1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "sm.c" 39 40 #include <stdio.h> 41 #include <string.h> 42 #include <inttypes.h> 43 44 #include "ble/le_device_db.h" 45 #include "ble/core.h" 46 #include "ble/sm.h" 47 #include "bluetooth_company_id.h" 48 #include "btstack_debug.h" 49 #include "btstack_event.h" 50 #include "btstack_linked_list.h" 51 #include "btstack_memory.h" 52 #include "gap.h" 53 #include "hci.h" 54 #include "hci_dump.h" 55 #include "l2cap.h" 56 57 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 58 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 59 #endif 60 61 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 62 #define IS_RESPONDER(role) (role) 63 #else 64 #ifdef ENABLE_LE_CENTRAL 65 // only central - never responder (avoid 'unused variable' warnings) 66 #define IS_RESPONDER(role) (0 && role) 67 #else 68 // only peripheral - always responder (avoid 'unused variable' warnings) 69 #define IS_RESPONDER(role) (1 || role) 70 #endif 71 #endif 72 73 #ifdef ENABLE_LE_SECURE_CONNECTIONS 74 // assert SM Public Key can be sent/received 75 #if HCI_ACL_PAYLOAD_SIZE < 69 76 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 77 #endif 78 79 // configure ECC implementations 80 #ifdef ENABLE_LE_SECURE_CONNECTIONS 81 #if defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) && defined(HAVE_MBEDTLS_ECC_P256) 82 #error "If you already have mbedTLS (HAVE_MBEDTLS_ECC_P256), please disable uECC (USE_MICRO_ECC_FOR_ECDH) in bstack_config.h" 83 #endif 84 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 85 #define USE_SOFTWARE_ECDH_IMPLEMENTATION 86 #define USE_MICRO_ECC_FOR_ECDH 87 #endif 88 #ifdef HAVE_MBEDTLS_ECC_P256 89 #define USE_SOFTWARE_ECDH_IMPLEMENTATION 90 #define USE_MBEDTLS_FOR_ECDH 91 #endif 92 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 93 94 // Software ECDH implementation provided by micro-ecc 95 #ifdef USE_MICRO_ECC_FOR_ECDH 96 #include "uECC.h" 97 #endif 98 #endif 99 100 // Software ECDH implementation provided by mbedTLS 101 #ifdef USE_MBEDTLS_FOR_ECDH 102 #include "mbedtls/config.h" 103 #include "mbedtls/platform.h" 104 #include "mbedtls/ecp.h" 105 #endif 106 107 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 108 #define ENABLE_CMAC_ENGINE 109 #endif 110 111 // 112 // SM internal types and globals 113 // 114 115 typedef enum { 116 DKG_W4_WORKING, 117 DKG_CALC_IRK, 118 DKG_W4_IRK, 119 DKG_CALC_DHK, 120 DKG_W4_DHK, 121 DKG_READY 122 } derived_key_generation_t; 123 124 typedef enum { 125 RAU_W4_WORKING, 126 RAU_IDLE, 127 RAU_GET_RANDOM, 128 RAU_W4_RANDOM, 129 RAU_GET_ENC, 130 RAU_W4_ENC, 131 RAU_SET_ADDRESS, 132 } random_address_update_t; 133 134 typedef enum { 135 CMAC_IDLE, 136 CMAC_CALC_SUBKEYS, 137 CMAC_W4_SUBKEYS, 138 CMAC_CALC_MI, 139 CMAC_W4_MI, 140 CMAC_CALC_MLAST, 141 CMAC_W4_MLAST 142 } cmac_state_t; 143 144 typedef enum { 145 JUST_WORKS, 146 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 147 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 148 OK_BOTH_INPUT, // Only input on both, both input PK 149 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 150 OOB // OOB available on both sides 151 } stk_generation_method_t; 152 153 typedef enum { 154 SM_USER_RESPONSE_IDLE, 155 SM_USER_RESPONSE_PENDING, 156 SM_USER_RESPONSE_CONFIRM, 157 SM_USER_RESPONSE_PASSKEY, 158 SM_USER_RESPONSE_DECLINE 159 } sm_user_response_t; 160 161 typedef enum { 162 SM_AES128_IDLE, 163 SM_AES128_ACTIVE 164 } sm_aes128_state_t; 165 166 typedef enum { 167 ADDRESS_RESOLUTION_IDLE, 168 ADDRESS_RESOLUTION_GENERAL, 169 ADDRESS_RESOLUTION_FOR_CONNECTION, 170 } address_resolution_mode_t; 171 172 typedef enum { 173 ADDRESS_RESOLUTION_SUCEEDED, 174 ADDRESS_RESOLUTION_FAILED, 175 } address_resolution_event_t; 176 177 typedef enum { 178 EC_KEY_GENERATION_IDLE, 179 EC_KEY_GENERATION_ACTIVE, 180 EC_KEY_GENERATION_W4_KEY, 181 EC_KEY_GENERATION_DONE, 182 } ec_key_generation_state_t; 183 184 typedef enum { 185 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 186 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 187 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 188 } sm_state_var_t; 189 190 // 191 // GLOBAL DATA 192 // 193 194 static uint8_t test_use_fixed_local_csrk; 195 196 // configuration 197 static uint8_t sm_accepted_stk_generation_methods; 198 static uint8_t sm_max_encryption_key_size; 199 static uint8_t sm_min_encryption_key_size; 200 static uint8_t sm_auth_req = 0; 201 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 202 static uint8_t sm_slave_request_security; 203 static uint32_t sm_fixed_passkey_in_display_role; 204 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 205 #ifdef ENABLE_LE_SECURE_CONNECTIONS 206 static uint8_t sm_have_ec_keypair; 207 #endif 208 209 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 210 static sm_key_t sm_persistent_er; 211 static sm_key_t sm_persistent_ir; 212 213 // derived from sm_persistent_ir 214 static sm_key_t sm_persistent_dhk; 215 static sm_key_t sm_persistent_irk; 216 static uint8_t sm_persistent_irk_ready = 0; // used for testing 217 static derived_key_generation_t dkg_state; 218 219 // derived from sm_persistent_er 220 // .. 221 222 // random address update 223 static random_address_update_t rau_state; 224 static bd_addr_t sm_random_address; 225 226 // CMAC Calculation: General 227 #ifdef ENABLE_CMAC_ENGINE 228 static cmac_state_t sm_cmac_state; 229 static uint16_t sm_cmac_message_len; 230 static sm_key_t sm_cmac_k; 231 static sm_key_t sm_cmac_x; 232 static sm_key_t sm_cmac_m_last; 233 static uint8_t sm_cmac_block_current; 234 static uint8_t sm_cmac_block_count; 235 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 236 static void (*sm_cmac_done_handler)(uint8_t * hash); 237 #endif 238 239 // CMAC for ATT Signed Writes 240 #ifdef ENABLE_LE_SIGNED_WRITE 241 static uint8_t sm_cmac_header[3]; 242 static const uint8_t * sm_cmac_message; 243 static uint8_t sm_cmac_sign_counter[4]; 244 #endif 245 246 // CMAC for Secure Connection functions 247 #ifdef ENABLE_LE_SECURE_CONNECTIONS 248 static sm_connection_t * sm_cmac_connection; 249 static uint8_t sm_cmac_sc_buffer[80]; 250 #endif 251 252 // resolvable private address lookup / CSRK calculation 253 static int sm_address_resolution_test; 254 static int sm_address_resolution_ah_calculation_active; 255 static uint8_t sm_address_resolution_addr_type; 256 static bd_addr_t sm_address_resolution_address; 257 static void * sm_address_resolution_context; 258 static address_resolution_mode_t sm_address_resolution_mode; 259 static btstack_linked_list_t sm_address_resolution_general_queue; 260 261 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 262 static sm_aes128_state_t sm_aes128_state; 263 static void * sm_aes128_context; 264 265 // use aes128 provided by MCU - not needed usually 266 #ifdef HAVE_AES128 267 static uint8_t aes128_result_flipped[16]; 268 static btstack_timer_source_t aes128_timer; 269 void btstack_aes128_calc(uint8_t * key, uint8_t * plaintext, uint8_t * result); 270 #endif 271 272 // random engine. store context (ususally sm_connection_t) 273 static void * sm_random_context; 274 275 // to receive hci events 276 static btstack_packet_callback_registration_t hci_event_callback_registration; 277 278 /* to dispatch sm event */ 279 static btstack_linked_list_t sm_event_handlers; 280 281 // LE Secure Connections 282 #ifdef ENABLE_LE_SECURE_CONNECTIONS 283 static ec_key_generation_state_t ec_key_generation_state; 284 static uint8_t ec_d[32]; 285 static uint8_t ec_q[64]; 286 #endif 287 288 // Software ECDH implementation provided by mbedtls 289 #ifdef USE_MBEDTLS_FOR_ECDH 290 static mbedtls_ecp_group mbedtls_ec_group; 291 #endif 292 293 // 294 // Volume 3, Part H, Chapter 24 295 // "Security shall be initiated by the Security Manager in the device in the master role. 296 // The device in the slave role shall be the responding device." 297 // -> master := initiator, slave := responder 298 // 299 300 // data needed for security setup 301 typedef struct sm_setup_context { 302 303 btstack_timer_source_t sm_timeout; 304 305 // used in all phases 306 uint8_t sm_pairing_failed_reason; 307 308 // user response, (Phase 1 and/or 2) 309 uint8_t sm_user_response; 310 uint8_t sm_keypress_notification; 311 312 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 313 int sm_key_distribution_send_set; 314 int sm_key_distribution_received_set; 315 316 // Phase 2 (Pairing over SMP) 317 stk_generation_method_t sm_stk_generation_method; 318 sm_key_t sm_tk; 319 uint8_t sm_use_secure_connections; 320 321 sm_key_t sm_c1_t3_value; // c1 calculation 322 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 323 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 324 sm_key_t sm_local_random; 325 sm_key_t sm_local_confirm; 326 sm_key_t sm_peer_random; 327 sm_key_t sm_peer_confirm; 328 uint8_t sm_m_addr_type; // address and type can be removed 329 uint8_t sm_s_addr_type; // '' 330 bd_addr_t sm_m_address; // '' 331 bd_addr_t sm_s_address; // '' 332 sm_key_t sm_ltk; 333 334 uint8_t sm_state_vars; 335 #ifdef ENABLE_LE_SECURE_CONNECTIONS 336 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 337 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 338 sm_key_t sm_local_nonce; // might be combined with sm_local_random 339 sm_key_t sm_dhkey; 340 sm_key_t sm_peer_dhkey_check; 341 sm_key_t sm_local_dhkey_check; 342 sm_key_t sm_ra; 343 sm_key_t sm_rb; 344 sm_key_t sm_t; // used for f5 and h6 345 sm_key_t sm_mackey; 346 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 347 #endif 348 349 // Phase 3 350 351 // key distribution, we generate 352 uint16_t sm_local_y; 353 uint16_t sm_local_div; 354 uint16_t sm_local_ediv; 355 uint8_t sm_local_rand[8]; 356 sm_key_t sm_local_ltk; 357 sm_key_t sm_local_csrk; 358 sm_key_t sm_local_irk; 359 // sm_local_address/addr_type not needed 360 361 // key distribution, received from peer 362 uint16_t sm_peer_y; 363 uint16_t sm_peer_div; 364 uint16_t sm_peer_ediv; 365 uint8_t sm_peer_rand[8]; 366 sm_key_t sm_peer_ltk; 367 sm_key_t sm_peer_irk; 368 sm_key_t sm_peer_csrk; 369 uint8_t sm_peer_addr_type; 370 bd_addr_t sm_peer_address; 371 372 } sm_setup_context_t; 373 374 // 375 static sm_setup_context_t the_setup; 376 static sm_setup_context_t * setup = &the_setup; 377 378 // active connection - the one for which the_setup is used for 379 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 380 381 // @returns 1 if oob data is available 382 // stores oob data in provided 16 byte buffer if not null 383 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 384 385 // horizontal: initiator capabilities 386 // vertial: responder capabilities 387 static const stk_generation_method_t stk_generation_method [5] [5] = { 388 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 389 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 390 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 391 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 392 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 393 }; 394 395 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 396 #ifdef ENABLE_LE_SECURE_CONNECTIONS 397 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 398 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 399 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 400 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 401 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 402 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 403 }; 404 #endif 405 406 static void sm_run(void); 407 static void sm_done_for_handle(hci_con_handle_t con_handle); 408 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 409 static inline int sm_calc_actual_encryption_key_size(int other); 410 static int sm_validate_stk_generation_method(void); 411 static void sm_handle_encryption_result(uint8_t * data); 412 413 static void log_info_hex16(const char * name, uint16_t value){ 414 log_info("%-6s 0x%04x", name, value); 415 } 416 417 // @returns 1 if all bytes are 0 418 static int sm_is_null(uint8_t * data, int size){ 419 int i; 420 for (i=0; i < size ; i++){ 421 if (data[i]) return 0; 422 } 423 return 1; 424 } 425 426 static int sm_is_null_random(uint8_t random[8]){ 427 return sm_is_null(random, 8); 428 } 429 430 static int sm_is_null_key(uint8_t * key){ 431 return sm_is_null(key, 16); 432 } 433 434 // Key utils 435 static void sm_reset_tk(void){ 436 int i; 437 for (i=0;i<16;i++){ 438 setup->sm_tk[i] = 0; 439 } 440 } 441 442 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 443 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 444 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 445 int i; 446 for (i = max_encryption_size ; i < 16 ; i++){ 447 key[15-i] = 0; 448 } 449 } 450 451 // SMP Timeout implementation 452 453 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 454 // the Security Manager Timer shall be reset and started. 455 // 456 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 457 // 458 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 459 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 460 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 461 // established. 462 463 static void sm_timeout_handler(btstack_timer_source_t * timer){ 464 log_info("SM timeout"); 465 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 466 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 467 sm_done_for_handle(sm_conn->sm_handle); 468 469 // trigger handling of next ready connection 470 sm_run(); 471 } 472 static void sm_timeout_start(sm_connection_t * sm_conn){ 473 btstack_run_loop_remove_timer(&setup->sm_timeout); 474 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 475 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 476 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 477 btstack_run_loop_add_timer(&setup->sm_timeout); 478 } 479 static void sm_timeout_stop(void){ 480 btstack_run_loop_remove_timer(&setup->sm_timeout); 481 } 482 static void sm_timeout_reset(sm_connection_t * sm_conn){ 483 sm_timeout_stop(); 484 sm_timeout_start(sm_conn); 485 } 486 487 // end of sm timeout 488 489 // GAP Random Address updates 490 static gap_random_address_type_t gap_random_adress_type; 491 static btstack_timer_source_t gap_random_address_update_timer; 492 static uint32_t gap_random_adress_update_period; 493 494 static void gap_random_address_trigger(void){ 495 if (rau_state != RAU_IDLE) return; 496 log_info("gap_random_address_trigger"); 497 rau_state = RAU_GET_RANDOM; 498 sm_run(); 499 } 500 501 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 502 UNUSED(timer); 503 504 log_info("GAP Random Address Update due"); 505 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 506 btstack_run_loop_add_timer(&gap_random_address_update_timer); 507 gap_random_address_trigger(); 508 } 509 510 static void gap_random_address_update_start(void){ 511 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 512 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 513 btstack_run_loop_add_timer(&gap_random_address_update_timer); 514 } 515 516 static void gap_random_address_update_stop(void){ 517 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 518 } 519 520 521 static void sm_random_start(void * context){ 522 sm_random_context = context; 523 hci_send_cmd(&hci_le_rand); 524 } 525 526 #ifdef HAVE_AES128 527 static void aes128_completed(btstack_timer_source_t * ts){ 528 UNUSED(ts); 529 sm_handle_encryption_result(&aes128_result_flipped[0]); 530 sm_run(); 531 } 532 #endif 533 534 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 535 // context is made availabe to aes128 result handler by this 536 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 537 sm_aes128_state = SM_AES128_ACTIVE; 538 sm_aes128_context = context; 539 540 #ifdef HAVE_AES128 541 // calc result directly 542 sm_key_t result; 543 btstack_aes128_calc(key, plaintext, result); 544 545 // log 546 log_info_key("key", key); 547 log_info_key("txt", plaintext); 548 log_info_key("res", result); 549 550 // flip 551 reverse_128(&result[0], &aes128_result_flipped[0]); 552 553 // deliver via timer 554 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 555 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 556 btstack_run_loop_add_timer(&aes128_timer); 557 #else 558 sm_key_t key_flipped, plaintext_flipped; 559 reverse_128(key, key_flipped); 560 reverse_128(plaintext, plaintext_flipped); 561 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 562 #endif 563 } 564 565 // ah(k,r) helper 566 // r = padding || r 567 // r - 24 bit value 568 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 569 // r'= padding || r 570 memset(r_prime, 0, 16); 571 memcpy(&r_prime[13], r, 3); 572 } 573 574 // d1 helper 575 // d' = padding || r || d 576 // d,r - 16 bit values 577 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 578 // d'= padding || r || d 579 memset(d1_prime, 0, 16); 580 big_endian_store_16(d1_prime, 12, r); 581 big_endian_store_16(d1_prime, 14, d); 582 } 583 584 // dm helper 585 // r’ = padding || r 586 // r - 64 bit value 587 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 588 memset(r_prime, 0, 16); 589 memcpy(&r_prime[8], r, 8); 590 } 591 592 // calculate arguments for first AES128 operation in C1 function 593 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){ 594 595 // p1 = pres || preq || rat’ || iat’ 596 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 597 // cant octet of pres becomes the most significant octet of p1. 598 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 599 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 600 // p1 is 0x05000800000302070710000001010001." 601 602 sm_key_t p1; 603 reverse_56(pres, &p1[0]); 604 reverse_56(preq, &p1[7]); 605 p1[14] = rat; 606 p1[15] = iat; 607 log_info_key("p1", p1); 608 log_info_key("r", r); 609 610 // t1 = r xor p1 611 int i; 612 for (i=0;i<16;i++){ 613 t1[i] = r[i] ^ p1[i]; 614 } 615 log_info_key("t1", t1); 616 } 617 618 // calculate arguments for second AES128 operation in C1 function 619 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 620 // p2 = padding || ia || ra 621 // "The least significant octet of ra becomes the least significant octet of p2 and 622 // the most significant octet of padding becomes the most significant octet of p2. 623 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 624 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 625 626 sm_key_t p2; 627 memset(p2, 0, 16); 628 memcpy(&p2[4], ia, 6); 629 memcpy(&p2[10], ra, 6); 630 log_info_key("p2", p2); 631 632 // c1 = e(k, t2_xor_p2) 633 int i; 634 for (i=0;i<16;i++){ 635 t3[i] = t2[i] ^ p2[i]; 636 } 637 log_info_key("t3", t3); 638 } 639 640 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 641 log_info_key("r1", r1); 642 log_info_key("r2", r2); 643 memcpy(&r_prime[8], &r2[8], 8); 644 memcpy(&r_prime[0], &r1[8], 8); 645 } 646 647 #ifdef ENABLE_LE_SECURE_CONNECTIONS 648 // Software implementations of crypto toolbox for LE Secure Connection 649 // TODO: replace with code to use AES Engine of HCI Controller 650 typedef uint8_t sm_key24_t[3]; 651 typedef uint8_t sm_key56_t[7]; 652 typedef uint8_t sm_key256_t[32]; 653 654 #if 0 655 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 656 uint32_t rk[RKLENGTH(KEYBITS)]; 657 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 658 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 659 } 660 661 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 662 memcpy(k1, k0, 16); 663 sm_shift_left_by_one_bit_inplace(16, k1); 664 if (k0[0] & 0x80){ 665 k1[15] ^= 0x87; 666 } 667 memcpy(k2, k1, 16); 668 sm_shift_left_by_one_bit_inplace(16, k2); 669 if (k1[0] & 0x80){ 670 k2[15] ^= 0x87; 671 } 672 } 673 674 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 675 sm_key_t k0, k1, k2, zero; 676 memset(zero, 0, 16); 677 678 aes128_calc_cyphertext(key, zero, k0); 679 calc_subkeys(k0, k1, k2); 680 681 int cmac_block_count = (cmac_message_len + 15) / 16; 682 683 // step 3: .. 684 if (cmac_block_count==0){ 685 cmac_block_count = 1; 686 } 687 688 // step 4: set m_last 689 sm_key_t cmac_m_last; 690 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 691 int i; 692 if (sm_cmac_last_block_complete){ 693 for (i=0;i<16;i++){ 694 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 695 } 696 } else { 697 int valid_octets_in_last_block = cmac_message_len & 0x0f; 698 for (i=0;i<16;i++){ 699 if (i < valid_octets_in_last_block){ 700 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 701 continue; 702 } 703 if (i == valid_octets_in_last_block){ 704 cmac_m_last[i] = 0x80 ^ k2[i]; 705 continue; 706 } 707 cmac_m_last[i] = k2[i]; 708 } 709 } 710 711 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 712 // LOG_KEY(cmac_m_last); 713 714 // Step 5 715 sm_key_t cmac_x; 716 memset(cmac_x, 0, 16); 717 718 // Step 6 719 sm_key_t sm_cmac_y; 720 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 721 for (i=0;i<16;i++){ 722 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 723 } 724 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 725 } 726 for (i=0;i<16;i++){ 727 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 728 } 729 730 // Step 7 731 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 732 } 733 #endif 734 #endif 735 736 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){ 737 event[0] = type; 738 event[1] = event_size - 2; 739 little_endian_store_16(event, 2, con_handle); 740 event[4] = addr_type; 741 reverse_bd_addr(address, &event[5]); 742 } 743 744 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 745 UNUSED(channel); 746 747 // log event 748 hci_dump_packet(packet_type, 1, packet, size); 749 // dispatch to all event handlers 750 btstack_linked_list_iterator_t it; 751 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 752 while (btstack_linked_list_iterator_has_next(&it)){ 753 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 754 entry->callback(packet_type, 0, packet, size); 755 } 756 } 757 758 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 759 uint8_t event[11]; 760 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 761 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 762 } 763 764 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){ 765 uint8_t event[15]; 766 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 767 little_endian_store_32(event, 11, passkey); 768 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 769 } 770 771 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){ 772 // fetch addr and addr type from db 773 bd_addr_t identity_address; 774 int identity_address_type; 775 le_device_db_info(index, &identity_address_type, identity_address, NULL); 776 777 uint8_t event[19]; 778 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 779 event[11] = identity_address_type; 780 reverse_bd_addr(identity_address, &event[12]); 781 event[18] = index; 782 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 783 } 784 785 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){ 786 787 uint8_t event[18]; 788 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 789 event[11] = result; 790 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 791 } 792 793 // decide on stk generation based on 794 // - pairing request 795 // - io capabilities 796 // - OOB data availability 797 static void sm_setup_tk(void){ 798 799 // default: just works 800 setup->sm_stk_generation_method = JUST_WORKS; 801 802 #ifdef ENABLE_LE_SECURE_CONNECTIONS 803 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 804 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 805 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 806 memset(setup->sm_ra, 0, 16); 807 memset(setup->sm_rb, 0, 16); 808 #else 809 setup->sm_use_secure_connections = 0; 810 #endif 811 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 812 813 // If both devices have not set the MITM option in the Authentication Requirements 814 // Flags, then the IO capabilities shall be ignored and the Just Works association 815 // model shall be used. 816 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 817 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 818 log_info("SM: MITM not required by both -> JUST WORKS"); 819 return; 820 } 821 822 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 823 824 // If both devices have out of band authentication data, then the Authentication 825 // Requirements Flags shall be ignored when selecting the pairing method and the 826 // Out of Band pairing method shall be used. 827 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 828 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 829 log_info("SM: have OOB data"); 830 log_info_key("OOB", setup->sm_tk); 831 setup->sm_stk_generation_method = OOB; 832 return; 833 } 834 835 // Reset TK as it has been setup in sm_init_setup 836 sm_reset_tk(); 837 838 // Also use just works if unknown io capabilites 839 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)){ 840 return; 841 } 842 843 // Otherwise the IO capabilities of the devices shall be used to determine the 844 // pairing method as defined in Table 2.4. 845 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 846 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 847 848 #ifdef ENABLE_LE_SECURE_CONNECTIONS 849 // table not define by default 850 if (setup->sm_use_secure_connections){ 851 generation_method = stk_generation_method_with_secure_connection; 852 } 853 #endif 854 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)]; 855 856 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 857 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); 858 } 859 860 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 861 int flags = 0; 862 if (key_set & SM_KEYDIST_ENC_KEY){ 863 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 864 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 865 } 866 if (key_set & SM_KEYDIST_ID_KEY){ 867 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 868 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 869 } 870 if (key_set & SM_KEYDIST_SIGN){ 871 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 872 } 873 return flags; 874 } 875 876 static void sm_setup_key_distribution(uint8_t key_set){ 877 setup->sm_key_distribution_received_set = 0; 878 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 879 } 880 881 // CSRK Key Lookup 882 883 884 static int sm_address_resolution_idle(void){ 885 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 886 } 887 888 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){ 889 memcpy(sm_address_resolution_address, addr, 6); 890 sm_address_resolution_addr_type = addr_type; 891 sm_address_resolution_test = 0; 892 sm_address_resolution_mode = mode; 893 sm_address_resolution_context = context; 894 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 895 } 896 897 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 898 // check if already in list 899 btstack_linked_list_iterator_t it; 900 sm_lookup_entry_t * entry; 901 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 902 while(btstack_linked_list_iterator_has_next(&it)){ 903 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 904 if (entry->address_type != address_type) continue; 905 if (memcmp(entry->address, address, 6)) continue; 906 // already in list 907 return BTSTACK_BUSY; 908 } 909 entry = btstack_memory_sm_lookup_entry_get(); 910 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 911 entry->address_type = (bd_addr_type_t) address_type; 912 memcpy(entry->address, address, 6); 913 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 914 sm_run(); 915 return 0; 916 } 917 918 // 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 919 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 920 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 921 } 922 static inline void dkg_next_state(void){ 923 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 924 } 925 static inline void rau_next_state(void){ 926 rau_state = (random_address_update_t) (((int)rau_state) + 1); 927 } 928 929 // CMAC calculation using AES Engine 930 #ifdef ENABLE_CMAC_ENGINE 931 932 static inline void sm_cmac_next_state(void){ 933 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 934 } 935 936 static int sm_cmac_last_block_complete(void){ 937 if (sm_cmac_message_len == 0) return 0; 938 return (sm_cmac_message_len & 0x0f) == 0; 939 } 940 941 int sm_cmac_ready(void){ 942 return sm_cmac_state == CMAC_IDLE; 943 } 944 945 // generic cmac calculation 946 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])){ 947 // Generalized CMAC 948 memcpy(sm_cmac_k, key, 16); 949 memset(sm_cmac_x, 0, 16); 950 sm_cmac_block_current = 0; 951 sm_cmac_message_len = message_len; 952 sm_cmac_done_handler = done_callback; 953 sm_cmac_get_byte = get_byte_callback; 954 955 // step 2: n := ceil(len/const_Bsize); 956 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 957 958 // step 3: .. 959 if (sm_cmac_block_count==0){ 960 sm_cmac_block_count = 1; 961 } 962 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 963 964 // first, we need to compute l for k1, k2, and m_last 965 sm_cmac_state = CMAC_CALC_SUBKEYS; 966 967 // let's go 968 sm_run(); 969 } 970 #endif 971 972 // cmac for ATT Message signing 973 #ifdef ENABLE_LE_SIGNED_WRITE 974 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 975 if (offset >= sm_cmac_message_len) { 976 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 977 return 0; 978 } 979 980 offset = sm_cmac_message_len - 1 - offset; 981 982 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 983 if (offset < 3){ 984 return sm_cmac_header[offset]; 985 } 986 int actual_message_len_incl_header = sm_cmac_message_len - 4; 987 if (offset < actual_message_len_incl_header){ 988 return sm_cmac_message[offset - 3]; 989 } 990 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 991 } 992 993 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)){ 994 // ATT Message Signing 995 sm_cmac_header[0] = opcode; 996 little_endian_store_16(sm_cmac_header, 1, con_handle); 997 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 998 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 999 sm_cmac_message = message; 1000 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 1001 } 1002 #endif 1003 1004 #ifdef ENABLE_CMAC_ENGINE 1005 static void sm_cmac_handle_aes_engine_ready(void){ 1006 switch (sm_cmac_state){ 1007 case CMAC_CALC_SUBKEYS: { 1008 sm_key_t const_zero; 1009 memset(const_zero, 0, 16); 1010 sm_cmac_next_state(); 1011 sm_aes128_start(sm_cmac_k, const_zero, NULL); 1012 break; 1013 } 1014 case CMAC_CALC_MI: { 1015 int j; 1016 sm_key_t y; 1017 for (j=0;j<16;j++){ 1018 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 1019 } 1020 sm_cmac_block_current++; 1021 sm_cmac_next_state(); 1022 sm_aes128_start(sm_cmac_k, y, NULL); 1023 break; 1024 } 1025 case CMAC_CALC_MLAST: { 1026 int i; 1027 sm_key_t y; 1028 for (i=0;i<16;i++){ 1029 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 1030 } 1031 log_info_key("Y", y); 1032 sm_cmac_block_current++; 1033 sm_cmac_next_state(); 1034 sm_aes128_start(sm_cmac_k, y, NULL); 1035 break; 1036 } 1037 default: 1038 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1039 break; 1040 } 1041 } 1042 1043 // CMAC Implementation using AES128 engine 1044 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1045 int i; 1046 int carry = 0; 1047 for (i=len-1; i >= 0 ; i--){ 1048 int new_carry = data[i] >> 7; 1049 data[i] = data[i] << 1 | carry; 1050 carry = new_carry; 1051 } 1052 } 1053 1054 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1055 switch (sm_cmac_state){ 1056 case CMAC_W4_SUBKEYS: { 1057 sm_key_t k1; 1058 memcpy(k1, data, 16); 1059 sm_shift_left_by_one_bit_inplace(16, k1); 1060 if (data[0] & 0x80){ 1061 k1[15] ^= 0x87; 1062 } 1063 sm_key_t k2; 1064 memcpy(k2, k1, 16); 1065 sm_shift_left_by_one_bit_inplace(16, k2); 1066 if (k1[0] & 0x80){ 1067 k2[15] ^= 0x87; 1068 } 1069 1070 log_info_key("k", sm_cmac_k); 1071 log_info_key("k1", k1); 1072 log_info_key("k2", k2); 1073 1074 // step 4: set m_last 1075 int i; 1076 if (sm_cmac_last_block_complete()){ 1077 for (i=0;i<16;i++){ 1078 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1079 } 1080 } else { 1081 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1082 for (i=0;i<16;i++){ 1083 if (i < valid_octets_in_last_block){ 1084 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1085 continue; 1086 } 1087 if (i == valid_octets_in_last_block){ 1088 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1089 continue; 1090 } 1091 sm_cmac_m_last[i] = k2[i]; 1092 } 1093 } 1094 1095 // next 1096 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1097 break; 1098 } 1099 case CMAC_W4_MI: 1100 memcpy(sm_cmac_x, data, 16); 1101 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1102 break; 1103 case CMAC_W4_MLAST: 1104 // done 1105 log_info("Setting CMAC Engine to IDLE"); 1106 sm_cmac_state = CMAC_IDLE; 1107 log_info_key("CMAC", data); 1108 sm_cmac_done_handler(data); 1109 break; 1110 default: 1111 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1112 break; 1113 } 1114 } 1115 #endif 1116 1117 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1118 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1119 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1120 switch (setup->sm_stk_generation_method){ 1121 case PK_RESP_INPUT: 1122 if (IS_RESPONDER(sm_conn->sm_role)){ 1123 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1124 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1125 } else { 1126 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)); 1127 } 1128 break; 1129 case PK_INIT_INPUT: 1130 if (IS_RESPONDER(sm_conn->sm_role)){ 1131 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)); 1132 } else { 1133 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1134 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1135 } 1136 break; 1137 case OK_BOTH_INPUT: 1138 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1139 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1140 break; 1141 case NK_BOTH_INPUT: 1142 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1143 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)); 1144 break; 1145 case JUST_WORKS: 1146 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1147 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1148 break; 1149 case OOB: 1150 // client already provided OOB data, let's skip notification. 1151 break; 1152 } 1153 } 1154 1155 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1156 int recv_flags; 1157 if (IS_RESPONDER(sm_conn->sm_role)){ 1158 // slave / responder 1159 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1160 } else { 1161 // master / initiator 1162 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1163 } 1164 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1165 return recv_flags == setup->sm_key_distribution_received_set; 1166 } 1167 1168 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1169 if (sm_active_connection_handle == con_handle){ 1170 sm_timeout_stop(); 1171 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1172 log_info("sm: connection 0x%x released setup context", con_handle); 1173 } 1174 } 1175 1176 static int sm_key_distribution_flags_for_auth_req(void){ 1177 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1178 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1179 // encryption information only if bonding requested 1180 flags |= SM_KEYDIST_ENC_KEY; 1181 } 1182 return flags; 1183 } 1184 1185 static void sm_reset_setup(void){ 1186 // fill in sm setup 1187 setup->sm_state_vars = 0; 1188 setup->sm_keypress_notification = 0xff; 1189 sm_reset_tk(); 1190 } 1191 1192 static void sm_init_setup(sm_connection_t * sm_conn){ 1193 1194 // fill in sm setup 1195 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1196 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1197 1198 // query client for OOB data 1199 int have_oob_data = 0; 1200 if (sm_get_oob_data) { 1201 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1202 } 1203 1204 sm_pairing_packet_t * local_packet; 1205 if (IS_RESPONDER(sm_conn->sm_role)){ 1206 // slave 1207 local_packet = &setup->sm_s_pres; 1208 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1209 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1210 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1211 } else { 1212 // master 1213 local_packet = &setup->sm_m_preq; 1214 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1215 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1216 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1217 1218 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1219 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1220 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1221 } 1222 1223 uint8_t auth_req = sm_auth_req; 1224 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1225 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1226 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1227 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1228 } 1229 1230 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1231 1232 sm_pairing_packet_t * remote_packet; 1233 int remote_key_request; 1234 if (IS_RESPONDER(sm_conn->sm_role)){ 1235 // slave / responder 1236 remote_packet = &setup->sm_m_preq; 1237 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1238 } else { 1239 // master / initiator 1240 remote_packet = &setup->sm_s_pres; 1241 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1242 } 1243 1244 // check key size 1245 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1246 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1247 1248 // decide on STK generation method 1249 sm_setup_tk(); 1250 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1251 1252 // check if STK generation method is acceptable by client 1253 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1254 1255 // identical to responder 1256 sm_setup_key_distribution(remote_key_request); 1257 1258 // JUST WORKS doens't provide authentication 1259 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1260 1261 return 0; 1262 } 1263 1264 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1265 1266 // cache and reset context 1267 int matched_device_id = sm_address_resolution_test; 1268 address_resolution_mode_t mode = sm_address_resolution_mode; 1269 void * context = sm_address_resolution_context; 1270 1271 // reset context 1272 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1273 sm_address_resolution_context = NULL; 1274 sm_address_resolution_test = -1; 1275 hci_con_handle_t con_handle = 0; 1276 1277 sm_connection_t * sm_connection; 1278 #ifdef ENABLE_LE_CENTRAL 1279 sm_key_t ltk; 1280 #endif 1281 switch (mode){ 1282 case ADDRESS_RESOLUTION_GENERAL: 1283 break; 1284 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1285 sm_connection = (sm_connection_t *) context; 1286 con_handle = sm_connection->sm_handle; 1287 switch (event){ 1288 case ADDRESS_RESOLUTION_SUCEEDED: 1289 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1290 sm_connection->sm_le_db_index = matched_device_id; 1291 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1292 if (sm_connection->sm_role) { 1293 // LTK request received before, IRK required -> start LTK calculation 1294 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1295 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1296 } 1297 break; 1298 } 1299 #ifdef ENABLE_LE_CENTRAL 1300 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1301 sm_connection->sm_security_request_received = 0; 1302 sm_connection->sm_bonding_requested = 0; 1303 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1304 if (!sm_is_null_key(ltk)){ 1305 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1306 } else { 1307 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1308 } 1309 #endif 1310 break; 1311 case ADDRESS_RESOLUTION_FAILED: 1312 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1313 if (sm_connection->sm_role) { 1314 // LTK request received before, IRK required -> negative LTK reply 1315 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1316 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1317 } 1318 break; 1319 } 1320 #ifdef ENABLE_LE_CENTRAL 1321 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1322 sm_connection->sm_security_request_received = 0; 1323 sm_connection->sm_bonding_requested = 0; 1324 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1325 #endif 1326 break; 1327 } 1328 break; 1329 default: 1330 break; 1331 } 1332 1333 switch (event){ 1334 case ADDRESS_RESOLUTION_SUCEEDED: 1335 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1336 break; 1337 case ADDRESS_RESOLUTION_FAILED: 1338 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1339 break; 1340 } 1341 } 1342 1343 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1344 1345 int le_db_index = -1; 1346 1347 // lookup device based on IRK 1348 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1349 int i; 1350 for (i=0; i < le_device_db_count(); i++){ 1351 sm_key_t irk; 1352 bd_addr_t address; 1353 int address_type; 1354 le_device_db_info(i, &address_type, address, irk); 1355 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1356 log_info("sm: device found for IRK, updating"); 1357 le_db_index = i; 1358 break; 1359 } 1360 } 1361 } 1362 1363 // if not found, lookup via public address if possible 1364 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1365 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1366 int i; 1367 for (i=0; i < le_device_db_count(); i++){ 1368 bd_addr_t address; 1369 int address_type; 1370 le_device_db_info(i, &address_type, address, NULL); 1371 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1372 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1373 log_info("sm: device found for public address, updating"); 1374 le_db_index = i; 1375 break; 1376 } 1377 } 1378 } 1379 1380 // if not found, add to db 1381 if (le_db_index < 0) { 1382 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1383 } 1384 1385 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1386 1387 if (le_db_index >= 0){ 1388 1389 #ifdef ENABLE_LE_SIGNED_WRITE 1390 // store local CSRK 1391 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1392 log_info("sm: store local CSRK"); 1393 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1394 le_device_db_local_counter_set(le_db_index, 0); 1395 } 1396 1397 // store remote CSRK 1398 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1399 log_info("sm: store remote CSRK"); 1400 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1401 le_device_db_remote_counter_set(le_db_index, 0); 1402 } 1403 #endif 1404 // store encryption information for secure connections: LTK generated by ECDH 1405 if (setup->sm_use_secure_connections){ 1406 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1407 uint8_t zero_rand[8]; 1408 memset(zero_rand, 0, 8); 1409 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1410 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1411 } 1412 1413 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1414 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1415 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1416 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1417 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1418 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1419 1420 } 1421 } 1422 1423 // keep le_db_index 1424 sm_conn->sm_le_db_index = le_db_index; 1425 } 1426 1427 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1428 setup->sm_pairing_failed_reason = reason; 1429 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1430 } 1431 1432 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1433 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1434 } 1435 1436 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1437 1438 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1439 static int sm_passkey_used(stk_generation_method_t method); 1440 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1441 1442 static void sm_log_ec_keypair(void){ 1443 log_info("Elliptic curve: X"); 1444 log_info_hexdump(&ec_q[0],32); 1445 log_info("Elliptic curve: Y"); 1446 log_info_hexdump(&ec_q[32],32); 1447 } 1448 1449 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1450 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1451 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1452 } else { 1453 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1454 } 1455 } 1456 1457 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1458 if (IS_RESPONDER(sm_conn->sm_role)){ 1459 // Responder 1460 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1461 } else { 1462 // Initiator role 1463 switch (setup->sm_stk_generation_method){ 1464 case JUST_WORKS: 1465 sm_sc_prepare_dhkey_check(sm_conn); 1466 break; 1467 1468 case NK_BOTH_INPUT: 1469 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1470 break; 1471 case PK_INIT_INPUT: 1472 case PK_RESP_INPUT: 1473 case OK_BOTH_INPUT: 1474 if (setup->sm_passkey_bit < 20) { 1475 sm_sc_start_calculating_local_confirm(sm_conn); 1476 } else { 1477 sm_sc_prepare_dhkey_check(sm_conn); 1478 } 1479 break; 1480 case OOB: 1481 // TODO: implement SC OOB 1482 break; 1483 } 1484 } 1485 } 1486 1487 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1488 return sm_cmac_sc_buffer[offset]; 1489 } 1490 1491 static void sm_sc_cmac_done(uint8_t * hash){ 1492 log_info("sm_sc_cmac_done: "); 1493 log_info_hexdump(hash, 16); 1494 1495 sm_connection_t * sm_conn = sm_cmac_connection; 1496 sm_cmac_connection = NULL; 1497 #ifdef ENABLE_CLASSIC 1498 link_key_type_t link_key_type; 1499 #endif 1500 1501 switch (sm_conn->sm_engine_state){ 1502 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1503 memcpy(setup->sm_local_confirm, hash, 16); 1504 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1505 break; 1506 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1507 // check 1508 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1509 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1510 break; 1511 } 1512 sm_sc_state_after_receiving_random(sm_conn); 1513 break; 1514 case SM_SC_W4_CALCULATE_G2: { 1515 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1516 big_endian_store_32(setup->sm_tk, 12, vab); 1517 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1518 sm_trigger_user_response(sm_conn); 1519 break; 1520 } 1521 case SM_SC_W4_CALCULATE_F5_SALT: 1522 memcpy(setup->sm_t, hash, 16); 1523 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1524 break; 1525 case SM_SC_W4_CALCULATE_F5_MACKEY: 1526 memcpy(setup->sm_mackey, hash, 16); 1527 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1528 break; 1529 case SM_SC_W4_CALCULATE_F5_LTK: 1530 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1531 // Errata Service Release to the Bluetooth Specification: ESR09 1532 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1533 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1534 memcpy(setup->sm_ltk, hash, 16); 1535 memcpy(setup->sm_local_ltk, hash, 16); 1536 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1537 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1538 break; 1539 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1540 memcpy(setup->sm_local_dhkey_check, hash, 16); 1541 if (IS_RESPONDER(sm_conn->sm_role)){ 1542 // responder 1543 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1544 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1545 } else { 1546 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1547 } 1548 } else { 1549 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1550 } 1551 break; 1552 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1553 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1554 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1555 break; 1556 } 1557 if (IS_RESPONDER(sm_conn->sm_role)){ 1558 // responder 1559 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1560 } else { 1561 // initiator 1562 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1563 } 1564 break; 1565 case SM_SC_W4_CALCULATE_H6_ILK: 1566 memcpy(setup->sm_t, hash, 16); 1567 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1568 break; 1569 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1570 #ifdef ENABLE_CLASSIC 1571 reverse_128(hash, setup->sm_t); 1572 link_key_type = sm_conn->sm_connection_authenticated ? 1573 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1574 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1575 if (IS_RESPONDER(sm_conn->sm_role)){ 1576 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1577 } else { 1578 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1579 } 1580 #endif 1581 if (IS_RESPONDER(sm_conn->sm_role)){ 1582 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1583 } else { 1584 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1585 } 1586 sm_done_for_handle(sm_conn->sm_handle); 1587 break; 1588 default: 1589 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1590 break; 1591 } 1592 sm_run(); 1593 } 1594 1595 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){ 1596 const uint16_t message_len = 65; 1597 sm_cmac_connection = sm_conn; 1598 memcpy(sm_cmac_sc_buffer, u, 32); 1599 memcpy(sm_cmac_sc_buffer+32, v, 32); 1600 sm_cmac_sc_buffer[64] = z; 1601 log_info("f4 key"); 1602 log_info_hexdump(x, 16); 1603 log_info("f4 message"); 1604 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1605 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1606 } 1607 1608 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1609 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1610 static const uint8_t f5_length[] = { 0x01, 0x00}; 1611 1612 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1613 1614 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1615 memset(dhkey, 0, 32); 1616 1617 #ifdef USE_MICRO_ECC_FOR_ECDH 1618 #if uECC_SUPPORTS_secp256r1 1619 // standard version 1620 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1621 #else 1622 // static version 1623 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1624 #endif 1625 #endif 1626 1627 #ifdef USE_MBEDTLS_FOR_ECDH 1628 // da * Pb 1629 mbedtls_mpi d; 1630 mbedtls_ecp_point Q; 1631 mbedtls_ecp_point DH; 1632 mbedtls_mpi_init(&d); 1633 mbedtls_ecp_point_init(&Q); 1634 mbedtls_ecp_point_init(&DH); 1635 mbedtls_mpi_read_binary(&d, ec_d, 32); 1636 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0] , 32); 1637 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 1638 mbedtls_mpi_lset(&Q.Z, 1); 1639 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1640 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1641 mbedtls_ecp_point_free(&DH); 1642 mbedtls_mpi_free(&d); 1643 mbedtls_ecp_point_free(&Q); 1644 #endif 1645 1646 log_info("dhkey"); 1647 log_info_hexdump(dhkey, 32); 1648 } 1649 #endif 1650 1651 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1652 // calculate salt for f5 1653 const uint16_t message_len = 32; 1654 sm_cmac_connection = sm_conn; 1655 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1656 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1657 } 1658 1659 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){ 1660 const uint16_t message_len = 53; 1661 sm_cmac_connection = sm_conn; 1662 1663 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1664 sm_cmac_sc_buffer[0] = 0; 1665 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1666 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1667 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1668 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1669 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1670 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1671 log_info("f5 key"); 1672 log_info_hexdump(t, 16); 1673 log_info("f5 message for MacKey"); 1674 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1675 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1676 } 1677 1678 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1679 sm_key56_t bd_addr_master, bd_addr_slave; 1680 bd_addr_master[0] = setup->sm_m_addr_type; 1681 bd_addr_slave[0] = setup->sm_s_addr_type; 1682 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1683 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1684 if (IS_RESPONDER(sm_conn->sm_role)){ 1685 // responder 1686 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1687 } else { 1688 // initiator 1689 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1690 } 1691 } 1692 1693 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1694 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1695 const uint16_t message_len = 53; 1696 sm_cmac_connection = sm_conn; 1697 sm_cmac_sc_buffer[0] = 1; 1698 // 1..52 setup before 1699 log_info("f5 key"); 1700 log_info_hexdump(t, 16); 1701 log_info("f5 message for LTK"); 1702 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1703 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1704 } 1705 1706 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1707 f5_ltk(sm_conn, setup->sm_t); 1708 } 1709 1710 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){ 1711 const uint16_t message_len = 65; 1712 sm_cmac_connection = sm_conn; 1713 memcpy(sm_cmac_sc_buffer, n1, 16); 1714 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1715 memcpy(sm_cmac_sc_buffer+32, r, 16); 1716 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1717 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1718 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1719 log_info("f6 key"); 1720 log_info_hexdump(w, 16); 1721 log_info("f6 message"); 1722 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1723 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1724 } 1725 1726 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1727 // - U is 256 bits 1728 // - V is 256 bits 1729 // - X is 128 bits 1730 // - Y is 128 bits 1731 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){ 1732 const uint16_t message_len = 80; 1733 sm_cmac_connection = sm_conn; 1734 memcpy(sm_cmac_sc_buffer, u, 32); 1735 memcpy(sm_cmac_sc_buffer+32, v, 32); 1736 memcpy(sm_cmac_sc_buffer+64, y, 16); 1737 log_info("g2 key"); 1738 log_info_hexdump(x, 16); 1739 log_info("g2 message"); 1740 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1741 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1742 } 1743 1744 static void g2_calculate(sm_connection_t * sm_conn) { 1745 // calc Va if numeric comparison 1746 if (IS_RESPONDER(sm_conn->sm_role)){ 1747 // responder 1748 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1749 } else { 1750 // initiator 1751 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1752 } 1753 } 1754 1755 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1756 uint8_t z = 0; 1757 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1758 // some form of passkey 1759 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1760 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1761 setup->sm_passkey_bit++; 1762 } 1763 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1764 } 1765 1766 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1767 uint8_t z = 0; 1768 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1769 // some form of passkey 1770 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1771 // sm_passkey_bit was increased before sending confirm value 1772 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1773 } 1774 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1775 } 1776 1777 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1778 1779 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1780 // calculate DHKEY 1781 sm_sc_calculate_dhkey(setup->sm_dhkey); 1782 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1783 #endif 1784 1785 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1786 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1787 return; 1788 } else { 1789 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1790 } 1791 1792 } 1793 1794 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1795 // calculate DHKCheck 1796 sm_key56_t bd_addr_master, bd_addr_slave; 1797 bd_addr_master[0] = setup->sm_m_addr_type; 1798 bd_addr_slave[0] = setup->sm_s_addr_type; 1799 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1800 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1801 uint8_t iocap_a[3]; 1802 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1803 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1804 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1805 uint8_t iocap_b[3]; 1806 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1807 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1808 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1809 if (IS_RESPONDER(sm_conn->sm_role)){ 1810 // responder 1811 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); 1812 } else { 1813 // initiator 1814 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); 1815 } 1816 } 1817 1818 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1819 // validate E = f6() 1820 sm_key56_t bd_addr_master, bd_addr_slave; 1821 bd_addr_master[0] = setup->sm_m_addr_type; 1822 bd_addr_slave[0] = setup->sm_s_addr_type; 1823 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1824 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1825 1826 uint8_t iocap_a[3]; 1827 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1828 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1829 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1830 uint8_t iocap_b[3]; 1831 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1832 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1833 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1834 if (IS_RESPONDER(sm_conn->sm_role)){ 1835 // responder 1836 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); 1837 } else { 1838 // initiator 1839 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); 1840 } 1841 } 1842 1843 1844 // 1845 // Link Key Conversion Function h6 1846 // 1847 // h6(W, keyID) = AES-CMACW(keyID) 1848 // - W is 128 bits 1849 // - keyID is 32 bits 1850 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1851 const uint16_t message_len = 4; 1852 sm_cmac_connection = sm_conn; 1853 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1854 log_info("h6 key"); 1855 log_info_hexdump(w, 16); 1856 log_info("h6 message"); 1857 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1858 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1859 } 1860 1861 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1862 // Errata Service Release to the Bluetooth Specification: ESR09 1863 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1864 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1865 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1866 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1867 } 1868 1869 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1870 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1871 } 1872 1873 #endif 1874 1875 // key management legacy connections: 1876 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1877 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1878 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1879 // - responder reconnects: responder uses LTK receveived from master 1880 1881 // key management secure connections: 1882 // - both devices store same LTK from ECDH key exchange. 1883 1884 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1885 static void sm_load_security_info(sm_connection_t * sm_connection){ 1886 int encryption_key_size; 1887 int authenticated; 1888 int authorized; 1889 1890 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1891 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1892 &encryption_key_size, &authenticated, &authorized); 1893 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1894 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1895 sm_connection->sm_connection_authenticated = authenticated; 1896 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1897 } 1898 #endif 1899 1900 #ifdef ENABLE_LE_PERIPHERAL 1901 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1902 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1903 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1904 // re-establish used key encryption size 1905 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1906 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1907 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1908 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1909 log_info("sm: received ltk request with key size %u, authenticated %u", 1910 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1911 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1912 } 1913 #endif 1914 1915 static void sm_run(void){ 1916 1917 btstack_linked_list_iterator_t it; 1918 1919 // assert that stack has already bootet 1920 if (hci_get_state() != HCI_STATE_WORKING) return; 1921 1922 // assert that we can send at least commands 1923 if (!hci_can_send_command_packet_now()) return; 1924 1925 // 1926 // non-connection related behaviour 1927 // 1928 1929 // distributed key generation 1930 switch (dkg_state){ 1931 case DKG_CALC_IRK: 1932 // already busy? 1933 if (sm_aes128_state == SM_AES128_IDLE) { 1934 // IRK = d1(IR, 1, 0) 1935 sm_key_t d1_prime; 1936 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1937 dkg_next_state(); 1938 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1939 return; 1940 } 1941 break; 1942 case DKG_CALC_DHK: 1943 // already busy? 1944 if (sm_aes128_state == SM_AES128_IDLE) { 1945 // DHK = d1(IR, 3, 0) 1946 sm_key_t d1_prime; 1947 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1948 dkg_next_state(); 1949 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1950 return; 1951 } 1952 break; 1953 default: 1954 break; 1955 } 1956 1957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1958 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1959 #ifdef USE_SOFTWARE_ECDH_IMPLEMENTATION 1960 sm_random_start(NULL); 1961 #else 1962 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1963 hci_send_cmd(&hci_le_read_local_p256_public_key); 1964 #endif 1965 return; 1966 } 1967 #endif 1968 1969 // random address updates 1970 switch (rau_state){ 1971 case RAU_GET_RANDOM: 1972 rau_next_state(); 1973 sm_random_start(NULL); 1974 return; 1975 case RAU_GET_ENC: 1976 // already busy? 1977 if (sm_aes128_state == SM_AES128_IDLE) { 1978 sm_key_t r_prime; 1979 sm_ah_r_prime(sm_random_address, r_prime); 1980 rau_next_state(); 1981 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1982 return; 1983 } 1984 break; 1985 case RAU_SET_ADDRESS: 1986 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1987 rau_state = RAU_IDLE; 1988 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1989 return; 1990 default: 1991 break; 1992 } 1993 1994 #ifdef ENABLE_CMAC_ENGINE 1995 // CMAC 1996 switch (sm_cmac_state){ 1997 case CMAC_CALC_SUBKEYS: 1998 case CMAC_CALC_MI: 1999 case CMAC_CALC_MLAST: 2000 // already busy? 2001 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2002 sm_cmac_handle_aes_engine_ready(); 2003 return; 2004 default: 2005 break; 2006 } 2007 #endif 2008 2009 // CSRK Lookup 2010 // -- if csrk lookup ready, find connection that require csrk lookup 2011 if (sm_address_resolution_idle()){ 2012 hci_connections_get_iterator(&it); 2013 while(btstack_linked_list_iterator_has_next(&it)){ 2014 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2015 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2016 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 2017 // and start lookup 2018 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); 2019 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 2020 break; 2021 } 2022 } 2023 } 2024 2025 // -- if csrk lookup ready, resolved addresses for received addresses 2026 if (sm_address_resolution_idle()) { 2027 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 2028 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 2029 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 2030 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 2031 btstack_memory_sm_lookup_entry_free(entry); 2032 } 2033 } 2034 2035 // -- Continue with CSRK device lookup by public or resolvable private address 2036 if (!sm_address_resolution_idle()){ 2037 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 2038 while (sm_address_resolution_test < le_device_db_count()){ 2039 int addr_type; 2040 bd_addr_t addr; 2041 sm_key_t irk; 2042 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 2043 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 2044 2045 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 2046 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 2047 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2048 break; 2049 } 2050 2051 if (sm_address_resolution_addr_type == 0){ 2052 sm_address_resolution_test++; 2053 continue; 2054 } 2055 2056 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2057 2058 log_info("LE Device Lookup: calculate AH"); 2059 log_info_key("IRK", irk); 2060 2061 sm_key_t r_prime; 2062 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2063 sm_address_resolution_ah_calculation_active = 1; 2064 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2065 return; 2066 } 2067 2068 if (sm_address_resolution_test >= le_device_db_count()){ 2069 log_info("LE Device Lookup: not found"); 2070 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2071 } 2072 } 2073 2074 // handle basic actions that don't requires the full context 2075 hci_connections_get_iterator(&it); 2076 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2077 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2078 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2079 switch(sm_connection->sm_engine_state){ 2080 // responder side 2081 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2082 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2083 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2084 return; 2085 2086 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2087 case SM_SC_RECEIVED_LTK_REQUEST: 2088 switch (sm_connection->sm_irk_lookup_state){ 2089 case IRK_LOOKUP_FAILED: 2090 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2091 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2092 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2093 return; 2094 default: 2095 break; 2096 } 2097 break; 2098 #endif 2099 default: 2100 break; 2101 } 2102 } 2103 2104 // 2105 // active connection handling 2106 // -- use loop to handle next connection if lock on setup context is released 2107 2108 while (1) { 2109 2110 // Find connections that requires setup context and make active if no other is locked 2111 hci_connections_get_iterator(&it); 2112 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2113 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2114 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2115 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2116 int done = 1; 2117 int err; 2118 UNUSED(err); 2119 switch (sm_connection->sm_engine_state) { 2120 #ifdef ENABLE_LE_PERIPHERAL 2121 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2122 // send packet if possible, 2123 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2124 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2125 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2126 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2127 } else { 2128 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2129 } 2130 // don't lock sxetup context yet 2131 done = 0; 2132 break; 2133 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2134 sm_reset_setup(); 2135 sm_init_setup(sm_connection); 2136 // recover pairing request 2137 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2138 err = sm_stk_generation_init(sm_connection); 2139 if (err){ 2140 setup->sm_pairing_failed_reason = err; 2141 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2142 break; 2143 } 2144 sm_timeout_start(sm_connection); 2145 // generate random number first, if we need to show passkey 2146 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2147 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2148 break; 2149 } 2150 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2151 break; 2152 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2153 sm_reset_setup(); 2154 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2155 break; 2156 #endif 2157 #ifdef ENABLE_LE_CENTRAL 2158 case SM_INITIATOR_PH0_HAS_LTK: 2159 sm_reset_setup(); 2160 sm_load_security_info(sm_connection); 2161 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2162 break; 2163 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2164 sm_reset_setup(); 2165 sm_init_setup(sm_connection); 2166 sm_timeout_start(sm_connection); 2167 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2168 break; 2169 #endif 2170 2171 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2172 case SM_SC_RECEIVED_LTK_REQUEST: 2173 switch (sm_connection->sm_irk_lookup_state){ 2174 case IRK_LOOKUP_SUCCEEDED: 2175 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2176 // start using context by loading security info 2177 sm_reset_setup(); 2178 sm_load_security_info(sm_connection); 2179 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2180 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2181 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2182 break; 2183 } 2184 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2185 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2186 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2187 // don't lock setup context yet 2188 return; 2189 default: 2190 // just wait until IRK lookup is completed 2191 // don't lock setup context yet 2192 done = 0; 2193 break; 2194 } 2195 break; 2196 #endif 2197 default: 2198 done = 0; 2199 break; 2200 } 2201 if (done){ 2202 sm_active_connection_handle = sm_connection->sm_handle; 2203 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); 2204 } 2205 } 2206 2207 // 2208 // active connection handling 2209 // 2210 2211 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2212 2213 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2214 if (!connection) { 2215 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2216 return; 2217 } 2218 2219 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2220 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2221 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2222 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2223 return; 2224 } 2225 #endif 2226 2227 // assert that we could send a SM PDU - not needed for all of the following 2228 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2229 log_info("cannot send now, requesting can send now event"); 2230 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2231 return; 2232 } 2233 2234 // send keypress notifications 2235 if (setup->sm_keypress_notification != 0xff){ 2236 uint8_t buffer[2]; 2237 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2238 buffer[1] = setup->sm_keypress_notification; 2239 setup->sm_keypress_notification = 0xff; 2240 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2241 return; 2242 } 2243 2244 sm_key_t plaintext; 2245 int key_distribution_flags; 2246 UNUSED(key_distribution_flags); 2247 2248 log_info("sm_run: state %u", connection->sm_engine_state); 2249 2250 switch (connection->sm_engine_state){ 2251 2252 // general 2253 case SM_GENERAL_SEND_PAIRING_FAILED: { 2254 uint8_t buffer[2]; 2255 buffer[0] = SM_CODE_PAIRING_FAILED; 2256 buffer[1] = setup->sm_pairing_failed_reason; 2257 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2258 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2259 sm_done_for_handle(connection->sm_handle); 2260 break; 2261 } 2262 2263 // responding state 2264 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2265 case SM_SC_W2_GET_RANDOM_A: 2266 sm_random_start(connection); 2267 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2268 break; 2269 case SM_SC_W2_GET_RANDOM_B: 2270 sm_random_start(connection); 2271 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2272 break; 2273 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2274 if (!sm_cmac_ready()) break; 2275 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2276 sm_sc_calculate_local_confirm(connection); 2277 break; 2278 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2279 if (!sm_cmac_ready()) break; 2280 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2281 sm_sc_calculate_remote_confirm(connection); 2282 break; 2283 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2284 if (!sm_cmac_ready()) break; 2285 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2286 sm_sc_calculate_f6_for_dhkey_check(connection); 2287 break; 2288 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2289 if (!sm_cmac_ready()) break; 2290 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2291 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2292 break; 2293 case SM_SC_W2_CALCULATE_F5_SALT: 2294 if (!sm_cmac_ready()) break; 2295 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2296 f5_calculate_salt(connection); 2297 break; 2298 case SM_SC_W2_CALCULATE_F5_MACKEY: 2299 if (!sm_cmac_ready()) break; 2300 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2301 f5_calculate_mackey(connection); 2302 break; 2303 case SM_SC_W2_CALCULATE_F5_LTK: 2304 if (!sm_cmac_ready()) break; 2305 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2306 f5_calculate_ltk(connection); 2307 break; 2308 case SM_SC_W2_CALCULATE_G2: 2309 if (!sm_cmac_ready()) break; 2310 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2311 g2_calculate(connection); 2312 break; 2313 case SM_SC_W2_CALCULATE_H6_ILK: 2314 if (!sm_cmac_ready()) break; 2315 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2316 h6_calculate_ilk(connection); 2317 break; 2318 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2319 if (!sm_cmac_ready()) break; 2320 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2321 h6_calculate_br_edr_link_key(connection); 2322 break; 2323 #endif 2324 2325 #ifdef ENABLE_LE_CENTRAL 2326 // initiator side 2327 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2328 sm_key_t peer_ltk_flipped; 2329 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2330 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2331 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2332 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2333 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2334 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2335 return; 2336 } 2337 2338 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2339 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2340 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2341 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2342 sm_timeout_reset(connection); 2343 break; 2344 #endif 2345 2346 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2347 2348 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2349 uint8_t buffer[65]; 2350 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2351 // 2352 reverse_256(&ec_q[0], &buffer[1]); 2353 reverse_256(&ec_q[32], &buffer[33]); 2354 2355 // stk generation method 2356 // passkey entry: notify app to show passkey or to request passkey 2357 switch (setup->sm_stk_generation_method){ 2358 case JUST_WORKS: 2359 case NK_BOTH_INPUT: 2360 if (IS_RESPONDER(connection->sm_role)){ 2361 // responder 2362 sm_sc_start_calculating_local_confirm(connection); 2363 } else { 2364 // initiator 2365 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2366 } 2367 break; 2368 case PK_INIT_INPUT: 2369 case PK_RESP_INPUT: 2370 case OK_BOTH_INPUT: 2371 // use random TK for display 2372 memcpy(setup->sm_ra, setup->sm_tk, 16); 2373 memcpy(setup->sm_rb, setup->sm_tk, 16); 2374 setup->sm_passkey_bit = 0; 2375 2376 if (IS_RESPONDER(connection->sm_role)){ 2377 // responder 2378 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2379 } else { 2380 // initiator 2381 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2382 } 2383 sm_trigger_user_response(connection); 2384 break; 2385 case OOB: 2386 // TODO: implement SC OOB 2387 break; 2388 } 2389 2390 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2391 sm_timeout_reset(connection); 2392 break; 2393 } 2394 case SM_SC_SEND_CONFIRMATION: { 2395 uint8_t buffer[17]; 2396 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2397 reverse_128(setup->sm_local_confirm, &buffer[1]); 2398 if (IS_RESPONDER(connection->sm_role)){ 2399 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2400 } else { 2401 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2402 } 2403 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2404 sm_timeout_reset(connection); 2405 break; 2406 } 2407 case SM_SC_SEND_PAIRING_RANDOM: { 2408 uint8_t buffer[17]; 2409 buffer[0] = SM_CODE_PAIRING_RANDOM; 2410 reverse_128(setup->sm_local_nonce, &buffer[1]); 2411 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2412 if (IS_RESPONDER(connection->sm_role)){ 2413 // responder 2414 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2415 } else { 2416 // initiator 2417 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2418 } 2419 } else { 2420 if (IS_RESPONDER(connection->sm_role)){ 2421 // responder 2422 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2423 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2424 } else { 2425 sm_sc_prepare_dhkey_check(connection); 2426 } 2427 } else { 2428 // initiator 2429 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2430 } 2431 } 2432 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2433 sm_timeout_reset(connection); 2434 break; 2435 } 2436 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2437 uint8_t buffer[17]; 2438 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2439 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2440 2441 if (IS_RESPONDER(connection->sm_role)){ 2442 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2443 } else { 2444 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2445 } 2446 2447 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2448 sm_timeout_reset(connection); 2449 break; 2450 } 2451 2452 #endif 2453 2454 #ifdef ENABLE_LE_PERIPHERAL 2455 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2456 // echo initiator for now 2457 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2458 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2459 2460 if (setup->sm_use_secure_connections){ 2461 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2462 // skip LTK/EDIV for SC 2463 log_info("sm: dropping encryption information flag"); 2464 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2465 } else { 2466 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2467 } 2468 2469 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); 2470 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); 2471 // update key distribution after ENC was dropped 2472 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2473 2474 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2475 sm_timeout_reset(connection); 2476 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2477 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2478 sm_trigger_user_response(connection); 2479 } 2480 return; 2481 #endif 2482 2483 case SM_PH2_SEND_PAIRING_RANDOM: { 2484 uint8_t buffer[17]; 2485 buffer[0] = SM_CODE_PAIRING_RANDOM; 2486 reverse_128(setup->sm_local_random, &buffer[1]); 2487 if (IS_RESPONDER(connection->sm_role)){ 2488 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2489 } else { 2490 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2491 } 2492 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2493 sm_timeout_reset(connection); 2494 break; 2495 } 2496 2497 case SM_PH2_GET_RANDOM_TK: 2498 case SM_PH2_C1_GET_RANDOM_A: 2499 case SM_PH2_C1_GET_RANDOM_B: 2500 case SM_PH3_GET_RANDOM: 2501 case SM_PH3_GET_DIV: 2502 sm_next_responding_state(connection); 2503 sm_random_start(connection); 2504 return; 2505 2506 case SM_PH2_C1_GET_ENC_B: 2507 case SM_PH2_C1_GET_ENC_D: 2508 // already busy? 2509 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2510 sm_next_responding_state(connection); 2511 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2512 return; 2513 2514 case SM_PH3_LTK_GET_ENC: 2515 case SM_RESPONDER_PH4_LTK_GET_ENC: 2516 // already busy? 2517 if (sm_aes128_state == SM_AES128_IDLE) { 2518 sm_key_t d_prime; 2519 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2520 sm_next_responding_state(connection); 2521 sm_aes128_start(sm_persistent_er, d_prime, connection); 2522 return; 2523 } 2524 break; 2525 2526 case SM_PH3_CSRK_GET_ENC: 2527 // already busy? 2528 if (sm_aes128_state == SM_AES128_IDLE) { 2529 sm_key_t d_prime; 2530 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2531 sm_next_responding_state(connection); 2532 sm_aes128_start(sm_persistent_er, d_prime, connection); 2533 return; 2534 } 2535 break; 2536 2537 case SM_PH2_C1_GET_ENC_C: 2538 // already busy? 2539 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2540 // calculate m_confirm using aes128 engine - step 1 2541 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); 2542 sm_next_responding_state(connection); 2543 sm_aes128_start(setup->sm_tk, plaintext, connection); 2544 break; 2545 case SM_PH2_C1_GET_ENC_A: 2546 // already busy? 2547 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2548 // calculate confirm using aes128 engine - step 1 2549 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); 2550 sm_next_responding_state(connection); 2551 sm_aes128_start(setup->sm_tk, plaintext, connection); 2552 break; 2553 case SM_PH2_CALC_STK: 2554 // already busy? 2555 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2556 // calculate STK 2557 if (IS_RESPONDER(connection->sm_role)){ 2558 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2559 } else { 2560 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2561 } 2562 sm_next_responding_state(connection); 2563 sm_aes128_start(setup->sm_tk, plaintext, connection); 2564 break; 2565 case SM_PH3_Y_GET_ENC: 2566 // already busy? 2567 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2568 // PH3B2 - calculate Y from - enc 2569 // Y = dm(DHK, Rand) 2570 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2571 sm_next_responding_state(connection); 2572 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2573 return; 2574 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2575 uint8_t buffer[17]; 2576 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2577 reverse_128(setup->sm_local_confirm, &buffer[1]); 2578 if (IS_RESPONDER(connection->sm_role)){ 2579 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2580 } else { 2581 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2582 } 2583 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2584 sm_timeout_reset(connection); 2585 return; 2586 } 2587 #ifdef ENABLE_LE_PERIPHERAL 2588 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2589 sm_key_t stk_flipped; 2590 reverse_128(setup->sm_ltk, stk_flipped); 2591 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2592 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2593 return; 2594 } 2595 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2596 sm_key_t ltk_flipped; 2597 reverse_128(setup->sm_ltk, ltk_flipped); 2598 connection->sm_engine_state = SM_RESPONDER_IDLE; 2599 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2600 return; 2601 } 2602 case SM_RESPONDER_PH4_Y_GET_ENC: 2603 // already busy? 2604 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2605 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2606 // Y = dm(DHK, Rand) 2607 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2608 sm_next_responding_state(connection); 2609 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2610 return; 2611 #endif 2612 #ifdef ENABLE_LE_CENTRAL 2613 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2614 sm_key_t stk_flipped; 2615 reverse_128(setup->sm_ltk, stk_flipped); 2616 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2617 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2618 return; 2619 } 2620 #endif 2621 2622 case SM_PH3_DISTRIBUTE_KEYS: 2623 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2624 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2625 uint8_t buffer[17]; 2626 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2627 reverse_128(setup->sm_ltk, &buffer[1]); 2628 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2629 sm_timeout_reset(connection); 2630 return; 2631 } 2632 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2633 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2634 uint8_t buffer[11]; 2635 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2636 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2637 reverse_64(setup->sm_local_rand, &buffer[3]); 2638 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2639 sm_timeout_reset(connection); 2640 return; 2641 } 2642 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2643 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2644 uint8_t buffer[17]; 2645 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2646 reverse_128(sm_persistent_irk, &buffer[1]); 2647 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2648 sm_timeout_reset(connection); 2649 return; 2650 } 2651 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2652 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2653 bd_addr_t local_address; 2654 uint8_t buffer[8]; 2655 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2656 switch (gap_random_address_get_mode()){ 2657 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2658 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2659 // public or static random 2660 gap_le_get_own_address(&buffer[1], local_address); 2661 break; 2662 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2663 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2664 // fallback to public 2665 gap_local_bd_addr(local_address); 2666 buffer[1] = 0; 2667 break; 2668 } 2669 reverse_bd_addr(local_address, &buffer[2]); 2670 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2671 sm_timeout_reset(connection); 2672 return; 2673 } 2674 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2675 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2676 2677 // hack to reproduce test runs 2678 if (test_use_fixed_local_csrk){ 2679 memset(setup->sm_local_csrk, 0xcc, 16); 2680 } 2681 2682 uint8_t buffer[17]; 2683 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2684 reverse_128(setup->sm_local_csrk, &buffer[1]); 2685 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2686 sm_timeout_reset(connection); 2687 return; 2688 } 2689 2690 // keys are sent 2691 if (IS_RESPONDER(connection->sm_role)){ 2692 // slave -> receive master keys if any 2693 if (sm_key_distribution_all_received(connection)){ 2694 sm_key_distribution_handle_all_received(connection); 2695 connection->sm_engine_state = SM_RESPONDER_IDLE; 2696 sm_done_for_handle(connection->sm_handle); 2697 } else { 2698 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2699 } 2700 } else { 2701 // master -> all done 2702 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2703 sm_done_for_handle(connection->sm_handle); 2704 } 2705 break; 2706 2707 default: 2708 break; 2709 } 2710 2711 // check again if active connection was released 2712 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2713 } 2714 } 2715 2716 // note: aes engine is ready as we just got the aes result 2717 static void sm_handle_encryption_result(uint8_t * data){ 2718 2719 sm_aes128_state = SM_AES128_IDLE; 2720 2721 if (sm_address_resolution_ah_calculation_active){ 2722 sm_address_resolution_ah_calculation_active = 0; 2723 // compare calulated address against connecting device 2724 uint8_t hash[3]; 2725 reverse_24(data, hash); 2726 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2727 log_info("LE Device Lookup: matched resolvable private address"); 2728 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2729 return; 2730 } 2731 // no match, try next 2732 sm_address_resolution_test++; 2733 return; 2734 } 2735 2736 switch (dkg_state){ 2737 case DKG_W4_IRK: 2738 reverse_128(data, sm_persistent_irk); 2739 log_info_key("irk", sm_persistent_irk); 2740 dkg_next_state(); 2741 return; 2742 case DKG_W4_DHK: 2743 reverse_128(data, sm_persistent_dhk); 2744 log_info_key("dhk", sm_persistent_dhk); 2745 dkg_next_state(); 2746 // SM Init Finished 2747 return; 2748 default: 2749 break; 2750 } 2751 2752 switch (rau_state){ 2753 case RAU_W4_ENC: 2754 reverse_24(data, &sm_random_address[3]); 2755 rau_next_state(); 2756 return; 2757 default: 2758 break; 2759 } 2760 2761 #ifdef ENABLE_CMAC_ENGINE 2762 switch (sm_cmac_state){ 2763 case CMAC_W4_SUBKEYS: 2764 case CMAC_W4_MI: 2765 case CMAC_W4_MLAST: 2766 { 2767 sm_key_t t; 2768 reverse_128(data, t); 2769 sm_cmac_handle_encryption_result(t); 2770 } 2771 return; 2772 default: 2773 break; 2774 } 2775 #endif 2776 2777 // retrieve sm_connection provided to sm_aes128_start_encryption 2778 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2779 if (!connection) return; 2780 switch (connection->sm_engine_state){ 2781 case SM_PH2_C1_W4_ENC_A: 2782 case SM_PH2_C1_W4_ENC_C: 2783 { 2784 sm_key_t t2; 2785 reverse_128(data, t2); 2786 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2787 } 2788 sm_next_responding_state(connection); 2789 return; 2790 case SM_PH2_C1_W4_ENC_B: 2791 reverse_128(data, setup->sm_local_confirm); 2792 log_info_key("c1!", setup->sm_local_confirm); 2793 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2794 return; 2795 case SM_PH2_C1_W4_ENC_D: 2796 { 2797 sm_key_t peer_confirm_test; 2798 reverse_128(data, peer_confirm_test); 2799 log_info_key("c1!", peer_confirm_test); 2800 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2801 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2802 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2803 return; 2804 } 2805 if (IS_RESPONDER(connection->sm_role)){ 2806 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2807 } else { 2808 connection->sm_engine_state = SM_PH2_CALC_STK; 2809 } 2810 } 2811 return; 2812 case SM_PH2_W4_STK: 2813 reverse_128(data, setup->sm_ltk); 2814 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2815 log_info_key("stk", setup->sm_ltk); 2816 if (IS_RESPONDER(connection->sm_role)){ 2817 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2818 } else { 2819 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2820 } 2821 return; 2822 case SM_PH3_Y_W4_ENC:{ 2823 sm_key_t y128; 2824 reverse_128(data, y128); 2825 setup->sm_local_y = big_endian_read_16(y128, 14); 2826 log_info_hex16("y", setup->sm_local_y); 2827 // PH3B3 - calculate EDIV 2828 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2829 log_info_hex16("ediv", setup->sm_local_ediv); 2830 // PH3B4 - calculate LTK - enc 2831 // LTK = d1(ER, DIV, 0)) 2832 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2833 return; 2834 } 2835 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2836 sm_key_t y128; 2837 reverse_128(data, y128); 2838 setup->sm_local_y = big_endian_read_16(y128, 14); 2839 log_info_hex16("y", setup->sm_local_y); 2840 2841 // PH3B3 - calculate DIV 2842 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2843 log_info_hex16("ediv", setup->sm_local_ediv); 2844 // PH3B4 - calculate LTK - enc 2845 // LTK = d1(ER, DIV, 0)) 2846 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2847 return; 2848 } 2849 case SM_PH3_LTK_W4_ENC: 2850 reverse_128(data, setup->sm_ltk); 2851 log_info_key("ltk", setup->sm_ltk); 2852 // calc CSRK next 2853 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2854 return; 2855 case SM_PH3_CSRK_W4_ENC: 2856 reverse_128(data, setup->sm_local_csrk); 2857 log_info_key("csrk", setup->sm_local_csrk); 2858 if (setup->sm_key_distribution_send_set){ 2859 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2860 } else { 2861 // no keys to send, just continue 2862 if (IS_RESPONDER(connection->sm_role)){ 2863 // slave -> receive master keys 2864 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2865 } else { 2866 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2867 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2868 } else { 2869 // master -> all done 2870 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2871 sm_done_for_handle(connection->sm_handle); 2872 } 2873 } 2874 } 2875 return; 2876 #ifdef ENABLE_LE_PERIPHERAL 2877 case SM_RESPONDER_PH4_LTK_W4_ENC: 2878 reverse_128(data, setup->sm_ltk); 2879 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2880 log_info_key("ltk", setup->sm_ltk); 2881 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2882 return; 2883 #endif 2884 default: 2885 break; 2886 } 2887 } 2888 2889 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2890 2891 #if (defined(USE_MICRO_ECC_FOR_ECDH) && !defined(WICED_VERSION)) || defined(USE_MBEDTLS_FOR_ECDH) 2892 // @return OK 2893 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2894 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2895 int offset = setup->sm_passkey_bit; 2896 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2897 while (size) { 2898 *buffer++ = setup->sm_peer_q[offset++]; 2899 size--; 2900 } 2901 setup->sm_passkey_bit = offset; 2902 return 1; 2903 } 2904 #endif 2905 #ifdef USE_MBEDTLS_FOR_ECDH 2906 // @return error - just wrap sm_generate_f_rng 2907 static int sm_generate_f_rng_mbedtls(void * context, unsigned char * buffer, size_t size){ 2908 UNUSED(context); 2909 return sm_generate_f_rng(buffer, size) == 0; 2910 } 2911 #endif /* USE_MBEDTLS_FOR_ECDH */ 2912 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2913 2914 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2915 static void sm_handle_random_result(uint8_t * data){ 2916 2917 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 2918 2919 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2920 int num_bytes = setup->sm_passkey_bit; 2921 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2922 num_bytes += 8; 2923 setup->sm_passkey_bit = num_bytes; 2924 2925 if (num_bytes >= 64){ 2926 2927 // init pre-generated random data from sm_peer_q 2928 setup->sm_passkey_bit = 0; 2929 2930 // generate EC key 2931 #ifdef USE_MICRO_ECC_FOR_ECDH 2932 2933 #ifndef WICED_VERSION 2934 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2935 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2936 uECC_set_rng(&sm_generate_f_rng); 2937 #endif /* WICED_VERSION */ 2938 2939 #if uECC_SUPPORTS_secp256r1 2940 // standard version 2941 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2942 2943 // disable RNG again, as returning no randmon data lets shared key generation fail 2944 log_info("disable uECC RNG in standard version after key generation"); 2945 uECC_set_rng(NULL); 2946 #else 2947 // static version 2948 uECC_make_key(ec_q, ec_d); 2949 #endif 2950 #endif /* USE_MICRO_ECC_FOR_ECDH */ 2951 2952 #ifdef USE_MBEDTLS_FOR_ECDH 2953 mbedtls_mpi d; 2954 mbedtls_ecp_point P; 2955 mbedtls_mpi_init(&d); 2956 mbedtls_ecp_point_init(&P); 2957 int res = mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng_mbedtls, NULL); 2958 log_info("gen keypair %x", res); 2959 mbedtls_mpi_write_binary(&P.X, &ec_q[0], 32); 2960 mbedtls_mpi_write_binary(&P.Y, &ec_q[32], 32); 2961 mbedtls_mpi_write_binary(&d, ec_d, 32); 2962 mbedtls_ecp_point_free(&P); 2963 mbedtls_mpi_free(&d); 2964 #endif /* USE_MBEDTLS_FOR_ECDH */ 2965 2966 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2967 log_info("Elliptic curve: d"); 2968 log_info_hexdump(ec_d,32); 2969 sm_log_ec_keypair(); 2970 } 2971 } 2972 #endif 2973 2974 switch (rau_state){ 2975 case RAU_W4_RANDOM: 2976 // non-resolvable vs. resolvable 2977 switch (gap_random_adress_type){ 2978 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2979 // resolvable: use random as prand and calc address hash 2980 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2981 memcpy(sm_random_address, data, 3); 2982 sm_random_address[0] &= 0x3f; 2983 sm_random_address[0] |= 0x40; 2984 rau_state = RAU_GET_ENC; 2985 break; 2986 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2987 default: 2988 // "The two most significant bits of the address shall be equal to ‘0’"" 2989 memcpy(sm_random_address, data, 6); 2990 sm_random_address[0] &= 0x3f; 2991 rau_state = RAU_SET_ADDRESS; 2992 break; 2993 } 2994 return; 2995 default: 2996 break; 2997 } 2998 2999 // retrieve sm_connection provided to sm_random_start 3000 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 3001 if (!connection) return; 3002 switch (connection->sm_engine_state){ 3003 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3004 case SM_SC_W4_GET_RANDOM_A: 3005 memcpy(&setup->sm_local_nonce[0], data, 8); 3006 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 3007 break; 3008 case SM_SC_W4_GET_RANDOM_B: 3009 memcpy(&setup->sm_local_nonce[8], data, 8); 3010 // initiator & jw/nc -> send pairing random 3011 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3012 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3013 break; 3014 } else { 3015 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3016 } 3017 break; 3018 #endif 3019 3020 case SM_PH2_W4_RANDOM_TK: 3021 { 3022 sm_reset_tk(); 3023 uint32_t tk; 3024 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 3025 // map random to 0-999999 without speding much cycles on a modulus operation 3026 tk = little_endian_read_32(data,0); 3027 tk = tk & 0xfffff; // 1048575 3028 if (tk >= 999999){ 3029 tk = tk - 999999; 3030 } 3031 } else { 3032 // override with pre-defined passkey 3033 tk = sm_fixed_passkey_in_display_role; 3034 } 3035 big_endian_store_32(setup->sm_tk, 12, tk); 3036 if (IS_RESPONDER(connection->sm_role)){ 3037 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 3038 } else { 3039 if (setup->sm_use_secure_connections){ 3040 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3041 } else { 3042 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3043 sm_trigger_user_response(connection); 3044 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3045 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3046 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3047 } 3048 } 3049 } 3050 return; 3051 } 3052 case SM_PH2_C1_W4_RANDOM_A: 3053 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 3054 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 3055 return; 3056 case SM_PH2_C1_W4_RANDOM_B: 3057 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 3058 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 3059 return; 3060 case SM_PH3_W4_RANDOM: 3061 reverse_64(data, setup->sm_local_rand); 3062 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 3063 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 3064 // no db for authenticated flag hack: store flag in bit 4 of LSB 3065 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 3066 connection->sm_engine_state = SM_PH3_GET_DIV; 3067 return; 3068 case SM_PH3_W4_DIV: 3069 // use 16 bit from random value as div 3070 setup->sm_local_div = big_endian_read_16(data, 0); 3071 log_info_hex16("div", setup->sm_local_div); 3072 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 3073 return; 3074 default: 3075 break; 3076 } 3077 } 3078 3079 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3080 3081 UNUSED(channel); // ok: there is no channel 3082 UNUSED(size); // ok: fixed format HCI events 3083 3084 sm_connection_t * sm_conn; 3085 hci_con_handle_t con_handle; 3086 3087 switch (packet_type) { 3088 3089 case HCI_EVENT_PACKET: 3090 switch (hci_event_packet_get_type(packet)) { 3091 3092 case BTSTACK_EVENT_STATE: 3093 // bt stack activated, get started 3094 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3095 log_info("HCI Working!"); 3096 3097 3098 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3099 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3100 if (!sm_have_ec_keypair){ 3101 setup->sm_passkey_bit = 0; 3102 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3103 } 3104 #endif 3105 // trigger Random Address generation if requested before 3106 switch (gap_random_adress_type){ 3107 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3108 rau_state = RAU_IDLE; 3109 break; 3110 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3111 rau_state = RAU_SET_ADDRESS; 3112 break; 3113 default: 3114 rau_state = RAU_GET_RANDOM; 3115 break; 3116 } 3117 sm_run(); 3118 } 3119 break; 3120 3121 case HCI_EVENT_LE_META: 3122 switch (packet[2]) { 3123 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3124 3125 log_info("sm: connected"); 3126 3127 if (packet[3]) return; // connection failed 3128 3129 con_handle = little_endian_read_16(packet, 4); 3130 sm_conn = sm_get_connection_for_handle(con_handle); 3131 if (!sm_conn) break; 3132 3133 sm_conn->sm_handle = con_handle; 3134 sm_conn->sm_role = packet[6]; 3135 sm_conn->sm_peer_addr_type = packet[7]; 3136 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3137 3138 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3139 3140 // reset security properties 3141 sm_conn->sm_connection_encrypted = 0; 3142 sm_conn->sm_connection_authenticated = 0; 3143 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3144 sm_conn->sm_le_db_index = -1; 3145 3146 // prepare CSRK lookup (does not involve setup) 3147 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3148 3149 // just connected -> everything else happens in sm_run() 3150 if (IS_RESPONDER(sm_conn->sm_role)){ 3151 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3152 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3153 if (sm_slave_request_security) { 3154 // request security if requested by app 3155 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3156 } else { 3157 // otherwise, wait for pairing request 3158 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3159 } 3160 } 3161 break; 3162 } else { 3163 // master 3164 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3165 } 3166 break; 3167 3168 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3169 con_handle = little_endian_read_16(packet, 3); 3170 sm_conn = sm_get_connection_for_handle(con_handle); 3171 if (!sm_conn) break; 3172 3173 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3174 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3175 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3176 break; 3177 } 3178 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3179 // PH2 SEND LTK as we need to exchange keys in PH3 3180 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3181 break; 3182 } 3183 3184 // store rand and ediv 3185 reverse_64(&packet[5], sm_conn->sm_local_rand); 3186 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3187 3188 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3189 // potentially stored LTK is from the master 3190 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3191 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3192 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3193 break; 3194 } 3195 // additionally check if remote is in LE Device DB if requested 3196 switch(sm_conn->sm_irk_lookup_state){ 3197 case IRK_LOOKUP_FAILED: 3198 log_info("LTK Request: device not in device db"); 3199 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3200 break; 3201 case IRK_LOOKUP_SUCCEEDED: 3202 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3203 break; 3204 default: 3205 // wait for irk look doen 3206 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3207 break; 3208 } 3209 break; 3210 } 3211 3212 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3213 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3214 #else 3215 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3216 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3217 #endif 3218 break; 3219 3220 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3221 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3222 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3223 log_error("Read Local P256 Public Key failed"); 3224 break; 3225 } 3226 3227 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3228 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3229 3230 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3231 sm_log_ec_keypair(); 3232 break; 3233 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3234 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3235 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3236 log_error("Generate DHKEY failed -> abort"); 3237 // abort pairing with 'unspecified reason' 3238 sm_pdu_received_in_wrong_state(sm_conn); 3239 break; 3240 } 3241 3242 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3243 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3244 log_info("dhkey"); 3245 log_info_hexdump(&setup->sm_dhkey[0], 32); 3246 3247 // trigger next step 3248 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3249 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3250 } 3251 break; 3252 #endif 3253 default: 3254 break; 3255 } 3256 break; 3257 3258 case HCI_EVENT_ENCRYPTION_CHANGE: 3259 con_handle = little_endian_read_16(packet, 3); 3260 sm_conn = sm_get_connection_for_handle(con_handle); 3261 if (!sm_conn) break; 3262 3263 sm_conn->sm_connection_encrypted = packet[5]; 3264 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3265 sm_conn->sm_actual_encryption_key_size); 3266 log_info("event handler, state %u", sm_conn->sm_engine_state); 3267 if (!sm_conn->sm_connection_encrypted) break; 3268 // continue if part of initial pairing 3269 switch (sm_conn->sm_engine_state){ 3270 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3271 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3272 sm_done_for_handle(sm_conn->sm_handle); 3273 break; 3274 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3275 if (IS_RESPONDER(sm_conn->sm_role)){ 3276 // slave 3277 if (setup->sm_use_secure_connections){ 3278 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3279 } else { 3280 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3281 } 3282 } else { 3283 // master 3284 if (sm_key_distribution_all_received(sm_conn)){ 3285 // skip receiving keys as there are none 3286 sm_key_distribution_handle_all_received(sm_conn); 3287 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3288 } else { 3289 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3290 } 3291 } 3292 break; 3293 default: 3294 break; 3295 } 3296 break; 3297 3298 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3299 con_handle = little_endian_read_16(packet, 3); 3300 sm_conn = sm_get_connection_for_handle(con_handle); 3301 if (!sm_conn) break; 3302 3303 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3304 log_info("event handler, state %u", sm_conn->sm_engine_state); 3305 // continue if part of initial pairing 3306 switch (sm_conn->sm_engine_state){ 3307 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3308 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3309 sm_done_for_handle(sm_conn->sm_handle); 3310 break; 3311 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3312 if (IS_RESPONDER(sm_conn->sm_role)){ 3313 // slave 3314 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3315 } else { 3316 // master 3317 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3318 } 3319 break; 3320 default: 3321 break; 3322 } 3323 break; 3324 3325 3326 case HCI_EVENT_DISCONNECTION_COMPLETE: 3327 con_handle = little_endian_read_16(packet, 3); 3328 sm_done_for_handle(con_handle); 3329 sm_conn = sm_get_connection_for_handle(con_handle); 3330 if (!sm_conn) break; 3331 3332 // delete stored bonding on disconnect with authentication failure in ph0 3333 if (sm_conn->sm_role == 0 3334 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3335 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3336 le_device_db_remove(sm_conn->sm_le_db_index); 3337 } 3338 3339 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3340 sm_conn->sm_handle = 0; 3341 break; 3342 3343 case HCI_EVENT_COMMAND_COMPLETE: 3344 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3345 sm_handle_encryption_result(&packet[6]); 3346 break; 3347 } 3348 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3349 sm_handle_random_result(&packet[6]); 3350 break; 3351 } 3352 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3353 // set local addr for le device db 3354 bd_addr_t addr; 3355 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3356 le_device_db_set_local_bd_addr(addr); 3357 } 3358 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3359 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(USE_SOFTWARE_ECDH_IMPLEMENTATION) 3360 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3361 // mbedTLS can also be used if already available (and malloc is supported) 3362 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add USE_MICRO_ECC_FOR_ECDH to btstack_config.h"); 3363 } 3364 #endif 3365 } 3366 break; 3367 default: 3368 break; 3369 } 3370 break; 3371 default: 3372 break; 3373 } 3374 3375 sm_run(); 3376 } 3377 3378 static inline int sm_calc_actual_encryption_key_size(int other){ 3379 if (other < sm_min_encryption_key_size) return 0; 3380 if (other < sm_max_encryption_key_size) return other; 3381 return sm_max_encryption_key_size; 3382 } 3383 3384 3385 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3386 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3387 switch (method){ 3388 case JUST_WORKS: 3389 case NK_BOTH_INPUT: 3390 return 1; 3391 default: 3392 return 0; 3393 } 3394 } 3395 // responder 3396 3397 static int sm_passkey_used(stk_generation_method_t method){ 3398 switch (method){ 3399 case PK_RESP_INPUT: 3400 return 1; 3401 default: 3402 return 0; 3403 } 3404 } 3405 #endif 3406 3407 /** 3408 * @return ok 3409 */ 3410 static int sm_validate_stk_generation_method(void){ 3411 // check if STK generation method is acceptable by client 3412 switch (setup->sm_stk_generation_method){ 3413 case JUST_WORKS: 3414 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3415 case PK_RESP_INPUT: 3416 case PK_INIT_INPUT: 3417 case OK_BOTH_INPUT: 3418 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3419 case OOB: 3420 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3421 case NK_BOTH_INPUT: 3422 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3423 return 1; 3424 default: 3425 return 0; 3426 } 3427 } 3428 3429 // size of complete sm_pdu used to validate input 3430 static const uint8_t sm_pdu_size[] = { 3431 0, // 0x00 invalid opcode 3432 7, // 0x01 pairing request 3433 7, // 0x02 pairing response 3434 17, // 0x03 pairing confirm 3435 17, // 0x04 pairing random 3436 2, // 0x05 pairing failed 3437 17, // 0x06 encryption information 3438 11, // 0x07 master identification 3439 17, // 0x08 identification information 3440 8, // 0x09 identify address information 3441 17, // 0x0a signing information 3442 2, // 0x0b security request 3443 65, // 0x0c pairing public key 3444 17, // 0x0d pairing dhk check 3445 2, // 0x0e keypress notification 3446 }; 3447 3448 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3449 3450 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3451 sm_run(); 3452 } 3453 3454 if (packet_type != SM_DATA_PACKET) return; 3455 if (size == 0) return; 3456 3457 uint8_t sm_pdu_code = packet[0]; 3458 3459 // validate pdu size 3460 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3461 if (sm_pdu_size[sm_pdu_code] != size) return; 3462 3463 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3464 if (!sm_conn) return; 3465 3466 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3467 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3468 return; 3469 } 3470 3471 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3472 3473 int err; 3474 UNUSED(err); 3475 3476 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3477 uint8_t buffer[5]; 3478 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3479 buffer[1] = 3; 3480 little_endian_store_16(buffer, 2, con_handle); 3481 buffer[4] = packet[1]; 3482 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3483 return; 3484 } 3485 3486 switch (sm_conn->sm_engine_state){ 3487 3488 // a sm timeout requries a new physical connection 3489 case SM_GENERAL_TIMEOUT: 3490 return; 3491 3492 #ifdef ENABLE_LE_CENTRAL 3493 3494 // Initiator 3495 case SM_INITIATOR_CONNECTED: 3496 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3497 sm_pdu_received_in_wrong_state(sm_conn); 3498 break; 3499 } 3500 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3501 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3502 break; 3503 } 3504 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3505 sm_key_t ltk; 3506 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3507 if (!sm_is_null_key(ltk)){ 3508 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3509 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3510 } else { 3511 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3512 } 3513 break; 3514 } 3515 // otherwise, store security request 3516 sm_conn->sm_security_request_received = 1; 3517 break; 3518 3519 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3520 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3521 sm_pdu_received_in_wrong_state(sm_conn); 3522 break; 3523 } 3524 // store pairing request 3525 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3526 err = sm_stk_generation_init(sm_conn); 3527 if (err){ 3528 setup->sm_pairing_failed_reason = err; 3529 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3530 break; 3531 } 3532 3533 // generate random number first, if we need to show passkey 3534 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3535 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3536 break; 3537 } 3538 3539 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3540 if (setup->sm_use_secure_connections){ 3541 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3542 if (setup->sm_stk_generation_method == JUST_WORKS){ 3543 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3544 sm_trigger_user_response(sm_conn); 3545 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3546 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3547 } 3548 } else { 3549 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3550 } 3551 break; 3552 } 3553 #endif 3554 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3555 sm_trigger_user_response(sm_conn); 3556 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3557 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3558 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3559 } 3560 break; 3561 3562 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3563 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3564 sm_pdu_received_in_wrong_state(sm_conn); 3565 break; 3566 } 3567 3568 // store s_confirm 3569 reverse_128(&packet[1], setup->sm_peer_confirm); 3570 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3571 break; 3572 3573 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3574 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3575 sm_pdu_received_in_wrong_state(sm_conn); 3576 break;; 3577 } 3578 3579 // received random value 3580 reverse_128(&packet[1], setup->sm_peer_random); 3581 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3582 break; 3583 #endif 3584 3585 #ifdef ENABLE_LE_PERIPHERAL 3586 // Responder 3587 case SM_RESPONDER_IDLE: 3588 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3589 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3590 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3591 sm_pdu_received_in_wrong_state(sm_conn); 3592 break;; 3593 } 3594 3595 // store pairing request 3596 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3597 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3598 break; 3599 #endif 3600 3601 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3602 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3603 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3604 sm_pdu_received_in_wrong_state(sm_conn); 3605 break; 3606 } 3607 3608 // store public key for DH Key calculation 3609 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3610 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3611 3612 // validate public key using micro-ecc 3613 err = 0; 3614 3615 #ifdef USE_MICRO_ECC_FOR_ECDH 3616 #if uECC_SUPPORTS_secp256r1 3617 // standard version 3618 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3619 #else 3620 // static version 3621 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3622 #endif 3623 #endif 3624 3625 #ifdef USE_MBEDTLS_FOR_ECDH 3626 mbedtls_ecp_point Q; 3627 mbedtls_ecp_point_init( &Q ); 3628 mbedtls_mpi_read_binary(&Q.X, &setup->sm_peer_q[0], 32); 3629 mbedtls_mpi_read_binary(&Q.Y, &setup->sm_peer_q[32], 32); 3630 mbedtls_mpi_lset(&Q.Z, 1); 3631 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3632 mbedtls_ecp_point_free( & Q); 3633 #endif 3634 3635 if (err){ 3636 log_error("sm: peer public key invalid %x", err); 3637 // uses "unspecified reason", there is no "public key invalid" error code 3638 sm_pdu_received_in_wrong_state(sm_conn); 3639 break; 3640 } 3641 3642 #ifndef USE_SOFTWARE_ECDH_IMPLEMENTATION 3643 // ask controller to calculate dhkey 3644 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3645 #endif 3646 3647 if (IS_RESPONDER(sm_conn->sm_role)){ 3648 // responder 3649 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3650 } else { 3651 // initiator 3652 // stk generation method 3653 // passkey entry: notify app to show passkey or to request passkey 3654 switch (setup->sm_stk_generation_method){ 3655 case JUST_WORKS: 3656 case NK_BOTH_INPUT: 3657 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3658 break; 3659 case PK_RESP_INPUT: 3660 sm_sc_start_calculating_local_confirm(sm_conn); 3661 break; 3662 case PK_INIT_INPUT: 3663 case OK_BOTH_INPUT: 3664 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3665 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3666 break; 3667 } 3668 sm_sc_start_calculating_local_confirm(sm_conn); 3669 break; 3670 case OOB: 3671 // TODO: implement SC OOB 3672 break; 3673 } 3674 } 3675 break; 3676 3677 case SM_SC_W4_CONFIRMATION: 3678 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3679 sm_pdu_received_in_wrong_state(sm_conn); 3680 break; 3681 } 3682 // received confirm value 3683 reverse_128(&packet[1], setup->sm_peer_confirm); 3684 3685 if (IS_RESPONDER(sm_conn->sm_role)){ 3686 // responder 3687 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3688 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3689 // still waiting for passkey 3690 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3691 break; 3692 } 3693 } 3694 sm_sc_start_calculating_local_confirm(sm_conn); 3695 } else { 3696 // initiator 3697 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3698 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3699 } else { 3700 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3701 } 3702 } 3703 break; 3704 3705 case SM_SC_W4_PAIRING_RANDOM: 3706 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3707 sm_pdu_received_in_wrong_state(sm_conn); 3708 break; 3709 } 3710 3711 // received random value 3712 reverse_128(&packet[1], setup->sm_peer_nonce); 3713 3714 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3715 // only check for JUST WORK/NC in initiator role AND passkey entry 3716 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3717 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3718 } 3719 3720 sm_sc_state_after_receiving_random(sm_conn); 3721 break; 3722 3723 case SM_SC_W2_CALCULATE_G2: 3724 case SM_SC_W4_CALCULATE_G2: 3725 case SM_SC_W4_CALCULATE_DHKEY: 3726 case SM_SC_W2_CALCULATE_F5_SALT: 3727 case SM_SC_W4_CALCULATE_F5_SALT: 3728 case SM_SC_W2_CALCULATE_F5_MACKEY: 3729 case SM_SC_W4_CALCULATE_F5_MACKEY: 3730 case SM_SC_W2_CALCULATE_F5_LTK: 3731 case SM_SC_W4_CALCULATE_F5_LTK: 3732 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3733 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3734 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3735 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3736 sm_pdu_received_in_wrong_state(sm_conn); 3737 break; 3738 } 3739 // store DHKey Check 3740 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3741 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3742 3743 // have we been only waiting for dhkey check command? 3744 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3745 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3746 } 3747 break; 3748 #endif 3749 3750 #ifdef ENABLE_LE_PERIPHERAL 3751 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3752 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3753 sm_pdu_received_in_wrong_state(sm_conn); 3754 break; 3755 } 3756 3757 // received confirm value 3758 reverse_128(&packet[1], setup->sm_peer_confirm); 3759 3760 // notify client to hide shown passkey 3761 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3762 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3763 } 3764 3765 // handle user cancel pairing? 3766 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3767 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3768 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3769 break; 3770 } 3771 3772 // wait for user action? 3773 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3774 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3775 break; 3776 } 3777 3778 // calculate and send local_confirm 3779 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3780 break; 3781 3782 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3783 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3784 sm_pdu_received_in_wrong_state(sm_conn); 3785 break;; 3786 } 3787 3788 // received random value 3789 reverse_128(&packet[1], setup->sm_peer_random); 3790 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3791 break; 3792 #endif 3793 3794 case SM_PH3_RECEIVE_KEYS: 3795 switch(sm_pdu_code){ 3796 case SM_CODE_ENCRYPTION_INFORMATION: 3797 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3798 reverse_128(&packet[1], setup->sm_peer_ltk); 3799 break; 3800 3801 case SM_CODE_MASTER_IDENTIFICATION: 3802 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3803 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3804 reverse_64(&packet[3], setup->sm_peer_rand); 3805 break; 3806 3807 case SM_CODE_IDENTITY_INFORMATION: 3808 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3809 reverse_128(&packet[1], setup->sm_peer_irk); 3810 break; 3811 3812 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3813 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3814 setup->sm_peer_addr_type = packet[1]; 3815 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3816 break; 3817 3818 case SM_CODE_SIGNING_INFORMATION: 3819 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3820 reverse_128(&packet[1], setup->sm_peer_csrk); 3821 break; 3822 default: 3823 // Unexpected PDU 3824 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3825 break; 3826 } 3827 // done with key distribution? 3828 if (sm_key_distribution_all_received(sm_conn)){ 3829 3830 sm_key_distribution_handle_all_received(sm_conn); 3831 3832 if (IS_RESPONDER(sm_conn->sm_role)){ 3833 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3834 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3835 } else { 3836 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3837 sm_done_for_handle(sm_conn->sm_handle); 3838 } 3839 } else { 3840 if (setup->sm_use_secure_connections){ 3841 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3842 } else { 3843 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3844 } 3845 } 3846 } 3847 break; 3848 default: 3849 // Unexpected PDU 3850 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3851 break; 3852 } 3853 3854 // try to send preparared packet 3855 sm_run(); 3856 } 3857 3858 // Security Manager Client API 3859 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3860 sm_get_oob_data = get_oob_data_callback; 3861 } 3862 3863 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3864 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3865 } 3866 3867 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3868 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3869 } 3870 3871 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3872 sm_min_encryption_key_size = min_size; 3873 sm_max_encryption_key_size = max_size; 3874 } 3875 3876 void sm_set_authentication_requirements(uint8_t auth_req){ 3877 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3878 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3879 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3880 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3881 } 3882 #endif 3883 sm_auth_req = auth_req; 3884 } 3885 3886 void sm_set_io_capabilities(io_capability_t io_capability){ 3887 sm_io_capabilities = io_capability; 3888 } 3889 3890 #ifdef ENABLE_LE_PERIPHERAL 3891 void sm_set_request_security(int enable){ 3892 sm_slave_request_security = enable; 3893 } 3894 #endif 3895 3896 void sm_set_er(sm_key_t er){ 3897 memcpy(sm_persistent_er, er, 16); 3898 } 3899 3900 void sm_set_ir(sm_key_t ir){ 3901 memcpy(sm_persistent_ir, ir, 16); 3902 } 3903 3904 // Testing support only 3905 void sm_test_set_irk(sm_key_t irk){ 3906 memcpy(sm_persistent_irk, irk, 16); 3907 sm_persistent_irk_ready = 1; 3908 } 3909 3910 void sm_test_use_fixed_local_csrk(void){ 3911 test_use_fixed_local_csrk = 1; 3912 } 3913 3914 void sm_init(void){ 3915 // set some (BTstack default) ER and IR 3916 int i; 3917 sm_key_t er; 3918 sm_key_t ir; 3919 for (i=0;i<16;i++){ 3920 er[i] = 0x30 + i; 3921 ir[i] = 0x90 + i; 3922 } 3923 sm_set_er(er); 3924 sm_set_ir(ir); 3925 // defaults 3926 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3927 | SM_STK_GENERATION_METHOD_OOB 3928 | SM_STK_GENERATION_METHOD_PASSKEY 3929 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3930 3931 sm_max_encryption_key_size = 16; 3932 sm_min_encryption_key_size = 7; 3933 3934 sm_fixed_passkey_in_display_role = 0xffffffff; 3935 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3936 3937 #ifdef ENABLE_CMAC_ENGINE 3938 sm_cmac_state = CMAC_IDLE; 3939 #endif 3940 dkg_state = DKG_W4_WORKING; 3941 rau_state = RAU_W4_WORKING; 3942 sm_aes128_state = SM_AES128_IDLE; 3943 sm_address_resolution_test = -1; // no private address to resolve yet 3944 sm_address_resolution_ah_calculation_active = 0; 3945 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3946 sm_address_resolution_general_queue = NULL; 3947 3948 gap_random_adress_update_period = 15 * 60 * 1000L; 3949 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3950 3951 test_use_fixed_local_csrk = 0; 3952 3953 // register for HCI Events from HCI 3954 hci_event_callback_registration.callback = &sm_event_packet_handler; 3955 hci_add_event_handler(&hci_event_callback_registration); 3956 3957 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3958 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3959 3960 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3961 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3962 #endif 3963 3964 #ifdef USE_MBEDTLS_FOR_ECDH 3965 mbedtls_ecp_group_init(&mbedtls_ec_group); 3966 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3967 #endif 3968 } 3969 3970 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3971 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3972 memcpy(&ec_q[0], qx, 32); 3973 memcpy(&ec_q[32], qy, 32); 3974 memcpy(ec_d, d, 32); 3975 sm_have_ec_keypair = 1; 3976 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3977 #else 3978 UNUSED(qx); 3979 UNUSED(qy); 3980 UNUSED(d); 3981 #endif 3982 } 3983 3984 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3985 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3986 while (*hex_string){ 3987 int high_nibble = nibble_for_char(*hex_string++); 3988 int low_nibble = nibble_for_char(*hex_string++); 3989 *buffer++ = (high_nibble << 4) | low_nibble; 3990 } 3991 } 3992 #endif 3993 3994 void sm_test_use_fixed_ec_keypair(void){ 3995 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3996 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3997 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3998 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3999 parse_hex(ec_d, ec_d_string); 4000 parse_hex(&ec_q[0], ec_qx_string); 4001 parse_hex(&ec_q[32], ec_qy_string); 4002 sm_have_ec_keypair = 1; 4003 ec_key_generation_state = EC_KEY_GENERATION_DONE; 4004 #endif 4005 } 4006 4007 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 4008 sm_fixed_passkey_in_display_role = passkey; 4009 } 4010 4011 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 4012 sm_reconstruct_ltk_without_le_device_db_entry = allow; 4013 } 4014 4015 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 4016 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 4017 if (!hci_con) return NULL; 4018 return &hci_con->sm_connection; 4019 } 4020 4021 // @returns 0 if not encrypted, 7-16 otherwise 4022 int sm_encryption_key_size(hci_con_handle_t con_handle){ 4023 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4024 if (!sm_conn) return 0; // wrong connection 4025 if (!sm_conn->sm_connection_encrypted) return 0; 4026 return sm_conn->sm_actual_encryption_key_size; 4027 } 4028 4029 int sm_authenticated(hci_con_handle_t con_handle){ 4030 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4031 if (!sm_conn) return 0; // wrong connection 4032 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 4033 return sm_conn->sm_connection_authenticated; 4034 } 4035 4036 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 4037 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4038 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 4039 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 4040 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 4041 return sm_conn->sm_connection_authorization_state; 4042 } 4043 4044 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 4045 switch (sm_conn->sm_engine_state){ 4046 case SM_GENERAL_IDLE: 4047 case SM_RESPONDER_IDLE: 4048 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 4049 sm_run(); 4050 break; 4051 default: 4052 break; 4053 } 4054 } 4055 4056 /** 4057 * @brief Trigger Security Request 4058 */ 4059 void sm_send_security_request(hci_con_handle_t con_handle){ 4060 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4061 if (!sm_conn) return; 4062 sm_send_security_request_for_connection(sm_conn); 4063 } 4064 4065 // request pairing 4066 void sm_request_pairing(hci_con_handle_t con_handle){ 4067 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4068 if (!sm_conn) return; // wrong connection 4069 4070 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 4071 if (IS_RESPONDER(sm_conn->sm_role)){ 4072 sm_send_security_request_for_connection(sm_conn); 4073 } else { 4074 // used as a trigger to start central/master/initiator security procedures 4075 uint16_t ediv; 4076 sm_key_t ltk; 4077 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 4078 switch (sm_conn->sm_irk_lookup_state){ 4079 case IRK_LOOKUP_FAILED: 4080 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4081 break; 4082 case IRK_LOOKUP_SUCCEEDED: 4083 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 4084 if (!sm_is_null_key(ltk) || ediv){ 4085 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 4086 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 4087 } else { 4088 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 4089 } 4090 break; 4091 default: 4092 sm_conn->sm_bonding_requested = 1; 4093 break; 4094 } 4095 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 4096 sm_conn->sm_bonding_requested = 1; 4097 } 4098 } 4099 sm_run(); 4100 } 4101 4102 // called by client app on authorization request 4103 void sm_authorization_decline(hci_con_handle_t con_handle){ 4104 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4105 if (!sm_conn) return; // wrong connection 4106 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 4107 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 4108 } 4109 4110 void sm_authorization_grant(hci_con_handle_t con_handle){ 4111 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4112 if (!sm_conn) return; // wrong connection 4113 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 4114 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 4115 } 4116 4117 // GAP Bonding API 4118 4119 void sm_bonding_decline(hci_con_handle_t con_handle){ 4120 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4121 if (!sm_conn) return; // wrong connection 4122 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4123 4124 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4125 switch (setup->sm_stk_generation_method){ 4126 case PK_RESP_INPUT: 4127 case PK_INIT_INPUT: 4128 case OK_BOTH_INPUT: 4129 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4130 break; 4131 case NK_BOTH_INPUT: 4132 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4133 break; 4134 case JUST_WORKS: 4135 case OOB: 4136 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4137 break; 4138 } 4139 } 4140 sm_run(); 4141 } 4142 4143 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4144 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4145 if (!sm_conn) return; // wrong connection 4146 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4147 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4148 if (setup->sm_use_secure_connections){ 4149 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4150 } else { 4151 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4152 } 4153 } 4154 4155 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4156 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4157 sm_sc_prepare_dhkey_check(sm_conn); 4158 } 4159 #endif 4160 4161 sm_run(); 4162 } 4163 4164 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4165 // for now, it's the same 4166 sm_just_works_confirm(con_handle); 4167 } 4168 4169 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4170 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4171 if (!sm_conn) return; // wrong connection 4172 sm_reset_tk(); 4173 big_endian_store_32(setup->sm_tk, 12, passkey); 4174 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4175 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4176 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4177 } 4178 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4179 memcpy(setup->sm_ra, setup->sm_tk, 16); 4180 memcpy(setup->sm_rb, setup->sm_tk, 16); 4181 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4182 sm_sc_start_calculating_local_confirm(sm_conn); 4183 } 4184 #endif 4185 sm_run(); 4186 } 4187 4188 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4189 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4190 if (!sm_conn) return; // wrong connection 4191 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4192 setup->sm_keypress_notification = action; 4193 sm_run(); 4194 } 4195 4196 /** 4197 * @brief Identify device in LE Device DB 4198 * @param handle 4199 * @returns index from le_device_db or -1 if not found/identified 4200 */ 4201 int sm_le_device_index(hci_con_handle_t con_handle ){ 4202 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4203 if (!sm_conn) return -1; 4204 return sm_conn->sm_le_db_index; 4205 } 4206 4207 static int gap_random_address_type_requires_updates(void){ 4208 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4209 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4210 return 1; 4211 } 4212 4213 static uint8_t own_address_type(void){ 4214 switch (gap_random_adress_type){ 4215 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4216 return BD_ADDR_TYPE_LE_PUBLIC; 4217 default: 4218 return BD_ADDR_TYPE_LE_RANDOM; 4219 } 4220 } 4221 4222 // GAP LE API 4223 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4224 gap_random_address_update_stop(); 4225 gap_random_adress_type = random_address_type; 4226 hci_le_set_own_address_type(own_address_type()); 4227 if (!gap_random_address_type_requires_updates()) return; 4228 gap_random_address_update_start(); 4229 gap_random_address_trigger(); 4230 } 4231 4232 gap_random_address_type_t gap_random_address_get_mode(void){ 4233 return gap_random_adress_type; 4234 } 4235 4236 void gap_random_address_set_update_period(int period_ms){ 4237 gap_random_adress_update_period = period_ms; 4238 if (!gap_random_address_type_requires_updates()) return; 4239 gap_random_address_update_stop(); 4240 gap_random_address_update_start(); 4241 } 4242 4243 void gap_random_address_set(bd_addr_t addr){ 4244 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4245 memcpy(sm_random_address, addr, 6); 4246 if (rau_state == RAU_W4_WORKING) return; 4247 rau_state = RAU_SET_ADDRESS; 4248 sm_run(); 4249 } 4250 4251 #ifdef ENABLE_LE_PERIPHERAL 4252 /* 4253 * @brief Set Advertisement Paramters 4254 * @param adv_int_min 4255 * @param adv_int_max 4256 * @param adv_type 4257 * @param direct_address_type 4258 * @param direct_address 4259 * @param channel_map 4260 * @param filter_policy 4261 * 4262 * @note own_address_type is used from gap_random_address_set_mode 4263 */ 4264 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4265 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4266 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4267 direct_address_typ, direct_address, channel_map, filter_policy); 4268 } 4269 #endif 4270