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 <stdio.h> 41 #include <string.h> 42 #include <inttypes.h> 43 44 #include "ble/le_device_db.h" 45 #include "ble/core.h" 46 #include "ble/sm.h" 47 #include "bluetooth_company_id.h" 48 #include "btstack_debug.h" 49 #include "btstack_event.h" 50 #include "btstack_linked_list.h" 51 #include "btstack_memory.h" 52 #include "gap.h" 53 #include "hci.h" 54 #include "hci_dump.h" 55 #include "l2cap.h" 56 57 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 58 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 59 #endif 60 61 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 62 #define IS_RESPONDER(role) (role) 63 #else 64 #ifdef ENABLE_LE_CENTRAL 65 // only central - never responder (avoid 'unused variable' warnings) 66 #define IS_RESPONDER(role) (0 && role) 67 #else 68 // only peripheral - always responder (avoid 'unused variable' warnings) 69 #define IS_RESPONDER(role) (1 || role) 70 #endif 71 #endif 72 73 #ifdef ENABLE_LE_SECURE_CONNECTIONS 74 // assert SM Public Key can be sent/received 75 #if HCI_ACL_PAYLOAD_SIZE < 69 76 #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" 77 #endif 78 79 // configure ECC implementations 80 #ifdef ENABLE_LE_SECURE_CONNECTIONS 81 #if defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) && defined(HAVE_MBEDTLS_ECC_P256) 82 #error "If you already have mbedTLS (HAVE_MBEDTLS_ECC_P256), please disable uECC (USE_MICRO_ECC_FOR_ECDH) in bstack_config.h" 83 #endif 84 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 85 #define USE_SOFTWARE_ECDH_IMPLEMENTATION 86 #define USE_MICRO_ECC_FOR_ECDH 87 #endif 88 #ifdef HAVE_MBEDTLS_ECC_P256 89 #define USE_SOFTWARE_ECDH_IMPLEMENTATION 90 #define USE_MBEDTLS_FOR_ECDH 91 #endif 92 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 93 94 // Software ECDH implementation provided by micro-ecc 95 #ifdef USE_MICRO_ECC_FOR_ECDH 96 #include "uECC.h" 97 #endif 98 #endif 99 100 // Software ECDH implementation provided by mbedTLS 101 #ifdef USE_MBEDTLS_FOR_ECDH 102 #include "mbedtls/config.h" 103 #include "mbedtls/platform.h" 104 #include "mbedtls/ecp.h" 105 #endif 106 107 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 108 #define ENABLE_CMAC_ENGINE 109 #endif 110 111 // 112 // SM internal types and globals 113 // 114 115 typedef enum { 116 DKG_W4_WORKING, 117 DKG_CALC_IRK, 118 DKG_W4_IRK, 119 DKG_CALC_DHK, 120 DKG_W4_DHK, 121 DKG_READY 122 } derived_key_generation_t; 123 124 typedef enum { 125 RAU_W4_WORKING, 126 RAU_IDLE, 127 RAU_GET_RANDOM, 128 RAU_W4_RANDOM, 129 RAU_GET_ENC, 130 RAU_W4_ENC, 131 RAU_SET_ADDRESS, 132 } random_address_update_t; 133 134 typedef enum { 135 CMAC_IDLE, 136 CMAC_CALC_SUBKEYS, 137 CMAC_W4_SUBKEYS, 138 CMAC_CALC_MI, 139 CMAC_W4_MI, 140 CMAC_CALC_MLAST, 141 CMAC_W4_MLAST 142 } cmac_state_t; 143 144 typedef enum { 145 JUST_WORKS, 146 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 147 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 148 OK_BOTH_INPUT, // Only input on both, both input PK 149 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 150 OOB // OOB available on both sides 151 } stk_generation_method_t; 152 153 typedef enum { 154 SM_USER_RESPONSE_IDLE, 155 SM_USER_RESPONSE_PENDING, 156 SM_USER_RESPONSE_CONFIRM, 157 SM_USER_RESPONSE_PASSKEY, 158 SM_USER_RESPONSE_DECLINE 159 } sm_user_response_t; 160 161 typedef enum { 162 SM_AES128_IDLE, 163 SM_AES128_ACTIVE 164 } sm_aes128_state_t; 165 166 typedef enum { 167 ADDRESS_RESOLUTION_IDLE, 168 ADDRESS_RESOLUTION_GENERAL, 169 ADDRESS_RESOLUTION_FOR_CONNECTION, 170 } address_resolution_mode_t; 171 172 typedef enum { 173 ADDRESS_RESOLUTION_SUCEEDED, 174 ADDRESS_RESOLUTION_FAILED, 175 } address_resolution_event_t; 176 177 typedef enum { 178 EC_KEY_GENERATION_IDLE, 179 EC_KEY_GENERATION_ACTIVE, 180 EC_KEY_GENERATION_W4_KEY, 181 EC_KEY_GENERATION_DONE, 182 } ec_key_generation_state_t; 183 184 typedef enum { 185 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 186 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 187 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 188 } sm_state_var_t; 189 190 typedef uint8_t sm_key24_t[3]; 191 typedef uint8_t sm_key56_t[7]; 192 typedef uint8_t sm_key256_t[32]; 193 194 // 195 // GLOBAL DATA 196 // 197 198 static uint8_t test_use_fixed_local_csrk; 199 200 // configuration 201 static uint8_t sm_accepted_stk_generation_methods; 202 static uint8_t sm_max_encryption_key_size; 203 static uint8_t sm_min_encryption_key_size; 204 static uint8_t sm_auth_req = 0; 205 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 206 static uint8_t sm_slave_request_security; 207 static uint32_t sm_fixed_passkey_in_display_role; 208 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 209 #ifdef ENABLE_LE_SECURE_CONNECTIONS 210 static uint8_t sm_have_ec_keypair; 211 #endif 212 213 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 214 static sm_key_t sm_persistent_er; 215 static sm_key_t sm_persistent_ir; 216 217 // derived from sm_persistent_ir 218 static sm_key_t sm_persistent_dhk; 219 static sm_key_t sm_persistent_irk; 220 static uint8_t sm_persistent_irk_ready = 0; // used for testing 221 static derived_key_generation_t dkg_state; 222 223 // derived from sm_persistent_er 224 // .. 225 226 // random address update 227 static random_address_update_t rau_state; 228 static bd_addr_t sm_random_address; 229 230 // CMAC Calculation: General 231 #ifdef ENABLE_CMAC_ENGINE 232 static cmac_state_t sm_cmac_state; 233 static uint16_t sm_cmac_message_len; 234 static sm_key_t sm_cmac_k; 235 static sm_key_t sm_cmac_x; 236 static sm_key_t sm_cmac_m_last; 237 static uint8_t sm_cmac_block_current; 238 static uint8_t sm_cmac_block_count; 239 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 240 static void (*sm_cmac_done_handler)(uint8_t * hash); 241 #endif 242 243 // CMAC for ATT Signed Writes 244 #ifdef ENABLE_LE_SIGNED_WRITE 245 static uint8_t sm_cmac_header[3]; 246 static const uint8_t * sm_cmac_message; 247 static uint8_t sm_cmac_sign_counter[4]; 248 #endif 249 250 // CMAC for Secure Connection functions 251 #ifdef ENABLE_LE_SECURE_CONNECTIONS 252 static sm_connection_t * sm_cmac_connection; 253 static uint8_t sm_cmac_sc_buffer[80]; 254 #endif 255 256 // resolvable private address lookup / CSRK calculation 257 static int sm_address_resolution_test; 258 static int sm_address_resolution_ah_calculation_active; 259 static uint8_t sm_address_resolution_addr_type; 260 static bd_addr_t sm_address_resolution_address; 261 static void * sm_address_resolution_context; 262 static address_resolution_mode_t sm_address_resolution_mode; 263 static btstack_linked_list_t sm_address_resolution_general_queue; 264 265 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 266 static sm_aes128_state_t sm_aes128_state; 267 static void * sm_aes128_context; 268 269 // use aes128 provided by MCU - not needed usually 270 #ifdef HAVE_AES128 271 static uint8_t aes128_result_flipped[16]; 272 static btstack_timer_source_t aes128_timer; 273 void btstack_aes128_calc(uint8_t * key, uint8_t * plaintext, uint8_t * result); 274 #endif 275 276 // random engine. store context (ususally sm_connection_t) 277 static void * sm_random_context; 278 279 // to receive hci events 280 static btstack_packet_callback_registration_t hci_event_callback_registration; 281 282 /* to dispatch sm event */ 283 static btstack_linked_list_t sm_event_handlers; 284 285 // LE Secure Connections 286 #ifdef ENABLE_LE_SECURE_CONNECTIONS 287 static ec_key_generation_state_t ec_key_generation_state; 288 static uint8_t ec_d[32]; 289 static uint8_t ec_q[64]; 290 #endif 291 292 // Software ECDH implementation provided by mbedtls 293 #ifdef USE_MBEDTLS_FOR_ECDH 294 static mbedtls_ecp_group mbedtls_ec_group; 295 #endif 296 297 // 298 // Volume 3, Part H, Chapter 24 299 // "Security shall be initiated by the Security Manager in the device in the master role. 300 // The device in the slave role shall be the responding device." 301 // -> master := initiator, slave := responder 302 // 303 304 // data needed for security setup 305 typedef struct sm_setup_context { 306 307 btstack_timer_source_t sm_timeout; 308 309 // used in all phases 310 uint8_t sm_pairing_failed_reason; 311 312 // user response, (Phase 1 and/or 2) 313 uint8_t sm_user_response; 314 uint8_t sm_keypress_notification; 315 316 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 317 int sm_key_distribution_send_set; 318 int sm_key_distribution_received_set; 319 320 // Phase 2 (Pairing over SMP) 321 stk_generation_method_t sm_stk_generation_method; 322 sm_key_t sm_tk; 323 uint8_t sm_use_secure_connections; 324 325 sm_key_t sm_c1_t3_value; // c1 calculation 326 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 327 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 328 sm_key_t sm_local_random; 329 sm_key_t sm_local_confirm; 330 sm_key_t sm_peer_random; 331 sm_key_t sm_peer_confirm; 332 uint8_t sm_m_addr_type; // address and type can be removed 333 uint8_t sm_s_addr_type; // '' 334 bd_addr_t sm_m_address; // '' 335 bd_addr_t sm_s_address; // '' 336 sm_key_t sm_ltk; 337 338 uint8_t sm_state_vars; 339 #ifdef ENABLE_LE_SECURE_CONNECTIONS 340 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 341 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 342 sm_key_t sm_local_nonce; // might be combined with sm_local_random 343 sm_key_t sm_dhkey; 344 sm_key_t sm_peer_dhkey_check; 345 sm_key_t sm_local_dhkey_check; 346 sm_key_t sm_ra; 347 sm_key_t sm_rb; 348 sm_key_t sm_t; // used for f5 and h6 349 sm_key_t sm_mackey; 350 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 351 #endif 352 353 // Phase 3 354 355 // key distribution, we generate 356 uint16_t sm_local_y; 357 uint16_t sm_local_div; 358 uint16_t sm_local_ediv; 359 uint8_t sm_local_rand[8]; 360 sm_key_t sm_local_ltk; 361 sm_key_t sm_local_csrk; 362 sm_key_t sm_local_irk; 363 // sm_local_address/addr_type not needed 364 365 // key distribution, received from peer 366 uint16_t sm_peer_y; 367 uint16_t sm_peer_div; 368 uint16_t sm_peer_ediv; 369 uint8_t sm_peer_rand[8]; 370 sm_key_t sm_peer_ltk; 371 sm_key_t sm_peer_irk; 372 sm_key_t sm_peer_csrk; 373 uint8_t sm_peer_addr_type; 374 bd_addr_t sm_peer_address; 375 376 } sm_setup_context_t; 377 378 // 379 static sm_setup_context_t the_setup; 380 static sm_setup_context_t * setup = &the_setup; 381 382 // active connection - the one for which the_setup is used for 383 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 384 385 // @returns 1 if oob data is available 386 // stores oob data in provided 16 byte buffer if not null 387 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 388 389 // horizontal: initiator capabilities 390 // vertial: responder capabilities 391 static const stk_generation_method_t stk_generation_method [5] [5] = { 392 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 393 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 394 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 395 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 396 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 397 }; 398 399 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 400 #ifdef ENABLE_LE_SECURE_CONNECTIONS 401 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 402 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 403 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 404 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 405 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 406 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 407 }; 408 #endif 409 410 static void sm_run(void); 411 static void sm_done_for_handle(hci_con_handle_t con_handle); 412 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 413 static inline int sm_calc_actual_encryption_key_size(int other); 414 static int sm_validate_stk_generation_method(void); 415 static void sm_handle_encryption_result(uint8_t * data); 416 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 417 418 static void log_info_hex16(const char * name, uint16_t value){ 419 log_info("%-6s 0x%04x", name, value); 420 } 421 422 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 423 // return packet[0]; 424 // } 425 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 426 return packet[1]; 427 } 428 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 429 return packet[2]; 430 } 431 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 432 return packet[3]; 433 } 434 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 435 return packet[4]; 436 } 437 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 438 return packet[5]; 439 } 440 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 441 return packet[6]; 442 } 443 444 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 445 packet[0] = code; 446 } 447 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 448 packet[1] = io_capability; 449 } 450 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 451 packet[2] = oob_data_flag; 452 } 453 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 454 packet[3] = auth_req; 455 } 456 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 457 packet[4] = max_encryption_key_size; 458 } 459 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 460 packet[5] = initiator_key_distribution; 461 } 462 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 463 packet[6] = responder_key_distribution; 464 } 465 466 // @returns 1 if all bytes are 0 467 static int sm_is_null(uint8_t * data, int size){ 468 int i; 469 for (i=0; i < size ; i++){ 470 if (data[i]) return 0; 471 } 472 return 1; 473 } 474 475 static int sm_is_null_random(uint8_t random[8]){ 476 return sm_is_null(random, 8); 477 } 478 479 static int sm_is_null_key(uint8_t * key){ 480 return sm_is_null(key, 16); 481 } 482 483 // Key utils 484 static void sm_reset_tk(void){ 485 int i; 486 for (i=0;i<16;i++){ 487 setup->sm_tk[i] = 0; 488 } 489 } 490 491 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 492 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 493 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 494 int i; 495 for (i = max_encryption_size ; i < 16 ; i++){ 496 key[15-i] = 0; 497 } 498 } 499 500 // SMP Timeout implementation 501 502 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 503 // the Security Manager Timer shall be reset and started. 504 // 505 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 506 // 507 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 508 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 509 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 510 // established. 511 512 static void sm_timeout_handler(btstack_timer_source_t * timer){ 513 log_info("SM timeout"); 514 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 515 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 516 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 517 sm_done_for_handle(sm_conn->sm_handle); 518 519 // trigger handling of next ready connection 520 sm_run(); 521 } 522 static void sm_timeout_start(sm_connection_t * sm_conn){ 523 btstack_run_loop_remove_timer(&setup->sm_timeout); 524 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 525 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 526 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 527 btstack_run_loop_add_timer(&setup->sm_timeout); 528 } 529 static void sm_timeout_stop(void){ 530 btstack_run_loop_remove_timer(&setup->sm_timeout); 531 } 532 static void sm_timeout_reset(sm_connection_t * sm_conn){ 533 sm_timeout_stop(); 534 sm_timeout_start(sm_conn); 535 } 536 537 // end of sm timeout 538 539 // GAP Random Address updates 540 static gap_random_address_type_t gap_random_adress_type; 541 static btstack_timer_source_t gap_random_address_update_timer; 542 static uint32_t gap_random_adress_update_period; 543 544 static void gap_random_address_trigger(void){ 545 if (rau_state != RAU_IDLE) return; 546 log_info("gap_random_address_trigger"); 547 rau_state = RAU_GET_RANDOM; 548 sm_run(); 549 } 550 551 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 552 UNUSED(timer); 553 554 log_info("GAP Random Address Update due"); 555 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 556 btstack_run_loop_add_timer(&gap_random_address_update_timer); 557 gap_random_address_trigger(); 558 } 559 560 static void gap_random_address_update_start(void){ 561 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 562 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 563 btstack_run_loop_add_timer(&gap_random_address_update_timer); 564 } 565 566 static void gap_random_address_update_stop(void){ 567 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 568 } 569 570 571 static void sm_random_start(void * context){ 572 sm_random_context = context; 573 hci_send_cmd(&hci_le_rand); 574 } 575 576 #ifdef HAVE_AES128 577 static void aes128_completed(btstack_timer_source_t * ts){ 578 UNUSED(ts); 579 sm_handle_encryption_result(&aes128_result_flipped[0]); 580 sm_run(); 581 } 582 #endif 583 584 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 585 // context is made availabe to aes128 result handler by this 586 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 587 sm_aes128_state = SM_AES128_ACTIVE; 588 sm_aes128_context = context; 589 590 #ifdef HAVE_AES128 591 // calc result directly 592 sm_key_t result; 593 btstack_aes128_calc(key, plaintext, result); 594 595 // log 596 log_info_key("key", key); 597 log_info_key("txt", plaintext); 598 log_info_key("res", result); 599 600 // flip 601 reverse_128(&result[0], &aes128_result_flipped[0]); 602 603 // deliver via timer 604 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 605 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 606 btstack_run_loop_add_timer(&aes128_timer); 607 #else 608 sm_key_t key_flipped, plaintext_flipped; 609 reverse_128(key, key_flipped); 610 reverse_128(plaintext, plaintext_flipped); 611 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 612 #endif 613 } 614 615 // ah(k,r) helper 616 // r = padding || r 617 // r - 24 bit value 618 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 619 // r'= padding || r 620 memset(r_prime, 0, 16); 621 memcpy(&r_prime[13], r, 3); 622 } 623 624 // d1 helper 625 // d' = padding || r || d 626 // d,r - 16 bit values 627 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 628 // d'= padding || r || d 629 memset(d1_prime, 0, 16); 630 big_endian_store_16(d1_prime, 12, r); 631 big_endian_store_16(d1_prime, 14, d); 632 } 633 634 // dm helper 635 // r’ = padding || r 636 // r - 64 bit value 637 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 638 memset(r_prime, 0, 16); 639 memcpy(&r_prime[8], r, 8); 640 } 641 642 // calculate arguments for first AES128 operation in C1 function 643 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){ 644 645 // p1 = pres || preq || rat’ || iat’ 646 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 647 // cant octet of pres becomes the most significant octet of p1. 648 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 649 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 650 // p1 is 0x05000800000302070710000001010001." 651 652 sm_key_t p1; 653 reverse_56(pres, &p1[0]); 654 reverse_56(preq, &p1[7]); 655 p1[14] = rat; 656 p1[15] = iat; 657 log_info_key("p1", p1); 658 log_info_key("r", r); 659 660 // t1 = r xor p1 661 int i; 662 for (i=0;i<16;i++){ 663 t1[i] = r[i] ^ p1[i]; 664 } 665 log_info_key("t1", t1); 666 } 667 668 // calculate arguments for second AES128 operation in C1 function 669 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 670 // p2 = padding || ia || ra 671 // "The least significant octet of ra becomes the least significant octet of p2 and 672 // the most significant octet of padding becomes the most significant octet of p2. 673 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 674 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 675 676 sm_key_t p2; 677 memset(p2, 0, 16); 678 memcpy(&p2[4], ia, 6); 679 memcpy(&p2[10], ra, 6); 680 log_info_key("p2", p2); 681 682 // c1 = e(k, t2_xor_p2) 683 int i; 684 for (i=0;i<16;i++){ 685 t3[i] = t2[i] ^ p2[i]; 686 } 687 log_info_key("t3", t3); 688 } 689 690 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 691 log_info_key("r1", r1); 692 log_info_key("r2", r2); 693 memcpy(&r_prime[8], &r2[8], 8); 694 memcpy(&r_prime[0], &r1[8], 8); 695 } 696 697 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 698 UNUSED(channel); 699 700 // log event 701 hci_dump_packet(packet_type, 1, packet, size); 702 // dispatch to all event handlers 703 btstack_linked_list_iterator_t it; 704 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 705 while (btstack_linked_list_iterator_has_next(&it)){ 706 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 707 entry->callback(packet_type, 0, packet, size); 708 } 709 } 710 711 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){ 712 event[0] = type; 713 event[1] = event_size - 2; 714 little_endian_store_16(event, 2, con_handle); 715 event[4] = addr_type; 716 reverse_bd_addr(address, &event[5]); 717 } 718 719 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 720 uint8_t event[11]; 721 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 722 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 723 } 724 725 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){ 726 uint8_t event[15]; 727 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 728 little_endian_store_32(event, 11, passkey); 729 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 730 } 731 732 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){ 733 // fetch addr and addr type from db 734 bd_addr_t identity_address; 735 int identity_address_type; 736 le_device_db_info(index, &identity_address_type, identity_address, NULL); 737 738 uint8_t event[19]; 739 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 740 event[11] = identity_address_type; 741 reverse_bd_addr(identity_address, &event[12]); 742 event[18] = index; 743 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 744 } 745 746 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){ 747 uint8_t event[12]; 748 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 749 event[11] = status; 750 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 751 } 752 753 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 754 uint8_t event[13]; 755 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 756 event[11] = status; 757 event[12] = reason; 758 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 759 } 760 761 // decide on stk generation based on 762 // - pairing request 763 // - io capabilities 764 // - OOB data availability 765 static void sm_setup_tk(void){ 766 767 // default: just works 768 setup->sm_stk_generation_method = JUST_WORKS; 769 770 #ifdef ENABLE_LE_SECURE_CONNECTIONS 771 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 772 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 773 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 774 memset(setup->sm_ra, 0, 16); 775 memset(setup->sm_rb, 0, 16); 776 #else 777 setup->sm_use_secure_connections = 0; 778 #endif 779 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 780 781 // If both devices have not set the MITM option in the Authentication Requirements 782 // Flags, then the IO capabilities shall be ignored and the Just Works association 783 // model shall be used. 784 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 785 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 786 log_info("SM: MITM not required by both -> JUST WORKS"); 787 return; 788 } 789 790 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 791 792 // If both devices have out of band authentication data, then the Authentication 793 // Requirements Flags shall be ignored when selecting the pairing method and the 794 // Out of Band pairing method shall be used. 795 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 796 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 797 log_info("SM: have OOB data"); 798 log_info_key("OOB", setup->sm_tk); 799 setup->sm_stk_generation_method = OOB; 800 return; 801 } 802 803 // Reset TK as it has been setup in sm_init_setup 804 sm_reset_tk(); 805 806 // Also use just works if unknown io capabilites 807 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)){ 808 return; 809 } 810 811 // Otherwise the IO capabilities of the devices shall be used to determine the 812 // pairing method as defined in Table 2.4. 813 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 814 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 815 816 #ifdef ENABLE_LE_SECURE_CONNECTIONS 817 // table not define by default 818 if (setup->sm_use_secure_connections){ 819 generation_method = stk_generation_method_with_secure_connection; 820 } 821 #endif 822 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)]; 823 824 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 825 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); 826 } 827 828 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 829 int flags = 0; 830 if (key_set & SM_KEYDIST_ENC_KEY){ 831 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 832 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 833 } 834 if (key_set & SM_KEYDIST_ID_KEY){ 835 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 836 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 837 } 838 if (key_set & SM_KEYDIST_SIGN){ 839 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 840 } 841 return flags; 842 } 843 844 static void sm_setup_key_distribution(uint8_t key_set){ 845 setup->sm_key_distribution_received_set = 0; 846 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 847 } 848 849 // CSRK Key Lookup 850 851 852 static int sm_address_resolution_idle(void){ 853 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 854 } 855 856 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){ 857 memcpy(sm_address_resolution_address, addr, 6); 858 sm_address_resolution_addr_type = addr_type; 859 sm_address_resolution_test = 0; 860 sm_address_resolution_mode = mode; 861 sm_address_resolution_context = context; 862 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 863 } 864 865 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 866 // check if already in list 867 btstack_linked_list_iterator_t it; 868 sm_lookup_entry_t * entry; 869 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 870 while(btstack_linked_list_iterator_has_next(&it)){ 871 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 872 if (entry->address_type != address_type) continue; 873 if (memcmp(entry->address, address, 6)) continue; 874 // already in list 875 return BTSTACK_BUSY; 876 } 877 entry = btstack_memory_sm_lookup_entry_get(); 878 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 879 entry->address_type = (bd_addr_type_t) address_type; 880 memcpy(entry->address, address, 6); 881 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 882 sm_run(); 883 return 0; 884 } 885 886 // while x_state++ for an enum is possible in C, it isn't in C++. we use this helpers to avoid compile errors for now 887 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 888 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 889 } 890 static inline void dkg_next_state(void){ 891 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 892 } 893 static inline void rau_next_state(void){ 894 rau_state = (random_address_update_t) (((int)rau_state) + 1); 895 } 896 897 // CMAC calculation using AES Engine 898 #ifdef ENABLE_CMAC_ENGINE 899 900 static inline void sm_cmac_next_state(void){ 901 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 902 } 903 904 static int sm_cmac_last_block_complete(void){ 905 if (sm_cmac_message_len == 0) return 0; 906 return (sm_cmac_message_len & 0x0f) == 0; 907 } 908 909 int sm_cmac_ready(void){ 910 return sm_cmac_state == CMAC_IDLE; 911 } 912 913 // generic cmac calculation 914 void sm_cmac_general_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t hash[8])){ 915 // Generalized CMAC 916 memcpy(sm_cmac_k, key, 16); 917 memset(sm_cmac_x, 0, 16); 918 sm_cmac_block_current = 0; 919 sm_cmac_message_len = message_len; 920 sm_cmac_done_handler = done_callback; 921 sm_cmac_get_byte = get_byte_callback; 922 923 // step 2: n := ceil(len/const_Bsize); 924 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 925 926 // step 3: .. 927 if (sm_cmac_block_count==0){ 928 sm_cmac_block_count = 1; 929 } 930 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 931 932 // first, we need to compute l for k1, k2, and m_last 933 sm_cmac_state = CMAC_CALC_SUBKEYS; 934 935 // let's go 936 sm_run(); 937 } 938 #endif 939 940 // cmac for ATT Message signing 941 #ifdef ENABLE_LE_SIGNED_WRITE 942 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 943 if (offset >= sm_cmac_message_len) { 944 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 945 return 0; 946 } 947 948 offset = sm_cmac_message_len - 1 - offset; 949 950 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 951 if (offset < 3){ 952 return sm_cmac_header[offset]; 953 } 954 int actual_message_len_incl_header = sm_cmac_message_len - 4; 955 if (offset < actual_message_len_incl_header){ 956 return sm_cmac_message[offset - 3]; 957 } 958 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 959 } 960 961 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)){ 962 // ATT Message Signing 963 sm_cmac_header[0] = opcode; 964 little_endian_store_16(sm_cmac_header, 1, con_handle); 965 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 966 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 967 sm_cmac_message = message; 968 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 969 } 970 #endif 971 972 #ifdef ENABLE_CMAC_ENGINE 973 static void sm_cmac_handle_aes_engine_ready(void){ 974 switch (sm_cmac_state){ 975 case CMAC_CALC_SUBKEYS: { 976 sm_key_t const_zero; 977 memset(const_zero, 0, 16); 978 sm_cmac_next_state(); 979 sm_aes128_start(sm_cmac_k, const_zero, NULL); 980 break; 981 } 982 case CMAC_CALC_MI: { 983 int j; 984 sm_key_t y; 985 for (j=0;j<16;j++){ 986 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 987 } 988 sm_cmac_block_current++; 989 sm_cmac_next_state(); 990 sm_aes128_start(sm_cmac_k, y, NULL); 991 break; 992 } 993 case CMAC_CALC_MLAST: { 994 int i; 995 sm_key_t y; 996 for (i=0;i<16;i++){ 997 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 998 } 999 log_info_key("Y", y); 1000 sm_cmac_block_current++; 1001 sm_cmac_next_state(); 1002 sm_aes128_start(sm_cmac_k, y, NULL); 1003 break; 1004 } 1005 default: 1006 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1007 break; 1008 } 1009 } 1010 1011 // CMAC Implementation using AES128 engine 1012 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1013 int i; 1014 int carry = 0; 1015 for (i=len-1; i >= 0 ; i--){ 1016 int new_carry = data[i] >> 7; 1017 data[i] = data[i] << 1 | carry; 1018 carry = new_carry; 1019 } 1020 } 1021 1022 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1023 switch (sm_cmac_state){ 1024 case CMAC_W4_SUBKEYS: { 1025 sm_key_t k1; 1026 memcpy(k1, data, 16); 1027 sm_shift_left_by_one_bit_inplace(16, k1); 1028 if (data[0] & 0x80){ 1029 k1[15] ^= 0x87; 1030 } 1031 sm_key_t k2; 1032 memcpy(k2, k1, 16); 1033 sm_shift_left_by_one_bit_inplace(16, k2); 1034 if (k1[0] & 0x80){ 1035 k2[15] ^= 0x87; 1036 } 1037 1038 log_info_key("k", sm_cmac_k); 1039 log_info_key("k1", k1); 1040 log_info_key("k2", k2); 1041 1042 // step 4: set m_last 1043 int i; 1044 if (sm_cmac_last_block_complete()){ 1045 for (i=0;i<16;i++){ 1046 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1047 } 1048 } else { 1049 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1050 for (i=0;i<16;i++){ 1051 if (i < valid_octets_in_last_block){ 1052 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1053 continue; 1054 } 1055 if (i == valid_octets_in_last_block){ 1056 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1057 continue; 1058 } 1059 sm_cmac_m_last[i] = k2[i]; 1060 } 1061 } 1062 1063 // next 1064 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1065 break; 1066 } 1067 case CMAC_W4_MI: 1068 memcpy(sm_cmac_x, data, 16); 1069 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1070 break; 1071 case CMAC_W4_MLAST: 1072 // done 1073 log_info("Setting CMAC Engine to IDLE"); 1074 sm_cmac_state = CMAC_IDLE; 1075 log_info_key("CMAC", data); 1076 sm_cmac_done_handler(data); 1077 break; 1078 default: 1079 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1080 break; 1081 } 1082 } 1083 #endif 1084 1085 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1086 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1087 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1088 switch (setup->sm_stk_generation_method){ 1089 case PK_RESP_INPUT: 1090 if (IS_RESPONDER(sm_conn->sm_role)){ 1091 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1092 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1093 } else { 1094 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)); 1095 } 1096 break; 1097 case PK_INIT_INPUT: 1098 if (IS_RESPONDER(sm_conn->sm_role)){ 1099 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)); 1100 } else { 1101 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1102 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1103 } 1104 break; 1105 case OK_BOTH_INPUT: 1106 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1107 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1108 break; 1109 case NK_BOTH_INPUT: 1110 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1111 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)); 1112 break; 1113 case JUST_WORKS: 1114 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1115 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1116 break; 1117 case OOB: 1118 // client already provided OOB data, let's skip notification. 1119 break; 1120 } 1121 } 1122 1123 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1124 int recv_flags; 1125 if (IS_RESPONDER(sm_conn->sm_role)){ 1126 // slave / responder 1127 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1128 } else { 1129 // master / initiator 1130 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1131 } 1132 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1133 return recv_flags == setup->sm_key_distribution_received_set; 1134 } 1135 1136 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1137 if (sm_active_connection_handle == con_handle){ 1138 sm_timeout_stop(); 1139 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1140 log_info("sm: connection 0x%x released setup context", con_handle); 1141 } 1142 } 1143 1144 static int sm_key_distribution_flags_for_auth_req(void){ 1145 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1146 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1147 // encryption information only if bonding requested 1148 flags |= SM_KEYDIST_ENC_KEY; 1149 } 1150 return flags; 1151 } 1152 1153 static void sm_reset_setup(void){ 1154 // fill in sm setup 1155 setup->sm_state_vars = 0; 1156 setup->sm_keypress_notification = 0xff; 1157 sm_reset_tk(); 1158 } 1159 1160 static void sm_init_setup(sm_connection_t * sm_conn){ 1161 1162 // fill in sm setup 1163 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1164 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1165 1166 // query client for OOB data 1167 int have_oob_data = 0; 1168 if (sm_get_oob_data) { 1169 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1170 } 1171 1172 sm_pairing_packet_t * local_packet; 1173 if (IS_RESPONDER(sm_conn->sm_role)){ 1174 // slave 1175 local_packet = &setup->sm_s_pres; 1176 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1177 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1178 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1179 } else { 1180 // master 1181 local_packet = &setup->sm_m_preq; 1182 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1183 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1184 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1185 1186 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1187 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1188 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1189 } 1190 1191 uint8_t auth_req = sm_auth_req; 1192 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1193 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1194 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1195 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1196 } 1197 1198 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1199 1200 sm_pairing_packet_t * remote_packet; 1201 int remote_key_request; 1202 if (IS_RESPONDER(sm_conn->sm_role)){ 1203 // slave / responder 1204 remote_packet = &setup->sm_m_preq; 1205 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1206 } else { 1207 // master / initiator 1208 remote_packet = &setup->sm_s_pres; 1209 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1210 } 1211 1212 // check key size 1213 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1214 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1215 1216 // decide on STK generation method 1217 sm_setup_tk(); 1218 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1219 1220 // check if STK generation method is acceptable by client 1221 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1222 1223 // identical to responder 1224 sm_setup_key_distribution(remote_key_request); 1225 1226 // JUST WORKS doens't provide authentication 1227 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1228 1229 return 0; 1230 } 1231 1232 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1233 1234 // cache and reset context 1235 int matched_device_id = sm_address_resolution_test; 1236 address_resolution_mode_t mode = sm_address_resolution_mode; 1237 void * context = sm_address_resolution_context; 1238 1239 // reset context 1240 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1241 sm_address_resolution_context = NULL; 1242 sm_address_resolution_test = -1; 1243 hci_con_handle_t con_handle = 0; 1244 1245 sm_connection_t * sm_connection; 1246 #ifdef ENABLE_LE_CENTRAL 1247 sm_key_t ltk; 1248 #endif 1249 switch (mode){ 1250 case ADDRESS_RESOLUTION_GENERAL: 1251 break; 1252 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1253 sm_connection = (sm_connection_t *) context; 1254 con_handle = sm_connection->sm_handle; 1255 switch (event){ 1256 case ADDRESS_RESOLUTION_SUCEEDED: 1257 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1258 sm_connection->sm_le_db_index = matched_device_id; 1259 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1260 if (sm_connection->sm_role) { 1261 // LTK request received before, IRK required -> start LTK calculation 1262 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1263 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1264 } 1265 break; 1266 } 1267 #ifdef ENABLE_LE_CENTRAL 1268 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1269 sm_connection->sm_security_request_received = 0; 1270 sm_connection->sm_bonding_requested = 0; 1271 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1272 if (!sm_is_null_key(ltk)){ 1273 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1274 } else { 1275 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1276 } 1277 #endif 1278 break; 1279 case ADDRESS_RESOLUTION_FAILED: 1280 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1281 if (sm_connection->sm_role) { 1282 // LTK request received before, IRK required -> negative LTK reply 1283 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1284 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1285 } 1286 break; 1287 } 1288 #ifdef ENABLE_LE_CENTRAL 1289 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1290 sm_connection->sm_security_request_received = 0; 1291 sm_connection->sm_bonding_requested = 0; 1292 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1293 #endif 1294 break; 1295 } 1296 break; 1297 default: 1298 break; 1299 } 1300 1301 switch (event){ 1302 case ADDRESS_RESOLUTION_SUCEEDED: 1303 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1304 break; 1305 case ADDRESS_RESOLUTION_FAILED: 1306 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1307 break; 1308 } 1309 } 1310 1311 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1312 1313 int le_db_index = -1; 1314 1315 // lookup device based on IRK 1316 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1317 int i; 1318 for (i=0; i < le_device_db_count(); i++){ 1319 sm_key_t irk; 1320 bd_addr_t address; 1321 int address_type; 1322 le_device_db_info(i, &address_type, address, irk); 1323 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1324 log_info("sm: device found for IRK, updating"); 1325 le_db_index = i; 1326 break; 1327 } 1328 } 1329 } 1330 1331 // if not found, lookup via public address if possible 1332 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1333 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1334 int i; 1335 for (i=0; i < le_device_db_count(); i++){ 1336 bd_addr_t address; 1337 int address_type; 1338 le_device_db_info(i, &address_type, address, NULL); 1339 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1340 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1341 log_info("sm: device found for public address, updating"); 1342 le_db_index = i; 1343 break; 1344 } 1345 } 1346 } 1347 1348 // if not found, add to db 1349 if (le_db_index < 0) { 1350 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1351 } 1352 1353 if (le_db_index >= 0){ 1354 1355 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1356 1357 #ifdef ENABLE_LE_SIGNED_WRITE 1358 // store local CSRK 1359 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1360 log_info("sm: store local CSRK"); 1361 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1362 le_device_db_local_counter_set(le_db_index, 0); 1363 } 1364 1365 // store remote CSRK 1366 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1367 log_info("sm: store remote CSRK"); 1368 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1369 le_device_db_remote_counter_set(le_db_index, 0); 1370 } 1371 #endif 1372 // store encryption information for secure connections: LTK generated by ECDH 1373 if (setup->sm_use_secure_connections){ 1374 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1375 uint8_t zero_rand[8]; 1376 memset(zero_rand, 0, 8); 1377 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1378 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1379 } 1380 1381 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1382 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1383 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1384 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1385 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1386 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1387 1388 } 1389 } 1390 1391 // keep le_db_index 1392 sm_conn->sm_le_db_index = le_db_index; 1393 } 1394 1395 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1396 setup->sm_pairing_failed_reason = reason; 1397 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1398 } 1399 1400 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1401 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1402 } 1403 1404 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1405 1406 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1407 static int sm_passkey_used(stk_generation_method_t method); 1408 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1409 1410 static void sm_log_ec_keypair(void){ 1411 log_info("Elliptic curve: X"); 1412 log_info_hexdump(&ec_q[0],32); 1413 log_info("Elliptic curve: Y"); 1414 log_info_hexdump(&ec_q[32],32); 1415 } 1416 1417 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1418 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1419 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1420 } else { 1421 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1422 } 1423 } 1424 1425 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1426 if (IS_RESPONDER(sm_conn->sm_role)){ 1427 // Responder 1428 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1429 } else { 1430 // Initiator role 1431 switch (setup->sm_stk_generation_method){ 1432 case JUST_WORKS: 1433 sm_sc_prepare_dhkey_check(sm_conn); 1434 break; 1435 1436 case NK_BOTH_INPUT: 1437 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1438 break; 1439 case PK_INIT_INPUT: 1440 case PK_RESP_INPUT: 1441 case OK_BOTH_INPUT: 1442 if (setup->sm_passkey_bit < 20) { 1443 sm_sc_start_calculating_local_confirm(sm_conn); 1444 } else { 1445 sm_sc_prepare_dhkey_check(sm_conn); 1446 } 1447 break; 1448 case OOB: 1449 // TODO: implement SC OOB 1450 break; 1451 } 1452 } 1453 } 1454 1455 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1456 return sm_cmac_sc_buffer[offset]; 1457 } 1458 1459 static void sm_sc_cmac_done(uint8_t * hash){ 1460 log_info("sm_sc_cmac_done: "); 1461 log_info_hexdump(hash, 16); 1462 1463 sm_connection_t * sm_conn = sm_cmac_connection; 1464 sm_cmac_connection = NULL; 1465 #ifdef ENABLE_CLASSIC 1466 link_key_type_t link_key_type; 1467 #endif 1468 1469 switch (sm_conn->sm_engine_state){ 1470 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1471 memcpy(setup->sm_local_confirm, hash, 16); 1472 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1473 break; 1474 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1475 // check 1476 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1477 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1478 break; 1479 } 1480 sm_sc_state_after_receiving_random(sm_conn); 1481 break; 1482 case SM_SC_W4_CALCULATE_G2: { 1483 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1484 big_endian_store_32(setup->sm_tk, 12, vab); 1485 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1486 sm_trigger_user_response(sm_conn); 1487 break; 1488 } 1489 case SM_SC_W4_CALCULATE_F5_SALT: 1490 memcpy(setup->sm_t, hash, 16); 1491 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1492 break; 1493 case SM_SC_W4_CALCULATE_F5_MACKEY: 1494 memcpy(setup->sm_mackey, hash, 16); 1495 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1496 break; 1497 case SM_SC_W4_CALCULATE_F5_LTK: 1498 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1499 // Errata Service Release to the Bluetooth Specification: ESR09 1500 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1501 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1502 memcpy(setup->sm_ltk, hash, 16); 1503 memcpy(setup->sm_local_ltk, hash, 16); 1504 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1505 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1506 break; 1507 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1508 memcpy(setup->sm_local_dhkey_check, hash, 16); 1509 if (IS_RESPONDER(sm_conn->sm_role)){ 1510 // responder 1511 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1512 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1513 } else { 1514 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1515 } 1516 } else { 1517 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1518 } 1519 break; 1520 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1521 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1522 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1523 break; 1524 } 1525 if (IS_RESPONDER(sm_conn->sm_role)){ 1526 // responder 1527 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1528 } else { 1529 // initiator 1530 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1531 } 1532 break; 1533 case SM_SC_W4_CALCULATE_H6_ILK: 1534 memcpy(setup->sm_t, hash, 16); 1535 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1536 break; 1537 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1538 #ifdef ENABLE_CLASSIC 1539 reverse_128(hash, setup->sm_t); 1540 link_key_type = sm_conn->sm_connection_authenticated ? 1541 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1542 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1543 if (IS_RESPONDER(sm_conn->sm_role)){ 1544 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1545 } else { 1546 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1547 } 1548 #endif 1549 if (IS_RESPONDER(sm_conn->sm_role)){ 1550 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1551 } else { 1552 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1553 } 1554 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1555 sm_done_for_handle(sm_conn->sm_handle); 1556 break; 1557 default: 1558 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1559 break; 1560 } 1561 sm_run(); 1562 } 1563 1564 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){ 1565 const uint16_t message_len = 65; 1566 sm_cmac_connection = sm_conn; 1567 memcpy(sm_cmac_sc_buffer, u, 32); 1568 memcpy(sm_cmac_sc_buffer+32, v, 32); 1569 sm_cmac_sc_buffer[64] = z; 1570 log_info("f4 key"); 1571 log_info_hexdump(x, 16); 1572 log_info("f4 message"); 1573 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1574 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1575 } 1576 1577 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1578 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1579 static const uint8_t f5_length[] = { 0x01, 0x00}; 1580 1581 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1582 1583 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1584 memset(dhkey, 0, 32); 1585 1586 #ifdef USE_MICRO_ECC_FOR_ECDH 1587 #if uECC_SUPPORTS_secp256r1 1588 // standard version 1589 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1590 #else 1591 // static version 1592 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1593 #endif 1594 #endif 1595 1596 #ifdef USE_MBEDTLS_FOR_ECDH 1597 // da * Pb 1598 mbedtls_mpi d; 1599 mbedtls_ecp_point Q; 1600 mbedtls_ecp_point DH; 1601 mbedtls_mpi_init(&d); 1602 mbedtls_ecp_point_init(&Q); 1603 mbedtls_ecp_point_init(&DH); 1604 mbedtls_mpi_read_binary(&d, ec_d, 32); 1605 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1606 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1607 mbedtls_mpi_lset(&Q.Z, 1); 1608 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1609 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1610 mbedtls_ecp_point_free(&DH); 1611 mbedtls_mpi_free(&d); 1612 mbedtls_ecp_point_free(&Q); 1613 #endif 1614 1615 log_info("dhkey"); 1616 log_info_hexdump(dhkey, 32); 1617 } 1618 #endif 1619 1620 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1621 // calculate salt for f5 1622 const uint16_t message_len = 32; 1623 sm_cmac_connection = sm_conn; 1624 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1625 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1626 } 1627 1628 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){ 1629 const uint16_t message_len = 53; 1630 sm_cmac_connection = sm_conn; 1631 1632 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1633 sm_cmac_sc_buffer[0] = 0; 1634 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1635 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1636 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1637 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1638 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1639 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1640 log_info("f5 key"); 1641 log_info_hexdump(t, 16); 1642 log_info("f5 message for MacKey"); 1643 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1644 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1645 } 1646 1647 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1648 sm_key56_t bd_addr_master, bd_addr_slave; 1649 bd_addr_master[0] = setup->sm_m_addr_type; 1650 bd_addr_slave[0] = setup->sm_s_addr_type; 1651 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1652 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1653 if (IS_RESPONDER(sm_conn->sm_role)){ 1654 // responder 1655 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1656 } else { 1657 // initiator 1658 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1659 } 1660 } 1661 1662 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1663 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1664 const uint16_t message_len = 53; 1665 sm_cmac_connection = sm_conn; 1666 sm_cmac_sc_buffer[0] = 1; 1667 // 1..52 setup before 1668 log_info("f5 key"); 1669 log_info_hexdump(t, 16); 1670 log_info("f5 message for LTK"); 1671 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1672 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1673 } 1674 1675 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1676 f5_ltk(sm_conn, setup->sm_t); 1677 } 1678 1679 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w, 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){ 1680 const uint16_t message_len = 65; 1681 sm_cmac_connection = sm_conn; 1682 memcpy(sm_cmac_sc_buffer, n1, 16); 1683 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1684 memcpy(sm_cmac_sc_buffer+32, r, 16); 1685 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1686 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1687 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1688 log_info("f6 key"); 1689 log_info_hexdump(w, 16); 1690 log_info("f6 message"); 1691 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1692 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1693 } 1694 1695 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1696 // - U is 256 bits 1697 // - V is 256 bits 1698 // - X is 128 bits 1699 // - Y is 128 bits 1700 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){ 1701 const uint16_t message_len = 80; 1702 sm_cmac_connection = sm_conn; 1703 memcpy(sm_cmac_sc_buffer, u, 32); 1704 memcpy(sm_cmac_sc_buffer+32, v, 32); 1705 memcpy(sm_cmac_sc_buffer+64, y, 16); 1706 log_info("g2 key"); 1707 log_info_hexdump(x, 16); 1708 log_info("g2 message"); 1709 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1710 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1711 } 1712 1713 static void g2_calculate(sm_connection_t * sm_conn) { 1714 // calc Va if numeric comparison 1715 if (IS_RESPONDER(sm_conn->sm_role)){ 1716 // responder 1717 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1718 } else { 1719 // initiator 1720 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1721 } 1722 } 1723 1724 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1725 uint8_t z = 0; 1726 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1727 // some form of passkey 1728 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1729 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1730 setup->sm_passkey_bit++; 1731 } 1732 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1733 } 1734 1735 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1736 uint8_t z = 0; 1737 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1738 // some form of passkey 1739 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1740 // sm_passkey_bit was increased before sending confirm value 1741 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1742 } 1743 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1744 } 1745 1746 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1747 1748 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1749 // calculate DHKEY 1750 sm_sc_calculate_dhkey(setup->sm_dhkey); 1751 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1752 #endif 1753 1754 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1755 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1756 return; 1757 } else { 1758 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1759 } 1760 1761 } 1762 1763 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1764 // calculate DHKCheck 1765 sm_key56_t bd_addr_master, bd_addr_slave; 1766 bd_addr_master[0] = setup->sm_m_addr_type; 1767 bd_addr_slave[0] = setup->sm_s_addr_type; 1768 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1769 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1770 uint8_t iocap_a[3]; 1771 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1772 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1773 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1774 uint8_t iocap_b[3]; 1775 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1776 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1777 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1778 if (IS_RESPONDER(sm_conn->sm_role)){ 1779 // responder 1780 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1781 } else { 1782 // initiator 1783 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1784 } 1785 } 1786 1787 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1788 // validate E = f6() 1789 sm_key56_t bd_addr_master, bd_addr_slave; 1790 bd_addr_master[0] = setup->sm_m_addr_type; 1791 bd_addr_slave[0] = setup->sm_s_addr_type; 1792 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1793 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1794 1795 uint8_t iocap_a[3]; 1796 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1797 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1798 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1799 uint8_t iocap_b[3]; 1800 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1801 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1802 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1803 if (IS_RESPONDER(sm_conn->sm_role)){ 1804 // responder 1805 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1806 } else { 1807 // initiator 1808 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1809 } 1810 } 1811 1812 1813 // 1814 // Link Key Conversion Function h6 1815 // 1816 // h6(W, keyID) = AES-CMACW(keyID) 1817 // - W is 128 bits 1818 // - keyID is 32 bits 1819 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1820 const uint16_t message_len = 4; 1821 sm_cmac_connection = sm_conn; 1822 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1823 log_info("h6 key"); 1824 log_info_hexdump(w, 16); 1825 log_info("h6 message"); 1826 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1827 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1828 } 1829 1830 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1831 // Errata Service Release to the Bluetooth Specification: ESR09 1832 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1833 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1834 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1835 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1836 } 1837 1838 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1839 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1840 } 1841 1842 #endif 1843 1844 // key management legacy connections: 1845 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1846 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1847 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1848 // - responder reconnects: responder uses LTK receveived from master 1849 1850 // key management secure connections: 1851 // - both devices store same LTK from ECDH key exchange. 1852 1853 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1854 static void sm_load_security_info(sm_connection_t * sm_connection){ 1855 int encryption_key_size; 1856 int authenticated; 1857 int authorized; 1858 1859 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1860 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1861 &encryption_key_size, &authenticated, &authorized); 1862 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1863 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1864 sm_connection->sm_connection_authenticated = authenticated; 1865 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1866 } 1867 #endif 1868 1869 #ifdef ENABLE_LE_PERIPHERAL 1870 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1871 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1872 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1873 // re-establish used key encryption size 1874 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1875 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1876 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1877 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1878 log_info("sm: received ltk request with key size %u, authenticated %u", 1879 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1880 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1881 } 1882 #endif 1883 1884 static void sm_run(void){ 1885 1886 btstack_linked_list_iterator_t it; 1887 1888 // assert that stack has already bootet 1889 if (hci_get_state() != HCI_STATE_WORKING) return; 1890 1891 // assert that we can send at least commands 1892 if (!hci_can_send_command_packet_now()) return; 1893 1894 // 1895 // non-connection related behaviour 1896 // 1897 1898 // distributed key generation 1899 switch (dkg_state){ 1900 case DKG_CALC_IRK: 1901 // already busy? 1902 if (sm_aes128_state == SM_AES128_IDLE) { 1903 // IRK = d1(IR, 1, 0) 1904 sm_key_t d1_prime; 1905 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1906 dkg_next_state(); 1907 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1908 return; 1909 } 1910 break; 1911 case DKG_CALC_DHK: 1912 // already busy? 1913 if (sm_aes128_state == SM_AES128_IDLE) { 1914 // DHK = d1(IR, 3, 0) 1915 sm_key_t d1_prime; 1916 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1917 dkg_next_state(); 1918 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1919 return; 1920 } 1921 break; 1922 default: 1923 break; 1924 } 1925 1926 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1927 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1928 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1929 sm_random_start(NULL); 1930 #else 1931 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1932 hci_send_cmd(&hci_le_read_local_p256_public_key); 1933 #endif 1934 return; 1935 } 1936 #endif 1937 1938 // random address updates 1939 switch (rau_state){ 1940 case RAU_GET_RANDOM: 1941 rau_next_state(); 1942 sm_random_start(NULL); 1943 return; 1944 case RAU_GET_ENC: 1945 // already busy? 1946 if (sm_aes128_state == SM_AES128_IDLE) { 1947 sm_key_t r_prime; 1948 sm_ah_r_prime(sm_random_address, r_prime); 1949 rau_next_state(); 1950 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1951 return; 1952 } 1953 break; 1954 case RAU_SET_ADDRESS: 1955 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1956 rau_state = RAU_IDLE; 1957 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1958 return; 1959 default: 1960 break; 1961 } 1962 1963 #ifdef ENABLE_CMAC_ENGINE 1964 // CMAC 1965 switch (sm_cmac_state){ 1966 case CMAC_CALC_SUBKEYS: 1967 case CMAC_CALC_MI: 1968 case CMAC_CALC_MLAST: 1969 // already busy? 1970 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1971 sm_cmac_handle_aes_engine_ready(); 1972 return; 1973 default: 1974 break; 1975 } 1976 #endif 1977 1978 // CSRK Lookup 1979 // -- if csrk lookup ready, find connection that require csrk lookup 1980 if (sm_address_resolution_idle()){ 1981 hci_connections_get_iterator(&it); 1982 while(btstack_linked_list_iterator_has_next(&it)){ 1983 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1984 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1985 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1986 // and start lookup 1987 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); 1988 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1989 break; 1990 } 1991 } 1992 } 1993 1994 // -- if csrk lookup ready, resolved addresses for received addresses 1995 if (sm_address_resolution_idle()) { 1996 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1997 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1998 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1999 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 2000 btstack_memory_sm_lookup_entry_free(entry); 2001 } 2002 } 2003 2004 // -- Continue with CSRK device lookup by public or resolvable private address 2005 if (!sm_address_resolution_idle()){ 2006 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 2007 while (sm_address_resolution_test < le_device_db_count()){ 2008 int addr_type; 2009 bd_addr_t addr; 2010 sm_key_t irk; 2011 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2012 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2013 2014 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2015 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2016 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2017 break; 2018 } 2019 2020 if (sm_address_resolution_addr_type == 0){ 2021 sm_address_resolution_test++; 2022 continue; 2023 } 2024 2025 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2026 2027 log_info("LE Device Lookup: calculate AH"); 2028 log_info_key("IRK", irk); 2029 2030 sm_key_t r_prime; 2031 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2032 sm_address_resolution_ah_calculation_active = 1; 2033 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2034 return; 2035 } 2036 2037 if (sm_address_resolution_test >= le_device_db_count()){ 2038 log_info("LE Device Lookup: not found"); 2039 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2040 } 2041 } 2042 2043 // handle basic actions that don't requires the full context 2044 hci_connections_get_iterator(&it); 2045 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2046 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2047 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2048 switch(sm_connection->sm_engine_state){ 2049 // responder side 2050 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2051 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2052 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2053 return; 2054 2055 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2056 case SM_SC_RECEIVED_LTK_REQUEST: 2057 switch (sm_connection->sm_irk_lookup_state){ 2058 case IRK_LOOKUP_FAILED: 2059 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2060 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2061 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2062 return; 2063 default: 2064 break; 2065 } 2066 break; 2067 #endif 2068 default: 2069 break; 2070 } 2071 } 2072 2073 // 2074 // active connection handling 2075 // -- use loop to handle next connection if lock on setup context is released 2076 2077 while (1) { 2078 2079 // Find connections that requires setup context and make active if no other is locked 2080 hci_connections_get_iterator(&it); 2081 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2082 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2083 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2084 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2085 int done = 1; 2086 int err; 2087 UNUSED(err); 2088 switch (sm_connection->sm_engine_state) { 2089 #ifdef ENABLE_LE_PERIPHERAL 2090 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2091 // send packet if possible, 2092 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2093 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2094 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2095 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2096 } else { 2097 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2098 } 2099 // don't lock sxetup context yet 2100 done = 0; 2101 break; 2102 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2103 sm_reset_setup(); 2104 sm_init_setup(sm_connection); 2105 // recover pairing request 2106 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2107 err = sm_stk_generation_init(sm_connection); 2108 if (err){ 2109 setup->sm_pairing_failed_reason = err; 2110 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2111 break; 2112 } 2113 sm_timeout_start(sm_connection); 2114 // generate random number first, if we need to show passkey 2115 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2116 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2117 break; 2118 } 2119 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2120 break; 2121 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2122 sm_reset_setup(); 2123 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2124 break; 2125 #endif 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 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2141 case SM_SC_RECEIVED_LTK_REQUEST: 2142 switch (sm_connection->sm_irk_lookup_state){ 2143 case IRK_LOOKUP_SUCCEEDED: 2144 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2145 // start using context by loading security info 2146 sm_reset_setup(); 2147 sm_load_security_info(sm_connection); 2148 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2149 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2150 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2151 break; 2152 } 2153 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2154 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2155 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2156 // don't lock setup context yet 2157 return; 2158 default: 2159 // just wait until IRK lookup is completed 2160 // don't lock setup context yet 2161 done = 0; 2162 break; 2163 } 2164 break; 2165 #endif 2166 default: 2167 done = 0; 2168 break; 2169 } 2170 if (done){ 2171 sm_active_connection_handle = sm_connection->sm_handle; 2172 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); 2173 } 2174 } 2175 2176 // 2177 // active connection handling 2178 // 2179 2180 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2181 2182 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2183 if (!connection) { 2184 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2185 return; 2186 } 2187 2188 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2189 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2190 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2191 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2192 return; 2193 } 2194 #endif 2195 2196 // assert that we could send a SM PDU - not needed for all of the following 2197 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2198 log_info("cannot send now, requesting can send now event"); 2199 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2200 return; 2201 } 2202 2203 // send keypress notifications 2204 if (setup->sm_keypress_notification != 0xff){ 2205 uint8_t buffer[2]; 2206 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2207 buffer[1] = setup->sm_keypress_notification; 2208 setup->sm_keypress_notification = 0xff; 2209 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2210 return; 2211 } 2212 2213 sm_key_t plaintext; 2214 int key_distribution_flags; 2215 UNUSED(key_distribution_flags); 2216 2217 log_info("sm_run: state %u", connection->sm_engine_state); 2218 2219 switch (connection->sm_engine_state){ 2220 2221 // general 2222 case SM_GENERAL_SEND_PAIRING_FAILED: { 2223 uint8_t buffer[2]; 2224 buffer[0] = SM_CODE_PAIRING_FAILED; 2225 buffer[1] = setup->sm_pairing_failed_reason; 2226 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2227 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2228 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2229 sm_done_for_handle(connection->sm_handle); 2230 break; 2231 } 2232 2233 // responding state 2234 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2235 case SM_SC_W2_GET_RANDOM_A: 2236 sm_random_start(connection); 2237 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2238 break; 2239 case SM_SC_W2_GET_RANDOM_B: 2240 sm_random_start(connection); 2241 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2242 break; 2243 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2244 if (!sm_cmac_ready()) break; 2245 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2246 sm_sc_calculate_local_confirm(connection); 2247 break; 2248 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2249 if (!sm_cmac_ready()) break; 2250 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2251 sm_sc_calculate_remote_confirm(connection); 2252 break; 2253 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2254 if (!sm_cmac_ready()) break; 2255 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2256 sm_sc_calculate_f6_for_dhkey_check(connection); 2257 break; 2258 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2259 if (!sm_cmac_ready()) break; 2260 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2261 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2262 break; 2263 case SM_SC_W2_CALCULATE_F5_SALT: 2264 if (!sm_cmac_ready()) break; 2265 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2266 f5_calculate_salt(connection); 2267 break; 2268 case SM_SC_W2_CALCULATE_F5_MACKEY: 2269 if (!sm_cmac_ready()) break; 2270 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2271 f5_calculate_mackey(connection); 2272 break; 2273 case SM_SC_W2_CALCULATE_F5_LTK: 2274 if (!sm_cmac_ready()) break; 2275 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2276 f5_calculate_ltk(connection); 2277 break; 2278 case SM_SC_W2_CALCULATE_G2: 2279 if (!sm_cmac_ready()) break; 2280 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2281 g2_calculate(connection); 2282 break; 2283 case SM_SC_W2_CALCULATE_H6_ILK: 2284 if (!sm_cmac_ready()) break; 2285 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2286 h6_calculate_ilk(connection); 2287 break; 2288 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2289 if (!sm_cmac_ready()) break; 2290 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2291 h6_calculate_br_edr_link_key(connection); 2292 break; 2293 #endif 2294 2295 #ifdef ENABLE_LE_CENTRAL 2296 // initiator side 2297 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2298 sm_key_t peer_ltk_flipped; 2299 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2300 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2301 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2302 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2303 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2304 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2305 return; 2306 } 2307 2308 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2309 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2310 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2311 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2312 sm_timeout_reset(connection); 2313 break; 2314 #endif 2315 2316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2317 2318 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2319 uint8_t buffer[65]; 2320 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2321 // 2322 reverse_256(&ec_q[0], &buffer[1]); 2323 reverse_256(&ec_q[32], &buffer[33]); 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 NK_BOTH_INPUT: 2330 if (IS_RESPONDER(connection->sm_role)){ 2331 // responder 2332 sm_sc_start_calculating_local_confirm(connection); 2333 } else { 2334 // initiator 2335 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2336 } 2337 break; 2338 case PK_INIT_INPUT: 2339 case PK_RESP_INPUT: 2340 case OK_BOTH_INPUT: 2341 // use random TK for display 2342 memcpy(setup->sm_ra, setup->sm_tk, 16); 2343 memcpy(setup->sm_rb, setup->sm_tk, 16); 2344 setup->sm_passkey_bit = 0; 2345 2346 if (IS_RESPONDER(connection->sm_role)){ 2347 // responder 2348 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2349 } else { 2350 // initiator 2351 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2352 } 2353 sm_trigger_user_response(connection); 2354 break; 2355 case OOB: 2356 // TODO: implement SC OOB 2357 break; 2358 } 2359 2360 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2361 sm_timeout_reset(connection); 2362 break; 2363 } 2364 case SM_SC_SEND_CONFIRMATION: { 2365 uint8_t buffer[17]; 2366 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2367 reverse_128(setup->sm_local_confirm, &buffer[1]); 2368 if (IS_RESPONDER(connection->sm_role)){ 2369 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2370 } else { 2371 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2372 } 2373 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2374 sm_timeout_reset(connection); 2375 break; 2376 } 2377 case SM_SC_SEND_PAIRING_RANDOM: { 2378 uint8_t buffer[17]; 2379 buffer[0] = SM_CODE_PAIRING_RANDOM; 2380 reverse_128(setup->sm_local_nonce, &buffer[1]); 2381 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2382 if (IS_RESPONDER(connection->sm_role)){ 2383 // responder 2384 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2385 } else { 2386 // initiator 2387 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2388 } 2389 } else { 2390 if (IS_RESPONDER(connection->sm_role)){ 2391 // responder 2392 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2393 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2394 } else { 2395 sm_sc_prepare_dhkey_check(connection); 2396 } 2397 } else { 2398 // initiator 2399 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2400 } 2401 } 2402 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2403 sm_timeout_reset(connection); 2404 break; 2405 } 2406 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2407 uint8_t buffer[17]; 2408 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2409 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2410 2411 if (IS_RESPONDER(connection->sm_role)){ 2412 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2413 } else { 2414 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2415 } 2416 2417 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2418 sm_timeout_reset(connection); 2419 break; 2420 } 2421 2422 #endif 2423 2424 #ifdef ENABLE_LE_PERIPHERAL 2425 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2426 // echo initiator for now 2427 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2428 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2429 2430 if (setup->sm_use_secure_connections){ 2431 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2432 // skip LTK/EDIV for SC 2433 log_info("sm: dropping encryption information flag"); 2434 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2435 } else { 2436 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2437 } 2438 2439 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); 2440 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); 2441 // update key distribution after ENC was dropped 2442 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2443 2444 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2445 sm_timeout_reset(connection); 2446 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2447 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2448 sm_trigger_user_response(connection); 2449 } 2450 return; 2451 #endif 2452 2453 case SM_PH2_SEND_PAIRING_RANDOM: { 2454 uint8_t buffer[17]; 2455 buffer[0] = SM_CODE_PAIRING_RANDOM; 2456 reverse_128(setup->sm_local_random, &buffer[1]); 2457 if (IS_RESPONDER(connection->sm_role)){ 2458 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2459 } else { 2460 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2461 } 2462 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2463 sm_timeout_reset(connection); 2464 break; 2465 } 2466 2467 case SM_PH2_GET_RANDOM_TK: 2468 case SM_PH2_C1_GET_RANDOM_A: 2469 case SM_PH2_C1_GET_RANDOM_B: 2470 case SM_PH3_GET_RANDOM: 2471 case SM_PH3_GET_DIV: 2472 sm_next_responding_state(connection); 2473 sm_random_start(connection); 2474 return; 2475 2476 case SM_PH2_C1_GET_ENC_B: 2477 case SM_PH2_C1_GET_ENC_D: 2478 // already busy? 2479 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2480 sm_next_responding_state(connection); 2481 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2482 return; 2483 2484 case SM_PH3_LTK_GET_ENC: 2485 case SM_RESPONDER_PH4_LTK_GET_ENC: 2486 // already busy? 2487 if (sm_aes128_state == SM_AES128_IDLE) { 2488 sm_key_t d_prime; 2489 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2490 sm_next_responding_state(connection); 2491 sm_aes128_start(sm_persistent_er, d_prime, connection); 2492 return; 2493 } 2494 break; 2495 2496 case SM_PH3_CSRK_GET_ENC: 2497 // already busy? 2498 if (sm_aes128_state == SM_AES128_IDLE) { 2499 sm_key_t d_prime; 2500 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2501 sm_next_responding_state(connection); 2502 sm_aes128_start(sm_persistent_er, d_prime, connection); 2503 return; 2504 } 2505 break; 2506 2507 case SM_PH2_C1_GET_ENC_C: 2508 // already busy? 2509 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2510 // calculate m_confirm using aes128 engine - step 1 2511 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, plaintext); 2512 sm_next_responding_state(connection); 2513 sm_aes128_start(setup->sm_tk, plaintext, connection); 2514 break; 2515 case SM_PH2_C1_GET_ENC_A: 2516 // already busy? 2517 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2518 // calculate confirm using aes128 engine - step 1 2519 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, plaintext); 2520 sm_next_responding_state(connection); 2521 sm_aes128_start(setup->sm_tk, plaintext, connection); 2522 break; 2523 case SM_PH2_CALC_STK: 2524 // already busy? 2525 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2526 // calculate STK 2527 if (IS_RESPONDER(connection->sm_role)){ 2528 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2529 } else { 2530 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2531 } 2532 sm_next_responding_state(connection); 2533 sm_aes128_start(setup->sm_tk, plaintext, connection); 2534 break; 2535 case SM_PH3_Y_GET_ENC: 2536 // already busy? 2537 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2538 // PH3B2 - calculate Y from - enc 2539 // Y = dm(DHK, Rand) 2540 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2541 sm_next_responding_state(connection); 2542 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2543 return; 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 // Y = dm(DHK, Rand) 2578 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2579 sm_next_responding_state(connection); 2580 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2581 return; 2582 #endif 2583 #ifdef ENABLE_LE_CENTRAL 2584 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2585 sm_key_t stk_flipped; 2586 reverse_128(setup->sm_ltk, stk_flipped); 2587 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2588 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2589 return; 2590 } 2591 #endif 2592 2593 case SM_PH3_DISTRIBUTE_KEYS: 2594 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2595 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2596 uint8_t buffer[17]; 2597 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2598 reverse_128(setup->sm_ltk, &buffer[1]); 2599 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2600 sm_timeout_reset(connection); 2601 return; 2602 } 2603 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2604 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2605 uint8_t buffer[11]; 2606 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2607 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2608 reverse_64(setup->sm_local_rand, &buffer[3]); 2609 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2610 sm_timeout_reset(connection); 2611 return; 2612 } 2613 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2614 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2615 uint8_t buffer[17]; 2616 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2617 reverse_128(sm_persistent_irk, &buffer[1]); 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_ADDRESS_INFORMATION){ 2623 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2624 bd_addr_t local_address; 2625 uint8_t buffer[8]; 2626 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2627 switch (gap_random_address_get_mode()){ 2628 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2629 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2630 // public or static random 2631 gap_le_get_own_address(&buffer[1], local_address); 2632 break; 2633 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2634 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2635 // fallback to public 2636 gap_local_bd_addr(local_address); 2637 buffer[1] = 0; 2638 break; 2639 } 2640 reverse_bd_addr(local_address, &buffer[2]); 2641 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2642 sm_timeout_reset(connection); 2643 return; 2644 } 2645 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2646 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2647 2648 // hack to reproduce test runs 2649 if (test_use_fixed_local_csrk){ 2650 memset(setup->sm_local_csrk, 0xcc, 16); 2651 } 2652 2653 uint8_t buffer[17]; 2654 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2655 reverse_128(setup->sm_local_csrk, &buffer[1]); 2656 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2657 sm_timeout_reset(connection); 2658 return; 2659 } 2660 2661 // keys are sent 2662 if (IS_RESPONDER(connection->sm_role)){ 2663 // slave -> receive master keys if any 2664 if (sm_key_distribution_all_received(connection)){ 2665 sm_key_distribution_handle_all_received(connection); 2666 connection->sm_engine_state = SM_RESPONDER_IDLE; 2667 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2668 sm_done_for_handle(connection->sm_handle); 2669 } else { 2670 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2671 } 2672 } else { 2673 // master -> all done 2674 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2675 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2676 sm_done_for_handle(connection->sm_handle); 2677 } 2678 break; 2679 2680 default: 2681 break; 2682 } 2683 2684 // check again if active connection was released 2685 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2686 } 2687 } 2688 2689 // note: aes engine is ready as we just got the aes result 2690 static void sm_handle_encryption_result(uint8_t * data){ 2691 2692 sm_aes128_state = SM_AES128_IDLE; 2693 2694 if (sm_address_resolution_ah_calculation_active){ 2695 sm_address_resolution_ah_calculation_active = 0; 2696 // compare calulated address against connecting device 2697 uint8_t hash[3]; 2698 reverse_24(data, hash); 2699 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2700 log_info("LE Device Lookup: matched resolvable private address"); 2701 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2702 return; 2703 } 2704 // no match, try next 2705 sm_address_resolution_test++; 2706 return; 2707 } 2708 2709 switch (dkg_state){ 2710 case DKG_W4_IRK: 2711 reverse_128(data, sm_persistent_irk); 2712 log_info_key("irk", sm_persistent_irk); 2713 dkg_next_state(); 2714 return; 2715 case DKG_W4_DHK: 2716 reverse_128(data, sm_persistent_dhk); 2717 log_info_key("dhk", sm_persistent_dhk); 2718 dkg_next_state(); 2719 // SM Init Finished 2720 return; 2721 default: 2722 break; 2723 } 2724 2725 switch (rau_state){ 2726 case RAU_W4_ENC: 2727 reverse_24(data, &sm_random_address[3]); 2728 rau_next_state(); 2729 return; 2730 default: 2731 break; 2732 } 2733 2734 #ifdef ENABLE_CMAC_ENGINE 2735 switch (sm_cmac_state){ 2736 case CMAC_W4_SUBKEYS: 2737 case CMAC_W4_MI: 2738 case CMAC_W4_MLAST: 2739 { 2740 sm_key_t t; 2741 reverse_128(data, t); 2742 sm_cmac_handle_encryption_result(t); 2743 } 2744 return; 2745 default: 2746 break; 2747 } 2748 #endif 2749 2750 // retrieve sm_connection provided to sm_aes128_start_encryption 2751 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2752 if (!connection) return; 2753 switch (connection->sm_engine_state){ 2754 case SM_PH2_C1_W4_ENC_A: 2755 case SM_PH2_C1_W4_ENC_C: 2756 { 2757 sm_key_t t2; 2758 reverse_128(data, t2); 2759 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2760 } 2761 sm_next_responding_state(connection); 2762 return; 2763 case SM_PH2_C1_W4_ENC_B: 2764 reverse_128(data, setup->sm_local_confirm); 2765 log_info_key("c1!", setup->sm_local_confirm); 2766 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2767 return; 2768 case SM_PH2_C1_W4_ENC_D: 2769 { 2770 sm_key_t peer_confirm_test; 2771 reverse_128(data, peer_confirm_test); 2772 log_info_key("c1!", peer_confirm_test); 2773 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2774 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2775 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2776 return; 2777 } 2778 if (IS_RESPONDER(connection->sm_role)){ 2779 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2780 } else { 2781 connection->sm_engine_state = SM_PH2_CALC_STK; 2782 } 2783 } 2784 return; 2785 case SM_PH2_W4_STK: 2786 reverse_128(data, setup->sm_ltk); 2787 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2788 log_info_key("stk", setup->sm_ltk); 2789 if (IS_RESPONDER(connection->sm_role)){ 2790 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2791 } else { 2792 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2793 } 2794 return; 2795 case SM_PH3_Y_W4_ENC:{ 2796 sm_key_t y128; 2797 reverse_128(data, y128); 2798 setup->sm_local_y = big_endian_read_16(y128, 14); 2799 log_info_hex16("y", setup->sm_local_y); 2800 // PH3B3 - calculate EDIV 2801 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2802 log_info_hex16("ediv", setup->sm_local_ediv); 2803 // PH3B4 - calculate LTK - enc 2804 // LTK = d1(ER, DIV, 0)) 2805 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2806 return; 2807 } 2808 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2809 sm_key_t y128; 2810 reverse_128(data, y128); 2811 setup->sm_local_y = big_endian_read_16(y128, 14); 2812 log_info_hex16("y", setup->sm_local_y); 2813 2814 // PH3B3 - calculate DIV 2815 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2816 log_info_hex16("ediv", setup->sm_local_ediv); 2817 // PH3B4 - calculate LTK - enc 2818 // LTK = d1(ER, DIV, 0)) 2819 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2820 return; 2821 } 2822 case SM_PH3_LTK_W4_ENC: 2823 reverse_128(data, setup->sm_ltk); 2824 log_info_key("ltk", setup->sm_ltk); 2825 // calc CSRK next 2826 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2827 return; 2828 case SM_PH3_CSRK_W4_ENC: 2829 reverse_128(data, setup->sm_local_csrk); 2830 log_info_key("csrk", setup->sm_local_csrk); 2831 if (setup->sm_key_distribution_send_set){ 2832 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2833 } else { 2834 // no keys to send, just continue 2835 if (IS_RESPONDER(connection->sm_role)){ 2836 // slave -> receive master keys 2837 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2838 } else { 2839 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2840 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2841 } else { 2842 // master -> all done 2843 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2844 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2845 sm_done_for_handle(connection->sm_handle); 2846 } 2847 } 2848 } 2849 return; 2850 #ifdef ENABLE_LE_PERIPHERAL 2851 case SM_RESPONDER_PH4_LTK_W4_ENC: 2852 reverse_128(data, setup->sm_ltk); 2853 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2854 log_info_key("ltk", setup->sm_ltk); 2855 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2856 return; 2857 #endif 2858 default: 2859 break; 2860 } 2861 } 2862 2863 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2864 2865 #if (defined(USE_MICRO_ECC_FOR_ECDH) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_FOR_ECDH) 2866 // @return OK 2867 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2868 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2869 int offset = setup->sm_passkey_bit; 2870 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2871 while (size) { 2872 *buffer++ = setup->sm_peer_q[offset++]; 2873 size--; 2874 } 2875 setup->sm_passkey_bit = offset; 2876 return 1; 2877 } 2878 #endif 2879 #ifdef USE_MBEDTLS_FOR_ECDH 2880 // @return error - just wrap sm_generate_f_rng 2881 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2882 UNUSED(context); 2883 return sm_generate_f_rng(buffer, size) == 0; 2884 } 2885 #endif /* USE_MBEDTLS_FOR_ECDH */ 2886 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2887 2888 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2889 static void sm_handle_random_result(uint8_t * data){ 2890 2891 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2892 2893 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2894 int num_bytes = setup->sm_passkey_bit; 2895 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2896 num_bytes += 8; 2897 setup->sm_passkey_bit = num_bytes; 2898 2899 if (num_bytes >= 64){ 2900 2901 // init pre-generated random data from sm_peer_q 2902 setup->sm_passkey_bit = 0; 2903 2904 // generate EC key 2905 #ifdef USE_MICRO_ECC_FOR_ECDH 2906 2907 #ifndef WICED_VERSION 2908 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2909 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2910 uECC_set_rng(&sm_generate_f_rng); 2911 #endif /* WICED_VERSION */ 2912 2913 #if uECC_SUPPORTS_secp256r1 2914 // standard version 2915 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2916 2917 // disable RNG again, as returning no randmon data lets shared key generation fail 2918 log_info("disable uECC RNG in standard version after key generation"); 2919 uECC_set_rng(NULL); 2920 #else 2921 // static version 2922 uECC_make_key(ec_q, ec_d); 2923 #endif 2924 #endif /* USE_MICRO_ECC_FOR_ECDH */ 2925 2926 #ifdef USE_MBEDTLS_FOR_ECDH 2927 mbedtls_mpi d; 2928 mbedtls_ecp_point P; 2929 mbedtls_mpi_init(&d); 2930 mbedtls_ecp_point_init(&P); 2931 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2932 log_info("gen keypair %x", res); 2933 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2934 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2935 mbedtls_mpi_write_binary(&d, ec_d, 32); 2936 mbedtls_ecp_point_free(&P); 2937 mbedtls_mpi_free(&d); 2938 #endif /* USE_MBEDTLS_FOR_ECDH */ 2939 2940 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2941 log_info("Elliptic curve: d"); 2942 log_info_hexdump(ec_d,32); 2943 sm_log_ec_keypair(); 2944 } 2945 } 2946 #endif 2947 2948 switch (rau_state){ 2949 case RAU_W4_RANDOM: 2950 // non-resolvable vs. resolvable 2951 switch (gap_random_adress_type){ 2952 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2953 // resolvable: use random as prand and calc address hash 2954 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2955 memcpy(sm_random_address, data, 3); 2956 sm_random_address[0] &= 0x3f; 2957 sm_random_address[0] |= 0x40; 2958 rau_state = RAU_GET_ENC; 2959 break; 2960 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2961 default: 2962 // "The two most significant bits of the address shall be equal to ‘0’"" 2963 memcpy(sm_random_address, data, 6); 2964 sm_random_address[0] &= 0x3f; 2965 rau_state = RAU_SET_ADDRESS; 2966 break; 2967 } 2968 return; 2969 default: 2970 break; 2971 } 2972 2973 // retrieve sm_connection provided to sm_random_start 2974 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2975 if (!connection) return; 2976 switch (connection->sm_engine_state){ 2977 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2978 case SM_SC_W4_GET_RANDOM_A: 2979 memcpy(&setup->sm_local_nonce[0], data, 8); 2980 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2981 break; 2982 case SM_SC_W4_GET_RANDOM_B: 2983 memcpy(&setup->sm_local_nonce[8], data, 8); 2984 // initiator & jw/nc -> send pairing random 2985 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2986 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2987 break; 2988 } else { 2989 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2990 } 2991 break; 2992 #endif 2993 2994 case SM_PH2_W4_RANDOM_TK: 2995 { 2996 sm_reset_tk(); 2997 uint32_t tk; 2998 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2999 // map random to 0-999999 without speding much cycles on a modulus operation 3000 tk = little_endian_read_32(data,0); 3001 tk = tk & 0xfffff; // 1048575 3002 if (tk >= 999999){ 3003 tk = tk - 999999; 3004 } 3005 } else { 3006 // override with pre-defined passkey 3007 tk = sm_fixed_passkey_in_display_role; 3008 } 3009 big_endian_store_32(setup->sm_tk, 12, tk); 3010 if (IS_RESPONDER(connection->sm_role)){ 3011 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3012 } else { 3013 if (setup->sm_use_secure_connections){ 3014 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3015 } else { 3016 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3017 sm_trigger_user_response(connection); 3018 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3019 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3020 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3021 } 3022 } 3023 } 3024 return; 3025 } 3026 case SM_PH2_C1_W4_RANDOM_A: 3027 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 3028 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 3029 return; 3030 case SM_PH2_C1_W4_RANDOM_B: 3031 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3032 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3033 return; 3034 case SM_PH3_W4_RANDOM: 3035 reverse_64(data, setup->sm_local_rand); 3036 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3037 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3038 // no db for authenticated flag hack: store flag in bit 4 of LSB 3039 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3040 connection->sm_engine_state = SM_PH3_GET_DIV; 3041 return; 3042 case SM_PH3_W4_DIV: 3043 // use 16 bit from random value as div 3044 setup->sm_local_div = big_endian_read_16(data, 0); 3045 log_info_hex16("div", setup->sm_local_div); 3046 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3047 return; 3048 default: 3049 break; 3050 } 3051 } 3052 3053 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3054 3055 UNUSED(channel); // ok: there is no channel 3056 UNUSED(size); // ok: fixed format HCI events 3057 3058 sm_connection_t * sm_conn; 3059 hci_con_handle_t con_handle; 3060 3061 switch (packet_type) { 3062 3063 case HCI_EVENT_PACKET: 3064 switch (hci_event_packet_get_type(packet)) { 3065 3066 case BTSTACK_EVENT_STATE: 3067 // bt stack activated, get started 3068 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3069 log_info("HCI Working!"); 3070 3071 3072 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3073 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3074 if (!sm_have_ec_keypair){ 3075 setup->sm_passkey_bit = 0; 3076 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3077 } 3078 #endif 3079 // trigger Random Address generation if requested before 3080 switch (gap_random_adress_type){ 3081 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3082 rau_state = RAU_IDLE; 3083 break; 3084 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3085 rau_state = RAU_SET_ADDRESS; 3086 break; 3087 default: 3088 rau_state = RAU_GET_RANDOM; 3089 break; 3090 } 3091 sm_run(); 3092 } 3093 break; 3094 3095 case HCI_EVENT_LE_META: 3096 switch (packet[2]) { 3097 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3098 3099 log_info("sm: connected"); 3100 3101 if (packet[3]) return; // connection failed 3102 3103 con_handle = little_endian_read_16(packet, 4); 3104 sm_conn = sm_get_connection_for_handle(con_handle); 3105 if (!sm_conn) break; 3106 3107 sm_conn->sm_handle = con_handle; 3108 sm_conn->sm_role = packet[6]; 3109 sm_conn->sm_peer_addr_type = packet[7]; 3110 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3111 3112 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3113 3114 // reset security properties 3115 sm_conn->sm_connection_encrypted = 0; 3116 sm_conn->sm_connection_authenticated = 0; 3117 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3118 sm_conn->sm_le_db_index = -1; 3119 3120 // prepare CSRK lookup (does not involve setup) 3121 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3122 3123 // just connected -> everything else happens in sm_run() 3124 if (IS_RESPONDER(sm_conn->sm_role)){ 3125 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3126 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3127 if (sm_slave_request_security) { 3128 // request security if requested by app 3129 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3130 } else { 3131 // otherwise, wait for pairing request 3132 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3133 } 3134 } 3135 break; 3136 } else { 3137 // master 3138 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3139 } 3140 break; 3141 3142 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3143 con_handle = little_endian_read_16(packet, 3); 3144 sm_conn = sm_get_connection_for_handle(con_handle); 3145 if (!sm_conn) break; 3146 3147 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3148 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3149 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3150 break; 3151 } 3152 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3153 // PH2 SEND LTK as we need to exchange keys in PH3 3154 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3155 break; 3156 } 3157 3158 // store rand and ediv 3159 reverse_64(&packet[5], sm_conn->sm_local_rand); 3160 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3161 3162 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3163 // potentially stored LTK is from the master 3164 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3165 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3166 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3167 break; 3168 } 3169 // additionally check if remote is in LE Device DB if requested 3170 switch(sm_conn->sm_irk_lookup_state){ 3171 case IRK_LOOKUP_FAILED: 3172 log_info("LTK Request: device not in device db"); 3173 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3174 break; 3175 case IRK_LOOKUP_SUCCEEDED: 3176 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3177 break; 3178 default: 3179 // wait for irk look doen 3180 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3181 break; 3182 } 3183 break; 3184 } 3185 3186 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3187 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3188 #else 3189 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3190 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3191 #endif 3192 break; 3193 3194 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3195 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3196 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3197 log_error("Read Local P256 Public Key failed"); 3198 break; 3199 } 3200 3201 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3202 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3203 3204 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3205 sm_log_ec_keypair(); 3206 break; 3207 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3208 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3209 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3210 log_error("Generate DHKEY failed -> abort"); 3211 // abort pairing with 'unspecified reason' 3212 sm_pdu_received_in_wrong_state(sm_conn); 3213 break; 3214 } 3215 3216 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3217 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3218 log_info("dhkey"); 3219 log_info_hexdump(&setup->sm_dhkey[0], 32); 3220 3221 // trigger next step 3222 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3223 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3224 } 3225 break; 3226 #endif 3227 default: 3228 break; 3229 } 3230 break; 3231 3232 case HCI_EVENT_ENCRYPTION_CHANGE: 3233 con_handle = little_endian_read_16(packet, 3); 3234 sm_conn = sm_get_connection_for_handle(con_handle); 3235 if (!sm_conn) break; 3236 3237 sm_conn->sm_connection_encrypted = packet[5]; 3238 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3239 sm_conn->sm_actual_encryption_key_size); 3240 log_info("event handler, state %u", sm_conn->sm_engine_state); 3241 if (!sm_conn->sm_connection_encrypted) break; 3242 // continue if part of initial pairing 3243 switch (sm_conn->sm_engine_state){ 3244 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3245 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3246 sm_done_for_handle(sm_conn->sm_handle); 3247 break; 3248 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3249 if (IS_RESPONDER(sm_conn->sm_role)){ 3250 // slave 3251 if (setup->sm_use_secure_connections){ 3252 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3253 } else { 3254 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3255 } 3256 } else { 3257 // master 3258 if (sm_key_distribution_all_received(sm_conn)){ 3259 // skip receiving keys as there are none 3260 sm_key_distribution_handle_all_received(sm_conn); 3261 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3262 } else { 3263 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3264 } 3265 } 3266 break; 3267 default: 3268 break; 3269 } 3270 break; 3271 3272 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3273 con_handle = little_endian_read_16(packet, 3); 3274 sm_conn = sm_get_connection_for_handle(con_handle); 3275 if (!sm_conn) break; 3276 3277 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3278 log_info("event handler, state %u", sm_conn->sm_engine_state); 3279 // continue if part of initial pairing 3280 switch (sm_conn->sm_engine_state){ 3281 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3282 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3283 sm_done_for_handle(sm_conn->sm_handle); 3284 break; 3285 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3286 if (IS_RESPONDER(sm_conn->sm_role)){ 3287 // slave 3288 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3289 } else { 3290 // master 3291 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3292 } 3293 break; 3294 default: 3295 break; 3296 } 3297 break; 3298 3299 3300 case HCI_EVENT_DISCONNECTION_COMPLETE: 3301 con_handle = little_endian_read_16(packet, 3); 3302 sm_done_for_handle(con_handle); 3303 sm_conn = sm_get_connection_for_handle(con_handle); 3304 if (!sm_conn) break; 3305 3306 // delete stored bonding on disconnect with authentication failure in ph0 3307 if (sm_conn->sm_role == 0 3308 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3309 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3310 le_device_db_remove(sm_conn->sm_le_db_index); 3311 } 3312 3313 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3314 3315 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3316 sm_conn->sm_handle = 0; 3317 break; 3318 3319 case HCI_EVENT_COMMAND_COMPLETE: 3320 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3321 sm_handle_encryption_result(&packet[6]); 3322 break; 3323 } 3324 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3325 sm_handle_random_result(&packet[6]); 3326 break; 3327 } 3328 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3329 // set local addr for le device db 3330 bd_addr_t addr; 3331 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3332 le_device_db_set_local_bd_addr(addr); 3333 } 3334 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3335 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3336 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3337 // mbedTLS can also be used if already available (and malloc is supported) 3338 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add USE_MICRO_ECC_FOR_ECDH to btstack_config.h"); 3339 } 3340 #endif 3341 } 3342 break; 3343 default: 3344 break; 3345 } 3346 break; 3347 default: 3348 break; 3349 } 3350 3351 sm_run(); 3352 } 3353 3354 static inline int sm_calc_actual_encryption_key_size(int other){ 3355 if (other < sm_min_encryption_key_size) return 0; 3356 if (other < sm_max_encryption_key_size) return other; 3357 return sm_max_encryption_key_size; 3358 } 3359 3360 3361 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3362 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3363 switch (method){ 3364 case JUST_WORKS: 3365 case NK_BOTH_INPUT: 3366 return 1; 3367 default: 3368 return 0; 3369 } 3370 } 3371 // responder 3372 3373 static int sm_passkey_used(stk_generation_method_t method){ 3374 switch (method){ 3375 case PK_RESP_INPUT: 3376 return 1; 3377 default: 3378 return 0; 3379 } 3380 } 3381 #endif 3382 3383 /** 3384 * @return ok 3385 */ 3386 static int sm_validate_stk_generation_method(void){ 3387 // check if STK generation method is acceptable by client 3388 switch (setup->sm_stk_generation_method){ 3389 case JUST_WORKS: 3390 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3391 case PK_RESP_INPUT: 3392 case PK_INIT_INPUT: 3393 case OK_BOTH_INPUT: 3394 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3395 case OOB: 3396 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3397 case NK_BOTH_INPUT: 3398 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3399 return 1; 3400 default: 3401 return 0; 3402 } 3403 } 3404 3405 // size of complete sm_pdu used to validate input 3406 static const uint8_t sm_pdu_size[] = { 3407 0, // 0x00 invalid opcode 3408 7, // 0x01 pairing request 3409 7, // 0x02 pairing response 3410 17, // 0x03 pairing confirm 3411 17, // 0x04 pairing random 3412 2, // 0x05 pairing failed 3413 17, // 0x06 encryption information 3414 11, // 0x07 master identification 3415 17, // 0x08 identification information 3416 8, // 0x09 identify address information 3417 17, // 0x0a signing information 3418 2, // 0x0b security request 3419 65, // 0x0c pairing public key 3420 17, // 0x0d pairing dhk check 3421 2, // 0x0e keypress notification 3422 }; 3423 3424 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3425 3426 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3427 sm_run(); 3428 } 3429 3430 if (packet_type != SM_DATA_PACKET) return; 3431 if (size == 0) return; 3432 3433 uint8_t sm_pdu_code = packet[0]; 3434 3435 // validate pdu size 3436 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3437 if (sm_pdu_size[sm_pdu_code] != size) return; 3438 3439 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3440 if (!sm_conn) return; 3441 3442 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3443 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3444 sm_done_for_handle(con_handle); 3445 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3446 return; 3447 } 3448 3449 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3450 3451 int err; 3452 UNUSED(err); 3453 3454 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3455 uint8_t buffer[5]; 3456 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3457 buffer[1] = 3; 3458 little_endian_store_16(buffer, 2, con_handle); 3459 buffer[4] = packet[1]; 3460 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3461 return; 3462 } 3463 3464 switch (sm_conn->sm_engine_state){ 3465 3466 // a sm timeout requries a new physical connection 3467 case SM_GENERAL_TIMEOUT: 3468 return; 3469 3470 #ifdef ENABLE_LE_CENTRAL 3471 3472 // Initiator 3473 case SM_INITIATOR_CONNECTED: 3474 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3475 sm_pdu_received_in_wrong_state(sm_conn); 3476 break; 3477 } 3478 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3479 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3480 break; 3481 } 3482 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3483 sm_key_t ltk; 3484 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3485 if (!sm_is_null_key(ltk)){ 3486 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3487 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3488 } else { 3489 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3490 } 3491 break; 3492 } 3493 // otherwise, store security request 3494 sm_conn->sm_security_request_received = 1; 3495 break; 3496 3497 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3498 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3499 sm_pdu_received_in_wrong_state(sm_conn); 3500 break; 3501 } 3502 // store pairing request 3503 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3504 err = sm_stk_generation_init(sm_conn); 3505 if (err){ 3506 setup->sm_pairing_failed_reason = err; 3507 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3508 break; 3509 } 3510 3511 // generate random number first, if we need to show passkey 3512 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3513 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3514 break; 3515 } 3516 3517 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3518 if (setup->sm_use_secure_connections){ 3519 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3520 if (setup->sm_stk_generation_method == JUST_WORKS){ 3521 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3522 sm_trigger_user_response(sm_conn); 3523 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3524 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3525 } 3526 } else { 3527 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3528 } 3529 break; 3530 } 3531 #endif 3532 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3533 sm_trigger_user_response(sm_conn); 3534 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3535 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3536 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3537 } 3538 break; 3539 3540 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3541 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3542 sm_pdu_received_in_wrong_state(sm_conn); 3543 break; 3544 } 3545 3546 // store s_confirm 3547 reverse_128(&packet[1], setup->sm_peer_confirm); 3548 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3549 break; 3550 3551 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3552 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3553 sm_pdu_received_in_wrong_state(sm_conn); 3554 break;; 3555 } 3556 3557 // received random value 3558 reverse_128(&packet[1], setup->sm_peer_random); 3559 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3560 break; 3561 #endif 3562 3563 #ifdef ENABLE_LE_PERIPHERAL 3564 // Responder 3565 case SM_RESPONDER_IDLE: 3566 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3567 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3568 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3569 sm_pdu_received_in_wrong_state(sm_conn); 3570 break;; 3571 } 3572 3573 // store pairing request 3574 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3575 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3576 break; 3577 #endif 3578 3579 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3580 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3581 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3582 sm_pdu_received_in_wrong_state(sm_conn); 3583 break; 3584 } 3585 3586 // store public key for DH Key calculation 3587 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3588 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3589 3590 // validate public key using micro-ecc 3591 err = 0; 3592 3593 #ifdef USE_MICRO_ECC_FOR_ECDH 3594 #if uECC_SUPPORTS_secp256r1 3595 // standard version 3596 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3597 #else 3598 // static version 3599 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3600 #endif 3601 #endif 3602 3603 #ifdef USE_MBEDTLS_FOR_ECDH 3604 mbedtls_ecp_point Q; 3605 mbedtls_ecp_point_init( &Q ); 3606 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3607 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3608 mbedtls_mpi_lset(&Q.Z, 1); 3609 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3610 mbedtls_ecp_point_free( & Q); 3611 #endif 3612 3613 if (err){ 3614 log_error("sm: peer public key invalid %x", err); 3615 // uses "unspecified reason", there is no "public key invalid" error code 3616 sm_pdu_received_in_wrong_state(sm_conn); 3617 break; 3618 } 3619 3620 #ifndef USE_SOFTWARE_ECDH_IMPLEMENTATION 3621 // ask controller to calculate dhkey 3622 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3623 #endif 3624 3625 if (IS_RESPONDER(sm_conn->sm_role)){ 3626 // responder 3627 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3628 } else { 3629 // initiator 3630 // stk generation method 3631 // passkey entry: notify app to show passkey or to request passkey 3632 switch (setup->sm_stk_generation_method){ 3633 case JUST_WORKS: 3634 case NK_BOTH_INPUT: 3635 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3636 break; 3637 case PK_RESP_INPUT: 3638 sm_sc_start_calculating_local_confirm(sm_conn); 3639 break; 3640 case PK_INIT_INPUT: 3641 case OK_BOTH_INPUT: 3642 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3643 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3644 break; 3645 } 3646 sm_sc_start_calculating_local_confirm(sm_conn); 3647 break; 3648 case OOB: 3649 // TODO: implement SC OOB 3650 break; 3651 } 3652 } 3653 break; 3654 3655 case SM_SC_W4_CONFIRMATION: 3656 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3657 sm_pdu_received_in_wrong_state(sm_conn); 3658 break; 3659 } 3660 // received confirm value 3661 reverse_128(&packet[1], setup->sm_peer_confirm); 3662 3663 if (IS_RESPONDER(sm_conn->sm_role)){ 3664 // responder 3665 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3666 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3667 // still waiting for passkey 3668 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3669 break; 3670 } 3671 } 3672 sm_sc_start_calculating_local_confirm(sm_conn); 3673 } else { 3674 // initiator 3675 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3676 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3677 } else { 3678 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3679 } 3680 } 3681 break; 3682 3683 case SM_SC_W4_PAIRING_RANDOM: 3684 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3685 sm_pdu_received_in_wrong_state(sm_conn); 3686 break; 3687 } 3688 3689 // received random value 3690 reverse_128(&packet[1], setup->sm_peer_nonce); 3691 3692 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3693 // only check for JUST WORK/NC in initiator role AND passkey entry 3694 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3695 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3696 } 3697 3698 sm_sc_state_after_receiving_random(sm_conn); 3699 break; 3700 3701 case SM_SC_W2_CALCULATE_G2: 3702 case SM_SC_W4_CALCULATE_G2: 3703 case SM_SC_W4_CALCULATE_DHKEY: 3704 case SM_SC_W2_CALCULATE_F5_SALT: 3705 case SM_SC_W4_CALCULATE_F5_SALT: 3706 case SM_SC_W2_CALCULATE_F5_MACKEY: 3707 case SM_SC_W4_CALCULATE_F5_MACKEY: 3708 case SM_SC_W2_CALCULATE_F5_LTK: 3709 case SM_SC_W4_CALCULATE_F5_LTK: 3710 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3711 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3712 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3713 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3714 sm_pdu_received_in_wrong_state(sm_conn); 3715 break; 3716 } 3717 // store DHKey Check 3718 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3719 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3720 3721 // have we been only waiting for dhkey check command? 3722 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3723 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3724 } 3725 break; 3726 #endif 3727 3728 #ifdef ENABLE_LE_PERIPHERAL 3729 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3730 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3731 sm_pdu_received_in_wrong_state(sm_conn); 3732 break; 3733 } 3734 3735 // received confirm value 3736 reverse_128(&packet[1], setup->sm_peer_confirm); 3737 3738 // notify client to hide shown passkey 3739 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3740 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3741 } 3742 3743 // handle user cancel pairing? 3744 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3745 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3746 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3747 break; 3748 } 3749 3750 // wait for user action? 3751 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3752 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3753 break; 3754 } 3755 3756 // calculate and send local_confirm 3757 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3758 break; 3759 3760 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3761 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3762 sm_pdu_received_in_wrong_state(sm_conn); 3763 break;; 3764 } 3765 3766 // received random value 3767 reverse_128(&packet[1], setup->sm_peer_random); 3768 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3769 break; 3770 #endif 3771 3772 case SM_PH3_RECEIVE_KEYS: 3773 switch(sm_pdu_code){ 3774 case SM_CODE_ENCRYPTION_INFORMATION: 3775 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3776 reverse_128(&packet[1], setup->sm_peer_ltk); 3777 break; 3778 3779 case SM_CODE_MASTER_IDENTIFICATION: 3780 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3781 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3782 reverse_64(&packet[3], setup->sm_peer_rand); 3783 break; 3784 3785 case SM_CODE_IDENTITY_INFORMATION: 3786 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3787 reverse_128(&packet[1], setup->sm_peer_irk); 3788 break; 3789 3790 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3791 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3792 setup->sm_peer_addr_type = packet[1]; 3793 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3794 break; 3795 3796 case SM_CODE_SIGNING_INFORMATION: 3797 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3798 reverse_128(&packet[1], setup->sm_peer_csrk); 3799 break; 3800 default: 3801 // Unexpected PDU 3802 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3803 break; 3804 } 3805 // done with key distribution? 3806 if (sm_key_distribution_all_received(sm_conn)){ 3807 3808 sm_key_distribution_handle_all_received(sm_conn); 3809 3810 if (IS_RESPONDER(sm_conn->sm_role)){ 3811 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3812 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3813 } else { 3814 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3815 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3816 sm_done_for_handle(sm_conn->sm_handle); 3817 } 3818 } else { 3819 if (setup->sm_use_secure_connections){ 3820 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3821 } else { 3822 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3823 } 3824 } 3825 } 3826 break; 3827 default: 3828 // Unexpected PDU 3829 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3830 break; 3831 } 3832 3833 // try to send preparared packet 3834 sm_run(); 3835 } 3836 3837 // Security Manager Client API 3838 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3839 sm_get_oob_data = get_oob_data_callback; 3840 } 3841 3842 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3843 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3844 } 3845 3846 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3847 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3848 } 3849 3850 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3851 sm_min_encryption_key_size = min_size; 3852 sm_max_encryption_key_size = max_size; 3853 } 3854 3855 void sm_set_authentication_requirements(uint8_t auth_req){ 3856 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3857 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3858 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3859 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3860 } 3861 #endif 3862 sm_auth_req = auth_req; 3863 } 3864 3865 void sm_set_io_capabilities(io_capability_t io_capability){ 3866 sm_io_capabilities = io_capability; 3867 } 3868 3869 #ifdef ENABLE_LE_PERIPHERAL 3870 void sm_set_request_security(int enable){ 3871 sm_slave_request_security = enable; 3872 } 3873 #endif 3874 3875 void sm_set_er(sm_key_t er){ 3876 memcpy(sm_persistent_er, er, 16); 3877 } 3878 3879 void sm_set_ir(sm_key_t ir){ 3880 memcpy(sm_persistent_ir, ir, 16); 3881 } 3882 3883 // Testing support only 3884 void sm_test_set_irk(sm_key_t irk){ 3885 memcpy(sm_persistent_irk, irk, 16); 3886 sm_persistent_irk_ready = 1; 3887 } 3888 3889 void sm_test_use_fixed_local_csrk(void){ 3890 test_use_fixed_local_csrk = 1; 3891 } 3892 3893 void sm_init(void){ 3894 // set some (BTstack default) ER and IR 3895 int i; 3896 sm_key_t er; 3897 sm_key_t ir; 3898 for (i=0;i<16;i++){ 3899 er[i] = 0x30 + i; 3900 ir[i] = 0x90 + i; 3901 } 3902 sm_set_er(er); 3903 sm_set_ir(ir); 3904 // defaults 3905 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3906 | SM_STK_GENERATION_METHOD_OOB 3907 | SM_STK_GENERATION_METHOD_PASSKEY 3908 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3909 3910 sm_max_encryption_key_size = 16; 3911 sm_min_encryption_key_size = 7; 3912 3913 sm_fixed_passkey_in_display_role = 0xffffffff; 3914 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3915 3916 #ifdef ENABLE_CMAC_ENGINE 3917 sm_cmac_state = CMAC_IDLE; 3918 #endif 3919 dkg_state = DKG_W4_WORKING; 3920 rau_state = RAU_W4_WORKING; 3921 sm_aes128_state = SM_AES128_IDLE; 3922 sm_address_resolution_test = -1; // no private address to resolve yet 3923 sm_address_resolution_ah_calculation_active = 0; 3924 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3925 sm_address_resolution_general_queue = NULL; 3926 3927 gap_random_adress_update_period = 15 * 60 * 1000L; 3928 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3929 3930 test_use_fixed_local_csrk = 0; 3931 3932 // register for HCI Events from HCI 3933 hci_event_callback_registration.callback = &sm_event_packet_handler; 3934 hci_add_event_handler(&hci_event_callback_registration); 3935 3936 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3937 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3938 3939 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3940 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3941 #endif 3942 3943 #ifdef USE_MBEDTLS_FOR_ECDH 3944 mbedtls_ecp_group_init(&mbedtls_ec_group); 3945 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3946 #endif 3947 } 3948 3949 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3950 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3951 memcpy(&ec_q[0], qx, 32); 3952 memcpy(&ec_q[32], qy, 32); 3953 memcpy(ec_d, d, 32); 3954 sm_have_ec_keypair = 1; 3955 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3956 #else 3957 UNUSED(qx); 3958 UNUSED(qy); 3959 UNUSED(d); 3960 #endif 3961 } 3962 3963 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3964 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3965 while (*hex_string){ 3966 int high_nibble = nibble_for_char(*hex_string++); 3967 int low_nibble = nibble_for_char(*hex_string++); 3968 *buffer++ = (high_nibble << 4) | low_nibble; 3969 } 3970 } 3971 #endif 3972 3973 void sm_test_use_fixed_ec_keypair(void){ 3974 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3975 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3976 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3977 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3978 parse_hex(ec_d, ec_d_string); 3979 parse_hex(&ec_q[0], ec_qx_string); 3980 parse_hex(&ec_q[32], ec_qy_string); 3981 sm_have_ec_keypair = 1; 3982 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3983 #endif 3984 } 3985 3986 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3987 sm_fixed_passkey_in_display_role = passkey; 3988 } 3989 3990 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3991 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3992 } 3993 3994 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3995 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3996 if (!hci_con) return NULL; 3997 return &hci_con->sm_connection; 3998 } 3999 4000 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4001 switch (sm_conn->sm_engine_state){ 4002 case SM_GENERAL_IDLE: 4003 case SM_RESPONDER_IDLE: 4004 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4005 sm_run(); 4006 break; 4007 default: 4008 break; 4009 } 4010 } 4011 4012 /** 4013 * @brief Trigger Security Request 4014 */ 4015 void sm_send_security_request(hci_con_handle_t con_handle){ 4016 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4017 if (!sm_conn) return; 4018 sm_send_security_request_for_connection(sm_conn); 4019 } 4020 4021 // request pairing 4022 void sm_request_pairing(hci_con_handle_t con_handle){ 4023 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4024 if (!sm_conn) return; // wrong connection 4025 4026 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4027 if (IS_RESPONDER(sm_conn->sm_role)){ 4028 sm_send_security_request_for_connection(sm_conn); 4029 } else { 4030 // used as a trigger to start central/master/initiator security procedures 4031 uint16_t ediv; 4032 sm_key_t ltk; 4033 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4034 switch (sm_conn->sm_irk_lookup_state){ 4035 case IRK_LOOKUP_FAILED: 4036 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4037 break; 4038 case IRK_LOOKUP_SUCCEEDED: 4039 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 4040 if (!sm_is_null_key(ltk) || ediv){ 4041 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 4042 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4043 } else { 4044 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4045 } 4046 break; 4047 default: 4048 sm_conn->sm_bonding_requested = 1; 4049 break; 4050 } 4051 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4052 sm_conn->sm_bonding_requested = 1; 4053 } 4054 } 4055 sm_run(); 4056 } 4057 4058 // called by client app on authorization request 4059 void sm_authorization_decline(hci_con_handle_t con_handle){ 4060 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4061 if (!sm_conn) return; // wrong connection 4062 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4063 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4064 } 4065 4066 void sm_authorization_grant(hci_con_handle_t con_handle){ 4067 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4068 if (!sm_conn) return; // wrong connection 4069 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4070 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4071 } 4072 4073 // GAP Bonding API 4074 4075 void sm_bonding_decline(hci_con_handle_t con_handle){ 4076 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4077 if (!sm_conn) return; // wrong connection 4078 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4079 4080 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4081 switch (setup->sm_stk_generation_method){ 4082 case PK_RESP_INPUT: 4083 case PK_INIT_INPUT: 4084 case OK_BOTH_INPUT: 4085 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4086 break; 4087 case NK_BOTH_INPUT: 4088 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4089 break; 4090 case JUST_WORKS: 4091 case OOB: 4092 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4093 break; 4094 } 4095 } 4096 sm_run(); 4097 } 4098 4099 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4100 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4101 if (!sm_conn) return; // wrong connection 4102 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4103 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4104 if (setup->sm_use_secure_connections){ 4105 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4106 } else { 4107 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4108 } 4109 } 4110 4111 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4112 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4113 sm_sc_prepare_dhkey_check(sm_conn); 4114 } 4115 #endif 4116 4117 sm_run(); 4118 } 4119 4120 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4121 // for now, it's the same 4122 sm_just_works_confirm(con_handle); 4123 } 4124 4125 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4126 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4127 if (!sm_conn) return; // wrong connection 4128 sm_reset_tk(); 4129 big_endian_store_32(setup->sm_tk, 12, passkey); 4130 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4131 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4132 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4133 } 4134 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4135 memcpy(setup->sm_ra, setup->sm_tk, 16); 4136 memcpy(setup->sm_rb, setup->sm_tk, 16); 4137 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4138 sm_sc_start_calculating_local_confirm(sm_conn); 4139 } 4140 #endif 4141 sm_run(); 4142 } 4143 4144 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4145 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4146 if (!sm_conn) return; // wrong connection 4147 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4148 setup->sm_keypress_notification = action; 4149 sm_run(); 4150 } 4151 4152 /** 4153 * @brief Identify device in LE Device DB 4154 * @param handle 4155 * @returns index from le_device_db or -1 if not found/identified 4156 */ 4157 int sm_le_device_index(hci_con_handle_t con_handle ){ 4158 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4159 if (!sm_conn) return -1; 4160 return sm_conn->sm_le_db_index; 4161 } 4162 4163 static int gap_random_address_type_requires_updates(void){ 4164 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4165 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4166 return 1; 4167 } 4168 4169 static uint8_t own_address_type(void){ 4170 switch (gap_random_adress_type){ 4171 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4172 return BD_ADDR_TYPE_LE_PUBLIC; 4173 default: 4174 return BD_ADDR_TYPE_LE_RANDOM; 4175 } 4176 } 4177 4178 // GAP LE API 4179 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4180 gap_random_address_update_stop(); 4181 gap_random_adress_type = random_address_type; 4182 hci_le_set_own_address_type(own_address_type()); 4183 if (!gap_random_address_type_requires_updates()) return; 4184 gap_random_address_update_start(); 4185 gap_random_address_trigger(); 4186 } 4187 4188 gap_random_address_type_t gap_random_address_get_mode(void){ 4189 return gap_random_adress_type; 4190 } 4191 4192 void gap_random_address_set_update_period(int period_ms){ 4193 gap_random_adress_update_period = period_ms; 4194 if (!gap_random_address_type_requires_updates()) return; 4195 gap_random_address_update_stop(); 4196 gap_random_address_update_start(); 4197 } 4198 4199 void gap_random_address_set(bd_addr_t addr){ 4200 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4201 memcpy(sm_random_address, addr, 6); 4202 if (rau_state == RAU_W4_WORKING) return; 4203 rau_state = RAU_SET_ADDRESS; 4204 sm_run(); 4205 } 4206 4207 #ifdef ENABLE_LE_PERIPHERAL 4208 /* 4209 * @brief Set Advertisement Paramters 4210 * @param adv_int_min 4211 * @param adv_int_max 4212 * @param adv_type 4213 * @param direct_address_type 4214 * @param direct_address 4215 * @param channel_map 4216 * @param filter_policy 4217 * 4218 * @note own_address_type is used from gap_random_address_set_mode 4219 */ 4220 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4221 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4222 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4223 direct_address_typ, direct_address, channel_map, filter_policy); 4224 } 4225 #endif 4226