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 if (le_db_index < 0) { 1323 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1324 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION 1325 hci_load_le_device_db_entry_into_resolving_list(le_db_index); 1326 #endif 1327 } 1328 1329 if (le_db_index >= 0){ 1330 1331 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1332 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1333 1334 #ifdef ENABLE_LE_SIGNED_WRITE 1335 // store local CSRK 1336 setup->sm_le_device_index = le_db_index; 1337 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1338 log_info("sm: store local CSRK"); 1339 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1340 le_device_db_local_counter_set(le_db_index, 0); 1341 } 1342 1343 // store remote CSRK 1344 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1345 log_info("sm: store remote CSRK"); 1346 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1347 le_device_db_remote_counter_set(le_db_index, 0); 1348 } 1349 #endif 1350 // store encryption information for secure connections: LTK generated by ECDH 1351 if (setup->sm_use_secure_connections){ 1352 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1353 uint8_t zero_rand[8]; 1354 memset(zero_rand, 0, 8); 1355 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1356 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1357 } 1358 1359 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1360 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1361 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1362 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1363 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1364 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1365 1366 } 1367 } 1368 } else { 1369 log_info("Ignoring received keys, bonding not enabled"); 1370 } 1371 1372 // keep le_db_index 1373 sm_conn->sm_le_db_index = le_db_index; 1374 } 1375 1376 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1377 setup->sm_pairing_failed_reason = reason; 1378 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1379 } 1380 1381 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1382 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1383 } 1384 1385 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1386 1387 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1388 static int sm_passkey_used(stk_generation_method_t method); 1389 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1390 1391 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1392 if (setup->sm_stk_generation_method == OOB){ 1393 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1394 } else { 1395 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); 1396 } 1397 } 1398 1399 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1400 if (IS_RESPONDER(sm_conn->sm_role)){ 1401 // Responder 1402 if (setup->sm_stk_generation_method == OOB){ 1403 // generate Nb 1404 log_info("Generate Nb"); 1405 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); 1406 } else { 1407 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1408 } 1409 } else { 1410 // Initiator role 1411 switch (setup->sm_stk_generation_method){ 1412 case JUST_WORKS: 1413 sm_sc_prepare_dhkey_check(sm_conn); 1414 break; 1415 1416 case NUMERIC_COMPARISON: 1417 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1418 break; 1419 case PK_INIT_INPUT: 1420 case PK_RESP_INPUT: 1421 case PK_BOTH_INPUT: 1422 if (setup->sm_passkey_bit < 20u) { 1423 sm_sc_start_calculating_local_confirm(sm_conn); 1424 } else { 1425 sm_sc_prepare_dhkey_check(sm_conn); 1426 } 1427 break; 1428 case OOB: 1429 sm_sc_prepare_dhkey_check(sm_conn); 1430 break; 1431 } 1432 } 1433 } 1434 1435 static void sm_sc_cmac_done(uint8_t * hash){ 1436 log_info("sm_sc_cmac_done: "); 1437 log_info_hexdump(hash, 16); 1438 1439 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1440 sm_sc_oob_state = SM_SC_OOB_IDLE; 1441 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1442 return; 1443 } 1444 1445 sm_connection_t * sm_conn = sm_cmac_connection; 1446 sm_cmac_connection = NULL; 1447 #ifdef ENABLE_CLASSIC 1448 link_key_type_t link_key_type; 1449 #endif 1450 1451 switch (sm_conn->sm_engine_state){ 1452 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1453 (void)memcpy(setup->sm_local_confirm, hash, 16); 1454 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1455 break; 1456 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1457 // check 1458 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1459 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1460 break; 1461 } 1462 sm_sc_state_after_receiving_random(sm_conn); 1463 break; 1464 case SM_SC_W4_CALCULATE_G2: { 1465 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1466 big_endian_store_32(setup->sm_tk, 12, vab); 1467 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1468 sm_trigger_user_response(sm_conn); 1469 break; 1470 } 1471 case SM_SC_W4_CALCULATE_F5_SALT: 1472 (void)memcpy(setup->sm_t, hash, 16); 1473 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1474 break; 1475 case SM_SC_W4_CALCULATE_F5_MACKEY: 1476 (void)memcpy(setup->sm_mackey, hash, 16); 1477 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1478 break; 1479 case SM_SC_W4_CALCULATE_F5_LTK: 1480 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1481 // Errata Service Release to the Bluetooth Specification: ESR09 1482 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1483 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1484 (void)memcpy(setup->sm_ltk, hash, 16); 1485 (void)memcpy(setup->sm_local_ltk, hash, 16); 1486 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1487 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1488 break; 1489 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1490 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1491 if (IS_RESPONDER(sm_conn->sm_role)){ 1492 // responder 1493 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1494 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1495 } else { 1496 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1497 } 1498 } else { 1499 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1500 } 1501 break; 1502 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1503 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1504 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1505 break; 1506 } 1507 if (IS_RESPONDER(sm_conn->sm_role)){ 1508 // responder 1509 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1510 } else { 1511 // initiator 1512 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1513 } 1514 break; 1515 case SM_SC_W4_CALCULATE_H6_ILK: 1516 (void)memcpy(setup->sm_t, hash, 16); 1517 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1518 break; 1519 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1520 #ifdef ENABLE_CLASSIC 1521 reverse_128(hash, setup->sm_t); 1522 link_key_type = sm_conn->sm_connection_authenticated ? 1523 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1524 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1525 if (IS_RESPONDER(sm_conn->sm_role)){ 1526 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1527 } else { 1528 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1529 } 1530 #endif 1531 if (IS_RESPONDER(sm_conn->sm_role)){ 1532 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1533 } else { 1534 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1535 } 1536 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1537 sm_done_for_handle(sm_conn->sm_handle); 1538 break; 1539 default: 1540 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1541 break; 1542 } 1543 sm_trigger_run(); 1544 } 1545 1546 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){ 1547 const uint16_t message_len = 65; 1548 sm_cmac_connection = sm_conn; 1549 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1550 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1551 sm_cmac_sc_buffer[64] = z; 1552 log_info("f4 key"); 1553 log_info_hexdump(x, 16); 1554 log_info("f4 message"); 1555 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1556 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1557 } 1558 1559 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1560 static const uint8_t f5_length[] = { 0x01, 0x00}; 1561 1562 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1563 1564 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1565 1566 log_info("f5_calculate_salt"); 1567 // calculate salt for f5 1568 const uint16_t message_len = 32; 1569 sm_cmac_connection = sm_conn; 1570 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1571 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1572 } 1573 1574 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){ 1575 const uint16_t message_len = 53; 1576 sm_cmac_connection = sm_conn; 1577 1578 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1579 sm_cmac_sc_buffer[0] = 0; 1580 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1581 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1582 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1583 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1584 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1585 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1586 log_info("f5 key"); 1587 log_info_hexdump(t, 16); 1588 log_info("f5 message for MacKey"); 1589 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1590 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1591 } 1592 1593 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1594 sm_key56_t bd_addr_master, bd_addr_slave; 1595 bd_addr_master[0] = setup->sm_m_addr_type; 1596 bd_addr_slave[0] = setup->sm_s_addr_type; 1597 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1598 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1599 if (IS_RESPONDER(sm_conn->sm_role)){ 1600 // responder 1601 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1602 } else { 1603 // initiator 1604 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1605 } 1606 } 1607 1608 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1609 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1610 const uint16_t message_len = 53; 1611 sm_cmac_connection = sm_conn; 1612 sm_cmac_sc_buffer[0] = 1; 1613 // 1..52 setup before 1614 log_info("f5 key"); 1615 log_info_hexdump(t, 16); 1616 log_info("f5 message for LTK"); 1617 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1618 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1619 } 1620 1621 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1622 f5_ltk(sm_conn, setup->sm_t); 1623 } 1624 1625 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){ 1626 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1627 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1628 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1629 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1630 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1631 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1632 } 1633 1634 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1635 const uint16_t message_len = 65; 1636 sm_cmac_connection = sm_conn; 1637 log_info("f6 key"); 1638 log_info_hexdump(w, 16); 1639 log_info("f6 message"); 1640 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1641 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1642 } 1643 1644 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1645 // - U is 256 bits 1646 // - V is 256 bits 1647 // - X is 128 bits 1648 // - Y is 128 bits 1649 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){ 1650 const uint16_t message_len = 80; 1651 sm_cmac_connection = sm_conn; 1652 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1653 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1654 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1655 log_info("g2 key"); 1656 log_info_hexdump(x, 16); 1657 log_info("g2 message"); 1658 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1659 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1660 } 1661 1662 static void g2_calculate(sm_connection_t * sm_conn) { 1663 // calc Va if numeric comparison 1664 if (IS_RESPONDER(sm_conn->sm_role)){ 1665 // responder 1666 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1667 } else { 1668 // initiator 1669 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1670 } 1671 } 1672 1673 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1674 uint8_t z = 0; 1675 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1676 // some form of passkey 1677 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1678 z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); 1679 setup->sm_passkey_bit++; 1680 } 1681 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1682 } 1683 1684 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1685 // OOB 1686 if (setup->sm_stk_generation_method == OOB){ 1687 if (IS_RESPONDER(sm_conn->sm_role)){ 1688 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1689 } else { 1690 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1691 } 1692 return; 1693 } 1694 1695 uint8_t z = 0; 1696 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1697 // some form of passkey 1698 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1699 // sm_passkey_bit was increased before sending confirm value 1700 z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); 1701 } 1702 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1703 } 1704 1705 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1706 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1707 1708 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1709 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1710 return; 1711 } else { 1712 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1713 } 1714 } 1715 1716 static void sm_sc_dhkey_calculated(void * arg){ 1717 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1718 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1719 if (sm_conn == NULL) return; 1720 1721 log_info("dhkey"); 1722 log_info_hexdump(&setup->sm_dhkey[0], 32); 1723 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1724 // trigger next step 1725 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1726 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1727 } 1728 sm_trigger_run(); 1729 } 1730 1731 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1732 // calculate DHKCheck 1733 sm_key56_t bd_addr_master, bd_addr_slave; 1734 bd_addr_master[0] = setup->sm_m_addr_type; 1735 bd_addr_slave[0] = setup->sm_s_addr_type; 1736 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1737 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1738 uint8_t iocap_a[3]; 1739 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1740 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1741 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1742 uint8_t iocap_b[3]; 1743 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1744 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1745 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1746 if (IS_RESPONDER(sm_conn->sm_role)){ 1747 // responder 1748 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1749 f6_engine(sm_conn, setup->sm_mackey); 1750 } else { 1751 // initiator 1752 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1753 f6_engine(sm_conn, setup->sm_mackey); 1754 } 1755 } 1756 1757 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1758 // validate E = f6() 1759 sm_key56_t bd_addr_master, bd_addr_slave; 1760 bd_addr_master[0] = setup->sm_m_addr_type; 1761 bd_addr_slave[0] = setup->sm_s_addr_type; 1762 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1763 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1764 1765 uint8_t iocap_a[3]; 1766 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1767 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1768 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1769 uint8_t iocap_b[3]; 1770 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1771 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1772 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1773 if (IS_RESPONDER(sm_conn->sm_role)){ 1774 // responder 1775 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1776 f6_engine(sm_conn, setup->sm_mackey); 1777 } else { 1778 // initiator 1779 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1780 f6_engine(sm_conn, setup->sm_mackey); 1781 } 1782 } 1783 1784 1785 // 1786 // Link Key Conversion Function h6 1787 // 1788 // h6(W, keyID) = AES-CMACW(keyID) 1789 // - W is 128 bits 1790 // - keyID is 32 bits 1791 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1792 const uint16_t message_len = 4; 1793 sm_cmac_connection = sm_conn; 1794 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1795 log_info("h6 key"); 1796 log_info_hexdump(w, 16); 1797 log_info("h6 message"); 1798 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1799 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1800 } 1801 1802 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1803 // Errata Service Release to the Bluetooth Specification: ESR09 1804 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1805 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1806 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1807 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1808 } 1809 1810 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1811 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1812 } 1813 1814 #endif 1815 1816 // key management legacy connections: 1817 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1818 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1819 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1820 // - responder reconnects: responder uses LTK receveived from master 1821 1822 // key management secure connections: 1823 // - both devices store same LTK from ECDH key exchange. 1824 1825 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1826 static void sm_load_security_info(sm_connection_t * sm_connection){ 1827 int encryption_key_size; 1828 int authenticated; 1829 int authorized; 1830 int secure_connection; 1831 1832 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1833 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1834 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1835 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); 1836 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1837 sm_connection->sm_connection_authenticated = authenticated; 1838 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1839 sm_connection->sm_connection_sc = secure_connection; 1840 } 1841 #endif 1842 1843 #ifdef ENABLE_LE_PERIPHERAL 1844 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1845 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1846 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1847 // re-establish used key encryption size 1848 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1849 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; 1850 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1851 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; 1852 // Legacy paring -> not SC 1853 sm_connection->sm_connection_sc = 0; 1854 log_info("sm: received ltk request with key size %u, authenticated %u", 1855 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1856 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1857 sm_trigger_run(); 1858 } 1859 #endif 1860 1861 // distributed key generation 1862 static bool sm_run_dpkg(void){ 1863 switch (dkg_state){ 1864 case DKG_CALC_IRK: 1865 // already busy? 1866 if (sm_aes128_state == SM_AES128_IDLE) { 1867 log_info("DKG_CALC_IRK started"); 1868 // IRK = d1(IR, 1, 0) 1869 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1870 sm_aes128_state = SM_AES128_ACTIVE; 1871 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1872 return true; 1873 } 1874 break; 1875 case DKG_CALC_DHK: 1876 // already busy? 1877 if (sm_aes128_state == SM_AES128_IDLE) { 1878 log_info("DKG_CALC_DHK started"); 1879 // DHK = d1(IR, 3, 0) 1880 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1881 sm_aes128_state = SM_AES128_ACTIVE; 1882 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1883 return true; 1884 } 1885 break; 1886 default: 1887 break; 1888 } 1889 return false; 1890 } 1891 1892 // random address updates 1893 static bool sm_run_rau(void){ 1894 switch (rau_state){ 1895 case RAU_GET_RANDOM: 1896 rau_state = RAU_W4_RANDOM; 1897 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1898 return true; 1899 case RAU_GET_ENC: 1900 // already busy? 1901 if (sm_aes128_state == SM_AES128_IDLE) { 1902 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1903 sm_aes128_state = SM_AES128_ACTIVE; 1904 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1905 return true; 1906 } 1907 break; 1908 case RAU_SET_ADDRESS: 1909 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1910 rau_state = RAU_IDLE; 1911 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1912 return true; 1913 default: 1914 break; 1915 } 1916 return false; 1917 } 1918 1919 // CSRK Lookup 1920 static bool sm_run_csrk(void){ 1921 btstack_linked_list_iterator_t it; 1922 1923 // -- if csrk lookup ready, find connection that require csrk lookup 1924 if (sm_address_resolution_idle()){ 1925 hci_connections_get_iterator(&it); 1926 while(btstack_linked_list_iterator_has_next(&it)){ 1927 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1928 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1929 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1930 // and start lookup 1931 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); 1932 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1933 break; 1934 } 1935 } 1936 } 1937 1938 // -- if csrk lookup ready, resolved addresses for received addresses 1939 if (sm_address_resolution_idle()) { 1940 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1941 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1942 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1943 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1944 btstack_memory_sm_lookup_entry_free(entry); 1945 } 1946 } 1947 1948 // -- Continue with CSRK device lookup by public or resolvable private address 1949 if (!sm_address_resolution_idle()){ 1950 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1951 while (sm_address_resolution_test < le_device_db_max_count()){ 1952 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1953 bd_addr_t addr; 1954 sm_key_t irk; 1955 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1956 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1957 1958 // skip unused entries 1959 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1960 sm_address_resolution_test++; 1961 continue; 1962 } 1963 1964 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1965 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1966 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1967 break; 1968 } 1969 1970 // if connection type is public, it must be a different one 1971 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1972 sm_address_resolution_test++; 1973 continue; 1974 } 1975 1976 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1977 1978 log_info("LE Device Lookup: calculate AH"); 1979 log_info_key("IRK", irk); 1980 1981 (void)memcpy(sm_aes128_key, irk, 16); 1982 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1983 sm_address_resolution_ah_calculation_active = 1; 1984 sm_aes128_state = SM_AES128_ACTIVE; 1985 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1986 return true; 1987 } 1988 1989 if (sm_address_resolution_test >= le_device_db_max_count()){ 1990 log_info("LE Device Lookup: not found"); 1991 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1992 } 1993 } 1994 return false; 1995 } 1996 1997 // SC OOB 1998 static bool sm_run_oob(void){ 1999 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2000 switch (sm_sc_oob_state){ 2001 case SM_SC_OOB_W2_CALC_CONFIRM: 2002 if (!sm_cmac_ready()) break; 2003 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 2004 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 2005 return true; 2006 default: 2007 break; 2008 } 2009 #endif 2010 return false; 2011 } 2012 2013 // handle basic actions that don't requires the full context 2014 static bool sm_run_basic(void){ 2015 btstack_linked_list_iterator_t it; 2016 hci_connections_get_iterator(&it); 2017 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2018 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2019 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2020 switch(sm_connection->sm_engine_state){ 2021 // responder side 2022 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2023 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2024 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2025 return true; 2026 2027 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2028 case SM_SC_RECEIVED_LTK_REQUEST: 2029 switch (sm_connection->sm_irk_lookup_state){ 2030 case IRK_LOOKUP_FAILED: 2031 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2032 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2033 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2034 return true; 2035 default: 2036 break; 2037 } 2038 break; 2039 #endif 2040 default: 2041 break; 2042 } 2043 } 2044 return false; 2045 } 2046 2047 static void sm_run_activate_connection(void){ 2048 // Find connections that requires setup context and make active if no other is locked 2049 btstack_linked_list_iterator_t it; 2050 hci_connections_get_iterator(&it); 2051 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2052 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2053 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2054 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2055 int done = 1; 2056 int err; 2057 UNUSED(err); 2058 2059 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2060 // assert ec key is ready 2061 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2062 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2063 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2064 sm_ec_generate_new_key(); 2065 } 2066 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2067 continue; 2068 } 2069 } 2070 #endif 2071 2072 switch (sm_connection->sm_engine_state) { 2073 #ifdef ENABLE_LE_PERIPHERAL 2074 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2075 // send packet if possible, 2076 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2077 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2078 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2079 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2080 } else { 2081 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2082 } 2083 // don't lock sxetup context yet 2084 done = 0; 2085 break; 2086 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2087 sm_reset_setup(); 2088 sm_init_setup(sm_connection); 2089 // recover pairing request 2090 (void)memcpy(&setup->sm_m_preq, 2091 &sm_connection->sm_m_preq, 2092 sizeof(sm_pairing_packet_t)); 2093 err = sm_stk_generation_init(sm_connection); 2094 2095 #ifdef ENABLE_TESTING_SUPPORT 2096 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2097 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2098 err = test_pairing_failure; 2099 } 2100 #endif 2101 if (err){ 2102 setup->sm_pairing_failed_reason = err; 2103 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2104 break; 2105 } 2106 sm_timeout_start(sm_connection); 2107 // generate random number first, if we need to show passkey 2108 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2109 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); 2110 break; 2111 } 2112 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2113 break; 2114 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2115 sm_reset_setup(); 2116 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2117 break; 2118 2119 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2120 case SM_SC_RECEIVED_LTK_REQUEST: 2121 switch (sm_connection->sm_irk_lookup_state){ 2122 case IRK_LOOKUP_SUCCEEDED: 2123 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2124 // start using context by loading security info 2125 sm_reset_setup(); 2126 sm_load_security_info(sm_connection); 2127 if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2128 (void)memcpy(setup->sm_ltk, 2129 setup->sm_peer_ltk, 16); 2130 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2131 break; 2132 } 2133 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2134 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2135 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2136 // don't lock setup context yet 2137 return; 2138 default: 2139 // just wait until IRK lookup is completed 2140 // don't lock setup context yet 2141 done = 0; 2142 break; 2143 } 2144 break; 2145 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2146 #endif /* ENABLE_LE_PERIPHERAL */ 2147 2148 #ifdef ENABLE_LE_CENTRAL 2149 case SM_INITIATOR_PH0_HAS_LTK: 2150 sm_reset_setup(); 2151 sm_load_security_info(sm_connection); 2152 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2153 break; 2154 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2155 sm_reset_setup(); 2156 sm_init_setup(sm_connection); 2157 sm_timeout_start(sm_connection); 2158 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2159 break; 2160 #endif 2161 2162 default: 2163 done = 0; 2164 break; 2165 } 2166 if (done){ 2167 sm_active_connection_handle = sm_connection->sm_handle; 2168 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); 2169 } 2170 } 2171 } 2172 2173 static void sm_run(void){ 2174 2175 // assert that stack has already bootet 2176 if (hci_get_state() != HCI_STATE_WORKING) return; 2177 2178 // assert that we can send at least commands 2179 if (!hci_can_send_command_packet_now()) return; 2180 2181 // pause until IR/ER are ready 2182 if (sm_persistent_keys_random_active) return; 2183 2184 bool done; 2185 2186 // 2187 // non-connection related behaviour 2188 // 2189 2190 done = sm_run_dpkg(); 2191 if (done) return; 2192 2193 done = sm_run_rau(); 2194 if (done) return; 2195 2196 done = sm_run_csrk(); 2197 if (done) return; 2198 2199 done = sm_run_oob(); 2200 if (done) return; 2201 2202 // assert that we can send at least commands - cmd might have been sent by crypto engine 2203 if (!hci_can_send_command_packet_now()) return; 2204 2205 // handle basic actions that don't requires the full context 2206 done = sm_run_basic(); 2207 if (done) return; 2208 2209 // 2210 // active connection handling 2211 // -- use loop to handle next connection if lock on setup context is released 2212 2213 while (true) { 2214 2215 sm_run_activate_connection(); 2216 2217 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2218 2219 // 2220 // active connection handling 2221 // 2222 2223 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2224 if (!connection) { 2225 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2226 return; 2227 } 2228 2229 // assert that we could send a SM PDU - not needed for all of the following 2230 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2231 log_info("cannot send now, requesting can send now event"); 2232 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2233 return; 2234 } 2235 2236 // send keypress notifications 2237 if (setup->sm_keypress_notification){ 2238 int i; 2239 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 2240 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2241 uint8_t action = 0; 2242 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2243 if (flags & (1u<<i)){ 2244 int clear_flag = 1; 2245 switch (i){ 2246 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2247 case SM_KEYPRESS_PASSKEY_CLEARED: 2248 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2249 default: 2250 break; 2251 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2252 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2253 num_actions--; 2254 clear_flag = num_actions == 0u; 2255 break; 2256 } 2257 if (clear_flag){ 2258 flags &= ~(1<<i); 2259 } 2260 action = i; 2261 break; 2262 } 2263 } 2264 setup->sm_keypress_notification = (num_actions << 5) | flags; 2265 2266 // send keypress notification 2267 uint8_t buffer[2]; 2268 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2269 buffer[1] = action; 2270 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2271 2272 // try 2273 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2274 return; 2275 } 2276 2277 int key_distribution_flags; 2278 UNUSED(key_distribution_flags); 2279 2280 log_info("sm_run: state %u", connection->sm_engine_state); 2281 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2282 log_info("sm_run // cannot send"); 2283 } 2284 switch (connection->sm_engine_state){ 2285 2286 // general 2287 case SM_GENERAL_SEND_PAIRING_FAILED: { 2288 uint8_t buffer[2]; 2289 buffer[0] = SM_CODE_PAIRING_FAILED; 2290 buffer[1] = setup->sm_pairing_failed_reason; 2291 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2292 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2293 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2294 sm_done_for_handle(connection->sm_handle); 2295 break; 2296 } 2297 2298 // responding state 2299 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2300 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2301 if (!sm_cmac_ready()) break; 2302 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2303 sm_sc_calculate_local_confirm(connection); 2304 break; 2305 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2306 if (!sm_cmac_ready()) break; 2307 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2308 sm_sc_calculate_remote_confirm(connection); 2309 break; 2310 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2311 if (!sm_cmac_ready()) break; 2312 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2313 sm_sc_calculate_f6_for_dhkey_check(connection); 2314 break; 2315 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2316 if (!sm_cmac_ready()) break; 2317 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2318 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2319 break; 2320 case SM_SC_W2_CALCULATE_F5_SALT: 2321 if (!sm_cmac_ready()) break; 2322 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2323 f5_calculate_salt(connection); 2324 break; 2325 case SM_SC_W2_CALCULATE_F5_MACKEY: 2326 if (!sm_cmac_ready()) break; 2327 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2328 f5_calculate_mackey(connection); 2329 break; 2330 case SM_SC_W2_CALCULATE_F5_LTK: 2331 if (!sm_cmac_ready()) break; 2332 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2333 f5_calculate_ltk(connection); 2334 break; 2335 case SM_SC_W2_CALCULATE_G2: 2336 if (!sm_cmac_ready()) break; 2337 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2338 g2_calculate(connection); 2339 break; 2340 case SM_SC_W2_CALCULATE_H6_ILK: 2341 if (!sm_cmac_ready()) break; 2342 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2343 h6_calculate_ilk(connection); 2344 break; 2345 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2346 if (!sm_cmac_ready()) break; 2347 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2348 h6_calculate_br_edr_link_key(connection); 2349 break; 2350 #endif 2351 2352 #ifdef ENABLE_LE_CENTRAL 2353 // initiator side 2354 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2355 sm_key_t peer_ltk_flipped; 2356 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2357 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2358 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2359 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2360 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2361 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2362 return; 2363 } 2364 2365 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2366 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2367 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2368 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2369 sm_timeout_reset(connection); 2370 break; 2371 #endif 2372 2373 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2374 2375 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2376 int trigger_user_response = 0; 2377 int trigger_start_calculating_local_confirm = 0; 2378 uint8_t buffer[65]; 2379 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2380 // 2381 reverse_256(&ec_q[0], &buffer[1]); 2382 reverse_256(&ec_q[32], &buffer[33]); 2383 2384 #ifdef ENABLE_TESTING_SUPPORT 2385 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2386 log_info("testing_support: invalidating public key"); 2387 // flip single bit of public key coordinate 2388 buffer[1] ^= 1; 2389 } 2390 #endif 2391 2392 // stk generation method 2393 // passkey entry: notify app to show passkey or to request passkey 2394 switch (setup->sm_stk_generation_method){ 2395 case JUST_WORKS: 2396 case NUMERIC_COMPARISON: 2397 if (IS_RESPONDER(connection->sm_role)){ 2398 // responder 2399 trigger_start_calculating_local_confirm = 1; 2400 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2401 } else { 2402 // initiator 2403 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2404 } 2405 break; 2406 case PK_INIT_INPUT: 2407 case PK_RESP_INPUT: 2408 case PK_BOTH_INPUT: 2409 // use random TK for display 2410 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2411 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2412 setup->sm_passkey_bit = 0; 2413 2414 if (IS_RESPONDER(connection->sm_role)){ 2415 // responder 2416 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2417 } else { 2418 // initiator 2419 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2420 } 2421 trigger_user_response = 1; 2422 break; 2423 case OOB: 2424 if (IS_RESPONDER(connection->sm_role)){ 2425 // responder 2426 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2427 } else { 2428 // initiator 2429 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2430 } 2431 break; 2432 } 2433 2434 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2435 sm_timeout_reset(connection); 2436 2437 // trigger user response and calc confirm after sending pdu 2438 if (trigger_user_response){ 2439 sm_trigger_user_response(connection); 2440 } 2441 if (trigger_start_calculating_local_confirm){ 2442 sm_sc_start_calculating_local_confirm(connection); 2443 } 2444 break; 2445 } 2446 case SM_SC_SEND_CONFIRMATION: { 2447 uint8_t buffer[17]; 2448 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2449 reverse_128(setup->sm_local_confirm, &buffer[1]); 2450 if (IS_RESPONDER(connection->sm_role)){ 2451 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2452 } else { 2453 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2454 } 2455 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2456 sm_timeout_reset(connection); 2457 break; 2458 } 2459 case SM_SC_SEND_PAIRING_RANDOM: { 2460 uint8_t buffer[17]; 2461 buffer[0] = SM_CODE_PAIRING_RANDOM; 2462 reverse_128(setup->sm_local_nonce, &buffer[1]); 2463 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2464 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ 2465 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2466 if (IS_RESPONDER(connection->sm_role)){ 2467 // responder 2468 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2469 } else { 2470 // initiator 2471 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2472 } 2473 } else { 2474 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2475 if (IS_RESPONDER(connection->sm_role)){ 2476 // responder 2477 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2478 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2479 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2480 } else { 2481 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2482 sm_sc_prepare_dhkey_check(connection); 2483 } 2484 } else { 2485 // initiator 2486 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2487 } 2488 } 2489 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2490 sm_timeout_reset(connection); 2491 break; 2492 } 2493 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2494 uint8_t buffer[17]; 2495 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2496 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2497 2498 if (IS_RESPONDER(connection->sm_role)){ 2499 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2500 } else { 2501 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2502 } 2503 2504 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2505 sm_timeout_reset(connection); 2506 break; 2507 } 2508 2509 #endif 2510 2511 #ifdef ENABLE_LE_PERIPHERAL 2512 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2513 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2514 2515 // start with initiator key dist flags 2516 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2517 2518 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2519 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2520 if (setup->sm_use_secure_connections){ 2521 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2522 } 2523 #endif 2524 // setup in response 2525 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); 2526 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); 2527 2528 // update key distribution after ENC was dropped 2529 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2530 2531 if (setup->sm_use_secure_connections){ 2532 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2533 } else { 2534 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2535 } 2536 2537 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2538 sm_timeout_reset(connection); 2539 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2540 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2541 sm_trigger_user_response(connection); 2542 } 2543 return; 2544 #endif 2545 2546 case SM_PH2_SEND_PAIRING_RANDOM: { 2547 uint8_t buffer[17]; 2548 buffer[0] = SM_CODE_PAIRING_RANDOM; 2549 reverse_128(setup->sm_local_random, &buffer[1]); 2550 if (IS_RESPONDER(connection->sm_role)){ 2551 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2552 } else { 2553 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2554 } 2555 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2556 sm_timeout_reset(connection); 2557 break; 2558 } 2559 2560 case SM_PH2_C1_GET_ENC_A: 2561 // already busy? 2562 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2563 // calculate confirm using aes128 engine - step 1 2564 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); 2565 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2566 sm_aes128_state = SM_AES128_ACTIVE; 2567 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); 2568 break; 2569 2570 case SM_PH2_C1_GET_ENC_C: 2571 // already busy? 2572 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2573 // calculate m_confirm using aes128 engine - step 1 2574 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); 2575 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2576 sm_aes128_state = SM_AES128_ACTIVE; 2577 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); 2578 break; 2579 2580 case SM_PH2_CALC_STK: 2581 // already busy? 2582 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2583 // calculate STK 2584 if (IS_RESPONDER(connection->sm_role)){ 2585 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2586 } else { 2587 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2588 } 2589 connection->sm_engine_state = SM_PH2_W4_STK; 2590 sm_aes128_state = SM_AES128_ACTIVE; 2591 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); 2592 break; 2593 2594 case SM_PH3_Y_GET_ENC: 2595 // already busy? 2596 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2597 // PH3B2 - calculate Y from - enc 2598 2599 // dm helper (was sm_dm_r_prime) 2600 // r' = padding || r 2601 // r - 64 bit value 2602 memset(&sm_aes128_plaintext[0], 0, 8); 2603 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2604 2605 // Y = dm(DHK, Rand) 2606 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2607 sm_aes128_state = SM_AES128_ACTIVE; 2608 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); 2609 break; 2610 2611 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2612 uint8_t buffer[17]; 2613 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2614 reverse_128(setup->sm_local_confirm, &buffer[1]); 2615 if (IS_RESPONDER(connection->sm_role)){ 2616 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2617 } else { 2618 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2619 } 2620 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2621 sm_timeout_reset(connection); 2622 return; 2623 } 2624 #ifdef ENABLE_LE_PERIPHERAL 2625 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2626 sm_key_t stk_flipped; 2627 reverse_128(setup->sm_ltk, stk_flipped); 2628 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2629 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2630 return; 2631 } 2632 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2633 sm_key_t ltk_flipped; 2634 reverse_128(setup->sm_ltk, ltk_flipped); 2635 connection->sm_engine_state = SM_RESPONDER_IDLE; 2636 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2637 sm_done_for_handle(connection->sm_handle); 2638 return; 2639 } 2640 case SM_RESPONDER_PH4_Y_GET_ENC: 2641 // already busy? 2642 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2643 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2644 2645 // dm helper (was sm_dm_r_prime) 2646 // r' = padding || r 2647 // r - 64 bit value 2648 memset(&sm_aes128_plaintext[0], 0, 8); 2649 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2650 2651 // Y = dm(DHK, Rand) 2652 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2653 sm_aes128_state = SM_AES128_ACTIVE; 2654 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); 2655 return; 2656 #endif 2657 #ifdef ENABLE_LE_CENTRAL 2658 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2659 sm_key_t stk_flipped; 2660 reverse_128(setup->sm_ltk, stk_flipped); 2661 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2662 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2663 return; 2664 } 2665 #endif 2666 2667 case SM_PH3_DISTRIBUTE_KEYS: 2668 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2669 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2670 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2671 uint8_t buffer[17]; 2672 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2673 reverse_128(setup->sm_ltk, &buffer[1]); 2674 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2675 sm_timeout_reset(connection); 2676 return; 2677 } 2678 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2679 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2680 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2681 uint8_t buffer[11]; 2682 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2683 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2684 reverse_64(setup->sm_local_rand, &buffer[3]); 2685 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2686 sm_timeout_reset(connection); 2687 return; 2688 } 2689 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2690 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2691 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2692 uint8_t buffer[17]; 2693 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2694 reverse_128(sm_persistent_irk, &buffer[1]); 2695 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2696 sm_timeout_reset(connection); 2697 return; 2698 } 2699 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2700 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2701 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2702 bd_addr_t local_address; 2703 uint8_t buffer[8]; 2704 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2705 switch (gap_random_address_get_mode()){ 2706 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2707 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2708 // public or static random 2709 gap_le_get_own_address(&buffer[1], local_address); 2710 break; 2711 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2712 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2713 // fallback to public 2714 gap_local_bd_addr(local_address); 2715 buffer[1] = 0; 2716 break; 2717 } 2718 reverse_bd_addr(local_address, &buffer[2]); 2719 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2720 sm_timeout_reset(connection); 2721 return; 2722 } 2723 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2724 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2725 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2726 2727 #ifdef ENABLE_LE_SIGNED_WRITE 2728 // hack to reproduce test runs 2729 if (test_use_fixed_local_csrk){ 2730 memset(setup->sm_local_csrk, 0xcc, 16); 2731 } 2732 2733 // store local CSRK 2734 if (setup->sm_le_device_index >= 0){ 2735 log_info("sm: store local CSRK"); 2736 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2737 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2738 } 2739 #endif 2740 2741 uint8_t buffer[17]; 2742 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2743 reverse_128(setup->sm_local_csrk, &buffer[1]); 2744 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2745 sm_timeout_reset(connection); 2746 return; 2747 } 2748 2749 // keys are sent 2750 if (IS_RESPONDER(connection->sm_role)){ 2751 // slave -> receive master keys if any 2752 if (sm_key_distribution_all_received(connection)){ 2753 sm_key_distribution_handle_all_received(connection); 2754 connection->sm_engine_state = SM_RESPONDER_IDLE; 2755 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2756 sm_done_for_handle(connection->sm_handle); 2757 } else { 2758 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2759 } 2760 } else { 2761 sm_master_pairing_success(connection); 2762 } 2763 break; 2764 2765 default: 2766 break; 2767 } 2768 2769 // check again if active connection was released 2770 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2771 } 2772 } 2773 2774 // sm_aes128_state stays active 2775 static void sm_handle_encryption_result_enc_a(void *arg){ 2776 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2777 sm_aes128_state = SM_AES128_IDLE; 2778 2779 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2780 if (connection == NULL) return; 2781 2782 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2783 sm_aes128_state = SM_AES128_ACTIVE; 2784 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); 2785 } 2786 2787 static void sm_handle_encryption_result_enc_b(void *arg){ 2788 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2789 sm_aes128_state = SM_AES128_IDLE; 2790 2791 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2792 if (connection == NULL) return; 2793 2794 log_info_key("c1!", setup->sm_local_confirm); 2795 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2796 sm_trigger_run(); 2797 } 2798 2799 // sm_aes128_state stays active 2800 static void sm_handle_encryption_result_enc_c(void *arg){ 2801 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2802 sm_aes128_state = SM_AES128_IDLE; 2803 2804 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2805 if (connection == NULL) return; 2806 2807 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2808 sm_aes128_state = SM_AES128_ACTIVE; 2809 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); 2810 } 2811 2812 static void sm_handle_encryption_result_enc_d(void * arg){ 2813 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2814 sm_aes128_state = SM_AES128_IDLE; 2815 2816 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2817 if (connection == NULL) return; 2818 2819 log_info_key("c1!", sm_aes128_ciphertext); 2820 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2821 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2822 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2823 sm_trigger_run(); 2824 return; 2825 } 2826 if (IS_RESPONDER(connection->sm_role)){ 2827 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2828 sm_trigger_run(); 2829 } else { 2830 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2831 sm_aes128_state = SM_AES128_ACTIVE; 2832 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); 2833 } 2834 } 2835 2836 static void sm_handle_encryption_result_enc_stk(void *arg){ 2837 sm_aes128_state = SM_AES128_IDLE; 2838 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2839 2840 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2841 if (connection == NULL) return; 2842 2843 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2844 log_info_key("stk", setup->sm_ltk); 2845 if (IS_RESPONDER(connection->sm_role)){ 2846 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2847 } else { 2848 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2849 } 2850 sm_trigger_run(); 2851 } 2852 2853 // sm_aes128_state stays active 2854 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2855 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2856 sm_aes128_state = SM_AES128_IDLE; 2857 2858 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2859 if (connection == NULL) return; 2860 2861 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2862 log_info_hex16("y", setup->sm_local_y); 2863 // PH3B3 - calculate EDIV 2864 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2865 log_info_hex16("ediv", setup->sm_local_ediv); 2866 // PH3B4 - calculate LTK - enc 2867 // LTK = d1(ER, DIV, 0)) 2868 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2869 sm_aes128_state = SM_AES128_ACTIVE; 2870 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); 2871 } 2872 2873 #ifdef ENABLE_LE_PERIPHERAL 2874 // sm_aes128_state stays active 2875 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2876 sm_aes128_state = SM_AES128_IDLE; 2877 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2878 2879 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2880 if (connection == NULL) return; 2881 2882 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2883 log_info_hex16("y", setup->sm_local_y); 2884 2885 // PH3B3 - calculate DIV 2886 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2887 log_info_hex16("ediv", setup->sm_local_ediv); 2888 // PH3B4 - calculate LTK - enc 2889 // LTK = d1(ER, DIV, 0)) 2890 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2891 sm_aes128_state = SM_AES128_ACTIVE; 2892 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph4_ltk, (void *)(uintptr_t) connection->sm_handle); 2893 } 2894 #endif 2895 2896 // sm_aes128_state stays active 2897 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2898 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2899 sm_aes128_state = SM_AES128_IDLE; 2900 2901 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2902 if (connection == NULL) return; 2903 2904 log_info_key("ltk", setup->sm_ltk); 2905 // calc CSRK next 2906 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2907 sm_aes128_state = SM_AES128_ACTIVE; 2908 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); 2909 } 2910 2911 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2912 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2913 sm_aes128_state = SM_AES128_IDLE; 2914 2915 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2916 if (connection == NULL) return; 2917 2918 sm_aes128_state = SM_AES128_IDLE; 2919 log_info_key("csrk", setup->sm_local_csrk); 2920 if (setup->sm_key_distribution_send_set){ 2921 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2922 } else { 2923 // no keys to send, just continue 2924 if (IS_RESPONDER(connection->sm_role)){ 2925 // slave -> receive master keys 2926 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2927 } else { 2928 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2929 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2930 } else { 2931 sm_master_pairing_success(connection); 2932 } 2933 } 2934 } 2935 sm_trigger_run(); 2936 } 2937 2938 #ifdef ENABLE_LE_PERIPHERAL 2939 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2940 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2941 sm_aes128_state = SM_AES128_IDLE; 2942 2943 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2944 if (connection == NULL) return; 2945 2946 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2947 log_info_key("ltk", setup->sm_ltk); 2948 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2949 sm_trigger_run(); 2950 } 2951 #endif 2952 2953 static void sm_handle_encryption_result_address_resolution(void *arg){ 2954 UNUSED(arg); 2955 sm_aes128_state = SM_AES128_IDLE; 2956 2957 sm_address_resolution_ah_calculation_active = 0; 2958 // compare calulated address against connecting device 2959 uint8_t * hash = &sm_aes128_ciphertext[13]; 2960 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2961 log_info("LE Device Lookup: matched resolvable private address"); 2962 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2963 sm_trigger_run(); 2964 return; 2965 } 2966 // no match, try next 2967 sm_address_resolution_test++; 2968 sm_trigger_run(); 2969 } 2970 2971 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2972 UNUSED(arg); 2973 sm_aes128_state = SM_AES128_IDLE; 2974 2975 log_info_key("irk", sm_persistent_irk); 2976 dkg_state = DKG_CALC_DHK; 2977 sm_trigger_run(); 2978 } 2979 2980 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2981 UNUSED(arg); 2982 sm_aes128_state = SM_AES128_IDLE; 2983 2984 log_info_key("dhk", sm_persistent_dhk); 2985 dkg_state = DKG_READY; 2986 sm_trigger_run(); 2987 } 2988 2989 static void sm_handle_encryption_result_rau(void *arg){ 2990 UNUSED(arg); 2991 sm_aes128_state = SM_AES128_IDLE; 2992 2993 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2994 rau_state = RAU_SET_ADDRESS; 2995 sm_trigger_run(); 2996 } 2997 2998 static void sm_handle_random_result_rau(void * arg){ 2999 UNUSED(arg); 3000 // non-resolvable vs. resolvable 3001 switch (gap_random_adress_type){ 3002 case GAP_RANDOM_ADDRESS_RESOLVABLE: 3003 // resolvable: use random as prand and calc address hash 3004 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 3005 sm_random_address[0u] &= 0x3fu; 3006 sm_random_address[0u] |= 0x40u; 3007 rau_state = RAU_GET_ENC; 3008 break; 3009 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 3010 default: 3011 // "The two most significant bits of the address shall be equal to ‘0’"" 3012 sm_random_address[0u] &= 0x3fu; 3013 rau_state = RAU_SET_ADDRESS; 3014 break; 3015 } 3016 sm_trigger_run(); 3017 } 3018 3019 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3020 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 3021 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3022 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3023 if (connection == NULL) return; 3024 3025 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3026 sm_trigger_run(); 3027 } 3028 3029 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 3030 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3031 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3032 if (connection == NULL) return; 3033 3034 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3035 sm_trigger_run(); 3036 } 3037 #endif 3038 3039 static void sm_handle_random_result_ph2_random(void * arg){ 3040 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3041 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3042 if (connection == NULL) return; 3043 3044 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3045 sm_trigger_run(); 3046 } 3047 3048 static void sm_handle_random_result_ph2_tk(void * arg){ 3049 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3050 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3051 if (connection == NULL) return; 3052 3053 sm_reset_tk(); 3054 uint32_t tk; 3055 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3056 // map random to 0-999999 without speding much cycles on a modulus operation 3057 tk = little_endian_read_32(sm_random_data,0); 3058 tk = tk & 0xfffff; // 1048575 3059 if (tk >= 999999u){ 3060 tk = tk - 999999u; 3061 } 3062 } else { 3063 // override with pre-defined passkey 3064 tk = sm_fixed_passkey_in_display_role; 3065 } 3066 big_endian_store_32(setup->sm_tk, 12, tk); 3067 if (IS_RESPONDER(connection->sm_role)){ 3068 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3069 } else { 3070 if (setup->sm_use_secure_connections){ 3071 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3072 } else { 3073 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3074 sm_trigger_user_response(connection); 3075 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3076 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3077 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); 3078 } 3079 } 3080 } 3081 sm_trigger_run(); 3082 } 3083 3084 static void sm_handle_random_result_ph3_div(void * arg){ 3085 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3086 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3087 if (connection == NULL) return; 3088 3089 // use 16 bit from random value as div 3090 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3091 log_info_hex16("div", setup->sm_local_div); 3092 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3093 sm_trigger_run(); 3094 } 3095 3096 static void sm_handle_random_result_ph3_random(void * arg){ 3097 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3098 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3099 if (connection == NULL) return; 3100 3101 reverse_64(sm_random_data, setup->sm_local_rand); 3102 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3103 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); 3104 // no db for authenticated flag hack: store flag in bit 4 of LSB 3105 setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); 3106 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3107 } 3108 static void sm_validate_er_ir(void){ 3109 // warn about default ER/IR 3110 int warning = 0; 3111 if (sm_ir_is_default()){ 3112 warning = 1; 3113 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3114 } 3115 if (sm_er_is_default()){ 3116 warning = 1; 3117 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3118 } 3119 if (warning) { 3120 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3121 } 3122 } 3123 3124 static void sm_handle_random_result_ir(void *arg){ 3125 sm_persistent_keys_random_active = 0; 3126 if (arg){ 3127 // key generated, store in tlv 3128 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3129 log_info("Generated IR key. Store in TLV status: %d", status); 3130 } 3131 log_info_key("IR", sm_persistent_ir); 3132 dkg_state = DKG_CALC_IRK; 3133 3134 if (test_use_fixed_local_irk){ 3135 log_info_key("IRK", sm_persistent_irk); 3136 dkg_state = DKG_CALC_DHK; 3137 } 3138 3139 sm_trigger_run(); 3140 } 3141 3142 static void sm_handle_random_result_er(void *arg){ 3143 sm_persistent_keys_random_active = 0; 3144 if (arg){ 3145 // key generated, store in tlv 3146 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3147 log_info("Generated ER key. Store in TLV status: %d", status); 3148 } 3149 log_info_key("ER", sm_persistent_er); 3150 3151 // try load ir 3152 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); 3153 if (key_size == 16){ 3154 // ok, let's continue 3155 log_info("IR from TLV"); 3156 sm_handle_random_result_ir( NULL ); 3157 } else { 3158 // invalid, generate new random one 3159 sm_persistent_keys_random_active = 1; 3160 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3161 } 3162 } 3163 3164 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3165 3166 UNUSED(channel); // ok: there is no channel 3167 UNUSED(size); // ok: fixed format HCI events 3168 3169 sm_connection_t * sm_conn; 3170 hci_con_handle_t con_handle; 3171 3172 switch (packet_type) { 3173 3174 case HCI_EVENT_PACKET: 3175 switch (hci_event_packet_get_type(packet)) { 3176 3177 case BTSTACK_EVENT_STATE: 3178 // bt stack activated, get started 3179 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3180 log_info("HCI Working!"); 3181 3182 // setup IR/ER with TLV 3183 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3184 if (sm_tlv_impl){ 3185 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); 3186 if (key_size == 16){ 3187 // ok, let's continue 3188 log_info("ER from TLV"); 3189 sm_handle_random_result_er( NULL ); 3190 } else { 3191 // invalid, generate random one 3192 sm_persistent_keys_random_active = 1; 3193 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3194 } 3195 } else { 3196 sm_validate_er_ir(); 3197 dkg_state = DKG_CALC_IRK; 3198 3199 if (test_use_fixed_local_irk){ 3200 log_info_key("IRK", sm_persistent_irk); 3201 dkg_state = DKG_CALC_DHK; 3202 } 3203 } 3204 3205 // restart random address updates after power cycle 3206 gap_random_address_set_mode(gap_random_adress_type); 3207 } 3208 break; 3209 3210 case HCI_EVENT_LE_META: 3211 switch (packet[2]) { 3212 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3213 3214 log_info("sm: connected"); 3215 3216 if (packet[3]) return; // connection failed 3217 3218 con_handle = little_endian_read_16(packet, 4); 3219 sm_conn = sm_get_connection_for_handle(con_handle); 3220 if (!sm_conn) break; 3221 3222 sm_conn->sm_handle = con_handle; 3223 sm_conn->sm_role = packet[6]; 3224 sm_conn->sm_peer_addr_type = packet[7]; 3225 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3226 3227 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3228 3229 // reset security properties 3230 sm_conn->sm_connection_encrypted = 0; 3231 sm_conn->sm_connection_authenticated = 0; 3232 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3233 sm_conn->sm_le_db_index = -1; 3234 3235 // prepare CSRK lookup (does not involve setup) 3236 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3237 3238 // just connected -> everything else happens in sm_run() 3239 if (IS_RESPONDER(sm_conn->sm_role)){ 3240 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3241 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3242 if (sm_slave_request_security) { 3243 // request security if requested by app 3244 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3245 } else { 3246 // otherwise, wait for pairing request 3247 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3248 } 3249 } 3250 break; 3251 } else { 3252 // master 3253 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3254 } 3255 break; 3256 3257 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3258 con_handle = little_endian_read_16(packet, 3); 3259 sm_conn = sm_get_connection_for_handle(con_handle); 3260 if (!sm_conn) break; 3261 3262 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3263 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3264 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3265 break; 3266 } 3267 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3268 // PH2 SEND LTK as we need to exchange keys in PH3 3269 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3270 break; 3271 } 3272 3273 // store rand and ediv 3274 reverse_64(&packet[5], sm_conn->sm_local_rand); 3275 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3276 3277 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3278 // potentially stored LTK is from the master 3279 if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3280 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3281 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3282 break; 3283 } 3284 // additionally check if remote is in LE Device DB if requested 3285 switch(sm_conn->sm_irk_lookup_state){ 3286 case IRK_LOOKUP_FAILED: 3287 log_info("LTK Request: device not in device db"); 3288 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3289 break; 3290 case IRK_LOOKUP_SUCCEEDED: 3291 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3292 break; 3293 default: 3294 // wait for irk look doen 3295 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3296 break; 3297 } 3298 break; 3299 } 3300 3301 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3302 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3303 #else 3304 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3305 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3306 #endif 3307 break; 3308 3309 default: 3310 break; 3311 } 3312 break; 3313 3314 case HCI_EVENT_ENCRYPTION_CHANGE: 3315 con_handle = little_endian_read_16(packet, 3); 3316 sm_conn = sm_get_connection_for_handle(con_handle); 3317 if (!sm_conn) break; 3318 3319 sm_conn->sm_connection_encrypted = packet[5]; 3320 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3321 sm_conn->sm_actual_encryption_key_size); 3322 log_info("event handler, state %u", sm_conn->sm_engine_state); 3323 3324 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3325 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3326 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3327 // notify client, if pairing was requested before 3328 if (sm_conn->sm_pairing_requested){ 3329 sm_conn->sm_pairing_requested = 0; 3330 if (sm_conn->sm_connection_encrypted){ 3331 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3332 } else { 3333 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3334 } 3335 } 3336 sm_done_for_handle(sm_conn->sm_handle); 3337 break; 3338 } 3339 3340 if (!sm_conn->sm_connection_encrypted) break; 3341 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3342 3343 // continue pairing 3344 switch (sm_conn->sm_engine_state){ 3345 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3346 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3347 sm_done_for_handle(sm_conn->sm_handle); 3348 break; 3349 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3350 if (IS_RESPONDER(sm_conn->sm_role)){ 3351 // slave 3352 if (setup->sm_use_secure_connections){ 3353 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3354 } else { 3355 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); 3356 } 3357 } else { 3358 // master 3359 if (sm_key_distribution_all_received(sm_conn)){ 3360 // skip receiving keys as there are none 3361 sm_key_distribution_handle_all_received(sm_conn); 3362 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); 3363 } else { 3364 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3365 } 3366 } 3367 break; 3368 default: 3369 break; 3370 } 3371 break; 3372 3373 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3374 con_handle = little_endian_read_16(packet, 3); 3375 sm_conn = sm_get_connection_for_handle(con_handle); 3376 if (!sm_conn) break; 3377 3378 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3379 log_info("event handler, state %u", sm_conn->sm_engine_state); 3380 // continue if part of initial pairing 3381 switch (sm_conn->sm_engine_state){ 3382 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3383 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3384 sm_done_for_handle(sm_conn->sm_handle); 3385 break; 3386 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3387 if (IS_RESPONDER(sm_conn->sm_role)){ 3388 // slave 3389 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); 3390 } else { 3391 // master 3392 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3393 } 3394 break; 3395 default: 3396 break; 3397 } 3398 break; 3399 3400 3401 case HCI_EVENT_DISCONNECTION_COMPLETE: 3402 con_handle = little_endian_read_16(packet, 3); 3403 sm_done_for_handle(con_handle); 3404 sm_conn = sm_get_connection_for_handle(con_handle); 3405 if (!sm_conn) break; 3406 3407 // delete stored bonding on disconnect with authentication failure in ph0 3408 if ((sm_conn->sm_role == 0u) 3409 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3410 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3411 le_device_db_remove(sm_conn->sm_le_db_index); 3412 } 3413 3414 // pairing failed, if it was ongoing 3415 switch (sm_conn->sm_engine_state){ 3416 case SM_GENERAL_IDLE: 3417 case SM_INITIATOR_CONNECTED: 3418 case SM_RESPONDER_IDLE: 3419 break; 3420 default: 3421 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3422 break; 3423 } 3424 3425 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3426 sm_conn->sm_handle = 0; 3427 break; 3428 3429 case HCI_EVENT_COMMAND_COMPLETE: 3430 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3431 // set local addr for le device db 3432 bd_addr_t addr; 3433 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3434 le_device_db_set_local_bd_addr(addr); 3435 } 3436 break; 3437 default: 3438 break; 3439 } 3440 break; 3441 default: 3442 break; 3443 } 3444 3445 sm_run(); 3446 } 3447 3448 static inline int sm_calc_actual_encryption_key_size(int other){ 3449 if (other < sm_min_encryption_key_size) return 0; 3450 if (other < sm_max_encryption_key_size) return other; 3451 return sm_max_encryption_key_size; 3452 } 3453 3454 3455 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3456 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3457 switch (method){ 3458 case JUST_WORKS: 3459 case NUMERIC_COMPARISON: 3460 return 1; 3461 default: 3462 return 0; 3463 } 3464 } 3465 // responder 3466 3467 static int sm_passkey_used(stk_generation_method_t method){ 3468 switch (method){ 3469 case PK_RESP_INPUT: 3470 return 1; 3471 default: 3472 return 0; 3473 } 3474 } 3475 3476 static int sm_passkey_entry(stk_generation_method_t method){ 3477 switch (method){ 3478 case PK_RESP_INPUT: 3479 case PK_INIT_INPUT: 3480 case PK_BOTH_INPUT: 3481 return 1; 3482 default: 3483 return 0; 3484 } 3485 } 3486 3487 #endif 3488 3489 /** 3490 * @return ok 3491 */ 3492 static int sm_validate_stk_generation_method(void){ 3493 // check if STK generation method is acceptable by client 3494 switch (setup->sm_stk_generation_method){ 3495 case JUST_WORKS: 3496 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; 3497 case PK_RESP_INPUT: 3498 case PK_INIT_INPUT: 3499 case PK_BOTH_INPUT: 3500 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; 3501 case OOB: 3502 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; 3503 case NUMERIC_COMPARISON: 3504 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; 3505 default: 3506 return 0; 3507 } 3508 } 3509 3510 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3511 3512 // size of complete sm_pdu used to validate input 3513 static const uint8_t sm_pdu_size[] = { 3514 0, // 0x00 invalid opcode 3515 7, // 0x01 pairing request 3516 7, // 0x02 pairing response 3517 17, // 0x03 pairing confirm 3518 17, // 0x04 pairing random 3519 2, // 0x05 pairing failed 3520 17, // 0x06 encryption information 3521 11, // 0x07 master identification 3522 17, // 0x08 identification information 3523 8, // 0x09 identify address information 3524 17, // 0x0a signing information 3525 2, // 0x0b security request 3526 65, // 0x0c pairing public key 3527 17, // 0x0d pairing dhk check 3528 2, // 0x0e keypress notification 3529 }; 3530 3531 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3532 sm_run(); 3533 } 3534 3535 if (packet_type != SM_DATA_PACKET) return; 3536 if (size == 0u) return; 3537 3538 uint8_t sm_pdu_code = packet[0]; 3539 3540 // validate pdu size 3541 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3542 if (sm_pdu_size[sm_pdu_code] != size) return; 3543 3544 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3545 if (!sm_conn) return; 3546 3547 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3548 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3549 sm_done_for_handle(con_handle); 3550 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3551 return; 3552 } 3553 3554 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3555 3556 int err; 3557 UNUSED(err); 3558 3559 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3560 uint8_t buffer[5]; 3561 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3562 buffer[1] = 3; 3563 little_endian_store_16(buffer, 2, con_handle); 3564 buffer[4] = packet[1]; 3565 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3566 return; 3567 } 3568 3569 switch (sm_conn->sm_engine_state){ 3570 3571 // a sm timeout requries a new physical connection 3572 case SM_GENERAL_TIMEOUT: 3573 return; 3574 3575 #ifdef ENABLE_LE_CENTRAL 3576 3577 // Initiator 3578 case SM_INITIATOR_CONNECTED: 3579 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3580 sm_pdu_received_in_wrong_state(sm_conn); 3581 break; 3582 } 3583 3584 // IRK complete? 3585 int have_ltk; 3586 uint8_t ltk[16]; 3587 switch (sm_conn->sm_irk_lookup_state){ 3588 case IRK_LOOKUP_FAILED: 3589 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3590 break; 3591 case IRK_LOOKUP_SUCCEEDED: 3592 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3593 have_ltk = !sm_is_null_key(ltk); 3594 log_info("central: security request - have_ltk %u", have_ltk); 3595 if (have_ltk){ 3596 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3597 } else { 3598 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3599 } 3600 break; 3601 default: 3602 break; 3603 } 3604 3605 // otherwise, store security request 3606 sm_conn->sm_security_request_received = 1; 3607 break; 3608 3609 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3610 // Core 5, Vol 3, Part H, 2.4.6: 3611 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3612 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3613 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3614 log_info("Ignoring Security Request"); 3615 break; 3616 } 3617 3618 // all other pdus are incorrect 3619 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3620 sm_pdu_received_in_wrong_state(sm_conn); 3621 break; 3622 } 3623 3624 // store pairing request 3625 (void)memcpy(&setup->sm_s_pres, packet, 3626 sizeof(sm_pairing_packet_t)); 3627 err = sm_stk_generation_init(sm_conn); 3628 3629 #ifdef ENABLE_TESTING_SUPPORT 3630 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3631 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3632 err = test_pairing_failure; 3633 } 3634 #endif 3635 3636 if (err){ 3637 setup->sm_pairing_failed_reason = err; 3638 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3639 break; 3640 } 3641 3642 // generate random number first, if we need to show passkey 3643 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3644 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); 3645 break; 3646 } 3647 3648 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3649 if (setup->sm_use_secure_connections){ 3650 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3651 if (setup->sm_stk_generation_method == JUST_WORKS){ 3652 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3653 sm_trigger_user_response(sm_conn); 3654 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3655 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3656 } 3657 } else { 3658 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3659 } 3660 break; 3661 } 3662 #endif 3663 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3664 sm_trigger_user_response(sm_conn); 3665 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3666 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3667 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); 3668 } 3669 break; 3670 3671 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3672 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3673 sm_pdu_received_in_wrong_state(sm_conn); 3674 break; 3675 } 3676 3677 // store s_confirm 3678 reverse_128(&packet[1], setup->sm_peer_confirm); 3679 3680 #ifdef ENABLE_TESTING_SUPPORT 3681 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3682 log_info("testing_support: reset confirm value"); 3683 memset(setup->sm_peer_confirm, 0, 16); 3684 } 3685 #endif 3686 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3687 break; 3688 3689 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3690 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3691 sm_pdu_received_in_wrong_state(sm_conn); 3692 break;; 3693 } 3694 3695 // received random value 3696 reverse_128(&packet[1], setup->sm_peer_random); 3697 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3698 break; 3699 #endif 3700 3701 #ifdef ENABLE_LE_PERIPHERAL 3702 // Responder 3703 case SM_RESPONDER_IDLE: 3704 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3705 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3706 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3707 sm_pdu_received_in_wrong_state(sm_conn); 3708 break;; 3709 } 3710 3711 // store pairing request 3712 (void)memcpy(&sm_conn->sm_m_preq, packet, 3713 sizeof(sm_pairing_packet_t)); 3714 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3715 break; 3716 #endif 3717 3718 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3719 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3720 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3721 sm_pdu_received_in_wrong_state(sm_conn); 3722 break; 3723 } 3724 3725 // store public key for DH Key calculation 3726 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3727 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3728 3729 // validate public key 3730 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3731 if (err){ 3732 log_error("sm: peer public key invalid %x", err); 3733 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3734 break; 3735 } 3736 3737 // start calculating dhkey 3738 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); 3739 3740 3741 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3742 if (IS_RESPONDER(sm_conn->sm_role)){ 3743 // responder 3744 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3745 } else { 3746 // initiator 3747 // stk generation method 3748 // passkey entry: notify app to show passkey or to request passkey 3749 switch (setup->sm_stk_generation_method){ 3750 case JUST_WORKS: 3751 case NUMERIC_COMPARISON: 3752 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3753 break; 3754 case PK_RESP_INPUT: 3755 sm_sc_start_calculating_local_confirm(sm_conn); 3756 break; 3757 case PK_INIT_INPUT: 3758 case PK_BOTH_INPUT: 3759 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3760 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3761 break; 3762 } 3763 sm_sc_start_calculating_local_confirm(sm_conn); 3764 break; 3765 case OOB: 3766 // generate Nx 3767 log_info("Generate Na"); 3768 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); 3769 break; 3770 } 3771 } 3772 break; 3773 3774 case SM_SC_W4_CONFIRMATION: 3775 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3776 sm_pdu_received_in_wrong_state(sm_conn); 3777 break; 3778 } 3779 // received confirm value 3780 reverse_128(&packet[1], setup->sm_peer_confirm); 3781 3782 #ifdef ENABLE_TESTING_SUPPORT 3783 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3784 log_info("testing_support: reset confirm value"); 3785 memset(setup->sm_peer_confirm, 0, 16); 3786 } 3787 #endif 3788 if (IS_RESPONDER(sm_conn->sm_role)){ 3789 // responder 3790 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3791 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3792 // still waiting for passkey 3793 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3794 break; 3795 } 3796 } 3797 sm_sc_start_calculating_local_confirm(sm_conn); 3798 } else { 3799 // initiator 3800 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3801 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); 3802 } else { 3803 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3804 } 3805 } 3806 break; 3807 3808 case SM_SC_W4_PAIRING_RANDOM: 3809 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3810 sm_pdu_received_in_wrong_state(sm_conn); 3811 break; 3812 } 3813 3814 // received random value 3815 reverse_128(&packet[1], setup->sm_peer_nonce); 3816 3817 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3818 // only check for JUST WORK/NC in initiator role OR passkey entry 3819 log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", 3820 IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), 3821 sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); 3822 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3823 || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { 3824 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3825 break; 3826 } 3827 3828 // OOB 3829 if (setup->sm_stk_generation_method == OOB){ 3830 3831 // setup local random, set to zero if remote did not receive our data 3832 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3833 if (IS_RESPONDER(sm_conn->sm_role)){ 3834 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ 3835 log_info("Reset rb as A does not have OOB data"); 3836 memset(setup->sm_rb, 0, 16); 3837 } else { 3838 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3839 log_info("Use stored rb"); 3840 log_info_hexdump(setup->sm_rb, 16); 3841 } 3842 } else { 3843 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ 3844 log_info("Reset ra as B does not have OOB data"); 3845 memset(setup->sm_ra, 0, 16); 3846 } else { 3847 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3848 log_info("Use stored ra"); 3849 log_info_hexdump(setup->sm_ra, 16); 3850 } 3851 } 3852 3853 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3854 if (setup->sm_have_oob_data){ 3855 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3856 break; 3857 } 3858 } 3859 3860 // TODO: we only get here for Responder role with JW/NC 3861 sm_sc_state_after_receiving_random(sm_conn); 3862 break; 3863 3864 case SM_SC_W2_CALCULATE_G2: 3865 case SM_SC_W4_CALCULATE_G2: 3866 case SM_SC_W4_CALCULATE_DHKEY: 3867 case SM_SC_W2_CALCULATE_F5_SALT: 3868 case SM_SC_W4_CALCULATE_F5_SALT: 3869 case SM_SC_W2_CALCULATE_F5_MACKEY: 3870 case SM_SC_W4_CALCULATE_F5_MACKEY: 3871 case SM_SC_W2_CALCULATE_F5_LTK: 3872 case SM_SC_W4_CALCULATE_F5_LTK: 3873 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3874 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3875 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3876 case SM_SC_W4_USER_RESPONSE: 3877 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3878 sm_pdu_received_in_wrong_state(sm_conn); 3879 break; 3880 } 3881 // store DHKey Check 3882 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3883 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3884 3885 // have we been only waiting for dhkey check command? 3886 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3887 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3888 } 3889 break; 3890 #endif 3891 3892 #ifdef ENABLE_LE_PERIPHERAL 3893 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3894 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3895 sm_pdu_received_in_wrong_state(sm_conn); 3896 break; 3897 } 3898 3899 // received confirm value 3900 reverse_128(&packet[1], setup->sm_peer_confirm); 3901 3902 #ifdef ENABLE_TESTING_SUPPORT 3903 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3904 log_info("testing_support: reset confirm value"); 3905 memset(setup->sm_peer_confirm, 0, 16); 3906 } 3907 #endif 3908 // notify client to hide shown passkey 3909 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3910 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3911 } 3912 3913 // handle user cancel pairing? 3914 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3915 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3916 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3917 break; 3918 } 3919 3920 // wait for user action? 3921 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3922 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3923 break; 3924 } 3925 3926 // calculate and send local_confirm 3927 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); 3928 break; 3929 3930 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3931 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3932 sm_pdu_received_in_wrong_state(sm_conn); 3933 break;; 3934 } 3935 3936 // received random value 3937 reverse_128(&packet[1], setup->sm_peer_random); 3938 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3939 break; 3940 #endif 3941 3942 case SM_PH3_RECEIVE_KEYS: 3943 switch(sm_pdu_code){ 3944 case SM_CODE_ENCRYPTION_INFORMATION: 3945 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3946 reverse_128(&packet[1], setup->sm_peer_ltk); 3947 break; 3948 3949 case SM_CODE_MASTER_IDENTIFICATION: 3950 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3951 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3952 reverse_64(&packet[3], setup->sm_peer_rand); 3953 break; 3954 3955 case SM_CODE_IDENTITY_INFORMATION: 3956 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3957 reverse_128(&packet[1], setup->sm_peer_irk); 3958 break; 3959 3960 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3961 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3962 setup->sm_peer_addr_type = packet[1]; 3963 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3964 break; 3965 3966 case SM_CODE_SIGNING_INFORMATION: 3967 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3968 reverse_128(&packet[1], setup->sm_peer_csrk); 3969 break; 3970 default: 3971 // Unexpected PDU 3972 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3973 break; 3974 } 3975 // done with key distribution? 3976 if (sm_key_distribution_all_received(sm_conn)){ 3977 3978 sm_key_distribution_handle_all_received(sm_conn); 3979 3980 if (IS_RESPONDER(sm_conn->sm_role)){ 3981 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3982 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3983 } else { 3984 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3985 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3986 sm_done_for_handle(sm_conn->sm_handle); 3987 } 3988 } else { 3989 if (setup->sm_use_secure_connections){ 3990 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3991 } else { 3992 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); 3993 } 3994 } 3995 } 3996 break; 3997 default: 3998 // Unexpected PDU 3999 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 4000 break; 4001 } 4002 4003 // try to send next pdu 4004 sm_trigger_run(); 4005 } 4006 4007 // Security Manager Client API 4008 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 4009 sm_get_oob_data = get_oob_data_callback; 4010 } 4011 4012 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)){ 4013 sm_get_sc_oob_data = get_sc_oob_data_callback; 4014 } 4015 4016 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 4017 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 4018 } 4019 4020 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 4021 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 4022 } 4023 4024 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 4025 sm_min_encryption_key_size = min_size; 4026 sm_max_encryption_key_size = max_size; 4027 } 4028 4029 void sm_set_authentication_requirements(uint8_t auth_req){ 4030 #ifndef ENABLE_LE_SECURE_CONNECTIONS 4031 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 4032 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 4033 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 4034 } 4035 #endif 4036 sm_auth_req = auth_req; 4037 } 4038 4039 void sm_set_io_capabilities(io_capability_t io_capability){ 4040 sm_io_capabilities = io_capability; 4041 } 4042 4043 #ifdef ENABLE_LE_PERIPHERAL 4044 void sm_set_request_security(int enable){ 4045 sm_slave_request_security = enable; 4046 } 4047 #endif 4048 4049 void sm_set_er(sm_key_t er){ 4050 (void)memcpy(sm_persistent_er, er, 16); 4051 } 4052 4053 void sm_set_ir(sm_key_t ir){ 4054 (void)memcpy(sm_persistent_ir, ir, 16); 4055 } 4056 4057 // Testing support only 4058 void sm_test_set_irk(sm_key_t irk){ 4059 (void)memcpy(sm_persistent_irk, irk, 16); 4060 dkg_state = DKG_CALC_DHK; 4061 test_use_fixed_local_irk = true; 4062 } 4063 4064 void sm_test_use_fixed_local_csrk(void){ 4065 test_use_fixed_local_csrk = true; 4066 } 4067 4068 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4069 static void sm_ec_generated(void * arg){ 4070 UNUSED(arg); 4071 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4072 // trigger pairing if pending for ec key 4073 sm_trigger_run(); 4074 } 4075 static void sm_ec_generate_new_key(void){ 4076 log_info("sm: generate new ec key"); 4077 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4078 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4079 } 4080 #endif 4081 4082 #ifdef ENABLE_TESTING_SUPPORT 4083 void sm_test_set_pairing_failure(int reason){ 4084 test_pairing_failure = reason; 4085 } 4086 #endif 4087 4088 void sm_init(void){ 4089 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4090 sm_er_ir_set_default(); 4091 4092 // defaults 4093 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4094 | SM_STK_GENERATION_METHOD_OOB 4095 | SM_STK_GENERATION_METHOD_PASSKEY 4096 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4097 4098 sm_max_encryption_key_size = 16; 4099 sm_min_encryption_key_size = 7; 4100 4101 sm_fixed_passkey_in_display_role = 0xffffffff; 4102 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4103 4104 #ifdef USE_CMAC_ENGINE 4105 sm_cmac_active = 0; 4106 #endif 4107 dkg_state = DKG_W4_WORKING; 4108 rau_state = RAU_IDLE; 4109 sm_aes128_state = SM_AES128_IDLE; 4110 sm_address_resolution_test = -1; // no private address to resolve yet 4111 sm_address_resolution_ah_calculation_active = 0; 4112 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4113 sm_address_resolution_general_queue = NULL; 4114 4115 gap_random_adress_update_period = 15 * 60 * 1000L; 4116 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4117 4118 test_use_fixed_local_csrk = false; 4119 4120 btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); 4121 4122 // register for HCI Events from HCI 4123 hci_event_callback_registration.callback = &sm_event_packet_handler; 4124 hci_add_event_handler(&hci_event_callback_registration); 4125 4126 // 4127 btstack_crypto_init(); 4128 4129 // init le_device_db 4130 le_device_db_init(); 4131 4132 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4133 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4134 4135 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4136 sm_ec_generate_new_key(); 4137 #endif 4138 } 4139 4140 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4141 sm_fixed_passkey_in_display_role = passkey; 4142 } 4143 4144 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4145 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4146 } 4147 4148 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4149 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4150 if (!hci_con) return NULL; 4151 return &hci_con->sm_connection; 4152 } 4153 4154 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4155 switch (sm_conn->sm_engine_state){ 4156 case SM_GENERAL_IDLE: 4157 case SM_RESPONDER_IDLE: 4158 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4159 sm_trigger_run(); 4160 break; 4161 default: 4162 break; 4163 } 4164 } 4165 4166 /** 4167 * @brief Trigger Security Request 4168 */ 4169 void sm_send_security_request(hci_con_handle_t con_handle){ 4170 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4171 if (!sm_conn) return; 4172 sm_send_security_request_for_connection(sm_conn); 4173 } 4174 4175 // request pairing 4176 void sm_request_pairing(hci_con_handle_t con_handle){ 4177 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4178 if (!sm_conn) return; // wrong connection 4179 4180 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4181 if (IS_RESPONDER(sm_conn->sm_role)){ 4182 sm_send_security_request_for_connection(sm_conn); 4183 } else { 4184 // used as a trigger to start central/master/initiator security procedures 4185 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4186 uint8_t ltk[16]; 4187 bool have_ltk; 4188 switch (sm_conn->sm_irk_lookup_state){ 4189 case IRK_LOOKUP_SUCCEEDED: 4190 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4191 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4192 have_ltk = !sm_is_null_key(ltk); 4193 log_info("have ltk %u", have_ltk); 4194 if (have_ltk){ 4195 sm_conn->sm_pairing_requested = 1; 4196 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4197 break; 4198 } 4199 #endif 4200 /* fall through */ 4201 4202 case IRK_LOOKUP_FAILED: 4203 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4204 break; 4205 default: 4206 log_info("irk lookup pending"); 4207 sm_conn->sm_pairing_requested = 1; 4208 break; 4209 } 4210 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4211 sm_conn->sm_pairing_requested = 1; 4212 } 4213 } 4214 sm_trigger_run(); 4215 } 4216 4217 // called by client app on authorization request 4218 void sm_authorization_decline(hci_con_handle_t con_handle){ 4219 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4220 if (!sm_conn) return; // wrong connection 4221 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4222 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4223 } 4224 4225 void sm_authorization_grant(hci_con_handle_t con_handle){ 4226 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4227 if (!sm_conn) return; // wrong connection 4228 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4229 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4230 } 4231 4232 // GAP Bonding API 4233 4234 void sm_bonding_decline(hci_con_handle_t con_handle){ 4235 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4236 if (!sm_conn) return; // wrong connection 4237 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4238 log_info("decline, state %u", sm_conn->sm_engine_state); 4239 switch(sm_conn->sm_engine_state){ 4240 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4241 case SM_SC_W4_USER_RESPONSE: 4242 case SM_SC_W4_CONFIRMATION: 4243 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4244 #endif 4245 case SM_PH1_W4_USER_RESPONSE: 4246 switch (setup->sm_stk_generation_method){ 4247 case PK_RESP_INPUT: 4248 case PK_INIT_INPUT: 4249 case PK_BOTH_INPUT: 4250 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4251 break; 4252 case NUMERIC_COMPARISON: 4253 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4254 break; 4255 case JUST_WORKS: 4256 case OOB: 4257 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4258 break; 4259 } 4260 break; 4261 default: 4262 break; 4263 } 4264 sm_trigger_run(); 4265 } 4266 4267 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4268 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4269 if (!sm_conn) return; // wrong connection 4270 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4271 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4272 if (setup->sm_use_secure_connections){ 4273 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4274 } else { 4275 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); 4276 } 4277 } 4278 4279 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4280 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4281 sm_sc_prepare_dhkey_check(sm_conn); 4282 } 4283 #endif 4284 4285 sm_trigger_run(); 4286 } 4287 4288 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4289 // for now, it's the same 4290 sm_just_works_confirm(con_handle); 4291 } 4292 4293 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4294 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4295 if (!sm_conn) return; // wrong connection 4296 sm_reset_tk(); 4297 big_endian_store_32(setup->sm_tk, 12, passkey); 4298 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4299 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4300 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); 4301 } 4302 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4303 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4304 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4305 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4306 sm_sc_start_calculating_local_confirm(sm_conn); 4307 } 4308 #endif 4309 sm_trigger_run(); 4310 } 4311 4312 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4313 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4314 if (!sm_conn) return; // wrong connection 4315 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4316 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4317 uint8_t flags = setup->sm_keypress_notification & 0x1fu; 4318 switch (action){ 4319 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4320 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4321 flags |= (1u << action); 4322 break; 4323 case SM_KEYPRESS_PASSKEY_CLEARED: 4324 // clear counter, keypress & erased flags + set passkey cleared 4325 flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); 4326 break; 4327 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4328 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4329 // erase actions queued 4330 num_actions--; 4331 if (num_actions == 0u){ 4332 // clear counter, keypress & erased flags 4333 flags &= 0x19u; 4334 } 4335 break; 4336 } 4337 num_actions++; 4338 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4339 break; 4340 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4341 if (flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4342 // enter actions queued 4343 num_actions--; 4344 if (num_actions == 0u){ 4345 // clear counter, keypress & erased flags 4346 flags &= 0x19u; 4347 } 4348 break; 4349 } 4350 num_actions++; 4351 flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4352 break; 4353 default: 4354 break; 4355 } 4356 setup->sm_keypress_notification = (num_actions << 5) | flags; 4357 sm_trigger_run(); 4358 } 4359 4360 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4361 static void sm_handle_random_result_oob(void * arg){ 4362 UNUSED(arg); 4363 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4364 sm_trigger_run(); 4365 } 4366 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4367 4368 static btstack_crypto_random_t sm_crypto_random_oob_request; 4369 4370 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4371 sm_sc_oob_callback = callback; 4372 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4373 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4374 return 0; 4375 } 4376 #endif 4377 4378 /** 4379 * @brief Get Identity Resolving state 4380 * @param con_handle 4381 * @return irk_lookup_state_t 4382 */ 4383 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4384 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4385 if (!sm_conn) return IRK_LOOKUP_IDLE; 4386 return sm_conn->sm_irk_lookup_state; 4387 } 4388 4389 /** 4390 * @brief Identify device in LE Device DB 4391 * @param handle 4392 * @returns index from le_device_db or -1 if not found/identified 4393 */ 4394 int sm_le_device_index(hci_con_handle_t con_handle ){ 4395 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4396 if (!sm_conn) return -1; 4397 return sm_conn->sm_le_db_index; 4398 } 4399 4400 static int gap_random_address_type_requires_updates(void){ 4401 switch (gap_random_adress_type){ 4402 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4403 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4404 return 0; 4405 default: 4406 return 1; 4407 } 4408 } 4409 4410 static uint8_t own_address_type(void){ 4411 switch (gap_random_adress_type){ 4412 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4413 return BD_ADDR_TYPE_LE_PUBLIC; 4414 default: 4415 return BD_ADDR_TYPE_LE_RANDOM; 4416 } 4417 } 4418 4419 // GAP LE API 4420 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4421 gap_random_address_update_stop(); 4422 gap_random_adress_type = random_address_type; 4423 hci_le_set_own_address_type(own_address_type()); 4424 if (!gap_random_address_type_requires_updates()) return; 4425 gap_random_address_update_start(); 4426 gap_random_address_trigger(); 4427 } 4428 4429 gap_random_address_type_t gap_random_address_get_mode(void){ 4430 return gap_random_adress_type; 4431 } 4432 4433 void gap_random_address_set_update_period(int period_ms){ 4434 gap_random_adress_update_period = period_ms; 4435 if (!gap_random_address_type_requires_updates()) return; 4436 gap_random_address_update_stop(); 4437 gap_random_address_update_start(); 4438 } 4439 4440 void gap_random_address_set(const bd_addr_t addr){ 4441 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4442 (void)memcpy(sm_random_address, addr, 6); 4443 rau_state = RAU_SET_ADDRESS; 4444 sm_trigger_run(); 4445 } 4446 4447 #ifdef ENABLE_LE_PERIPHERAL 4448 /* 4449 * @brief Set Advertisement Paramters 4450 * @param adv_int_min 4451 * @param adv_int_max 4452 * @param adv_type 4453 * @param direct_address_type 4454 * @param direct_address 4455 * @param channel_map 4456 * @param filter_policy 4457 * 4458 * @note own_address_type is used from gap_random_address_set_mode 4459 */ 4460 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4461 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4462 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4463 direct_address_typ, direct_address, channel_map, filter_policy); 4464 } 4465 #endif 4466 4467 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4468 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4469 // wrong connection 4470 if (!sm_conn) return 0; 4471 // already encrypted 4472 if (sm_conn->sm_connection_encrypted) return 0; 4473 // only central can re-encrypt 4474 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4475 // irk status? 4476 switch(sm_conn->sm_irk_lookup_state){ 4477 case IRK_LOOKUP_FAILED: 4478 // done, cannot setup encryption 4479 return 0; 4480 case IRK_LOOKUP_SUCCEEDED: 4481 break; 4482 default: 4483 // IR Lookup pending 4484 return 1; 4485 } 4486 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4487 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4488 } 4489 4490 void sm_set_secure_connections_only_mode(bool enable){ 4491 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4492 sm_sc_only_mode = enable; 4493 #else 4494 // SC Only mode not possible without support for SC 4495 btstack_assert(enable == false); 4496 #endif 4497 } 4498 4499 const uint8_t * gap_get_persistent_irk(void){ 4500 return sm_persistent_irk; 4501 } 4502