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_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 745 uint8_t event[18]; 746 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 747 event[11] = result; 748 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 749 } 750 751 // decide on stk generation based on 752 // - pairing request 753 // - io capabilities 754 // - OOB data availability 755 static void sm_setup_tk(void){ 756 757 // default: just works 758 setup->sm_stk_generation_method = JUST_WORKS; 759 760 #ifdef ENABLE_LE_SECURE_CONNECTIONS 761 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 762 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 763 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 764 memset(setup->sm_ra, 0, 16); 765 memset(setup->sm_rb, 0, 16); 766 #else 767 setup->sm_use_secure_connections = 0; 768 #endif 769 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 770 771 // If both devices have not set the MITM option in the Authentication Requirements 772 // Flags, then the IO capabilities shall be ignored and the Just Works association 773 // model shall be used. 774 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 775 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 776 log_info("SM: MITM not required by both -> JUST WORKS"); 777 return; 778 } 779 780 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 781 782 // If both devices have out of band authentication data, then the Authentication 783 // Requirements Flags shall be ignored when selecting the pairing method and the 784 // Out of Band pairing method shall be used. 785 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 786 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 787 log_info("SM: have OOB data"); 788 log_info_key("OOB", setup->sm_tk); 789 setup->sm_stk_generation_method = OOB; 790 return; 791 } 792 793 // Reset TK as it has been setup in sm_init_setup 794 sm_reset_tk(); 795 796 // Also use just works if unknown io capabilites 797 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)){ 798 return; 799 } 800 801 // Otherwise the IO capabilities of the devices shall be used to determine the 802 // pairing method as defined in Table 2.4. 803 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 804 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 805 806 #ifdef ENABLE_LE_SECURE_CONNECTIONS 807 // table not define by default 808 if (setup->sm_use_secure_connections){ 809 generation_method = stk_generation_method_with_secure_connection; 810 } 811 #endif 812 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)]; 813 814 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 815 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); 816 } 817 818 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 819 int flags = 0; 820 if (key_set & SM_KEYDIST_ENC_KEY){ 821 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 822 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 823 } 824 if (key_set & SM_KEYDIST_ID_KEY){ 825 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 826 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 827 } 828 if (key_set & SM_KEYDIST_SIGN){ 829 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 830 } 831 return flags; 832 } 833 834 static void sm_setup_key_distribution(uint8_t key_set){ 835 setup->sm_key_distribution_received_set = 0; 836 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 837 } 838 839 // CSRK Key Lookup 840 841 842 static int sm_address_resolution_idle(void){ 843 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 844 } 845 846 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){ 847 memcpy(sm_address_resolution_address, addr, 6); 848 sm_address_resolution_addr_type = addr_type; 849 sm_address_resolution_test = 0; 850 sm_address_resolution_mode = mode; 851 sm_address_resolution_context = context; 852 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 853 } 854 855 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 856 // check if already in list 857 btstack_linked_list_iterator_t it; 858 sm_lookup_entry_t * entry; 859 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 860 while(btstack_linked_list_iterator_has_next(&it)){ 861 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 862 if (entry->address_type != address_type) continue; 863 if (memcmp(entry->address, address, 6)) continue; 864 // already in list 865 return BTSTACK_BUSY; 866 } 867 entry = btstack_memory_sm_lookup_entry_get(); 868 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 869 entry->address_type = (bd_addr_type_t) address_type; 870 memcpy(entry->address, address, 6); 871 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 872 sm_run(); 873 return 0; 874 } 875 876 // 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 877 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 878 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 879 } 880 static inline void dkg_next_state(void){ 881 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 882 } 883 static inline void rau_next_state(void){ 884 rau_state = (random_address_update_t) (((int)rau_state) + 1); 885 } 886 887 // CMAC calculation using AES Engine 888 #ifdef ENABLE_CMAC_ENGINE 889 890 static inline void sm_cmac_next_state(void){ 891 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 892 } 893 894 static int sm_cmac_last_block_complete(void){ 895 if (sm_cmac_message_len == 0) return 0; 896 return (sm_cmac_message_len & 0x0f) == 0; 897 } 898 899 int sm_cmac_ready(void){ 900 return sm_cmac_state == CMAC_IDLE; 901 } 902 903 // generic cmac calculation 904 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])){ 905 // Generalized CMAC 906 memcpy(sm_cmac_k, key, 16); 907 memset(sm_cmac_x, 0, 16); 908 sm_cmac_block_current = 0; 909 sm_cmac_message_len = message_len; 910 sm_cmac_done_handler = done_callback; 911 sm_cmac_get_byte = get_byte_callback; 912 913 // step 2: n := ceil(len/const_Bsize); 914 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 915 916 // step 3: .. 917 if (sm_cmac_block_count==0){ 918 sm_cmac_block_count = 1; 919 } 920 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 921 922 // first, we need to compute l for k1, k2, and m_last 923 sm_cmac_state = CMAC_CALC_SUBKEYS; 924 925 // let's go 926 sm_run(); 927 } 928 #endif 929 930 // cmac for ATT Message signing 931 #ifdef ENABLE_LE_SIGNED_WRITE 932 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 933 if (offset >= sm_cmac_message_len) { 934 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 935 return 0; 936 } 937 938 offset = sm_cmac_message_len - 1 - offset; 939 940 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 941 if (offset < 3){ 942 return sm_cmac_header[offset]; 943 } 944 int actual_message_len_incl_header = sm_cmac_message_len - 4; 945 if (offset < actual_message_len_incl_header){ 946 return sm_cmac_message[offset - 3]; 947 } 948 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 949 } 950 951 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)){ 952 // ATT Message Signing 953 sm_cmac_header[0] = opcode; 954 little_endian_store_16(sm_cmac_header, 1, con_handle); 955 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 956 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 957 sm_cmac_message = message; 958 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 959 } 960 #endif 961 962 #ifdef ENABLE_CMAC_ENGINE 963 static void sm_cmac_handle_aes_engine_ready(void){ 964 switch (sm_cmac_state){ 965 case CMAC_CALC_SUBKEYS: { 966 sm_key_t const_zero; 967 memset(const_zero, 0, 16); 968 sm_cmac_next_state(); 969 sm_aes128_start(sm_cmac_k, const_zero, NULL); 970 break; 971 } 972 case CMAC_CALC_MI: { 973 int j; 974 sm_key_t y; 975 for (j=0;j<16;j++){ 976 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 977 } 978 sm_cmac_block_current++; 979 sm_cmac_next_state(); 980 sm_aes128_start(sm_cmac_k, y, NULL); 981 break; 982 } 983 case CMAC_CALC_MLAST: { 984 int i; 985 sm_key_t y; 986 for (i=0;i<16;i++){ 987 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 988 } 989 log_info_key("Y", y); 990 sm_cmac_block_current++; 991 sm_cmac_next_state(); 992 sm_aes128_start(sm_cmac_k, y, NULL); 993 break; 994 } 995 default: 996 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 997 break; 998 } 999 } 1000 1001 // CMAC Implementation using AES128 engine 1002 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1003 int i; 1004 int carry = 0; 1005 for (i=len-1; i >= 0 ; i--){ 1006 int new_carry = data[i] >> 7; 1007 data[i] = data[i] << 1 | carry; 1008 carry = new_carry; 1009 } 1010 } 1011 1012 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1013 switch (sm_cmac_state){ 1014 case CMAC_W4_SUBKEYS: { 1015 sm_key_t k1; 1016 memcpy(k1, data, 16); 1017 sm_shift_left_by_one_bit_inplace(16, k1); 1018 if (data[0] & 0x80){ 1019 k1[15] ^= 0x87; 1020 } 1021 sm_key_t k2; 1022 memcpy(k2, k1, 16); 1023 sm_shift_left_by_one_bit_inplace(16, k2); 1024 if (k1[0] & 0x80){ 1025 k2[15] ^= 0x87; 1026 } 1027 1028 log_info_key("k", sm_cmac_k); 1029 log_info_key("k1", k1); 1030 log_info_key("k2", k2); 1031 1032 // step 4: set m_last 1033 int i; 1034 if (sm_cmac_last_block_complete()){ 1035 for (i=0;i<16;i++){ 1036 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1037 } 1038 } else { 1039 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1040 for (i=0;i<16;i++){ 1041 if (i < valid_octets_in_last_block){ 1042 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1043 continue; 1044 } 1045 if (i == valid_octets_in_last_block){ 1046 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1047 continue; 1048 } 1049 sm_cmac_m_last[i] = k2[i]; 1050 } 1051 } 1052 1053 // next 1054 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1055 break; 1056 } 1057 case CMAC_W4_MI: 1058 memcpy(sm_cmac_x, data, 16); 1059 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1060 break; 1061 case CMAC_W4_MLAST: 1062 // done 1063 log_info("Setting CMAC Engine to IDLE"); 1064 sm_cmac_state = CMAC_IDLE; 1065 log_info_key("CMAC", data); 1066 sm_cmac_done_handler(data); 1067 break; 1068 default: 1069 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1070 break; 1071 } 1072 } 1073 #endif 1074 1075 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1076 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1077 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1078 switch (setup->sm_stk_generation_method){ 1079 case PK_RESP_INPUT: 1080 if (IS_RESPONDER(sm_conn->sm_role)){ 1081 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1082 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1083 } else { 1084 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)); 1085 } 1086 break; 1087 case PK_INIT_INPUT: 1088 if (IS_RESPONDER(sm_conn->sm_role)){ 1089 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)); 1090 } else { 1091 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1092 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1093 } 1094 break; 1095 case OK_BOTH_INPUT: 1096 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1097 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1098 break; 1099 case NK_BOTH_INPUT: 1100 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1101 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)); 1102 break; 1103 case JUST_WORKS: 1104 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1105 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1106 break; 1107 case OOB: 1108 // client already provided OOB data, let's skip notification. 1109 break; 1110 } 1111 } 1112 1113 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1114 int recv_flags; 1115 if (IS_RESPONDER(sm_conn->sm_role)){ 1116 // slave / responder 1117 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1118 } else { 1119 // master / initiator 1120 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1121 } 1122 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1123 return recv_flags == setup->sm_key_distribution_received_set; 1124 } 1125 1126 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1127 if (sm_active_connection_handle == con_handle){ 1128 sm_timeout_stop(); 1129 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1130 log_info("sm: connection 0x%x released setup context", con_handle); 1131 } 1132 } 1133 1134 static int sm_key_distribution_flags_for_auth_req(void){ 1135 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1136 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1137 // encryption information only if bonding requested 1138 flags |= SM_KEYDIST_ENC_KEY; 1139 } 1140 return flags; 1141 } 1142 1143 static void sm_reset_setup(void){ 1144 // fill in sm setup 1145 setup->sm_state_vars = 0; 1146 setup->sm_keypress_notification = 0xff; 1147 sm_reset_tk(); 1148 } 1149 1150 static void sm_init_setup(sm_connection_t * sm_conn){ 1151 1152 // fill in sm setup 1153 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1154 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1155 1156 // query client for OOB data 1157 int have_oob_data = 0; 1158 if (sm_get_oob_data) { 1159 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1160 } 1161 1162 sm_pairing_packet_t * local_packet; 1163 if (IS_RESPONDER(sm_conn->sm_role)){ 1164 // slave 1165 local_packet = &setup->sm_s_pres; 1166 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1167 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1168 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1169 } else { 1170 // master 1171 local_packet = &setup->sm_m_preq; 1172 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1173 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1174 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1175 1176 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1177 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1178 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1179 } 1180 1181 uint8_t auth_req = sm_auth_req; 1182 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1183 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1184 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1185 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1186 } 1187 1188 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1189 1190 sm_pairing_packet_t * remote_packet; 1191 int remote_key_request; 1192 if (IS_RESPONDER(sm_conn->sm_role)){ 1193 // slave / responder 1194 remote_packet = &setup->sm_m_preq; 1195 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1196 } else { 1197 // master / initiator 1198 remote_packet = &setup->sm_s_pres; 1199 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1200 } 1201 1202 // check key size 1203 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1204 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1205 1206 // decide on STK generation method 1207 sm_setup_tk(); 1208 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1209 1210 // check if STK generation method is acceptable by client 1211 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1212 1213 // identical to responder 1214 sm_setup_key_distribution(remote_key_request); 1215 1216 // JUST WORKS doens't provide authentication 1217 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1218 1219 return 0; 1220 } 1221 1222 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1223 1224 // cache and reset context 1225 int matched_device_id = sm_address_resolution_test; 1226 address_resolution_mode_t mode = sm_address_resolution_mode; 1227 void * context = sm_address_resolution_context; 1228 1229 // reset context 1230 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1231 sm_address_resolution_context = NULL; 1232 sm_address_resolution_test = -1; 1233 hci_con_handle_t con_handle = 0; 1234 1235 sm_connection_t * sm_connection; 1236 #ifdef ENABLE_LE_CENTRAL 1237 sm_key_t ltk; 1238 #endif 1239 switch (mode){ 1240 case ADDRESS_RESOLUTION_GENERAL: 1241 break; 1242 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1243 sm_connection = (sm_connection_t *) context; 1244 con_handle = sm_connection->sm_handle; 1245 switch (event){ 1246 case ADDRESS_RESOLUTION_SUCEEDED: 1247 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1248 sm_connection->sm_le_db_index = matched_device_id; 1249 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1250 if (sm_connection->sm_role) { 1251 // LTK request received before, IRK required -> start LTK calculation 1252 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1253 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1254 } 1255 break; 1256 } 1257 #ifdef ENABLE_LE_CENTRAL 1258 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1259 sm_connection->sm_security_request_received = 0; 1260 sm_connection->sm_bonding_requested = 0; 1261 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1262 if (!sm_is_null_key(ltk)){ 1263 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1264 } else { 1265 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1266 } 1267 #endif 1268 break; 1269 case ADDRESS_RESOLUTION_FAILED: 1270 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1271 if (sm_connection->sm_role) { 1272 // LTK request received before, IRK required -> negative LTK reply 1273 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1274 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1275 } 1276 break; 1277 } 1278 #ifdef ENABLE_LE_CENTRAL 1279 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1280 sm_connection->sm_security_request_received = 0; 1281 sm_connection->sm_bonding_requested = 0; 1282 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1283 #endif 1284 break; 1285 } 1286 break; 1287 default: 1288 break; 1289 } 1290 1291 switch (event){ 1292 case ADDRESS_RESOLUTION_SUCEEDED: 1293 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1294 break; 1295 case ADDRESS_RESOLUTION_FAILED: 1296 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1297 break; 1298 } 1299 } 1300 1301 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1302 1303 int le_db_index = -1; 1304 1305 // lookup device based on IRK 1306 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1307 int i; 1308 for (i=0; i < le_device_db_count(); i++){ 1309 sm_key_t irk; 1310 bd_addr_t address; 1311 int address_type; 1312 le_device_db_info(i, &address_type, address, irk); 1313 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1314 log_info("sm: device found for IRK, updating"); 1315 le_db_index = i; 1316 break; 1317 } 1318 } 1319 } 1320 1321 // if not found, lookup via public address if possible 1322 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1323 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1324 int i; 1325 for (i=0; i < le_device_db_count(); i++){ 1326 bd_addr_t address; 1327 int address_type; 1328 le_device_db_info(i, &address_type, address, NULL); 1329 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1330 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1331 log_info("sm: device found for public address, updating"); 1332 le_db_index = i; 1333 break; 1334 } 1335 } 1336 } 1337 1338 // if not found, add to db 1339 if (le_db_index < 0) { 1340 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1341 } 1342 1343 if (le_db_index >= 0){ 1344 1345 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1346 1347 #ifdef ENABLE_LE_SIGNED_WRITE 1348 // store local CSRK 1349 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1350 log_info("sm: store local CSRK"); 1351 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1352 le_device_db_local_counter_set(le_db_index, 0); 1353 } 1354 1355 // store remote CSRK 1356 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1357 log_info("sm: store remote CSRK"); 1358 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1359 le_device_db_remote_counter_set(le_db_index, 0); 1360 } 1361 #endif 1362 // store encryption information for secure connections: LTK generated by ECDH 1363 if (setup->sm_use_secure_connections){ 1364 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1365 uint8_t zero_rand[8]; 1366 memset(zero_rand, 0, 8); 1367 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1368 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1369 } 1370 1371 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1372 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1373 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1374 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1375 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1376 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1377 1378 } 1379 } 1380 1381 // keep le_db_index 1382 sm_conn->sm_le_db_index = le_db_index; 1383 } 1384 1385 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1386 setup->sm_pairing_failed_reason = reason; 1387 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1388 } 1389 1390 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1391 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1392 } 1393 1394 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1395 1396 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1397 static int sm_passkey_used(stk_generation_method_t method); 1398 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1399 1400 static void sm_log_ec_keypair(void){ 1401 log_info("Elliptic curve: X"); 1402 log_info_hexdump(&ec_q[0],32); 1403 log_info("Elliptic curve: Y"); 1404 log_info_hexdump(&ec_q[32],32); 1405 } 1406 1407 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1408 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1409 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1410 } else { 1411 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1412 } 1413 } 1414 1415 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1416 if (IS_RESPONDER(sm_conn->sm_role)){ 1417 // Responder 1418 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1419 } else { 1420 // Initiator role 1421 switch (setup->sm_stk_generation_method){ 1422 case JUST_WORKS: 1423 sm_sc_prepare_dhkey_check(sm_conn); 1424 break; 1425 1426 case NK_BOTH_INPUT: 1427 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1428 break; 1429 case PK_INIT_INPUT: 1430 case PK_RESP_INPUT: 1431 case OK_BOTH_INPUT: 1432 if (setup->sm_passkey_bit < 20) { 1433 sm_sc_start_calculating_local_confirm(sm_conn); 1434 } else { 1435 sm_sc_prepare_dhkey_check(sm_conn); 1436 } 1437 break; 1438 case OOB: 1439 // TODO: implement SC OOB 1440 break; 1441 } 1442 } 1443 } 1444 1445 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1446 return sm_cmac_sc_buffer[offset]; 1447 } 1448 1449 static void sm_sc_cmac_done(uint8_t * hash){ 1450 log_info("sm_sc_cmac_done: "); 1451 log_info_hexdump(hash, 16); 1452 1453 sm_connection_t * sm_conn = sm_cmac_connection; 1454 sm_cmac_connection = NULL; 1455 #ifdef ENABLE_CLASSIC 1456 link_key_type_t link_key_type; 1457 #endif 1458 1459 switch (sm_conn->sm_engine_state){ 1460 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1461 memcpy(setup->sm_local_confirm, hash, 16); 1462 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1463 break; 1464 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1465 // check 1466 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1467 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1468 break; 1469 } 1470 sm_sc_state_after_receiving_random(sm_conn); 1471 break; 1472 case SM_SC_W4_CALCULATE_G2: { 1473 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1474 big_endian_store_32(setup->sm_tk, 12, vab); 1475 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1476 sm_trigger_user_response(sm_conn); 1477 break; 1478 } 1479 case SM_SC_W4_CALCULATE_F5_SALT: 1480 memcpy(setup->sm_t, hash, 16); 1481 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1482 break; 1483 case SM_SC_W4_CALCULATE_F5_MACKEY: 1484 memcpy(setup->sm_mackey, hash, 16); 1485 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1486 break; 1487 case SM_SC_W4_CALCULATE_F5_LTK: 1488 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1489 // Errata Service Release to the Bluetooth Specification: ESR09 1490 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1491 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1492 memcpy(setup->sm_ltk, hash, 16); 1493 memcpy(setup->sm_local_ltk, hash, 16); 1494 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1495 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1496 break; 1497 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1498 memcpy(setup->sm_local_dhkey_check, hash, 16); 1499 if (IS_RESPONDER(sm_conn->sm_role)){ 1500 // responder 1501 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1502 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1503 } else { 1504 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1505 } 1506 } else { 1507 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1508 } 1509 break; 1510 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1511 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1512 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1513 break; 1514 } 1515 if (IS_RESPONDER(sm_conn->sm_role)){ 1516 // responder 1517 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1518 } else { 1519 // initiator 1520 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1521 } 1522 break; 1523 case SM_SC_W4_CALCULATE_H6_ILK: 1524 memcpy(setup->sm_t, hash, 16); 1525 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1526 break; 1527 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1528 #ifdef ENABLE_CLASSIC 1529 reverse_128(hash, setup->sm_t); 1530 link_key_type = sm_conn->sm_connection_authenticated ? 1531 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1532 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1533 if (IS_RESPONDER(sm_conn->sm_role)){ 1534 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1535 } else { 1536 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1537 } 1538 #endif 1539 if (IS_RESPONDER(sm_conn->sm_role)){ 1540 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1541 } else { 1542 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1543 } 1544 sm_done_for_handle(sm_conn->sm_handle); 1545 break; 1546 default: 1547 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1548 break; 1549 } 1550 sm_run(); 1551 } 1552 1553 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){ 1554 const uint16_t message_len = 65; 1555 sm_cmac_connection = sm_conn; 1556 memcpy(sm_cmac_sc_buffer, u, 32); 1557 memcpy(sm_cmac_sc_buffer+32, v, 32); 1558 sm_cmac_sc_buffer[64] = z; 1559 log_info("f4 key"); 1560 log_info_hexdump(x, 16); 1561 log_info("f4 message"); 1562 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1563 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1564 } 1565 1566 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1567 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1568 static const uint8_t f5_length[] = { 0x01, 0x00}; 1569 1570 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1571 1572 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1573 memset(dhkey, 0, 32); 1574 1575 #ifdef USE_MICRO_ECC_FOR_ECDH 1576 #if uECC_SUPPORTS_secp256r1 1577 // standard version 1578 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1579 #else 1580 // static version 1581 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1582 #endif 1583 #endif 1584 1585 #ifdef USE_MBEDTLS_FOR_ECDH 1586 // da * Pb 1587 mbedtls_mpi d; 1588 mbedtls_ecp_point Q; 1589 mbedtls_ecp_point DH; 1590 mbedtls_mpi_init(&d); 1591 mbedtls_ecp_point_init(&Q); 1592 mbedtls_ecp_point_init(&DH); 1593 mbedtls_mpi_read_binary(&d, ec_d, 32); 1594 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1595 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1596 mbedtls_mpi_lset(&Q.Z, 1); 1597 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1598 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1599 mbedtls_ecp_point_free(&DH); 1600 mbedtls_mpi_free(&d); 1601 mbedtls_ecp_point_free(&Q); 1602 #endif 1603 1604 log_info("dhkey"); 1605 log_info_hexdump(dhkey, 32); 1606 } 1607 #endif 1608 1609 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1610 // calculate salt for f5 1611 const uint16_t message_len = 32; 1612 sm_cmac_connection = sm_conn; 1613 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1614 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1615 } 1616 1617 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){ 1618 const uint16_t message_len = 53; 1619 sm_cmac_connection = sm_conn; 1620 1621 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1622 sm_cmac_sc_buffer[0] = 0; 1623 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1624 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1625 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1626 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1627 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1628 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1629 log_info("f5 key"); 1630 log_info_hexdump(t, 16); 1631 log_info("f5 message for MacKey"); 1632 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1633 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1634 } 1635 1636 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1637 sm_key56_t bd_addr_master, bd_addr_slave; 1638 bd_addr_master[0] = setup->sm_m_addr_type; 1639 bd_addr_slave[0] = setup->sm_s_addr_type; 1640 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1641 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1642 if (IS_RESPONDER(sm_conn->sm_role)){ 1643 // responder 1644 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1645 } else { 1646 // initiator 1647 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1648 } 1649 } 1650 1651 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1652 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1653 const uint16_t message_len = 53; 1654 sm_cmac_connection = sm_conn; 1655 sm_cmac_sc_buffer[0] = 1; 1656 // 1..52 setup before 1657 log_info("f5 key"); 1658 log_info_hexdump(t, 16); 1659 log_info("f5 message for LTK"); 1660 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1661 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1662 } 1663 1664 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1665 f5_ltk(sm_conn, setup->sm_t); 1666 } 1667 1668 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){ 1669 const uint16_t message_len = 65; 1670 sm_cmac_connection = sm_conn; 1671 memcpy(sm_cmac_sc_buffer, n1, 16); 1672 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1673 memcpy(sm_cmac_sc_buffer+32, r, 16); 1674 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1675 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1676 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1677 log_info("f6 key"); 1678 log_info_hexdump(w, 16); 1679 log_info("f6 message"); 1680 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1681 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1682 } 1683 1684 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1685 // - U is 256 bits 1686 // - V is 256 bits 1687 // - X is 128 bits 1688 // - Y is 128 bits 1689 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){ 1690 const uint16_t message_len = 80; 1691 sm_cmac_connection = sm_conn; 1692 memcpy(sm_cmac_sc_buffer, u, 32); 1693 memcpy(sm_cmac_sc_buffer+32, v, 32); 1694 memcpy(sm_cmac_sc_buffer+64, y, 16); 1695 log_info("g2 key"); 1696 log_info_hexdump(x, 16); 1697 log_info("g2 message"); 1698 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1699 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1700 } 1701 1702 static void g2_calculate(sm_connection_t * sm_conn) { 1703 // calc Va if numeric comparison 1704 if (IS_RESPONDER(sm_conn->sm_role)){ 1705 // responder 1706 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1707 } else { 1708 // initiator 1709 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1710 } 1711 } 1712 1713 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1714 uint8_t z = 0; 1715 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1716 // some form of passkey 1717 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1718 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1719 setup->sm_passkey_bit++; 1720 } 1721 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1722 } 1723 1724 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1725 uint8_t z = 0; 1726 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1727 // some form of passkey 1728 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1729 // sm_passkey_bit was increased before sending confirm value 1730 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1731 } 1732 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1733 } 1734 1735 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1736 1737 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1738 // calculate DHKEY 1739 sm_sc_calculate_dhkey(setup->sm_dhkey); 1740 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1741 #endif 1742 1743 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1744 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1745 return; 1746 } else { 1747 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1748 } 1749 1750 } 1751 1752 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1753 // calculate DHKCheck 1754 sm_key56_t bd_addr_master, bd_addr_slave; 1755 bd_addr_master[0] = setup->sm_m_addr_type; 1756 bd_addr_slave[0] = setup->sm_s_addr_type; 1757 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1758 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1759 uint8_t iocap_a[3]; 1760 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1761 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1762 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1763 uint8_t iocap_b[3]; 1764 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1765 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1766 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1767 if (IS_RESPONDER(sm_conn->sm_role)){ 1768 // responder 1769 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); 1770 } else { 1771 // initiator 1772 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); 1773 } 1774 } 1775 1776 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1777 // validate E = f6() 1778 sm_key56_t bd_addr_master, bd_addr_slave; 1779 bd_addr_master[0] = setup->sm_m_addr_type; 1780 bd_addr_slave[0] = setup->sm_s_addr_type; 1781 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1782 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1783 1784 uint8_t iocap_a[3]; 1785 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1786 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1787 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1788 uint8_t iocap_b[3]; 1789 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1790 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1791 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1792 if (IS_RESPONDER(sm_conn->sm_role)){ 1793 // responder 1794 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); 1795 } else { 1796 // initiator 1797 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); 1798 } 1799 } 1800 1801 1802 // 1803 // Link Key Conversion Function h6 1804 // 1805 // h6(W, keyID) = AES-CMACW(keyID) 1806 // - W is 128 bits 1807 // - keyID is 32 bits 1808 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1809 const uint16_t message_len = 4; 1810 sm_cmac_connection = sm_conn; 1811 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1812 log_info("h6 key"); 1813 log_info_hexdump(w, 16); 1814 log_info("h6 message"); 1815 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1816 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1817 } 1818 1819 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1820 // Errata Service Release to the Bluetooth Specification: ESR09 1821 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1822 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1823 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1824 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1825 } 1826 1827 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1828 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1829 } 1830 1831 #endif 1832 1833 // key management legacy connections: 1834 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1835 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1836 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1837 // - responder reconnects: responder uses LTK receveived from master 1838 1839 // key management secure connections: 1840 // - both devices store same LTK from ECDH key exchange. 1841 1842 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1843 static void sm_load_security_info(sm_connection_t * sm_connection){ 1844 int encryption_key_size; 1845 int authenticated; 1846 int authorized; 1847 1848 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1849 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1850 &encryption_key_size, &authenticated, &authorized); 1851 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1852 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1853 sm_connection->sm_connection_authenticated = authenticated; 1854 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1855 } 1856 #endif 1857 1858 #ifdef ENABLE_LE_PERIPHERAL 1859 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1860 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1861 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1862 // re-establish used key encryption size 1863 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1864 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1865 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1866 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1867 log_info("sm: received ltk request with key size %u, authenticated %u", 1868 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1869 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1870 } 1871 #endif 1872 1873 static void sm_run(void){ 1874 1875 btstack_linked_list_iterator_t it; 1876 1877 // assert that stack has already bootet 1878 if (hci_get_state() != HCI_STATE_WORKING) return; 1879 1880 // assert that we can send at least commands 1881 if (!hci_can_send_command_packet_now()) return; 1882 1883 // 1884 // non-connection related behaviour 1885 // 1886 1887 // distributed key generation 1888 switch (dkg_state){ 1889 case DKG_CALC_IRK: 1890 // already busy? 1891 if (sm_aes128_state == SM_AES128_IDLE) { 1892 // IRK = d1(IR, 1, 0) 1893 sm_key_t d1_prime; 1894 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1895 dkg_next_state(); 1896 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1897 return; 1898 } 1899 break; 1900 case DKG_CALC_DHK: 1901 // already busy? 1902 if (sm_aes128_state == SM_AES128_IDLE) { 1903 // DHK = d1(IR, 3, 0) 1904 sm_key_t d1_prime; 1905 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1906 dkg_next_state(); 1907 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1908 return; 1909 } 1910 break; 1911 default: 1912 break; 1913 } 1914 1915 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1916 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1917 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1918 sm_random_start(NULL); 1919 #else 1920 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1921 hci_send_cmd(&hci_le_read_local_p256_public_key); 1922 #endif 1923 return; 1924 } 1925 #endif 1926 1927 // random address updates 1928 switch (rau_state){ 1929 case RAU_GET_RANDOM: 1930 rau_next_state(); 1931 sm_random_start(NULL); 1932 return; 1933 case RAU_GET_ENC: 1934 // already busy? 1935 if (sm_aes128_state == SM_AES128_IDLE) { 1936 sm_key_t r_prime; 1937 sm_ah_r_prime(sm_random_address, r_prime); 1938 rau_next_state(); 1939 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1940 return; 1941 } 1942 break; 1943 case RAU_SET_ADDRESS: 1944 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1945 rau_state = RAU_IDLE; 1946 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1947 return; 1948 default: 1949 break; 1950 } 1951 1952 #ifdef ENABLE_CMAC_ENGINE 1953 // CMAC 1954 switch (sm_cmac_state){ 1955 case CMAC_CALC_SUBKEYS: 1956 case CMAC_CALC_MI: 1957 case CMAC_CALC_MLAST: 1958 // already busy? 1959 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1960 sm_cmac_handle_aes_engine_ready(); 1961 return; 1962 default: 1963 break; 1964 } 1965 #endif 1966 1967 // CSRK Lookup 1968 // -- if csrk lookup ready, find connection that require csrk lookup 1969 if (sm_address_resolution_idle()){ 1970 hci_connections_get_iterator(&it); 1971 while(btstack_linked_list_iterator_has_next(&it)){ 1972 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1973 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1974 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1975 // and start lookup 1976 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); 1977 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1978 break; 1979 } 1980 } 1981 } 1982 1983 // -- if csrk lookup ready, resolved addresses for received addresses 1984 if (sm_address_resolution_idle()) { 1985 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1986 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1987 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1988 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1989 btstack_memory_sm_lookup_entry_free(entry); 1990 } 1991 } 1992 1993 // -- Continue with CSRK device lookup by public or resolvable private address 1994 if (!sm_address_resolution_idle()){ 1995 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1996 while (sm_address_resolution_test < le_device_db_count()){ 1997 int addr_type; 1998 bd_addr_t addr; 1999 sm_key_t irk; 2000 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2001 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2002 2003 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2004 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2005 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2006 break; 2007 } 2008 2009 if (sm_address_resolution_addr_type == 0){ 2010 sm_address_resolution_test++; 2011 continue; 2012 } 2013 2014 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2015 2016 log_info("LE Device Lookup: calculate AH"); 2017 log_info_key("IRK", irk); 2018 2019 sm_key_t r_prime; 2020 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2021 sm_address_resolution_ah_calculation_active = 1; 2022 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2023 return; 2024 } 2025 2026 if (sm_address_resolution_test >= le_device_db_count()){ 2027 log_info("LE Device Lookup: not found"); 2028 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2029 } 2030 } 2031 2032 // handle basic actions that don't requires the full context 2033 hci_connections_get_iterator(&it); 2034 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2035 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2036 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2037 switch(sm_connection->sm_engine_state){ 2038 // responder side 2039 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2040 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2041 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2042 return; 2043 2044 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2045 case SM_SC_RECEIVED_LTK_REQUEST: 2046 switch (sm_connection->sm_irk_lookup_state){ 2047 case IRK_LOOKUP_FAILED: 2048 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2049 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2050 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2051 return; 2052 default: 2053 break; 2054 } 2055 break; 2056 #endif 2057 default: 2058 break; 2059 } 2060 } 2061 2062 // 2063 // active connection handling 2064 // -- use loop to handle next connection if lock on setup context is released 2065 2066 while (1) { 2067 2068 // Find connections that requires setup context and make active if no other is locked 2069 hci_connections_get_iterator(&it); 2070 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2071 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2072 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2073 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2074 int done = 1; 2075 int err; 2076 UNUSED(err); 2077 switch (sm_connection->sm_engine_state) { 2078 #ifdef ENABLE_LE_PERIPHERAL 2079 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2080 // send packet if possible, 2081 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2082 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2083 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2084 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2085 } else { 2086 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2087 } 2088 // don't lock sxetup context yet 2089 done = 0; 2090 break; 2091 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2092 sm_reset_setup(); 2093 sm_init_setup(sm_connection); 2094 // recover pairing request 2095 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2096 err = sm_stk_generation_init(sm_connection); 2097 if (err){ 2098 setup->sm_pairing_failed_reason = err; 2099 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2100 break; 2101 } 2102 sm_timeout_start(sm_connection); 2103 // generate random number first, if we need to show passkey 2104 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2105 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2106 break; 2107 } 2108 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2109 break; 2110 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2111 sm_reset_setup(); 2112 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2113 break; 2114 #endif 2115 #ifdef ENABLE_LE_CENTRAL 2116 case SM_INITIATOR_PH0_HAS_LTK: 2117 sm_reset_setup(); 2118 sm_load_security_info(sm_connection); 2119 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2120 break; 2121 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2122 sm_reset_setup(); 2123 sm_init_setup(sm_connection); 2124 sm_timeout_start(sm_connection); 2125 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2126 break; 2127 #endif 2128 2129 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2130 case SM_SC_RECEIVED_LTK_REQUEST: 2131 switch (sm_connection->sm_irk_lookup_state){ 2132 case IRK_LOOKUP_SUCCEEDED: 2133 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2134 // start using context by loading security info 2135 sm_reset_setup(); 2136 sm_load_security_info(sm_connection); 2137 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2138 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2139 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2140 break; 2141 } 2142 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2143 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2144 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2145 // don't lock setup context yet 2146 return; 2147 default: 2148 // just wait until IRK lookup is completed 2149 // don't lock setup context yet 2150 done = 0; 2151 break; 2152 } 2153 break; 2154 #endif 2155 default: 2156 done = 0; 2157 break; 2158 } 2159 if (done){ 2160 sm_active_connection_handle = sm_connection->sm_handle; 2161 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); 2162 } 2163 } 2164 2165 // 2166 // active connection handling 2167 // 2168 2169 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2170 2171 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2172 if (!connection) { 2173 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2174 return; 2175 } 2176 2177 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2178 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2179 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2180 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2181 return; 2182 } 2183 #endif 2184 2185 // assert that we could send a SM PDU - not needed for all of the following 2186 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2187 log_info("cannot send now, requesting can send now event"); 2188 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2189 return; 2190 } 2191 2192 // send keypress notifications 2193 if (setup->sm_keypress_notification != 0xff){ 2194 uint8_t buffer[2]; 2195 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2196 buffer[1] = setup->sm_keypress_notification; 2197 setup->sm_keypress_notification = 0xff; 2198 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2199 return; 2200 } 2201 2202 sm_key_t plaintext; 2203 int key_distribution_flags; 2204 UNUSED(key_distribution_flags); 2205 2206 log_info("sm_run: state %u", connection->sm_engine_state); 2207 2208 switch (connection->sm_engine_state){ 2209 2210 // general 2211 case SM_GENERAL_SEND_PAIRING_FAILED: { 2212 uint8_t buffer[2]; 2213 buffer[0] = SM_CODE_PAIRING_FAILED; 2214 buffer[1] = setup->sm_pairing_failed_reason; 2215 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2216 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2217 sm_done_for_handle(connection->sm_handle); 2218 break; 2219 } 2220 2221 // responding state 2222 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2223 case SM_SC_W2_GET_RANDOM_A: 2224 sm_random_start(connection); 2225 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2226 break; 2227 case SM_SC_W2_GET_RANDOM_B: 2228 sm_random_start(connection); 2229 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2230 break; 2231 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2232 if (!sm_cmac_ready()) break; 2233 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2234 sm_sc_calculate_local_confirm(connection); 2235 break; 2236 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2237 if (!sm_cmac_ready()) break; 2238 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2239 sm_sc_calculate_remote_confirm(connection); 2240 break; 2241 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2242 if (!sm_cmac_ready()) break; 2243 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2244 sm_sc_calculate_f6_for_dhkey_check(connection); 2245 break; 2246 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2247 if (!sm_cmac_ready()) break; 2248 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2249 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2250 break; 2251 case SM_SC_W2_CALCULATE_F5_SALT: 2252 if (!sm_cmac_ready()) break; 2253 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2254 f5_calculate_salt(connection); 2255 break; 2256 case SM_SC_W2_CALCULATE_F5_MACKEY: 2257 if (!sm_cmac_ready()) break; 2258 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2259 f5_calculate_mackey(connection); 2260 break; 2261 case SM_SC_W2_CALCULATE_F5_LTK: 2262 if (!sm_cmac_ready()) break; 2263 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2264 f5_calculate_ltk(connection); 2265 break; 2266 case SM_SC_W2_CALCULATE_G2: 2267 if (!sm_cmac_ready()) break; 2268 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2269 g2_calculate(connection); 2270 break; 2271 case SM_SC_W2_CALCULATE_H6_ILK: 2272 if (!sm_cmac_ready()) break; 2273 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2274 h6_calculate_ilk(connection); 2275 break; 2276 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2277 if (!sm_cmac_ready()) break; 2278 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2279 h6_calculate_br_edr_link_key(connection); 2280 break; 2281 #endif 2282 2283 #ifdef ENABLE_LE_CENTRAL 2284 // initiator side 2285 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2286 sm_key_t peer_ltk_flipped; 2287 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2288 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2289 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2290 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2291 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2292 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2293 return; 2294 } 2295 2296 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2297 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2298 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2299 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2300 sm_timeout_reset(connection); 2301 break; 2302 #endif 2303 2304 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2305 2306 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2307 uint8_t buffer[65]; 2308 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2309 // 2310 reverse_256(&ec_q[0], &buffer[1]); 2311 reverse_256(&ec_q[32], &buffer[33]); 2312 2313 // stk generation method 2314 // passkey entry: notify app to show passkey or to request passkey 2315 switch (setup->sm_stk_generation_method){ 2316 case JUST_WORKS: 2317 case NK_BOTH_INPUT: 2318 if (IS_RESPONDER(connection->sm_role)){ 2319 // responder 2320 sm_sc_start_calculating_local_confirm(connection); 2321 } else { 2322 // initiator 2323 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2324 } 2325 break; 2326 case PK_INIT_INPUT: 2327 case PK_RESP_INPUT: 2328 case OK_BOTH_INPUT: 2329 // use random TK for display 2330 memcpy(setup->sm_ra, setup->sm_tk, 16); 2331 memcpy(setup->sm_rb, setup->sm_tk, 16); 2332 setup->sm_passkey_bit = 0; 2333 2334 if (IS_RESPONDER(connection->sm_role)){ 2335 // responder 2336 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2337 } else { 2338 // initiator 2339 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2340 } 2341 sm_trigger_user_response(connection); 2342 break; 2343 case OOB: 2344 // TODO: implement SC OOB 2345 break; 2346 } 2347 2348 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2349 sm_timeout_reset(connection); 2350 break; 2351 } 2352 case SM_SC_SEND_CONFIRMATION: { 2353 uint8_t buffer[17]; 2354 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2355 reverse_128(setup->sm_local_confirm, &buffer[1]); 2356 if (IS_RESPONDER(connection->sm_role)){ 2357 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2358 } else { 2359 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2360 } 2361 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2362 sm_timeout_reset(connection); 2363 break; 2364 } 2365 case SM_SC_SEND_PAIRING_RANDOM: { 2366 uint8_t buffer[17]; 2367 buffer[0] = SM_CODE_PAIRING_RANDOM; 2368 reverse_128(setup->sm_local_nonce, &buffer[1]); 2369 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2370 if (IS_RESPONDER(connection->sm_role)){ 2371 // responder 2372 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2373 } else { 2374 // initiator 2375 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2376 } 2377 } else { 2378 if (IS_RESPONDER(connection->sm_role)){ 2379 // responder 2380 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2381 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2382 } else { 2383 sm_sc_prepare_dhkey_check(connection); 2384 } 2385 } else { 2386 // initiator 2387 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2388 } 2389 } 2390 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2391 sm_timeout_reset(connection); 2392 break; 2393 } 2394 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2395 uint8_t buffer[17]; 2396 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2397 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2398 2399 if (IS_RESPONDER(connection->sm_role)){ 2400 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2401 } else { 2402 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2403 } 2404 2405 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2406 sm_timeout_reset(connection); 2407 break; 2408 } 2409 2410 #endif 2411 2412 #ifdef ENABLE_LE_PERIPHERAL 2413 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2414 // echo initiator for now 2415 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2416 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2417 2418 if (setup->sm_use_secure_connections){ 2419 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2420 // skip LTK/EDIV for SC 2421 log_info("sm: dropping encryption information flag"); 2422 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2423 } else { 2424 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2425 } 2426 2427 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); 2428 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); 2429 // update key distribution after ENC was dropped 2430 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2431 2432 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2433 sm_timeout_reset(connection); 2434 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2435 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2436 sm_trigger_user_response(connection); 2437 } 2438 return; 2439 #endif 2440 2441 case SM_PH2_SEND_PAIRING_RANDOM: { 2442 uint8_t buffer[17]; 2443 buffer[0] = SM_CODE_PAIRING_RANDOM; 2444 reverse_128(setup->sm_local_random, &buffer[1]); 2445 if (IS_RESPONDER(connection->sm_role)){ 2446 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2447 } else { 2448 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2449 } 2450 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2451 sm_timeout_reset(connection); 2452 break; 2453 } 2454 2455 case SM_PH2_GET_RANDOM_TK: 2456 case SM_PH2_C1_GET_RANDOM_A: 2457 case SM_PH2_C1_GET_RANDOM_B: 2458 case SM_PH3_GET_RANDOM: 2459 case SM_PH3_GET_DIV: 2460 sm_next_responding_state(connection); 2461 sm_random_start(connection); 2462 return; 2463 2464 case SM_PH2_C1_GET_ENC_B: 2465 case SM_PH2_C1_GET_ENC_D: 2466 // already busy? 2467 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2468 sm_next_responding_state(connection); 2469 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2470 return; 2471 2472 case SM_PH3_LTK_GET_ENC: 2473 case SM_RESPONDER_PH4_LTK_GET_ENC: 2474 // already busy? 2475 if (sm_aes128_state == SM_AES128_IDLE) { 2476 sm_key_t d_prime; 2477 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2478 sm_next_responding_state(connection); 2479 sm_aes128_start(sm_persistent_er, d_prime, connection); 2480 return; 2481 } 2482 break; 2483 2484 case SM_PH3_CSRK_GET_ENC: 2485 // already busy? 2486 if (sm_aes128_state == SM_AES128_IDLE) { 2487 sm_key_t d_prime; 2488 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2489 sm_next_responding_state(connection); 2490 sm_aes128_start(sm_persistent_er, d_prime, connection); 2491 return; 2492 } 2493 break; 2494 2495 case SM_PH2_C1_GET_ENC_C: 2496 // already busy? 2497 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2498 // calculate m_confirm using aes128 engine - step 1 2499 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); 2500 sm_next_responding_state(connection); 2501 sm_aes128_start(setup->sm_tk, plaintext, connection); 2502 break; 2503 case SM_PH2_C1_GET_ENC_A: 2504 // already busy? 2505 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2506 // calculate confirm using aes128 engine - step 1 2507 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); 2508 sm_next_responding_state(connection); 2509 sm_aes128_start(setup->sm_tk, plaintext, connection); 2510 break; 2511 case SM_PH2_CALC_STK: 2512 // already busy? 2513 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2514 // calculate STK 2515 if (IS_RESPONDER(connection->sm_role)){ 2516 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2517 } else { 2518 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2519 } 2520 sm_next_responding_state(connection); 2521 sm_aes128_start(setup->sm_tk, plaintext, connection); 2522 break; 2523 case SM_PH3_Y_GET_ENC: 2524 // already busy? 2525 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2526 // PH3B2 - calculate Y from - enc 2527 // Y = dm(DHK, Rand) 2528 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2529 sm_next_responding_state(connection); 2530 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2531 return; 2532 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2533 uint8_t buffer[17]; 2534 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2535 reverse_128(setup->sm_local_confirm, &buffer[1]); 2536 if (IS_RESPONDER(connection->sm_role)){ 2537 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2538 } else { 2539 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2540 } 2541 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2542 sm_timeout_reset(connection); 2543 return; 2544 } 2545 #ifdef ENABLE_LE_PERIPHERAL 2546 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2547 sm_key_t stk_flipped; 2548 reverse_128(setup->sm_ltk, stk_flipped); 2549 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2550 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2551 return; 2552 } 2553 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2554 sm_key_t ltk_flipped; 2555 reverse_128(setup->sm_ltk, ltk_flipped); 2556 connection->sm_engine_state = SM_RESPONDER_IDLE; 2557 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2558 sm_done_for_handle(connection->sm_handle); 2559 return; 2560 } 2561 case SM_RESPONDER_PH4_Y_GET_ENC: 2562 // already busy? 2563 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2564 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2565 // Y = dm(DHK, Rand) 2566 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2567 sm_next_responding_state(connection); 2568 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2569 return; 2570 #endif 2571 #ifdef ENABLE_LE_CENTRAL 2572 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2573 sm_key_t stk_flipped; 2574 reverse_128(setup->sm_ltk, stk_flipped); 2575 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2576 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2577 return; 2578 } 2579 #endif 2580 2581 case SM_PH3_DISTRIBUTE_KEYS: 2582 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2583 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2584 uint8_t buffer[17]; 2585 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2586 reverse_128(setup->sm_ltk, &buffer[1]); 2587 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2588 sm_timeout_reset(connection); 2589 return; 2590 } 2591 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2592 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2593 uint8_t buffer[11]; 2594 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2595 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2596 reverse_64(setup->sm_local_rand, &buffer[3]); 2597 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2598 sm_timeout_reset(connection); 2599 return; 2600 } 2601 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2602 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2603 uint8_t buffer[17]; 2604 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2605 reverse_128(sm_persistent_irk, &buffer[1]); 2606 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2607 sm_timeout_reset(connection); 2608 return; 2609 } 2610 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2611 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2612 bd_addr_t local_address; 2613 uint8_t buffer[8]; 2614 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2615 switch (gap_random_address_get_mode()){ 2616 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2617 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2618 // public or static random 2619 gap_le_get_own_address(&buffer[1], local_address); 2620 break; 2621 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2622 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2623 // fallback to public 2624 gap_local_bd_addr(local_address); 2625 buffer[1] = 0; 2626 break; 2627 } 2628 reverse_bd_addr(local_address, &buffer[2]); 2629 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2630 sm_timeout_reset(connection); 2631 return; 2632 } 2633 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2634 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2635 2636 // hack to reproduce test runs 2637 if (test_use_fixed_local_csrk){ 2638 memset(setup->sm_local_csrk, 0xcc, 16); 2639 } 2640 2641 uint8_t buffer[17]; 2642 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2643 reverse_128(setup->sm_local_csrk, &buffer[1]); 2644 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2645 sm_timeout_reset(connection); 2646 return; 2647 } 2648 2649 // keys are sent 2650 if (IS_RESPONDER(connection->sm_role)){ 2651 // slave -> receive master keys if any 2652 if (sm_key_distribution_all_received(connection)){ 2653 sm_key_distribution_handle_all_received(connection); 2654 connection->sm_engine_state = SM_RESPONDER_IDLE; 2655 sm_done_for_handle(connection->sm_handle); 2656 } else { 2657 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2658 } 2659 } else { 2660 // master -> all done 2661 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2662 sm_done_for_handle(connection->sm_handle); 2663 } 2664 break; 2665 2666 default: 2667 break; 2668 } 2669 2670 // check again if active connection was released 2671 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2672 } 2673 } 2674 2675 // note: aes engine is ready as we just got the aes result 2676 static void sm_handle_encryption_result(uint8_t * data){ 2677 2678 sm_aes128_state = SM_AES128_IDLE; 2679 2680 if (sm_address_resolution_ah_calculation_active){ 2681 sm_address_resolution_ah_calculation_active = 0; 2682 // compare calulated address against connecting device 2683 uint8_t hash[3]; 2684 reverse_24(data, hash); 2685 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2686 log_info("LE Device Lookup: matched resolvable private address"); 2687 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2688 return; 2689 } 2690 // no match, try next 2691 sm_address_resolution_test++; 2692 return; 2693 } 2694 2695 switch (dkg_state){ 2696 case DKG_W4_IRK: 2697 reverse_128(data, sm_persistent_irk); 2698 log_info_key("irk", sm_persistent_irk); 2699 dkg_next_state(); 2700 return; 2701 case DKG_W4_DHK: 2702 reverse_128(data, sm_persistent_dhk); 2703 log_info_key("dhk", sm_persistent_dhk); 2704 dkg_next_state(); 2705 // SM Init Finished 2706 return; 2707 default: 2708 break; 2709 } 2710 2711 switch (rau_state){ 2712 case RAU_W4_ENC: 2713 reverse_24(data, &sm_random_address[3]); 2714 rau_next_state(); 2715 return; 2716 default: 2717 break; 2718 } 2719 2720 #ifdef ENABLE_CMAC_ENGINE 2721 switch (sm_cmac_state){ 2722 case CMAC_W4_SUBKEYS: 2723 case CMAC_W4_MI: 2724 case CMAC_W4_MLAST: 2725 { 2726 sm_key_t t; 2727 reverse_128(data, t); 2728 sm_cmac_handle_encryption_result(t); 2729 } 2730 return; 2731 default: 2732 break; 2733 } 2734 #endif 2735 2736 // retrieve sm_connection provided to sm_aes128_start_encryption 2737 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2738 if (!connection) return; 2739 switch (connection->sm_engine_state){ 2740 case SM_PH2_C1_W4_ENC_A: 2741 case SM_PH2_C1_W4_ENC_C: 2742 { 2743 sm_key_t t2; 2744 reverse_128(data, t2); 2745 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2746 } 2747 sm_next_responding_state(connection); 2748 return; 2749 case SM_PH2_C1_W4_ENC_B: 2750 reverse_128(data, setup->sm_local_confirm); 2751 log_info_key("c1!", setup->sm_local_confirm); 2752 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2753 return; 2754 case SM_PH2_C1_W4_ENC_D: 2755 { 2756 sm_key_t peer_confirm_test; 2757 reverse_128(data, peer_confirm_test); 2758 log_info_key("c1!", peer_confirm_test); 2759 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2760 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2761 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2762 return; 2763 } 2764 if (IS_RESPONDER(connection->sm_role)){ 2765 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2766 } else { 2767 connection->sm_engine_state = SM_PH2_CALC_STK; 2768 } 2769 } 2770 return; 2771 case SM_PH2_W4_STK: 2772 reverse_128(data, setup->sm_ltk); 2773 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2774 log_info_key("stk", setup->sm_ltk); 2775 if (IS_RESPONDER(connection->sm_role)){ 2776 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2777 } else { 2778 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2779 } 2780 return; 2781 case SM_PH3_Y_W4_ENC:{ 2782 sm_key_t y128; 2783 reverse_128(data, y128); 2784 setup->sm_local_y = big_endian_read_16(y128, 14); 2785 log_info_hex16("y", setup->sm_local_y); 2786 // PH3B3 - calculate EDIV 2787 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2788 log_info_hex16("ediv", setup->sm_local_ediv); 2789 // PH3B4 - calculate LTK - enc 2790 // LTK = d1(ER, DIV, 0)) 2791 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2792 return; 2793 } 2794 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2795 sm_key_t y128; 2796 reverse_128(data, y128); 2797 setup->sm_local_y = big_endian_read_16(y128, 14); 2798 log_info_hex16("y", setup->sm_local_y); 2799 2800 // PH3B3 - calculate DIV 2801 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2802 log_info_hex16("ediv", setup->sm_local_ediv); 2803 // PH3B4 - calculate LTK - enc 2804 // LTK = d1(ER, DIV, 0)) 2805 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2806 return; 2807 } 2808 case SM_PH3_LTK_W4_ENC: 2809 reverse_128(data, setup->sm_ltk); 2810 log_info_key("ltk", setup->sm_ltk); 2811 // calc CSRK next 2812 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2813 return; 2814 case SM_PH3_CSRK_W4_ENC: 2815 reverse_128(data, setup->sm_local_csrk); 2816 log_info_key("csrk", setup->sm_local_csrk); 2817 if (setup->sm_key_distribution_send_set){ 2818 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2819 } else { 2820 // no keys to send, just continue 2821 if (IS_RESPONDER(connection->sm_role)){ 2822 // slave -> receive master keys 2823 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2824 } else { 2825 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2826 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2827 } else { 2828 // master -> all done 2829 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2830 sm_done_for_handle(connection->sm_handle); 2831 } 2832 } 2833 } 2834 return; 2835 #ifdef ENABLE_LE_PERIPHERAL 2836 case SM_RESPONDER_PH4_LTK_W4_ENC: 2837 reverse_128(data, setup->sm_ltk); 2838 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2839 log_info_key("ltk", setup->sm_ltk); 2840 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2841 return; 2842 #endif 2843 default: 2844 break; 2845 } 2846 } 2847 2848 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2849 2850 #if (defined(USE_MICRO_ECC_FOR_ECDH) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_FOR_ECDH) 2851 // @return OK 2852 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2853 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2854 int offset = setup->sm_passkey_bit; 2855 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2856 while (size) { 2857 *buffer++ = setup->sm_peer_q[offset++]; 2858 size--; 2859 } 2860 setup->sm_passkey_bit = offset; 2861 return 1; 2862 } 2863 #endif 2864 #ifdef USE_MBEDTLS_FOR_ECDH 2865 // @return error - just wrap sm_generate_f_rng 2866 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2867 UNUSED(context); 2868 return sm_generate_f_rng(buffer, size) == 0; 2869 } 2870 #endif /* USE_MBEDTLS_FOR_ECDH */ 2871 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2872 2873 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2874 static void sm_handle_random_result(uint8_t * data){ 2875 2876 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2877 2878 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2879 int num_bytes = setup->sm_passkey_bit; 2880 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2881 num_bytes += 8; 2882 setup->sm_passkey_bit = num_bytes; 2883 2884 if (num_bytes >= 64){ 2885 2886 // init pre-generated random data from sm_peer_q 2887 setup->sm_passkey_bit = 0; 2888 2889 // generate EC key 2890 #ifdef USE_MICRO_ECC_FOR_ECDH 2891 2892 #ifndef WICED_VERSION 2893 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2894 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2895 uECC_set_rng(&sm_generate_f_rng); 2896 #endif /* WICED_VERSION */ 2897 2898 #if uECC_SUPPORTS_secp256r1 2899 // standard version 2900 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2901 2902 // disable RNG again, as returning no randmon data lets shared key generation fail 2903 log_info("disable uECC RNG in standard version after key generation"); 2904 uECC_set_rng(NULL); 2905 #else 2906 // static version 2907 uECC_make_key(ec_q, ec_d); 2908 #endif 2909 #endif /* USE_MICRO_ECC_FOR_ECDH */ 2910 2911 #ifdef USE_MBEDTLS_FOR_ECDH 2912 mbedtls_mpi d; 2913 mbedtls_ecp_point P; 2914 mbedtls_mpi_init(&d); 2915 mbedtls_ecp_point_init(&P); 2916 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2917 log_info("gen keypair %x", res); 2918 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2919 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2920 mbedtls_mpi_write_binary(&d, ec_d, 32); 2921 mbedtls_ecp_point_free(&P); 2922 mbedtls_mpi_free(&d); 2923 #endif /* USE_MBEDTLS_FOR_ECDH */ 2924 2925 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2926 log_info("Elliptic curve: d"); 2927 log_info_hexdump(ec_d,32); 2928 sm_log_ec_keypair(); 2929 } 2930 } 2931 #endif 2932 2933 switch (rau_state){ 2934 case RAU_W4_RANDOM: 2935 // non-resolvable vs. resolvable 2936 switch (gap_random_adress_type){ 2937 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2938 // resolvable: use random as prand and calc address hash 2939 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2940 memcpy(sm_random_address, data, 3); 2941 sm_random_address[0] &= 0x3f; 2942 sm_random_address[0] |= 0x40; 2943 rau_state = RAU_GET_ENC; 2944 break; 2945 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2946 default: 2947 // "The two most significant bits of the address shall be equal to ‘0’"" 2948 memcpy(sm_random_address, data, 6); 2949 sm_random_address[0] &= 0x3f; 2950 rau_state = RAU_SET_ADDRESS; 2951 break; 2952 } 2953 return; 2954 default: 2955 break; 2956 } 2957 2958 // retrieve sm_connection provided to sm_random_start 2959 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2960 if (!connection) return; 2961 switch (connection->sm_engine_state){ 2962 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2963 case SM_SC_W4_GET_RANDOM_A: 2964 memcpy(&setup->sm_local_nonce[0], data, 8); 2965 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2966 break; 2967 case SM_SC_W4_GET_RANDOM_B: 2968 memcpy(&setup->sm_local_nonce[8], data, 8); 2969 // initiator & jw/nc -> send pairing random 2970 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2971 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2972 break; 2973 } else { 2974 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2975 } 2976 break; 2977 #endif 2978 2979 case SM_PH2_W4_RANDOM_TK: 2980 { 2981 sm_reset_tk(); 2982 uint32_t tk; 2983 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2984 // map random to 0-999999 without speding much cycles on a modulus operation 2985 tk = little_endian_read_32(data,0); 2986 tk = tk & 0xfffff; // 1048575 2987 if (tk >= 999999){ 2988 tk = tk - 999999; 2989 } 2990 } else { 2991 // override with pre-defined passkey 2992 tk = sm_fixed_passkey_in_display_role; 2993 } 2994 big_endian_store_32(setup->sm_tk, 12, tk); 2995 if (IS_RESPONDER(connection->sm_role)){ 2996 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2997 } else { 2998 if (setup->sm_use_secure_connections){ 2999 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3000 } else { 3001 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3002 sm_trigger_user_response(connection); 3003 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3004 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3005 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3006 } 3007 } 3008 } 3009 return; 3010 } 3011 case SM_PH2_C1_W4_RANDOM_A: 3012 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 3013 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 3014 return; 3015 case SM_PH2_C1_W4_RANDOM_B: 3016 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3017 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3018 return; 3019 case SM_PH3_W4_RANDOM: 3020 reverse_64(data, setup->sm_local_rand); 3021 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3022 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3023 // no db for authenticated flag hack: store flag in bit 4 of LSB 3024 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3025 connection->sm_engine_state = SM_PH3_GET_DIV; 3026 return; 3027 case SM_PH3_W4_DIV: 3028 // use 16 bit from random value as div 3029 setup->sm_local_div = big_endian_read_16(data, 0); 3030 log_info_hex16("div", setup->sm_local_div); 3031 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3032 return; 3033 default: 3034 break; 3035 } 3036 } 3037 3038 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3039 3040 UNUSED(channel); // ok: there is no channel 3041 UNUSED(size); // ok: fixed format HCI events 3042 3043 sm_connection_t * sm_conn; 3044 hci_con_handle_t con_handle; 3045 3046 switch (packet_type) { 3047 3048 case HCI_EVENT_PACKET: 3049 switch (hci_event_packet_get_type(packet)) { 3050 3051 case BTSTACK_EVENT_STATE: 3052 // bt stack activated, get started 3053 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3054 log_info("HCI Working!"); 3055 3056 3057 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3058 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3059 if (!sm_have_ec_keypair){ 3060 setup->sm_passkey_bit = 0; 3061 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3062 } 3063 #endif 3064 // trigger Random Address generation if requested before 3065 switch (gap_random_adress_type){ 3066 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3067 rau_state = RAU_IDLE; 3068 break; 3069 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3070 rau_state = RAU_SET_ADDRESS; 3071 break; 3072 default: 3073 rau_state = RAU_GET_RANDOM; 3074 break; 3075 } 3076 sm_run(); 3077 } 3078 break; 3079 3080 case HCI_EVENT_LE_META: 3081 switch (packet[2]) { 3082 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3083 3084 log_info("sm: connected"); 3085 3086 if (packet[3]) return; // connection failed 3087 3088 con_handle = little_endian_read_16(packet, 4); 3089 sm_conn = sm_get_connection_for_handle(con_handle); 3090 if (!sm_conn) break; 3091 3092 sm_conn->sm_handle = con_handle; 3093 sm_conn->sm_role = packet[6]; 3094 sm_conn->sm_peer_addr_type = packet[7]; 3095 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3096 3097 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3098 3099 // reset security properties 3100 sm_conn->sm_connection_encrypted = 0; 3101 sm_conn->sm_connection_authenticated = 0; 3102 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3103 sm_conn->sm_le_db_index = -1; 3104 3105 // prepare CSRK lookup (does not involve setup) 3106 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3107 3108 // just connected -> everything else happens in sm_run() 3109 if (IS_RESPONDER(sm_conn->sm_role)){ 3110 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3111 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3112 if (sm_slave_request_security) { 3113 // request security if requested by app 3114 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3115 } else { 3116 // otherwise, wait for pairing request 3117 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3118 } 3119 } 3120 break; 3121 } else { 3122 // master 3123 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3124 } 3125 break; 3126 3127 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3128 con_handle = little_endian_read_16(packet, 3); 3129 sm_conn = sm_get_connection_for_handle(con_handle); 3130 if (!sm_conn) break; 3131 3132 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3133 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3134 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3135 break; 3136 } 3137 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3138 // PH2 SEND LTK as we need to exchange keys in PH3 3139 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3140 break; 3141 } 3142 3143 // store rand and ediv 3144 reverse_64(&packet[5], sm_conn->sm_local_rand); 3145 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3146 3147 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3148 // potentially stored LTK is from the master 3149 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3150 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3151 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3152 break; 3153 } 3154 // additionally check if remote is in LE Device DB if requested 3155 switch(sm_conn->sm_irk_lookup_state){ 3156 case IRK_LOOKUP_FAILED: 3157 log_info("LTK Request: device not in device db"); 3158 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3159 break; 3160 case IRK_LOOKUP_SUCCEEDED: 3161 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3162 break; 3163 default: 3164 // wait for irk look doen 3165 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3166 break; 3167 } 3168 break; 3169 } 3170 3171 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3172 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3173 #else 3174 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3175 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3176 #endif 3177 break; 3178 3179 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3180 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3181 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3182 log_error("Read Local P256 Public Key failed"); 3183 break; 3184 } 3185 3186 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3187 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3188 3189 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3190 sm_log_ec_keypair(); 3191 break; 3192 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3193 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3194 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3195 log_error("Generate DHKEY failed -> abort"); 3196 // abort pairing with 'unspecified reason' 3197 sm_pdu_received_in_wrong_state(sm_conn); 3198 break; 3199 } 3200 3201 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3202 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3203 log_info("dhkey"); 3204 log_info_hexdump(&setup->sm_dhkey[0], 32); 3205 3206 // trigger next step 3207 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3208 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3209 } 3210 break; 3211 #endif 3212 default: 3213 break; 3214 } 3215 break; 3216 3217 case HCI_EVENT_ENCRYPTION_CHANGE: 3218 con_handle = little_endian_read_16(packet, 3); 3219 sm_conn = sm_get_connection_for_handle(con_handle); 3220 if (!sm_conn) break; 3221 3222 sm_conn->sm_connection_encrypted = packet[5]; 3223 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3224 sm_conn->sm_actual_encryption_key_size); 3225 log_info("event handler, state %u", sm_conn->sm_engine_state); 3226 if (!sm_conn->sm_connection_encrypted) break; 3227 // continue if part of initial pairing 3228 switch (sm_conn->sm_engine_state){ 3229 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3230 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3231 sm_done_for_handle(sm_conn->sm_handle); 3232 break; 3233 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3234 if (IS_RESPONDER(sm_conn->sm_role)){ 3235 // slave 3236 if (setup->sm_use_secure_connections){ 3237 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3238 } else { 3239 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3240 } 3241 } else { 3242 // master 3243 if (sm_key_distribution_all_received(sm_conn)){ 3244 // skip receiving keys as there are none 3245 sm_key_distribution_handle_all_received(sm_conn); 3246 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3247 } else { 3248 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3249 } 3250 } 3251 break; 3252 default: 3253 break; 3254 } 3255 break; 3256 3257 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3258 con_handle = little_endian_read_16(packet, 3); 3259 sm_conn = sm_get_connection_for_handle(con_handle); 3260 if (!sm_conn) break; 3261 3262 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3263 log_info("event handler, state %u", sm_conn->sm_engine_state); 3264 // continue if part of initial pairing 3265 switch (sm_conn->sm_engine_state){ 3266 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3267 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3268 sm_done_for_handle(sm_conn->sm_handle); 3269 break; 3270 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3271 if (IS_RESPONDER(sm_conn->sm_role)){ 3272 // slave 3273 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3274 } else { 3275 // master 3276 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3277 } 3278 break; 3279 default: 3280 break; 3281 } 3282 break; 3283 3284 3285 case HCI_EVENT_DISCONNECTION_COMPLETE: 3286 con_handle = little_endian_read_16(packet, 3); 3287 sm_done_for_handle(con_handle); 3288 sm_conn = sm_get_connection_for_handle(con_handle); 3289 if (!sm_conn) break; 3290 3291 // delete stored bonding on disconnect with authentication failure in ph0 3292 if (sm_conn->sm_role == 0 3293 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3294 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3295 le_device_db_remove(sm_conn->sm_le_db_index); 3296 } 3297 3298 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3299 sm_conn->sm_handle = 0; 3300 break; 3301 3302 case HCI_EVENT_COMMAND_COMPLETE: 3303 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3304 sm_handle_encryption_result(&packet[6]); 3305 break; 3306 } 3307 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3308 sm_handle_random_result(&packet[6]); 3309 break; 3310 } 3311 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3312 // set local addr for le device db 3313 bd_addr_t addr; 3314 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3315 le_device_db_set_local_bd_addr(addr); 3316 } 3317 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3318 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3319 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3320 // mbedTLS can also be used if already available (and malloc is supported) 3321 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add USE_MICRO_ECC_FOR_ECDH to btstack_config.h"); 3322 } 3323 #endif 3324 } 3325 break; 3326 default: 3327 break; 3328 } 3329 break; 3330 default: 3331 break; 3332 } 3333 3334 sm_run(); 3335 } 3336 3337 static inline int sm_calc_actual_encryption_key_size(int other){ 3338 if (other < sm_min_encryption_key_size) return 0; 3339 if (other < sm_max_encryption_key_size) return other; 3340 return sm_max_encryption_key_size; 3341 } 3342 3343 3344 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3345 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3346 switch (method){ 3347 case JUST_WORKS: 3348 case NK_BOTH_INPUT: 3349 return 1; 3350 default: 3351 return 0; 3352 } 3353 } 3354 // responder 3355 3356 static int sm_passkey_used(stk_generation_method_t method){ 3357 switch (method){ 3358 case PK_RESP_INPUT: 3359 return 1; 3360 default: 3361 return 0; 3362 } 3363 } 3364 #endif 3365 3366 /** 3367 * @return ok 3368 */ 3369 static int sm_validate_stk_generation_method(void){ 3370 // check if STK generation method is acceptable by client 3371 switch (setup->sm_stk_generation_method){ 3372 case JUST_WORKS: 3373 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3374 case PK_RESP_INPUT: 3375 case PK_INIT_INPUT: 3376 case OK_BOTH_INPUT: 3377 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3378 case OOB: 3379 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3380 case NK_BOTH_INPUT: 3381 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3382 return 1; 3383 default: 3384 return 0; 3385 } 3386 } 3387 3388 // size of complete sm_pdu used to validate input 3389 static const uint8_t sm_pdu_size[] = { 3390 0, // 0x00 invalid opcode 3391 7, // 0x01 pairing request 3392 7, // 0x02 pairing response 3393 17, // 0x03 pairing confirm 3394 17, // 0x04 pairing random 3395 2, // 0x05 pairing failed 3396 17, // 0x06 encryption information 3397 11, // 0x07 master identification 3398 17, // 0x08 identification information 3399 8, // 0x09 identify address information 3400 17, // 0x0a signing information 3401 2, // 0x0b security request 3402 65, // 0x0c pairing public key 3403 17, // 0x0d pairing dhk check 3404 2, // 0x0e keypress notification 3405 }; 3406 3407 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3408 3409 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3410 sm_run(); 3411 } 3412 3413 if (packet_type != SM_DATA_PACKET) return; 3414 if (size == 0) return; 3415 3416 uint8_t sm_pdu_code = packet[0]; 3417 3418 // validate pdu size 3419 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3420 if (sm_pdu_size[sm_pdu_code] != size) return; 3421 3422 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3423 if (!sm_conn) return; 3424 3425 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3426 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3427 return; 3428 } 3429 3430 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3431 3432 int err; 3433 UNUSED(err); 3434 3435 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3436 uint8_t buffer[5]; 3437 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3438 buffer[1] = 3; 3439 little_endian_store_16(buffer, 2, con_handle); 3440 buffer[4] = packet[1]; 3441 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3442 return; 3443 } 3444 3445 switch (sm_conn->sm_engine_state){ 3446 3447 // a sm timeout requries a new physical connection 3448 case SM_GENERAL_TIMEOUT: 3449 return; 3450 3451 #ifdef ENABLE_LE_CENTRAL 3452 3453 // Initiator 3454 case SM_INITIATOR_CONNECTED: 3455 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3456 sm_pdu_received_in_wrong_state(sm_conn); 3457 break; 3458 } 3459 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3460 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3461 break; 3462 } 3463 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3464 sm_key_t ltk; 3465 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3466 if (!sm_is_null_key(ltk)){ 3467 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3468 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3469 } else { 3470 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3471 } 3472 break; 3473 } 3474 // otherwise, store security request 3475 sm_conn->sm_security_request_received = 1; 3476 break; 3477 3478 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3479 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3480 sm_pdu_received_in_wrong_state(sm_conn); 3481 break; 3482 } 3483 // store pairing request 3484 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3485 err = sm_stk_generation_init(sm_conn); 3486 if (err){ 3487 setup->sm_pairing_failed_reason = err; 3488 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3489 break; 3490 } 3491 3492 // generate random number first, if we need to show passkey 3493 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3494 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3495 break; 3496 } 3497 3498 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3499 if (setup->sm_use_secure_connections){ 3500 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3501 if (setup->sm_stk_generation_method == JUST_WORKS){ 3502 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3503 sm_trigger_user_response(sm_conn); 3504 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3505 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3506 } 3507 } else { 3508 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3509 } 3510 break; 3511 } 3512 #endif 3513 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3514 sm_trigger_user_response(sm_conn); 3515 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3516 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3517 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3518 } 3519 break; 3520 3521 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3522 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3523 sm_pdu_received_in_wrong_state(sm_conn); 3524 break; 3525 } 3526 3527 // store s_confirm 3528 reverse_128(&packet[1], setup->sm_peer_confirm); 3529 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3530 break; 3531 3532 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3533 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3534 sm_pdu_received_in_wrong_state(sm_conn); 3535 break;; 3536 } 3537 3538 // received random value 3539 reverse_128(&packet[1], setup->sm_peer_random); 3540 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3541 break; 3542 #endif 3543 3544 #ifdef ENABLE_LE_PERIPHERAL 3545 // Responder 3546 case SM_RESPONDER_IDLE: 3547 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3548 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3549 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3550 sm_pdu_received_in_wrong_state(sm_conn); 3551 break;; 3552 } 3553 3554 // store pairing request 3555 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3556 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3557 break; 3558 #endif 3559 3560 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3561 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3562 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3563 sm_pdu_received_in_wrong_state(sm_conn); 3564 break; 3565 } 3566 3567 // store public key for DH Key calculation 3568 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3569 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3570 3571 // validate public key using micro-ecc 3572 err = 0; 3573 3574 #ifdef USE_MICRO_ECC_FOR_ECDH 3575 #if uECC_SUPPORTS_secp256r1 3576 // standard version 3577 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3578 #else 3579 // static version 3580 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3581 #endif 3582 #endif 3583 3584 #ifdef USE_MBEDTLS_FOR_ECDH 3585 mbedtls_ecp_point Q; 3586 mbedtls_ecp_point_init( &Q ); 3587 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3588 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3589 mbedtls_mpi_lset(&Q.Z, 1); 3590 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3591 mbedtls_ecp_point_free( & Q); 3592 #endif 3593 3594 if (err){ 3595 log_error("sm: peer public key invalid %x", err); 3596 // uses "unspecified reason", there is no "public key invalid" error code 3597 sm_pdu_received_in_wrong_state(sm_conn); 3598 break; 3599 } 3600 3601 #ifndef USE_SOFTWARE_ECDH_IMPLEMENTATION 3602 // ask controller to calculate dhkey 3603 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3604 #endif 3605 3606 if (IS_RESPONDER(sm_conn->sm_role)){ 3607 // responder 3608 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3609 } else { 3610 // initiator 3611 // stk generation method 3612 // passkey entry: notify app to show passkey or to request passkey 3613 switch (setup->sm_stk_generation_method){ 3614 case JUST_WORKS: 3615 case NK_BOTH_INPUT: 3616 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3617 break; 3618 case PK_RESP_INPUT: 3619 sm_sc_start_calculating_local_confirm(sm_conn); 3620 break; 3621 case PK_INIT_INPUT: 3622 case OK_BOTH_INPUT: 3623 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3624 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3625 break; 3626 } 3627 sm_sc_start_calculating_local_confirm(sm_conn); 3628 break; 3629 case OOB: 3630 // TODO: implement SC OOB 3631 break; 3632 } 3633 } 3634 break; 3635 3636 case SM_SC_W4_CONFIRMATION: 3637 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3638 sm_pdu_received_in_wrong_state(sm_conn); 3639 break; 3640 } 3641 // received confirm value 3642 reverse_128(&packet[1], setup->sm_peer_confirm); 3643 3644 if (IS_RESPONDER(sm_conn->sm_role)){ 3645 // responder 3646 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3647 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3648 // still waiting for passkey 3649 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3650 break; 3651 } 3652 } 3653 sm_sc_start_calculating_local_confirm(sm_conn); 3654 } else { 3655 // initiator 3656 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3657 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3658 } else { 3659 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3660 } 3661 } 3662 break; 3663 3664 case SM_SC_W4_PAIRING_RANDOM: 3665 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3666 sm_pdu_received_in_wrong_state(sm_conn); 3667 break; 3668 } 3669 3670 // received random value 3671 reverse_128(&packet[1], setup->sm_peer_nonce); 3672 3673 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3674 // only check for JUST WORK/NC in initiator role AND passkey entry 3675 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3676 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3677 } 3678 3679 sm_sc_state_after_receiving_random(sm_conn); 3680 break; 3681 3682 case SM_SC_W2_CALCULATE_G2: 3683 case SM_SC_W4_CALCULATE_G2: 3684 case SM_SC_W4_CALCULATE_DHKEY: 3685 case SM_SC_W2_CALCULATE_F5_SALT: 3686 case SM_SC_W4_CALCULATE_F5_SALT: 3687 case SM_SC_W2_CALCULATE_F5_MACKEY: 3688 case SM_SC_W4_CALCULATE_F5_MACKEY: 3689 case SM_SC_W2_CALCULATE_F5_LTK: 3690 case SM_SC_W4_CALCULATE_F5_LTK: 3691 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3692 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3693 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3694 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3695 sm_pdu_received_in_wrong_state(sm_conn); 3696 break; 3697 } 3698 // store DHKey Check 3699 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3700 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3701 3702 // have we been only waiting for dhkey check command? 3703 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3704 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3705 } 3706 break; 3707 #endif 3708 3709 #ifdef ENABLE_LE_PERIPHERAL 3710 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3711 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3712 sm_pdu_received_in_wrong_state(sm_conn); 3713 break; 3714 } 3715 3716 // received confirm value 3717 reverse_128(&packet[1], setup->sm_peer_confirm); 3718 3719 // notify client to hide shown passkey 3720 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3721 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3722 } 3723 3724 // handle user cancel pairing? 3725 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3726 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3727 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3728 break; 3729 } 3730 3731 // wait for user action? 3732 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3733 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3734 break; 3735 } 3736 3737 // calculate and send local_confirm 3738 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3739 break; 3740 3741 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3742 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3743 sm_pdu_received_in_wrong_state(sm_conn); 3744 break;; 3745 } 3746 3747 // received random value 3748 reverse_128(&packet[1], setup->sm_peer_random); 3749 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3750 break; 3751 #endif 3752 3753 case SM_PH3_RECEIVE_KEYS: 3754 switch(sm_pdu_code){ 3755 case SM_CODE_ENCRYPTION_INFORMATION: 3756 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3757 reverse_128(&packet[1], setup->sm_peer_ltk); 3758 break; 3759 3760 case SM_CODE_MASTER_IDENTIFICATION: 3761 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3762 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3763 reverse_64(&packet[3], setup->sm_peer_rand); 3764 break; 3765 3766 case SM_CODE_IDENTITY_INFORMATION: 3767 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3768 reverse_128(&packet[1], setup->sm_peer_irk); 3769 break; 3770 3771 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3772 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3773 setup->sm_peer_addr_type = packet[1]; 3774 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3775 break; 3776 3777 case SM_CODE_SIGNING_INFORMATION: 3778 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3779 reverse_128(&packet[1], setup->sm_peer_csrk); 3780 break; 3781 default: 3782 // Unexpected PDU 3783 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3784 break; 3785 } 3786 // done with key distribution? 3787 if (sm_key_distribution_all_received(sm_conn)){ 3788 3789 sm_key_distribution_handle_all_received(sm_conn); 3790 3791 if (IS_RESPONDER(sm_conn->sm_role)){ 3792 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3793 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3794 } else { 3795 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3796 sm_done_for_handle(sm_conn->sm_handle); 3797 } 3798 } else { 3799 if (setup->sm_use_secure_connections){ 3800 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3801 } else { 3802 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3803 } 3804 } 3805 } 3806 break; 3807 default: 3808 // Unexpected PDU 3809 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3810 break; 3811 } 3812 3813 // try to send preparared packet 3814 sm_run(); 3815 } 3816 3817 // Security Manager Client API 3818 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3819 sm_get_oob_data = get_oob_data_callback; 3820 } 3821 3822 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3823 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3824 } 3825 3826 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3827 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3828 } 3829 3830 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3831 sm_min_encryption_key_size = min_size; 3832 sm_max_encryption_key_size = max_size; 3833 } 3834 3835 void sm_set_authentication_requirements(uint8_t auth_req){ 3836 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3837 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3838 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3839 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3840 } 3841 #endif 3842 sm_auth_req = auth_req; 3843 } 3844 3845 void sm_set_io_capabilities(io_capability_t io_capability){ 3846 sm_io_capabilities = io_capability; 3847 } 3848 3849 #ifdef ENABLE_LE_PERIPHERAL 3850 void sm_set_request_security(int enable){ 3851 sm_slave_request_security = enable; 3852 } 3853 #endif 3854 3855 void sm_set_er(sm_key_t er){ 3856 memcpy(sm_persistent_er, er, 16); 3857 } 3858 3859 void sm_set_ir(sm_key_t ir){ 3860 memcpy(sm_persistent_ir, ir, 16); 3861 } 3862 3863 // Testing support only 3864 void sm_test_set_irk(sm_key_t irk){ 3865 memcpy(sm_persistent_irk, irk, 16); 3866 sm_persistent_irk_ready = 1; 3867 } 3868 3869 void sm_test_use_fixed_local_csrk(void){ 3870 test_use_fixed_local_csrk = 1; 3871 } 3872 3873 void sm_init(void){ 3874 // set some (BTstack default) ER and IR 3875 int i; 3876 sm_key_t er; 3877 sm_key_t ir; 3878 for (i=0;i<16;i++){ 3879 er[i] = 0x30 + i; 3880 ir[i] = 0x90 + i; 3881 } 3882 sm_set_er(er); 3883 sm_set_ir(ir); 3884 // defaults 3885 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3886 | SM_STK_GENERATION_METHOD_OOB 3887 | SM_STK_GENERATION_METHOD_PASSKEY 3888 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3889 3890 sm_max_encryption_key_size = 16; 3891 sm_min_encryption_key_size = 7; 3892 3893 sm_fixed_passkey_in_display_role = 0xffffffff; 3894 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3895 3896 #ifdef ENABLE_CMAC_ENGINE 3897 sm_cmac_state = CMAC_IDLE; 3898 #endif 3899 dkg_state = DKG_W4_WORKING; 3900 rau_state = RAU_W4_WORKING; 3901 sm_aes128_state = SM_AES128_IDLE; 3902 sm_address_resolution_test = -1; // no private address to resolve yet 3903 sm_address_resolution_ah_calculation_active = 0; 3904 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3905 sm_address_resolution_general_queue = NULL; 3906 3907 gap_random_adress_update_period = 15 * 60 * 1000L; 3908 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3909 3910 test_use_fixed_local_csrk = 0; 3911 3912 // register for HCI Events from HCI 3913 hci_event_callback_registration.callback = &sm_event_packet_handler; 3914 hci_add_event_handler(&hci_event_callback_registration); 3915 3916 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3917 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3918 3919 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3920 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3921 #endif 3922 3923 #ifdef USE_MBEDTLS_FOR_ECDH 3924 mbedtls_ecp_group_init(&mbedtls_ec_group); 3925 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3926 #endif 3927 } 3928 3929 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3930 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3931 memcpy(&ec_q[0], qx, 32); 3932 memcpy(&ec_q[32], qy, 32); 3933 memcpy(ec_d, d, 32); 3934 sm_have_ec_keypair = 1; 3935 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3936 #else 3937 UNUSED(qx); 3938 UNUSED(qy); 3939 UNUSED(d); 3940 #endif 3941 } 3942 3943 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3944 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3945 while (*hex_string){ 3946 int high_nibble = nibble_for_char(*hex_string++); 3947 int low_nibble = nibble_for_char(*hex_string++); 3948 *buffer++ = (high_nibble << 4) | low_nibble; 3949 } 3950 } 3951 #endif 3952 3953 void sm_test_use_fixed_ec_keypair(void){ 3954 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3955 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3956 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3957 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3958 parse_hex(ec_d, ec_d_string); 3959 parse_hex(&ec_q[0], ec_qx_string); 3960 parse_hex(&ec_q[32], ec_qy_string); 3961 sm_have_ec_keypair = 1; 3962 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3963 #endif 3964 } 3965 3966 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3967 sm_fixed_passkey_in_display_role = passkey; 3968 } 3969 3970 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3971 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3972 } 3973 3974 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3975 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3976 if (!hci_con) return NULL; 3977 return &hci_con->sm_connection; 3978 } 3979 3980 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3981 switch (sm_conn->sm_engine_state){ 3982 case SM_GENERAL_IDLE: 3983 case SM_RESPONDER_IDLE: 3984 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3985 sm_run(); 3986 break; 3987 default: 3988 break; 3989 } 3990 } 3991 3992 /** 3993 * @brief Trigger Security Request 3994 */ 3995 void sm_send_security_request(hci_con_handle_t con_handle){ 3996 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3997 if (!sm_conn) return; 3998 sm_send_security_request_for_connection(sm_conn); 3999 } 4000 4001 // request pairing 4002 void sm_request_pairing(hci_con_handle_t con_handle){ 4003 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4004 if (!sm_conn) return; // wrong connection 4005 4006 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4007 if (IS_RESPONDER(sm_conn->sm_role)){ 4008 sm_send_security_request_for_connection(sm_conn); 4009 } else { 4010 // used as a trigger to start central/master/initiator security procedures 4011 uint16_t ediv; 4012 sm_key_t ltk; 4013 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4014 switch (sm_conn->sm_irk_lookup_state){ 4015 case IRK_LOOKUP_FAILED: 4016 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4017 break; 4018 case IRK_LOOKUP_SUCCEEDED: 4019 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 4020 if (!sm_is_null_key(ltk) || ediv){ 4021 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 4022 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4023 } else { 4024 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4025 } 4026 break; 4027 default: 4028 sm_conn->sm_bonding_requested = 1; 4029 break; 4030 } 4031 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4032 sm_conn->sm_bonding_requested = 1; 4033 } 4034 } 4035 sm_run(); 4036 } 4037 4038 // called by client app on authorization request 4039 void sm_authorization_decline(hci_con_handle_t con_handle){ 4040 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4041 if (!sm_conn) return; // wrong connection 4042 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4043 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4044 } 4045 4046 void sm_authorization_grant(hci_con_handle_t con_handle){ 4047 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4048 if (!sm_conn) return; // wrong connection 4049 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4050 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4051 } 4052 4053 // GAP Bonding API 4054 4055 void sm_bonding_decline(hci_con_handle_t con_handle){ 4056 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4057 if (!sm_conn) return; // wrong connection 4058 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4059 4060 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4061 switch (setup->sm_stk_generation_method){ 4062 case PK_RESP_INPUT: 4063 case PK_INIT_INPUT: 4064 case OK_BOTH_INPUT: 4065 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4066 break; 4067 case NK_BOTH_INPUT: 4068 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4069 break; 4070 case JUST_WORKS: 4071 case OOB: 4072 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4073 break; 4074 } 4075 } 4076 sm_run(); 4077 } 4078 4079 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4080 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4081 if (!sm_conn) return; // wrong connection 4082 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4083 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4084 if (setup->sm_use_secure_connections){ 4085 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4086 } else { 4087 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4088 } 4089 } 4090 4091 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4092 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4093 sm_sc_prepare_dhkey_check(sm_conn); 4094 } 4095 #endif 4096 4097 sm_run(); 4098 } 4099 4100 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4101 // for now, it's the same 4102 sm_just_works_confirm(con_handle); 4103 } 4104 4105 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4106 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4107 if (!sm_conn) return; // wrong connection 4108 sm_reset_tk(); 4109 big_endian_store_32(setup->sm_tk, 12, passkey); 4110 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4111 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4112 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4113 } 4114 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4115 memcpy(setup->sm_ra, setup->sm_tk, 16); 4116 memcpy(setup->sm_rb, setup->sm_tk, 16); 4117 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4118 sm_sc_start_calculating_local_confirm(sm_conn); 4119 } 4120 #endif 4121 sm_run(); 4122 } 4123 4124 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4125 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4126 if (!sm_conn) return; // wrong connection 4127 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4128 setup->sm_keypress_notification = action; 4129 sm_run(); 4130 } 4131 4132 /** 4133 * @brief Identify device in LE Device DB 4134 * @param handle 4135 * @returns index from le_device_db or -1 if not found/identified 4136 */ 4137 int sm_le_device_index(hci_con_handle_t con_handle ){ 4138 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4139 if (!sm_conn) return -1; 4140 return sm_conn->sm_le_db_index; 4141 } 4142 4143 static int gap_random_address_type_requires_updates(void){ 4144 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4145 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4146 return 1; 4147 } 4148 4149 static uint8_t own_address_type(void){ 4150 switch (gap_random_adress_type){ 4151 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4152 return BD_ADDR_TYPE_LE_PUBLIC; 4153 default: 4154 return BD_ADDR_TYPE_LE_RANDOM; 4155 } 4156 } 4157 4158 // GAP LE API 4159 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4160 gap_random_address_update_stop(); 4161 gap_random_adress_type = random_address_type; 4162 hci_le_set_own_address_type(own_address_type()); 4163 if (!gap_random_address_type_requires_updates()) return; 4164 gap_random_address_update_start(); 4165 gap_random_address_trigger(); 4166 } 4167 4168 gap_random_address_type_t gap_random_address_get_mode(void){ 4169 return gap_random_adress_type; 4170 } 4171 4172 void gap_random_address_set_update_period(int period_ms){ 4173 gap_random_adress_update_period = period_ms; 4174 if (!gap_random_address_type_requires_updates()) return; 4175 gap_random_address_update_stop(); 4176 gap_random_address_update_start(); 4177 } 4178 4179 void gap_random_address_set(bd_addr_t addr){ 4180 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4181 memcpy(sm_random_address, addr, 6); 4182 if (rau_state == RAU_W4_WORKING) return; 4183 rau_state = RAU_SET_ADDRESS; 4184 sm_run(); 4185 } 4186 4187 #ifdef ENABLE_LE_PERIPHERAL 4188 /* 4189 * @brief Set Advertisement Paramters 4190 * @param adv_int_min 4191 * @param adv_int_max 4192 * @param adv_type 4193 * @param direct_address_type 4194 * @param direct_address 4195 * @param channel_map 4196 * @param filter_policy 4197 * 4198 * @note own_address_type is used from gap_random_address_set_mode 4199 */ 4200 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4201 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4202 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4203 direct_address_typ, direct_address, channel_map, filter_policy); 4204 } 4205 #endif 4206