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 #ifdef ENABLE_TESTING_SUPPORT 201 static uint8_t test_pairing_failure; 202 #endif 203 204 // configuration 205 static uint8_t sm_accepted_stk_generation_methods; 206 static uint8_t sm_max_encryption_key_size; 207 static uint8_t sm_min_encryption_key_size; 208 static uint8_t sm_auth_req = 0; 209 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 210 static uint8_t sm_slave_request_security; 211 static uint32_t sm_fixed_passkey_in_display_role; 212 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 213 #ifdef ENABLE_LE_SECURE_CONNECTIONS 214 static uint8_t sm_have_ec_keypair; 215 #endif 216 217 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 218 static sm_key_t sm_persistent_er; 219 static sm_key_t sm_persistent_ir; 220 221 // derived from sm_persistent_ir 222 static sm_key_t sm_persistent_dhk; 223 static sm_key_t sm_persistent_irk; 224 static uint8_t sm_persistent_irk_ready = 0; // used for testing 225 static derived_key_generation_t dkg_state; 226 227 // derived from sm_persistent_er 228 // .. 229 230 // random address update 231 static random_address_update_t rau_state; 232 static bd_addr_t sm_random_address; 233 234 // CMAC Calculation: General 235 #ifdef ENABLE_CMAC_ENGINE 236 static cmac_state_t sm_cmac_state; 237 static uint16_t sm_cmac_message_len; 238 static sm_key_t sm_cmac_k; 239 static sm_key_t sm_cmac_x; 240 static sm_key_t sm_cmac_m_last; 241 static uint8_t sm_cmac_block_current; 242 static uint8_t sm_cmac_block_count; 243 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 244 static void (*sm_cmac_done_handler)(uint8_t * hash); 245 #endif 246 247 // CMAC for ATT Signed Writes 248 #ifdef ENABLE_LE_SIGNED_WRITE 249 static uint8_t sm_cmac_header[3]; 250 static const uint8_t * sm_cmac_message; 251 static uint8_t sm_cmac_sign_counter[4]; 252 #endif 253 254 // CMAC for Secure Connection functions 255 #ifdef ENABLE_LE_SECURE_CONNECTIONS 256 static sm_connection_t * sm_cmac_connection; 257 static uint8_t sm_cmac_sc_buffer[80]; 258 #endif 259 260 // resolvable private address lookup / CSRK calculation 261 static int sm_address_resolution_test; 262 static int sm_address_resolution_ah_calculation_active; 263 static uint8_t sm_address_resolution_addr_type; 264 static bd_addr_t sm_address_resolution_address; 265 static void * sm_address_resolution_context; 266 static address_resolution_mode_t sm_address_resolution_mode; 267 static btstack_linked_list_t sm_address_resolution_general_queue; 268 269 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 270 static sm_aes128_state_t sm_aes128_state; 271 static void * sm_aes128_context; 272 273 // use aes128 provided by MCU - not needed usually 274 #ifdef HAVE_AES128 275 static uint8_t aes128_result_flipped[16]; 276 static btstack_timer_source_t aes128_timer; 277 void btstack_aes128_calc(uint8_t * key, uint8_t * plaintext, uint8_t * result); 278 #endif 279 280 // random engine. store context (ususally sm_connection_t) 281 static void * sm_random_context; 282 283 // to receive hci events 284 static btstack_packet_callback_registration_t hci_event_callback_registration; 285 286 /* to dispatch sm event */ 287 static btstack_linked_list_t sm_event_handlers; 288 289 // LE Secure Connections 290 #ifdef ENABLE_LE_SECURE_CONNECTIONS 291 static ec_key_generation_state_t ec_key_generation_state; 292 static uint8_t ec_d[32]; 293 static uint8_t ec_q[64]; 294 #endif 295 296 // Software ECDH implementation provided by mbedtls 297 #ifdef USE_MBEDTLS_FOR_ECDH 298 static mbedtls_ecp_group mbedtls_ec_group; 299 #endif 300 301 // 302 // Volume 3, Part H, Chapter 24 303 // "Security shall be initiated by the Security Manager in the device in the master role. 304 // The device in the slave role shall be the responding device." 305 // -> master := initiator, slave := responder 306 // 307 308 // data needed for security setup 309 typedef struct sm_setup_context { 310 311 btstack_timer_source_t sm_timeout; 312 313 // used in all phases 314 uint8_t sm_pairing_failed_reason; 315 316 // user response, (Phase 1 and/or 2) 317 uint8_t sm_user_response; 318 uint8_t sm_keypress_notification; 319 320 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 321 int sm_key_distribution_send_set; 322 int sm_key_distribution_received_set; 323 324 // Phase 2 (Pairing over SMP) 325 stk_generation_method_t sm_stk_generation_method; 326 sm_key_t sm_tk; 327 uint8_t sm_use_secure_connections; 328 329 sm_key_t sm_c1_t3_value; // c1 calculation 330 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 331 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 332 sm_key_t sm_local_random; 333 sm_key_t sm_local_confirm; 334 sm_key_t sm_peer_random; 335 sm_key_t sm_peer_confirm; 336 uint8_t sm_m_addr_type; // address and type can be removed 337 uint8_t sm_s_addr_type; // '' 338 bd_addr_t sm_m_address; // '' 339 bd_addr_t sm_s_address; // '' 340 sm_key_t sm_ltk; 341 342 uint8_t sm_state_vars; 343 #ifdef ENABLE_LE_SECURE_CONNECTIONS 344 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 345 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 346 sm_key_t sm_local_nonce; // might be combined with sm_local_random 347 sm_key_t sm_dhkey; 348 sm_key_t sm_peer_dhkey_check; 349 sm_key_t sm_local_dhkey_check; 350 sm_key_t sm_ra; 351 sm_key_t sm_rb; 352 sm_key_t sm_t; // used for f5 and h6 353 sm_key_t sm_mackey; 354 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 355 #endif 356 357 // Phase 3 358 359 // key distribution, we generate 360 uint16_t sm_local_y; 361 uint16_t sm_local_div; 362 uint16_t sm_local_ediv; 363 uint8_t sm_local_rand[8]; 364 sm_key_t sm_local_ltk; 365 sm_key_t sm_local_csrk; 366 sm_key_t sm_local_irk; 367 // sm_local_address/addr_type not needed 368 369 // key distribution, received from peer 370 uint16_t sm_peer_y; 371 uint16_t sm_peer_div; 372 uint16_t sm_peer_ediv; 373 uint8_t sm_peer_rand[8]; 374 sm_key_t sm_peer_ltk; 375 sm_key_t sm_peer_irk; 376 sm_key_t sm_peer_csrk; 377 uint8_t sm_peer_addr_type; 378 bd_addr_t sm_peer_address; 379 380 } sm_setup_context_t; 381 382 // 383 static sm_setup_context_t the_setup; 384 static sm_setup_context_t * setup = &the_setup; 385 386 // active connection - the one for which the_setup is used for 387 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 388 389 // @returns 1 if oob data is available 390 // stores oob data in provided 16 byte buffer if not null 391 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 392 393 // horizontal: initiator capabilities 394 // vertial: responder capabilities 395 static const stk_generation_method_t stk_generation_method [5] [5] = { 396 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 397 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 398 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 399 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 400 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 401 }; 402 403 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 404 #ifdef ENABLE_LE_SECURE_CONNECTIONS 405 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 406 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 407 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 408 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 409 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 410 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 411 }; 412 #endif 413 414 static void sm_run(void); 415 static void sm_done_for_handle(hci_con_handle_t con_handle); 416 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 417 static inline int sm_calc_actual_encryption_key_size(int other); 418 static int sm_validate_stk_generation_method(void); 419 static void sm_handle_encryption_result(uint8_t * data); 420 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 421 422 static void log_info_hex16(const char * name, uint16_t value){ 423 log_info("%-6s 0x%04x", name, value); 424 } 425 426 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 427 // return packet[0]; 428 // } 429 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 430 return packet[1]; 431 } 432 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 433 return packet[2]; 434 } 435 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 436 return packet[3]; 437 } 438 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 439 return packet[4]; 440 } 441 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 442 return packet[5]; 443 } 444 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 445 return packet[6]; 446 } 447 448 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 449 packet[0] = code; 450 } 451 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 452 packet[1] = io_capability; 453 } 454 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 455 packet[2] = oob_data_flag; 456 } 457 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 458 packet[3] = auth_req; 459 } 460 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 461 packet[4] = max_encryption_key_size; 462 } 463 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 464 packet[5] = initiator_key_distribution; 465 } 466 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 467 packet[6] = responder_key_distribution; 468 } 469 470 // @returns 1 if all bytes are 0 471 static int sm_is_null(uint8_t * data, int size){ 472 int i; 473 for (i=0; i < size ; i++){ 474 if (data[i]) return 0; 475 } 476 return 1; 477 } 478 479 static int sm_is_null_random(uint8_t random[8]){ 480 return sm_is_null(random, 8); 481 } 482 483 static int sm_is_null_key(uint8_t * key){ 484 return sm_is_null(key, 16); 485 } 486 487 // Key utils 488 static void sm_reset_tk(void){ 489 int i; 490 for (i=0;i<16;i++){ 491 setup->sm_tk[i] = 0; 492 } 493 } 494 495 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 496 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 497 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 498 int i; 499 for (i = max_encryption_size ; i < 16 ; i++){ 500 key[15-i] = 0; 501 } 502 } 503 504 // SMP Timeout implementation 505 506 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 507 // the Security Manager Timer shall be reset and started. 508 // 509 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 510 // 511 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 512 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 513 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 514 // established. 515 516 static void sm_timeout_handler(btstack_timer_source_t * timer){ 517 log_info("SM timeout"); 518 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 519 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 520 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 521 sm_done_for_handle(sm_conn->sm_handle); 522 523 // trigger handling of next ready connection 524 sm_run(); 525 } 526 static void sm_timeout_start(sm_connection_t * sm_conn){ 527 btstack_run_loop_remove_timer(&setup->sm_timeout); 528 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 529 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 530 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 531 btstack_run_loop_add_timer(&setup->sm_timeout); 532 } 533 static void sm_timeout_stop(void){ 534 btstack_run_loop_remove_timer(&setup->sm_timeout); 535 } 536 static void sm_timeout_reset(sm_connection_t * sm_conn){ 537 sm_timeout_stop(); 538 sm_timeout_start(sm_conn); 539 } 540 541 // end of sm timeout 542 543 // GAP Random Address updates 544 static gap_random_address_type_t gap_random_adress_type; 545 static btstack_timer_source_t gap_random_address_update_timer; 546 static uint32_t gap_random_adress_update_period; 547 548 static void gap_random_address_trigger(void){ 549 if (rau_state != RAU_IDLE) return; 550 log_info("gap_random_address_trigger"); 551 rau_state = RAU_GET_RANDOM; 552 sm_run(); 553 } 554 555 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 556 UNUSED(timer); 557 558 log_info("GAP Random Address Update due"); 559 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 560 btstack_run_loop_add_timer(&gap_random_address_update_timer); 561 gap_random_address_trigger(); 562 } 563 564 static void gap_random_address_update_start(void){ 565 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 566 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 567 btstack_run_loop_add_timer(&gap_random_address_update_timer); 568 } 569 570 static void gap_random_address_update_stop(void){ 571 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 572 } 573 574 575 static void sm_random_start(void * context){ 576 sm_random_context = context; 577 hci_send_cmd(&hci_le_rand); 578 } 579 580 #ifdef HAVE_AES128 581 static void aes128_completed(btstack_timer_source_t * ts){ 582 UNUSED(ts); 583 sm_handle_encryption_result(&aes128_result_flipped[0]); 584 sm_run(); 585 } 586 #endif 587 588 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 589 // context is made availabe to aes128 result handler by this 590 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 591 sm_aes128_state = SM_AES128_ACTIVE; 592 sm_aes128_context = context; 593 594 #ifdef HAVE_AES128 595 // calc result directly 596 sm_key_t result; 597 btstack_aes128_calc(key, plaintext, result); 598 599 // log 600 log_info_key("key", key); 601 log_info_key("txt", plaintext); 602 log_info_key("res", result); 603 604 // flip 605 reverse_128(&result[0], &aes128_result_flipped[0]); 606 607 // deliver via timer 608 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 609 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 610 btstack_run_loop_add_timer(&aes128_timer); 611 #else 612 sm_key_t key_flipped, plaintext_flipped; 613 reverse_128(key, key_flipped); 614 reverse_128(plaintext, plaintext_flipped); 615 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 616 #endif 617 } 618 619 // ah(k,r) helper 620 // r = padding || r 621 // r - 24 bit value 622 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 623 // r'= padding || r 624 memset(r_prime, 0, 16); 625 memcpy(&r_prime[13], r, 3); 626 } 627 628 // d1 helper 629 // d' = padding || r || d 630 // d,r - 16 bit values 631 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 632 // d'= padding || r || d 633 memset(d1_prime, 0, 16); 634 big_endian_store_16(d1_prime, 12, r); 635 big_endian_store_16(d1_prime, 14, d); 636 } 637 638 // dm helper 639 // r’ = padding || r 640 // r - 64 bit value 641 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 642 memset(r_prime, 0, 16); 643 memcpy(&r_prime[8], r, 8); 644 } 645 646 // calculate arguments for first AES128 operation in C1 function 647 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){ 648 649 // p1 = pres || preq || rat’ || iat’ 650 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 651 // cant octet of pres becomes the most significant octet of p1. 652 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 653 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 654 // p1 is 0x05000800000302070710000001010001." 655 656 sm_key_t p1; 657 reverse_56(pres, &p1[0]); 658 reverse_56(preq, &p1[7]); 659 p1[14] = rat; 660 p1[15] = iat; 661 log_info_key("p1", p1); 662 log_info_key("r", r); 663 664 // t1 = r xor p1 665 int i; 666 for (i=0;i<16;i++){ 667 t1[i] = r[i] ^ p1[i]; 668 } 669 log_info_key("t1", t1); 670 } 671 672 // calculate arguments for second AES128 operation in C1 function 673 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 674 // p2 = padding || ia || ra 675 // "The least significant octet of ra becomes the least significant octet of p2 and 676 // the most significant octet of padding becomes the most significant octet of p2. 677 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 678 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 679 680 sm_key_t p2; 681 memset(p2, 0, 16); 682 memcpy(&p2[4], ia, 6); 683 memcpy(&p2[10], ra, 6); 684 log_info_key("p2", p2); 685 686 // c1 = e(k, t2_xor_p2) 687 int i; 688 for (i=0;i<16;i++){ 689 t3[i] = t2[i] ^ p2[i]; 690 } 691 log_info_key("t3", t3); 692 } 693 694 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 695 log_info_key("r1", r1); 696 log_info_key("r2", r2); 697 memcpy(&r_prime[8], &r2[8], 8); 698 memcpy(&r_prime[0], &r1[8], 8); 699 } 700 701 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 702 UNUSED(channel); 703 704 // log event 705 hci_dump_packet(packet_type, 1, packet, size); 706 // dispatch to all event handlers 707 btstack_linked_list_iterator_t it; 708 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 709 while (btstack_linked_list_iterator_has_next(&it)){ 710 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 711 entry->callback(packet_type, 0, packet, size); 712 } 713 } 714 715 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){ 716 event[0] = type; 717 event[1] = event_size - 2; 718 little_endian_store_16(event, 2, con_handle); 719 event[4] = addr_type; 720 reverse_bd_addr(address, &event[5]); 721 } 722 723 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 724 uint8_t event[11]; 725 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 726 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 727 } 728 729 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){ 730 uint8_t event[15]; 731 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 732 little_endian_store_32(event, 11, passkey); 733 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 734 } 735 736 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){ 737 // fetch addr and addr type from db 738 bd_addr_t identity_address; 739 int identity_address_type; 740 le_device_db_info(index, &identity_address_type, identity_address, NULL); 741 742 uint8_t event[19]; 743 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 744 event[11] = identity_address_type; 745 reverse_bd_addr(identity_address, &event[12]); 746 event[18] = index; 747 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 748 } 749 750 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 751 uint8_t event[12]; 752 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 753 event[11] = status; 754 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 755 } 756 757 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 758 uint8_t event[13]; 759 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 760 event[11] = status; 761 event[12] = reason; 762 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 763 } 764 765 // decide on stk generation based on 766 // - pairing request 767 // - io capabilities 768 // - OOB data availability 769 static void sm_setup_tk(void){ 770 771 // default: just works 772 setup->sm_stk_generation_method = JUST_WORKS; 773 774 #ifdef ENABLE_LE_SECURE_CONNECTIONS 775 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 776 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 777 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 778 memset(setup->sm_ra, 0, 16); 779 memset(setup->sm_rb, 0, 16); 780 #else 781 setup->sm_use_secure_connections = 0; 782 #endif 783 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 784 785 // If both devices have not set the MITM option in the Authentication Requirements 786 // Flags, then the IO capabilities shall be ignored and the Just Works association 787 // model shall be used. 788 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 789 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 790 log_info("SM: MITM not required by both -> JUST WORKS"); 791 return; 792 } 793 794 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 795 796 // If both devices have out of band authentication data, then the Authentication 797 // Requirements Flags shall be ignored when selecting the pairing method and the 798 // Out of Band pairing method shall be used. 799 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 800 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 801 log_info("SM: have OOB data"); 802 log_info_key("OOB", setup->sm_tk); 803 setup->sm_stk_generation_method = OOB; 804 return; 805 } 806 807 // Reset TK as it has been setup in sm_init_setup 808 sm_reset_tk(); 809 810 // Also use just works if unknown io capabilites 811 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)){ 812 return; 813 } 814 815 // Otherwise the IO capabilities of the devices shall be used to determine the 816 // pairing method as defined in Table 2.4. 817 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 818 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 819 820 #ifdef ENABLE_LE_SECURE_CONNECTIONS 821 // table not define by default 822 if (setup->sm_use_secure_connections){ 823 generation_method = stk_generation_method_with_secure_connection; 824 } 825 #endif 826 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)]; 827 828 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 829 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); 830 } 831 832 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 833 int flags = 0; 834 if (key_set & SM_KEYDIST_ENC_KEY){ 835 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 836 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 837 } 838 if (key_set & SM_KEYDIST_ID_KEY){ 839 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 840 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 841 } 842 if (key_set & SM_KEYDIST_SIGN){ 843 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 844 } 845 return flags; 846 } 847 848 static void sm_setup_key_distribution(uint8_t key_set){ 849 setup->sm_key_distribution_received_set = 0; 850 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 851 } 852 853 // CSRK Key Lookup 854 855 856 static int sm_address_resolution_idle(void){ 857 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 858 } 859 860 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){ 861 memcpy(sm_address_resolution_address, addr, 6); 862 sm_address_resolution_addr_type = addr_type; 863 sm_address_resolution_test = 0; 864 sm_address_resolution_mode = mode; 865 sm_address_resolution_context = context; 866 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 867 } 868 869 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 870 // check if already in list 871 btstack_linked_list_iterator_t it; 872 sm_lookup_entry_t * entry; 873 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 874 while(btstack_linked_list_iterator_has_next(&it)){ 875 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 876 if (entry->address_type != address_type) continue; 877 if (memcmp(entry->address, address, 6)) continue; 878 // already in list 879 return BTSTACK_BUSY; 880 } 881 entry = btstack_memory_sm_lookup_entry_get(); 882 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 883 entry->address_type = (bd_addr_type_t) address_type; 884 memcpy(entry->address, address, 6); 885 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 886 sm_run(); 887 return 0; 888 } 889 890 // 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 891 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 892 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 893 } 894 static inline void dkg_next_state(void){ 895 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 896 } 897 static inline void rau_next_state(void){ 898 rau_state = (random_address_update_t) (((int)rau_state) + 1); 899 } 900 901 // CMAC calculation using AES Engine 902 #ifdef ENABLE_CMAC_ENGINE 903 904 static inline void sm_cmac_next_state(void){ 905 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 906 } 907 908 static int sm_cmac_last_block_complete(void){ 909 if (sm_cmac_message_len == 0) return 0; 910 return (sm_cmac_message_len & 0x0f) == 0; 911 } 912 913 int sm_cmac_ready(void){ 914 return sm_cmac_state == CMAC_IDLE; 915 } 916 917 // generic cmac calculation 918 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])){ 919 // Generalized CMAC 920 memcpy(sm_cmac_k, key, 16); 921 memset(sm_cmac_x, 0, 16); 922 sm_cmac_block_current = 0; 923 sm_cmac_message_len = message_len; 924 sm_cmac_done_handler = done_callback; 925 sm_cmac_get_byte = get_byte_callback; 926 927 // step 2: n := ceil(len/const_Bsize); 928 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 929 930 // step 3: .. 931 if (sm_cmac_block_count==0){ 932 sm_cmac_block_count = 1; 933 } 934 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 935 936 // first, we need to compute l for k1, k2, and m_last 937 sm_cmac_state = CMAC_CALC_SUBKEYS; 938 939 // let's go 940 sm_run(); 941 } 942 #endif 943 944 // cmac for ATT Message signing 945 #ifdef ENABLE_LE_SIGNED_WRITE 946 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 947 if (offset >= sm_cmac_message_len) { 948 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 949 return 0; 950 } 951 952 offset = sm_cmac_message_len - 1 - offset; 953 954 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 955 if (offset < 3){ 956 return sm_cmac_header[offset]; 957 } 958 int actual_message_len_incl_header = sm_cmac_message_len - 4; 959 if (offset < actual_message_len_incl_header){ 960 return sm_cmac_message[offset - 3]; 961 } 962 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 963 } 964 965 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)){ 966 // ATT Message Signing 967 sm_cmac_header[0] = opcode; 968 little_endian_store_16(sm_cmac_header, 1, con_handle); 969 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 970 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 971 sm_cmac_message = message; 972 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 973 } 974 #endif 975 976 #ifdef ENABLE_CMAC_ENGINE 977 static void sm_cmac_handle_aes_engine_ready(void){ 978 switch (sm_cmac_state){ 979 case CMAC_CALC_SUBKEYS: { 980 sm_key_t const_zero; 981 memset(const_zero, 0, 16); 982 sm_cmac_next_state(); 983 sm_aes128_start(sm_cmac_k, const_zero, NULL); 984 break; 985 } 986 case CMAC_CALC_MI: { 987 int j; 988 sm_key_t y; 989 for (j=0;j<16;j++){ 990 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 991 } 992 sm_cmac_block_current++; 993 sm_cmac_next_state(); 994 sm_aes128_start(sm_cmac_k, y, NULL); 995 break; 996 } 997 case CMAC_CALC_MLAST: { 998 int i; 999 sm_key_t y; 1000 for (i=0;i<16;i++){ 1001 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 1002 } 1003 log_info_key("Y", y); 1004 sm_cmac_block_current++; 1005 sm_cmac_next_state(); 1006 sm_aes128_start(sm_cmac_k, y, NULL); 1007 break; 1008 } 1009 default: 1010 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1011 break; 1012 } 1013 } 1014 1015 // CMAC Implementation using AES128 engine 1016 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1017 int i; 1018 int carry = 0; 1019 for (i=len-1; i >= 0 ; i--){ 1020 int new_carry = data[i] >> 7; 1021 data[i] = data[i] << 1 | carry; 1022 carry = new_carry; 1023 } 1024 } 1025 1026 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1027 switch (sm_cmac_state){ 1028 case CMAC_W4_SUBKEYS: { 1029 sm_key_t k1; 1030 memcpy(k1, data, 16); 1031 sm_shift_left_by_one_bit_inplace(16, k1); 1032 if (data[0] & 0x80){ 1033 k1[15] ^= 0x87; 1034 } 1035 sm_key_t k2; 1036 memcpy(k2, k1, 16); 1037 sm_shift_left_by_one_bit_inplace(16, k2); 1038 if (k1[0] & 0x80){ 1039 k2[15] ^= 0x87; 1040 } 1041 1042 log_info_key("k", sm_cmac_k); 1043 log_info_key("k1", k1); 1044 log_info_key("k2", k2); 1045 1046 // step 4: set m_last 1047 int i; 1048 if (sm_cmac_last_block_complete()){ 1049 for (i=0;i<16;i++){ 1050 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1051 } 1052 } else { 1053 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1054 for (i=0;i<16;i++){ 1055 if (i < valid_octets_in_last_block){ 1056 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1057 continue; 1058 } 1059 if (i == valid_octets_in_last_block){ 1060 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1061 continue; 1062 } 1063 sm_cmac_m_last[i] = k2[i]; 1064 } 1065 } 1066 1067 // next 1068 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1069 break; 1070 } 1071 case CMAC_W4_MI: 1072 memcpy(sm_cmac_x, data, 16); 1073 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1074 break; 1075 case CMAC_W4_MLAST: 1076 // done 1077 log_info("Setting CMAC Engine to IDLE"); 1078 sm_cmac_state = CMAC_IDLE; 1079 log_info_key("CMAC", data); 1080 sm_cmac_done_handler(data); 1081 break; 1082 default: 1083 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1084 break; 1085 } 1086 } 1087 #endif 1088 1089 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1090 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1091 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1092 switch (setup->sm_stk_generation_method){ 1093 case PK_RESP_INPUT: 1094 if (IS_RESPONDER(sm_conn->sm_role)){ 1095 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1096 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1097 } else { 1098 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)); 1099 } 1100 break; 1101 case PK_INIT_INPUT: 1102 if (IS_RESPONDER(sm_conn->sm_role)){ 1103 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)); 1104 } else { 1105 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1106 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1107 } 1108 break; 1109 case OK_BOTH_INPUT: 1110 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1111 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1112 break; 1113 case NK_BOTH_INPUT: 1114 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1115 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)); 1116 break; 1117 case JUST_WORKS: 1118 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1119 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1120 break; 1121 case OOB: 1122 // client already provided OOB data, let's skip notification. 1123 break; 1124 } 1125 } 1126 1127 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1128 int recv_flags; 1129 if (IS_RESPONDER(sm_conn->sm_role)){ 1130 // slave / responder 1131 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1132 } else { 1133 // master / initiator 1134 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1135 } 1136 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1137 return recv_flags == setup->sm_key_distribution_received_set; 1138 } 1139 1140 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1141 if (sm_active_connection_handle == con_handle){ 1142 sm_timeout_stop(); 1143 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1144 log_info("sm: connection 0x%x released setup context", con_handle); 1145 } 1146 } 1147 1148 static int sm_key_distribution_flags_for_auth_req(void){ 1149 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1150 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1151 // encryption information only if bonding requested 1152 flags |= SM_KEYDIST_ENC_KEY; 1153 } 1154 return flags; 1155 } 1156 1157 static void sm_reset_setup(void){ 1158 // fill in sm setup 1159 setup->sm_state_vars = 0; 1160 setup->sm_keypress_notification = 0xff; 1161 sm_reset_tk(); 1162 } 1163 1164 static void sm_init_setup(sm_connection_t * sm_conn){ 1165 1166 // fill in sm setup 1167 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1168 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1169 1170 // query client for OOB data 1171 int have_oob_data = 0; 1172 if (sm_get_oob_data) { 1173 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1174 } 1175 1176 sm_pairing_packet_t * local_packet; 1177 if (IS_RESPONDER(sm_conn->sm_role)){ 1178 // slave 1179 local_packet = &setup->sm_s_pres; 1180 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1181 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1182 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1183 } else { 1184 // master 1185 local_packet = &setup->sm_m_preq; 1186 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1187 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1188 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1189 1190 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1191 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1192 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1193 } 1194 1195 uint8_t auth_req = sm_auth_req; 1196 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1197 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1198 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1199 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1200 } 1201 1202 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1203 1204 sm_pairing_packet_t * remote_packet; 1205 int remote_key_request; 1206 if (IS_RESPONDER(sm_conn->sm_role)){ 1207 // slave / responder 1208 remote_packet = &setup->sm_m_preq; 1209 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1210 } else { 1211 // master / initiator 1212 remote_packet = &setup->sm_s_pres; 1213 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1214 } 1215 1216 // check key size 1217 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1218 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1219 1220 // decide on STK generation method 1221 sm_setup_tk(); 1222 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1223 1224 // check if STK generation method is acceptable by client 1225 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1226 1227 // identical to responder 1228 sm_setup_key_distribution(remote_key_request); 1229 1230 // JUST WORKS doens't provide authentication 1231 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1232 1233 return 0; 1234 } 1235 1236 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1237 1238 // cache and reset context 1239 int matched_device_id = sm_address_resolution_test; 1240 address_resolution_mode_t mode = sm_address_resolution_mode; 1241 void * context = sm_address_resolution_context; 1242 1243 // reset context 1244 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1245 sm_address_resolution_context = NULL; 1246 sm_address_resolution_test = -1; 1247 hci_con_handle_t con_handle = 0; 1248 1249 sm_connection_t * sm_connection; 1250 #ifdef ENABLE_LE_CENTRAL 1251 sm_key_t ltk; 1252 #endif 1253 switch (mode){ 1254 case ADDRESS_RESOLUTION_GENERAL: 1255 break; 1256 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1257 sm_connection = (sm_connection_t *) context; 1258 con_handle = sm_connection->sm_handle; 1259 switch (event){ 1260 case ADDRESS_RESOLUTION_SUCEEDED: 1261 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1262 sm_connection->sm_le_db_index = matched_device_id; 1263 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1264 if (sm_connection->sm_role) { 1265 // LTK request received before, IRK required -> start LTK calculation 1266 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1267 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1268 } 1269 break; 1270 } 1271 #ifdef ENABLE_LE_CENTRAL 1272 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1273 sm_connection->sm_security_request_received = 0; 1274 sm_connection->sm_bonding_requested = 0; 1275 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1276 if (!sm_is_null_key(ltk)){ 1277 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1278 } else { 1279 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1280 } 1281 #endif 1282 break; 1283 case ADDRESS_RESOLUTION_FAILED: 1284 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1285 if (sm_connection->sm_role) { 1286 // LTK request received before, IRK required -> negative LTK reply 1287 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1288 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1289 } 1290 break; 1291 } 1292 #ifdef ENABLE_LE_CENTRAL 1293 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1294 sm_connection->sm_security_request_received = 0; 1295 sm_connection->sm_bonding_requested = 0; 1296 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1297 #endif 1298 break; 1299 } 1300 break; 1301 default: 1302 break; 1303 } 1304 1305 switch (event){ 1306 case ADDRESS_RESOLUTION_SUCEEDED: 1307 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1308 break; 1309 case ADDRESS_RESOLUTION_FAILED: 1310 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1311 break; 1312 } 1313 } 1314 1315 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1316 1317 int le_db_index = -1; 1318 1319 // lookup device based on IRK 1320 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1321 int i; 1322 for (i=0; i < le_device_db_max_count(); i++){ 1323 sm_key_t irk; 1324 bd_addr_t address; 1325 int address_type; 1326 le_device_db_info(i, &address_type, address, irk); 1327 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1328 log_info("sm: device found for IRK, updating"); 1329 le_db_index = i; 1330 break; 1331 } 1332 } 1333 } 1334 1335 // if not found, lookup via public address if possible 1336 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1337 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1338 int i; 1339 for (i=0; i < le_device_db_max_count(); i++){ 1340 bd_addr_t address; 1341 int address_type; 1342 le_device_db_info(i, &address_type, address, NULL); 1343 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1344 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1345 log_info("sm: device found for public address, updating"); 1346 le_db_index = i; 1347 break; 1348 } 1349 } 1350 } 1351 1352 // if not found, add to db 1353 if (le_db_index < 0) { 1354 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1355 } 1356 1357 if (le_db_index >= 0){ 1358 1359 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1360 1361 #ifdef ENABLE_LE_SIGNED_WRITE 1362 // store local CSRK 1363 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1364 log_info("sm: store local CSRK"); 1365 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1366 le_device_db_local_counter_set(le_db_index, 0); 1367 } 1368 1369 // store remote CSRK 1370 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1371 log_info("sm: store remote CSRK"); 1372 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1373 le_device_db_remote_counter_set(le_db_index, 0); 1374 } 1375 #endif 1376 // store encryption information for secure connections: LTK generated by ECDH 1377 if (setup->sm_use_secure_connections){ 1378 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1379 uint8_t zero_rand[8]; 1380 memset(zero_rand, 0, 8); 1381 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1382 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1383 } 1384 1385 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1386 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1387 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1388 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1389 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1390 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1391 1392 } 1393 } 1394 1395 // keep le_db_index 1396 sm_conn->sm_le_db_index = le_db_index; 1397 } 1398 1399 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1400 setup->sm_pairing_failed_reason = reason; 1401 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1402 } 1403 1404 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1405 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1406 } 1407 1408 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1409 1410 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1411 static int sm_passkey_used(stk_generation_method_t method); 1412 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1413 1414 static void sm_log_ec_keypair(void){ 1415 log_info("Elliptic curve: X"); 1416 log_info_hexdump(&ec_q[0],32); 1417 log_info("Elliptic curve: Y"); 1418 log_info_hexdump(&ec_q[32],32); 1419 } 1420 1421 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1422 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1423 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1424 } else { 1425 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1426 } 1427 } 1428 1429 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1430 if (IS_RESPONDER(sm_conn->sm_role)){ 1431 // Responder 1432 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1433 } else { 1434 // Initiator role 1435 switch (setup->sm_stk_generation_method){ 1436 case JUST_WORKS: 1437 sm_sc_prepare_dhkey_check(sm_conn); 1438 break; 1439 1440 case NK_BOTH_INPUT: 1441 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1442 break; 1443 case PK_INIT_INPUT: 1444 case PK_RESP_INPUT: 1445 case OK_BOTH_INPUT: 1446 if (setup->sm_passkey_bit < 20) { 1447 sm_sc_start_calculating_local_confirm(sm_conn); 1448 } else { 1449 sm_sc_prepare_dhkey_check(sm_conn); 1450 } 1451 break; 1452 case OOB: 1453 // TODO: implement SC OOB 1454 break; 1455 } 1456 } 1457 } 1458 1459 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1460 return sm_cmac_sc_buffer[offset]; 1461 } 1462 1463 static void sm_sc_cmac_done(uint8_t * hash){ 1464 log_info("sm_sc_cmac_done: "); 1465 log_info_hexdump(hash, 16); 1466 1467 sm_connection_t * sm_conn = sm_cmac_connection; 1468 sm_cmac_connection = NULL; 1469 #ifdef ENABLE_CLASSIC 1470 link_key_type_t link_key_type; 1471 #endif 1472 1473 switch (sm_conn->sm_engine_state){ 1474 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1475 memcpy(setup->sm_local_confirm, hash, 16); 1476 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1477 break; 1478 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1479 // check 1480 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1481 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1482 break; 1483 } 1484 sm_sc_state_after_receiving_random(sm_conn); 1485 break; 1486 case SM_SC_W4_CALCULATE_G2: { 1487 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1488 big_endian_store_32(setup->sm_tk, 12, vab); 1489 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1490 sm_trigger_user_response(sm_conn); 1491 break; 1492 } 1493 case SM_SC_W4_CALCULATE_F5_SALT: 1494 memcpy(setup->sm_t, hash, 16); 1495 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1496 break; 1497 case SM_SC_W4_CALCULATE_F5_MACKEY: 1498 memcpy(setup->sm_mackey, hash, 16); 1499 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1500 break; 1501 case SM_SC_W4_CALCULATE_F5_LTK: 1502 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1503 // Errata Service Release to the Bluetooth Specification: ESR09 1504 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1505 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1506 memcpy(setup->sm_ltk, hash, 16); 1507 memcpy(setup->sm_local_ltk, hash, 16); 1508 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1509 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1510 break; 1511 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1512 memcpy(setup->sm_local_dhkey_check, hash, 16); 1513 if (IS_RESPONDER(sm_conn->sm_role)){ 1514 // responder 1515 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1516 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1517 } else { 1518 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1519 } 1520 } else { 1521 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1522 } 1523 break; 1524 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1525 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1526 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1527 break; 1528 } 1529 if (IS_RESPONDER(sm_conn->sm_role)){ 1530 // responder 1531 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1532 } else { 1533 // initiator 1534 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1535 } 1536 break; 1537 case SM_SC_W4_CALCULATE_H6_ILK: 1538 memcpy(setup->sm_t, hash, 16); 1539 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1540 break; 1541 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1542 #ifdef ENABLE_CLASSIC 1543 reverse_128(hash, setup->sm_t); 1544 link_key_type = sm_conn->sm_connection_authenticated ? 1545 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1546 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1547 if (IS_RESPONDER(sm_conn->sm_role)){ 1548 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1549 } else { 1550 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1551 } 1552 #endif 1553 if (IS_RESPONDER(sm_conn->sm_role)){ 1554 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1555 } else { 1556 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1557 } 1558 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1559 sm_done_for_handle(sm_conn->sm_handle); 1560 break; 1561 default: 1562 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1563 break; 1564 } 1565 sm_run(); 1566 } 1567 1568 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){ 1569 const uint16_t message_len = 65; 1570 sm_cmac_connection = sm_conn; 1571 memcpy(sm_cmac_sc_buffer, u, 32); 1572 memcpy(sm_cmac_sc_buffer+32, v, 32); 1573 sm_cmac_sc_buffer[64] = z; 1574 log_info("f4 key"); 1575 log_info_hexdump(x, 16); 1576 log_info("f4 message"); 1577 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1578 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1579 } 1580 1581 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1582 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1583 static const uint8_t f5_length[] = { 0x01, 0x00}; 1584 1585 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1586 1587 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1588 memset(dhkey, 0, 32); 1589 1590 #ifdef USE_MICRO_ECC_FOR_ECDH 1591 #if uECC_SUPPORTS_secp256r1 1592 // standard version 1593 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1594 #else 1595 // static version 1596 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1597 #endif 1598 #endif 1599 1600 #ifdef USE_MBEDTLS_FOR_ECDH 1601 // da * Pb 1602 mbedtls_mpi d; 1603 mbedtls_ecp_point Q; 1604 mbedtls_ecp_point DH; 1605 mbedtls_mpi_init(&d); 1606 mbedtls_ecp_point_init(&Q); 1607 mbedtls_ecp_point_init(&DH); 1608 mbedtls_mpi_read_binary(&d, ec_d, 32); 1609 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1610 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1611 mbedtls_mpi_lset(&Q.Z, 1); 1612 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1613 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1614 mbedtls_ecp_point_free(&DH); 1615 mbedtls_mpi_free(&d); 1616 mbedtls_ecp_point_free(&Q); 1617 #endif 1618 1619 log_info("dhkey"); 1620 log_info_hexdump(dhkey, 32); 1621 } 1622 #endif 1623 1624 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1625 // calculate salt for f5 1626 const uint16_t message_len = 32; 1627 sm_cmac_connection = sm_conn; 1628 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1629 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1630 } 1631 1632 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){ 1633 const uint16_t message_len = 53; 1634 sm_cmac_connection = sm_conn; 1635 1636 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1637 sm_cmac_sc_buffer[0] = 0; 1638 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1639 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1640 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1641 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1642 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1643 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1644 log_info("f5 key"); 1645 log_info_hexdump(t, 16); 1646 log_info("f5 message for MacKey"); 1647 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1648 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1649 } 1650 1651 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1652 sm_key56_t bd_addr_master, bd_addr_slave; 1653 bd_addr_master[0] = setup->sm_m_addr_type; 1654 bd_addr_slave[0] = setup->sm_s_addr_type; 1655 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1656 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1657 if (IS_RESPONDER(sm_conn->sm_role)){ 1658 // responder 1659 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1660 } else { 1661 // initiator 1662 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1663 } 1664 } 1665 1666 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1667 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1668 const uint16_t message_len = 53; 1669 sm_cmac_connection = sm_conn; 1670 sm_cmac_sc_buffer[0] = 1; 1671 // 1..52 setup before 1672 log_info("f5 key"); 1673 log_info_hexdump(t, 16); 1674 log_info("f5 message for LTK"); 1675 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1676 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1677 } 1678 1679 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1680 f5_ltk(sm_conn, setup->sm_t); 1681 } 1682 1683 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){ 1684 const uint16_t message_len = 65; 1685 sm_cmac_connection = sm_conn; 1686 memcpy(sm_cmac_sc_buffer, n1, 16); 1687 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1688 memcpy(sm_cmac_sc_buffer+32, r, 16); 1689 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1690 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1691 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1692 log_info("f6 key"); 1693 log_info_hexdump(w, 16); 1694 log_info("f6 message"); 1695 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1696 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1697 } 1698 1699 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1700 // - U is 256 bits 1701 // - V is 256 bits 1702 // - X is 128 bits 1703 // - Y is 128 bits 1704 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){ 1705 const uint16_t message_len = 80; 1706 sm_cmac_connection = sm_conn; 1707 memcpy(sm_cmac_sc_buffer, u, 32); 1708 memcpy(sm_cmac_sc_buffer+32, v, 32); 1709 memcpy(sm_cmac_sc_buffer+64, y, 16); 1710 log_info("g2 key"); 1711 log_info_hexdump(x, 16); 1712 log_info("g2 message"); 1713 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1714 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1715 } 1716 1717 static void g2_calculate(sm_connection_t * sm_conn) { 1718 // calc Va if numeric comparison 1719 if (IS_RESPONDER(sm_conn->sm_role)){ 1720 // responder 1721 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1722 } else { 1723 // initiator 1724 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1725 } 1726 } 1727 1728 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1729 uint8_t z = 0; 1730 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1731 // some form of passkey 1732 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1733 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1734 setup->sm_passkey_bit++; 1735 } 1736 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1737 } 1738 1739 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1740 uint8_t z = 0; 1741 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1742 // some form of passkey 1743 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1744 // sm_passkey_bit was increased before sending confirm value 1745 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1746 } 1747 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1748 } 1749 1750 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1751 1752 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1753 // calculate DHKEY 1754 sm_sc_calculate_dhkey(setup->sm_dhkey); 1755 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1756 #endif 1757 1758 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1759 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1760 return; 1761 } else { 1762 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1763 } 1764 1765 } 1766 1767 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1768 // calculate DHKCheck 1769 sm_key56_t bd_addr_master, bd_addr_slave; 1770 bd_addr_master[0] = setup->sm_m_addr_type; 1771 bd_addr_slave[0] = setup->sm_s_addr_type; 1772 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1773 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1774 uint8_t iocap_a[3]; 1775 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1776 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1777 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1778 uint8_t iocap_b[3]; 1779 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1780 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1781 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1782 if (IS_RESPONDER(sm_conn->sm_role)){ 1783 // responder 1784 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); 1785 } else { 1786 // initiator 1787 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); 1788 } 1789 } 1790 1791 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1792 // validate E = f6() 1793 sm_key56_t bd_addr_master, bd_addr_slave; 1794 bd_addr_master[0] = setup->sm_m_addr_type; 1795 bd_addr_slave[0] = setup->sm_s_addr_type; 1796 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1797 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1798 1799 uint8_t iocap_a[3]; 1800 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1801 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1802 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1803 uint8_t iocap_b[3]; 1804 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1805 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1806 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1807 if (IS_RESPONDER(sm_conn->sm_role)){ 1808 // responder 1809 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); 1810 } else { 1811 // initiator 1812 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); 1813 } 1814 } 1815 1816 1817 // 1818 // Link Key Conversion Function h6 1819 // 1820 // h6(W, keyID) = AES-CMACW(keyID) 1821 // - W is 128 bits 1822 // - keyID is 32 bits 1823 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1824 const uint16_t message_len = 4; 1825 sm_cmac_connection = sm_conn; 1826 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1827 log_info("h6 key"); 1828 log_info_hexdump(w, 16); 1829 log_info("h6 message"); 1830 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1831 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1832 } 1833 1834 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1835 // Errata Service Release to the Bluetooth Specification: ESR09 1836 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1837 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1838 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1839 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1840 } 1841 1842 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1843 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1844 } 1845 1846 #endif 1847 1848 // key management legacy connections: 1849 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1850 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1851 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1852 // - responder reconnects: responder uses LTK receveived from master 1853 1854 // key management secure connections: 1855 // - both devices store same LTK from ECDH key exchange. 1856 1857 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1858 static void sm_load_security_info(sm_connection_t * sm_connection){ 1859 int encryption_key_size; 1860 int authenticated; 1861 int authorized; 1862 1863 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1864 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1865 &encryption_key_size, &authenticated, &authorized); 1866 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1867 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1868 sm_connection->sm_connection_authenticated = authenticated; 1869 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1870 } 1871 #endif 1872 1873 #ifdef ENABLE_LE_PERIPHERAL 1874 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1875 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1876 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1877 // re-establish used key encryption size 1878 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1879 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1880 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1881 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1882 log_info("sm: received ltk request with key size %u, authenticated %u", 1883 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1884 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1885 } 1886 #endif 1887 1888 static void sm_run(void){ 1889 1890 btstack_linked_list_iterator_t it; 1891 1892 // assert that stack has already bootet 1893 if (hci_get_state() != HCI_STATE_WORKING) return; 1894 1895 // assert that we can send at least commands 1896 if (!hci_can_send_command_packet_now()) return; 1897 1898 // 1899 // non-connection related behaviour 1900 // 1901 1902 // distributed key generation 1903 switch (dkg_state){ 1904 case DKG_CALC_IRK: 1905 // already busy? 1906 if (sm_aes128_state == SM_AES128_IDLE) { 1907 // IRK = d1(IR, 1, 0) 1908 sm_key_t d1_prime; 1909 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1910 dkg_next_state(); 1911 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1912 return; 1913 } 1914 break; 1915 case DKG_CALC_DHK: 1916 // already busy? 1917 if (sm_aes128_state == SM_AES128_IDLE) { 1918 // DHK = d1(IR, 3, 0) 1919 sm_key_t d1_prime; 1920 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1921 dkg_next_state(); 1922 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1923 return; 1924 } 1925 break; 1926 default: 1927 break; 1928 } 1929 1930 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1931 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1932 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1933 sm_random_start(NULL); 1934 #else 1935 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1936 hci_send_cmd(&hci_le_read_local_p256_public_key); 1937 #endif 1938 return; 1939 } 1940 #endif 1941 1942 // random address updates 1943 switch (rau_state){ 1944 case RAU_GET_RANDOM: 1945 rau_next_state(); 1946 sm_random_start(NULL); 1947 return; 1948 case RAU_GET_ENC: 1949 // already busy? 1950 if (sm_aes128_state == SM_AES128_IDLE) { 1951 sm_key_t r_prime; 1952 sm_ah_r_prime(sm_random_address, r_prime); 1953 rau_next_state(); 1954 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1955 return; 1956 } 1957 break; 1958 case RAU_SET_ADDRESS: 1959 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1960 rau_state = RAU_IDLE; 1961 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1962 return; 1963 default: 1964 break; 1965 } 1966 1967 #ifdef ENABLE_CMAC_ENGINE 1968 // CMAC 1969 switch (sm_cmac_state){ 1970 case CMAC_CALC_SUBKEYS: 1971 case CMAC_CALC_MI: 1972 case CMAC_CALC_MLAST: 1973 // already busy? 1974 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1975 sm_cmac_handle_aes_engine_ready(); 1976 return; 1977 default: 1978 break; 1979 } 1980 #endif 1981 1982 // CSRK Lookup 1983 // -- if csrk lookup ready, find connection that require csrk lookup 1984 if (sm_address_resolution_idle()){ 1985 hci_connections_get_iterator(&it); 1986 while(btstack_linked_list_iterator_has_next(&it)){ 1987 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1988 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1989 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1990 // and start lookup 1991 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); 1992 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1993 break; 1994 } 1995 } 1996 } 1997 1998 // -- if csrk lookup ready, resolved addresses for received addresses 1999 if (sm_address_resolution_idle()) { 2000 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 2001 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 2002 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 2003 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 2004 btstack_memory_sm_lookup_entry_free(entry); 2005 } 2006 } 2007 2008 // -- Continue with CSRK device lookup by public or resolvable private address 2009 if (!sm_address_resolution_idle()){ 2010 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 2011 while (sm_address_resolution_test < le_device_db_max_count()){ 2012 int addr_type; 2013 bd_addr_t addr; 2014 sm_key_t irk; 2015 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2016 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2017 2018 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2019 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2020 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2021 break; 2022 } 2023 2024 if (sm_address_resolution_addr_type == 0){ 2025 sm_address_resolution_test++; 2026 continue; 2027 } 2028 2029 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2030 2031 log_info("LE Device Lookup: calculate AH"); 2032 log_info_key("IRK", irk); 2033 2034 sm_key_t r_prime; 2035 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2036 sm_address_resolution_ah_calculation_active = 1; 2037 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2038 return; 2039 } 2040 2041 if (sm_address_resolution_test >= le_device_db_max_count()){ 2042 log_info("LE Device Lookup: not found"); 2043 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2044 } 2045 } 2046 2047 // handle basic actions that don't requires the full context 2048 hci_connections_get_iterator(&it); 2049 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2050 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2051 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2052 switch(sm_connection->sm_engine_state){ 2053 // responder side 2054 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2055 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2056 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2057 return; 2058 2059 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2060 case SM_SC_RECEIVED_LTK_REQUEST: 2061 switch (sm_connection->sm_irk_lookup_state){ 2062 case IRK_LOOKUP_FAILED: 2063 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2064 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2065 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2066 return; 2067 default: 2068 break; 2069 } 2070 break; 2071 #endif 2072 default: 2073 break; 2074 } 2075 } 2076 2077 // 2078 // active connection handling 2079 // -- use loop to handle next connection if lock on setup context is released 2080 2081 while (1) { 2082 2083 // Find connections that requires setup context and make active if no other is locked 2084 hci_connections_get_iterator(&it); 2085 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2086 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2087 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2088 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2089 int done = 1; 2090 int err; 2091 UNUSED(err); 2092 switch (sm_connection->sm_engine_state) { 2093 #ifdef ENABLE_LE_PERIPHERAL 2094 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2095 // send packet if possible, 2096 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2097 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2098 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2099 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2100 } else { 2101 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2102 } 2103 // don't lock sxetup context yet 2104 done = 0; 2105 break; 2106 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2107 sm_reset_setup(); 2108 sm_init_setup(sm_connection); 2109 // recover pairing request 2110 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2111 err = sm_stk_generation_init(sm_connection); 2112 2113 #ifdef ENABLE_TESTING_SUPPORT 2114 if (test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2115 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2116 err = test_pairing_failure; 2117 } 2118 #endif 2119 if (err){ 2120 setup->sm_pairing_failed_reason = err; 2121 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2122 break; 2123 } 2124 sm_timeout_start(sm_connection); 2125 // generate random number first, if we need to show passkey 2126 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2127 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2128 break; 2129 } 2130 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2131 break; 2132 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2133 sm_reset_setup(); 2134 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2135 break; 2136 #endif 2137 #ifdef ENABLE_LE_CENTRAL 2138 case SM_INITIATOR_PH0_HAS_LTK: 2139 sm_reset_setup(); 2140 sm_load_security_info(sm_connection); 2141 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2142 break; 2143 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2144 sm_reset_setup(); 2145 sm_init_setup(sm_connection); 2146 sm_timeout_start(sm_connection); 2147 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2148 break; 2149 #endif 2150 2151 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2152 case SM_SC_RECEIVED_LTK_REQUEST: 2153 switch (sm_connection->sm_irk_lookup_state){ 2154 case IRK_LOOKUP_SUCCEEDED: 2155 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2156 // start using context by loading security info 2157 sm_reset_setup(); 2158 sm_load_security_info(sm_connection); 2159 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2160 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2161 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2162 break; 2163 } 2164 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2165 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2166 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2167 // don't lock setup context yet 2168 return; 2169 default: 2170 // just wait until IRK lookup is completed 2171 // don't lock setup context yet 2172 done = 0; 2173 break; 2174 } 2175 break; 2176 #endif 2177 default: 2178 done = 0; 2179 break; 2180 } 2181 if (done){ 2182 sm_active_connection_handle = sm_connection->sm_handle; 2183 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); 2184 } 2185 } 2186 2187 // 2188 // active connection handling 2189 // 2190 2191 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2192 2193 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2194 if (!connection) { 2195 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2196 return; 2197 } 2198 2199 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2200 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2201 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2202 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2203 return; 2204 } 2205 #endif 2206 2207 // assert that we could send a SM PDU - not needed for all of the following 2208 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2209 log_info("cannot send now, requesting can send now event"); 2210 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2211 return; 2212 } 2213 2214 // send keypress notifications 2215 if (setup->sm_keypress_notification != 0xff){ 2216 uint8_t buffer[2]; 2217 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2218 buffer[1] = setup->sm_keypress_notification; 2219 setup->sm_keypress_notification = 0xff; 2220 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2221 return; 2222 } 2223 2224 sm_key_t plaintext; 2225 int key_distribution_flags; 2226 UNUSED(key_distribution_flags); 2227 2228 log_info("sm_run: state %u", connection->sm_engine_state); 2229 2230 switch (connection->sm_engine_state){ 2231 2232 // general 2233 case SM_GENERAL_SEND_PAIRING_FAILED: { 2234 uint8_t buffer[2]; 2235 buffer[0] = SM_CODE_PAIRING_FAILED; 2236 buffer[1] = setup->sm_pairing_failed_reason; 2237 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2238 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2239 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2240 sm_done_for_handle(connection->sm_handle); 2241 break; 2242 } 2243 2244 // responding state 2245 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2246 case SM_SC_W2_GET_RANDOM_A: 2247 sm_random_start(connection); 2248 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2249 break; 2250 case SM_SC_W2_GET_RANDOM_B: 2251 sm_random_start(connection); 2252 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2253 break; 2254 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2255 if (!sm_cmac_ready()) break; 2256 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2257 sm_sc_calculate_local_confirm(connection); 2258 break; 2259 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2260 if (!sm_cmac_ready()) break; 2261 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2262 sm_sc_calculate_remote_confirm(connection); 2263 break; 2264 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2265 if (!sm_cmac_ready()) break; 2266 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2267 sm_sc_calculate_f6_for_dhkey_check(connection); 2268 break; 2269 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2270 if (!sm_cmac_ready()) break; 2271 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2272 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2273 break; 2274 case SM_SC_W2_CALCULATE_F5_SALT: 2275 if (!sm_cmac_ready()) break; 2276 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2277 f5_calculate_salt(connection); 2278 break; 2279 case SM_SC_W2_CALCULATE_F5_MACKEY: 2280 if (!sm_cmac_ready()) break; 2281 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2282 f5_calculate_mackey(connection); 2283 break; 2284 case SM_SC_W2_CALCULATE_F5_LTK: 2285 if (!sm_cmac_ready()) break; 2286 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2287 f5_calculate_ltk(connection); 2288 break; 2289 case SM_SC_W2_CALCULATE_G2: 2290 if (!sm_cmac_ready()) break; 2291 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2292 g2_calculate(connection); 2293 break; 2294 case SM_SC_W2_CALCULATE_H6_ILK: 2295 if (!sm_cmac_ready()) break; 2296 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2297 h6_calculate_ilk(connection); 2298 break; 2299 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2300 if (!sm_cmac_ready()) break; 2301 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2302 h6_calculate_br_edr_link_key(connection); 2303 break; 2304 #endif 2305 2306 #ifdef ENABLE_LE_CENTRAL 2307 // initiator side 2308 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2309 sm_key_t peer_ltk_flipped; 2310 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2311 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2312 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2313 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2314 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2315 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2316 return; 2317 } 2318 2319 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2320 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2321 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2322 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2323 sm_timeout_reset(connection); 2324 break; 2325 #endif 2326 2327 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2328 2329 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2330 uint8_t buffer[65]; 2331 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2332 // 2333 reverse_256(&ec_q[0], &buffer[1]); 2334 reverse_256(&ec_q[32], &buffer[33]); 2335 2336 // stk generation method 2337 // passkey entry: notify app to show passkey or to request passkey 2338 switch (setup->sm_stk_generation_method){ 2339 case JUST_WORKS: 2340 case NK_BOTH_INPUT: 2341 if (IS_RESPONDER(connection->sm_role)){ 2342 // responder 2343 sm_sc_start_calculating_local_confirm(connection); 2344 } else { 2345 // initiator 2346 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2347 } 2348 break; 2349 case PK_INIT_INPUT: 2350 case PK_RESP_INPUT: 2351 case OK_BOTH_INPUT: 2352 // use random TK for display 2353 memcpy(setup->sm_ra, setup->sm_tk, 16); 2354 memcpy(setup->sm_rb, setup->sm_tk, 16); 2355 setup->sm_passkey_bit = 0; 2356 2357 if (IS_RESPONDER(connection->sm_role)){ 2358 // responder 2359 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2360 } else { 2361 // initiator 2362 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2363 } 2364 sm_trigger_user_response(connection); 2365 break; 2366 case OOB: 2367 // TODO: implement SC OOB 2368 break; 2369 } 2370 2371 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2372 sm_timeout_reset(connection); 2373 break; 2374 } 2375 case SM_SC_SEND_CONFIRMATION: { 2376 uint8_t buffer[17]; 2377 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2378 reverse_128(setup->sm_local_confirm, &buffer[1]); 2379 if (IS_RESPONDER(connection->sm_role)){ 2380 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2381 } else { 2382 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2383 } 2384 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2385 sm_timeout_reset(connection); 2386 break; 2387 } 2388 case SM_SC_SEND_PAIRING_RANDOM: { 2389 uint8_t buffer[17]; 2390 buffer[0] = SM_CODE_PAIRING_RANDOM; 2391 reverse_128(setup->sm_local_nonce, &buffer[1]); 2392 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2393 if (IS_RESPONDER(connection->sm_role)){ 2394 // responder 2395 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2396 } else { 2397 // initiator 2398 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2399 } 2400 } else { 2401 if (IS_RESPONDER(connection->sm_role)){ 2402 // responder 2403 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2404 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2405 } else { 2406 sm_sc_prepare_dhkey_check(connection); 2407 } 2408 } else { 2409 // initiator 2410 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2411 } 2412 } 2413 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2414 sm_timeout_reset(connection); 2415 break; 2416 } 2417 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2418 uint8_t buffer[17]; 2419 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2420 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2421 2422 if (IS_RESPONDER(connection->sm_role)){ 2423 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2424 } else { 2425 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2426 } 2427 2428 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2429 sm_timeout_reset(connection); 2430 break; 2431 } 2432 2433 #endif 2434 2435 #ifdef ENABLE_LE_PERIPHERAL 2436 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2437 // echo initiator for now 2438 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2439 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2440 2441 if (setup->sm_use_secure_connections){ 2442 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2443 // skip LTK/EDIV for SC 2444 log_info("sm: dropping encryption information flag"); 2445 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2446 } else { 2447 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2448 } 2449 2450 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); 2451 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); 2452 // update key distribution after ENC was dropped 2453 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2454 2455 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2456 sm_timeout_reset(connection); 2457 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2458 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2459 sm_trigger_user_response(connection); 2460 } 2461 return; 2462 #endif 2463 2464 case SM_PH2_SEND_PAIRING_RANDOM: { 2465 uint8_t buffer[17]; 2466 buffer[0] = SM_CODE_PAIRING_RANDOM; 2467 reverse_128(setup->sm_local_random, &buffer[1]); 2468 if (IS_RESPONDER(connection->sm_role)){ 2469 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2470 } else { 2471 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2472 } 2473 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2474 sm_timeout_reset(connection); 2475 break; 2476 } 2477 2478 case SM_PH2_GET_RANDOM_TK: 2479 case SM_PH2_C1_GET_RANDOM_A: 2480 case SM_PH2_C1_GET_RANDOM_B: 2481 case SM_PH3_GET_RANDOM: 2482 case SM_PH3_GET_DIV: 2483 sm_next_responding_state(connection); 2484 sm_random_start(connection); 2485 return; 2486 2487 case SM_PH2_C1_GET_ENC_B: 2488 case SM_PH2_C1_GET_ENC_D: 2489 // already busy? 2490 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2491 sm_next_responding_state(connection); 2492 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2493 return; 2494 2495 case SM_PH3_LTK_GET_ENC: 2496 case SM_RESPONDER_PH4_LTK_GET_ENC: 2497 // already busy? 2498 if (sm_aes128_state == SM_AES128_IDLE) { 2499 sm_key_t d_prime; 2500 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2501 sm_next_responding_state(connection); 2502 sm_aes128_start(sm_persistent_er, d_prime, connection); 2503 return; 2504 } 2505 break; 2506 2507 case SM_PH3_CSRK_GET_ENC: 2508 // already busy? 2509 if (sm_aes128_state == SM_AES128_IDLE) { 2510 sm_key_t d_prime; 2511 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2512 sm_next_responding_state(connection); 2513 sm_aes128_start(sm_persistent_er, d_prime, connection); 2514 return; 2515 } 2516 break; 2517 2518 case SM_PH2_C1_GET_ENC_C: 2519 // already busy? 2520 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2521 // calculate m_confirm using aes128 engine - step 1 2522 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); 2523 sm_next_responding_state(connection); 2524 sm_aes128_start(setup->sm_tk, plaintext, connection); 2525 break; 2526 case SM_PH2_C1_GET_ENC_A: 2527 // already busy? 2528 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2529 // calculate confirm using aes128 engine - step 1 2530 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); 2531 sm_next_responding_state(connection); 2532 sm_aes128_start(setup->sm_tk, plaintext, connection); 2533 break; 2534 case SM_PH2_CALC_STK: 2535 // already busy? 2536 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2537 // calculate STK 2538 if (IS_RESPONDER(connection->sm_role)){ 2539 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2540 } else { 2541 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2542 } 2543 sm_next_responding_state(connection); 2544 sm_aes128_start(setup->sm_tk, plaintext, connection); 2545 break; 2546 case SM_PH3_Y_GET_ENC: 2547 // already busy? 2548 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2549 // PH3B2 - calculate Y from - enc 2550 // Y = dm(DHK, Rand) 2551 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2552 sm_next_responding_state(connection); 2553 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2554 return; 2555 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2556 uint8_t buffer[17]; 2557 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2558 reverse_128(setup->sm_local_confirm, &buffer[1]); 2559 if (IS_RESPONDER(connection->sm_role)){ 2560 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2561 } else { 2562 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2563 } 2564 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2565 sm_timeout_reset(connection); 2566 return; 2567 } 2568 #ifdef ENABLE_LE_PERIPHERAL 2569 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2570 sm_key_t stk_flipped; 2571 reverse_128(setup->sm_ltk, stk_flipped); 2572 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2573 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2574 return; 2575 } 2576 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2577 sm_key_t ltk_flipped; 2578 reverse_128(setup->sm_ltk, ltk_flipped); 2579 connection->sm_engine_state = SM_RESPONDER_IDLE; 2580 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2581 sm_done_for_handle(connection->sm_handle); 2582 return; 2583 } 2584 case SM_RESPONDER_PH4_Y_GET_ENC: 2585 // already busy? 2586 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2587 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2588 // Y = dm(DHK, Rand) 2589 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2590 sm_next_responding_state(connection); 2591 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2592 return; 2593 #endif 2594 #ifdef ENABLE_LE_CENTRAL 2595 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2596 sm_key_t stk_flipped; 2597 reverse_128(setup->sm_ltk, stk_flipped); 2598 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2599 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2600 return; 2601 } 2602 #endif 2603 2604 case SM_PH3_DISTRIBUTE_KEYS: 2605 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2606 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2607 uint8_t buffer[17]; 2608 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2609 reverse_128(setup->sm_ltk, &buffer[1]); 2610 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2611 sm_timeout_reset(connection); 2612 return; 2613 } 2614 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2615 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2616 uint8_t buffer[11]; 2617 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2618 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2619 reverse_64(setup->sm_local_rand, &buffer[3]); 2620 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2621 sm_timeout_reset(connection); 2622 return; 2623 } 2624 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2625 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2626 uint8_t buffer[17]; 2627 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2628 reverse_128(sm_persistent_irk, &buffer[1]); 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_IDENTITY_ADDRESS_INFORMATION){ 2634 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2635 bd_addr_t local_address; 2636 uint8_t buffer[8]; 2637 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2638 switch (gap_random_address_get_mode()){ 2639 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2640 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2641 // public or static random 2642 gap_le_get_own_address(&buffer[1], local_address); 2643 break; 2644 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2645 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2646 // fallback to public 2647 gap_local_bd_addr(local_address); 2648 buffer[1] = 0; 2649 break; 2650 } 2651 reverse_bd_addr(local_address, &buffer[2]); 2652 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2653 sm_timeout_reset(connection); 2654 return; 2655 } 2656 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2657 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2658 2659 // hack to reproduce test runs 2660 if (test_use_fixed_local_csrk){ 2661 memset(setup->sm_local_csrk, 0xcc, 16); 2662 } 2663 2664 uint8_t buffer[17]; 2665 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2666 reverse_128(setup->sm_local_csrk, &buffer[1]); 2667 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2668 sm_timeout_reset(connection); 2669 return; 2670 } 2671 2672 // keys are sent 2673 if (IS_RESPONDER(connection->sm_role)){ 2674 // slave -> receive master keys if any 2675 if (sm_key_distribution_all_received(connection)){ 2676 sm_key_distribution_handle_all_received(connection); 2677 connection->sm_engine_state = SM_RESPONDER_IDLE; 2678 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2679 sm_done_for_handle(connection->sm_handle); 2680 } else { 2681 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2682 } 2683 } else { 2684 // master -> all done 2685 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2686 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2687 sm_done_for_handle(connection->sm_handle); 2688 } 2689 break; 2690 2691 default: 2692 break; 2693 } 2694 2695 // check again if active connection was released 2696 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2697 } 2698 } 2699 2700 // note: aes engine is ready as we just got the aes result 2701 static void sm_handle_encryption_result(uint8_t * data){ 2702 2703 sm_aes128_state = SM_AES128_IDLE; 2704 2705 if (sm_address_resolution_ah_calculation_active){ 2706 sm_address_resolution_ah_calculation_active = 0; 2707 // compare calulated address against connecting device 2708 uint8_t hash[3]; 2709 reverse_24(data, hash); 2710 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2711 log_info("LE Device Lookup: matched resolvable private address"); 2712 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2713 return; 2714 } 2715 // no match, try next 2716 sm_address_resolution_test++; 2717 return; 2718 } 2719 2720 switch (dkg_state){ 2721 case DKG_W4_IRK: 2722 reverse_128(data, sm_persistent_irk); 2723 log_info_key("irk", sm_persistent_irk); 2724 dkg_next_state(); 2725 return; 2726 case DKG_W4_DHK: 2727 reverse_128(data, sm_persistent_dhk); 2728 log_info_key("dhk", sm_persistent_dhk); 2729 dkg_next_state(); 2730 // SM Init Finished 2731 return; 2732 default: 2733 break; 2734 } 2735 2736 switch (rau_state){ 2737 case RAU_W4_ENC: 2738 reverse_24(data, &sm_random_address[3]); 2739 rau_next_state(); 2740 return; 2741 default: 2742 break; 2743 } 2744 2745 #ifdef ENABLE_CMAC_ENGINE 2746 switch (sm_cmac_state){ 2747 case CMAC_W4_SUBKEYS: 2748 case CMAC_W4_MI: 2749 case CMAC_W4_MLAST: 2750 { 2751 sm_key_t t; 2752 reverse_128(data, t); 2753 sm_cmac_handle_encryption_result(t); 2754 } 2755 return; 2756 default: 2757 break; 2758 } 2759 #endif 2760 2761 // retrieve sm_connection provided to sm_aes128_start_encryption 2762 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2763 if (!connection) return; 2764 switch (connection->sm_engine_state){ 2765 case SM_PH2_C1_W4_ENC_A: 2766 case SM_PH2_C1_W4_ENC_C: 2767 { 2768 sm_key_t t2; 2769 reverse_128(data, t2); 2770 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2771 } 2772 sm_next_responding_state(connection); 2773 return; 2774 case SM_PH2_C1_W4_ENC_B: 2775 reverse_128(data, setup->sm_local_confirm); 2776 log_info_key("c1!", setup->sm_local_confirm); 2777 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2778 return; 2779 case SM_PH2_C1_W4_ENC_D: 2780 { 2781 sm_key_t peer_confirm_test; 2782 reverse_128(data, peer_confirm_test); 2783 log_info_key("c1!", peer_confirm_test); 2784 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2785 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2786 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2787 return; 2788 } 2789 if (IS_RESPONDER(connection->sm_role)){ 2790 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2791 } else { 2792 connection->sm_engine_state = SM_PH2_CALC_STK; 2793 } 2794 } 2795 return; 2796 case SM_PH2_W4_STK: 2797 reverse_128(data, setup->sm_ltk); 2798 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2799 log_info_key("stk", setup->sm_ltk); 2800 if (IS_RESPONDER(connection->sm_role)){ 2801 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2802 } else { 2803 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2804 } 2805 return; 2806 case SM_PH3_Y_W4_ENC:{ 2807 sm_key_t y128; 2808 reverse_128(data, y128); 2809 setup->sm_local_y = big_endian_read_16(y128, 14); 2810 log_info_hex16("y", setup->sm_local_y); 2811 // PH3B3 - calculate EDIV 2812 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2813 log_info_hex16("ediv", setup->sm_local_ediv); 2814 // PH3B4 - calculate LTK - enc 2815 // LTK = d1(ER, DIV, 0)) 2816 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2817 return; 2818 } 2819 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2820 sm_key_t y128; 2821 reverse_128(data, y128); 2822 setup->sm_local_y = big_endian_read_16(y128, 14); 2823 log_info_hex16("y", setup->sm_local_y); 2824 2825 // PH3B3 - calculate DIV 2826 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2827 log_info_hex16("ediv", setup->sm_local_ediv); 2828 // PH3B4 - calculate LTK - enc 2829 // LTK = d1(ER, DIV, 0)) 2830 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2831 return; 2832 } 2833 case SM_PH3_LTK_W4_ENC: 2834 reverse_128(data, setup->sm_ltk); 2835 log_info_key("ltk", setup->sm_ltk); 2836 // calc CSRK next 2837 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2838 return; 2839 case SM_PH3_CSRK_W4_ENC: 2840 reverse_128(data, setup->sm_local_csrk); 2841 log_info_key("csrk", setup->sm_local_csrk); 2842 if (setup->sm_key_distribution_send_set){ 2843 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2844 } else { 2845 // no keys to send, just continue 2846 if (IS_RESPONDER(connection->sm_role)){ 2847 // slave -> receive master keys 2848 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2849 } else { 2850 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2851 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2852 } else { 2853 // master -> all done 2854 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2855 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2856 sm_done_for_handle(connection->sm_handle); 2857 } 2858 } 2859 } 2860 return; 2861 #ifdef ENABLE_LE_PERIPHERAL 2862 case SM_RESPONDER_PH4_LTK_W4_ENC: 2863 reverse_128(data, setup->sm_ltk); 2864 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2865 log_info_key("ltk", setup->sm_ltk); 2866 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2867 return; 2868 #endif 2869 default: 2870 break; 2871 } 2872 } 2873 2874 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2875 2876 #if (defined(USE_MICRO_ECC_FOR_ECDH) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_FOR_ECDH) 2877 // @return OK 2878 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2879 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2880 int offset = setup->sm_passkey_bit; 2881 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2882 while (size) { 2883 *buffer++ = setup->sm_peer_q[offset++]; 2884 size--; 2885 } 2886 setup->sm_passkey_bit = offset; 2887 return 1; 2888 } 2889 #endif 2890 #ifdef USE_MBEDTLS_FOR_ECDH 2891 // @return error - just wrap sm_generate_f_rng 2892 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2893 UNUSED(context); 2894 return sm_generate_f_rng(buffer, size) == 0; 2895 } 2896 #endif /* USE_MBEDTLS_FOR_ECDH */ 2897 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2898 2899 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2900 static void sm_handle_random_result(uint8_t * data){ 2901 2902 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2903 2904 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2905 int num_bytes = setup->sm_passkey_bit; 2906 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2907 num_bytes += 8; 2908 setup->sm_passkey_bit = num_bytes; 2909 2910 if (num_bytes >= 64){ 2911 2912 // init pre-generated random data from sm_peer_q 2913 setup->sm_passkey_bit = 0; 2914 2915 // generate EC key 2916 #ifdef USE_MICRO_ECC_FOR_ECDH 2917 2918 #ifndef WICED_VERSION 2919 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2920 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2921 uECC_set_rng(&sm_generate_f_rng); 2922 #endif /* WICED_VERSION */ 2923 2924 #if uECC_SUPPORTS_secp256r1 2925 // standard version 2926 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2927 2928 // disable RNG again, as returning no randmon data lets shared key generation fail 2929 log_info("disable uECC RNG in standard version after key generation"); 2930 uECC_set_rng(NULL); 2931 #else 2932 // static version 2933 uECC_make_key(ec_q, ec_d); 2934 #endif 2935 #endif /* USE_MICRO_ECC_FOR_ECDH */ 2936 2937 #ifdef USE_MBEDTLS_FOR_ECDH 2938 mbedtls_mpi d; 2939 mbedtls_ecp_point P; 2940 mbedtls_mpi_init(&d); 2941 mbedtls_ecp_point_init(&P); 2942 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2943 log_info("gen keypair %x", res); 2944 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2945 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2946 mbedtls_mpi_write_binary(&d, ec_d, 32); 2947 mbedtls_ecp_point_free(&P); 2948 mbedtls_mpi_free(&d); 2949 #endif /* USE_MBEDTLS_FOR_ECDH */ 2950 2951 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2952 log_info("Elliptic curve: d"); 2953 log_info_hexdump(ec_d,32); 2954 sm_log_ec_keypair(); 2955 } 2956 } 2957 #endif 2958 2959 switch (rau_state){ 2960 case RAU_W4_RANDOM: 2961 // non-resolvable vs. resolvable 2962 switch (gap_random_adress_type){ 2963 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2964 // resolvable: use random as prand and calc address hash 2965 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2966 memcpy(sm_random_address, data, 3); 2967 sm_random_address[0] &= 0x3f; 2968 sm_random_address[0] |= 0x40; 2969 rau_state = RAU_GET_ENC; 2970 break; 2971 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2972 default: 2973 // "The two most significant bits of the address shall be equal to ‘0’"" 2974 memcpy(sm_random_address, data, 6); 2975 sm_random_address[0] &= 0x3f; 2976 rau_state = RAU_SET_ADDRESS; 2977 break; 2978 } 2979 return; 2980 default: 2981 break; 2982 } 2983 2984 // retrieve sm_connection provided to sm_random_start 2985 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2986 if (!connection) return; 2987 switch (connection->sm_engine_state){ 2988 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2989 case SM_SC_W4_GET_RANDOM_A: 2990 memcpy(&setup->sm_local_nonce[0], data, 8); 2991 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2992 break; 2993 case SM_SC_W4_GET_RANDOM_B: 2994 memcpy(&setup->sm_local_nonce[8], data, 8); 2995 // initiator & jw/nc -> send pairing random 2996 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2997 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2998 break; 2999 } else { 3000 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3001 } 3002 break; 3003 #endif 3004 3005 case SM_PH2_W4_RANDOM_TK: 3006 { 3007 sm_reset_tk(); 3008 uint32_t tk; 3009 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3010 // map random to 0-999999 without speding much cycles on a modulus operation 3011 tk = little_endian_read_32(data,0); 3012 tk = tk & 0xfffff; // 1048575 3013 if (tk >= 999999){ 3014 tk = tk - 999999; 3015 } 3016 } else { 3017 // override with pre-defined passkey 3018 tk = sm_fixed_passkey_in_display_role; 3019 } 3020 big_endian_store_32(setup->sm_tk, 12, tk); 3021 if (IS_RESPONDER(connection->sm_role)){ 3022 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3023 } else { 3024 if (setup->sm_use_secure_connections){ 3025 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3026 } else { 3027 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3028 sm_trigger_user_response(connection); 3029 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3030 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3031 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3032 } 3033 } 3034 } 3035 return; 3036 } 3037 case SM_PH2_C1_W4_RANDOM_A: 3038 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 3039 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 3040 return; 3041 case SM_PH2_C1_W4_RANDOM_B: 3042 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3043 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3044 return; 3045 case SM_PH3_W4_RANDOM: 3046 reverse_64(data, setup->sm_local_rand); 3047 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3048 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3049 // no db for authenticated flag hack: store flag in bit 4 of LSB 3050 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3051 connection->sm_engine_state = SM_PH3_GET_DIV; 3052 return; 3053 case SM_PH3_W4_DIV: 3054 // use 16 bit from random value as div 3055 setup->sm_local_div = big_endian_read_16(data, 0); 3056 log_info_hex16("div", setup->sm_local_div); 3057 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3058 return; 3059 default: 3060 break; 3061 } 3062 } 3063 3064 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3065 3066 UNUSED(channel); // ok: there is no channel 3067 UNUSED(size); // ok: fixed format HCI events 3068 3069 sm_connection_t * sm_conn; 3070 hci_con_handle_t con_handle; 3071 3072 switch (packet_type) { 3073 3074 case HCI_EVENT_PACKET: 3075 switch (hci_event_packet_get_type(packet)) { 3076 3077 case BTSTACK_EVENT_STATE: 3078 // bt stack activated, get started 3079 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3080 log_info("HCI Working!"); 3081 3082 3083 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3084 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3085 if (!sm_have_ec_keypair){ 3086 setup->sm_passkey_bit = 0; 3087 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3088 } 3089 #endif 3090 // trigger Random Address generation if requested before 3091 switch (gap_random_adress_type){ 3092 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3093 rau_state = RAU_IDLE; 3094 break; 3095 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3096 rau_state = RAU_SET_ADDRESS; 3097 break; 3098 default: 3099 rau_state = RAU_GET_RANDOM; 3100 break; 3101 } 3102 sm_run(); 3103 } 3104 break; 3105 3106 case HCI_EVENT_LE_META: 3107 switch (packet[2]) { 3108 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3109 3110 log_info("sm: connected"); 3111 3112 if (packet[3]) return; // connection failed 3113 3114 con_handle = little_endian_read_16(packet, 4); 3115 sm_conn = sm_get_connection_for_handle(con_handle); 3116 if (!sm_conn) break; 3117 3118 sm_conn->sm_handle = con_handle; 3119 sm_conn->sm_role = packet[6]; 3120 sm_conn->sm_peer_addr_type = packet[7]; 3121 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3122 3123 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3124 3125 // reset security properties 3126 sm_conn->sm_connection_encrypted = 0; 3127 sm_conn->sm_connection_authenticated = 0; 3128 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3129 sm_conn->sm_le_db_index = -1; 3130 3131 // prepare CSRK lookup (does not involve setup) 3132 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3133 3134 // just connected -> everything else happens in sm_run() 3135 if (IS_RESPONDER(sm_conn->sm_role)){ 3136 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3137 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3138 if (sm_slave_request_security) { 3139 // request security if requested by app 3140 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3141 } else { 3142 // otherwise, wait for pairing request 3143 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3144 } 3145 } 3146 break; 3147 } else { 3148 // master 3149 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3150 } 3151 break; 3152 3153 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3154 con_handle = little_endian_read_16(packet, 3); 3155 sm_conn = sm_get_connection_for_handle(con_handle); 3156 if (!sm_conn) break; 3157 3158 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3159 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3160 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3161 break; 3162 } 3163 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3164 // PH2 SEND LTK as we need to exchange keys in PH3 3165 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3166 break; 3167 } 3168 3169 // store rand and ediv 3170 reverse_64(&packet[5], sm_conn->sm_local_rand); 3171 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3172 3173 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3174 // potentially stored LTK is from the master 3175 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3176 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3177 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3178 break; 3179 } 3180 // additionally check if remote is in LE Device DB if requested 3181 switch(sm_conn->sm_irk_lookup_state){ 3182 case IRK_LOOKUP_FAILED: 3183 log_info("LTK Request: device not in device db"); 3184 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3185 break; 3186 case IRK_LOOKUP_SUCCEEDED: 3187 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3188 break; 3189 default: 3190 // wait for irk look doen 3191 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3192 break; 3193 } 3194 break; 3195 } 3196 3197 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3198 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3199 #else 3200 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3201 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3202 #endif 3203 break; 3204 3205 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3206 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3207 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3208 log_error("Read Local P256 Public Key failed"); 3209 break; 3210 } 3211 3212 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3213 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3214 3215 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3216 sm_log_ec_keypair(); 3217 break; 3218 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3219 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3220 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3221 log_error("Generate DHKEY failed -> abort"); 3222 // abort pairing with 'unspecified reason' 3223 sm_pdu_received_in_wrong_state(sm_conn); 3224 break; 3225 } 3226 3227 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3228 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3229 log_info("dhkey"); 3230 log_info_hexdump(&setup->sm_dhkey[0], 32); 3231 3232 // trigger next step 3233 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3234 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3235 } 3236 break; 3237 #endif 3238 default: 3239 break; 3240 } 3241 break; 3242 3243 case HCI_EVENT_ENCRYPTION_CHANGE: 3244 con_handle = little_endian_read_16(packet, 3); 3245 sm_conn = sm_get_connection_for_handle(con_handle); 3246 if (!sm_conn) break; 3247 3248 sm_conn->sm_connection_encrypted = packet[5]; 3249 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3250 sm_conn->sm_actual_encryption_key_size); 3251 log_info("event handler, state %u", sm_conn->sm_engine_state); 3252 if (!sm_conn->sm_connection_encrypted) break; 3253 // continue if part of initial pairing 3254 switch (sm_conn->sm_engine_state){ 3255 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3256 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3257 sm_done_for_handle(sm_conn->sm_handle); 3258 break; 3259 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3260 if (IS_RESPONDER(sm_conn->sm_role)){ 3261 // slave 3262 if (setup->sm_use_secure_connections){ 3263 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3264 } else { 3265 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3266 } 3267 } else { 3268 // master 3269 if (sm_key_distribution_all_received(sm_conn)){ 3270 // skip receiving keys as there are none 3271 sm_key_distribution_handle_all_received(sm_conn); 3272 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3273 } else { 3274 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3275 } 3276 } 3277 break; 3278 default: 3279 break; 3280 } 3281 break; 3282 3283 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3284 con_handle = little_endian_read_16(packet, 3); 3285 sm_conn = sm_get_connection_for_handle(con_handle); 3286 if (!sm_conn) break; 3287 3288 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3289 log_info("event handler, state %u", sm_conn->sm_engine_state); 3290 // continue if part of initial pairing 3291 switch (sm_conn->sm_engine_state){ 3292 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3293 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3294 sm_done_for_handle(sm_conn->sm_handle); 3295 break; 3296 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3297 if (IS_RESPONDER(sm_conn->sm_role)){ 3298 // slave 3299 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3300 } else { 3301 // master 3302 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3303 } 3304 break; 3305 default: 3306 break; 3307 } 3308 break; 3309 3310 3311 case HCI_EVENT_DISCONNECTION_COMPLETE: 3312 con_handle = little_endian_read_16(packet, 3); 3313 sm_done_for_handle(con_handle); 3314 sm_conn = sm_get_connection_for_handle(con_handle); 3315 if (!sm_conn) break; 3316 3317 // delete stored bonding on disconnect with authentication failure in ph0 3318 if (sm_conn->sm_role == 0 3319 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3320 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3321 le_device_db_remove(sm_conn->sm_le_db_index); 3322 } 3323 3324 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3325 3326 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3327 sm_conn->sm_handle = 0; 3328 break; 3329 3330 case HCI_EVENT_COMMAND_COMPLETE: 3331 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3332 sm_handle_encryption_result(&packet[6]); 3333 break; 3334 } 3335 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3336 sm_handle_random_result(&packet[6]); 3337 break; 3338 } 3339 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3340 // set local addr for le device db 3341 bd_addr_t addr; 3342 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3343 le_device_db_set_local_bd_addr(addr); 3344 } 3345 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3346 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3347 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3348 // mbedTLS can also be used if already available (and malloc is supported) 3349 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add USE_MICRO_ECC_FOR_ECDH to btstack_config.h"); 3350 } 3351 #endif 3352 } 3353 break; 3354 default: 3355 break; 3356 } 3357 break; 3358 default: 3359 break; 3360 } 3361 3362 sm_run(); 3363 } 3364 3365 static inline int sm_calc_actual_encryption_key_size(int other){ 3366 if (other < sm_min_encryption_key_size) return 0; 3367 if (other < sm_max_encryption_key_size) return other; 3368 return sm_max_encryption_key_size; 3369 } 3370 3371 3372 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3373 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3374 switch (method){ 3375 case JUST_WORKS: 3376 case NK_BOTH_INPUT: 3377 return 1; 3378 default: 3379 return 0; 3380 } 3381 } 3382 // responder 3383 3384 static int sm_passkey_used(stk_generation_method_t method){ 3385 switch (method){ 3386 case PK_RESP_INPUT: 3387 return 1; 3388 default: 3389 return 0; 3390 } 3391 } 3392 #endif 3393 3394 /** 3395 * @return ok 3396 */ 3397 static int sm_validate_stk_generation_method(void){ 3398 // check if STK generation method is acceptable by client 3399 switch (setup->sm_stk_generation_method){ 3400 case JUST_WORKS: 3401 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3402 case PK_RESP_INPUT: 3403 case PK_INIT_INPUT: 3404 case OK_BOTH_INPUT: 3405 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3406 case OOB: 3407 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3408 case NK_BOTH_INPUT: 3409 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3410 return 1; 3411 default: 3412 return 0; 3413 } 3414 } 3415 3416 // size of complete sm_pdu used to validate input 3417 static const uint8_t sm_pdu_size[] = { 3418 0, // 0x00 invalid opcode 3419 7, // 0x01 pairing request 3420 7, // 0x02 pairing response 3421 17, // 0x03 pairing confirm 3422 17, // 0x04 pairing random 3423 2, // 0x05 pairing failed 3424 17, // 0x06 encryption information 3425 11, // 0x07 master identification 3426 17, // 0x08 identification information 3427 8, // 0x09 identify address information 3428 17, // 0x0a signing information 3429 2, // 0x0b security request 3430 65, // 0x0c pairing public key 3431 17, // 0x0d pairing dhk check 3432 2, // 0x0e keypress notification 3433 }; 3434 3435 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3436 3437 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3438 sm_run(); 3439 } 3440 3441 if (packet_type != SM_DATA_PACKET) return; 3442 if (size == 0) return; 3443 3444 uint8_t sm_pdu_code = packet[0]; 3445 3446 // validate pdu size 3447 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3448 if (sm_pdu_size[sm_pdu_code] != size) return; 3449 3450 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3451 if (!sm_conn) return; 3452 3453 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3454 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3455 sm_done_for_handle(con_handle); 3456 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3457 return; 3458 } 3459 3460 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3461 3462 int err; 3463 UNUSED(err); 3464 3465 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3466 uint8_t buffer[5]; 3467 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3468 buffer[1] = 3; 3469 little_endian_store_16(buffer, 2, con_handle); 3470 buffer[4] = packet[1]; 3471 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3472 return; 3473 } 3474 3475 switch (sm_conn->sm_engine_state){ 3476 3477 // a sm timeout requries a new physical connection 3478 case SM_GENERAL_TIMEOUT: 3479 return; 3480 3481 #ifdef ENABLE_LE_CENTRAL 3482 3483 // Initiator 3484 case SM_INITIATOR_CONNECTED: 3485 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3486 sm_pdu_received_in_wrong_state(sm_conn); 3487 break; 3488 } 3489 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3490 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3491 break; 3492 } 3493 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3494 sm_key_t ltk; 3495 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3496 if (!sm_is_null_key(ltk)){ 3497 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3498 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3499 } else { 3500 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3501 } 3502 break; 3503 } 3504 // otherwise, store security request 3505 sm_conn->sm_security_request_received = 1; 3506 break; 3507 3508 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3509 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3510 sm_pdu_received_in_wrong_state(sm_conn); 3511 break; 3512 } 3513 // store pairing request 3514 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3515 err = sm_stk_generation_init(sm_conn); 3516 if (err){ 3517 setup->sm_pairing_failed_reason = err; 3518 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3519 break; 3520 } 3521 3522 // generate random number first, if we need to show passkey 3523 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3524 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3525 break; 3526 } 3527 3528 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3529 if (setup->sm_use_secure_connections){ 3530 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3531 if (setup->sm_stk_generation_method == JUST_WORKS){ 3532 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3533 sm_trigger_user_response(sm_conn); 3534 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3535 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3536 } 3537 } else { 3538 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3539 } 3540 break; 3541 } 3542 #endif 3543 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3544 sm_trigger_user_response(sm_conn); 3545 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3546 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3547 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3548 } 3549 break; 3550 3551 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3552 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3553 sm_pdu_received_in_wrong_state(sm_conn); 3554 break; 3555 } 3556 3557 // store s_confirm 3558 reverse_128(&packet[1], setup->sm_peer_confirm); 3559 3560 #ifdef ENABLE_TESTING_SUPPORT 3561 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3562 log_info("testing_support: reset confirm value"); 3563 memset(setup->sm_peer_confirm, 0, 16); 3564 } 3565 #endif 3566 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3567 break; 3568 3569 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3570 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3571 sm_pdu_received_in_wrong_state(sm_conn); 3572 break;; 3573 } 3574 3575 // received random value 3576 reverse_128(&packet[1], setup->sm_peer_random); 3577 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3578 break; 3579 #endif 3580 3581 #ifdef ENABLE_LE_PERIPHERAL 3582 // Responder 3583 case SM_RESPONDER_IDLE: 3584 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3585 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3586 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3587 sm_pdu_received_in_wrong_state(sm_conn); 3588 break;; 3589 } 3590 3591 // store pairing request 3592 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3593 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3594 break; 3595 #endif 3596 3597 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3598 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3599 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3600 sm_pdu_received_in_wrong_state(sm_conn); 3601 break; 3602 } 3603 3604 // store public key for DH Key calculation 3605 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3606 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3607 3608 // validate public key using micro-ecc 3609 err = 0; 3610 3611 #ifdef USE_MICRO_ECC_FOR_ECDH 3612 #if uECC_SUPPORTS_secp256r1 3613 // standard version 3614 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3615 #else 3616 // static version 3617 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3618 #endif 3619 #endif 3620 3621 #ifdef USE_MBEDTLS_FOR_ECDH 3622 mbedtls_ecp_point Q; 3623 mbedtls_ecp_point_init( &Q ); 3624 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3625 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3626 mbedtls_mpi_lset(&Q.Z, 1); 3627 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3628 mbedtls_ecp_point_free( & Q); 3629 #endif 3630 3631 if (err){ 3632 log_error("sm: peer public key invalid %x", err); 3633 // uses "unspecified reason", there is no "public key invalid" error code 3634 sm_pdu_received_in_wrong_state(sm_conn); 3635 break; 3636 } 3637 3638 #ifndef USE_SOFTWARE_ECDH_IMPLEMENTATION 3639 // ask controller to calculate dhkey 3640 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3641 #endif 3642 3643 if (IS_RESPONDER(sm_conn->sm_role)){ 3644 // responder 3645 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3646 } else { 3647 // initiator 3648 // stk generation method 3649 // passkey entry: notify app to show passkey or to request passkey 3650 switch (setup->sm_stk_generation_method){ 3651 case JUST_WORKS: 3652 case NK_BOTH_INPUT: 3653 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3654 break; 3655 case PK_RESP_INPUT: 3656 sm_sc_start_calculating_local_confirm(sm_conn); 3657 break; 3658 case PK_INIT_INPUT: 3659 case OK_BOTH_INPUT: 3660 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3661 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3662 break; 3663 } 3664 sm_sc_start_calculating_local_confirm(sm_conn); 3665 break; 3666 case OOB: 3667 // TODO: implement SC OOB 3668 break; 3669 } 3670 } 3671 break; 3672 3673 case SM_SC_W4_CONFIRMATION: 3674 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3675 sm_pdu_received_in_wrong_state(sm_conn); 3676 break; 3677 } 3678 // received confirm value 3679 reverse_128(&packet[1], setup->sm_peer_confirm); 3680 3681 #ifdef ENABLE_TESTING_SUPPORT 3682 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3683 log_info("testing_support: reset confirm value"); 3684 memset(setup->sm_peer_confirm, 0, 16); 3685 } 3686 #endif 3687 if (IS_RESPONDER(sm_conn->sm_role)){ 3688 // responder 3689 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3690 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3691 // still waiting for passkey 3692 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3693 break; 3694 } 3695 } 3696 sm_sc_start_calculating_local_confirm(sm_conn); 3697 } else { 3698 // initiator 3699 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3700 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3701 } else { 3702 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3703 } 3704 } 3705 break; 3706 3707 case SM_SC_W4_PAIRING_RANDOM: 3708 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3709 sm_pdu_received_in_wrong_state(sm_conn); 3710 break; 3711 } 3712 3713 // received random value 3714 reverse_128(&packet[1], setup->sm_peer_nonce); 3715 3716 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3717 // only check for JUST WORK/NC in initiator role AND passkey entry 3718 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3719 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3720 } 3721 3722 sm_sc_state_after_receiving_random(sm_conn); 3723 break; 3724 3725 case SM_SC_W2_CALCULATE_G2: 3726 case SM_SC_W4_CALCULATE_G2: 3727 case SM_SC_W4_CALCULATE_DHKEY: 3728 case SM_SC_W2_CALCULATE_F5_SALT: 3729 case SM_SC_W4_CALCULATE_F5_SALT: 3730 case SM_SC_W2_CALCULATE_F5_MACKEY: 3731 case SM_SC_W4_CALCULATE_F5_MACKEY: 3732 case SM_SC_W2_CALCULATE_F5_LTK: 3733 case SM_SC_W4_CALCULATE_F5_LTK: 3734 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3735 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3736 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3737 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3738 sm_pdu_received_in_wrong_state(sm_conn); 3739 break; 3740 } 3741 // store DHKey Check 3742 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3743 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3744 3745 // have we been only waiting for dhkey check command? 3746 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3747 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3748 } 3749 break; 3750 #endif 3751 3752 #ifdef ENABLE_LE_PERIPHERAL 3753 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3754 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3755 sm_pdu_received_in_wrong_state(sm_conn); 3756 break; 3757 } 3758 3759 // received confirm value 3760 reverse_128(&packet[1], setup->sm_peer_confirm); 3761 3762 #ifdef ENABLE_TESTING_SUPPORT 3763 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3764 log_info("testing_support: reset confirm value"); 3765 memset(setup->sm_peer_confirm, 0, 16); 3766 } 3767 #endif 3768 // notify client to hide shown passkey 3769 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3770 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3771 } 3772 3773 // handle user cancel pairing? 3774 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3775 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3776 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3777 break; 3778 } 3779 3780 // wait for user action? 3781 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3782 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3783 break; 3784 } 3785 3786 // calculate and send local_confirm 3787 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3788 break; 3789 3790 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3791 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3792 sm_pdu_received_in_wrong_state(sm_conn); 3793 break;; 3794 } 3795 3796 // received random value 3797 reverse_128(&packet[1], setup->sm_peer_random); 3798 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3799 break; 3800 #endif 3801 3802 case SM_PH3_RECEIVE_KEYS: 3803 switch(sm_pdu_code){ 3804 case SM_CODE_ENCRYPTION_INFORMATION: 3805 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3806 reverse_128(&packet[1], setup->sm_peer_ltk); 3807 break; 3808 3809 case SM_CODE_MASTER_IDENTIFICATION: 3810 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3811 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3812 reverse_64(&packet[3], setup->sm_peer_rand); 3813 break; 3814 3815 case SM_CODE_IDENTITY_INFORMATION: 3816 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3817 reverse_128(&packet[1], setup->sm_peer_irk); 3818 break; 3819 3820 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3821 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3822 setup->sm_peer_addr_type = packet[1]; 3823 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3824 break; 3825 3826 case SM_CODE_SIGNING_INFORMATION: 3827 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3828 reverse_128(&packet[1], setup->sm_peer_csrk); 3829 break; 3830 default: 3831 // Unexpected PDU 3832 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3833 break; 3834 } 3835 // done with key distribution? 3836 if (sm_key_distribution_all_received(sm_conn)){ 3837 3838 sm_key_distribution_handle_all_received(sm_conn); 3839 3840 if (IS_RESPONDER(sm_conn->sm_role)){ 3841 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3842 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3843 } else { 3844 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3845 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3846 sm_done_for_handle(sm_conn->sm_handle); 3847 } 3848 } else { 3849 if (setup->sm_use_secure_connections){ 3850 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3851 } else { 3852 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3853 } 3854 } 3855 } 3856 break; 3857 default: 3858 // Unexpected PDU 3859 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3860 break; 3861 } 3862 3863 // try to send preparared packet 3864 sm_run(); 3865 } 3866 3867 // Security Manager Client API 3868 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3869 sm_get_oob_data = get_oob_data_callback; 3870 } 3871 3872 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3873 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3874 } 3875 3876 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3877 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3878 } 3879 3880 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3881 sm_min_encryption_key_size = min_size; 3882 sm_max_encryption_key_size = max_size; 3883 } 3884 3885 void sm_set_authentication_requirements(uint8_t auth_req){ 3886 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3887 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3888 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3889 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3890 } 3891 #endif 3892 sm_auth_req = auth_req; 3893 } 3894 3895 void sm_set_io_capabilities(io_capability_t io_capability){ 3896 sm_io_capabilities = io_capability; 3897 } 3898 3899 #ifdef ENABLE_LE_PERIPHERAL 3900 void sm_set_request_security(int enable){ 3901 sm_slave_request_security = enable; 3902 } 3903 #endif 3904 3905 void sm_set_er(sm_key_t er){ 3906 memcpy(sm_persistent_er, er, 16); 3907 } 3908 3909 void sm_set_ir(sm_key_t ir){ 3910 memcpy(sm_persistent_ir, ir, 16); 3911 } 3912 3913 // Testing support only 3914 void sm_test_set_irk(sm_key_t irk){ 3915 memcpy(sm_persistent_irk, irk, 16); 3916 sm_persistent_irk_ready = 1; 3917 } 3918 3919 void sm_test_use_fixed_local_csrk(void){ 3920 test_use_fixed_local_csrk = 1; 3921 } 3922 3923 #ifdef ENABLE_TESTING_SUPPORT 3924 void sm_test_set_pairing_failure(int reason){ 3925 test_pairing_failure = reason; 3926 } 3927 #endif 3928 3929 void sm_init(void){ 3930 // set some (BTstack default) ER and IR 3931 int i; 3932 sm_key_t er; 3933 sm_key_t ir; 3934 for (i=0;i<16;i++){ 3935 er[i] = 0x30 + i; 3936 ir[i] = 0x90 + i; 3937 } 3938 sm_set_er(er); 3939 sm_set_ir(ir); 3940 // defaults 3941 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3942 | SM_STK_GENERATION_METHOD_OOB 3943 | SM_STK_GENERATION_METHOD_PASSKEY 3944 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3945 3946 sm_max_encryption_key_size = 16; 3947 sm_min_encryption_key_size = 7; 3948 3949 sm_fixed_passkey_in_display_role = 0xffffffff; 3950 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3951 3952 #ifdef ENABLE_CMAC_ENGINE 3953 sm_cmac_state = CMAC_IDLE; 3954 #endif 3955 dkg_state = DKG_W4_WORKING; 3956 rau_state = RAU_W4_WORKING; 3957 sm_aes128_state = SM_AES128_IDLE; 3958 sm_address_resolution_test = -1; // no private address to resolve yet 3959 sm_address_resolution_ah_calculation_active = 0; 3960 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3961 sm_address_resolution_general_queue = NULL; 3962 3963 gap_random_adress_update_period = 15 * 60 * 1000L; 3964 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3965 3966 test_use_fixed_local_csrk = 0; 3967 3968 // register for HCI Events from HCI 3969 hci_event_callback_registration.callback = &sm_event_packet_handler; 3970 hci_add_event_handler(&hci_event_callback_registration); 3971 3972 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3973 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3974 3975 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3976 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3977 #endif 3978 3979 #ifdef USE_MBEDTLS_FOR_ECDH 3980 mbedtls_ecp_group_init(&mbedtls_ec_group); 3981 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3982 #endif 3983 } 3984 3985 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3986 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3987 memcpy(&ec_q[0], qx, 32); 3988 memcpy(&ec_q[32], qy, 32); 3989 memcpy(ec_d, d, 32); 3990 sm_have_ec_keypair = 1; 3991 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3992 #else 3993 UNUSED(qx); 3994 UNUSED(qy); 3995 UNUSED(d); 3996 #endif 3997 } 3998 3999 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4000 static void parse_hex(uint8_t * buffer, const char * hex_string){ 4001 while (*hex_string){ 4002 int high_nibble = nibble_for_char(*hex_string++); 4003 int low_nibble = nibble_for_char(*hex_string++); 4004 *buffer++ = (high_nibble << 4) | low_nibble; 4005 } 4006 } 4007 #endif 4008 4009 void sm_test_use_fixed_ec_keypair(void){ 4010 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4011 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 4012 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 4013 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 4014 parse_hex(ec_d, ec_d_string); 4015 parse_hex(&ec_q[0], ec_qx_string); 4016 parse_hex(&ec_q[32], ec_qy_string); 4017 sm_have_ec_keypair = 1; 4018 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4019 #endif 4020 } 4021 4022 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4023 sm_fixed_passkey_in_display_role = passkey; 4024 } 4025 4026 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4027 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4028 } 4029 4030 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4031 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4032 if (!hci_con) return NULL; 4033 return &hci_con->sm_connection; 4034 } 4035 4036 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4037 switch (sm_conn->sm_engine_state){ 4038 case SM_GENERAL_IDLE: 4039 case SM_RESPONDER_IDLE: 4040 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4041 sm_run(); 4042 break; 4043 default: 4044 break; 4045 } 4046 } 4047 4048 /** 4049 * @brief Trigger Security Request 4050 */ 4051 void sm_send_security_request(hci_con_handle_t con_handle){ 4052 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4053 if (!sm_conn) return; 4054 sm_send_security_request_for_connection(sm_conn); 4055 } 4056 4057 // request pairing 4058 void sm_request_pairing(hci_con_handle_t con_handle){ 4059 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4060 if (!sm_conn) return; // wrong connection 4061 4062 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4063 if (IS_RESPONDER(sm_conn->sm_role)){ 4064 sm_send_security_request_for_connection(sm_conn); 4065 } else { 4066 // used as a trigger to start central/master/initiator security procedures 4067 uint16_t ediv; 4068 sm_key_t ltk; 4069 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4070 switch (sm_conn->sm_irk_lookup_state){ 4071 case IRK_LOOKUP_FAILED: 4072 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4073 break; 4074 case IRK_LOOKUP_SUCCEEDED: 4075 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 4076 if (!sm_is_null_key(ltk) || ediv){ 4077 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 4078 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4079 } else { 4080 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4081 } 4082 break; 4083 default: 4084 sm_conn->sm_bonding_requested = 1; 4085 break; 4086 } 4087 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4088 sm_conn->sm_bonding_requested = 1; 4089 } 4090 } 4091 sm_run(); 4092 } 4093 4094 // called by client app on authorization request 4095 void sm_authorization_decline(hci_con_handle_t con_handle){ 4096 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4097 if (!sm_conn) return; // wrong connection 4098 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4099 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4100 } 4101 4102 void sm_authorization_grant(hci_con_handle_t con_handle){ 4103 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4104 if (!sm_conn) return; // wrong connection 4105 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4106 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4107 } 4108 4109 // GAP Bonding API 4110 4111 void sm_bonding_decline(hci_con_handle_t con_handle){ 4112 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4113 if (!sm_conn) return; // wrong connection 4114 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4115 4116 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4117 switch (setup->sm_stk_generation_method){ 4118 case PK_RESP_INPUT: 4119 case PK_INIT_INPUT: 4120 case OK_BOTH_INPUT: 4121 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4122 break; 4123 case NK_BOTH_INPUT: 4124 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4125 break; 4126 case JUST_WORKS: 4127 case OOB: 4128 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4129 break; 4130 } 4131 } 4132 sm_run(); 4133 } 4134 4135 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4136 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4137 if (!sm_conn) return; // wrong connection 4138 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4139 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4140 if (setup->sm_use_secure_connections){ 4141 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4142 } else { 4143 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4144 } 4145 } 4146 4147 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4148 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4149 sm_sc_prepare_dhkey_check(sm_conn); 4150 } 4151 #endif 4152 4153 sm_run(); 4154 } 4155 4156 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4157 // for now, it's the same 4158 sm_just_works_confirm(con_handle); 4159 } 4160 4161 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4162 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4163 if (!sm_conn) return; // wrong connection 4164 sm_reset_tk(); 4165 big_endian_store_32(setup->sm_tk, 12, passkey); 4166 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4167 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4168 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4169 } 4170 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4171 memcpy(setup->sm_ra, setup->sm_tk, 16); 4172 memcpy(setup->sm_rb, setup->sm_tk, 16); 4173 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4174 sm_sc_start_calculating_local_confirm(sm_conn); 4175 } 4176 #endif 4177 sm_run(); 4178 } 4179 4180 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4181 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4182 if (!sm_conn) return; // wrong connection 4183 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4184 setup->sm_keypress_notification = action; 4185 sm_run(); 4186 } 4187 4188 /** 4189 * @brief Identify device in LE Device DB 4190 * @param handle 4191 * @returns index from le_device_db or -1 if not found/identified 4192 */ 4193 int sm_le_device_index(hci_con_handle_t con_handle ){ 4194 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4195 if (!sm_conn) return -1; 4196 return sm_conn->sm_le_db_index; 4197 } 4198 4199 static int gap_random_address_type_requires_updates(void){ 4200 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4201 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4202 return 1; 4203 } 4204 4205 static uint8_t own_address_type(void){ 4206 switch (gap_random_adress_type){ 4207 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4208 return BD_ADDR_TYPE_LE_PUBLIC; 4209 default: 4210 return BD_ADDR_TYPE_LE_RANDOM; 4211 } 4212 } 4213 4214 // GAP LE API 4215 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4216 gap_random_address_update_stop(); 4217 gap_random_adress_type = random_address_type; 4218 hci_le_set_own_address_type(own_address_type()); 4219 if (!gap_random_address_type_requires_updates()) return; 4220 gap_random_address_update_start(); 4221 gap_random_address_trigger(); 4222 } 4223 4224 gap_random_address_type_t gap_random_address_get_mode(void){ 4225 return gap_random_adress_type; 4226 } 4227 4228 void gap_random_address_set_update_period(int period_ms){ 4229 gap_random_adress_update_period = period_ms; 4230 if (!gap_random_address_type_requires_updates()) return; 4231 gap_random_address_update_stop(); 4232 gap_random_address_update_start(); 4233 } 4234 4235 void gap_random_address_set(bd_addr_t addr){ 4236 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4237 memcpy(sm_random_address, addr, 6); 4238 if (rau_state == RAU_W4_WORKING) return; 4239 rau_state = RAU_SET_ADDRESS; 4240 sm_run(); 4241 } 4242 4243 #ifdef ENABLE_LE_PERIPHERAL 4244 /* 4245 * @brief Set Advertisement Paramters 4246 * @param adv_int_min 4247 * @param adv_int_max 4248 * @param adv_type 4249 * @param direct_address_type 4250 * @param direct_address 4251 * @param channel_map 4252 * @param filter_policy 4253 * 4254 * @note own_address_type is used from gap_random_address_set_mode 4255 */ 4256 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4257 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4258 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4259 direct_address_typ, direct_address, channel_map, filter_policy); 4260 } 4261 #endif 4262