void)memcpy(setup->sm_ltk, hash, 16); 1469 (void)memcpy(setup->sm_local_ltk, hash, 16); 1470 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1471 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1472 break; 1473 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1474 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1475 if (IS_RESPONDER(sm_conn->sm_role)){ 1476 // responder 1477 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1478 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1479 } else { 1480 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1481 } 1482 } else { 1483 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1484 } 1485 break; 1486 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1487 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1488 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1489 break; 1490 } 1491 if (IS_RESPONDER(sm_conn->sm_role)){ 1492 // responder 1493 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1494 } else { 1495 // initiator 1496 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1497 } 1498 break; 1499 case SM_SC_W4_CALCULATE_H6_ILK: 1500 (void)memcpy(setup->sm_t, hash, 16); 1501 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1502 break; 1503 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1504 #ifdef ENABLE_CLASSIC 1505 reverse_128(hash, setup->sm_t); 1506 link_key_type = sm_conn->sm_connection_authenticated ? 1507 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1508 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1509 if (IS_RESPONDER(sm_conn->sm_role)){ 1510 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1511 } else { 1512 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1513 } 1514 #endif 1515 if (IS_RESPONDER(sm_conn->sm_role)){ 1516 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1517 } else { 1518 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1519 } 1520 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1521 sm_done_for_handle(sm_conn->sm_handle); 1522 break; 1523 default: 1524 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1525 break; 1526 } 1527 sm_run(); 1528 } 1529 1530 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){ 1531 const uint16_t message_len = 65; 1532 sm_cmac_connection = sm_conn; 1533 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1534 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1535 sm_cmac_sc_buffer[64] = z; 1536 log_info("f4 key"); 1537 log_info_hexdump(x, 16); 1538 log_info("f4 message"); 1539 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1540 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1541 } 1542 1543 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1544 static const uint8_t f5_length[] = { 0x01, 0x00}; 1545 1546 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1547 1548 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1549 1550 log_info("f5_calculate_salt"); 1551 // calculate salt for f5 1552 const uint16_t message_len = 32; 1553 sm_cmac_connection = sm_conn; 1554 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1555 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1556 } 1557 1558 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){ 1559 const uint16_t message_len = 53; 1560 sm_cmac_connection = sm_conn; 1561 1562 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1563 sm_cmac_sc_buffer[0] = 0; 1564 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1565 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1566 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1567 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1568 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1569 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1570 log_info("f5 key"); 1571 log_info_hexdump(t, 16); 1572 log_info("f5 message for MacKey"); 1573 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1574 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1575 } 1576 1577 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1578 sm_key56_t bd_addr_master, bd_addr_slave; 1579 bd_addr_master[0] = setup->sm_m_addr_type; 1580 bd_addr_slave[0] = setup->sm_s_addr_type; 1581 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1582 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1583 if (IS_RESPONDER(sm_conn->sm_role)){ 1584 // responder 1585 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1586 } else { 1587 // initiator 1588 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1589 } 1590 } 1591 1592 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1593 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1594 const uint16_t message_len = 53; 1595 sm_cmac_connection = sm_conn; 1596 sm_cmac_sc_buffer[0] = 1; 1597 // 1..52 setup before 1598 log_info("f5 key"); 1599 log_info_hexdump(t, 16); 1600 log_info("f5 message for LTK"); 1601 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1602 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1603 } 1604 1605 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1606 f5_ltk(sm_conn, setup->sm_t); 1607 } 1608 1609 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){ 1610 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1611 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1612 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1613 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1614 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1615 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1616 } 1617 1618 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1619 const uint16_t message_len = 65; 1620 sm_cmac_connection = sm_conn; 1621 log_info("f6 key"); 1622 log_info_hexdump(w, 16); 1623 log_info("f6 message"); 1624 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1625 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1626 } 1627 1628 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1629 // - U is 256 bits 1630 // - V is 256 bits 1631 // - X is 128 bits 1632 // - Y is 128 bits 1633 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){ 1634 const uint16_t message_len = 80; 1635 sm_cmac_connection = sm_conn; 1636 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1637 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1638 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1639 log_info("g2 key"); 1640 log_info_hexdump(x, 16); 1641 log_info("g2 message"); 1642 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1643 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1644 } 1645 1646 static void g2_calculate(sm_connection_t * sm_conn) { 1647 // calc Va if numeric comparison 1648 if (IS_RESPONDER(sm_conn->sm_role)){ 1649 // responder 1650 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1651 } else { 1652 // initiator 1653 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1654 } 1655 } 1656 1657 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1658 uint8_t z = 0; 1659 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1660 // some form of passkey 1661 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1662 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1663 setup->sm_passkey_bit++; 1664 } 1665 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1666 } 1667 1668 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1669 // OOB 1670 if (setup->sm_stk_generation_method == OOB){ 1671 if (IS_RESPONDER(sm_conn->sm_role)){ 1672 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1673 } else { 1674 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1675 } 1676 return; 1677 } 1678 1679 uint8_t z = 0; 1680 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1681 // some form of passkey 1682 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1683 // sm_passkey_bit was increased before sending confirm value 1684 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1685 } 1686 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1687 } 1688 1689 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1690 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1691 1692 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1693 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1694 return; 1695 } else { 1696 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1697 } 1698 } 1699 1700 static void sm_sc_dhkey_calculated(void * arg){ 1701 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1702 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1703 if (sm_conn == NULL) return; 1704 1705 log_info("dhkey"); 1706 log_info_hexdump(&setup->sm_dhkey[0], 32); 1707 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1708 // trigger next step 1709 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1710 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1711 } 1712 sm_run(); 1713 } 1714 1715 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1716 // calculate DHKCheck 1717 sm_key56_t bd_addr_master, bd_addr_slave; 1718 bd_addr_master[0] = setup->sm_m_addr_type; 1719 bd_addr_slave[0] = setup->sm_s_addr_type; 1720 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1721 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1722 uint8_t iocap_a[3]; 1723 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1724 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1725 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1726 uint8_t iocap_b[3]; 1727 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1728 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1729 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1730 if (IS_RESPONDER(sm_conn->sm_role)){ 1731 // responder 1732 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1733 f6_engine(sm_conn, setup->sm_mackey); 1734 } else { 1735 // initiator 1736 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1737 f6_engine(sm_conn, setup->sm_mackey); 1738 } 1739 } 1740 1741 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1742 // validate E = f6() 1743 sm_key56_t bd_addr_master, bd_addr_slave; 1744 bd_addr_master[0] = setup->sm_m_addr_type; 1745 bd_addr_slave[0] = setup->sm_s_addr_type; 1746 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1747 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1748 1749 uint8_t iocap_a[3]; 1750 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1751 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1752 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1753 uint8_t iocap_b[3]; 1754 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1755 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1756 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1757 if (IS_RESPONDER(sm_conn->sm_role)){ 1758 // responder 1759 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1760 f6_engine(sm_conn, setup->sm_mackey); 1761 } else { 1762 // initiator 1763 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1764 f6_engine(sm_conn, setup->sm_mackey); 1765 } 1766 } 1767 1768 1769 // 1770 // Link Key Conversion Function h6 1771 // 1772 // h6(W, keyID) = AES-CMACW(keyID) 1773 // - W is 128 bits 1774 // - keyID is 32 bits 1775 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1776 const uint16_t message_len = 4; 1777 sm_cmac_connection = sm_conn; 1778 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1779 log_info("h6 key"); 1780 log_info_hexdump(w, 16); 1781 log_info("h6 message"); 1782 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1783 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1784 } 1785 1786 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1787 // Errata Service Release to the Bluetooth Specification: ESR09 1788 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1789 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1790 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1791 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1792 } 1793 1794 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1795 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1796 } 1797 1798 #endif 1799 1800 // key management legacy connections: 1801 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1802 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1803 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1804 // - responder reconnects: responder uses LTK receveived from master 1805 1806 // key management secure connections: 1807 // - both devices store same LTK from ECDH key exchange. 1808 1809 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1810 static void sm_load_security_info(sm_connection_t * sm_connection){ 1811 int encryption_key_size; 1812 int authenticated; 1813 int authorized; 1814 int secure_connection; 1815 1816 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1817 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1818 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1819 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); 1820 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1821 sm_connection->sm_connection_authenticated = authenticated; 1822 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1823 sm_connection->sm_connection_sc = secure_connection; 1824 } 1825 #endif 1826 1827 #ifdef ENABLE_LE_PERIPHERAL 1828 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1829 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1830 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1831 // re-establish used key encryption size 1832 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1833 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 1834 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1835 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 1836 // Legacy paring -> not SC 1837 sm_connection->sm_connection_sc = 0; 1838 log_info("sm: received ltk request with key size %u, authenticated %u", 1839 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1840 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1841 sm_run(); 1842 } 1843 #endif 1844 1845 // distributed key generation 1846 static bool sm_run_dpkg(void){ 1847 switch (dkg_state){ 1848 case DKG_CALC_IRK: 1849 // already busy? 1850 if (sm_aes128_state == SM_AES128_IDLE) { 1851 log_info("DKG_CALC_IRK started"); 1852 // IRK = d1(IR, 1, 0) 1853 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1854 sm_aes128_state = SM_AES128_ACTIVE; 1855 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1856 return true; 1857 } 1858 break; 1859 case DKG_CALC_DHK: 1860 // already busy? 1861 if (sm_aes128_state == SM_AES128_IDLE) { 1862 log_info("DKG_CALC_DHK started"); 1863 // DHK = d1(IR, 3, 0) 1864 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1865 sm_aes128_state = SM_AES128_ACTIVE; 1866 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1867 return true; 1868 } 1869 break; 1870 default: 1871 break; 1872 } 1873 return false; 1874 } 1875 1876 // random address updates 1877 static bool sm_run_rau(void){ 1878 switch (rau_state){ 1879 case RAU_GET_RANDOM: 1880 rau_state = RAU_W4_RANDOM; 1881 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1882 return true; 1883 case RAU_GET_ENC: 1884 // already busy? 1885 if (sm_aes128_state == SM_AES128_IDLE) { 1886 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1887 sm_aes128_state = SM_AES128_ACTIVE; 1888 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1889 return true; 1890 } 1891 break; 1892 case RAU_SET_ADDRESS: 1893 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1894 rau_state = RAU_IDLE; 1895 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1896 return true; 1897 default: 1898 break; 1899 } 1900 return false; 1901 } 1902 1903 // CSRK Lookup 1904 static bool sm_run_csrk(void){ 1905 btstack_linked_list_iterator_t it; 1906 1907 // -- if csrk lookup ready, find connection that require csrk lookup 1908 if (sm_address_resolution_idle()){ 1909 hci_connections_get_iterator(&it); 1910 while(btstack_linked_list_iterator_has_next(&it)){ 1911 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1912 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1913 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1914 // and start lookup 1915 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); 1916 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1917 break; 1918 } 1919 } 1920 } 1921 1922 // -- if csrk lookup ready, resolved addresses for received addresses 1923 if (sm_address_resolution_idle()) { 1924 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1925 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1926 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1927 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1928 btstack_memory_sm_lookup_entry_free(entry); 1929 } 1930 } 1931 1932 // -- Continue with CSRK device lookup by public or resolvable private address 1933 if (!sm_address_resolution_idle()){ 1934 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1935 while (sm_address_resolution_test < le_device_db_max_count()){ 1936 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1937 bd_addr_t addr; 1938 sm_key_t irk; 1939 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1940 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1941 1942 // skip unused entries 1943 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1944 sm_address_resolution_test++; 1945 continue; 1946 } 1947 1948 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1949 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1950 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1951 break; 1952 } 1953 1954 // if connection type is public, it must be a different one 1955 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1956 sm_address_resolution_test++; 1957 continue; 1958 } 1959 1960 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1961 1962 log_info("LE Device Lookup: calculate AH"); 1963 log_info_key("IRK", irk); 1964 1965 (void)memcpy(sm_aes128_key, irk, 16); 1966 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1967 sm_address_resolution_ah_calculation_active = 1; 1968 sm_aes128_state = SM_AES128_ACTIVE; 1969 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1970 return true; 1971 } 1972 1973 if (sm_address_resolution_test >= le_device_db_max_count()){ 1974 log_info("LE Device Lookup: not found"); 1975 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1976 } 1977 } 1978 return false; 1979 } 1980 1981 // SC OOB 1982 static bool sm_run_oob(void){ 1983 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1984 switch (sm_sc_oob_state){ 1985 case SM_SC_OOB_W2_CALC_CONFIRM: 1986 if (!sm_cmac_ready()) break; 1987 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1988 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1989 return true; 1990 default: 1991 break; 1992 } 1993 #endif 1994 return false; 1995 } 1996 1997 // handle basic actions that don't requires the full context 1998 static bool sm_run_basic(void){ 1999 btstack_linked_list_iterator_t it; 2000 hci_connections_get_iterator(&it); 2001 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2002 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2003 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2004 switch(sm_connection->sm_engine_state){ 2005 // responder side 2006 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2007 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2008 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2009 return true; 2010 2011 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2012 case SM_SC_RECEIVED_LTK_REQUEST: 2013 switch (sm_connection->sm_irk_lookup_state){ 2014 case IRK_LOOKUP_FAILED: 2015 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2016 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2017 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2018 return true; 2019 default: 2020 break; 2021 } 2022 break; 2023 #endif 2024 default: 2025 break; 2026 } 2027 } 2028 return false; 2029 } 2030 2031 static void sm_run_activate_connection(void){ 2032 // Find connections that requires setup context and make active if no other is locked 2033 btstack_linked_list_iterator_t it; 2034 hci_connections_get_iterator(&it); 2035 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2036 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2037 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2038 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2039 int done = 1; 2040 int err; 2041 UNUSED(err); 2042 2043 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2044 // assert ec key is ready 2045 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2046 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2047 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2048 sm_ec_generate_new_key(); 2049 } 2050 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2051 continue; 2052 } 2053 } 2054 #endif 2055 2056 switch (sm_connection->sm_engine_state) { 2057 #ifdef ENABLE_LE_PERIPHERAL 2058 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2059 // send packet if possible, 2060 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2061 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2062 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2063 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2064 } else { 2065 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2066 } 2067 // don't lock sxetup context yet 2068 done = 0; 2069 break; 2070 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2071 sm_reset_setup(); 2072 sm_init_setup(sm_connection); 2073 // recover pairing request 2074 (void)memcpy(&setup->sm_m_preq, 2075 &sm_connection->sm_m_preq, 2076 sizeof(sm_pairing_packet_t)); 2077 err = sm_stk_generation_init(sm_connection); 2078 2079 #ifdef ENABLE_TESTING_SUPPORT 2080 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2081 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2082 err = test_pairing_failure; 2083 } 2084 #endif 2085 if (err){ 2086 setup->sm_pairing_failed_reason = err; 2087 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2088 break; 2089 } 2090 sm_timeout_start(sm_connection); 2091 // generate random number first, if we need to show passkey 2092 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2093 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); 2094 break; 2095 } 2096 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2097 break; 2098 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2099 sm_reset_setup(); 2100 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2101 break; 2102 2103 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2104 case SM_SC_RECEIVED_LTK_REQUEST: 2105 switch (sm_connection->sm_irk_lookup_state){ 2106 case IRK_LOOKUP_SUCCEEDED: 2107 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2108 // start using context by loading security info 2109 sm_reset_setup(); 2110 sm_load_security_info(sm_connection); 2111 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2112 (void)memcpy(setup->sm_ltk, 2113 setup->sm_peer_ltk, 16); 2114 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2115 break; 2116 } 2117 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2118 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2119 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2120 // don't lock setup context yet 2121 return; 2122 default: 2123 // just wait until IRK lookup is completed 2124 // don't lock setup context yet 2125 done = 0; 2126 break; 2127 } 2128 break; 2129 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2130 #endif /* ENABLE_LE_PERIPHERAL */ 2131 2132 #ifdef ENABLE_LE_CENTRAL 2133 case SM_INITIATOR_PH0_HAS_LTK: 2134 sm_reset_setup(); 2135 sm_load_security_info(sm_connection); 2136 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2137 break; 2138 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2139 sm_reset_setup(); 2140 sm_init_setup(sm_connection); 2141 sm_timeout_start(sm_connection); 2142 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2143 break; 2144 #endif 2145 2146 default: 2147 done = 0; 2148 break; 2149 } 2150 if (done){ 2151 sm_active_connection_handle = sm_connection->sm_handle; 2152 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); 2153 } 2154 } 2155 } 2156 2157 static void sm_run(void){ 2158 2159 // assert that stack has already bootet 2160 if (hci_get_state() != HCI_STATE_WORKING) return; 2161 2162 // assert that we can send at least commands 2163 if (!hci_can_send_command_packet_now()) return; 2164 2165 // pause until IR/ER are ready 2166 if (sm_persistent_keys_random_active) return; 2167 2168 bool done; 2169 2170 // 2171 // non-connection related behaviour 2172 // 2173 2174 done = sm_run_dpkg(); 2175 if (done) return; 2176 2177 done = sm_run_rau(); 2178 if (done) return; 2179 2180 done = sm_run_csrk(); 2181 if (done) return; 2182 2183 done = sm_run_oob(); 2184 if (done) return; 2185 2186 // assert that we can send at least commands - cmd might have been sent by crypto engine 2187 if (!hci_can_send_command_packet_now()) return; 2188 2189 // handle basic actions that don't requires the full context 2190 done = sm_run_basic(); 2191 if (done) return; 2192 2193 // 2194 // active connection handling 2195 // -- use loop to handle next connection if lock on setup context is released 2196 2197 while (true) { 2198 2199 sm_run_activate_connection(); 2200 2201 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2202 2203 // 2204 // active connection handling 2205 // 2206 2207 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2208 if (!connection) { 2209 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2210 return; 2211 } 2212 2213 // assert that we could send a SM PDU - not needed for all of the following 2214 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2215 log_info("cannot send now, requesting can send now event"); 2216 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2217 return; 2218 } 2219 2220 // send keypress notifications 2221 if (setup->sm_keypress_notification){ 2222 int i; 2223 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2224 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2225 uint8_t action = 0; 2226 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2227 if (flags & (1u<<i)){ 2228 int clear_flag = 1; 2229 switch (i){ 2230 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2231 case SM_KEYPRESS_PASSKEY_CLEARED: 2232 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2233 default: 2234 break; 2235 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2236 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2237 num_actions--; 2238 clear_flag = num_actions == 0u; 2239 break; 2240 } 2241 if (clear_flag){ 2242 flags &= ~(1<<i); 2243 } 2244 action = i; 2245 break; 2246 } 2247 } 2248 setup->sm_keypress_notification = (num_actions << 5) | flags; 2249 2250 // send keypress notification 2251 uint8_t buffer[2]; 2252 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2253 buffer[1] = action; 2254 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2255 2256 // try 2257 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2258 return; 2259 } 2260 2261 int key_distribution_flags; 2262 UNUSED(key_distribution_flags); 2263 2264 log_info("sm_run: state %u", connection->sm_engine_state); 2265 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2266 log_info("sm_run // cannot send"); 2267 } 2268 switch (connection->sm_engine_state){ 2269 2270 // general 2271 case SM_GENERAL_SEND_PAIRING_FAILED: { 2272 uint8_t buffer[2]; 2273 buffer[0] = SM_CODE_PAIRING_FAILED; 2274 buffer[1] = setup->sm_pairing_failed_reason; 2275 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2276 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2277 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2278 sm_done_for_handle(connection->sm_handle); 2279 break; 2280 } 2281 2282 // responding state 2283 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2284 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2285 if (!sm_cmac_ready()) break; 2286 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2287 sm_sc_calculate_local_confirm(connection); 2288 break; 2289 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2290 if (!sm_cmac_ready()) break; 2291 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2292 sm_sc_calculate_remote_confirm(connection); 2293 break; 2294 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2295 if (!sm_cmac_ready()) break; 2296 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2297 sm_sc_calculate_f6_for_dhkey_check(connection); 2298 break; 2299 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2300 if (!sm_cmac_ready()) break; 2301 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2302 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2303 break; 2304 case SM_SC_W2_CALCULATE_F5_SALT: 2305 if (!sm_cmac_ready()) break; 2306 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2307 f5_calculate_salt(connection); 2308 break; 2309 case SM_SC_W2_CALCULATE_F5_MACKEY: 2310 if (!sm_cmac_ready()) break; 2311 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2312 f5_calculate_mackey(connection); 2313 break; 2314 case SM_SC_W2_CALCULATE_F5_LTK: 2315 if (!sm_cmac_ready()) break; 2316 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2317 f5_calculate_ltk(connection); 2318 break; 2319 case SM_SC_W2_CALCULATE_G2: 2320 if (!sm_cmac_ready()) break; 2321 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2322 g2_calculate(connection); 2323 break; 2324 case SM_SC_W2_CALCULATE_H6_ILK: 2325 if (!sm_cmac_ready()) break; 2326 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2327 h6_calculate_ilk(connection); 2328 break; 2329 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2330 if (!sm_cmac_ready()) break; 2331 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2332 h6_calculate_br_edr_link_key(connection); 2333 break; 2334 #endif 2335 2336 #ifdef ENABLE_LE_CENTRAL 2337 // initiator side 2338 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2339 sm_key_t peer_ltk_flipped; 2340 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2341 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2342 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2343 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2344 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2345 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2346 return; 2347 } 2348 2349 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2350 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2351 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2352 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2353 sm_timeout_reset(connection); 2354 break; 2355 #endif 2356 2357 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2358 2359 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2360 int trigger_user_response = 0; 2361 int trigger_start_calculating_local_confirm = 0; 2362 uint8_t buffer[65]; 2363 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2364 // 2365 reverse_256(&ec_q[0], &buffer[1]); 2366 reverse_256(&ec_q[32], &buffer[33]); 2367 2368 #ifdef ENABLE_TESTING_SUPPORT 2369 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2370 log_info("testing_support: invalidating public key"); 2371 // flip single bit of public key coordinate 2372 buffer[1] ^= 1; 2373 } 2374 #endif 2375 2376 // stk generation method 2377 // passkey entry: notify app to show passkey or to request passkey 2378 switch (setup->sm_stk_generation_method){ 2379 case JUST_WORKS: 2380 case NUMERIC_COMPARISON: 2381 if (IS_RESPONDER(connection->sm_role)){ 2382 // responder 2383 trigger_start_calculating_local_confirm = 1; 2384 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2385 } else { 2386 // initiator 2387 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2388 } 2389 break; 2390 case PK_INIT_INPUT: 2391 case PK_RESP_INPUT: 2392 case PK_BOTH_INPUT: 2393 // use random TK for display 2394 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2395 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2396 setup->sm_passkey_bit = 0; 2397 2398 if (IS_RESPONDER(connection->sm_role)){ 2399 // responder 2400 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2401 } else { 2402 // initiator 2403 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2404 } 2405 trigger_user_response = 1; 2406 break; 2407 case OOB: 2408 if (IS_RESPONDER(connection->sm_role)){ 2409 // responder 2410 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2411 } else { 2412 // initiator 2413 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2414 } 2415 break; 2416 } 2417 2418 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2419 sm_timeout_reset(connection); 2420 2421 // trigger user response and calc confirm after sending pdu 2422 if (trigger_user_response){ 2423 sm_trigger_user_response(connection); 2424 } 2425 if (trigger_start_calculating_local_confirm){ 2426 sm_sc_start_calculating_local_confirm(connection); 2427 } 2428 break; 2429 } 2430 case SM_SC_SEND_CONFIRMATION: { 2431 uint8_t buffer[17]; 2432 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2433 reverse_128(setup->sm_local_confirm, &buffer[1]); 2434 if (IS_RESPONDER(connection->sm_role)){ 2435 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2436 } else { 2437 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2438 } 2439 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2440 sm_timeout_reset(connection); 2441 break; 2442 } 2443 case SM_SC_SEND_PAIRING_RANDOM: { 2444 uint8_t buffer[17]; 2445 buffer[0] = SM_CODE_PAIRING_RANDOM; 2446 reverse_128(setup->sm_local_nonce, &buffer[1]); 2447 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2448 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2449 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2450 if (IS_RESPONDER(connection->sm_role)){ 2451 // responder 2452 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2453 } else { 2454 // initiator 2455 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2456 } 2457 } else { 2458 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2459 if (IS_RESPONDER(connection->sm_role)){ 2460 // responder 2461 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2462 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2463 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2464 } else { 2465 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2466 sm_sc_prepare_dhkey_check(connection); 2467 } 2468 } else { 2469 // initiator 2470 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2471 } 2472 } 2473 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2474 sm_timeout_reset(connection); 2475 break; 2476 } 2477 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2478 uint8_t buffer[17]; 2479 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2480 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2481 2482 if (IS_RESPONDER(connection->sm_role)){ 2483 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2484 } else { 2485 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2486 } 2487 2488 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2489 sm_timeout_reset(connection); 2490 break; 2491 } 2492 2493 #endif 2494 2495 #ifdef ENABLE_LE_PERIPHERAL 2496 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2497 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2498 2499 // start with initiator key dist flags 2500 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2501 2502 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2503 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2504 if (setup->sm_use_secure_connections){ 2505 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2506 } 2507 #endif 2508 // setup in response 2509 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); 2510 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); 2511 2512 // update key distribution after ENC was dropped 2513 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2514 2515 if (setup->sm_use_secure_connections){ 2516 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2517 } else { 2518 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2519 } 2520 2521 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2522 sm_timeout_reset(connection); 2523 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2524 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2525 sm_trigger_user_response(connection); 2526 } 2527 return; 2528 #endif 2529 2530 case SM_PH2_SEND_PAIRING_RANDOM: { 2531 uint8_t buffer[17]; 2532 buffer[0] = SM_CODE_PAIRING_RANDOM; 2533 reverse_128(setup->sm_local_random, &buffer[1]); 2534 if (IS_RESPONDER(connection->sm_role)){ 2535 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2536 } else { 2537 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2538 } 2539 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2540 sm_timeout_reset(connection); 2541 break; 2542 } 2543 2544 case SM_PH2_C1_GET_ENC_A: 2545 // already busy? 2546 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2547 // calculate confirm using aes128 engine - step 1 2548 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); 2549 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 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_a, (void *)(uintptr_t) connection->sm_handle); 2552 break; 2553 2554 case SM_PH2_C1_GET_ENC_C: 2555 // already busy? 2556 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2557 // calculate m_confirm using aes128 engine - step 1 2558 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); 2559 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2560 sm_aes128_state = SM_AES128_ACTIVE; 2561 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); 2562 break; 2563 2564 case SM_PH2_CALC_STK: 2565 // already busy? 2566 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2567 // calculate STK 2568 if (IS_RESPONDER(connection->sm_role)){ 2569 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2570 } else { 2571 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2572 } 2573 connection->sm_engine_state = SM_PH2_W4_STK; 2574 sm_aes128_state = SM_AES128_ACTIVE; 2575 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); 2576 break; 2577 2578 case SM_PH3_Y_GET_ENC: 2579 // already busy? 2580 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2581 // PH3B2 - calculate Y from - enc 2582 2583 // dm helper (was sm_dm_r_prime) 2584 // r' = padding || r 2585 // r - 64 bit value 2586 memset(&sm_aes128_plaintext[0], 0, 8); 2587 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2588 2589 // Y = dm(DHK, Rand) 2590 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2591 sm_aes128_state = SM_AES128_ACTIVE; 2592 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); 2593 break; 2594 2595 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2596 uint8_t buffer[17]; 2597 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2598 reverse_128(setup->sm_local_confirm, &buffer[1]); 2599 if (IS_RESPONDER(connection->sm_role)){ 2600 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2601 } else { 2602 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2603 } 2604 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2605 sm_timeout_reset(connection); 2606 return; 2607 } 2608 #ifdef ENABLE_LE_PERIPHERAL 2609 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2610 sm_key_t stk_flipped; 2611 reverse_128(setup->sm_ltk, stk_flipped); 2612 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2613 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2614 return; 2615 } 2616 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2617 sm_key_t ltk_flipped; 2618 reverse_128(setup->sm_ltk, ltk_flipped); 2619 connection->sm_engine_state = SM_RESPONDER_IDLE; 2620 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2621 sm_done_for_handle(connection->sm_handle); 2622 return; 2623 } 2624 case SM_RESPONDER_PH4_Y_GET_ENC: 2625 // already busy? 2626 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2627 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2628 2629 // dm helper (was sm_dm_r_prime) 2630 // r' = padding || r 2631 // r - 64 bit value 2632 memset(&sm_aes128_plaintext[0], 0, 8); 2633 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2634 2635 // Y = dm(DHK, Rand) 2636 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2637 sm_aes128_state = SM_AES128_ACTIVE; 2638 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); 2639 return; 2640 #endif 2641 #ifdef ENABLE_LE_CENTRAL 2642 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2643 sm_key_t stk_flipped; 2644 reverse_128(setup->sm_ltk, stk_flipped); 2645 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2646 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2647 return; 2648 } 2649 #endif 2650 2651 case SM_PH3_DISTRIBUTE_KEYS: 2652 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2653 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2654 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2655 uint8_t buffer[17]; 2656 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2657 reverse_128(setup->sm_ltk, &buffer[1]); 2658 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2659 sm_timeout_reset(connection); 2660 return; 2661 } 2662 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2663 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2664 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2665 uint8_t buffer[11]; 2666 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2667 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2668 reverse_64(setup->sm_local_rand, &buffer[3]); 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_INFORMATION){ 2674 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2675 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2676 uint8_t buffer[17]; 2677 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2678 reverse_128(sm_persistent_irk, &buffer[1]); 2679 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2680 sm_timeout_reset(connection); 2681 return; 2682 } 2683 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2684 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2685 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2686 bd_addr_t local_address; 2687 uint8_t buffer[8]; 2688 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2689 switch (gap_random_address_get_mode()){ 2690 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2691 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2692 // public or static random 2693 gap_le_get_own_address(&buffer[1], local_address); 2694 break; 2695 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2696 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2697 // fallback to public 2698 gap_local_bd_addr(local_address); 2699 buffer[1] = 0; 2700 break; 2701 } 2702 reverse_bd_addr(local_address, &buffer[2]); 2703 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2704 sm_timeout_reset(connection); 2705 return; 2706 } 2707 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2708 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2709 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2710 2711 #ifdef ENABLE_LE_SIGNED_WRITE 2712 // hack to reproduce test runs 2713 if (test_use_fixed_local_csrk){ 2714 memset(setup->sm_local_csrk, 0xcc, 16); 2715 } 2716 2717 // store local CSRK 2718 if (setup->sm_le_device_index >= 0){ 2719 log_info("sm: store local CSRK"); 2720 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2721 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2722 } 2723 #endif 2724 2725 uint8_t buffer[17]; 2726 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2727 reverse_128(setup->sm_local_csrk, &buffer[1]); 2728 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2729 sm_timeout_reset(connection); 2730 return; 2731 } 2732 2733 // keys are sent 2734 if (IS_RESPONDER(connection->sm_role)){ 2735 // slave -> receive master keys if any 2736 if (sm_key_distribution_all_received(connection)){ 2737 sm_key_distribution_handle_all_received(connection); 2738 connection->sm_engine_state = SM_RESPONDER_IDLE; 2739 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2740 sm_done_for_handle(connection->sm_handle); 2741 } else { 2742 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2743 } 2744 } else { 2745 sm_master_pairing_success(connection); 2746 } 2747 break; 2748 2749 default: 2750 break; 2751 } 2752 2753 // check again if active connection was released 2754 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2755 } 2756 } 2757 2758 // sm_aes128_state stays active 2759 static void sm_handle_encryption_result_enc_a(void *arg){ 2760 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2761 sm_aes128_state = SM_AES128_IDLE; 2762 2763 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2764 if (connection == NULL) return; 2765 2766 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2767 sm_aes128_state = SM_AES128_ACTIVE; 2768 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); 2769 } 2770 2771 static void sm_handle_encryption_result_enc_b(void *arg){ 2772 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2773 sm_aes128_state = SM_AES128_IDLE; 2774 2775 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2776 if (connection == NULL) return; 2777 2778 log_info_key("c1!", setup->sm_local_confirm); 2779 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2780 sm_run(); 2781 } 2782 2783 // sm_aes128_state stays active 2784 static void sm_handle_encryption_result_enc_c(void *arg){ 2785 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2786 sm_aes128_state = SM_AES128_IDLE; 2787 2788 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2789 if (connection == NULL) return; 2790 2791 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2792 sm_aes128_state = SM_AES128_ACTIVE; 2793 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); 2794 } 2795 2796 static void sm_handle_encryption_result_enc_d(void * arg){ 2797 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2798 sm_aes128_state = SM_AES128_IDLE; 2799 2800 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2801 if (connection == NULL) return; 2802 2803 log_info_key("c1!", sm_aes128_ciphertext); 2804 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2805 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2806 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2807 sm_run(); 2808 return; 2809 } 2810 if (IS_RESPONDER(connection->sm_role)){ 2811 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2812 sm_run(); 2813 } else { 2814 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2815 sm_aes128_state = SM_AES128_ACTIVE; 2816 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); 2817 } 2818 } 2819 2820 static void sm_handle_encryption_result_enc_stk(void *arg){ 2821 sm_aes128_state = SM_AES128_IDLE; 2822 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2823 2824 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2825 if (connection == NULL) return; 2826 2827 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2828 log_info_key("stk", setup->sm_ltk); 2829 if (IS_RESPONDER(connection->sm_role)){ 2830 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2831 } else { 2832 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2833 } 2834 sm_run(); 2835 } 2836 2837 // sm_aes128_state stays active 2838 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2839 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2840 sm_aes128_state = SM_AES128_IDLE; 2841 2842 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2843 if (connection == NULL) return; 2844 2845 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2846 log_info_hex16("y", setup->sm_local_y); 2847 // PH3B3 - calculate EDIV 2848 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2849 log_info_hex16("ediv", setup->sm_local_ediv); 2850 // PH3B4 - calculate LTK - enc 2851 // LTK = d1(ER, DIV, 0)) 2852 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2853 sm_aes128_state = SM_AES128_ACTIVE; 2854 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); 2855 } 2856 2857 #ifdef ENABLE_LE_PERIPHERAL 2858 // sm_aes128_state stays active 2859 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2860 sm_aes128_state = SM_AES128_IDLE; 2861 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2862 2863 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2864 if (connection == NULL) return; 2865 2866 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2867 log_info_hex16("y", setup->sm_local_y); 2868 2869 // PH3B3 - calculate DIV 2870 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2871 log_info_hex16("ediv", setup->sm_local_ediv); 2872 // PH3B4 - calculate LTK - enc 2873 // LTK = d1(ER, DIV, 0)) 2874 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2875 sm_aes128_state = SM_AES128_ACTIVE; 2876 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); 2877 } 2878 #endif 2879 2880 // sm_aes128_state stays active 2881 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2882 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2883 sm_aes128_state = SM_AES128_IDLE; 2884 2885 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2886 if (connection == NULL) return; 2887 2888 log_info_key("ltk", setup->sm_ltk); 2889 // calc CSRK next 2890 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2891 sm_aes128_state = SM_AES128_ACTIVE; 2892 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); 2893 } 2894 2895 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2896 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2897 sm_aes128_state = SM_AES128_IDLE; 2898 2899 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2900 if (connection == NULL) return; 2901 2902 sm_aes128_state = SM_AES128_IDLE; 2903 log_info_key("csrk", setup->sm_local_csrk); 2904 if (setup->sm_key_distribution_send_set){ 2905 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2906 } else { 2907 // no keys to send, just continue 2908 if (IS_RESPONDER(connection->sm_role)){ 2909 // slave -> receive master keys 2910 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2911 } else { 2912 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2913 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2914 } else { 2915 sm_master_pairing_success(connection); 2916 } 2917 } 2918 } 2919 sm_run(); 2920 } 2921 2922 #ifdef ENABLE_LE_PERIPHERAL 2923 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2924 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2925 sm_aes128_state = SM_AES128_IDLE; 2926 2927 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2928 if (connection == NULL) return; 2929 2930 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2931 log_info_key("ltk", setup->sm_ltk); 2932 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2933 sm_run(); 2934 } 2935 #endif 2936 2937 static void sm_handle_encryption_result_address_resolution(void *arg){ 2938 UNUSED(arg); 2939 sm_aes128_state = SM_AES128_IDLE; 2940 2941 sm_address_resolution_ah_calculation_active = 0; 2942 // compare calulated address against connecting device 2943 uint8_t * hash = &sm_aes128_ciphertext[13]; 2944 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2945 log_info("LE Device Lookup: matched resolvable private address"); 2946 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2947 sm_run(); 2948 return; 2949 } 2950 // no match, try next 2951 sm_address_resolution_test++; 2952 sm_run(); 2953 } 2954 2955 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2956 UNUSED(arg); 2957 sm_aes128_state = SM_AES128_IDLE; 2958 2959 log_info_key("irk", sm_persistent_irk); 2960 dkg_state = DKG_CALC_DHK; 2961 sm_run(); 2962 } 2963 2964 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2965 UNUSED(arg); 2966 sm_aes128_state = SM_AES128_IDLE; 2967 2968 log_info_key("dhk", sm_persistent_dhk); 2969 dkg_state = DKG_READY; 2970 sm_run(); 2971 } 2972 2973 static void sm_handle_encryption_result_rau(void *arg){ 2974 UNUSED(arg); 2975 sm_aes128_state = SM_AES128_IDLE; 2976 2977 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2978 rau_state = RAU_SET_ADDRESS; 2979 sm_run(); 2980 } 2981 2982 static void sm_handle_random_result_rau(void * arg){ 2983 UNUSED(arg); 2984 // non-resolvable vs. resolvable 2985 switch (gap_random_adress_type){ 2986 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2987 // resolvable: use random as prand and calc address hash 2988 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2989 sm_random_address[0u] &= 0x3fu; 2990 sm_random_address[0u] |= 0x40u; 2991 rau_state = RAU_GET_ENC; 2992 break; 2993 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2994 default: 2995 // "The two most significant bits of the address shall be equal to ‘0’"" 2996 sm_random_address[0u] &= 0x3fu; 2997 rau_state = RAU_SET_ADDRESS; 2998 break; 2999 } 3000 sm_run(); 3001 } 3002 3003 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3004 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3005 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3006 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3007 if (connection == NULL) return; 3008 3009 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3010 sm_run(); 3011 } 3012 3013 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(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_SC_W2_CMAC_FOR_CONFIRMATION; 3019 sm_run(); 3020 } 3021 #endif 3022 3023 static void sm_handle_random_result_ph2_random(void * arg){ 3024 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3025 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3026 if (connection == NULL) return; 3027 3028 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3029 sm_run(); 3030 } 3031 3032 static void sm_handle_random_result_ph2_tk(void * arg){ 3033 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3034 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3035 if (connection == NULL) return; 3036 3037 sm_reset_tk(); 3038 uint32_t tk; 3039 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3040 // map random to 0-999999 without speding much cycles on a modulus operation 3041 tk = little_endian_read_32(sm_random_data,0); 3042 tk = tk & 0xfffff; // 1048575 3043 if (tk >= 999999u){ 3044 tk = tk - 999999u; 3045 } 3046 } else { 3047 // override with pre-defined passkey 3048 tk = sm_fixed_passkey_in_display_role; 3049 } 3050 big_endian_store_32(setup->sm_tk, 12, tk); 3051 if (IS_RESPONDER(connection->sm_role)){ 3052 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3053 } else { 3054 if (setup->sm_use_secure_connections){ 3055 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3056 } else { 3057 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3058 sm_trigger_user_response(connection); 3059 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3060 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3061 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); 3062 } 3063 } 3064 } 3065 sm_run(); 3066 } 3067 3068 static void sm_handle_random_result_ph3_div(void * arg){ 3069 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3070 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3071 if (connection == NULL) return; 3072 3073 // use 16 bit from random value as div 3074 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3075 log_info_hex16("div", setup->sm_local_div); 3076 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3077 sm_run(); 3078 } 3079 3080 static void sm_handle_random_result_ph3_random(void * arg){ 3081 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3082 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3083 if (connection == NULL) return; 3084 3085 reverse_64(sm_random_data, setup->sm_local_rand); 3086 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3087 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3088 // no db for authenticated flag hack: store flag in bit 4 of LSB 3089 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3090 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3091 } 3092 static void sm_validate_er_ir(void){ 3093 // warn about default ER/IR 3094 int warning = 0; 3095 if (sm_ir_is_default()){ 3096 warning = 1; 3097 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3098 } 3099 if (sm_er_is_default()){ 3100 warning = 1; 3101 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3102 } 3103 if (warning) { 3104 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3105 } 3106 } 3107 3108 static void sm_handle_random_result_ir(void *arg){ 3109 sm_persistent_keys_random_active = 0; 3110 if (arg){ 3111 // key generated, store in tlv 3112 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3113 log_info("Generated IR key. Store in TLV status: %d", status); 3114 } 3115 log_info_key("IR", sm_persistent_ir); 3116 dkg_state = DKG_CALC_IRK; 3117 3118 if (test_use_fixed_local_irk){ 3119 log_info_key("IRK", sm_persistent_irk); 3120 dkg_state = DKG_CALC_DHK; 3121 } 3122 3123 sm_run(); 3124 } 3125 3126 static void sm_handle_random_result_er(void *arg){ 3127 sm_persistent_keys_random_active = 0; 3128 if (arg){ 3129 // key generated, store in tlv 3130 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3131 log_info("Generated ER key. Store in TLV status: %d", status); 3132 } 3133 log_info_key("ER", sm_persistent_er); 3134 3135 // try load ir 3136 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3137 if (key_size == 16){ 3138 // ok, let's continue 3139 log_info("IR from TLV"); 3140 sm_handle_random_result_ir( NULL ); 3141 } else { 3142 // invalid, generate new random one 3143 sm_persistent_keys_random_active = 1; 3144 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3145 } 3146 } 3147 3148 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3149 3150 UNUSED(channel); // ok: there is no channel 3151 UNUSED(size); // ok: fixed format HCI events 3152 3153 sm_connection_t * sm_conn; 3154 hci_con_handle_t con_handle; 3155 3156 switch (packet_type) { 3157 3158 case HCI_EVENT_PACKET: 3159 switch (hci_event_packet_get_type(packet)) { 3160 3161 case BTSTACK_EVENT_STATE: 3162 // bt stack activated, get started 3163 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3164 log_info("HCI Working!"); 3165 3166 // setup IR/ER with TLV 3167 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3168 if (sm_tlv_impl){ 3169 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3170 if (key_size == 16){ 3171 // ok, let's continue 3172 log_info("ER from TLV"); 3173 sm_handle_random_result_er( NULL ); 3174 } else { 3175 // invalid, generate random one 3176 sm_persistent_keys_random_active = 1; 3177 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3178 } 3179 } else { 3180 sm_validate_er_ir(); 3181 dkg_state = DKG_CALC_IRK; 3182 3183 if (test_use_fixed_local_irk){ 3184 log_info_key("IRK", sm_persistent_irk); 3185 dkg_state = DKG_CALC_DHK; 3186 } 3187 } 3188 3189 // restart random address updates after power cycle 3190 gap_random_address_set_mode(gap_random_adress_type); 3191 } 3192 break; 3193 3194 case HCI_EVENT_LE_META: 3195 switch (packet[2]) { 3196 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3197 3198 log_info("sm: connected"); 3199 3200 if (packet[3]) return; // connection failed 3201 3202 con_handle = little_endian_read_16(packet, 4); 3203 sm_conn = sm_get_connection_for_handle(con_handle); 3204 if (!sm_conn) break; 3205 3206 sm_conn->sm_handle = con_handle; 3207 sm_conn->sm_role = packet[6]; 3208 sm_conn->sm_peer_addr_type = packet[7]; 3209 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3210 3211 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3212 3213 // reset security properties 3214 sm_conn->sm_connection_encrypted = 0; 3215 sm_conn->sm_connection_authenticated = 0; 3216 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3217 sm_conn->sm_le_db_index = -1; 3218 3219 // prepare CSRK lookup (does not involve setup) 3220 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3221 3222 // just connected -> everything else happens in sm_run() 3223 if (IS_RESPONDER(sm_conn->sm_role)){ 3224 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3225 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3226 if (sm_slave_request_security) { 3227 // request security if requested by app 3228 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3229 } else { 3230 // otherwise, wait for pairing request 3231 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3232 } 3233 } 3234 break; 3235 } else { 3236 // master 3237 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3238 } 3239 break; 3240 3241 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3242 con_handle = little_endian_read_16(packet, 3); 3243 sm_conn = sm_get_connection_for_handle(con_handle); 3244 if (!sm_conn) break; 3245 3246 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3247 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3248 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3249 break; 3250 } 3251 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3252 // PH2 SEND LTK as we need to exchange keys in PH3 3253 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3254 break; 3255 } 3256 3257 // store rand and ediv 3258 reverse_64(&packet[5], sm_conn->sm_local_rand); 3259 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3260 3261 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3262 // potentially stored LTK is from the master 3263 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3264 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3265 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3266 break; 3267 } 3268 // additionally check if remote is in LE Device DB if requested 3269 switch(sm_conn->sm_irk_lookup_state){ 3270 case IRK_LOOKUP_FAILED: 3271 log_info("LTK Request: device not in device db"); 3272 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3273 break; 3274 case IRK_LOOKUP_SUCCEEDED: 3275 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3276 break; 3277 default: 3278 // wait for irk look doen 3279 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3280 break; 3281 } 3282 break; 3283 } 3284 3285 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3286 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3287 #else 3288 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3289 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3290 #endif 3291 break; 3292 3293 default: 3294 break; 3295 } 3296 break; 3297 3298 case HCI_EVENT_ENCRYPTION_CHANGE: 3299 con_handle = little_endian_read_16(packet, 3); 3300 sm_conn = sm_get_connection_for_handle(con_handle); 3301 if (!sm_conn) break; 3302 3303 sm_conn->sm_connection_encrypted = packet[5]; 3304 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3305 sm_conn->sm_actual_encryption_key_size); 3306 log_info("event handler, state %u", sm_conn->sm_engine_state); 3307 3308 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3309 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3310 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3311 // notify client, if pairing was requested before 3312 if (sm_conn->sm_pairing_requested){ 3313 sm_conn->sm_pairing_requested = 0; 3314 if (sm_conn->sm_connection_encrypted){ 3315 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3316 } else { 3317 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3318 } 3319 } 3320 sm_done_for_handle(sm_conn->sm_handle); 3321 break; 3322 } 3323 3324 if (!sm_conn->sm_connection_encrypted) break; 3325 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3326 3327 // continue pairing 3328 switch (sm_conn->sm_engine_state){ 3329 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3330 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3331 sm_done_for_handle(sm_conn->sm_handle); 3332 break; 3333 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3334 if (IS_RESPONDER(sm_conn->sm_role)){ 3335 // slave 3336 if (setup->sm_use_secure_connections){ 3337 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3338 } else { 3339 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); 3340 } 3341 } else { 3342 // master 3343 if (sm_key_distribution_all_received(sm_conn)){ 3344 // skip receiving keys as there are none 3345 sm_key_distribution_handle_all_received(sm_conn); 3346 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); 3347 } else { 3348 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3349 } 3350 } 3351 break; 3352 default: 3353 break; 3354 } 3355 break; 3356 3357 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3358 con_handle = little_endian_read_16(packet, 3); 3359 sm_conn = sm_get_connection_for_handle(con_handle); 3360 if (!sm_conn) break; 3361 3362 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3363 log_info("event handler, state %u", sm_conn->sm_engine_state); 3364 // continue if part of initial pairing 3365 switch (sm_conn->sm_engine_state){ 3366 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3367 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3368 sm_done_for_handle(sm_conn->sm_handle); 3369 break; 3370 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3371 if (IS_RESPONDER(sm_conn->sm_role)){ 3372 // slave 3373 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); 3374 } else { 3375 // master 3376 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3377 } 3378 break; 3379 default: 3380 break; 3381 } 3382 break; 3383 3384 3385 case HCI_EVENT_DISCONNECTION_COMPLETE: 3386 con_handle = little_endian_read_16(packet, 3); 3387 sm_done_for_handle(con_handle); 3388 sm_conn = sm_get_connection_for_handle(con_handle); 3389 if (!sm_conn) break; 3390 3391 // delete stored bonding on disconnect with authentication failure in ph0 3392 if ((sm_conn->sm_role == 0u) 3393 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3394 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3395 le_device_db_remove(sm_conn->sm_le_db_index); 3396 } 3397 3398 // pairing failed, if it was ongoing 3399 switch (sm_conn->sm_engine_state){ 3400 case SM_GENERAL_IDLE: 3401 case SM_INITIATOR_CONNECTED: 3402 case SM_RESPONDER_IDLE: 3403 break; 3404 default: 3405 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3406 break; 3407 } 3408 3409 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3410 sm_conn->sm_handle = 0; 3411 break; 3412 3413 case HCI_EVENT_COMMAND_COMPLETE: 3414 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3415 // set local addr for le device db 3416 bd_addr_t addr; 3417 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3418 le_device_db_set_local_bd_addr(addr); 3419 } 3420 break; 3421 default: 3422 break; 3423 } 3424 break; 3425 default: 3426 break; 3427 } 3428 3429 sm_run(); 3430 } 3431 3432 static inline int sm_calc_actual_encryption_key_size(int other){ 3433 if (other < sm_min_encryption_key_size) return 0; 3434 if (other < sm_max_encryption_key_size) return other; 3435 return sm_max_encryption_key_size; 3436 } 3437 3438 3439 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3440 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3441 switch (method){ 3442 case JUST_WORKS: 3443 case NUMERIC_COMPARISON: 3444 return 1; 3445 default: 3446 return 0; 3447 } 3448 } 3449 // responder 3450 3451 static int sm_passkey_used(stk_generation_method_t method){ 3452 switch (method){ 3453 case PK_RESP_INPUT: 3454 return 1; 3455 default: 3456 return 0; 3457 } 3458 } 3459 3460 static int sm_passkey_entry(stk_generation_method_t method){ 3461 switch (method){ 3462 case PK_RESP_INPUT: 3463 case PK_INIT_INPUT: 3464 case PK_BOTH_INPUT: 3465 return 1; 3466 default: 3467 return 0; 3468 } 3469 } 3470 3471 #endif 3472 3473 /** 3474 * @return ok 3475 */ 3476 static int sm_validate_stk_generation_method(void){ 3477 // check if STK generation method is acceptable by client 3478 switch (setup->sm_stk_generation_method){ 3479 case JUST_WORKS: 3480 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 3481 case PK_RESP_INPUT: 3482 case PK_INIT_INPUT: 3483 case PK_BOTH_INPUT: 3484 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 3485 case OOB: 3486 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 3487 case NUMERIC_COMPARISON: 3488 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 3489 default: 3490 return 0; 3491 } 3492 } 3493 3494 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3495 3496 // size of complete sm_pdu used to validate input 3497 static const uint8_t sm_pdu_size[] = { 3498 0, // 0x00 invalid opcode 3499 7, // 0x01 pairing request 3500 7, // 0x02 pairing response 3501 17, // 0x03 pairing confirm 3502 17, // 0x04 pairing random 3503 2, // 0x05 pairing failed 3504 17, // 0x06 encryption information 3505 11, // 0x07 master identification 3506 17, // 0x08 identification information 3507 8, // 0x09 identify address information 3508 17, // 0x0a signing information 3509 2, // 0x0b security request 3510 65, // 0x0c pairing public key 3511 17, // 0x0d pairing dhk check 3512 2, // 0x0e keypress notification 3513 }; 3514 3515 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3516 sm_run(); 3517 } 3518 3519 if (packet_type != SM_DATA_PACKET) return; 3520 if (size == 0u) return; 3521 3522 uint8_t sm_pdu_code = packet[0]; 3523 3524 // validate pdu size 3525 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3526 if (sm_pdu_size[sm_pdu_code] != size) return; 3527 3528 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3529 if (!sm_conn) return; 3530 3531 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3532 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3533 sm_done_for_handle(con_handle); 3534 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3535 return; 3536 } 3537 3538 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3539 3540 int err; 3541 UNUSED(err); 3542 3543 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3544 uint8_t buffer[5]; 3545 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3546 buffer[1] = 3; 3547 little_endian_store_16(buffer, 2, con_handle); 3548 buffer[4] = packet[1]; 3549 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3550 return; 3551 } 3552 3553 switch (sm_conn->sm_engine_state){ 3554 3555 // a sm timeout requries a new physical connection 3556 case SM_GENERAL_TIMEOUT: 3557 return; 3558 3559 #ifdef ENABLE_LE_CENTRAL 3560 3561 // Initiator 3562 case SM_INITIATOR_CONNECTED: 3563 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3564 sm_pdu_received_in_wrong_state(sm_conn); 3565 break; 3566 } 3567 3568 // IRK complete? 3569 int have_ltk; 3570 uint8_t ltk[16]; 3571 switch (sm_conn->sm_irk_lookup_state){ 3572 case IRK_LOOKUP_FAILED: 3573 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3574 break; 3575 case IRK_LOOKUP_SUCCEEDED: 3576 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3577 have_ltk = !sm_is_null_key(ltk); 3578 log_info("central: security request - have_ltk %u", have_ltk); 3579 if (have_ltk){ 3580 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3581 } else { 3582 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3583 } 3584 break; 3585 default: 3586 break; 3587 } 3588 3589 // otherwise, store security request 3590 sm_conn->sm_security_request_received = 1; 3591 break; 3592 3593 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3594 // Core 5, Vol 3, Part H, 2.4.6: 3595 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3596 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3597 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3598 log_info("Ignoring Security Request"); 3599 break; 3600 } 3601 3602 // all other pdus are incorrect 3603 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3604 sm_pdu_received_in_wrong_state(sm_conn); 3605 break; 3606 } 3607 3608 // store pairing request 3609 (void)memcpy(&setup->sm_s_pres, packet, 3610 sizeof(sm_pairing_packet_t)); 3611 err = sm_stk_generation_init(sm_conn); 3612 3613 #ifdef ENABLE_TESTING_SUPPORT 3614 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3615 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3616 err = test_pairing_failure; 3617 } 3618 #endif 3619 3620 if (err){ 3621 setup->sm_pairing_failed_reason = err; 3622 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3623 break; 3624 } 3625 3626 // generate random number first, if we need to show passkey 3627 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3628 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); 3629 break; 3630 } 3631 3632 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3633 if (setup->sm_use_secure_connections){ 3634 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3635 if (setup->sm_stk_generation_method == JUST_WORKS){ 3636 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3637 sm_trigger_user_response(sm_conn); 3638 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3639 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3640 } 3641 } else { 3642 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3643 } 3644 break; 3645 } 3646 #endif 3647 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3648 sm_trigger_user_response(sm_conn); 3649 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3650 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3651 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); 3652 } 3653 break; 3654 3655 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3656 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3657 sm_pdu_received_in_wrong_state(sm_conn); 3658 break; 3659 } 3660 3661 // store s_confirm 3662 reverse_128(&packet[1], setup->sm_peer_confirm); 3663 3664 #ifdef ENABLE_TESTING_SUPPORT 3665 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3666 log_info("testing_support: reset confirm value"); 3667 memset(setup->sm_peer_confirm, 0, 16); 3668 } 3669 #endif 3670 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3671 break; 3672 3673 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3674 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3675 sm_pdu_received_in_wrong_state(sm_conn); 3676 break;; 3677 } 3678 3679 // received random value 3680 reverse_128(&packet[1], setup->sm_peer_random); 3681 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3682 break; 3683 #endif 3684 3685 #ifdef ENABLE_LE_PERIPHERAL 3686 // Responder 3687 case SM_RESPONDER_IDLE: 3688 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3689 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3690 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3691 sm_pdu_received_in_wrong_state(sm_conn); 3692 break;; 3693 } 3694 3695 // store pairing request 3696 (void)memcpy(&sm_conn->sm_m_preq, packet, 3697 sizeof(sm_pairing_packet_t)); 3698 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3699 break; 3700 #endif 3701 3702 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3703 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3704 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3705 sm_pdu_received_in_wrong_state(sm_conn); 3706 break; 3707 } 3708 3709 // store public key for DH Key calculation 3710 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3711 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3712 3713 // validate public key 3714 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3715 if (err){ 3716 log_error("sm: peer public key invalid %x", err); 3717 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3718 break; 3719 } 3720 3721 // start calculating dhkey 3722 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); 3723 3724 3725 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3726 if (IS_RESPONDER(sm_conn->sm_role)){ 3727 // responder 3728 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3729 } else { 3730 // initiator 3731 // stk generation method 3732 // passkey entry: notify app to show passkey or to request passkey 3733 switch (setup->sm_stk_generation_method){ 3734 case JUST_WORKS: 3735 case NUMERIC_COMPARISON: 3736 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3737 break; 3738 case PK_RESP_INPUT: 3739 sm_sc_start_calculating_local_confirm(sm_conn); 3740 break; 3741 case PK_INIT_INPUT: 3742 case PK_BOTH_INPUT: 3743 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3744 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3745 break; 3746 } 3747 sm_sc_start_calculating_local_confirm(sm_conn); 3748 break; 3749 case OOB: 3750 // generate Nx 3751 log_info("Generate Na"); 3752 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); 3753 break; 3754 } 3755 } 3756 break; 3757 3758 case SM_SC_W4_CONFIRMATION: 3759 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3760 sm_pdu_received_in_wrong_state(sm_conn); 3761 break; 3762 } 3763 // received confirm value 3764 reverse_128(&packet[1], setup->sm_peer_confirm); 3765 3766 #ifdef ENABLE_TESTING_SUPPORT 3767 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3768 log_info("testing_support: reset confirm value"); 3769 memset(setup->sm_peer_confirm, 0, 16); 3770 } 3771 #endif 3772 if (IS_RESPONDER(sm_conn->sm_role)){ 3773 // responder 3774 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3775 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3776 // still waiting for passkey 3777 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3778 break; 3779 } 3780 } 3781 sm_sc_start_calculating_local_confirm(sm_conn); 3782 } else { 3783 // initiator 3784 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3785 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); 3786 } else { 3787 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3788 } 3789 } 3790 break; 3791 3792 case SM_SC_W4_PAIRING_RANDOM: 3793 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3794 sm_pdu_received_in_wrong_state(sm_conn); 3795 break; 3796 } 3797 3798 // received random value 3799 reverse_128(&packet[1], setup->sm_peer_nonce); 3800 3801 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3802 // only check for JUST WORK/NC in initiator role OR passkey entry 3803 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 3804 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 3805 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 3806 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3807 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 3808 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3809 break; 3810 } 3811 3812 // OOB 3813 if (setup->sm_stk_generation_method == OOB){ 3814 3815 // setup local random, set to zero if remote did not receive our data 3816 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3817 if (IS_RESPONDER(sm_conn->sm_role)){ 3818 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 3819 log_info("Reset rb as A does not have OOB data"); 3820 memset(setup->sm_rb, 0, 16); 3821 } else { 3822 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3823 log_info("Use stored rb"); 3824 log_info_hexdump(setup->sm_rb, 16); 3825 } 3826 } else { 3827 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 3828 log_info("Reset ra as B does not have OOB data"); 3829 memset(setup->sm_ra, 0, 16); 3830 } else { 3831 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3832 log_info("Use stored ra"); 3833 log_info_hexdump(setup->sm_ra, 16); 3834 } 3835 } 3836 3837 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3838 if (setup->sm_have_oob_data){ 3839 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3840 break; 3841 } 3842 } 3843 3844 // TODO: we only get here for Responder role with JW/NC 3845 sm_sc_state_after_receiving_random(sm_conn); 3846 break; 3847 3848 case SM_SC_W2_CALCULATE_G2: 3849 case SM_SC_W4_CALCULATE_G2: 3850 case SM_SC_W4_CALCULATE_DHKEY: 3851 case SM_SC_W2_CALCULATE_F5_SALT: 3852 case SM_SC_W4_CALCULATE_F5_SALT: 3853 case SM_SC_W2_CALCULATE_F5_MACKEY: 3854 case SM_SC_W4_CALCULATE_F5_MACKEY: 3855 case SM_SC_W2_CALCULATE_F5_LTK: 3856 case SM_SC_W4_CALCULATE_F5_LTK: 3857 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3858 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3859 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3860 case SM_SC_W4_USER_RESPONSE: 3861 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3862 sm_pdu_received_in_wrong_state(sm_conn); 3863 break; 3864 } 3865 // store DHKey Check 3866 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3867 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3868 3869 // have we been only waiting for dhkey check command? 3870 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3871 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3872 } 3873 break; 3874 #endif 3875 3876 #ifdef ENABLE_LE_PERIPHERAL 3877 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3878 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3879 sm_pdu_received_in_wrong_state(sm_conn); 3880 break; 3881 } 3882 3883 // received confirm value 3884 reverse_128(&packet[1], setup->sm_peer_confirm); 3885 3886 #ifdef ENABLE_TESTING_SUPPORT 3887 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3888 log_info("testing_support: reset confirm value"); 3889 memset(setup->sm_peer_confirm, 0, 16); 3890 } 3891 #endif 3892 // notify client to hide shown passkey 3893 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3894 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3895 } 3896 3897 // handle user cancel pairing? 3898 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3899 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3900 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3901 break; 3902 } 3903 3904 // wait for user action? 3905 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3906 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3907 break; 3908 } 3909 3910 // calculate and send local_confirm 3911 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); 3912 break; 3913 3914 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3915 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3916 sm_pdu_received_in_wrong_state(sm_conn); 3917 break;; 3918 } 3919 3920 // received random value 3921 reverse_128(&packet[1], setup->sm_peer_random); 3922 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3923 break; 3924 #endif 3925 3926 case SM_PH3_RECEIVE_KEYS: 3927 switch(sm_pdu_code){ 3928 case SM_CODE_ENCRYPTION_INFORMATION: 3929 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3930 reverse_128(&packet[1], setup->sm_peer_ltk); 3931 break; 3932 3933 case SM_CODE_MASTER_IDENTIFICATION: 3934 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3935 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3936 reverse_64(&packet[3], setup->sm_peer_rand); 3937 break; 3938 3939 case SM_CODE_IDENTITY_INFORMATION: 3940 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3941 reverse_128(&packet[1], setup->sm_peer_irk); 3942 break; 3943 3944 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3945 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3946 setup->sm_peer_addr_type = packet[1]; 3947 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3948 break; 3949 3950 case SM_CODE_SIGNING_INFORMATION: 3951 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3952 reverse_128(&packet[1], setup->sm_peer_csrk); 3953 break; 3954 default: 3955 // Unexpected PDU 3956 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3957 break; 3958 } 3959 // done with key distribution? 3960 if (sm_key_distribution_all_received(sm_conn)){ 3961 3962 sm_key_distribution_handle_all_received(sm_conn); 3963 3964 if (IS_RESPONDER(sm_conn->sm_role)){ 3965 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3966 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3967 } else { 3968 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3969 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3970 sm_done_for_handle(sm_conn->sm_handle); 3971 } 3972 } else { 3973 if (setup->sm_use_secure_connections){ 3974 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3975 } else { 3976 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); 3977 } 3978 } 3979 } 3980 break; 3981 default: 3982 // Unexpected PDU 3983 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3984 break; 3985 } 3986 3987 // try to send preparared packet 3988 sm_run(); 3989 } 3990 3991 // Security Manager Client API 3992 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3993 sm_get_oob_data = get_oob_data_callback; 3994 } 3995 3996 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)){ 3997 sm_get_sc_oob_data = get_sc_oob_data_callback; 3998 } 3999 4000 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4001 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4002 } 4003 4004 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4005 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4006 } 4007 4008 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4009 sm_min_encryption_key_size = min_size; 4010 sm_max_encryption_key_size = max_size; 4011 } 4012 4013 void sm_set_authentication_requirements(uint8_t auth_req){ 4014 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4015 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4016 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4017 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4018 } 4019 #endif 4020 sm_auth_req = auth_req; 4021 } 4022 4023 void sm_set_io_capabilities(io_capability_t io_capability){ 4024 sm_io_capabilities = io_capability; 4025 } 4026 4027 #ifdef ENABLE_LE_PERIPHERAL 4028 void sm_set_request_security(int enable){ 4029 sm_slave_request_security = enable; 4030 } 4031 #endif 4032 4033 void sm_set_er(sm_key_t er){ 4034 (void)memcpy(sm_persistent_er, er, 16); 4035 } 4036 4037 void sm_set_ir(sm_key_t ir){ 4038 (void)memcpy(sm_persistent_ir, ir, 16); 4039 } 4040 4041 // Testing support only 4042 void sm_test_set_irk(sm_key_t irk){ 4043 (void)memcpy(sm_persistent_irk, irk, 16); 4044 dkg_state = DKG_CALC_DHK; 4045 test_use_fixed_local_irk = true; 4046 } 4047 4048 void sm_test_use_fixed_local_csrk(void){ 4049 test_use_fixed_local_csrk = true; 4050 } 4051 4052 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4053 static void sm_ec_generated(void * arg){ 4054 UNUSED(arg); 4055 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4056 // trigger pairing if pending for ec key 4057 sm_run(); 4058 } 4059 static void sm_ec_generate_new_key(void){ 4060 log_info("sm: generate new ec key"); 4061 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4062 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4063 } 4064 #endif 4065 4066 #ifdef ENABLE_TESTING_SUPPORT 4067 void sm_test_set_pairing_failure(int reason){ 4068 test_pairing_failure = reason; 4069 } 4070 #endif 4071 4072 void sm_init(void){ 4073 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4074 sm_er_ir_set_default(); 4075 4076 // defaults 4077 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4078 | SM_STK_GENERATION_METHOD_OOB 4079 | SM_STK_GENERATION_METHOD_PASSKEY 4080 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4081 4082 sm_max_encryption_key_size = 16; 4083 sm_min_encryption_key_size = 7; 4084 4085 sm_fixed_passkey_in_display_role = 0xffffffff; 4086 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4087 4088 #ifdef USE_CMAC_ENGINE 4089 sm_cmac_active = 0; 4090 #endif 4091 dkg_state = DKG_W4_WORKING; 4092 rau_state = RAU_IDLE; 4093 sm_aes128_state = SM_AES128_IDLE; 4094 sm_address_resolution_test = -1; // no private address to resolve yet 4095 sm_address_resolution_ah_calculation_active = 0; 4096 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4097 sm_address_resolution_general_queue = NULL; 4098 4099 gap_random_adress_update_period = 15 * 60 * 1000L; 4100 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4101 4102 test_use_fixed_local_csrk = false; 4103 4104 // register for HCI Events from HCI 4105 hci_event_callback_registration.callback = &sm_event_packet_handler; 4106 hci_add_event_handler(&hci_event_callback_registration); 4107 4108 // 4109 btstack_crypto_init(); 4110 4111 // init le_device_db 4112 le_device_db_init(); 4113 4114 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4115 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4116 4117 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4118 sm_ec_generate_new_key(); 4119 #endif 4120 } 4121 4122 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4123 sm_fixed_passkey_in_display_role = passkey; 4124 } 4125 4126 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4127 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4128 } 4129 4130 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4131 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4132 if (!hci_con) return NULL; 4133 return &hci_con->sm_connection; 4134 } 4135 4136 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4137 switch (sm_conn->sm_engine_state){ 4138 case SM_GENERAL_IDLE: 4139 case SM_RESPONDER_IDLE: 4140 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4141 sm_run(); 4142 break; 4143 default: 4144 break; 4145 } 4146 } 4147 4148 /** 4149 * @brief Trigger Security Request 4150 */ 4151 void sm_send_security_request(hci_con_handle_t con_handle){ 4152 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4153 if (!sm_conn) return; 4154 sm_send_security_request_for_connection(sm_conn); 4155 } 4156 4157 // request pairing 4158 void sm_request_pairing(hci_con_handle_t con_handle){ 4159 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4160 if (!sm_conn) return; // wrong connection 4161 4162 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4163 if (IS_RESPONDER(sm_conn->sm_role)){ 4164 sm_send_security_request_for_connection(sm_conn); 4165 } else { 4166 // used as a trigger to start central/master/initiator security procedures 4167 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4168 uint8_t ltk[16]; 4169 bool have_ltk; 4170 switch (sm_conn->sm_irk_lookup_state){ 4171 case IRK_LOOKUP_SUCCEEDED: 4172 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4173 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4174 have_ltk = !sm_is_null_key(ltk); 4175 log_info("have ltk %u", have_ltk); 4176 if (have_ltk){ 4177 sm_conn->sm_pairing_requested = 1; 4178 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4179 break; 4180 } 4181 #endif 4182 /* fall through */ 4183 4184 case IRK_LOOKUP_FAILED: 4185 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4186 break; 4187 default: 4188 log_info("irk lookup pending"); 4189 sm_conn->sm_pairing_requested = 1; 4190 break; 4191 } 4192 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4193 sm_conn->sm_pairing_requested = 1; 4194 } 4195 } 4196 sm_run(); 4197 } 4198 4199 // called by client app on authorization request 4200 void sm_authorization_decline(hci_con_handle_t con_handle){ 4201 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4202 if (!sm_conn) return; // wrong connection 4203 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4204 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4205 } 4206 4207 void sm_authorization_grant(hci_con_handle_t con_handle){ 4208 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4209 if (!sm_conn) return; // wrong connection 4210 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4211 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4212 } 4213 4214 // GAP Bonding API 4215 4216 void sm_bonding_decline(hci_con_handle_t con_handle){ 4217 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4218 if (!sm_conn) return; // wrong connection 4219 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4220 log_info("decline, state %u", sm_conn->sm_engine_state); 4221 switch(sm_conn->sm_engine_state){ 4222 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4223 case SM_SC_W4_USER_RESPONSE: 4224 case SM_SC_W4_CONFIRMATION: 4225 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4226 #endif 4227 case SM_PH1_W4_USER_RESPONSE: 4228 switch (setup->sm_stk_generation_method){ 4229 case PK_RESP_INPUT: 4230 case PK_INIT_INPUT: 4231 case PK_BOTH_INPUT: 4232 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4233 break; 4234 case NUMERIC_COMPARISON: 4235 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4236 break; 4237 case JUST_WORKS: 4238 case OOB: 4239 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4240 break; 4241 } 4242 break; 4243 default: 4244 break; 4245 } 4246 sm_run(); 4247 } 4248 4249 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4250 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4251 if (!sm_conn) return; // wrong connection 4252 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4253 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4254 if (setup->sm_use_secure_connections){ 4255 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4256 } else { 4257 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); 4258 } 4259 } 4260 4261 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4262 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4263 sm_sc_prepare_dhkey_check(sm_conn); 4264 } 4265 #endif 4266 4267 sm_run(); 4268 } 4269 4270 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4271 // for now, it's the same 4272 sm_just_works_confirm(con_handle); 4273 } 4274 4275 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4276 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4277 if (!sm_conn) return; // wrong connection 4278 sm_reset_tk(); 4279 big_endian_store_32(setup->sm_tk, 12, passkey); 4280 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4281 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4282 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); 4283 } 4284 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4285 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4286 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4287 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4288 sm_sc_start_calculating_local_confirm(sm_conn); 4289 } 4290 #endif 4291 sm_run(); 4292 } 4293 4294 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4295 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4296 if (!sm_conn) return; // wrong connection 4297 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4298 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4299 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 4300 switch (action){ 4301 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4302 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4303 flags |= (1u << action); 4304 break; 4305 case SM_KEYPRESS_PASSKEY_CLEARED: 4306 // clear counter, keypress & erased flags + set passkey cleared 4307 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 4308 break; 4309 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4310 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4311 // erase actions queued 4312 num_actions--; 4313 if (num_actions == 0u){ 4314 // clear counter, keypress & erased flags 4315 flags &= 0x19u; 4316 } 4317 break; 4318 } 4319 num_actions++; 4320 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4321 break; 4322 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4323 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4324 // enter actions queued 4325 num_actions--; 4326 if (num_actions == 0u){ 4327 // clear counter, keypress & erased flags 4328 flags &= 0x19u; 4329 } 4330 break; 4331 } 4332 num_actions++; 4333 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4334 break; 4335 default: 4336 break; 4337 } 4338 setup->sm_keypress_notification = (num_actions << 5) | flags; 4339 sm_run(); 4340 } 4341 4342 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4343 static void sm_handle_random_result_oob(void * arg){ 4344 UNUSED(arg); 4345 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4346 sm_run(); 4347 } 4348 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4349 4350 static btstack_crypto_random_t sm_crypto_random_oob_request; 4351 4352 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4353 sm_sc_oob_callback = callback; 4354 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4355 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4356 return 0; 4357 } 4358 #endif 4359 4360 /** 4361 * @brief Get Identity Resolving state 4362 * @param con_handle 4363 * @return irk_lookup_state_t 4364 */ 4365 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4366 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4367 if (!sm_conn) return IRK_LOOKUP_IDLE; 4368 return sm_conn->sm_irk_lookup_state; 4369 } 4370 4371 /** 4372 * @brief Identify device in LE Device DB 4373 * @param handle 4374 * @returns index from le_device_db or -1 if not found/identified 4375 */ 4376 int sm_le_device_index(hci_con_handle_t con_handle ){ 4377 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4378 if (!sm_conn) return -1; 4379 return sm_conn->sm_le_db_index; 4380 } 4381 4382 static int gap_random_address_type_requires_updates(void){ 4383 switch (gap_random_adress_type){ 4384 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4385 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4386 return 0; 4387 default: 4388 return 1; 4389 } 4390 } 4391 4392 static uint8_t own_address_type(void){ 4393 switch (gap_random_adress_type){ 4394 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4395 return BD_ADDR_TYPE_LE_PUBLIC; 4396 default: 4397 return BD_ADDR_TYPE_LE_RANDOM; 4398 } 4399 } 4400 4401 // GAP LE API 4402 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4403 gap_random_address_update_stop(); 4404 gap_random_adress_type = random_address_type; 4405 hci_le_set_own_address_type(own_address_type()); 4406 if (!gap_random_address_type_requires_updates()) return; 4407 gap_random_address_update_start(); 4408 gap_random_address_trigger(); 4409 } 4410 4411 gap_random_address_type_t gap_random_address_get_mode(void){ 4412 return gap_random_adress_type; 4413 } 4414 4415 void gap_random_address_set_update_period(int period_ms){ 4416 gap_random_adress_update_period = period_ms; 4417 if (!gap_random_address_type_requires_updates()) return; 4418 gap_random_address_update_stop(); 4419 gap_random_address_update_start(); 4420 } 4421 4422 void gap_random_address_set(const bd_addr_t addr){ 4423 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4424 (void)memcpy(sm_random_address, addr, 6); 4425 rau_state = RAU_SET_ADDRESS; 4426 sm_run(); 4427 } 4428 4429 #ifdef ENABLE_LE_PERIPHERAL 4430 /* 4431 * @brief Set Advertisement Paramters 4432 * @param adv_int_min 4433 * @param adv_int_max 4434 * @param adv_type 4435 * @param direct_address_type 4436 * @param direct_address 4437 * @param channel_map 4438 * @param filter_policy 4439 * 4440 * @note own_address_type is used from gap_random_address_set_mode 4441 */ 4442 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4443 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4444 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4445 direct_address_typ, direct_address, channel_map, filter_policy); 4446 } 4447 #endif 4448 4449 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4450 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4451 // wrong connection 4452 if (!sm_conn) return 0; 4453 // already encrypted 4454 if (sm_conn->sm_connection_encrypted) return 0; 4455 // only central can re-encrypt 4456 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4457 // irk status? 4458 switch(sm_conn->sm_irk_lookup_state){ 4459 case IRK_LOOKUP_FAILED: 4460 // done, cannot setup encryption 4461 return 0; 4462 case IRK_LOOKUP_SUCCEEDED: 4463 break; 4464 default: 4465 // IR Lookup pending 4466 return 1; 4467 } 4468 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4469 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4470 } 4471 4472 void sm_set_secure_connections_only_mode(bool enable){ 4473 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4474 sm_sc_only_mode = enable; 4475 #else 4476 // SC Only mode not possible without support for SC 4477 btstack_assert(enable == false); 4478 #endif 4479 } 4480 4481 const uint8_t * gap_get_persistent_irk(void){ 4482 return sm_persistent_irk; 4483 } 4484