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 // Software ECDH implementation provided by micro-ecc 80 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 81 #include "uECC.h" 82 #endif 83 #endif 84 85 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 86 #define ENABLE_CMAC_ENGINE 87 #endif 88 89 // 90 // SM internal types and globals 91 // 92 93 typedef enum { 94 DKG_W4_WORKING, 95 DKG_CALC_IRK, 96 DKG_W4_IRK, 97 DKG_CALC_DHK, 98 DKG_W4_DHK, 99 DKG_READY 100 } derived_key_generation_t; 101 102 typedef enum { 103 RAU_W4_WORKING, 104 RAU_IDLE, 105 RAU_GET_RANDOM, 106 RAU_W4_RANDOM, 107 RAU_GET_ENC, 108 RAU_W4_ENC, 109 RAU_SET_ADDRESS, 110 } random_address_update_t; 111 112 typedef enum { 113 CMAC_IDLE, 114 CMAC_CALC_SUBKEYS, 115 CMAC_W4_SUBKEYS, 116 CMAC_CALC_MI, 117 CMAC_W4_MI, 118 CMAC_CALC_MLAST, 119 CMAC_W4_MLAST 120 } cmac_state_t; 121 122 typedef enum { 123 JUST_WORKS, 124 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 125 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 126 OK_BOTH_INPUT, // Only input on both, both input PK 127 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 128 OOB // OOB available on both sides 129 } stk_generation_method_t; 130 131 typedef enum { 132 SM_USER_RESPONSE_IDLE, 133 SM_USER_RESPONSE_PENDING, 134 SM_USER_RESPONSE_CONFIRM, 135 SM_USER_RESPONSE_PASSKEY, 136 SM_USER_RESPONSE_DECLINE 137 } sm_user_response_t; 138 139 typedef enum { 140 SM_AES128_IDLE, 141 SM_AES128_ACTIVE 142 } sm_aes128_state_t; 143 144 typedef enum { 145 ADDRESS_RESOLUTION_IDLE, 146 ADDRESS_RESOLUTION_GENERAL, 147 ADDRESS_RESOLUTION_FOR_CONNECTION, 148 } address_resolution_mode_t; 149 150 typedef enum { 151 ADDRESS_RESOLUTION_SUCEEDED, 152 ADDRESS_RESOLUTION_FAILED, 153 } address_resolution_event_t; 154 155 typedef enum { 156 EC_KEY_GENERATION_IDLE, 157 EC_KEY_GENERATION_ACTIVE, 158 EC_KEY_GENERATION_W4_KEY, 159 EC_KEY_GENERATION_DONE, 160 } ec_key_generation_state_t; 161 162 typedef enum { 163 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 164 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 165 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 166 } sm_state_var_t; 167 168 // 169 // GLOBAL DATA 170 // 171 172 static uint8_t test_use_fixed_local_csrk; 173 174 // configuration 175 static uint8_t sm_accepted_stk_generation_methods; 176 static uint8_t sm_max_encryption_key_size; 177 static uint8_t sm_min_encryption_key_size; 178 static uint8_t sm_auth_req = 0; 179 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 180 static uint8_t sm_slave_request_security; 181 static uint32_t sm_fixed_legacy_pairing_passkey_in_display_role; 182 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 183 #ifdef ENABLE_LE_SECURE_CONNECTIONS 184 static uint8_t sm_have_ec_keypair; 185 #endif 186 187 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 188 static sm_key_t sm_persistent_er; 189 static sm_key_t sm_persistent_ir; 190 191 // derived from sm_persistent_ir 192 static sm_key_t sm_persistent_dhk; 193 static sm_key_t sm_persistent_irk; 194 static uint8_t sm_persistent_irk_ready = 0; // used for testing 195 static derived_key_generation_t dkg_state; 196 197 // derived from sm_persistent_er 198 // .. 199 200 // random address update 201 static random_address_update_t rau_state; 202 static bd_addr_t sm_random_address; 203 204 // CMAC Calculation: General 205 #ifdef ENABLE_CMAC_ENGINE 206 static cmac_state_t sm_cmac_state; 207 static uint16_t sm_cmac_message_len; 208 static sm_key_t sm_cmac_k; 209 static sm_key_t sm_cmac_x; 210 static sm_key_t sm_cmac_m_last; 211 static uint8_t sm_cmac_block_current; 212 static uint8_t sm_cmac_block_count; 213 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 214 static void (*sm_cmac_done_handler)(uint8_t * hash); 215 #endif 216 217 // CMAC for ATT Signed Writes 218 #ifdef ENABLE_LE_SIGNED_WRITE 219 static uint8_t sm_cmac_header[3]; 220 static const uint8_t * sm_cmac_message; 221 static uint8_t sm_cmac_sign_counter[4]; 222 #endif 223 224 // CMAC for Secure Connection functions 225 #ifdef ENABLE_LE_SECURE_CONNECTIONS 226 static sm_connection_t * sm_cmac_connection; 227 static uint8_t sm_cmac_sc_buffer[80]; 228 #endif 229 230 // resolvable private address lookup / CSRK calculation 231 static int sm_address_resolution_test; 232 static int sm_address_resolution_ah_calculation_active; 233 static uint8_t sm_address_resolution_addr_type; 234 static bd_addr_t sm_address_resolution_address; 235 static void * sm_address_resolution_context; 236 static address_resolution_mode_t sm_address_resolution_mode; 237 static btstack_linked_list_t sm_address_resolution_general_queue; 238 239 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 240 static sm_aes128_state_t sm_aes128_state; 241 static void * sm_aes128_context; 242 243 // use aes128 provided by MCU - not needed usually 244 #ifdef HAVE_AES128 245 static uint8_t aes128_result_flipped[16]; 246 static btstack_timer_source_t aes128_timer; 247 void btstack_aes128_calc(uint8_t * key, uint8_t * plaintext, uint8_t * result); 248 #endif 249 250 // random engine. store context (ususally sm_connection_t) 251 static void * sm_random_context; 252 253 // to receive hci events 254 static btstack_packet_callback_registration_t hci_event_callback_registration; 255 256 /* to dispatch sm event */ 257 static btstack_linked_list_t sm_event_handlers; 258 259 // LE Secure Connections 260 #ifdef ENABLE_LE_SECURE_CONNECTIONS 261 static ec_key_generation_state_t ec_key_generation_state; 262 static uint8_t ec_d[32]; 263 static uint8_t ec_q[64]; 264 #endif 265 266 // 267 // Volume 3, Part H, Chapter 24 268 // "Security shall be initiated by the Security Manager in the device in the master role. 269 // The device in the slave role shall be the responding device." 270 // -> master := initiator, slave := responder 271 // 272 273 // data needed for security setup 274 typedef struct sm_setup_context { 275 276 btstack_timer_source_t sm_timeout; 277 278 // used in all phases 279 uint8_t sm_pairing_failed_reason; 280 281 // user response, (Phase 1 and/or 2) 282 uint8_t sm_user_response; 283 uint8_t sm_keypress_notification; 284 285 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 286 int sm_key_distribution_send_set; 287 int sm_key_distribution_received_set; 288 289 // Phase 2 (Pairing over SMP) 290 stk_generation_method_t sm_stk_generation_method; 291 sm_key_t sm_tk; 292 uint8_t sm_use_secure_connections; 293 294 sm_key_t sm_c1_t3_value; // c1 calculation 295 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 296 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 297 sm_key_t sm_local_random; 298 sm_key_t sm_local_confirm; 299 sm_key_t sm_peer_random; 300 sm_key_t sm_peer_confirm; 301 uint8_t sm_m_addr_type; // address and type can be removed 302 uint8_t sm_s_addr_type; // '' 303 bd_addr_t sm_m_address; // '' 304 bd_addr_t sm_s_address; // '' 305 sm_key_t sm_ltk; 306 307 uint8_t sm_state_vars; 308 #ifdef ENABLE_LE_SECURE_CONNECTIONS 309 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 310 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 311 sm_key_t sm_local_nonce; // might be combined with sm_local_random 312 sm_key_t sm_dhkey; 313 sm_key_t sm_peer_dhkey_check; 314 sm_key_t sm_local_dhkey_check; 315 sm_key_t sm_ra; 316 sm_key_t sm_rb; 317 sm_key_t sm_t; // used for f5 and h6 318 sm_key_t sm_mackey; 319 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 320 #endif 321 322 // Phase 3 323 324 // key distribution, we generate 325 uint16_t sm_local_y; 326 uint16_t sm_local_div; 327 uint16_t sm_local_ediv; 328 uint8_t sm_local_rand[8]; 329 sm_key_t sm_local_ltk; 330 sm_key_t sm_local_csrk; 331 sm_key_t sm_local_irk; 332 // sm_local_address/addr_type not needed 333 334 // key distribution, received from peer 335 uint16_t sm_peer_y; 336 uint16_t sm_peer_div; 337 uint16_t sm_peer_ediv; 338 uint8_t sm_peer_rand[8]; 339 sm_key_t sm_peer_ltk; 340 sm_key_t sm_peer_irk; 341 sm_key_t sm_peer_csrk; 342 uint8_t sm_peer_addr_type; 343 bd_addr_t sm_peer_address; 344 345 } sm_setup_context_t; 346 347 // 348 static sm_setup_context_t the_setup; 349 static sm_setup_context_t * setup = &the_setup; 350 351 // active connection - the one for which the_setup is used for 352 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 353 354 // @returns 1 if oob data is available 355 // stores oob data in provided 16 byte buffer if not null 356 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 357 358 // horizontal: initiator capabilities 359 // vertial: responder capabilities 360 static const stk_generation_method_t stk_generation_method [5] [5] = { 361 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 362 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 363 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 364 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 365 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 366 }; 367 368 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 369 #ifdef ENABLE_LE_SECURE_CONNECTIONS 370 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 373 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 374 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 375 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 376 }; 377 #endif 378 379 static void sm_run(void); 380 static void sm_done_for_handle(hci_con_handle_t con_handle); 381 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 382 static inline int sm_calc_actual_encryption_key_size(int other); 383 static int sm_validate_stk_generation_method(void); 384 static void sm_handle_encryption_result(uint8_t * data); 385 386 static void log_info_hex16(const char * name, uint16_t value){ 387 log_info("%-6s 0x%04x", name, value); 388 } 389 390 // @returns 1 if all bytes are 0 391 static int sm_is_null(uint8_t * data, int size){ 392 int i; 393 for (i=0; i < size ; i++){ 394 if (data[i]) return 0; 395 } 396 return 1; 397 } 398 399 static int sm_is_null_random(uint8_t random[8]){ 400 return sm_is_null(random, 8); 401 } 402 403 static int sm_is_null_key(uint8_t * key){ 404 return sm_is_null(key, 16); 405 } 406 407 // Key utils 408 static void sm_reset_tk(void){ 409 int i; 410 for (i=0;i<16;i++){ 411 setup->sm_tk[i] = 0; 412 } 413 } 414 415 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 416 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 417 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 418 int i; 419 for (i = max_encryption_size ; i < 16 ; i++){ 420 key[15-i] = 0; 421 } 422 } 423 424 // SMP Timeout implementation 425 426 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 427 // the Security Manager Timer shall be reset and started. 428 // 429 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 430 // 431 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 432 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 433 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 434 // established. 435 436 static void sm_timeout_handler(btstack_timer_source_t * timer){ 437 log_info("SM timeout"); 438 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 439 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 440 sm_done_for_handle(sm_conn->sm_handle); 441 442 // trigger handling of next ready connection 443 sm_run(); 444 } 445 static void sm_timeout_start(sm_connection_t * sm_conn){ 446 btstack_run_loop_remove_timer(&setup->sm_timeout); 447 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 448 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 449 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 450 btstack_run_loop_add_timer(&setup->sm_timeout); 451 } 452 static void sm_timeout_stop(void){ 453 btstack_run_loop_remove_timer(&setup->sm_timeout); 454 } 455 static void sm_timeout_reset(sm_connection_t * sm_conn){ 456 sm_timeout_stop(); 457 sm_timeout_start(sm_conn); 458 } 459 460 // end of sm timeout 461 462 // GAP Random Address updates 463 static gap_random_address_type_t gap_random_adress_type; 464 static btstack_timer_source_t gap_random_address_update_timer; 465 static uint32_t gap_random_adress_update_period; 466 467 static void gap_random_address_trigger(void){ 468 if (rau_state != RAU_IDLE) return; 469 log_info("gap_random_address_trigger"); 470 rau_state = RAU_GET_RANDOM; 471 sm_run(); 472 } 473 474 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 475 UNUSED(timer); 476 477 log_info("GAP Random Address Update due"); 478 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 479 btstack_run_loop_add_timer(&gap_random_address_update_timer); 480 gap_random_address_trigger(); 481 } 482 483 static void gap_random_address_update_start(void){ 484 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 485 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 486 btstack_run_loop_add_timer(&gap_random_address_update_timer); 487 } 488 489 static void gap_random_address_update_stop(void){ 490 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 491 } 492 493 494 static void sm_random_start(void * context){ 495 sm_random_context = context; 496 hci_send_cmd(&hci_le_rand); 497 } 498 499 #ifdef HAVE_AES128 500 static void aes128_completed(btstack_timer_source_t * ts){ 501 UNUSED(ts); 502 sm_handle_encryption_result(&aes128_result_flipped[0]); 503 sm_run(); 504 } 505 #endif 506 507 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 508 // context is made availabe to aes128 result handler by this 509 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 510 sm_aes128_state = SM_AES128_ACTIVE; 511 sm_aes128_context = context; 512 513 #ifdef HAVE_AES128 514 // calc result directly 515 sm_key_t result; 516 btstack_aes128_calc(key, plaintext, result); 517 518 // log 519 log_info_key("key", key); 520 log_info_key("txt", plaintext); 521 log_info_key("res", result); 522 523 // flip 524 reverse_128(&result[0], &aes128_result_flipped[0]); 525 526 // deliver via timer 527 btstack_run_loop_set_timer_handler(&aes128_timer, &aes128_completed); 528 btstack_run_loop_set_timer(&aes128_timer, 0); // no delay 529 btstack_run_loop_add_timer(&aes128_timer); 530 #else 531 sm_key_t key_flipped, plaintext_flipped; 532 reverse_128(key, key_flipped); 533 reverse_128(plaintext, plaintext_flipped); 534 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 535 #endif 536 } 537 538 // ah(k,r) helper 539 // r = padding || r 540 // r - 24 bit value 541 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 542 // r'= padding || r 543 memset(r_prime, 0, 16); 544 memcpy(&r_prime[13], r, 3); 545 } 546 547 // d1 helper 548 // d' = padding || r || d 549 // d,r - 16 bit values 550 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 551 // d'= padding || r || d 552 memset(d1_prime, 0, 16); 553 big_endian_store_16(d1_prime, 12, r); 554 big_endian_store_16(d1_prime, 14, d); 555 } 556 557 // dm helper 558 // r’ = padding || r 559 // r - 64 bit value 560 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 561 memset(r_prime, 0, 16); 562 memcpy(&r_prime[8], r, 8); 563 } 564 565 // calculate arguments for first AES128 operation in C1 function 566 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){ 567 568 // p1 = pres || preq || rat’ || iat’ 569 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 570 // cant octet of pres becomes the most significant octet of p1. 571 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 572 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 573 // p1 is 0x05000800000302070710000001010001." 574 575 sm_key_t p1; 576 reverse_56(pres, &p1[0]); 577 reverse_56(preq, &p1[7]); 578 p1[14] = rat; 579 p1[15] = iat; 580 log_info_key("p1", p1); 581 log_info_key("r", r); 582 583 // t1 = r xor p1 584 int i; 585 for (i=0;i<16;i++){ 586 t1[i] = r[i] ^ p1[i]; 587 } 588 log_info_key("t1", t1); 589 } 590 591 // calculate arguments for second AES128 operation in C1 function 592 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 593 // p2 = padding || ia || ra 594 // "The least significant octet of ra becomes the least significant octet of p2 and 595 // the most significant octet of padding becomes the most significant octet of p2. 596 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 597 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 598 599 sm_key_t p2; 600 memset(p2, 0, 16); 601 memcpy(&p2[4], ia, 6); 602 memcpy(&p2[10], ra, 6); 603 log_info_key("p2", p2); 604 605 // c1 = e(k, t2_xor_p2) 606 int i; 607 for (i=0;i<16;i++){ 608 t3[i] = t2[i] ^ p2[i]; 609 } 610 log_info_key("t3", t3); 611 } 612 613 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 614 log_info_key("r1", r1); 615 log_info_key("r2", r2); 616 memcpy(&r_prime[8], &r2[8], 8); 617 memcpy(&r_prime[0], &r1[8], 8); 618 } 619 620 #ifdef ENABLE_LE_SECURE_CONNECTIONS 621 // Software implementations of crypto toolbox for LE Secure Connection 622 // TODO: replace with code to use AES Engine of HCI Controller 623 typedef uint8_t sm_key24_t[3]; 624 typedef uint8_t sm_key56_t[7]; 625 typedef uint8_t sm_key256_t[32]; 626 627 #if 0 628 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 629 uint32_t rk[RKLENGTH(KEYBITS)]; 630 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 631 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 632 } 633 634 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 635 memcpy(k1, k0, 16); 636 sm_shift_left_by_one_bit_inplace(16, k1); 637 if (k0[0] & 0x80){ 638 k1[15] ^= 0x87; 639 } 640 memcpy(k2, k1, 16); 641 sm_shift_left_by_one_bit_inplace(16, k2); 642 if (k1[0] & 0x80){ 643 k2[15] ^= 0x87; 644 } 645 } 646 647 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 648 sm_key_t k0, k1, k2, zero; 649 memset(zero, 0, 16); 650 651 aes128_calc_cyphertext(key, zero, k0); 652 calc_subkeys(k0, k1, k2); 653 654 int cmac_block_count = (cmac_message_len + 15) / 16; 655 656 // step 3: .. 657 if (cmac_block_count==0){ 658 cmac_block_count = 1; 659 } 660 661 // step 4: set m_last 662 sm_key_t cmac_m_last; 663 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 664 int i; 665 if (sm_cmac_last_block_complete){ 666 for (i=0;i<16;i++){ 667 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 668 } 669 } else { 670 int valid_octets_in_last_block = cmac_message_len & 0x0f; 671 for (i=0;i<16;i++){ 672 if (i < valid_octets_in_last_block){ 673 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 674 continue; 675 } 676 if (i == valid_octets_in_last_block){ 677 cmac_m_last[i] = 0x80 ^ k2[i]; 678 continue; 679 } 680 cmac_m_last[i] = k2[i]; 681 } 682 } 683 684 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 685 // LOG_KEY(cmac_m_last); 686 687 // Step 5 688 sm_key_t cmac_x; 689 memset(cmac_x, 0, 16); 690 691 // Step 6 692 sm_key_t sm_cmac_y; 693 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 694 for (i=0;i<16;i++){ 695 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 696 } 697 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 698 } 699 for (i=0;i<16;i++){ 700 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 701 } 702 703 // Step 7 704 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 705 } 706 #endif 707 #endif 708 709 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){ 710 event[0] = type; 711 event[1] = event_size - 2; 712 little_endian_store_16(event, 2, con_handle); 713 event[4] = addr_type; 714 reverse_bd_addr(address, &event[5]); 715 } 716 717 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 718 UNUSED(channel); 719 720 // log event 721 hci_dump_packet(packet_type, 1, packet, size); 722 // dispatch to all event handlers 723 btstack_linked_list_iterator_t it; 724 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 725 while (btstack_linked_list_iterator_has_next(&it)){ 726 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 727 entry->callback(packet_type, 0, packet, size); 728 } 729 } 730 731 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 732 uint8_t event[11]; 733 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 734 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 735 } 736 737 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){ 738 uint8_t event[15]; 739 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 740 little_endian_store_32(event, 11, passkey); 741 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 742 } 743 744 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){ 745 // fetch addr and addr type from db 746 bd_addr_t identity_address; 747 int identity_address_type; 748 le_device_db_info(index, &identity_address_type, identity_address, NULL); 749 750 uint8_t event[19]; 751 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 752 event[11] = identity_address_type; 753 reverse_bd_addr(identity_address, &event[12]); 754 event[18] = index; 755 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 756 } 757 758 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){ 759 760 uint8_t event[18]; 761 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 762 event[11] = result; 763 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 764 } 765 766 // decide on stk generation based on 767 // - pairing request 768 // - io capabilities 769 // - OOB data availability 770 static void sm_setup_tk(void){ 771 772 // default: just works 773 setup->sm_stk_generation_method = JUST_WORKS; 774 775 #ifdef ENABLE_LE_SECURE_CONNECTIONS 776 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 777 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 778 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 779 memset(setup->sm_ra, 0, 16); 780 memset(setup->sm_rb, 0, 16); 781 #else 782 setup->sm_use_secure_connections = 0; 783 #endif 784 785 // If both devices have not set the MITM option in the Authentication Requirements 786 // Flags, then the IO capabilities shall be ignored and the Just Works association 787 // model shall be used. 788 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 789 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 790 log_info("SM: MITM not required by both -> JUST WORKS"); 791 return; 792 } 793 794 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 795 796 // If both devices have out of band authentication data, then the Authentication 797 // Requirements Flags shall be ignored when selecting the pairing method and the 798 // Out of Band pairing method shall be used. 799 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 800 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 801 log_info("SM: have OOB data"); 802 log_info_key("OOB", setup->sm_tk); 803 setup->sm_stk_generation_method = OOB; 804 return; 805 } 806 807 // Reset TK as it has been setup in sm_init_setup 808 sm_reset_tk(); 809 810 // Also use just works if unknown io capabilites 811 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 812 return; 813 } 814 815 // Otherwise the IO capabilities of the devices shall be used to determine the 816 // pairing method as defined in Table 2.4. 817 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 818 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 819 820 #ifdef ENABLE_LE_SECURE_CONNECTIONS 821 // table not define by default 822 if (setup->sm_use_secure_connections){ 823 generation_method = stk_generation_method_with_secure_connection; 824 } 825 #endif 826 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 827 828 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 829 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 830 } 831 832 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 833 int flags = 0; 834 if (key_set & SM_KEYDIST_ENC_KEY){ 835 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 836 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 837 } 838 if (key_set & SM_KEYDIST_ID_KEY){ 839 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 840 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 841 } 842 if (key_set & SM_KEYDIST_SIGN){ 843 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 844 } 845 return flags; 846 } 847 848 static void sm_setup_key_distribution(uint8_t key_set){ 849 setup->sm_key_distribution_received_set = 0; 850 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 851 } 852 853 // CSRK Key Lookup 854 855 856 static int sm_address_resolution_idle(void){ 857 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 858 } 859 860 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 861 memcpy(sm_address_resolution_address, addr, 6); 862 sm_address_resolution_addr_type = addr_type; 863 sm_address_resolution_test = 0; 864 sm_address_resolution_mode = mode; 865 sm_address_resolution_context = context; 866 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 867 } 868 869 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 870 // check if already in list 871 btstack_linked_list_iterator_t it; 872 sm_lookup_entry_t * entry; 873 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 874 while(btstack_linked_list_iterator_has_next(&it)){ 875 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 876 if (entry->address_type != address_type) continue; 877 if (memcmp(entry->address, address, 6)) continue; 878 // already in list 879 return BTSTACK_BUSY; 880 } 881 entry = btstack_memory_sm_lookup_entry_get(); 882 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 883 entry->address_type = (bd_addr_type_t) address_type; 884 memcpy(entry->address, address, 6); 885 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 886 sm_run(); 887 return 0; 888 } 889 890 // while x_state++ for an enum is possible in C, it isn't in C++. we use this helpers to avoid compile errors for now 891 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 892 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 893 } 894 static inline void dkg_next_state(void){ 895 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 896 } 897 static inline void rau_next_state(void){ 898 rau_state = (random_address_update_t) (((int)rau_state) + 1); 899 } 900 901 // CMAC calculation using AES Engine 902 #ifdef ENABLE_CMAC_ENGINE 903 904 static inline void sm_cmac_next_state(void){ 905 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 906 } 907 908 static int sm_cmac_last_block_complete(void){ 909 if (sm_cmac_message_len == 0) return 0; 910 return (sm_cmac_message_len & 0x0f) == 0; 911 } 912 913 int sm_cmac_ready(void){ 914 return sm_cmac_state == CMAC_IDLE; 915 } 916 917 // generic cmac calculation 918 void sm_cmac_general_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t hash[8])){ 919 // Generalized CMAC 920 memcpy(sm_cmac_k, key, 16); 921 memset(sm_cmac_x, 0, 16); 922 sm_cmac_block_current = 0; 923 sm_cmac_message_len = message_len; 924 sm_cmac_done_handler = done_callback; 925 sm_cmac_get_byte = get_byte_callback; 926 927 // step 2: n := ceil(len/const_Bsize); 928 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 929 930 // step 3: .. 931 if (sm_cmac_block_count==0){ 932 sm_cmac_block_count = 1; 933 } 934 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 935 936 // first, we need to compute l for k1, k2, and m_last 937 sm_cmac_state = CMAC_CALC_SUBKEYS; 938 939 // let's go 940 sm_run(); 941 } 942 #endif 943 944 // cmac for ATT Message signing 945 #ifdef ENABLE_LE_SIGNED_WRITE 946 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 947 if (offset >= sm_cmac_message_len) { 948 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 949 return 0; 950 } 951 952 offset = sm_cmac_message_len - 1 - offset; 953 954 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 955 if (offset < 3){ 956 return sm_cmac_header[offset]; 957 } 958 int actual_message_len_incl_header = sm_cmac_message_len - 4; 959 if (offset < actual_message_len_incl_header){ 960 return sm_cmac_message[offset - 3]; 961 } 962 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 963 } 964 965 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 966 // ATT Message Signing 967 sm_cmac_header[0] = opcode; 968 little_endian_store_16(sm_cmac_header, 1, con_handle); 969 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 970 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 971 sm_cmac_message = message; 972 sm_cmac_general_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 973 } 974 #endif 975 976 #ifdef ENABLE_CMAC_ENGINE 977 static void sm_cmac_handle_aes_engine_ready(void){ 978 switch (sm_cmac_state){ 979 case CMAC_CALC_SUBKEYS: { 980 sm_key_t const_zero; 981 memset(const_zero, 0, 16); 982 sm_cmac_next_state(); 983 sm_aes128_start(sm_cmac_k, const_zero, NULL); 984 break; 985 } 986 case CMAC_CALC_MI: { 987 int j; 988 sm_key_t y; 989 for (j=0;j<16;j++){ 990 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 991 } 992 sm_cmac_block_current++; 993 sm_cmac_next_state(); 994 sm_aes128_start(sm_cmac_k, y, NULL); 995 break; 996 } 997 case CMAC_CALC_MLAST: { 998 int i; 999 sm_key_t y; 1000 for (i=0;i<16;i++){ 1001 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 1002 } 1003 log_info_key("Y", y); 1004 sm_cmac_block_current++; 1005 sm_cmac_next_state(); 1006 sm_aes128_start(sm_cmac_k, y, NULL); 1007 break; 1008 } 1009 default: 1010 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 1011 break; 1012 } 1013 } 1014 1015 // CMAC Implementation using AES128 engine 1016 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 1017 int i; 1018 int carry = 0; 1019 for (i=len-1; i >= 0 ; i--){ 1020 int new_carry = data[i] >> 7; 1021 data[i] = data[i] << 1 | carry; 1022 carry = new_carry; 1023 } 1024 } 1025 1026 static void sm_cmac_handle_encryption_result(sm_key_t data){ 1027 switch (sm_cmac_state){ 1028 case CMAC_W4_SUBKEYS: { 1029 sm_key_t k1; 1030 memcpy(k1, data, 16); 1031 sm_shift_left_by_one_bit_inplace(16, k1); 1032 if (data[0] & 0x80){ 1033 k1[15] ^= 0x87; 1034 } 1035 sm_key_t k2; 1036 memcpy(k2, k1, 16); 1037 sm_shift_left_by_one_bit_inplace(16, k2); 1038 if (k1[0] & 0x80){ 1039 k2[15] ^= 0x87; 1040 } 1041 1042 log_info_key("k", sm_cmac_k); 1043 log_info_key("k1", k1); 1044 log_info_key("k2", k2); 1045 1046 // step 4: set m_last 1047 int i; 1048 if (sm_cmac_last_block_complete()){ 1049 for (i=0;i<16;i++){ 1050 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1051 } 1052 } else { 1053 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1054 for (i=0;i<16;i++){ 1055 if (i < valid_octets_in_last_block){ 1056 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1057 continue; 1058 } 1059 if (i == valid_octets_in_last_block){ 1060 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1061 continue; 1062 } 1063 sm_cmac_m_last[i] = k2[i]; 1064 } 1065 } 1066 1067 // next 1068 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1069 break; 1070 } 1071 case CMAC_W4_MI: 1072 memcpy(sm_cmac_x, data, 16); 1073 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1074 break; 1075 case CMAC_W4_MLAST: 1076 // done 1077 log_info("Setting CMAC Engine to IDLE"); 1078 sm_cmac_state = CMAC_IDLE; 1079 log_info_key("CMAC", data); 1080 sm_cmac_done_handler(data); 1081 break; 1082 default: 1083 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1084 break; 1085 } 1086 } 1087 #endif 1088 1089 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1090 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1091 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1092 switch (setup->sm_stk_generation_method){ 1093 case PK_RESP_INPUT: 1094 if (IS_RESPONDER(sm_conn->sm_role)){ 1095 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1096 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1097 } else { 1098 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1099 } 1100 break; 1101 case PK_INIT_INPUT: 1102 if (IS_RESPONDER(sm_conn->sm_role)){ 1103 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1104 } else { 1105 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1106 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1107 } 1108 break; 1109 case OK_BOTH_INPUT: 1110 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1111 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1112 break; 1113 case NK_BOTH_INPUT: 1114 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1115 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1116 break; 1117 case JUST_WORKS: 1118 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1119 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1120 break; 1121 case OOB: 1122 // client already provided OOB data, let's skip notification. 1123 break; 1124 } 1125 } 1126 1127 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1128 int recv_flags; 1129 if (IS_RESPONDER(sm_conn->sm_role)){ 1130 // slave / responder 1131 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1132 } else { 1133 // master / initiator 1134 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1135 } 1136 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1137 return recv_flags == setup->sm_key_distribution_received_set; 1138 } 1139 1140 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1141 if (sm_active_connection_handle == con_handle){ 1142 sm_timeout_stop(); 1143 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 1144 log_info("sm: connection 0x%x released setup context", con_handle); 1145 } 1146 } 1147 1148 static int sm_key_distribution_flags_for_auth_req(void){ 1149 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1150 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1151 // encryption information only if bonding requested 1152 flags |= SM_KEYDIST_ENC_KEY; 1153 } 1154 return flags; 1155 } 1156 1157 static void sm_reset_setup(void){ 1158 // fill in sm setup 1159 setup->sm_state_vars = 0; 1160 setup->sm_keypress_notification = 0xff; 1161 sm_reset_tk(); 1162 } 1163 1164 static void sm_init_setup(sm_connection_t * sm_conn){ 1165 1166 // fill in sm setup 1167 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1168 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1169 1170 // query client for OOB data 1171 int have_oob_data = 0; 1172 if (sm_get_oob_data) { 1173 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1174 } 1175 1176 sm_pairing_packet_t * local_packet; 1177 if (IS_RESPONDER(sm_conn->sm_role)){ 1178 // slave 1179 local_packet = &setup->sm_s_pres; 1180 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1181 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1182 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1183 } else { 1184 // master 1185 local_packet = &setup->sm_m_preq; 1186 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1187 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1188 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1189 1190 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1191 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1192 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1193 } 1194 1195 uint8_t auth_req = sm_auth_req; 1196 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1197 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1198 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1199 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1200 } 1201 1202 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1203 1204 sm_pairing_packet_t * remote_packet; 1205 int remote_key_request; 1206 if (IS_RESPONDER(sm_conn->sm_role)){ 1207 // slave / responder 1208 remote_packet = &setup->sm_m_preq; 1209 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1210 } else { 1211 // master / initiator 1212 remote_packet = &setup->sm_s_pres; 1213 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1214 } 1215 1216 // check key size 1217 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1218 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1219 1220 // decide on STK generation method 1221 sm_setup_tk(); 1222 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1223 1224 // check if STK generation method is acceptable by client 1225 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1226 1227 // identical to responder 1228 sm_setup_key_distribution(remote_key_request); 1229 1230 // JUST WORKS doens't provide authentication 1231 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1232 1233 return 0; 1234 } 1235 1236 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1237 1238 // cache and reset context 1239 int matched_device_id = sm_address_resolution_test; 1240 address_resolution_mode_t mode = sm_address_resolution_mode; 1241 void * context = sm_address_resolution_context; 1242 1243 // reset context 1244 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1245 sm_address_resolution_context = NULL; 1246 sm_address_resolution_test = -1; 1247 hci_con_handle_t con_handle = 0; 1248 1249 sm_connection_t * sm_connection; 1250 #ifdef ENABLE_LE_CENTRAL 1251 sm_key_t ltk; 1252 #endif 1253 switch (mode){ 1254 case ADDRESS_RESOLUTION_GENERAL: 1255 break; 1256 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1257 sm_connection = (sm_connection_t *) context; 1258 con_handle = sm_connection->sm_handle; 1259 switch (event){ 1260 case ADDRESS_RESOLUTION_SUCEEDED: 1261 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1262 sm_connection->sm_le_db_index = matched_device_id; 1263 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1264 if (sm_connection->sm_role) { 1265 // LTK request received before, IRK required -> start LTK calculation 1266 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1267 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1268 } 1269 break; 1270 } 1271 #ifdef ENABLE_LE_CENTRAL 1272 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1273 sm_connection->sm_security_request_received = 0; 1274 sm_connection->sm_bonding_requested = 0; 1275 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1276 if (!sm_is_null_key(ltk)){ 1277 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1278 } else { 1279 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1280 } 1281 #endif 1282 break; 1283 case ADDRESS_RESOLUTION_FAILED: 1284 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1285 if (sm_connection->sm_role) { 1286 // LTK request received before, IRK required -> negative LTK reply 1287 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1288 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1289 } 1290 break; 1291 } 1292 #ifdef ENABLE_LE_CENTRAL 1293 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1294 sm_connection->sm_security_request_received = 0; 1295 sm_connection->sm_bonding_requested = 0; 1296 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1297 #endif 1298 break; 1299 } 1300 break; 1301 default: 1302 break; 1303 } 1304 1305 switch (event){ 1306 case ADDRESS_RESOLUTION_SUCEEDED: 1307 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1308 break; 1309 case ADDRESS_RESOLUTION_FAILED: 1310 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1311 break; 1312 } 1313 } 1314 1315 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1316 1317 int le_db_index = -1; 1318 1319 // lookup device based on IRK 1320 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1321 int i; 1322 for (i=0; i < le_device_db_count(); i++){ 1323 sm_key_t irk; 1324 bd_addr_t address; 1325 int address_type; 1326 le_device_db_info(i, &address_type, address, irk); 1327 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1328 log_info("sm: device found for IRK, updating"); 1329 le_db_index = i; 1330 break; 1331 } 1332 } 1333 } 1334 1335 // if not found, lookup via public address if possible 1336 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1337 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1338 int i; 1339 for (i=0; i < le_device_db_count(); i++){ 1340 bd_addr_t address; 1341 int address_type; 1342 le_device_db_info(i, &address_type, address, NULL); 1343 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1344 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1345 log_info("sm: device found for public address, updating"); 1346 le_db_index = i; 1347 break; 1348 } 1349 } 1350 } 1351 1352 // if not found, add to db 1353 if (le_db_index < 0) { 1354 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1355 } 1356 1357 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1358 1359 if (le_db_index >= 0){ 1360 1361 #ifdef ENABLE_LE_SIGNED_WRITE 1362 // store local CSRK 1363 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1364 log_info("sm: store local CSRK"); 1365 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1366 le_device_db_local_counter_set(le_db_index, 0); 1367 } 1368 1369 // store remote CSRK 1370 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1371 log_info("sm: store remote CSRK"); 1372 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1373 le_device_db_remote_counter_set(le_db_index, 0); 1374 } 1375 #endif 1376 // store encryption information for secure connections: LTK generated by ECDH 1377 if (setup->sm_use_secure_connections){ 1378 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1379 uint8_t zero_rand[8]; 1380 memset(zero_rand, 0, 8); 1381 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1382 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1383 } 1384 1385 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1386 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1387 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1388 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1389 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1390 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1391 1392 } 1393 } 1394 1395 // keep le_db_index 1396 sm_conn->sm_le_db_index = le_db_index; 1397 } 1398 1399 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1400 setup->sm_pairing_failed_reason = reason; 1401 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1402 } 1403 1404 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1405 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1406 } 1407 1408 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1409 1410 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1411 static int sm_passkey_used(stk_generation_method_t method); 1412 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1413 1414 static void sm_log_ec_keypair(void){ 1415 log_info("Elliptic curve: X"); 1416 log_info_hexdump(&ec_q[0],32); 1417 log_info("Elliptic curve: Y"); 1418 log_info_hexdump(&ec_q[32],32); 1419 } 1420 1421 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1422 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1423 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1424 } else { 1425 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1426 } 1427 } 1428 1429 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1430 if (IS_RESPONDER(sm_conn->sm_role)){ 1431 // Responder 1432 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1433 } else { 1434 // Initiator role 1435 switch (setup->sm_stk_generation_method){ 1436 case JUST_WORKS: 1437 sm_sc_prepare_dhkey_check(sm_conn); 1438 break; 1439 1440 case NK_BOTH_INPUT: 1441 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1442 break; 1443 case PK_INIT_INPUT: 1444 case PK_RESP_INPUT: 1445 case OK_BOTH_INPUT: 1446 if (setup->sm_passkey_bit < 20) { 1447 sm_sc_start_calculating_local_confirm(sm_conn); 1448 } else { 1449 sm_sc_prepare_dhkey_check(sm_conn); 1450 } 1451 break; 1452 case OOB: 1453 // TODO: implement SC OOB 1454 break; 1455 } 1456 } 1457 } 1458 1459 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1460 return sm_cmac_sc_buffer[offset]; 1461 } 1462 1463 static void sm_sc_cmac_done(uint8_t * hash){ 1464 log_info("sm_sc_cmac_done: "); 1465 log_info_hexdump(hash, 16); 1466 1467 sm_connection_t * sm_conn = sm_cmac_connection; 1468 sm_cmac_connection = NULL; 1469 #ifdef ENABLE_CLASSIC 1470 link_key_type_t link_key_type; 1471 #endif 1472 1473 switch (sm_conn->sm_engine_state){ 1474 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1475 memcpy(setup->sm_local_confirm, hash, 16); 1476 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1477 break; 1478 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1479 // check 1480 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1481 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1482 break; 1483 } 1484 sm_sc_state_after_receiving_random(sm_conn); 1485 break; 1486 case SM_SC_W4_CALCULATE_G2: { 1487 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1488 big_endian_store_32(setup->sm_tk, 12, vab); 1489 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1490 sm_trigger_user_response(sm_conn); 1491 break; 1492 } 1493 case SM_SC_W4_CALCULATE_F5_SALT: 1494 memcpy(setup->sm_t, hash, 16); 1495 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1496 break; 1497 case SM_SC_W4_CALCULATE_F5_MACKEY: 1498 memcpy(setup->sm_mackey, hash, 16); 1499 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1500 break; 1501 case SM_SC_W4_CALCULATE_F5_LTK: 1502 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1503 // Errata Service Release to the Bluetooth Specification: ESR09 1504 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1505 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1506 memcpy(setup->sm_ltk, hash, 16); 1507 memcpy(setup->sm_local_ltk, hash, 16); 1508 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1509 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1510 break; 1511 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1512 memcpy(setup->sm_local_dhkey_check, hash, 16); 1513 if (IS_RESPONDER(sm_conn->sm_role)){ 1514 // responder 1515 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1516 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1517 } else { 1518 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1519 } 1520 } else { 1521 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1522 } 1523 break; 1524 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1525 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1526 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1527 break; 1528 } 1529 if (IS_RESPONDER(sm_conn->sm_role)){ 1530 // responder 1531 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1532 } else { 1533 // initiator 1534 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1535 } 1536 break; 1537 case SM_SC_W4_CALCULATE_H6_ILK: 1538 memcpy(setup->sm_t, hash, 16); 1539 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1540 break; 1541 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1542 #ifdef ENABLE_CLASSIC 1543 reverse_128(hash, setup->sm_t); 1544 link_key_type = sm_conn->sm_connection_authenticated ? 1545 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1546 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1547 if (IS_RESPONDER(sm_conn->sm_role)){ 1548 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1549 } else { 1550 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1551 } 1552 #endif 1553 if (IS_RESPONDER(sm_conn->sm_role)){ 1554 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1555 } else { 1556 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1557 } 1558 sm_done_for_handle(sm_conn->sm_handle); 1559 break; 1560 default: 1561 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1562 break; 1563 } 1564 sm_run(); 1565 } 1566 1567 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){ 1568 const uint16_t message_len = 65; 1569 sm_cmac_connection = sm_conn; 1570 memcpy(sm_cmac_sc_buffer, u, 32); 1571 memcpy(sm_cmac_sc_buffer+32, v, 32); 1572 sm_cmac_sc_buffer[64] = z; 1573 log_info("f4 key"); 1574 log_info_hexdump(x, 16); 1575 log_info("f4 message"); 1576 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1577 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1578 } 1579 1580 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1581 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1582 static const uint8_t f5_length[] = { 0x01, 0x00}; 1583 1584 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 1585 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1586 memset(dhkey, 0, 32); 1587 #if uECC_SUPPORTS_secp256r1 1588 // standard version 1589 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey, uECC_secp256r1()); 1590 #else 1591 // static version 1592 uECC_shared_secret(setup->sm_peer_q, ec_d, dhkey); 1593 #endif 1594 log_info("dhkey"); 1595 log_info_hexdump(dhkey, 32); 1596 } 1597 #endif 1598 1599 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1600 // calculate salt for f5 1601 const uint16_t message_len = 32; 1602 sm_cmac_connection = sm_conn; 1603 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1604 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1605 } 1606 1607 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){ 1608 const uint16_t message_len = 53; 1609 sm_cmac_connection = sm_conn; 1610 1611 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1612 sm_cmac_sc_buffer[0] = 0; 1613 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1614 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1615 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1616 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1617 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1618 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1619 log_info("f5 key"); 1620 log_info_hexdump(t, 16); 1621 log_info("f5 message for MacKey"); 1622 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1623 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1624 } 1625 1626 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1627 sm_key56_t bd_addr_master, bd_addr_slave; 1628 bd_addr_master[0] = setup->sm_m_addr_type; 1629 bd_addr_slave[0] = setup->sm_s_addr_type; 1630 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1631 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1632 if (IS_RESPONDER(sm_conn->sm_role)){ 1633 // responder 1634 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1635 } else { 1636 // initiator 1637 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1638 } 1639 } 1640 1641 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1642 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1643 const uint16_t message_len = 53; 1644 sm_cmac_connection = sm_conn; 1645 sm_cmac_sc_buffer[0] = 1; 1646 // 1..52 setup before 1647 log_info("f5 key"); 1648 log_info_hexdump(t, 16); 1649 log_info("f5 message for LTK"); 1650 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1651 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1652 } 1653 1654 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1655 f5_ltk(sm_conn, setup->sm_t); 1656 } 1657 1658 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){ 1659 const uint16_t message_len = 65; 1660 sm_cmac_connection = sm_conn; 1661 memcpy(sm_cmac_sc_buffer, n1, 16); 1662 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1663 memcpy(sm_cmac_sc_buffer+32, r, 16); 1664 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1665 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1666 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1667 log_info("f6 key"); 1668 log_info_hexdump(w, 16); 1669 log_info("f6 message"); 1670 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1671 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1672 } 1673 1674 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1675 // - U is 256 bits 1676 // - V is 256 bits 1677 // - X is 128 bits 1678 // - Y is 128 bits 1679 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){ 1680 const uint16_t message_len = 80; 1681 sm_cmac_connection = sm_conn; 1682 memcpy(sm_cmac_sc_buffer, u, 32); 1683 memcpy(sm_cmac_sc_buffer+32, v, 32); 1684 memcpy(sm_cmac_sc_buffer+64, y, 16); 1685 log_info("g2 key"); 1686 log_info_hexdump(x, 16); 1687 log_info("g2 message"); 1688 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1689 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1690 } 1691 1692 static void g2_calculate(sm_connection_t * sm_conn) { 1693 // calc Va if numeric comparison 1694 if (IS_RESPONDER(sm_conn->sm_role)){ 1695 // responder 1696 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1697 } else { 1698 // initiator 1699 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1700 } 1701 } 1702 1703 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1704 uint8_t z = 0; 1705 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1706 // some form of passkey 1707 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1708 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1709 setup->sm_passkey_bit++; 1710 } 1711 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1712 } 1713 1714 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1715 uint8_t z = 0; 1716 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1717 // some form of passkey 1718 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1719 // sm_passkey_bit was increased before sending confirm value 1720 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1721 } 1722 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1723 } 1724 1725 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1726 1727 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 1728 // calculate DHKEY 1729 sm_sc_calculate_dhkey(setup->sm_dhkey); 1730 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1731 #endif 1732 1733 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1734 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1735 return; 1736 } else { 1737 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1738 } 1739 1740 } 1741 1742 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1743 // calculate DHKCheck 1744 sm_key56_t bd_addr_master, bd_addr_slave; 1745 bd_addr_master[0] = setup->sm_m_addr_type; 1746 bd_addr_slave[0] = setup->sm_s_addr_type; 1747 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1748 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1749 uint8_t iocap_a[3]; 1750 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1751 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1752 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1753 uint8_t iocap_b[3]; 1754 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1755 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1756 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1757 if (IS_RESPONDER(sm_conn->sm_role)){ 1758 // responder 1759 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); 1760 } else { 1761 // initiator 1762 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); 1763 } 1764 } 1765 1766 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1767 // validate E = f6() 1768 sm_key56_t bd_addr_master, bd_addr_slave; 1769 bd_addr_master[0] = setup->sm_m_addr_type; 1770 bd_addr_slave[0] = setup->sm_s_addr_type; 1771 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1772 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1773 1774 uint8_t iocap_a[3]; 1775 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1776 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1777 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1778 uint8_t iocap_b[3]; 1779 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1780 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1781 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1782 if (IS_RESPONDER(sm_conn->sm_role)){ 1783 // responder 1784 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1785 } else { 1786 // initiator 1787 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); 1788 } 1789 } 1790 1791 1792 // 1793 // Link Key Conversion Function h6 1794 // 1795 // h6(W, keyID) = AES-CMACW(keyID) 1796 // - W is 128 bits 1797 // - keyID is 32 bits 1798 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1799 const uint16_t message_len = 4; 1800 sm_cmac_connection = sm_conn; 1801 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1802 log_info("h6 key"); 1803 log_info_hexdump(w, 16); 1804 log_info("h6 message"); 1805 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1806 sm_cmac_general_start(w, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1807 } 1808 1809 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1810 // Errata Service Release to the Bluetooth Specification: ESR09 1811 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1812 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1813 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1814 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1815 } 1816 1817 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1818 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1819 } 1820 1821 #endif 1822 1823 // key management legacy connections: 1824 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1825 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1826 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1827 // - responder reconnects: responder uses LTK receveived from master 1828 1829 // key management secure connections: 1830 // - both devices store same LTK from ECDH key exchange. 1831 1832 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1833 static void sm_load_security_info(sm_connection_t * sm_connection){ 1834 int encryption_key_size; 1835 int authenticated; 1836 int authorized; 1837 1838 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1839 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1840 &encryption_key_size, &authenticated, &authorized); 1841 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1842 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1843 sm_connection->sm_connection_authenticated = authenticated; 1844 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1845 } 1846 #endif 1847 1848 #ifdef ENABLE_LE_PERIPHERAL 1849 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1850 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1851 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1852 // re-establish used key encryption size 1853 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1854 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1855 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1856 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1857 log_info("sm: received ltk request with key size %u, authenticated %u", 1858 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1859 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1860 } 1861 #endif 1862 1863 static void sm_run(void){ 1864 1865 btstack_linked_list_iterator_t it; 1866 1867 // assert that stack has already bootet 1868 if (hci_get_state() != HCI_STATE_WORKING) return; 1869 1870 // assert that we can send at least commands 1871 if (!hci_can_send_command_packet_now()) return; 1872 1873 // 1874 // non-connection related behaviour 1875 // 1876 1877 // distributed key generation 1878 switch (dkg_state){ 1879 case DKG_CALC_IRK: 1880 // already busy? 1881 if (sm_aes128_state == SM_AES128_IDLE) { 1882 // IRK = d1(IR, 1, 0) 1883 sm_key_t d1_prime; 1884 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1885 dkg_next_state(); 1886 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1887 return; 1888 } 1889 break; 1890 case DKG_CALC_DHK: 1891 // already busy? 1892 if (sm_aes128_state == SM_AES128_IDLE) { 1893 // DHK = d1(IR, 3, 0) 1894 sm_key_t d1_prime; 1895 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1896 dkg_next_state(); 1897 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1898 return; 1899 } 1900 break; 1901 default: 1902 break; 1903 } 1904 1905 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1906 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1907 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 1908 sm_random_start(NULL); 1909 #else 1910 ec_key_generation_state = EC_KEY_GENERATION_W4_KEY; 1911 hci_send_cmd(&hci_le_read_local_p256_public_key); 1912 #endif 1913 return; 1914 } 1915 #endif 1916 1917 // random address updates 1918 switch (rau_state){ 1919 case RAU_GET_RANDOM: 1920 rau_next_state(); 1921 sm_random_start(NULL); 1922 return; 1923 case RAU_GET_ENC: 1924 // already busy? 1925 if (sm_aes128_state == SM_AES128_IDLE) { 1926 sm_key_t r_prime; 1927 sm_ah_r_prime(sm_random_address, r_prime); 1928 rau_next_state(); 1929 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1930 return; 1931 } 1932 break; 1933 case RAU_SET_ADDRESS: 1934 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1935 rau_state = RAU_IDLE; 1936 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1937 return; 1938 default: 1939 break; 1940 } 1941 1942 #ifdef ENABLE_CMAC_ENGINE 1943 // CMAC 1944 switch (sm_cmac_state){ 1945 case CMAC_CALC_SUBKEYS: 1946 case CMAC_CALC_MI: 1947 case CMAC_CALC_MLAST: 1948 // already busy? 1949 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1950 sm_cmac_handle_aes_engine_ready(); 1951 return; 1952 default: 1953 break; 1954 } 1955 #endif 1956 1957 // CSRK Lookup 1958 // -- if csrk lookup ready, find connection that require csrk lookup 1959 if (sm_address_resolution_idle()){ 1960 hci_connections_get_iterator(&it); 1961 while(btstack_linked_list_iterator_has_next(&it)){ 1962 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1963 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1964 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1965 // and start lookup 1966 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); 1967 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1968 break; 1969 } 1970 } 1971 } 1972 1973 // -- if csrk lookup ready, resolved addresses for received addresses 1974 if (sm_address_resolution_idle()) { 1975 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1976 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1977 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1978 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1979 btstack_memory_sm_lookup_entry_free(entry); 1980 } 1981 } 1982 1983 // -- Continue with CSRK device lookup by public or resolvable private address 1984 if (!sm_address_resolution_idle()){ 1985 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1986 while (sm_address_resolution_test < le_device_db_count()){ 1987 int addr_type; 1988 bd_addr_t addr; 1989 sm_key_t irk; 1990 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1991 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1992 1993 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1994 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1995 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1996 break; 1997 } 1998 1999 if (sm_address_resolution_addr_type == 0){ 2000 sm_address_resolution_test++; 2001 continue; 2002 } 2003 2004 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2005 2006 log_info("LE Device Lookup: calculate AH"); 2007 log_info_key("IRK", irk); 2008 2009 sm_key_t r_prime; 2010 sm_ah_r_prime(sm_address_resolution_address, r_prime); 2011 sm_address_resolution_ah_calculation_active = 1; 2012 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 2013 return; 2014 } 2015 2016 if (sm_address_resolution_test >= le_device_db_count()){ 2017 log_info("LE Device Lookup: not found"); 2018 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 2019 } 2020 } 2021 2022 // handle basic actions that don't requires the full context 2023 hci_connections_get_iterator(&it); 2024 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2025 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2026 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2027 switch(sm_connection->sm_engine_state){ 2028 // responder side 2029 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2030 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2031 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2032 return; 2033 2034 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2035 case SM_SC_RECEIVED_LTK_REQUEST: 2036 switch (sm_connection->sm_irk_lookup_state){ 2037 case IRK_LOOKUP_FAILED: 2038 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 2039 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2040 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2041 return; 2042 default: 2043 break; 2044 } 2045 break; 2046 #endif 2047 default: 2048 break; 2049 } 2050 } 2051 2052 // 2053 // active connection handling 2054 // -- use loop to handle next connection if lock on setup context is released 2055 2056 while (1) { 2057 2058 // Find connections that requires setup context and make active if no other is locked 2059 hci_connections_get_iterator(&it); 2060 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 2061 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2062 sm_connection_t * sm_connection = &hci_connection->sm_connection; 2063 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 2064 int done = 1; 2065 int err; 2066 UNUSED(err); 2067 switch (sm_connection->sm_engine_state) { 2068 #ifdef ENABLE_LE_PERIPHERAL 2069 case SM_RESPONDER_SEND_SECURITY_REQUEST: 2070 // send packet if possible, 2071 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 2072 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 2073 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 2074 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2075 } else { 2076 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2077 } 2078 // don't lock sxetup context yet 2079 done = 0; 2080 break; 2081 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 2082 sm_reset_setup(); 2083 sm_init_setup(sm_connection); 2084 // recover pairing request 2085 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2086 err = sm_stk_generation_init(sm_connection); 2087 if (err){ 2088 setup->sm_pairing_failed_reason = err; 2089 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2090 break; 2091 } 2092 sm_timeout_start(sm_connection); 2093 // generate random number first, if we need to show passkey 2094 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2095 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 2096 break; 2097 } 2098 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2099 break; 2100 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2101 sm_reset_setup(); 2102 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2103 break; 2104 #endif 2105 #ifdef ENABLE_LE_CENTRAL 2106 case SM_INITIATOR_PH0_HAS_LTK: 2107 sm_reset_setup(); 2108 sm_load_security_info(sm_connection); 2109 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2110 break; 2111 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2112 sm_reset_setup(); 2113 sm_init_setup(sm_connection); 2114 sm_timeout_start(sm_connection); 2115 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2116 break; 2117 #endif 2118 2119 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2120 case SM_SC_RECEIVED_LTK_REQUEST: 2121 switch (sm_connection->sm_irk_lookup_state){ 2122 case IRK_LOOKUP_SUCCEEDED: 2123 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2124 // start using context by loading security info 2125 sm_reset_setup(); 2126 sm_load_security_info(sm_connection); 2127 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2128 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2129 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2130 break; 2131 } 2132 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2133 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2134 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2135 // don't lock setup context yet 2136 return; 2137 default: 2138 // just wait until IRK lookup is completed 2139 // don't lock setup context yet 2140 done = 0; 2141 break; 2142 } 2143 break; 2144 #endif 2145 default: 2146 done = 0; 2147 break; 2148 } 2149 if (done){ 2150 sm_active_connection_handle = sm_connection->sm_handle; 2151 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); 2152 } 2153 } 2154 2155 // 2156 // active connection handling 2157 // 2158 2159 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2160 2161 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2162 if (!connection) { 2163 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2164 return; 2165 } 2166 2167 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) 2168 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_NEEDED){ 2169 setup->sm_state_vars &= ~SM_STATE_VAR_DHKEY_NEEDED; 2170 hci_send_cmd(&hci_le_generate_dhkey, &setup->sm_peer_q[0], &setup->sm_peer_q[32]); 2171 return; 2172 } 2173 #endif 2174 2175 // assert that we could send a SM PDU - not needed for all of the following 2176 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2177 log_info("cannot send now, requesting can send now event"); 2178 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2179 return; 2180 } 2181 2182 // send keypress notifications 2183 if (setup->sm_keypress_notification != 0xff){ 2184 uint8_t buffer[2]; 2185 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2186 buffer[1] = setup->sm_keypress_notification; 2187 setup->sm_keypress_notification = 0xff; 2188 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2189 return; 2190 } 2191 2192 sm_key_t plaintext; 2193 int key_distribution_flags; 2194 UNUSED(key_distribution_flags); 2195 2196 log_info("sm_run: state %u", connection->sm_engine_state); 2197 2198 switch (connection->sm_engine_state){ 2199 2200 // general 2201 case SM_GENERAL_SEND_PAIRING_FAILED: { 2202 uint8_t buffer[2]; 2203 buffer[0] = SM_CODE_PAIRING_FAILED; 2204 buffer[1] = setup->sm_pairing_failed_reason; 2205 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2206 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2207 sm_done_for_handle(connection->sm_handle); 2208 break; 2209 } 2210 2211 // responding state 2212 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2213 case SM_SC_W2_GET_RANDOM_A: 2214 sm_random_start(connection); 2215 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 2216 break; 2217 case SM_SC_W2_GET_RANDOM_B: 2218 sm_random_start(connection); 2219 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2220 break; 2221 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2222 if (!sm_cmac_ready()) break; 2223 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2224 sm_sc_calculate_local_confirm(connection); 2225 break; 2226 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2227 if (!sm_cmac_ready()) break; 2228 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2229 sm_sc_calculate_remote_confirm(connection); 2230 break; 2231 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2232 if (!sm_cmac_ready()) break; 2233 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2234 sm_sc_calculate_f6_for_dhkey_check(connection); 2235 break; 2236 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2237 if (!sm_cmac_ready()) break; 2238 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2239 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2240 break; 2241 case SM_SC_W2_CALCULATE_F5_SALT: 2242 if (!sm_cmac_ready()) break; 2243 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2244 f5_calculate_salt(connection); 2245 break; 2246 case SM_SC_W2_CALCULATE_F5_MACKEY: 2247 if (!sm_cmac_ready()) break; 2248 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2249 f5_calculate_mackey(connection); 2250 break; 2251 case SM_SC_W2_CALCULATE_F5_LTK: 2252 if (!sm_cmac_ready()) break; 2253 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2254 f5_calculate_ltk(connection); 2255 break; 2256 case SM_SC_W2_CALCULATE_G2: 2257 if (!sm_cmac_ready()) break; 2258 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2259 g2_calculate(connection); 2260 break; 2261 case SM_SC_W2_CALCULATE_H6_ILK: 2262 if (!sm_cmac_ready()) break; 2263 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2264 h6_calculate_ilk(connection); 2265 break; 2266 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2267 if (!sm_cmac_ready()) break; 2268 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2269 h6_calculate_br_edr_link_key(connection); 2270 break; 2271 #endif 2272 2273 #ifdef ENABLE_LE_CENTRAL 2274 // initiator side 2275 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2276 sm_key_t peer_ltk_flipped; 2277 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2278 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2279 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2280 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2281 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2282 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2283 return; 2284 } 2285 2286 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2287 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2288 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2289 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2290 sm_timeout_reset(connection); 2291 break; 2292 #endif 2293 2294 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2295 2296 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2297 uint8_t buffer[65]; 2298 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2299 // 2300 reverse_256(&ec_q[0], &buffer[1]); 2301 reverse_256(&ec_q[32], &buffer[33]); 2302 2303 // stk generation method 2304 // passkey entry: notify app to show passkey or to request passkey 2305 switch (setup->sm_stk_generation_method){ 2306 case JUST_WORKS: 2307 case NK_BOTH_INPUT: 2308 if (IS_RESPONDER(connection->sm_role)){ 2309 // responder 2310 sm_sc_start_calculating_local_confirm(connection); 2311 } else { 2312 // initiator 2313 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2314 } 2315 break; 2316 case PK_INIT_INPUT: 2317 case PK_RESP_INPUT: 2318 case OK_BOTH_INPUT: 2319 // use random TK for display 2320 memcpy(setup->sm_ra, setup->sm_tk, 16); 2321 memcpy(setup->sm_rb, setup->sm_tk, 16); 2322 setup->sm_passkey_bit = 0; 2323 2324 if (IS_RESPONDER(connection->sm_role)){ 2325 // responder 2326 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2327 } else { 2328 // initiator 2329 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2330 } 2331 sm_trigger_user_response(connection); 2332 break; 2333 case OOB: 2334 // TODO: implement SC OOB 2335 break; 2336 } 2337 2338 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2339 sm_timeout_reset(connection); 2340 break; 2341 } 2342 case SM_SC_SEND_CONFIRMATION: { 2343 uint8_t buffer[17]; 2344 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2345 reverse_128(setup->sm_local_confirm, &buffer[1]); 2346 if (IS_RESPONDER(connection->sm_role)){ 2347 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2348 } else { 2349 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2350 } 2351 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2352 sm_timeout_reset(connection); 2353 break; 2354 } 2355 case SM_SC_SEND_PAIRING_RANDOM: { 2356 uint8_t buffer[17]; 2357 buffer[0] = SM_CODE_PAIRING_RANDOM; 2358 reverse_128(setup->sm_local_nonce, &buffer[1]); 2359 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2360 if (IS_RESPONDER(connection->sm_role)){ 2361 // responder 2362 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2363 } else { 2364 // initiator 2365 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2366 } 2367 } else { 2368 if (IS_RESPONDER(connection->sm_role)){ 2369 // responder 2370 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2371 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2372 } else { 2373 sm_sc_prepare_dhkey_check(connection); 2374 } 2375 } else { 2376 // initiator 2377 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2378 } 2379 } 2380 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2381 sm_timeout_reset(connection); 2382 break; 2383 } 2384 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2385 uint8_t buffer[17]; 2386 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2387 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2388 2389 if (IS_RESPONDER(connection->sm_role)){ 2390 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2391 } else { 2392 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2393 } 2394 2395 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2396 sm_timeout_reset(connection); 2397 break; 2398 } 2399 2400 #endif 2401 2402 #ifdef ENABLE_LE_PERIPHERAL 2403 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2404 // echo initiator for now 2405 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2406 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2407 2408 if (setup->sm_use_secure_connections){ 2409 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2410 // skip LTK/EDIV for SC 2411 log_info("sm: dropping encryption information flag"); 2412 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2413 } else { 2414 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2415 } 2416 2417 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); 2418 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); 2419 // update key distribution after ENC was dropped 2420 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2421 2422 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2423 sm_timeout_reset(connection); 2424 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2425 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2426 sm_trigger_user_response(connection); 2427 } 2428 return; 2429 #endif 2430 2431 case SM_PH2_SEND_PAIRING_RANDOM: { 2432 uint8_t buffer[17]; 2433 buffer[0] = SM_CODE_PAIRING_RANDOM; 2434 reverse_128(setup->sm_local_random, &buffer[1]); 2435 if (IS_RESPONDER(connection->sm_role)){ 2436 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2437 } else { 2438 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2439 } 2440 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2441 sm_timeout_reset(connection); 2442 break; 2443 } 2444 2445 case SM_PH2_GET_RANDOM_TK: 2446 case SM_PH2_C1_GET_RANDOM_A: 2447 case SM_PH2_C1_GET_RANDOM_B: 2448 case SM_PH3_GET_RANDOM: 2449 case SM_PH3_GET_DIV: 2450 sm_next_responding_state(connection); 2451 sm_random_start(connection); 2452 return; 2453 2454 case SM_PH2_C1_GET_ENC_B: 2455 case SM_PH2_C1_GET_ENC_D: 2456 // already busy? 2457 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2458 sm_next_responding_state(connection); 2459 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2460 return; 2461 2462 case SM_PH3_LTK_GET_ENC: 2463 case SM_RESPONDER_PH4_LTK_GET_ENC: 2464 // already busy? 2465 if (sm_aes128_state == SM_AES128_IDLE) { 2466 sm_key_t d_prime; 2467 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2468 sm_next_responding_state(connection); 2469 sm_aes128_start(sm_persistent_er, d_prime, connection); 2470 return; 2471 } 2472 break; 2473 2474 case SM_PH3_CSRK_GET_ENC: 2475 // already busy? 2476 if (sm_aes128_state == SM_AES128_IDLE) { 2477 sm_key_t d_prime; 2478 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2479 sm_next_responding_state(connection); 2480 sm_aes128_start(sm_persistent_er, d_prime, connection); 2481 return; 2482 } 2483 break; 2484 2485 case SM_PH2_C1_GET_ENC_C: 2486 // already busy? 2487 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2488 // calculate m_confirm using aes128 engine - step 1 2489 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); 2490 sm_next_responding_state(connection); 2491 sm_aes128_start(setup->sm_tk, plaintext, connection); 2492 break; 2493 case SM_PH2_C1_GET_ENC_A: 2494 // already busy? 2495 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2496 // calculate confirm using aes128 engine - step 1 2497 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); 2498 sm_next_responding_state(connection); 2499 sm_aes128_start(setup->sm_tk, plaintext, connection); 2500 break; 2501 case SM_PH2_CALC_STK: 2502 // already busy? 2503 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2504 // calculate STK 2505 if (IS_RESPONDER(connection->sm_role)){ 2506 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2507 } else { 2508 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2509 } 2510 sm_next_responding_state(connection); 2511 sm_aes128_start(setup->sm_tk, plaintext, connection); 2512 break; 2513 case SM_PH3_Y_GET_ENC: 2514 // already busy? 2515 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2516 // PH3B2 - calculate Y from - enc 2517 // Y = dm(DHK, Rand) 2518 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2519 sm_next_responding_state(connection); 2520 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2521 return; 2522 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2523 uint8_t buffer[17]; 2524 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2525 reverse_128(setup->sm_local_confirm, &buffer[1]); 2526 if (IS_RESPONDER(connection->sm_role)){ 2527 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2528 } else { 2529 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2530 } 2531 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2532 sm_timeout_reset(connection); 2533 return; 2534 } 2535 #ifdef ENABLE_LE_PERIPHERAL 2536 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2537 sm_key_t stk_flipped; 2538 reverse_128(setup->sm_ltk, stk_flipped); 2539 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2540 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2541 return; 2542 } 2543 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2544 sm_key_t ltk_flipped; 2545 reverse_128(setup->sm_ltk, ltk_flipped); 2546 connection->sm_engine_state = SM_RESPONDER_IDLE; 2547 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2548 return; 2549 } 2550 case SM_RESPONDER_PH4_Y_GET_ENC: 2551 // already busy? 2552 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2553 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2554 // Y = dm(DHK, Rand) 2555 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2556 sm_next_responding_state(connection); 2557 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2558 return; 2559 #endif 2560 #ifdef ENABLE_LE_CENTRAL 2561 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2562 sm_key_t stk_flipped; 2563 reverse_128(setup->sm_ltk, stk_flipped); 2564 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2565 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2566 return; 2567 } 2568 #endif 2569 2570 case SM_PH3_DISTRIBUTE_KEYS: 2571 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2572 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2573 uint8_t buffer[17]; 2574 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2575 reverse_128(setup->sm_ltk, &buffer[1]); 2576 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2577 sm_timeout_reset(connection); 2578 return; 2579 } 2580 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2581 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2582 uint8_t buffer[11]; 2583 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2584 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2585 reverse_64(setup->sm_local_rand, &buffer[3]); 2586 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2587 sm_timeout_reset(connection); 2588 return; 2589 } 2590 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2591 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2592 uint8_t buffer[17]; 2593 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2594 reverse_128(sm_persistent_irk, &buffer[1]); 2595 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2596 sm_timeout_reset(connection); 2597 return; 2598 } 2599 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2600 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2601 bd_addr_t local_address; 2602 uint8_t buffer[8]; 2603 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2604 switch (gap_random_address_get_mode()){ 2605 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2606 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2607 // public or static random 2608 gap_le_get_own_address(&buffer[1], local_address); 2609 break; 2610 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2611 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2612 // fallback to public 2613 gap_local_bd_addr(local_address); 2614 buffer[1] = 0; 2615 break; 2616 } 2617 reverse_bd_addr(local_address, &buffer[2]); 2618 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2619 sm_timeout_reset(connection); 2620 return; 2621 } 2622 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2623 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2624 2625 // hack to reproduce test runs 2626 if (test_use_fixed_local_csrk){ 2627 memset(setup->sm_local_csrk, 0xcc, 16); 2628 } 2629 2630 uint8_t buffer[17]; 2631 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2632 reverse_128(setup->sm_local_csrk, &buffer[1]); 2633 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2634 sm_timeout_reset(connection); 2635 return; 2636 } 2637 2638 // keys are sent 2639 if (IS_RESPONDER(connection->sm_role)){ 2640 // slave -> receive master keys if any 2641 if (sm_key_distribution_all_received(connection)){ 2642 sm_key_distribution_handle_all_received(connection); 2643 connection->sm_engine_state = SM_RESPONDER_IDLE; 2644 sm_done_for_handle(connection->sm_handle); 2645 } else { 2646 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2647 } 2648 } else { 2649 // master -> all done 2650 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2651 sm_done_for_handle(connection->sm_handle); 2652 } 2653 break; 2654 2655 default: 2656 break; 2657 } 2658 2659 // check again if active connection was released 2660 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2661 } 2662 } 2663 2664 // note: aes engine is ready as we just got the aes result 2665 static void sm_handle_encryption_result(uint8_t * data){ 2666 2667 sm_aes128_state = SM_AES128_IDLE; 2668 2669 if (sm_address_resolution_ah_calculation_active){ 2670 sm_address_resolution_ah_calculation_active = 0; 2671 // compare calulated address against connecting device 2672 uint8_t hash[3]; 2673 reverse_24(data, hash); 2674 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2675 log_info("LE Device Lookup: matched resolvable private address"); 2676 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2677 return; 2678 } 2679 // no match, try next 2680 sm_address_resolution_test++; 2681 return; 2682 } 2683 2684 switch (dkg_state){ 2685 case DKG_W4_IRK: 2686 reverse_128(data, sm_persistent_irk); 2687 log_info_key("irk", sm_persistent_irk); 2688 dkg_next_state(); 2689 return; 2690 case DKG_W4_DHK: 2691 reverse_128(data, sm_persistent_dhk); 2692 log_info_key("dhk", sm_persistent_dhk); 2693 dkg_next_state(); 2694 // SM Init Finished 2695 return; 2696 default: 2697 break; 2698 } 2699 2700 switch (rau_state){ 2701 case RAU_W4_ENC: 2702 reverse_24(data, &sm_random_address[3]); 2703 rau_next_state(); 2704 return; 2705 default: 2706 break; 2707 } 2708 2709 #ifdef ENABLE_CMAC_ENGINE 2710 switch (sm_cmac_state){ 2711 case CMAC_W4_SUBKEYS: 2712 case CMAC_W4_MI: 2713 case CMAC_W4_MLAST: 2714 { 2715 sm_key_t t; 2716 reverse_128(data, t); 2717 sm_cmac_handle_encryption_result(t); 2718 } 2719 return; 2720 default: 2721 break; 2722 } 2723 #endif 2724 2725 // retrieve sm_connection provided to sm_aes128_start_encryption 2726 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2727 if (!connection) return; 2728 switch (connection->sm_engine_state){ 2729 case SM_PH2_C1_W4_ENC_A: 2730 case SM_PH2_C1_W4_ENC_C: 2731 { 2732 sm_key_t t2; 2733 reverse_128(data, t2); 2734 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2735 } 2736 sm_next_responding_state(connection); 2737 return; 2738 case SM_PH2_C1_W4_ENC_B: 2739 reverse_128(data, setup->sm_local_confirm); 2740 log_info_key("c1!", setup->sm_local_confirm); 2741 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2742 return; 2743 case SM_PH2_C1_W4_ENC_D: 2744 { 2745 sm_key_t peer_confirm_test; 2746 reverse_128(data, peer_confirm_test); 2747 log_info_key("c1!", peer_confirm_test); 2748 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2749 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2750 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2751 return; 2752 } 2753 if (IS_RESPONDER(connection->sm_role)){ 2754 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2755 } else { 2756 connection->sm_engine_state = SM_PH2_CALC_STK; 2757 } 2758 } 2759 return; 2760 case SM_PH2_W4_STK: 2761 reverse_128(data, setup->sm_ltk); 2762 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2763 log_info_key("stk", setup->sm_ltk); 2764 if (IS_RESPONDER(connection->sm_role)){ 2765 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2766 } else { 2767 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2768 } 2769 return; 2770 case SM_PH3_Y_W4_ENC:{ 2771 sm_key_t y128; 2772 reverse_128(data, y128); 2773 setup->sm_local_y = big_endian_read_16(y128, 14); 2774 log_info_hex16("y", setup->sm_local_y); 2775 // PH3B3 - calculate EDIV 2776 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2777 log_info_hex16("ediv", setup->sm_local_ediv); 2778 // PH3B4 - calculate LTK - enc 2779 // LTK = d1(ER, DIV, 0)) 2780 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2781 return; 2782 } 2783 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2784 sm_key_t y128; 2785 reverse_128(data, y128); 2786 setup->sm_local_y = big_endian_read_16(y128, 14); 2787 log_info_hex16("y", setup->sm_local_y); 2788 2789 // PH3B3 - calculate DIV 2790 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2791 log_info_hex16("ediv", setup->sm_local_ediv); 2792 // PH3B4 - calculate LTK - enc 2793 // LTK = d1(ER, DIV, 0)) 2794 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2795 return; 2796 } 2797 case SM_PH3_LTK_W4_ENC: 2798 reverse_128(data, setup->sm_ltk); 2799 log_info_key("ltk", setup->sm_ltk); 2800 // calc CSRK next 2801 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2802 return; 2803 case SM_PH3_CSRK_W4_ENC: 2804 reverse_128(data, setup->sm_local_csrk); 2805 log_info_key("csrk", setup->sm_local_csrk); 2806 if (setup->sm_key_distribution_send_set){ 2807 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2808 } else { 2809 // no keys to send, just continue 2810 if (IS_RESPONDER(connection->sm_role)){ 2811 // slave -> receive master keys 2812 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2813 } else { 2814 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2815 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2816 } else { 2817 // master -> all done 2818 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2819 sm_done_for_handle(connection->sm_handle); 2820 } 2821 } 2822 } 2823 return; 2824 #ifdef ENABLE_LE_PERIPHERAL 2825 case SM_RESPONDER_PH4_LTK_W4_ENC: 2826 reverse_128(data, setup->sm_ltk); 2827 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2828 log_info_key("ltk", setup->sm_ltk); 2829 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2830 return; 2831 #endif 2832 default: 2833 break; 2834 } 2835 } 2836 2837 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2838 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 2839 #if !defined(WICED_VERSION) 2840 // @return OK 2841 static int sm_generate_f_rng(unsigned char * buffer, unsigned size){ 2842 if (ec_key_generation_state != EC_KEY_GENERATION_ACTIVE) return 0; 2843 int offset = setup->sm_passkey_bit; 2844 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2845 while (size) { 2846 *buffer++ = setup->sm_peer_q[offset++]; 2847 size--; 2848 } 2849 setup->sm_passkey_bit = offset; 2850 return 1; 2851 } 2852 #endif 2853 #endif 2854 #endif 2855 2856 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2857 static void sm_handle_random_result(uint8_t * data){ 2858 2859 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) 2860 2861 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2862 int num_bytes = setup->sm_passkey_bit; 2863 memcpy(&setup->sm_peer_q[num_bytes], data, 8); 2864 num_bytes += 8; 2865 setup->sm_passkey_bit = num_bytes; 2866 2867 if (num_bytes >= 64){ 2868 2869 // init pre-generated random data from sm_peer_q 2870 setup->sm_passkey_bit = 0; 2871 2872 // generate EC key 2873 #ifndef WICED_VERSION 2874 log_info("set uECC RNG for initial key generation with 64 random bytes"); 2875 // micro-ecc from WICED SDK uses its wiced_crypto_get_random by default - no need to set it 2876 uECC_set_rng(&sm_generate_f_rng); 2877 #endif /* WICED_VERSION */ 2878 2879 #if uECC_SUPPORTS_secp256r1 2880 // standard version 2881 uECC_make_key(ec_q, ec_d, uECC_secp256r1()); 2882 2883 // disable RNG again, as returning no randmon data lets shared key generation fail 2884 log_info("disable uECC RNG in standard version after key generation"); 2885 uECC_set_rng(NULL); 2886 #else 2887 // static version 2888 uECC_make_key(ec_q, ec_d); 2889 #endif /* ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS */ 2890 2891 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2892 log_info("Elliptic curve: d"); 2893 log_info_hexdump(ec_d,32); 2894 sm_log_ec_keypair(); 2895 } 2896 } 2897 #endif 2898 2899 switch (rau_state){ 2900 case RAU_W4_RANDOM: 2901 // non-resolvable vs. resolvable 2902 switch (gap_random_adress_type){ 2903 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2904 // resolvable: use random as prand and calc address hash 2905 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2906 memcpy(sm_random_address, data, 3); 2907 sm_random_address[0] &= 0x3f; 2908 sm_random_address[0] |= 0x40; 2909 rau_state = RAU_GET_ENC; 2910 break; 2911 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2912 default: 2913 // "The two most significant bits of the address shall be equal to ‘0’"" 2914 memcpy(sm_random_address, data, 6); 2915 sm_random_address[0] &= 0x3f; 2916 rau_state = RAU_SET_ADDRESS; 2917 break; 2918 } 2919 return; 2920 default: 2921 break; 2922 } 2923 2924 // retrieve sm_connection provided to sm_random_start 2925 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2926 if (!connection) return; 2927 switch (connection->sm_engine_state){ 2928 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2929 case SM_SC_W4_GET_RANDOM_A: 2930 memcpy(&setup->sm_local_nonce[0], data, 8); 2931 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2932 break; 2933 case SM_SC_W4_GET_RANDOM_B: 2934 memcpy(&setup->sm_local_nonce[8], data, 8); 2935 // initiator & jw/nc -> send pairing random 2936 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2937 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2938 break; 2939 } else { 2940 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2941 } 2942 break; 2943 #endif 2944 2945 case SM_PH2_W4_RANDOM_TK: 2946 { 2947 sm_reset_tk(); 2948 uint32_t tk; 2949 if (sm_fixed_legacy_pairing_passkey_in_display_role == 0xffffffff){ 2950 // map random to 0-999999 without speding much cycles on a modulus operation 2951 tk = little_endian_read_32(data,0); 2952 tk = tk & 0xfffff; // 1048575 2953 if (tk >= 999999){ 2954 tk = tk - 999999; 2955 } 2956 } else { 2957 // override with pre-defined passkey 2958 tk = sm_fixed_legacy_pairing_passkey_in_display_role; 2959 } 2960 big_endian_store_32(setup->sm_tk, 12, tk); 2961 if (IS_RESPONDER(connection->sm_role)){ 2962 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2963 } else { 2964 if (setup->sm_use_secure_connections){ 2965 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2966 } else { 2967 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2968 sm_trigger_user_response(connection); 2969 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2970 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2971 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2972 } 2973 } 2974 } 2975 return; 2976 } 2977 case SM_PH2_C1_W4_RANDOM_A: 2978 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2979 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2980 return; 2981 case SM_PH2_C1_W4_RANDOM_B: 2982 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2983 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2984 return; 2985 case SM_PH3_W4_RANDOM: 2986 reverse_64(data, setup->sm_local_rand); 2987 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2988 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2989 // no db for authenticated flag hack: store flag in bit 4 of LSB 2990 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2991 connection->sm_engine_state = SM_PH3_GET_DIV; 2992 return; 2993 case SM_PH3_W4_DIV: 2994 // use 16 bit from random value as div 2995 setup->sm_local_div = big_endian_read_16(data, 0); 2996 log_info_hex16("div", setup->sm_local_div); 2997 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2998 return; 2999 default: 3000 break; 3001 } 3002 } 3003 3004 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3005 3006 UNUSED(channel); 3007 UNUSED(size); 3008 3009 sm_connection_t * sm_conn; 3010 hci_con_handle_t con_handle; 3011 3012 switch (packet_type) { 3013 3014 case HCI_EVENT_PACKET: 3015 switch (hci_event_packet_get_type(packet)) { 3016 3017 case BTSTACK_EVENT_STATE: 3018 // bt stack activated, get started 3019 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 3020 log_info("HCI Working!"); 3021 3022 3023 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 3024 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3025 if (!sm_have_ec_keypair){ 3026 setup->sm_passkey_bit = 0; 3027 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3028 } 3029 #endif 3030 // trigger Random Address generation if requested before 3031 switch (gap_random_adress_type){ 3032 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3033 rau_state = RAU_IDLE; 3034 break; 3035 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 3036 rau_state = RAU_SET_ADDRESS; 3037 break; 3038 default: 3039 rau_state = RAU_GET_RANDOM; 3040 break; 3041 } 3042 sm_run(); 3043 } 3044 break; 3045 3046 case HCI_EVENT_LE_META: 3047 switch (packet[2]) { 3048 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 3049 3050 log_info("sm: connected"); 3051 3052 if (packet[3]) return; // connection failed 3053 3054 con_handle = little_endian_read_16(packet, 4); 3055 sm_conn = sm_get_connection_for_handle(con_handle); 3056 if (!sm_conn) break; 3057 3058 sm_conn->sm_handle = con_handle; 3059 sm_conn->sm_role = packet[6]; 3060 sm_conn->sm_peer_addr_type = packet[7]; 3061 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 3062 3063 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 3064 3065 // reset security properties 3066 sm_conn->sm_connection_encrypted = 0; 3067 sm_conn->sm_connection_authenticated = 0; 3068 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 3069 sm_conn->sm_le_db_index = -1; 3070 3071 // prepare CSRK lookup (does not involve setup) 3072 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 3073 3074 // just connected -> everything else happens in sm_run() 3075 if (IS_RESPONDER(sm_conn->sm_role)){ 3076 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 3077 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3078 if (sm_slave_request_security) { 3079 // request security if requested by app 3080 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3081 } else { 3082 // otherwise, wait for pairing request 3083 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3084 } 3085 } 3086 break; 3087 } else { 3088 // master 3089 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3090 } 3091 break; 3092 3093 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 3094 con_handle = little_endian_read_16(packet, 3); 3095 sm_conn = sm_get_connection_for_handle(con_handle); 3096 if (!sm_conn) break; 3097 3098 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 3099 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 3100 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 3101 break; 3102 } 3103 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 3104 // PH2 SEND LTK as we need to exchange keys in PH3 3105 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 3106 break; 3107 } 3108 3109 // store rand and ediv 3110 reverse_64(&packet[5], sm_conn->sm_local_rand); 3111 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 3112 3113 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 3114 // potentially stored LTK is from the master 3115 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 3116 if (sm_reconstruct_ltk_without_le_device_db_entry){ 3117 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3118 break; 3119 } 3120 // additionally check if remote is in LE Device DB if requested 3121 switch(sm_conn->sm_irk_lookup_state){ 3122 case IRK_LOOKUP_FAILED: 3123 log_info("LTK Request: device not in device db"); 3124 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3125 break; 3126 case IRK_LOOKUP_SUCCEEDED: 3127 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 3128 break; 3129 default: 3130 // wait for irk look doen 3131 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3132 break; 3133 } 3134 break; 3135 } 3136 3137 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3138 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3139 #else 3140 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3141 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3142 #endif 3143 break; 3144 3145 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) 3146 case HCI_SUBEVENT_LE_READ_LOCAL_P256_PUBLIC_KEY_COMPLETE: 3147 if (hci_subevent_le_read_local_p256_public_key_complete_get_status(packet)){ 3148 log_error("Read Local P256 Public Key failed"); 3149 break; 3150 } 3151 3152 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_x(packet, &ec_q[0]); 3153 hci_subevent_le_read_local_p256_public_key_complete_get_dhkey_y(packet, &ec_q[32]); 3154 3155 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3156 sm_log_ec_keypair(); 3157 break; 3158 case HCI_SUBEVENT_LE_GENERATE_DHKEY_COMPLETE: 3159 sm_conn = sm_get_connection_for_handle(sm_active_connection_handle); 3160 if (hci_subevent_le_generate_dhkey_complete_get_status(packet)){ 3161 log_error("Generate DHKEY failed -> abort"); 3162 // abort pairing with 'unspecified reason' 3163 sm_pdu_received_in_wrong_state(sm_conn); 3164 break; 3165 } 3166 3167 hci_subevent_le_generate_dhkey_complete_get_dhkey(packet, &setup->sm_dhkey[0]); 3168 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 3169 log_info("dhkey"); 3170 log_info_hexdump(&setup->sm_dhkey[0], 32); 3171 3172 // trigger next step 3173 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 3174 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 3175 } 3176 break; 3177 #endif 3178 default: 3179 break; 3180 } 3181 break; 3182 3183 case HCI_EVENT_ENCRYPTION_CHANGE: 3184 con_handle = little_endian_read_16(packet, 3); 3185 sm_conn = sm_get_connection_for_handle(con_handle); 3186 if (!sm_conn) break; 3187 3188 sm_conn->sm_connection_encrypted = packet[5]; 3189 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3190 sm_conn->sm_actual_encryption_key_size); 3191 log_info("event handler, state %u", sm_conn->sm_engine_state); 3192 if (!sm_conn->sm_connection_encrypted) break; 3193 // continue if part of initial pairing 3194 switch (sm_conn->sm_engine_state){ 3195 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3196 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3197 sm_done_for_handle(sm_conn->sm_handle); 3198 break; 3199 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3200 if (IS_RESPONDER(sm_conn->sm_role)){ 3201 // slave 3202 if (setup->sm_use_secure_connections){ 3203 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3204 } else { 3205 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3206 } 3207 } else { 3208 // master 3209 if (sm_key_distribution_all_received(sm_conn)){ 3210 // skip receiving keys as there are none 3211 sm_key_distribution_handle_all_received(sm_conn); 3212 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3213 } else { 3214 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3215 } 3216 } 3217 break; 3218 default: 3219 break; 3220 } 3221 break; 3222 3223 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3224 con_handle = little_endian_read_16(packet, 3); 3225 sm_conn = sm_get_connection_for_handle(con_handle); 3226 if (!sm_conn) break; 3227 3228 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3229 log_info("event handler, state %u", sm_conn->sm_engine_state); 3230 // continue if part of initial pairing 3231 switch (sm_conn->sm_engine_state){ 3232 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3233 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3234 sm_done_for_handle(sm_conn->sm_handle); 3235 break; 3236 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3237 if (IS_RESPONDER(sm_conn->sm_role)){ 3238 // slave 3239 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3240 } else { 3241 // master 3242 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3243 } 3244 break; 3245 default: 3246 break; 3247 } 3248 break; 3249 3250 3251 case HCI_EVENT_DISCONNECTION_COMPLETE: 3252 con_handle = little_endian_read_16(packet, 3); 3253 sm_done_for_handle(con_handle); 3254 sm_conn = sm_get_connection_for_handle(con_handle); 3255 if (!sm_conn) break; 3256 3257 // delete stored bonding on disconnect with authentication failure in ph0 3258 if (sm_conn->sm_role == 0 3259 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3260 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3261 le_device_db_remove(sm_conn->sm_le_db_index); 3262 } 3263 3264 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3265 sm_conn->sm_handle = 0; 3266 break; 3267 3268 case HCI_EVENT_COMMAND_COMPLETE: 3269 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 3270 sm_handle_encryption_result(&packet[6]); 3271 break; 3272 } 3273 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 3274 sm_handle_random_result(&packet[6]); 3275 break; 3276 } 3277 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3278 // set local addr for le device db 3279 bd_addr_t addr; 3280 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3281 le_device_db_set_local_bd_addr(addr); 3282 } 3283 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_local_supported_commands)){ 3284 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS) 3285 if ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1+34] & 0x06) != 0x06){ 3286 log_error("LE Secure Connections enabled, but HCI Controller doesn't support it. Please add ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS to btstack_config.h"); 3287 } 3288 #endif 3289 } 3290 break; 3291 default: 3292 break; 3293 } 3294 break; 3295 default: 3296 break; 3297 } 3298 3299 sm_run(); 3300 } 3301 3302 static inline int sm_calc_actual_encryption_key_size(int other){ 3303 if (other < sm_min_encryption_key_size) return 0; 3304 if (other < sm_max_encryption_key_size) return other; 3305 return sm_max_encryption_key_size; 3306 } 3307 3308 3309 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3310 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3311 switch (method){ 3312 case JUST_WORKS: 3313 case NK_BOTH_INPUT: 3314 return 1; 3315 default: 3316 return 0; 3317 } 3318 } 3319 // responder 3320 3321 static int sm_passkey_used(stk_generation_method_t method){ 3322 switch (method){ 3323 case PK_RESP_INPUT: 3324 return 1; 3325 default: 3326 return 0; 3327 } 3328 } 3329 #endif 3330 3331 /** 3332 * @return ok 3333 */ 3334 static int sm_validate_stk_generation_method(void){ 3335 // check if STK generation method is acceptable by client 3336 switch (setup->sm_stk_generation_method){ 3337 case JUST_WORKS: 3338 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3339 case PK_RESP_INPUT: 3340 case PK_INIT_INPUT: 3341 case OK_BOTH_INPUT: 3342 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3343 case OOB: 3344 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3345 case NK_BOTH_INPUT: 3346 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3347 return 1; 3348 default: 3349 return 0; 3350 } 3351 } 3352 3353 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3354 3355 UNUSED(size); 3356 3357 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3358 sm_run(); 3359 } 3360 3361 if (packet_type != SM_DATA_PACKET) return; 3362 3363 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3364 if (!sm_conn) return; 3365 3366 if (packet[0] == SM_CODE_PAIRING_FAILED){ 3367 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3368 return; 3369 } 3370 3371 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 3372 3373 int err; 3374 UNUSED(err); 3375 3376 if (packet[0] == SM_CODE_KEYPRESS_NOTIFICATION){ 3377 uint8_t buffer[5]; 3378 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3379 buffer[1] = 3; 3380 little_endian_store_16(buffer, 2, con_handle); 3381 buffer[4] = packet[1]; 3382 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3383 return; 3384 } 3385 3386 switch (sm_conn->sm_engine_state){ 3387 3388 // a sm timeout requries a new physical connection 3389 case SM_GENERAL_TIMEOUT: 3390 return; 3391 3392 #ifdef ENABLE_LE_CENTRAL 3393 3394 // Initiator 3395 case SM_INITIATOR_CONNECTED: 3396 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3397 sm_pdu_received_in_wrong_state(sm_conn); 3398 break; 3399 } 3400 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3401 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3402 break; 3403 } 3404 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3405 sm_key_t ltk; 3406 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3407 if (!sm_is_null_key(ltk)){ 3408 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3409 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3410 } else { 3411 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3412 } 3413 break; 3414 } 3415 // otherwise, store security request 3416 sm_conn->sm_security_request_received = 1; 3417 break; 3418 3419 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3420 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3421 sm_pdu_received_in_wrong_state(sm_conn); 3422 break; 3423 } 3424 // store pairing request 3425 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3426 err = sm_stk_generation_init(sm_conn); 3427 if (err){ 3428 setup->sm_pairing_failed_reason = err; 3429 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3430 break; 3431 } 3432 3433 // generate random number first, if we need to show passkey 3434 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3435 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3436 break; 3437 } 3438 3439 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3440 if (setup->sm_use_secure_connections){ 3441 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3442 if (setup->sm_stk_generation_method == JUST_WORKS){ 3443 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3444 sm_trigger_user_response(sm_conn); 3445 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3446 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3447 } 3448 } else { 3449 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3450 } 3451 break; 3452 } 3453 #endif 3454 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3455 sm_trigger_user_response(sm_conn); 3456 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3457 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3458 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3459 } 3460 break; 3461 3462 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3463 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3464 sm_pdu_received_in_wrong_state(sm_conn); 3465 break; 3466 } 3467 3468 // store s_confirm 3469 reverse_128(&packet[1], setup->sm_peer_confirm); 3470 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3471 break; 3472 3473 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3474 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3475 sm_pdu_received_in_wrong_state(sm_conn); 3476 break;; 3477 } 3478 3479 // received random value 3480 reverse_128(&packet[1], setup->sm_peer_random); 3481 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3482 break; 3483 #endif 3484 3485 #ifdef ENABLE_LE_PERIPHERAL 3486 // Responder 3487 case SM_RESPONDER_IDLE: 3488 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3489 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3490 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3491 sm_pdu_received_in_wrong_state(sm_conn); 3492 break;; 3493 } 3494 3495 // store pairing request 3496 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3497 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3498 break; 3499 #endif 3500 3501 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3502 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3503 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3504 sm_pdu_received_in_wrong_state(sm_conn); 3505 break; 3506 } 3507 3508 // store public key for DH Key calculation 3509 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3510 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3511 3512 #ifdef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 3513 // validate public key 3514 err = 0; 3515 #if uECC_SUPPORTS_secp256r1 3516 // standard version 3517 err = uECC_valid_public_key(setup->sm_peer_q, uECC_secp256r1()) == 0; 3518 #else 3519 // static version 3520 err = uECC_valid_public_key(setup->sm_peer_q) == 0; 3521 #endif 3522 if (err){ 3523 log_error("sm: peer public key invalid %x", err); 3524 // uses "unspecified reason", there is no "public key invalid" error code 3525 sm_pdu_received_in_wrong_state(sm_conn); 3526 break; 3527 } 3528 #endif 3529 3530 #ifndef ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS 3531 // start calculating dhkey 3532 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_NEEDED; 3533 #endif 3534 3535 if (IS_RESPONDER(sm_conn->sm_role)){ 3536 // responder 3537 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3538 } else { 3539 // initiator 3540 // stk generation method 3541 // passkey entry: notify app to show passkey or to request passkey 3542 switch (setup->sm_stk_generation_method){ 3543 case JUST_WORKS: 3544 case NK_BOTH_INPUT: 3545 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3546 break; 3547 case PK_RESP_INPUT: 3548 sm_sc_start_calculating_local_confirm(sm_conn); 3549 break; 3550 case PK_INIT_INPUT: 3551 case OK_BOTH_INPUT: 3552 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3553 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3554 break; 3555 } 3556 sm_sc_start_calculating_local_confirm(sm_conn); 3557 break; 3558 case OOB: 3559 // TODO: implement SC OOB 3560 break; 3561 } 3562 } 3563 break; 3564 3565 case SM_SC_W4_CONFIRMATION: 3566 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3567 sm_pdu_received_in_wrong_state(sm_conn); 3568 break; 3569 } 3570 // received confirm value 3571 reverse_128(&packet[1], setup->sm_peer_confirm); 3572 3573 if (IS_RESPONDER(sm_conn->sm_role)){ 3574 // responder 3575 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3576 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3577 // still waiting for passkey 3578 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3579 break; 3580 } 3581 } 3582 sm_sc_start_calculating_local_confirm(sm_conn); 3583 } else { 3584 // initiator 3585 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3586 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3587 } else { 3588 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3589 } 3590 } 3591 break; 3592 3593 case SM_SC_W4_PAIRING_RANDOM: 3594 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3595 sm_pdu_received_in_wrong_state(sm_conn); 3596 break; 3597 } 3598 3599 // received random value 3600 reverse_128(&packet[1], setup->sm_peer_nonce); 3601 3602 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3603 // only check for JUST WORK/NC in initiator role AND passkey entry 3604 if (sm_conn->sm_role || sm_passkey_used(setup->sm_stk_generation_method)) { 3605 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3606 } 3607 3608 sm_sc_state_after_receiving_random(sm_conn); 3609 break; 3610 3611 case SM_SC_W2_CALCULATE_G2: 3612 case SM_SC_W4_CALCULATE_G2: 3613 case SM_SC_W4_CALCULATE_DHKEY: 3614 case SM_SC_W2_CALCULATE_F5_SALT: 3615 case SM_SC_W4_CALCULATE_F5_SALT: 3616 case SM_SC_W2_CALCULATE_F5_MACKEY: 3617 case SM_SC_W4_CALCULATE_F5_MACKEY: 3618 case SM_SC_W2_CALCULATE_F5_LTK: 3619 case SM_SC_W4_CALCULATE_F5_LTK: 3620 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3621 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3622 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3623 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3624 sm_pdu_received_in_wrong_state(sm_conn); 3625 break; 3626 } 3627 // store DHKey Check 3628 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3629 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3630 3631 // have we been only waiting for dhkey check command? 3632 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3633 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3634 } 3635 break; 3636 #endif 3637 3638 #ifdef ENABLE_LE_PERIPHERAL 3639 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3640 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3641 sm_pdu_received_in_wrong_state(sm_conn); 3642 break; 3643 } 3644 3645 // received confirm value 3646 reverse_128(&packet[1], setup->sm_peer_confirm); 3647 3648 // notify client to hide shown passkey 3649 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3650 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3651 } 3652 3653 // handle user cancel pairing? 3654 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3655 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3656 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3657 break; 3658 } 3659 3660 // wait for user action? 3661 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3662 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3663 break; 3664 } 3665 3666 // calculate and send local_confirm 3667 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3668 break; 3669 3670 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3671 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3672 sm_pdu_received_in_wrong_state(sm_conn); 3673 break;; 3674 } 3675 3676 // received random value 3677 reverse_128(&packet[1], setup->sm_peer_random); 3678 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3679 break; 3680 #endif 3681 3682 case SM_PH3_RECEIVE_KEYS: 3683 switch(packet[0]){ 3684 case SM_CODE_ENCRYPTION_INFORMATION: 3685 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3686 reverse_128(&packet[1], setup->sm_peer_ltk); 3687 break; 3688 3689 case SM_CODE_MASTER_IDENTIFICATION: 3690 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3691 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3692 reverse_64(&packet[3], setup->sm_peer_rand); 3693 break; 3694 3695 case SM_CODE_IDENTITY_INFORMATION: 3696 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3697 reverse_128(&packet[1], setup->sm_peer_irk); 3698 break; 3699 3700 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3701 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3702 setup->sm_peer_addr_type = packet[1]; 3703 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3704 break; 3705 3706 case SM_CODE_SIGNING_INFORMATION: 3707 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3708 reverse_128(&packet[1], setup->sm_peer_csrk); 3709 break; 3710 default: 3711 // Unexpected PDU 3712 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3713 break; 3714 } 3715 // done with key distribution? 3716 if (sm_key_distribution_all_received(sm_conn)){ 3717 3718 sm_key_distribution_handle_all_received(sm_conn); 3719 3720 if (IS_RESPONDER(sm_conn->sm_role)){ 3721 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3722 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3723 } else { 3724 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3725 sm_done_for_handle(sm_conn->sm_handle); 3726 } 3727 } else { 3728 if (setup->sm_use_secure_connections){ 3729 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3730 } else { 3731 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3732 } 3733 } 3734 } 3735 break; 3736 default: 3737 // Unexpected PDU 3738 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3739 break; 3740 } 3741 3742 // try to send preparared packet 3743 sm_run(); 3744 } 3745 3746 // Security Manager Client API 3747 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3748 sm_get_oob_data = get_oob_data_callback; 3749 } 3750 3751 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3752 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3753 } 3754 3755 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3756 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3757 } 3758 3759 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3760 sm_min_encryption_key_size = min_size; 3761 sm_max_encryption_key_size = max_size; 3762 } 3763 3764 void sm_set_authentication_requirements(uint8_t auth_req){ 3765 sm_auth_req = auth_req; 3766 } 3767 3768 void sm_set_io_capabilities(io_capability_t io_capability){ 3769 sm_io_capabilities = io_capability; 3770 } 3771 3772 #ifdef ENABLE_LE_PERIPHERAL 3773 void sm_set_request_security(int enable){ 3774 sm_slave_request_security = enable; 3775 } 3776 #endif 3777 3778 void sm_set_er(sm_key_t er){ 3779 memcpy(sm_persistent_er, er, 16); 3780 } 3781 3782 void sm_set_ir(sm_key_t ir){ 3783 memcpy(sm_persistent_ir, ir, 16); 3784 } 3785 3786 // Testing support only 3787 void sm_test_set_irk(sm_key_t irk){ 3788 memcpy(sm_persistent_irk, irk, 16); 3789 sm_persistent_irk_ready = 1; 3790 } 3791 3792 void sm_test_use_fixed_local_csrk(void){ 3793 test_use_fixed_local_csrk = 1; 3794 } 3795 3796 void sm_init(void){ 3797 // set some (BTstack default) ER and IR 3798 int i; 3799 sm_key_t er; 3800 sm_key_t ir; 3801 for (i=0;i<16;i++){ 3802 er[i] = 0x30 + i; 3803 ir[i] = 0x90 + i; 3804 } 3805 sm_set_er(er); 3806 sm_set_ir(ir); 3807 // defaults 3808 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3809 | SM_STK_GENERATION_METHOD_OOB 3810 | SM_STK_GENERATION_METHOD_PASSKEY 3811 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3812 3813 sm_max_encryption_key_size = 16; 3814 sm_min_encryption_key_size = 7; 3815 3816 sm_fixed_legacy_pairing_passkey_in_display_role = 0xffffffff; 3817 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3818 3819 #ifdef ENABLE_CMAC_ENGINE 3820 sm_cmac_state = CMAC_IDLE; 3821 #endif 3822 dkg_state = DKG_W4_WORKING; 3823 rau_state = RAU_W4_WORKING; 3824 sm_aes128_state = SM_AES128_IDLE; 3825 sm_address_resolution_test = -1; // no private address to resolve yet 3826 sm_address_resolution_ah_calculation_active = 0; 3827 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3828 sm_address_resolution_general_queue = NULL; 3829 3830 gap_random_adress_update_period = 15 * 60 * 1000L; 3831 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3832 3833 test_use_fixed_local_csrk = 0; 3834 3835 // register for HCI Events from HCI 3836 hci_event_callback_registration.callback = &sm_event_packet_handler; 3837 hci_add_event_handler(&hci_event_callback_registration); 3838 3839 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3840 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3841 3842 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3843 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3844 #endif 3845 } 3846 3847 void sm_use_fixed_ec_keypair(uint8_t * qx, uint8_t * qy, uint8_t * d){ 3848 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3849 memcpy(&ec_q[0], qx, 32); 3850 memcpy(&ec_q[32], qy, 32); 3851 memcpy(ec_d, d, 32); 3852 sm_have_ec_keypair = 1; 3853 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3854 #else 3855 UNUSED(qx); 3856 UNUSED(qy); 3857 UNUSED(d); 3858 #endif 3859 } 3860 3861 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3862 static void parse_hex(uint8_t * buffer, const char * hex_string){ 3863 while (*hex_string){ 3864 int high_nibble = nibble_for_char(*hex_string++); 3865 int low_nibble = nibble_for_char(*hex_string++); 3866 *buffer++ = (high_nibble << 4) | low_nibble; 3867 } 3868 } 3869 #endif 3870 3871 void sm_test_use_fixed_ec_keypair(void){ 3872 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3873 const char * ec_d_string = "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"; 3874 const char * ec_qx_string = "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"; 3875 const char * ec_qy_string = "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"; 3876 parse_hex(ec_d, ec_d_string); 3877 parse_hex(&ec_q[0], ec_qx_string); 3878 parse_hex(&ec_q[32], ec_qy_string); 3879 sm_have_ec_keypair = 1; 3880 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3881 #endif 3882 } 3883 3884 void sm_use_fixed_legacy_pairing_passkey_in_display_role(uint32_t passkey){ 3885 sm_fixed_legacy_pairing_passkey_in_display_role = passkey; 3886 } 3887 3888 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3889 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3890 } 3891 3892 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3893 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3894 if (!hci_con) return NULL; 3895 return &hci_con->sm_connection; 3896 } 3897 3898 // @returns 0 if not encrypted, 7-16 otherwise 3899 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3900 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3901 if (!sm_conn) return 0; // wrong connection 3902 if (!sm_conn->sm_connection_encrypted) return 0; 3903 return sm_conn->sm_actual_encryption_key_size; 3904 } 3905 3906 int sm_authenticated(hci_con_handle_t con_handle){ 3907 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3908 if (!sm_conn) return 0; // wrong connection 3909 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3910 return sm_conn->sm_connection_authenticated; 3911 } 3912 3913 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3914 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3915 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3916 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3917 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3918 return sm_conn->sm_connection_authorization_state; 3919 } 3920 3921 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3922 switch (sm_conn->sm_engine_state){ 3923 case SM_GENERAL_IDLE: 3924 case SM_RESPONDER_IDLE: 3925 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3926 sm_run(); 3927 break; 3928 default: 3929 break; 3930 } 3931 } 3932 3933 /** 3934 * @brief Trigger Security Request 3935 */ 3936 void sm_send_security_request(hci_con_handle_t con_handle){ 3937 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3938 if (!sm_conn) return; 3939 sm_send_security_request_for_connection(sm_conn); 3940 } 3941 3942 // request pairing 3943 void sm_request_pairing(hci_con_handle_t con_handle){ 3944 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3945 if (!sm_conn) return; // wrong connection 3946 3947 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3948 if (IS_RESPONDER(sm_conn->sm_role)){ 3949 sm_send_security_request_for_connection(sm_conn); 3950 } else { 3951 // used as a trigger to start central/master/initiator security procedures 3952 uint16_t ediv; 3953 sm_key_t ltk; 3954 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3955 switch (sm_conn->sm_irk_lookup_state){ 3956 case IRK_LOOKUP_FAILED: 3957 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3958 break; 3959 case IRK_LOOKUP_SUCCEEDED: 3960 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3961 if (!sm_is_null_key(ltk) || ediv){ 3962 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3963 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3964 } else { 3965 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3966 } 3967 break; 3968 default: 3969 sm_conn->sm_bonding_requested = 1; 3970 break; 3971 } 3972 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3973 sm_conn->sm_bonding_requested = 1; 3974 } 3975 } 3976 sm_run(); 3977 } 3978 3979 // called by client app on authorization request 3980 void sm_authorization_decline(hci_con_handle_t con_handle){ 3981 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3982 if (!sm_conn) return; // wrong connection 3983 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3984 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3985 } 3986 3987 void sm_authorization_grant(hci_con_handle_t con_handle){ 3988 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3989 if (!sm_conn) return; // wrong connection 3990 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3991 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3992 } 3993 3994 // GAP Bonding API 3995 3996 void sm_bonding_decline(hci_con_handle_t con_handle){ 3997 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3998 if (!sm_conn) return; // wrong connection 3999 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 4000 4001 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4002 switch (setup->sm_stk_generation_method){ 4003 case PK_RESP_INPUT: 4004 case PK_INIT_INPUT: 4005 case OK_BOTH_INPUT: 4006 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 4007 break; 4008 case NK_BOTH_INPUT: 4009 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 4010 break; 4011 case JUST_WORKS: 4012 case OOB: 4013 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 4014 break; 4015 } 4016 } 4017 sm_run(); 4018 } 4019 4020 void sm_just_works_confirm(hci_con_handle_t con_handle){ 4021 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4022 if (!sm_conn) return; // wrong connection 4023 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 4024 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4025 if (setup->sm_use_secure_connections){ 4026 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 4027 } else { 4028 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4029 } 4030 } 4031 4032 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4033 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4034 sm_sc_prepare_dhkey_check(sm_conn); 4035 } 4036 #endif 4037 4038 sm_run(); 4039 } 4040 4041 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 4042 // for now, it's the same 4043 sm_just_works_confirm(con_handle); 4044 } 4045 4046 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 4047 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4048 if (!sm_conn) return; // wrong connection 4049 sm_reset_tk(); 4050 big_endian_store_32(setup->sm_tk, 12, passkey); 4051 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 4052 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 4053 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 4054 } 4055 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4056 memcpy(setup->sm_ra, setup->sm_tk, 16); 4057 memcpy(setup->sm_rb, setup->sm_tk, 16); 4058 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 4059 sm_sc_start_calculating_local_confirm(sm_conn); 4060 } 4061 #endif 4062 sm_run(); 4063 } 4064 4065 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 4066 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4067 if (!sm_conn) return; // wrong connection 4068 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 4069 setup->sm_keypress_notification = action; 4070 sm_run(); 4071 } 4072 4073 /** 4074 * @brief Identify device in LE Device DB 4075 * @param handle 4076 * @returns index from le_device_db or -1 if not found/identified 4077 */ 4078 int sm_le_device_index(hci_con_handle_t con_handle ){ 4079 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4080 if (!sm_conn) return -1; 4081 return sm_conn->sm_le_db_index; 4082 } 4083 4084 static int gap_random_address_type_requires_updates(void){ 4085 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4086 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 4087 return 1; 4088 } 4089 4090 static uint8_t own_address_type(void){ 4091 switch (gap_random_adress_type){ 4092 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4093 return BD_ADDR_TYPE_LE_PUBLIC; 4094 default: 4095 return BD_ADDR_TYPE_LE_RANDOM; 4096 } 4097 } 4098 4099 // GAP LE API 4100 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4101 gap_random_address_update_stop(); 4102 gap_random_adress_type = random_address_type; 4103 hci_le_set_own_address_type(own_address_type()); 4104 if (!gap_random_address_type_requires_updates()) return; 4105 gap_random_address_update_start(); 4106 gap_random_address_trigger(); 4107 } 4108 4109 gap_random_address_type_t gap_random_address_get_mode(void){ 4110 return gap_random_adress_type; 4111 } 4112 4113 void gap_random_address_set_update_period(int period_ms){ 4114 gap_random_adress_update_period = period_ms; 4115 if (!gap_random_address_type_requires_updates()) return; 4116 gap_random_address_update_stop(); 4117 gap_random_address_update_start(); 4118 } 4119 4120 void gap_random_address_set(bd_addr_t addr){ 4121 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4122 memcpy(sm_random_address, addr, 6); 4123 if (rau_state == RAU_W4_WORKING) return; 4124 rau_state = RAU_SET_ADDRESS; 4125 sm_run(); 4126 } 4127 4128 #ifdef ENABLE_LE_PERIPHERAL 4129 /* 4130 * @brief Set Advertisement Paramters 4131 * @param adv_int_min 4132 * @param adv_int_max 4133 * @param adv_type 4134 * @param direct_address_type 4135 * @param direct_address 4136 * @param channel_map 4137 * @param filter_policy 4138 * 4139 * @note own_address_type is used from gap_random_address_set_mode 4140 */ 4141 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4142 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4143 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4144 direct_address_typ, direct_address, channel_map, filter_policy); 4145 } 4146 #endif 4147 4148