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_random_t sm_crypto_random_oob_request; 250 static btstack_crypto_aes128_t sm_crypto_aes128_request; 251 #ifdef ENABLE_LE_SECURE_CONNECTIONS 252 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_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 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 407 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 408 static void sm_handle_encryption_result_enc_stk(void *arg); 409 static void sm_handle_encryption_result_rau(void *arg); 410 static void sm_handle_random_result_ph2_tk(void * arg); 411 static void sm_handle_random_result_rau(void * arg); 412 #ifdef ENABLE_LE_SECURE_CONNECTIONS 413 static void sm_handle_random_result_sc_get_random(void * arg); 414 #endif 415 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 418 static void log_info_hex16(const char * name, uint16_t value){ 419 log_info("%-6s 0x%04x", name, value); 420 } 421 422 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 423 // return packet[0]; 424 // } 425 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 426 return packet[1]; 427 } 428 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 429 return packet[2]; 430 } 431 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 432 return packet[3]; 433 } 434 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 435 return packet[4]; 436 } 437 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 438 return packet[5]; 439 } 440 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 441 return packet[6]; 442 } 443 444 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 445 packet[0] = code; 446 } 447 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 448 packet[1] = io_capability; 449 } 450 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 451 packet[2] = oob_data_flag; 452 } 453 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 454 packet[3] = auth_req; 455 } 456 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 457 packet[4] = max_encryption_key_size; 458 } 459 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 460 packet[5] = initiator_key_distribution; 461 } 462 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 463 packet[6] = responder_key_distribution; 464 } 465 466 // @returns 1 if all bytes are 0 467 static int sm_is_null(uint8_t * data, int size){ 468 int i; 469 for (i=0; i < size ; i++){ 470 if (data[i]) return 0; 471 } 472 return 1; 473 } 474 475 static int sm_is_null_random(uint8_t random[8]){ 476 return sm_is_null(random, 8); 477 } 478 479 static int sm_is_null_key(uint8_t * key){ 480 return sm_is_null(key, 16); 481 } 482 483 // Key utils 484 static void sm_reset_tk(void){ 485 int i; 486 for (i=0;i<16;i++){ 487 setup->sm_tk[i] = 0; 488 } 489 } 490 491 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 492 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 493 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 494 int i; 495 for (i = max_encryption_size ; i < 16 ; i++){ 496 key[15-i] = 0; 497 } 498 } 499 500 // SMP Timeout implementation 501 502 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 503 // the Security Manager Timer shall be reset and started. 504 // 505 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 506 // 507 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 508 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 509 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 510 // established. 511 512 static void sm_timeout_handler(btstack_timer_source_t * timer){ 513 log_info("SM timeout"); 514 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 515 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 516 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 517 sm_done_for_handle(sm_conn->sm_handle); 518 519 // trigger handling of next ready connection 520 sm_run(); 521 } 522 static void sm_timeout_start(sm_connection_t * sm_conn){ 523 btstack_run_loop_remove_timer(&setup->sm_timeout); 524 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 525 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 526 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 527 btstack_run_loop_add_timer(&setup->sm_timeout); 528 } 529 static void sm_timeout_stop(void){ 530 btstack_run_loop_remove_timer(&setup->sm_timeout); 531 } 532 static void sm_timeout_reset(sm_connection_t * sm_conn){ 533 sm_timeout_stop(); 534 sm_timeout_start(sm_conn); 535 } 536 537 // end of sm timeout 538 539 // GAP Random Address updates 540 static gap_random_address_type_t gap_random_adress_type; 541 static btstack_timer_source_t gap_random_address_update_timer; 542 static uint32_t gap_random_adress_update_period; 543 544 static void gap_random_address_trigger(void){ 545 log_info("gap_random_address_trigger"); 546 if (rau_state != RAU_IDLE) return; 547 rau_state = RAU_W4_RANDOM; 548 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 549 } 550 551 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 552 UNUSED(timer); 553 554 log_info("GAP Random Address Update due"); 555 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 556 btstack_run_loop_add_timer(&gap_random_address_update_timer); 557 gap_random_address_trigger(); 558 } 559 560 static void gap_random_address_update_start(void){ 561 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 562 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 563 btstack_run_loop_add_timer(&gap_random_address_update_timer); 564 } 565 566 static void gap_random_address_update_stop(void){ 567 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 568 } 569 570 // ah(k,r) helper 571 // r = padding || r 572 // r - 24 bit value 573 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 574 // r'= padding || r 575 memset(r_prime, 0, 16); 576 memcpy(&r_prime[13], r, 3); 577 } 578 579 // d1 helper 580 // d' = padding || r || d 581 // d,r - 16 bit values 582 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 583 // d'= padding || r || d 584 memset(d1_prime, 0, 16); 585 big_endian_store_16(d1_prime, 12, r); 586 big_endian_store_16(d1_prime, 14, d); 587 } 588 589 // dm helper 590 // r’ = padding || r 591 // r - 64 bit value 592 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 593 memset(r_prime, 0, 16); 594 memcpy(&r_prime[8], r, 8); 595 } 596 597 // calculate arguments for first AES128 operation in C1 function 598 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){ 599 600 // p1 = pres || preq || rat’ || iat’ 601 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 602 // cant octet of pres becomes the most significant octet of p1. 603 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 604 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 605 // p1 is 0x05000800000302070710000001010001." 606 607 sm_key_t p1; 608 reverse_56(pres, &p1[0]); 609 reverse_56(preq, &p1[7]); 610 p1[14] = rat; 611 p1[15] = iat; 612 log_info_key("p1", p1); 613 log_info_key("r", r); 614 615 // t1 = r xor p1 616 int i; 617 for (i=0;i<16;i++){ 618 t1[i] = r[i] ^ p1[i]; 619 } 620 log_info_key("t1", t1); 621 } 622 623 // calculate arguments for second AES128 operation in C1 function 624 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 625 // p2 = padding || ia || ra 626 // "The least significant octet of ra becomes the least significant octet of p2 and 627 // the most significant octet of padding becomes the most significant octet of p2. 628 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 629 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 630 631 sm_key_t p2; 632 memset(p2, 0, 16); 633 memcpy(&p2[4], ia, 6); 634 memcpy(&p2[10], ra, 6); 635 log_info_key("p2", p2); 636 637 // c1 = e(k, t2_xor_p2) 638 int i; 639 for (i=0;i<16;i++){ 640 t3[i] = t2[i] ^ p2[i]; 641 } 642 log_info_key("t3", t3); 643 } 644 645 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 646 log_info_key("r1", r1); 647 log_info_key("r2", r2); 648 memcpy(&r_prime[8], &r2[8], 8); 649 memcpy(&r_prime[0], &r1[8], 8); 650 } 651 652 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 653 UNUSED(channel); 654 655 // log event 656 hci_dump_packet(packet_type, 1, packet, size); 657 // dispatch to all event handlers 658 btstack_linked_list_iterator_t it; 659 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 660 while (btstack_linked_list_iterator_has_next(&it)){ 661 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 662 entry->callback(packet_type, 0, packet, size); 663 } 664 } 665 666 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){ 667 event[0] = type; 668 event[1] = event_size - 2; 669 little_endian_store_16(event, 2, con_handle); 670 event[4] = addr_type; 671 reverse_bd_addr(address, &event[5]); 672 } 673 674 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 675 uint8_t event[11]; 676 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 677 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 678 } 679 680 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){ 681 uint8_t event[15]; 682 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 683 little_endian_store_32(event, 11, passkey); 684 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 685 } 686 687 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){ 688 // fetch addr and addr type from db 689 bd_addr_t identity_address; 690 int identity_address_type; 691 le_device_db_info(index, &identity_address_type, identity_address, NULL); 692 693 uint8_t event[19]; 694 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 695 event[11] = identity_address_type; 696 reverse_bd_addr(identity_address, &event[12]); 697 event[18] = index; 698 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 699 } 700 701 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){ 702 uint8_t event[12]; 703 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 704 event[11] = status; 705 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 706 } 707 708 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 709 uint8_t event[13]; 710 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 711 event[11] = status; 712 event[12] = reason; 713 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 714 } 715 716 // decide on stk generation based on 717 // - pairing request 718 // - io capabilities 719 // - OOB data availability 720 static void sm_setup_tk(void){ 721 722 // default: just works 723 setup->sm_stk_generation_method = JUST_WORKS; 724 725 #ifdef ENABLE_LE_SECURE_CONNECTIONS 726 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 727 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 728 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 729 #else 730 setup->sm_use_secure_connections = 0; 731 #endif 732 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 733 734 735 // decide if OOB will be used based on SC vs. Legacy and oob flags 736 int use_oob = 0; 737 if (setup->sm_use_secure_connections){ 738 // In LE Secure Connections pairing, the out of band method is used if at least 739 // one device has the peer device's out of band authentication data available. 740 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 741 } else { 742 // In LE legacy pairing, the out of band method is used if both the devices have 743 // the other device's out of band authentication data available. 744 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 745 } 746 if (use_oob){ 747 log_info("SM: have OOB data"); 748 log_info_key("OOB", setup->sm_tk); 749 setup->sm_stk_generation_method = OOB; 750 return; 751 } 752 753 // If both devices have not set the MITM option in the Authentication Requirements 754 // Flags, then the IO capabilities shall be ignored and the Just Works association 755 // model shall be used. 756 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 757 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 758 log_info("SM: MITM not required by both -> JUST WORKS"); 759 return; 760 } 761 762 // Reset TK as it has been setup in sm_init_setup 763 sm_reset_tk(); 764 765 // Also use just works if unknown io capabilites 766 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)){ 767 return; 768 } 769 770 // Otherwise the IO capabilities of the devices shall be used to determine the 771 // pairing method as defined in Table 2.4. 772 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 773 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 774 775 #ifdef ENABLE_LE_SECURE_CONNECTIONS 776 // table not define by default 777 if (setup->sm_use_secure_connections){ 778 generation_method = stk_generation_method_with_secure_connection; 779 } 780 #endif 781 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)]; 782 783 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 784 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); 785 } 786 787 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 788 int flags = 0; 789 if (key_set & SM_KEYDIST_ENC_KEY){ 790 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 791 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 792 } 793 if (key_set & SM_KEYDIST_ID_KEY){ 794 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 795 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 796 } 797 if (key_set & SM_KEYDIST_SIGN){ 798 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 799 } 800 return flags; 801 } 802 803 static void sm_setup_key_distribution(uint8_t key_set){ 804 setup->sm_key_distribution_received_set = 0; 805 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 806 } 807 808 // CSRK Key Lookup 809 810 811 static int sm_address_resolution_idle(void){ 812 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 813 } 814 815 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){ 816 memcpy(sm_address_resolution_address, addr, 6); 817 sm_address_resolution_addr_type = addr_type; 818 sm_address_resolution_test = 0; 819 sm_address_resolution_mode = mode; 820 sm_address_resolution_context = context; 821 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 822 } 823 824 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 825 // check if already in list 826 btstack_linked_list_iterator_t it; 827 sm_lookup_entry_t * entry; 828 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 829 while(btstack_linked_list_iterator_has_next(&it)){ 830 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 831 if (entry->address_type != address_type) continue; 832 if (memcmp(entry->address, address, 6)) continue; 833 // already in list 834 return BTSTACK_BUSY; 835 } 836 entry = btstack_memory_sm_lookup_entry_get(); 837 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 838 entry->address_type = (bd_addr_type_t) address_type; 839 memcpy(entry->address, address, 6); 840 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 841 sm_run(); 842 return 0; 843 } 844 845 // CMAC calculation using AES Engineq 846 #ifdef USE_CMAC_ENGINE 847 848 static void sm_cmac_done_trampoline(void * arg){ 849 UNUSED(arg); 850 sm_cmac_active = 0; 851 (*sm_cmac_done_callback)(sm_cmac_hash); 852 sm_run(); 853 } 854 855 int sm_cmac_ready(void){ 856 return sm_cmac_active == 0; 857 } 858 859 // generic cmac calculation 860 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)){ 861 sm_cmac_active = 1; 862 sm_cmac_done_callback = done_callback; 863 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 864 } 865 #endif 866 867 // cmac for ATT Message signing 868 #ifdef ENABLE_LE_SIGNED_WRITE 869 870 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)){ 871 sm_cmac_active = 1; 872 sm_cmac_done_callback = done_callback; 873 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 874 } 875 876 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 877 if (offset >= sm_cmac_signed_write_message_len) { 878 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 879 return 0; 880 } 881 882 offset = sm_cmac_signed_write_message_len - 1 - offset; 883 884 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 885 if (offset < 3){ 886 return sm_cmac_signed_write_header[offset]; 887 } 888 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 889 if (offset < actual_message_len_incl_header){ 890 return sm_cmac_signed_write_message[offset - 3]; 891 } 892 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 893 } 894 895 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)){ 896 // ATT Message Signing 897 sm_cmac_signed_write_header[0] = opcode; 898 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 899 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 900 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 901 sm_cmac_signed_write_message = message; 902 sm_cmac_signed_write_message_len = total_message_len; 903 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 904 } 905 #endif 906 907 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 908 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 909 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 910 switch (setup->sm_stk_generation_method){ 911 case PK_RESP_INPUT: 912 if (IS_RESPONDER(sm_conn->sm_role)){ 913 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 914 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 915 } else { 916 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)); 917 } 918 break; 919 case PK_INIT_INPUT: 920 if (IS_RESPONDER(sm_conn->sm_role)){ 921 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)); 922 } else { 923 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 924 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 925 } 926 break; 927 case PK_BOTH_INPUT: 928 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 929 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 930 break; 931 case NUMERIC_COMPARISON: 932 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 933 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)); 934 break; 935 case JUST_WORKS: 936 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 937 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 938 break; 939 case OOB: 940 // client already provided OOB data, let's skip notification. 941 break; 942 } 943 } 944 945 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 946 int recv_flags; 947 if (IS_RESPONDER(sm_conn->sm_role)){ 948 // slave / responder 949 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 950 } else { 951 // master / initiator 952 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 953 } 954 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 955 return recv_flags == setup->sm_key_distribution_received_set; 956 } 957 958 static void sm_done_for_handle(hci_con_handle_t con_handle){ 959 if (sm_active_connection_handle == con_handle){ 960 sm_timeout_stop(); 961 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 962 log_info("sm: connection 0x%x released setup context", con_handle); 963 } 964 } 965 966 static int sm_key_distribution_flags_for_auth_req(void){ 967 968 int flags = SM_KEYDIST_ID_KEY; 969 if (sm_auth_req & SM_AUTHREQ_BONDING){ 970 // encryption and signing information only if bonding requested 971 flags |= SM_KEYDIST_ENC_KEY; 972 #ifdef ENABLE_LE_SIGNED_WRITE 973 flags |= SM_KEYDIST_SIGN; 974 #endif 975 } 976 return flags; 977 } 978 979 static void sm_reset_setup(void){ 980 // fill in sm setup 981 setup->sm_state_vars = 0; 982 setup->sm_keypress_notification = 0; 983 sm_reset_tk(); 984 } 985 986 static void sm_init_setup(sm_connection_t * sm_conn){ 987 988 // fill in sm setup 989 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 990 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 991 992 // query client for Legacy Pairing OOB data 993 setup->sm_have_oob_data = 0; 994 if (sm_get_oob_data) { 995 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 996 } 997 998 // if available and SC supported, also ask for SC OOB Data 999 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1000 memset(setup->sm_ra, 0, 16); 1001 memset(setup->sm_rb, 0, 16); 1002 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1003 if (sm_get_sc_oob_data){ 1004 if (IS_RESPONDER(sm_conn->sm_role)){ 1005 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1006 sm_conn->sm_peer_addr_type, 1007 sm_conn->sm_peer_address, 1008 setup->sm_peer_confirm, 1009 setup->sm_ra); 1010 } else { 1011 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1012 sm_conn->sm_peer_addr_type, 1013 sm_conn->sm_peer_address, 1014 setup->sm_peer_confirm, 1015 setup->sm_rb); 1016 } 1017 } else { 1018 setup->sm_have_oob_data = 0; 1019 } 1020 } 1021 #endif 1022 1023 sm_pairing_packet_t * local_packet; 1024 if (IS_RESPONDER(sm_conn->sm_role)){ 1025 // slave 1026 local_packet = &setup->sm_s_pres; 1027 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1028 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1029 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1030 } else { 1031 // master 1032 local_packet = &setup->sm_m_preq; 1033 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1034 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1035 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1036 1037 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1038 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1039 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1040 } 1041 1042 uint8_t auth_req = sm_auth_req; 1043 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1044 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1045 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1046 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1047 } 1048 1049 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1050 1051 sm_pairing_packet_t * remote_packet; 1052 int remote_key_request; 1053 if (IS_RESPONDER(sm_conn->sm_role)){ 1054 // slave / responder 1055 remote_packet = &setup->sm_m_preq; 1056 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1057 } else { 1058 // master / initiator 1059 remote_packet = &setup->sm_s_pres; 1060 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1061 } 1062 1063 // check key size 1064 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1065 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1066 1067 // decide on STK generation method 1068 sm_setup_tk(); 1069 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1070 1071 // check if STK generation method is acceptable by client 1072 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1073 1074 // identical to responder 1075 sm_setup_key_distribution(remote_key_request); 1076 1077 // JUST WORKS doens't provide authentication 1078 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1079 1080 return 0; 1081 } 1082 1083 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1084 1085 // cache and reset context 1086 int matched_device_id = sm_address_resolution_test; 1087 address_resolution_mode_t mode = sm_address_resolution_mode; 1088 void * context = sm_address_resolution_context; 1089 1090 // reset context 1091 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1092 sm_address_resolution_context = NULL; 1093 sm_address_resolution_test = -1; 1094 hci_con_handle_t con_handle = 0; 1095 1096 sm_connection_t * sm_connection; 1097 #ifdef ENABLE_LE_CENTRAL 1098 sm_key_t ltk; 1099 #endif 1100 switch (mode){ 1101 case ADDRESS_RESOLUTION_GENERAL: 1102 break; 1103 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1104 sm_connection = (sm_connection_t *) context; 1105 con_handle = sm_connection->sm_handle; 1106 switch (event){ 1107 case ADDRESS_RESOLUTION_SUCEEDED: 1108 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1109 sm_connection->sm_le_db_index = matched_device_id; 1110 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1111 if (sm_connection->sm_role) { 1112 // LTK request received before, IRK required -> start LTK calculation 1113 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1114 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1115 } 1116 break; 1117 } 1118 #ifdef ENABLE_LE_CENTRAL 1119 log_info("central: bonding requested %u, prev security request %u", sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received); 1120 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1121 sm_connection->sm_security_request_received = 0; 1122 sm_connection->sm_pairing_requested = 0; 1123 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1124 if (!sm_is_null_key(ltk)){ 1125 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1126 } else { 1127 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1128 } 1129 #endif 1130 break; 1131 case ADDRESS_RESOLUTION_FAILED: 1132 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1133 if (sm_connection->sm_role) { 1134 // LTK request received before, IRK required -> negative LTK reply 1135 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1136 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1137 } 1138 break; 1139 } 1140 #ifdef ENABLE_LE_CENTRAL 1141 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1142 sm_connection->sm_security_request_received = 0; 1143 sm_connection->sm_pairing_requested = 0; 1144 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1145 #endif 1146 break; 1147 } 1148 break; 1149 default: 1150 break; 1151 } 1152 1153 switch (event){ 1154 case ADDRESS_RESOLUTION_SUCEEDED: 1155 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1156 break; 1157 case ADDRESS_RESOLUTION_FAILED: 1158 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1159 break; 1160 } 1161 } 1162 1163 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1164 1165 int le_db_index = -1; 1166 1167 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1168 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1169 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1170 & SM_AUTHREQ_BONDING ) != 0; 1171 1172 if (bonding_enabed){ 1173 1174 // lookup device based on IRK 1175 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1176 int i; 1177 for (i=0; i < le_device_db_max_count(); i++){ 1178 sm_key_t irk; 1179 bd_addr_t address; 1180 int address_type; 1181 le_device_db_info(i, &address_type, address, irk); 1182 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1183 log_info("sm: device found for IRK, updating"); 1184 le_db_index = i; 1185 break; 1186 } 1187 } 1188 } 1189 1190 // if not found, lookup via public address if possible 1191 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1192 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1193 int i; 1194 for (i=0; i < le_device_db_max_count(); i++){ 1195 bd_addr_t address; 1196 int address_type; 1197 le_device_db_info(i, &address_type, address, NULL); 1198 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1199 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1200 log_info("sm: device found for public address, updating"); 1201 le_db_index = i; 1202 break; 1203 } 1204 } 1205 } 1206 1207 // if not found, add to db 1208 if (le_db_index < 0) { 1209 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1210 } 1211 1212 if (le_db_index >= 0){ 1213 1214 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1215 1216 #ifdef ENABLE_LE_SIGNED_WRITE 1217 // store local CSRK 1218 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1219 log_info("sm: store local CSRK"); 1220 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1221 le_device_db_local_counter_set(le_db_index, 0); 1222 } 1223 1224 // store remote CSRK 1225 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1226 log_info("sm: store remote CSRK"); 1227 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1228 le_device_db_remote_counter_set(le_db_index, 0); 1229 } 1230 #endif 1231 // store encryption information for secure connections: LTK generated by ECDH 1232 if (setup->sm_use_secure_connections){ 1233 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1234 uint8_t zero_rand[8]; 1235 memset(zero_rand, 0, 8); 1236 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1237 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1238 } 1239 1240 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1241 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1242 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1243 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1244 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1245 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1246 1247 } 1248 } 1249 } else { 1250 log_info("Ignoring received keys, bonding not enabled"); 1251 } 1252 1253 // keep le_db_index 1254 sm_conn->sm_le_db_index = le_db_index; 1255 } 1256 1257 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1258 setup->sm_pairing_failed_reason = reason; 1259 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1260 } 1261 1262 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1263 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1264 } 1265 1266 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1267 1268 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1269 static int sm_passkey_used(stk_generation_method_t method); 1270 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1271 1272 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1273 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1274 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1275 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1276 } else { 1277 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1278 } 1279 } 1280 1281 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1282 if (IS_RESPONDER(sm_conn->sm_role)){ 1283 // Responder 1284 if (setup->sm_stk_generation_method == OOB){ 1285 // generate Nb 1286 log_info("Generate Nb"); 1287 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1288 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1289 } else { 1290 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1291 } 1292 } else { 1293 // Initiator role 1294 switch (setup->sm_stk_generation_method){ 1295 case JUST_WORKS: 1296 sm_sc_prepare_dhkey_check(sm_conn); 1297 break; 1298 1299 case NUMERIC_COMPARISON: 1300 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1301 break; 1302 case PK_INIT_INPUT: 1303 case PK_RESP_INPUT: 1304 case PK_BOTH_INPUT: 1305 if (setup->sm_passkey_bit < 20) { 1306 sm_sc_start_calculating_local_confirm(sm_conn); 1307 } else { 1308 sm_sc_prepare_dhkey_check(sm_conn); 1309 } 1310 break; 1311 case OOB: 1312 sm_sc_prepare_dhkey_check(sm_conn); 1313 break; 1314 } 1315 } 1316 } 1317 1318 static void sm_sc_cmac_done(uint8_t * hash){ 1319 log_info("sm_sc_cmac_done: "); 1320 log_info_hexdump(hash, 16); 1321 1322 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1323 sm_sc_oob_state = SM_SC_OOB_IDLE; 1324 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1325 return; 1326 } 1327 1328 sm_connection_t * sm_conn = sm_cmac_connection; 1329 sm_cmac_connection = NULL; 1330 #ifdef ENABLE_CLASSIC 1331 link_key_type_t link_key_type; 1332 #endif 1333 1334 switch (sm_conn->sm_engine_state){ 1335 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1336 memcpy(setup->sm_local_confirm, hash, 16); 1337 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1338 break; 1339 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1340 // check 1341 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1342 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1343 break; 1344 } 1345 sm_sc_state_after_receiving_random(sm_conn); 1346 break; 1347 case SM_SC_W4_CALCULATE_G2: { 1348 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1349 big_endian_store_32(setup->sm_tk, 12, vab); 1350 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1351 sm_trigger_user_response(sm_conn); 1352 break; 1353 } 1354 case SM_SC_W4_CALCULATE_F5_SALT: 1355 memcpy(setup->sm_t, hash, 16); 1356 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1357 break; 1358 case SM_SC_W4_CALCULATE_F5_MACKEY: 1359 memcpy(setup->sm_mackey, hash, 16); 1360 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1361 break; 1362 case SM_SC_W4_CALCULATE_F5_LTK: 1363 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1364 // Errata Service Release to the Bluetooth Specification: ESR09 1365 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1366 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1367 memcpy(setup->sm_ltk, hash, 16); 1368 memcpy(setup->sm_local_ltk, hash, 16); 1369 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1370 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1371 break; 1372 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1373 memcpy(setup->sm_local_dhkey_check, hash, 16); 1374 if (IS_RESPONDER(sm_conn->sm_role)){ 1375 // responder 1376 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1377 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1378 } else { 1379 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1380 } 1381 } else { 1382 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1383 } 1384 break; 1385 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1386 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1387 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1388 break; 1389 } 1390 if (IS_RESPONDER(sm_conn->sm_role)){ 1391 // responder 1392 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1393 } else { 1394 // initiator 1395 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1396 } 1397 break; 1398 case SM_SC_W4_CALCULATE_H6_ILK: 1399 memcpy(setup->sm_t, hash, 16); 1400 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1401 break; 1402 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1403 #ifdef ENABLE_CLASSIC 1404 reverse_128(hash, setup->sm_t); 1405 link_key_type = sm_conn->sm_connection_authenticated ? 1406 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1407 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1408 if (IS_RESPONDER(sm_conn->sm_role)){ 1409 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1410 } else { 1411 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1412 } 1413 #endif 1414 if (IS_RESPONDER(sm_conn->sm_role)){ 1415 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1416 } else { 1417 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1418 } 1419 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1420 sm_done_for_handle(sm_conn->sm_handle); 1421 break; 1422 default: 1423 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1424 break; 1425 } 1426 sm_run(); 1427 } 1428 1429 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){ 1430 const uint16_t message_len = 65; 1431 sm_cmac_connection = sm_conn; 1432 memcpy(sm_cmac_sc_buffer, u, 32); 1433 memcpy(sm_cmac_sc_buffer+32, v, 32); 1434 sm_cmac_sc_buffer[64] = z; 1435 log_info("f4 key"); 1436 log_info_hexdump(x, 16); 1437 log_info("f4 message"); 1438 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1439 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1440 } 1441 1442 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1443 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1444 static const uint8_t f5_length[] = { 0x01, 0x00}; 1445 1446 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1447 log_info("f5_calculate_salt"); 1448 // calculate salt for f5 1449 const uint16_t message_len = 32; 1450 sm_cmac_connection = sm_conn; 1451 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1452 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1453 } 1454 1455 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){ 1456 const uint16_t message_len = 53; 1457 sm_cmac_connection = sm_conn; 1458 1459 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1460 sm_cmac_sc_buffer[0] = 0; 1461 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1462 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1463 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1464 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1465 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1466 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1467 log_info("f5 key"); 1468 log_info_hexdump(t, 16); 1469 log_info("f5 message for MacKey"); 1470 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1471 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1472 } 1473 1474 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1475 sm_key56_t bd_addr_master, bd_addr_slave; 1476 bd_addr_master[0] = setup->sm_m_addr_type; 1477 bd_addr_slave[0] = setup->sm_s_addr_type; 1478 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1479 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1480 if (IS_RESPONDER(sm_conn->sm_role)){ 1481 // responder 1482 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1483 } else { 1484 // initiator 1485 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1486 } 1487 } 1488 1489 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1490 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1491 const uint16_t message_len = 53; 1492 sm_cmac_connection = sm_conn; 1493 sm_cmac_sc_buffer[0] = 1; 1494 // 1..52 setup before 1495 log_info("f5 key"); 1496 log_info_hexdump(t, 16); 1497 log_info("f5 message for LTK"); 1498 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1499 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1500 } 1501 1502 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1503 f5_ltk(sm_conn, setup->sm_t); 1504 } 1505 1506 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){ 1507 const uint16_t message_len = 65; 1508 sm_cmac_connection = sm_conn; 1509 memcpy(sm_cmac_sc_buffer, n1, 16); 1510 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1511 memcpy(sm_cmac_sc_buffer+32, r, 16); 1512 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1513 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1514 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1515 log_info("f6 key"); 1516 log_info_hexdump(w, 16); 1517 log_info("f6 message"); 1518 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1519 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1520 } 1521 1522 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1523 // - U is 256 bits 1524 // - V is 256 bits 1525 // - X is 128 bits 1526 // - Y is 128 bits 1527 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){ 1528 const uint16_t message_len = 80; 1529 sm_cmac_connection = sm_conn; 1530 memcpy(sm_cmac_sc_buffer, u, 32); 1531 memcpy(sm_cmac_sc_buffer+32, v, 32); 1532 memcpy(sm_cmac_sc_buffer+64, y, 16); 1533 log_info("g2 key"); 1534 log_info_hexdump(x, 16); 1535 log_info("g2 message"); 1536 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1537 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1538 } 1539 1540 static void g2_calculate(sm_connection_t * sm_conn) { 1541 // calc Va if numeric comparison 1542 if (IS_RESPONDER(sm_conn->sm_role)){ 1543 // responder 1544 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1545 } else { 1546 // initiator 1547 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1548 } 1549 } 1550 1551 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1552 uint8_t z = 0; 1553 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1554 // some form of passkey 1555 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1556 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1557 setup->sm_passkey_bit++; 1558 } 1559 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1560 } 1561 1562 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1563 // OOB 1564 if (setup->sm_stk_generation_method == OOB){ 1565 if (IS_RESPONDER(sm_conn->sm_role)){ 1566 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1567 } else { 1568 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1569 } 1570 return; 1571 } 1572 1573 uint8_t z = 0; 1574 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1575 // some form of passkey 1576 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1577 // sm_passkey_bit was increased before sending confirm value 1578 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1579 } 1580 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1581 } 1582 1583 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1584 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1585 1586 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1587 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1588 return; 1589 } else { 1590 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1591 } 1592 } 1593 1594 static void sm_sc_dhkey_calculated(void * arg){ 1595 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1596 log_info("dhkey"); 1597 log_info_hexdump(&setup->sm_dhkey[0], 32); 1598 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1599 // trigger next step 1600 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1601 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1602 } 1603 sm_run(); 1604 } 1605 1606 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1607 // calculate DHKCheck 1608 sm_key56_t bd_addr_master, bd_addr_slave; 1609 bd_addr_master[0] = setup->sm_m_addr_type; 1610 bd_addr_slave[0] = setup->sm_s_addr_type; 1611 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1612 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1613 uint8_t iocap_a[3]; 1614 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1615 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1616 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1617 uint8_t iocap_b[3]; 1618 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1619 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1620 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1621 if (IS_RESPONDER(sm_conn->sm_role)){ 1622 // responder 1623 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); 1624 } else { 1625 // initiator 1626 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); 1627 } 1628 } 1629 1630 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1631 // validate E = f6() 1632 sm_key56_t bd_addr_master, bd_addr_slave; 1633 bd_addr_master[0] = setup->sm_m_addr_type; 1634 bd_addr_slave[0] = setup->sm_s_addr_type; 1635 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1636 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1637 1638 uint8_t iocap_a[3]; 1639 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1640 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1641 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1642 uint8_t iocap_b[3]; 1643 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1644 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1645 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1646 if (IS_RESPONDER(sm_conn->sm_role)){ 1647 // responder 1648 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); 1649 } else { 1650 // initiator 1651 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); 1652 } 1653 } 1654 1655 1656 // 1657 // Link Key Conversion Function h6 1658 // 1659 // h6(W, keyID) = AES-CMACW(keyID) 1660 // - W is 128 bits 1661 // - keyID is 32 bits 1662 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1663 const uint16_t message_len = 4; 1664 sm_cmac_connection = sm_conn; 1665 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1666 log_info("h6 key"); 1667 log_info_hexdump(w, 16); 1668 log_info("h6 message"); 1669 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1670 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1671 } 1672 1673 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1674 // Errata Service Release to the Bluetooth Specification: ESR09 1675 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1676 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1677 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1678 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1679 } 1680 1681 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1682 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1683 } 1684 1685 #endif 1686 1687 // key management legacy connections: 1688 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1689 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1690 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1691 // - responder reconnects: responder uses LTK receveived from master 1692 1693 // key management secure connections: 1694 // - both devices store same LTK from ECDH key exchange. 1695 1696 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1697 static void sm_load_security_info(sm_connection_t * sm_connection){ 1698 int encryption_key_size; 1699 int authenticated; 1700 int authorized; 1701 1702 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1703 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1704 &encryption_key_size, &authenticated, &authorized); 1705 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1706 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1707 sm_connection->sm_connection_authenticated = authenticated; 1708 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1709 } 1710 #endif 1711 1712 #ifdef ENABLE_LE_PERIPHERAL 1713 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1714 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1715 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1716 // re-establish used key encryption size 1717 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1718 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1719 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1720 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1721 log_info("sm: received ltk request with key size %u, authenticated %u", 1722 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1723 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1724 sm_run(); 1725 } 1726 #endif 1727 1728 static void sm_run(void){ 1729 1730 btstack_linked_list_iterator_t it; 1731 1732 // assert that stack has already bootet 1733 if (hci_get_state() != HCI_STATE_WORKING) return; 1734 1735 // assert that we can send at least commands 1736 if (!hci_can_send_command_packet_now()) return; 1737 1738 // 1739 // non-connection related behaviour 1740 // 1741 1742 // distributed key generation 1743 switch (dkg_state){ 1744 case DKG_CALC_IRK: 1745 // already busy? 1746 if (sm_aes128_state == SM_AES128_IDLE) { 1747 log_info("DKG_CALC_IRK started"); 1748 // IRK = d1(IR, 1, 0) 1749 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1750 sm_aes128_state = SM_AES128_ACTIVE; 1751 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1752 return; 1753 } 1754 break; 1755 case DKG_CALC_DHK: 1756 // already busy? 1757 if (sm_aes128_state == SM_AES128_IDLE) { 1758 log_info("DKG_CALC_DHK started"); 1759 // DHK = d1(IR, 3, 0) 1760 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1761 sm_aes128_state = SM_AES128_ACTIVE; 1762 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1763 return; 1764 } 1765 break; 1766 default: 1767 break; 1768 } 1769 1770 // random address updates 1771 switch (rau_state){ 1772 case RAU_GET_ENC: 1773 // already busy? 1774 if (sm_aes128_state == SM_AES128_IDLE) { 1775 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1776 sm_aes128_state = SM_AES128_ACTIVE; 1777 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1778 return; 1779 } 1780 break; 1781 case RAU_SET_ADDRESS: 1782 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1783 rau_state = RAU_IDLE; 1784 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1785 return; 1786 default: 1787 break; 1788 } 1789 1790 // CSRK Lookup 1791 // -- if csrk lookup ready, find connection that require csrk lookup 1792 if (sm_address_resolution_idle()){ 1793 hci_connections_get_iterator(&it); 1794 while(btstack_linked_list_iterator_has_next(&it)){ 1795 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1796 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1797 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1798 // and start lookup 1799 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); 1800 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1801 break; 1802 } 1803 } 1804 } 1805 1806 // -- if csrk lookup ready, resolved addresses for received addresses 1807 if (sm_address_resolution_idle()) { 1808 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1809 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1810 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1811 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1812 btstack_memory_sm_lookup_entry_free(entry); 1813 } 1814 } 1815 1816 // -- Continue with CSRK device lookup by public or resolvable private address 1817 if (!sm_address_resolution_idle()){ 1818 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1819 while (sm_address_resolution_test < le_device_db_max_count()){ 1820 int addr_type; 1821 bd_addr_t addr; 1822 sm_key_t irk; 1823 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1824 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1825 1826 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1827 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1828 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1829 break; 1830 } 1831 1832 if (sm_address_resolution_addr_type == 0){ 1833 sm_address_resolution_test++; 1834 continue; 1835 } 1836 1837 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1838 1839 log_info("LE Device Lookup: calculate AH"); 1840 log_info_key("IRK", irk); 1841 1842 memcpy(sm_aes128_key, irk, 16); 1843 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1844 sm_address_resolution_ah_calculation_active = 1; 1845 sm_aes128_state = SM_AES128_ACTIVE; 1846 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1847 return; 1848 } 1849 1850 if (sm_address_resolution_test >= le_device_db_max_count()){ 1851 log_info("LE Device Lookup: not found"); 1852 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1853 } 1854 } 1855 1856 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1857 switch (sm_sc_oob_state){ 1858 case SM_SC_OOB_W2_CALC_CONFIRM: 1859 if (!sm_cmac_ready()) break; 1860 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1861 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1862 return; 1863 default: 1864 break; 1865 } 1866 #endif 1867 1868 // handle basic actions that don't requires the full context 1869 hci_connections_get_iterator(&it); 1870 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1871 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1872 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1873 switch(sm_connection->sm_engine_state){ 1874 // responder side 1875 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1876 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1877 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1878 return; 1879 1880 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1881 case SM_SC_RECEIVED_LTK_REQUEST: 1882 switch (sm_connection->sm_irk_lookup_state){ 1883 case IRK_LOOKUP_FAILED: 1884 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1885 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1886 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1887 return; 1888 default: 1889 break; 1890 } 1891 break; 1892 #endif 1893 default: 1894 break; 1895 } 1896 } 1897 1898 // 1899 // active connection handling 1900 // -- use loop to handle next connection if lock on setup context is released 1901 1902 while (1) { 1903 1904 // Find connections that requires setup context and make active if no other is locked 1905 hci_connections_get_iterator(&it); 1906 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1907 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1908 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1909 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1910 int done = 1; 1911 int err; 1912 UNUSED(err); 1913 switch (sm_connection->sm_engine_state) { 1914 #ifdef ENABLE_LE_PERIPHERAL 1915 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1916 // send packet if possible, 1917 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1918 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1919 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1920 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1921 } else { 1922 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1923 } 1924 // don't lock sxetup context yet 1925 done = 0; 1926 break; 1927 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1928 sm_reset_setup(); 1929 sm_init_setup(sm_connection); 1930 // recover pairing request 1931 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1932 err = sm_stk_generation_init(sm_connection); 1933 1934 #ifdef ENABLE_TESTING_SUPPORT 1935 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1936 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1937 err = test_pairing_failure; 1938 } 1939 #endif 1940 if (err){ 1941 setup->sm_pairing_failed_reason = err; 1942 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1943 break; 1944 } 1945 sm_timeout_start(sm_connection); 1946 // generate random number first, if we need to show passkey 1947 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1948 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1949 break; 1950 } 1951 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1952 break; 1953 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1954 sm_reset_setup(); 1955 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1956 break; 1957 #endif 1958 #ifdef ENABLE_LE_CENTRAL 1959 case SM_INITIATOR_PH0_HAS_LTK: 1960 sm_reset_setup(); 1961 sm_load_security_info(sm_connection); 1962 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1963 break; 1964 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1965 sm_reset_setup(); 1966 sm_init_setup(sm_connection); 1967 sm_timeout_start(sm_connection); 1968 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1969 break; 1970 #endif 1971 1972 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1973 case SM_SC_RECEIVED_LTK_REQUEST: 1974 switch (sm_connection->sm_irk_lookup_state){ 1975 case IRK_LOOKUP_SUCCEEDED: 1976 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 1977 // start using context by loading security info 1978 sm_reset_setup(); 1979 sm_load_security_info(sm_connection); 1980 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 1981 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 1982 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 1983 break; 1984 } 1985 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 1986 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1987 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1988 // don't lock setup context yet 1989 return; 1990 default: 1991 // just wait until IRK lookup is completed 1992 // don't lock setup context yet 1993 done = 0; 1994 break; 1995 } 1996 break; 1997 #endif 1998 default: 1999 done = 0; 2000 break; 2001 } 2002 if (done){ 2003 sm_active_connection_handle = sm_connection->sm_handle; 2004 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); 2005 } 2006 } 2007 2008 // 2009 // active connection handling 2010 // 2011 2012 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2013 2014 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2015 if (!connection) { 2016 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2017 return; 2018 } 2019 2020 // assert that we could send a SM PDU - not needed for all of the following 2021 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2022 log_info("cannot send now, requesting can send now event"); 2023 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2024 return; 2025 } 2026 2027 // send keypress notifications 2028 if (setup->sm_keypress_notification){ 2029 int i; 2030 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2031 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2032 uint8_t action = 0; 2033 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2034 if (flags & (1<<i)){ 2035 int clear_flag = 1; 2036 switch (i){ 2037 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2038 case SM_KEYPRESS_PASSKEY_CLEARED: 2039 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2040 default: 2041 break; 2042 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2043 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2044 num_actions--; 2045 clear_flag = num_actions == 0; 2046 break; 2047 } 2048 if (clear_flag){ 2049 flags &= ~(1<<i); 2050 } 2051 action = i; 2052 break; 2053 } 2054 } 2055 setup->sm_keypress_notification = (num_actions << 5) | flags; 2056 2057 // send keypress notification 2058 uint8_t buffer[2]; 2059 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2060 buffer[1] = action; 2061 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2062 2063 // try 2064 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2065 return; 2066 } 2067 2068 int key_distribution_flags; 2069 UNUSED(key_distribution_flags); 2070 2071 log_info("sm_run: state %u", connection->sm_engine_state); 2072 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2073 log_info("sm_run // cannot send"); 2074 } 2075 switch (connection->sm_engine_state){ 2076 2077 // general 2078 case SM_GENERAL_SEND_PAIRING_FAILED: { 2079 uint8_t buffer[2]; 2080 buffer[0] = SM_CODE_PAIRING_FAILED; 2081 buffer[1] = setup->sm_pairing_failed_reason; 2082 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2083 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2084 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2085 sm_done_for_handle(connection->sm_handle); 2086 break; 2087 } 2088 2089 // responding state 2090 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2091 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2092 if (!sm_cmac_ready()) break; 2093 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2094 sm_sc_calculate_local_confirm(connection); 2095 break; 2096 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2097 if (!sm_cmac_ready()) break; 2098 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2099 sm_sc_calculate_remote_confirm(connection); 2100 break; 2101 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2102 if (!sm_cmac_ready()) break; 2103 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2104 sm_sc_calculate_f6_for_dhkey_check(connection); 2105 break; 2106 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2107 if (!sm_cmac_ready()) break; 2108 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2109 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2110 break; 2111 case SM_SC_W2_CALCULATE_F5_SALT: 2112 if (!sm_cmac_ready()) break; 2113 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2114 f5_calculate_salt(connection); 2115 break; 2116 case SM_SC_W2_CALCULATE_F5_MACKEY: 2117 if (!sm_cmac_ready()) break; 2118 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2119 f5_calculate_mackey(connection); 2120 break; 2121 case SM_SC_W2_CALCULATE_F5_LTK: 2122 if (!sm_cmac_ready()) break; 2123 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2124 f5_calculate_ltk(connection); 2125 break; 2126 case SM_SC_W2_CALCULATE_G2: 2127 if (!sm_cmac_ready()) break; 2128 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2129 g2_calculate(connection); 2130 break; 2131 case SM_SC_W2_CALCULATE_H6_ILK: 2132 if (!sm_cmac_ready()) break; 2133 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2134 h6_calculate_ilk(connection); 2135 break; 2136 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2137 if (!sm_cmac_ready()) break; 2138 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2139 h6_calculate_br_edr_link_key(connection); 2140 break; 2141 #endif 2142 2143 #ifdef ENABLE_LE_CENTRAL 2144 // initiator side 2145 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2146 sm_key_t peer_ltk_flipped; 2147 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2148 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2149 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2150 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2151 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2152 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2153 return; 2154 } 2155 2156 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2157 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2158 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2159 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2160 sm_timeout_reset(connection); 2161 break; 2162 #endif 2163 2164 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2165 2166 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2167 int trigger_user_response = 0; 2168 2169 uint8_t buffer[65]; 2170 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2171 // 2172 reverse_256(&ec_q[0], &buffer[1]); 2173 reverse_256(&ec_q[32], &buffer[33]); 2174 2175 // stk generation method 2176 // passkey entry: notify app to show passkey or to request passkey 2177 switch (setup->sm_stk_generation_method){ 2178 case JUST_WORKS: 2179 case NUMERIC_COMPARISON: 2180 if (IS_RESPONDER(connection->sm_role)){ 2181 // responder 2182 sm_sc_start_calculating_local_confirm(connection); 2183 } else { 2184 // initiator 2185 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2186 } 2187 break; 2188 case PK_INIT_INPUT: 2189 case PK_RESP_INPUT: 2190 case PK_BOTH_INPUT: 2191 // use random TK for display 2192 memcpy(setup->sm_ra, setup->sm_tk, 16); 2193 memcpy(setup->sm_rb, setup->sm_tk, 16); 2194 setup->sm_passkey_bit = 0; 2195 2196 if (IS_RESPONDER(connection->sm_role)){ 2197 // responder 2198 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2199 } else { 2200 // initiator 2201 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2202 } 2203 trigger_user_response = 1; 2204 break; 2205 case OOB: 2206 if (IS_RESPONDER(connection->sm_role)){ 2207 // responder 2208 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2209 } else { 2210 // initiator 2211 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2212 } 2213 break; 2214 } 2215 2216 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2217 sm_timeout_reset(connection); 2218 2219 // trigger user response after sending pdu 2220 if (trigger_user_response){ 2221 sm_trigger_user_response(connection); 2222 } 2223 break; 2224 } 2225 case SM_SC_SEND_CONFIRMATION: { 2226 uint8_t buffer[17]; 2227 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2228 reverse_128(setup->sm_local_confirm, &buffer[1]); 2229 if (IS_RESPONDER(connection->sm_role)){ 2230 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2231 } else { 2232 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2233 } 2234 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2235 sm_timeout_reset(connection); 2236 break; 2237 } 2238 case SM_SC_SEND_PAIRING_RANDOM: { 2239 uint8_t buffer[17]; 2240 buffer[0] = SM_CODE_PAIRING_RANDOM; 2241 reverse_128(setup->sm_local_nonce, &buffer[1]); 2242 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2243 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2244 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2245 if (IS_RESPONDER(connection->sm_role)){ 2246 // responder 2247 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2248 } else { 2249 // initiator 2250 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2251 } 2252 } else { 2253 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2254 if (IS_RESPONDER(connection->sm_role)){ 2255 // responder 2256 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2257 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2258 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2259 } else { 2260 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2261 sm_sc_prepare_dhkey_check(connection); 2262 } 2263 } else { 2264 // initiator 2265 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2266 } 2267 } 2268 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2269 sm_timeout_reset(connection); 2270 break; 2271 } 2272 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2273 uint8_t buffer[17]; 2274 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2275 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2276 2277 if (IS_RESPONDER(connection->sm_role)){ 2278 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2279 } else { 2280 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2281 } 2282 2283 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2284 sm_timeout_reset(connection); 2285 break; 2286 } 2287 2288 #endif 2289 2290 #ifdef ENABLE_LE_PERIPHERAL 2291 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2292 // echo initiator for now 2293 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2294 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2295 2296 if (setup->sm_use_secure_connections){ 2297 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2298 // skip LTK/EDIV for SC 2299 log_info("sm: dropping encryption information flag"); 2300 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2301 } else { 2302 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2303 } 2304 2305 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); 2306 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); 2307 // update key distribution after ENC was dropped 2308 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2309 2310 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2311 sm_timeout_reset(connection); 2312 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2313 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2314 sm_trigger_user_response(connection); 2315 } 2316 return; 2317 #endif 2318 2319 case SM_PH2_SEND_PAIRING_RANDOM: { 2320 uint8_t buffer[17]; 2321 buffer[0] = SM_CODE_PAIRING_RANDOM; 2322 reverse_128(setup->sm_local_random, &buffer[1]); 2323 if (IS_RESPONDER(connection->sm_role)){ 2324 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2325 } else { 2326 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2327 } 2328 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2329 sm_timeout_reset(connection); 2330 break; 2331 } 2332 2333 case SM_PH2_C1_GET_ENC_A: 2334 // already busy? 2335 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2336 // calculate confirm using aes128 engine - step 1 2337 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); 2338 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2339 sm_aes128_state = SM_AES128_ACTIVE; 2340 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2341 break; 2342 2343 case SM_PH2_C1_GET_ENC_C: 2344 // already busy? 2345 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2346 // calculate m_confirm using aes128 engine - step 1 2347 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); 2348 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2349 sm_aes128_state = SM_AES128_ACTIVE; 2350 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2351 break; 2352 2353 case SM_PH2_CALC_STK: 2354 // already busy? 2355 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2356 // calculate STK 2357 if (IS_RESPONDER(connection->sm_role)){ 2358 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2359 } else { 2360 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2361 } 2362 connection->sm_engine_state = SM_PH2_W4_STK; 2363 sm_aes128_state = SM_AES128_ACTIVE; 2364 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2365 break; 2366 2367 case SM_PH3_Y_GET_ENC: 2368 // already busy? 2369 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2370 // PH3B2 - calculate Y from - enc 2371 // Y = dm(DHK, Rand) 2372 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2373 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2374 sm_aes128_state = SM_AES128_ACTIVE; 2375 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); 2376 break; 2377 2378 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2379 uint8_t buffer[17]; 2380 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2381 reverse_128(setup->sm_local_confirm, &buffer[1]); 2382 if (IS_RESPONDER(connection->sm_role)){ 2383 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2384 } else { 2385 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2386 } 2387 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2388 sm_timeout_reset(connection); 2389 return; 2390 } 2391 #ifdef ENABLE_LE_PERIPHERAL 2392 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2393 sm_key_t stk_flipped; 2394 reverse_128(setup->sm_ltk, stk_flipped); 2395 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2396 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2397 return; 2398 } 2399 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2400 sm_key_t ltk_flipped; 2401 reverse_128(setup->sm_ltk, ltk_flipped); 2402 connection->sm_engine_state = SM_RESPONDER_IDLE; 2403 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2404 sm_done_for_handle(connection->sm_handle); 2405 return; 2406 } 2407 case SM_RESPONDER_PH4_Y_GET_ENC: 2408 // already busy? 2409 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2410 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2411 // Y = dm(DHK, Rand) 2412 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2413 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2414 sm_aes128_state = SM_AES128_ACTIVE; 2415 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); 2416 return; 2417 #endif 2418 #ifdef ENABLE_LE_CENTRAL 2419 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2420 sm_key_t stk_flipped; 2421 reverse_128(setup->sm_ltk, stk_flipped); 2422 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2423 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2424 return; 2425 } 2426 #endif 2427 2428 case SM_PH3_DISTRIBUTE_KEYS: 2429 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2430 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2431 uint8_t buffer[17]; 2432 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2433 reverse_128(setup->sm_ltk, &buffer[1]); 2434 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2435 sm_timeout_reset(connection); 2436 return; 2437 } 2438 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2439 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2440 uint8_t buffer[11]; 2441 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2442 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2443 reverse_64(setup->sm_local_rand, &buffer[3]); 2444 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2445 sm_timeout_reset(connection); 2446 return; 2447 } 2448 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2449 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2450 uint8_t buffer[17]; 2451 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2452 reverse_128(sm_persistent_irk, &buffer[1]); 2453 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2454 sm_timeout_reset(connection); 2455 return; 2456 } 2457 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2458 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2459 bd_addr_t local_address; 2460 uint8_t buffer[8]; 2461 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2462 switch (gap_random_address_get_mode()){ 2463 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2464 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2465 // public or static random 2466 gap_le_get_own_address(&buffer[1], local_address); 2467 break; 2468 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2469 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2470 // fallback to public 2471 gap_local_bd_addr(local_address); 2472 buffer[1] = 0; 2473 break; 2474 } 2475 reverse_bd_addr(local_address, &buffer[2]); 2476 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2477 sm_timeout_reset(connection); 2478 return; 2479 } 2480 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2481 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2482 2483 // hack to reproduce test runs 2484 if (test_use_fixed_local_csrk){ 2485 memset(setup->sm_local_csrk, 0xcc, 16); 2486 } 2487 2488 uint8_t buffer[17]; 2489 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2490 reverse_128(setup->sm_local_csrk, &buffer[1]); 2491 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2492 sm_timeout_reset(connection); 2493 return; 2494 } 2495 2496 // keys are sent 2497 if (IS_RESPONDER(connection->sm_role)){ 2498 // slave -> receive master keys if any 2499 if (sm_key_distribution_all_received(connection)){ 2500 sm_key_distribution_handle_all_received(connection); 2501 connection->sm_engine_state = SM_RESPONDER_IDLE; 2502 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2503 sm_done_for_handle(connection->sm_handle); 2504 } else { 2505 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2506 } 2507 } else { 2508 // master -> all done 2509 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2510 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2511 sm_done_for_handle(connection->sm_handle); 2512 } 2513 break; 2514 2515 default: 2516 break; 2517 } 2518 2519 // check again if active connection was released 2520 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2521 } 2522 } 2523 2524 // sm_aes128_state stays active 2525 static void sm_handle_encryption_result_enc_a(void *arg){ 2526 sm_connection_t * connection = (sm_connection_t*) arg; 2527 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2528 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); 2529 } 2530 2531 static void sm_handle_encryption_result_enc_b(void *arg){ 2532 sm_connection_t * connection = (sm_connection_t*) arg; 2533 sm_aes128_state = SM_AES128_IDLE; 2534 log_info_key("c1!", setup->sm_local_confirm); 2535 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2536 sm_run(); 2537 } 2538 2539 // sm_aes128_state stays active 2540 static void sm_handle_encryption_result_enc_c(void *arg){ 2541 sm_connection_t * connection = (sm_connection_t*) arg; 2542 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2543 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); 2544 } 2545 2546 static void sm_handle_encryption_result_enc_d(void * arg){ 2547 sm_connection_t * connection = (sm_connection_t*) arg; 2548 sm_aes128_state = SM_AES128_IDLE; 2549 log_info_key("c1!", sm_aes128_ciphertext); 2550 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2551 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2552 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2553 sm_run(); 2554 return; 2555 } 2556 if (IS_RESPONDER(connection->sm_role)){ 2557 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2558 sm_run(); 2559 } else { 2560 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2561 sm_aes128_state = SM_AES128_ACTIVE; 2562 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2563 } 2564 } 2565 2566 static void sm_handle_encryption_result_enc_stk(void *arg){ 2567 sm_connection_t * connection = (sm_connection_t*) arg; 2568 sm_aes128_state = SM_AES128_IDLE; 2569 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2570 log_info_key("stk", setup->sm_ltk); 2571 if (IS_RESPONDER(connection->sm_role)){ 2572 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2573 } else { 2574 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2575 } 2576 sm_run(); 2577 } 2578 2579 // sm_aes128_state stays active 2580 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2581 sm_connection_t * connection = (sm_connection_t*) arg; 2582 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2583 log_info_hex16("y", setup->sm_local_y); 2584 // PH3B3 - calculate EDIV 2585 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2586 log_info_hex16("ediv", setup->sm_local_ediv); 2587 // PH3B4 - calculate LTK - enc 2588 // LTK = d1(ER, DIV, 0)) 2589 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2590 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); 2591 } 2592 2593 // sm_aes128_state stays active 2594 static void sm_handle_encryption_result_enc_ph4_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 2599 // PH3B3 - calculate DIV 2600 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2601 log_info_hex16("ediv", setup->sm_local_ediv); 2602 // PH3B4 - calculate LTK - enc 2603 // LTK = d1(ER, DIV, 0)) 2604 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2605 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); 2606 } 2607 2608 // sm_aes128_state stays active 2609 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2610 sm_connection_t * connection = (sm_connection_t*) arg; 2611 log_info_key("ltk", setup->sm_ltk); 2612 // calc CSRK next 2613 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2614 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); 2615 } 2616 2617 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2618 sm_connection_t * connection = (sm_connection_t*) arg; 2619 sm_aes128_state = SM_AES128_IDLE; 2620 log_info_key("csrk", setup->sm_local_csrk); 2621 if (setup->sm_key_distribution_send_set){ 2622 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2623 } else { 2624 // no keys to send, just continue 2625 if (IS_RESPONDER(connection->sm_role)){ 2626 // slave -> receive master keys 2627 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2628 } else { 2629 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2630 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2631 } else { 2632 // master -> all done 2633 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2634 sm_done_for_handle(connection->sm_handle); 2635 } 2636 } 2637 } 2638 sm_run(); 2639 } 2640 2641 #ifdef ENABLE_LE_PERIPHERAL 2642 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2643 sm_connection_t * connection = (sm_connection_t*) arg; 2644 sm_aes128_state = SM_AES128_IDLE; 2645 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2646 log_info_key("ltk", setup->sm_ltk); 2647 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2648 sm_run(); 2649 } 2650 #endif 2651 2652 static void sm_handle_encryption_result_address_resolution(void *arg){ 2653 UNUSED(arg); 2654 sm_aes128_state = SM_AES128_IDLE; 2655 sm_address_resolution_ah_calculation_active = 0; 2656 // compare calulated address against connecting device 2657 uint8_t * hash = &sm_aes128_ciphertext[13]; 2658 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2659 log_info("LE Device Lookup: matched resolvable private address"); 2660 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2661 sm_run(); 2662 return; 2663 } 2664 // no match, try next 2665 sm_address_resolution_test++; 2666 sm_run(); 2667 } 2668 2669 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2670 UNUSED(arg); 2671 sm_aes128_state = SM_AES128_IDLE; 2672 log_info_key("irk", sm_persistent_irk); 2673 dkg_state = DKG_CALC_DHK; 2674 sm_run(); 2675 } 2676 2677 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2678 UNUSED(arg); 2679 sm_aes128_state = SM_AES128_IDLE; 2680 log_info_key("dhk", sm_persistent_dhk); 2681 dkg_state = DKG_READY; 2682 // DKG calculation complete => SM Init Finished 2683 sm_run(); 2684 } 2685 2686 static void sm_handle_encryption_result_rau(void *arg){ 2687 UNUSED(arg); 2688 sm_aes128_state = SM_AES128_IDLE; 2689 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2690 rau_state = RAU_SET_ADDRESS; 2691 sm_run(); 2692 } 2693 2694 static void sm_handle_random_result_rau(void * arg){ 2695 UNUSED(arg); 2696 // non-resolvable vs. resolvable 2697 switch (gap_random_adress_type){ 2698 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2699 // resolvable: use random as prand and calc address hash 2700 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2701 sm_random_address[0] &= 0x3f; 2702 sm_random_address[0] |= 0x40; 2703 rau_state = RAU_GET_ENC; 2704 break; 2705 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2706 default: 2707 // "The two most significant bits of the address shall be equal to ‘0’"" 2708 sm_random_address[0] &= 0x3f; 2709 rau_state = RAU_SET_ADDRESS; 2710 break; 2711 } 2712 sm_run(); 2713 } 2714 2715 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2716 static void sm_handle_random_result_sc_get_random(void * arg){ 2717 sm_connection_t * connection = (sm_connection_t*) arg; 2718 2719 // OOB 2720 if (setup->sm_stk_generation_method == OOB){ 2721 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2722 sm_run(); 2723 return; 2724 } 2725 2726 // initiator & jw/nc -> send pairing random 2727 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2728 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2729 } else { 2730 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2731 } 2732 sm_run(); 2733 } 2734 #endif 2735 2736 static void sm_handle_random_result_ph2_random(void * arg){ 2737 sm_connection_t * connection = (sm_connection_t*) arg; 2738 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2739 sm_run(); 2740 } 2741 2742 static void sm_handle_random_result_ph2_tk(void * arg){ 2743 sm_connection_t * connection = (sm_connection_t*) arg; 2744 sm_reset_tk(); 2745 uint32_t tk; 2746 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2747 // map random to 0-999999 without speding much cycles on a modulus operation 2748 tk = little_endian_read_32(sm_random_data,0); 2749 tk = tk & 0xfffff; // 1048575 2750 if (tk >= 999999){ 2751 tk = tk - 999999; 2752 } 2753 } else { 2754 // override with pre-defined passkey 2755 tk = sm_fixed_passkey_in_display_role; 2756 } 2757 big_endian_store_32(setup->sm_tk, 12, tk); 2758 if (IS_RESPONDER(connection->sm_role)){ 2759 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2760 } else { 2761 if (setup->sm_use_secure_connections){ 2762 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2763 } else { 2764 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2765 sm_trigger_user_response(connection); 2766 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2767 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2768 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2769 } 2770 } 2771 } 2772 sm_run(); 2773 } 2774 2775 static void sm_handle_random_result_ph3_div(void * arg){ 2776 sm_connection_t * connection = (sm_connection_t*) arg; 2777 // use 16 bit from random value as div 2778 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2779 log_info_hex16("div", setup->sm_local_div); 2780 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2781 sm_run(); 2782 } 2783 2784 static void sm_handle_random_result_ph3_random(void * arg){ 2785 sm_connection_t * connection = (sm_connection_t*) arg; 2786 reverse_64(sm_random_data, setup->sm_local_rand); 2787 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2788 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2789 // no db for authenticated flag hack: store flag in bit 4 of LSB 2790 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2791 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2792 } 2793 2794 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2795 2796 UNUSED(channel); // ok: there is no channel 2797 UNUSED(size); // ok: fixed format HCI events 2798 2799 sm_connection_t * sm_conn; 2800 hci_con_handle_t con_handle; 2801 2802 switch (packet_type) { 2803 2804 case HCI_EVENT_PACKET: 2805 switch (hci_event_packet_get_type(packet)) { 2806 2807 case BTSTACK_EVENT_STATE: 2808 // bt stack activated, get started 2809 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2810 log_info("HCI Working!"); 2811 2812 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2813 2814 // trigger Random Address generation if requested before 2815 switch (gap_random_adress_type){ 2816 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2817 rau_state = RAU_IDLE; 2818 break; 2819 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2820 rau_state = RAU_SET_ADDRESS; 2821 break; 2822 default: 2823 rau_state = RAU_W4_RANDOM; 2824 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2825 break; 2826 } 2827 sm_run(); 2828 } 2829 break; 2830 2831 case HCI_EVENT_LE_META: 2832 switch (packet[2]) { 2833 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2834 2835 log_info("sm: connected"); 2836 2837 if (packet[3]) return; // connection failed 2838 2839 con_handle = little_endian_read_16(packet, 4); 2840 sm_conn = sm_get_connection_for_handle(con_handle); 2841 if (!sm_conn) break; 2842 2843 sm_conn->sm_handle = con_handle; 2844 sm_conn->sm_role = packet[6]; 2845 sm_conn->sm_peer_addr_type = packet[7]; 2846 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2847 2848 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2849 2850 // reset security properties 2851 sm_conn->sm_connection_encrypted = 0; 2852 sm_conn->sm_connection_authenticated = 0; 2853 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2854 sm_conn->sm_le_db_index = -1; 2855 2856 // prepare CSRK lookup (does not involve setup) 2857 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2858 2859 // just connected -> everything else happens in sm_run() 2860 if (IS_RESPONDER(sm_conn->sm_role)){ 2861 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2862 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2863 if (sm_slave_request_security) { 2864 // request security if requested by app 2865 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2866 } else { 2867 // otherwise, wait for pairing request 2868 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2869 } 2870 } 2871 break; 2872 } else { 2873 // master 2874 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2875 } 2876 break; 2877 2878 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2879 con_handle = little_endian_read_16(packet, 3); 2880 sm_conn = sm_get_connection_for_handle(con_handle); 2881 if (!sm_conn) break; 2882 2883 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2884 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2885 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2886 break; 2887 } 2888 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2889 // PH2 SEND LTK as we need to exchange keys in PH3 2890 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2891 break; 2892 } 2893 2894 // store rand and ediv 2895 reverse_64(&packet[5], sm_conn->sm_local_rand); 2896 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2897 2898 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2899 // potentially stored LTK is from the master 2900 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2901 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2902 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2903 break; 2904 } 2905 // additionally check if remote is in LE Device DB if requested 2906 switch(sm_conn->sm_irk_lookup_state){ 2907 case IRK_LOOKUP_FAILED: 2908 log_info("LTK Request: device not in device db"); 2909 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2910 break; 2911 case IRK_LOOKUP_SUCCEEDED: 2912 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2913 break; 2914 default: 2915 // wait for irk look doen 2916 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2917 break; 2918 } 2919 break; 2920 } 2921 2922 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2923 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2924 #else 2925 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2926 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2927 #endif 2928 break; 2929 2930 default: 2931 break; 2932 } 2933 break; 2934 2935 case HCI_EVENT_ENCRYPTION_CHANGE: 2936 con_handle = little_endian_read_16(packet, 3); 2937 sm_conn = sm_get_connection_for_handle(con_handle); 2938 if (!sm_conn) break; 2939 2940 sm_conn->sm_connection_encrypted = packet[5]; 2941 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2942 sm_conn->sm_actual_encryption_key_size); 2943 log_info("event handler, state %u", sm_conn->sm_engine_state); 2944 if (!sm_conn->sm_connection_encrypted) break; 2945 // continue if part of initial pairing 2946 switch (sm_conn->sm_engine_state){ 2947 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2948 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2949 sm_done_for_handle(sm_conn->sm_handle); 2950 break; 2951 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2952 if (IS_RESPONDER(sm_conn->sm_role)){ 2953 // slave 2954 if (setup->sm_use_secure_connections){ 2955 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2956 } else { 2957 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2958 } 2959 } else { 2960 // master 2961 if (sm_key_distribution_all_received(sm_conn)){ 2962 // skip receiving keys as there are none 2963 sm_key_distribution_handle_all_received(sm_conn); 2964 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2965 } else { 2966 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2967 } 2968 } 2969 break; 2970 default: 2971 break; 2972 } 2973 break; 2974 2975 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2976 con_handle = little_endian_read_16(packet, 3); 2977 sm_conn = sm_get_connection_for_handle(con_handle); 2978 if (!sm_conn) break; 2979 2980 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2981 log_info("event handler, state %u", sm_conn->sm_engine_state); 2982 // continue if part of initial pairing 2983 switch (sm_conn->sm_engine_state){ 2984 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2985 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2986 sm_done_for_handle(sm_conn->sm_handle); 2987 break; 2988 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2989 if (IS_RESPONDER(sm_conn->sm_role)){ 2990 // slave 2991 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2992 } else { 2993 // master 2994 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2995 } 2996 break; 2997 default: 2998 break; 2999 } 3000 break; 3001 3002 3003 case HCI_EVENT_DISCONNECTION_COMPLETE: 3004 con_handle = little_endian_read_16(packet, 3); 3005 sm_done_for_handle(con_handle); 3006 sm_conn = sm_get_connection_for_handle(con_handle); 3007 if (!sm_conn) break; 3008 3009 // delete stored bonding on disconnect with authentication failure in ph0 3010 if (sm_conn->sm_role == 0 3011 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3012 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3013 le_device_db_remove(sm_conn->sm_le_db_index); 3014 } 3015 3016 // pairing failed, if it was ongoing 3017 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3018 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3019 } 3020 3021 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3022 sm_conn->sm_handle = 0; 3023 break; 3024 3025 case HCI_EVENT_COMMAND_COMPLETE: 3026 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3027 // set local addr for le device db 3028 bd_addr_t addr; 3029 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3030 le_device_db_set_local_bd_addr(addr); 3031 } 3032 break; 3033 default: 3034 break; 3035 } 3036 break; 3037 default: 3038 break; 3039 } 3040 3041 sm_run(); 3042 } 3043 3044 static inline int sm_calc_actual_encryption_key_size(int other){ 3045 if (other < sm_min_encryption_key_size) return 0; 3046 if (other < sm_max_encryption_key_size) return other; 3047 return sm_max_encryption_key_size; 3048 } 3049 3050 3051 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3052 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3053 switch (method){ 3054 case JUST_WORKS: 3055 case NUMERIC_COMPARISON: 3056 return 1; 3057 default: 3058 return 0; 3059 } 3060 } 3061 // responder 3062 3063 static int sm_passkey_used(stk_generation_method_t method){ 3064 switch (method){ 3065 case PK_RESP_INPUT: 3066 return 1; 3067 default: 3068 return 0; 3069 } 3070 } 3071 3072 static int sm_passkey_entry(stk_generation_method_t method){ 3073 switch (method){ 3074 case PK_RESP_INPUT: 3075 case PK_INIT_INPUT: 3076 case PK_BOTH_INPUT: 3077 return 1; 3078 default: 3079 return 0; 3080 } 3081 } 3082 3083 #endif 3084 3085 /** 3086 * @return ok 3087 */ 3088 static int sm_validate_stk_generation_method(void){ 3089 // check if STK generation method is acceptable by client 3090 switch (setup->sm_stk_generation_method){ 3091 case JUST_WORKS: 3092 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3093 case PK_RESP_INPUT: 3094 case PK_INIT_INPUT: 3095 case PK_BOTH_INPUT: 3096 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3097 case OOB: 3098 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3099 case NUMERIC_COMPARISON: 3100 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3101 return 1; 3102 default: 3103 return 0; 3104 } 3105 } 3106 3107 // size of complete sm_pdu used to validate input 3108 static const uint8_t sm_pdu_size[] = { 3109 0, // 0x00 invalid opcode 3110 7, // 0x01 pairing request 3111 7, // 0x02 pairing response 3112 17, // 0x03 pairing confirm 3113 17, // 0x04 pairing random 3114 2, // 0x05 pairing failed 3115 17, // 0x06 encryption information 3116 11, // 0x07 master identification 3117 17, // 0x08 identification information 3118 8, // 0x09 identify address information 3119 17, // 0x0a signing information 3120 2, // 0x0b security request 3121 65, // 0x0c pairing public key 3122 17, // 0x0d pairing dhk check 3123 2, // 0x0e keypress notification 3124 }; 3125 3126 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3127 3128 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3129 sm_run(); 3130 } 3131 3132 if (packet_type != SM_DATA_PACKET) return; 3133 if (size == 0) return; 3134 3135 uint8_t sm_pdu_code = packet[0]; 3136 3137 // validate pdu size 3138 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3139 if (sm_pdu_size[sm_pdu_code] != size) return; 3140 3141 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3142 if (!sm_conn) return; 3143 3144 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3145 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3146 sm_done_for_handle(con_handle); 3147 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3148 return; 3149 } 3150 3151 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3152 3153 int err; 3154 UNUSED(err); 3155 3156 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3157 uint8_t buffer[5]; 3158 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3159 buffer[1] = 3; 3160 little_endian_store_16(buffer, 2, con_handle); 3161 buffer[4] = packet[1]; 3162 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3163 return; 3164 } 3165 3166 switch (sm_conn->sm_engine_state){ 3167 3168 // a sm timeout requries a new physical connection 3169 case SM_GENERAL_TIMEOUT: 3170 return; 3171 3172 #ifdef ENABLE_LE_CENTRAL 3173 3174 // Initiator 3175 case SM_INITIATOR_CONNECTED: 3176 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3177 sm_pdu_received_in_wrong_state(sm_conn); 3178 break; 3179 } 3180 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3181 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3182 break; 3183 } 3184 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3185 sm_key_t ltk; 3186 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3187 if (!sm_is_null_key(ltk)){ 3188 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3189 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3190 } else { 3191 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3192 } 3193 break; 3194 } 3195 // otherwise, store security request 3196 sm_conn->sm_security_request_received = 1; 3197 break; 3198 3199 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3200 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3201 sm_pdu_received_in_wrong_state(sm_conn); 3202 break; 3203 } 3204 3205 // store pairing request 3206 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3207 err = sm_stk_generation_init(sm_conn); 3208 3209 #ifdef ENABLE_TESTING_SUPPORT 3210 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3211 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3212 err = test_pairing_failure; 3213 } 3214 #endif 3215 3216 if (err){ 3217 setup->sm_pairing_failed_reason = err; 3218 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3219 break; 3220 } 3221 3222 // generate random number first, if we need to show passkey 3223 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3224 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3225 break; 3226 } 3227 3228 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3229 if (setup->sm_use_secure_connections){ 3230 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3231 if (setup->sm_stk_generation_method == JUST_WORKS){ 3232 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3233 sm_trigger_user_response(sm_conn); 3234 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3235 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3236 } 3237 } else { 3238 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3239 } 3240 break; 3241 } 3242 #endif 3243 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3244 sm_trigger_user_response(sm_conn); 3245 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3246 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3247 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3248 } 3249 break; 3250 3251 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3252 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3253 sm_pdu_received_in_wrong_state(sm_conn); 3254 break; 3255 } 3256 3257 // store s_confirm 3258 reverse_128(&packet[1], setup->sm_peer_confirm); 3259 3260 #ifdef ENABLE_TESTING_SUPPORT 3261 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3262 log_info("testing_support: reset confirm value"); 3263 memset(setup->sm_peer_confirm, 0, 16); 3264 } 3265 #endif 3266 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3267 break; 3268 3269 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3270 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3271 sm_pdu_received_in_wrong_state(sm_conn); 3272 break;; 3273 } 3274 3275 // received random value 3276 reverse_128(&packet[1], setup->sm_peer_random); 3277 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3278 break; 3279 #endif 3280 3281 #ifdef ENABLE_LE_PERIPHERAL 3282 // Responder 3283 case SM_RESPONDER_IDLE: 3284 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3285 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3286 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3287 sm_pdu_received_in_wrong_state(sm_conn); 3288 break;; 3289 } 3290 3291 // store pairing request 3292 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3293 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3294 break; 3295 #endif 3296 3297 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3298 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3299 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3300 sm_pdu_received_in_wrong_state(sm_conn); 3301 break; 3302 } 3303 3304 // store public key for DH Key calculation 3305 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3306 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3307 3308 // validate public key 3309 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3310 if (err){ 3311 log_error("sm: peer public key invalid %x", err); 3312 // uses "unspecified reason", there is no "public key invalid" error code 3313 sm_pdu_received_in_wrong_state(sm_conn); 3314 break; 3315 } 3316 3317 // start calculating dhkey 3318 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3319 3320 3321 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3322 if (IS_RESPONDER(sm_conn->sm_role)){ 3323 // responder 3324 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3325 } else { 3326 // initiator 3327 // stk generation method 3328 // passkey entry: notify app to show passkey or to request passkey 3329 switch (setup->sm_stk_generation_method){ 3330 case JUST_WORKS: 3331 case NUMERIC_COMPARISON: 3332 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3333 break; 3334 case PK_RESP_INPUT: 3335 sm_sc_start_calculating_local_confirm(sm_conn); 3336 break; 3337 case PK_INIT_INPUT: 3338 case PK_BOTH_INPUT: 3339 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3340 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3341 break; 3342 } 3343 sm_sc_start_calculating_local_confirm(sm_conn); 3344 break; 3345 case OOB: 3346 // generate Nx 3347 log_info("Generate Na"); 3348 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3349 break; 3350 } 3351 } 3352 break; 3353 3354 case SM_SC_W4_CONFIRMATION: 3355 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3356 sm_pdu_received_in_wrong_state(sm_conn); 3357 break; 3358 } 3359 // received confirm value 3360 reverse_128(&packet[1], setup->sm_peer_confirm); 3361 3362 #ifdef ENABLE_TESTING_SUPPORT 3363 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3364 log_info("testing_support: reset confirm value"); 3365 memset(setup->sm_peer_confirm, 0, 16); 3366 } 3367 #endif 3368 if (IS_RESPONDER(sm_conn->sm_role)){ 3369 // responder 3370 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3371 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3372 // still waiting for passkey 3373 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3374 break; 3375 } 3376 } 3377 sm_sc_start_calculating_local_confirm(sm_conn); 3378 } else { 3379 // initiator 3380 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3381 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3382 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3383 } else { 3384 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3385 } 3386 } 3387 break; 3388 3389 case SM_SC_W4_PAIRING_RANDOM: 3390 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3391 sm_pdu_received_in_wrong_state(sm_conn); 3392 break; 3393 } 3394 3395 // received random value 3396 reverse_128(&packet[1], setup->sm_peer_nonce); 3397 3398 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3399 // only check for JUST WORK/NC in initiator role OR passkey entry 3400 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3401 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3402 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3403 break; 3404 } 3405 3406 // OOB 3407 if (setup->sm_stk_generation_method == OOB){ 3408 3409 // setup local random, set to zero if remote did not receive our data 3410 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3411 if (IS_RESPONDER(sm_conn->sm_role)){ 3412 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3413 log_info("Reset rb as A does not have OOB data"); 3414 memset(setup->sm_rb, 0, 16); 3415 } else { 3416 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3417 log_info("Use stored rb"); 3418 log_info_hexdump(setup->sm_rb, 16); 3419 } 3420 } else { 3421 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3422 log_info("Reset ra as B does not have OOB data"); 3423 memset(setup->sm_ra, 0, 16); 3424 } else { 3425 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3426 log_info("Use stored ra"); 3427 log_info_hexdump(setup->sm_ra, 16); 3428 } 3429 } 3430 3431 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3432 if (setup->sm_have_oob_data){ 3433 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3434 break; 3435 } 3436 } 3437 3438 // TODO: we only get here for Responder role with JW/NC 3439 sm_sc_state_after_receiving_random(sm_conn); 3440 break; 3441 3442 case SM_SC_W2_CALCULATE_G2: 3443 case SM_SC_W4_CALCULATE_G2: 3444 case SM_SC_W4_CALCULATE_DHKEY: 3445 case SM_SC_W2_CALCULATE_F5_SALT: 3446 case SM_SC_W4_CALCULATE_F5_SALT: 3447 case SM_SC_W2_CALCULATE_F5_MACKEY: 3448 case SM_SC_W4_CALCULATE_F5_MACKEY: 3449 case SM_SC_W2_CALCULATE_F5_LTK: 3450 case SM_SC_W4_CALCULATE_F5_LTK: 3451 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3452 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3453 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3454 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3455 sm_pdu_received_in_wrong_state(sm_conn); 3456 break; 3457 } 3458 // store DHKey Check 3459 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3460 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3461 3462 // have we been only waiting for dhkey check command? 3463 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3464 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3465 } 3466 break; 3467 #endif 3468 3469 #ifdef ENABLE_LE_PERIPHERAL 3470 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3471 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3472 sm_pdu_received_in_wrong_state(sm_conn); 3473 break; 3474 } 3475 3476 // received confirm value 3477 reverse_128(&packet[1], setup->sm_peer_confirm); 3478 3479 #ifdef ENABLE_TESTING_SUPPORT 3480 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3481 log_info("testing_support: reset confirm value"); 3482 memset(setup->sm_peer_confirm, 0, 16); 3483 } 3484 #endif 3485 // notify client to hide shown passkey 3486 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3487 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3488 } 3489 3490 // handle user cancel pairing? 3491 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3492 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3493 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3494 break; 3495 } 3496 3497 // wait for user action? 3498 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3499 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3500 break; 3501 } 3502 3503 // calculate and send local_confirm 3504 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3505 break; 3506 3507 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3508 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3509 sm_pdu_received_in_wrong_state(sm_conn); 3510 break;; 3511 } 3512 3513 // received random value 3514 reverse_128(&packet[1], setup->sm_peer_random); 3515 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3516 break; 3517 #endif 3518 3519 case SM_PH3_RECEIVE_KEYS: 3520 switch(sm_pdu_code){ 3521 case SM_CODE_ENCRYPTION_INFORMATION: 3522 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3523 reverse_128(&packet[1], setup->sm_peer_ltk); 3524 break; 3525 3526 case SM_CODE_MASTER_IDENTIFICATION: 3527 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3528 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3529 reverse_64(&packet[3], setup->sm_peer_rand); 3530 break; 3531 3532 case SM_CODE_IDENTITY_INFORMATION: 3533 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3534 reverse_128(&packet[1], setup->sm_peer_irk); 3535 break; 3536 3537 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3538 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3539 setup->sm_peer_addr_type = packet[1]; 3540 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3541 break; 3542 3543 case SM_CODE_SIGNING_INFORMATION: 3544 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3545 reverse_128(&packet[1], setup->sm_peer_csrk); 3546 break; 3547 default: 3548 // Unexpected PDU 3549 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3550 break; 3551 } 3552 // done with key distribution? 3553 if (sm_key_distribution_all_received(sm_conn)){ 3554 3555 sm_key_distribution_handle_all_received(sm_conn); 3556 3557 if (IS_RESPONDER(sm_conn->sm_role)){ 3558 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3559 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3560 } else { 3561 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3562 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3563 sm_done_for_handle(sm_conn->sm_handle); 3564 } 3565 } else { 3566 if (setup->sm_use_secure_connections){ 3567 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3568 } else { 3569 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3570 } 3571 } 3572 } 3573 break; 3574 default: 3575 // Unexpected PDU 3576 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3577 break; 3578 } 3579 3580 // try to send preparared packet 3581 sm_run(); 3582 } 3583 3584 // Security Manager Client API 3585 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3586 sm_get_oob_data = get_oob_data_callback; 3587 } 3588 3589 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)){ 3590 sm_get_sc_oob_data = get_sc_oob_data_callback; 3591 } 3592 3593 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3594 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3595 } 3596 3597 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3598 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3599 } 3600 3601 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3602 sm_min_encryption_key_size = min_size; 3603 sm_max_encryption_key_size = max_size; 3604 } 3605 3606 void sm_set_authentication_requirements(uint8_t auth_req){ 3607 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3608 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3609 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3610 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3611 } 3612 #endif 3613 sm_auth_req = auth_req; 3614 } 3615 3616 void sm_set_io_capabilities(io_capability_t io_capability){ 3617 sm_io_capabilities = io_capability; 3618 } 3619 3620 #ifdef ENABLE_LE_PERIPHERAL 3621 void sm_set_request_security(int enable){ 3622 sm_slave_request_security = enable; 3623 } 3624 #endif 3625 3626 void sm_set_er(sm_key_t er){ 3627 memcpy(sm_persistent_er, er, 16); 3628 } 3629 3630 void sm_set_ir(sm_key_t ir){ 3631 memcpy(sm_persistent_ir, ir, 16); 3632 } 3633 3634 // Testing support only 3635 void sm_test_set_irk(sm_key_t irk){ 3636 memcpy(sm_persistent_irk, irk, 16); 3637 sm_persistent_irk_ready = 1; 3638 } 3639 3640 void sm_test_use_fixed_local_csrk(void){ 3641 test_use_fixed_local_csrk = 1; 3642 } 3643 3644 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3645 static void sm_ec_generated(void * arg){ 3646 UNUSED(arg); 3647 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3648 } 3649 #endif 3650 3651 #ifdef ENABLE_TESTING_SUPPORT 3652 void sm_test_set_pairing_failure(int reason){ 3653 test_pairing_failure = reason; 3654 } 3655 #endif 3656 3657 void sm_init(void){ 3658 // set some (BTstack default) ER and IR 3659 int i; 3660 sm_key_t er; 3661 sm_key_t ir; 3662 for (i=0;i<16;i++){ 3663 er[i] = 0x30 + i; 3664 ir[i] = 0x90 + i; 3665 } 3666 sm_set_er(er); 3667 sm_set_ir(ir); 3668 // defaults 3669 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3670 | SM_STK_GENERATION_METHOD_OOB 3671 | SM_STK_GENERATION_METHOD_PASSKEY 3672 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3673 3674 sm_max_encryption_key_size = 16; 3675 sm_min_encryption_key_size = 7; 3676 3677 sm_fixed_passkey_in_display_role = 0xffffffff; 3678 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3679 3680 #ifdef USE_CMAC_ENGINE 3681 sm_cmac_active = 0; 3682 #endif 3683 dkg_state = DKG_W4_WORKING; 3684 rau_state = RAU_W4_WORKING; 3685 sm_aes128_state = SM_AES128_IDLE; 3686 sm_address_resolution_test = -1; // no private address to resolve yet 3687 sm_address_resolution_ah_calculation_active = 0; 3688 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3689 sm_address_resolution_general_queue = NULL; 3690 3691 gap_random_adress_update_period = 15 * 60 * 1000L; 3692 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3693 3694 test_use_fixed_local_csrk = 0; 3695 3696 // register for HCI Events from HCI 3697 hci_event_callback_registration.callback = &sm_event_packet_handler; 3698 hci_add_event_handler(&hci_event_callback_registration); 3699 3700 // 3701 btstack_crypto_init(); 3702 3703 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3704 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3705 3706 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3707 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3708 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3709 #endif 3710 } 3711 3712 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3713 sm_fixed_passkey_in_display_role = passkey; 3714 } 3715 3716 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3717 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3718 } 3719 3720 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3721 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3722 if (!hci_con) return NULL; 3723 return &hci_con->sm_connection; 3724 } 3725 3726 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3727 switch (sm_conn->sm_engine_state){ 3728 case SM_GENERAL_IDLE: 3729 case SM_RESPONDER_IDLE: 3730 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3731 sm_run(); 3732 break; 3733 default: 3734 break; 3735 } 3736 } 3737 3738 /** 3739 * @brief Trigger Security Request 3740 */ 3741 void sm_send_security_request(hci_con_handle_t con_handle){ 3742 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3743 if (!sm_conn) return; 3744 sm_send_security_request_for_connection(sm_conn); 3745 } 3746 3747 // request pairing 3748 void sm_request_pairing(hci_con_handle_t con_handle){ 3749 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3750 if (!sm_conn) return; // wrong connection 3751 3752 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3753 if (IS_RESPONDER(sm_conn->sm_role)){ 3754 sm_send_security_request_for_connection(sm_conn); 3755 } else { 3756 // used as a trigger to start central/master/initiator security procedures 3757 uint16_t ediv; 3758 sm_key_t ltk; 3759 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3760 switch (sm_conn->sm_irk_lookup_state){ 3761 case IRK_LOOKUP_FAILED: 3762 log_info("irk lookup failed, send pairing request"); 3763 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3764 break; 3765 case IRK_LOOKUP_SUCCEEDED: 3766 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3767 if (!sm_is_null_key(ltk) || ediv){ 3768 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3769 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3770 } else { 3771 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3772 } 3773 break; 3774 default: 3775 log_info("irk lookup pending"); 3776 sm_conn->sm_pairing_requested = 1; 3777 break; 3778 } 3779 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3780 sm_conn->sm_pairing_requested = 1; 3781 } 3782 } 3783 sm_run(); 3784 } 3785 3786 // called by client app on authorization request 3787 void sm_authorization_decline(hci_con_handle_t con_handle){ 3788 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3789 if (!sm_conn) return; // wrong connection 3790 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3791 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3792 } 3793 3794 void sm_authorization_grant(hci_con_handle_t con_handle){ 3795 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3796 if (!sm_conn) return; // wrong connection 3797 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3798 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3799 } 3800 3801 // GAP Bonding API 3802 3803 void sm_bonding_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 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3807 log_info("decline, state %u", sm_conn->sm_engine_state); 3808 switch(sm_conn->sm_engine_state){ 3809 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3810 case SM_SC_W4_USER_RESPONSE: 3811 case SM_SC_W4_CONFIRMATION: 3812 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3813 #endif 3814 case SM_PH1_W4_USER_RESPONSE: 3815 switch (setup->sm_stk_generation_method){ 3816 case PK_RESP_INPUT: 3817 case PK_INIT_INPUT: 3818 case PK_BOTH_INPUT: 3819 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3820 break; 3821 case NUMERIC_COMPARISON: 3822 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3823 break; 3824 case JUST_WORKS: 3825 case OOB: 3826 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3827 break; 3828 } 3829 break; 3830 default: 3831 break; 3832 } 3833 sm_run(); 3834 } 3835 3836 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3837 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3838 if (!sm_conn) return; // wrong connection 3839 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3840 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3841 if (setup->sm_use_secure_connections){ 3842 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3843 } else { 3844 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3845 } 3846 } 3847 3848 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3849 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3850 sm_sc_prepare_dhkey_check(sm_conn); 3851 } 3852 #endif 3853 3854 sm_run(); 3855 } 3856 3857 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3858 // for now, it's the same 3859 sm_just_works_confirm(con_handle); 3860 } 3861 3862 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3863 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3864 if (!sm_conn) return; // wrong connection 3865 sm_reset_tk(); 3866 big_endian_store_32(setup->sm_tk, 12, passkey); 3867 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3868 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3869 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3870 } 3871 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3872 memcpy(setup->sm_ra, setup->sm_tk, 16); 3873 memcpy(setup->sm_rb, setup->sm_tk, 16); 3874 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3875 sm_sc_start_calculating_local_confirm(sm_conn); 3876 } 3877 #endif 3878 sm_run(); 3879 } 3880 3881 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3882 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3883 if (!sm_conn) return; // wrong connection 3884 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3885 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3886 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3887 switch (action){ 3888 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3889 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3890 flags |= (1 << action); 3891 break; 3892 case SM_KEYPRESS_PASSKEY_CLEARED: 3893 // clear counter, keypress & erased flags + set passkey cleared 3894 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3895 break; 3896 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3897 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3898 // erase actions queued 3899 num_actions--; 3900 if (num_actions == 0){ 3901 // clear counter, keypress & erased flags 3902 flags &= 0x19; 3903 } 3904 break; 3905 } 3906 num_actions++; 3907 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3908 break; 3909 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3910 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3911 // enter actions queued 3912 num_actions--; 3913 if (num_actions == 0){ 3914 // clear counter, keypress & erased flags 3915 flags &= 0x19; 3916 } 3917 break; 3918 } 3919 num_actions++; 3920 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3921 break; 3922 default: 3923 break; 3924 } 3925 setup->sm_keypress_notification = (num_actions << 5) | flags; 3926 sm_run(); 3927 } 3928 3929 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3930 static void sm_handle_random_result_oob(void * arg){ 3931 UNUSED(arg); 3932 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3933 sm_run(); 3934 } 3935 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3936 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3937 sm_sc_oob_callback = callback; 3938 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3939 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3940 return 0; 3941 } 3942 #endif 3943 3944 /** 3945 * @brief Identify device in LE Device DB 3946 * @param handle 3947 * @returns index from le_device_db or -1 if not found/identified 3948 */ 3949 int sm_le_device_index(hci_con_handle_t con_handle ){ 3950 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3951 if (!sm_conn) return -1; 3952 return sm_conn->sm_le_db_index; 3953 } 3954 3955 static int gap_random_address_type_requires_updates(void){ 3956 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3957 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3958 return 1; 3959 } 3960 3961 static uint8_t own_address_type(void){ 3962 switch (gap_random_adress_type){ 3963 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3964 return BD_ADDR_TYPE_LE_PUBLIC; 3965 default: 3966 return BD_ADDR_TYPE_LE_RANDOM; 3967 } 3968 } 3969 3970 // GAP LE API 3971 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3972 gap_random_address_update_stop(); 3973 gap_random_adress_type = random_address_type; 3974 hci_le_set_own_address_type(own_address_type()); 3975 if (!gap_random_address_type_requires_updates()) return; 3976 gap_random_address_update_start(); 3977 gap_random_address_trigger(); 3978 } 3979 3980 gap_random_address_type_t gap_random_address_get_mode(void){ 3981 return gap_random_adress_type; 3982 } 3983 3984 void gap_random_address_set_update_period(int period_ms){ 3985 gap_random_adress_update_period = period_ms; 3986 if (!gap_random_address_type_requires_updates()) return; 3987 gap_random_address_update_stop(); 3988 gap_random_address_update_start(); 3989 } 3990 3991 void gap_random_address_set(bd_addr_t addr){ 3992 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 3993 memcpy(sm_random_address, addr, 6); 3994 if (rau_state == RAU_W4_WORKING) return; 3995 rau_state = RAU_SET_ADDRESS; 3996 sm_run(); 3997 } 3998 3999 #ifdef ENABLE_LE_PERIPHERAL 4000 /* 4001 * @brief Set Advertisement Paramters 4002 * @param adv_int_min 4003 * @param adv_int_max 4004 * @param adv_type 4005 * @param direct_address_type 4006 * @param direct_address 4007 * @param channel_map 4008 * @param filter_policy 4009 * 4010 * @note own_address_type is used from gap_random_address_set_mode 4011 */ 4012 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4013 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4014 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4015 direct_address_typ, direct_address, channel_map, filter_policy); 4016 } 4017 #endif 4018