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_crypto.h" 48 #include "btstack_debug.h" 49 #include "btstack_event.h" 50 #include "btstack_linked_list.h" 51 #include "btstack_memory.h" 52 #include "btstack_tlv.h" 53 #include "gap.h" 54 #include "hci.h" 55 #include "hci_dump.h" 56 #include "l2cap.h" 57 58 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 59 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 60 #endif 61 62 // assert SM Public Key can be sent/received 63 #ifdef ENABLE_LE_SECURE_CONNECTIONS 64 #if HCI_ACL_PAYLOAD_SIZE < 69 65 #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" 66 #endif 67 #endif 68 69 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 70 #define IS_RESPONDER(role) (role) 71 #else 72 #ifdef ENABLE_LE_CENTRAL 73 // only central - never responder (avoid 'unused variable' warnings) 74 #define IS_RESPONDER(role) (0 && role) 75 #else 76 // only peripheral - always responder (avoid 'unused variable' warnings) 77 #define IS_RESPONDER(role) (1 || role) 78 #endif 79 #endif 80 81 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 82 #define USE_CMAC_ENGINE 83 #endif 84 85 #define BTSTACK_TAG32(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) 86 87 // 88 // SM internal types and globals 89 // 90 91 typedef enum { 92 DKG_W4_WORKING, 93 DKG_CALC_IRK, 94 DKG_CALC_DHK, 95 DKG_READY 96 } derived_key_generation_t; 97 98 typedef enum { 99 RAU_IDLE, 100 RAU_GET_RANDOM, 101 RAU_W4_RANDOM, 102 RAU_GET_ENC, 103 RAU_W4_ENC, 104 RAU_SET_ADDRESS, 105 } random_address_update_t; 106 107 typedef enum { 108 CMAC_IDLE, 109 CMAC_CALC_SUBKEYS, 110 CMAC_W4_SUBKEYS, 111 CMAC_CALC_MI, 112 CMAC_W4_MI, 113 CMAC_CALC_MLAST, 114 CMAC_W4_MLAST 115 } cmac_state_t; 116 117 typedef enum { 118 JUST_WORKS, 119 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 120 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 121 PK_BOTH_INPUT, // Only input on both, both input PK 122 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 123 OOB // OOB available on one (SC) or both sides (legacy) 124 } stk_generation_method_t; 125 126 typedef enum { 127 SM_USER_RESPONSE_IDLE, 128 SM_USER_RESPONSE_PENDING, 129 SM_USER_RESPONSE_CONFIRM, 130 SM_USER_RESPONSE_PASSKEY, 131 SM_USER_RESPONSE_DECLINE 132 } sm_user_response_t; 133 134 typedef enum { 135 SM_AES128_IDLE, 136 SM_AES128_ACTIVE 137 } sm_aes128_state_t; 138 139 typedef enum { 140 ADDRESS_RESOLUTION_IDLE, 141 ADDRESS_RESOLUTION_GENERAL, 142 ADDRESS_RESOLUTION_FOR_CONNECTION, 143 } address_resolution_mode_t; 144 145 typedef enum { 146 ADDRESS_RESOLUTION_SUCEEDED, 147 ADDRESS_RESOLUTION_FAILED, 148 } address_resolution_event_t; 149 150 typedef enum { 151 EC_KEY_GENERATION_IDLE, 152 EC_KEY_GENERATION_ACTIVE, 153 EC_KEY_GENERATION_DONE, 154 } ec_key_generation_state_t; 155 156 typedef enum { 157 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 158 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 159 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 160 } sm_state_var_t; 161 162 typedef enum { 163 SM_SC_OOB_IDLE, 164 SM_SC_OOB_W4_RANDOM, 165 SM_SC_OOB_W2_CALC_CONFIRM, 166 SM_SC_OOB_W4_CONFIRM, 167 } sm_sc_oob_state_t; 168 169 typedef uint8_t sm_key24_t[3]; 170 typedef uint8_t sm_key56_t[7]; 171 typedef uint8_t sm_key256_t[32]; 172 173 // 174 // GLOBAL DATA 175 // 176 177 static bool test_use_fixed_local_csrk; 178 static bool test_use_fixed_local_irk; 179 180 #ifdef ENABLE_TESTING_SUPPORT 181 static uint8_t test_pairing_failure; 182 #endif 183 184 // configuration 185 static uint8_t sm_accepted_stk_generation_methods; 186 static uint8_t sm_max_encryption_key_size; 187 static uint8_t sm_min_encryption_key_size; 188 static uint8_t sm_auth_req = 0; 189 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 190 static uint8_t sm_slave_request_security; 191 static uint32_t sm_fixed_passkey_in_display_role; 192 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 193 194 #ifdef ENABLE_LE_SECURE_CONNECTIONS 195 static uint8_t sm_sc_oob_random[16]; 196 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 197 static sm_sc_oob_state_t sm_sc_oob_state; 198 #endif 199 200 201 static uint8_t sm_persistent_keys_random_active; 202 static const btstack_tlv_t * sm_tlv_impl; 203 static void * sm_tlv_context; 204 205 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 206 static sm_key_t sm_persistent_er; 207 static sm_key_t sm_persistent_ir; 208 209 // derived from sm_persistent_ir 210 static sm_key_t sm_persistent_dhk; 211 static sm_key_t sm_persistent_irk; 212 static derived_key_generation_t dkg_state; 213 214 // derived from sm_persistent_er 215 // .. 216 217 // random address update 218 static random_address_update_t rau_state; 219 static bd_addr_t sm_random_address; 220 221 #ifdef USE_CMAC_ENGINE 222 // CMAC Calculation: General 223 static btstack_crypto_aes128_cmac_t sm_cmac_request; 224 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 225 static uint8_t sm_cmac_active; 226 static uint8_t sm_cmac_hash[16]; 227 #endif 228 229 // CMAC for ATT Signed Writes 230 #ifdef ENABLE_LE_SIGNED_WRITE 231 static uint16_t sm_cmac_signed_write_message_len; 232 static uint8_t sm_cmac_signed_write_header[3]; 233 static const uint8_t * sm_cmac_signed_write_message; 234 static uint8_t sm_cmac_signed_write_sign_counter[4]; 235 #endif 236 237 // CMAC for Secure Connection functions 238 #ifdef ENABLE_LE_SECURE_CONNECTIONS 239 static sm_connection_t * sm_cmac_connection; 240 static uint8_t sm_cmac_sc_buffer[80]; 241 #endif 242 243 // resolvable private address lookup / CSRK calculation 244 static int sm_address_resolution_test; 245 static int sm_address_resolution_ah_calculation_active; 246 static uint8_t sm_address_resolution_addr_type; 247 static bd_addr_t sm_address_resolution_address; 248 static void * sm_address_resolution_context; 249 static address_resolution_mode_t sm_address_resolution_mode; 250 static btstack_linked_list_t sm_address_resolution_general_queue; 251 252 // aes128 crypto engine. 253 static sm_aes128_state_t sm_aes128_state; 254 255 // crypto 256 static btstack_crypto_random_t sm_crypto_random_request; 257 static btstack_crypto_aes128_t sm_crypto_aes128_request; 258 #ifdef ENABLE_LE_SECURE_CONNECTIONS 259 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 260 #endif 261 262 // temp storage for random data 263 static uint8_t sm_random_data[8]; 264 static uint8_t sm_aes128_key[16]; 265 static uint8_t sm_aes128_plaintext[16]; 266 static uint8_t sm_aes128_ciphertext[16]; 267 268 // to receive hci events 269 static btstack_packet_callback_registration_t hci_event_callback_registration; 270 271 /* to dispatch sm event */ 272 static btstack_linked_list_t sm_event_handlers; 273 274 // LE Secure Connections 275 #ifdef ENABLE_LE_SECURE_CONNECTIONS 276 static ec_key_generation_state_t ec_key_generation_state; 277 static uint8_t ec_q[64]; 278 #endif 279 280 // 281 // Volume 3, Part H, Chapter 24 282 // "Security shall be initiated by the Security Manager in the device in the master role. 283 // The device in the slave role shall be the responding device." 284 // -> master := initiator, slave := responder 285 // 286 287 // data needed for security setup 288 typedef struct sm_setup_context { 289 290 btstack_timer_source_t sm_timeout; 291 292 // used in all phases 293 uint8_t sm_pairing_failed_reason; 294 295 // user response, (Phase 1 and/or 2) 296 uint8_t sm_user_response; 297 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 298 299 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 300 uint8_t sm_key_distribution_send_set; 301 uint8_t sm_key_distribution_sent_set; 302 uint8_t sm_key_distribution_received_set; 303 304 // Phase 2 (Pairing over SMP) 305 stk_generation_method_t sm_stk_generation_method; 306 sm_key_t sm_tk; 307 uint8_t sm_have_oob_data; 308 uint8_t sm_use_secure_connections; 309 310 sm_key_t sm_c1_t3_value; // c1 calculation 311 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 312 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 313 sm_key_t sm_local_random; 314 sm_key_t sm_local_confirm; 315 sm_key_t sm_peer_random; 316 sm_key_t sm_peer_confirm; 317 uint8_t sm_m_addr_type; // address and type can be removed 318 uint8_t sm_s_addr_type; // '' 319 bd_addr_t sm_m_address; // '' 320 bd_addr_t sm_s_address; // '' 321 sm_key_t sm_ltk; 322 323 uint8_t sm_state_vars; 324 #ifdef ENABLE_LE_SECURE_CONNECTIONS 325 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 326 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 327 sm_key_t sm_local_nonce; // might be combined with sm_local_random 328 sm_key_t sm_dhkey; 329 sm_key_t sm_peer_dhkey_check; 330 sm_key_t sm_local_dhkey_check; 331 sm_key_t sm_ra; 332 sm_key_t sm_rb; 333 sm_key_t sm_t; // used for f5 and h6 334 sm_key_t sm_mackey; 335 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 336 #endif 337 338 // Phase 3 339 340 // key distribution, we generate 341 uint16_t sm_local_y; 342 uint16_t sm_local_div; 343 uint16_t sm_local_ediv; 344 uint8_t sm_local_rand[8]; 345 sm_key_t sm_local_ltk; 346 sm_key_t sm_local_csrk; 347 sm_key_t sm_local_irk; 348 // sm_local_address/addr_type not needed 349 350 // key distribution, received from peer 351 uint16_t sm_peer_y; 352 uint16_t sm_peer_div; 353 uint16_t sm_peer_ediv; 354 uint8_t sm_peer_rand[8]; 355 sm_key_t sm_peer_ltk; 356 sm_key_t sm_peer_irk; 357 sm_key_t sm_peer_csrk; 358 uint8_t sm_peer_addr_type; 359 bd_addr_t sm_peer_address; 360 #ifdef ENABLE_LE_SIGNED_WRITE 361 int sm_le_device_index; 362 #endif 363 364 } sm_setup_context_t; 365 366 // 367 static sm_setup_context_t the_setup; 368 static sm_setup_context_t * setup = &the_setup; 369 370 // active connection - the one for which the_setup is used for 371 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 372 373 // @returns 1 if oob data is available 374 // stores oob data in provided 16 byte buffer if not null 375 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 376 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); 377 378 static void sm_run(void); 379 static void sm_done_for_handle(hci_con_handle_t con_handle); 380 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 381 static inline int sm_calc_actual_encryption_key_size(int other); 382 static int sm_validate_stk_generation_method(void); 383 static void sm_handle_encryption_result_address_resolution(void *arg); 384 static void sm_handle_encryption_result_dkg_dhk(void *arg); 385 static void sm_handle_encryption_result_dkg_irk(void *arg); 386 static void sm_handle_encryption_result_enc_a(void *arg); 387 static void sm_handle_encryption_result_enc_b(void *arg); 388 static void sm_handle_encryption_result_enc_c(void *arg); 389 static void sm_handle_encryption_result_enc_csrk(void *arg); 390 static void sm_handle_encryption_result_enc_d(void * arg); 391 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 392 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 393 #ifdef ENABLE_LE_PERIPHERAL 394 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 395 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 396 #endif 397 static void sm_handle_encryption_result_enc_stk(void *arg); 398 static void sm_handle_encryption_result_rau(void *arg); 399 static void sm_handle_random_result_ph2_tk(void * arg); 400 static void sm_handle_random_result_rau(void * arg); 401 #ifdef ENABLE_LE_SECURE_CONNECTIONS 402 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)); 403 static void sm_ec_generate_new_key(void); 404 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); 405 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); 406 static int sm_passkey_entry(stk_generation_method_t method); 407 #endif 408 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 409 410 static void log_info_hex16(const char * name, uint16_t value){ 411 log_info("%-6s 0x%04x", name, value); 412 } 413 414 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 415 // return packet[0]; 416 // } 417 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 418 return packet[1]; 419 } 420 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 421 return packet[2]; 422 } 423 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 424 return packet[3]; 425 } 426 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 427 return packet[4]; 428 } 429 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 430 return packet[5]; 431 } 432 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 433 return packet[6]; 434 } 435 436 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 437 packet[0] = code; 438 } 439 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 440 packet[1] = io_capability; 441 } 442 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 443 packet[2] = oob_data_flag; 444 } 445 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 446 packet[3] = auth_req; 447 } 448 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 449 packet[4] = max_encryption_key_size; 450 } 451 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 452 packet[5] = initiator_key_distribution; 453 } 454 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 455 packet[6] = responder_key_distribution; 456 } 457 458 // @returns 1 if all bytes are 0 459 static int sm_is_null(uint8_t * data, int size){ 460 int i; 461 for (i=0; i < size ; i++){ 462 if (data[i]) return 0; 463 } 464 return 1; 465 } 466 467 static int sm_is_null_random(uint8_t random[8]){ 468 return sm_is_null(random, 8); 469 } 470 471 static int sm_is_null_key(uint8_t * key){ 472 return sm_is_null(key, 16); 473 } 474 475 // Key utils 476 static void sm_reset_tk(void){ 477 int i; 478 for (i=0;i<16;i++){ 479 setup->sm_tk[i] = 0; 480 } 481 } 482 483 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 484 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 485 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 486 int i; 487 for (i = max_encryption_size ; i < 16 ; i++){ 488 key[15-i] = 0; 489 } 490 } 491 492 // ER / IR checks 493 static void sm_er_ir_set_default(void){ 494 int i; 495 for (i=0;i<16;i++){ 496 sm_persistent_er[i] = 0x30 + i; 497 sm_persistent_ir[i] = 0x90 + i; 498 } 499 } 500 501 static int sm_er_is_default(void){ 502 int i; 503 for (i=0;i<16;i++){ 504 if (sm_persistent_er[i] != (0x30+i)) return 0; 505 } 506 return 1; 507 } 508 509 static int sm_ir_is_default(void){ 510 int i; 511 for (i=0;i<16;i++){ 512 if (sm_persistent_ir[i] != (0x90+i)) return 0; 513 } 514 return 1; 515 } 516 517 // SMP Timeout implementation 518 519 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 520 // the Security Manager Timer shall be reset and started. 521 // 522 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 523 // 524 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 525 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 526 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 527 // established. 528 529 static void sm_timeout_handler(btstack_timer_source_t * timer){ 530 log_info("SM timeout"); 531 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 532 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 533 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 534 sm_done_for_handle(sm_conn->sm_handle); 535 536 // trigger handling of next ready connection 537 sm_run(); 538 } 539 static void sm_timeout_start(sm_connection_t * sm_conn){ 540 btstack_run_loop_remove_timer(&setup->sm_timeout); 541 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 542 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 543 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 544 btstack_run_loop_add_timer(&setup->sm_timeout); 545 } 546 static void sm_timeout_stop(void){ 547 btstack_run_loop_remove_timer(&setup->sm_timeout); 548 } 549 static void sm_timeout_reset(sm_connection_t * sm_conn){ 550 sm_timeout_stop(); 551 sm_timeout_start(sm_conn); 552 } 553 554 // end of sm timeout 555 556 // GAP Random Address updates 557 static gap_random_address_type_t gap_random_adress_type; 558 static btstack_timer_source_t gap_random_address_update_timer; 559 static uint32_t gap_random_adress_update_period; 560 561 static void gap_random_address_trigger(void){ 562 log_info("gap_random_address_trigger, state %u", rau_state); 563 if (rau_state != RAU_IDLE) return; 564 rau_state = RAU_GET_RANDOM; 565 sm_run(); 566 } 567 568 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 569 UNUSED(timer); 570 571 log_info("GAP Random Address Update due"); 572 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 573 btstack_run_loop_add_timer(&gap_random_address_update_timer); 574 gap_random_address_trigger(); 575 } 576 577 static void gap_random_address_update_start(void){ 578 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 579 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 580 btstack_run_loop_add_timer(&gap_random_address_update_timer); 581 } 582 583 static void gap_random_address_update_stop(void){ 584 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 585 } 586 587 // ah(k,r) helper 588 // r = padding || r 589 // r - 24 bit value 590 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 591 // r'= padding || r 592 memset(r_prime, 0, 16); 593 (void)memcpy(&r_prime[13], r, 3); 594 } 595 596 // d1 helper 597 // d' = padding || r || d 598 // d,r - 16 bit values 599 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 600 // d'= padding || r || d 601 memset(d1_prime, 0, 16); 602 big_endian_store_16(d1_prime, 12, r); 603 big_endian_store_16(d1_prime, 14, d); 604 } 605 606 // calculate arguments for first AES128 operation in C1 function 607 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){ 608 609 // p1 = pres || preq || rat’ || iat’ 610 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 611 // cant octet of pres becomes the most significant octet of p1. 612 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 613 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 614 // p1 is 0x05000800000302070710000001010001." 615 616 sm_key_t p1; 617 reverse_56(pres, &p1[0]); 618 reverse_56(preq, &p1[7]); 619 p1[14] = rat; 620 p1[15] = iat; 621 log_info_key("p1", p1); 622 log_info_key("r", r); 623 624 // t1 = r xor p1 625 int i; 626 for (i=0;i<16;i++){ 627 t1[i] = r[i] ^ p1[i]; 628 } 629 log_info_key("t1", t1); 630 } 631 632 // calculate arguments for second AES128 operation in C1 function 633 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 634 // p2 = padding || ia || ra 635 // "The least significant octet of ra becomes the least significant octet of p2 and 636 // the most significant octet of padding becomes the most significant octet of p2. 637 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 638 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 639 640 sm_key_t p2; 641 memset(p2, 0, 16); 642 (void)memcpy(&p2[4], ia, 6); 643 (void)memcpy(&p2[10], ra, 6); 644 log_info_key("p2", p2); 645 646 // c1 = e(k, t2_xor_p2) 647 int i; 648 for (i=0;i<16;i++){ 649 t3[i] = t2[i] ^ p2[i]; 650 } 651 log_info_key("t3", t3); 652 } 653 654 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 655 log_info_key("r1", r1); 656 log_info_key("r2", r2); 657 (void)memcpy(&r_prime[8], &r2[8], 8); 658 (void)memcpy(&r_prime[0], &r1[8], 8); 659 } 660 661 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 662 UNUSED(channel); 663 664 // log event 665 hci_dump_packet(packet_type, 1, packet, size); 666 // dispatch to all event handlers 667 btstack_linked_list_iterator_t it; 668 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 669 while (btstack_linked_list_iterator_has_next(&it)){ 670 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 671 entry->callback(packet_type, 0, packet, size); 672 } 673 } 674 675 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){ 676 event[0] = type; 677 event[1] = event_size - 2; 678 little_endian_store_16(event, 2, con_handle); 679 event[4] = addr_type; 680 reverse_bd_addr(address, &event[5]); 681 } 682 683 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 684 uint8_t event[11]; 685 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 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){ 690 uint8_t event[15]; 691 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 692 little_endian_store_32(event, 11, passkey); 693 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 694 } 695 696 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){ 697 // fetch addr and addr type from db, only called for valid entries 698 bd_addr_t identity_address; 699 int identity_address_type; 700 le_device_db_info(index, &identity_address_type, identity_address, NULL); 701 702 uint8_t event[20]; 703 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 704 event[11] = identity_address_type; 705 reverse_bd_addr(identity_address, &event[12]); 706 little_endian_store_16(event, 18, index); 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 708 } 709 710 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){ 711 uint8_t event[12]; 712 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 713 event[11] = status; 714 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 715 } 716 717 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 718 uint8_t event[13]; 719 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 720 event[11] = status; 721 event[12] = reason; 722 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 723 } 724 725 // decide on stk generation based on 726 // - pairing request 727 // - io capabilities 728 // - OOB data availability 729 static void sm_setup_tk(void){ 730 731 // horizontal: initiator capabilities 732 // vertial: responder capabilities 733 static const stk_generation_method_t stk_generation_method [5] [5] = { 734 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 735 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 736 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 737 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 738 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 739 }; 740 741 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 742 #ifdef ENABLE_LE_SECURE_CONNECTIONS 743 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 744 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 745 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 746 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 747 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 748 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 749 }; 750 #endif 751 752 // default: just works 753 setup->sm_stk_generation_method = JUST_WORKS; 754 755 #ifdef ENABLE_LE_SECURE_CONNECTIONS 756 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 757 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 758 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 759 #else 760 setup->sm_use_secure_connections = 0; 761 #endif 762 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 763 764 765 // decide if OOB will be used based on SC vs. Legacy and oob flags 766 int use_oob = 0; 767 if (setup->sm_use_secure_connections){ 768 // In LE Secure Connections pairing, the out of band method is used if at least 769 // one device has the peer device's out of band authentication data available. 770 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 771 } else { 772 // In LE legacy pairing, the out of band method is used if both the devices have 773 // the other device's out of band authentication data available. 774 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 775 } 776 if (use_oob){ 777 log_info("SM: have OOB data"); 778 log_info_key("OOB", setup->sm_tk); 779 setup->sm_stk_generation_method = OOB; 780 return; 781 } 782 783 // If both devices have not set the MITM option in the Authentication Requirements 784 // Flags, then the IO capabilities shall be ignored and the Just Works association 785 // model shall be used. 786 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 787 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 788 log_info("SM: MITM not required by both -> JUST WORKS"); 789 return; 790 } 791 792 // Reset TK as it has been setup in sm_init_setup 793 sm_reset_tk(); 794 795 // Also use just works if unknown io capabilites 796 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)){ 797 return; 798 } 799 800 // Otherwise the IO capabilities of the devices shall be used to determine the 801 // pairing method as defined in Table 2.4. 802 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 803 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 804 805 #ifdef ENABLE_LE_SECURE_CONNECTIONS 806 // table not define by default 807 if (setup->sm_use_secure_connections){ 808 generation_method = stk_generation_method_with_secure_connection; 809 } 810 #endif 811 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)]; 812 813 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 814 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); 815 } 816 817 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 818 int flags = 0; 819 if (key_set & SM_KEYDIST_ENC_KEY){ 820 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 821 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 822 } 823 if (key_set & SM_KEYDIST_ID_KEY){ 824 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 825 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 826 } 827 if (key_set & SM_KEYDIST_SIGN){ 828 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 829 } 830 return flags; 831 } 832 833 static void sm_setup_key_distribution(uint8_t key_set){ 834 setup->sm_key_distribution_received_set = 0; 835 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 836 setup->sm_key_distribution_sent_set = 0; 837 #ifdef ENABLE_LE_SIGNED_WRITE 838 setup->sm_le_device_index = -1; 839 #endif 840 } 841 842 // CSRK Key Lookup 843 844 845 static int sm_address_resolution_idle(void){ 846 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 847 } 848 849 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){ 850 (void)memcpy(sm_address_resolution_address, addr, 6); 851 sm_address_resolution_addr_type = addr_type; 852 sm_address_resolution_test = 0; 853 sm_address_resolution_mode = mode; 854 sm_address_resolution_context = context; 855 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 856 } 857 858 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 859 // check if already in list 860 btstack_linked_list_iterator_t it; 861 sm_lookup_entry_t * entry; 862 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 863 while(btstack_linked_list_iterator_has_next(&it)){ 864 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 865 if (entry->address_type != address_type) continue; 866 if (memcmp(entry->address, address, 6)) continue; 867 // already in list 868 return BTSTACK_BUSY; 869 } 870 entry = btstack_memory_sm_lookup_entry_get(); 871 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 872 entry->address_type = (bd_addr_type_t) address_type; 873 (void)memcpy(entry->address, address, 6); 874 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 875 sm_run(); 876 return 0; 877 } 878 879 // CMAC calculation using AES Engineq 880 #ifdef USE_CMAC_ENGINE 881 882 static void sm_cmac_done_trampoline(void * arg){ 883 UNUSED(arg); 884 sm_cmac_active = 0; 885 (*sm_cmac_done_callback)(sm_cmac_hash); 886 sm_run(); 887 } 888 889 int sm_cmac_ready(void){ 890 return sm_cmac_active == 0; 891 } 892 #endif 893 894 #ifdef ENABLE_LE_SECURE_CONNECTIONS 895 // generic cmac calculation 896 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)){ 897 sm_cmac_active = 1; 898 sm_cmac_done_callback = done_callback; 899 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 900 } 901 #endif 902 903 // cmac for ATT Message signing 904 #ifdef ENABLE_LE_SIGNED_WRITE 905 906 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)){ 907 sm_cmac_active = 1; 908 sm_cmac_done_callback = done_callback; 909 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 910 } 911 912 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 913 if (offset >= sm_cmac_signed_write_message_len) { 914 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 915 return 0; 916 } 917 918 offset = sm_cmac_signed_write_message_len - 1 - offset; 919 920 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 921 if (offset < 3){ 922 return sm_cmac_signed_write_header[offset]; 923 } 924 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 925 if (offset < actual_message_len_incl_header){ 926 return sm_cmac_signed_write_message[offset - 3]; 927 } 928 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 929 } 930 931 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)){ 932 // ATT Message Signing 933 sm_cmac_signed_write_header[0] = opcode; 934 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 935 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 936 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 937 sm_cmac_signed_write_message = message; 938 sm_cmac_signed_write_message_len = total_message_len; 939 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 940 } 941 #endif 942 943 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 944 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 945 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 946 switch (setup->sm_stk_generation_method){ 947 case PK_RESP_INPUT: 948 if (IS_RESPONDER(sm_conn->sm_role)){ 949 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 950 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 951 } else { 952 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)); 953 } 954 break; 955 case PK_INIT_INPUT: 956 if (IS_RESPONDER(sm_conn->sm_role)){ 957 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)); 958 } else { 959 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 960 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 961 } 962 break; 963 case PK_BOTH_INPUT: 964 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 965 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 966 break; 967 case NUMERIC_COMPARISON: 968 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 969 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)); 970 break; 971 case JUST_WORKS: 972 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 973 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 974 break; 975 case OOB: 976 // client already provided OOB data, let's skip notification. 977 break; 978 } 979 } 980 981 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 982 int recv_flags; 983 if (IS_RESPONDER(sm_conn->sm_role)){ 984 // slave / responder 985 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 986 } else { 987 // master / initiator 988 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 989 } 990 991 #ifdef ENABLE_LE_SECURE_CONNECTIONS 992 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 993 if (setup->sm_use_secure_connections){ 994 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 995 } 996 #endif 997 998 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 999 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 1000 } 1001 1002 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1003 if (sm_active_connection_handle == con_handle){ 1004 sm_timeout_stop(); 1005 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1006 log_info("sm: connection 0x%x released setup context", con_handle); 1007 1008 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1009 // generate new ec key after each pairing (that used it) 1010 if (setup->sm_use_secure_connections){ 1011 sm_ec_generate_new_key(); 1012 } 1013 #endif 1014 } 1015 } 1016 1017 static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done 1018 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 1019 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 1020 sm_done_for_handle(connection->sm_handle); 1021 } 1022 1023 static int sm_key_distribution_flags_for_auth_req(void){ 1024 1025 int flags = SM_KEYDIST_ID_KEY; 1026 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1027 // encryption and signing information only if bonding requested 1028 flags |= SM_KEYDIST_ENC_KEY; 1029 #ifdef ENABLE_LE_SIGNED_WRITE 1030 flags |= SM_KEYDIST_SIGN; 1031 #endif 1032 } 1033 return flags; 1034 } 1035 1036 static void sm_reset_setup(void){ 1037 // fill in sm setup 1038 setup->sm_state_vars = 0; 1039 setup->sm_keypress_notification = 0; 1040 sm_reset_tk(); 1041 } 1042 1043 static void sm_init_setup(sm_connection_t * sm_conn){ 1044 1045 // fill in sm setup 1046 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1047 (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1048 1049 // query client for Legacy Pairing OOB data 1050 setup->sm_have_oob_data = 0; 1051 if (sm_get_oob_data) { 1052 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1053 } 1054 1055 // if available and SC supported, also ask for SC OOB Data 1056 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1057 memset(setup->sm_ra, 0, 16); 1058 memset(setup->sm_rb, 0, 16); 1059 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1060 if (sm_get_sc_oob_data){ 1061 if (IS_RESPONDER(sm_conn->sm_role)){ 1062 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1063 sm_conn->sm_peer_addr_type, 1064 sm_conn->sm_peer_address, 1065 setup->sm_peer_confirm, 1066 setup->sm_ra); 1067 } else { 1068 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1069 sm_conn->sm_peer_addr_type, 1070 sm_conn->sm_peer_address, 1071 setup->sm_peer_confirm, 1072 setup->sm_rb); 1073 } 1074 } else { 1075 setup->sm_have_oob_data = 0; 1076 } 1077 } 1078 #endif 1079 1080 sm_pairing_packet_t * local_packet; 1081 if (IS_RESPONDER(sm_conn->sm_role)){ 1082 // slave 1083 local_packet = &setup->sm_s_pres; 1084 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1085 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1086 (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1087 } else { 1088 // master 1089 local_packet = &setup->sm_m_preq; 1090 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1091 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1092 (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1093 1094 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1095 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1096 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1097 } 1098 1099 uint8_t auth_req = sm_auth_req; 1100 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1101 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1102 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1103 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1104 } 1105 1106 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1107 1108 sm_pairing_packet_t * remote_packet; 1109 int remote_key_request; 1110 if (IS_RESPONDER(sm_conn->sm_role)){ 1111 // slave / responder 1112 remote_packet = &setup->sm_m_preq; 1113 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1114 } else { 1115 // master / initiator 1116 remote_packet = &setup->sm_s_pres; 1117 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1118 } 1119 1120 // check key size 1121 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1122 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1123 1124 // decide on STK generation method / SC 1125 sm_setup_tk(); 1126 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1127 1128 // check if STK generation method is acceptable by client 1129 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1130 1131 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1132 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1133 if (setup->sm_use_secure_connections){ 1134 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1135 } 1136 #endif 1137 1138 // identical to responder 1139 sm_setup_key_distribution(remote_key_request); 1140 1141 // JUST WORKS doens't provide authentication 1142 sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; 1143 1144 return 0; 1145 } 1146 1147 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1148 1149 // cache and reset context 1150 int matched_device_id = sm_address_resolution_test; 1151 address_resolution_mode_t mode = sm_address_resolution_mode; 1152 void * context = sm_address_resolution_context; 1153 1154 // reset context 1155 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1156 sm_address_resolution_context = NULL; 1157 sm_address_resolution_test = -1; 1158 hci_con_handle_t con_handle = 0; 1159 1160 sm_connection_t * sm_connection; 1161 #ifdef ENABLE_LE_CENTRAL 1162 sm_key_t ltk; 1163 int have_ltk; 1164 int pairing_need; 1165 #endif 1166 switch (mode){ 1167 case ADDRESS_RESOLUTION_GENERAL: 1168 break; 1169 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1170 sm_connection = (sm_connection_t *) context; 1171 con_handle = sm_connection->sm_handle; 1172 switch (event){ 1173 case ADDRESS_RESOLUTION_SUCEEDED: 1174 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1175 sm_connection->sm_le_db_index = matched_device_id; 1176 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1177 if (sm_connection->sm_role) { 1178 // LTK request received before, IRK required -> start LTK calculation 1179 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1180 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1181 } 1182 break; 1183 } 1184 #ifdef ENABLE_LE_CENTRAL 1185 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 1186 have_ltk = !sm_is_null_key(ltk); 1187 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1188 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1189 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1190 // reset requests 1191 sm_connection->sm_security_request_received = 0; 1192 sm_connection->sm_pairing_requested = 0; 1193 1194 // have ltk -> start encryption 1195 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1196 // "When a bond has been created between two devices, any reconnection should result in the local device 1197 // enabling or requesting encryption with the remote device before initiating any service request." 1198 if (have_ltk){ 1199 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1200 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1201 break; 1202 #else 1203 log_info("central: defer enabling encryption for bonded device"); 1204 #endif 1205 } 1206 // pairint_request -> send pairing request 1207 if (pairing_need){ 1208 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1209 break; 1210 } 1211 #endif 1212 break; 1213 case ADDRESS_RESOLUTION_FAILED: 1214 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1215 if (sm_connection->sm_role) { 1216 // LTK request received before, IRK required -> negative LTK reply 1217 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1218 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1219 } 1220 break; 1221 } 1222 #ifdef ENABLE_LE_CENTRAL 1223 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1224 sm_connection->sm_security_request_received = 0; 1225 sm_connection->sm_pairing_requested = 0; 1226 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1227 #endif 1228 break; 1229 } 1230 break; 1231 default: 1232 break; 1233 } 1234 1235 switch (event){ 1236 case ADDRESS_RESOLUTION_SUCEEDED: 1237 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1238 break; 1239 case ADDRESS_RESOLUTION_FAILED: 1240 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1241 break; 1242 } 1243 } 1244 1245 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1246 1247 int le_db_index = -1; 1248 1249 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1250 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1251 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1252 & SM_AUTHREQ_BONDING ) != 0; 1253 1254 if (bonding_enabed){ 1255 1256 // lookup device based on IRK 1257 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1258 int i; 1259 for (i=0; i < le_device_db_max_count(); i++){ 1260 sm_key_t irk; 1261 bd_addr_t address; 1262 int address_type = BD_ADDR_TYPE_UNKNOWN; 1263 le_device_db_info(i, &address_type, address, irk); 1264 // skip unused entries 1265 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1266 // compare IRK 1267 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1268 1269 log_info("sm: device found for IRK, updating"); 1270 le_db_index = i; 1271 break; 1272 } 1273 } else { 1274 // assert IRK is set to zero 1275 memset(setup->sm_peer_irk, 0, 16); 1276 } 1277 1278 // if not found, lookup via public address if possible 1279 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1280 if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ 1281 int i; 1282 for (i=0; i < le_device_db_max_count(); i++){ 1283 bd_addr_t address; 1284 int address_type = BD_ADDR_TYPE_UNKNOWN; 1285 le_device_db_info(i, &address_type, address, NULL); 1286 // skip unused entries 1287 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1288 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1289 if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ 1290 log_info("sm: device found for public address, updating"); 1291 le_db_index = i; 1292 break; 1293 } 1294 } 1295 } 1296 1297 // if not found, add to db 1298 if (le_db_index < 0) { 1299 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1300 } 1301 1302 if (le_db_index >= 0){ 1303 1304 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1305 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1306 1307 #ifdef ENABLE_LE_SIGNED_WRITE 1308 // store local CSRK 1309 setup->sm_le_device_index = le_db_index; 1310 if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1311 log_info("sm: store local CSRK"); 1312 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1313 le_device_db_local_counter_set(le_db_index, 0); 1314 } 1315 1316 // store remote CSRK 1317 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1318 log_info("sm: store remote CSRK"); 1319 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1320 le_device_db_remote_counter_set(le_db_index, 0); 1321 } 1322 #endif 1323 // store encryption information for secure connections: LTK generated by ECDH 1324 if (setup->sm_use_secure_connections){ 1325 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1326 uint8_t zero_rand[8]; 1327 memset(zero_rand, 0, 8); 1328 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1329 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); 1330 } 1331 1332 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1333 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1334 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1335 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1336 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1337 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); 1338 1339 } 1340 } 1341 } else { 1342 log_info("Ignoring received keys, bonding not enabled"); 1343 } 1344 1345 // keep le_db_index 1346 sm_conn->sm_le_db_index = le_db_index; 1347 } 1348 1349 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1350 setup->sm_pairing_failed_reason = reason; 1351 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1352 } 1353 1354 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1355 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1356 } 1357 1358 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1359 1360 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1361 static int sm_passkey_used(stk_generation_method_t method); 1362 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1363 1364 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1365 if (setup->sm_stk_generation_method == OOB){ 1366 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1367 } else { 1368 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); 1369 } 1370 } 1371 1372 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1373 if (IS_RESPONDER(sm_conn->sm_role)){ 1374 // Responder 1375 if (setup->sm_stk_generation_method == OOB){ 1376 // generate Nb 1377 log_info("Generate Nb"); 1378 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); 1379 } else { 1380 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1381 } 1382 } else { 1383 // Initiator role 1384 switch (setup->sm_stk_generation_method){ 1385 case JUST_WORKS: 1386 sm_sc_prepare_dhkey_check(sm_conn); 1387 break; 1388 1389 case NUMERIC_COMPARISON: 1390 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1391 break; 1392 case PK_INIT_INPUT: 1393 case PK_RESP_INPUT: 1394 case PK_BOTH_INPUT: 1395 if (setup->sm_passkey_bit < 20) { 1396 sm_sc_start_calculating_local_confirm(sm_conn); 1397 } else { 1398 sm_sc_prepare_dhkey_check(sm_conn); 1399 } 1400 break; 1401 case OOB: 1402 sm_sc_prepare_dhkey_check(sm_conn); 1403 break; 1404 } 1405 } 1406 } 1407 1408 static void sm_sc_cmac_done(uint8_t * hash){ 1409 log_info("sm_sc_cmac_done: "); 1410 log_info_hexdump(hash, 16); 1411 1412 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1413 sm_sc_oob_state = SM_SC_OOB_IDLE; 1414 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1415 return; 1416 } 1417 1418 sm_connection_t * sm_conn = sm_cmac_connection; 1419 sm_cmac_connection = NULL; 1420 #ifdef ENABLE_CLASSIC 1421 link_key_type_t link_key_type; 1422 #endif 1423 1424 switch (sm_conn->sm_engine_state){ 1425 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1426 (void)memcpy(setup->sm_local_confirm, hash, 16); 1427 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1428 break; 1429 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1430 // check 1431 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1432 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1433 break; 1434 } 1435 sm_sc_state_after_receiving_random(sm_conn); 1436 break; 1437 case SM_SC_W4_CALCULATE_G2: { 1438 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1439 big_endian_store_32(setup->sm_tk, 12, vab); 1440 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1441 sm_trigger_user_response(sm_conn); 1442 break; 1443 } 1444 case SM_SC_W4_CALCULATE_F5_SALT: 1445 (void)memcpy(setup->sm_t, hash, 16); 1446 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1447 break; 1448 case SM_SC_W4_CALCULATE_F5_MACKEY: 1449 (void)memcpy(setup->sm_mackey, hash, 16); 1450 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1451 break; 1452 case SM_SC_W4_CALCULATE_F5_LTK: 1453 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1454 // Errata Service Release to the Bluetooth Specification: ESR09 1455 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1456 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1457 (void)memcpy(setup->sm_ltk, hash, 16); 1458 (void)memcpy(setup->sm_local_ltk, hash, 16); 1459 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1460 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1461 break; 1462 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1463 (void)memcpy(setup->sm_local_dhkey_check, hash, 16); 1464 if (IS_RESPONDER(sm_conn->sm_role)){ 1465 // responder 1466 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1467 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1468 } else { 1469 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1470 } 1471 } else { 1472 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1473 } 1474 break; 1475 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1476 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1477 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1478 break; 1479 } 1480 if (IS_RESPONDER(sm_conn->sm_role)){ 1481 // responder 1482 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1483 } else { 1484 // initiator 1485 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1486 } 1487 break; 1488 case SM_SC_W4_CALCULATE_H6_ILK: 1489 (void)memcpy(setup->sm_t, hash, 16); 1490 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1491 break; 1492 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1493 #ifdef ENABLE_CLASSIC 1494 reverse_128(hash, setup->sm_t); 1495 link_key_type = sm_conn->sm_connection_authenticated ? 1496 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1497 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1498 if (IS_RESPONDER(sm_conn->sm_role)){ 1499 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1500 } else { 1501 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1502 } 1503 #endif 1504 if (IS_RESPONDER(sm_conn->sm_role)){ 1505 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1506 } else { 1507 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1508 } 1509 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1510 sm_done_for_handle(sm_conn->sm_handle); 1511 break; 1512 default: 1513 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1514 break; 1515 } 1516 sm_run(); 1517 } 1518 1519 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){ 1520 const uint16_t message_len = 65; 1521 sm_cmac_connection = sm_conn; 1522 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1523 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1524 sm_cmac_sc_buffer[64] = z; 1525 log_info("f4 key"); 1526 log_info_hexdump(x, 16); 1527 log_info("f4 message"); 1528 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1529 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1530 } 1531 1532 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1533 static const uint8_t f5_length[] = { 0x01, 0x00}; 1534 1535 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1536 1537 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1538 1539 log_info("f5_calculate_salt"); 1540 // calculate salt for f5 1541 const uint16_t message_len = 32; 1542 sm_cmac_connection = sm_conn; 1543 (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1544 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1545 } 1546 1547 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){ 1548 const uint16_t message_len = 53; 1549 sm_cmac_connection = sm_conn; 1550 1551 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1552 sm_cmac_sc_buffer[0] = 0; 1553 (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); 1554 (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); 1555 (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); 1556 (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); 1557 (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); 1558 (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); 1559 log_info("f5 key"); 1560 log_info_hexdump(t, 16); 1561 log_info("f5 message for MacKey"); 1562 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1563 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1564 } 1565 1566 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1567 sm_key56_t bd_addr_master, bd_addr_slave; 1568 bd_addr_master[0] = setup->sm_m_addr_type; 1569 bd_addr_slave[0] = setup->sm_s_addr_type; 1570 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1571 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1572 if (IS_RESPONDER(sm_conn->sm_role)){ 1573 // responder 1574 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1575 } else { 1576 // initiator 1577 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1578 } 1579 } 1580 1581 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1582 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1583 const uint16_t message_len = 53; 1584 sm_cmac_connection = sm_conn; 1585 sm_cmac_sc_buffer[0] = 1; 1586 // 1..52 setup before 1587 log_info("f5 key"); 1588 log_info_hexdump(t, 16); 1589 log_info("f5 message for LTK"); 1590 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1591 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1592 } 1593 1594 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1595 f5_ltk(sm_conn, setup->sm_t); 1596 } 1597 1598 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){ 1599 (void)memcpy(sm_cmac_sc_buffer, n1, 16); 1600 (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); 1601 (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); 1602 (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); 1603 (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); 1604 (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); 1605 } 1606 1607 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ 1608 const uint16_t message_len = 65; 1609 sm_cmac_connection = sm_conn; 1610 log_info("f6 key"); 1611 log_info_hexdump(w, 16); 1612 log_info("f6 message"); 1613 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1614 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1615 } 1616 1617 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1618 // - U is 256 bits 1619 // - V is 256 bits 1620 // - X is 128 bits 1621 // - Y is 128 bits 1622 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){ 1623 const uint16_t message_len = 80; 1624 sm_cmac_connection = sm_conn; 1625 (void)memcpy(sm_cmac_sc_buffer, u, 32); 1626 (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); 1627 (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); 1628 log_info("g2 key"); 1629 log_info_hexdump(x, 16); 1630 log_info("g2 message"); 1631 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1632 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1633 } 1634 1635 static void g2_calculate(sm_connection_t * sm_conn) { 1636 // calc Va if numeric comparison 1637 if (IS_RESPONDER(sm_conn->sm_role)){ 1638 // responder 1639 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1640 } else { 1641 // initiator 1642 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1643 } 1644 } 1645 1646 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1647 uint8_t z = 0; 1648 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1649 // some form of passkey 1650 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1651 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1652 setup->sm_passkey_bit++; 1653 } 1654 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1655 } 1656 1657 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1658 // OOB 1659 if (setup->sm_stk_generation_method == OOB){ 1660 if (IS_RESPONDER(sm_conn->sm_role)){ 1661 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1662 } else { 1663 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1664 } 1665 return; 1666 } 1667 1668 uint8_t z = 0; 1669 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1670 // some form of passkey 1671 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1672 // sm_passkey_bit was increased before sending confirm value 1673 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1674 } 1675 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1676 } 1677 1678 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1679 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) ? 1 : 0); 1680 1681 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1682 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1683 return; 1684 } else { 1685 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1686 } 1687 } 1688 1689 static void sm_sc_dhkey_calculated(void * arg){ 1690 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 1691 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 1692 if (sm_conn == NULL) return; 1693 1694 log_info("dhkey"); 1695 log_info_hexdump(&setup->sm_dhkey[0], 32); 1696 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1697 // trigger next step 1698 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1699 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1700 } 1701 sm_run(); 1702 } 1703 1704 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1705 // calculate DHKCheck 1706 sm_key56_t bd_addr_master, bd_addr_slave; 1707 bd_addr_master[0] = setup->sm_m_addr_type; 1708 bd_addr_slave[0] = setup->sm_s_addr_type; 1709 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1710 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1711 uint8_t iocap_a[3]; 1712 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1713 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1714 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1715 uint8_t iocap_b[3]; 1716 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1717 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1718 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1719 if (IS_RESPONDER(sm_conn->sm_role)){ 1720 // responder 1721 f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1722 f6_engine(sm_conn, setup->sm_mackey); 1723 } else { 1724 // initiator 1725 f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1726 f6_engine(sm_conn, setup->sm_mackey); 1727 } 1728 } 1729 1730 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1731 // validate E = f6() 1732 sm_key56_t bd_addr_master, bd_addr_slave; 1733 bd_addr_master[0] = setup->sm_m_addr_type; 1734 bd_addr_slave[0] = setup->sm_s_addr_type; 1735 (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1736 (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1737 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_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1749 f6_engine(sm_conn, setup->sm_mackey); 1750 } else { 1751 // initiator 1752 f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1753 f6_engine(sm_conn, setup->sm_mackey); 1754 } 1755 } 1756 1757 1758 // 1759 // Link Key Conversion Function h6 1760 // 1761 // h6(W, keyID) = AES-CMACW(keyID) 1762 // - W is 128 bits 1763 // - keyID is 32 bits 1764 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1765 const uint16_t message_len = 4; 1766 sm_cmac_connection = sm_conn; 1767 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1768 log_info("h6 key"); 1769 log_info_hexdump(w, 16); 1770 log_info("h6 message"); 1771 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1772 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1773 } 1774 1775 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1776 // Errata Service Release to the Bluetooth Specification: ESR09 1777 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1778 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1779 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1780 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1781 } 1782 1783 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1784 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1785 } 1786 1787 #endif 1788 1789 // key management legacy connections: 1790 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1791 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1792 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1793 // - responder reconnects: responder uses LTK receveived from master 1794 1795 // key management secure connections: 1796 // - both devices store same LTK from ECDH key exchange. 1797 1798 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1799 static void sm_load_security_info(sm_connection_t * sm_connection){ 1800 int encryption_key_size; 1801 int authenticated; 1802 int authorized; 1803 int secure_connection; 1804 1805 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1806 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1807 &encryption_key_size, &authenticated, &authorized, &secure_connection); 1808 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); 1809 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1810 sm_connection->sm_connection_authenticated = authenticated; 1811 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1812 sm_connection->sm_connection_sc = secure_connection; 1813 } 1814 #endif 1815 1816 #ifdef ENABLE_LE_PERIPHERAL 1817 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1818 (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1819 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1820 // re-establish used key encryption size 1821 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1822 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1823 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1824 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1825 // Legacy paring -> not SC 1826 sm_connection->sm_connection_sc = 0; 1827 log_info("sm: received ltk request with key size %u, authenticated %u", 1828 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1829 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1830 sm_run(); 1831 } 1832 #endif 1833 1834 static void sm_run(void){ 1835 1836 btstack_linked_list_iterator_t it; 1837 1838 // assert that stack has already bootet 1839 if (hci_get_state() != HCI_STATE_WORKING) return; 1840 1841 // assert that we can send at least commands 1842 if (!hci_can_send_command_packet_now()) return; 1843 1844 // pause until IR/ER are ready 1845 if (sm_persistent_keys_random_active) return; 1846 1847 // 1848 // non-connection related behaviour 1849 // 1850 1851 // distributed key generation 1852 switch (dkg_state){ 1853 case DKG_CALC_IRK: 1854 // already busy? 1855 if (sm_aes128_state == SM_AES128_IDLE) { 1856 log_info("DKG_CALC_IRK started"); 1857 // IRK = d1(IR, 1, 0) 1858 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1859 sm_aes128_state = SM_AES128_ACTIVE; 1860 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1861 return; 1862 } 1863 break; 1864 case DKG_CALC_DHK: 1865 // already busy? 1866 if (sm_aes128_state == SM_AES128_IDLE) { 1867 log_info("DKG_CALC_DHK started"); 1868 // DHK = d1(IR, 3, 0) 1869 sm_d1_d_prime(3, 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_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1872 return; 1873 } 1874 break; 1875 default: 1876 break; 1877 } 1878 1879 // random address updates 1880 switch (rau_state){ 1881 case RAU_GET_RANDOM: 1882 rau_state = RAU_W4_RANDOM; 1883 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); 1884 return; 1885 case RAU_GET_ENC: 1886 // already busy? 1887 if (sm_aes128_state == SM_AES128_IDLE) { 1888 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1889 sm_aes128_state = SM_AES128_ACTIVE; 1890 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1891 return; 1892 } 1893 break; 1894 case RAU_SET_ADDRESS: 1895 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1896 rau_state = RAU_IDLE; 1897 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1898 return; 1899 default: 1900 break; 1901 } 1902 1903 // CSRK Lookup 1904 // -- if csrk lookup ready, find connection that require csrk lookup 1905 if (sm_address_resolution_idle()){ 1906 hci_connections_get_iterator(&it); 1907 while(btstack_linked_list_iterator_has_next(&it)){ 1908 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1909 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1910 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1911 // and start lookup 1912 sm_address_resolution_start_lookup(sm_connection->sm_peer_addr_type, sm_connection->sm_handle, sm_connection->sm_peer_address, ADDRESS_RESOLUTION_FOR_CONNECTION, sm_connection); 1913 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1914 break; 1915 } 1916 } 1917 } 1918 1919 // -- if csrk lookup ready, resolved addresses for received addresses 1920 if (sm_address_resolution_idle()) { 1921 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1922 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1923 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1924 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1925 btstack_memory_sm_lookup_entry_free(entry); 1926 } 1927 } 1928 1929 // -- Continue with CSRK device lookup by public or resolvable private address 1930 if (!sm_address_resolution_idle()){ 1931 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1932 while (sm_address_resolution_test < le_device_db_max_count()){ 1933 int addr_type = BD_ADDR_TYPE_UNKNOWN; 1934 bd_addr_t addr; 1935 sm_key_t irk; 1936 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1937 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1938 1939 // skip unused entries 1940 if (addr_type == BD_ADDR_TYPE_UNKNOWN){ 1941 sm_address_resolution_test++; 1942 continue; 1943 } 1944 1945 if ((sm_address_resolution_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ 1946 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1947 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1948 break; 1949 } 1950 1951 // if connection type is public, it must be a different one 1952 if (sm_address_resolution_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1953 sm_address_resolution_test++; 1954 continue; 1955 } 1956 1957 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1958 1959 log_info("LE Device Lookup: calculate AH"); 1960 log_info_key("IRK", irk); 1961 1962 (void)memcpy(sm_aes128_key, irk, 16); 1963 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1964 sm_address_resolution_ah_calculation_active = 1; 1965 sm_aes128_state = SM_AES128_ACTIVE; 1966 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1967 return; 1968 } 1969 1970 if (sm_address_resolution_test >= le_device_db_max_count()){ 1971 log_info("LE Device Lookup: not found"); 1972 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1973 } 1974 } 1975 1976 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1977 switch (sm_sc_oob_state){ 1978 case SM_SC_OOB_W2_CALC_CONFIRM: 1979 if (!sm_cmac_ready()) break; 1980 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1981 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1982 return; 1983 default: 1984 break; 1985 } 1986 #endif 1987 1988 // assert that we can send at least commands - cmd might have been sent by crypto engine 1989 if (!hci_can_send_command_packet_now()) return; 1990 1991 // handle basic actions that don't requires the full context 1992 hci_connections_get_iterator(&it); 1993 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1994 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1995 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1996 switch(sm_connection->sm_engine_state){ 1997 // responder side 1998 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1999 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2000 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2001 return; 2002 2003 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2004 case SM_SC_RECEIVED_LTK_REQUEST: 2005 switch (sm_connection->sm_irk_lookup_state){ 2006 case IRK_LOOKUP_FAILED: 2007 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2008 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2009 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2010 return; 2011 default: 2012 break; 2013 } 2014 break; 2015 #endif 2016 default: 2017 break; 2018 } 2019 } 2020 2021 // 2022 // active connection handling 2023 // -- use loop to handle next connection if lock on setup context is released 2024 2025 while (true) { 2026 2027 // Find connections that requires setup context and make active if no other is locked 2028 hci_connections_get_iterator(&it); 2029 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2030 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2031 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2032 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2033 int done = 1; 2034 int err; 2035 UNUSED(err); 2036 2037 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2038 // assert ec key is ready 2039 if ((sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) 2040 || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST)){ 2041 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 2042 sm_ec_generate_new_key(); 2043 } 2044 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 2045 continue; 2046 } 2047 } 2048 #endif 2049 2050 switch (sm_connection->sm_engine_state) { 2051 #ifdef ENABLE_LE_PERIPHERAL 2052 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2053 // send packet if possible, 2054 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2055 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, sm_auth_req}; 2056 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2057 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2058 } else { 2059 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2060 } 2061 // don't lock sxetup context yet 2062 done = 0; 2063 break; 2064 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2065 sm_reset_setup(); 2066 sm_init_setup(sm_connection); 2067 // recover pairing request 2068 (void)memcpy(&setup->sm_m_preq, 2069 &sm_connection->sm_m_preq, 2070 sizeof(sm_pairing_packet_t)); 2071 err = sm_stk_generation_init(sm_connection); 2072 2073 #ifdef ENABLE_TESTING_SUPPORT 2074 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2075 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2076 err = test_pairing_failure; 2077 } 2078 #endif 2079 if (err){ 2080 setup->sm_pairing_failed_reason = err; 2081 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2082 break; 2083 } 2084 sm_timeout_start(sm_connection); 2085 // generate random number first, if we need to show passkey 2086 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2087 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); 2088 break; 2089 } 2090 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2091 break; 2092 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2093 sm_reset_setup(); 2094 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2095 break; 2096 2097 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2098 case SM_SC_RECEIVED_LTK_REQUEST: 2099 switch (sm_connection->sm_irk_lookup_state){ 2100 case IRK_LOOKUP_SUCCEEDED: 2101 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2102 // start using context by loading security info 2103 sm_reset_setup(); 2104 sm_load_security_info(sm_connection); 2105 if ((setup->sm_peer_ediv == 0) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2106 (void)memcpy(setup->sm_ltk, 2107 setup->sm_peer_ltk, 16); 2108 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2109 break; 2110 } 2111 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2112 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2113 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2114 // don't lock setup context yet 2115 return; 2116 default: 2117 // just wait until IRK lookup is completed 2118 // don't lock setup context yet 2119 done = 0; 2120 break; 2121 } 2122 break; 2123 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2124 #endif /* ENABLE_LE_PERIPHERAL */ 2125 2126 #ifdef ENABLE_LE_CENTRAL 2127 case SM_INITIATOR_PH0_HAS_LTK: 2128 sm_reset_setup(); 2129 sm_load_security_info(sm_connection); 2130 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2131 break; 2132 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2133 sm_reset_setup(); 2134 sm_init_setup(sm_connection); 2135 sm_timeout_start(sm_connection); 2136 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2137 break; 2138 #endif 2139 2140 default: 2141 done = 0; 2142 break; 2143 } 2144 if (done){ 2145 sm_active_connection_handle = sm_connection->sm_handle; 2146 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); 2147 } 2148 } 2149 2150 // 2151 // active connection handling 2152 // 2153 2154 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2155 2156 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2157 if (!connection) { 2158 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2159 return; 2160 } 2161 2162 // assert that we could send a SM PDU - not needed for all of the following 2163 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2164 log_info("cannot send now, requesting can send now event"); 2165 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2166 return; 2167 } 2168 2169 // send keypress notifications 2170 if (setup->sm_keypress_notification){ 2171 int i; 2172 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2173 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2174 uint8_t action = 0; 2175 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2176 if (flags & (1<<i)){ 2177 int clear_flag = 1; 2178 switch (i){ 2179 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2180 case SM_KEYPRESS_PASSKEY_CLEARED: 2181 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2182 default: 2183 break; 2184 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2185 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2186 num_actions--; 2187 clear_flag = num_actions == 0; 2188 break; 2189 } 2190 if (clear_flag){ 2191 flags &= ~(1<<i); 2192 } 2193 action = i; 2194 break; 2195 } 2196 } 2197 setup->sm_keypress_notification = (num_actions << 5) | flags; 2198 2199 // send keypress notification 2200 uint8_t buffer[2]; 2201 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2202 buffer[1] = action; 2203 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2204 2205 // try 2206 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2207 return; 2208 } 2209 2210 int key_distribution_flags; 2211 UNUSED(key_distribution_flags); 2212 2213 log_info("sm_run: state %u", connection->sm_engine_state); 2214 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2215 log_info("sm_run // cannot send"); 2216 } 2217 switch (connection->sm_engine_state){ 2218 2219 // general 2220 case SM_GENERAL_SEND_PAIRING_FAILED: { 2221 uint8_t buffer[2]; 2222 buffer[0] = SM_CODE_PAIRING_FAILED; 2223 buffer[1] = setup->sm_pairing_failed_reason; 2224 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2225 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2226 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2227 sm_done_for_handle(connection->sm_handle); 2228 break; 2229 } 2230 2231 // responding state 2232 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2233 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2234 if (!sm_cmac_ready()) break; 2235 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2236 sm_sc_calculate_local_confirm(connection); 2237 break; 2238 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2239 if (!sm_cmac_ready()) break; 2240 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2241 sm_sc_calculate_remote_confirm(connection); 2242 break; 2243 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2244 if (!sm_cmac_ready()) break; 2245 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2246 sm_sc_calculate_f6_for_dhkey_check(connection); 2247 break; 2248 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2249 if (!sm_cmac_ready()) break; 2250 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2251 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2252 break; 2253 case SM_SC_W2_CALCULATE_F5_SALT: 2254 if (!sm_cmac_ready()) break; 2255 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2256 f5_calculate_salt(connection); 2257 break; 2258 case SM_SC_W2_CALCULATE_F5_MACKEY: 2259 if (!sm_cmac_ready()) break; 2260 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2261 f5_calculate_mackey(connection); 2262 break; 2263 case SM_SC_W2_CALCULATE_F5_LTK: 2264 if (!sm_cmac_ready()) break; 2265 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2266 f5_calculate_ltk(connection); 2267 break; 2268 case SM_SC_W2_CALCULATE_G2: 2269 if (!sm_cmac_ready()) break; 2270 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2271 g2_calculate(connection); 2272 break; 2273 case SM_SC_W2_CALCULATE_H6_ILK: 2274 if (!sm_cmac_ready()) break; 2275 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2276 h6_calculate_ilk(connection); 2277 break; 2278 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2279 if (!sm_cmac_ready()) break; 2280 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2281 h6_calculate_br_edr_link_key(connection); 2282 break; 2283 #endif 2284 2285 #ifdef ENABLE_LE_CENTRAL 2286 // initiator side 2287 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2288 sm_key_t peer_ltk_flipped; 2289 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2290 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2291 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2292 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2293 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2294 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2295 return; 2296 } 2297 2298 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2299 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2300 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2301 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2302 sm_timeout_reset(connection); 2303 break; 2304 #endif 2305 2306 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2307 2308 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2309 int trigger_user_response = 0; 2310 int trigger_start_calculating_local_confirm = 0; 2311 uint8_t buffer[65]; 2312 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2313 // 2314 reverse_256(&ec_q[0], &buffer[1]); 2315 reverse_256(&ec_q[32], &buffer[33]); 2316 2317 #ifdef ENABLE_TESTING_SUPPORT 2318 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2319 log_info("testing_support: invalidating public key"); 2320 // flip single bit of public key coordinate 2321 buffer[1] ^= 1; 2322 } 2323 #endif 2324 2325 // stk generation method 2326 // passkey entry: notify app to show passkey or to request passkey 2327 switch (setup->sm_stk_generation_method){ 2328 case JUST_WORKS: 2329 case NUMERIC_COMPARISON: 2330 if (IS_RESPONDER(connection->sm_role)){ 2331 // responder 2332 trigger_start_calculating_local_confirm = 1; 2333 connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; 2334 } else { 2335 // initiator 2336 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2337 } 2338 break; 2339 case PK_INIT_INPUT: 2340 case PK_RESP_INPUT: 2341 case PK_BOTH_INPUT: 2342 // use random TK for display 2343 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 2344 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 2345 setup->sm_passkey_bit = 0; 2346 2347 if (IS_RESPONDER(connection->sm_role)){ 2348 // responder 2349 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2350 } else { 2351 // initiator 2352 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2353 } 2354 trigger_user_response = 1; 2355 break; 2356 case OOB: 2357 if (IS_RESPONDER(connection->sm_role)){ 2358 // responder 2359 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2360 } else { 2361 // initiator 2362 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2363 } 2364 break; 2365 } 2366 2367 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2368 sm_timeout_reset(connection); 2369 2370 // trigger user response and calc confirm after sending pdu 2371 if (trigger_user_response){ 2372 sm_trigger_user_response(connection); 2373 } 2374 if (trigger_start_calculating_local_confirm){ 2375 sm_sc_start_calculating_local_confirm(connection); 2376 } 2377 break; 2378 } 2379 case SM_SC_SEND_CONFIRMATION: { 2380 uint8_t buffer[17]; 2381 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2382 reverse_128(setup->sm_local_confirm, &buffer[1]); 2383 if (IS_RESPONDER(connection->sm_role)){ 2384 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2385 } else { 2386 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2387 } 2388 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2389 sm_timeout_reset(connection); 2390 break; 2391 } 2392 case SM_SC_SEND_PAIRING_RANDOM: { 2393 uint8_t buffer[17]; 2394 buffer[0] = SM_CODE_PAIRING_RANDOM; 2395 reverse_128(setup->sm_local_nonce, &buffer[1]); 2396 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2397 if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20)){ 2398 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2399 if (IS_RESPONDER(connection->sm_role)){ 2400 // responder 2401 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2402 } else { 2403 // initiator 2404 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2405 } 2406 } else { 2407 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2408 if (IS_RESPONDER(connection->sm_role)){ 2409 // responder 2410 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2411 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2412 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2413 } else { 2414 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2415 sm_sc_prepare_dhkey_check(connection); 2416 } 2417 } else { 2418 // initiator 2419 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2420 } 2421 } 2422 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2423 sm_timeout_reset(connection); 2424 break; 2425 } 2426 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2427 uint8_t buffer[17]; 2428 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2429 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2430 2431 if (IS_RESPONDER(connection->sm_role)){ 2432 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2433 } else { 2434 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2435 } 2436 2437 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2438 sm_timeout_reset(connection); 2439 break; 2440 } 2441 2442 #endif 2443 2444 #ifdef ENABLE_LE_PERIPHERAL 2445 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2446 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2447 2448 // start with initiator key dist flags 2449 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2450 2451 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2452 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2453 if (setup->sm_use_secure_connections){ 2454 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2455 } 2456 #endif 2457 // setup in response 2458 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); 2459 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); 2460 2461 // update key distribution after ENC was dropped 2462 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2463 2464 if (setup->sm_use_secure_connections){ 2465 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2466 } else { 2467 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2468 } 2469 2470 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2471 sm_timeout_reset(connection); 2472 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2473 if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ 2474 sm_trigger_user_response(connection); 2475 } 2476 return; 2477 #endif 2478 2479 case SM_PH2_SEND_PAIRING_RANDOM: { 2480 uint8_t buffer[17]; 2481 buffer[0] = SM_CODE_PAIRING_RANDOM; 2482 reverse_128(setup->sm_local_random, &buffer[1]); 2483 if (IS_RESPONDER(connection->sm_role)){ 2484 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2485 } else { 2486 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2487 } 2488 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2489 sm_timeout_reset(connection); 2490 break; 2491 } 2492 2493 case SM_PH2_C1_GET_ENC_A: 2494 // already busy? 2495 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2496 // calculate confirm using aes128 engine - step 1 2497 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); 2498 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2499 sm_aes128_state = SM_AES128_ACTIVE; 2500 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); 2501 break; 2502 2503 case SM_PH2_C1_GET_ENC_C: 2504 // already busy? 2505 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2506 // calculate m_confirm using aes128 engine - step 1 2507 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); 2508 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2509 sm_aes128_state = SM_AES128_ACTIVE; 2510 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); 2511 break; 2512 2513 case SM_PH2_CALC_STK: 2514 // already busy? 2515 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2516 // calculate STK 2517 if (IS_RESPONDER(connection->sm_role)){ 2518 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2519 } else { 2520 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2521 } 2522 connection->sm_engine_state = SM_PH2_W4_STK; 2523 sm_aes128_state = SM_AES128_ACTIVE; 2524 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); 2525 break; 2526 2527 case SM_PH3_Y_GET_ENC: 2528 // already busy? 2529 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2530 // PH3B2 - calculate Y from - enc 2531 2532 // dm helper (was sm_dm_r_prime) 2533 // r' = padding || r 2534 // r - 64 bit value 2535 memset(&sm_aes128_plaintext[0], 0, 8); 2536 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2537 2538 // Y = dm(DHK, Rand) 2539 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2540 sm_aes128_state = SM_AES128_ACTIVE; 2541 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); 2542 break; 2543 2544 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2545 uint8_t buffer[17]; 2546 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2547 reverse_128(setup->sm_local_confirm, &buffer[1]); 2548 if (IS_RESPONDER(connection->sm_role)){ 2549 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2550 } else { 2551 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2552 } 2553 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2554 sm_timeout_reset(connection); 2555 return; 2556 } 2557 #ifdef ENABLE_LE_PERIPHERAL 2558 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2559 sm_key_t stk_flipped; 2560 reverse_128(setup->sm_ltk, stk_flipped); 2561 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2562 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2563 return; 2564 } 2565 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2566 sm_key_t ltk_flipped; 2567 reverse_128(setup->sm_ltk, ltk_flipped); 2568 connection->sm_engine_state = SM_RESPONDER_IDLE; 2569 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2570 sm_done_for_handle(connection->sm_handle); 2571 return; 2572 } 2573 case SM_RESPONDER_PH4_Y_GET_ENC: 2574 // already busy? 2575 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2576 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2577 2578 // dm helper (was sm_dm_r_prime) 2579 // r' = padding || r 2580 // r - 64 bit value 2581 memset(&sm_aes128_plaintext[0], 0, 8); 2582 (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); 2583 2584 // Y = dm(DHK, Rand) 2585 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2586 sm_aes128_state = SM_AES128_ACTIVE; 2587 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); 2588 return; 2589 #endif 2590 #ifdef ENABLE_LE_CENTRAL 2591 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2592 sm_key_t stk_flipped; 2593 reverse_128(setup->sm_ltk, stk_flipped); 2594 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2595 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2596 return; 2597 } 2598 #endif 2599 2600 case SM_PH3_DISTRIBUTE_KEYS: 2601 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2602 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2603 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2604 uint8_t buffer[17]; 2605 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2606 reverse_128(setup->sm_ltk, &buffer[1]); 2607 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2608 sm_timeout_reset(connection); 2609 return; 2610 } 2611 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2612 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2613 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2614 uint8_t buffer[11]; 2615 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2616 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2617 reverse_64(setup->sm_local_rand, &buffer[3]); 2618 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2619 sm_timeout_reset(connection); 2620 return; 2621 } 2622 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2623 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2624 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2625 uint8_t buffer[17]; 2626 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2627 reverse_128(sm_persistent_irk, &buffer[1]); 2628 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2629 sm_timeout_reset(connection); 2630 return; 2631 } 2632 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2633 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2634 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2635 bd_addr_t local_address; 2636 uint8_t buffer[8]; 2637 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2638 switch (gap_random_address_get_mode()){ 2639 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2640 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2641 // public or static random 2642 gap_le_get_own_address(&buffer[1], local_address); 2643 break; 2644 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2645 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2646 // fallback to public 2647 gap_local_bd_addr(local_address); 2648 buffer[1] = 0; 2649 break; 2650 } 2651 reverse_bd_addr(local_address, &buffer[2]); 2652 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2653 sm_timeout_reset(connection); 2654 return; 2655 } 2656 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2657 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2658 setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2659 2660 #ifdef ENABLE_LE_SIGNED_WRITE 2661 // hack to reproduce test runs 2662 if (test_use_fixed_local_csrk){ 2663 memset(setup->sm_local_csrk, 0xcc, 16); 2664 } 2665 2666 // store local CSRK 2667 if (setup->sm_le_device_index >= 0){ 2668 log_info("sm: store local CSRK"); 2669 le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); 2670 le_device_db_local_counter_set(setup->sm_le_device_index, 0); 2671 } 2672 #endif 2673 2674 uint8_t buffer[17]; 2675 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2676 reverse_128(setup->sm_local_csrk, &buffer[1]); 2677 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2678 sm_timeout_reset(connection); 2679 return; 2680 } 2681 2682 // keys are sent 2683 if (IS_RESPONDER(connection->sm_role)){ 2684 // slave -> receive master keys if any 2685 if (sm_key_distribution_all_received(connection)){ 2686 sm_key_distribution_handle_all_received(connection); 2687 connection->sm_engine_state = SM_RESPONDER_IDLE; 2688 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2689 sm_done_for_handle(connection->sm_handle); 2690 } else { 2691 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2692 } 2693 } else { 2694 sm_master_pairing_success(connection); 2695 } 2696 break; 2697 2698 default: 2699 break; 2700 } 2701 2702 // check again if active connection was released 2703 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2704 } 2705 } 2706 2707 // sm_aes128_state stays active 2708 static void sm_handle_encryption_result_enc_a(void *arg){ 2709 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2710 sm_aes128_state = SM_AES128_IDLE; 2711 2712 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2713 if (connection == NULL) return; 2714 2715 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2716 sm_aes128_state = SM_AES128_ACTIVE; 2717 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); 2718 } 2719 2720 static void sm_handle_encryption_result_enc_b(void *arg){ 2721 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2722 sm_aes128_state = SM_AES128_IDLE; 2723 2724 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2725 if (connection == NULL) return; 2726 2727 log_info_key("c1!", setup->sm_local_confirm); 2728 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2729 sm_run(); 2730 } 2731 2732 // sm_aes128_state stays active 2733 static void sm_handle_encryption_result_enc_c(void *arg){ 2734 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2735 sm_aes128_state = SM_AES128_IDLE; 2736 2737 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2738 if (connection == NULL) return; 2739 2740 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2741 sm_aes128_state = SM_AES128_ACTIVE; 2742 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); 2743 } 2744 2745 static void sm_handle_encryption_result_enc_d(void * arg){ 2746 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2747 sm_aes128_state = SM_AES128_IDLE; 2748 2749 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2750 if (connection == NULL) return; 2751 2752 log_info_key("c1!", sm_aes128_ciphertext); 2753 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2754 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2755 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2756 sm_run(); 2757 return; 2758 } 2759 if (IS_RESPONDER(connection->sm_role)){ 2760 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2761 sm_run(); 2762 } else { 2763 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2764 sm_aes128_state = SM_AES128_ACTIVE; 2765 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); 2766 } 2767 } 2768 2769 static void sm_handle_encryption_result_enc_stk(void *arg){ 2770 sm_aes128_state = SM_AES128_IDLE; 2771 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2772 2773 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2774 if (connection == NULL) return; 2775 2776 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2777 log_info_key("stk", setup->sm_ltk); 2778 if (IS_RESPONDER(connection->sm_role)){ 2779 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2780 } else { 2781 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2782 } 2783 sm_run(); 2784 } 2785 2786 // sm_aes128_state stays active 2787 static void sm_handle_encryption_result_enc_ph3_y(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 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2795 log_info_hex16("y", setup->sm_local_y); 2796 // PH3B3 - calculate EDIV 2797 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2798 log_info_hex16("ediv", setup->sm_local_ediv); 2799 // PH3B4 - calculate LTK - enc 2800 // LTK = d1(ER, DIV, 0)) 2801 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2802 sm_aes128_state = SM_AES128_ACTIVE; 2803 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); 2804 } 2805 2806 #ifdef ENABLE_LE_PERIPHERAL 2807 // sm_aes128_state stays active 2808 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2809 sm_aes128_state = SM_AES128_IDLE; 2810 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2811 2812 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2813 if (connection == NULL) return; 2814 2815 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2816 log_info_hex16("y", setup->sm_local_y); 2817 2818 // PH3B3 - calculate DIV 2819 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2820 log_info_hex16("ediv", setup->sm_local_ediv); 2821 // PH3B4 - calculate LTK - enc 2822 // LTK = d1(ER, DIV, 0)) 2823 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2824 sm_aes128_state = SM_AES128_ACTIVE; 2825 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); 2826 } 2827 #endif 2828 2829 // sm_aes128_state stays active 2830 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2831 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2832 sm_aes128_state = SM_AES128_IDLE; 2833 2834 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2835 if (connection == NULL) return; 2836 2837 log_info_key("ltk", setup->sm_ltk); 2838 // calc CSRK next 2839 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2840 sm_aes128_state = SM_AES128_ACTIVE; 2841 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); 2842 } 2843 2844 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2845 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2846 sm_aes128_state = SM_AES128_IDLE; 2847 2848 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2849 if (connection == NULL) return; 2850 2851 sm_aes128_state = SM_AES128_IDLE; 2852 log_info_key("csrk", setup->sm_local_csrk); 2853 if (setup->sm_key_distribution_send_set){ 2854 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2855 } else { 2856 // no keys to send, just continue 2857 if (IS_RESPONDER(connection->sm_role)){ 2858 // slave -> receive master keys 2859 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2860 } else { 2861 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2862 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2863 } else { 2864 sm_master_pairing_success(connection); 2865 } 2866 } 2867 } 2868 sm_run(); 2869 } 2870 2871 #ifdef ENABLE_LE_PERIPHERAL 2872 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2873 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2874 sm_aes128_state = SM_AES128_IDLE; 2875 2876 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2877 if (connection == NULL) return; 2878 2879 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2880 log_info_key("ltk", setup->sm_ltk); 2881 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2882 sm_run(); 2883 } 2884 #endif 2885 2886 static void sm_handle_encryption_result_address_resolution(void *arg){ 2887 UNUSED(arg); 2888 sm_aes128_state = SM_AES128_IDLE; 2889 2890 sm_address_resolution_ah_calculation_active = 0; 2891 // compare calulated address against connecting device 2892 uint8_t * hash = &sm_aes128_ciphertext[13]; 2893 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2894 log_info("LE Device Lookup: matched resolvable private address"); 2895 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2896 sm_run(); 2897 return; 2898 } 2899 // no match, try next 2900 sm_address_resolution_test++; 2901 sm_run(); 2902 } 2903 2904 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2905 UNUSED(arg); 2906 sm_aes128_state = SM_AES128_IDLE; 2907 2908 log_info_key("irk", sm_persistent_irk); 2909 dkg_state = DKG_CALC_DHK; 2910 sm_run(); 2911 } 2912 2913 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2914 UNUSED(arg); 2915 sm_aes128_state = SM_AES128_IDLE; 2916 2917 log_info_key("dhk", sm_persistent_dhk); 2918 dkg_state = DKG_READY; 2919 sm_run(); 2920 } 2921 2922 static void sm_handle_encryption_result_rau(void *arg){ 2923 UNUSED(arg); 2924 sm_aes128_state = SM_AES128_IDLE; 2925 2926 (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2927 rau_state = RAU_SET_ADDRESS; 2928 sm_run(); 2929 } 2930 2931 static void sm_handle_random_result_rau(void * arg){ 2932 UNUSED(arg); 2933 // non-resolvable vs. resolvable 2934 switch (gap_random_adress_type){ 2935 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2936 // resolvable: use random as prand and calc address hash 2937 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2938 sm_random_address[0] &= 0x3f; 2939 sm_random_address[0] |= 0x40; 2940 rau_state = RAU_GET_ENC; 2941 break; 2942 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2943 default: 2944 // "The two most significant bits of the address shall be equal to ‘0’"" 2945 sm_random_address[0] &= 0x3f; 2946 rau_state = RAU_SET_ADDRESS; 2947 break; 2948 } 2949 sm_run(); 2950 } 2951 2952 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2953 static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ 2954 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2955 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2956 if (connection == NULL) return; 2957 2958 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2959 sm_run(); 2960 } 2961 2962 static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ 2963 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2964 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2965 if (connection == NULL) return; 2966 2967 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2968 sm_run(); 2969 } 2970 #endif 2971 2972 static void sm_handle_random_result_ph2_random(void * arg){ 2973 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2974 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2975 if (connection == NULL) return; 2976 2977 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2978 sm_run(); 2979 } 2980 2981 static void sm_handle_random_result_ph2_tk(void * arg){ 2982 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 2983 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 2984 if (connection == NULL) return; 2985 2986 sm_reset_tk(); 2987 uint32_t tk; 2988 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2989 // map random to 0-999999 without speding much cycles on a modulus operation 2990 tk = little_endian_read_32(sm_random_data,0); 2991 tk = tk & 0xfffff; // 1048575 2992 if (tk >= 999999){ 2993 tk = tk - 999999; 2994 } 2995 } else { 2996 // override with pre-defined passkey 2997 tk = sm_fixed_passkey_in_display_role; 2998 } 2999 big_endian_store_32(setup->sm_tk, 12, tk); 3000 if (IS_RESPONDER(connection->sm_role)){ 3001 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3002 } else { 3003 if (setup->sm_use_secure_connections){ 3004 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3005 } else { 3006 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3007 sm_trigger_user_response(connection); 3008 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3009 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3010 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); 3011 } 3012 } 3013 } 3014 sm_run(); 3015 } 3016 3017 static void sm_handle_random_result_ph3_div(void * arg){ 3018 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; 3019 sm_connection_t * connection = sm_get_connection_for_handle(con_handle); 3020 if (connection == NULL) return; 3021 3022 // use 16 bit from random value as div 3023 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 3024 log_info_hex16("div", setup->sm_local_div); 3025 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3026 sm_run(); 3027 } 3028 3029 static void sm_handle_random_result_ph3_random(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 reverse_64(sm_random_data, setup->sm_local_rand); 3035 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3036 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3037 // no db for authenticated flag hack: store flag in bit 4 of LSB 3038 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3039 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); 3040 } 3041 static void sm_validate_er_ir(void){ 3042 // warn about default ER/IR 3043 int warning = 0; 3044 if (sm_ir_is_default()){ 3045 warning = 1; 3046 log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); 3047 } 3048 if (sm_er_is_default()){ 3049 warning = 1; 3050 log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); 3051 } 3052 if (warning) { 3053 log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); 3054 } 3055 } 3056 3057 static void sm_handle_random_result_ir(void *arg){ 3058 sm_persistent_keys_random_active = 0; 3059 if (arg){ 3060 // key generated, store in tlv 3061 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16); 3062 log_info("Generated IR key. Store in TLV status: %d", status); 3063 } 3064 log_info_key("IR", sm_persistent_ir); 3065 dkg_state = DKG_CALC_IRK; 3066 3067 if (test_use_fixed_local_irk){ 3068 log_info_key("IRK", sm_persistent_irk); 3069 dkg_state = DKG_CALC_DHK; 3070 } 3071 3072 sm_run(); 3073 } 3074 3075 static void sm_handle_random_result_er(void *arg){ 3076 sm_persistent_keys_random_active = 0; 3077 if (arg){ 3078 // key generated, store in tlv 3079 int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16); 3080 log_info("Generated ER key. Store in TLV status: %d", status); 3081 } 3082 log_info_key("ER", sm_persistent_er); 3083 3084 // try load ir 3085 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16); 3086 if (key_size == 16){ 3087 // ok, let's continue 3088 log_info("IR from TLV"); 3089 sm_handle_random_result_ir( NULL ); 3090 } else { 3091 // invalid, generate new random one 3092 sm_persistent_keys_random_active = 1; 3093 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); 3094 } 3095 } 3096 3097 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3098 3099 UNUSED(channel); // ok: there is no channel 3100 UNUSED(size); // ok: fixed format HCI events 3101 3102 sm_connection_t * sm_conn; 3103 hci_con_handle_t con_handle; 3104 3105 switch (packet_type) { 3106 3107 case HCI_EVENT_PACKET: 3108 switch (hci_event_packet_get_type(packet)) { 3109 3110 case BTSTACK_EVENT_STATE: 3111 // bt stack activated, get started 3112 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3113 log_info("HCI Working!"); 3114 3115 // setup IR/ER with TLV 3116 btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); 3117 if (sm_tlv_impl){ 3118 int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16); 3119 if (key_size == 16){ 3120 // ok, let's continue 3121 log_info("ER from TLV"); 3122 sm_handle_random_result_er( NULL ); 3123 } else { 3124 // invalid, generate random one 3125 sm_persistent_keys_random_active = 1; 3126 btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); 3127 } 3128 } else { 3129 sm_validate_er_ir(); 3130 dkg_state = DKG_CALC_IRK; 3131 3132 if (test_use_fixed_local_irk){ 3133 log_info_key("IRK", sm_persistent_irk); 3134 dkg_state = DKG_CALC_DHK; 3135 } 3136 } 3137 3138 // restart random address updates after power cycle 3139 gap_random_address_set_mode(gap_random_adress_type); 3140 } 3141 break; 3142 3143 case HCI_EVENT_LE_META: 3144 switch (packet[2]) { 3145 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3146 3147 log_info("sm: connected"); 3148 3149 if (packet[3]) return; // connection failed 3150 3151 con_handle = little_endian_read_16(packet, 4); 3152 sm_conn = sm_get_connection_for_handle(con_handle); 3153 if (!sm_conn) break; 3154 3155 sm_conn->sm_handle = con_handle; 3156 sm_conn->sm_role = packet[6]; 3157 sm_conn->sm_peer_addr_type = packet[7]; 3158 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3159 3160 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3161 3162 // reset security properties 3163 sm_conn->sm_connection_encrypted = 0; 3164 sm_conn->sm_connection_authenticated = 0; 3165 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3166 sm_conn->sm_le_db_index = -1; 3167 3168 // prepare CSRK lookup (does not involve setup) 3169 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3170 3171 // just connected -> everything else happens in sm_run() 3172 if (IS_RESPONDER(sm_conn->sm_role)){ 3173 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3174 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3175 if (sm_slave_request_security) { 3176 // request security if requested by app 3177 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3178 } else { 3179 // otherwise, wait for pairing request 3180 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3181 } 3182 } 3183 break; 3184 } else { 3185 // master 3186 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3187 } 3188 break; 3189 3190 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3191 con_handle = little_endian_read_16(packet, 3); 3192 sm_conn = sm_get_connection_for_handle(con_handle); 3193 if (!sm_conn) break; 3194 3195 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3196 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3197 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3198 break; 3199 } 3200 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3201 // PH2 SEND LTK as we need to exchange keys in PH3 3202 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3203 break; 3204 } 3205 3206 // store rand and ediv 3207 reverse_64(&packet[5], sm_conn->sm_local_rand); 3208 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3209 3210 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3211 // potentially stored LTK is from the master 3212 if ((sm_conn->sm_local_ediv != 0) || !sm_is_null_random(sm_conn->sm_local_rand)){ 3213 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3214 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3215 break; 3216 } 3217 // additionally check if remote is in LE Device DB if requested 3218 switch(sm_conn->sm_irk_lookup_state){ 3219 case IRK_LOOKUP_FAILED: 3220 log_info("LTK Request: device not in device db"); 3221 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3222 break; 3223 case IRK_LOOKUP_SUCCEEDED: 3224 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3225 break; 3226 default: 3227 // wait for irk look doen 3228 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3229 break; 3230 } 3231 break; 3232 } 3233 3234 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3235 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3236 #else 3237 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3238 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3239 #endif 3240 break; 3241 3242 default: 3243 break; 3244 } 3245 break; 3246 3247 case HCI_EVENT_ENCRYPTION_CHANGE: 3248 con_handle = little_endian_read_16(packet, 3); 3249 sm_conn = sm_get_connection_for_handle(con_handle); 3250 if (!sm_conn) break; 3251 3252 sm_conn->sm_connection_encrypted = packet[5]; 3253 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3254 sm_conn->sm_actual_encryption_key_size); 3255 log_info("event handler, state %u", sm_conn->sm_engine_state); 3256 3257 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3258 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3259 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3260 // notify client, if pairing was requested before 3261 if (sm_conn->sm_pairing_requested){ 3262 sm_conn->sm_pairing_requested = 0; 3263 if (sm_conn->sm_connection_encrypted){ 3264 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3265 } else { 3266 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3267 } 3268 } 3269 sm_done_for_handle(sm_conn->sm_handle); 3270 break; 3271 } 3272 3273 if (!sm_conn->sm_connection_encrypted) break; 3274 sm_conn->sm_connection_sc = setup->sm_use_secure_connections; 3275 3276 // continue pairing 3277 switch (sm_conn->sm_engine_state){ 3278 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3279 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3280 sm_done_for_handle(sm_conn->sm_handle); 3281 break; 3282 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3283 if (IS_RESPONDER(sm_conn->sm_role)){ 3284 // slave 3285 if (setup->sm_use_secure_connections){ 3286 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3287 } else { 3288 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); 3289 } 3290 } else { 3291 // master 3292 if (sm_key_distribution_all_received(sm_conn)){ 3293 // skip receiving keys as there are none 3294 sm_key_distribution_handle_all_received(sm_conn); 3295 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); 3296 } else { 3297 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3298 } 3299 } 3300 break; 3301 default: 3302 break; 3303 } 3304 break; 3305 3306 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3307 con_handle = little_endian_read_16(packet, 3); 3308 sm_conn = sm_get_connection_for_handle(con_handle); 3309 if (!sm_conn) break; 3310 3311 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3312 log_info("event handler, state %u", sm_conn->sm_engine_state); 3313 // continue if part of initial pairing 3314 switch (sm_conn->sm_engine_state){ 3315 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3316 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3317 sm_done_for_handle(sm_conn->sm_handle); 3318 break; 3319 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3320 if (IS_RESPONDER(sm_conn->sm_role)){ 3321 // slave 3322 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); 3323 } else { 3324 // master 3325 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3326 } 3327 break; 3328 default: 3329 break; 3330 } 3331 break; 3332 3333 3334 case HCI_EVENT_DISCONNECTION_COMPLETE: 3335 con_handle = little_endian_read_16(packet, 3); 3336 sm_done_for_handle(con_handle); 3337 sm_conn = sm_get_connection_for_handle(con_handle); 3338 if (!sm_conn) break; 3339 3340 // delete stored bonding on disconnect with authentication failure in ph0 3341 if ((sm_conn->sm_role == 0) 3342 && (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED) 3343 && (packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE)){ 3344 le_device_db_remove(sm_conn->sm_le_db_index); 3345 } 3346 3347 // pairing failed, if it was ongoing 3348 switch (sm_conn->sm_engine_state){ 3349 case SM_GENERAL_IDLE: 3350 case SM_INITIATOR_CONNECTED: 3351 case SM_RESPONDER_IDLE: 3352 break; 3353 default: 3354 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3355 break; 3356 } 3357 3358 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3359 sm_conn->sm_handle = 0; 3360 break; 3361 3362 case HCI_EVENT_COMMAND_COMPLETE: 3363 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3364 // set local addr for le device db 3365 bd_addr_t addr; 3366 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3367 le_device_db_set_local_bd_addr(addr); 3368 } 3369 break; 3370 default: 3371 break; 3372 } 3373 break; 3374 default: 3375 break; 3376 } 3377 3378 sm_run(); 3379 } 3380 3381 static inline int sm_calc_actual_encryption_key_size(int other){ 3382 if (other < sm_min_encryption_key_size) return 0; 3383 if (other < sm_max_encryption_key_size) return other; 3384 return sm_max_encryption_key_size; 3385 } 3386 3387 3388 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3389 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3390 switch (method){ 3391 case JUST_WORKS: 3392 case NUMERIC_COMPARISON: 3393 return 1; 3394 default: 3395 return 0; 3396 } 3397 } 3398 // responder 3399 3400 static int sm_passkey_used(stk_generation_method_t method){ 3401 switch (method){ 3402 case PK_RESP_INPUT: 3403 return 1; 3404 default: 3405 return 0; 3406 } 3407 } 3408 3409 static int sm_passkey_entry(stk_generation_method_t method){ 3410 switch (method){ 3411 case PK_RESP_INPUT: 3412 case PK_INIT_INPUT: 3413 case PK_BOTH_INPUT: 3414 return 1; 3415 default: 3416 return 0; 3417 } 3418 } 3419 3420 #endif 3421 3422 /** 3423 * @return ok 3424 */ 3425 static int sm_validate_stk_generation_method(void){ 3426 // check if STK generation method is acceptable by client 3427 switch (setup->sm_stk_generation_method){ 3428 case JUST_WORKS: 3429 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3430 case PK_RESP_INPUT: 3431 case PK_INIT_INPUT: 3432 case PK_BOTH_INPUT: 3433 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3434 case OOB: 3435 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3436 case NUMERIC_COMPARISON: 3437 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3438 default: 3439 return 0; 3440 } 3441 } 3442 3443 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3444 3445 // size of complete sm_pdu used to validate input 3446 static const uint8_t sm_pdu_size[] = { 3447 0, // 0x00 invalid opcode 3448 7, // 0x01 pairing request 3449 7, // 0x02 pairing response 3450 17, // 0x03 pairing confirm 3451 17, // 0x04 pairing random 3452 2, // 0x05 pairing failed 3453 17, // 0x06 encryption information 3454 11, // 0x07 master identification 3455 17, // 0x08 identification information 3456 8, // 0x09 identify address information 3457 17, // 0x0a signing information 3458 2, // 0x0b security request 3459 65, // 0x0c pairing public key 3460 17, // 0x0d pairing dhk check 3461 2, // 0x0e keypress notification 3462 }; 3463 3464 if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ 3465 sm_run(); 3466 } 3467 3468 if (packet_type != SM_DATA_PACKET) return; 3469 if (size == 0) return; 3470 3471 uint8_t sm_pdu_code = packet[0]; 3472 3473 // validate pdu size 3474 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3475 if (sm_pdu_size[sm_pdu_code] != size) return; 3476 3477 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3478 if (!sm_conn) return; 3479 3480 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3481 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3482 sm_done_for_handle(con_handle); 3483 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3484 return; 3485 } 3486 3487 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3488 3489 int err; 3490 UNUSED(err); 3491 3492 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3493 uint8_t buffer[5]; 3494 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3495 buffer[1] = 3; 3496 little_endian_store_16(buffer, 2, con_handle); 3497 buffer[4] = packet[1]; 3498 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3499 return; 3500 } 3501 3502 switch (sm_conn->sm_engine_state){ 3503 3504 // a sm timeout requries a new physical connection 3505 case SM_GENERAL_TIMEOUT: 3506 return; 3507 3508 #ifdef ENABLE_LE_CENTRAL 3509 3510 // Initiator 3511 case SM_INITIATOR_CONNECTED: 3512 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3513 sm_pdu_received_in_wrong_state(sm_conn); 3514 break; 3515 } 3516 3517 // IRK complete? 3518 int have_ltk; 3519 uint8_t ltk[16]; 3520 switch (sm_conn->sm_irk_lookup_state){ 3521 case IRK_LOOKUP_FAILED: 3522 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3523 break; 3524 case IRK_LOOKUP_SUCCEEDED: 3525 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 3526 have_ltk = !sm_is_null_key(ltk); 3527 log_info("central: security request - have_ltk %u", have_ltk); 3528 if (have_ltk){ 3529 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3530 } else { 3531 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3532 } 3533 break; 3534 default: 3535 break; 3536 } 3537 3538 // otherwise, store security request 3539 sm_conn->sm_security_request_received = 1; 3540 break; 3541 3542 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3543 // Core 5, Vol 3, Part H, 2.4.6: 3544 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3545 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3546 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3547 log_info("Ignoring Security Request"); 3548 break; 3549 } 3550 3551 // all other pdus are incorrect 3552 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3553 sm_pdu_received_in_wrong_state(sm_conn); 3554 break; 3555 } 3556 3557 // store pairing request 3558 (void)memcpy(&setup->sm_s_pres, packet, 3559 sizeof(sm_pairing_packet_t)); 3560 err = sm_stk_generation_init(sm_conn); 3561 3562 #ifdef ENABLE_TESTING_SUPPORT 3563 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3564 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3565 err = test_pairing_failure; 3566 } 3567 #endif 3568 3569 if (err){ 3570 setup->sm_pairing_failed_reason = err; 3571 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3572 break; 3573 } 3574 3575 // generate random number first, if we need to show passkey 3576 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3577 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); 3578 break; 3579 } 3580 3581 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3582 if (setup->sm_use_secure_connections){ 3583 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3584 if (setup->sm_stk_generation_method == JUST_WORKS){ 3585 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3586 sm_trigger_user_response(sm_conn); 3587 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3588 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3589 } 3590 } else { 3591 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3592 } 3593 break; 3594 } 3595 #endif 3596 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3597 sm_trigger_user_response(sm_conn); 3598 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3599 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3600 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); 3601 } 3602 break; 3603 3604 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3605 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3606 sm_pdu_received_in_wrong_state(sm_conn); 3607 break; 3608 } 3609 3610 // store s_confirm 3611 reverse_128(&packet[1], setup->sm_peer_confirm); 3612 3613 #ifdef ENABLE_TESTING_SUPPORT 3614 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3615 log_info("testing_support: reset confirm value"); 3616 memset(setup->sm_peer_confirm, 0, 16); 3617 } 3618 #endif 3619 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3620 break; 3621 3622 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3623 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3624 sm_pdu_received_in_wrong_state(sm_conn); 3625 break;; 3626 } 3627 3628 // received random value 3629 reverse_128(&packet[1], setup->sm_peer_random); 3630 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3631 break; 3632 #endif 3633 3634 #ifdef ENABLE_LE_PERIPHERAL 3635 // Responder 3636 case SM_RESPONDER_IDLE: 3637 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3638 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3639 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3640 sm_pdu_received_in_wrong_state(sm_conn); 3641 break;; 3642 } 3643 3644 // store pairing request 3645 (void)memcpy(&sm_conn->sm_m_preq, packet, 3646 sizeof(sm_pairing_packet_t)); 3647 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3648 break; 3649 #endif 3650 3651 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3652 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3653 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3654 sm_pdu_received_in_wrong_state(sm_conn); 3655 break; 3656 } 3657 3658 // store public key for DH Key calculation 3659 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3660 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3661 3662 // validate public key 3663 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3664 if (err){ 3665 log_error("sm: peer public key invalid %x", err); 3666 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3667 break; 3668 } 3669 3670 // start calculating dhkey 3671 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); 3672 3673 3674 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3675 if (IS_RESPONDER(sm_conn->sm_role)){ 3676 // responder 3677 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3678 } else { 3679 // initiator 3680 // stk generation method 3681 // passkey entry: notify app to show passkey or to request passkey 3682 switch (setup->sm_stk_generation_method){ 3683 case JUST_WORKS: 3684 case NUMERIC_COMPARISON: 3685 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3686 break; 3687 case PK_RESP_INPUT: 3688 sm_sc_start_calculating_local_confirm(sm_conn); 3689 break; 3690 case PK_INIT_INPUT: 3691 case PK_BOTH_INPUT: 3692 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3693 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3694 break; 3695 } 3696 sm_sc_start_calculating_local_confirm(sm_conn); 3697 break; 3698 case OOB: 3699 // generate Nx 3700 log_info("Generate Na"); 3701 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); 3702 break; 3703 } 3704 } 3705 break; 3706 3707 case SM_SC_W4_CONFIRMATION: 3708 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3709 sm_pdu_received_in_wrong_state(sm_conn); 3710 break; 3711 } 3712 // received confirm value 3713 reverse_128(&packet[1], setup->sm_peer_confirm); 3714 3715 #ifdef ENABLE_TESTING_SUPPORT 3716 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3717 log_info("testing_support: reset confirm value"); 3718 memset(setup->sm_peer_confirm, 0, 16); 3719 } 3720 #endif 3721 if (IS_RESPONDER(sm_conn->sm_role)){ 3722 // responder 3723 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3724 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3725 // still waiting for passkey 3726 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3727 break; 3728 } 3729 } 3730 sm_sc_start_calculating_local_confirm(sm_conn); 3731 } else { 3732 // initiator 3733 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3734 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); 3735 } else { 3736 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3737 } 3738 } 3739 break; 3740 3741 case SM_SC_W4_PAIRING_RANDOM: 3742 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3743 sm_pdu_received_in_wrong_state(sm_conn); 3744 break; 3745 } 3746 3747 // received random value 3748 reverse_128(&packet[1], setup->sm_peer_nonce); 3749 3750 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3751 // only check for JUST WORK/NC in initiator role OR passkey entry 3752 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3753 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3754 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3755 break; 3756 } 3757 3758 // OOB 3759 if (setup->sm_stk_generation_method == OOB){ 3760 3761 // setup local random, set to zero if remote did not receive our data 3762 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3763 if (IS_RESPONDER(sm_conn->sm_role)){ 3764 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3765 log_info("Reset rb as A does not have OOB data"); 3766 memset(setup->sm_rb, 0, 16); 3767 } else { 3768 (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3769 log_info("Use stored rb"); 3770 log_info_hexdump(setup->sm_rb, 16); 3771 } 3772 } else { 3773 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3774 log_info("Reset ra as B does not have OOB data"); 3775 memset(setup->sm_ra, 0, 16); 3776 } else { 3777 (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3778 log_info("Use stored ra"); 3779 log_info_hexdump(setup->sm_ra, 16); 3780 } 3781 } 3782 3783 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3784 if (setup->sm_have_oob_data){ 3785 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3786 break; 3787 } 3788 } 3789 3790 // TODO: we only get here for Responder role with JW/NC 3791 sm_sc_state_after_receiving_random(sm_conn); 3792 break; 3793 3794 case SM_SC_W2_CALCULATE_G2: 3795 case SM_SC_W4_CALCULATE_G2: 3796 case SM_SC_W4_CALCULATE_DHKEY: 3797 case SM_SC_W2_CALCULATE_F5_SALT: 3798 case SM_SC_W4_CALCULATE_F5_SALT: 3799 case SM_SC_W2_CALCULATE_F5_MACKEY: 3800 case SM_SC_W4_CALCULATE_F5_MACKEY: 3801 case SM_SC_W2_CALCULATE_F5_LTK: 3802 case SM_SC_W4_CALCULATE_F5_LTK: 3803 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3804 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3805 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3806 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3807 sm_pdu_received_in_wrong_state(sm_conn); 3808 break; 3809 } 3810 // store DHKey Check 3811 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3812 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3813 3814 // have we been only waiting for dhkey check command? 3815 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3816 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3817 } 3818 break; 3819 #endif 3820 3821 #ifdef ENABLE_LE_PERIPHERAL 3822 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3823 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3824 sm_pdu_received_in_wrong_state(sm_conn); 3825 break; 3826 } 3827 3828 // received confirm value 3829 reverse_128(&packet[1], setup->sm_peer_confirm); 3830 3831 #ifdef ENABLE_TESTING_SUPPORT 3832 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3833 log_info("testing_support: reset confirm value"); 3834 memset(setup->sm_peer_confirm, 0, 16); 3835 } 3836 #endif 3837 // notify client to hide shown passkey 3838 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3839 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3840 } 3841 3842 // handle user cancel pairing? 3843 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3844 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3845 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3846 break; 3847 } 3848 3849 // wait for user action? 3850 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3851 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3852 break; 3853 } 3854 3855 // calculate and send local_confirm 3856 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); 3857 break; 3858 3859 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3860 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3861 sm_pdu_received_in_wrong_state(sm_conn); 3862 break;; 3863 } 3864 3865 // received random value 3866 reverse_128(&packet[1], setup->sm_peer_random); 3867 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3868 break; 3869 #endif 3870 3871 case SM_PH3_RECEIVE_KEYS: 3872 switch(sm_pdu_code){ 3873 case SM_CODE_ENCRYPTION_INFORMATION: 3874 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3875 reverse_128(&packet[1], setup->sm_peer_ltk); 3876 break; 3877 3878 case SM_CODE_MASTER_IDENTIFICATION: 3879 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3880 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3881 reverse_64(&packet[3], setup->sm_peer_rand); 3882 break; 3883 3884 case SM_CODE_IDENTITY_INFORMATION: 3885 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3886 reverse_128(&packet[1], setup->sm_peer_irk); 3887 break; 3888 3889 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3890 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3891 setup->sm_peer_addr_type = packet[1]; 3892 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3893 break; 3894 3895 case SM_CODE_SIGNING_INFORMATION: 3896 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3897 reverse_128(&packet[1], setup->sm_peer_csrk); 3898 break; 3899 default: 3900 // Unexpected PDU 3901 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3902 break; 3903 } 3904 // done with key distribution? 3905 if (sm_key_distribution_all_received(sm_conn)){ 3906 3907 sm_key_distribution_handle_all_received(sm_conn); 3908 3909 if (IS_RESPONDER(sm_conn->sm_role)){ 3910 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3911 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3912 } else { 3913 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3914 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3915 sm_done_for_handle(sm_conn->sm_handle); 3916 } 3917 } else { 3918 if (setup->sm_use_secure_connections){ 3919 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3920 } else { 3921 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); 3922 } 3923 } 3924 } 3925 break; 3926 default: 3927 // Unexpected PDU 3928 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3929 break; 3930 } 3931 3932 // try to send preparared packet 3933 sm_run(); 3934 } 3935 3936 // Security Manager Client API 3937 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3938 sm_get_oob_data = get_oob_data_callback; 3939 } 3940 3941 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)){ 3942 sm_get_sc_oob_data = get_sc_oob_data_callback; 3943 } 3944 3945 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3946 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3947 } 3948 3949 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3950 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3951 } 3952 3953 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3954 sm_min_encryption_key_size = min_size; 3955 sm_max_encryption_key_size = max_size; 3956 } 3957 3958 void sm_set_authentication_requirements(uint8_t auth_req){ 3959 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3960 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3961 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3962 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3963 } 3964 #endif 3965 sm_auth_req = auth_req; 3966 } 3967 3968 void sm_set_io_capabilities(io_capability_t io_capability){ 3969 sm_io_capabilities = io_capability; 3970 } 3971 3972 #ifdef ENABLE_LE_PERIPHERAL 3973 void sm_set_request_security(int enable){ 3974 sm_slave_request_security = enable; 3975 } 3976 #endif 3977 3978 void sm_set_er(sm_key_t er){ 3979 (void)memcpy(sm_persistent_er, er, 16); 3980 } 3981 3982 void sm_set_ir(sm_key_t ir){ 3983 (void)memcpy(sm_persistent_ir, ir, 16); 3984 } 3985 3986 // Testing support only 3987 void sm_test_set_irk(sm_key_t irk){ 3988 (void)memcpy(sm_persistent_irk, irk, 16); 3989 dkg_state = DKG_CALC_DHK; 3990 test_use_fixed_local_irk = true; 3991 } 3992 3993 void sm_test_use_fixed_local_csrk(void){ 3994 test_use_fixed_local_csrk = true; 3995 } 3996 3997 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3998 static void sm_ec_generated(void * arg){ 3999 UNUSED(arg); 4000 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4001 // trigger pairing if pending for ec key 4002 sm_run(); 4003 } 4004 static void sm_ec_generate_new_key(void){ 4005 log_info("sm: generate new ec key"); 4006 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 4007 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 4008 } 4009 #endif 4010 4011 #ifdef ENABLE_TESTING_SUPPORT 4012 void sm_test_set_pairing_failure(int reason){ 4013 test_pairing_failure = reason; 4014 } 4015 #endif 4016 4017 void sm_init(void){ 4018 // set default ER and IR values (should be unique - set by app or sm later using TLV) 4019 sm_er_ir_set_default(); 4020 4021 // defaults 4022 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 4023 | SM_STK_GENERATION_METHOD_OOB 4024 | SM_STK_GENERATION_METHOD_PASSKEY 4025 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 4026 4027 sm_max_encryption_key_size = 16; 4028 sm_min_encryption_key_size = 7; 4029 4030 sm_fixed_passkey_in_display_role = 0xffffffff; 4031 sm_reconstruct_ltk_without_le_device_db_entry = 1; 4032 4033 #ifdef USE_CMAC_ENGINE 4034 sm_cmac_active = 0; 4035 #endif 4036 dkg_state = DKG_W4_WORKING; 4037 rau_state = RAU_IDLE; 4038 sm_aes128_state = SM_AES128_IDLE; 4039 sm_address_resolution_test = -1; // no private address to resolve yet 4040 sm_address_resolution_ah_calculation_active = 0; 4041 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 4042 sm_address_resolution_general_queue = NULL; 4043 4044 gap_random_adress_update_period = 15 * 60 * 1000L; 4045 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 4046 4047 test_use_fixed_local_csrk = false; 4048 4049 // register for HCI Events from HCI 4050 hci_event_callback_registration.callback = &sm_event_packet_handler; 4051 hci_add_event_handler(&hci_event_callback_registration); 4052 4053 // 4054 btstack_crypto_init(); 4055 4056 // init le_device_db 4057 le_device_db_init(); 4058 4059 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 4060 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4061 4062 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4063 sm_ec_generate_new_key(); 4064 #endif 4065 } 4066 4067 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4068 sm_fixed_passkey_in_display_role = passkey; 4069 } 4070 4071 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4072 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4073 } 4074 4075 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4076 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4077 if (!hci_con) return NULL; 4078 return &hci_con->sm_connection; 4079 } 4080 4081 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4082 switch (sm_conn->sm_engine_state){ 4083 case SM_GENERAL_IDLE: 4084 case SM_RESPONDER_IDLE: 4085 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4086 sm_run(); 4087 break; 4088 default: 4089 break; 4090 } 4091 } 4092 4093 /** 4094 * @brief Trigger Security Request 4095 */ 4096 void sm_send_security_request(hci_con_handle_t con_handle){ 4097 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4098 if (!sm_conn) return; 4099 sm_send_security_request_for_connection(sm_conn); 4100 } 4101 4102 // request pairing 4103 void sm_request_pairing(hci_con_handle_t con_handle){ 4104 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4105 if (!sm_conn) return; // wrong connection 4106 4107 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4108 if (IS_RESPONDER(sm_conn->sm_role)){ 4109 sm_send_security_request_for_connection(sm_conn); 4110 } else { 4111 // used as a trigger to start central/master/initiator security procedures 4112 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4113 uint8_t ltk[16]; 4114 bool have_ltk; 4115 switch (sm_conn->sm_irk_lookup_state){ 4116 case IRK_LOOKUP_SUCCEEDED: 4117 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 4118 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); 4119 have_ltk = !sm_is_null_key(ltk); 4120 log_info("have ltk %u", have_ltk); 4121 if (have_ltk){ 4122 sm_conn->sm_pairing_requested = 1; 4123 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4124 break; 4125 } 4126 #endif 4127 /* fall through */ 4128 4129 case IRK_LOOKUP_FAILED: 4130 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4131 break; 4132 default: 4133 log_info("irk lookup pending"); 4134 sm_conn->sm_pairing_requested = 1; 4135 break; 4136 } 4137 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4138 sm_conn->sm_pairing_requested = 1; 4139 } 4140 } 4141 sm_run(); 4142 } 4143 4144 // called by client app on authorization request 4145 void sm_authorization_decline(hci_con_handle_t con_handle){ 4146 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4147 if (!sm_conn) return; // wrong connection 4148 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4149 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4150 } 4151 4152 void sm_authorization_grant(hci_con_handle_t con_handle){ 4153 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4154 if (!sm_conn) return; // wrong connection 4155 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4156 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4157 } 4158 4159 // GAP Bonding API 4160 4161 void sm_bonding_decline(hci_con_handle_t con_handle){ 4162 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4163 if (!sm_conn) return; // wrong connection 4164 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4165 log_info("decline, state %u", sm_conn->sm_engine_state); 4166 switch(sm_conn->sm_engine_state){ 4167 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4168 case SM_SC_W4_USER_RESPONSE: 4169 case SM_SC_W4_CONFIRMATION: 4170 case SM_SC_W4_PUBLIC_KEY_COMMAND: 4171 #endif 4172 case SM_PH1_W4_USER_RESPONSE: 4173 switch (setup->sm_stk_generation_method){ 4174 case PK_RESP_INPUT: 4175 case PK_INIT_INPUT: 4176 case PK_BOTH_INPUT: 4177 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 4178 break; 4179 case NUMERIC_COMPARISON: 4180 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4181 break; 4182 case JUST_WORKS: 4183 case OOB: 4184 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4185 break; 4186 } 4187 break; 4188 default: 4189 break; 4190 } 4191 sm_run(); 4192 } 4193 4194 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4195 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4196 if (!sm_conn) return; // wrong connection 4197 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4198 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4199 if (setup->sm_use_secure_connections){ 4200 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4201 } else { 4202 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); 4203 } 4204 } 4205 4206 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4207 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4208 sm_sc_prepare_dhkey_check(sm_conn); 4209 } 4210 #endif 4211 4212 sm_run(); 4213 } 4214 4215 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4216 // for now, it's the same 4217 sm_just_works_confirm(con_handle); 4218 } 4219 4220 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4221 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4222 if (!sm_conn) return; // wrong connection 4223 sm_reset_tk(); 4224 big_endian_store_32(setup->sm_tk, 12, passkey); 4225 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4226 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4227 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); 4228 } 4229 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4230 (void)memcpy(setup->sm_ra, setup->sm_tk, 16); 4231 (void)memcpy(setup->sm_rb, setup->sm_tk, 16); 4232 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4233 sm_sc_start_calculating_local_confirm(sm_conn); 4234 } 4235 #endif 4236 sm_run(); 4237 } 4238 4239 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4240 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4241 if (!sm_conn) return; // wrong connection 4242 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4243 uint8_t num_actions = setup->sm_keypress_notification >> 5; 4244 uint8_t flags = setup->sm_keypress_notification & 0x1f; 4245 switch (action){ 4246 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4247 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4248 flags |= (1 << action); 4249 break; 4250 case SM_KEYPRESS_PASSKEY_CLEARED: 4251 // clear counter, keypress & erased flags + set passkey cleared 4252 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 4253 break; 4254 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4255 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4256 // erase actions queued 4257 num_actions--; 4258 if (num_actions == 0){ 4259 // clear counter, keypress & erased flags 4260 flags &= 0x19; 4261 } 4262 break; 4263 } 4264 num_actions++; 4265 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4266 break; 4267 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4268 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4269 // enter actions queued 4270 num_actions--; 4271 if (num_actions == 0){ 4272 // clear counter, keypress & erased flags 4273 flags &= 0x19; 4274 } 4275 break; 4276 } 4277 num_actions++; 4278 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4279 break; 4280 default: 4281 break; 4282 } 4283 setup->sm_keypress_notification = (num_actions << 5) | flags; 4284 sm_run(); 4285 } 4286 4287 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4288 static void sm_handle_random_result_oob(void * arg){ 4289 UNUSED(arg); 4290 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4291 sm_run(); 4292 } 4293 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4294 4295 static btstack_crypto_random_t sm_crypto_random_oob_request; 4296 4297 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4298 sm_sc_oob_callback = callback; 4299 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4300 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4301 return 0; 4302 } 4303 #endif 4304 4305 /** 4306 * @brief Get Identity Resolving state 4307 * @param con_handle 4308 * @return irk_lookup_state_t 4309 */ 4310 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ 4311 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4312 if (!sm_conn) return IRK_LOOKUP_IDLE; 4313 return sm_conn->sm_irk_lookup_state; 4314 } 4315 4316 /** 4317 * @brief Identify device in LE Device DB 4318 * @param handle 4319 * @returns index from le_device_db or -1 if not found/identified 4320 */ 4321 int sm_le_device_index(hci_con_handle_t con_handle ){ 4322 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4323 if (!sm_conn) return -1; 4324 return sm_conn->sm_le_db_index; 4325 } 4326 4327 static int gap_random_address_type_requires_updates(void){ 4328 switch (gap_random_adress_type){ 4329 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4330 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4331 return 0; 4332 default: 4333 return 1; 4334 } 4335 } 4336 4337 static uint8_t own_address_type(void){ 4338 switch (gap_random_adress_type){ 4339 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4340 return BD_ADDR_TYPE_LE_PUBLIC; 4341 default: 4342 return BD_ADDR_TYPE_LE_RANDOM; 4343 } 4344 } 4345 4346 // GAP LE API 4347 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4348 gap_random_address_update_stop(); 4349 gap_random_adress_type = random_address_type; 4350 hci_le_set_own_address_type(own_address_type()); 4351 if (!gap_random_address_type_requires_updates()) return; 4352 gap_random_address_update_start(); 4353 gap_random_address_trigger(); 4354 } 4355 4356 gap_random_address_type_t gap_random_address_get_mode(void){ 4357 return gap_random_adress_type; 4358 } 4359 4360 void gap_random_address_set_update_period(int period_ms){ 4361 gap_random_adress_update_period = period_ms; 4362 if (!gap_random_address_type_requires_updates()) return; 4363 gap_random_address_update_stop(); 4364 gap_random_address_update_start(); 4365 } 4366 4367 void gap_random_address_set(bd_addr_t addr){ 4368 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4369 (void)memcpy(sm_random_address, addr, 6); 4370 rau_state = RAU_SET_ADDRESS; 4371 sm_run(); 4372 } 4373 4374 #ifdef ENABLE_LE_PERIPHERAL 4375 /* 4376 * @brief Set Advertisement Paramters 4377 * @param adv_int_min 4378 * @param adv_int_max 4379 * @param adv_type 4380 * @param direct_address_type 4381 * @param direct_address 4382 * @param channel_map 4383 * @param filter_policy 4384 * 4385 * @note own_address_type is used from gap_random_address_set_mode 4386 */ 4387 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4388 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4389 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4390 direct_address_typ, direct_address, channel_map, filter_policy); 4391 } 4392 #endif 4393 4394 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4395 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4396 // wrong connection 4397 if (!sm_conn) return 0; 4398 // already encrypted 4399 if (sm_conn->sm_connection_encrypted) return 0; 4400 // only central can re-encrypt 4401 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4402 // irk status? 4403 switch(sm_conn->sm_irk_lookup_state){ 4404 case IRK_LOOKUP_FAILED: 4405 // done, cannot setup encryption 4406 return 0; 4407 case IRK_LOOKUP_SUCCEEDED: 4408 break; 4409 default: 4410 // IR Lookup pending 4411 return 1; 4412 } 4413 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4414 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4415 } 4416