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); 416 417 static void log_info_hex16(const char * name, uint16_t value){ 418 log_info("%-6s 0x%04x", name, value); 419 } 420 421 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 422 // return packet[0]; 423 // } 424 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 425 return packet[1]; 426 } 427 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 428 return packet[2]; 429 } 430 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 431 return packet[3]; 432 } 433 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 434 return packet[4]; 435 } 436 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 437 return packet[5]; 438 } 439 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 440 return packet[6]; 441 } 442 443 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 444 packet[0] = code; 445 } 446 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 447 packet[1] = io_capability; 448 } 449 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 450 packet[2] = oob_data_flag; 451 } 452 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 453 packet[3] = auth_req; 454 } 455 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 456 packet[4] = max_encryption_key_size; 457 } 458 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 459 packet[5] = initiator_key_distribution; 460 } 461 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 462 packet[6] = responder_key_distribution; 463 } 464 465 // @returns 1 if all bytes are 0 466 static int sm_is_null(uint8_t * data, int size){ 467 int i; 468 for (i=0; i < size ; i++){ 469 if (data[i]) return 0; 470 } 471 return 1; 472 } 473 474 static int sm_is_null_random(uint8_t random[8]){ 475 return sm_is_null(random, 8); 476 } 477 478 static int sm_is_null_key(uint8_t * key){ 479 return sm_is_null(key, 16); 480 } 481 482 // Key utils 483 static void sm_reset_tk(void){ 484 int i; 485 for (i=0;i<16;i++){ 486 setup->sm_tk[i] = 0; 487 } 488 } 489 490 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 491 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 492 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 493 int i; 494 for (i = max_encryption_size ; i < 16 ; i++){ 495 key[15-i] = 0; 496 } 497 } 498 499 // SMP Timeout implementation 500 501 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 502 // the Security Manager Timer shall be reset and started. 503 // 504 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 505 // 506 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 507 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 508 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 509 // established. 510 511 static void sm_timeout_handler(btstack_timer_source_t * timer){ 512 log_info("SM timeout"); 513 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 514 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 515 sm_done_for_handle(sm_conn->sm_handle); 516 517 // trigger handling of next ready connection 518 sm_run(); 519 } 520 static void sm_timeout_start(sm_connection_t * sm_conn){ 521 btstack_run_loop_remove_timer(&setup->sm_timeout); 522 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 523 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 524 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 525 btstack_run_loop_add_timer(&setup->sm_timeout); 526 } 527 static void sm_timeout_stop(void){ 528 btstack_run_loop_remove_timer(&setup->sm_timeout); 529 } 530 static void sm_timeout_reset(sm_connection_t * sm_conn){ 531 sm_timeout_stop(); 532 sm_timeout_start(sm_conn); 533 } 534 535 // end of sm timeout 536 537 // GAP Random Address updates 538 static gap_random_address_type_t gap_random_adress_type; 539 static btstack_timer_source_t gap_random_address_update_timer; 540 static uint32_t gap_random_adress_update_period; 541 542 static void gap_random_address_trigger(void){ 543 if (rau_state != RAU_IDLE) return; 544 log_info("gap_random_address_trigger"); 545 rau_state = RAU_GET_RANDOM; 546 sm_run(); 547 } 548 549 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 550 UNUSED(timer); 551 552 log_info("GAP Random Address Update due"); 553 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 554 btstack_run_loop_add_timer(&gap_random_address_update_timer); 555 gap_random_address_trigger(); 556 } 557 558 static void gap_random_address_update_start(void){ 559 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 560 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 561 btstack_run_loop_add_timer(&gap_random_address_update_timer); 562 } 563 564 static void gap_random_address_update_stop(void){ 565 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 566 } 567 568 569 static void sm_random_start(void * context){ 570 sm_random_context = context; 571 hci_send_cmd(&hci_le_rand); 572 } 573 574 #ifdef HAVE_AES128 575 static void aes128_completed(btstack_timer_source_t * ts){ 576 UNUSED(ts); 577 sm_handle_encryption_result(&aes128_result_flipped[0]); 578 sm_run(); 579 } 580 #endif 581 582 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 583 // context is made availabe to aes128 result handler by this 584 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 585 sm_aes128_state = SM_AES128_ACTIVE; 586 sm_aes128_context = context; 587 588 #ifdef HAVE_AES128 589 // calc result directly 590 sm_key_t result; 591 btstack_aes128_calc(key, plaintext, result); 592 593 // log 594 log_info_key("key", key); 595 log_info_key("txt", plaintext); 596 log_info_key("res", result); 597 598 // flip 599 reverse_128(&result[0], &aes128_result_flipped[0]); 600 601 // deliver via timer 602 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 603 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 604 btstack_run_loop_add_timer(&aes128_timer); 605 #else 606 sm_key_t key_flipped, plaintext_flipped; 607 reverse_128(key, key_flipped); 608 reverse_128(plaintext, plaintext_flipped); 609 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 610 #endif 611 } 612 613 // ah(k,r) helper 614 // r = padding || r 615 // r - 24 bit value 616 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 617 // r'= padding || r 618 memset(r_prime, 0, 16); 619 memcpy(&r_prime[13], r, 3); 620 } 621 622 // d1 helper 623 // d' = padding || r || d 624 // d,r - 16 bit values 625 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 626 // d'= padding || r || d 627 memset(d1_prime, 0, 16); 628 big_endian_store_16(d1_prime, 12, r); 629 big_endian_store_16(d1_prime, 14, d); 630 } 631 632 // dm helper 633 // r’ = padding || r 634 // r - 64 bit value 635 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 636 memset(r_prime, 0, 16); 637 memcpy(&r_prime[8], r, 8); 638 } 639 640 // calculate arguments for first AES128 operation in C1 function 641 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){ 642 643 // p1 = pres || preq || rat’ || iat’ 644 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 645 // cant octet of pres becomes the most significant octet of p1. 646 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 647 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 648 // p1 is 0x05000800000302070710000001010001." 649 650 sm_key_t p1; 651 reverse_56(pres, &p1[0]); 652 reverse_56(preq, &p1[7]); 653 p1[14] = rat; 654 p1[15] = iat; 655 log_info_key("p1", p1); 656 log_info_key("r", r); 657 658 // t1 = r xor p1 659 int i; 660 for (i=0;i<16;i++){ 661 t1[i] = r[i] ^ p1[i]; 662 } 663 log_info_key("t1", t1); 664 } 665 666 // calculate arguments for second AES128 operation in C1 function 667 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 668 // p2 = padding || ia || ra 669 // "The least significant octet of ra becomes the least significant octet of p2 and 670 // the most significant octet of padding becomes the most significant octet of p2. 671 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 672 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 673 674 sm_key_t p2; 675 memset(p2, 0, 16); 676 memcpy(&p2[4], ia, 6); 677 memcpy(&p2[10], ra, 6); 678 log_info_key("p2", p2); 679 680 // c1 = e(k, t2_xor_p2) 681 int i; 682 for (i=0;i<16;i++){ 683 t3[i] = t2[i] ^ p2[i]; 684 } 685 log_info_key("t3", t3); 686 } 687 688 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 689 log_info_key("r1", r1); 690 log_info_key("r2", r2); 691 memcpy(&r_prime[8], &r2[8], 8); 692 memcpy(&r_prime[0], &r1[8], 8); 693 } 694 695 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){ 696 event[0] = type; 697 event[1] = event_size - 2; 698 little_endian_store_16(event, 2, con_handle); 699 event[4] = addr_type; 700 reverse_bd_addr(address, &event[5]); 701 } 702 703 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 704 UNUSED(channel); 705 706 // log event 707 hci_dump_packet(packet_type, 1, packet, size); 708 // dispatch to all event handlers 709 btstack_linked_list_iterator_t it; 710 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 711 while (btstack_linked_list_iterator_has_next(&it)){ 712 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 713 entry->callback(packet_type, 0, packet, size); 714 } 715 } 716 717 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 718 uint8_t event[11]; 719 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 720 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 721 } 722 723 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){ 724 uint8_t event[15]; 725 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 726 little_endian_store_32(event, 11, passkey); 727 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 728 } 729 730 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){ 731 // fetch addr and addr type from db 732 bd_addr_t identity_address; 733 int identity_address_type; 734 le_device_db_info(index, &identity_address_type, identity_address, NULL); 735 736 uint8_t event[19]; 737 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 738 event[11] = identity_address_type; 739 reverse_bd_addr(identity_address, &event[12]); 740 event[18] = index; 741 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 742 } 743 744 static void sm_notify_client_authorization(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 745 746 uint8_t event[18]; 747 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 748 event[11] = result; 749 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 750 } 751 752 // decide on stk generation based on 753 // - pairing request 754 // - io capabilities 755 // - OOB data availability 756 static void sm_setup_tk(void){ 757 758 // default: just works 759 setup->sm_stk_generation_method = JUST_WORKS; 760 761 #ifdef ENABLE_LE_SECURE_CONNECTIONS 762 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 763 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 764 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 765 memset(setup->sm_ra, 0, 16); 766 memset(setup->sm_rb, 0, 16); 767 #else 768 setup->sm_use_secure_connections = 0; 769 #endif 770 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 771 772 // If both devices have not set the MITM option in the Authentication Requirements 773 // Flags, then the IO capabilities shall be ignored and the Just Works association 774 // model shall be used. 775 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 776 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 777 log_info("SM: MITM not required by both -> JUST WORKS"); 778 return; 779 } 780 781 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 782 783 // If both devices have out of band authentication data, then the Authentication 784 // Requirements Flags shall be ignored when selecting the pairing method and the 785 // Out of Band pairing method shall be used. 786 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 787 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 788 log_info("SM: have OOB data"); 789 log_info_key("OOB", setup->sm_tk); 790 setup->sm_stk_generation_method = OOB; 791 return; 792 } 793 794 // Reset TK as it has been setup in sm_init_setup 795 sm_reset_tk(); 796 797 // Also use just works if unknown io capabilites 798 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 799 return; 800 } 801 802 // Otherwise the IO capabilities of the devices shall be used to determine the 803 // pairing method as defined in Table 2.4. 804 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 805 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 806 807 #ifdef ENABLE_LE_SECURE_CONNECTIONS 808 // table not define by default 809 if (setup->sm_use_secure_connections){ 810 generation_method = stk_generation_method_with_secure_connection; 811 } 812 #endif 813 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 814 815 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 816 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 817 } 818 819 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 820 int flags = 0; 821 if (key_set & SM_KEYDIST_ENC_KEY){ 822 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 823 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 824 } 825 if (key_set & SM_KEYDIST_ID_KEY){ 826 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 827 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 828 } 829 if (key_set & SM_KEYDIST_SIGN){ 830 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 831 } 832 return flags; 833 } 834 835 static void sm_setup_key_distribution(uint8_t key_set){ 836 setup->sm_key_distribution_received_set = 0; 837 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 838 } 839 840 // CSRK Key Lookup 841 842 843 static int sm_address_resolution_idle(void){ 844 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 845 } 846 847 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){ 848 memcpy(sm_address_resolution_address, addr, 6); 849 sm_address_resolution_addr_type = addr_type; 850 sm_address_resolution_test = 0; 851 sm_address_resolution_mode = mode; 852 sm_address_resolution_context = context; 853 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 854 } 855 856 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 857 // check if already in list 858 btstack_linked_list_iterator_t it; 859 sm_lookup_entry_t * entry; 860 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 861 while(btstack_linked_list_iterator_has_next(&it)){ 862 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 863 if (entry->address_type != address_type) continue; 864 if (memcmp(entry->address, address, 6)) continue; 865 // already in list 866 return BTSTACK_BUSY; 867 } 868 entry = btstack_memory_sm_lookup_entry_get(); 869 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 870 entry->address_type = (bd_addr_type_t) address_type; 871 memcpy(entry->address, address, 6); 872 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 873 sm_run(); 874 return 0; 875 } 876 877 // 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 878 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 879 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 880 } 881 static inline void dkg_next_state(void){ 882 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 883 } 884 static inline void rau_next_state(void){ 885 rau_state = (random_address_update_t) (((int)rau_state) + 1); 886 } 887 888 // CMAC calculation using AES Engine 889 #ifdef ENABLE_CMAC_ENGINE 890 891 static inline void sm_cmac_next_state(void){ 892 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 893 } 894 895 static int sm_cmac_last_block_complete(void){ 896 if (sm_cmac_message_len == 0) return 0; 897 return (sm_cmac_message_len & 0x0f) == 0; 898 } 899 900 int sm_cmac_ready(void){ 901 return sm_cmac_state == CMAC_IDLE; 902 } 903 904 // generic cmac calculation 905 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])){ 906 // Generalized CMAC 907 memcpy(sm_cmac_k, key, 16); 908 memset(sm_cmac_x, 0, 16); 909 sm_cmac_block_current = 0; 910 sm_cmac_message_len = message_len; 911 sm_cmac_done_handler = done_callback; 912 sm_cmac_get_byte = get_byte_callback; 913 914 // step 2: n := ceil(len/const_Bsize); 915 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 916 917 // step 3: .. 918 if (sm_cmac_block_count==0){ 919 sm_cmac_block_count = 1; 920 } 921 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 922 923 // first, we need to compute l for k1, k2, and m_last 924 sm_cmac_state = CMAC_CALC_SUBKEYS; 925 926 // let's go 927 sm_run(); 928 } 929 #endif 930 931 // cmac for ATT Message signing 932 #ifdef ENABLE_LE_SIGNED_WRITE 933 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 934 if (offset >= sm_cmac_message_len) { 935 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 936 return 0; 937 } 938 939 offset = sm_cmac_message_len - 1 - offset; 940 941 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 942 if (offset < 3){ 943 return sm_cmac_header[offset]; 944 } 945 int actual_message_len_incl_header = sm_cmac_message_len - 4; 946 if (offset < actual_message_len_incl_header){ 947 return sm_cmac_message[offset - 3]; 948 } 949 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 950 } 951 952 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)){ 953 // ATT Message Signing 954 sm_cmac_header[0] = opcode; 955 little_endian_store_16(sm_cmac_header, 1, con_handle); 956 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 957 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 958 sm_cmac_message = message; 959 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 960 } 961 #endif 962 963 #ifdef ENABLE_CMAC_ENGINE 964 static void sm_cmac_handle_aes_engine_ready(void){ 965 switch (sm_cmac_state){ 966 case CMAC_CALC_SUBKEYS: { 967 sm_key_t const_zero; 968 memset(const_zero, 0, 16); 969 sm_cmac_next_state(); 970 sm_aes128_start(sm_cmac_k, const_zero, NULL); 971 break; 972 } 973 case CMAC_CALC_MI: { 974 int j; 975 sm_key_t y; 976 for (j=0;j<16;j++){ 977 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 978 } 979 sm_cmac_block_current++; 980 sm_cmac_next_state(); 981 sm_aes128_start(sm_cmac_k, y, NULL); 982 break; 983 } 984 case CMAC_CALC_MLAST: { 985 int i; 986 sm_key_t y; 987 for (i=0;i<16;i++){ 988 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 989 } 990 log_info_key("Y", y); 991 sm_cmac_block_current++; 992 sm_cmac_next_state(); 993 sm_aes128_start(sm_cmac_k, y, NULL); 994 break; 995 } 996 default: 997 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 998 break; 999 } 1000 } 1001 1002 // CMAC Implementation using AES128 engine 1003 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1004 int i; 1005 int carry = 0; 1006 for (i=len-1; i >= 0 ; i--){ 1007 int new_carry = data[i] >> 7; 1008 data[i] = data[i] << 1 | carry; 1009 carry = new_carry; 1010 } 1011 } 1012 1013 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1014 switch (sm_cmac_state){ 1015 case CMAC_W4_SUBKEYS: { 1016 sm_key_t k1; 1017 memcpy(k1, data, 16); 1018 sm_shift_left_by_one_bit_inplace(16, k1); 1019 if (data[0] & 0x80){ 1020 k1[15] ^= 0x87; 1021 } 1022 sm_key_t k2; 1023 memcpy(k2, k1, 16); 1024 sm_shift_left_by_one_bit_inplace(16, k2); 1025 if (k1[0] & 0x80){ 1026 k2[15] ^= 0x87; 1027 } 1028 1029 log_info_key("k", sm_cmac_k); 1030 log_info_key("k1", k1); 1031 log_info_key("k2", k2); 1032 1033 // step 4: set m_last 1034 int i; 1035 if (sm_cmac_last_block_complete()){ 1036 for (i=0;i<16;i++){ 1037 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1038 } 1039 } else { 1040 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1041 for (i=0;i<16;i++){ 1042 if (i < valid_octets_in_last_block){ 1043 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1044 continue; 1045 } 1046 if (i == valid_octets_in_last_block){ 1047 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1048 continue; 1049 } 1050 sm_cmac_m_last[i] = k2[i]; 1051 } 1052 } 1053 1054 // next 1055 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1056 break; 1057 } 1058 case CMAC_W4_MI: 1059 memcpy(sm_cmac_x, data, 16); 1060 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1061 break; 1062 case CMAC_W4_MLAST: 1063 // done 1064 log_info("Setting CMAC Engine to IDLE"); 1065 sm_cmac_state = CMAC_IDLE; 1066 log_info_key("CMAC", data); 1067 sm_cmac_done_handler(data); 1068 break; 1069 default: 1070 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1071 break; 1072 } 1073 } 1074 #endif 1075 1076 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1077 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1078 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1079 switch (setup->sm_stk_generation_method){ 1080 case PK_RESP_INPUT: 1081 if (IS_RESPONDER(sm_conn->sm_role)){ 1082 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1083 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1084 } else { 1085 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)); 1086 } 1087 break; 1088 case PK_INIT_INPUT: 1089 if (IS_RESPONDER(sm_conn->sm_role)){ 1090 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)); 1091 } else { 1092 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1093 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1094 } 1095 break; 1096 case OK_BOTH_INPUT: 1097 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1098 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1099 break; 1100 case NK_BOTH_INPUT: 1101 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1102 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)); 1103 break; 1104 case JUST_WORKS: 1105 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1106 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1107 break; 1108 case OOB: 1109 // client already provided OOB data, let's skip notification. 1110 break; 1111 } 1112 } 1113 1114 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1115 int recv_flags; 1116 if (IS_RESPONDER(sm_conn->sm_role)){ 1117 // slave / responder 1118 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1119 } else { 1120 // master / initiator 1121 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1122 } 1123 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1124 return recv_flags == setup->sm_key_distribution_received_set; 1125 } 1126 1127 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1128 if (sm_active_connection_handle == con_handle){ 1129 sm_timeout_stop(); 1130 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1131 log_info("sm: connection 0x%x released setup context", con_handle); 1132 } 1133 } 1134 1135 static int sm_key_distribution_flags_for_auth_req(void){ 1136 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1137 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1138 // encryption information only if bonding requested 1139 flags |= SM_KEYDIST_ENC_KEY; 1140 } 1141 return flags; 1142 } 1143 1144 static void sm_reset_setup(void){ 1145 // fill in sm setup 1146 setup->sm_state_vars = 0; 1147 setup->sm_keypress_notification = 0xff; 1148 sm_reset_tk(); 1149 } 1150 1151 static void sm_init_setup(sm_connection_t * sm_conn){ 1152 1153 // fill in sm setup 1154 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1155 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1156 1157 // query client for OOB data 1158 int have_oob_data = 0; 1159 if (sm_get_oob_data) { 1160 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1161 } 1162 1163 sm_pairing_packet_t * local_packet; 1164 if (IS_RESPONDER(sm_conn->sm_role)){ 1165 // slave 1166 local_packet = &setup->sm_s_pres; 1167 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1168 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1169 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1170 } else { 1171 // master 1172 local_packet = &setup->sm_m_preq; 1173 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1174 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1175 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1176 1177 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1178 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1179 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1180 } 1181 1182 uint8_t auth_req = sm_auth_req; 1183 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1184 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1185 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1186 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1187 } 1188 1189 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1190 1191 sm_pairing_packet_t * remote_packet; 1192 int remote_key_request; 1193 if (IS_RESPONDER(sm_conn->sm_role)){ 1194 // slave / responder 1195 remote_packet = &setup->sm_m_preq; 1196 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1197 } else { 1198 // master / initiator 1199 remote_packet = &setup->sm_s_pres; 1200 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1201 } 1202 1203 // check key size 1204 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1205 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1206 1207 // decide on STK generation method 1208 sm_setup_tk(); 1209 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1210 1211 // check if STK generation method is acceptable by client 1212 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1213 1214 // identical to responder 1215 sm_setup_key_distribution(remote_key_request); 1216 1217 // JUST WORKS doens't provide authentication 1218 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1219 1220 return 0; 1221 } 1222 1223 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1224 1225 // cache and reset context 1226 int matched_device_id = sm_address_resolution_test; 1227 address_resolution_mode_t mode = sm_address_resolution_mode; 1228 void * context = sm_address_resolution_context; 1229 1230 // reset context 1231 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1232 sm_address_resolution_context = NULL; 1233 sm_address_resolution_test = -1; 1234 hci_con_handle_t con_handle = 0; 1235 1236 sm_connection_t * sm_connection; 1237 #ifdef ENABLE_LE_CENTRAL 1238 sm_key_t ltk; 1239 #endif 1240 switch (mode){ 1241 case ADDRESS_RESOLUTION_GENERAL: 1242 break; 1243 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1244 sm_connection = (sm_connection_t *) context; 1245 con_handle = sm_connection->sm_handle; 1246 switch (event){ 1247 case ADDRESS_RESOLUTION_SUCEEDED: 1248 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1249 sm_connection->sm_le_db_index = matched_device_id; 1250 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1251 if (sm_connection->sm_role) { 1252 // LTK request received before, IRK required -> start LTK calculation 1253 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1254 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1255 } 1256 break; 1257 } 1258 #ifdef ENABLE_LE_CENTRAL 1259 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1260 sm_connection->sm_security_request_received = 0; 1261 sm_connection->sm_bonding_requested = 0; 1262 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1263 if (!sm_is_null_key(ltk)){ 1264 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1265 } else { 1266 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1267 } 1268 #endif 1269 break; 1270 case ADDRESS_RESOLUTION_FAILED: 1271 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1272 if (sm_connection->sm_role) { 1273 // LTK request received before, IRK required -> negative LTK reply 1274 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1275 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1276 } 1277 break; 1278 } 1279 #ifdef ENABLE_LE_CENTRAL 1280 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1281 sm_connection->sm_security_request_received = 0; 1282 sm_connection->sm_bonding_requested = 0; 1283 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1284 #endif 1285 break; 1286 } 1287 break; 1288 default: 1289 break; 1290 } 1291 1292 switch (event){ 1293 case ADDRESS_RESOLUTION_SUCEEDED: 1294 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1295 break; 1296 case ADDRESS_RESOLUTION_FAILED: 1297 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1298 break; 1299 } 1300 } 1301 1302 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1303 1304 int le_db_index = -1; 1305 1306 // lookup device based on IRK 1307 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1308 int i; 1309 for (i=0; i < le_device_db_count(); i++){ 1310 sm_key_t irk; 1311 bd_addr_t address; 1312 int address_type; 1313 le_device_db_info(i, &address_type, address, irk); 1314 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1315 log_info("sm: device found for IRK, updating"); 1316 le_db_index = i; 1317 break; 1318 } 1319 } 1320 } 1321 1322 // if not found, lookup via public address if possible 1323 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1324 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1325 int i; 1326 for (i=0; i < le_device_db_count(); i++){ 1327 bd_addr_t address; 1328 int address_type; 1329 le_device_db_info(i, &address_type, address, NULL); 1330 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1331 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1332 log_info("sm: device found for public address, updating"); 1333 le_db_index = i; 1334 break; 1335 } 1336 } 1337 } 1338 1339 // if not found, add to db 1340 if (le_db_index < 0) { 1341 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1342 } 1343 1344 if (le_db_index >= 0){ 1345 1346 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1347 1348 #ifdef ENABLE_LE_SIGNED_WRITE 1349 // store local CSRK 1350 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1351 log_info("sm: store local CSRK"); 1352 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1353 le_device_db_local_counter_set(le_db_index, 0); 1354 } 1355 1356 // store remote CSRK 1357 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1358 log_info("sm: store remote CSRK"); 1359 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1360 le_device_db_remote_counter_set(le_db_index, 0); 1361 } 1362 #endif 1363 // store encryption information for secure connections: LTK generated by ECDH 1364 if (setup->sm_use_secure_connections){ 1365 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1366 uint8_t zero_rand[8]; 1367 memset(zero_rand, 0, 8); 1368 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1369 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1370 } 1371 1372 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1373 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1374 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1375 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1376 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1377 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1378 1379 } 1380 } 1381 1382 // keep le_db_index 1383 sm_conn->sm_le_db_index = le_db_index; 1384 } 1385 1386 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1387 setup->sm_pairing_failed_reason = reason; 1388 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1389 } 1390 1391 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1392 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1393 } 1394 1395 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1396 1397 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1398 static int sm_passkey_used(stk_generation_method_t method); 1399 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1400 1401 static void sm_log_ec_keypair(void){ 1402 log_info("Elliptic curve: X"); 1403 log_info_hexdump(&ec_q[0],32); 1404 log_info("Elliptic curve: Y"); 1405 log_info_hexdump(&ec_q[32],32); 1406 } 1407 1408 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1409 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1410 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1411 } else { 1412 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1413 } 1414 } 1415 1416 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1417 if (IS_RESPONDER(sm_conn->sm_role)){ 1418 // Responder 1419 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1420 } else { 1421 // Initiator role 1422 switch (setup->sm_stk_generation_method){ 1423 case JUST_WORKS: 1424 sm_sc_prepare_dhkey_check(sm_conn); 1425 break; 1426 1427 case NK_BOTH_INPUT: 1428 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1429 break; 1430 case PK_INIT_INPUT: 1431 case PK_RESP_INPUT: 1432 case OK_BOTH_INPUT: 1433 if (setup->sm_passkey_bit < 20) { 1434 sm_sc_start_calculating_local_confirm(sm_conn); 1435 } else { 1436 sm_sc_prepare_dhkey_check(sm_conn); 1437 } 1438 break; 1439 case OOB: 1440 // TODO: implement SC OOB 1441 break; 1442 } 1443 } 1444 } 1445 1446 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1447 return sm_cmac_sc_buffer[offset]; 1448 } 1449 1450 static void sm_sc_cmac_done(uint8_t * hash){ 1451 log_info("sm_sc_cmac_done: "); 1452 log_info_hexdump(hash, 16); 1453 1454 sm_connection_t * sm_conn = sm_cmac_connection; 1455 sm_cmac_connection = NULL; 1456 #ifdef ENABLE_CLASSIC 1457 link_key_type_t link_key_type; 1458 #endif 1459 1460 switch (sm_conn->sm_engine_state){ 1461 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1462 memcpy(setup->sm_local_confirm, hash, 16); 1463 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1464 break; 1465 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1466 // check 1467 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1468 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1469 break; 1470 } 1471 sm_sc_state_after_receiving_random(sm_conn); 1472 break; 1473 case SM_SC_W4_CALCULATE_G2: { 1474 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1475 big_endian_store_32(setup->sm_tk, 12, vab); 1476 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1477 sm_trigger_user_response(sm_conn); 1478 break; 1479 } 1480 case SM_SC_W4_CALCULATE_F5_SALT: 1481 memcpy(setup->sm_t, hash, 16); 1482 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1483 break; 1484 case SM_SC_W4_CALCULATE_F5_MACKEY: 1485 memcpy(setup->sm_mackey, hash, 16); 1486 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1487 break; 1488 case SM_SC_W4_CALCULATE_F5_LTK: 1489 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1490 // Errata Service Release to the Bluetooth Specification: ESR09 1491 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1492 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1493 memcpy(setup->sm_ltk, hash, 16); 1494 memcpy(setup->sm_local_ltk, hash, 16); 1495 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1496 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1497 break; 1498 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1499 memcpy(setup->sm_local_dhkey_check, hash, 16); 1500 if (IS_RESPONDER(sm_conn->sm_role)){ 1501 // responder 1502 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1503 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1504 } else { 1505 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1506 } 1507 } else { 1508 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1509 } 1510 break; 1511 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1512 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1513 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1514 break; 1515 } 1516 if (IS_RESPONDER(sm_conn->sm_role)){ 1517 // responder 1518 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1519 } else { 1520 // initiator 1521 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1522 } 1523 break; 1524 case SM_SC_W4_CALCULATE_H6_ILK: 1525 memcpy(setup->sm_t, hash, 16); 1526 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1527 break; 1528 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1529 #ifdef ENABLE_CLASSIC 1530 reverse_128(hash, setup->sm_t); 1531 link_key_type = sm_conn->sm_connection_authenticated ? 1532 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1533 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1534 if (IS_RESPONDER(sm_conn->sm_role)){ 1535 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1536 } else { 1537 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1538 } 1539 #endif 1540 if (IS_RESPONDER(sm_conn->sm_role)){ 1541 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1542 } else { 1543 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1544 } 1545 sm_done_for_handle(sm_conn->sm_handle); 1546 break; 1547 default: 1548 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1549 break; 1550 } 1551 sm_run(); 1552 } 1553 1554 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1555 const uint16_t message_len = 65; 1556 sm_cmac_connection = sm_conn; 1557 memcpy(sm_cmac_sc_buffer, u, 32); 1558 memcpy(sm_cmac_sc_buffer+32, v, 32); 1559 sm_cmac_sc_buffer[64] = z; 1560 log_info("f4 key"); 1561 log_info_hexdump(x, 16); 1562 log_info("f4 message"); 1563 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1564 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1565 } 1566 1567 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1568 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1569 static const uint8_t f5_length[] = { 0x01, 0x00}; 1570 1571 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1572 1573 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1574 memset(dhkey, 0, 32); 1575 1576 #ifdef USE_MICRO_ECC_FOR_ECDH 1577 #if uECC_SUPPORTS_secp256r1 1578 // standard version 1579 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1580 #else 1581 // static version 1582 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1583 #endif 1584 #endif 1585 1586 #ifdef USE_MBEDTLS_FOR_ECDH 1587 // da * Pb 1588 mbedtls_mpi d; 1589 mbedtls_ecp_point Q; 1590 mbedtls_ecp_point DH; 1591 mbedtls_mpi_init(&d); 1592 mbedtls_ecp_point_init(&Q); 1593 mbedtls_ecp_point_init(&DH); 1594 mbedtls_mpi_read_binary(&d, ec_d, 32); 1595 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1596 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1597 mbedtls_mpi_lset(&Q.Z, 1); 1598 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1599 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1600 mbedtls_ecp_point_free(&DH); 1601 mbedtls_mpi_free(&d); 1602 mbedtls_ecp_point_free(&Q); 1603 #endif 1604 1605 log_info("dhkey"); 1606 log_info_hexdump(dhkey, 32); 1607 } 1608 #endif 1609 1610 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1611 // calculate salt for f5 1612 const uint16_t message_len = 32; 1613 sm_cmac_connection = sm_conn; 1614 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1615 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1616 } 1617 1618 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){ 1619 const uint16_t message_len = 53; 1620 sm_cmac_connection = sm_conn; 1621 1622 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1623 sm_cmac_sc_buffer[0] = 0; 1624 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1625 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1626 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1627 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1628 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1629 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1630 log_info("f5 key"); 1631 log_info_hexdump(t, 16); 1632 log_info("f5 message for MacKey"); 1633 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1634 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1635 } 1636 1637 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1638 sm_key56_t bd_addr_master, bd_addr_slave; 1639 bd_addr_master[0] = setup->sm_m_addr_type; 1640 bd_addr_slave[0] = setup->sm_s_addr_type; 1641 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1642 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1643 if (IS_RESPONDER(sm_conn->sm_role)){ 1644 // responder 1645 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1646 } else { 1647 // initiator 1648 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1649 } 1650 } 1651 1652 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1653 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1654 const uint16_t message_len = 53; 1655 sm_cmac_connection = sm_conn; 1656 sm_cmac_sc_buffer[0] = 1; 1657 // 1..52 setup before 1658 log_info("f5 key"); 1659 log_info_hexdump(t, 16); 1660 log_info("f5 message for LTK"); 1661 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1662 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1663 } 1664 1665 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1666 f5_ltk(sm_conn, setup->sm_t); 1667 } 1668 1669 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){ 1670 const uint16_t message_len = 65; 1671 sm_cmac_connection = sm_conn; 1672 memcpy(sm_cmac_sc_buffer, n1, 16); 1673 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1674 memcpy(sm_cmac_sc_buffer+32, r, 16); 1675 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1676 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1677 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1678 log_info("f6 key"); 1679 log_info_hexdump(w, 16); 1680 log_info("f6 message"); 1681 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1682 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1683 } 1684 1685 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1686 // - U is 256 bits 1687 // - V is 256 bits 1688 // - X is 128 bits 1689 // - Y is 128 bits 1690 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){ 1691 const uint16_t message_len = 80; 1692 sm_cmac_connection = sm_conn; 1693 memcpy(sm_cmac_sc_buffer, u, 32); 1694 memcpy(sm_cmac_sc_buffer+32, v, 32); 1695 memcpy(sm_cmac_sc_buffer+64, y, 16); 1696 log_info("g2 key"); 1697 log_info_hexdump(x, 16); 1698 log_info("g2 message"); 1699 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1700 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1701 } 1702 1703 static void g2_calculate(sm_connection_t * sm_conn) { 1704 // calc Va if numeric comparison 1705 if (IS_RESPONDER(sm_conn->sm_role)){ 1706 // responder 1707 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1708 } else { 1709 // initiator 1710 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1711 } 1712 } 1713 1714 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1715 uint8_t z = 0; 1716 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1717 // some form of passkey 1718 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1719 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1720 setup->sm_passkey_bit++; 1721 } 1722 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1723 } 1724 1725 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1726 uint8_t z = 0; 1727 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1728 // some form of passkey 1729 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1730 // sm_passkey_bit was increased before sending confirm value 1731 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1732 } 1733 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1734 } 1735 1736 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1737 1738 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1739 // calculate DHKEY 1740 sm_sc_calculate_dhkey(setup->sm_dhkey); 1741 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1742 #endif 1743 1744 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1745 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1746 return; 1747 } else { 1748 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1749 } 1750 1751 } 1752 1753 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1754 // calculate DHKCheck 1755 sm_key56_t bd_addr_master, bd_addr_slave; 1756 bd_addr_master[0] = setup->sm_m_addr_type; 1757 bd_addr_slave[0] = setup->sm_s_addr_type; 1758 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1759 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1760 uint8_t iocap_a[3]; 1761 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1762 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1763 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1764 uint8_t iocap_b[3]; 1765 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1766 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1767 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1768 if (IS_RESPONDER(sm_conn->sm_role)){ 1769 // responder 1770 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); 1771 } else { 1772 // initiator 1773 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); 1774 } 1775 } 1776 1777 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1778 // validate E = f6() 1779 sm_key56_t bd_addr_master, bd_addr_slave; 1780 bd_addr_master[0] = setup->sm_m_addr_type; 1781 bd_addr_slave[0] = setup->sm_s_addr_type; 1782 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1783 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1784 1785 uint8_t iocap_a[3]; 1786 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1787 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1788 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1789 uint8_t iocap_b[3]; 1790 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1791 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1792 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1793 if (IS_RESPONDER(sm_conn->sm_role)){ 1794 // responder 1795 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); 1796 } else { 1797 // initiator 1798 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); 1799 } 1800 } 1801 1802 1803 // 1804 // Link Key Conversion Function h6 1805 // 1806 // h6(W, keyID) = AES-CMACW(keyID) 1807 // - W is 128 bits 1808 // - keyID is 32 bits 1809 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1810 const uint16_t message_len = 4; 1811 sm_cmac_connection = sm_conn; 1812 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1813 log_info("h6 key"); 1814 log_info_hexdump(w, 16); 1815 log_info("h6 message"); 1816 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1817 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1818 } 1819 1820 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1821 // Errata Service Release to the Bluetooth Specification: ESR09 1822 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1823 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1824 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1825 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1826 } 1827 1828 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1829 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1830 } 1831 1832 #endif 1833 1834 // key management legacy connections: 1835 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1836 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1837 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1838 // - responder reconnects: responder uses LTK receveived from master 1839 1840 // key management secure connections: 1841 // - both devices store same LTK from ECDH key exchange. 1842 1843 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1844 static void sm_load_security_info(sm_connection_t * sm_connection){ 1845 int encryption_key_size; 1846 int authenticated; 1847 int authorized; 1848 1849 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1850 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1851 &encryption_key_size, &authenticated, &authorized); 1852 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1853 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1854 sm_connection->sm_connection_authenticated = authenticated; 1855 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1856 } 1857 #endif 1858 1859 #ifdef ENABLE_LE_PERIPHERAL 1860 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1861 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1862 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1863 // re-establish used key encryption size 1864 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1865 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1866 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1867 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1868 log_info("sm: received ltk request with key size %u, authenticated %u", 1869 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1870 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1871 } 1872 #endif 1873 1874 static void sm_run(void){ 1875 1876 btstack_linked_list_iterator_t it; 1877 1878 // assert that stack has already bootet 1879 if (hci_get_state() != HCI_STATE_WORKING) return; 1880 1881 // assert that we can send at least commands 1882 if (!hci_can_send_command_packet_now()) return; 1883 1884 // 1885 // non-connection related behaviour 1886 // 1887 1888 // distributed key generation 1889 switch (dkg_state){ 1890 case DKG_CALC_IRK: 1891 // already busy? 1892 if (sm_aes128_state == SM_AES128_IDLE) { 1893 // IRK = d1(IR, 1, 0) 1894 sm_key_t d1_prime; 1895 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1896 dkg_next_state(); 1897 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1898 return; 1899 } 1900 break; 1901 case DKG_CALC_DHK: 1902 // already busy? 1903 if (sm_aes128_state == SM_AES128_IDLE) { 1904 // DHK = d1(IR, 3, 0) 1905 sm_key_t d1_prime; 1906 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1907 dkg_next_state(); 1908 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1909 return; 1910 } 1911 break; 1912 default: 1913 break; 1914 } 1915 1916 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1917 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1918 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1919 sm_random_start(NULL); 1920 #else 1921 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1922 hci_send_cmd(&hci_le_read_local_p256_public_key); 1923 #endif 1924 return; 1925 } 1926 #endif 1927 1928 // random address updates 1929 switch (rau_state){ 1930 case RAU_GET_RANDOM: 1931 rau_next_state(); 1932 sm_random_start(NULL); 1933 return; 1934 case RAU_GET_ENC: 1935 // already busy? 1936 if (sm_aes128_state == SM_AES128_IDLE) { 1937 sm_key_t r_prime; 1938 sm_ah_r_prime(sm_random_address, r_prime); 1939 rau_next_state(); 1940 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1941 return; 1942 } 1943 break; 1944 case RAU_SET_ADDRESS: 1945 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1946 rau_state = RAU_IDLE; 1947 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1948 return; 1949 default: 1950 break; 1951 } 1952 1953 #ifdef ENABLE_CMAC_ENGINE 1954 // CMAC 1955 switch (sm_cmac_state){ 1956 case CMAC_CALC_SUBKEYS: 1957 case CMAC_CALC_MI: 1958 case CMAC_CALC_MLAST: 1959 // already busy? 1960 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1961 sm_cmac_handle_aes_engine_ready(); 1962 return; 1963 default: 1964 break; 1965 } 1966 #endif 1967 1968 // CSRK Lookup 1969 // -- if csrk lookup ready, find connection that require csrk lookup 1970 if (sm_address_resolution_idle()){ 1971 hci_connections_get_iterator(&it); 1972 while(btstack_linked_list_iterator_has_next(&it)){ 1973 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1974 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1975 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1976 // and start lookup 1977 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); 1978 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1979 break; 1980 } 1981 } 1982 } 1983 1984 // -- if csrk lookup ready, resolved addresses for received addresses 1985 if (sm_address_resolution_idle()) { 1986 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1987 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1988 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1989 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1990 btstack_memory_sm_lookup_entry_free(entry); 1991 } 1992 } 1993 1994 // -- Continue with CSRK device lookup by public or resolvable private address 1995 if (!sm_address_resolution_idle()){ 1996 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1997 while (sm_address_resolution_test < le_device_db_count()){ 1998 int addr_type; 1999 bd_addr_t addr; 2000 sm_key_t irk; 2001 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2002 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2003 2004 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2005 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2006 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2007 break; 2008 } 2009 2010 if (sm_address_resolution_addr_type == 0){ 2011 sm_address_resolution_test++; 2012 continue; 2013 } 2014 2015 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2016 2017 log_info("LE Device Lookup: calculate AH"); 2018 log_info_key("IRK", irk); 2019 2020 sm_key_t r_prime; 2021 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2022 sm_address_resolution_ah_calculation_active = 1; 2023 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2024 return; 2025 } 2026 2027 if (sm_address_resolution_test >= le_device_db_count()){ 2028 log_info("LE Device Lookup: not found"); 2029 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2030 } 2031 } 2032 2033 // handle basic actions that don't requires the full context 2034 hci_connections_get_iterator(&it); 2035 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2036 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2037 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2038 switch(sm_connection->sm_engine_state){ 2039 // responder side 2040 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2041 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2042 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2043 return; 2044 2045 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2046 case SM_SC_RECEIVED_LTK_REQUEST: 2047 switch (sm_connection->sm_irk_lookup_state){ 2048 case IRK_LOOKUP_FAILED: 2049 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2050 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2051 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2052 return; 2053 default: 2054 break; 2055 } 2056 break; 2057 #endif 2058 default: 2059 break; 2060 } 2061 } 2062 2063 // 2064 // active connection handling 2065 // -- use loop to handle next connection if lock on setup context is released 2066 2067 while (1) { 2068 2069 // Find connections that requires setup context and make active if no other is locked 2070 hci_connections_get_iterator(&it); 2071 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2072 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2073 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2074 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2075 int done = 1; 2076 int err; 2077 UNUSED(err); 2078 switch (sm_connection->sm_engine_state) { 2079 #ifdef ENABLE_LE_PERIPHERAL 2080 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2081 // send packet if possible, 2082 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2083 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2084 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2085 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2086 } else { 2087 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2088 } 2089 // don't lock sxetup context yet 2090 done = 0; 2091 break; 2092 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2093 sm_reset_setup(); 2094 sm_init_setup(sm_connection); 2095 // recover pairing request 2096 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2097 err = sm_stk_generation_init(sm_connection); 2098 if (err){ 2099 setup->sm_pairing_failed_reason = err; 2100 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2101 break; 2102 } 2103 sm_timeout_start(sm_connection); 2104 // generate random number first, if we need to show passkey 2105 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2106 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2107 break; 2108 } 2109 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2110 break; 2111 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2112 sm_reset_setup(); 2113 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2114 break; 2115 #endif 2116 #ifdef ENABLE_LE_CENTRAL 2117 case SM_INITIATOR_PH0_HAS_LTK: 2118 sm_reset_setup(); 2119 sm_load_security_info(sm_connection); 2120 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2121 break; 2122 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2123 sm_reset_setup(); 2124 sm_init_setup(sm_connection); 2125 sm_timeout_start(sm_connection); 2126 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2127 break; 2128 #endif 2129 2130 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2131 case SM_SC_RECEIVED_LTK_REQUEST: 2132 switch (sm_connection->sm_irk_lookup_state){ 2133 case IRK_LOOKUP_SUCCEEDED: 2134 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2135 // start using context by loading security info 2136 sm_reset_setup(); 2137 sm_load_security_info(sm_connection); 2138 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2139 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2140 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2141 break; 2142 } 2143 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2144 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2145 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2146 // don't lock setup context yet 2147 return; 2148 default: 2149 // just wait until IRK lookup is completed 2150 // don't lock setup context yet 2151 done = 0; 2152 break; 2153 } 2154 break; 2155 #endif 2156 default: 2157 done = 0; 2158 break; 2159 } 2160 if (done){ 2161 sm_active_connection_handle = sm_connection->sm_handle; 2162 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); 2163 } 2164 } 2165 2166 // 2167 // active connection handling 2168 // 2169 2170 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2171 2172 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2173 if (!connection) { 2174 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2175 return; 2176 } 2177 2178 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2179 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2180 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2181 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2182 return; 2183 } 2184 #endif 2185 2186 // assert that we could send a SM PDU - not needed for all of the following 2187 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2188 log_info("cannot send now, requesting can send now event"); 2189 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2190 return; 2191 } 2192 2193 // send keypress notifications 2194 if (setup->sm_keypress_notification != 0xff){ 2195 uint8_t buffer[2]; 2196 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2197 buffer[1] = setup->sm_keypress_notification; 2198 setup->sm_keypress_notification = 0xff; 2199 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2200 return; 2201 } 2202 2203 sm_key_t plaintext; 2204 int key_distribution_flags; 2205 UNUSED(key_distribution_flags); 2206 2207 log_info("sm_run: state %u", connection->sm_engine_state); 2208 2209 switch (connection->sm_engine_state){ 2210 2211 // general 2212 case SM_GENERAL_SEND_PAIRING_FAILED: { 2213 uint8_t buffer[2]; 2214 buffer[0] = SM_CODE_PAIRING_FAILED; 2215 buffer[1] = setup->sm_pairing_failed_reason; 2216 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2217 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2218 sm_done_for_handle(connection->sm_handle); 2219 break; 2220 } 2221 2222 // responding state 2223 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2224 case SM_SC_W2_GET_RANDOM_A: 2225 sm_random_start(connection); 2226 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2227 break; 2228 case SM_SC_W2_GET_RANDOM_B: 2229 sm_random_start(connection); 2230 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2231 break; 2232 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2233 if (!sm_cmac_ready()) break; 2234 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2235 sm_sc_calculate_local_confirm(connection); 2236 break; 2237 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2238 if (!sm_cmac_ready()) break; 2239 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2240 sm_sc_calculate_remote_confirm(connection); 2241 break; 2242 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2243 if (!sm_cmac_ready()) break; 2244 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2245 sm_sc_calculate_f6_for_dhkey_check(connection); 2246 break; 2247 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2248 if (!sm_cmac_ready()) break; 2249 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2250 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2251 break; 2252 case SM_SC_W2_CALCULATE_F5_SALT: 2253 if (!sm_cmac_ready()) break; 2254 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2255 f5_calculate_salt(connection); 2256 break; 2257 case SM_SC_W2_CALCULATE_F5_MACKEY: 2258 if (!sm_cmac_ready()) break; 2259 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2260 f5_calculate_mackey(connection); 2261 break; 2262 case SM_SC_W2_CALCULATE_F5_LTK: 2263 if (!sm_cmac_ready()) break; 2264 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2265 f5_calculate_ltk(connection); 2266 break; 2267 case SM_SC_W2_CALCULATE_G2: 2268 if (!sm_cmac_ready()) break; 2269 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2270 g2_calculate(connection); 2271 break; 2272 case SM_SC_W2_CALCULATE_H6_ILK: 2273 if (!sm_cmac_ready()) break; 2274 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2275 h6_calculate_ilk(connection); 2276 break; 2277 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2278 if (!sm_cmac_ready()) break; 2279 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2280 h6_calculate_br_edr_link_key(connection); 2281 break; 2282 #endif 2283 2284 #ifdef ENABLE_LE_CENTRAL 2285 // initiator side 2286 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2287 sm_key_t peer_ltk_flipped; 2288 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2289 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2290 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2291 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2292 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2293 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2294 return; 2295 } 2296 2297 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2298 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2299 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2300 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2301 sm_timeout_reset(connection); 2302 break; 2303 #endif 2304 2305 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2306 2307 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2308 uint8_t buffer[65]; 2309 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2310 // 2311 reverse_256(&ec_q[0], &buffer[1]); 2312 reverse_256(&ec_q[32], &buffer[33]); 2313 2314 // stk generation method 2315 // passkey entry: notify app to show passkey or to request passkey 2316 switch (setup->sm_stk_generation_method){ 2317 case JUST_WORKS: 2318 case NK_BOTH_INPUT: 2319 if (IS_RESPONDER(connection->sm_role)){ 2320 // responder 2321 sm_sc_start_calculating_local_confirm(connection); 2322 } else { 2323 // initiator 2324 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2325 } 2326 break; 2327 case PK_INIT_INPUT: 2328 case PK_RESP_INPUT: 2329 case OK_BOTH_INPUT: 2330 // use random TK for display 2331 memcpy(setup->sm_ra, setup->sm_tk, 16); 2332 memcpy(setup->sm_rb, setup->sm_tk, 16); 2333 setup->sm_passkey_bit = 0; 2334 2335 if (IS_RESPONDER(connection->sm_role)){ 2336 // responder 2337 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2338 } else { 2339 // initiator 2340 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2341 } 2342 sm_trigger_user_response(connection); 2343 break; 2344 case OOB: 2345 // TODO: implement SC OOB 2346 break; 2347 } 2348 2349 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2350 sm_timeout_reset(connection); 2351 break; 2352 } 2353 case SM_SC_SEND_CONFIRMATION: { 2354 uint8_t buffer[17]; 2355 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2356 reverse_128(setup->sm_local_confirm, &buffer[1]); 2357 if (IS_RESPONDER(connection->sm_role)){ 2358 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2359 } else { 2360 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2361 } 2362 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2363 sm_timeout_reset(connection); 2364 break; 2365 } 2366 case SM_SC_SEND_PAIRING_RANDOM: { 2367 uint8_t buffer[17]; 2368 buffer[0] = SM_CODE_PAIRING_RANDOM; 2369 reverse_128(setup->sm_local_nonce, &buffer[1]); 2370 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2371 if (IS_RESPONDER(connection->sm_role)){ 2372 // responder 2373 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2374 } else { 2375 // initiator 2376 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2377 } 2378 } else { 2379 if (IS_RESPONDER(connection->sm_role)){ 2380 // responder 2381 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2382 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2383 } else { 2384 sm_sc_prepare_dhkey_check(connection); 2385 } 2386 } else { 2387 // initiator 2388 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2389 } 2390 } 2391 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2392 sm_timeout_reset(connection); 2393 break; 2394 } 2395 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2396 uint8_t buffer[17]; 2397 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2398 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2399 2400 if (IS_RESPONDER(connection->sm_role)){ 2401 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2402 } else { 2403 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2404 } 2405 2406 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2407 sm_timeout_reset(connection); 2408 break; 2409 } 2410 2411 #endif 2412 2413 #ifdef ENABLE_LE_PERIPHERAL 2414 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2415 // echo initiator for now 2416 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2417 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2418 2419 if (setup->sm_use_secure_connections){ 2420 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2421 // skip LTK/EDIV for SC 2422 log_info("sm: dropping encryption information flag"); 2423 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2424 } else { 2425 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2426 } 2427 2428 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); 2429 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); 2430 // update key distribution after ENC was dropped 2431 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2432 2433 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2434 sm_timeout_reset(connection); 2435 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2436 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2437 sm_trigger_user_response(connection); 2438 } 2439 return; 2440 #endif 2441 2442 case SM_PH2_SEND_PAIRING_RANDOM: { 2443 uint8_t buffer[17]; 2444 buffer[0] = SM_CODE_PAIRING_RANDOM; 2445 reverse_128(setup->sm_local_random, &buffer[1]); 2446 if (IS_RESPONDER(connection->sm_role)){ 2447 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2448 } else { 2449 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2450 } 2451 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2452 sm_timeout_reset(connection); 2453 break; 2454 } 2455 2456 case SM_PH2_GET_RANDOM_TK: 2457 case SM_PH2_C1_GET_RANDOM_A: 2458 case SM_PH2_C1_GET_RANDOM_B: 2459 case SM_PH3_GET_RANDOM: 2460 case SM_PH3_GET_DIV: 2461 sm_next_responding_state(connection); 2462 sm_random_start(connection); 2463 return; 2464 2465 case SM_PH2_C1_GET_ENC_B: 2466 case SM_PH2_C1_GET_ENC_D: 2467 // already busy? 2468 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2469 sm_next_responding_state(connection); 2470 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2471 return; 2472 2473 case SM_PH3_LTK_GET_ENC: 2474 case SM_RESPONDER_PH4_LTK_GET_ENC: 2475 // already busy? 2476 if (sm_aes128_state == SM_AES128_IDLE) { 2477 sm_key_t d_prime; 2478 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2479 sm_next_responding_state(connection); 2480 sm_aes128_start(sm_persistent_er, d_prime, connection); 2481 return; 2482 } 2483 break; 2484 2485 case SM_PH3_CSRK_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, 1, 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_PH2_C1_GET_ENC_C: 2497 // already busy? 2498 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2499 // calculate m_confirm using aes128 engine - step 1 2500 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); 2501 sm_next_responding_state(connection); 2502 sm_aes128_start(setup->sm_tk, plaintext, connection); 2503 break; 2504 case SM_PH2_C1_GET_ENC_A: 2505 // already busy? 2506 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2507 // calculate confirm using aes128 engine - step 1 2508 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); 2509 sm_next_responding_state(connection); 2510 sm_aes128_start(setup->sm_tk, plaintext, connection); 2511 break; 2512 case SM_PH2_CALC_STK: 2513 // already busy? 2514 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2515 // calculate STK 2516 if (IS_RESPONDER(connection->sm_role)){ 2517 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2518 } else { 2519 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2520 } 2521 sm_next_responding_state(connection); 2522 sm_aes128_start(setup->sm_tk, plaintext, connection); 2523 break; 2524 case SM_PH3_Y_GET_ENC: 2525 // already busy? 2526 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2527 // PH3B2 - calculate Y from - enc 2528 // Y = dm(DHK, Rand) 2529 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2530 sm_next_responding_state(connection); 2531 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2532 return; 2533 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2534 uint8_t buffer[17]; 2535 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2536 reverse_128(setup->sm_local_confirm, &buffer[1]); 2537 if (IS_RESPONDER(connection->sm_role)){ 2538 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2539 } else { 2540 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2541 } 2542 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2543 sm_timeout_reset(connection); 2544 return; 2545 } 2546 #ifdef ENABLE_LE_PERIPHERAL 2547 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2548 sm_key_t stk_flipped; 2549 reverse_128(setup->sm_ltk, stk_flipped); 2550 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2551 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2552 return; 2553 } 2554 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2555 sm_key_t ltk_flipped; 2556 reverse_128(setup->sm_ltk, ltk_flipped); 2557 connection->sm_engine_state = SM_RESPONDER_IDLE; 2558 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2559 sm_done_for_handle(connection->sm_handle); 2560 return; 2561 } 2562 case SM_RESPONDER_PH4_Y_GET_ENC: 2563 // already busy? 2564 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2565 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2566 // Y = dm(DHK, Rand) 2567 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2568 sm_next_responding_state(connection); 2569 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2570 return; 2571 #endif 2572 #ifdef ENABLE_LE_CENTRAL 2573 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2574 sm_key_t stk_flipped; 2575 reverse_128(setup->sm_ltk, stk_flipped); 2576 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2577 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2578 return; 2579 } 2580 #endif 2581 2582 case SM_PH3_DISTRIBUTE_KEYS: 2583 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2584 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2585 uint8_t buffer[17]; 2586 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2587 reverse_128(setup->sm_ltk, &buffer[1]); 2588 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2589 sm_timeout_reset(connection); 2590 return; 2591 } 2592 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2593 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2594 uint8_t buffer[11]; 2595 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2596 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2597 reverse_64(setup->sm_local_rand, &buffer[3]); 2598 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2599 sm_timeout_reset(connection); 2600 return; 2601 } 2602 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2603 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2604 uint8_t buffer[17]; 2605 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2606 reverse_128(sm_persistent_irk, &buffer[1]); 2607 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2608 sm_timeout_reset(connection); 2609 return; 2610 } 2611 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2612 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2613 bd_addr_t local_address; 2614 uint8_t buffer[8]; 2615 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2616 switch (gap_random_address_get_mode()){ 2617 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2618 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2619 // public or static random 2620 gap_le_get_own_address(&buffer[1], local_address); 2621 break; 2622 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2623 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2624 // fallback to public 2625 gap_local_bd_addr(local_address); 2626 buffer[1] = 0; 2627 break; 2628 } 2629 reverse_bd_addr(local_address, &buffer[2]); 2630 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2631 sm_timeout_reset(connection); 2632 return; 2633 } 2634 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2635 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2636 2637 // hack to reproduce test runs 2638 if (test_use_fixed_local_csrk){ 2639 memset(setup->sm_local_csrk, 0xcc, 16); 2640 } 2641 2642 uint8_t buffer[17]; 2643 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2644 reverse_128(setup->sm_local_csrk, &buffer[1]); 2645 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2646 sm_timeout_reset(connection); 2647 return; 2648 } 2649 2650 // keys are sent 2651 if (IS_RESPONDER(connection->sm_role)){ 2652 // slave -> receive master keys if any 2653 if (sm_key_distribution_all_received(connection)){ 2654 sm_key_distribution_handle_all_received(connection); 2655 connection->sm_engine_state = SM_RESPONDER_IDLE; 2656 sm_done_for_handle(connection->sm_handle); 2657 } else { 2658 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2659 } 2660 } else { 2661 // master -> all done 2662 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2663 sm_done_for_handle(connection->sm_handle); 2664 } 2665 break; 2666 2667 default: 2668 break; 2669 } 2670 2671 // check again if active connection was released 2672 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2673 } 2674 } 2675 2676 // note: aes engine is ready as we just got the aes result 2677 static void sm_handle_encryption_result(uint8_t * data){ 2678 2679 sm_aes128_state = SM_AES128_IDLE; 2680 2681 if (sm_address_resolution_ah_calculation_active){ 2682 sm_address_resolution_ah_calculation_active = 0; 2683 // compare calulated address against connecting device 2684 uint8_t hash[3]; 2685 reverse_24(data, hash); 2686 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2687 log_info("LE Device Lookup: matched resolvable private address"); 2688 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2689 return; 2690 } 2691 // no match, try next 2692 sm_address_resolution_test++; 2693 return; 2694 } 2695 2696 switch (dkg_state){ 2697 case DKG_W4_IRK: 2698 reverse_128(data, sm_persistent_irk); 2699 log_info_key("irk", sm_persistent_irk); 2700 dkg_next_state(); 2701 return; 2702 case DKG_W4_DHK: 2703 reverse_128(data, sm_persistent_dhk); 2704 log_info_key("dhk", sm_persistent_dhk); 2705 dkg_next_state(); 2706 // SM Init Finished 2707 return; 2708 default: 2709 break; 2710 } 2711 2712 switch (rau_state){ 2713 case RAU_W4_ENC: 2714 reverse_24(data, &sm_random_address[3]); 2715 rau_next_state(); 2716 return; 2717 default: 2718 break; 2719 } 2720 2721 #ifdef ENABLE_CMAC_ENGINE 2722 switch (sm_cmac_state){ 2723 case CMAC_W4_SUBKEYS: 2724 case CMAC_W4_MI: 2725 case CMAC_W4_MLAST: 2726 { 2727 sm_key_t t; 2728 reverse_128(data, t); 2729 sm_cmac_handle_encryption_result(t); 2730 } 2731 return; 2732 default: 2733 break; 2734 } 2735 #endif 2736 2737 // retrieve sm_connection provided to sm_aes128_start_encryption 2738 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2739 if (!connection) return; 2740 switch (connection->sm_engine_state){ 2741 case SM_PH2_C1_W4_ENC_A: 2742 case SM_PH2_C1_W4_ENC_C: 2743 { 2744 sm_key_t t2; 2745 reverse_128(data, t2); 2746 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2747 } 2748 sm_next_responding_state(connection); 2749 return; 2750 case SM_PH2_C1_W4_ENC_B: 2751 reverse_128(data, setup->sm_local_confirm); 2752 log_info_key("c1!", setup->sm_local_confirm); 2753 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2754 return; 2755 case SM_PH2_C1_W4_ENC_D: 2756 { 2757 sm_key_t peer_confirm_test; 2758 reverse_128(data, peer_confirm_test); 2759 log_info_key("c1!", peer_confirm_test); 2760 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2761 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2762 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2763 return; 2764 } 2765 if (IS_RESPONDER(connection->sm_role)){ 2766 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2767 } else { 2768 connection->sm_engine_state = SM_PH2_CALC_STK; 2769 } 2770 } 2771 return; 2772 case SM_PH2_W4_STK: 2773 reverse_128(data, setup->sm_ltk); 2774 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2775 log_info_key("stk", setup->sm_ltk); 2776 if (IS_RESPONDER(connection->sm_role)){ 2777 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2778 } else { 2779 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2780 } 2781 return; 2782 case SM_PH3_Y_W4_ENC:{ 2783 sm_key_t y128; 2784 reverse_128(data, y128); 2785 setup->sm_local_y = big_endian_read_16(y128, 14); 2786 log_info_hex16("y", setup->sm_local_y); 2787 // PH3B3 - calculate EDIV 2788 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2789 log_info_hex16("ediv", setup->sm_local_ediv); 2790 // PH3B4 - calculate LTK - enc 2791 // LTK = d1(ER, DIV, 0)) 2792 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2793 return; 2794 } 2795 case SM_RESPONDER_PH4_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 2801 // PH3B3 - calculate DIV 2802 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2803 log_info_hex16("ediv", setup->sm_local_ediv); 2804 // PH3B4 - calculate LTK - enc 2805 // LTK = d1(ER, DIV, 0)) 2806 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2807 return; 2808 } 2809 case SM_PH3_LTK_W4_ENC: 2810 reverse_128(data, setup->sm_ltk); 2811 log_info_key("ltk", setup->sm_ltk); 2812 // calc CSRK next 2813 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2814 return; 2815 case SM_PH3_CSRK_W4_ENC: 2816 reverse_128(data, setup->sm_local_csrk); 2817 log_info_key("csrk", setup->sm_local_csrk); 2818 if (setup->sm_key_distribution_send_set){ 2819 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2820 } else { 2821 // no keys to send, just continue 2822 if (IS_RESPONDER(connection->sm_role)){ 2823 // slave -> receive master keys 2824 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2825 } else { 2826 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2827 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2828 } else { 2829 // master -> all done 2830 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2831 sm_done_for_handle(connection->sm_handle); 2832 } 2833 } 2834 } 2835 return; 2836 #ifdef ENABLE_LE_PERIPHERAL 2837 case SM_RESPONDER_PH4_LTK_W4_ENC: 2838 reverse_128(data, setup->sm_ltk); 2839 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2840 log_info_key("ltk", setup->sm_ltk); 2841 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2842 return; 2843 #endif 2844 default: 2845 break; 2846 } 2847 } 2848 2849 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2850 2851 #if (defined(USE_MICRO_ECC_FOR_ECDH) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_FOR_ECDH) 2852 // @return OK 2853 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2854 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2855 int offset = setup->sm_passkey_bit; 2856 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2857 while (size) { 2858 *buffer++ = setup->sm_peer_q[offset++]; 2859 size--; 2860 } 2861 setup->sm_passkey_bit = offset; 2862 return 1; 2863 } 2864 #endif 2865 #ifdef USE_MBEDTLS_FOR_ECDH 2866 // @return error - just wrap sm_generate_f_rng 2867 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2868 UNUSED(context); 2869 return sm_generate_f_rng(buffer, size) == 0; 2870 } 2871 #endif /* USE_MBEDTLS_FOR_ECDH */ 2872 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2873 2874 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2875 static void sm_handle_random_result(uint8_t * data){ 2876 2877 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2878 2879 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2880 int num_bytes = setup->sm_passkey_bit; 2881 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2882 num_bytes += 8; 2883 setup->sm_passkey_bit = num_bytes; 2884 2885 if (num_bytes >= 64){ 2886 2887 // init pre-generated random data from sm_peer_q 2888 setup->sm_passkey_bit = 0; 2889 2890 // generate EC key 2891 #ifdef USE_MICRO_ECC_FOR_ECDH 2892 2893 #ifndef WICED_VERSION 2894 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2895 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2896 uECC_set_rng(&sm_generate_f_rng); 2897 #endif /* WICED_VERSION */ 2898 2899 #if uECC_SUPPORTS_secp256r1 2900 // standard version 2901 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2902 2903 // disable RNG again, as returning no randmon data lets shared key generation fail 2904 log_info("disable uECC RNG in standard version after key generation"); 2905 uECC_set_rng(NULL); 2906 #else 2907 // static version 2908 uECC_make_key(ec_q, ec_d); 2909 #endif 2910 #endif /* USE_MICRO_ECC_FOR_ECDH */ 2911 2912 #ifdef USE_MBEDTLS_FOR_ECDH 2913 mbedtls_mpi d; 2914 mbedtls_ecp_point P; 2915 mbedtls_mpi_init(&d); 2916 mbedtls_ecp_point_init(&P); 2917 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2918 log_info("gen keypair %x", res); 2919 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2920 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2921 mbedtls_mpi_write_binary(&d, ec_d, 32); 2922 mbedtls_ecp_point_free(&P); 2923 mbedtls_mpi_free(&d); 2924 #endif /* USE_MBEDTLS_FOR_ECDH */ 2925 2926 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2927 log_info("Elliptic curve: d"); 2928 log_info_hexdump(ec_d,32); 2929 sm_log_ec_keypair(); 2930 } 2931 } 2932 #endif 2933 2934 switch (rau_state){ 2935 case RAU_W4_RANDOM: 2936 // non-resolvable vs. resolvable 2937 switch (gap_random_adress_type){ 2938 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2939 // resolvable: use random as prand and calc address hash 2940 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2941 memcpy(sm_random_address, data, 3); 2942 sm_random_address[0] &= 0x3f; 2943 sm_random_address[0] |= 0x40; 2944 rau_state = RAU_GET_ENC; 2945 break; 2946 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2947 default: 2948 // "The two most significant bits of the address shall be equal to ‘0’"" 2949 memcpy(sm_random_address, data, 6); 2950 sm_random_address[0] &= 0x3f; 2951 rau_state = RAU_SET_ADDRESS; 2952 break; 2953 } 2954 return; 2955 default: 2956 break; 2957 } 2958 2959 // retrieve sm_connection provided to sm_random_start 2960 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2961 if (!connection) return; 2962 switch (connection->sm_engine_state){ 2963 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2964 case SM_SC_W4_GET_RANDOM_A: 2965 memcpy(&setup->sm_local_nonce[0], data, 8); 2966 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2967 break; 2968 case SM_SC_W4_GET_RANDOM_B: 2969 memcpy(&setup->sm_local_nonce[8], data, 8); 2970 // initiator & jw/nc -> send pairing random 2971 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2972 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2973 break; 2974 } else { 2975 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2976 } 2977 break; 2978 #endif 2979 2980 case SM_PH2_W4_RANDOM_TK: 2981 { 2982 sm_reset_tk(); 2983 uint32_t tk; 2984 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2985 // map random to 0-999999 without speding much cycles on a modulus operation 2986 tk = little_endian_read_32(data,0); 2987 tk = tk & 0xfffff; // 1048575 2988 if (tk >= 999999){ 2989 tk = tk - 999999; 2990 } 2991 } else { 2992 // override with pre-defined passkey 2993 tk = sm_fixed_passkey_in_display_role; 2994 } 2995 big_endian_store_32(setup->sm_tk, 12, tk); 2996 if (IS_RESPONDER(connection->sm_role)){ 2997 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2998 } else { 2999 if (setup->sm_use_secure_connections){ 3000 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3001 } else { 3002 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3003 sm_trigger_user_response(connection); 3004 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3005 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3006 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3007 } 3008 } 3009 } 3010 return; 3011 } 3012 case SM_PH2_C1_W4_RANDOM_A: 3013 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 3014 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 3015 return; 3016 case SM_PH2_C1_W4_RANDOM_B: 3017 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3018 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3019 return; 3020 case SM_PH3_W4_RANDOM: 3021 reverse_64(data, setup->sm_local_rand); 3022 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3023 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3024 // no db for authenticated flag hack: store flag in bit 4 of LSB 3025 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3026 connection->sm_engine_state = SM_PH3_GET_DIV; 3027 return; 3028 case SM_PH3_W4_DIV: 3029 // use 16 bit from random value as div 3030 setup->sm_local_div = big_endian_read_16(data, 0); 3031 log_info_hex16("div", setup->sm_local_div); 3032 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3033 return; 3034 default: 3035 break; 3036 } 3037 } 3038 3039 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3040 3041 UNUSED(channel); // ok: there is no channel 3042 UNUSED(size); // ok: fixed format HCI events 3043 3044 sm_connection_t * sm_conn; 3045 hci_con_handle_t con_handle; 3046 3047 switch (packet_type) { 3048 3049 case HCI_EVENT_PACKET: 3050 switch (hci_event_packet_get_type(packet)) { 3051 3052 case BTSTACK_EVENT_STATE: 3053 // bt stack activated, get started 3054 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3055 log_info("HCI Working!"); 3056 3057 3058 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3059 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3060 if (!sm_have_ec_keypair){ 3061 setup->sm_passkey_bit = 0; 3062 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3063 } 3064 #endif 3065 // trigger Random Address generation if requested before 3066 switch (gap_random_adress_type){ 3067 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3068 rau_state = RAU_IDLE; 3069 break; 3070 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3071 rau_state = RAU_SET_ADDRESS; 3072 break; 3073 default: 3074 rau_state = RAU_GET_RANDOM; 3075 break; 3076 } 3077 sm_run(); 3078 } 3079 break; 3080 3081 case HCI_EVENT_LE_META: 3082 switch (packet[2]) { 3083 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3084 3085 log_info("sm: connected"); 3086 3087 if (packet[3]) return; // connection failed 3088 3089 con_handle = little_endian_read_16(packet, 4); 3090 sm_conn = sm_get_connection_for_handle(con_handle); 3091 if (!sm_conn) break; 3092 3093 sm_conn->sm_handle = con_handle; 3094 sm_conn->sm_role = packet[6]; 3095 sm_conn->sm_peer_addr_type = packet[7]; 3096 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3097 3098 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3099 3100 // reset security properties 3101 sm_conn->sm_connection_encrypted = 0; 3102 sm_conn->sm_connection_authenticated = 0; 3103 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3104 sm_conn->sm_le_db_index = -1; 3105 3106 // prepare CSRK lookup (does not involve setup) 3107 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3108 3109 // just connected -> everything else happens in sm_run() 3110 if (IS_RESPONDER(sm_conn->sm_role)){ 3111 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3112 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3113 if (sm_slave_request_security) { 3114 // request security if requested by app 3115 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3116 } else { 3117 // otherwise, wait for pairing request 3118 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3119 } 3120 } 3121 break; 3122 } else { 3123 // master 3124 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3125 } 3126 break; 3127 3128 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3129 con_handle = little_endian_read_16(packet, 3); 3130 sm_conn = sm_get_connection_for_handle(con_handle); 3131 if (!sm_conn) break; 3132 3133 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3134 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3135 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3136 break; 3137 } 3138 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3139 // PH2 SEND LTK as we need to exchange keys in PH3 3140 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3141 break; 3142 } 3143 3144 // store rand and ediv 3145 reverse_64(&packet[5], sm_conn->sm_local_rand); 3146 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3147 3148 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3149 // potentially stored LTK is from the master 3150 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3151 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3152 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3153 break; 3154 } 3155 // additionally check if remote is in LE Device DB if requested 3156 switch(sm_conn->sm_irk_lookup_state){ 3157 case IRK_LOOKUP_FAILED: 3158 log_info("LTK Request: device not in device db"); 3159 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3160 break; 3161 case IRK_LOOKUP_SUCCEEDED: 3162 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3163 break; 3164 default: 3165 // wait for irk look doen 3166 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3167 break; 3168 } 3169 break; 3170 } 3171 3172 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3173 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3174 #else 3175 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3176 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3177 #endif 3178 break; 3179 3180 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3181 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3182 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3183 log_error("Read Local P256 Public Key failed"); 3184 break; 3185 } 3186 3187 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3188 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3189 3190 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3191 sm_log_ec_keypair(); 3192 break; 3193 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3194 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3195 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3196 log_error("Generate DHKEY failed -> abort"); 3197 // abort pairing with 'unspecified reason' 3198 sm_pdu_received_in_wrong_state(sm_conn); 3199 break; 3200 } 3201 3202 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3203 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3204 log_info("dhkey"); 3205 log_info_hexdump(&setup->sm_dhkey[0], 32); 3206 3207 // trigger next step 3208 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3209 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3210 } 3211 break; 3212 #endif 3213 default: 3214 break; 3215 } 3216 break; 3217 3218 case HCI_EVENT_ENCRYPTION_CHANGE: 3219 con_handle = little_endian_read_16(packet, 3); 3220 sm_conn = sm_get_connection_for_handle(con_handle); 3221 if (!sm_conn) break; 3222 3223 sm_conn->sm_connection_encrypted = packet[5]; 3224 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3225 sm_conn->sm_actual_encryption_key_size); 3226 log_info("event handler, state %u", sm_conn->sm_engine_state); 3227 if (!sm_conn->sm_connection_encrypted) break; 3228 // continue if part of initial pairing 3229 switch (sm_conn->sm_engine_state){ 3230 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3231 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3232 sm_done_for_handle(sm_conn->sm_handle); 3233 break; 3234 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3235 if (IS_RESPONDER(sm_conn->sm_role)){ 3236 // slave 3237 if (setup->sm_use_secure_connections){ 3238 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3239 } else { 3240 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3241 } 3242 } else { 3243 // master 3244 if (sm_key_distribution_all_received(sm_conn)){ 3245 // skip receiving keys as there are none 3246 sm_key_distribution_handle_all_received(sm_conn); 3247 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3248 } else { 3249 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3250 } 3251 } 3252 break; 3253 default: 3254 break; 3255 } 3256 break; 3257 3258 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3259 con_handle = little_endian_read_16(packet, 3); 3260 sm_conn = sm_get_connection_for_handle(con_handle); 3261 if (!sm_conn) break; 3262 3263 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3264 log_info("event handler, state %u", sm_conn->sm_engine_state); 3265 // continue if part of initial pairing 3266 switch (sm_conn->sm_engine_state){ 3267 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3268 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3269 sm_done_for_handle(sm_conn->sm_handle); 3270 break; 3271 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3272 if (IS_RESPONDER(sm_conn->sm_role)){ 3273 // slave 3274 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3275 } else { 3276 // master 3277 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3278 } 3279 break; 3280 default: 3281 break; 3282 } 3283 break; 3284 3285 3286 case HCI_EVENT_DISCONNECTION_COMPLETE: 3287 con_handle = little_endian_read_16(packet, 3); 3288 sm_done_for_handle(con_handle); 3289 sm_conn = sm_get_connection_for_handle(con_handle); 3290 if (!sm_conn) break; 3291 3292 // delete stored bonding on disconnect with authentication failure in ph0 3293 if (sm_conn->sm_role == 0 3294 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3295 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3296 le_device_db_remove(sm_conn->sm_le_db_index); 3297 } 3298 3299 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3300 sm_conn->sm_handle = 0; 3301 break; 3302 3303 case HCI_EVENT_COMMAND_COMPLETE: 3304 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3305 sm_handle_encryption_result(&packet[6]); 3306 break; 3307 } 3308 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3309 sm_handle_random_result(&packet[6]); 3310 break; 3311 } 3312 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3313 // set local addr for le device db 3314 bd_addr_t addr; 3315 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3316 le_device_db_set_local_bd_addr(addr); 3317 } 3318 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3319 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3320 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3321 // mbedTLS can also be used if already available (and malloc is supported) 3322 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add USE_MICRO_ECC_FOR_ECDH to btstack_config.h"); 3323 } 3324 #endif 3325 } 3326 break; 3327 default: 3328 break; 3329 } 3330 break; 3331 default: 3332 break; 3333 } 3334 3335 sm_run(); 3336 } 3337 3338 static inline int sm_calc_actual_encryption_key_size(int other){ 3339 if (other < sm_min_encryption_key_size) return 0; 3340 if (other < sm_max_encryption_key_size) return other; 3341 return sm_max_encryption_key_size; 3342 } 3343 3344 3345 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3346 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3347 switch (method){ 3348 case JUST_WORKS: 3349 case NK_BOTH_INPUT: 3350 return 1; 3351 default: 3352 return 0; 3353 } 3354 } 3355 // responder 3356 3357 static int sm_passkey_used(stk_generation_method_t method){ 3358 switch (method){ 3359 case PK_RESP_INPUT: 3360 return 1; 3361 default: 3362 return 0; 3363 } 3364 } 3365 #endif 3366 3367 /** 3368 * @return ok 3369 */ 3370 static int sm_validate_stk_generation_method(void){ 3371 // check if STK generation method is acceptable by client 3372 switch (setup->sm_stk_generation_method){ 3373 case JUST_WORKS: 3374 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3375 case PK_RESP_INPUT: 3376 case PK_INIT_INPUT: 3377 case OK_BOTH_INPUT: 3378 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3379 case OOB: 3380 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3381 case NK_BOTH_INPUT: 3382 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3383 return 1; 3384 default: 3385 return 0; 3386 } 3387 } 3388 3389 // size of complete sm_pdu used to validate input 3390 static const uint8_t sm_pdu_size[] = { 3391 0, // 0x00 invalid opcode 3392 7, // 0x01 pairing request 3393 7, // 0x02 pairing response 3394 17, // 0x03 pairing confirm 3395 17, // 0x04 pairing random 3396 2, // 0x05 pairing failed 3397 17, // 0x06 encryption information 3398 11, // 0x07 master identification 3399 17, // 0x08 identification information 3400 8, // 0x09 identify address information 3401 17, // 0x0a signing information 3402 2, // 0x0b security request 3403 65, // 0x0c pairing public key 3404 17, // 0x0d pairing dhk check 3405 2, // 0x0e keypress notification 3406 }; 3407 3408 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3409 3410 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3411 sm_run(); 3412 } 3413 3414 if (packet_type != SM_DATA_PACKET) return; 3415 if (size == 0) return; 3416 3417 uint8_t sm_pdu_code = packet[0]; 3418 3419 // validate pdu size 3420 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3421 if (sm_pdu_size[sm_pdu_code] != size) return; 3422 3423 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3424 if (!sm_conn) return; 3425 3426 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3427 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3428 return; 3429 } 3430 3431 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3432 3433 int err; 3434 UNUSED(err); 3435 3436 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3437 uint8_t buffer[5]; 3438 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3439 buffer[1] = 3; 3440 little_endian_store_16(buffer, 2, con_handle); 3441 buffer[4] = packet[1]; 3442 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3443 return; 3444 } 3445 3446 switch (sm_conn->sm_engine_state){ 3447 3448 // a sm timeout requries a new physical connection 3449 case SM_GENERAL_TIMEOUT: 3450 return; 3451 3452 #ifdef ENABLE_LE_CENTRAL 3453 3454 // Initiator 3455 case SM_INITIATOR_CONNECTED: 3456 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3457 sm_pdu_received_in_wrong_state(sm_conn); 3458 break; 3459 } 3460 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3461 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3462 break; 3463 } 3464 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3465 sm_key_t ltk; 3466 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3467 if (!sm_is_null_key(ltk)){ 3468 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3469 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3470 } else { 3471 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3472 } 3473 break; 3474 } 3475 // otherwise, store security request 3476 sm_conn->sm_security_request_received = 1; 3477 break; 3478 3479 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3480 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3481 sm_pdu_received_in_wrong_state(sm_conn); 3482 break; 3483 } 3484 // store pairing request 3485 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3486 err = sm_stk_generation_init(sm_conn); 3487 if (err){ 3488 setup->sm_pairing_failed_reason = err; 3489 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3490 break; 3491 } 3492 3493 // generate random number first, if we need to show passkey 3494 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3495 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3496 break; 3497 } 3498 3499 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3500 if (setup->sm_use_secure_connections){ 3501 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3502 if (setup->sm_stk_generation_method == JUST_WORKS){ 3503 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3504 sm_trigger_user_response(sm_conn); 3505 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3506 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3507 } 3508 } else { 3509 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3510 } 3511 break; 3512 } 3513 #endif 3514 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3515 sm_trigger_user_response(sm_conn); 3516 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3517 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3518 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3519 } 3520 break; 3521 3522 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3523 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3524 sm_pdu_received_in_wrong_state(sm_conn); 3525 break; 3526 } 3527 3528 // store s_confirm 3529 reverse_128(&packet[1], setup->sm_peer_confirm); 3530 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3531 break; 3532 3533 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3534 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3535 sm_pdu_received_in_wrong_state(sm_conn); 3536 break;; 3537 } 3538 3539 // received random value 3540 reverse_128(&packet[1], setup->sm_peer_random); 3541 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3542 break; 3543 #endif 3544 3545 #ifdef ENABLE_LE_PERIPHERAL 3546 // Responder 3547 case SM_RESPONDER_IDLE: 3548 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3549 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3550 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3551 sm_pdu_received_in_wrong_state(sm_conn); 3552 break;; 3553 } 3554 3555 // store pairing request 3556 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3557 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3558 break; 3559 #endif 3560 3561 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3562 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3563 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3564 sm_pdu_received_in_wrong_state(sm_conn); 3565 break; 3566 } 3567 3568 // store public key for DH Key calculation 3569 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3570 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3571 3572 // validate public key using micro-ecc 3573 err = 0; 3574 3575 #ifdef USE_MICRO_ECC_FOR_ECDH 3576 #if uECC_SUPPORTS_secp256r1 3577 // standard version 3578 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3579 #else 3580 // static version 3581 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3582 #endif 3583 #endif 3584 3585 #ifdef USE_MBEDTLS_FOR_ECDH 3586 mbedtls_ecp_point Q; 3587 mbedtls_ecp_point_init( &Q ); 3588 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3589 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3590 mbedtls_mpi_lset(&Q.Z, 1); 3591 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3592 mbedtls_ecp_point_free( & Q); 3593 #endif 3594 3595 if (err){ 3596 log_error("sm: peer public key invalid %x", err); 3597 // uses "unspecified reason", there is no "public key invalid" error code 3598 sm_pdu_received_in_wrong_state(sm_conn); 3599 break; 3600 } 3601 3602 #ifndef USE_SOFTWARE_ECDH_IMPLEMENTATION 3603 // ask controller to calculate dhkey 3604 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3605 #endif 3606 3607 if (IS_RESPONDER(sm_conn->sm_role)){ 3608 // responder 3609 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3610 } else { 3611 // initiator 3612 // stk generation method 3613 // passkey entry: notify app to show passkey or to request passkey 3614 switch (setup->sm_stk_generation_method){ 3615 case JUST_WORKS: 3616 case NK_BOTH_INPUT: 3617 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3618 break; 3619 case PK_RESP_INPUT: 3620 sm_sc_start_calculating_local_confirm(sm_conn); 3621 break; 3622 case PK_INIT_INPUT: 3623 case OK_BOTH_INPUT: 3624 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3625 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3626 break; 3627 } 3628 sm_sc_start_calculating_local_confirm(sm_conn); 3629 break; 3630 case OOB: 3631 // TODO: implement SC OOB 3632 break; 3633 } 3634 } 3635 break; 3636 3637 case SM_SC_W4_CONFIRMATION: 3638 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3639 sm_pdu_received_in_wrong_state(sm_conn); 3640 break; 3641 } 3642 // received confirm value 3643 reverse_128(&packet[1], setup->sm_peer_confirm); 3644 3645 if (IS_RESPONDER(sm_conn->sm_role)){ 3646 // responder 3647 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3648 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3649 // still waiting for passkey 3650 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3651 break; 3652 } 3653 } 3654 sm_sc_start_calculating_local_confirm(sm_conn); 3655 } else { 3656 // initiator 3657 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3658 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3659 } else { 3660 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3661 } 3662 } 3663 break; 3664 3665 case SM_SC_W4_PAIRING_RANDOM: 3666 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3667 sm_pdu_received_in_wrong_state(sm_conn); 3668 break; 3669 } 3670 3671 // received random value 3672 reverse_128(&packet[1], setup->sm_peer_nonce); 3673 3674 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3675 // only check for JUST WORK/NC in initiator role AND passkey entry 3676 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3677 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3678 } 3679 3680 sm_sc_state_after_receiving_random(sm_conn); 3681 break; 3682 3683 case SM_SC_W2_CALCULATE_G2: 3684 case SM_SC_W4_CALCULATE_G2: 3685 case SM_SC_W4_CALCULATE_DHKEY: 3686 case SM_SC_W2_CALCULATE_F5_SALT: 3687 case SM_SC_W4_CALCULATE_F5_SALT: 3688 case SM_SC_W2_CALCULATE_F5_MACKEY: 3689 case SM_SC_W4_CALCULATE_F5_MACKEY: 3690 case SM_SC_W2_CALCULATE_F5_LTK: 3691 case SM_SC_W4_CALCULATE_F5_LTK: 3692 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3693 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3694 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3695 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3696 sm_pdu_received_in_wrong_state(sm_conn); 3697 break; 3698 } 3699 // store DHKey Check 3700 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3701 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3702 3703 // have we been only waiting for dhkey check command? 3704 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3705 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3706 } 3707 break; 3708 #endif 3709 3710 #ifdef ENABLE_LE_PERIPHERAL 3711 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3712 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3713 sm_pdu_received_in_wrong_state(sm_conn); 3714 break; 3715 } 3716 3717 // received confirm value 3718 reverse_128(&packet[1], setup->sm_peer_confirm); 3719 3720 // notify client to hide shown passkey 3721 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3722 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3723 } 3724 3725 // handle user cancel pairing? 3726 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3727 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3728 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3729 break; 3730 } 3731 3732 // wait for user action? 3733 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3734 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3735 break; 3736 } 3737 3738 // calculate and send local_confirm 3739 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3740 break; 3741 3742 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3743 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3744 sm_pdu_received_in_wrong_state(sm_conn); 3745 break;; 3746 } 3747 3748 // received random value 3749 reverse_128(&packet[1], setup->sm_peer_random); 3750 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3751 break; 3752 #endif 3753 3754 case SM_PH3_RECEIVE_KEYS: 3755 switch(sm_pdu_code){ 3756 case SM_CODE_ENCRYPTION_INFORMATION: 3757 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3758 reverse_128(&packet[1], setup->sm_peer_ltk); 3759 break; 3760 3761 case SM_CODE_MASTER_IDENTIFICATION: 3762 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3763 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3764 reverse_64(&packet[3], setup->sm_peer_rand); 3765 break; 3766 3767 case SM_CODE_IDENTITY_INFORMATION: 3768 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3769 reverse_128(&packet[1], setup->sm_peer_irk); 3770 break; 3771 3772 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3773 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3774 setup->sm_peer_addr_type = packet[1]; 3775 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3776 break; 3777 3778 case SM_CODE_SIGNING_INFORMATION: 3779 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3780 reverse_128(&packet[1], setup->sm_peer_csrk); 3781 break; 3782 default: 3783 // Unexpected PDU 3784 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3785 break; 3786 } 3787 // done with key distribution? 3788 if (sm_key_distribution_all_received(sm_conn)){ 3789 3790 sm_key_distribution_handle_all_received(sm_conn); 3791 3792 if (IS_RESPONDER(sm_conn->sm_role)){ 3793 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3794 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3795 } else { 3796 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3797 sm_done_for_handle(sm_conn->sm_handle); 3798 } 3799 } else { 3800 if (setup->sm_use_secure_connections){ 3801 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3802 } else { 3803 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3804 } 3805 } 3806 } 3807 break; 3808 default: 3809 // Unexpected PDU 3810 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3811 break; 3812 } 3813 3814 // try to send preparared packet 3815 sm_run(); 3816 } 3817 3818 // Security Manager Client API 3819 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3820 sm_get_oob_data = get_oob_data_callback; 3821 } 3822 3823 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3824 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3825 } 3826 3827 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3828 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3829 } 3830 3831 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3832 sm_min_encryption_key_size = min_size; 3833 sm_max_encryption_key_size = max_size; 3834 } 3835 3836 void sm_set_authentication_requirements(uint8_t auth_req){ 3837 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3838 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3839 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3840 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3841 } 3842 #endif 3843 sm_auth_req = auth_req; 3844 } 3845 3846 void sm_set_io_capabilities(io_capability_t io_capability){ 3847 sm_io_capabilities = io_capability; 3848 } 3849 3850 #ifdef ENABLE_LE_PERIPHERAL 3851 void sm_set_request_security(int enable){ 3852 sm_slave_request_security = enable; 3853 } 3854 #endif 3855 3856 void sm_set_er(sm_key_t er){ 3857 memcpy(sm_persistent_er, er, 16); 3858 } 3859 3860 void sm_set_ir(sm_key_t ir){ 3861 memcpy(sm_persistent_ir, ir, 16); 3862 } 3863 3864 // Testing support only 3865 void sm_test_set_irk(sm_key_t irk){ 3866 memcpy(sm_persistent_irk, irk, 16); 3867 sm_persistent_irk_ready = 1; 3868 } 3869 3870 void sm_test_use_fixed_local_csrk(void){ 3871 test_use_fixed_local_csrk = 1; 3872 } 3873 3874 void sm_init(void){ 3875 // set some (BTstack default) ER and IR 3876 int i; 3877 sm_key_t er; 3878 sm_key_t ir; 3879 for (i=0;i<16;i++){ 3880 er[i] = 0x30 + i; 3881 ir[i] = 0x90 + i; 3882 } 3883 sm_set_er(er); 3884 sm_set_ir(ir); 3885 // defaults 3886 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3887 | SM_STK_GENERATION_METHOD_OOB 3888 | SM_STK_GENERATION_METHOD_PASSKEY 3889 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3890 3891 sm_max_encryption_key_size = 16; 3892 sm_min_encryption_key_size = 7; 3893 3894 sm_fixed_passkey_in_display_role = 0xffffffff; 3895 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3896 3897 #ifdef ENABLE_CMAC_ENGINE 3898 sm_cmac_state = CMAC_IDLE; 3899 #endif 3900 dkg_state = DKG_W4_WORKING; 3901 rau_state = RAU_W4_WORKING; 3902 sm_aes128_state = SM_AES128_IDLE; 3903 sm_address_resolution_test = -1; // no private address to resolve yet 3904 sm_address_resolution_ah_calculation_active = 0; 3905 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3906 sm_address_resolution_general_queue = NULL; 3907 3908 gap_random_adress_update_period = 15 * 60 * 1000L; 3909 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3910 3911 test_use_fixed_local_csrk = 0; 3912 3913 // register for HCI Events from HCI 3914 hci_event_callback_registration.callback = &sm_event_packet_handler; 3915 hci_add_event_handler(&hci_event_callback_registration); 3916 3917 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3918 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3919 3920 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3921 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3922 #endif 3923 3924 #ifdef USE_MBEDTLS_FOR_ECDH 3925 mbedtls_ecp_group_init(&mbedtls_ec_group); 3926 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3927 #endif 3928 } 3929 3930 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3931 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3932 memcpy(&ec_q[0], qx, 32); 3933 memcpy(&ec_q[32], qy, 32); 3934 memcpy(ec_d, d, 32); 3935 sm_have_ec_keypair = 1; 3936 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3937 #else 3938 UNUSED(qx); 3939 UNUSED(qy); 3940 UNUSED(d); 3941 #endif 3942 } 3943 3944 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3945 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3946 while (*hex_string){ 3947 int high_nibble = nibble_for_char(*hex_string++); 3948 int low_nibble = nibble_for_char(*hex_string++); 3949 *buffer++ = (high_nibble << 4) | low_nibble; 3950 } 3951 } 3952 #endif 3953 3954 void sm_test_use_fixed_ec_keypair(void){ 3955 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3956 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3957 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3958 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3959 parse_hex(ec_d, ec_d_string); 3960 parse_hex(&ec_q[0], ec_qx_string); 3961 parse_hex(&ec_q[32], ec_qy_string); 3962 sm_have_ec_keypair = 1; 3963 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3964 #endif 3965 } 3966 3967 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3968 sm_fixed_passkey_in_display_role = passkey; 3969 } 3970 3971 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3972 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3973 } 3974 3975 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3976 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3977 if (!hci_con) return NULL; 3978 return &hci_con->sm_connection; 3979 } 3980 3981 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3982 switch (sm_conn->sm_engine_state){ 3983 case SM_GENERAL_IDLE: 3984 case SM_RESPONDER_IDLE: 3985 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3986 sm_run(); 3987 break; 3988 default: 3989 break; 3990 } 3991 } 3992 3993 /** 3994 * @brief Trigger Security Request 3995 */ 3996 void sm_send_security_request(hci_con_handle_t con_handle){ 3997 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3998 if (!sm_conn) return; 3999 sm_send_security_request_for_connection(sm_conn); 4000 } 4001 4002 // request pairing 4003 void sm_request_pairing(hci_con_handle_t con_handle){ 4004 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4005 if (!sm_conn) return; // wrong connection 4006 4007 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4008 if (IS_RESPONDER(sm_conn->sm_role)){ 4009 sm_send_security_request_for_connection(sm_conn); 4010 } else { 4011 // used as a trigger to start central/master/initiator security procedures 4012 uint16_t ediv; 4013 sm_key_t ltk; 4014 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4015 switch (sm_conn->sm_irk_lookup_state){ 4016 case IRK_LOOKUP_FAILED: 4017 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4018 break; 4019 case IRK_LOOKUP_SUCCEEDED: 4020 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 4021 if (!sm_is_null_key(ltk) || ediv){ 4022 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 4023 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4024 } else { 4025 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4026 } 4027 break; 4028 default: 4029 sm_conn->sm_bonding_requested = 1; 4030 break; 4031 } 4032 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4033 sm_conn->sm_bonding_requested = 1; 4034 } 4035 } 4036 sm_run(); 4037 } 4038 4039 // called by client app on authorization request 4040 void sm_authorization_decline(hci_con_handle_t con_handle){ 4041 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4042 if (!sm_conn) return; // wrong connection 4043 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4044 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4045 } 4046 4047 void sm_authorization_grant(hci_con_handle_t con_handle){ 4048 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4049 if (!sm_conn) return; // wrong connection 4050 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4051 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4052 } 4053 4054 // GAP Bonding API 4055 4056 void sm_bonding_decline(hci_con_handle_t con_handle){ 4057 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4058 if (!sm_conn) return; // wrong connection 4059 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4060 4061 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4062 switch (setup->sm_stk_generation_method){ 4063 case PK_RESP_INPUT: 4064 case PK_INIT_INPUT: 4065 case OK_BOTH_INPUT: 4066 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4067 break; 4068 case NK_BOTH_INPUT: 4069 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4070 break; 4071 case JUST_WORKS: 4072 case OOB: 4073 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4074 break; 4075 } 4076 } 4077 sm_run(); 4078 } 4079 4080 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4081 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4082 if (!sm_conn) return; // wrong connection 4083 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4084 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4085 if (setup->sm_use_secure_connections){ 4086 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4087 } else { 4088 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4089 } 4090 } 4091 4092 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4093 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4094 sm_sc_prepare_dhkey_check(sm_conn); 4095 } 4096 #endif 4097 4098 sm_run(); 4099 } 4100 4101 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4102 // for now, it's the same 4103 sm_just_works_confirm(con_handle); 4104 } 4105 4106 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4107 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4108 if (!sm_conn) return; // wrong connection 4109 sm_reset_tk(); 4110 big_endian_store_32(setup->sm_tk, 12, passkey); 4111 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4112 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4113 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4114 } 4115 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4116 memcpy(setup->sm_ra, setup->sm_tk, 16); 4117 memcpy(setup->sm_rb, setup->sm_tk, 16); 4118 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4119 sm_sc_start_calculating_local_confirm(sm_conn); 4120 } 4121 #endif 4122 sm_run(); 4123 } 4124 4125 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4126 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4127 if (!sm_conn) return; // wrong connection 4128 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4129 setup->sm_keypress_notification = action; 4130 sm_run(); 4131 } 4132 4133 /** 4134 * @brief Identify device in LE Device DB 4135 * @param handle 4136 * @returns index from le_device_db or -1 if not found/identified 4137 */ 4138 int sm_le_device_index(hci_con_handle_t con_handle ){ 4139 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4140 if (!sm_conn) return -1; 4141 return sm_conn->sm_le_db_index; 4142 } 4143 4144 static int gap_random_address_type_requires_updates(void){ 4145 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4146 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4147 return 1; 4148 } 4149 4150 static uint8_t own_address_type(void){ 4151 switch (gap_random_adress_type){ 4152 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4153 return BD_ADDR_TYPE_LE_PUBLIC; 4154 default: 4155 return BD_ADDR_TYPE_LE_RANDOM; 4156 } 4157 } 4158 4159 // GAP LE API 4160 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4161 gap_random_address_update_stop(); 4162 gap_random_adress_type = random_address_type; 4163 hci_le_set_own_address_type(own_address_type()); 4164 if (!gap_random_address_type_requires_updates()) return; 4165 gap_random_address_update_start(); 4166 gap_random_address_trigger(); 4167 } 4168 4169 gap_random_address_type_t gap_random_address_get_mode(void){ 4170 return gap_random_adress_type; 4171 } 4172 4173 void gap_random_address_set_update_period(int period_ms){ 4174 gap_random_adress_update_period = period_ms; 4175 if (!gap_random_address_type_requires_updates()) return; 4176 gap_random_address_update_stop(); 4177 gap_random_address_update_start(); 4178 } 4179 4180 void gap_random_address_set(bd_addr_t addr){ 4181 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4182 memcpy(sm_random_address, addr, 6); 4183 if (rau_state == RAU_W4_WORKING) return; 4184 rau_state = RAU_SET_ADDRESS; 4185 sm_run(); 4186 } 4187 4188 #ifdef ENABLE_LE_PERIPHERAL 4189 /* 4190 * @brief Set Advertisement Paramters 4191 * @param adv_int_min 4192 * @param adv_int_max 4193 * @param adv_type 4194 * @param direct_address_type 4195 * @param direct_address 4196 * @param channel_map 4197 * @param filter_policy 4198 * 4199 * @note own_address_type is used from gap_random_address_set_mode 4200 */ 4201 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4202 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4203 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4204 direct_address_typ, direct_address, channel_map, filter_policy); 4205 } 4206 #endif 4207