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_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "gap.h" 54 #include "hci.h" 55 #include "hci_dump.h" 56 #include "l2cap.h" 57 58 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 59 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 60 #endif 61 62 // assert SM Public Key can be sent/received 63 #ifdef ENABLE_LE_SECURE_CONNECTIONS 64 #if HCI_ACL_PAYLOAD_SIZE < 69 65 #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" 66 #endif 67 #endif 68 69 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 70 #define IS_RESPONDER(role) (role) 71 #else 72 #ifdef ENABLE_LE_CENTRAL 73 // only central - never responder (avoid 'unused variable' warnings) 74 #define IS_RESPONDER(role) (0 && role) 75 #else 76 // only peripheral - always responder (avoid 'unused variable' warnings) 77 #define IS_RESPONDER(role) (1 || role) 78 #endif 79 #endif 80 81 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 82 #define USE_CMAC_ENGINE 83 #endif 84 85 // 86 // SM internal types and globals 87 // 88 89 typedef enum { 90 DKG_W4_WORKING, 91 DKG_CALC_IRK, 92 DKG_CALC_DHK, 93 DKG_READY 94 } derived_key_generation_t; 95 96 typedef enum { 97 RAU_W4_WORKING, 98 RAU_IDLE, 99 RAU_W4_RANDOM, 100 RAU_GET_ENC, 101 RAU_W4_ENC, 102 RAU_SET_ADDRESS, 103 } random_address_update_t; 104 105 typedef enum { 106 CMAC_IDLE, 107 CMAC_CALC_SUBKEYS, 108 CMAC_W4_SUBKEYS, 109 CMAC_CALC_MI, 110 CMAC_W4_MI, 111 CMAC_CALC_MLAST, 112 CMAC_W4_MLAST 113 } cmac_state_t; 114 115 typedef enum { 116 JUST_WORKS, 117 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 118 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 119 PK_BOTH_INPUT, // Only input on both, both input PK 120 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 121 OOB // OOB available on one (SC) or both sides (legacy) 122 } stk_generation_method_t; 123 124 typedef enum { 125 SM_USER_RESPONSE_IDLE, 126 SM_USER_RESPONSE_PENDING, 127 SM_USER_RESPONSE_CONFIRM, 128 SM_USER_RESPONSE_PASSKEY, 129 SM_USER_RESPONSE_DECLINE 130 } sm_user_response_t; 131 132 typedef enum { 133 SM_AES128_IDLE, 134 SM_AES128_ACTIVE 135 } sm_aes128_state_t; 136 137 typedef enum { 138 ADDRESS_RESOLUTION_IDLE, 139 ADDRESS_RESOLUTION_GENERAL, 140 ADDRESS_RESOLUTION_FOR_CONNECTION, 141 } address_resolution_mode_t; 142 143 typedef enum { 144 ADDRESS_RESOLUTION_SUCEEDED, 145 ADDRESS_RESOLUTION_FAILED, 146 } address_resolution_event_t; 147 148 typedef enum { 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static uint8_t sm_persistent_irk_ready = 0; // used for testing 204 static derived_key_generation_t dkg_state; 205 206 // derived from sm_persistent_er 207 // .. 208 209 // random address update 210 static random_address_update_t rau_state; 211 static bd_addr_t sm_random_address; 212 213 #ifdef USE_CMAC_ENGINE 214 // CMAC Calculation: General 215 static btstack_crypto_aes128_cmac_t sm_cmac_request; 216 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 217 static uint8_t sm_cmac_active; 218 static uint8_t sm_cmac_hash[16]; 219 #endif 220 221 // CMAC for ATT Signed Writes 222 #ifdef ENABLE_LE_SIGNED_WRITE 223 static uint16_t sm_cmac_signed_write_message_len; 224 static uint8_t sm_cmac_signed_write_header[3]; 225 static const uint8_t * sm_cmac_signed_write_message; 226 static uint8_t sm_cmac_signed_write_sign_counter[4]; 227 #endif 228 229 // CMAC for Secure Connection functions 230 #ifdef ENABLE_LE_SECURE_CONNECTIONS 231 static sm_connection_t * sm_cmac_connection; 232 static uint8_t sm_cmac_sc_buffer[80]; 233 #endif 234 235 // resolvable private address lookup / CSRK calculation 236 static int sm_address_resolution_test; 237 static int sm_address_resolution_ah_calculation_active; 238 static uint8_t sm_address_resolution_addr_type; 239 static bd_addr_t sm_address_resolution_address; 240 static void * sm_address_resolution_context; 241 static address_resolution_mode_t sm_address_resolution_mode; 242 static btstack_linked_list_t sm_address_resolution_general_queue; 243 244 // aes128 crypto engine. 245 static sm_aes128_state_t sm_aes128_state; 246 247 // crypto 248 static btstack_crypto_random_t sm_crypto_random_request; 249 static btstack_crypto_aes128_t sm_crypto_aes128_request; 250 #ifdef ENABLE_LE_SECURE_CONNECTIONS 251 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 252 static btstack_crypto_random_t sm_crypto_random_oob_request; 253 #endif 254 255 // temp storage for random data 256 static uint8_t sm_random_data[8]; 257 static uint8_t sm_aes128_key[16]; 258 static uint8_t sm_aes128_plaintext[16]; 259 static uint8_t sm_aes128_ciphertext[16]; 260 261 // to receive hci events 262 static btstack_packet_callback_registration_t hci_event_callback_registration; 263 264 /* to dispatch sm event */ 265 static btstack_linked_list_t sm_event_handlers; 266 267 // LE Secure Connections 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static ec_key_generation_state_t ec_key_generation_state; 270 static uint8_t ec_q[64]; 271 #endif 272 273 // 274 // Volume 3, Part H, Chapter 24 275 // "Security shall be initiated by the Security Manager in the device in the master role. 276 // The device in the slave role shall be the responding device." 277 // -> master := initiator, slave := responder 278 // 279 280 // data needed for security setup 281 typedef struct sm_setup_context { 282 283 btstack_timer_source_t sm_timeout; 284 285 // used in all phases 286 uint8_t sm_pairing_failed_reason; 287 288 // user response, (Phase 1 and/or 2) 289 uint8_t sm_user_response; 290 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 291 292 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 293 int sm_key_distribution_send_set; 294 int sm_key_distribution_received_set; 295 296 // Phase 2 (Pairing over SMP) 297 stk_generation_method_t sm_stk_generation_method; 298 sm_key_t sm_tk; 299 uint8_t sm_have_oob_data; 300 uint8_t sm_use_secure_connections; 301 302 sm_key_t sm_c1_t3_value; // c1 calculation 303 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 304 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 305 sm_key_t sm_local_random; 306 sm_key_t sm_local_confirm; 307 sm_key_t sm_peer_random; 308 sm_key_t sm_peer_confirm; 309 uint8_t sm_m_addr_type; // address and type can be removed 310 uint8_t sm_s_addr_type; // '' 311 bd_addr_t sm_m_address; // '' 312 bd_addr_t sm_s_address; // '' 313 sm_key_t sm_ltk; 314 315 uint8_t sm_state_vars; 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 318 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 319 sm_key_t sm_local_nonce; // might be combined with sm_local_random 320 sm_key_t sm_dhkey; 321 sm_key_t sm_peer_dhkey_check; 322 sm_key_t sm_local_dhkey_check; 323 sm_key_t sm_ra; 324 sm_key_t sm_rb; 325 sm_key_t sm_t; // used for f5 and h6 326 sm_key_t sm_mackey; 327 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 328 #endif 329 330 // Phase 3 331 332 // key distribution, we generate 333 uint16_t sm_local_y; 334 uint16_t sm_local_div; 335 uint16_t sm_local_ediv; 336 uint8_t sm_local_rand[8]; 337 sm_key_t sm_local_ltk; 338 sm_key_t sm_local_csrk; 339 sm_key_t sm_local_irk; 340 // sm_local_address/addr_type not needed 341 342 // key distribution, received from peer 343 uint16_t sm_peer_y; 344 uint16_t sm_peer_div; 345 uint16_t sm_peer_ediv; 346 uint8_t sm_peer_rand[8]; 347 sm_key_t sm_peer_ltk; 348 sm_key_t sm_peer_irk; 349 sm_key_t sm_peer_csrk; 350 uint8_t sm_peer_addr_type; 351 bd_addr_t sm_peer_address; 352 353 } sm_setup_context_t; 354 355 // 356 static sm_setup_context_t the_setup; 357 static sm_setup_context_t * setup = &the_setup; 358 359 // active connection - the one for which the_setup is used for 360 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 361 362 // @returns 1 if oob data is available 363 // stores oob data in provided 16 byte buffer if not null 364 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 365 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 366 367 // horizontal: initiator capabilities 368 // vertial: responder capabilities 369 static const stk_generation_method_t stk_generation_method [5] [5] = { 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 373 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 374 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 375 }; 376 377 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 378 #ifdef ENABLE_LE_SECURE_CONNECTIONS 379 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 380 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 381 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 382 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 383 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 384 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 385 }; 386 #endif 387 388 static void sm_run(void); 389 #ifdef USE_CMAC_ENGINE 390 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 391 #endif 392 static void sm_done_for_handle(hci_con_handle_t con_handle); 393 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 394 static inline int sm_calc_actual_encryption_key_size(int other); 395 static int sm_validate_stk_generation_method(void); 396 static void sm_handle_encryption_result_address_resolution(void *arg); 397 static void sm_handle_encryption_result_dkg_dhk(void *arg); 398 static void sm_handle_encryption_result_dkg_irk(void *arg); 399 static void sm_handle_encryption_result_enc_a(void *arg); 400 static void sm_handle_encryption_result_enc_b(void *arg); 401 static void sm_handle_encryption_result_enc_c(void *arg); 402 static void sm_handle_encryption_result_enc_csrk(void *arg); 403 static void sm_handle_encryption_result_enc_d(void * arg); 404 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 405 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 406 #ifdef ENABLE_LE_PERIPHERAL 407 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 408 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 409 #endif 410 static void sm_handle_encryption_result_enc_stk(void *arg); 411 static void sm_handle_encryption_result_rau(void *arg); 412 static void sm_handle_random_result_ph2_tk(void * arg); 413 static void sm_handle_random_result_rau(void * arg); 414 #ifdef ENABLE_LE_SECURE_CONNECTIONS 415 static void sm_handle_random_result_sc_get_random(void * arg); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 #endif 418 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 419 420 static void log_info_hex16(const char * name, uint16_t value){ 421 log_info("%-6s 0x%04x", name, value); 422 } 423 424 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 425 // return packet[0]; 426 // } 427 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 428 return packet[1]; 429 } 430 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 431 return packet[2]; 432 } 433 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 434 return packet[3]; 435 } 436 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 437 return packet[4]; 438 } 439 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 440 return packet[5]; 441 } 442 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 443 return packet[6]; 444 } 445 446 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 447 packet[0] = code; 448 } 449 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 450 packet[1] = io_capability; 451 } 452 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 453 packet[2] = oob_data_flag; 454 } 455 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 456 packet[3] = auth_req; 457 } 458 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 459 packet[4] = max_encryption_key_size; 460 } 461 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 462 packet[5] = initiator_key_distribution; 463 } 464 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 465 packet[6] = responder_key_distribution; 466 } 467 468 // @returns 1 if all bytes are 0 469 static int sm_is_null(uint8_t * data, int size){ 470 int i; 471 for (i=0; i < size ; i++){ 472 if (data[i]) return 0; 473 } 474 return 1; 475 } 476 477 static int sm_is_null_random(uint8_t random[8]){ 478 return sm_is_null(random, 8); 479 } 480 481 static int sm_is_null_key(uint8_t * key){ 482 return sm_is_null(key, 16); 483 } 484 485 // Key utils 486 static void sm_reset_tk(void){ 487 int i; 488 for (i=0;i<16;i++){ 489 setup->sm_tk[i] = 0; 490 } 491 } 492 493 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 494 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 495 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 496 int i; 497 for (i = max_encryption_size ; i < 16 ; i++){ 498 key[15-i] = 0; 499 } 500 } 501 502 // SMP Timeout implementation 503 504 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 505 // the Security Manager Timer shall be reset and started. 506 // 507 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 508 // 509 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 510 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 511 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 512 // established. 513 514 static void sm_timeout_handler(btstack_timer_source_t * timer){ 515 log_info("SM timeout"); 516 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 517 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 518 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 519 sm_done_for_handle(sm_conn->sm_handle); 520 521 // trigger handling of next ready connection 522 sm_run(); 523 } 524 static void sm_timeout_start(sm_connection_t * sm_conn){ 525 btstack_run_loop_remove_timer(&setup->sm_timeout); 526 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 527 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 528 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 529 btstack_run_loop_add_timer(&setup->sm_timeout); 530 } 531 static void sm_timeout_stop(void){ 532 btstack_run_loop_remove_timer(&setup->sm_timeout); 533 } 534 static void sm_timeout_reset(sm_connection_t * sm_conn){ 535 sm_timeout_stop(); 536 sm_timeout_start(sm_conn); 537 } 538 539 // end of sm timeout 540 541 // GAP Random Address updates 542 static gap_random_address_type_t gap_random_adress_type; 543 static btstack_timer_source_t gap_random_address_update_timer; 544 static uint32_t gap_random_adress_update_period; 545 546 static void gap_random_address_trigger(void){ 547 log_info("gap_random_address_trigger"); 548 if (rau_state != RAU_IDLE) return; 549 rau_state = RAU_W4_RANDOM; 550 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 551 } 552 553 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 554 UNUSED(timer); 555 556 log_info("GAP Random Address Update due"); 557 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 558 btstack_run_loop_add_timer(&gap_random_address_update_timer); 559 gap_random_address_trigger(); 560 } 561 562 static void gap_random_address_update_start(void){ 563 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 564 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 565 btstack_run_loop_add_timer(&gap_random_address_update_timer); 566 } 567 568 static void gap_random_address_update_stop(void){ 569 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 570 } 571 572 // ah(k,r) helper 573 // r = padding || r 574 // r - 24 bit value 575 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 576 // r'= padding || r 577 memset(r_prime, 0, 16); 578 memcpy(&r_prime[13], r, 3); 579 } 580 581 // d1 helper 582 // d' = padding || r || d 583 // d,r - 16 bit values 584 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 585 // d'= padding || r || d 586 memset(d1_prime, 0, 16); 587 big_endian_store_16(d1_prime, 12, r); 588 big_endian_store_16(d1_prime, 14, d); 589 } 590 591 // dm helper 592 // r’ = padding || r 593 // r - 64 bit value 594 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 595 memset(r_prime, 0, 16); 596 memcpy(&r_prime[8], r, 8); 597 } 598 599 // calculate arguments for first AES128 operation in C1 function 600 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){ 601 602 // p1 = pres || preq || rat’ || iat’ 603 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 604 // cant octet of pres becomes the most significant octet of p1. 605 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 606 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 607 // p1 is 0x05000800000302070710000001010001." 608 609 sm_key_t p1; 610 reverse_56(pres, &p1[0]); 611 reverse_56(preq, &p1[7]); 612 p1[14] = rat; 613 p1[15] = iat; 614 log_info_key("p1", p1); 615 log_info_key("r", r); 616 617 // t1 = r xor p1 618 int i; 619 for (i=0;i<16;i++){ 620 t1[i] = r[i] ^ p1[i]; 621 } 622 log_info_key("t1", t1); 623 } 624 625 // calculate arguments for second AES128 operation in C1 function 626 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 627 // p2 = padding || ia || ra 628 // "The least significant octet of ra becomes the least significant octet of p2 and 629 // the most significant octet of padding becomes the most significant octet of p2. 630 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 631 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 632 633 sm_key_t p2; 634 memset(p2, 0, 16); 635 memcpy(&p2[4], ia, 6); 636 memcpy(&p2[10], ra, 6); 637 log_info_key("p2", p2); 638 639 // c1 = e(k, t2_xor_p2) 640 int i; 641 for (i=0;i<16;i++){ 642 t3[i] = t2[i] ^ p2[i]; 643 } 644 log_info_key("t3", t3); 645 } 646 647 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 648 log_info_key("r1", r1); 649 log_info_key("r2", r2); 650 memcpy(&r_prime[8], &r2[8], 8); 651 memcpy(&r_prime[0], &r1[8], 8); 652 } 653 654 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 655 UNUSED(channel); 656 657 // log event 658 hci_dump_packet(packet_type, 1, packet, size); 659 // dispatch to all event handlers 660 btstack_linked_list_iterator_t it; 661 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 662 while (btstack_linked_list_iterator_has_next(&it)){ 663 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 664 entry->callback(packet_type, 0, packet, size); 665 } 666 } 667 668 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){ 669 event[0] = type; 670 event[1] = event_size - 2; 671 little_endian_store_16(event, 2, con_handle); 672 event[4] = addr_type; 673 reverse_bd_addr(address, &event[5]); 674 } 675 676 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 677 uint8_t event[11]; 678 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 679 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 680 } 681 682 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){ 683 uint8_t event[15]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 little_endian_store_32(event, 11, passkey); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 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){ 690 // fetch addr and addr type from db 691 bd_addr_t identity_address; 692 int identity_address_type; 693 le_device_db_info(index, &identity_address_type, identity_address, NULL); 694 695 uint8_t event[19]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 event[11] = identity_address_type; 698 reverse_bd_addr(identity_address, &event[12]); 699 event[18] = index; 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 704 uint8_t event[12]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = status; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 711 uint8_t event[13]; 712 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 713 event[11] = status; 714 event[12] = reason; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 735 736 737 // decide if OOB will be used based on SC vs. Legacy and oob flags 738 int use_oob = 0; 739 if (setup->sm_use_secure_connections){ 740 // In LE Secure Connections pairing, the out of band method is used if at least 741 // one device has the peer device's out of band authentication data available. 742 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 743 } else { 744 // In LE legacy pairing, the out of band method is used if both the devices have 745 // the other device's out of band authentication data available. 746 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 747 } 748 if (use_oob){ 749 log_info("SM: have OOB data"); 750 log_info_key("OOB", setup->sm_tk); 751 setup->sm_stk_generation_method = OOB; 752 return; 753 } 754 755 // If both devices have not set the MITM option in the Authentication Requirements 756 // Flags, then the IO capabilities shall be ignored and the Just Works association 757 // model shall be used. 758 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 759 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 760 log_info("SM: MITM not required by both -> JUST WORKS"); 761 return; 762 } 763 764 // Reset TK as it has been setup in sm_init_setup 765 sm_reset_tk(); 766 767 // Also use just works if unknown io capabilites 768 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)){ 769 return; 770 } 771 772 // Otherwise the IO capabilities of the devices shall be used to determine the 773 // pairing method as defined in Table 2.4. 774 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 775 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 776 777 #ifdef ENABLE_LE_SECURE_CONNECTIONS 778 // table not define by default 779 if (setup->sm_use_secure_connections){ 780 generation_method = stk_generation_method_with_secure_connection; 781 } 782 #endif 783 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)]; 784 785 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 786 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); 787 } 788 789 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 790 int flags = 0; 791 if (key_set & SM_KEYDIST_ENC_KEY){ 792 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 794 } 795 if (key_set & SM_KEYDIST_ID_KEY){ 796 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 797 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 798 } 799 if (key_set & SM_KEYDIST_SIGN){ 800 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 801 } 802 return flags; 803 } 804 805 static void sm_setup_key_distribution(uint8_t key_set){ 806 setup->sm_key_distribution_received_set = 0; 807 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 808 } 809 810 // CSRK Key Lookup 811 812 813 static int sm_address_resolution_idle(void){ 814 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 815 } 816 817 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){ 818 memcpy(sm_address_resolution_address, addr, 6); 819 sm_address_resolution_addr_type = addr_type; 820 sm_address_resolution_test = 0; 821 sm_address_resolution_mode = mode; 822 sm_address_resolution_context = context; 823 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 824 } 825 826 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 827 // check if already in list 828 btstack_linked_list_iterator_t it; 829 sm_lookup_entry_t * entry; 830 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 831 while(btstack_linked_list_iterator_has_next(&it)){ 832 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 833 if (entry->address_type != address_type) continue; 834 if (memcmp(entry->address, address, 6)) continue; 835 // already in list 836 return BTSTACK_BUSY; 837 } 838 entry = btstack_memory_sm_lookup_entry_get(); 839 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 840 entry->address_type = (bd_addr_type_t) address_type; 841 memcpy(entry->address, address, 6); 842 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 843 sm_run(); 844 return 0; 845 } 846 847 // CMAC calculation using AES Engineq 848 #ifdef USE_CMAC_ENGINE 849 850 static void sm_cmac_done_trampoline(void * arg){ 851 UNUSED(arg); 852 sm_cmac_active = 0; 853 (*sm_cmac_done_callback)(sm_cmac_hash); 854 sm_run(); 855 } 856 857 int sm_cmac_ready(void){ 858 return sm_cmac_active == 0; 859 } 860 861 // generic cmac calculation 862 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 863 sm_cmac_active = 1; 864 sm_cmac_done_callback = done_callback; 865 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 866 } 867 #endif 868 869 // cmac for ATT Message signing 870 #ifdef ENABLE_LE_SIGNED_WRITE 871 872 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 873 sm_cmac_active = 1; 874 sm_cmac_done_callback = done_callback; 875 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 876 } 877 878 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_signed_write_message_len) { 880 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_signed_write_message_len - 1 - offset; 885 886 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_signed_write_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_signed_write_message[offset - 3]; 893 } 894 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 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)){ 898 // ATT Message Signing 899 sm_cmac_signed_write_header[0] = opcode; 900 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 901 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 902 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 903 sm_cmac_signed_write_message = message; 904 sm_cmac_signed_write_message_len = total_message_len; 905 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 906 } 907 #endif 908 909 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 910 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 911 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 912 switch (setup->sm_stk_generation_method){ 913 case PK_RESP_INPUT: 914 if (IS_RESPONDER(sm_conn->sm_role)){ 915 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 916 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 917 } else { 918 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)); 919 } 920 break; 921 case PK_INIT_INPUT: 922 if (IS_RESPONDER(sm_conn->sm_role)){ 923 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)); 924 } else { 925 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 926 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 927 } 928 break; 929 case PK_BOTH_INPUT: 930 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 931 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 932 break; 933 case NUMERIC_COMPARISON: 934 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 935 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)); 936 break; 937 case JUST_WORKS: 938 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 939 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 940 break; 941 case OOB: 942 // client already provided OOB data, let's skip notification. 943 break; 944 } 945 } 946 947 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 948 int recv_flags; 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 // slave / responder 951 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 952 } else { 953 // master / initiator 954 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 955 } 956 957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 958 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 959 if (setup->sm_use_secure_connections){ 960 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 961 } 962 #endif 963 964 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 965 return recv_flags == setup->sm_key_distribution_received_set; 966 } 967 968 static void sm_done_for_handle(hci_con_handle_t con_handle){ 969 if (sm_active_connection_handle == con_handle){ 970 sm_timeout_stop(); 971 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 972 log_info("sm: connection 0x%x released setup context", con_handle); 973 } 974 } 975 976 static int sm_key_distribution_flags_for_auth_req(void){ 977 978 int flags = SM_KEYDIST_ID_KEY; 979 if (sm_auth_req & SM_AUTHREQ_BONDING){ 980 // encryption and signing information only if bonding requested 981 flags |= SM_KEYDIST_ENC_KEY; 982 #ifdef ENABLE_LE_SIGNED_WRITE 983 flags |= SM_KEYDIST_SIGN; 984 #endif 985 } 986 return flags; 987 } 988 989 static void sm_reset_setup(void){ 990 // fill in sm setup 991 setup->sm_state_vars = 0; 992 setup->sm_keypress_notification = 0; 993 sm_reset_tk(); 994 } 995 996 static void sm_init_setup(sm_connection_t * sm_conn){ 997 998 // fill in sm setup 999 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1000 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1001 1002 // query client for Legacy Pairing OOB data 1003 setup->sm_have_oob_data = 0; 1004 if (sm_get_oob_data) { 1005 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1006 } 1007 1008 // if available and SC supported, also ask for SC OOB Data 1009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1010 memset(setup->sm_ra, 0, 16); 1011 memset(setup->sm_rb, 0, 16); 1012 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1013 if (sm_get_sc_oob_data){ 1014 if (IS_RESPONDER(sm_conn->sm_role)){ 1015 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1016 sm_conn->sm_peer_addr_type, 1017 sm_conn->sm_peer_address, 1018 setup->sm_peer_confirm, 1019 setup->sm_ra); 1020 } else { 1021 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1022 sm_conn->sm_peer_addr_type, 1023 sm_conn->sm_peer_address, 1024 setup->sm_peer_confirm, 1025 setup->sm_rb); 1026 } 1027 } else { 1028 setup->sm_have_oob_data = 0; 1029 } 1030 } 1031 #endif 1032 1033 sm_pairing_packet_t * local_packet; 1034 if (IS_RESPONDER(sm_conn->sm_role)){ 1035 // slave 1036 local_packet = &setup->sm_s_pres; 1037 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1038 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1039 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1040 } else { 1041 // master 1042 local_packet = &setup->sm_m_preq; 1043 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1044 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1045 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1046 1047 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1048 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1049 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1050 } 1051 1052 uint8_t auth_req = sm_auth_req; 1053 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1054 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1055 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1056 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1057 } 1058 1059 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1060 1061 sm_pairing_packet_t * remote_packet; 1062 int remote_key_request; 1063 if (IS_RESPONDER(sm_conn->sm_role)){ 1064 // slave / responder 1065 remote_packet = &setup->sm_m_preq; 1066 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1067 } else { 1068 // master / initiator 1069 remote_packet = &setup->sm_s_pres; 1070 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1071 } 1072 1073 // check key size 1074 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1075 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1076 1077 // decide on STK generation method / SC 1078 sm_setup_tk(); 1079 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1080 1081 // check if STK generation method is acceptable by client 1082 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1083 1084 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1085 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1086 if (setup->sm_use_secure_connections){ 1087 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1088 } 1089 #endif 1090 1091 // identical to responder 1092 sm_setup_key_distribution(remote_key_request); 1093 1094 // JUST WORKS doens't provide authentication 1095 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1096 1097 return 0; 1098 } 1099 1100 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1101 1102 // cache and reset context 1103 int matched_device_id = sm_address_resolution_test; 1104 address_resolution_mode_t mode = sm_address_resolution_mode; 1105 void * context = sm_address_resolution_context; 1106 1107 // reset context 1108 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1109 sm_address_resolution_context = NULL; 1110 sm_address_resolution_test = -1; 1111 hci_con_handle_t con_handle = 0; 1112 1113 sm_connection_t * sm_connection; 1114 #ifdef ENABLE_LE_CENTRAL 1115 sm_key_t ltk; 1116 #endif 1117 switch (mode){ 1118 case ADDRESS_RESOLUTION_GENERAL: 1119 break; 1120 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1121 sm_connection = (sm_connection_t *) context; 1122 con_handle = sm_connection->sm_handle; 1123 switch (event){ 1124 case ADDRESS_RESOLUTION_SUCEEDED: 1125 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1126 sm_connection->sm_le_db_index = matched_device_id; 1127 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1128 if (sm_connection->sm_role) { 1129 // LTK request received before, IRK required -> start LTK calculation 1130 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1131 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1132 } 1133 break; 1134 } 1135 #ifdef ENABLE_LE_CENTRAL 1136 log_info("central: bonding requested %u, prev security request %u", sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received); 1137 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1138 sm_connection->sm_security_request_received = 0; 1139 sm_connection->sm_pairing_requested = 0; 1140 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1141 if (!sm_is_null_key(ltk)){ 1142 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1143 } else { 1144 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1145 } 1146 #endif 1147 break; 1148 case ADDRESS_RESOLUTION_FAILED: 1149 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1150 if (sm_connection->sm_role) { 1151 // LTK request received before, IRK required -> negative LTK reply 1152 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1153 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1154 } 1155 break; 1156 } 1157 #ifdef ENABLE_LE_CENTRAL 1158 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1159 sm_connection->sm_security_request_received = 0; 1160 sm_connection->sm_pairing_requested = 0; 1161 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1162 #endif 1163 break; 1164 } 1165 break; 1166 default: 1167 break; 1168 } 1169 1170 switch (event){ 1171 case ADDRESS_RESOLUTION_SUCEEDED: 1172 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1173 break; 1174 case ADDRESS_RESOLUTION_FAILED: 1175 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1176 break; 1177 } 1178 } 1179 1180 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1181 1182 int le_db_index = -1; 1183 1184 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1185 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1186 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1187 & SM_AUTHREQ_BONDING ) != 0; 1188 1189 if (bonding_enabed){ 1190 1191 // lookup device based on IRK 1192 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1193 int i; 1194 for (i=0; i < le_device_db_max_count(); i++){ 1195 sm_key_t irk; 1196 bd_addr_t address; 1197 int address_type; 1198 le_device_db_info(i, &address_type, address, irk); 1199 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1200 log_info("sm: device found for IRK, updating"); 1201 le_db_index = i; 1202 break; 1203 } 1204 } 1205 } 1206 1207 // if not found, lookup via public address if possible 1208 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1209 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1210 int i; 1211 for (i=0; i < le_device_db_max_count(); i++){ 1212 bd_addr_t address; 1213 int address_type; 1214 le_device_db_info(i, &address_type, address, NULL); 1215 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1216 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1217 log_info("sm: device found for public address, updating"); 1218 le_db_index = i; 1219 break; 1220 } 1221 } 1222 } 1223 1224 // if not found, add to db 1225 if (le_db_index < 0) { 1226 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1227 } 1228 1229 if (le_db_index >= 0){ 1230 1231 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1232 1233 #ifdef ENABLE_LE_SIGNED_WRITE 1234 // store local CSRK 1235 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1236 log_info("sm: store local CSRK"); 1237 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1238 le_device_db_local_counter_set(le_db_index, 0); 1239 } 1240 1241 // store remote CSRK 1242 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1243 log_info("sm: store remote CSRK"); 1244 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1245 le_device_db_remote_counter_set(le_db_index, 0); 1246 } 1247 #endif 1248 // store encryption information for secure connections: LTK generated by ECDH 1249 if (setup->sm_use_secure_connections){ 1250 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1251 uint8_t zero_rand[8]; 1252 memset(zero_rand, 0, 8); 1253 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1254 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1255 } 1256 1257 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1258 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1259 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1260 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1261 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1262 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1263 1264 } 1265 } 1266 } else { 1267 log_info("Ignoring received keys, bonding not enabled"); 1268 } 1269 1270 // keep le_db_index 1271 sm_conn->sm_le_db_index = le_db_index; 1272 } 1273 1274 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1275 setup->sm_pairing_failed_reason = reason; 1276 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1277 } 1278 1279 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1280 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1281 } 1282 1283 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1284 1285 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1286 static int sm_passkey_used(stk_generation_method_t method); 1287 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1288 1289 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1290 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1291 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1292 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1293 } else { 1294 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1295 } 1296 } 1297 1298 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1299 if (IS_RESPONDER(sm_conn->sm_role)){ 1300 // Responder 1301 if (setup->sm_stk_generation_method == OOB){ 1302 // generate Nb 1303 log_info("Generate Nb"); 1304 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1305 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1306 } else { 1307 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1308 } 1309 } else { 1310 // Initiator role 1311 switch (setup->sm_stk_generation_method){ 1312 case JUST_WORKS: 1313 sm_sc_prepare_dhkey_check(sm_conn); 1314 break; 1315 1316 case NUMERIC_COMPARISON: 1317 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1318 break; 1319 case PK_INIT_INPUT: 1320 case PK_RESP_INPUT: 1321 case PK_BOTH_INPUT: 1322 if (setup->sm_passkey_bit < 20) { 1323 sm_sc_start_calculating_local_confirm(sm_conn); 1324 } else { 1325 sm_sc_prepare_dhkey_check(sm_conn); 1326 } 1327 break; 1328 case OOB: 1329 sm_sc_prepare_dhkey_check(sm_conn); 1330 break; 1331 } 1332 } 1333 } 1334 1335 static void sm_sc_cmac_done(uint8_t * hash){ 1336 log_info("sm_sc_cmac_done: "); 1337 log_info_hexdump(hash, 16); 1338 1339 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1340 sm_sc_oob_state = SM_SC_OOB_IDLE; 1341 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1342 return; 1343 } 1344 1345 sm_connection_t * sm_conn = sm_cmac_connection; 1346 sm_cmac_connection = NULL; 1347 #ifdef ENABLE_CLASSIC 1348 link_key_type_t link_key_type; 1349 #endif 1350 1351 switch (sm_conn->sm_engine_state){ 1352 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1353 memcpy(setup->sm_local_confirm, hash, 16); 1354 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1355 break; 1356 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1357 // check 1358 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1359 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1360 break; 1361 } 1362 sm_sc_state_after_receiving_random(sm_conn); 1363 break; 1364 case SM_SC_W4_CALCULATE_G2: { 1365 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1366 big_endian_store_32(setup->sm_tk, 12, vab); 1367 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1368 sm_trigger_user_response(sm_conn); 1369 break; 1370 } 1371 case SM_SC_W4_CALCULATE_F5_SALT: 1372 memcpy(setup->sm_t, hash, 16); 1373 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1374 break; 1375 case SM_SC_W4_CALCULATE_F5_MACKEY: 1376 memcpy(setup->sm_mackey, hash, 16); 1377 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1378 break; 1379 case SM_SC_W4_CALCULATE_F5_LTK: 1380 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1381 // Errata Service Release to the Bluetooth Specification: ESR09 1382 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1383 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1384 memcpy(setup->sm_ltk, hash, 16); 1385 memcpy(setup->sm_local_ltk, hash, 16); 1386 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1387 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1388 break; 1389 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1390 memcpy(setup->sm_local_dhkey_check, hash, 16); 1391 if (IS_RESPONDER(sm_conn->sm_role)){ 1392 // responder 1393 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1394 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1395 } else { 1396 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1397 } 1398 } else { 1399 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1400 } 1401 break; 1402 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1403 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1404 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1405 break; 1406 } 1407 if (IS_RESPONDER(sm_conn->sm_role)){ 1408 // responder 1409 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1410 } else { 1411 // initiator 1412 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1413 } 1414 break; 1415 case SM_SC_W4_CALCULATE_H6_ILK: 1416 memcpy(setup->sm_t, hash, 16); 1417 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1418 break; 1419 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1420 #ifdef ENABLE_CLASSIC 1421 reverse_128(hash, setup->sm_t); 1422 link_key_type = sm_conn->sm_connection_authenticated ? 1423 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1424 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1425 if (IS_RESPONDER(sm_conn->sm_role)){ 1426 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1427 } else { 1428 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1429 } 1430 #endif 1431 if (IS_RESPONDER(sm_conn->sm_role)){ 1432 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1433 } else { 1434 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1435 } 1436 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1437 sm_done_for_handle(sm_conn->sm_handle); 1438 break; 1439 default: 1440 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1441 break; 1442 } 1443 sm_run(); 1444 } 1445 1446 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){ 1447 const uint16_t message_len = 65; 1448 sm_cmac_connection = sm_conn; 1449 memcpy(sm_cmac_sc_buffer, u, 32); 1450 memcpy(sm_cmac_sc_buffer+32, v, 32); 1451 sm_cmac_sc_buffer[64] = z; 1452 log_info("f4 key"); 1453 log_info_hexdump(x, 16); 1454 log_info("f4 message"); 1455 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1456 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1457 } 1458 1459 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1460 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1461 static const uint8_t f5_length[] = { 0x01, 0x00}; 1462 1463 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1464 log_info("f5_calculate_salt"); 1465 // calculate salt for f5 1466 const uint16_t message_len = 32; 1467 sm_cmac_connection = sm_conn; 1468 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1469 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1470 } 1471 1472 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){ 1473 const uint16_t message_len = 53; 1474 sm_cmac_connection = sm_conn; 1475 1476 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1477 sm_cmac_sc_buffer[0] = 0; 1478 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1479 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1480 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1481 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1482 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1483 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1484 log_info("f5 key"); 1485 log_info_hexdump(t, 16); 1486 log_info("f5 message for MacKey"); 1487 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1488 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1489 } 1490 1491 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1492 sm_key56_t bd_addr_master, bd_addr_slave; 1493 bd_addr_master[0] = setup->sm_m_addr_type; 1494 bd_addr_slave[0] = setup->sm_s_addr_type; 1495 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1496 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1497 if (IS_RESPONDER(sm_conn->sm_role)){ 1498 // responder 1499 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1500 } else { 1501 // initiator 1502 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1503 } 1504 } 1505 1506 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1507 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1508 const uint16_t message_len = 53; 1509 sm_cmac_connection = sm_conn; 1510 sm_cmac_sc_buffer[0] = 1; 1511 // 1..52 setup before 1512 log_info("f5 key"); 1513 log_info_hexdump(t, 16); 1514 log_info("f5 message for LTK"); 1515 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1516 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1517 } 1518 1519 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1520 f5_ltk(sm_conn, setup->sm_t); 1521 } 1522 1523 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){ 1524 const uint16_t message_len = 65; 1525 sm_cmac_connection = sm_conn; 1526 memcpy(sm_cmac_sc_buffer, n1, 16); 1527 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1528 memcpy(sm_cmac_sc_buffer+32, r, 16); 1529 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1530 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1531 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1532 log_info("f6 key"); 1533 log_info_hexdump(w, 16); 1534 log_info("f6 message"); 1535 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1536 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1537 } 1538 1539 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1540 // - U is 256 bits 1541 // - V is 256 bits 1542 // - X is 128 bits 1543 // - Y is 128 bits 1544 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){ 1545 const uint16_t message_len = 80; 1546 sm_cmac_connection = sm_conn; 1547 memcpy(sm_cmac_sc_buffer, u, 32); 1548 memcpy(sm_cmac_sc_buffer+32, v, 32); 1549 memcpy(sm_cmac_sc_buffer+64, y, 16); 1550 log_info("g2 key"); 1551 log_info_hexdump(x, 16); 1552 log_info("g2 message"); 1553 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1554 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1555 } 1556 1557 static void g2_calculate(sm_connection_t * sm_conn) { 1558 // calc Va if numeric comparison 1559 if (IS_RESPONDER(sm_conn->sm_role)){ 1560 // responder 1561 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1562 } else { 1563 // initiator 1564 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1565 } 1566 } 1567 1568 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1569 uint8_t z = 0; 1570 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1571 // some form of passkey 1572 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1573 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1574 setup->sm_passkey_bit++; 1575 } 1576 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1577 } 1578 1579 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1580 // OOB 1581 if (setup->sm_stk_generation_method == OOB){ 1582 if (IS_RESPONDER(sm_conn->sm_role)){ 1583 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1584 } else { 1585 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1586 } 1587 return; 1588 } 1589 1590 uint8_t z = 0; 1591 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1592 // some form of passkey 1593 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1594 // sm_passkey_bit was increased before sending confirm value 1595 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1596 } 1597 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1598 } 1599 1600 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1601 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1602 1603 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1604 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1605 return; 1606 } else { 1607 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1608 } 1609 } 1610 1611 static void sm_sc_dhkey_calculated(void * arg){ 1612 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1613 log_info("dhkey"); 1614 log_info_hexdump(&setup->sm_dhkey[0], 32); 1615 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1616 // trigger next step 1617 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1618 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1619 } 1620 sm_run(); 1621 } 1622 1623 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1624 // calculate DHKCheck 1625 sm_key56_t bd_addr_master, bd_addr_slave; 1626 bd_addr_master[0] = setup->sm_m_addr_type; 1627 bd_addr_slave[0] = setup->sm_s_addr_type; 1628 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1629 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1630 uint8_t iocap_a[3]; 1631 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1632 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1633 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1634 uint8_t iocap_b[3]; 1635 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1636 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1637 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1638 if (IS_RESPONDER(sm_conn->sm_role)){ 1639 // responder 1640 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); 1641 } else { 1642 // initiator 1643 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); 1644 } 1645 } 1646 1647 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1648 // validate E = f6() 1649 sm_key56_t bd_addr_master, bd_addr_slave; 1650 bd_addr_master[0] = setup->sm_m_addr_type; 1651 bd_addr_slave[0] = setup->sm_s_addr_type; 1652 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1653 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1654 1655 uint8_t iocap_a[3]; 1656 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1657 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1658 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1659 uint8_t iocap_b[3]; 1660 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1661 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1662 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1663 if (IS_RESPONDER(sm_conn->sm_role)){ 1664 // responder 1665 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); 1666 } else { 1667 // initiator 1668 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); 1669 } 1670 } 1671 1672 1673 // 1674 // Link Key Conversion Function h6 1675 // 1676 // h6(W, keyID) = AES-CMACW(keyID) 1677 // - W is 128 bits 1678 // - keyID is 32 bits 1679 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1680 const uint16_t message_len = 4; 1681 sm_cmac_connection = sm_conn; 1682 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1683 log_info("h6 key"); 1684 log_info_hexdump(w, 16); 1685 log_info("h6 message"); 1686 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1687 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1688 } 1689 1690 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1691 // Errata Service Release to the Bluetooth Specification: ESR09 1692 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1693 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1694 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1695 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1696 } 1697 1698 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1699 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1700 } 1701 1702 #endif 1703 1704 // key management legacy connections: 1705 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1706 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1707 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1708 // - responder reconnects: responder uses LTK receveived from master 1709 1710 // key management secure connections: 1711 // - both devices store same LTK from ECDH key exchange. 1712 1713 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1714 static void sm_load_security_info(sm_connection_t * sm_connection){ 1715 int encryption_key_size; 1716 int authenticated; 1717 int authorized; 1718 1719 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1720 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1721 &encryption_key_size, &authenticated, &authorized); 1722 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1723 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1724 sm_connection->sm_connection_authenticated = authenticated; 1725 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1726 } 1727 #endif 1728 1729 #ifdef ENABLE_LE_PERIPHERAL 1730 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1731 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1732 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1733 // re-establish used key encryption size 1734 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1735 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1736 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1737 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1738 log_info("sm: received ltk request with key size %u, authenticated %u", 1739 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1740 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1741 sm_run(); 1742 } 1743 #endif 1744 1745 static void sm_run(void){ 1746 1747 btstack_linked_list_iterator_t it; 1748 1749 // assert that stack has already bootet 1750 if (hci_get_state() != HCI_STATE_WORKING) return; 1751 1752 // assert that we can send at least commands 1753 if (!hci_can_send_command_packet_now()) return; 1754 1755 // 1756 // non-connection related behaviour 1757 // 1758 1759 // distributed key generation 1760 switch (dkg_state){ 1761 case DKG_CALC_IRK: 1762 // already busy? 1763 if (sm_aes128_state == SM_AES128_IDLE) { 1764 log_info("DKG_CALC_IRK started"); 1765 // IRK = d1(IR, 1, 0) 1766 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1767 sm_aes128_state = SM_AES128_ACTIVE; 1768 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1769 return; 1770 } 1771 break; 1772 case DKG_CALC_DHK: 1773 // already busy? 1774 if (sm_aes128_state == SM_AES128_IDLE) { 1775 log_info("DKG_CALC_DHK started"); 1776 // DHK = d1(IR, 3, 0) 1777 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1778 sm_aes128_state = SM_AES128_ACTIVE; 1779 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1780 return; 1781 } 1782 break; 1783 default: 1784 break; 1785 } 1786 1787 // random address updates 1788 switch (rau_state){ 1789 case RAU_GET_ENC: 1790 // already busy? 1791 if (sm_aes128_state == SM_AES128_IDLE) { 1792 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1793 sm_aes128_state = SM_AES128_ACTIVE; 1794 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1795 return; 1796 } 1797 break; 1798 case RAU_SET_ADDRESS: 1799 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1800 rau_state = RAU_IDLE; 1801 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1802 return; 1803 default: 1804 break; 1805 } 1806 1807 // CSRK Lookup 1808 // -- if csrk lookup ready, find connection that require csrk lookup 1809 if (sm_address_resolution_idle()){ 1810 hci_connections_get_iterator(&it); 1811 while(btstack_linked_list_iterator_has_next(&it)){ 1812 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1813 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1814 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1815 // and start lookup 1816 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); 1817 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1818 break; 1819 } 1820 } 1821 } 1822 1823 // -- if csrk lookup ready, resolved addresses for received addresses 1824 if (sm_address_resolution_idle()) { 1825 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1826 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1827 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1828 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1829 btstack_memory_sm_lookup_entry_free(entry); 1830 } 1831 } 1832 1833 // -- Continue with CSRK device lookup by public or resolvable private address 1834 if (!sm_address_resolution_idle()){ 1835 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1836 while (sm_address_resolution_test < le_device_db_max_count()){ 1837 int addr_type; 1838 bd_addr_t addr; 1839 sm_key_t irk; 1840 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1841 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1842 1843 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1844 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1845 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1846 break; 1847 } 1848 1849 if (sm_address_resolution_addr_type == 0){ 1850 sm_address_resolution_test++; 1851 continue; 1852 } 1853 1854 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1855 1856 log_info("LE Device Lookup: calculate AH"); 1857 log_info_key("IRK", irk); 1858 1859 memcpy(sm_aes128_key, irk, 16); 1860 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1861 sm_address_resolution_ah_calculation_active = 1; 1862 sm_aes128_state = SM_AES128_ACTIVE; 1863 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1864 return; 1865 } 1866 1867 if (sm_address_resolution_test >= le_device_db_max_count()){ 1868 log_info("LE Device Lookup: not found"); 1869 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1870 } 1871 } 1872 1873 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1874 switch (sm_sc_oob_state){ 1875 case SM_SC_OOB_W2_CALC_CONFIRM: 1876 if (!sm_cmac_ready()) break; 1877 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1878 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1879 return; 1880 default: 1881 break; 1882 } 1883 #endif 1884 1885 // handle basic actions that don't requires the full context 1886 hci_connections_get_iterator(&it); 1887 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1888 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1889 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1890 switch(sm_connection->sm_engine_state){ 1891 // responder side 1892 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1893 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1894 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1895 return; 1896 1897 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1898 case SM_SC_RECEIVED_LTK_REQUEST: 1899 switch (sm_connection->sm_irk_lookup_state){ 1900 case IRK_LOOKUP_FAILED: 1901 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1902 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1903 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1904 return; 1905 default: 1906 break; 1907 } 1908 break; 1909 #endif 1910 default: 1911 break; 1912 } 1913 } 1914 1915 // 1916 // active connection handling 1917 // -- use loop to handle next connection if lock on setup context is released 1918 1919 while (1) { 1920 1921 // Find connections that requires setup context and make active if no other is locked 1922 hci_connections_get_iterator(&it); 1923 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1924 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1925 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1926 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1927 int done = 1; 1928 int err; 1929 UNUSED(err); 1930 switch (sm_connection->sm_engine_state) { 1931 #ifdef ENABLE_LE_PERIPHERAL 1932 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1933 // send packet if possible, 1934 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1935 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1936 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1937 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1938 } else { 1939 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1940 } 1941 // don't lock sxetup context yet 1942 done = 0; 1943 break; 1944 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1945 sm_reset_setup(); 1946 sm_init_setup(sm_connection); 1947 // recover pairing request 1948 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1949 err = sm_stk_generation_init(sm_connection); 1950 1951 #ifdef ENABLE_TESTING_SUPPORT 1952 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1953 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1954 err = test_pairing_failure; 1955 } 1956 #endif 1957 if (err){ 1958 setup->sm_pairing_failed_reason = err; 1959 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1960 break; 1961 } 1962 sm_timeout_start(sm_connection); 1963 // generate random number first, if we need to show passkey 1964 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1965 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1966 break; 1967 } 1968 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1969 break; 1970 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1971 sm_reset_setup(); 1972 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1973 break; 1974 #endif 1975 #ifdef ENABLE_LE_CENTRAL 1976 case SM_INITIATOR_PH0_HAS_LTK: 1977 sm_reset_setup(); 1978 sm_load_security_info(sm_connection); 1979 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1980 break; 1981 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1982 sm_reset_setup(); 1983 sm_init_setup(sm_connection); 1984 sm_timeout_start(sm_connection); 1985 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1986 break; 1987 #endif 1988 1989 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1990 case SM_SC_RECEIVED_LTK_REQUEST: 1991 switch (sm_connection->sm_irk_lookup_state){ 1992 case IRK_LOOKUP_SUCCEEDED: 1993 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 1994 // start using context by loading security info 1995 sm_reset_setup(); 1996 sm_load_security_info(sm_connection); 1997 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 1998 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 1999 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2000 break; 2001 } 2002 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2003 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2004 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2005 // don't lock setup context yet 2006 return; 2007 default: 2008 // just wait until IRK lookup is completed 2009 // don't lock setup context yet 2010 done = 0; 2011 break; 2012 } 2013 break; 2014 #endif 2015 default: 2016 done = 0; 2017 break; 2018 } 2019 if (done){ 2020 sm_active_connection_handle = sm_connection->sm_handle; 2021 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); 2022 } 2023 } 2024 2025 // 2026 // active connection handling 2027 // 2028 2029 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2030 2031 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2032 if (!connection) { 2033 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2034 return; 2035 } 2036 2037 // assert that we could send a SM PDU - not needed for all of the following 2038 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2039 log_info("cannot send now, requesting can send now event"); 2040 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2041 return; 2042 } 2043 2044 // send keypress notifications 2045 if (setup->sm_keypress_notification){ 2046 int i; 2047 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2048 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2049 uint8_t action = 0; 2050 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2051 if (flags & (1<<i)){ 2052 int clear_flag = 1; 2053 switch (i){ 2054 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2055 case SM_KEYPRESS_PASSKEY_CLEARED: 2056 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2057 default: 2058 break; 2059 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2060 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2061 num_actions--; 2062 clear_flag = num_actions == 0; 2063 break; 2064 } 2065 if (clear_flag){ 2066 flags &= ~(1<<i); 2067 } 2068 action = i; 2069 break; 2070 } 2071 } 2072 setup->sm_keypress_notification = (num_actions << 5) | flags; 2073 2074 // send keypress notification 2075 uint8_t buffer[2]; 2076 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2077 buffer[1] = action; 2078 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2079 2080 // try 2081 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2082 return; 2083 } 2084 2085 int key_distribution_flags; 2086 UNUSED(key_distribution_flags); 2087 2088 log_info("sm_run: state %u", connection->sm_engine_state); 2089 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2090 log_info("sm_run // cannot send"); 2091 } 2092 switch (connection->sm_engine_state){ 2093 2094 // general 2095 case SM_GENERAL_SEND_PAIRING_FAILED: { 2096 uint8_t buffer[2]; 2097 buffer[0] = SM_CODE_PAIRING_FAILED; 2098 buffer[1] = setup->sm_pairing_failed_reason; 2099 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2100 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2101 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2102 sm_done_for_handle(connection->sm_handle); 2103 break; 2104 } 2105 2106 // responding state 2107 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2108 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2109 if (!sm_cmac_ready()) break; 2110 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2111 sm_sc_calculate_local_confirm(connection); 2112 break; 2113 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2114 if (!sm_cmac_ready()) break; 2115 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2116 sm_sc_calculate_remote_confirm(connection); 2117 break; 2118 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2119 if (!sm_cmac_ready()) break; 2120 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2121 sm_sc_calculate_f6_for_dhkey_check(connection); 2122 break; 2123 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2124 if (!sm_cmac_ready()) break; 2125 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2126 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2127 break; 2128 case SM_SC_W2_CALCULATE_F5_SALT: 2129 if (!sm_cmac_ready()) break; 2130 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2131 f5_calculate_salt(connection); 2132 break; 2133 case SM_SC_W2_CALCULATE_F5_MACKEY: 2134 if (!sm_cmac_ready()) break; 2135 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2136 f5_calculate_mackey(connection); 2137 break; 2138 case SM_SC_W2_CALCULATE_F5_LTK: 2139 if (!sm_cmac_ready()) break; 2140 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2141 f5_calculate_ltk(connection); 2142 break; 2143 case SM_SC_W2_CALCULATE_G2: 2144 if (!sm_cmac_ready()) break; 2145 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2146 g2_calculate(connection); 2147 break; 2148 case SM_SC_W2_CALCULATE_H6_ILK: 2149 if (!sm_cmac_ready()) break; 2150 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2151 h6_calculate_ilk(connection); 2152 break; 2153 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2154 if (!sm_cmac_ready()) break; 2155 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2156 h6_calculate_br_edr_link_key(connection); 2157 break; 2158 #endif 2159 2160 #ifdef ENABLE_LE_CENTRAL 2161 // initiator side 2162 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2163 sm_key_t peer_ltk_flipped; 2164 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2165 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2166 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2167 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2168 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2169 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2170 return; 2171 } 2172 2173 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2174 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2175 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2176 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2177 sm_timeout_reset(connection); 2178 break; 2179 #endif 2180 2181 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2182 2183 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2184 int trigger_user_response = 0; 2185 2186 uint8_t buffer[65]; 2187 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2188 // 2189 reverse_256(&ec_q[0], &buffer[1]); 2190 reverse_256(&ec_q[32], &buffer[33]); 2191 2192 // stk generation method 2193 // passkey entry: notify app to show passkey or to request passkey 2194 switch (setup->sm_stk_generation_method){ 2195 case JUST_WORKS: 2196 case NUMERIC_COMPARISON: 2197 if (IS_RESPONDER(connection->sm_role)){ 2198 // responder 2199 sm_sc_start_calculating_local_confirm(connection); 2200 } else { 2201 // initiator 2202 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2203 } 2204 break; 2205 case PK_INIT_INPUT: 2206 case PK_RESP_INPUT: 2207 case PK_BOTH_INPUT: 2208 // use random TK for display 2209 memcpy(setup->sm_ra, setup->sm_tk, 16); 2210 memcpy(setup->sm_rb, setup->sm_tk, 16); 2211 setup->sm_passkey_bit = 0; 2212 2213 if (IS_RESPONDER(connection->sm_role)){ 2214 // responder 2215 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2216 } else { 2217 // initiator 2218 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2219 } 2220 trigger_user_response = 1; 2221 break; 2222 case OOB: 2223 if (IS_RESPONDER(connection->sm_role)){ 2224 // responder 2225 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2226 } else { 2227 // initiator 2228 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2229 } 2230 break; 2231 } 2232 2233 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2234 sm_timeout_reset(connection); 2235 2236 // trigger user response after sending pdu 2237 if (trigger_user_response){ 2238 sm_trigger_user_response(connection); 2239 } 2240 break; 2241 } 2242 case SM_SC_SEND_CONFIRMATION: { 2243 uint8_t buffer[17]; 2244 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2245 reverse_128(setup->sm_local_confirm, &buffer[1]); 2246 if (IS_RESPONDER(connection->sm_role)){ 2247 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2248 } else { 2249 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2250 } 2251 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2252 sm_timeout_reset(connection); 2253 break; 2254 } 2255 case SM_SC_SEND_PAIRING_RANDOM: { 2256 uint8_t buffer[17]; 2257 buffer[0] = SM_CODE_PAIRING_RANDOM; 2258 reverse_128(setup->sm_local_nonce, &buffer[1]); 2259 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2260 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2261 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2262 if (IS_RESPONDER(connection->sm_role)){ 2263 // responder 2264 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2265 } else { 2266 // initiator 2267 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2268 } 2269 } else { 2270 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2271 if (IS_RESPONDER(connection->sm_role)){ 2272 // responder 2273 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2274 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2275 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2276 } else { 2277 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2278 sm_sc_prepare_dhkey_check(connection); 2279 } 2280 } else { 2281 // initiator 2282 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2283 } 2284 } 2285 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2286 sm_timeout_reset(connection); 2287 break; 2288 } 2289 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2290 uint8_t buffer[17]; 2291 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2292 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2293 2294 if (IS_RESPONDER(connection->sm_role)){ 2295 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2296 } else { 2297 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2298 } 2299 2300 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2301 sm_timeout_reset(connection); 2302 break; 2303 } 2304 2305 #endif 2306 2307 #ifdef ENABLE_LE_PERIPHERAL 2308 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2309 // echo initiator for now 2310 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2311 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2312 2313 if (setup->sm_use_secure_connections){ 2314 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2315 } else { 2316 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2317 } 2318 2319 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); 2320 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); 2321 // update key distribution after ENC was dropped 2322 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2323 2324 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2325 sm_timeout_reset(connection); 2326 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2327 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2328 sm_trigger_user_response(connection); 2329 } 2330 return; 2331 #endif 2332 2333 case SM_PH2_SEND_PAIRING_RANDOM: { 2334 uint8_t buffer[17]; 2335 buffer[0] = SM_CODE_PAIRING_RANDOM; 2336 reverse_128(setup->sm_local_random, &buffer[1]); 2337 if (IS_RESPONDER(connection->sm_role)){ 2338 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2339 } else { 2340 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2341 } 2342 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2343 sm_timeout_reset(connection); 2344 break; 2345 } 2346 2347 case SM_PH2_C1_GET_ENC_A: 2348 // already busy? 2349 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2350 // calculate confirm using aes128 engine - step 1 2351 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, sm_aes128_plaintext); 2352 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2353 sm_aes128_state = SM_AES128_ACTIVE; 2354 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2355 break; 2356 2357 case SM_PH2_C1_GET_ENC_C: 2358 // already busy? 2359 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2360 // calculate m_confirm using aes128 engine - step 1 2361 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, sm_aes128_plaintext); 2362 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2363 sm_aes128_state = SM_AES128_ACTIVE; 2364 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2365 break; 2366 2367 case SM_PH2_CALC_STK: 2368 // already busy? 2369 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2370 // calculate STK 2371 if (IS_RESPONDER(connection->sm_role)){ 2372 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2373 } else { 2374 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2375 } 2376 connection->sm_engine_state = SM_PH2_W4_STK; 2377 sm_aes128_state = SM_AES128_ACTIVE; 2378 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2379 break; 2380 2381 case SM_PH3_Y_GET_ENC: 2382 // already busy? 2383 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2384 // PH3B2 - calculate Y from - enc 2385 // Y = dm(DHK, Rand) 2386 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2387 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2388 sm_aes128_state = SM_AES128_ACTIVE; 2389 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph3_y, connection); 2390 break; 2391 2392 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2393 uint8_t buffer[17]; 2394 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2395 reverse_128(setup->sm_local_confirm, &buffer[1]); 2396 if (IS_RESPONDER(connection->sm_role)){ 2397 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2398 } else { 2399 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2400 } 2401 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2402 sm_timeout_reset(connection); 2403 return; 2404 } 2405 #ifdef ENABLE_LE_PERIPHERAL 2406 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2407 sm_key_t stk_flipped; 2408 reverse_128(setup->sm_ltk, stk_flipped); 2409 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2410 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2411 return; 2412 } 2413 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2414 sm_key_t ltk_flipped; 2415 reverse_128(setup->sm_ltk, ltk_flipped); 2416 connection->sm_engine_state = SM_RESPONDER_IDLE; 2417 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2418 sm_done_for_handle(connection->sm_handle); 2419 return; 2420 } 2421 case SM_RESPONDER_PH4_Y_GET_ENC: 2422 // already busy? 2423 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2424 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2425 // Y = dm(DHK, Rand) 2426 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2427 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2428 sm_aes128_state = SM_AES128_ACTIVE; 2429 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph4_y, connection); 2430 return; 2431 #endif 2432 #ifdef ENABLE_LE_CENTRAL 2433 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2434 sm_key_t stk_flipped; 2435 reverse_128(setup->sm_ltk, stk_flipped); 2436 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2437 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2438 return; 2439 } 2440 #endif 2441 2442 case SM_PH3_DISTRIBUTE_KEYS: 2443 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2444 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2445 uint8_t buffer[17]; 2446 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2447 reverse_128(setup->sm_ltk, &buffer[1]); 2448 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2449 sm_timeout_reset(connection); 2450 return; 2451 } 2452 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2453 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2454 uint8_t buffer[11]; 2455 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2456 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2457 reverse_64(setup->sm_local_rand, &buffer[3]); 2458 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2459 sm_timeout_reset(connection); 2460 return; 2461 } 2462 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2463 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2464 uint8_t buffer[17]; 2465 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2466 reverse_128(sm_persistent_irk, &buffer[1]); 2467 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2468 sm_timeout_reset(connection); 2469 return; 2470 } 2471 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2472 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2473 bd_addr_t local_address; 2474 uint8_t buffer[8]; 2475 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2476 switch (gap_random_address_get_mode()){ 2477 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2478 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2479 // public or static random 2480 gap_le_get_own_address(&buffer[1], local_address); 2481 break; 2482 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2483 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2484 // fallback to public 2485 gap_local_bd_addr(local_address); 2486 buffer[1] = 0; 2487 break; 2488 } 2489 reverse_bd_addr(local_address, &buffer[2]); 2490 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2491 sm_timeout_reset(connection); 2492 return; 2493 } 2494 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2495 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2496 2497 // hack to reproduce test runs 2498 if (test_use_fixed_local_csrk){ 2499 memset(setup->sm_local_csrk, 0xcc, 16); 2500 } 2501 2502 uint8_t buffer[17]; 2503 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2504 reverse_128(setup->sm_local_csrk, &buffer[1]); 2505 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2506 sm_timeout_reset(connection); 2507 return; 2508 } 2509 2510 // keys are sent 2511 if (IS_RESPONDER(connection->sm_role)){ 2512 // slave -> receive master keys if any 2513 if (sm_key_distribution_all_received(connection)){ 2514 sm_key_distribution_handle_all_received(connection); 2515 connection->sm_engine_state = SM_RESPONDER_IDLE; 2516 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2517 sm_done_for_handle(connection->sm_handle); 2518 } else { 2519 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2520 } 2521 } else { 2522 // master -> all done 2523 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2524 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2525 sm_done_for_handle(connection->sm_handle); 2526 } 2527 break; 2528 2529 default: 2530 break; 2531 } 2532 2533 // check again if active connection was released 2534 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2535 } 2536 } 2537 2538 // sm_aes128_state stays active 2539 static void sm_handle_encryption_result_enc_a(void *arg){ 2540 sm_connection_t * connection = (sm_connection_t*) arg; 2541 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2542 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, setup->sm_local_confirm, sm_handle_encryption_result_enc_b, connection); 2543 } 2544 2545 static void sm_handle_encryption_result_enc_b(void *arg){ 2546 sm_connection_t * connection = (sm_connection_t*) arg; 2547 sm_aes128_state = SM_AES128_IDLE; 2548 log_info_key("c1!", setup->sm_local_confirm); 2549 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2550 sm_run(); 2551 } 2552 2553 // sm_aes128_state stays active 2554 static void sm_handle_encryption_result_enc_c(void *arg){ 2555 sm_connection_t * connection = (sm_connection_t*) arg; 2556 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2557 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, sm_aes128_ciphertext, sm_handle_encryption_result_enc_d, connection); 2558 } 2559 2560 static void sm_handle_encryption_result_enc_d(void * arg){ 2561 sm_connection_t * connection = (sm_connection_t*) arg; 2562 sm_aes128_state = SM_AES128_IDLE; 2563 log_info_key("c1!", sm_aes128_ciphertext); 2564 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2565 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2566 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2567 sm_run(); 2568 return; 2569 } 2570 if (IS_RESPONDER(connection->sm_role)){ 2571 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2572 sm_run(); 2573 } else { 2574 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2575 sm_aes128_state = SM_AES128_ACTIVE; 2576 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2577 } 2578 } 2579 2580 static void sm_handle_encryption_result_enc_stk(void *arg){ 2581 sm_connection_t * connection = (sm_connection_t*) arg; 2582 sm_aes128_state = SM_AES128_IDLE; 2583 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2584 log_info_key("stk", setup->sm_ltk); 2585 if (IS_RESPONDER(connection->sm_role)){ 2586 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2587 } else { 2588 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2589 } 2590 sm_run(); 2591 } 2592 2593 // sm_aes128_state stays active 2594 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2595 sm_connection_t * connection = (sm_connection_t*) arg; 2596 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2597 log_info_hex16("y", setup->sm_local_y); 2598 // PH3B3 - calculate EDIV 2599 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2600 log_info_hex16("ediv", setup->sm_local_ediv); 2601 // PH3B4 - calculate LTK - enc 2602 // LTK = d1(ER, DIV, 0)) 2603 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2604 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph3_ltk, connection); 2605 } 2606 2607 #ifdef ENABLE_LE_PERIPHERAL 2608 // sm_aes128_state stays active 2609 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2610 sm_connection_t * connection = (sm_connection_t*) arg; 2611 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2612 log_info_hex16("y", setup->sm_local_y); 2613 2614 // PH3B3 - calculate DIV 2615 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2616 log_info_hex16("ediv", setup->sm_local_ediv); 2617 // PH3B4 - calculate LTK - enc 2618 // LTK = d1(ER, DIV, 0)) 2619 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2620 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph4_ltk, connection); 2621 } 2622 #endif 2623 2624 // sm_aes128_state stays active 2625 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2626 sm_connection_t * connection = (sm_connection_t*) arg; 2627 log_info_key("ltk", setup->sm_ltk); 2628 // calc CSRK next 2629 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2630 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_local_csrk, sm_handle_encryption_result_enc_csrk, connection); 2631 } 2632 2633 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2634 sm_connection_t * connection = (sm_connection_t*) arg; 2635 sm_aes128_state = SM_AES128_IDLE; 2636 log_info_key("csrk", setup->sm_local_csrk); 2637 if (setup->sm_key_distribution_send_set){ 2638 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2639 } else { 2640 // no keys to send, just continue 2641 if (IS_RESPONDER(connection->sm_role)){ 2642 // slave -> receive master keys 2643 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2644 } else { 2645 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2646 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2647 } else { 2648 // master -> all done 2649 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2650 sm_done_for_handle(connection->sm_handle); 2651 } 2652 } 2653 } 2654 sm_run(); 2655 } 2656 2657 #ifdef ENABLE_LE_PERIPHERAL 2658 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2659 sm_connection_t * connection = (sm_connection_t*) arg; 2660 sm_aes128_state = SM_AES128_IDLE; 2661 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2662 log_info_key("ltk", setup->sm_ltk); 2663 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2664 sm_run(); 2665 } 2666 #endif 2667 2668 static void sm_handle_encryption_result_address_resolution(void *arg){ 2669 UNUSED(arg); 2670 sm_aes128_state = SM_AES128_IDLE; 2671 sm_address_resolution_ah_calculation_active = 0; 2672 // compare calulated address against connecting device 2673 uint8_t * hash = &sm_aes128_ciphertext[13]; 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 sm_run(); 2678 return; 2679 } 2680 // no match, try next 2681 sm_address_resolution_test++; 2682 sm_run(); 2683 } 2684 2685 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2686 UNUSED(arg); 2687 sm_aes128_state = SM_AES128_IDLE; 2688 log_info_key("irk", sm_persistent_irk); 2689 dkg_state = DKG_CALC_DHK; 2690 sm_run(); 2691 } 2692 2693 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2694 UNUSED(arg); 2695 sm_aes128_state = SM_AES128_IDLE; 2696 log_info_key("dhk", sm_persistent_dhk); 2697 dkg_state = DKG_READY; 2698 // DKG calculation complete => SM Init Finished 2699 sm_run(); 2700 } 2701 2702 static void sm_handle_encryption_result_rau(void *arg){ 2703 UNUSED(arg); 2704 sm_aes128_state = SM_AES128_IDLE; 2705 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2706 rau_state = RAU_SET_ADDRESS; 2707 sm_run(); 2708 } 2709 2710 static void sm_handle_random_result_rau(void * arg){ 2711 UNUSED(arg); 2712 // non-resolvable vs. resolvable 2713 switch (gap_random_adress_type){ 2714 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2715 // resolvable: use random as prand and calc address hash 2716 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2717 sm_random_address[0] &= 0x3f; 2718 sm_random_address[0] |= 0x40; 2719 rau_state = RAU_GET_ENC; 2720 break; 2721 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2722 default: 2723 // "The two most significant bits of the address shall be equal to ‘0’"" 2724 sm_random_address[0] &= 0x3f; 2725 rau_state = RAU_SET_ADDRESS; 2726 break; 2727 } 2728 sm_run(); 2729 } 2730 2731 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2732 static void sm_handle_random_result_sc_get_random(void * arg){ 2733 sm_connection_t * connection = (sm_connection_t*) arg; 2734 2735 // OOB 2736 if (setup->sm_stk_generation_method == OOB){ 2737 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2738 sm_run(); 2739 return; 2740 } 2741 2742 // initiator & jw/nc -> send pairing random 2743 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2744 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2745 } else { 2746 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2747 } 2748 sm_run(); 2749 } 2750 #endif 2751 2752 static void sm_handle_random_result_ph2_random(void * arg){ 2753 sm_connection_t * connection = (sm_connection_t*) arg; 2754 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2755 sm_run(); 2756 } 2757 2758 static void sm_handle_random_result_ph2_tk(void * arg){ 2759 sm_connection_t * connection = (sm_connection_t*) arg; 2760 sm_reset_tk(); 2761 uint32_t tk; 2762 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2763 // map random to 0-999999 without speding much cycles on a modulus operation 2764 tk = little_endian_read_32(sm_random_data,0); 2765 tk = tk & 0xfffff; // 1048575 2766 if (tk >= 999999){ 2767 tk = tk - 999999; 2768 } 2769 } else { 2770 // override with pre-defined passkey 2771 tk = sm_fixed_passkey_in_display_role; 2772 } 2773 big_endian_store_32(setup->sm_tk, 12, tk); 2774 if (IS_RESPONDER(connection->sm_role)){ 2775 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2776 } else { 2777 if (setup->sm_use_secure_connections){ 2778 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2779 } else { 2780 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2781 sm_trigger_user_response(connection); 2782 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2783 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2784 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2785 } 2786 } 2787 } 2788 sm_run(); 2789 } 2790 2791 static void sm_handle_random_result_ph3_div(void * arg){ 2792 sm_connection_t * connection = (sm_connection_t*) arg; 2793 // use 16 bit from random value as div 2794 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2795 log_info_hex16("div", setup->sm_local_div); 2796 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2797 sm_run(); 2798 } 2799 2800 static void sm_handle_random_result_ph3_random(void * arg){ 2801 sm_connection_t * connection = (sm_connection_t*) arg; 2802 reverse_64(sm_random_data, setup->sm_local_rand); 2803 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2804 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2805 // no db for authenticated flag hack: store flag in bit 4 of LSB 2806 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2807 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2808 } 2809 2810 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2811 2812 UNUSED(channel); // ok: there is no channel 2813 UNUSED(size); // ok: fixed format HCI events 2814 2815 sm_connection_t * sm_conn; 2816 hci_con_handle_t con_handle; 2817 2818 switch (packet_type) { 2819 2820 case HCI_EVENT_PACKET: 2821 switch (hci_event_packet_get_type(packet)) { 2822 2823 case BTSTACK_EVENT_STATE: 2824 // bt stack activated, get started 2825 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2826 log_info("HCI Working!"); 2827 2828 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2829 2830 // trigger Random Address generation if requested before 2831 switch (gap_random_adress_type){ 2832 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2833 rau_state = RAU_IDLE; 2834 break; 2835 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2836 rau_state = RAU_SET_ADDRESS; 2837 break; 2838 default: 2839 rau_state = RAU_W4_RANDOM; 2840 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2841 break; 2842 } 2843 sm_run(); 2844 } 2845 break; 2846 2847 case HCI_EVENT_LE_META: 2848 switch (packet[2]) { 2849 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2850 2851 log_info("sm: connected"); 2852 2853 if (packet[3]) return; // connection failed 2854 2855 con_handle = little_endian_read_16(packet, 4); 2856 sm_conn = sm_get_connection_for_handle(con_handle); 2857 if (!sm_conn) break; 2858 2859 sm_conn->sm_handle = con_handle; 2860 sm_conn->sm_role = packet[6]; 2861 sm_conn->sm_peer_addr_type = packet[7]; 2862 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2863 2864 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2865 2866 // reset security properties 2867 sm_conn->sm_connection_encrypted = 0; 2868 sm_conn->sm_connection_authenticated = 0; 2869 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2870 sm_conn->sm_le_db_index = -1; 2871 2872 // prepare CSRK lookup (does not involve setup) 2873 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2874 2875 // just connected -> everything else happens in sm_run() 2876 if (IS_RESPONDER(sm_conn->sm_role)){ 2877 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2878 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2879 if (sm_slave_request_security) { 2880 // request security if requested by app 2881 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2882 } else { 2883 // otherwise, wait for pairing request 2884 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2885 } 2886 } 2887 break; 2888 } else { 2889 // master 2890 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2891 } 2892 break; 2893 2894 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2895 con_handle = little_endian_read_16(packet, 3); 2896 sm_conn = sm_get_connection_for_handle(con_handle); 2897 if (!sm_conn) break; 2898 2899 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2900 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2901 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2902 break; 2903 } 2904 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2905 // PH2 SEND LTK as we need to exchange keys in PH3 2906 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2907 break; 2908 } 2909 2910 // store rand and ediv 2911 reverse_64(&packet[5], sm_conn->sm_local_rand); 2912 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2913 2914 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2915 // potentially stored LTK is from the master 2916 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2917 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2918 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2919 break; 2920 } 2921 // additionally check if remote is in LE Device DB if requested 2922 switch(sm_conn->sm_irk_lookup_state){ 2923 case IRK_LOOKUP_FAILED: 2924 log_info("LTK Request: device not in device db"); 2925 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2926 break; 2927 case IRK_LOOKUP_SUCCEEDED: 2928 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2929 break; 2930 default: 2931 // wait for irk look doen 2932 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2933 break; 2934 } 2935 break; 2936 } 2937 2938 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2939 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2940 #else 2941 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2942 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2943 #endif 2944 break; 2945 2946 default: 2947 break; 2948 } 2949 break; 2950 2951 case HCI_EVENT_ENCRYPTION_CHANGE: 2952 con_handle = little_endian_read_16(packet, 3); 2953 sm_conn = sm_get_connection_for_handle(con_handle); 2954 if (!sm_conn) break; 2955 2956 sm_conn->sm_connection_encrypted = packet[5]; 2957 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2958 sm_conn->sm_actual_encryption_key_size); 2959 log_info("event handler, state %u", sm_conn->sm_engine_state); 2960 if (!sm_conn->sm_connection_encrypted) break; 2961 // continue if part of initial pairing 2962 switch (sm_conn->sm_engine_state){ 2963 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2964 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2965 sm_done_for_handle(sm_conn->sm_handle); 2966 break; 2967 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2968 if (IS_RESPONDER(sm_conn->sm_role)){ 2969 // slave 2970 if (setup->sm_use_secure_connections){ 2971 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2972 } else { 2973 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2974 } 2975 } else { 2976 // master 2977 if (sm_key_distribution_all_received(sm_conn)){ 2978 // skip receiving keys as there are none 2979 sm_key_distribution_handle_all_received(sm_conn); 2980 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2981 } else { 2982 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2983 } 2984 } 2985 break; 2986 default: 2987 break; 2988 } 2989 break; 2990 2991 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2992 con_handle = little_endian_read_16(packet, 3); 2993 sm_conn = sm_get_connection_for_handle(con_handle); 2994 if (!sm_conn) break; 2995 2996 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2997 log_info("event handler, state %u", sm_conn->sm_engine_state); 2998 // continue if part of initial pairing 2999 switch (sm_conn->sm_engine_state){ 3000 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3001 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3002 sm_done_for_handle(sm_conn->sm_handle); 3003 break; 3004 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3005 if (IS_RESPONDER(sm_conn->sm_role)){ 3006 // slave 3007 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3008 } else { 3009 // master 3010 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3011 } 3012 break; 3013 default: 3014 break; 3015 } 3016 break; 3017 3018 3019 case HCI_EVENT_DISCONNECTION_COMPLETE: 3020 con_handle = little_endian_read_16(packet, 3); 3021 sm_done_for_handle(con_handle); 3022 sm_conn = sm_get_connection_for_handle(con_handle); 3023 if (!sm_conn) break; 3024 3025 // delete stored bonding on disconnect with authentication failure in ph0 3026 if (sm_conn->sm_role == 0 3027 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3028 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3029 le_device_db_remove(sm_conn->sm_le_db_index); 3030 } 3031 3032 // pairing failed, if it was ongoing 3033 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3034 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3035 } 3036 3037 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3038 sm_conn->sm_handle = 0; 3039 break; 3040 3041 case HCI_EVENT_COMMAND_COMPLETE: 3042 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3043 // set local addr for le device db 3044 bd_addr_t addr; 3045 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3046 le_device_db_set_local_bd_addr(addr); 3047 } 3048 break; 3049 default: 3050 break; 3051 } 3052 break; 3053 default: 3054 break; 3055 } 3056 3057 sm_run(); 3058 } 3059 3060 static inline int sm_calc_actual_encryption_key_size(int other){ 3061 if (other < sm_min_encryption_key_size) return 0; 3062 if (other < sm_max_encryption_key_size) return other; 3063 return sm_max_encryption_key_size; 3064 } 3065 3066 3067 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3068 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3069 switch (method){ 3070 case JUST_WORKS: 3071 case NUMERIC_COMPARISON: 3072 return 1; 3073 default: 3074 return 0; 3075 } 3076 } 3077 // responder 3078 3079 static int sm_passkey_used(stk_generation_method_t method){ 3080 switch (method){ 3081 case PK_RESP_INPUT: 3082 return 1; 3083 default: 3084 return 0; 3085 } 3086 } 3087 3088 static int sm_passkey_entry(stk_generation_method_t method){ 3089 switch (method){ 3090 case PK_RESP_INPUT: 3091 case PK_INIT_INPUT: 3092 case PK_BOTH_INPUT: 3093 return 1; 3094 default: 3095 return 0; 3096 } 3097 } 3098 3099 #endif 3100 3101 /** 3102 * @return ok 3103 */ 3104 static int sm_validate_stk_generation_method(void){ 3105 // check if STK generation method is acceptable by client 3106 switch (setup->sm_stk_generation_method){ 3107 case JUST_WORKS: 3108 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3109 case PK_RESP_INPUT: 3110 case PK_INIT_INPUT: 3111 case PK_BOTH_INPUT: 3112 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3113 case OOB: 3114 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3115 case NUMERIC_COMPARISON: 3116 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3117 return 1; 3118 default: 3119 return 0; 3120 } 3121 } 3122 3123 // size of complete sm_pdu used to validate input 3124 static const uint8_t sm_pdu_size[] = { 3125 0, // 0x00 invalid opcode 3126 7, // 0x01 pairing request 3127 7, // 0x02 pairing response 3128 17, // 0x03 pairing confirm 3129 17, // 0x04 pairing random 3130 2, // 0x05 pairing failed 3131 17, // 0x06 encryption information 3132 11, // 0x07 master identification 3133 17, // 0x08 identification information 3134 8, // 0x09 identify address information 3135 17, // 0x0a signing information 3136 2, // 0x0b security request 3137 65, // 0x0c pairing public key 3138 17, // 0x0d pairing dhk check 3139 2, // 0x0e keypress notification 3140 }; 3141 3142 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3143 3144 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3145 sm_run(); 3146 } 3147 3148 if (packet_type != SM_DATA_PACKET) return; 3149 if (size == 0) return; 3150 3151 uint8_t sm_pdu_code = packet[0]; 3152 3153 // validate pdu size 3154 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3155 if (sm_pdu_size[sm_pdu_code] != size) return; 3156 3157 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3158 if (!sm_conn) return; 3159 3160 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3161 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3162 sm_done_for_handle(con_handle); 3163 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3164 return; 3165 } 3166 3167 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3168 3169 int err; 3170 UNUSED(err); 3171 3172 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3173 uint8_t buffer[5]; 3174 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3175 buffer[1] = 3; 3176 little_endian_store_16(buffer, 2, con_handle); 3177 buffer[4] = packet[1]; 3178 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3179 return; 3180 } 3181 3182 switch (sm_conn->sm_engine_state){ 3183 3184 // a sm timeout requries a new physical connection 3185 case SM_GENERAL_TIMEOUT: 3186 return; 3187 3188 #ifdef ENABLE_LE_CENTRAL 3189 3190 // Initiator 3191 case SM_INITIATOR_CONNECTED: 3192 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3193 sm_pdu_received_in_wrong_state(sm_conn); 3194 break; 3195 } 3196 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3197 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3198 break; 3199 } 3200 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3201 sm_key_t ltk; 3202 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3203 if (!sm_is_null_key(ltk)){ 3204 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3205 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3206 } else { 3207 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3208 } 3209 break; 3210 } 3211 // otherwise, store security request 3212 sm_conn->sm_security_request_received = 1; 3213 break; 3214 3215 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3216 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3217 sm_pdu_received_in_wrong_state(sm_conn); 3218 break; 3219 } 3220 3221 // store pairing request 3222 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3223 err = sm_stk_generation_init(sm_conn); 3224 3225 #ifdef ENABLE_TESTING_SUPPORT 3226 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3227 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3228 err = test_pairing_failure; 3229 } 3230 #endif 3231 3232 if (err){ 3233 setup->sm_pairing_failed_reason = err; 3234 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3235 break; 3236 } 3237 3238 // generate random number first, if we need to show passkey 3239 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3240 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3241 break; 3242 } 3243 3244 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3245 if (setup->sm_use_secure_connections){ 3246 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3247 if (setup->sm_stk_generation_method == JUST_WORKS){ 3248 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3249 sm_trigger_user_response(sm_conn); 3250 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3251 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3252 } 3253 } else { 3254 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3255 } 3256 break; 3257 } 3258 #endif 3259 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3260 sm_trigger_user_response(sm_conn); 3261 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3262 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3263 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3264 } 3265 break; 3266 3267 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3268 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3269 sm_pdu_received_in_wrong_state(sm_conn); 3270 break; 3271 } 3272 3273 // store s_confirm 3274 reverse_128(&packet[1], setup->sm_peer_confirm); 3275 3276 #ifdef ENABLE_TESTING_SUPPORT 3277 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3278 log_info("testing_support: reset confirm value"); 3279 memset(setup->sm_peer_confirm, 0, 16); 3280 } 3281 #endif 3282 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3283 break; 3284 3285 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3286 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3287 sm_pdu_received_in_wrong_state(sm_conn); 3288 break;; 3289 } 3290 3291 // received random value 3292 reverse_128(&packet[1], setup->sm_peer_random); 3293 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3294 break; 3295 #endif 3296 3297 #ifdef ENABLE_LE_PERIPHERAL 3298 // Responder 3299 case SM_RESPONDER_IDLE: 3300 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3301 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3302 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3303 sm_pdu_received_in_wrong_state(sm_conn); 3304 break;; 3305 } 3306 3307 // store pairing request 3308 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3309 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3310 break; 3311 #endif 3312 3313 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3314 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3315 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3316 sm_pdu_received_in_wrong_state(sm_conn); 3317 break; 3318 } 3319 3320 // store public key for DH Key calculation 3321 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3322 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3323 3324 // validate public key 3325 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3326 if (err){ 3327 log_error("sm: peer public key invalid %x", err); 3328 // uses "unspecified reason", there is no "public key invalid" error code 3329 sm_pdu_received_in_wrong_state(sm_conn); 3330 break; 3331 } 3332 3333 // start calculating dhkey 3334 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3335 3336 3337 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3338 if (IS_RESPONDER(sm_conn->sm_role)){ 3339 // responder 3340 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3341 } else { 3342 // initiator 3343 // stk generation method 3344 // passkey entry: notify app to show passkey or to request passkey 3345 switch (setup->sm_stk_generation_method){ 3346 case JUST_WORKS: 3347 case NUMERIC_COMPARISON: 3348 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3349 break; 3350 case PK_RESP_INPUT: 3351 sm_sc_start_calculating_local_confirm(sm_conn); 3352 break; 3353 case PK_INIT_INPUT: 3354 case PK_BOTH_INPUT: 3355 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3356 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3357 break; 3358 } 3359 sm_sc_start_calculating_local_confirm(sm_conn); 3360 break; 3361 case OOB: 3362 // generate Nx 3363 log_info("Generate Na"); 3364 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3365 break; 3366 } 3367 } 3368 break; 3369 3370 case SM_SC_W4_CONFIRMATION: 3371 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3372 sm_pdu_received_in_wrong_state(sm_conn); 3373 break; 3374 } 3375 // received confirm value 3376 reverse_128(&packet[1], setup->sm_peer_confirm); 3377 3378 #ifdef ENABLE_TESTING_SUPPORT 3379 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3380 log_info("testing_support: reset confirm value"); 3381 memset(setup->sm_peer_confirm, 0, 16); 3382 } 3383 #endif 3384 if (IS_RESPONDER(sm_conn->sm_role)){ 3385 // responder 3386 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3387 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3388 // still waiting for passkey 3389 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3390 break; 3391 } 3392 } 3393 sm_sc_start_calculating_local_confirm(sm_conn); 3394 } else { 3395 // initiator 3396 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3397 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3398 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3399 } else { 3400 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3401 } 3402 } 3403 break; 3404 3405 case SM_SC_W4_PAIRING_RANDOM: 3406 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3407 sm_pdu_received_in_wrong_state(sm_conn); 3408 break; 3409 } 3410 3411 // received random value 3412 reverse_128(&packet[1], setup->sm_peer_nonce); 3413 3414 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3415 // only check for JUST WORK/NC in initiator role OR passkey entry 3416 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3417 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3418 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3419 break; 3420 } 3421 3422 // OOB 3423 if (setup->sm_stk_generation_method == OOB){ 3424 3425 // setup local random, set to zero if remote did not receive our data 3426 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3427 if (IS_RESPONDER(sm_conn->sm_role)){ 3428 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3429 log_info("Reset rb as A does not have OOB data"); 3430 memset(setup->sm_rb, 0, 16); 3431 } else { 3432 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3433 log_info("Use stored rb"); 3434 log_info_hexdump(setup->sm_rb, 16); 3435 } 3436 } else { 3437 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3438 log_info("Reset ra as B does not have OOB data"); 3439 memset(setup->sm_ra, 0, 16); 3440 } else { 3441 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3442 log_info("Use stored ra"); 3443 log_info_hexdump(setup->sm_ra, 16); 3444 } 3445 } 3446 3447 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3448 if (setup->sm_have_oob_data){ 3449 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3450 break; 3451 } 3452 } 3453 3454 // TODO: we only get here for Responder role with JW/NC 3455 sm_sc_state_after_receiving_random(sm_conn); 3456 break; 3457 3458 case SM_SC_W2_CALCULATE_G2: 3459 case SM_SC_W4_CALCULATE_G2: 3460 case SM_SC_W4_CALCULATE_DHKEY: 3461 case SM_SC_W2_CALCULATE_F5_SALT: 3462 case SM_SC_W4_CALCULATE_F5_SALT: 3463 case SM_SC_W2_CALCULATE_F5_MACKEY: 3464 case SM_SC_W4_CALCULATE_F5_MACKEY: 3465 case SM_SC_W2_CALCULATE_F5_LTK: 3466 case SM_SC_W4_CALCULATE_F5_LTK: 3467 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3468 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3469 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3470 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3471 sm_pdu_received_in_wrong_state(sm_conn); 3472 break; 3473 } 3474 // store DHKey Check 3475 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3476 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3477 3478 // have we been only waiting for dhkey check command? 3479 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3480 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3481 } 3482 break; 3483 #endif 3484 3485 #ifdef ENABLE_LE_PERIPHERAL 3486 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3487 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3488 sm_pdu_received_in_wrong_state(sm_conn); 3489 break; 3490 } 3491 3492 // received confirm value 3493 reverse_128(&packet[1], setup->sm_peer_confirm); 3494 3495 #ifdef ENABLE_TESTING_SUPPORT 3496 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3497 log_info("testing_support: reset confirm value"); 3498 memset(setup->sm_peer_confirm, 0, 16); 3499 } 3500 #endif 3501 // notify client to hide shown passkey 3502 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3503 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3504 } 3505 3506 // handle user cancel pairing? 3507 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3508 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3509 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3510 break; 3511 } 3512 3513 // wait for user action? 3514 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3515 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3516 break; 3517 } 3518 3519 // calculate and send local_confirm 3520 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3521 break; 3522 3523 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3524 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3525 sm_pdu_received_in_wrong_state(sm_conn); 3526 break;; 3527 } 3528 3529 // received random value 3530 reverse_128(&packet[1], setup->sm_peer_random); 3531 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3532 break; 3533 #endif 3534 3535 case SM_PH3_RECEIVE_KEYS: 3536 switch(sm_pdu_code){ 3537 case SM_CODE_ENCRYPTION_INFORMATION: 3538 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3539 reverse_128(&packet[1], setup->sm_peer_ltk); 3540 break; 3541 3542 case SM_CODE_MASTER_IDENTIFICATION: 3543 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3544 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3545 reverse_64(&packet[3], setup->sm_peer_rand); 3546 break; 3547 3548 case SM_CODE_IDENTITY_INFORMATION: 3549 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3550 reverse_128(&packet[1], setup->sm_peer_irk); 3551 break; 3552 3553 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3554 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3555 setup->sm_peer_addr_type = packet[1]; 3556 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3557 break; 3558 3559 case SM_CODE_SIGNING_INFORMATION: 3560 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3561 reverse_128(&packet[1], setup->sm_peer_csrk); 3562 break; 3563 default: 3564 // Unexpected PDU 3565 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3566 break; 3567 } 3568 // done with key distribution? 3569 if (sm_key_distribution_all_received(sm_conn)){ 3570 3571 sm_key_distribution_handle_all_received(sm_conn); 3572 3573 if (IS_RESPONDER(sm_conn->sm_role)){ 3574 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3575 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3576 } else { 3577 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3578 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3579 sm_done_for_handle(sm_conn->sm_handle); 3580 } 3581 } else { 3582 if (setup->sm_use_secure_connections){ 3583 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3584 } else { 3585 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3586 } 3587 } 3588 } 3589 break; 3590 default: 3591 // Unexpected PDU 3592 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3593 break; 3594 } 3595 3596 // try to send preparared packet 3597 sm_run(); 3598 } 3599 3600 // Security Manager Client API 3601 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3602 sm_get_oob_data = get_oob_data_callback; 3603 } 3604 3605 void sm_register_sc_oob_data_callback( int (*get_sc_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random)){ 3606 sm_get_sc_oob_data = get_sc_oob_data_callback; 3607 } 3608 3609 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3610 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3611 } 3612 3613 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3614 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3615 } 3616 3617 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3618 sm_min_encryption_key_size = min_size; 3619 sm_max_encryption_key_size = max_size; 3620 } 3621 3622 void sm_set_authentication_requirements(uint8_t auth_req){ 3623 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3624 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3625 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3626 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3627 } 3628 #endif 3629 sm_auth_req = auth_req; 3630 } 3631 3632 void sm_set_io_capabilities(io_capability_t io_capability){ 3633 sm_io_capabilities = io_capability; 3634 } 3635 3636 #ifdef ENABLE_LE_PERIPHERAL 3637 void sm_set_request_security(int enable){ 3638 sm_slave_request_security = enable; 3639 } 3640 #endif 3641 3642 void sm_set_er(sm_key_t er){ 3643 memcpy(sm_persistent_er, er, 16); 3644 } 3645 3646 void sm_set_ir(sm_key_t ir){ 3647 memcpy(sm_persistent_ir, ir, 16); 3648 } 3649 3650 // Testing support only 3651 void sm_test_set_irk(sm_key_t irk){ 3652 memcpy(sm_persistent_irk, irk, 16); 3653 sm_persistent_irk_ready = 1; 3654 } 3655 3656 void sm_test_use_fixed_local_csrk(void){ 3657 test_use_fixed_local_csrk = 1; 3658 } 3659 3660 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3661 static void sm_ec_generated(void * arg){ 3662 UNUSED(arg); 3663 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3664 } 3665 #endif 3666 3667 #ifdef ENABLE_TESTING_SUPPORT 3668 void sm_test_set_pairing_failure(int reason){ 3669 test_pairing_failure = reason; 3670 } 3671 #endif 3672 3673 void sm_init(void){ 3674 // set some (BTstack default) ER and IR 3675 int i; 3676 sm_key_t er; 3677 sm_key_t ir; 3678 for (i=0;i<16;i++){ 3679 er[i] = 0x30 + i; 3680 ir[i] = 0x90 + i; 3681 } 3682 sm_set_er(er); 3683 sm_set_ir(ir); 3684 // defaults 3685 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3686 | SM_STK_GENERATION_METHOD_OOB 3687 | SM_STK_GENERATION_METHOD_PASSKEY 3688 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3689 3690 sm_max_encryption_key_size = 16; 3691 sm_min_encryption_key_size = 7; 3692 3693 sm_fixed_passkey_in_display_role = 0xffffffff; 3694 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3695 3696 #ifdef USE_CMAC_ENGINE 3697 sm_cmac_active = 0; 3698 #endif 3699 dkg_state = DKG_W4_WORKING; 3700 rau_state = RAU_W4_WORKING; 3701 sm_aes128_state = SM_AES128_IDLE; 3702 sm_address_resolution_test = -1; // no private address to resolve yet 3703 sm_address_resolution_ah_calculation_active = 0; 3704 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3705 sm_address_resolution_general_queue = NULL; 3706 3707 gap_random_adress_update_period = 15 * 60 * 1000L; 3708 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3709 3710 test_use_fixed_local_csrk = 0; 3711 3712 // register for HCI Events from HCI 3713 hci_event_callback_registration.callback = &sm_event_packet_handler; 3714 hci_add_event_handler(&hci_event_callback_registration); 3715 3716 // 3717 btstack_crypto_init(); 3718 3719 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3720 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3721 3722 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3723 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3724 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3725 #endif 3726 } 3727 3728 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3729 sm_fixed_passkey_in_display_role = passkey; 3730 } 3731 3732 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3733 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3734 } 3735 3736 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3737 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3738 if (!hci_con) return NULL; 3739 return &hci_con->sm_connection; 3740 } 3741 3742 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3743 switch (sm_conn->sm_engine_state){ 3744 case SM_GENERAL_IDLE: 3745 case SM_RESPONDER_IDLE: 3746 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3747 sm_run(); 3748 break; 3749 default: 3750 break; 3751 } 3752 } 3753 3754 /** 3755 * @brief Trigger Security Request 3756 */ 3757 void sm_send_security_request(hci_con_handle_t con_handle){ 3758 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3759 if (!sm_conn) return; 3760 sm_send_security_request_for_connection(sm_conn); 3761 } 3762 3763 // request pairing 3764 void sm_request_pairing(hci_con_handle_t con_handle){ 3765 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3766 if (!sm_conn) return; // wrong connection 3767 3768 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3769 if (IS_RESPONDER(sm_conn->sm_role)){ 3770 sm_send_security_request_for_connection(sm_conn); 3771 } else { 3772 // used as a trigger to start central/master/initiator security procedures 3773 uint16_t ediv; 3774 sm_key_t ltk; 3775 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3776 switch (sm_conn->sm_irk_lookup_state){ 3777 case IRK_LOOKUP_FAILED: 3778 log_info("irk lookup failed, send pairing request"); 3779 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3780 break; 3781 case IRK_LOOKUP_SUCCEEDED: 3782 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3783 if (!sm_is_null_key(ltk) || ediv){ 3784 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3785 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3786 } else { 3787 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3788 } 3789 break; 3790 default: 3791 log_info("irk lookup pending"); 3792 sm_conn->sm_pairing_requested = 1; 3793 break; 3794 } 3795 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3796 sm_conn->sm_pairing_requested = 1; 3797 } 3798 } 3799 sm_run(); 3800 } 3801 3802 // called by client app on authorization request 3803 void sm_authorization_decline(hci_con_handle_t con_handle){ 3804 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3805 if (!sm_conn) return; // wrong connection 3806 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3807 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3808 } 3809 3810 void sm_authorization_grant(hci_con_handle_t con_handle){ 3811 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3812 if (!sm_conn) return; // wrong connection 3813 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3814 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3815 } 3816 3817 // GAP Bonding API 3818 3819 void sm_bonding_decline(hci_con_handle_t con_handle){ 3820 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3821 if (!sm_conn) return; // wrong connection 3822 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3823 log_info("decline, state %u", sm_conn->sm_engine_state); 3824 switch(sm_conn->sm_engine_state){ 3825 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3826 case SM_SC_W4_USER_RESPONSE: 3827 case SM_SC_W4_CONFIRMATION: 3828 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3829 #endif 3830 case SM_PH1_W4_USER_RESPONSE: 3831 switch (setup->sm_stk_generation_method){ 3832 case PK_RESP_INPUT: 3833 case PK_INIT_INPUT: 3834 case PK_BOTH_INPUT: 3835 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3836 break; 3837 case NUMERIC_COMPARISON: 3838 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3839 break; 3840 case JUST_WORKS: 3841 case OOB: 3842 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3843 break; 3844 } 3845 break; 3846 default: 3847 break; 3848 } 3849 sm_run(); 3850 } 3851 3852 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3853 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3854 if (!sm_conn) return; // wrong connection 3855 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3856 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3857 if (setup->sm_use_secure_connections){ 3858 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3859 } else { 3860 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3861 } 3862 } 3863 3864 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3865 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3866 sm_sc_prepare_dhkey_check(sm_conn); 3867 } 3868 #endif 3869 3870 sm_run(); 3871 } 3872 3873 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3874 // for now, it's the same 3875 sm_just_works_confirm(con_handle); 3876 } 3877 3878 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3879 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3880 if (!sm_conn) return; // wrong connection 3881 sm_reset_tk(); 3882 big_endian_store_32(setup->sm_tk, 12, passkey); 3883 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3884 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3885 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3886 } 3887 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3888 memcpy(setup->sm_ra, setup->sm_tk, 16); 3889 memcpy(setup->sm_rb, setup->sm_tk, 16); 3890 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3891 sm_sc_start_calculating_local_confirm(sm_conn); 3892 } 3893 #endif 3894 sm_run(); 3895 } 3896 3897 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3898 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3899 if (!sm_conn) return; // wrong connection 3900 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3901 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3902 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3903 switch (action){ 3904 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3905 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3906 flags |= (1 << action); 3907 break; 3908 case SM_KEYPRESS_PASSKEY_CLEARED: 3909 // clear counter, keypress & erased flags + set passkey cleared 3910 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3911 break; 3912 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3913 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3914 // erase actions queued 3915 num_actions--; 3916 if (num_actions == 0){ 3917 // clear counter, keypress & erased flags 3918 flags &= 0x19; 3919 } 3920 break; 3921 } 3922 num_actions++; 3923 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3924 break; 3925 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3926 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3927 // enter actions queued 3928 num_actions--; 3929 if (num_actions == 0){ 3930 // clear counter, keypress & erased flags 3931 flags &= 0x19; 3932 } 3933 break; 3934 } 3935 num_actions++; 3936 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3937 break; 3938 default: 3939 break; 3940 } 3941 setup->sm_keypress_notification = (num_actions << 5) | flags; 3942 sm_run(); 3943 } 3944 3945 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3946 static void sm_handle_random_result_oob(void * arg){ 3947 UNUSED(arg); 3948 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3949 sm_run(); 3950 } 3951 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3952 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3953 sm_sc_oob_callback = callback; 3954 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3955 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3956 return 0; 3957 } 3958 #endif 3959 3960 /** 3961 * @brief Identify device in LE Device DB 3962 * @param handle 3963 * @returns index from le_device_db or -1 if not found/identified 3964 */ 3965 int sm_le_device_index(hci_con_handle_t con_handle ){ 3966 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3967 if (!sm_conn) return -1; 3968 return sm_conn->sm_le_db_index; 3969 } 3970 3971 static int gap_random_address_type_requires_updates(void){ 3972 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3973 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3974 return 1; 3975 } 3976 3977 static uint8_t own_address_type(void){ 3978 switch (gap_random_adress_type){ 3979 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3980 return BD_ADDR_TYPE_LE_PUBLIC; 3981 default: 3982 return BD_ADDR_TYPE_LE_RANDOM; 3983 } 3984 } 3985 3986 // GAP LE API 3987 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3988 gap_random_address_update_stop(); 3989 gap_random_adress_type = random_address_type; 3990 hci_le_set_own_address_type(own_address_type()); 3991 if (!gap_random_address_type_requires_updates()) return; 3992 gap_random_address_update_start(); 3993 gap_random_address_trigger(); 3994 } 3995 3996 gap_random_address_type_t gap_random_address_get_mode(void){ 3997 return gap_random_adress_type; 3998 } 3999 4000 void gap_random_address_set_update_period(int period_ms){ 4001 gap_random_adress_update_period = period_ms; 4002 if (!gap_random_address_type_requires_updates()) return; 4003 gap_random_address_update_stop(); 4004 gap_random_address_update_start(); 4005 } 4006 4007 void gap_random_address_set(bd_addr_t addr){ 4008 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4009 memcpy(sm_random_address, addr, 6); 4010 if (rau_state == RAU_W4_WORKING) return; 4011 rau_state = RAU_SET_ADDRESS; 4012 sm_run(); 4013 } 4014 4015 #ifdef ENABLE_LE_PERIPHERAL 4016 /* 4017 * @brief Set Advertisement Paramters 4018 * @param adv_int_min 4019 * @param adv_int_max 4020 * @param adv_type 4021 * @param direct_address_type 4022 * @param direct_address 4023 * @param channel_map 4024 * @param filter_policy 4025 * 4026 * @note own_address_type is used from gap_random_address_set_mode 4027 */ 4028 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4029 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4030 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4031 direct_address_typ, direct_address, channel_map, filter_policy); 4032 } 4033 #endif 4034