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 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 80 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 81 #else 82 // #define USE_MBEDTLS_FOR_ECDH 83 #define USE_MICROECC_FOR_ECDH 84 #endif 85 #endif 86 87 // Software ECDH implementation provided by mbedtls 88 #ifdef USE_MBEDTLS_FOR_ECDH 89 #include "mbedtls/config.h" 90 #include "mbedtls/platform.h" 91 #include "mbedtls/ecp.h" 92 #include "sm_mbedtls_allocator.h" 93 #endif 94 95 // Software ECDH implementation provided by micro-ecc 96 #ifdef USE_MICROECC_FOR_ECDH 97 #include "uECC.h" 98 #endif 99 100 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 101 #define ENABLE_CMAC_ENGINE 102 #endif 103 104 // 105 // SM internal types and globals 106 // 107 108 typedef enum { 109 DKG_W4_WORKING, 110 DKG_CALC_IRK, 111 DKG_W4_IRK, 112 DKG_CALC_DHK, 113 DKG_W4_DHK, 114 DKG_READY 115 } derived_key_generation_t; 116 117 typedef enum { 118 RAU_W4_WORKING, 119 RAU_IDLE, 120 RAU_GET_RANDOM, 121 RAU_W4_RANDOM, 122 RAU_GET_ENC, 123 RAU_W4_ENC, 124 RAU_SET_ADDRESS, 125 } random_address_update_t; 126 127 typedef enum { 128 CMAC_IDLE, 129 CMAC_CALC_SUBKEYS, 130 CMAC_W4_SUBKEYS, 131 CMAC_CALC_MI, 132 CMAC_W4_MI, 133 CMAC_CALC_MLAST, 134 CMAC_W4_MLAST 135 } cmac_state_t; 136 137 typedef enum { 138 JUST_WORKS, 139 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 140 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 141 OK_BOTH_INPUT, // Only input on both, both input PK 142 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 143 OOB // OOB available on both sides 144 } stk_generation_method_t; 145 146 typedef enum { 147 SM_USER_RESPONSE_IDLE, 148 SM_USER_RESPONSE_PENDING, 149 SM_USER_RESPONSE_CONFIRM, 150 SM_USER_RESPONSE_PASSKEY, 151 SM_USER_RESPONSE_DECLINE 152 } sm_user_response_t; 153 154 typedef enum { 155 SM_AES128_IDLE, 156 SM_AES128_ACTIVE 157 } sm_aes128_state_t; 158 159 typedef enum { 160 ADDRESS_RESOLUTION_IDLE, 161 ADDRESS_RESOLUTION_GENERAL, 162 ADDRESS_RESOLUTION_FOR_CONNECTION, 163 } address_resolution_mode_t; 164 165 typedef enum { 166 ADDRESS_RESOLUTION_SUCEEDED, 167 ADDRESS_RESOLUTION_FAILED, 168 } address_resolution_event_t; 169 170 typedef enum { 171 EC_KEY_GENERATION_IDLE, 172 EC_KEY_GENERATION_ACTIVE, 173 EC_KEY_GENERATION_W4_KEY, 174 EC_KEY_GENERATION_DONE, 175 } ec_key_generation_state_t; 176 177 typedef enum { 178 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 179 } sm_state_var_t; 180 181 // 182 // GLOBAL DATA 183 // 184 185 static uint8_t test_use_fixed_local_csrk; 186 187 // configuration 188 static uint8_t sm_accepted_stk_generation_methods; 189 static uint8_t sm_max_encryption_key_size; 190 static uint8_t sm_min_encryption_key_size; 191 static uint8_t sm_auth_req = 0; 192 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 193 static uint8_t sm_slave_request_security; 194 #ifdef ENABLE_LE_SECURE_CONNECTIONS 195 static uint8_t sm_have_ec_keypair; 196 #endif 197 198 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 199 static sm_key_t sm_persistent_er; 200 static sm_key_t sm_persistent_ir; 201 202 // derived from sm_persistent_ir 203 static sm_key_t sm_persistent_dhk; 204 static sm_key_t sm_persistent_irk; 205 static uint8_t sm_persistent_irk_ready = 0; // used for testing 206 static derived_key_generation_t dkg_state; 207 208 // derived from sm_persistent_er 209 // .. 210 211 // random address update 212 static random_address_update_t rau_state; 213 static bd_addr_t sm_random_address; 214 215 // CMAC Calculation: General 216 #ifdef ENABLE_CMAC_ENGINE 217 static cmac_state_t sm_cmac_state; 218 static uint16_t sm_cmac_message_len; 219 static sm_key_t sm_cmac_k; 220 static sm_key_t sm_cmac_x; 221 static sm_key_t sm_cmac_m_last; 222 static uint8_t sm_cmac_block_current; 223 static uint8_t sm_cmac_block_count; 224 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 225 static void (*sm_cmac_done_handler)(uint8_t * hash); 226 #endif 227 228 // CMAC for ATT Signed Writes 229 #ifdef ENABLE_LE_SIGNED_WRITE 230 static uint8_t sm_cmac_header[3]; 231 static const uint8_t * sm_cmac_message; 232 static uint8_t sm_cmac_sign_counter[4]; 233 #endif 234 235 // CMAC for Secure Connection functions 236 #ifdef ENABLE_LE_SECURE_CONNECTIONS 237 static sm_connection_t * sm_cmac_connection; 238 static uint8_t sm_cmac_sc_buffer[80]; 239 #endif 240 241 // resolvable private address lookup / CSRK calculation 242 static int sm_address_resolution_test; 243 static int sm_address_resolution_ah_calculation_active; 244 static uint8_t sm_address_resolution_addr_type; 245 static bd_addr_t sm_address_resolution_address; 246 static void * sm_address_resolution_context; 247 static address_resolution_mode_t sm_address_resolution_mode; 248 static btstack_linked_list_t sm_address_resolution_general_queue; 249 250 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 251 static sm_aes128_state_t sm_aes128_state; 252 static void * sm_aes128_context; 253 254 // use aes128 provided by MCU - not needed usually 255 #ifdef HAVE_AES128 256 static uint8_t aes128_result_flipped[16]; 257 static btstack_timer_source_t aes128_timer; 258 void btstack_aes128_calc(uint8_t * key, uint8_t * plaintext, uint8_t * result); 259 #endif 260 261 // random engine. store context (ususally sm_connection_t) 262 static void * sm_random_context; 263 264 // to receive hci events 265 static btstack_packet_callback_registration_t hci_event_callback_registration; 266 267 /* to dispatch sm event */ 268 static btstack_linked_list_t sm_event_handlers; 269 270 // LE Secure Connections 271 #ifdef ENABLE_LE_SECURE_CONNECTIONS 272 static ec_key_generation_state_t ec_key_generation_state; 273 static uint8_t ec_d[32]; 274 static uint8_t ec_q[64]; 275 #endif 276 277 // Software ECDH implementation provided by mbedtls 278 #ifdef USE_MBEDTLS_FOR_ECDH 279 // group is always valid 280 static mbedtls_ecp_group mbedtls_ec_group; 281 #ifndef HAVE_MALLOC 282 // COMP Method with Window 2 283 // 1300 bytes with 23 allocations 284 // #define MBEDTLS_ALLOC_BUFFER_SIZE (1300+23*sizeof(void *)) 285 // NAIVE Method with safe cond assignments (without safe cond, order changes and allocations fail) 286 #define MBEDTLS_ALLOC_BUFFER_SIZE (700+18*sizeof(void *)) 287 static uint8_t mbedtls_memory_buffer[MBEDTLS_ALLOC_BUFFER_SIZE]; 288 #endif 289 #endif 290 291 // 292 // Volume 3, Part H, Chapter 24 293 // "Security shall be initiated by the Security Manager in the device in the master role. 294 // The device in the slave role shall be the responding device." 295 // -> master := initiator, slave := responder 296 // 297 298 // data needed for security setup 299 typedef struct sm_setup_context { 300 301 btstack_timer_source_t sm_timeout; 302 303 // used in all phases 304 uint8_t sm_pairing_failed_reason; 305 306 // user response, (Phase 1 and/or 2) 307 uint8_t sm_user_response; 308 uint8_t sm_keypress_notification; 309 310 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 311 int sm_key_distribution_send_set; 312 int sm_key_distribution_received_set; 313 314 // Phase 2 (Pairing over SMP) 315 stk_generation_method_t sm_stk_generation_method; 316 sm_key_t sm_tk; 317 uint8_t sm_use_secure_connections; 318 319 sm_key_t sm_c1_t3_value; // c1 calculation 320 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 321 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 322 sm_key_t sm_local_random; 323 sm_key_t sm_local_confirm; 324 sm_key_t sm_peer_random; 325 sm_key_t sm_peer_confirm; 326 uint8_t sm_m_addr_type; // address and type can be removed 327 uint8_t sm_s_addr_type; // '' 328 bd_addr_t sm_m_address; // '' 329 bd_addr_t sm_s_address; // '' 330 sm_key_t sm_ltk; 331 332 uint8_t sm_state_vars; 333 #ifdef ENABLE_LE_SECURE_CONNECTIONS 334 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 335 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 336 sm_key_t sm_local_nonce; // might be combined with sm_local_random 337 sm_key_t sm_peer_dhkey_check; 338 sm_key_t sm_local_dhkey_check; 339 sm_key_t sm_ra; 340 sm_key_t sm_rb; 341 sm_key_t sm_t; // used for f5 and h6 342 sm_key_t sm_mackey; 343 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 344 #endif 345 346 // Phase 3 347 348 // key distribution, we generate 349 uint16_t sm_local_y; 350 uint16_t sm_local_div; 351 uint16_t sm_local_ediv; 352 uint8_t sm_local_rand[8]; 353 sm_key_t sm_local_ltk; 354 sm_key_t sm_local_csrk; 355 sm_key_t sm_local_irk; 356 // sm_local_address/addr_type not needed 357 358 // key distribution, received from peer 359 uint16_t sm_peer_y; 360 uint16_t sm_peer_div; 361 uint16_t sm_peer_ediv; 362 uint8_t sm_peer_rand[8]; 363 sm_key_t sm_peer_ltk; 364 sm_key_t sm_peer_irk; 365 sm_key_t sm_peer_csrk; 366 uint8_t sm_peer_addr_type; 367 bd_addr_t sm_peer_address; 368 369 } sm_setup_context_t; 370 371 // 372 static sm_setup_context_t the_setup; 373 static sm_setup_context_t * setup = &the_setup; 374 375 // active connection - the one for which the_setup is used for 376 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 377 378 // @returns 1 if oob data is available 379 // stores oob data in provided 16 byte buffer if not null 380 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 381 382 // horizontal: initiator capabilities 383 // vertial: responder capabilities 384 static const stk_generation_method_t stk_generation_method [5] [5] = { 385 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 386 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 387 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 388 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 389 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 390 }; 391 392 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 393 #ifdef ENABLE_LE_SECURE_CONNECTIONS 394 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 395 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 396 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 397 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 398 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 399 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 400 }; 401 #endif 402 403 static void sm_run(void); 404 static void sm_done_for_handle(hci_con_handle_t con_handle); 405 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 406 static inline int sm_calc_actual_encryption_key_size(int other); 407 static int sm_validate_stk_generation_method(void); 408 static void sm_handle_encryption_result(uint8_t * data); 409 410 static void log_info_hex16(const char * name, uint16_t value){ 411 log_info("%-6s 0x%04x", name, value); 412 } 413 414 // @returns 1 if all bytes are 0 415 static int sm_is_null(uint8_t * data, int size){ 416 int i; 417 for (i=0; i < size ; i++){ 418 if (data[i]) return 0; 419 } 420 return 1; 421 } 422 423 static int sm_is_null_random(uint8_t random[8]){ 424 return sm_is_null(random, 8); 425 } 426 427 static int sm_is_null_key(uint8_t * key){ 428 return sm_is_null(key, 16); 429 } 430 431 // Key utils 432 static void sm_reset_tk(void){ 433 int i; 434 for (i=0;i<16;i++){ 435 setup->sm_tk[i] = 0; 436 } 437 } 438 439 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 440 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 441 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 442 int i; 443 for (i = max_encryption_size ; i < 16 ; i++){ 444 key[15-i] = 0; 445 } 446 } 447 448 // SMP Timeout implementation 449 450 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 451 // the Security Manager Timer shall be reset and started. 452 // 453 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 454 // 455 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 456 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 457 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 458 // established. 459 460 static void sm_timeout_handler(btstack_timer_source_t * timer){ 461 log_info("SM timeout"); 462 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 463 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 464 sm_done_for_handle(sm_conn->sm_handle); 465 466 // trigger handling of next ready connection 467 sm_run(); 468 } 469 static void sm_timeout_start(sm_connection_t * sm_conn){ 470 btstack_run_loop_remove_timer(&setup->sm_timeout); 471 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 472 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 473 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 474 btstack_run_loop_add_timer(&setup->sm_timeout); 475 } 476 static void sm_timeout_stop(void){ 477 btstack_run_loop_remove_timer(&setup->sm_timeout); 478 } 479 static void sm_timeout_reset(sm_connection_t * sm_conn){ 480 sm_timeout_stop(); 481 sm_timeout_start(sm_conn); 482 } 483 484 // end of sm timeout 485 486 // GAP Random Address updates 487 static gap_random_address_type_t gap_random_adress_type; 488 static btstack_timer_source_t gap_random_address_update_timer; 489 static uint32_t gap_random_adress_update_period; 490 491 static void gap_random_address_trigger(void){ 492 if (rau_state != RAU_IDLE) return; 493 log_info("gap_random_address_trigger"); 494 rau_state = RAU_GET_RANDOM; 495 sm_run(); 496 } 497 498 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 499 UNUSED(timer); 500 501 log_info("GAP Random Address Update due"); 502 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 503 btstack_run_loop_add_timer(&gap_random_address_update_timer); 504 gap_random_address_trigger(); 505 } 506 507 static void gap_random_address_update_start(void){ 508 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 509 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 510 btstack_run_loop_add_timer(&gap_random_address_update_timer); 511 } 512 513 static void gap_random_address_update_stop(void){ 514 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 515 } 516 517 518 static void sm_random_start(void * context){ 519 sm_random_context = context; 520 hci_send_cmd(&hci_le_rand); 521 } 522 523 #ifdef HAVE_AES128 524 static void aes128_completed(btstack_timer_source_t * ts){ 525 UNUSED(ts); 526 sm_handle_encryption_result(&aes128_result_flipped[0]); 527 sm_run(); 528 } 529 #endif 530 531 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 532 // context is made availabe to aes128 result handler by this 533 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 534 sm_aes128_state = SM_AES128_ACTIVE; 535 sm_aes128_context = context; 536 537 #ifdef HAVE_AES128 538 // calc result directly 539 sm_key_t result; 540 btstack_aes128_calc(key, plaintext, result); 541 542 // log 543 log_info_key("key", key); 544 log_info_key("txt", plaintext); 545 log_info_key("res", result); 546 547 // flip 548 reverse_128(&result[0], &aes128_result_flipped[0]); 549 550 // deliver via timer 551 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 552 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 553 btstack_run_loop_add_timer(&aes128_timer); 554 #else 555 sm_key_t key_flipped, plaintext_flipped; 556 reverse_128(key, key_flipped); 557 reverse_128(plaintext, plaintext_flipped); 558 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 559 #endif 560 } 561 562 // ah(k,r) helper 563 // r = padding || r 564 // r - 24 bit value 565 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 566 // r'= padding || r 567 memset(r_prime, 0, 16); 568 memcpy(&r_prime[13], r, 3); 569 } 570 571 // d1 helper 572 // d' = padding || r || d 573 // d,r - 16 bit values 574 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 575 // d'= padding || r || d 576 memset(d1_prime, 0, 16); 577 big_endian_store_16(d1_prime, 12, r); 578 big_endian_store_16(d1_prime, 14, d); 579 } 580 581 // dm helper 582 // r’ = padding || r 583 // r - 64 bit value 584 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 585 memset(r_prime, 0, 16); 586 memcpy(&r_prime[8], r, 8); 587 } 588 589 // calculate arguments for first AES128 operation in C1 function 590 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){ 591 592 // p1 = pres || preq || rat’ || iat’ 593 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 594 // cant octet of pres becomes the most significant octet of p1. 595 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 596 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 597 // p1 is 0x05000800000302070710000001010001." 598 599 sm_key_t p1; 600 reverse_56(pres, &p1[0]); 601 reverse_56(preq, &p1[7]); 602 p1[14] = rat; 603 p1[15] = iat; 604 log_info_key("p1", p1); 605 log_info_key("r", r); 606 607 // t1 = r xor p1 608 int i; 609 for (i=0;i<16;i++){ 610 t1[i] = r[i] ^ p1[i]; 611 } 612 log_info_key("t1", t1); 613 } 614 615 // calculate arguments for second AES128 operation in C1 function 616 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 617 // p2 = padding || ia || ra 618 // "The least significant octet of ra becomes the least significant octet of p2 and 619 // the most significant octet of padding becomes the most significant octet of p2. 620 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 621 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 622 623 sm_key_t p2; 624 memset(p2, 0, 16); 625 memcpy(&p2[4], ia, 6); 626 memcpy(&p2[10], ra, 6); 627 log_info_key("p2", p2); 628 629 // c1 = e(k, t2_xor_p2) 630 int i; 631 for (i=0;i<16;i++){ 632 t3[i] = t2[i] ^ p2[i]; 633 } 634 log_info_key("t3", t3); 635 } 636 637 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 638 log_info_key("r1", r1); 639 log_info_key("r2", r2); 640 memcpy(&r_prime[8], &r2[8], 8); 641 memcpy(&r_prime[0], &r1[8], 8); 642 } 643 644 #ifdef ENABLE_LE_SECURE_CONNECTIONS 645 // Software implementations of crypto toolbox for LE Secure Connection 646 // TODO: replace with code to use AES Engine of HCI Controller 647 typedef uint8_t sm_key24_t[3]; 648 typedef uint8_t sm_key56_t[7]; 649 typedef uint8_t sm_key256_t[32]; 650 651 #if 0 652 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 653 uint32_t rk[RKLENGTH(KEYBITS)]; 654 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 655 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 656 } 657 658 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 659 memcpy(k1, k0, 16); 660 sm_shift_left_by_one_bit_inplace(16, k1); 661 if (k0[0] & 0x80){ 662 k1[15] ^= 0x87; 663 } 664 memcpy(k2, k1, 16); 665 sm_shift_left_by_one_bit_inplace(16, k2); 666 if (k1[0] & 0x80){ 667 k2[15] ^= 0x87; 668 } 669 } 670 671 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 672 sm_key_t k0, k1, k2, zero; 673 memset(zero, 0, 16); 674 675 aes128_calc_cyphertext(key, zero, k0); 676 calc_subkeys(k0, k1, k2); 677 678 int cmac_block_count = (cmac_message_len + 15) / 16; 679 680 // step 3: .. 681 if (cmac_block_count==0){ 682 cmac_block_count = 1; 683 } 684 685 // step 4: set m_last 686 sm_key_t cmac_m_last; 687 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 688 int i; 689 if (sm_cmac_last_block_complete){ 690 for (i=0;i<16;i++){ 691 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 692 } 693 } else { 694 int valid_octets_in_last_block = cmac_message_len & 0x0f; 695 for (i=0;i<16;i++){ 696 if (i < valid_octets_in_last_block){ 697 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 698 continue; 699 } 700 if (i == valid_octets_in_last_block){ 701 cmac_m_last[i] = 0x80 ^ k2[i]; 702 continue; 703 } 704 cmac_m_last[i] = k2[i]; 705 } 706 } 707 708 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 709 // LOG_KEY(cmac_m_last); 710 711 // Step 5 712 sm_key_t cmac_x; 713 memset(cmac_x, 0, 16); 714 715 // Step 6 716 sm_key_t sm_cmac_y; 717 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 718 for (i=0;i<16;i++){ 719 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 720 } 721 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 722 } 723 for (i=0;i<16;i++){ 724 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 725 } 726 727 // Step 7 728 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 729 } 730 #endif 731 #endif 732 733 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){ 734 event[0] = type; 735 event[1] = event_size - 2; 736 little_endian_store_16(event, 2, con_handle); 737 event[4] = addr_type; 738 reverse_bd_addr(address, &event[5]); 739 } 740 741 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 742 UNUSED(channel); 743 744 // log event 745 hci_dump_packet(packet_type, 1, packet, size); 746 // dispatch to all event handlers 747 btstack_linked_list_iterator_t it; 748 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 749 while (btstack_linked_list_iterator_has_next(&it)){ 750 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 751 entry->callback(packet_type, 0, packet, size); 752 } 753 } 754 755 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 756 uint8_t event[11]; 757 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 758 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 759 } 760 761 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){ 762 uint8_t event[15]; 763 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 764 little_endian_store_32(event, 11, passkey); 765 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 766 } 767 768 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){ 769 // fetch addr and addr type from db 770 bd_addr_t identity_address; 771 int identity_address_type; 772 le_device_db_info(index, &identity_address_type, identity_address, NULL); 773 774 uint8_t event[19]; 775 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 776 event[11] = identity_address_type; 777 reverse_bd_addr(identity_address, &event[12]); 778 event[18] = index; 779 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 780 } 781 782 static void sm_notify_client_authorization(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 783 784 uint8_t event[18]; 785 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 786 event[11] = result; 787 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 788 } 789 790 // decide on stk generation based on 791 // - pairing request 792 // - io capabilities 793 // - OOB data availability 794 static void sm_setup_tk(void){ 795 796 // default: just works 797 setup->sm_stk_generation_method = JUST_WORKS; 798 799 #ifdef ENABLE_LE_SECURE_CONNECTIONS 800 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 801 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 802 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 803 memset(setup->sm_ra, 0, 16); 804 memset(setup->sm_rb, 0, 16); 805 #else 806 setup->sm_use_secure_connections = 0; 807 #endif 808 809 // If both devices have not set the MITM option in the Authentication Requirements 810 // Flags, then the IO capabilities shall be ignored and the Just Works association 811 // model shall be used. 812 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 813 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 814 log_info("SM: MITM not required by both -> JUST WORKS"); 815 return; 816 } 817 818 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 819 820 // If both devices have out of band authentication data, then the Authentication 821 // Requirements Flags shall be ignored when selecting the pairing method and the 822 // Out of Band pairing method shall be used. 823 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 824 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 825 log_info("SM: have OOB data"); 826 log_info_key("OOB", setup->sm_tk); 827 setup->sm_stk_generation_method = OOB; 828 return; 829 } 830 831 // Reset TK as it has been setup in sm_init_setup 832 sm_reset_tk(); 833 834 // Also use just works if unknown io capabilites 835 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)){ 836 return; 837 } 838 839 // Otherwise the IO capabilities of the devices shall be used to determine the 840 // pairing method as defined in Table 2.4. 841 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 842 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 843 844 #ifdef ENABLE_LE_SECURE_CONNECTIONS 845 // table not define by default 846 if (setup->sm_use_secure_connections){ 847 generation_method = stk_generation_method_with_secure_connection; 848 } 849 #endif 850 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)]; 851 852 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 853 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); 854 } 855 856 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 857 int flags = 0; 858 if (key_set & SM_KEYDIST_ENC_KEY){ 859 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 860 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 861 } 862 if (key_set & SM_KEYDIST_ID_KEY){ 863 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 864 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 865 } 866 if (key_set & SM_KEYDIST_SIGN){ 867 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 868 } 869 return flags; 870 } 871 872 static void sm_setup_key_distribution(uint8_t key_set){ 873 setup->sm_key_distribution_received_set = 0; 874 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 875 } 876 877 // CSRK Key Lookup 878 879 880 static int sm_address_resolution_idle(void){ 881 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 882 } 883 884 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){ 885 memcpy(sm_address_resolution_address, addr, 6); 886 sm_address_resolution_addr_type = addr_type; 887 sm_address_resolution_test = 0; 888 sm_address_resolution_mode = mode; 889 sm_address_resolution_context = context; 890 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 891 } 892 893 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 894 // check if already in list 895 btstack_linked_list_iterator_t it; 896 sm_lookup_entry_t * entry; 897 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 898 while(btstack_linked_list_iterator_has_next(&it)){ 899 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 900 if (entry->address_type != address_type) continue; 901 if (memcmp(entry->address, address, 6)) continue; 902 // already in list 903 return BTSTACK_BUSY; 904 } 905 entry = btstack_memory_sm_lookup_entry_get(); 906 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 907 entry->address_type = (bd_addr_type_t) address_type; 908 memcpy(entry->address, address, 6); 909 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 910 sm_run(); 911 return 0; 912 } 913 914 // 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 915 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 916 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 917 } 918 static inline void dkg_next_state(void){ 919 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 920 } 921 static inline void rau_next_state(void){ 922 rau_state = (random_address_update_t) (((int)rau_state) + 1); 923 } 924 925 // CMAC calculation using AES Engine 926 #ifdef ENABLE_CMAC_ENGINE 927 928 static inline void sm_cmac_next_state(void){ 929 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 930 } 931 932 static int sm_cmac_last_block_complete(void){ 933 if (sm_cmac_message_len == 0) return 0; 934 return (sm_cmac_message_len & 0x0f) == 0; 935 } 936 937 int sm_cmac_ready(void){ 938 return sm_cmac_state == CMAC_IDLE; 939 } 940 941 // generic cmac calculation 942 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])){ 943 // Generalized CMAC 944 memcpy(sm_cmac_k, key, 16); 945 memset(sm_cmac_x, 0, 16); 946 sm_cmac_block_current = 0; 947 sm_cmac_message_len = message_len; 948 sm_cmac_done_handler = done_callback; 949 sm_cmac_get_byte = get_byte_callback; 950 951 // step 2: n := ceil(len/const_Bsize); 952 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 953 954 // step 3: .. 955 if (sm_cmac_block_count==0){ 956 sm_cmac_block_count = 1; 957 } 958 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 959 960 // first, we need to compute l for k1, k2, and m_last 961 sm_cmac_state = CMAC_CALC_SUBKEYS; 962 963 // let's go 964 sm_run(); 965 } 966 #endif 967 968 // cmac for ATT Message signing 969 #ifdef ENABLE_LE_SIGNED_WRITE 970 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 971 if (offset >= sm_cmac_message_len) { 972 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 973 return 0; 974 } 975 976 offset = sm_cmac_message_len - 1 - offset; 977 978 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 979 if (offset < 3){ 980 return sm_cmac_header[offset]; 981 } 982 int actual_message_len_incl_header = sm_cmac_message_len - 4; 983 if (offset < actual_message_len_incl_header){ 984 return sm_cmac_message[offset - 3]; 985 } 986 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 987 } 988 989 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)){ 990 // ATT Message Signing 991 sm_cmac_header[0] = opcode; 992 little_endian_store_16(sm_cmac_header, 1, con_handle); 993 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 994 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 995 sm_cmac_message = message; 996 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 997 } 998 #endif 999 1000 #ifdef ENABLE_CMAC_ENGINE 1001 static void sm_cmac_handle_aes_engine_ready(void){ 1002 switch (sm_cmac_state){ 1003 case CMAC_CALC_SUBKEYS: { 1004 sm_key_t const_zero; 1005 memset(const_zero, 0, 16); 1006 sm_cmac_next_state(); 1007 sm_aes128_start(sm_cmac_k, const_zero, NULL); 1008 break; 1009 } 1010 case CMAC_CALC_MI: { 1011 int j; 1012 sm_key_t y; 1013 for (j=0;j<16;j++){ 1014 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 1015 } 1016 sm_cmac_block_current++; 1017 sm_cmac_next_state(); 1018 sm_aes128_start(sm_cmac_k, y, NULL); 1019 break; 1020 } 1021 case CMAC_CALC_MLAST: { 1022 int i; 1023 sm_key_t y; 1024 for (i=0;i<16;i++){ 1025 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 1026 } 1027 log_info_key("Y", y); 1028 sm_cmac_block_current++; 1029 sm_cmac_next_state(); 1030 sm_aes128_start(sm_cmac_k, y, NULL); 1031 break; 1032 } 1033 default: 1034 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1035 break; 1036 } 1037 } 1038 1039 // CMAC Implementation using AES128 engine 1040 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1041 int i; 1042 int carry = 0; 1043 for (i=len-1; i >= 0 ; i--){ 1044 int new_carry = data[i] >> 7; 1045 data[i] = data[i] << 1 | carry; 1046 carry = new_carry; 1047 } 1048 } 1049 1050 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1051 switch (sm_cmac_state){ 1052 case CMAC_W4_SUBKEYS: { 1053 sm_key_t k1; 1054 memcpy(k1, data, 16); 1055 sm_shift_left_by_one_bit_inplace(16, k1); 1056 if (data[0] & 0x80){ 1057 k1[15] ^= 0x87; 1058 } 1059 sm_key_t k2; 1060 memcpy(k2, k1, 16); 1061 sm_shift_left_by_one_bit_inplace(16, k2); 1062 if (k1[0] & 0x80){ 1063 k2[15] ^= 0x87; 1064 } 1065 1066 log_info_key("k", sm_cmac_k); 1067 log_info_key("k1", k1); 1068 log_info_key("k2", k2); 1069 1070 // step 4: set m_last 1071 int i; 1072 if (sm_cmac_last_block_complete()){ 1073 for (i=0;i<16;i++){ 1074 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1075 } 1076 } else { 1077 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1078 for (i=0;i<16;i++){ 1079 if (i < valid_octets_in_last_block){ 1080 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1081 continue; 1082 } 1083 if (i == valid_octets_in_last_block){ 1084 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1085 continue; 1086 } 1087 sm_cmac_m_last[i] = k2[i]; 1088 } 1089 } 1090 1091 // next 1092 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1093 break; 1094 } 1095 case CMAC_W4_MI: 1096 memcpy(sm_cmac_x, data, 16); 1097 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1098 break; 1099 case CMAC_W4_MLAST: 1100 // done 1101 log_info("Setting CMAC Engine to IDLE"); 1102 sm_cmac_state = CMAC_IDLE; 1103 log_info_key("CMAC", data); 1104 sm_cmac_done_handler(data); 1105 break; 1106 default: 1107 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1108 break; 1109 } 1110 } 1111 #endif 1112 1113 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1114 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1115 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1116 switch (setup->sm_stk_generation_method){ 1117 case PK_RESP_INPUT: 1118 if (IS_RESPONDER(sm_conn->sm_role)){ 1119 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1120 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1121 } else { 1122 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)); 1123 } 1124 break; 1125 case PK_INIT_INPUT: 1126 if (IS_RESPONDER(sm_conn->sm_role)){ 1127 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)); 1128 } else { 1129 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1130 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1131 } 1132 break; 1133 case OK_BOTH_INPUT: 1134 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1135 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1136 break; 1137 case NK_BOTH_INPUT: 1138 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1139 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)); 1140 break; 1141 case JUST_WORKS: 1142 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1143 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1144 break; 1145 case OOB: 1146 // client already provided OOB data, let's skip notification. 1147 break; 1148 } 1149 } 1150 1151 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1152 int recv_flags; 1153 if (IS_RESPONDER(sm_conn->sm_role)){ 1154 // slave / responder 1155 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1156 } else { 1157 // master / initiator 1158 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1159 } 1160 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1161 return recv_flags == setup->sm_key_distribution_received_set; 1162 } 1163 1164 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1165 if (sm_active_connection_handle == con_handle){ 1166 sm_timeout_stop(); 1167 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1168 log_info("sm: connection 0x%x released setup context", con_handle); 1169 } 1170 } 1171 1172 static int sm_key_distribution_flags_for_auth_req(void){ 1173 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1174 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1175 // encryption information only if bonding requested 1176 flags |= SM_KEYDIST_ENC_KEY; 1177 } 1178 return flags; 1179 } 1180 1181 static void sm_reset_setup(void){ 1182 // fill in sm setup 1183 setup->sm_state_vars = 0; 1184 setup->sm_keypress_notification = 0xff; 1185 sm_reset_tk(); 1186 } 1187 1188 static void sm_init_setup(sm_connection_t * sm_conn){ 1189 1190 // fill in sm setup 1191 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1192 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1193 1194 // query client for OOB data 1195 int have_oob_data = 0; 1196 if (sm_get_oob_data) { 1197 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1198 } 1199 1200 sm_pairing_packet_t * local_packet; 1201 if (IS_RESPONDER(sm_conn->sm_role)){ 1202 // slave 1203 local_packet = &setup->sm_s_pres; 1204 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1205 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1206 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1207 } else { 1208 // master 1209 local_packet = &setup->sm_m_preq; 1210 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1211 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1212 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1213 1214 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1215 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1216 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1217 } 1218 1219 uint8_t auth_req = sm_auth_req; 1220 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1221 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1222 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1223 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1224 } 1225 1226 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1227 1228 sm_pairing_packet_t * remote_packet; 1229 int remote_key_request; 1230 if (IS_RESPONDER(sm_conn->sm_role)){ 1231 // slave / responder 1232 remote_packet = &setup->sm_m_preq; 1233 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1234 } else { 1235 // master / initiator 1236 remote_packet = &setup->sm_s_pres; 1237 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1238 } 1239 1240 // check key size 1241 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1242 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1243 1244 // decide on STK generation method 1245 sm_setup_tk(); 1246 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1247 1248 // check if STK generation method is acceptable by client 1249 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1250 1251 // identical to responder 1252 sm_setup_key_distribution(remote_key_request); 1253 1254 // JUST WORKS doens't provide authentication 1255 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1256 1257 return 0; 1258 } 1259 1260 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1261 1262 // cache and reset context 1263 int matched_device_id = sm_address_resolution_test; 1264 address_resolution_mode_t mode = sm_address_resolution_mode; 1265 void * context = sm_address_resolution_context; 1266 1267 // reset context 1268 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1269 sm_address_resolution_context = NULL; 1270 sm_address_resolution_test = -1; 1271 hci_con_handle_t con_handle = 0; 1272 1273 sm_connection_t * sm_connection; 1274 #ifdef ENABLE_LE_CENTRAL 1275 sm_key_t ltk; 1276 #endif 1277 switch (mode){ 1278 case ADDRESS_RESOLUTION_GENERAL: 1279 break; 1280 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1281 sm_connection = (sm_connection_t *) context; 1282 con_handle = sm_connection->sm_handle; 1283 switch (event){ 1284 case ADDRESS_RESOLUTION_SUCEEDED: 1285 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1286 sm_connection->sm_le_db_index = matched_device_id; 1287 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1288 #ifdef ENABLE_LE_CENTRAL 1289 if (sm_connection->sm_role) break; 1290 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1291 sm_connection->sm_security_request_received = 0; 1292 sm_connection->sm_bonding_requested = 0; 1293 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1294 if (!sm_is_null_key(ltk)){ 1295 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1296 } else { 1297 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1298 } 1299 #endif 1300 break; 1301 case ADDRESS_RESOLUTION_FAILED: 1302 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1303 #ifdef ENABLE_LE_CENTRAL 1304 if (sm_connection->sm_role) break; 1305 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1306 sm_connection->sm_security_request_received = 0; 1307 sm_connection->sm_bonding_requested = 0; 1308 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1309 #endif 1310 break; 1311 } 1312 break; 1313 default: 1314 break; 1315 } 1316 1317 switch (event){ 1318 case ADDRESS_RESOLUTION_SUCEEDED: 1319 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1320 break; 1321 case ADDRESS_RESOLUTION_FAILED: 1322 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1323 break; 1324 } 1325 } 1326 1327 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1328 1329 int le_db_index = -1; 1330 1331 // lookup device based on IRK 1332 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1333 int i; 1334 for (i=0; i < le_device_db_count(); i++){ 1335 sm_key_t irk; 1336 bd_addr_t address; 1337 int address_type; 1338 le_device_db_info(i, &address_type, address, irk); 1339 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1340 log_info("sm: device found for IRK, updating"); 1341 le_db_index = i; 1342 break; 1343 } 1344 } 1345 } 1346 1347 // if not found, lookup via public address if possible 1348 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1349 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1350 int i; 1351 for (i=0; i < le_device_db_count(); i++){ 1352 bd_addr_t address; 1353 int address_type; 1354 le_device_db_info(i, &address_type, address, NULL); 1355 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1356 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1357 log_info("sm: device found for public address, updating"); 1358 le_db_index = i; 1359 break; 1360 } 1361 } 1362 } 1363 1364 // if not found, add to db 1365 if (le_db_index < 0) { 1366 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1367 } 1368 1369 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1370 1371 if (le_db_index >= 0){ 1372 1373 #ifdef ENABLE_LE_SIGNED_WRITE 1374 // store local CSRK 1375 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1376 log_info("sm: store local CSRK"); 1377 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1378 le_device_db_local_counter_set(le_db_index, 0); 1379 } 1380 1381 // store remote CSRK 1382 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1383 log_info("sm: store remote CSRK"); 1384 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1385 le_device_db_remote_counter_set(le_db_index, 0); 1386 } 1387 #endif 1388 // store encryption information for secure connections: LTK generated by ECDH 1389 if (setup->sm_use_secure_connections){ 1390 log_info("sm: store SC LTK (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1391 uint8_t zero_rand[8]; 1392 memset(zero_rand, 0, 8); 1393 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1394 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1395 } 1396 1397 // store encryption infromation for legacy pairing: peer LTK, EDIV, RAND 1398 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1399 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1400 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1401 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1402 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1403 1404 } 1405 } 1406 1407 // keep le_db_index 1408 sm_conn->sm_le_db_index = le_db_index; 1409 } 1410 1411 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1412 setup->sm_pairing_failed_reason = reason; 1413 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1414 } 1415 1416 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1417 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1418 } 1419 1420 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1421 1422 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1423 static int sm_passkey_used(stk_generation_method_t method); 1424 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1425 1426 static void sm_log_ec_keypair(void){ 1427 log_info("Elliptic curve: X"); 1428 log_info_hexdump(&ec_q[0],32); 1429 log_info("Elliptic curve: Y"); 1430 log_info_hexdump(&ec_q[32],32); 1431 } 1432 1433 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1434 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1435 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1436 } else { 1437 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1438 } 1439 } 1440 1441 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1442 if (IS_RESPONDER(sm_conn->sm_role)){ 1443 // Responder 1444 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1445 } else { 1446 // Initiator role 1447 switch (setup->sm_stk_generation_method){ 1448 case JUST_WORKS: 1449 sm_sc_prepare_dhkey_check(sm_conn); 1450 break; 1451 1452 case NK_BOTH_INPUT: 1453 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1454 break; 1455 case PK_INIT_INPUT: 1456 case PK_RESP_INPUT: 1457 case OK_BOTH_INPUT: 1458 if (setup->sm_passkey_bit < 20) { 1459 sm_sc_start_calculating_local_confirm(sm_conn); 1460 } else { 1461 sm_sc_prepare_dhkey_check(sm_conn); 1462 } 1463 break; 1464 case OOB: 1465 // TODO: implement SC OOB 1466 break; 1467 } 1468 } 1469 } 1470 1471 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1472 return sm_cmac_sc_buffer[offset]; 1473 } 1474 1475 static void sm_sc_cmac_done(uint8_t * hash){ 1476 log_info("sm_sc_cmac_done: "); 1477 log_info_hexdump(hash, 16); 1478 1479 sm_connection_t * sm_conn = sm_cmac_connection; 1480 sm_cmac_connection = NULL; 1481 link_key_type_t link_key_type; 1482 1483 switch (sm_conn->sm_engine_state){ 1484 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1485 memcpy(setup->sm_local_confirm, hash, 16); 1486 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1487 break; 1488 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1489 // check 1490 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1491 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1492 break; 1493 } 1494 sm_sc_state_after_receiving_random(sm_conn); 1495 break; 1496 case SM_SC_W4_CALCULATE_G2: { 1497 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1498 big_endian_store_32(setup->sm_tk, 12, vab); 1499 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1500 sm_trigger_user_response(sm_conn); 1501 break; 1502 } 1503 case SM_SC_W4_CALCULATE_F5_SALT: 1504 memcpy(setup->sm_t, hash, 16); 1505 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1506 break; 1507 case SM_SC_W4_CALCULATE_F5_MACKEY: 1508 memcpy(setup->sm_mackey, hash, 16); 1509 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1510 break; 1511 case SM_SC_W4_CALCULATE_F5_LTK: 1512 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1513 // Errata Service Release to the Bluetooth Specification: ESR09 1514 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1515 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1516 memcpy(setup->sm_ltk, hash, 16); 1517 memcpy(setup->sm_local_ltk, hash, 16); 1518 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1519 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1520 break; 1521 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1522 memcpy(setup->sm_local_dhkey_check, hash, 16); 1523 if (IS_RESPONDER(sm_conn->sm_role)){ 1524 // responder 1525 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1526 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1527 } else { 1528 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1529 } 1530 } else { 1531 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1532 } 1533 break; 1534 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1535 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1536 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1537 break; 1538 } 1539 if (IS_RESPONDER(sm_conn->sm_role)){ 1540 // responder 1541 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1542 } else { 1543 // initiator 1544 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1545 } 1546 break; 1547 case SM_SC_W4_CALCULATE_H6_ILK: 1548 memcpy(setup->sm_t, hash, 16); 1549 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1550 break; 1551 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1552 reverse_128(hash, setup->sm_t); 1553 link_key_type = sm_conn->sm_connection_authenticated ? 1554 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1555 if (IS_RESPONDER(sm_conn->sm_role)){ 1556 #ifdef ENABLE_CLASSIC 1557 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1558 #endif 1559 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1560 } else { 1561 #ifdef ENABLE_CLASSIC 1562 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1563 #endif 1564 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1565 } 1566 sm_done_for_handle(sm_conn->sm_handle); 1567 break; 1568 default: 1569 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1570 break; 1571 } 1572 sm_run(); 1573 } 1574 1575 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){ 1576 const uint16_t message_len = 65; 1577 sm_cmac_connection = sm_conn; 1578 memcpy(sm_cmac_sc_buffer, u, 32); 1579 memcpy(sm_cmac_sc_buffer+32, v, 32); 1580 sm_cmac_sc_buffer[64] = z; 1581 log_info("f4 key"); 1582 log_info_hexdump(x, 16); 1583 log_info("f4 message"); 1584 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1585 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1586 } 1587 1588 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1589 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1590 static const uint8_t f5_length[] = { 0x01, 0x00}; 1591 1592 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1593 memset(dhkey, 0, 32); 1594 #ifdef USE_MBEDTLS_FOR_ECDH 1595 // da * Pb 1596 mbedtls_mpi d; 1597 mbedtls_ecp_point Q; 1598 mbedtls_ecp_point DH; 1599 mbedtls_mpi_init(&d); 1600 mbedtls_ecp_point_init(&Q); 1601 mbedtls_ecp_point_init(&DH); 1602 mbedtls_mpi_read_binary(&d, ec_d, 32); 1603 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1604 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1605 mbedtls_mpi_lset(&Q.Z, 1); 1606 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1607 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1608 mbedtls_ecp_point_free(&DH); 1609 mbedtls_mpi_free(&d); 1610 mbedtls_ecp_point_free(&Q); 1611 #endif 1612 #ifdef USE_MICROECC_FOR_ECDH 1613 #if uECC_SUPPORTS_secp256r1 1614 // standard version 1615 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1616 #else 1617 // static version 1618 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1619 #endif 1620 #endif 1621 log_info("dhkey"); 1622 log_info_hexdump(dhkey, 32); 1623 } 1624 1625 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1626 // calculate DHKEY 1627 sm_key256_t dhkey; 1628 sm_sc_calculate_dhkey(dhkey); 1629 1630 // calculate salt for f5 1631 const uint16_t message_len = 32; 1632 sm_cmac_connection = sm_conn; 1633 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1634 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1635 } 1636 1637 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){ 1638 const uint16_t message_len = 53; 1639 sm_cmac_connection = sm_conn; 1640 1641 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1642 sm_cmac_sc_buffer[0] = 0; 1643 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1644 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1645 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1646 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1647 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1648 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1649 log_info("f5 key"); 1650 log_info_hexdump(t, 16); 1651 log_info("f5 message for MacKey"); 1652 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1653 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1654 } 1655 1656 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1657 sm_key56_t bd_addr_master, bd_addr_slave; 1658 bd_addr_master[0] = setup->sm_m_addr_type; 1659 bd_addr_slave[0] = setup->sm_s_addr_type; 1660 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1661 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1662 if (IS_RESPONDER(sm_conn->sm_role)){ 1663 // responder 1664 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1665 } else { 1666 // initiator 1667 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1668 } 1669 } 1670 1671 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1672 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1673 const uint16_t message_len = 53; 1674 sm_cmac_connection = sm_conn; 1675 sm_cmac_sc_buffer[0] = 1; 1676 // 1..52 setup before 1677 log_info("f5 key"); 1678 log_info_hexdump(t, 16); 1679 log_info("f5 message for LTK"); 1680 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1681 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1682 } 1683 1684 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1685 f5_ltk(sm_conn, setup->sm_t); 1686 } 1687 1688 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){ 1689 const uint16_t message_len = 65; 1690 sm_cmac_connection = sm_conn; 1691 memcpy(sm_cmac_sc_buffer, n1, 16); 1692 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1693 memcpy(sm_cmac_sc_buffer+32, r, 16); 1694 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1695 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1696 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1697 log_info("f6 key"); 1698 log_info_hexdump(w, 16); 1699 log_info("f6 message"); 1700 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1701 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1702 } 1703 1704 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1705 // - U is 256 bits 1706 // - V is 256 bits 1707 // - X is 128 bits 1708 // - Y is 128 bits 1709 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){ 1710 const uint16_t message_len = 80; 1711 sm_cmac_connection = sm_conn; 1712 memcpy(sm_cmac_sc_buffer, u, 32); 1713 memcpy(sm_cmac_sc_buffer+32, v, 32); 1714 memcpy(sm_cmac_sc_buffer+64, y, 16); 1715 log_info("g2 key"); 1716 log_info_hexdump(x, 16); 1717 log_info("g2 message"); 1718 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1719 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1720 } 1721 1722 static void g2_calculate(sm_connection_t * sm_conn) { 1723 // calc Va if numeric comparison 1724 if (IS_RESPONDER(sm_conn->sm_role)){ 1725 // responder 1726 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1727 } else { 1728 // initiator 1729 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1730 } 1731 } 1732 1733 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1734 uint8_t z = 0; 1735 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1736 // some form of passkey 1737 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1738 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1739 setup->sm_passkey_bit++; 1740 } 1741 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1742 } 1743 1744 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1745 uint8_t z = 0; 1746 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1747 // some form of passkey 1748 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1749 // sm_passkey_bit was increased before sending confirm value 1750 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1751 } 1752 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1753 } 1754 1755 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1756 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1757 } 1758 1759 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1760 // calculate DHKCheck 1761 sm_key56_t bd_addr_master, bd_addr_slave; 1762 bd_addr_master[0] = setup->sm_m_addr_type; 1763 bd_addr_slave[0] = setup->sm_s_addr_type; 1764 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1765 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1766 uint8_t iocap_a[3]; 1767 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1768 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1769 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1770 uint8_t iocap_b[3]; 1771 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1772 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1773 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1774 if (IS_RESPONDER(sm_conn->sm_role)){ 1775 // responder 1776 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); 1777 } else { 1778 // initiator 1779 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); 1780 } 1781 } 1782 1783 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1784 // validate E = f6() 1785 sm_key56_t bd_addr_master, bd_addr_slave; 1786 bd_addr_master[0] = setup->sm_m_addr_type; 1787 bd_addr_slave[0] = setup->sm_s_addr_type; 1788 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1789 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1790 1791 uint8_t iocap_a[3]; 1792 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1793 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1794 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1795 uint8_t iocap_b[3]; 1796 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1797 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1798 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1799 if (IS_RESPONDER(sm_conn->sm_role)){ 1800 // responder 1801 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); 1802 } else { 1803 // initiator 1804 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); 1805 } 1806 } 1807 1808 1809 // 1810 // Link Key Conversion Function h6 1811 // 1812 // h6(W, keyID) = AES-CMACW(keyID) 1813 // - W is 128 bits 1814 // - keyID is 32 bits 1815 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1816 const uint16_t message_len = 4; 1817 sm_cmac_connection = sm_conn; 1818 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1819 log_info("h6 key"); 1820 log_info_hexdump(w, 16); 1821 log_info("h6 message"); 1822 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1823 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1824 } 1825 1826 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1827 // Errata Service Release to the Bluetooth Specification: ESR09 1828 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1829 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1830 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1831 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1832 } 1833 1834 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1835 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1836 } 1837 1838 #endif 1839 1840 // key management legacy connections: 1841 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1842 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1843 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1844 // - responder reconnects: responder uses LTK receveived from master 1845 1846 // key management secure connections: 1847 // - both devices store same LTK from ECDH key exchange. 1848 1849 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1850 static void sm_load_security_info(sm_connection_t * sm_connection){ 1851 int encryption_key_size; 1852 int authenticated; 1853 int authorized; 1854 1855 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1856 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1857 &encryption_key_size, &authenticated, &authorized); 1858 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1859 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1860 sm_connection->sm_connection_authenticated = authenticated; 1861 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1862 } 1863 #endif 1864 1865 #ifdef ENABLE_LE_PERIPHERAL 1866 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1867 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1868 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1869 // re-establish used key encryption size 1870 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1871 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1872 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1873 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1874 log_info("sm: received ltk request with key size %u, authenticated %u", 1875 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1876 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1877 } 1878 #endif 1879 1880 static void sm_run(void){ 1881 1882 btstack_linked_list_iterator_t it; 1883 1884 // assert that we can send at least commands 1885 if (!hci_can_send_command_packet_now()) return; 1886 1887 // 1888 // non-connection related behaviour 1889 // 1890 1891 // distributed key generation 1892 switch (dkg_state){ 1893 case DKG_CALC_IRK: 1894 // already busy? 1895 if (sm_aes128_state == SM_AES128_IDLE) { 1896 // IRK = d1(IR, 1, 0) 1897 sm_key_t d1_prime; 1898 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1899 dkg_next_state(); 1900 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1901 return; 1902 } 1903 break; 1904 case DKG_CALC_DHK: 1905 // already busy? 1906 if (sm_aes128_state == SM_AES128_IDLE) { 1907 // DHK = d1(IR, 3, 0) 1908 sm_key_t d1_prime; 1909 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1910 dkg_next_state(); 1911 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1912 return; 1913 } 1914 break; 1915 default: 1916 break; 1917 } 1918 1919 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1920 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1921 #ifndef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 1922 sm_random_start(NULL); 1923 #else 1924 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1925 hci_send_cmd(&hci_le_read_local_p256_public_key); 1926 #endif 1927 return; 1928 } 1929 #endif 1930 1931 // random address updates 1932 switch (rau_state){ 1933 case RAU_GET_RANDOM: 1934 rau_next_state(); 1935 sm_random_start(NULL); 1936 return; 1937 case RAU_GET_ENC: 1938 // already busy? 1939 if (sm_aes128_state == SM_AES128_IDLE) { 1940 sm_key_t r_prime; 1941 sm_ah_r_prime(sm_random_address, r_prime); 1942 rau_next_state(); 1943 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1944 return; 1945 } 1946 break; 1947 case RAU_SET_ADDRESS: 1948 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1949 rau_state = RAU_IDLE; 1950 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1951 return; 1952 default: 1953 break; 1954 } 1955 1956 #ifdef ENABLE_CMAC_ENGINE 1957 // CMAC 1958 switch (sm_cmac_state){ 1959 case CMAC_CALC_SUBKEYS: 1960 case CMAC_CALC_MI: 1961 case CMAC_CALC_MLAST: 1962 // already busy? 1963 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1964 sm_cmac_handle_aes_engine_ready(); 1965 return; 1966 default: 1967 break; 1968 } 1969 #endif 1970 1971 // CSRK Lookup 1972 // -- if csrk lookup ready, find connection that require csrk lookup 1973 if (sm_address_resolution_idle()){ 1974 hci_connections_get_iterator(&it); 1975 while(btstack_linked_list_iterator_has_next(&it)){ 1976 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1977 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1978 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1979 // and start lookup 1980 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); 1981 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1982 break; 1983 } 1984 } 1985 } 1986 1987 // -- if csrk lookup ready, resolved addresses for received addresses 1988 if (sm_address_resolution_idle()) { 1989 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1990 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1991 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1992 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1993 btstack_memory_sm_lookup_entry_free(entry); 1994 } 1995 } 1996 1997 // -- Continue with CSRK device lookup by public or resolvable private address 1998 if (!sm_address_resolution_idle()){ 1999 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 2000 while (sm_address_resolution_test < le_device_db_count()){ 2001 int addr_type; 2002 bd_addr_t addr; 2003 sm_key_t irk; 2004 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2005 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2006 2007 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2008 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2009 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2010 break; 2011 } 2012 2013 if (sm_address_resolution_addr_type == 0){ 2014 sm_address_resolution_test++; 2015 continue; 2016 } 2017 2018 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2019 2020 log_info("LE Device Lookup: calculate AH"); 2021 log_info_key("IRK", irk); 2022 2023 sm_key_t r_prime; 2024 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2025 sm_address_resolution_ah_calculation_active = 1; 2026 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2027 return; 2028 } 2029 2030 if (sm_address_resolution_test >= le_device_db_count()){ 2031 log_info("LE Device Lookup: not found"); 2032 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2033 } 2034 } 2035 2036 // handle basic actions that don't requires the full context 2037 hci_connections_get_iterator(&it); 2038 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2039 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2040 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2041 switch(sm_connection->sm_engine_state){ 2042 // responder side 2043 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2044 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2045 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2046 return; 2047 2048 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2049 case SM_SC_RECEIVED_LTK_REQUEST: 2050 switch (sm_connection->sm_irk_lookup_state){ 2051 case IRK_LOOKUP_FAILED: 2052 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2053 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2054 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2055 return; 2056 default: 2057 break; 2058 } 2059 break; 2060 #endif 2061 default: 2062 break; 2063 } 2064 } 2065 2066 // 2067 // active connection handling 2068 // -- use loop to handle next connection if lock on setup context is released 2069 2070 while (1) { 2071 2072 // Find connections that requires setup context and make active if no other is locked 2073 hci_connections_get_iterator(&it); 2074 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2075 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2076 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2077 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2078 int done = 1; 2079 int err; 2080 UNUSED(err); 2081 switch (sm_connection->sm_engine_state) { 2082 #ifdef ENABLE_LE_PERIPHERAL 2083 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2084 // send packet if possible, 2085 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2086 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2087 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2088 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2089 } else { 2090 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2091 } 2092 // don't lock sxetup context yet 2093 done = 0; 2094 break; 2095 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2096 sm_reset_setup(); 2097 sm_init_setup(sm_connection); 2098 // recover pairing request 2099 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2100 err = sm_stk_generation_init(sm_connection); 2101 if (err){ 2102 setup->sm_pairing_failed_reason = err; 2103 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2104 break; 2105 } 2106 sm_timeout_start(sm_connection); 2107 // generate random number first, if we need to show passkey 2108 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2109 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2110 break; 2111 } 2112 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2113 break; 2114 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2115 sm_reset_setup(); 2116 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2117 break; 2118 #endif 2119 #ifdef ENABLE_LE_CENTRAL 2120 case SM_INITIATOR_PH0_HAS_LTK: 2121 sm_reset_setup(); 2122 sm_load_security_info(sm_connection); 2123 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2124 break; 2125 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2126 sm_reset_setup(); 2127 sm_init_setup(sm_connection); 2128 sm_timeout_start(sm_connection); 2129 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2130 break; 2131 #endif 2132 2133 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2134 case SM_SC_RECEIVED_LTK_REQUEST: 2135 switch (sm_connection->sm_irk_lookup_state){ 2136 case IRK_LOOKUP_SUCCEEDED: 2137 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2138 // start using context by loading security info 2139 sm_reset_setup(); 2140 sm_load_security_info(sm_connection); 2141 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2142 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2143 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2144 break; 2145 } 2146 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2147 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2148 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2149 // don't lock setup context yet 2150 return; 2151 default: 2152 // just wait until IRK lookup is completed 2153 // don't lock setup context yet 2154 done = 0; 2155 break; 2156 } 2157 break; 2158 #endif 2159 default: 2160 done = 0; 2161 break; 2162 } 2163 if (done){ 2164 sm_active_connection_handle = sm_connection->sm_handle; 2165 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); 2166 } 2167 } 2168 2169 // 2170 // active connection handling 2171 // 2172 2173 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2174 2175 // assert that we could send a SM PDU - not needed for all of the following 2176 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2177 log_info("cannot send now, requesting can send now event"); 2178 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2179 return; 2180 } 2181 2182 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2183 if (!connection) { 2184 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2185 return; 2186 } 2187 2188 // send keypress notifications 2189 if (setup->sm_keypress_notification != 0xff){ 2190 uint8_t buffer[2]; 2191 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2192 buffer[1] = setup->sm_keypress_notification; 2193 setup->sm_keypress_notification = 0xff; 2194 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2195 return; 2196 } 2197 2198 sm_key_t plaintext; 2199 int key_distribution_flags; 2200 UNUSED(key_distribution_flags); 2201 2202 log_info("sm_run: state %u", connection->sm_engine_state); 2203 2204 switch (connection->sm_engine_state){ 2205 2206 // general 2207 case SM_GENERAL_SEND_PAIRING_FAILED: { 2208 uint8_t buffer[2]; 2209 buffer[0] = SM_CODE_PAIRING_FAILED; 2210 buffer[1] = setup->sm_pairing_failed_reason; 2211 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2212 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2213 sm_done_for_handle(connection->sm_handle); 2214 break; 2215 } 2216 2217 // responding state 2218 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2219 case SM_SC_W2_GET_RANDOM_A: 2220 sm_random_start(connection); 2221 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2222 break; 2223 case SM_SC_W2_GET_RANDOM_B: 2224 sm_random_start(connection); 2225 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2226 break; 2227 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2228 if (!sm_cmac_ready()) break; 2229 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2230 sm_sc_calculate_local_confirm(connection); 2231 break; 2232 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2233 if (!sm_cmac_ready()) break; 2234 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2235 sm_sc_calculate_remote_confirm(connection); 2236 break; 2237 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2238 if (!sm_cmac_ready()) break; 2239 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2240 sm_sc_calculate_f6_for_dhkey_check(connection); 2241 break; 2242 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2243 if (!sm_cmac_ready()) break; 2244 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2245 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2246 break; 2247 case SM_SC_W2_CALCULATE_F5_SALT: 2248 if (!sm_cmac_ready()) break; 2249 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2250 f5_calculate_salt(connection); 2251 break; 2252 case SM_SC_W2_CALCULATE_F5_MACKEY: 2253 if (!sm_cmac_ready()) break; 2254 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2255 f5_calculate_mackey(connection); 2256 break; 2257 case SM_SC_W2_CALCULATE_F5_LTK: 2258 if (!sm_cmac_ready()) break; 2259 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2260 f5_calculate_ltk(connection); 2261 break; 2262 case SM_SC_W2_CALCULATE_G2: 2263 if (!sm_cmac_ready()) break; 2264 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2265 g2_calculate(connection); 2266 break; 2267 case SM_SC_W2_CALCULATE_H6_ILK: 2268 if (!sm_cmac_ready()) break; 2269 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2270 h6_calculate_ilk(connection); 2271 break; 2272 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2273 if (!sm_cmac_ready()) break; 2274 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2275 h6_calculate_br_edr_link_key(connection); 2276 break; 2277 #endif 2278 2279 #ifdef ENABLE_LE_CENTRAL 2280 // initiator side 2281 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2282 sm_key_t peer_ltk_flipped; 2283 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2284 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2285 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2286 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2287 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2288 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2289 return; 2290 } 2291 2292 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2293 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2294 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2295 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2296 sm_timeout_reset(connection); 2297 break; 2298 #endif 2299 2300 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2301 2302 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2303 uint8_t buffer[65]; 2304 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2305 // 2306 reverse_256(&ec_q[0], &buffer[1]); 2307 reverse_256(&ec_q[32], &buffer[33]); 2308 2309 // stk generation method 2310 // passkey entry: notify app to show passkey or to request passkey 2311 switch (setup->sm_stk_generation_method){ 2312 case JUST_WORKS: 2313 case NK_BOTH_INPUT: 2314 if (IS_RESPONDER(connection->sm_role)){ 2315 // responder 2316 sm_sc_start_calculating_local_confirm(connection); 2317 } else { 2318 // initiator 2319 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2320 } 2321 break; 2322 case PK_INIT_INPUT: 2323 case PK_RESP_INPUT: 2324 case OK_BOTH_INPUT: 2325 // use random TK for display 2326 memcpy(setup->sm_ra, setup->sm_tk, 16); 2327 memcpy(setup->sm_rb, setup->sm_tk, 16); 2328 setup->sm_passkey_bit = 0; 2329 2330 if (IS_RESPONDER(connection->sm_role)){ 2331 // responder 2332 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2333 } else { 2334 // initiator 2335 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2336 } 2337 sm_trigger_user_response(connection); 2338 break; 2339 case OOB: 2340 // TODO: implement SC OOB 2341 break; 2342 } 2343 2344 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2345 sm_timeout_reset(connection); 2346 break; 2347 } 2348 case SM_SC_SEND_CONFIRMATION: { 2349 uint8_t buffer[17]; 2350 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2351 reverse_128(setup->sm_local_confirm, &buffer[1]); 2352 if (IS_RESPONDER(connection->sm_role)){ 2353 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2354 } else { 2355 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2356 } 2357 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2358 sm_timeout_reset(connection); 2359 break; 2360 } 2361 case SM_SC_SEND_PAIRING_RANDOM: { 2362 uint8_t buffer[17]; 2363 buffer[0] = SM_CODE_PAIRING_RANDOM; 2364 reverse_128(setup->sm_local_nonce, &buffer[1]); 2365 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2366 if (IS_RESPONDER(connection->sm_role)){ 2367 // responder 2368 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2369 } else { 2370 // initiator 2371 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2372 } 2373 } else { 2374 if (IS_RESPONDER(connection->sm_role)){ 2375 // responder 2376 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2377 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2378 } else { 2379 sm_sc_prepare_dhkey_check(connection); 2380 } 2381 } else { 2382 // initiator 2383 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2384 } 2385 } 2386 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2387 sm_timeout_reset(connection); 2388 break; 2389 } 2390 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2391 uint8_t buffer[17]; 2392 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2393 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2394 2395 if (IS_RESPONDER(connection->sm_role)){ 2396 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2397 } else { 2398 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2399 } 2400 2401 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2402 sm_timeout_reset(connection); 2403 break; 2404 } 2405 2406 #endif 2407 2408 #ifdef ENABLE_LE_PERIPHERAL 2409 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2410 // echo initiator for now 2411 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2412 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2413 2414 if (setup->sm_use_secure_connections){ 2415 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2416 // skip LTK/EDIV for SC 2417 log_info("sm: dropping encryption information flag"); 2418 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2419 } else { 2420 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2421 } 2422 2423 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); 2424 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); 2425 // update key distribution after ENC was dropped 2426 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2427 2428 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2429 sm_timeout_reset(connection); 2430 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2431 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2432 sm_trigger_user_response(connection); 2433 } 2434 return; 2435 #endif 2436 2437 case SM_PH2_SEND_PAIRING_RANDOM: { 2438 uint8_t buffer[17]; 2439 buffer[0] = SM_CODE_PAIRING_RANDOM; 2440 reverse_128(setup->sm_local_random, &buffer[1]); 2441 if (IS_RESPONDER(connection->sm_role)){ 2442 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2443 } else { 2444 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2445 } 2446 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2447 sm_timeout_reset(connection); 2448 break; 2449 } 2450 2451 case SM_PH2_GET_RANDOM_TK: 2452 case SM_PH2_C1_GET_RANDOM_A: 2453 case SM_PH2_C1_GET_RANDOM_B: 2454 case SM_PH3_GET_RANDOM: 2455 case SM_PH3_GET_DIV: 2456 sm_next_responding_state(connection); 2457 sm_random_start(connection); 2458 return; 2459 2460 case SM_PH2_C1_GET_ENC_B: 2461 case SM_PH2_C1_GET_ENC_D: 2462 // already busy? 2463 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2464 sm_next_responding_state(connection); 2465 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2466 return; 2467 2468 case SM_PH3_LTK_GET_ENC: 2469 case SM_RESPONDER_PH4_LTK_GET_ENC: 2470 // already busy? 2471 if (sm_aes128_state == SM_AES128_IDLE) { 2472 sm_key_t d_prime; 2473 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2474 sm_next_responding_state(connection); 2475 sm_aes128_start(sm_persistent_er, d_prime, connection); 2476 return; 2477 } 2478 break; 2479 2480 case SM_PH3_CSRK_GET_ENC: 2481 // already busy? 2482 if (sm_aes128_state == SM_AES128_IDLE) { 2483 sm_key_t d_prime; 2484 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2485 sm_next_responding_state(connection); 2486 sm_aes128_start(sm_persistent_er, d_prime, connection); 2487 return; 2488 } 2489 break; 2490 2491 case SM_PH2_C1_GET_ENC_C: 2492 // already busy? 2493 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2494 // calculate m_confirm using aes128 engine - step 1 2495 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); 2496 sm_next_responding_state(connection); 2497 sm_aes128_start(setup->sm_tk, plaintext, connection); 2498 break; 2499 case SM_PH2_C1_GET_ENC_A: 2500 // already busy? 2501 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2502 // calculate confirm using aes128 engine - step 1 2503 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); 2504 sm_next_responding_state(connection); 2505 sm_aes128_start(setup->sm_tk, plaintext, connection); 2506 break; 2507 case SM_PH2_CALC_STK: 2508 // already busy? 2509 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2510 // calculate STK 2511 if (IS_RESPONDER(connection->sm_role)){ 2512 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2513 } else { 2514 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2515 } 2516 sm_next_responding_state(connection); 2517 sm_aes128_start(setup->sm_tk, plaintext, connection); 2518 break; 2519 case SM_PH3_Y_GET_ENC: 2520 // already busy? 2521 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2522 // PH3B2 - calculate Y from - enc 2523 // Y = dm(DHK, Rand) 2524 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2525 sm_next_responding_state(connection); 2526 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2527 return; 2528 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2529 uint8_t buffer[17]; 2530 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2531 reverse_128(setup->sm_local_confirm, &buffer[1]); 2532 if (IS_RESPONDER(connection->sm_role)){ 2533 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2534 } else { 2535 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2536 } 2537 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2538 sm_timeout_reset(connection); 2539 return; 2540 } 2541 #ifdef ENABLE_LE_PERIPHERAL 2542 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2543 sm_key_t stk_flipped; 2544 reverse_128(setup->sm_ltk, stk_flipped); 2545 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2546 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2547 return; 2548 } 2549 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2550 sm_key_t ltk_flipped; 2551 reverse_128(setup->sm_ltk, ltk_flipped); 2552 connection->sm_engine_state = SM_RESPONDER_IDLE; 2553 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2554 return; 2555 } 2556 case SM_RESPONDER_PH4_Y_GET_ENC: 2557 // already busy? 2558 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2559 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2560 // Y = dm(DHK, Rand) 2561 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2562 sm_next_responding_state(connection); 2563 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2564 return; 2565 #endif 2566 #ifdef ENABLE_LE_CENTRAL 2567 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2568 sm_key_t stk_flipped; 2569 reverse_128(setup->sm_ltk, stk_flipped); 2570 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2571 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2572 return; 2573 } 2574 #endif 2575 2576 case SM_PH3_DISTRIBUTE_KEYS: 2577 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2578 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2579 uint8_t buffer[17]; 2580 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2581 reverse_128(setup->sm_ltk, &buffer[1]); 2582 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2583 sm_timeout_reset(connection); 2584 return; 2585 } 2586 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2587 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2588 uint8_t buffer[11]; 2589 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2590 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2591 reverse_64(setup->sm_local_rand, &buffer[3]); 2592 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2593 sm_timeout_reset(connection); 2594 return; 2595 } 2596 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2597 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2598 uint8_t buffer[17]; 2599 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2600 reverse_128(sm_persistent_irk, &buffer[1]); 2601 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2602 sm_timeout_reset(connection); 2603 return; 2604 } 2605 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2606 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2607 bd_addr_t local_address; 2608 uint8_t buffer[8]; 2609 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2610 gap_le_get_own_address(&buffer[1], local_address); 2611 reverse_bd_addr(local_address, &buffer[2]); 2612 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2613 sm_timeout_reset(connection); 2614 return; 2615 } 2616 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2617 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2618 2619 // hack to reproduce test runs 2620 if (test_use_fixed_local_csrk){ 2621 memset(setup->sm_local_csrk, 0xcc, 16); 2622 } 2623 2624 uint8_t buffer[17]; 2625 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2626 reverse_128(setup->sm_local_csrk, &buffer[1]); 2627 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2628 sm_timeout_reset(connection); 2629 return; 2630 } 2631 2632 // keys are sent 2633 if (IS_RESPONDER(connection->sm_role)){ 2634 // slave -> receive master keys if any 2635 if (sm_key_distribution_all_received(connection)){ 2636 sm_key_distribution_handle_all_received(connection); 2637 connection->sm_engine_state = SM_RESPONDER_IDLE; 2638 sm_done_for_handle(connection->sm_handle); 2639 } else { 2640 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2641 } 2642 } else { 2643 // master -> all done 2644 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2645 sm_done_for_handle(connection->sm_handle); 2646 } 2647 break; 2648 2649 default: 2650 break; 2651 } 2652 2653 // check again if active connection was released 2654 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2655 } 2656 } 2657 2658 // note: aes engine is ready as we just got the aes result 2659 static void sm_handle_encryption_result(uint8_t * data){ 2660 2661 sm_aes128_state = SM_AES128_IDLE; 2662 2663 if (sm_address_resolution_ah_calculation_active){ 2664 sm_address_resolution_ah_calculation_active = 0; 2665 // compare calulated address against connecting device 2666 uint8_t hash[3]; 2667 reverse_24(data, hash); 2668 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2669 log_info("LE Device Lookup: matched resolvable private address"); 2670 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2671 return; 2672 } 2673 // no match, try next 2674 sm_address_resolution_test++; 2675 return; 2676 } 2677 2678 switch (dkg_state){ 2679 case DKG_W4_IRK: 2680 reverse_128(data, sm_persistent_irk); 2681 log_info_key("irk", sm_persistent_irk); 2682 dkg_next_state(); 2683 return; 2684 case DKG_W4_DHK: 2685 reverse_128(data, sm_persistent_dhk); 2686 log_info_key("dhk", sm_persistent_dhk); 2687 dkg_next_state(); 2688 // SM Init Finished 2689 return; 2690 default: 2691 break; 2692 } 2693 2694 switch (rau_state){ 2695 case RAU_W4_ENC: 2696 reverse_24(data, &sm_random_address[3]); 2697 rau_next_state(); 2698 return; 2699 default: 2700 break; 2701 } 2702 2703 #ifdef ENABLE_CMAC_ENGINE 2704 switch (sm_cmac_state){ 2705 case CMAC_W4_SUBKEYS: 2706 case CMAC_W4_MI: 2707 case CMAC_W4_MLAST: 2708 { 2709 sm_key_t t; 2710 reverse_128(data, t); 2711 sm_cmac_handle_encryption_result(t); 2712 } 2713 return; 2714 default: 2715 break; 2716 } 2717 #endif 2718 2719 // retrieve sm_connection provided to sm_aes128_start_encryption 2720 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2721 if (!connection) return; 2722 switch (connection->sm_engine_state){ 2723 case SM_PH2_C1_W4_ENC_A: 2724 case SM_PH2_C1_W4_ENC_C: 2725 { 2726 sm_key_t t2; 2727 reverse_128(data, t2); 2728 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2729 } 2730 sm_next_responding_state(connection); 2731 return; 2732 case SM_PH2_C1_W4_ENC_B: 2733 reverse_128(data, setup->sm_local_confirm); 2734 log_info_key("c1!", setup->sm_local_confirm); 2735 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2736 return; 2737 case SM_PH2_C1_W4_ENC_D: 2738 { 2739 sm_key_t peer_confirm_test; 2740 reverse_128(data, peer_confirm_test); 2741 log_info_key("c1!", peer_confirm_test); 2742 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2743 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2744 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2745 return; 2746 } 2747 if (IS_RESPONDER(connection->sm_role)){ 2748 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2749 } else { 2750 connection->sm_engine_state = SM_PH2_CALC_STK; 2751 } 2752 } 2753 return; 2754 case SM_PH2_W4_STK: 2755 reverse_128(data, setup->sm_ltk); 2756 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2757 log_info_key("stk", setup->sm_ltk); 2758 if (IS_RESPONDER(connection->sm_role)){ 2759 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2760 } else { 2761 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2762 } 2763 return; 2764 case SM_PH3_Y_W4_ENC:{ 2765 sm_key_t y128; 2766 reverse_128(data, y128); 2767 setup->sm_local_y = big_endian_read_16(y128, 14); 2768 log_info_hex16("y", setup->sm_local_y); 2769 // PH3B3 - calculate EDIV 2770 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2771 log_info_hex16("ediv", setup->sm_local_ediv); 2772 // PH3B4 - calculate LTK - enc 2773 // LTK = d1(ER, DIV, 0)) 2774 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2775 return; 2776 } 2777 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2778 sm_key_t y128; 2779 reverse_128(data, y128); 2780 setup->sm_local_y = big_endian_read_16(y128, 14); 2781 log_info_hex16("y", setup->sm_local_y); 2782 2783 // PH3B3 - calculate DIV 2784 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2785 log_info_hex16("ediv", setup->sm_local_ediv); 2786 // PH3B4 - calculate LTK - enc 2787 // LTK = d1(ER, DIV, 0)) 2788 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2789 return; 2790 } 2791 case SM_PH3_LTK_W4_ENC: 2792 reverse_128(data, setup->sm_ltk); 2793 log_info_key("ltk", setup->sm_ltk); 2794 // calc CSRK next 2795 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2796 return; 2797 case SM_PH3_CSRK_W4_ENC: 2798 reverse_128(data, setup->sm_local_csrk); 2799 log_info_key("csrk", setup->sm_local_csrk); 2800 if (setup->sm_key_distribution_send_set){ 2801 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2802 } else { 2803 // no keys to send, just continue 2804 if (IS_RESPONDER(connection->sm_role)){ 2805 // slave -> receive master keys 2806 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2807 } else { 2808 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2809 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2810 } else { 2811 // master -> all done 2812 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2813 sm_done_for_handle(connection->sm_handle); 2814 } 2815 } 2816 } 2817 return; 2818 #ifdef ENABLE_LE_PERIPHERAL 2819 case SM_RESPONDER_PH4_LTK_W4_ENC: 2820 reverse_128(data, setup->sm_ltk); 2821 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2822 log_info_key("ltk", setup->sm_ltk); 2823 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2824 return; 2825 #endif 2826 default: 2827 break; 2828 } 2829 } 2830 2831 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2832 #ifndef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 2833 #if !defined(WICED_VERSION) || defined(USE_MBEDTLS_FOR_ECDH) 2834 // @return OK 2835 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2836 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2837 int offset = setup->sm_passkey_bit; 2838 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2839 while (size) { 2840 *buffer++ = setup->sm_peer_q[offset++]; 2841 size--; 2842 } 2843 setup->sm_passkey_bit = offset; 2844 return 1; 2845 } 2846 #endif 2847 #ifdef USE_MBEDTLS_FOR_ECDH 2848 // @return error 2849 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2850 UNUSED(context); 2851 return sm_generate_f_rng(buffer, size) == 1; 2852 } 2853 #endif 2854 #endif 2855 #endif 2856 2857 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2858 static void sm_handle_random_result(uint8_t * data){ 2859 2860 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2861 #ifndef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 2862 2863 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2864 int num_bytes = setup->sm_passkey_bit; 2865 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2866 num_bytes += 8; 2867 setup->sm_passkey_bit = num_bytes; 2868 2869 if (num_bytes >= 64){ 2870 2871 // init pre-generated random data from sm_peer_q 2872 setup->sm_passkey_bit = 0; 2873 2874 // generate EC key 2875 #ifdef USE_MBEDTLS_FOR_ECDH 2876 mbedtls_mpi d; 2877 mbedtls_ecp_point P; 2878 mbedtls_mpi_init(&d); 2879 mbedtls_ecp_point_init(&P); 2880 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2881 log_info("gen keypair %x", res); 2882 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2883 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2884 mbedtls_mpi_write_binary(&d, ec_d, 32); 2885 mbedtls_ecp_point_free(&P); 2886 mbedtls_mpi_free(&d); 2887 #endif 2888 2889 #ifdef USE_MICROECC_FOR_ECDH 2890 2891 #ifndef WICED_VERSION 2892 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2893 uECC_set_rng(&sm_generate_f_rng); 2894 #endif /* WICED_VERSION */ 2895 2896 #if uECC_SUPPORTS_secp256r1 2897 // standard version 2898 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2899 #else 2900 // static version 2901 uECC_make_key(ec_q, ec_d); 2902 #endif 2903 #endif /* USE_MICROECC_FOR_ECDH */ 2904 2905 #ifndef WICED_VERSION 2906 // disable rng generator as we don't have any random bits left 2907 // we can do this because we don't generate another key 2908 // we need to to this because shared key calculation fails if rng returns 0 2909 uECC_set_rng(NULL); 2910 #endif /* WICED_VERSION */ 2911 2912 #endif /* USE_MICROECC_FOR_ECDH */ 2913 2914 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2915 log_info("Elliptic curve: d"); 2916 log_info_hexdump(ec_d,32); 2917 sm_log_ec_keypair(); 2918 } 2919 } 2920 #endif 2921 #endif 2922 2923 switch (rau_state){ 2924 case RAU_W4_RANDOM: 2925 // non-resolvable vs. resolvable 2926 switch (gap_random_adress_type){ 2927 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2928 // resolvable: use random as prand and calc address hash 2929 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2930 memcpy(sm_random_address, data, 3); 2931 sm_random_address[0] &= 0x3f; 2932 sm_random_address[0] |= 0x40; 2933 rau_state = RAU_GET_ENC; 2934 break; 2935 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2936 default: 2937 // "The two most significant bits of the address shall be equal to ‘0’"" 2938 memcpy(sm_random_address, data, 6); 2939 sm_random_address[0] &= 0x3f; 2940 rau_state = RAU_SET_ADDRESS; 2941 break; 2942 } 2943 return; 2944 default: 2945 break; 2946 } 2947 2948 // retrieve sm_connection provided to sm_random_start 2949 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2950 if (!connection) return; 2951 switch (connection->sm_engine_state){ 2952 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2953 case SM_SC_W4_GET_RANDOM_A: 2954 memcpy(&setup->sm_local_nonce[0], data, 8); 2955 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2956 break; 2957 case SM_SC_W4_GET_RANDOM_B: 2958 memcpy(&setup->sm_local_nonce[8], data, 8); 2959 // initiator & jw/nc -> send pairing random 2960 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2961 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2962 break; 2963 } else { 2964 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2965 } 2966 break; 2967 #endif 2968 2969 case SM_PH2_W4_RANDOM_TK: 2970 { 2971 // map random to 0-999999 without speding much cycles on a modulus operation 2972 uint32_t tk = little_endian_read_32(data,0); 2973 tk = tk & 0xfffff; // 1048575 2974 if (tk >= 999999){ 2975 tk = tk - 999999; 2976 } 2977 sm_reset_tk(); 2978 big_endian_store_32(setup->sm_tk, 12, tk); 2979 if (IS_RESPONDER(connection->sm_role)){ 2980 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2981 } else { 2982 if (setup->sm_use_secure_connections){ 2983 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2984 } else { 2985 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2986 sm_trigger_user_response(connection); 2987 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2988 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2989 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2990 } 2991 } 2992 } 2993 return; 2994 } 2995 case SM_PH2_C1_W4_RANDOM_A: 2996 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2997 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2998 return; 2999 case SM_PH2_C1_W4_RANDOM_B: 3000 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3001 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3002 return; 3003 case SM_PH3_W4_RANDOM: 3004 reverse_64(data, setup->sm_local_rand); 3005 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3006 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3007 // no db for authenticated flag hack: store flag in bit 4 of LSB 3008 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3009 connection->sm_engine_state = SM_PH3_GET_DIV; 3010 return; 3011 case SM_PH3_W4_DIV: 3012 // use 16 bit from random value as div 3013 setup->sm_local_div = big_endian_read_16(data, 0); 3014 log_info_hex16("div", setup->sm_local_div); 3015 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3016 return; 3017 default: 3018 break; 3019 } 3020 } 3021 3022 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3023 3024 UNUSED(channel); 3025 UNUSED(size); 3026 3027 sm_connection_t * sm_conn; 3028 hci_con_handle_t con_handle; 3029 3030 switch (packet_type) { 3031 3032 case HCI_EVENT_PACKET: 3033 switch (hci_event_packet_get_type(packet)) { 3034 3035 case BTSTACK_EVENT_STATE: 3036 // bt stack activated, get started 3037 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3038 log_info("HCI Working!"); 3039 3040 // set local addr for le device db 3041 bd_addr_t local_bd_addr; 3042 gap_local_bd_addr(local_bd_addr); 3043 le_device_db_set_local_bd_addr(local_bd_addr); 3044 3045 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3046 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3047 if (!sm_have_ec_keypair){ 3048 setup->sm_passkey_bit = 0; 3049 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3050 } 3051 #endif 3052 // trigger Random Address generation if requested before 3053 switch (gap_random_adress_type){ 3054 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3055 rau_state = RAU_IDLE; 3056 break; 3057 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3058 rau_state = RAU_SET_ADDRESS; 3059 break; 3060 default: 3061 rau_state = RAU_GET_RANDOM; 3062 break; 3063 } 3064 sm_run(); 3065 } 3066 break; 3067 3068 case HCI_EVENT_LE_META: 3069 switch (packet[2]) { 3070 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3071 3072 log_info("sm: connected"); 3073 3074 if (packet[3]) return; // connection failed 3075 3076 con_handle = little_endian_read_16(packet, 4); 3077 sm_conn = sm_get_connection_for_handle(con_handle); 3078 if (!sm_conn) break; 3079 3080 sm_conn->sm_handle = con_handle; 3081 sm_conn->sm_role = packet[6]; 3082 sm_conn->sm_peer_addr_type = packet[7]; 3083 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3084 3085 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3086 3087 // reset security properties 3088 sm_conn->sm_connection_encrypted = 0; 3089 sm_conn->sm_connection_authenticated = 0; 3090 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3091 sm_conn->sm_le_db_index = -1; 3092 3093 // prepare CSRK lookup (does not involve setup) 3094 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3095 3096 // just connected -> everything else happens in sm_run() 3097 if (IS_RESPONDER(sm_conn->sm_role)){ 3098 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3099 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3100 if (sm_slave_request_security) { 3101 // request security if requested by app 3102 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3103 } else { 3104 // otherwise, wait for pairing request 3105 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3106 } 3107 } 3108 break; 3109 } else { 3110 // master 3111 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3112 } 3113 break; 3114 3115 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3116 con_handle = little_endian_read_16(packet, 3); 3117 sm_conn = sm_get_connection_for_handle(con_handle); 3118 if (!sm_conn) break; 3119 3120 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3121 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3122 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3123 break; 3124 } 3125 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3126 // PH2 SEND LTK as we need to exchange keys in PH3 3127 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3128 break; 3129 } 3130 3131 // store rand and ediv 3132 reverse_64(&packet[5], sm_conn->sm_local_rand); 3133 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3134 3135 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3136 // potentially stored LTK is from the master 3137 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3138 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3139 break; 3140 } 3141 3142 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3143 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3144 #else 3145 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3146 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3147 #endif 3148 break; 3149 3150 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3151 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3152 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3153 log_error("Read Local P256 Public Key failed"); 3154 break; 3155 } 3156 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3157 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3158 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3159 sm_log_ec_keypair(); 3160 break; 3161 #endif 3162 default: 3163 break; 3164 } 3165 break; 3166 3167 case HCI_EVENT_ENCRYPTION_CHANGE: 3168 con_handle = little_endian_read_16(packet, 3); 3169 sm_conn = sm_get_connection_for_handle(con_handle); 3170 if (!sm_conn) break; 3171 3172 sm_conn->sm_connection_encrypted = packet[5]; 3173 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3174 sm_conn->sm_actual_encryption_key_size); 3175 log_info("event handler, state %u", sm_conn->sm_engine_state); 3176 if (!sm_conn->sm_connection_encrypted) break; 3177 // continue if part of initial pairing 3178 switch (sm_conn->sm_engine_state){ 3179 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3180 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3181 sm_done_for_handle(sm_conn->sm_handle); 3182 break; 3183 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3184 if (IS_RESPONDER(sm_conn->sm_role)){ 3185 // slave 3186 if (setup->sm_use_secure_connections){ 3187 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3188 } else { 3189 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3190 } 3191 } else { 3192 // master 3193 if (sm_key_distribution_all_received(sm_conn)){ 3194 // skip receiving keys as there are none 3195 sm_key_distribution_handle_all_received(sm_conn); 3196 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3197 } else { 3198 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3199 } 3200 } 3201 break; 3202 default: 3203 break; 3204 } 3205 break; 3206 3207 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3208 con_handle = little_endian_read_16(packet, 3); 3209 sm_conn = sm_get_connection_for_handle(con_handle); 3210 if (!sm_conn) break; 3211 3212 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3213 log_info("event handler, state %u", sm_conn->sm_engine_state); 3214 // continue if part of initial pairing 3215 switch (sm_conn->sm_engine_state){ 3216 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3217 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3218 sm_done_for_handle(sm_conn->sm_handle); 3219 break; 3220 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3221 if (IS_RESPONDER(sm_conn->sm_role)){ 3222 // slave 3223 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3224 } else { 3225 // master 3226 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3227 } 3228 break; 3229 default: 3230 break; 3231 } 3232 break; 3233 3234 3235 case HCI_EVENT_DISCONNECTION_COMPLETE: 3236 con_handle = little_endian_read_16(packet, 3); 3237 sm_done_for_handle(con_handle); 3238 sm_conn = sm_get_connection_for_handle(con_handle); 3239 if (!sm_conn) break; 3240 3241 // delete stored bonding on disconnect with authentication failure in ph0 3242 if (sm_conn->sm_role == 0 3243 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3244 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3245 le_device_db_remove(sm_conn->sm_le_db_index); 3246 } 3247 3248 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3249 sm_conn->sm_handle = 0; 3250 break; 3251 3252 case HCI_EVENT_COMMAND_COMPLETE: 3253 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3254 sm_handle_encryption_result(&packet[6]); 3255 break; 3256 } 3257 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3258 sm_handle_random_result(&packet[6]); 3259 break; 3260 } 3261 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3262 // Hack for Nordic nRF5 series that doesn't have public address: 3263 // - with patches from port/nrf5-zephyr, hci_read_bd_addr returns random static address 3264 // - we use this as default for advertisements/connections 3265 if (hci_get_manufacturer() == BLUETOOTH_COMPANY_ID_NORDIC_SEMICONDUCTOR_ASA){ 3266 log_info("nRF5: using (fake) public address as random static address"); 3267 bd_addr_t addr; 3268 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3269 gap_random_address_set(addr); 3270 } 3271 } 3272 break; 3273 default: 3274 break; 3275 } 3276 break; 3277 default: 3278 break; 3279 } 3280 3281 sm_run(); 3282 } 3283 3284 static inline int sm_calc_actual_encryption_key_size(int other){ 3285 if (other < sm_min_encryption_key_size) return 0; 3286 if (other < sm_max_encryption_key_size) return other; 3287 return sm_max_encryption_key_size; 3288 } 3289 3290 3291 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3292 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3293 switch (method){ 3294 case JUST_WORKS: 3295 case NK_BOTH_INPUT: 3296 return 1; 3297 default: 3298 return 0; 3299 } 3300 } 3301 // responder 3302 3303 static int sm_passkey_used(stk_generation_method_t method){ 3304 switch (method){ 3305 case PK_RESP_INPUT: 3306 return 1; 3307 default: 3308 return 0; 3309 } 3310 } 3311 #endif 3312 3313 /** 3314 * @return ok 3315 */ 3316 static int sm_validate_stk_generation_method(void){ 3317 // check if STK generation method is acceptable by client 3318 switch (setup->sm_stk_generation_method){ 3319 case JUST_WORKS: 3320 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3321 case PK_RESP_INPUT: 3322 case PK_INIT_INPUT: 3323 case OK_BOTH_INPUT: 3324 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3325 case OOB: 3326 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3327 case NK_BOTH_INPUT: 3328 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3329 return 1; 3330 default: 3331 return 0; 3332 } 3333 } 3334 3335 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3336 3337 UNUSED(size); 3338 3339 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3340 sm_run(); 3341 } 3342 3343 if (packet_type != SM_DATA_PACKET) return; 3344 3345 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3346 if (!sm_conn) return; 3347 3348 if (packet[0] == SM_CODE_PAIRING_FAILED){ 3349 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3350 return; 3351 } 3352 3353 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 3354 3355 int err; 3356 UNUSED(err); 3357 3358 if (packet[0] == SM_CODE_KEYPRESS_NOTIFICATION){ 3359 uint8_t buffer[5]; 3360 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3361 buffer[1] = 3; 3362 little_endian_store_16(buffer, 2, con_handle); 3363 buffer[4] = packet[1]; 3364 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3365 return; 3366 } 3367 3368 switch (sm_conn->sm_engine_state){ 3369 3370 // a sm timeout requries a new physical connection 3371 case SM_GENERAL_TIMEOUT: 3372 return; 3373 3374 #ifdef ENABLE_LE_CENTRAL 3375 3376 // Initiator 3377 case SM_INITIATOR_CONNECTED: 3378 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3379 sm_pdu_received_in_wrong_state(sm_conn); 3380 break; 3381 } 3382 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3383 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3384 break; 3385 } 3386 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3387 sm_key_t ltk; 3388 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3389 if (!sm_is_null_key(ltk)){ 3390 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3391 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3392 } else { 3393 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3394 } 3395 break; 3396 } 3397 // otherwise, store security request 3398 sm_conn->sm_security_request_received = 1; 3399 break; 3400 3401 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3402 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3403 sm_pdu_received_in_wrong_state(sm_conn); 3404 break; 3405 } 3406 // store pairing request 3407 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3408 err = sm_stk_generation_init(sm_conn); 3409 if (err){ 3410 setup->sm_pairing_failed_reason = err; 3411 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3412 break; 3413 } 3414 3415 // generate random number first, if we need to show passkey 3416 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3417 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3418 break; 3419 } 3420 3421 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3422 if (setup->sm_use_secure_connections){ 3423 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3424 if (setup->sm_stk_generation_method == JUST_WORKS){ 3425 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3426 sm_trigger_user_response(sm_conn); 3427 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3428 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3429 } 3430 } else { 3431 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3432 } 3433 break; 3434 } 3435 #endif 3436 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3437 sm_trigger_user_response(sm_conn); 3438 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3439 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3440 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3441 } 3442 break; 3443 3444 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3445 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3446 sm_pdu_received_in_wrong_state(sm_conn); 3447 break; 3448 } 3449 3450 // store s_confirm 3451 reverse_128(&packet[1], setup->sm_peer_confirm); 3452 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3453 break; 3454 3455 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3456 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3457 sm_pdu_received_in_wrong_state(sm_conn); 3458 break;; 3459 } 3460 3461 // received random value 3462 reverse_128(&packet[1], setup->sm_peer_random); 3463 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3464 break; 3465 #endif 3466 3467 #ifdef ENABLE_LE_PERIPHERAL 3468 // Responder 3469 case SM_RESPONDER_IDLE: 3470 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3471 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3472 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3473 sm_pdu_received_in_wrong_state(sm_conn); 3474 break;; 3475 } 3476 3477 // store pairing request 3478 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3479 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3480 break; 3481 #endif 3482 3483 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3484 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3485 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3486 sm_pdu_received_in_wrong_state(sm_conn); 3487 break; 3488 } 3489 3490 // store public key for DH Key calculation 3491 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3492 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3493 3494 // validate public key 3495 err = 0; 3496 3497 #ifdef USE_MBEDTLS_FOR_ECDH 3498 mbedtls_ecp_point Q; 3499 mbedtls_ecp_point_init( &Q ); 3500 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3501 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3502 mbedtls_mpi_lset(&Q.Z, 1); 3503 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3504 mbedtls_ecp_point_free( & Q); 3505 #endif 3506 #ifdef USE_MICROECC_FOR_ECDH 3507 #if uECC_SUPPORTS_secp256r1 3508 // standard version 3509 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3510 #else 3511 // static version 3512 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3513 #endif 3514 #endif 3515 3516 if (err){ 3517 log_error("sm: peer public key invalid %x", err); 3518 // uses "unspecified reason", there is no "public key invalid" error code 3519 sm_pdu_received_in_wrong_state(sm_conn); 3520 break; 3521 } 3522 3523 if (IS_RESPONDER(sm_conn->sm_role)){ 3524 // responder 3525 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3526 } else { 3527 // initiator 3528 // stk generation method 3529 // passkey entry: notify app to show passkey or to request passkey 3530 switch (setup->sm_stk_generation_method){ 3531 case JUST_WORKS: 3532 case NK_BOTH_INPUT: 3533 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3534 break; 3535 case PK_RESP_INPUT: 3536 sm_sc_start_calculating_local_confirm(sm_conn); 3537 break; 3538 case PK_INIT_INPUT: 3539 case OK_BOTH_INPUT: 3540 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3541 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3542 break; 3543 } 3544 sm_sc_start_calculating_local_confirm(sm_conn); 3545 break; 3546 case OOB: 3547 // TODO: implement SC OOB 3548 break; 3549 } 3550 } 3551 break; 3552 3553 case SM_SC_W4_CONFIRMATION: 3554 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3555 sm_pdu_received_in_wrong_state(sm_conn); 3556 break; 3557 } 3558 // received confirm value 3559 reverse_128(&packet[1], setup->sm_peer_confirm); 3560 3561 if (IS_RESPONDER(sm_conn->sm_role)){ 3562 // responder 3563 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3564 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3565 // still waiting for passkey 3566 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3567 break; 3568 } 3569 } 3570 sm_sc_start_calculating_local_confirm(sm_conn); 3571 } else { 3572 // initiator 3573 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3574 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3575 } else { 3576 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3577 } 3578 } 3579 break; 3580 3581 case SM_SC_W4_PAIRING_RANDOM: 3582 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3583 sm_pdu_received_in_wrong_state(sm_conn); 3584 break; 3585 } 3586 3587 // received random value 3588 reverse_128(&packet[1], setup->sm_peer_nonce); 3589 3590 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3591 // only check for JUST WORK/NC in initiator role AND passkey entry 3592 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3593 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3594 } 3595 3596 sm_sc_state_after_receiving_random(sm_conn); 3597 break; 3598 3599 case SM_SC_W2_CALCULATE_G2: 3600 case SM_SC_W4_CALCULATE_G2: 3601 case SM_SC_W2_CALCULATE_F5_SALT: 3602 case SM_SC_W4_CALCULATE_F5_SALT: 3603 case SM_SC_W2_CALCULATE_F5_MACKEY: 3604 case SM_SC_W4_CALCULATE_F5_MACKEY: 3605 case SM_SC_W2_CALCULATE_F5_LTK: 3606 case SM_SC_W4_CALCULATE_F5_LTK: 3607 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3608 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3609 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3610 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3611 sm_pdu_received_in_wrong_state(sm_conn); 3612 break; 3613 } 3614 // store DHKey Check 3615 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3616 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3617 3618 // have we been only waiting for dhkey check command? 3619 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3620 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3621 } 3622 break; 3623 #endif 3624 3625 #ifdef ENABLE_LE_PERIPHERAL 3626 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3627 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3628 sm_pdu_received_in_wrong_state(sm_conn); 3629 break; 3630 } 3631 3632 // received confirm value 3633 reverse_128(&packet[1], setup->sm_peer_confirm); 3634 3635 // notify client to hide shown passkey 3636 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3637 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3638 } 3639 3640 // handle user cancel pairing? 3641 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3642 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3643 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3644 break; 3645 } 3646 3647 // wait for user action? 3648 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3649 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3650 break; 3651 } 3652 3653 // calculate and send local_confirm 3654 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3655 break; 3656 3657 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3658 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3659 sm_pdu_received_in_wrong_state(sm_conn); 3660 break;; 3661 } 3662 3663 // received random value 3664 reverse_128(&packet[1], setup->sm_peer_random); 3665 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3666 break; 3667 #endif 3668 3669 case SM_PH3_RECEIVE_KEYS: 3670 switch(packet[0]){ 3671 case SM_CODE_ENCRYPTION_INFORMATION: 3672 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3673 reverse_128(&packet[1], setup->sm_peer_ltk); 3674 break; 3675 3676 case SM_CODE_MASTER_IDENTIFICATION: 3677 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3678 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3679 reverse_64(&packet[3], setup->sm_peer_rand); 3680 break; 3681 3682 case SM_CODE_IDENTITY_INFORMATION: 3683 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3684 reverse_128(&packet[1], setup->sm_peer_irk); 3685 break; 3686 3687 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3688 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3689 setup->sm_peer_addr_type = packet[1]; 3690 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3691 break; 3692 3693 case SM_CODE_SIGNING_INFORMATION: 3694 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3695 reverse_128(&packet[1], setup->sm_peer_csrk); 3696 break; 3697 default: 3698 // Unexpected PDU 3699 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3700 break; 3701 } 3702 // done with key distribution? 3703 if (sm_key_distribution_all_received(sm_conn)){ 3704 3705 sm_key_distribution_handle_all_received(sm_conn); 3706 3707 if (IS_RESPONDER(sm_conn->sm_role)){ 3708 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3709 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3710 } else { 3711 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3712 sm_done_for_handle(sm_conn->sm_handle); 3713 } 3714 } else { 3715 if (setup->sm_use_secure_connections){ 3716 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3717 } else { 3718 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3719 } 3720 } 3721 } 3722 break; 3723 default: 3724 // Unexpected PDU 3725 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3726 break; 3727 } 3728 3729 // try to send preparared packet 3730 sm_run(); 3731 } 3732 3733 // Security Manager Client API 3734 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3735 sm_get_oob_data = get_oob_data_callback; 3736 } 3737 3738 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3739 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3740 } 3741 3742 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3743 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3744 } 3745 3746 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3747 sm_min_encryption_key_size = min_size; 3748 sm_max_encryption_key_size = max_size; 3749 } 3750 3751 void sm_set_authentication_requirements(uint8_t auth_req){ 3752 sm_auth_req = auth_req; 3753 } 3754 3755 void sm_set_io_capabilities(io_capability_t io_capability){ 3756 sm_io_capabilities = io_capability; 3757 } 3758 3759 #ifdef ENABLE_LE_PERIPHERAL 3760 void sm_set_request_security(int enable){ 3761 sm_slave_request_security = enable; 3762 } 3763 #endif 3764 3765 void sm_set_er(sm_key_t er){ 3766 memcpy(sm_persistent_er, er, 16); 3767 } 3768 3769 void sm_set_ir(sm_key_t ir){ 3770 memcpy(sm_persistent_ir, ir, 16); 3771 } 3772 3773 // Testing support only 3774 void sm_test_set_irk(sm_key_t irk){ 3775 memcpy(sm_persistent_irk, irk, 16); 3776 sm_persistent_irk_ready = 1; 3777 } 3778 3779 void sm_test_use_fixed_local_csrk(void){ 3780 test_use_fixed_local_csrk = 1; 3781 } 3782 3783 void sm_init(void){ 3784 // set some (BTstack default) ER and IR 3785 int i; 3786 sm_key_t er; 3787 sm_key_t ir; 3788 for (i=0;i<16;i++){ 3789 er[i] = 0x30 + i; 3790 ir[i] = 0x90 + i; 3791 } 3792 sm_set_er(er); 3793 sm_set_ir(ir); 3794 // defaults 3795 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3796 | SM_STK_GENERATION_METHOD_OOB 3797 | SM_STK_GENERATION_METHOD_PASSKEY 3798 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3799 3800 sm_max_encryption_key_size = 16; 3801 sm_min_encryption_key_size = 7; 3802 3803 #ifdef ENABLE_CMAC_ENGINE 3804 sm_cmac_state = CMAC_IDLE; 3805 #endif 3806 dkg_state = DKG_W4_WORKING; 3807 rau_state = RAU_W4_WORKING; 3808 sm_aes128_state = SM_AES128_IDLE; 3809 sm_address_resolution_test = -1; // no private address to resolve yet 3810 sm_address_resolution_ah_calculation_active = 0; 3811 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3812 sm_address_resolution_general_queue = NULL; 3813 3814 gap_random_adress_update_period = 15 * 60 * 1000L; 3815 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3816 3817 test_use_fixed_local_csrk = 0; 3818 3819 // register for HCI Events from HCI 3820 hci_event_callback_registration.callback = &sm_event_packet_handler; 3821 hci_add_event_handler(&hci_event_callback_registration); 3822 3823 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3824 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3825 3826 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3827 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3828 #endif 3829 3830 #ifdef USE_MBEDTLS_FOR_ECDH 3831 #ifndef HAVE_MALLOC 3832 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3833 #endif 3834 mbedtls_ecp_group_init(&mbedtls_ec_group); 3835 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3836 #endif 3837 } 3838 3839 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3840 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3841 memcpy(&ec_q[0], qx, 32); 3842 memcpy(&ec_q[32], qy, 32); 3843 memcpy(ec_d, d, 32); 3844 sm_have_ec_keypair = 1; 3845 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3846 #else 3847 UNUSED(qx); 3848 UNUSED(qy); 3849 UNUSED(d); 3850 #endif 3851 } 3852 3853 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3854 #ifndef USE_MBEDTLS_FOR_ECDH 3855 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3856 while (*hex_string){ 3857 int high_nibble = nibble_for_char(*hex_string++); 3858 int low_nibble = nibble_for_char(*hex_string++); 3859 *buffer++ = (high_nibble << 4) | low_nibble; 3860 } 3861 } 3862 #endif 3863 #endif 3864 3865 void sm_test_use_fixed_ec_keypair(void){ 3866 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3867 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3868 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3869 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3870 #ifdef USE_MBEDTLS_FOR_ECDH 3871 // use test keypair from spec 3872 mbedtls_mpi x; 3873 mbedtls_mpi_init(&x); 3874 mbedtls_mpi_read_string( &x, 16, ec_d_string); 3875 mbedtls_mpi_write_binary(&x, ec_d, 32); 3876 mbedtls_mpi_read_string( &x, 16, ec_qx_string); 3877 mbedtls_mpi_write_binary(&x, &ec_q[0], 32); 3878 mbedtls_mpi_read_string( &x, 16, ec_qy_string); 3879 mbedtls_mpi_write_binary(&x, &ec_q[32], 32); 3880 mbedtls_mpi_free(&x); 3881 #else 3882 parse_hex(ec_d, ec_d_string); 3883 parse_hex(&ec_q[0], ec_qx_string); 3884 parse_hex(&ec_q[32], ec_qy_string); 3885 #endif 3886 sm_have_ec_keypair = 1; 3887 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3888 #endif 3889 } 3890 3891 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3892 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3893 if (!hci_con) return NULL; 3894 return &hci_con->sm_connection; 3895 } 3896 3897 // @returns 0 if not encrypted, 7-16 otherwise 3898 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3899 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3900 if (!sm_conn) return 0; // wrong connection 3901 if (!sm_conn->sm_connection_encrypted) return 0; 3902 return sm_conn->sm_actual_encryption_key_size; 3903 } 3904 3905 int sm_authenticated(hci_con_handle_t con_handle){ 3906 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3907 if (!sm_conn) return 0; // wrong connection 3908 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3909 return sm_conn->sm_connection_authenticated; 3910 } 3911 3912 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3913 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3914 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3915 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3916 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3917 return sm_conn->sm_connection_authorization_state; 3918 } 3919 3920 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3921 switch (sm_conn->sm_engine_state){ 3922 case SM_GENERAL_IDLE: 3923 case SM_RESPONDER_IDLE: 3924 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3925 sm_run(); 3926 break; 3927 default: 3928 break; 3929 } 3930 } 3931 3932 /** 3933 * @brief Trigger Security Request 3934 */ 3935 void sm_send_security_request(hci_con_handle_t con_handle){ 3936 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3937 if (!sm_conn) return; 3938 sm_send_security_request_for_connection(sm_conn); 3939 } 3940 3941 // request pairing 3942 void sm_request_pairing(hci_con_handle_t con_handle){ 3943 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3944 if (!sm_conn) return; // wrong connection 3945 3946 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3947 if (IS_RESPONDER(sm_conn->sm_role)){ 3948 sm_send_security_request_for_connection(sm_conn); 3949 } else { 3950 // used as a trigger to start central/master/initiator security procedures 3951 uint16_t ediv; 3952 sm_key_t ltk; 3953 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3954 switch (sm_conn->sm_irk_lookup_state){ 3955 case IRK_LOOKUP_FAILED: 3956 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3957 break; 3958 case IRK_LOOKUP_SUCCEEDED: 3959 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3960 if (!sm_is_null_key(ltk) || ediv){ 3961 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3962 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3963 } else { 3964 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3965 } 3966 break; 3967 default: 3968 sm_conn->sm_bonding_requested = 1; 3969 break; 3970 } 3971 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3972 sm_conn->sm_bonding_requested = 1; 3973 } 3974 } 3975 sm_run(); 3976 } 3977 3978 // called by client app on authorization request 3979 void sm_authorization_decline(hci_con_handle_t con_handle){ 3980 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3981 if (!sm_conn) return; // wrong connection 3982 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3983 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3984 } 3985 3986 void sm_authorization_grant(hci_con_handle_t con_handle){ 3987 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3988 if (!sm_conn) return; // wrong connection 3989 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3990 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3991 } 3992 3993 // GAP Bonding API 3994 3995 void sm_bonding_decline(hci_con_handle_t con_handle){ 3996 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3997 if (!sm_conn) return; // wrong connection 3998 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3999 4000 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4001 switch (setup->sm_stk_generation_method){ 4002 case PK_RESP_INPUT: 4003 case PK_INIT_INPUT: 4004 case OK_BOTH_INPUT: 4005 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4006 break; 4007 case NK_BOTH_INPUT: 4008 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4009 break; 4010 case JUST_WORKS: 4011 case OOB: 4012 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4013 break; 4014 } 4015 } 4016 sm_run(); 4017 } 4018 4019 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4020 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4021 if (!sm_conn) return; // wrong connection 4022 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4023 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4024 if (setup->sm_use_secure_connections){ 4025 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4026 } else { 4027 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4028 } 4029 } 4030 4031 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4032 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4033 sm_sc_prepare_dhkey_check(sm_conn); 4034 } 4035 #endif 4036 4037 sm_run(); 4038 } 4039 4040 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4041 // for now, it's the same 4042 sm_just_works_confirm(con_handle); 4043 } 4044 4045 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4046 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4047 if (!sm_conn) return; // wrong connection 4048 sm_reset_tk(); 4049 big_endian_store_32(setup->sm_tk, 12, passkey); 4050 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4051 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4052 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4053 } 4054 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4055 memcpy(setup->sm_ra, setup->sm_tk, 16); 4056 memcpy(setup->sm_rb, setup->sm_tk, 16); 4057 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4058 sm_sc_start_calculating_local_confirm(sm_conn); 4059 } 4060 #endif 4061 sm_run(); 4062 } 4063 4064 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4065 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4066 if (!sm_conn) return; // wrong connection 4067 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4068 setup->sm_keypress_notification = action; 4069 sm_run(); 4070 } 4071 4072 /** 4073 * @brief Identify device in LE Device DB 4074 * @param handle 4075 * @returns index from le_device_db or -1 if not found/identified 4076 */ 4077 int sm_le_device_index(hci_con_handle_t con_handle ){ 4078 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4079 if (!sm_conn) return -1; 4080 return sm_conn->sm_le_db_index; 4081 } 4082 4083 static int gap_random_address_type_requires_updates(void){ 4084 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4085 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4086 return 1; 4087 } 4088 4089 static uint8_t own_address_type(void){ 4090 switch (gap_random_adress_type){ 4091 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4092 return BD_ADDR_TYPE_LE_PUBLIC; 4093 default: 4094 return BD_ADDR_TYPE_LE_RANDOM; 4095 } 4096 } 4097 4098 // GAP LE API 4099 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4100 gap_random_address_update_stop(); 4101 gap_random_adress_type = random_address_type; 4102 hci_le_set_own_address_type(own_address_type()); 4103 if (!gap_random_address_type_requires_updates()) return; 4104 gap_random_address_update_start(); 4105 gap_random_address_trigger(); 4106 } 4107 4108 gap_random_address_type_t gap_random_address_get_mode(void){ 4109 return gap_random_adress_type; 4110 } 4111 4112 void gap_random_address_set_update_period(int period_ms){ 4113 gap_random_adress_update_period = period_ms; 4114 if (!gap_random_address_type_requires_updates()) return; 4115 gap_random_address_update_stop(); 4116 gap_random_address_update_start(); 4117 } 4118 4119 void gap_random_address_set(bd_addr_t addr){ 4120 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4121 memcpy(sm_random_address, addr, 6); 4122 if (rau_state == RAU_W4_WORKING) return; 4123 rau_state = RAU_SET_ADDRESS; 4124 sm_run(); 4125 } 4126 4127 #ifdef ENABLE_LE_PERIPHERAL 4128 /* 4129 * @brief Set Advertisement Paramters 4130 * @param adv_int_min 4131 * @param adv_int_max 4132 * @param adv_type 4133 * @param direct_address_type 4134 * @param direct_address 4135 * @param channel_map 4136 * @param filter_policy 4137 * 4138 * @note own_address_type is used from gap_random_address_set_mode 4139 */ 4140 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4141 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4142 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4143 direct_address_typ, direct_address, channel_map, filter_policy); 4144 } 4145 #endif 4146 4147