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 /* to schedule calls to sm_run */ 277 static btstack_timer_source_t sm_run_timer; 278 279 // LE Secure Connections 280 #ifdef ENABLE_LE_SECURE_CONNECTIONS 281 static ec_key_generation_state_t ec_key_generation_state; 282 static uint8_t ec_q[64]; 283 #endif 284 285 // 286 // Volume 3, Part H, Chapter 24 287 // "Security shall be initiated by the Security Manager in the device in the master role. 288 // The device in the slave role shall be the responding device." 289 // -> master := initiator, slave := responder 290 // 291 292 // data needed for security setup 293 typedef struct sm_setup_context { 294 295 btstack_timer_source_t sm_timeout; 296 297 // used in all phases 298 uint8_t sm_pairing_failed_reason; 299 300 // user response, (Phase 1 and/or 2) 301 uint8_t sm_user_response; 302 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 303 304 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 305 uint8_t sm_key_distribution_send_set; 306 uint8_t sm_key_distribution_sent_set; 307 uint8_t sm_key_distribution_received_set; 308 309 // Phase 2 (Pairing over SMP) 310 stk_generation_method_t sm_stk_generation_method; 311 sm_key_t sm_tk; 312 uint8_t sm_have_oob_data; 313 uint8_t sm_use_secure_connections; 314 315 sm_key_t sm_c1_t3_value; // c1 calculation 316 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 317 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 318 sm_key_t sm_local_random; 319 sm_key_t sm_local_confirm; 320 sm_key_t sm_peer_random; 321 sm_key_t sm_peer_confirm; 322 uint8_t sm_m_addr_type; // address and type can be removed 323 uint8_t sm_s_addr_type; // '' 324 bd_addr_t sm_m_address; // '' 325 bd_addr_t sm_s_address; // '' 326 sm_key_t sm_ltk; 327 328 uint8_t sm_state_vars; 329 #ifdef ENABLE_LE_SECURE_CONNECTIONS 330 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 331 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 332 sm_key_t sm_local_nonce; // might be combined with sm_local_random 333 uint8_t sm_dhkey[32]; 334 sm_key_t sm_peer_dhkey_check; 335 sm_key_t sm_local_dhkey_check; 336 sm_key_t sm_ra; 337 sm_key_t sm_rb; 338 sm_key_t sm_t; // used for f5 and h6 339 sm_key_t sm_mackey; 340 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 341 #endif 342 343 // Phase 3 344 345 // key distribution, we generate 346 uint16_t sm_local_y; 347 uint16_t sm_local_div; 348 uint16_t sm_local_ediv; 349 uint8_t sm_local_rand[8]; 350 sm_key_t sm_local_ltk; 351 sm_key_t sm_local_csrk; 352 sm_key_t sm_local_irk; 353 // sm_local_address/addr_type not needed 354 355 // key distribution, received from peer 356 uint16_t sm_peer_y; 357 uint16_t sm_peer_div; 358 uint16_t sm_peer_ediv; 359 uint8_t sm_peer_rand[8]; 360 sm_key_t sm_peer_ltk; 361 sm_key_t sm_peer_irk; 362 sm_key_t sm_peer_csrk; 363 uint8_t sm_peer_addr_type; 364 bd_addr_t sm_peer_address; 365 #ifdef ENABLE_LE_SIGNED_WRITE 366 int sm_le_device_index; 367 #endif 368 369 } sm_setup_context_t; 370 371 // 372 static sm_setup_context_t the_setup; 373 static sm_setup_context_t * setup = &the_setup; 374 375 // active connection - the one for which the_setup is used for 376 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 377 378 // @returns 1 if oob data is available 379 // stores oob data in provided 16 byte buffer if not null 380 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 381 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); 382 383 static void sm_run(void); 384 static void sm_done_for_handle(hci_con_handle_t con_handle); 385 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 386 static inline int sm_calc_actual_encryption_key_size(int other); 387 static int sm_validate_stk_generation_method(void); 388 static void sm_handle_encryption_result_address_resolution(void *arg); 389 static void sm_handle_encryption_result_dkg_dhk(void *arg); 390 static void sm_handle_encryption_result_dkg_irk(void *arg); 391 static void sm_handle_encryption_result_enc_a(void *arg); 392 static void sm_handle_encryption_result_enc_b(void *arg); 393 static void sm_handle_encryption_result_enc_c(void *arg); 394 static void sm_handle_encryption_result_enc_csrk(void *arg); 395 static void sm_handle_encryption_result_enc_d(void * arg); 396 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 397 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 398 #ifdef ENABLE_LE_PERIPHERAL 399 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 400 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 401 #endif 402 static void sm_handle_encryption_result_enc_stk(void *arg); 403 static void sm_handle_encryption_result_rau(void *arg); 404 static void sm_handle_random_result_ph2_tk(void * arg); 405 static void sm_handle_random_result_rau(void * arg); 406 #ifdef ENABLE_LE_SECURE_CONNECTIONS 407 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)); 408 static void sm_ec_generate_new_key(void); 409 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 410 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 411 static int sm_passkey_entry(stk_generation_method_t method); 412 #endif 413 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 414 415 static void log_info_hex16(const char * name, uint16_t value){ 416 log_info("%-6s 0x%04x", name, value); 417 } 418 419 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 420 // return packet[0]; 421 // } 422 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 423 return packet[1]; 424 } 425 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 426 return packet[2]; 427 } 428 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 429 return packet[3]; 430 } 431 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 432 return packet[4]; 433 } 434 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 435 return packet[5]; 436 } 437 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 438 return packet[6]; 439 } 440 441 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 442 packet[0] = code; 443 } 444 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 445 packet[1] = io_capability; 446 } 447 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 448 packet[2] = oob_data_flag; 449 } 450 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 451 packet[3] = auth_req; 452 } 453 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 454 packet[4] = max_encryption_key_size; 455 } 456 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 457 packet[5] = initiator_key_distribution; 458 } 459 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 460 packet[6] = responder_key_distribution; 461 } 462 463 // @returns 1 if all bytes are 0 464 static int sm_is_null(uint8_t * data, int size){ 465 int i; 466 for (i=0; i < size ; i++){ 467 if (data[i] != 0) { 468 return 0; 469 } 470 } 471 return 1; 472 } 473 474 static int sm_is_null_random(uint8_t random[8]){ 475 return sm_is_null(random, 8); 476 } 477 478 static int sm_is_null_key(uint8_t * key){ 479 return sm_is_null(key, 16); 480 } 481 482 // sm_trigger_run allows to schedule callback from main run loop // reduces stack depth 483 static void sm_run_timer_handler(btstack_timer_source_t * ts){ 484 UNUSED(ts); 485 sm_run(); 486 } 487 static void sm_trigger_run(void){ 488 (void)btstack_run_loop_remove_timer(&sm_run_timer); 489 btstack_run_loop_set_timer(&sm_run_timer, 0); 490 btstack_run_loop_add_timer(&sm_run_timer); 491 } 492 493 // Key utils 494 static void sm_reset_tk(void){ 495 int i; 496 for (i=0;i<16;i++){ 497 setup->sm_tk[i] = 0; 498 } 499 } 500 501 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 502 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 503 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 504 int i; 505 for (i = max_encryption_size ; i < 16 ; i++){ 506 key[15-i] = 0; 507 } 508 } 509 510 // ER / IR checks 511 static void sm_er_ir_set_default(void){ 512 int i; 513 for (i=0;i<16;i++){ 514 sm_persistent_er[i] = 0x30 + i; 515 sm_persistent_ir[i] = 0x90 + i; 516 } 517 } 518 519 static int sm_er_is_default(void){ 520 int i; 521 for (i=0;i<16;i++){ 522 if (sm_persistent_er[i] != (0x30+i)) return 0; 523 } 524 return 1; 525 } 526 527 static int sm_ir_is_default(void){ 528 int i; 529 for (i=0;i<16;i++){ 530 if (sm_persistent_ir[i] != (0x90+i)) return 0; 531 } 532 return 1; 533 } 534 535 // SMP Timeout implementation 536 537 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 538 // the Security Manager Timer shall be reset and started. 539 // 540 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 541 // 542 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 543 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 544 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 545 // established. 546 547 static void sm_timeout_handler(btstack_timer_source_t * timer){ 548 log_info("SM timeout"); 549 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 550 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 551 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 552 sm_done_for_handle(sm_conn->sm_handle); 553 554 // trigger handling of next ready connection 555 sm_run(); 556 } 557 static void sm_timeout_start(sm_connection_t * sm_conn){ 558 btstack_run_loop_remove_timer(&setup->sm_timeout); 559 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 560 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 561 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 562 btstack_run_loop_add_timer(&setup->sm_timeout); 563 } 564 static void sm_timeout_stop(void){ 565 btstack_run_loop_remove_timer(&setup->sm_timeout); 566 } 567 static void sm_timeout_reset(sm_connection_t * sm_conn){ 568 sm_timeout_stop(); 569 sm_timeout_start(sm_conn); 570 } 571 572 // end of sm timeout 573 574 // GAP Random Address updates 575 static gap_random_address_type_t gap_random_adress_type; 576 static btstack_timer_source_t gap_random_address_update_timer; 577 static uint32_t gap_random_adress_update_period; 578 579 static void gap_random_address_trigger(void){ 580 log_info("gap_random_address_trigger, state %u", rau_state); 581 if (rau_state != RAU_IDLE) return; 582 rau_state = RAU_GET_RANDOM; 583 sm_trigger_run(); 584 } 585 586 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 587 UNUSED(timer); 588 589 log_info("GAP Random Address Update due"); 590 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 591 btstack_run_loop_add_timer(&gap_random_address_update_timer); 592 gap_random_address_trigger(); 593 } 594 595 static void gap_random_address_update_start(void){ 596 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 597 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 598 btstack_run_loop_add_timer(&gap_random_address_update_timer); 599 } 600 601 static void gap_random_address_update_stop(void){ 602 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 603 } 604 605 // ah(k,r) helper 606 // r = padding || r 607 // r - 24 bit value 608 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 609 // r'= padding || r 610 memset(r_prime, 0, 16); 611 (void)memcpy(&r_prime[13], r, 3); 612 } 613 614 // d1 helper 615 // d' = padding || r || d 616 // d,r - 16 bit values 617 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 618 // d'= padding || r || d 619 memset(d1_prime, 0, 16); 620 big_endian_store_16(d1_prime, 12, r); 621 big_endian_store_16(d1_prime, 14, d); 622 } 623 624 // calculate arguments for first AES128 operation in C1 function 625 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){ 626 627 // p1 = pres || preq || rat’ || iat’ 628 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 629 // cant octet of pres becomes the most significant octet of p1. 630 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 631 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 632 // p1 is 0x05000800000302070710000001010001." 633 634 sm_key_t p1; 635 reverse_56(pres, &p1[0]); 636 reverse_56(preq, &p1[7]); 637 p1[14] = rat; 638 p1[15] = iat; 639 log_info_key("p1", p1); 640 log_info_key("r", r); 641 642 // t1 = r xor p1 643 int i; 644 for (i=0;i<16;i++){ 645 t1[i] = r[i] ^ p1[i]; 646 } 647 log_info_key("t1", t1); 648 } 649 650 // calculate arguments for second AES128 operation in C1 function 651 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 652 // p2 = padding || ia || ra 653 // "The least significant octet of ra becomes the least significant octet of p2 and 654 // the most significant octet of padding becomes the most significant octet of p2. 655 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 656 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 657 658 sm_key_t p2; 659 memset(p2, 0, 16); 660 (void)memcpy(&p2[4], ia, 6); 661 (void)memcpy(&p2[10], ra, 6); 662 log_info_key("p2", p2); 663 664 // c1 = e(k, t2_xor_p2) 665 int i; 666 for (i=0;i<16;i++){ 667 t3[i] = t2[i] ^ p2[i]; 668 } 669 log_info_key("t3", t3); 670 } 671 672 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 673 log_info_key("r1", r1); 674 log_info_key("r2", r2); 675 (void)memcpy(&r_prime[8], &r2[8], 8); 676 (void)memcpy(&r_prime[0], &r1[8], 8); 677 } 678 679 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 680 UNUSED(channel); 681 682 // log event 683 hci_dump_packet(packet_type, 1, packet, size); 684 // dispatch to all event handlers 685 btstack_linked_list_iterator_t it; 686 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 687 while (btstack_linked_list_iterator_has_next(&it)){ 688 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 689 entry->callback(packet_type, 0, packet, size); 690 } 691 } 692 693 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){ 694 event[0] = type; 695 event[1] = event_size - 2; 696 little_endian_store_16(event, 2, con_handle); 697 event[4] = addr_type; 698 reverse_bd_addr(address, &event[5]); 699 } 700 701 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 702 uint8_t event[11]; 703 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 704 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 705 } 706 707 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){ 708 uint8_t event[15]; 709 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 710 little_endian_store_32(event, 11, passkey); 711 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 712 } 713 714 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){ 715 // fetch addr and addr type from db, only called for valid entries 716 bd_addr_t identity_address; 717 int identity_address_type; 718 le_device_db_info(index, &identity_address_type, identity_address, NULL); 719 720 uint8_t event[20]; 721 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 722 event[11] = identity_address_type; 723 reverse_bd_addr(identity_address, &event[12]); 724 little_endian_store_16(event, 18, index); 725 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 726 } 727 728 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){ 729 uint8_t event[12]; 730 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 731 event[11] = status; 732 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 733 } 734 735 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 736 uint8_t event[13]; 737 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 738 event[11] = status; 739 event[12] = reason; 740 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 741 } 742 743 // decide on stk generation based on 744 // - pairing request 745 // - io capabilities 746 // - OOB data availability 747 static void sm_setup_tk(void){ 748 749 // horizontal: initiator capabilities 750 // vertial: responder capabilities 751 static const stk_generation_method_t stk_generation_method [5] [5] = { 752 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 753 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 754 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 755 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 756 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 757 }; 758 759 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 760 #ifdef ENABLE_LE_SECURE_CONNECTIONS 761 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 762 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 763 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 764 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 765 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 766 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 767 }; 768 #endif 769 770 // default: just works 771 setup->sm_stk_generation_method = JUST_WORKS; 772 773 #ifdef ENABLE_LE_SECURE_CONNECTIONS 774 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 775 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 776 & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; 777 #else 778 setup->sm_use_secure_connections = 0; 779 #endif 780 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 781 782 783 // decide if OOB will be used based on SC vs. Legacy and oob flags 784 int use_oob = 0; 785 if (setup->sm_use_secure_connections){ 786 // In LE Secure Connections pairing, the out of band method is used if at least 787 // one device has the peer device's out of band authentication data available. 788 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 789 } else { 790 // In LE legacy pairing, the out of band method is used if both the devices have 791 // the other device's out of band authentication data available. 792 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 793 } 794 if (use_oob){ 795 log_info("SM: have OOB data"); 796 log_info_key("OOB", setup->sm_tk); 797 setup->sm_stk_generation_method = OOB; 798 return; 799 } 800 801 // If both devices have not set the MITM option in the Authentication Requirements 802 // Flags, then the IO capabilities shall be ignored and the Just Works association 803 // model shall be used. 804 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) 805 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ 806 log_info("SM: MITM not required by both -> JUST WORKS"); 807 return; 808 } 809 810 // Reset TK as it has been setup in sm_init_setup 811 sm_reset_tk(); 812 813 // Also use just works if unknown io capabilites 814 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)){ 815 return; 816 } 817 818 // Otherwise the IO capabilities of the devices shall be used to determine the 819 // pairing method as defined in Table 2.4. 820 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 821 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 822 823 #ifdef ENABLE_LE_SECURE_CONNECTIONS 824 // table not define by default 825 if (setup->sm_use_secure_connections){ 826 generation_method = stk_generation_method_with_secure_connection; 827 } 828 #endif 829 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)]; 830 831 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 832 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); 833 } 834 835 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 836 int flags = 0; 837 if (key_set & SM_KEYDIST_ENC_KEY){ 838 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 839 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 840 } 841 if (key_set & SM_KEYDIST_ID_KEY){ 842 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 843 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 844 } 845 if (key_set & SM_KEYDIST_SIGN){ 846 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 847 } 848 return flags; 849 } 850 851 static void sm_setup_key_distribution(uint8_t key_set){ 852 setup->sm_key_distribution_received_set = 0; 853 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 854 setup->sm_key_distribution_sent_set = 0; 855 #ifdef ENABLE_LE_SIGNED_WRITE 856 setup->sm_le_device_index = -1; 857 #endif 858 } 859 860 // CSRK Key Lookup 861 862 863 static int sm_address_resolution_idle(void){ 864 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 865 } 866 867 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){ 868 (void)memcpy(sm_address_resolution_address, addr, 6); 869 sm_address_resolution_addr_type = addr_type; 870 sm_address_resolution_test = 0; 871 sm_address_resolution_mode = mode; 872 sm_address_resolution_context = context; 873 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 874 } 875 876 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 877 // check if already in list 878 btstack_linked_list_iterator_t it; 879 sm_lookup_entry_t * entry; 880 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 881 while(btstack_linked_list_iterator_has_next(&it)){ 882 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 883 if (entry->address_type != address_type) continue; 884 if (memcmp(entry->address, address, 6)) continue; 885 // already in list 886 return BTSTACK_BUSY; 887 } 888 entry = btstack_memory_sm_lookup_entry_get(); 889 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 890 entry->address_type = (bd_addr_type_t) address_type; 891 (void)memcpy(entry->address, address, 6); 892 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 893 sm_trigger_run(); 894 return 0; 895 } 896 897 // CMAC calculation using AES Engineq 898 #ifdef USE_CMAC_ENGINE 899 900 static void sm_cmac_done_trampoline(void * arg){ 901 UNUSED(arg); 902 sm_cmac_active = 0; 903 (*sm_cmac_done_callback)(sm_cmac_hash); 904 sm_trigger_run(); 905 } 906 907 int sm_cmac_ready(void){ 908 return sm_cmac_active == 0u; 909 } 910 #endif 911 912 #ifdef ENABLE_LE_SECURE_CONNECTIONS 913 // generic cmac calculation 914 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)){ 915 sm_cmac_active = 1; 916 sm_cmac_done_callback = done_callback; 917 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 918 } 919 #endif 920 921 // cmac for ATT Message signing 922 #ifdef ENABLE_LE_SIGNED_WRITE 923 924 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)){ 925 sm_cmac_active = 1; 926 sm_cmac_done_callback = done_callback; 927 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 928 } 929 930 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 931 if (offset >= sm_cmac_signed_write_message_len) { 932 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 933 return 0; 934 } 935 936 offset = sm_cmac_signed_write_message_len - 1 - offset; 937 938 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 939 if (offset < 3){ 940 return sm_cmac_signed_write_header[offset]; 941 } 942 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 943 if (offset < actual_message_len_incl_header){ 944 return sm_cmac_signed_write_message[offset - 3]; 945 } 946 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 947 } 948 949 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)){ 950 // ATT Message Signing 951 sm_cmac_signed_write_header[0] = opcode; 952 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 953 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 954 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 955 sm_cmac_signed_write_message = message; 956 sm_cmac_signed_write_message_len = total_message_len; 957 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 958 } 959 #endif 960 961 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 962 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 963 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 964 switch (setup->sm_stk_generation_method){ 965 case PK_RESP_INPUT: 966 if (IS_RESPONDER(sm_conn->sm_role)){ 967 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 968 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 969 } else { 970 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)); 971 } 972 break; 973 case PK_INIT_INPUT: 974 if (IS_RESPONDER(sm_conn->sm_role)){ 975 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)); 976 } else { 977 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 978 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 979 } 980 break; 981 case PK_BOTH_INPUT: 982 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 983 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 984 break; 985 case NUMERIC_COMPARISON: 986 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 987 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)); 988 break; 989 case JUST_WORKS: 990 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 991 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 992 break; 993 case OOB: 994 // client already provided OOB data, let's skip notification. 995 break; 996 } 997 } 998 999 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1000 int recv_flags; 1001 if (IS_RESPONDER(sm_conn->sm_role)){ 1002 // slave / responder 1003 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1004 } else { 1005 // master / initiator 1006 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1007 } 1008 1009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1010 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1011 if (setup->sm_use_secure_connections){ 1012 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 1013 } 1014 #endif 1015 1016 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1017 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 1018 } 1019 1020 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1021 if (sm_active_connection_handle == con_handle){ 1022 sm_timeout_stop(); 1023 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1024 log_info("sm: connection 0x%x released setup context", con_handle); 1025 1026 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1027 // generate new ec key after each pairing (that used it) 1028 if (setup->sm_use_secure_connections){ 1029 sm_ec_generate_new_key(); 1030 } 1031 #endif 1032 } 1033 } 1034 1035 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1036 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1037 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 1038 sm_done_for_handle(connection->sm_handle); 1039 } 1040 1041 static int sm_key_distribution_flags_for_auth_req(void){ 1042 1043 int flags = SM_KEYDIST_ID_KEY; 1044 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1045 // encryption and signing information only if bonding requested 1046 flags |= SM_KEYDIST_ENC_KEY; 1047 #ifdef ENABLE_LE_SIGNED_WRITE 1048 flags |= SM_KEYDIST_SIGN; 1049 #endif 1050 } 1051 return flags; 1052 } 1053 1054 static void sm_reset_setup(void){ 1055 // fill in sm setup 1056 setup->sm_state_vars = 0; 1057 setup->sm_keypress_notification = 0; 1058 sm_reset_tk(); 1059 } 1060 1061 static void sm_init_setup(sm_connection_t * sm_conn){ 1062 1063 // fill in sm setup 1064 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1065 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1066 1067 // query client for Legacy Pairing OOB data 1068 setup->sm_have_oob_data = 0; 1069 if (sm_get_oob_data) { 1070 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1071 } 1072 1073 // if available and SC supported, also ask for SC OOB Data 1074 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1075 memset(setup->sm_ra, 0, 16); 1076 memset(setup->sm_rb, 0, 16); 1077 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1078 if (sm_get_sc_oob_data){ 1079 if (IS_RESPONDER(sm_conn->sm_role)){ 1080 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1081 sm_conn->sm_peer_addr_type, 1082 sm_conn->sm_peer_address, 1083 setup->sm_peer_confirm, 1084 setup->sm_ra); 1085 } else { 1086 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1087 sm_conn->sm_peer_addr_type, 1088 sm_conn->sm_peer_address, 1089 setup->sm_peer_confirm, 1090 setup->sm_rb); 1091 } 1092 } else { 1093 setup->sm_have_oob_data = 0; 1094 } 1095 } 1096 #endif 1097 1098 sm_pairing_packet_t * local_packet; 1099 if (IS_RESPONDER(sm_conn->sm_role)){ 1100 // slave 1101 local_packet = &setup->sm_s_pres; 1102 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1103 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1104 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1105 } else { 1106 // master 1107 local_packet = &setup->sm_m_preq; 1108 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1109 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1110 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1111 1112 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1113 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1114 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1115 } 1116 1117 uint8_t auth_req = sm_auth_req; 1118 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1119 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1120 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1121 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1122 } 1123 1124 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1125 1126 sm_pairing_packet_t * remote_packet; 1127 int remote_key_request; 1128 if (IS_RESPONDER(sm_conn->sm_role)){ 1129 // slave / responder 1130 remote_packet = &setup->sm_m_preq; 1131 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1132 } else { 1133 // master / initiator 1134 remote_packet = &setup->sm_s_pres; 1135 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1136 } 1137 1138 // check key size 1139 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1140 if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; 1141 1142 // decide on STK generation method / SC 1143 sm_setup_tk(); 1144 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1145 1146 // check if STK generation method is acceptable by client 1147 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1148 1149 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1150 // check LE SC Only mode 1151 if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ 1152 log_info("SC Only mode active but SC not possible"); 1153 return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1154 } 1155 1156 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1157 if (setup->sm_use_secure_connections){ 1158 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1159 } 1160 #endif 1161 1162 // identical to responder 1163 sm_setup_key_distribution(remote_key_request); 1164 1165 // JUST WORKS doens't provide authentication 1166 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1167 1168 return 0; 1169 } 1170 1171 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1172 1173 // cache and reset context 1174 int matched_device_id = sm_address_resolution_test; 1175 address_resolution_mode_t mode = sm_address_resolution_mode; 1176 void * context = sm_address_resolution_context; 1177 1178 // reset context 1179 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1180 sm_address_resolution_context = NULL; 1181 sm_address_resolution_test = -1; 1182 hci_con_handle_t con_handle = 0; 1183 1184 sm_connection_t * sm_connection; 1185 #ifdef ENABLE_LE_CENTRAL 1186 sm_key_t ltk; 1187 int have_ltk; 1188 int pairing_need; 1189 #endif 1190 switch (mode){ 1191 case ADDRESS_RESOLUTION_GENERAL: 1192 break; 1193 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1194 sm_connection = (sm_connection_t *) context; 1195 con_handle = sm_connection->sm_handle; 1196 switch (event){ 1197 case ADDRESS_RESOLUTION_SUCEEDED: 1198 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1199 sm_connection->sm_le_db_index = matched_device_id; 1200 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1201 if (sm_connection->sm_role) { 1202 // LTK request received before, IRK required -> start LTK calculation 1203 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1204 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1205 } 1206 break; 1207 } 1208 #ifdef ENABLE_LE_CENTRAL 1209 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 1210 have_ltk = !sm_is_null_key(ltk); 1211 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1212 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1213 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1214 // reset requests 1215 sm_connection->sm_security_request_received = 0; 1216 sm_connection->sm_pairing_requested = 0; 1217 1218 // have ltk -> start encryption 1219 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1220 // "When a bond has been created between two devices, any reconnection should result in the local device 1221 // enabling or requesting encryption with the remote device before initiating any service request." 1222 if (have_ltk){ 1223 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1224 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1225 break; 1226 #else 1227 log_info("central: defer enabling encryption for bonded device"); 1228 #endif 1229 } 1230 // pairint_request -> send pairing request 1231 if (pairing_need){ 1232 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1233 break; 1234 } 1235 #endif 1236 break; 1237 case ADDRESS_RESOLUTION_FAILED: 1238 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1239 if (sm_connection->sm_role) { 1240 // LTK request received before, IRK required -> negative LTK reply 1241 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1242 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1243 } 1244 break; 1245 } 1246 #ifdef ENABLE_LE_CENTRAL 1247 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1248 sm_connection->sm_security_request_received = 0; 1249 sm_connection->sm_pairing_requested = 0; 1250 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1251 #endif 1252 break; 1253 } 1254 break; 1255 default: 1256 break; 1257 } 1258 1259 switch (event){ 1260 case ADDRESS_RESOLUTION_SUCEEDED: 1261 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1262 break; 1263 case ADDRESS_RESOLUTION_FAILED: 1264 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1265 break; 1266 } 1267 } 1268 1269 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1270 1271 int le_db_index = -1; 1272 1273 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1274 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1275 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1276 & SM_AUTHREQ_BONDING ) != 0u; 1277 1278 if (bonding_enabed){ 1279 1280 // lookup device based on IRK 1281 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1282 int i; 1283 for (i=0; i < le_device_db_max_count(); i++){ 1284 sm_key_t irk; 1285 bd_addr_t address; 1286 int address_type = BD_ADDR_TYPE_UNKNOWN; 1287 le_device_db_info(i, &address_type, address, irk); 1288 // skip unused entries 1289 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1290 // compare IRK 1291 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1292 1293 log_info("sm: device found for IRK, updating"); 1294 le_db_index = i; 1295 break; 1296 } 1297 } else { 1298 // assert IRK is set to zero 1299 memset(setup->sm_peer_irk, 0, 16); 1300 } 1301 1302 // if not found, lookup via public address if possible 1303 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1304 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1305 int i; 1306 for (i=0; i < le_device_db_max_count(); i++){ 1307 bd_addr_t address; 1308 int address_type = BD_ADDR_TYPE_UNKNOWN; 1309 le_device_db_info(i, &address_type, address, NULL); 1310 // skip unused entries 1311 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1312 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1313 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1314 log_info("sm: device found for public address, updating"); 1315 le_db_index = i; 1316 break; 1317 } 1318 } 1319 } 1320 1321 // if not found, add to db 1322 bool new_to_le_device_db = false; 1323 if (le_db_index < 0) { 1324 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1325 new_to_le_device_db = true; 1326 } 1327 1328 if (le_db_index >= 0){ 1329 1330 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1331 if (!new_to_le_device_db){ 1332 hci_remove_le_device_db_entry_from_resolving_list(le_db_index); 1333 } 1334 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1335 #else 1336 UNUSED(new_to_le_device_db); 1337 #endif 1338 1339 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1340 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1341 1342 #ifdef ENABLE_LE_SIGNED_WRITE 1343 // store local CSRK 1344 setup->sm_le_device_index = le_db_index; 1345 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1346 log_info("sm: store local CSRK"); 1347 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1348 le_device_db_local_counter_set(le_db_index, 0); 1349 } 1350 1351 // store remote CSRK 1352 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1353 log_info("sm: store remote CSRK"); 1354 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1355 le_device_db_remote_counter_set(le_db_index, 0); 1356 } 1357 #endif 1358 // store encryption information for secure connections: LTK generated by ECDH 1359 if (setup->sm_use_secure_connections){ 1360 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1361 uint8_t zero_rand[8]; 1362 memset(zero_rand, 0, 8); 1363 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1364 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1365 } 1366 1367 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1368 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1369 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1370 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1371 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1372 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1373 1374 } 1375 } 1376 } else { 1377 log_info("Ignoring received keys, bonding not enabled"); 1378 } 1379 1380 // keep le_db_index 1381 sm_conn->sm_le_db_index = le_db_index; 1382 } 1383 1384 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1385 setup->sm_pairing_failed_reason = reason; 1386 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1387 } 1388 1389 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1390 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1391 } 1392 1393 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1394 1395 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1396 static int sm_passkey_used(stk_generation_method_t method); 1397 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1398 1399 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1400 if (setup->sm_stk_generation_method == OOB){ 1401 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1402 } else { 1403 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); 1404 } 1405 } 1406 1407 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1408 if (IS_RESPONDER(sm_conn->sm_role)){ 1409 // Responder 1410 if (setup->sm_stk_generation_method == OOB){ 1411 // generate Nb 1412 log_info("Generate Nb"); 1413 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); 1414 } else { 1415 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1416 } 1417 } else { 1418 // Initiator role 1419 switch (setup->sm_stk_generation_method){ 1420 case JUST_WORKS: 1421 sm_sc_prepare_dhkey_check(sm_conn); 1422 break; 1423 1424 case NUMERIC_COMPARISON: 1425 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1426 break; 1427 case PK_INIT_INPUT: 1428 case PK_RESP_INPUT: 1429 case PK_BOTH_INPUT: 1430 if (setup->sm_passkey_bit < 20u) { 1431 sm_sc_start_calculating_local_confirm(sm_conn); 1432 } else { 1433 sm_sc_prepare_dhkey_check(sm_conn); 1434 } 1435 break; 1436 case OOB: 1437 sm_sc_prepare_dhkey_check(sm_conn); 1438 break; 1439 } 1440 } 1441 } 1442 1443 static void sm_sc_cmac_done(uint8_t * hash){ 1444 log_info("sm_sc_cmac_done: "); 1445 log_info_hexdump(hash, 16); 1446 1447 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1448 sm_sc_oob_state = SM_SC_OOB_IDLE; 1449 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1450 return; 1451 } 1452 1453 sm_connection_t * sm_conn = sm_cmac_connection; 1454 sm_cmac_connection = NULL; 1455 #ifdef ENABLE_CLASSIC 1456 link_key_type_t link_key_type; 1457 #endif 1458 1459 switch (sm_conn->sm_engine_state){ 1460 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1461 (void)memcpy(setup->sm_local_confirm, hash, 16); 1462 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1463 break; 1464 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1465 // check 1466 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1467 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1468 break; 1469 } 1470 sm_sc_state_after_receiving_random(sm_conn); 1471 break; 1472 case SM_SC_W4_CALCULATE_G2: { 1473 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1474 big_endian_store_32(setup->sm_tk, 12, vab); 1475 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1476 sm_trigger_user_response(sm_conn); 1477 break; 1478 } 1479 case SM_SC_W4_CALCULATE_F5_SALT: 1480 (void)memcpy(setup->sm_t, hash, 16); 1481 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1482 break; 1483 case SM_SC_W4_CALCULATE_F5_MACKEY: 1484 (void)memcpy(setup->sm_mackey, hash, 16); 1485 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1486 break; 1487 case SM_SC_W4_CALCULATE_F5_LTK: 1488 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1489 // Errata Service Release to the Bluetooth Specification: ESR09 1490 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1491 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1492 (void)memcpy(setup->sm_ltk, hash, 16); 1493 (void)memcpy(setup->sm_local_ltk, hash, 16); 1494 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1495 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1496 break; 1497 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1498 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1499 if (IS_RESPONDER(sm_conn->sm_role)){ 1500 // responder 1501 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1502 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1503 } else { 1504 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1505 } 1506 } else { 1507 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1508 } 1509 break; 1510 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1511 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1512 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1513 break; 1514 } 1515 if (IS_RESPONDER(sm_conn->sm_role)){ 1516 // responder 1517 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1518 } else { 1519 // initiator 1520 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1521 } 1522 break; 1523 case SM_SC_W4_CALCULATE_H6_ILK: 1524 (void)memcpy(setup->sm_t, hash, 16); 1525 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1526 break; 1527 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1528 #ifdef ENABLE_CLASSIC 1529 reverse_128(hash, setup->sm_t); 1530 link_key_type = sm_conn->sm_connection_authenticated ? 1531 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1532 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1533 if (IS_RESPONDER(sm_conn->sm_role)){ 1534 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1535 } else { 1536 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1537 } 1538 #endif 1539 if (IS_RESPONDER(sm_conn->sm_role)){ 1540 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1541 } else { 1542 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1543 } 1544 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1545 sm_done_for_handle(sm_conn->sm_handle); 1546 break; 1547 default: 1548 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1549 break; 1550 } 1551 sm_trigger_run(); 1552 } 1553 1554 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){ 1555 const uint16_t message_len = 65; 1556 sm_cmac_connection = sm_conn; 1557 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1558 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1559 sm_cmac_sc_buffer[64] = z; 1560 log_info("f4 key"); 1561 log_info_hexdump(x, 16); 1562 log_info("f4 message"); 1563 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1564 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1565 } 1566 1567 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1568 static const uint8_t f5_length[] = { 0x01, 0x00}; 1569 1570 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1571 1572 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1573 1574 log_info("f5_calculate_salt"); 1575 // calculate salt for f5 1576 const uint16_t message_len = 32; 1577 sm_cmac_connection = sm_conn; 1578 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1579 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1580 } 1581 1582 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){ 1583 const uint16_t message_len = 53; 1584 sm_cmac_connection = sm_conn; 1585 1586 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1587 sm_cmac_sc_buffer[0] = 0; 1588 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1589 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1590 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1591 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1592 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1593 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1594 log_info("f5 key"); 1595 log_info_hexdump(t, 16); 1596 log_info("f5 message for MacKey"); 1597 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1598 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1599 } 1600 1601 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1602 sm_key56_t bd_addr_master, bd_addr_slave; 1603 bd_addr_master[0] = setup->sm_m_addr_type; 1604 bd_addr_slave[0] = setup->sm_s_addr_type; 1605 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1606 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1607 if (IS_RESPONDER(sm_conn->sm_role)){ 1608 // responder 1609 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1610 } else { 1611 // initiator 1612 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1613 } 1614 } 1615 1616 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1617 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1618 const uint16_t message_len = 53; 1619 sm_cmac_connection = sm_conn; 1620 sm_cmac_sc_buffer[0] = 1; 1621 // 1..52 setup before 1622 log_info("f5 key"); 1623 log_info_hexdump(t, 16); 1624 log_info("f5 message for LTK"); 1625 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1626 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1627 } 1628 1629 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1630 f5_ltk(sm_conn, setup->sm_t); 1631 } 1632 1633 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){ 1634 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1635 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1636 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1637 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1638 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1639 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1640 } 1641 1642 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1643 const uint16_t message_len = 65; 1644 sm_cmac_connection = sm_conn; 1645 log_info("f6 key"); 1646 log_info_hexdump(w, 16); 1647 log_info("f6 message"); 1648 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1649 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1650 } 1651 1652 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1653 // - U is 256 bits 1654 // - V is 256 bits 1655 // - X is 128 bits 1656 // - Y is 128 bits 1657 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){ 1658 const uint16_t message_len = 80; 1659 sm_cmac_connection = sm_conn; 1660 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1661 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1662 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1663 log_info("g2 key"); 1664 log_info_hexdump(x, 16); 1665 log_info("g2 message"); 1666 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1667 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1668 } 1669 1670 static void g2_calculate(sm_connection_t * sm_conn) { 1671 // calc Va if numeric comparison 1672 if (IS_RESPONDER(sm_conn->sm_role)){ 1673 // responder 1674 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1675 } else { 1676 // initiator 1677 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1678 } 1679 } 1680 1681 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1682 uint8_t z = 0; 1683 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1684 // some form of passkey 1685 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1686 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1687 setup->sm_passkey_bit++; 1688 } 1689 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1690 } 1691 1692 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1693 // OOB 1694 if (setup->sm_stk_generation_method == OOB){ 1695 if (IS_RESPONDER(sm_conn->sm_role)){ 1696 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1697 } else { 1698 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1699 } 1700 return; 1701 } 1702 1703 uint8_t z = 0; 1704 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1705 // some form of passkey 1706 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1707 // sm_passkey_bit was increased before sending confirm value 1708 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1709 } 1710 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1711 } 1712 1713 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1714 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1715 1716 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1717 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1718 return; 1719 } else { 1720 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1721 } 1722 } 1723 1724 static void sm_sc_dhkey_calculated(void * arg){ 1725 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1726 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1727 if (sm_conn == NULL) return; 1728 1729 log_info("dhkey"); 1730 log_info_hexdump(&setup->sm_dhkey[0], 32); 1731 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1732 // trigger next step 1733 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1734 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1735 } 1736 sm_trigger_run(); 1737 } 1738 1739 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1740 // calculate DHKCheck 1741 sm_key56_t bd_addr_master, bd_addr_slave; 1742 bd_addr_master[0] = setup->sm_m_addr_type; 1743 bd_addr_slave[0] = setup->sm_s_addr_type; 1744 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1745 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1746 uint8_t iocap_a[3]; 1747 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1748 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1749 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1750 uint8_t iocap_b[3]; 1751 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1752 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1753 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1754 if (IS_RESPONDER(sm_conn->sm_role)){ 1755 // responder 1756 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1757 f6_engine(sm_conn, setup->sm_mackey); 1758 } else { 1759 // initiator 1760 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1761 f6_engine(sm_conn, setup->sm_mackey); 1762 } 1763 } 1764 1765 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1766 // validate E = f6() 1767 sm_key56_t bd_addr_master, bd_addr_slave; 1768 bd_addr_master[0] = setup->sm_m_addr_type; 1769 bd_addr_slave[0] = setup->sm_s_addr_type; 1770 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1771 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1772 1773 uint8_t iocap_a[3]; 1774 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1775 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1776 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1777 uint8_t iocap_b[3]; 1778 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1779 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1780 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1781 if (IS_RESPONDER(sm_conn->sm_role)){ 1782 // responder 1783 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1784 f6_engine(sm_conn, setup->sm_mackey); 1785 } else { 1786 // initiator 1787 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1788 f6_engine(sm_conn, setup->sm_mackey); 1789 } 1790 } 1791 1792 1793 // 1794 // Link Key Conversion Function h6 1795 // 1796 // h6(W, keyID) = AES-CMACW(keyID) 1797 // - W is 128 bits 1798 // - keyID is 32 bits 1799 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1800 const uint16_t message_len = 4; 1801 sm_cmac_connection = sm_conn; 1802 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1803 log_info("h6 key"); 1804 log_info_hexdump(w, 16); 1805 log_info("h6 message"); 1806 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1807 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1808 } 1809 1810 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1811 // Errata Service Release to the Bluetooth Specification: ESR09 1812 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1813 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1814 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1815 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1816 } 1817 1818 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1819 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1820 } 1821 1822 #endif 1823 1824 // key management legacy connections: 1825 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1826 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1827 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1828 // - responder reconnects: responder uses LTK receveived from master 1829 1830 // key management secure connections: 1831 // - both devices store same LTK from ECDH key exchange. 1832 1833 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1834 static void sm_load_security_info(sm_connection_t * sm_connection){ 1835 int encryption_key_size; 1836 int authenticated; 1837 int authorized; 1838 int secure_connection; 1839 1840 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1841 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1842 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1843 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); 1844 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1845 sm_connection->sm_connection_authenticated = authenticated; 1846 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1847 sm_connection->sm_connection_sc = secure_connection; 1848 } 1849 #endif 1850 1851 #ifdef ENABLE_LE_PERIPHERAL 1852 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1853 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1854 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1855 // re-establish used key encryption size 1856 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1857 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 1858 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1859 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 1860 // Legacy paring -> not SC 1861 sm_connection->sm_connection_sc = 0; 1862 log_info("sm: received ltk request with key size %u, authenticated %u", 1863 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1864 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1865 sm_trigger_run(); 1866 } 1867 #endif 1868 1869 // distributed key generation 1870 static bool sm_run_dpkg(void){ 1871 switch (dkg_state){ 1872 case DKG_CALC_IRK: 1873 // already busy? 1874 if (sm_aes128_state == SM_AES128_IDLE) { 1875 log_info("DKG_CALC_IRK started"); 1876 // IRK = d1(IR, 1, 0) 1877 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1878 sm_aes128_state = SM_AES128_ACTIVE; 1879 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1880 return true; 1881 } 1882 break; 1883 case DKG_CALC_DHK: 1884 // already busy? 1885 if (sm_aes128_state == SM_AES128_IDLE) { 1886 log_info("DKG_CALC_DHK started"); 1887 // DHK = d1(IR, 3, 0) 1888 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1889 sm_aes128_state = SM_AES128_ACTIVE; 1890 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1891 return true; 1892 } 1893 break; 1894 default: 1895 break; 1896 } 1897 return false; 1898 } 1899 1900 // random address updates 1901 static bool sm_run_rau(void){ 1902 switch (rau_state){ 1903 case RAU_GET_RANDOM: 1904 rau_state = RAU_W4_RANDOM; 1905 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1906 return true; 1907 case RAU_GET_ENC: 1908 // already busy? 1909 if (sm_aes128_state == SM_AES128_IDLE) { 1910 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1911 sm_aes128_state = SM_AES128_ACTIVE; 1912 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1913 return true; 1914 } 1915 break; 1916 case RAU_SET_ADDRESS: 1917 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1918 rau_state = RAU_IDLE; 1919 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1920 return true; 1921 default: 1922 break; 1923 } 1924 return false; 1925 } 1926 1927 // CSRK Lookup 1928 static bool sm_run_csrk(void){ 1929 btstack_linked_list_iterator_t it; 1930 1931 // -- if csrk lookup ready, find connection that require csrk lookup 1932 if (sm_address_resolution_idle()){ 1933 hci_connections_get_iterator(&it); 1934 while(btstack_linked_list_iterator_has_next(&it)){ 1935 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1936 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1937 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1938 // and start lookup 1939 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); 1940 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1941 break; 1942 } 1943 } 1944 } 1945 1946 // -- if csrk lookup ready, resolved addresses for received addresses 1947 if (sm_address_resolution_idle()) { 1948 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1949 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1950 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1951 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1952 btstack_memory_sm_lookup_entry_free(entry); 1953 } 1954 } 1955 1956 // -- Continue with CSRK device lookup by public or resolvable private address 1957 if (!sm_address_resolution_idle()){ 1958 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1959 while (sm_address_resolution_test < le_device_db_max_count()){ 1960 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1961 bd_addr_t addr; 1962 sm_key_t irk; 1963 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1964 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1965 1966 // skip unused entries 1967 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1968 sm_address_resolution_test++; 1969 continue; 1970 } 1971 1972 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1973 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1974 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1975 break; 1976 } 1977 1978 // if connection type is public, it must be a different one 1979 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1980 sm_address_resolution_test++; 1981 continue; 1982 } 1983 1984 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1985 1986 log_info("LE Device Lookup: calculate AH"); 1987 log_info_key("IRK", irk); 1988 1989 (void)memcpy(sm_aes128_key, irk, 16); 1990 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1991 sm_address_resolution_ah_calculation_active = 1; 1992 sm_aes128_state = SM_AES128_ACTIVE; 1993 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1994 return true; 1995 } 1996 1997 if (sm_address_resolution_test >= le_device_db_max_count()){ 1998 log_info("LE Device Lookup: not found"); 1999 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2000 } 2001 } 2002 return false; 2003 } 2004 2005 // SC OOB 2006 static bool sm_run_oob(void){ 2007 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2008 switch (sm_sc_oob_state){ 2009 case SM_SC_OOB_W2_CALC_CONFIRM: 2010 if (!sm_cmac_ready()) break; 2011 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 2012 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 2013 return true; 2014 default: 2015 break; 2016 } 2017 #endif 2018 return false; 2019 } 2020 2021 // handle basic actions that don't requires the full context 2022 static bool sm_run_basic(void){ 2023 btstack_linked_list_iterator_t it; 2024 hci_connections_get_iterator(&it); 2025 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2026 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2027 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2028 switch(sm_connection->sm_engine_state){ 2029 // responder side 2030 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2031 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2032 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2033 return true; 2034 2035 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2036 case SM_SC_RECEIVED_LTK_REQUEST: 2037 switch (sm_connection->sm_irk_lookup_state){ 2038 case IRK_LOOKUP_FAILED: 2039 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2040 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2041 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2042 return true; 2043 default: 2044 break; 2045 } 2046 break; 2047 #endif 2048 default: 2049 break; 2050 } 2051 } 2052 return false; 2053 } 2054 2055 static void sm_run_activate_connection(void){ 2056 // Find connections that requires setup context and make active if no other is locked 2057 btstack_linked_list_iterator_t it; 2058 hci_connections_get_iterator(&it); 2059 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2060 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2061 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2062 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2063 int done = 1; 2064 int err; 2065 UNUSED(err); 2066 2067 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2068 // assert ec key is ready 2069 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2070 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2071 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2072 sm_ec_generate_new_key(); 2073 } 2074 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2075 continue; 2076 } 2077 } 2078 #endif 2079 2080 switch (sm_connection->sm_engine_state) { 2081 #ifdef ENABLE_LE_PERIPHERAL 2082 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2083 // send packet if possible, 2084 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2085 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2086 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2087 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2088 } else { 2089 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2090 } 2091 // don't lock sxetup context yet 2092 done = 0; 2093 break; 2094 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2095 sm_reset_setup(); 2096 sm_init_setup(sm_connection); 2097 // recover pairing request 2098 (void)memcpy(&setup->sm_m_preq, 2099 &sm_connection->sm_m_preq, 2100 sizeof(sm_pairing_packet_t)); 2101 err = sm_stk_generation_init(sm_connection); 2102 2103 #ifdef ENABLE_TESTING_SUPPORT 2104 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2105 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2106 err = test_pairing_failure; 2107 } 2108 #endif 2109 if (err){ 2110 setup->sm_pairing_failed_reason = err; 2111 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2112 break; 2113 } 2114 sm_timeout_start(sm_connection); 2115 // generate random number first, if we need to show passkey 2116 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2117 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); 2118 break; 2119 } 2120 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2121 break; 2122 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2123 sm_reset_setup(); 2124 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2125 break; 2126 2127 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2128 case SM_SC_RECEIVED_LTK_REQUEST: 2129 switch (sm_connection->sm_irk_lookup_state){ 2130 case IRK_LOOKUP_SUCCEEDED: 2131 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2132 // start using context by loading security info 2133 sm_reset_setup(); 2134 sm_load_security_info(sm_connection); 2135 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2136 (void)memcpy(setup->sm_ltk, 2137 setup->sm_peer_ltk, 16); 2138 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2139 break; 2140 } 2141 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2142 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2143 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2144 // don't lock setup context yet 2145 return; 2146 default: 2147 // just wait until IRK lookup is completed 2148 // don't lock setup context yet 2149 done = 0; 2150 break; 2151 } 2152 break; 2153 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2154 #endif /* ENABLE_LE_PERIPHERAL */ 2155 2156 #ifdef ENABLE_LE_CENTRAL 2157 case SM_INITIATOR_PH0_HAS_LTK: 2158 sm_reset_setup(); 2159 sm_load_security_info(sm_connection); 2160 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2161 break; 2162 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2163 sm_reset_setup(); 2164 sm_init_setup(sm_connection); 2165 sm_timeout_start(sm_connection); 2166 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2167 break; 2168 #endif 2169 2170 default: 2171 done = 0; 2172 break; 2173 } 2174 if (done){ 2175 sm_active_connection_handle = sm_connection->sm_handle; 2176 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); 2177 } 2178 } 2179 } 2180 2181 static void sm_run(void){ 2182 2183 // assert that stack has already bootet 2184 if (hci_get_state() != HCI_STATE_WORKING) return; 2185 2186 // assert that we can send at least commands 2187 if (!hci_can_send_command_packet_now()) return; 2188 2189 // pause until IR/ER are ready 2190 if (sm_persistent_keys_random_active) return; 2191 2192 bool done; 2193 2194 // 2195 // non-connection related behaviour 2196 // 2197 2198 done = sm_run_dpkg(); 2199 if (done) return; 2200 2201 done = sm_run_rau(); 2202 if (done) return; 2203 2204 done = sm_run_csrk(); 2205 if (done) return; 2206 2207 done = sm_run_oob(); 2208 if (done) return; 2209 2210 // assert that we can send at least commands - cmd might have been sent by crypto engine 2211 if (!hci_can_send_command_packet_now()) return; 2212 2213 // handle basic actions that don't requires the full context 2214 done = sm_run_basic(); 2215 if (done) return; 2216 2217 // 2218 // active connection handling 2219 // -- use loop to handle next connection if lock on setup context is released 2220 2221 while (true) { 2222 2223 sm_run_activate_connection(); 2224 2225 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2226 2227 // 2228 // active connection handling 2229 // 2230 2231 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2232 if (!connection) { 2233 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2234 return; 2235 } 2236 2237 // assert that we could send a SM PDU - not needed for all of the following 2238 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2239 log_info("cannot send now, requesting can send now event"); 2240 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2241 return; 2242 } 2243 2244 // send keypress notifications 2245 if (setup->sm_keypress_notification){ 2246 int i; 2247 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2248 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2249 uint8_t action = 0; 2250 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2251 if (flags & (1u<<i)){ 2252 int clear_flag = 1; 2253 switch (i){ 2254 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2255 case SM_KEYPRESS_PASSKEY_CLEARED: 2256 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2257 default: 2258 break; 2259 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2260 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2261 num_actions--; 2262 clear_flag = num_actions == 0u; 2263 break; 2264 } 2265 if (clear_flag){ 2266 flags &= ~(1<<i); 2267 } 2268 action = i; 2269 break; 2270 } 2271 } 2272 setup->sm_keypress_notification = (num_actions << 5) | flags; 2273 2274 // send keypress notification 2275 uint8_t buffer[2]; 2276 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2277 buffer[1] = action; 2278 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2279 2280 // try 2281 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2282 return; 2283 } 2284 2285 int key_distribution_flags; 2286 UNUSED(key_distribution_flags); 2287 2288 log_info("sm_run: state %u", connection->sm_engine_state); 2289 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2290 log_info("sm_run // cannot send"); 2291 } 2292 switch (connection->sm_engine_state){ 2293 2294 // general 2295 case SM_GENERAL_SEND_PAIRING_FAILED: { 2296 uint8_t buffer[2]; 2297 buffer[0] = SM_CODE_PAIRING_FAILED; 2298 buffer[1] = setup->sm_pairing_failed_reason; 2299 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2300 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2301 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2302 sm_done_for_handle(connection->sm_handle); 2303 break; 2304 } 2305 2306 // responding state 2307 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2308 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2309 if (!sm_cmac_ready()) break; 2310 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2311 sm_sc_calculate_local_confirm(connection); 2312 break; 2313 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2314 if (!sm_cmac_ready()) break; 2315 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2316 sm_sc_calculate_remote_confirm(connection); 2317 break; 2318 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2319 if (!sm_cmac_ready()) break; 2320 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2321 sm_sc_calculate_f6_for_dhkey_check(connection); 2322 break; 2323 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2324 if (!sm_cmac_ready()) break; 2325 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2326 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2327 break; 2328 case SM_SC_W2_CALCULATE_F5_SALT: 2329 if (!sm_cmac_ready()) break; 2330 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2331 f5_calculate_salt(connection); 2332 break; 2333 case SM_SC_W2_CALCULATE_F5_MACKEY: 2334 if (!sm_cmac_ready()) break; 2335 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2336 f5_calculate_mackey(connection); 2337 break; 2338 case SM_SC_W2_CALCULATE_F5_LTK: 2339 if (!sm_cmac_ready()) break; 2340 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2341 f5_calculate_ltk(connection); 2342 break; 2343 case SM_SC_W2_CALCULATE_G2: 2344 if (!sm_cmac_ready()) break; 2345 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2346 g2_calculate(connection); 2347 break; 2348 case SM_SC_W2_CALCULATE_H6_ILK: 2349 if (!sm_cmac_ready()) break; 2350 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2351 h6_calculate_ilk(connection); 2352 break; 2353 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2354 if (!sm_cmac_ready()) break; 2355 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2356 h6_calculate_br_edr_link_key(connection); 2357 break; 2358 #endif 2359 2360 #ifdef ENABLE_LE_CENTRAL 2361 // initiator side 2362 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2363 sm_key_t peer_ltk_flipped; 2364 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2365 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2366 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2367 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2368 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2369 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2370 return; 2371 } 2372 2373 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2374 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2375 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2376 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2377 sm_timeout_reset(connection); 2378 break; 2379 #endif 2380 2381 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2382 2383 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2384 int trigger_user_response = 0; 2385 int trigger_start_calculating_local_confirm = 0; 2386 uint8_t buffer[65]; 2387 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2388 // 2389 reverse_256(&ec_q[0], &buffer[1]); 2390 reverse_256(&ec_q[32], &buffer[33]); 2391 2392 #ifdef ENABLE_TESTING_SUPPORT 2393 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2394 log_info("testing_support: invalidating public key"); 2395 // flip single bit of public key coordinate 2396 buffer[1] ^= 1; 2397 } 2398 #endif 2399 2400 // stk generation method 2401 // passkey entry: notify app to show passkey or to request passkey 2402 switch (setup->sm_stk_generation_method){ 2403 case JUST_WORKS: 2404 case NUMERIC_COMPARISON: 2405 if (IS_RESPONDER(connection->sm_role)){ 2406 // responder 2407 trigger_start_calculating_local_confirm = 1; 2408 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2409 } else { 2410 // initiator 2411 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2412 } 2413 break; 2414 case PK_INIT_INPUT: 2415 case PK_RESP_INPUT: 2416 case PK_BOTH_INPUT: 2417 // use random TK for display 2418 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2419 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2420 setup->sm_passkey_bit = 0; 2421 2422 if (IS_RESPONDER(connection->sm_role)){ 2423 // responder 2424 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2425 } else { 2426 // initiator 2427 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2428 } 2429 trigger_user_response = 1; 2430 break; 2431 case OOB: 2432 if (IS_RESPONDER(connection->sm_role)){ 2433 // responder 2434 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2435 } else { 2436 // initiator 2437 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2438 } 2439 break; 2440 } 2441 2442 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2443 sm_timeout_reset(connection); 2444 2445 // trigger user response and calc confirm after sending pdu 2446 if (trigger_user_response){ 2447 sm_trigger_user_response(connection); 2448 } 2449 if (trigger_start_calculating_local_confirm){ 2450 sm_sc_start_calculating_local_confirm(connection); 2451 } 2452 break; 2453 } 2454 case SM_SC_SEND_CONFIRMATION: { 2455 uint8_t buffer[17]; 2456 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2457 reverse_128(setup->sm_local_confirm, &buffer[1]); 2458 if (IS_RESPONDER(connection->sm_role)){ 2459 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2460 } else { 2461 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2462 } 2463 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2464 sm_timeout_reset(connection); 2465 break; 2466 } 2467 case SM_SC_SEND_PAIRING_RANDOM: { 2468 uint8_t buffer[17]; 2469 buffer[0] = SM_CODE_PAIRING_RANDOM; 2470 reverse_128(setup->sm_local_nonce, &buffer[1]); 2471 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2472 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2473 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2474 if (IS_RESPONDER(connection->sm_role)){ 2475 // responder 2476 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2477 } else { 2478 // initiator 2479 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2480 } 2481 } else { 2482 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2483 if (IS_RESPONDER(connection->sm_role)){ 2484 // responder 2485 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2486 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2487 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2488 } else { 2489 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2490 sm_sc_prepare_dhkey_check(connection); 2491 } 2492 } else { 2493 // initiator 2494 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2495 } 2496 } 2497 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2498 sm_timeout_reset(connection); 2499 break; 2500 } 2501 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2502 uint8_t buffer[17]; 2503 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2504 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2505 2506 if (IS_RESPONDER(connection->sm_role)){ 2507 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2508 } else { 2509 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2510 } 2511 2512 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2513 sm_timeout_reset(connection); 2514 break; 2515 } 2516 2517 #endif 2518 2519 #ifdef ENABLE_LE_PERIPHERAL 2520 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2521 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2522 2523 // start with initiator key dist flags 2524 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2525 2526 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2527 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2528 if (setup->sm_use_secure_connections){ 2529 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2530 } 2531 #endif 2532 // setup in response 2533 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); 2534 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); 2535 2536 // update key distribution after ENC was dropped 2537 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2538 2539 if (setup->sm_use_secure_connections){ 2540 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2541 } else { 2542 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2543 } 2544 2545 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2546 sm_timeout_reset(connection); 2547 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2548 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2549 sm_trigger_user_response(connection); 2550 } 2551 return; 2552 #endif 2553 2554 case SM_PH2_SEND_PAIRING_RANDOM: { 2555 uint8_t buffer[17]; 2556 buffer[0] = SM_CODE_PAIRING_RANDOM; 2557 reverse_128(setup->sm_local_random, &buffer[1]); 2558 if (IS_RESPONDER(connection->sm_role)){ 2559 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2560 } else { 2561 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2562 } 2563 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2564 sm_timeout_reset(connection); 2565 break; 2566 } 2567 2568 case SM_PH2_C1_GET_ENC_A: 2569 // already busy? 2570 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2571 // calculate confirm using aes128 engine - step 1 2572 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); 2573 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2574 sm_aes128_state = SM_AES128_ACTIVE; 2575 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); 2576 break; 2577 2578 case SM_PH2_C1_GET_ENC_C: 2579 // already busy? 2580 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2581 // calculate m_confirm using aes128 engine - step 1 2582 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); 2583 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2584 sm_aes128_state = SM_AES128_ACTIVE; 2585 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); 2586 break; 2587 2588 case SM_PH2_CALC_STK: 2589 // already busy? 2590 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2591 // calculate STK 2592 if (IS_RESPONDER(connection->sm_role)){ 2593 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2594 } else { 2595 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2596 } 2597 connection->sm_engine_state = SM_PH2_W4_STK; 2598 sm_aes128_state = SM_AES128_ACTIVE; 2599 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); 2600 break; 2601 2602 case SM_PH3_Y_GET_ENC: 2603 // already busy? 2604 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2605 // PH3B2 - calculate Y from - enc 2606 2607 // dm helper (was sm_dm_r_prime) 2608 // r' = padding || r 2609 // r - 64 bit value 2610 memset(&sm_aes128_plaintext[0], 0, 8); 2611 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2612 2613 // Y = dm(DHK, Rand) 2614 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2615 sm_aes128_state = SM_AES128_ACTIVE; 2616 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); 2617 break; 2618 2619 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2620 uint8_t buffer[17]; 2621 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2622 reverse_128(setup->sm_local_confirm, &buffer[1]); 2623 if (IS_RESPONDER(connection->sm_role)){ 2624 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2625 } else { 2626 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2627 } 2628 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2629 sm_timeout_reset(connection); 2630 return; 2631 } 2632 #ifdef ENABLE_LE_PERIPHERAL 2633 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2634 sm_key_t stk_flipped; 2635 reverse_128(setup->sm_ltk, stk_flipped); 2636 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2637 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2638 return; 2639 } 2640 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2641 sm_key_t ltk_flipped; 2642 reverse_128(setup->sm_ltk, ltk_flipped); 2643 connection->sm_engine_state = SM_RESPONDER_IDLE; 2644 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2645 sm_done_for_handle(connection->sm_handle); 2646 return; 2647 } 2648 case SM_RESPONDER_PH4_Y_GET_ENC: 2649 // already busy? 2650 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2651 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2652 2653 // dm helper (was sm_dm_r_prime) 2654 // r' = padding || r 2655 // r - 64 bit value 2656 memset(&sm_aes128_plaintext[0], 0, 8); 2657 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2658 2659 // Y = dm(DHK, Rand) 2660 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2661 sm_aes128_state = SM_AES128_ACTIVE; 2662 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); 2663 return; 2664 #endif 2665 #ifdef ENABLE_LE_CENTRAL 2666 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2667 sm_key_t stk_flipped; 2668 reverse_128(setup->sm_ltk, stk_flipped); 2669 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2670 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2671 return; 2672 } 2673 #endif 2674 2675 case SM_PH3_DISTRIBUTE_KEYS: 2676 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2677 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2678 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2679 uint8_t buffer[17]; 2680 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2681 reverse_128(setup->sm_ltk, &buffer[1]); 2682 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2683 sm_timeout_reset(connection); 2684 return; 2685 } 2686 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2687 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2688 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2689 uint8_t buffer[11]; 2690 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2691 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2692 reverse_64(setup->sm_local_rand, &buffer[3]); 2693 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2694 sm_timeout_reset(connection); 2695 return; 2696 } 2697 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2698 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2699 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2700 uint8_t buffer[17]; 2701 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2702 reverse_128(sm_persistent_irk, &buffer[1]); 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_IDENTITY_ADDRESS_INFORMATION){ 2708 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2709 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2710 bd_addr_t local_address; 2711 uint8_t buffer[8]; 2712 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2713 switch (gap_random_address_get_mode()){ 2714 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2715 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2716 // public or static random 2717 gap_le_get_own_address(&buffer[1], local_address); 2718 break; 2719 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2720 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2721 // fallback to public 2722 gap_local_bd_addr(local_address); 2723 buffer[1] = 0; 2724 break; 2725 } 2726 reverse_bd_addr(local_address, &buffer[2]); 2727 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2728 sm_timeout_reset(connection); 2729 return; 2730 } 2731 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2732 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2733 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2734 2735 #ifdef ENABLE_LE_SIGNED_WRITE 2736 // hack to reproduce test runs 2737 if (test_use_fixed_local_csrk){ 2738 memset(setup->sm_local_csrk, 0xcc, 16); 2739 } 2740 2741 // store local CSRK 2742 if (setup->sm_le_device_index >= 0){ 2743 log_info("sm: store local CSRK"); 2744 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2745 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2746 } 2747 #endif 2748 2749 uint8_t buffer[17]; 2750 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2751 reverse_128(setup->sm_local_csrk, &buffer[1]); 2752 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2753 sm_timeout_reset(connection); 2754 return; 2755 } 2756 2757 // keys are sent 2758 if (IS_RESPONDER(connection->sm_role)){ 2759 // slave -> receive master keys if any 2760 if (sm_key_distribution_all_received(connection)){ 2761 sm_key_distribution_handle_all_received(connection); 2762 connection->sm_engine_state = SM_RESPONDER_IDLE; 2763 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2764 sm_done_for_handle(connection->sm_handle); 2765 } else { 2766 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2767 } 2768 } else { 2769 sm_master_pairing_success(connection); 2770 } 2771 break; 2772 2773 default: 2774 break; 2775 } 2776 2777 // check again if active connection was released 2778 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2779 } 2780 } 2781 2782 // sm_aes128_state stays active 2783 static void sm_handle_encryption_result_enc_a(void *arg){ 2784 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2785 sm_aes128_state = SM_AES128_IDLE; 2786 2787 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2788 if (connection == NULL) return; 2789 2790 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2791 sm_aes128_state = SM_AES128_ACTIVE; 2792 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); 2793 } 2794 2795 static void sm_handle_encryption_result_enc_b(void *arg){ 2796 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2797 sm_aes128_state = SM_AES128_IDLE; 2798 2799 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2800 if (connection == NULL) return; 2801 2802 log_info_key("c1!", setup->sm_local_confirm); 2803 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2804 sm_trigger_run(); 2805 } 2806 2807 // sm_aes128_state stays active 2808 static void sm_handle_encryption_result_enc_c(void *arg){ 2809 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2810 sm_aes128_state = SM_AES128_IDLE; 2811 2812 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2813 if (connection == NULL) return; 2814 2815 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2816 sm_aes128_state = SM_AES128_ACTIVE; 2817 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); 2818 } 2819 2820 static void sm_handle_encryption_result_enc_d(void * arg){ 2821 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2822 sm_aes128_state = SM_AES128_IDLE; 2823 2824 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2825 if (connection == NULL) return; 2826 2827 log_info_key("c1!", sm_aes128_ciphertext); 2828 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2829 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2830 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2831 sm_trigger_run(); 2832 return; 2833 } 2834 if (IS_RESPONDER(connection->sm_role)){ 2835 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2836 sm_trigger_run(); 2837 } else { 2838 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2839 sm_aes128_state = SM_AES128_ACTIVE; 2840 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); 2841 } 2842 } 2843 2844 static void sm_handle_encryption_result_enc_stk(void *arg){ 2845 sm_aes128_state = SM_AES128_IDLE; 2846 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2847 2848 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2849 if (connection == NULL) return; 2850 2851 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2852 log_info_key("stk", setup->sm_ltk); 2853 if (IS_RESPONDER(connection->sm_role)){ 2854 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2855 } else { 2856 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2857 } 2858 sm_trigger_run(); 2859 } 2860 2861 // sm_aes128_state stays active 2862 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2863 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2864 sm_aes128_state = SM_AES128_IDLE; 2865 2866 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2867 if (connection == NULL) return; 2868 2869 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2870 log_info_hex16("y", setup->sm_local_y); 2871 // PH3B3 - calculate EDIV 2872 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2873 log_info_hex16("ediv", setup->sm_local_ediv); 2874 // PH3B4 - calculate LTK - enc 2875 // LTK = d1(ER, DIV, 0)) 2876 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2877 sm_aes128_state = SM_AES128_ACTIVE; 2878 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); 2879 } 2880 2881 #ifdef ENABLE_LE_PERIPHERAL 2882 // sm_aes128_state stays active 2883 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2884 sm_aes128_state = SM_AES128_IDLE; 2885 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2886 2887 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2888 if (connection == NULL) return; 2889 2890 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2891 log_info_hex16("y", setup->sm_local_y); 2892 2893 // PH3B3 - calculate DIV 2894 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2895 log_info_hex16("ediv", setup->sm_local_ediv); 2896 // PH3B4 - calculate LTK - enc 2897 // LTK = d1(ER, DIV, 0)) 2898 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2899 sm_aes128_state = SM_AES128_ACTIVE; 2900 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); 2901 } 2902 #endif 2903 2904 // sm_aes128_state stays active 2905 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2906 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2907 sm_aes128_state = SM_AES128_IDLE; 2908 2909 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2910 if (connection == NULL) return; 2911 2912 log_info_key("ltk", setup->sm_ltk); 2913 // calc CSRK next 2914 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2915 sm_aes128_state = SM_AES128_ACTIVE; 2916 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); 2917 } 2918 2919 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2920 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2921 sm_aes128_state = SM_AES128_IDLE; 2922 2923 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2924 if (connection == NULL) return; 2925 2926 sm_aes128_state = SM_AES128_IDLE; 2927 log_info_key("csrk", setup->sm_local_csrk); 2928 if (setup->sm_key_distribution_send_set){ 2929 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2930 } else { 2931 // no keys to send, just continue 2932 if (IS_RESPONDER(connection->sm_role)){ 2933 // slave -> receive master keys 2934 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2935 } else { 2936 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2937 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2938 } else { 2939 sm_master_pairing_success(connection); 2940 } 2941 } 2942 } 2943 sm_trigger_run(); 2944 } 2945 2946 #ifdef ENABLE_LE_PERIPHERAL 2947 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2948 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2949 sm_aes128_state = SM_AES128_IDLE; 2950 2951 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2952 if (connection == NULL) return; 2953 2954 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2955 log_info_key("ltk", setup->sm_ltk); 2956 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2957 sm_trigger_run(); 2958 } 2959 #endif 2960 2961 static void sm_handle_encryption_result_address_resolution(void *arg){ 2962 UNUSED(arg); 2963 sm_aes128_state = SM_AES128_IDLE; 2964 2965 sm_address_resolution_ah_calculation_active = 0; 2966 // compare calulated address against connecting device 2967 uint8_t * hash = &sm_aes128_ciphertext[13]; 2968 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2969 log_info("LE Device Lookup: matched resolvable private address"); 2970 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2971 sm_trigger_run(); 2972 return; 2973 } 2974 // no match, try next 2975 sm_address_resolution_test++; 2976 sm_trigger_run(); 2977 } 2978 2979 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2980 UNUSED(arg); 2981 sm_aes128_state = SM_AES128_IDLE; 2982 2983 log_info_key("irk", sm_persistent_irk); 2984 dkg_state = DKG_CALC_DHK; 2985 sm_trigger_run(); 2986 } 2987 2988 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2989 UNUSED(arg); 2990 sm_aes128_state = SM_AES128_IDLE; 2991 2992 log_info_key("dhk", sm_persistent_dhk); 2993 dkg_state = DKG_READY; 2994 sm_trigger_run(); 2995 } 2996 2997 static void sm_handle_encryption_result_rau(void *arg){ 2998 UNUSED(arg); 2999 sm_aes128_state = SM_AES128_IDLE; 3000 3001 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 3002 rau_state = RAU_SET_ADDRESS; 3003 sm_trigger_run(); 3004 } 3005 3006 static void sm_handle_random_result_rau(void * arg){ 3007 UNUSED(arg); 3008 // non-resolvable vs. resolvable 3009 switch (gap_random_adress_type){ 3010 case GAP_RANDOM_ADDRESS_RESOLVABLE: 3011 // resolvable: use random as prand and calc address hash 3012 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 3013 sm_random_address[0u] &= 0x3fu; 3014 sm_random_address[0u] |= 0x40u; 3015 rau_state = RAU_GET_ENC; 3016 break; 3017 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 3018 default: 3019 // "The two most significant bits of the address shall be equal to ‘0’"" 3020 sm_random_address[0u] &= 0x3fu; 3021 rau_state = RAU_SET_ADDRESS; 3022 break; 3023 } 3024 sm_trigger_run(); 3025 } 3026 3027 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3028 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3029 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3030 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3031 if (connection == NULL) return; 3032 3033 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3034 sm_trigger_run(); 3035 } 3036 3037 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3038 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3039 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3040 if (connection == NULL) return; 3041 3042 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3043 sm_trigger_run(); 3044 } 3045 #endif 3046 3047 static void sm_handle_random_result_ph2_random(void * arg){ 3048 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3049 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3050 if (connection == NULL) return; 3051 3052 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3053 sm_trigger_run(); 3054 } 3055 3056 static void sm_handle_random_result_ph2_tk(void * arg){ 3057 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3058 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3059 if (connection == NULL) return; 3060 3061 sm_reset_tk(); 3062 uint32_t tk; 3063 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3064 // map random to 0-999999 without speding much cycles on a modulus operation 3065 tk = little_endian_read_32(sm_random_data,0); 3066 tk = tk & 0xfffff; // 1048575 3067 if (tk >= 999999u){ 3068 tk = tk - 999999u; 3069 } 3070 } else { 3071 // override with pre-defined passkey 3072 tk = sm_fixed_passkey_in_display_role; 3073 } 3074 big_endian_store_32(setup->sm_tk, 12, tk); 3075 if (IS_RESPONDER(connection->sm_role)){ 3076 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3077 } else { 3078 if (setup->sm_use_secure_connections){ 3079 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3080 } else { 3081 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3082 sm_trigger_user_response(connection); 3083 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3084 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3085 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); 3086 } 3087 } 3088 } 3089 sm_trigger_run(); 3090 } 3091 3092 static void sm_handle_random_result_ph3_div(void * arg){ 3093 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3094 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3095 if (connection == NULL) return; 3096 3097 // use 16 bit from random value as div 3098 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3099 log_info_hex16("div", setup->sm_local_div); 3100 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3101 sm_trigger_run(); 3102 } 3103 3104 static void sm_handle_random_result_ph3_random(void * arg){ 3105 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3106 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3107 if (connection == NULL) return; 3108 3109 reverse_64(sm_random_data, setup->sm_local_rand); 3110 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3111 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3112 // no db for authenticated flag hack: store flag in bit 4 of LSB 3113 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3114 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3115 } 3116 static void sm_validate_er_ir(void){ 3117 // warn about default ER/IR 3118 int warning = 0; 3119 if (sm_ir_is_default()){ 3120 warning = 1; 3121 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3122 } 3123 if (sm_er_is_default()){ 3124 warning = 1; 3125 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3126 } 3127 if (warning) { 3128 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3129 } 3130 } 3131 3132 static void sm_handle_random_result_ir(void *arg){ 3133 sm_persistent_keys_random_active = 0; 3134 if (arg){ 3135 // key generated, store in tlv 3136 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3137 log_info("Generated IR key. Store in TLV status: %d", status); 3138 } 3139 log_info_key("IR", sm_persistent_ir); 3140 dkg_state = DKG_CALC_IRK; 3141 3142 if (test_use_fixed_local_irk){ 3143 log_info_key("IRK", sm_persistent_irk); 3144 dkg_state = DKG_CALC_DHK; 3145 } 3146 3147 sm_trigger_run(); 3148 } 3149 3150 static void sm_handle_random_result_er(void *arg){ 3151 sm_persistent_keys_random_active = 0; 3152 if (arg){ 3153 // key generated, store in tlv 3154 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3155 log_info("Generated ER key. Store in TLV status: %d", status); 3156 } 3157 log_info_key("ER", sm_persistent_er); 3158 3159 // try load ir 3160 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3161 if (key_size == 16){ 3162 // ok, let's continue 3163 log_info("IR from TLV"); 3164 sm_handle_random_result_ir( NULL ); 3165 } else { 3166 // invalid, generate new random one 3167 sm_persistent_keys_random_active = 1; 3168 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3169 } 3170 } 3171 3172 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3173 3174 UNUSED(channel); // ok: there is no channel 3175 UNUSED(size); // ok: fixed format HCI events 3176 3177 sm_connection_t * sm_conn; 3178 hci_con_handle_t con_handle; 3179 3180 switch (packet_type) { 3181 3182 case HCI_EVENT_PACKET: 3183 switch (hci_event_packet_get_type(packet)) { 3184 3185 case BTSTACK_EVENT_STATE: 3186 // bt stack activated, get started 3187 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3188 log_info("HCI Working!"); 3189 3190 // setup IR/ER with TLV 3191 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3192 if (sm_tlv_impl){ 3193 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3194 if (key_size == 16){ 3195 // ok, let's continue 3196 log_info("ER from TLV"); 3197 sm_handle_random_result_er( NULL ); 3198 } else { 3199 // invalid, generate random one 3200 sm_persistent_keys_random_active = 1; 3201 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3202 } 3203 } else { 3204 sm_validate_er_ir(); 3205 dkg_state = DKG_CALC_IRK; 3206 3207 if (test_use_fixed_local_irk){ 3208 log_info_key("IRK", sm_persistent_irk); 3209 dkg_state = DKG_CALC_DHK; 3210 } 3211 } 3212 3213 // restart random address updates after power cycle 3214 gap_random_address_set_mode(gap_random_adress_type); 3215 } 3216 break; 3217 3218 case HCI_EVENT_LE_META: 3219 switch (packet[2]) { 3220 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3221 3222 log_info("sm: connected"); 3223 3224 if (packet[3]) return; // connection failed 3225 3226 con_handle = little_endian_read_16(packet, 4); 3227 sm_conn = sm_get_connection_for_handle(con_handle); 3228 if (!sm_conn) break; 3229 3230 sm_conn->sm_handle = con_handle; 3231 sm_conn->sm_role = packet[6]; 3232 sm_conn->sm_peer_addr_type = packet[7]; 3233 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3234 3235 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3236 3237 // reset security properties 3238 sm_conn->sm_connection_encrypted = 0; 3239 sm_conn->sm_connection_authenticated = 0; 3240 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3241 sm_conn->sm_le_db_index = -1; 3242 3243 // prepare CSRK lookup (does not involve setup) 3244 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3245 3246 // just connected -> everything else happens in sm_run() 3247 if (IS_RESPONDER(sm_conn->sm_role)){ 3248 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3249 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3250 if (sm_slave_request_security) { 3251 // request security if requested by app 3252 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3253 } else { 3254 // otherwise, wait for pairing request 3255 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3256 } 3257 } 3258 break; 3259 } else { 3260 // master 3261 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3262 } 3263 break; 3264 3265 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3266 con_handle = little_endian_read_16(packet, 3); 3267 sm_conn = sm_get_connection_for_handle(con_handle); 3268 if (!sm_conn) break; 3269 3270 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3271 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3272 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3273 break; 3274 } 3275 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3276 // PH2 SEND LTK as we need to exchange keys in PH3 3277 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3278 break; 3279 } 3280 3281 // store rand and ediv 3282 reverse_64(&packet[5], sm_conn->sm_local_rand); 3283 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3284 3285 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3286 // potentially stored LTK is from the master 3287 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3288 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3289 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3290 break; 3291 } 3292 // additionally check if remote is in LE Device DB if requested 3293 switch(sm_conn->sm_irk_lookup_state){ 3294 case IRK_LOOKUP_FAILED: 3295 log_info("LTK Request: device not in device db"); 3296 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3297 break; 3298 case IRK_LOOKUP_SUCCEEDED: 3299 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3300 break; 3301 default: 3302 // wait for irk look doen 3303 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3304 break; 3305 } 3306 break; 3307 } 3308 3309 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3310 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3311 #else 3312 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3313 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3314 #endif 3315 break; 3316 3317 default: 3318 break; 3319 } 3320 break; 3321 3322 case HCI_EVENT_ENCRYPTION_CHANGE: 3323 con_handle = little_endian_read_16(packet, 3); 3324 sm_conn = sm_get_connection_for_handle(con_handle); 3325 if (!sm_conn) break; 3326 3327 sm_conn->sm_connection_encrypted = packet[5]; 3328 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3329 sm_conn->sm_actual_encryption_key_size); 3330 log_info("event handler, state %u", sm_conn->sm_engine_state); 3331 3332 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3333 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3334 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3335 // notify client, if pairing was requested before 3336 if (sm_conn->sm_pairing_requested){ 3337 sm_conn->sm_pairing_requested = 0; 3338 if (sm_conn->sm_connection_encrypted){ 3339 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3340 } else { 3341 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3342 } 3343 } 3344 sm_done_for_handle(sm_conn->sm_handle); 3345 break; 3346 } 3347 3348 if (!sm_conn->sm_connection_encrypted) break; 3349 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3350 3351 // continue pairing 3352 switch (sm_conn->sm_engine_state){ 3353 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3354 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3355 sm_done_for_handle(sm_conn->sm_handle); 3356 break; 3357 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3358 if (IS_RESPONDER(sm_conn->sm_role)){ 3359 // slave 3360 if (setup->sm_use_secure_connections){ 3361 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3362 } else { 3363 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 3364 } 3365 } else { 3366 // master 3367 if (sm_key_distribution_all_received(sm_conn)){ 3368 // skip receiving keys as there are none 3369 sm_key_distribution_handle_all_received(sm_conn); 3370 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); 3371 } else { 3372 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3373 } 3374 } 3375 break; 3376 default: 3377 break; 3378 } 3379 break; 3380 3381 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3382 con_handle = little_endian_read_16(packet, 3); 3383 sm_conn = sm_get_connection_for_handle(con_handle); 3384 if (!sm_conn) break; 3385 3386 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3387 log_info("event handler, state %u", sm_conn->sm_engine_state); 3388 // continue if part of initial pairing 3389 switch (sm_conn->sm_engine_state){ 3390 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3391 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3392 sm_done_for_handle(sm_conn->sm_handle); 3393 break; 3394 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3395 if (IS_RESPONDER(sm_conn->sm_role)){ 3396 // slave 3397 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); 3398 } else { 3399 // master 3400 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3401 } 3402 break; 3403 default: 3404 break; 3405 } 3406 break; 3407 3408 3409 case HCI_EVENT_DISCONNECTION_COMPLETE: 3410 con_handle = little_endian_read_16(packet, 3); 3411 sm_done_for_handle(con_handle); 3412 sm_conn = sm_get_connection_for_handle(con_handle); 3413 if (!sm_conn) break; 3414 3415 // delete stored bonding on disconnect with authentication failure in ph0 3416 if ((sm_conn->sm_role == 0u) 3417 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3418 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3419 le_device_db_remove(sm_conn->sm_le_db_index); 3420 } 3421 3422 // pairing failed, if it was ongoing 3423 switch (sm_conn->sm_engine_state){ 3424 case SM_GENERAL_IDLE: 3425 case SM_INITIATOR_CONNECTED: 3426 case SM_RESPONDER_IDLE: 3427 break; 3428 default: 3429 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3430 break; 3431 } 3432 3433 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3434 sm_conn->sm_handle = 0; 3435 break; 3436 3437 case HCI_EVENT_COMMAND_COMPLETE: 3438 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3439 // set local addr for le device db 3440 bd_addr_t addr; 3441 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3442 le_device_db_set_local_bd_addr(addr); 3443 } 3444 break; 3445 default: 3446 break; 3447 } 3448 break; 3449 default: 3450 break; 3451 } 3452 3453 sm_run(); 3454 } 3455 3456 static inline int sm_calc_actual_encryption_key_size(int other){ 3457 if (other < sm_min_encryption_key_size) return 0; 3458 if (other < sm_max_encryption_key_size) return other; 3459 return sm_max_encryption_key_size; 3460 } 3461 3462 3463 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3464 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3465 switch (method){ 3466 case JUST_WORKS: 3467 case NUMERIC_COMPARISON: 3468 return 1; 3469 default: 3470 return 0; 3471 } 3472 } 3473 // responder 3474 3475 static int sm_passkey_used(stk_generation_method_t method){ 3476 switch (method){ 3477 case PK_RESP_INPUT: 3478 return 1; 3479 default: 3480 return 0; 3481 } 3482 } 3483 3484 static int sm_passkey_entry(stk_generation_method_t method){ 3485 switch (method){ 3486 case PK_RESP_INPUT: 3487 case PK_INIT_INPUT: 3488 case PK_BOTH_INPUT: 3489 return 1; 3490 default: 3491 return 0; 3492 } 3493 } 3494 3495 #endif 3496 3497 /** 3498 * @return ok 3499 */ 3500 static int sm_validate_stk_generation_method(void){ 3501 // check if STK generation method is acceptable by client 3502 switch (setup->sm_stk_generation_method){ 3503 case JUST_WORKS: 3504 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 3505 case PK_RESP_INPUT: 3506 case PK_INIT_INPUT: 3507 case PK_BOTH_INPUT: 3508 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 3509 case OOB: 3510 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 3511 case NUMERIC_COMPARISON: 3512 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 3513 default: 3514 return 0; 3515 } 3516 } 3517 3518 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3519 3520 // size of complete sm_pdu used to validate input 3521 static const uint8_t sm_pdu_size[] = { 3522 0, // 0x00 invalid opcode 3523 7, // 0x01 pairing request 3524 7, // 0x02 pairing response 3525 17, // 0x03 pairing confirm 3526 17, // 0x04 pairing random 3527 2, // 0x05 pairing failed 3528 17, // 0x06 encryption information 3529 11, // 0x07 master identification 3530 17, // 0x08 identification information 3531 8, // 0x09 identify address information 3532 17, // 0x0a signing information 3533 2, // 0x0b security request 3534 65, // 0x0c pairing public key 3535 17, // 0x0d pairing dhk check 3536 2, // 0x0e keypress notification 3537 }; 3538 3539 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3540 sm_run(); 3541 } 3542 3543 if (packet_type != SM_DATA_PACKET) return; 3544 if (size == 0u) return; 3545 3546 uint8_t sm_pdu_code = packet[0]; 3547 3548 // validate pdu size 3549 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3550 if (sm_pdu_size[sm_pdu_code] != size) return; 3551 3552 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3553 if (!sm_conn) return; 3554 3555 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3556 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3557 sm_done_for_handle(con_handle); 3558 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3559 return; 3560 } 3561 3562 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3563 3564 int err; 3565 UNUSED(err); 3566 3567 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3568 uint8_t buffer[5]; 3569 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3570 buffer[1] = 3; 3571 little_endian_store_16(buffer, 2, con_handle); 3572 buffer[4] = packet[1]; 3573 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3574 return; 3575 } 3576 3577 switch (sm_conn->sm_engine_state){ 3578 3579 // a sm timeout requries a new physical connection 3580 case SM_GENERAL_TIMEOUT: 3581 return; 3582 3583 #ifdef ENABLE_LE_CENTRAL 3584 3585 // Initiator 3586 case SM_INITIATOR_CONNECTED: 3587 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3588 sm_pdu_received_in_wrong_state(sm_conn); 3589 break; 3590 } 3591 3592 // IRK complete? 3593 int have_ltk; 3594 uint8_t ltk[16]; 3595 switch (sm_conn->sm_irk_lookup_state){ 3596 case IRK_LOOKUP_FAILED: 3597 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3598 break; 3599 case IRK_LOOKUP_SUCCEEDED: 3600 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3601 have_ltk = !sm_is_null_key(ltk); 3602 log_info("central: security request - have_ltk %u", have_ltk); 3603 if (have_ltk){ 3604 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3605 } else { 3606 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3607 } 3608 break; 3609 default: 3610 break; 3611 } 3612 3613 // otherwise, store security request 3614 sm_conn->sm_security_request_received = 1; 3615 break; 3616 3617 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3618 // Core 5, Vol 3, Part H, 2.4.6: 3619 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3620 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3621 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3622 log_info("Ignoring Security Request"); 3623 break; 3624 } 3625 3626 // all other pdus are incorrect 3627 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3628 sm_pdu_received_in_wrong_state(sm_conn); 3629 break; 3630 } 3631 3632 // store pairing request 3633 (void)memcpy(&setup->sm_s_pres, packet, 3634 sizeof(sm_pairing_packet_t)); 3635 err = sm_stk_generation_init(sm_conn); 3636 3637 #ifdef ENABLE_TESTING_SUPPORT 3638 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3639 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3640 err = test_pairing_failure; 3641 } 3642 #endif 3643 3644 if (err){ 3645 setup->sm_pairing_failed_reason = err; 3646 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3647 break; 3648 } 3649 3650 // generate random number first, if we need to show passkey 3651 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3652 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); 3653 break; 3654 } 3655 3656 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3657 if (setup->sm_use_secure_connections){ 3658 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3659 if (setup->sm_stk_generation_method == JUST_WORKS){ 3660 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3661 sm_trigger_user_response(sm_conn); 3662 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3663 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3664 } 3665 } else { 3666 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3667 } 3668 break; 3669 } 3670 #endif 3671 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3672 sm_trigger_user_response(sm_conn); 3673 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3674 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3675 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); 3676 } 3677 break; 3678 3679 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3680 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3681 sm_pdu_received_in_wrong_state(sm_conn); 3682 break; 3683 } 3684 3685 // store s_confirm 3686 reverse_128(&packet[1], setup->sm_peer_confirm); 3687 3688 #ifdef ENABLE_TESTING_SUPPORT 3689 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3690 log_info("testing_support: reset confirm value"); 3691 memset(setup->sm_peer_confirm, 0, 16); 3692 } 3693 #endif 3694 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3695 break; 3696 3697 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3698 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3699 sm_pdu_received_in_wrong_state(sm_conn); 3700 break;; 3701 } 3702 3703 // received random value 3704 reverse_128(&packet[1], setup->sm_peer_random); 3705 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3706 break; 3707 #endif 3708 3709 #ifdef ENABLE_LE_PERIPHERAL 3710 // Responder 3711 case SM_RESPONDER_IDLE: 3712 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3713 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3714 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3715 sm_pdu_received_in_wrong_state(sm_conn); 3716 break;; 3717 } 3718 3719 // store pairing request 3720 (void)memcpy(&sm_conn->sm_m_preq, packet, 3721 sizeof(sm_pairing_packet_t)); 3722 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3723 break; 3724 #endif 3725 3726 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3727 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3728 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3729 sm_pdu_received_in_wrong_state(sm_conn); 3730 break; 3731 } 3732 3733 // store public key for DH Key calculation 3734 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3735 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3736 3737 // validate public key 3738 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3739 if (err){ 3740 log_error("sm: peer public key invalid %x", err); 3741 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3742 break; 3743 } 3744 3745 // start calculating dhkey 3746 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); 3747 3748 3749 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3750 if (IS_RESPONDER(sm_conn->sm_role)){ 3751 // responder 3752 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3753 } else { 3754 // initiator 3755 // stk generation method 3756 // passkey entry: notify app to show passkey or to request passkey 3757 switch (setup->sm_stk_generation_method){ 3758 case JUST_WORKS: 3759 case NUMERIC_COMPARISON: 3760 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3761 break; 3762 case PK_RESP_INPUT: 3763 sm_sc_start_calculating_local_confirm(sm_conn); 3764 break; 3765 case PK_INIT_INPUT: 3766 case PK_BOTH_INPUT: 3767 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3768 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3769 break; 3770 } 3771 sm_sc_start_calculating_local_confirm(sm_conn); 3772 break; 3773 case OOB: 3774 // generate Nx 3775 log_info("Generate Na"); 3776 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); 3777 break; 3778 } 3779 } 3780 break; 3781 3782 case SM_SC_W4_CONFIRMATION: 3783 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3784 sm_pdu_received_in_wrong_state(sm_conn); 3785 break; 3786 } 3787 // received confirm value 3788 reverse_128(&packet[1], setup->sm_peer_confirm); 3789 3790 #ifdef ENABLE_TESTING_SUPPORT 3791 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3792 log_info("testing_support: reset confirm value"); 3793 memset(setup->sm_peer_confirm, 0, 16); 3794 } 3795 #endif 3796 if (IS_RESPONDER(sm_conn->sm_role)){ 3797 // responder 3798 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3799 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3800 // still waiting for passkey 3801 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3802 break; 3803 } 3804 } 3805 sm_sc_start_calculating_local_confirm(sm_conn); 3806 } else { 3807 // initiator 3808 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3809 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); 3810 } else { 3811 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3812 } 3813 } 3814 break; 3815 3816 case SM_SC_W4_PAIRING_RANDOM: 3817 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3818 sm_pdu_received_in_wrong_state(sm_conn); 3819 break; 3820 } 3821 3822 // received random value 3823 reverse_128(&packet[1], setup->sm_peer_nonce); 3824 3825 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3826 // only check for JUST WORK/NC in initiator role OR passkey entry 3827 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 3828 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 3829 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 3830 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3831 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 3832 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3833 break; 3834 } 3835 3836 // OOB 3837 if (setup->sm_stk_generation_method == OOB){ 3838 3839 // setup local random, set to zero if remote did not receive our data 3840 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3841 if (IS_RESPONDER(sm_conn->sm_role)){ 3842 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 3843 log_info("Reset rb as A does not have OOB data"); 3844 memset(setup->sm_rb, 0, 16); 3845 } else { 3846 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3847 log_info("Use stored rb"); 3848 log_info_hexdump(setup->sm_rb, 16); 3849 } 3850 } else { 3851 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 3852 log_info("Reset ra as B does not have OOB data"); 3853 memset(setup->sm_ra, 0, 16); 3854 } else { 3855 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3856 log_info("Use stored ra"); 3857 log_info_hexdump(setup->sm_ra, 16); 3858 } 3859 } 3860 3861 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3862 if (setup->sm_have_oob_data){ 3863 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3864 break; 3865 } 3866 } 3867 3868 // TODO: we only get here for Responder role with JW/NC 3869 sm_sc_state_after_receiving_random(sm_conn); 3870 break; 3871 3872 case SM_SC_W2_CALCULATE_G2: 3873 case SM_SC_W4_CALCULATE_G2: 3874 case SM_SC_W4_CALCULATE_DHKEY: 3875 case SM_SC_W2_CALCULATE_F5_SALT: 3876 case SM_SC_W4_CALCULATE_F5_SALT: 3877 case SM_SC_W2_CALCULATE_F5_MACKEY: 3878 case SM_SC_W4_CALCULATE_F5_MACKEY: 3879 case SM_SC_W2_CALCULATE_F5_LTK: 3880 case SM_SC_W4_CALCULATE_F5_LTK: 3881 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3882 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3883 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3884 case SM_SC_W4_USER_RESPONSE: 3885 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3886 sm_pdu_received_in_wrong_state(sm_conn); 3887 break; 3888 } 3889 // store DHKey Check 3890 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3891 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3892 3893 // have we been only waiting for dhkey check command? 3894 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3895 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3896 } 3897 break; 3898 #endif 3899 3900 #ifdef ENABLE_LE_PERIPHERAL 3901 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3902 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3903 sm_pdu_received_in_wrong_state(sm_conn); 3904 break; 3905 } 3906 3907 // received confirm value 3908 reverse_128(&packet[1], setup->sm_peer_confirm); 3909 3910 #ifdef ENABLE_TESTING_SUPPORT 3911 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3912 log_info("testing_support: reset confirm value"); 3913 memset(setup->sm_peer_confirm, 0, 16); 3914 } 3915 #endif 3916 // notify client to hide shown passkey 3917 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3918 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3919 } 3920 3921 // handle user cancel pairing? 3922 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3923 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3924 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3925 break; 3926 } 3927 3928 // wait for user action? 3929 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3930 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3931 break; 3932 } 3933 3934 // calculate and send local_confirm 3935 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); 3936 break; 3937 3938 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3939 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3940 sm_pdu_received_in_wrong_state(sm_conn); 3941 break;; 3942 } 3943 3944 // received random value 3945 reverse_128(&packet[1], setup->sm_peer_random); 3946 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3947 break; 3948 #endif 3949 3950 case SM_PH3_RECEIVE_KEYS: 3951 switch(sm_pdu_code){ 3952 case SM_CODE_ENCRYPTION_INFORMATION: 3953 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3954 reverse_128(&packet[1], setup->sm_peer_ltk); 3955 break; 3956 3957 case SM_CODE_MASTER_IDENTIFICATION: 3958 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3959 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3960 reverse_64(&packet[3], setup->sm_peer_rand); 3961 break; 3962 3963 case SM_CODE_IDENTITY_INFORMATION: 3964 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3965 reverse_128(&packet[1], setup->sm_peer_irk); 3966 break; 3967 3968 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3969 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3970 setup->sm_peer_addr_type = packet[1]; 3971 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3972 break; 3973 3974 case SM_CODE_SIGNING_INFORMATION: 3975 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3976 reverse_128(&packet[1], setup->sm_peer_csrk); 3977 break; 3978 default: 3979 // Unexpected PDU 3980 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3981 break; 3982 } 3983 // done with key distribution? 3984 if (sm_key_distribution_all_received(sm_conn)){ 3985 3986 sm_key_distribution_handle_all_received(sm_conn); 3987 3988 if (IS_RESPONDER(sm_conn->sm_role)){ 3989 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3990 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3991 } else { 3992 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3993 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3994 sm_done_for_handle(sm_conn->sm_handle); 3995 } 3996 } else { 3997 if (setup->sm_use_secure_connections){ 3998 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3999 } else { 4000 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); 4001 } 4002 } 4003 } 4004 break; 4005 default: 4006 // Unexpected PDU 4007 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 4008 break; 4009 } 4010 4011 // try to send next pdu 4012 sm_trigger_run(); 4013 } 4014 4015 // Security Manager Client API 4016 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 4017 sm_get_oob_data = get_oob_data_callback; 4018 } 4019 4020 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)){ 4021 sm_get_sc_oob_data = get_sc_oob_data_callback; 4022 } 4023 4024 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4025 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4026 } 4027 4028 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4029 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4030 } 4031 4032 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4033 sm_min_encryption_key_size = min_size; 4034 sm_max_encryption_key_size = max_size; 4035 } 4036 4037 void sm_set_authentication_requirements(uint8_t auth_req){ 4038 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4039 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4040 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4041 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4042 } 4043 #endif 4044 sm_auth_req = auth_req; 4045 } 4046 4047 void sm_set_io_capabilities(io_capability_t io_capability){ 4048 sm_io_capabilities = io_capability; 4049 } 4050 4051 #ifdef ENABLE_LE_PERIPHERAL 4052 void sm_set_request_security(int enable){ 4053 sm_slave_request_security = enable; 4054 } 4055 #endif 4056 4057 void sm_set_er(sm_key_t er){ 4058 (void)memcpy(sm_persistent_er, er, 16); 4059 } 4060 4061 void sm_set_ir(sm_key_t ir){ 4062 (void)memcpy(sm_persistent_ir, ir, 16); 4063 } 4064 4065 // Testing support only 4066 void sm_test_set_irk(sm_key_t irk){ 4067 (void)memcpy(sm_persistent_irk, irk, 16); 4068 dkg_state = DKG_CALC_DHK; 4069 test_use_fixed_local_irk = true; 4070 } 4071 4072 void sm_test_use_fixed_local_csrk(void){ 4073 test_use_fixed_local_csrk = true; 4074 } 4075 4076 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4077 static void sm_ec_generated(void * arg){ 4078 UNUSED(arg); 4079 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4080 // trigger pairing if pending for ec key 4081 sm_trigger_run(); 4082 } 4083 static void sm_ec_generate_new_key(void){ 4084 log_info("sm: generate new ec key"); 4085 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4086 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4087 } 4088 #endif 4089 4090 #ifdef ENABLE_TESTING_SUPPORT 4091 void sm_test_set_pairing_failure(int reason){ 4092 test_pairing_failure = reason; 4093 } 4094 #endif 4095 4096 void sm_init(void){ 4097 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4098 sm_er_ir_set_default(); 4099 4100 // defaults 4101 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4102 | SM_STK_GENERATION_METHOD_OOB 4103 | SM_STK_GENERATION_METHOD_PASSKEY 4104 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4105 4106 sm_max_encryption_key_size = 16; 4107 sm_min_encryption_key_size = 7; 4108 4109 sm_fixed_passkey_in_display_role = 0xffffffff; 4110 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4111 4112 #ifdef USE_CMAC_ENGINE 4113 sm_cmac_active = 0; 4114 #endif 4115 dkg_state = DKG_W4_WORKING; 4116 rau_state = RAU_IDLE; 4117 sm_aes128_state = SM_AES128_IDLE; 4118 sm_address_resolution_test = -1; // no private address to resolve yet 4119 sm_address_resolution_ah_calculation_active = 0; 4120 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4121 sm_address_resolution_general_queue = NULL; 4122 4123 gap_random_adress_update_period = 15 * 60 * 1000L; 4124 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4125 4126 test_use_fixed_local_csrk = false; 4127 4128 btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); 4129 4130 // register for HCI Events from HCI 4131 hci_event_callback_registration.callback = &sm_event_packet_handler; 4132 hci_add_event_handler(&hci_event_callback_registration); 4133 4134 // 4135 btstack_crypto_init(); 4136 4137 // init le_device_db 4138 le_device_db_init(); 4139 4140 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4141 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4142 4143 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4144 sm_ec_generate_new_key(); 4145 #endif 4146 } 4147 4148 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4149 sm_fixed_passkey_in_display_role = passkey; 4150 } 4151 4152 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4153 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4154 } 4155 4156 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4157 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4158 if (!hci_con) return NULL; 4159 return &hci_con->sm_connection; 4160 } 4161 4162 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4163 switch (sm_conn->sm_engine_state){ 4164 case SM_GENERAL_IDLE: 4165 case SM_RESPONDER_IDLE: 4166 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4167 sm_trigger_run(); 4168 break; 4169 default: 4170 break; 4171 } 4172 } 4173 4174 /** 4175 * @brief Trigger Security Request 4176 */ 4177 void sm_send_security_request(hci_con_handle_t con_handle){ 4178 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4179 if (!sm_conn) return; 4180 sm_send_security_request_for_connection(sm_conn); 4181 } 4182 4183 // request pairing 4184 void sm_request_pairing(hci_con_handle_t con_handle){ 4185 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4186 if (!sm_conn) return; // wrong connection 4187 4188 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4189 if (IS_RESPONDER(sm_conn->sm_role)){ 4190 sm_send_security_request_for_connection(sm_conn); 4191 } else { 4192 // used as a trigger to start central/master/initiator security procedures 4193 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4194 uint8_t ltk[16]; 4195 bool have_ltk; 4196 switch (sm_conn->sm_irk_lookup_state){ 4197 case IRK_LOOKUP_SUCCEEDED: 4198 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4199 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4200 have_ltk = !sm_is_null_key(ltk); 4201 log_info("have ltk %u", have_ltk); 4202 if (have_ltk){ 4203 sm_conn->sm_pairing_requested = 1; 4204 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4205 break; 4206 } 4207 #endif 4208 /* fall through */ 4209 4210 case IRK_LOOKUP_FAILED: 4211 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4212 break; 4213 default: 4214 log_info("irk lookup pending"); 4215 sm_conn->sm_pairing_requested = 1; 4216 break; 4217 } 4218 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4219 sm_conn->sm_pairing_requested = 1; 4220 } 4221 } 4222 sm_trigger_run(); 4223 } 4224 4225 // called by client app on authorization request 4226 void sm_authorization_decline(hci_con_handle_t con_handle){ 4227 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4228 if (!sm_conn) return; // wrong connection 4229 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4230 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4231 } 4232 4233 void sm_authorization_grant(hci_con_handle_t con_handle){ 4234 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4235 if (!sm_conn) return; // wrong connection 4236 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4237 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4238 } 4239 4240 // GAP Bonding API 4241 4242 void sm_bonding_decline(hci_con_handle_t con_handle){ 4243 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4244 if (!sm_conn) return; // wrong connection 4245 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4246 log_info("decline, state %u", sm_conn->sm_engine_state); 4247 switch(sm_conn->sm_engine_state){ 4248 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4249 case SM_SC_W4_USER_RESPONSE: 4250 case SM_SC_W4_CONFIRMATION: 4251 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4252 #endif 4253 case SM_PH1_W4_USER_RESPONSE: 4254 switch (setup->sm_stk_generation_method){ 4255 case PK_RESP_INPUT: 4256 case PK_INIT_INPUT: 4257 case PK_BOTH_INPUT: 4258 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4259 break; 4260 case NUMERIC_COMPARISON: 4261 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4262 break; 4263 case JUST_WORKS: 4264 case OOB: 4265 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4266 break; 4267 } 4268 break; 4269 default: 4270 break; 4271 } 4272 sm_trigger_run(); 4273 } 4274 4275 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4276 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4277 if (!sm_conn) return; // wrong connection 4278 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4279 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4280 if (setup->sm_use_secure_connections){ 4281 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4282 } else { 4283 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); 4284 } 4285 } 4286 4287 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4288 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4289 sm_sc_prepare_dhkey_check(sm_conn); 4290 } 4291 #endif 4292 4293 sm_trigger_run(); 4294 } 4295 4296 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4297 // for now, it's the same 4298 sm_just_works_confirm(con_handle); 4299 } 4300 4301 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4302 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4303 if (!sm_conn) return; // wrong connection 4304 sm_reset_tk(); 4305 big_endian_store_32(setup->sm_tk, 12, passkey); 4306 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4307 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4308 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); 4309 } 4310 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4311 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4312 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4313 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4314 sm_sc_start_calculating_local_confirm(sm_conn); 4315 } 4316 #endif 4317 sm_trigger_run(); 4318 } 4319 4320 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4321 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4322 if (!sm_conn) return; // wrong connection 4323 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4324 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4325 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 4326 switch (action){ 4327 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4328 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4329 flags |= (1u << action); 4330 break; 4331 case SM_KEYPRESS_PASSKEY_CLEARED: 4332 // clear counter, keypress & erased flags + set passkey cleared 4333 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 4334 break; 4335 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4336 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4337 // erase actions queued 4338 num_actions--; 4339 if (num_actions == 0u){ 4340 // clear counter, keypress & erased flags 4341 flags &= 0x19u; 4342 } 4343 break; 4344 } 4345 num_actions++; 4346 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4347 break; 4348 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4349 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4350 // enter actions queued 4351 num_actions--; 4352 if (num_actions == 0u){ 4353 // clear counter, keypress & erased flags 4354 flags &= 0x19u; 4355 } 4356 break; 4357 } 4358 num_actions++; 4359 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4360 break; 4361 default: 4362 break; 4363 } 4364 setup->sm_keypress_notification = (num_actions << 5) | flags; 4365 sm_trigger_run(); 4366 } 4367 4368 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4369 static void sm_handle_random_result_oob(void * arg){ 4370 UNUSED(arg); 4371 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4372 sm_trigger_run(); 4373 } 4374 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4375 4376 static btstack_crypto_random_t sm_crypto_random_oob_request; 4377 4378 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4379 sm_sc_oob_callback = callback; 4380 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4381 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4382 return 0; 4383 } 4384 #endif 4385 4386 /** 4387 * @brief Get Identity Resolving state 4388 * @param con_handle 4389 * @return irk_lookup_state_t 4390 */ 4391 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4392 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4393 if (!sm_conn) return IRK_LOOKUP_IDLE; 4394 return sm_conn->sm_irk_lookup_state; 4395 } 4396 4397 /** 4398 * @brief Identify device in LE Device DB 4399 * @param handle 4400 * @returns index from le_device_db or -1 if not found/identified 4401 */ 4402 int sm_le_device_index(hci_con_handle_t con_handle ){ 4403 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4404 if (!sm_conn) return -1; 4405 return sm_conn->sm_le_db_index; 4406 } 4407 4408 static int gap_random_address_type_requires_updates(void){ 4409 switch (gap_random_adress_type){ 4410 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4411 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4412 return 0; 4413 default: 4414 return 1; 4415 } 4416 } 4417 4418 static uint8_t own_address_type(void){ 4419 switch (gap_random_adress_type){ 4420 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4421 return BD_ADDR_TYPE_LE_PUBLIC; 4422 default: 4423 return BD_ADDR_TYPE_LE_RANDOM; 4424 } 4425 } 4426 4427 // GAP LE API 4428 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4429 gap_random_address_update_stop(); 4430 gap_random_adress_type = random_address_type; 4431 hci_le_set_own_address_type(own_address_type()); 4432 if (!gap_random_address_type_requires_updates()) return; 4433 gap_random_address_update_start(); 4434 gap_random_address_trigger(); 4435 } 4436 4437 gap_random_address_type_t gap_random_address_get_mode(void){ 4438 return gap_random_adress_type; 4439 } 4440 4441 void gap_random_address_set_update_period(int period_ms){ 4442 gap_random_adress_update_period = period_ms; 4443 if (!gap_random_address_type_requires_updates()) return; 4444 gap_random_address_update_stop(); 4445 gap_random_address_update_start(); 4446 } 4447 4448 void gap_random_address_set(const bd_addr_t addr){ 4449 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4450 (void)memcpy(sm_random_address, addr, 6); 4451 rau_state = RAU_SET_ADDRESS; 4452 sm_trigger_run(); 4453 } 4454 4455 #ifdef ENABLE_LE_PERIPHERAL 4456 /* 4457 * @brief Set Advertisement Paramters 4458 * @param adv_int_min 4459 * @param adv_int_max 4460 * @param adv_type 4461 * @param direct_address_type 4462 * @param direct_address 4463 * @param channel_map 4464 * @param filter_policy 4465 * 4466 * @note own_address_type is used from gap_random_address_set_mode 4467 */ 4468 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4469 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4470 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4471 direct_address_typ, direct_address, channel_map, filter_policy); 4472 } 4473 #endif 4474 4475 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4476 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4477 // wrong connection 4478 if (!sm_conn) return 0; 4479 // already encrypted 4480 if (sm_conn->sm_connection_encrypted) return 0; 4481 // only central can re-encrypt 4482 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4483 // irk status? 4484 switch(sm_conn->sm_irk_lookup_state){ 4485 case IRK_LOOKUP_FAILED: 4486 // done, cannot setup encryption 4487 return 0; 4488 case IRK_LOOKUP_SUCCEEDED: 4489 break; 4490 default: 4491 // IR Lookup pending 4492 return 1; 4493 } 4494 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4495 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4496 } 4497 4498 void sm_set_secure_connections_only_mode(bool enable){ 4499 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4500 sm_sc_only_mode = enable; 4501 #else 4502 // SC Only mode not possible without support for SC 4503 btstack_assert(enable == false); 4504 #endif 4505 } 4506 4507 const uint8_t * gap_get_persistent_irk(void){ 4508 return sm_persistent_irk; 4509 } 4510