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 <string.h> 41 #include <inttypes.h> 42 43 #include "ble/le_device_db.h" 44 #include "ble/core.h" 45 #include "ble/sm.h" 46 #include "bluetooth_company_id.h" 47 #include "btstack_crypto.h" 48 #include "btstack_debug.h" 49 #include "btstack_event.h" 50 #include "btstack_linked_list.h" 51 #include "btstack_memory.h" 52 #include "gap.h" 53 #include "hci.h" 54 #include "hci_dump.h" 55 #include "l2cap.h" 56 57 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 58 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 59 #endif 60 61 // assert SM Public Key can be sent/received 62 #ifdef ENABLE_LE_SECURE_CONNECTIONS 63 #if HCI_ACL_PAYLOAD_SIZE < 69 64 #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" 65 #endif 66 #endif 67 68 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 69 #define IS_RESPONDER(role) (role) 70 #else 71 #ifdef ENABLE_LE_CENTRAL 72 // only central - never responder (avoid 'unused variable' warnings) 73 #define IS_RESPONDER(role) (0 && role) 74 #else 75 // only peripheral - always responder (avoid 'unused variable' warnings) 76 #define IS_RESPONDER(role) (1 || role) 77 #endif 78 #endif 79 80 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 81 #define USE_CMAC_ENGINE 82 #endif 83 84 // 85 // SM internal types and globals 86 // 87 88 typedef enum { 89 DKG_W4_WORKING, 90 DKG_CALC_IRK, 91 DKG_CALC_DHK, 92 DKG_READY 93 } derived_key_generation_t; 94 95 typedef enum { 96 RAU_W4_WORKING, 97 RAU_IDLE, 98 RAU_W4_RANDOM, 99 RAU_GET_ENC, 100 RAU_W4_ENC, 101 RAU_SET_ADDRESS, 102 } random_address_update_t; 103 104 typedef enum { 105 CMAC_IDLE, 106 CMAC_CALC_SUBKEYS, 107 CMAC_W4_SUBKEYS, 108 CMAC_CALC_MI, 109 CMAC_W4_MI, 110 CMAC_CALC_MLAST, 111 CMAC_W4_MLAST 112 } cmac_state_t; 113 114 typedef enum { 115 JUST_WORKS, 116 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 117 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 118 PK_BOTH_INPUT, // Only input on both, both input PK 119 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 120 OOB // OOB available on one (SC) or both sides (legacy) 121 } stk_generation_method_t; 122 123 typedef enum { 124 SM_USER_RESPONSE_IDLE, 125 SM_USER_RESPONSE_PENDING, 126 SM_USER_RESPONSE_CONFIRM, 127 SM_USER_RESPONSE_PASSKEY, 128 SM_USER_RESPONSE_DECLINE 129 } sm_user_response_t; 130 131 typedef enum { 132 SM_AES128_IDLE, 133 SM_AES128_ACTIVE 134 } sm_aes128_state_t; 135 136 typedef enum { 137 ADDRESS_RESOLUTION_IDLE, 138 ADDRESS_RESOLUTION_GENERAL, 139 ADDRESS_RESOLUTION_FOR_CONNECTION, 140 } address_resolution_mode_t; 141 142 typedef enum { 143 ADDRESS_RESOLUTION_SUCEEDED, 144 ADDRESS_RESOLUTION_FAILED, 145 } address_resolution_event_t; 146 147 typedef enum { 148 EC_KEY_GENERATION_IDLE, 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static uint8_t sm_persistent_irk_ready = 0; // used for testing 204 static derived_key_generation_t dkg_state; 205 206 // derived from sm_persistent_er 207 // .. 208 209 // random address update 210 static random_address_update_t rau_state; 211 static bd_addr_t sm_random_address; 212 213 #ifdef USE_CMAC_ENGINE 214 // CMAC Calculation: General 215 static btstack_crypto_aes128_cmac_t sm_cmac_request; 216 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 217 static uint8_t sm_cmac_active; 218 static uint8_t sm_cmac_hash[16]; 219 #endif 220 221 // CMAC for ATT Signed Writes 222 #ifdef ENABLE_LE_SIGNED_WRITE 223 static uint16_t sm_cmac_signed_write_message_len; 224 static uint8_t sm_cmac_signed_write_header[3]; 225 static const uint8_t * sm_cmac_signed_write_message; 226 static uint8_t sm_cmac_signed_write_sign_counter[4]; 227 #endif 228 229 // CMAC for Secure Connection functions 230 #ifdef ENABLE_LE_SECURE_CONNECTIONS 231 static sm_connection_t * sm_cmac_connection; 232 static uint8_t sm_cmac_sc_buffer[80]; 233 #endif 234 235 // resolvable private address lookup / CSRK calculation 236 static int sm_address_resolution_test; 237 static int sm_address_resolution_ah_calculation_active; 238 static uint8_t sm_address_resolution_addr_type; 239 static bd_addr_t sm_address_resolution_address; 240 static void * sm_address_resolution_context; 241 static address_resolution_mode_t sm_address_resolution_mode; 242 static btstack_linked_list_t sm_address_resolution_general_queue; 243 244 // aes128 crypto engine. 245 static sm_aes128_state_t sm_aes128_state; 246 247 // crypto 248 static btstack_crypto_random_t sm_crypto_random_request; 249 static btstack_crypto_aes128_t sm_crypto_aes128_request; 250 #ifdef ENABLE_LE_SECURE_CONNECTIONS 251 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 252 static btstack_crypto_random_t sm_crypto_random_oob_request; 253 #endif 254 255 // temp storage for random data 256 static uint8_t sm_random_data[8]; 257 static uint8_t sm_aes128_key[16]; 258 static uint8_t sm_aes128_plaintext[16]; 259 static uint8_t sm_aes128_ciphertext[16]; 260 261 // to receive hci events 262 static btstack_packet_callback_registration_t hci_event_callback_registration; 263 264 /* to dispatch sm event */ 265 static btstack_linked_list_t sm_event_handlers; 266 267 // LE Secure Connections 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static ec_key_generation_state_t ec_key_generation_state; 270 static uint8_t ec_q[64]; 271 #endif 272 273 // 274 // Volume 3, Part H, Chapter 24 275 // "Security shall be initiated by the Security Manager in the device in the master role. 276 // The device in the slave role shall be the responding device." 277 // -> master := initiator, slave := responder 278 // 279 280 // data needed for security setup 281 typedef struct sm_setup_context { 282 283 btstack_timer_source_t sm_timeout; 284 285 // used in all phases 286 uint8_t sm_pairing_failed_reason; 287 288 // user response, (Phase 1 and/or 2) 289 uint8_t sm_user_response; 290 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 291 292 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 293 int sm_key_distribution_send_set; 294 int sm_key_distribution_received_set; 295 296 // Phase 2 (Pairing over SMP) 297 stk_generation_method_t sm_stk_generation_method; 298 sm_key_t sm_tk; 299 uint8_t sm_have_oob_data; 300 uint8_t sm_use_secure_connections; 301 302 sm_key_t sm_c1_t3_value; // c1 calculation 303 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 304 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 305 sm_key_t sm_local_random; 306 sm_key_t sm_local_confirm; 307 sm_key_t sm_peer_random; 308 sm_key_t sm_peer_confirm; 309 uint8_t sm_m_addr_type; // address and type can be removed 310 uint8_t sm_s_addr_type; // '' 311 bd_addr_t sm_m_address; // '' 312 bd_addr_t sm_s_address; // '' 313 sm_key_t sm_ltk; 314 315 uint8_t sm_state_vars; 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 318 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 319 sm_key_t sm_local_nonce; // might be combined with sm_local_random 320 sm_key_t sm_dhkey; 321 sm_key_t sm_peer_dhkey_check; 322 sm_key_t sm_local_dhkey_check; 323 sm_key_t sm_ra; 324 sm_key_t sm_rb; 325 sm_key_t sm_t; // used for f5 and h6 326 sm_key_t sm_mackey; 327 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 328 #endif 329 330 // Phase 3 331 332 // key distribution, we generate 333 uint16_t sm_local_y; 334 uint16_t sm_local_div; 335 uint16_t sm_local_ediv; 336 uint8_t sm_local_rand[8]; 337 sm_key_t sm_local_ltk; 338 sm_key_t sm_local_csrk; 339 sm_key_t sm_local_irk; 340 // sm_local_address/addr_type not needed 341 342 // key distribution, received from peer 343 uint16_t sm_peer_y; 344 uint16_t sm_peer_div; 345 uint16_t sm_peer_ediv; 346 uint8_t sm_peer_rand[8]; 347 sm_key_t sm_peer_ltk; 348 sm_key_t sm_peer_irk; 349 sm_key_t sm_peer_csrk; 350 uint8_t sm_peer_addr_type; 351 bd_addr_t sm_peer_address; 352 353 } sm_setup_context_t; 354 355 // 356 static sm_setup_context_t the_setup; 357 static sm_setup_context_t * setup = &the_setup; 358 359 // active connection - the one for which the_setup is used for 360 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 361 362 // @returns 1 if oob data is available 363 // stores oob data in provided 16 byte buffer if not null 364 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 365 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 366 367 // horizontal: initiator capabilities 368 // vertial: responder capabilities 369 static const stk_generation_method_t stk_generation_method [5] [5] = { 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 373 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 374 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 375 }; 376 377 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 378 #ifdef ENABLE_LE_SECURE_CONNECTIONS 379 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 380 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 381 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 382 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 383 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 384 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 385 }; 386 #endif 387 388 static void sm_run(void); 389 #ifdef USE_CMAC_ENGINE 390 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 391 #endif 392 static void sm_done_for_handle(hci_con_handle_t con_handle); 393 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 394 static inline int sm_calc_actual_encryption_key_size(int other); 395 static int sm_validate_stk_generation_method(void); 396 static void sm_handle_encryption_result_address_resolution(void *arg); 397 static void sm_handle_encryption_result_dkg_dhk(void *arg); 398 static void sm_handle_encryption_result_dkg_irk(void *arg); 399 static void sm_handle_encryption_result_enc_a(void *arg); 400 static void sm_handle_encryption_result_enc_b(void *arg); 401 static void sm_handle_encryption_result_enc_c(void *arg); 402 static void sm_handle_encryption_result_enc_csrk(void *arg); 403 static void sm_handle_encryption_result_enc_d(void * arg); 404 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 405 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 406 #ifdef ENABLE_LE_PERIPHERAL 407 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 408 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 409 #endif 410 static void sm_handle_encryption_result_enc_stk(void *arg); 411 static void sm_handle_encryption_result_rau(void *arg); 412 static void sm_handle_random_result_ph2_tk(void * arg); 413 static void sm_handle_random_result_rau(void * arg); 414 #ifdef ENABLE_LE_SECURE_CONNECTIONS 415 static void sm_ec_generate_new_key(void); 416 static void sm_handle_random_result_sc_get_random(void * arg); 417 static int sm_passkey_entry(stk_generation_method_t method); 418 #endif 419 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 420 421 static void log_info_hex16(const char * name, uint16_t value){ 422 log_info("%-6s 0x%04x", name, value); 423 } 424 425 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 426 // return packet[0]; 427 // } 428 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 429 return packet[1]; 430 } 431 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 432 return packet[2]; 433 } 434 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 435 return packet[3]; 436 } 437 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 438 return packet[4]; 439 } 440 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 441 return packet[5]; 442 } 443 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 444 return packet[6]; 445 } 446 447 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 448 packet[0] = code; 449 } 450 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 451 packet[1] = io_capability; 452 } 453 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 454 packet[2] = oob_data_flag; 455 } 456 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 457 packet[3] = auth_req; 458 } 459 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 460 packet[4] = max_encryption_key_size; 461 } 462 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 463 packet[5] = initiator_key_distribution; 464 } 465 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 466 packet[6] = responder_key_distribution; 467 } 468 469 // @returns 1 if all bytes are 0 470 static int sm_is_null(uint8_t * data, int size){ 471 int i; 472 for (i=0; i < size ; i++){ 473 if (data[i]) return 0; 474 } 475 return 1; 476 } 477 478 static int sm_is_null_random(uint8_t random[8]){ 479 return sm_is_null(random, 8); 480 } 481 482 static int sm_is_null_key(uint8_t * key){ 483 return sm_is_null(key, 16); 484 } 485 486 // Key utils 487 static void sm_reset_tk(void){ 488 int i; 489 for (i=0;i<16;i++){ 490 setup->sm_tk[i] = 0; 491 } 492 } 493 494 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 495 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 496 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 497 int i; 498 for (i = max_encryption_size ; i < 16 ; i++){ 499 key[15-i] = 0; 500 } 501 } 502 503 // SMP Timeout implementation 504 505 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 506 // the Security Manager Timer shall be reset and started. 507 // 508 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 509 // 510 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 511 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 512 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 513 // established. 514 515 static void sm_timeout_handler(btstack_timer_source_t * timer){ 516 log_info("SM timeout"); 517 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 518 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 519 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 520 sm_done_for_handle(sm_conn->sm_handle); 521 522 // trigger handling of next ready connection 523 sm_run(); 524 } 525 static void sm_timeout_start(sm_connection_t * sm_conn){ 526 btstack_run_loop_remove_timer(&setup->sm_timeout); 527 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 528 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 529 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 530 btstack_run_loop_add_timer(&setup->sm_timeout); 531 } 532 static void sm_timeout_stop(void){ 533 btstack_run_loop_remove_timer(&setup->sm_timeout); 534 } 535 static void sm_timeout_reset(sm_connection_t * sm_conn){ 536 sm_timeout_stop(); 537 sm_timeout_start(sm_conn); 538 } 539 540 // end of sm timeout 541 542 // GAP Random Address updates 543 static gap_random_address_type_t gap_random_adress_type; 544 static btstack_timer_source_t gap_random_address_update_timer; 545 static uint32_t gap_random_adress_update_period; 546 547 static void gap_random_address_trigger(void){ 548 log_info("gap_random_address_trigger"); 549 if (rau_state != RAU_IDLE) return; 550 rau_state = RAU_W4_RANDOM; 551 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 552 } 553 554 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 555 UNUSED(timer); 556 557 log_info("GAP Random Address Update due"); 558 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 559 btstack_run_loop_add_timer(&gap_random_address_update_timer); 560 gap_random_address_trigger(); 561 } 562 563 static void gap_random_address_update_start(void){ 564 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 565 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 566 btstack_run_loop_add_timer(&gap_random_address_update_timer); 567 } 568 569 static void gap_random_address_update_stop(void){ 570 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 571 } 572 573 // ah(k,r) helper 574 // r = padding || r 575 // r - 24 bit value 576 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 577 // r'= padding || r 578 memset(r_prime, 0, 16); 579 memcpy(&r_prime[13], r, 3); 580 } 581 582 // d1 helper 583 // d' = padding || r || d 584 // d,r - 16 bit values 585 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 586 // d'= padding || r || d 587 memset(d1_prime, 0, 16); 588 big_endian_store_16(d1_prime, 12, r); 589 big_endian_store_16(d1_prime, 14, d); 590 } 591 592 // dm helper 593 // r’ = padding || r 594 // r - 64 bit value 595 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 596 memset(r_prime, 0, 16); 597 memcpy(&r_prime[8], r, 8); 598 } 599 600 // calculate arguments for first AES128 operation in C1 function 601 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){ 602 603 // p1 = pres || preq || rat’ || iat’ 604 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 605 // cant octet of pres becomes the most significant octet of p1. 606 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 607 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 608 // p1 is 0x05000800000302070710000001010001." 609 610 sm_key_t p1; 611 reverse_56(pres, &p1[0]); 612 reverse_56(preq, &p1[7]); 613 p1[14] = rat; 614 p1[15] = iat; 615 log_info_key("p1", p1); 616 log_info_key("r", r); 617 618 // t1 = r xor p1 619 int i; 620 for (i=0;i<16;i++){ 621 t1[i] = r[i] ^ p1[i]; 622 } 623 log_info_key("t1", t1); 624 } 625 626 // calculate arguments for second AES128 operation in C1 function 627 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 628 // p2 = padding || ia || ra 629 // "The least significant octet of ra becomes the least significant octet of p2 and 630 // the most significant octet of padding becomes the most significant octet of p2. 631 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 632 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 633 634 sm_key_t p2; 635 memset(p2, 0, 16); 636 memcpy(&p2[4], ia, 6); 637 memcpy(&p2[10], ra, 6); 638 log_info_key("p2", p2); 639 640 // c1 = e(k, t2_xor_p2) 641 int i; 642 for (i=0;i<16;i++){ 643 t3[i] = t2[i] ^ p2[i]; 644 } 645 log_info_key("t3", t3); 646 } 647 648 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 649 log_info_key("r1", r1); 650 log_info_key("r2", r2); 651 memcpy(&r_prime[8], &r2[8], 8); 652 memcpy(&r_prime[0], &r1[8], 8); 653 } 654 655 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 656 UNUSED(channel); 657 658 // log event 659 hci_dump_packet(packet_type, 1, packet, size); 660 // dispatch to all event handlers 661 btstack_linked_list_iterator_t it; 662 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 663 while (btstack_linked_list_iterator_has_next(&it)){ 664 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 665 entry->callback(packet_type, 0, packet, size); 666 } 667 } 668 669 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){ 670 event[0] = type; 671 event[1] = event_size - 2; 672 little_endian_store_16(event, 2, con_handle); 673 event[4] = addr_type; 674 reverse_bd_addr(address, &event[5]); 675 } 676 677 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 678 uint8_t event[11]; 679 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 680 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 681 } 682 683 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){ 684 uint8_t event[15]; 685 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 686 little_endian_store_32(event, 11, passkey); 687 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 688 } 689 690 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){ 691 // fetch addr and addr type from db 692 bd_addr_t identity_address; 693 int identity_address_type; 694 le_device_db_info(index, &identity_address_type, identity_address, NULL); 695 696 uint8_t event[20]; 697 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 698 event[11] = identity_address_type; 699 reverse_bd_addr(identity_address, &event[12]); 700 little_endian_store_16(event, 18, index); 701 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 702 } 703 704 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){ 705 uint8_t event[12]; 706 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 707 event[11] = status; 708 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 709 } 710 711 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 712 uint8_t event[13]; 713 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 714 event[11] = status; 715 event[12] = reason; 716 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 717 } 718 719 // decide on stk generation based on 720 // - pairing request 721 // - io capabilities 722 // - OOB data availability 723 static void sm_setup_tk(void){ 724 725 // default: just works 726 setup->sm_stk_generation_method = JUST_WORKS; 727 728 #ifdef ENABLE_LE_SECURE_CONNECTIONS 729 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 730 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 731 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 732 #else 733 setup->sm_use_secure_connections = 0; 734 #endif 735 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 736 737 738 // decide if OOB will be used based on SC vs. Legacy and oob flags 739 int use_oob = 0; 740 if (setup->sm_use_secure_connections){ 741 // In LE Secure Connections pairing, the out of band method is used if at least 742 // one device has the peer device's out of band authentication data available. 743 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 744 } else { 745 // In LE legacy pairing, the out of band method is used if both the devices have 746 // the other device's out of band authentication data available. 747 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 748 } 749 if (use_oob){ 750 log_info("SM: have OOB data"); 751 log_info_key("OOB", setup->sm_tk); 752 setup->sm_stk_generation_method = OOB; 753 return; 754 } 755 756 // If both devices have not set the MITM option in the Authentication Requirements 757 // Flags, then the IO capabilities shall be ignored and the Just Works association 758 // model shall be used. 759 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 760 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 761 log_info("SM: MITM not required by both -> JUST WORKS"); 762 return; 763 } 764 765 // Reset TK as it has been setup in sm_init_setup 766 sm_reset_tk(); 767 768 // Also use just works if unknown io capabilites 769 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)){ 770 return; 771 } 772 773 // Otherwise the IO capabilities of the devices shall be used to determine the 774 // pairing method as defined in Table 2.4. 775 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 776 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 777 778 #ifdef ENABLE_LE_SECURE_CONNECTIONS 779 // table not define by default 780 if (setup->sm_use_secure_connections){ 781 generation_method = stk_generation_method_with_secure_connection; 782 } 783 #endif 784 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)]; 785 786 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 787 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); 788 } 789 790 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 791 int flags = 0; 792 if (key_set & SM_KEYDIST_ENC_KEY){ 793 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 794 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 795 } 796 if (key_set & SM_KEYDIST_ID_KEY){ 797 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 798 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 799 } 800 if (key_set & SM_KEYDIST_SIGN){ 801 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 802 } 803 return flags; 804 } 805 806 static void sm_setup_key_distribution(uint8_t key_set){ 807 setup->sm_key_distribution_received_set = 0; 808 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 809 } 810 811 // CSRK Key Lookup 812 813 814 static int sm_address_resolution_idle(void){ 815 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 816 } 817 818 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){ 819 memcpy(sm_address_resolution_address, addr, 6); 820 sm_address_resolution_addr_type = addr_type; 821 sm_address_resolution_test = 0; 822 sm_address_resolution_mode = mode; 823 sm_address_resolution_context = context; 824 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 825 } 826 827 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 828 // check if already in list 829 btstack_linked_list_iterator_t it; 830 sm_lookup_entry_t * entry; 831 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 832 while(btstack_linked_list_iterator_has_next(&it)){ 833 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 834 if (entry->address_type != address_type) continue; 835 if (memcmp(entry->address, address, 6)) continue; 836 // already in list 837 return BTSTACK_BUSY; 838 } 839 entry = btstack_memory_sm_lookup_entry_get(); 840 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 841 entry->address_type = (bd_addr_type_t) address_type; 842 memcpy(entry->address, address, 6); 843 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 844 sm_run(); 845 return 0; 846 } 847 848 // CMAC calculation using AES Engineq 849 #ifdef USE_CMAC_ENGINE 850 851 static void sm_cmac_done_trampoline(void * arg){ 852 UNUSED(arg); 853 sm_cmac_active = 0; 854 (*sm_cmac_done_callback)(sm_cmac_hash); 855 sm_run(); 856 } 857 858 int sm_cmac_ready(void){ 859 return sm_cmac_active == 0; 860 } 861 862 // generic cmac calculation 863 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)){ 864 sm_cmac_active = 1; 865 sm_cmac_done_callback = done_callback; 866 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 867 } 868 #endif 869 870 // cmac for ATT Message signing 871 #ifdef ENABLE_LE_SIGNED_WRITE 872 873 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)){ 874 sm_cmac_active = 1; 875 sm_cmac_done_callback = done_callback; 876 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 877 } 878 879 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 880 if (offset >= sm_cmac_signed_write_message_len) { 881 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 882 return 0; 883 } 884 885 offset = sm_cmac_signed_write_message_len - 1 - offset; 886 887 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 888 if (offset < 3){ 889 return sm_cmac_signed_write_header[offset]; 890 } 891 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 892 if (offset < actual_message_len_incl_header){ 893 return sm_cmac_signed_write_message[offset - 3]; 894 } 895 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 896 } 897 898 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)){ 899 // ATT Message Signing 900 sm_cmac_signed_write_header[0] = opcode; 901 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 902 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 903 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 904 sm_cmac_signed_write_message = message; 905 sm_cmac_signed_write_message_len = total_message_len; 906 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 907 } 908 #endif 909 910 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 911 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 912 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 913 switch (setup->sm_stk_generation_method){ 914 case PK_RESP_INPUT: 915 if (IS_RESPONDER(sm_conn->sm_role)){ 916 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 917 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 918 } else { 919 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)); 920 } 921 break; 922 case PK_INIT_INPUT: 923 if (IS_RESPONDER(sm_conn->sm_role)){ 924 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)); 925 } else { 926 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 927 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 928 } 929 break; 930 case PK_BOTH_INPUT: 931 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 932 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 933 break; 934 case NUMERIC_COMPARISON: 935 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 936 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)); 937 break; 938 case JUST_WORKS: 939 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 940 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 941 break; 942 case OOB: 943 // client already provided OOB data, let's skip notification. 944 break; 945 } 946 } 947 948 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 949 int recv_flags; 950 if (IS_RESPONDER(sm_conn->sm_role)){ 951 // slave / responder 952 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 953 } else { 954 // master / initiator 955 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 956 } 957 958 #ifdef ENABLE_LE_SECURE_CONNECTIONS 959 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 960 if (setup->sm_use_secure_connections){ 961 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 962 } 963 #endif 964 965 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 966 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 967 } 968 969 static void sm_done_for_handle(hci_con_handle_t con_handle){ 970 if (sm_active_connection_handle == con_handle){ 971 sm_timeout_stop(); 972 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 973 log_info("sm: connection 0x%x released setup context", con_handle); 974 975 #ifdef ENABLE_LE_SECURE_CONNECTIONS 976 // generate new ec key after each pairing (that used it) 977 if (setup->sm_use_secure_connections){ 978 sm_ec_generate_new_key(); 979 } 980 #endif 981 } 982 } 983 984 static int sm_key_distribution_flags_for_auth_req(void){ 985 986 int flags = SM_KEYDIST_ID_KEY; 987 if (sm_auth_req & SM_AUTHREQ_BONDING){ 988 // encryption and signing information only if bonding requested 989 flags |= SM_KEYDIST_ENC_KEY; 990 #ifdef ENABLE_LE_SIGNED_WRITE 991 flags |= SM_KEYDIST_SIGN; 992 #endif 993 } 994 return flags; 995 } 996 997 static void sm_reset_setup(void){ 998 // fill in sm setup 999 setup->sm_state_vars = 0; 1000 setup->sm_keypress_notification = 0; 1001 sm_reset_tk(); 1002 } 1003 1004 static void sm_init_setup(sm_connection_t * sm_conn){ 1005 1006 // fill in sm setup 1007 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1008 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1009 1010 // query client for Legacy Pairing OOB data 1011 setup->sm_have_oob_data = 0; 1012 if (sm_get_oob_data) { 1013 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1014 } 1015 1016 // if available and SC supported, also ask for SC OOB Data 1017 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1018 memset(setup->sm_ra, 0, 16); 1019 memset(setup->sm_rb, 0, 16); 1020 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1021 if (sm_get_sc_oob_data){ 1022 if (IS_RESPONDER(sm_conn->sm_role)){ 1023 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1024 sm_conn->sm_peer_addr_type, 1025 sm_conn->sm_peer_address, 1026 setup->sm_peer_confirm, 1027 setup->sm_ra); 1028 } else { 1029 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1030 sm_conn->sm_peer_addr_type, 1031 sm_conn->sm_peer_address, 1032 setup->sm_peer_confirm, 1033 setup->sm_rb); 1034 } 1035 } else { 1036 setup->sm_have_oob_data = 0; 1037 } 1038 } 1039 #endif 1040 1041 sm_pairing_packet_t * local_packet; 1042 if (IS_RESPONDER(sm_conn->sm_role)){ 1043 // slave 1044 local_packet = &setup->sm_s_pres; 1045 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1046 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1047 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1048 } else { 1049 // master 1050 local_packet = &setup->sm_m_preq; 1051 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1052 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1053 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1054 1055 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1056 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1057 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1058 } 1059 1060 uint8_t auth_req = sm_auth_req; 1061 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1062 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1063 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1064 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1065 } 1066 1067 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1068 1069 sm_pairing_packet_t * remote_packet; 1070 int remote_key_request; 1071 if (IS_RESPONDER(sm_conn->sm_role)){ 1072 // slave / responder 1073 remote_packet = &setup->sm_m_preq; 1074 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1075 } else { 1076 // master / initiator 1077 remote_packet = &setup->sm_s_pres; 1078 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1079 } 1080 1081 // check key size 1082 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1083 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1084 1085 // decide on STK generation method / SC 1086 sm_setup_tk(); 1087 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1088 1089 // check if STK generation method is acceptable by client 1090 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1091 1092 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1093 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1094 if (setup->sm_use_secure_connections){ 1095 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1096 } 1097 #endif 1098 1099 // identical to responder 1100 sm_setup_key_distribution(remote_key_request); 1101 1102 // JUST WORKS doens't provide authentication 1103 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1104 1105 return 0; 1106 } 1107 1108 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1109 1110 // cache and reset context 1111 int matched_device_id = sm_address_resolution_test; 1112 address_resolution_mode_t mode = sm_address_resolution_mode; 1113 void * context = sm_address_resolution_context; 1114 1115 // reset context 1116 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1117 sm_address_resolution_context = NULL; 1118 sm_address_resolution_test = -1; 1119 hci_con_handle_t con_handle = 0; 1120 1121 sm_connection_t * sm_connection; 1122 #ifdef ENABLE_LE_CENTRAL 1123 sm_key_t ltk; 1124 int have_ltk; 1125 int pairing_need; 1126 #endif 1127 switch (mode){ 1128 case ADDRESS_RESOLUTION_GENERAL: 1129 break; 1130 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1131 sm_connection = (sm_connection_t *) context; 1132 con_handle = sm_connection->sm_handle; 1133 switch (event){ 1134 case ADDRESS_RESOLUTION_SUCEEDED: 1135 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1136 sm_connection->sm_le_db_index = matched_device_id; 1137 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1138 if (sm_connection->sm_role) { 1139 // LTK request received before, IRK required -> start LTK calculation 1140 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1141 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1142 } 1143 break; 1144 } 1145 #ifdef ENABLE_LE_CENTRAL 1146 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1147 have_ltk = !sm_is_null_key(ltk); 1148 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1149 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1150 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1151 // reset requests 1152 sm_connection->sm_security_request_received = 0; 1153 sm_connection->sm_pairing_requested = 0; 1154 1155 // have ltk -> start encryption 1156 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1157 // "When a bond has been created between two devices, any reconnection should result in the local device 1158 // enabling or requesting encryption with the remote device before initiating any service request." 1159 if (have_ltk){ 1160 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1161 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1162 break; 1163 #else 1164 log_info("central: defer enabling encryption for bonded device"); 1165 #endif 1166 } 1167 // pairint_request -> send pairing request 1168 if (pairing_need){ 1169 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1170 break; 1171 } 1172 #endif 1173 break; 1174 case ADDRESS_RESOLUTION_FAILED: 1175 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1176 if (sm_connection->sm_role) { 1177 // LTK request received before, IRK required -> negative LTK reply 1178 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1179 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1180 } 1181 break; 1182 } 1183 #ifdef ENABLE_LE_CENTRAL 1184 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1185 sm_connection->sm_security_request_received = 0; 1186 sm_connection->sm_pairing_requested = 0; 1187 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1188 #endif 1189 break; 1190 } 1191 break; 1192 default: 1193 break; 1194 } 1195 1196 switch (event){ 1197 case ADDRESS_RESOLUTION_SUCEEDED: 1198 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1199 break; 1200 case ADDRESS_RESOLUTION_FAILED: 1201 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1202 break; 1203 } 1204 } 1205 1206 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1207 1208 int le_db_index = -1; 1209 1210 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1211 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1212 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1213 & SM_AUTHREQ_BONDING ) != 0; 1214 1215 if (bonding_enabed){ 1216 1217 // lookup device based on IRK 1218 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1219 int i; 1220 for (i=0; i < le_device_db_max_count(); i++){ 1221 sm_key_t irk; 1222 bd_addr_t address; 1223 int address_type = BD_ADDR_TYPE_UNKNOWN; 1224 le_device_db_info(i, &address_type, address, irk); 1225 // check if valid entry retrieved 1226 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1227 // compare IRK 1228 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1229 1230 log_info("sm: device found for IRK, updating"); 1231 le_db_index = i; 1232 break; 1233 } 1234 } else { 1235 // assert IRK is set to zero 1236 memset(setup->sm_peer_irk, 0, 16); 1237 } 1238 1239 // if not found, lookup via public address if possible 1240 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1241 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1242 int i; 1243 for (i=0; i < le_device_db_max_count(); i++){ 1244 bd_addr_t address; 1245 int address_type; 1246 le_device_db_info(i, &address_type, address, NULL); 1247 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1248 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1249 log_info("sm: device found for public address, updating"); 1250 le_db_index = i; 1251 break; 1252 } 1253 } 1254 } 1255 1256 // if not found, add to db 1257 if (le_db_index < 0) { 1258 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1259 } 1260 1261 if (le_db_index >= 0){ 1262 1263 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1264 1265 #ifdef ENABLE_LE_SIGNED_WRITE 1266 // store local CSRK 1267 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1268 log_info("sm: store local CSRK"); 1269 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1270 le_device_db_local_counter_set(le_db_index, 0); 1271 } 1272 1273 // store remote CSRK 1274 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1275 log_info("sm: store remote CSRK"); 1276 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1277 le_device_db_remote_counter_set(le_db_index, 0); 1278 } 1279 #endif 1280 // store encryption information for secure connections: LTK generated by ECDH 1281 if (setup->sm_use_secure_connections){ 1282 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1283 uint8_t zero_rand[8]; 1284 memset(zero_rand, 0, 8); 1285 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1286 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1287 } 1288 1289 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1290 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1291 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1292 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1293 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1294 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1295 1296 } 1297 } 1298 } else { 1299 log_info("Ignoring received keys, bonding not enabled"); 1300 } 1301 1302 // keep le_db_index 1303 sm_conn->sm_le_db_index = le_db_index; 1304 } 1305 1306 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1307 setup->sm_pairing_failed_reason = reason; 1308 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1309 } 1310 1311 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1312 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1313 } 1314 1315 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1316 1317 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1318 static int sm_passkey_used(stk_generation_method_t method); 1319 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1320 1321 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1322 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1323 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1324 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1325 } else { 1326 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1327 } 1328 } 1329 1330 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1331 if (IS_RESPONDER(sm_conn->sm_role)){ 1332 // Responder 1333 if (setup->sm_stk_generation_method == OOB){ 1334 // generate Nb 1335 log_info("Generate Nb"); 1336 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1337 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1338 } else { 1339 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1340 } 1341 } else { 1342 // Initiator role 1343 switch (setup->sm_stk_generation_method){ 1344 case JUST_WORKS: 1345 sm_sc_prepare_dhkey_check(sm_conn); 1346 break; 1347 1348 case NUMERIC_COMPARISON: 1349 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1350 break; 1351 case PK_INIT_INPUT: 1352 case PK_RESP_INPUT: 1353 case PK_BOTH_INPUT: 1354 if (setup->sm_passkey_bit < 20) { 1355 sm_sc_start_calculating_local_confirm(sm_conn); 1356 } else { 1357 sm_sc_prepare_dhkey_check(sm_conn); 1358 } 1359 break; 1360 case OOB: 1361 sm_sc_prepare_dhkey_check(sm_conn); 1362 break; 1363 } 1364 } 1365 } 1366 1367 static void sm_sc_cmac_done(uint8_t * hash){ 1368 log_info("sm_sc_cmac_done: "); 1369 log_info_hexdump(hash, 16); 1370 1371 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1372 sm_sc_oob_state = SM_SC_OOB_IDLE; 1373 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1374 return; 1375 } 1376 1377 sm_connection_t * sm_conn = sm_cmac_connection; 1378 sm_cmac_connection = NULL; 1379 #ifdef ENABLE_CLASSIC 1380 link_key_type_t link_key_type; 1381 #endif 1382 1383 switch (sm_conn->sm_engine_state){ 1384 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1385 memcpy(setup->sm_local_confirm, hash, 16); 1386 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1387 break; 1388 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1389 // check 1390 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1391 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1392 break; 1393 } 1394 sm_sc_state_after_receiving_random(sm_conn); 1395 break; 1396 case SM_SC_W4_CALCULATE_G2: { 1397 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1398 big_endian_store_32(setup->sm_tk, 12, vab); 1399 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1400 sm_trigger_user_response(sm_conn); 1401 break; 1402 } 1403 case SM_SC_W4_CALCULATE_F5_SALT: 1404 memcpy(setup->sm_t, hash, 16); 1405 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1406 break; 1407 case SM_SC_W4_CALCULATE_F5_MACKEY: 1408 memcpy(setup->sm_mackey, hash, 16); 1409 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1410 break; 1411 case SM_SC_W4_CALCULATE_F5_LTK: 1412 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1413 // Errata Service Release to the Bluetooth Specification: ESR09 1414 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1415 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1416 memcpy(setup->sm_ltk, hash, 16); 1417 memcpy(setup->sm_local_ltk, hash, 16); 1418 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1419 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1420 break; 1421 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1422 memcpy(setup->sm_local_dhkey_check, hash, 16); 1423 if (IS_RESPONDER(sm_conn->sm_role)){ 1424 // responder 1425 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1426 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1427 } else { 1428 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1429 } 1430 } else { 1431 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1432 } 1433 break; 1434 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1435 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1436 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1437 break; 1438 } 1439 if (IS_RESPONDER(sm_conn->sm_role)){ 1440 // responder 1441 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1442 } else { 1443 // initiator 1444 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1445 } 1446 break; 1447 case SM_SC_W4_CALCULATE_H6_ILK: 1448 memcpy(setup->sm_t, hash, 16); 1449 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1450 break; 1451 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1452 #ifdef ENABLE_CLASSIC 1453 reverse_128(hash, setup->sm_t); 1454 link_key_type = sm_conn->sm_connection_authenticated ? 1455 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1456 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1457 if (IS_RESPONDER(sm_conn->sm_role)){ 1458 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1459 } else { 1460 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1461 } 1462 #endif 1463 if (IS_RESPONDER(sm_conn->sm_role)){ 1464 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1465 } else { 1466 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1467 } 1468 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1469 sm_done_for_handle(sm_conn->sm_handle); 1470 break; 1471 default: 1472 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1473 break; 1474 } 1475 sm_run(); 1476 } 1477 1478 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){ 1479 const uint16_t message_len = 65; 1480 sm_cmac_connection = sm_conn; 1481 memcpy(sm_cmac_sc_buffer, u, 32); 1482 memcpy(sm_cmac_sc_buffer+32, v, 32); 1483 sm_cmac_sc_buffer[64] = z; 1484 log_info("f4 key"); 1485 log_info_hexdump(x, 16); 1486 log_info("f4 message"); 1487 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1488 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1489 } 1490 1491 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1492 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1493 static const uint8_t f5_length[] = { 0x01, 0x00}; 1494 1495 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1496 log_info("f5_calculate_salt"); 1497 // calculate salt for f5 1498 const uint16_t message_len = 32; 1499 sm_cmac_connection = sm_conn; 1500 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1501 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1502 } 1503 1504 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){ 1505 const uint16_t message_len = 53; 1506 sm_cmac_connection = sm_conn; 1507 1508 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1509 sm_cmac_sc_buffer[0] = 0; 1510 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1511 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1512 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1513 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1514 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1515 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1516 log_info("f5 key"); 1517 log_info_hexdump(t, 16); 1518 log_info("f5 message for MacKey"); 1519 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1520 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1521 } 1522 1523 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1524 sm_key56_t bd_addr_master, bd_addr_slave; 1525 bd_addr_master[0] = setup->sm_m_addr_type; 1526 bd_addr_slave[0] = setup->sm_s_addr_type; 1527 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1528 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1529 if (IS_RESPONDER(sm_conn->sm_role)){ 1530 // responder 1531 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1532 } else { 1533 // initiator 1534 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1535 } 1536 } 1537 1538 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1539 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1540 const uint16_t message_len = 53; 1541 sm_cmac_connection = sm_conn; 1542 sm_cmac_sc_buffer[0] = 1; 1543 // 1..52 setup before 1544 log_info("f5 key"); 1545 log_info_hexdump(t, 16); 1546 log_info("f5 message for LTK"); 1547 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1548 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1549 } 1550 1551 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1552 f5_ltk(sm_conn, setup->sm_t); 1553 } 1554 1555 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){ 1556 const uint16_t message_len = 65; 1557 sm_cmac_connection = sm_conn; 1558 memcpy(sm_cmac_sc_buffer, n1, 16); 1559 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1560 memcpy(sm_cmac_sc_buffer+32, r, 16); 1561 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1562 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1563 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1564 log_info("f6 key"); 1565 log_info_hexdump(w, 16); 1566 log_info("f6 message"); 1567 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1568 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1569 } 1570 1571 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1572 // - U is 256 bits 1573 // - V is 256 bits 1574 // - X is 128 bits 1575 // - Y is 128 bits 1576 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){ 1577 const uint16_t message_len = 80; 1578 sm_cmac_connection = sm_conn; 1579 memcpy(sm_cmac_sc_buffer, u, 32); 1580 memcpy(sm_cmac_sc_buffer+32, v, 32); 1581 memcpy(sm_cmac_sc_buffer+64, y, 16); 1582 log_info("g2 key"); 1583 log_info_hexdump(x, 16); 1584 log_info("g2 message"); 1585 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1586 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1587 } 1588 1589 static void g2_calculate(sm_connection_t * sm_conn) { 1590 // calc Va if numeric comparison 1591 if (IS_RESPONDER(sm_conn->sm_role)){ 1592 // responder 1593 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1594 } else { 1595 // initiator 1596 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1597 } 1598 } 1599 1600 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1601 uint8_t z = 0; 1602 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1603 // some form of passkey 1604 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1605 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1606 setup->sm_passkey_bit++; 1607 } 1608 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1609 } 1610 1611 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1612 // OOB 1613 if (setup->sm_stk_generation_method == OOB){ 1614 if (IS_RESPONDER(sm_conn->sm_role)){ 1615 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1616 } else { 1617 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1618 } 1619 return; 1620 } 1621 1622 uint8_t z = 0; 1623 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1624 // some form of passkey 1625 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1626 // sm_passkey_bit was increased before sending confirm value 1627 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1628 } 1629 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1630 } 1631 1632 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1633 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1634 1635 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1636 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1637 return; 1638 } else { 1639 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1640 } 1641 } 1642 1643 static void sm_sc_dhkey_calculated(void * arg){ 1644 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1645 log_info("dhkey"); 1646 log_info_hexdump(&setup->sm_dhkey[0], 32); 1647 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1648 // trigger next step 1649 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1650 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1651 } 1652 sm_run(); 1653 } 1654 1655 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1656 // calculate DHKCheck 1657 sm_key56_t bd_addr_master, bd_addr_slave; 1658 bd_addr_master[0] = setup->sm_m_addr_type; 1659 bd_addr_slave[0] = setup->sm_s_addr_type; 1660 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1661 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1662 uint8_t iocap_a[3]; 1663 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1664 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1665 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1666 uint8_t iocap_b[3]; 1667 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1668 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1669 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1670 if (IS_RESPONDER(sm_conn->sm_role)){ 1671 // responder 1672 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); 1673 } else { 1674 // initiator 1675 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); 1676 } 1677 } 1678 1679 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1680 // validate E = f6() 1681 sm_key56_t bd_addr_master, bd_addr_slave; 1682 bd_addr_master[0] = setup->sm_m_addr_type; 1683 bd_addr_slave[0] = setup->sm_s_addr_type; 1684 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1685 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1686 1687 uint8_t iocap_a[3]; 1688 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1689 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1690 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1691 uint8_t iocap_b[3]; 1692 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1693 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1694 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1695 if (IS_RESPONDER(sm_conn->sm_role)){ 1696 // responder 1697 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); 1698 } else { 1699 // initiator 1700 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); 1701 } 1702 } 1703 1704 1705 // 1706 // Link Key Conversion Function h6 1707 // 1708 // h6(W, keyID) = AES-CMACW(keyID) 1709 // - W is 128 bits 1710 // - keyID is 32 bits 1711 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1712 const uint16_t message_len = 4; 1713 sm_cmac_connection = sm_conn; 1714 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1715 log_info("h6 key"); 1716 log_info_hexdump(w, 16); 1717 log_info("h6 message"); 1718 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1719 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1720 } 1721 1722 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1723 // Errata Service Release to the Bluetooth Specification: ESR09 1724 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1725 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1726 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1727 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1728 } 1729 1730 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1731 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1732 } 1733 1734 #endif 1735 1736 // key management legacy connections: 1737 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1738 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1739 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1740 // - responder reconnects: responder uses LTK receveived from master 1741 1742 // key management secure connections: 1743 // - both devices store same LTK from ECDH key exchange. 1744 1745 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1746 static void sm_load_security_info(sm_connection_t * sm_connection){ 1747 int encryption_key_size; 1748 int authenticated; 1749 int authorized; 1750 1751 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1752 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1753 &encryption_key_size, &authenticated, &authorized); 1754 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1755 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1756 sm_connection->sm_connection_authenticated = authenticated; 1757 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1758 } 1759 #endif 1760 1761 #ifdef ENABLE_LE_PERIPHERAL 1762 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1763 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1764 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1765 // re-establish used key encryption size 1766 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1767 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1768 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1769 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1770 log_info("sm: received ltk request with key size %u, authenticated %u", 1771 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1772 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1773 sm_run(); 1774 } 1775 #endif 1776 1777 static void sm_run(void){ 1778 1779 btstack_linked_list_iterator_t it; 1780 1781 // assert that stack has already bootet 1782 if (hci_get_state() != HCI_STATE_WORKING) return; 1783 1784 // assert that we can send at least commands 1785 if (!hci_can_send_command_packet_now()) return; 1786 1787 // 1788 // non-connection related behaviour 1789 // 1790 1791 // distributed key generation 1792 switch (dkg_state){ 1793 case DKG_CALC_IRK: 1794 // already busy? 1795 if (sm_aes128_state == SM_AES128_IDLE) { 1796 log_info("DKG_CALC_IRK started"); 1797 // IRK = d1(IR, 1, 0) 1798 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1799 sm_aes128_state = SM_AES128_ACTIVE; 1800 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1801 return; 1802 } 1803 break; 1804 case DKG_CALC_DHK: 1805 // already busy? 1806 if (sm_aes128_state == SM_AES128_IDLE) { 1807 log_info("DKG_CALC_DHK started"); 1808 // DHK = d1(IR, 3, 0) 1809 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1810 sm_aes128_state = SM_AES128_ACTIVE; 1811 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1812 return; 1813 } 1814 break; 1815 default: 1816 break; 1817 } 1818 1819 // random address updates 1820 switch (rau_state){ 1821 case RAU_GET_ENC: 1822 // already busy? 1823 if (sm_aes128_state == SM_AES128_IDLE) { 1824 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1825 sm_aes128_state = SM_AES128_ACTIVE; 1826 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1827 return; 1828 } 1829 break; 1830 case RAU_SET_ADDRESS: 1831 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1832 rau_state = RAU_IDLE; 1833 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1834 return; 1835 default: 1836 break; 1837 } 1838 1839 // CSRK Lookup 1840 // -- if csrk lookup ready, find connection that require csrk lookup 1841 if (sm_address_resolution_idle()){ 1842 hci_connections_get_iterator(&it); 1843 while(btstack_linked_list_iterator_has_next(&it)){ 1844 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1845 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1846 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1847 // and start lookup 1848 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); 1849 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1850 break; 1851 } 1852 } 1853 } 1854 1855 // -- if csrk lookup ready, resolved addresses for received addresses 1856 if (sm_address_resolution_idle()) { 1857 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1858 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1859 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1860 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1861 btstack_memory_sm_lookup_entry_free(entry); 1862 } 1863 } 1864 1865 // -- Continue with CSRK device lookup by public or resolvable private address 1866 if (!sm_address_resolution_idle()){ 1867 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1868 while (sm_address_resolution_test < le_device_db_max_count()){ 1869 int addr_type; 1870 bd_addr_t addr; 1871 sm_key_t irk; 1872 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1873 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1874 1875 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1876 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1877 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1878 break; 1879 } 1880 1881 if (sm_address_resolution_addr_type == 0){ 1882 sm_address_resolution_test++; 1883 continue; 1884 } 1885 1886 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1887 1888 log_info("LE Device Lookup: calculate AH"); 1889 log_info_key("IRK", irk); 1890 1891 memcpy(sm_aes128_key, irk, 16); 1892 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1893 sm_address_resolution_ah_calculation_active = 1; 1894 sm_aes128_state = SM_AES128_ACTIVE; 1895 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1896 return; 1897 } 1898 1899 if (sm_address_resolution_test >= le_device_db_max_count()){ 1900 log_info("LE Device Lookup: not found"); 1901 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1902 } 1903 } 1904 1905 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1906 switch (sm_sc_oob_state){ 1907 case SM_SC_OOB_W2_CALC_CONFIRM: 1908 if (!sm_cmac_ready()) break; 1909 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1910 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1911 return; 1912 default: 1913 break; 1914 } 1915 #endif 1916 1917 // assert that we can send at least commands - cmd might have been sent by crypto engine 1918 if (!hci_can_send_command_packet_now()) return; 1919 1920 // handle basic actions that don't requires the full context 1921 hci_connections_get_iterator(&it); 1922 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1923 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1924 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1925 switch(sm_connection->sm_engine_state){ 1926 // responder side 1927 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1928 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1929 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1930 return; 1931 1932 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1933 case SM_SC_RECEIVED_LTK_REQUEST: 1934 switch (sm_connection->sm_irk_lookup_state){ 1935 case IRK_LOOKUP_FAILED: 1936 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1937 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1938 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1939 return; 1940 default: 1941 break; 1942 } 1943 break; 1944 #endif 1945 default: 1946 break; 1947 } 1948 } 1949 1950 // 1951 // active connection handling 1952 // -- use loop to handle next connection if lock on setup context is released 1953 1954 while (1) { 1955 1956 // Find connections that requires setup context and make active if no other is locked 1957 hci_connections_get_iterator(&it); 1958 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1959 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1960 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1961 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1962 int done = 1; 1963 int err; 1964 UNUSED(err); 1965 1966 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1967 // assert ec key is ready 1968 if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED 1969 || sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST){ 1970 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 1971 sm_ec_generate_new_key(); 1972 } 1973 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 1974 continue; 1975 } 1976 } 1977 #endif 1978 1979 switch (sm_connection->sm_engine_state) { 1980 #ifdef ENABLE_LE_PERIPHERAL 1981 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1982 // send packet if possible, 1983 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1984 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1985 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1986 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1987 } else { 1988 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1989 } 1990 // don't lock sxetup context yet 1991 done = 0; 1992 break; 1993 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1994 sm_reset_setup(); 1995 sm_init_setup(sm_connection); 1996 // recover pairing request 1997 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1998 err = sm_stk_generation_init(sm_connection); 1999 2000 #ifdef ENABLE_TESTING_SUPPORT 2001 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2002 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2003 err = test_pairing_failure; 2004 } 2005 #endif 2006 if (err){ 2007 setup->sm_pairing_failed_reason = err; 2008 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2009 break; 2010 } 2011 sm_timeout_start(sm_connection); 2012 // generate random number first, if we need to show passkey 2013 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2014 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 2015 break; 2016 } 2017 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2018 break; 2019 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2020 sm_reset_setup(); 2021 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2022 break; 2023 2024 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2025 case SM_SC_RECEIVED_LTK_REQUEST: 2026 switch (sm_connection->sm_irk_lookup_state){ 2027 case IRK_LOOKUP_SUCCEEDED: 2028 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2029 // start using context by loading security info 2030 sm_reset_setup(); 2031 sm_load_security_info(sm_connection); 2032 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2033 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2034 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2035 break; 2036 } 2037 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2038 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2039 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2040 // don't lock setup context yet 2041 return; 2042 default: 2043 // just wait until IRK lookup is completed 2044 // don't lock setup context yet 2045 done = 0; 2046 break; 2047 } 2048 break; 2049 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2050 #endif /* ENABLE_LE_PERIPHERAL */ 2051 2052 #ifdef ENABLE_LE_CENTRAL 2053 case SM_INITIATOR_PH0_HAS_LTK: 2054 sm_reset_setup(); 2055 sm_load_security_info(sm_connection); 2056 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2057 break; 2058 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2059 sm_reset_setup(); 2060 sm_init_setup(sm_connection); 2061 sm_timeout_start(sm_connection); 2062 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2063 break; 2064 #endif 2065 2066 default: 2067 done = 0; 2068 break; 2069 } 2070 if (done){ 2071 sm_active_connection_handle = sm_connection->sm_handle; 2072 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); 2073 } 2074 } 2075 2076 // 2077 // active connection handling 2078 // 2079 2080 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2081 2082 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2083 if (!connection) { 2084 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2085 return; 2086 } 2087 2088 // assert that we could send a SM PDU - not needed for all of the following 2089 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2090 log_info("cannot send now, requesting can send now event"); 2091 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2092 return; 2093 } 2094 2095 // send keypress notifications 2096 if (setup->sm_keypress_notification){ 2097 int i; 2098 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2099 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2100 uint8_t action = 0; 2101 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2102 if (flags & (1<<i)){ 2103 int clear_flag = 1; 2104 switch (i){ 2105 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2106 case SM_KEYPRESS_PASSKEY_CLEARED: 2107 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2108 default: 2109 break; 2110 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2111 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2112 num_actions--; 2113 clear_flag = num_actions == 0; 2114 break; 2115 } 2116 if (clear_flag){ 2117 flags &= ~(1<<i); 2118 } 2119 action = i; 2120 break; 2121 } 2122 } 2123 setup->sm_keypress_notification = (num_actions << 5) | flags; 2124 2125 // send keypress notification 2126 uint8_t buffer[2]; 2127 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2128 buffer[1] = action; 2129 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2130 2131 // try 2132 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2133 return; 2134 } 2135 2136 int key_distribution_flags; 2137 UNUSED(key_distribution_flags); 2138 2139 log_info("sm_run: state %u", connection->sm_engine_state); 2140 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2141 log_info("sm_run // cannot send"); 2142 } 2143 switch (connection->sm_engine_state){ 2144 2145 // general 2146 case SM_GENERAL_SEND_PAIRING_FAILED: { 2147 uint8_t buffer[2]; 2148 buffer[0] = SM_CODE_PAIRING_FAILED; 2149 buffer[1] = setup->sm_pairing_failed_reason; 2150 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2151 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2152 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2153 sm_done_for_handle(connection->sm_handle); 2154 break; 2155 } 2156 2157 // responding state 2158 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2159 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2160 if (!sm_cmac_ready()) break; 2161 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2162 sm_sc_calculate_local_confirm(connection); 2163 break; 2164 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2165 if (!sm_cmac_ready()) break; 2166 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2167 sm_sc_calculate_remote_confirm(connection); 2168 break; 2169 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2170 if (!sm_cmac_ready()) break; 2171 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2172 sm_sc_calculate_f6_for_dhkey_check(connection); 2173 break; 2174 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2175 if (!sm_cmac_ready()) break; 2176 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2177 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2178 break; 2179 case SM_SC_W2_CALCULATE_F5_SALT: 2180 if (!sm_cmac_ready()) break; 2181 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2182 f5_calculate_salt(connection); 2183 break; 2184 case SM_SC_W2_CALCULATE_F5_MACKEY: 2185 if (!sm_cmac_ready()) break; 2186 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2187 f5_calculate_mackey(connection); 2188 break; 2189 case SM_SC_W2_CALCULATE_F5_LTK: 2190 if (!sm_cmac_ready()) break; 2191 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2192 f5_calculate_ltk(connection); 2193 break; 2194 case SM_SC_W2_CALCULATE_G2: 2195 if (!sm_cmac_ready()) break; 2196 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2197 g2_calculate(connection); 2198 break; 2199 case SM_SC_W2_CALCULATE_H6_ILK: 2200 if (!sm_cmac_ready()) break; 2201 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2202 h6_calculate_ilk(connection); 2203 break; 2204 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2205 if (!sm_cmac_ready()) break; 2206 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2207 h6_calculate_br_edr_link_key(connection); 2208 break; 2209 #endif 2210 2211 #ifdef ENABLE_LE_CENTRAL 2212 // initiator side 2213 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2214 sm_key_t peer_ltk_flipped; 2215 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2216 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2217 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2218 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2219 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2220 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2221 return; 2222 } 2223 2224 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2225 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2226 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2227 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2228 sm_timeout_reset(connection); 2229 break; 2230 #endif 2231 2232 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2233 2234 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2235 int trigger_user_response = 0; 2236 2237 uint8_t buffer[65]; 2238 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2239 // 2240 reverse_256(&ec_q[0], &buffer[1]); 2241 reverse_256(&ec_q[32], &buffer[33]); 2242 2243 #ifdef ENABLE_TESTING_SUPPORT 2244 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2245 log_info("testing_support: invalidating public key"); 2246 // flip single bit of public key coordinate 2247 buffer[1] ^= 1; 2248 } 2249 #endif 2250 2251 // stk generation method 2252 // passkey entry: notify app to show passkey or to request passkey 2253 switch (setup->sm_stk_generation_method){ 2254 case JUST_WORKS: 2255 case NUMERIC_COMPARISON: 2256 if (IS_RESPONDER(connection->sm_role)){ 2257 // responder 2258 sm_sc_start_calculating_local_confirm(connection); 2259 } else { 2260 // initiator 2261 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2262 } 2263 break; 2264 case PK_INIT_INPUT: 2265 case PK_RESP_INPUT: 2266 case PK_BOTH_INPUT: 2267 // use random TK for display 2268 memcpy(setup->sm_ra, setup->sm_tk, 16); 2269 memcpy(setup->sm_rb, setup->sm_tk, 16); 2270 setup->sm_passkey_bit = 0; 2271 2272 if (IS_RESPONDER(connection->sm_role)){ 2273 // responder 2274 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2275 } else { 2276 // initiator 2277 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2278 } 2279 trigger_user_response = 1; 2280 break; 2281 case OOB: 2282 if (IS_RESPONDER(connection->sm_role)){ 2283 // responder 2284 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2285 } else { 2286 // initiator 2287 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2288 } 2289 break; 2290 } 2291 2292 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2293 sm_timeout_reset(connection); 2294 2295 // trigger user response after sending pdu 2296 if (trigger_user_response){ 2297 sm_trigger_user_response(connection); 2298 } 2299 break; 2300 } 2301 case SM_SC_SEND_CONFIRMATION: { 2302 uint8_t buffer[17]; 2303 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2304 reverse_128(setup->sm_local_confirm, &buffer[1]); 2305 if (IS_RESPONDER(connection->sm_role)){ 2306 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2307 } else { 2308 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2309 } 2310 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2311 sm_timeout_reset(connection); 2312 break; 2313 } 2314 case SM_SC_SEND_PAIRING_RANDOM: { 2315 uint8_t buffer[17]; 2316 buffer[0] = SM_CODE_PAIRING_RANDOM; 2317 reverse_128(setup->sm_local_nonce, &buffer[1]); 2318 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2319 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2320 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2321 if (IS_RESPONDER(connection->sm_role)){ 2322 // responder 2323 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2324 } else { 2325 // initiator 2326 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2327 } 2328 } else { 2329 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2330 if (IS_RESPONDER(connection->sm_role)){ 2331 // responder 2332 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2333 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2334 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2335 } else { 2336 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2337 sm_sc_prepare_dhkey_check(connection); 2338 } 2339 } else { 2340 // initiator 2341 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2342 } 2343 } 2344 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2345 sm_timeout_reset(connection); 2346 break; 2347 } 2348 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2349 uint8_t buffer[17]; 2350 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2351 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2352 2353 if (IS_RESPONDER(connection->sm_role)){ 2354 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2355 } else { 2356 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2357 } 2358 2359 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2360 sm_timeout_reset(connection); 2361 break; 2362 } 2363 2364 #endif 2365 2366 #ifdef ENABLE_LE_PERIPHERAL 2367 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2368 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2369 2370 // start with initiator key dist flags 2371 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2372 2373 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2374 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2375 if (setup->sm_use_secure_connections){ 2376 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2377 } 2378 #endif 2379 // setup in response 2380 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); 2381 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); 2382 2383 // update key distribution after ENC was dropped 2384 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2385 2386 if (setup->sm_use_secure_connections){ 2387 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2388 } else { 2389 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2390 } 2391 2392 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2393 sm_timeout_reset(connection); 2394 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2395 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2396 sm_trigger_user_response(connection); 2397 } 2398 return; 2399 #endif 2400 2401 case SM_PH2_SEND_PAIRING_RANDOM: { 2402 uint8_t buffer[17]; 2403 buffer[0] = SM_CODE_PAIRING_RANDOM; 2404 reverse_128(setup->sm_local_random, &buffer[1]); 2405 if (IS_RESPONDER(connection->sm_role)){ 2406 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2407 } else { 2408 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2409 } 2410 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2411 sm_timeout_reset(connection); 2412 break; 2413 } 2414 2415 case SM_PH2_C1_GET_ENC_A: 2416 // already busy? 2417 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2418 // calculate confirm using aes128 engine - step 1 2419 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); 2420 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2421 sm_aes128_state = SM_AES128_ACTIVE; 2422 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2423 break; 2424 2425 case SM_PH2_C1_GET_ENC_C: 2426 // already busy? 2427 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2428 // calculate m_confirm using aes128 engine - step 1 2429 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); 2430 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2431 sm_aes128_state = SM_AES128_ACTIVE; 2432 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2433 break; 2434 2435 case SM_PH2_CALC_STK: 2436 // already busy? 2437 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2438 // calculate STK 2439 if (IS_RESPONDER(connection->sm_role)){ 2440 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2441 } else { 2442 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2443 } 2444 connection->sm_engine_state = SM_PH2_W4_STK; 2445 sm_aes128_state = SM_AES128_ACTIVE; 2446 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2447 break; 2448 2449 case SM_PH3_Y_GET_ENC: 2450 // already busy? 2451 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2452 // PH3B2 - calculate Y from - enc 2453 // Y = dm(DHK, Rand) 2454 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2455 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2456 sm_aes128_state = SM_AES128_ACTIVE; 2457 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); 2458 break; 2459 2460 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2461 uint8_t buffer[17]; 2462 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2463 reverse_128(setup->sm_local_confirm, &buffer[1]); 2464 if (IS_RESPONDER(connection->sm_role)){ 2465 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2466 } else { 2467 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2468 } 2469 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2470 sm_timeout_reset(connection); 2471 return; 2472 } 2473 #ifdef ENABLE_LE_PERIPHERAL 2474 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2475 sm_key_t stk_flipped; 2476 reverse_128(setup->sm_ltk, stk_flipped); 2477 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2478 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2479 return; 2480 } 2481 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2482 sm_key_t ltk_flipped; 2483 reverse_128(setup->sm_ltk, ltk_flipped); 2484 connection->sm_engine_state = SM_RESPONDER_IDLE; 2485 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2486 sm_done_for_handle(connection->sm_handle); 2487 return; 2488 } 2489 case SM_RESPONDER_PH4_Y_GET_ENC: 2490 // already busy? 2491 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2492 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2493 // Y = dm(DHK, Rand) 2494 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2495 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2496 sm_aes128_state = SM_AES128_ACTIVE; 2497 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); 2498 return; 2499 #endif 2500 #ifdef ENABLE_LE_CENTRAL 2501 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2502 sm_key_t stk_flipped; 2503 reverse_128(setup->sm_ltk, stk_flipped); 2504 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2505 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2506 return; 2507 } 2508 #endif 2509 2510 case SM_PH3_DISTRIBUTE_KEYS: 2511 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2512 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2513 uint8_t buffer[17]; 2514 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2515 reverse_128(setup->sm_ltk, &buffer[1]); 2516 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2517 sm_timeout_reset(connection); 2518 return; 2519 } 2520 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2521 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2522 uint8_t buffer[11]; 2523 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2524 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2525 reverse_64(setup->sm_local_rand, &buffer[3]); 2526 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2527 sm_timeout_reset(connection); 2528 return; 2529 } 2530 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2531 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2532 uint8_t buffer[17]; 2533 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2534 reverse_128(sm_persistent_irk, &buffer[1]); 2535 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2536 sm_timeout_reset(connection); 2537 return; 2538 } 2539 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2540 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2541 bd_addr_t local_address; 2542 uint8_t buffer[8]; 2543 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2544 switch (gap_random_address_get_mode()){ 2545 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2546 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2547 // public or static random 2548 gap_le_get_own_address(&buffer[1], local_address); 2549 break; 2550 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2551 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2552 // fallback to public 2553 gap_local_bd_addr(local_address); 2554 buffer[1] = 0; 2555 break; 2556 } 2557 reverse_bd_addr(local_address, &buffer[2]); 2558 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2559 sm_timeout_reset(connection); 2560 return; 2561 } 2562 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2563 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2564 2565 // hack to reproduce test runs 2566 if (test_use_fixed_local_csrk){ 2567 memset(setup->sm_local_csrk, 0xcc, 16); 2568 } 2569 2570 uint8_t buffer[17]; 2571 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2572 reverse_128(setup->sm_local_csrk, &buffer[1]); 2573 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2574 sm_timeout_reset(connection); 2575 return; 2576 } 2577 2578 // keys are sent 2579 if (IS_RESPONDER(connection->sm_role)){ 2580 // slave -> receive master keys if any 2581 if (sm_key_distribution_all_received(connection)){ 2582 sm_key_distribution_handle_all_received(connection); 2583 connection->sm_engine_state = SM_RESPONDER_IDLE; 2584 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2585 sm_done_for_handle(connection->sm_handle); 2586 } else { 2587 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2588 } 2589 } else { 2590 // master -> all done 2591 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2592 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2593 sm_done_for_handle(connection->sm_handle); 2594 } 2595 break; 2596 2597 default: 2598 break; 2599 } 2600 2601 // check again if active connection was released 2602 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2603 } 2604 } 2605 2606 // sm_aes128_state stays active 2607 static void sm_handle_encryption_result_enc_a(void *arg){ 2608 sm_connection_t * connection = (sm_connection_t*) arg; 2609 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2610 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); 2611 } 2612 2613 static void sm_handle_encryption_result_enc_b(void *arg){ 2614 sm_connection_t * connection = (sm_connection_t*) arg; 2615 sm_aes128_state = SM_AES128_IDLE; 2616 log_info_key("c1!", setup->sm_local_confirm); 2617 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2618 sm_run(); 2619 } 2620 2621 // sm_aes128_state stays active 2622 static void sm_handle_encryption_result_enc_c(void *arg){ 2623 sm_connection_t * connection = (sm_connection_t*) arg; 2624 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2625 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); 2626 } 2627 2628 static void sm_handle_encryption_result_enc_d(void * arg){ 2629 sm_connection_t * connection = (sm_connection_t*) arg; 2630 sm_aes128_state = SM_AES128_IDLE; 2631 log_info_key("c1!", sm_aes128_ciphertext); 2632 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2633 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2634 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2635 sm_run(); 2636 return; 2637 } 2638 if (IS_RESPONDER(connection->sm_role)){ 2639 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2640 sm_run(); 2641 } else { 2642 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2643 sm_aes128_state = SM_AES128_ACTIVE; 2644 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2645 } 2646 } 2647 2648 static void sm_handle_encryption_result_enc_stk(void *arg){ 2649 sm_connection_t * connection = (sm_connection_t*) arg; 2650 sm_aes128_state = SM_AES128_IDLE; 2651 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2652 log_info_key("stk", setup->sm_ltk); 2653 if (IS_RESPONDER(connection->sm_role)){ 2654 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2655 } else { 2656 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2657 } 2658 sm_run(); 2659 } 2660 2661 // sm_aes128_state stays active 2662 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2663 sm_connection_t * connection = (sm_connection_t*) arg; 2664 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2665 log_info_hex16("y", setup->sm_local_y); 2666 // PH3B3 - calculate EDIV 2667 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2668 log_info_hex16("ediv", setup->sm_local_ediv); 2669 // PH3B4 - calculate LTK - enc 2670 // LTK = d1(ER, DIV, 0)) 2671 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2672 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); 2673 } 2674 2675 #ifdef ENABLE_LE_PERIPHERAL 2676 // sm_aes128_state stays active 2677 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2678 sm_connection_t * connection = (sm_connection_t*) arg; 2679 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2680 log_info_hex16("y", setup->sm_local_y); 2681 2682 // PH3B3 - calculate DIV 2683 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2684 log_info_hex16("ediv", setup->sm_local_ediv); 2685 // PH3B4 - calculate LTK - enc 2686 // LTK = d1(ER, DIV, 0)) 2687 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2688 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); 2689 } 2690 #endif 2691 2692 // sm_aes128_state stays active 2693 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2694 sm_connection_t * connection = (sm_connection_t*) arg; 2695 log_info_key("ltk", setup->sm_ltk); 2696 // calc CSRK next 2697 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2698 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); 2699 } 2700 2701 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2702 sm_connection_t * connection = (sm_connection_t*) arg; 2703 sm_aes128_state = SM_AES128_IDLE; 2704 log_info_key("csrk", setup->sm_local_csrk); 2705 if (setup->sm_key_distribution_send_set){ 2706 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2707 } else { 2708 // no keys to send, just continue 2709 if (IS_RESPONDER(connection->sm_role)){ 2710 // slave -> receive master keys 2711 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2712 } else { 2713 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2714 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2715 } else { 2716 // master -> all done 2717 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2718 sm_done_for_handle(connection->sm_handle); 2719 } 2720 } 2721 } 2722 sm_run(); 2723 } 2724 2725 #ifdef ENABLE_LE_PERIPHERAL 2726 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2727 sm_connection_t * connection = (sm_connection_t*) arg; 2728 sm_aes128_state = SM_AES128_IDLE; 2729 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2730 log_info_key("ltk", setup->sm_ltk); 2731 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2732 sm_run(); 2733 } 2734 #endif 2735 2736 static void sm_handle_encryption_result_address_resolution(void *arg){ 2737 UNUSED(arg); 2738 sm_aes128_state = SM_AES128_IDLE; 2739 sm_address_resolution_ah_calculation_active = 0; 2740 // compare calulated address against connecting device 2741 uint8_t * hash = &sm_aes128_ciphertext[13]; 2742 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2743 log_info("LE Device Lookup: matched resolvable private address"); 2744 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2745 sm_run(); 2746 return; 2747 } 2748 // no match, try next 2749 sm_address_resolution_test++; 2750 sm_run(); 2751 } 2752 2753 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2754 UNUSED(arg); 2755 sm_aes128_state = SM_AES128_IDLE; 2756 log_info_key("irk", sm_persistent_irk); 2757 dkg_state = DKG_CALC_DHK; 2758 sm_run(); 2759 } 2760 2761 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2762 UNUSED(arg); 2763 sm_aes128_state = SM_AES128_IDLE; 2764 log_info_key("dhk", sm_persistent_dhk); 2765 dkg_state = DKG_READY; 2766 // DKG calculation complete => SM Init Finished 2767 sm_run(); 2768 } 2769 2770 static void sm_handle_encryption_result_rau(void *arg){ 2771 UNUSED(arg); 2772 sm_aes128_state = SM_AES128_IDLE; 2773 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2774 rau_state = RAU_SET_ADDRESS; 2775 sm_run(); 2776 } 2777 2778 static void sm_handle_random_result_rau(void * arg){ 2779 UNUSED(arg); 2780 // non-resolvable vs. resolvable 2781 switch (gap_random_adress_type){ 2782 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2783 // resolvable: use random as prand and calc address hash 2784 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2785 sm_random_address[0] &= 0x3f; 2786 sm_random_address[0] |= 0x40; 2787 rau_state = RAU_GET_ENC; 2788 break; 2789 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2790 default: 2791 // "The two most significant bits of the address shall be equal to ‘0’"" 2792 sm_random_address[0] &= 0x3f; 2793 rau_state = RAU_SET_ADDRESS; 2794 break; 2795 } 2796 sm_run(); 2797 } 2798 2799 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2800 static void sm_handle_random_result_sc_get_random(void * arg){ 2801 sm_connection_t * connection = (sm_connection_t*) arg; 2802 2803 // OOB 2804 if (setup->sm_stk_generation_method == OOB){ 2805 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2806 sm_run(); 2807 return; 2808 } 2809 2810 // initiator & jw/nc -> send pairing random 2811 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2812 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2813 } else { 2814 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2815 } 2816 sm_run(); 2817 } 2818 #endif 2819 2820 static void sm_handle_random_result_ph2_random(void * arg){ 2821 sm_connection_t * connection = (sm_connection_t*) arg; 2822 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2823 sm_run(); 2824 } 2825 2826 static void sm_handle_random_result_ph2_tk(void * arg){ 2827 sm_connection_t * connection = (sm_connection_t*) arg; 2828 sm_reset_tk(); 2829 uint32_t tk; 2830 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2831 // map random to 0-999999 without speding much cycles on a modulus operation 2832 tk = little_endian_read_32(sm_random_data,0); 2833 tk = tk & 0xfffff; // 1048575 2834 if (tk >= 999999){ 2835 tk = tk - 999999; 2836 } 2837 } else { 2838 // override with pre-defined passkey 2839 tk = sm_fixed_passkey_in_display_role; 2840 } 2841 big_endian_store_32(setup->sm_tk, 12, tk); 2842 if (IS_RESPONDER(connection->sm_role)){ 2843 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2844 } else { 2845 if (setup->sm_use_secure_connections){ 2846 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2847 } else { 2848 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2849 sm_trigger_user_response(connection); 2850 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2851 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2852 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2853 } 2854 } 2855 } 2856 sm_run(); 2857 } 2858 2859 static void sm_handle_random_result_ph3_div(void * arg){ 2860 sm_connection_t * connection = (sm_connection_t*) arg; 2861 // use 16 bit from random value as div 2862 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2863 log_info_hex16("div", setup->sm_local_div); 2864 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2865 sm_run(); 2866 } 2867 2868 static void sm_handle_random_result_ph3_random(void * arg){ 2869 sm_connection_t * connection = (sm_connection_t*) arg; 2870 reverse_64(sm_random_data, setup->sm_local_rand); 2871 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2872 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2873 // no db for authenticated flag hack: store flag in bit 4 of LSB 2874 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2875 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2876 } 2877 2878 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2879 2880 UNUSED(channel); // ok: there is no channel 2881 UNUSED(size); // ok: fixed format HCI events 2882 2883 sm_connection_t * sm_conn; 2884 hci_con_handle_t con_handle; 2885 2886 switch (packet_type) { 2887 2888 case HCI_EVENT_PACKET: 2889 switch (hci_event_packet_get_type(packet)) { 2890 2891 case BTSTACK_EVENT_STATE: 2892 // bt stack activated, get started 2893 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2894 log_info("HCI Working!"); 2895 2896 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2897 2898 // trigger Random Address generation if requested before 2899 switch (gap_random_adress_type){ 2900 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2901 rau_state = RAU_IDLE; 2902 break; 2903 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2904 rau_state = RAU_SET_ADDRESS; 2905 break; 2906 default: 2907 rau_state = RAU_W4_RANDOM; 2908 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2909 break; 2910 } 2911 sm_run(); 2912 } 2913 break; 2914 2915 case HCI_EVENT_LE_META: 2916 switch (packet[2]) { 2917 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2918 2919 log_info("sm: connected"); 2920 2921 if (packet[3]) return; // connection failed 2922 2923 con_handle = little_endian_read_16(packet, 4); 2924 sm_conn = sm_get_connection_for_handle(con_handle); 2925 if (!sm_conn) break; 2926 2927 sm_conn->sm_handle = con_handle; 2928 sm_conn->sm_role = packet[6]; 2929 sm_conn->sm_peer_addr_type = packet[7]; 2930 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2931 2932 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2933 2934 // reset security properties 2935 sm_conn->sm_connection_encrypted = 0; 2936 sm_conn->sm_connection_authenticated = 0; 2937 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2938 sm_conn->sm_le_db_index = -1; 2939 2940 // prepare CSRK lookup (does not involve setup) 2941 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2942 2943 // just connected -> everything else happens in sm_run() 2944 if (IS_RESPONDER(sm_conn->sm_role)){ 2945 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2946 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2947 if (sm_slave_request_security) { 2948 // request security if requested by app 2949 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2950 } else { 2951 // otherwise, wait for pairing request 2952 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2953 } 2954 } 2955 break; 2956 } else { 2957 // master 2958 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2959 } 2960 break; 2961 2962 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2963 con_handle = little_endian_read_16(packet, 3); 2964 sm_conn = sm_get_connection_for_handle(con_handle); 2965 if (!sm_conn) break; 2966 2967 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2968 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2969 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2970 break; 2971 } 2972 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2973 // PH2 SEND LTK as we need to exchange keys in PH3 2974 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2975 break; 2976 } 2977 2978 // store rand and ediv 2979 reverse_64(&packet[5], sm_conn->sm_local_rand); 2980 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2981 2982 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2983 // potentially stored LTK is from the master 2984 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2985 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2986 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2987 break; 2988 } 2989 // additionally check if remote is in LE Device DB if requested 2990 switch(sm_conn->sm_irk_lookup_state){ 2991 case IRK_LOOKUP_FAILED: 2992 log_info("LTK Request: device not in device db"); 2993 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2994 break; 2995 case IRK_LOOKUP_SUCCEEDED: 2996 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2997 break; 2998 default: 2999 // wait for irk look doen 3000 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 3001 break; 3002 } 3003 break; 3004 } 3005 3006 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3007 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 3008 #else 3009 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 3010 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 3011 #endif 3012 break; 3013 3014 default: 3015 break; 3016 } 3017 break; 3018 3019 case HCI_EVENT_ENCRYPTION_CHANGE: 3020 con_handle = little_endian_read_16(packet, 3); 3021 sm_conn = sm_get_connection_for_handle(con_handle); 3022 if (!sm_conn) break; 3023 3024 sm_conn->sm_connection_encrypted = packet[5]; 3025 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3026 sm_conn->sm_actual_encryption_key_size); 3027 log_info("event handler, state %u", sm_conn->sm_engine_state); 3028 3029 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3030 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3031 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3032 // notify client, if pairing was requested before 3033 if (sm_conn->sm_pairing_requested){ 3034 sm_conn->sm_pairing_requested = 0; 3035 if (sm_conn->sm_connection_encrypted){ 3036 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3037 } else { 3038 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3039 } 3040 } 3041 sm_done_for_handle(sm_conn->sm_handle); 3042 break; 3043 } 3044 3045 if (!sm_conn->sm_connection_encrypted) break; 3046 3047 // continue pairing 3048 switch (sm_conn->sm_engine_state){ 3049 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3050 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3051 sm_done_for_handle(sm_conn->sm_handle); 3052 break; 3053 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3054 if (IS_RESPONDER(sm_conn->sm_role)){ 3055 // slave 3056 if (setup->sm_use_secure_connections){ 3057 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3058 } else { 3059 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3060 } 3061 } else { 3062 // master 3063 if (sm_key_distribution_all_received(sm_conn)){ 3064 // skip receiving keys as there are none 3065 sm_key_distribution_handle_all_received(sm_conn); 3066 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3067 } else { 3068 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3069 } 3070 } 3071 break; 3072 default: 3073 break; 3074 } 3075 break; 3076 3077 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3078 con_handle = little_endian_read_16(packet, 3); 3079 sm_conn = sm_get_connection_for_handle(con_handle); 3080 if (!sm_conn) break; 3081 3082 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3083 log_info("event handler, state %u", sm_conn->sm_engine_state); 3084 // continue if part of initial pairing 3085 switch (sm_conn->sm_engine_state){ 3086 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3087 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3088 sm_done_for_handle(sm_conn->sm_handle); 3089 break; 3090 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3091 if (IS_RESPONDER(sm_conn->sm_role)){ 3092 // slave 3093 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3094 } else { 3095 // master 3096 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3097 } 3098 break; 3099 default: 3100 break; 3101 } 3102 break; 3103 3104 3105 case HCI_EVENT_DISCONNECTION_COMPLETE: 3106 con_handle = little_endian_read_16(packet, 3); 3107 sm_done_for_handle(con_handle); 3108 sm_conn = sm_get_connection_for_handle(con_handle); 3109 if (!sm_conn) break; 3110 3111 // delete stored bonding on disconnect with authentication failure in ph0 3112 if (sm_conn->sm_role == 0 3113 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3114 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3115 le_device_db_remove(sm_conn->sm_le_db_index); 3116 } 3117 3118 // pairing failed, if it was ongoing 3119 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3120 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3121 } 3122 3123 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3124 sm_conn->sm_handle = 0; 3125 break; 3126 3127 case HCI_EVENT_COMMAND_COMPLETE: 3128 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3129 // set local addr for le device db 3130 bd_addr_t addr; 3131 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3132 le_device_db_set_local_bd_addr(addr); 3133 } 3134 break; 3135 default: 3136 break; 3137 } 3138 break; 3139 default: 3140 break; 3141 } 3142 3143 sm_run(); 3144 } 3145 3146 static inline int sm_calc_actual_encryption_key_size(int other){ 3147 if (other < sm_min_encryption_key_size) return 0; 3148 if (other < sm_max_encryption_key_size) return other; 3149 return sm_max_encryption_key_size; 3150 } 3151 3152 3153 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3154 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3155 switch (method){ 3156 case JUST_WORKS: 3157 case NUMERIC_COMPARISON: 3158 return 1; 3159 default: 3160 return 0; 3161 } 3162 } 3163 // responder 3164 3165 static int sm_passkey_used(stk_generation_method_t method){ 3166 switch (method){ 3167 case PK_RESP_INPUT: 3168 return 1; 3169 default: 3170 return 0; 3171 } 3172 } 3173 3174 static int sm_passkey_entry(stk_generation_method_t method){ 3175 switch (method){ 3176 case PK_RESP_INPUT: 3177 case PK_INIT_INPUT: 3178 case PK_BOTH_INPUT: 3179 return 1; 3180 default: 3181 return 0; 3182 } 3183 } 3184 3185 #endif 3186 3187 /** 3188 * @return ok 3189 */ 3190 static int sm_validate_stk_generation_method(void){ 3191 // check if STK generation method is acceptable by client 3192 switch (setup->sm_stk_generation_method){ 3193 case JUST_WORKS: 3194 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3195 case PK_RESP_INPUT: 3196 case PK_INIT_INPUT: 3197 case PK_BOTH_INPUT: 3198 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3199 case OOB: 3200 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3201 case NUMERIC_COMPARISON: 3202 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3203 default: 3204 return 0; 3205 } 3206 } 3207 3208 // size of complete sm_pdu used to validate input 3209 static const uint8_t sm_pdu_size[] = { 3210 0, // 0x00 invalid opcode 3211 7, // 0x01 pairing request 3212 7, // 0x02 pairing response 3213 17, // 0x03 pairing confirm 3214 17, // 0x04 pairing random 3215 2, // 0x05 pairing failed 3216 17, // 0x06 encryption information 3217 11, // 0x07 master identification 3218 17, // 0x08 identification information 3219 8, // 0x09 identify address information 3220 17, // 0x0a signing information 3221 2, // 0x0b security request 3222 65, // 0x0c pairing public key 3223 17, // 0x0d pairing dhk check 3224 2, // 0x0e keypress notification 3225 }; 3226 3227 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3228 3229 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3230 sm_run(); 3231 } 3232 3233 if (packet_type != SM_DATA_PACKET) return; 3234 if (size == 0) return; 3235 3236 uint8_t sm_pdu_code = packet[0]; 3237 3238 // validate pdu size 3239 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3240 if (sm_pdu_size[sm_pdu_code] != size) return; 3241 3242 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3243 if (!sm_conn) return; 3244 3245 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3246 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3247 sm_done_for_handle(con_handle); 3248 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3249 return; 3250 } 3251 3252 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3253 3254 int err; 3255 UNUSED(err); 3256 3257 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3258 uint8_t buffer[5]; 3259 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3260 buffer[1] = 3; 3261 little_endian_store_16(buffer, 2, con_handle); 3262 buffer[4] = packet[1]; 3263 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3264 return; 3265 } 3266 3267 switch (sm_conn->sm_engine_state){ 3268 3269 // a sm timeout requries a new physical connection 3270 case SM_GENERAL_TIMEOUT: 3271 return; 3272 3273 #ifdef ENABLE_LE_CENTRAL 3274 3275 // Initiator 3276 case SM_INITIATOR_CONNECTED: 3277 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3278 sm_pdu_received_in_wrong_state(sm_conn); 3279 break; 3280 } 3281 3282 // IRK complete? 3283 switch (sm_conn->sm_irk_lookup_state){ 3284 case IRK_LOOKUP_FAILED: 3285 case IRK_LOOKUP_SUCCEEDED: 3286 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3287 break; 3288 default: 3289 break; 3290 } 3291 3292 // otherwise, store security request 3293 sm_conn->sm_security_request_received = 1; 3294 break; 3295 3296 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3297 // Core 5, Vol 3, Part H, 2.4.6: 3298 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3299 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3300 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3301 log_info("Ignoring Security Request"); 3302 break; 3303 } 3304 3305 // all other pdus are incorrect 3306 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3307 sm_pdu_received_in_wrong_state(sm_conn); 3308 break; 3309 } 3310 3311 // store pairing request 3312 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3313 err = sm_stk_generation_init(sm_conn); 3314 3315 #ifdef ENABLE_TESTING_SUPPORT 3316 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3317 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3318 err = test_pairing_failure; 3319 } 3320 #endif 3321 3322 if (err){ 3323 setup->sm_pairing_failed_reason = err; 3324 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3325 break; 3326 } 3327 3328 // generate random number first, if we need to show passkey 3329 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3330 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3331 break; 3332 } 3333 3334 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3335 if (setup->sm_use_secure_connections){ 3336 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3337 if (setup->sm_stk_generation_method == JUST_WORKS){ 3338 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3339 sm_trigger_user_response(sm_conn); 3340 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3341 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3342 } 3343 } else { 3344 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3345 } 3346 break; 3347 } 3348 #endif 3349 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3350 sm_trigger_user_response(sm_conn); 3351 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3352 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3353 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3354 } 3355 break; 3356 3357 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3358 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3359 sm_pdu_received_in_wrong_state(sm_conn); 3360 break; 3361 } 3362 3363 // store s_confirm 3364 reverse_128(&packet[1], setup->sm_peer_confirm); 3365 3366 #ifdef ENABLE_TESTING_SUPPORT 3367 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3368 log_info("testing_support: reset confirm value"); 3369 memset(setup->sm_peer_confirm, 0, 16); 3370 } 3371 #endif 3372 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3373 break; 3374 3375 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3376 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3377 sm_pdu_received_in_wrong_state(sm_conn); 3378 break;; 3379 } 3380 3381 // received random value 3382 reverse_128(&packet[1], setup->sm_peer_random); 3383 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3384 break; 3385 #endif 3386 3387 #ifdef ENABLE_LE_PERIPHERAL 3388 // Responder 3389 case SM_RESPONDER_IDLE: 3390 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3391 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3392 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3393 sm_pdu_received_in_wrong_state(sm_conn); 3394 break;; 3395 } 3396 3397 // store pairing request 3398 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3399 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3400 break; 3401 #endif 3402 3403 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3404 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3405 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3406 sm_pdu_received_in_wrong_state(sm_conn); 3407 break; 3408 } 3409 3410 // store public key for DH Key calculation 3411 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3412 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3413 3414 // validate public key 3415 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3416 if (err){ 3417 log_error("sm: peer public key invalid %x", err); 3418 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3419 break; 3420 } 3421 3422 // start calculating dhkey 3423 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3424 3425 3426 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3427 if (IS_RESPONDER(sm_conn->sm_role)){ 3428 // responder 3429 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3430 } else { 3431 // initiator 3432 // stk generation method 3433 // passkey entry: notify app to show passkey or to request passkey 3434 switch (setup->sm_stk_generation_method){ 3435 case JUST_WORKS: 3436 case NUMERIC_COMPARISON: 3437 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3438 break; 3439 case PK_RESP_INPUT: 3440 sm_sc_start_calculating_local_confirm(sm_conn); 3441 break; 3442 case PK_INIT_INPUT: 3443 case PK_BOTH_INPUT: 3444 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3445 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3446 break; 3447 } 3448 sm_sc_start_calculating_local_confirm(sm_conn); 3449 break; 3450 case OOB: 3451 // generate Nx 3452 log_info("Generate Na"); 3453 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3454 break; 3455 } 3456 } 3457 break; 3458 3459 case SM_SC_W4_CONFIRMATION: 3460 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3461 sm_pdu_received_in_wrong_state(sm_conn); 3462 break; 3463 } 3464 // received confirm value 3465 reverse_128(&packet[1], setup->sm_peer_confirm); 3466 3467 #ifdef ENABLE_TESTING_SUPPORT 3468 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3469 log_info("testing_support: reset confirm value"); 3470 memset(setup->sm_peer_confirm, 0, 16); 3471 } 3472 #endif 3473 if (IS_RESPONDER(sm_conn->sm_role)){ 3474 // responder 3475 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3476 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3477 // still waiting for passkey 3478 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3479 break; 3480 } 3481 } 3482 sm_sc_start_calculating_local_confirm(sm_conn); 3483 } else { 3484 // initiator 3485 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3486 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3487 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3488 } else { 3489 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3490 } 3491 } 3492 break; 3493 3494 case SM_SC_W4_PAIRING_RANDOM: 3495 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3496 sm_pdu_received_in_wrong_state(sm_conn); 3497 break; 3498 } 3499 3500 // received random value 3501 reverse_128(&packet[1], setup->sm_peer_nonce); 3502 3503 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3504 // only check for JUST WORK/NC in initiator role OR passkey entry 3505 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3506 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3507 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3508 break; 3509 } 3510 3511 // OOB 3512 if (setup->sm_stk_generation_method == OOB){ 3513 3514 // setup local random, set to zero if remote did not receive our data 3515 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3516 if (IS_RESPONDER(sm_conn->sm_role)){ 3517 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3518 log_info("Reset rb as A does not have OOB data"); 3519 memset(setup->sm_rb, 0, 16); 3520 } else { 3521 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3522 log_info("Use stored rb"); 3523 log_info_hexdump(setup->sm_rb, 16); 3524 } 3525 } else { 3526 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3527 log_info("Reset ra as B does not have OOB data"); 3528 memset(setup->sm_ra, 0, 16); 3529 } else { 3530 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3531 log_info("Use stored ra"); 3532 log_info_hexdump(setup->sm_ra, 16); 3533 } 3534 } 3535 3536 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3537 if (setup->sm_have_oob_data){ 3538 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3539 break; 3540 } 3541 } 3542 3543 // TODO: we only get here for Responder role with JW/NC 3544 sm_sc_state_after_receiving_random(sm_conn); 3545 break; 3546 3547 case SM_SC_W2_CALCULATE_G2: 3548 case SM_SC_W4_CALCULATE_G2: 3549 case SM_SC_W4_CALCULATE_DHKEY: 3550 case SM_SC_W2_CALCULATE_F5_SALT: 3551 case SM_SC_W4_CALCULATE_F5_SALT: 3552 case SM_SC_W2_CALCULATE_F5_MACKEY: 3553 case SM_SC_W4_CALCULATE_F5_MACKEY: 3554 case SM_SC_W2_CALCULATE_F5_LTK: 3555 case SM_SC_W4_CALCULATE_F5_LTK: 3556 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3557 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3558 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3559 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3560 sm_pdu_received_in_wrong_state(sm_conn); 3561 break; 3562 } 3563 // store DHKey Check 3564 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3565 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3566 3567 // have we been only waiting for dhkey check command? 3568 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3569 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3570 } 3571 break; 3572 #endif 3573 3574 #ifdef ENABLE_LE_PERIPHERAL 3575 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3576 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3577 sm_pdu_received_in_wrong_state(sm_conn); 3578 break; 3579 } 3580 3581 // received confirm value 3582 reverse_128(&packet[1], setup->sm_peer_confirm); 3583 3584 #ifdef ENABLE_TESTING_SUPPORT 3585 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3586 log_info("testing_support: reset confirm value"); 3587 memset(setup->sm_peer_confirm, 0, 16); 3588 } 3589 #endif 3590 // notify client to hide shown passkey 3591 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3592 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3593 } 3594 3595 // handle user cancel pairing? 3596 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3597 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3598 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3599 break; 3600 } 3601 3602 // wait for user action? 3603 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3604 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3605 break; 3606 } 3607 3608 // calculate and send local_confirm 3609 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3610 break; 3611 3612 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3613 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3614 sm_pdu_received_in_wrong_state(sm_conn); 3615 break;; 3616 } 3617 3618 // received random value 3619 reverse_128(&packet[1], setup->sm_peer_random); 3620 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3621 break; 3622 #endif 3623 3624 case SM_PH3_RECEIVE_KEYS: 3625 switch(sm_pdu_code){ 3626 case SM_CODE_ENCRYPTION_INFORMATION: 3627 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3628 reverse_128(&packet[1], setup->sm_peer_ltk); 3629 break; 3630 3631 case SM_CODE_MASTER_IDENTIFICATION: 3632 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3633 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3634 reverse_64(&packet[3], setup->sm_peer_rand); 3635 break; 3636 3637 case SM_CODE_IDENTITY_INFORMATION: 3638 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3639 reverse_128(&packet[1], setup->sm_peer_irk); 3640 break; 3641 3642 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3643 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3644 setup->sm_peer_addr_type = packet[1]; 3645 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3646 break; 3647 3648 case SM_CODE_SIGNING_INFORMATION: 3649 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3650 reverse_128(&packet[1], setup->sm_peer_csrk); 3651 break; 3652 default: 3653 // Unexpected PDU 3654 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3655 break; 3656 } 3657 // done with key distribution? 3658 if (sm_key_distribution_all_received(sm_conn)){ 3659 3660 sm_key_distribution_handle_all_received(sm_conn); 3661 3662 if (IS_RESPONDER(sm_conn->sm_role)){ 3663 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3664 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3665 } else { 3666 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3667 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3668 sm_done_for_handle(sm_conn->sm_handle); 3669 } 3670 } else { 3671 if (setup->sm_use_secure_connections){ 3672 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3673 } else { 3674 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3675 } 3676 } 3677 } 3678 break; 3679 default: 3680 // Unexpected PDU 3681 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3682 break; 3683 } 3684 3685 // try to send preparared packet 3686 sm_run(); 3687 } 3688 3689 // Security Manager Client API 3690 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3691 sm_get_oob_data = get_oob_data_callback; 3692 } 3693 3694 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)){ 3695 sm_get_sc_oob_data = get_sc_oob_data_callback; 3696 } 3697 3698 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3699 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3700 } 3701 3702 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3703 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3704 } 3705 3706 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3707 sm_min_encryption_key_size = min_size; 3708 sm_max_encryption_key_size = max_size; 3709 } 3710 3711 void sm_set_authentication_requirements(uint8_t auth_req){ 3712 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3713 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3714 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3715 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3716 } 3717 #endif 3718 sm_auth_req = auth_req; 3719 } 3720 3721 void sm_set_io_capabilities(io_capability_t io_capability){ 3722 sm_io_capabilities = io_capability; 3723 } 3724 3725 #ifdef ENABLE_LE_PERIPHERAL 3726 void sm_set_request_security(int enable){ 3727 sm_slave_request_security = enable; 3728 } 3729 #endif 3730 3731 void sm_set_er(sm_key_t er){ 3732 memcpy(sm_persistent_er, er, 16); 3733 } 3734 3735 void sm_set_ir(sm_key_t ir){ 3736 memcpy(sm_persistent_ir, ir, 16); 3737 } 3738 3739 // Testing support only 3740 void sm_test_set_irk(sm_key_t irk){ 3741 memcpy(sm_persistent_irk, irk, 16); 3742 sm_persistent_irk_ready = 1; 3743 } 3744 3745 void sm_test_use_fixed_local_csrk(void){ 3746 test_use_fixed_local_csrk = 1; 3747 } 3748 3749 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3750 static void sm_ec_generated(void * arg){ 3751 UNUSED(arg); 3752 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3753 // trigger pairing if pending for ec key 3754 sm_run(); 3755 } 3756 static void sm_ec_generate_new_key(void){ 3757 log_info("sm: generate new ec key"); 3758 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3759 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3760 } 3761 #endif 3762 3763 #ifdef ENABLE_TESTING_SUPPORT 3764 void sm_test_set_pairing_failure(int reason){ 3765 test_pairing_failure = reason; 3766 } 3767 #endif 3768 3769 void sm_init(void){ 3770 // set some (BTstack default) ER and IR 3771 int i; 3772 sm_key_t er; 3773 sm_key_t ir; 3774 for (i=0;i<16;i++){ 3775 er[i] = 0x30 + i; 3776 ir[i] = 0x90 + i; 3777 } 3778 sm_set_er(er); 3779 sm_set_ir(ir); 3780 // defaults 3781 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3782 | SM_STK_GENERATION_METHOD_OOB 3783 | SM_STK_GENERATION_METHOD_PASSKEY 3784 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3785 3786 sm_max_encryption_key_size = 16; 3787 sm_min_encryption_key_size = 7; 3788 3789 sm_fixed_passkey_in_display_role = 0xffffffff; 3790 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3791 3792 #ifdef USE_CMAC_ENGINE 3793 sm_cmac_active = 0; 3794 #endif 3795 dkg_state = DKG_W4_WORKING; 3796 rau_state = RAU_W4_WORKING; 3797 sm_aes128_state = SM_AES128_IDLE; 3798 sm_address_resolution_test = -1; // no private address to resolve yet 3799 sm_address_resolution_ah_calculation_active = 0; 3800 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3801 sm_address_resolution_general_queue = NULL; 3802 3803 gap_random_adress_update_period = 15 * 60 * 1000L; 3804 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3805 3806 test_use_fixed_local_csrk = 0; 3807 3808 // register for HCI Events from HCI 3809 hci_event_callback_registration.callback = &sm_event_packet_handler; 3810 hci_add_event_handler(&hci_event_callback_registration); 3811 3812 // 3813 btstack_crypto_init(); 3814 3815 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3816 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3817 3818 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3819 sm_ec_generate_new_key(); 3820 #endif 3821 } 3822 3823 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3824 sm_fixed_passkey_in_display_role = passkey; 3825 } 3826 3827 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3828 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3829 } 3830 3831 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3832 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3833 if (!hci_con) return NULL; 3834 return &hci_con->sm_connection; 3835 } 3836 3837 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3838 switch (sm_conn->sm_engine_state){ 3839 case SM_GENERAL_IDLE: 3840 case SM_RESPONDER_IDLE: 3841 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3842 sm_run(); 3843 break; 3844 default: 3845 break; 3846 } 3847 } 3848 3849 /** 3850 * @brief Trigger Security Request 3851 */ 3852 void sm_send_security_request(hci_con_handle_t con_handle){ 3853 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3854 if (!sm_conn) return; 3855 sm_send_security_request_for_connection(sm_conn); 3856 } 3857 3858 // request pairing 3859 void sm_request_pairing(hci_con_handle_t con_handle){ 3860 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3861 if (!sm_conn) return; // wrong connection 3862 3863 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3864 if (IS_RESPONDER(sm_conn->sm_role)){ 3865 sm_send_security_request_for_connection(sm_conn); 3866 } else { 3867 // used as a trigger to start central/master/initiator security procedures 3868 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3869 uint8_t ltk[16]; 3870 switch (sm_conn->sm_irk_lookup_state){ 3871 case IRK_LOOKUP_SUCCEEDED: 3872 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 3873 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3874 int have_ltk = !sm_is_null_key(ltk); 3875 log_info("have ltk %u", have_ltk); 3876 // trigger 'pairing complete' event on encryption change 3877 sm_conn->sm_pairing_requested = 1; 3878 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3879 break; 3880 #endif 3881 /* explicit fall-through */ 3882 3883 case IRK_LOOKUP_FAILED: 3884 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3885 break; 3886 default: 3887 log_info("irk lookup pending"); 3888 sm_conn->sm_pairing_requested = 1; 3889 break; 3890 } 3891 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3892 sm_conn->sm_pairing_requested = 1; 3893 } 3894 } 3895 sm_run(); 3896 } 3897 3898 // called by client app on authorization request 3899 void sm_authorization_decline(hci_con_handle_t con_handle){ 3900 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3901 if (!sm_conn) return; // wrong connection 3902 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3903 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3904 } 3905 3906 void sm_authorization_grant(hci_con_handle_t con_handle){ 3907 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3908 if (!sm_conn) return; // wrong connection 3909 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3910 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3911 } 3912 3913 // GAP Bonding API 3914 3915 void sm_bonding_decline(hci_con_handle_t con_handle){ 3916 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3917 if (!sm_conn) return; // wrong connection 3918 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3919 log_info("decline, state %u", sm_conn->sm_engine_state); 3920 switch(sm_conn->sm_engine_state){ 3921 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3922 case SM_SC_W4_USER_RESPONSE: 3923 case SM_SC_W4_CONFIRMATION: 3924 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3925 #endif 3926 case SM_PH1_W4_USER_RESPONSE: 3927 switch (setup->sm_stk_generation_method){ 3928 case PK_RESP_INPUT: 3929 case PK_INIT_INPUT: 3930 case PK_BOTH_INPUT: 3931 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3932 break; 3933 case NUMERIC_COMPARISON: 3934 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3935 break; 3936 case JUST_WORKS: 3937 case OOB: 3938 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3939 break; 3940 } 3941 break; 3942 default: 3943 break; 3944 } 3945 sm_run(); 3946 } 3947 3948 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3949 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3950 if (!sm_conn) return; // wrong connection 3951 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3952 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3953 if (setup->sm_use_secure_connections){ 3954 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3955 } else { 3956 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3957 } 3958 } 3959 3960 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3961 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3962 sm_sc_prepare_dhkey_check(sm_conn); 3963 } 3964 #endif 3965 3966 sm_run(); 3967 } 3968 3969 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3970 // for now, it's the same 3971 sm_just_works_confirm(con_handle); 3972 } 3973 3974 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3975 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3976 if (!sm_conn) return; // wrong connection 3977 sm_reset_tk(); 3978 big_endian_store_32(setup->sm_tk, 12, passkey); 3979 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3980 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3981 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3982 } 3983 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3984 memcpy(setup->sm_ra, setup->sm_tk, 16); 3985 memcpy(setup->sm_rb, setup->sm_tk, 16); 3986 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3987 sm_sc_start_calculating_local_confirm(sm_conn); 3988 } 3989 #endif 3990 sm_run(); 3991 } 3992 3993 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3994 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3995 if (!sm_conn) return; // wrong connection 3996 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3997 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3998 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3999 switch (action){ 4000 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 4001 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 4002 flags |= (1 << action); 4003 break; 4004 case SM_KEYPRESS_PASSKEY_CLEARED: 4005 // clear counter, keypress & erased flags + set passkey cleared 4006 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 4007 break; 4008 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 4009 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 4010 // erase actions queued 4011 num_actions--; 4012 if (num_actions == 0){ 4013 // clear counter, keypress & erased flags 4014 flags &= 0x19; 4015 } 4016 break; 4017 } 4018 num_actions++; 4019 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4020 break; 4021 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4022 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4023 // enter actions queued 4024 num_actions--; 4025 if (num_actions == 0){ 4026 // clear counter, keypress & erased flags 4027 flags &= 0x19; 4028 } 4029 break; 4030 } 4031 num_actions++; 4032 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4033 break; 4034 default: 4035 break; 4036 } 4037 setup->sm_keypress_notification = (num_actions << 5) | flags; 4038 sm_run(); 4039 } 4040 4041 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4042 static void sm_handle_random_result_oob(void * arg){ 4043 UNUSED(arg); 4044 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4045 sm_run(); 4046 } 4047 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4048 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4049 sm_sc_oob_callback = callback; 4050 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4051 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4052 return 0; 4053 } 4054 #endif 4055 4056 /** 4057 * @brief Identify device in LE Device DB 4058 * @param handle 4059 * @returns index from le_device_db or -1 if not found/identified 4060 */ 4061 int sm_le_device_index(hci_con_handle_t con_handle ){ 4062 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4063 if (!sm_conn) return -1; 4064 return sm_conn->sm_le_db_index; 4065 } 4066 4067 static int gap_random_address_type_requires_updates(void){ 4068 switch (gap_random_adress_type){ 4069 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4070 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4071 return 0; 4072 default: 4073 return 1; 4074 } 4075 } 4076 4077 static uint8_t own_address_type(void){ 4078 switch (gap_random_adress_type){ 4079 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4080 return BD_ADDR_TYPE_LE_PUBLIC; 4081 default: 4082 return BD_ADDR_TYPE_LE_RANDOM; 4083 } 4084 } 4085 4086 // GAP LE API 4087 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4088 gap_random_address_update_stop(); 4089 gap_random_adress_type = random_address_type; 4090 hci_le_set_own_address_type(own_address_type()); 4091 if (!gap_random_address_type_requires_updates()) return; 4092 gap_random_address_update_start(); 4093 gap_random_address_trigger(); 4094 } 4095 4096 gap_random_address_type_t gap_random_address_get_mode(void){ 4097 return gap_random_adress_type; 4098 } 4099 4100 void gap_random_address_set_update_period(int period_ms){ 4101 gap_random_adress_update_period = period_ms; 4102 if (!gap_random_address_type_requires_updates()) return; 4103 gap_random_address_update_stop(); 4104 gap_random_address_update_start(); 4105 } 4106 4107 void gap_random_address_set(bd_addr_t addr){ 4108 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4109 memcpy(sm_random_address, addr, 6); 4110 if (rau_state == RAU_W4_WORKING) return; 4111 rau_state = RAU_SET_ADDRESS; 4112 sm_run(); 4113 } 4114 4115 #ifdef ENABLE_LE_PERIPHERAL 4116 /* 4117 * @brief Set Advertisement Paramters 4118 * @param adv_int_min 4119 * @param adv_int_max 4120 * @param adv_type 4121 * @param direct_address_type 4122 * @param direct_address 4123 * @param channel_map 4124 * @param filter_policy 4125 * 4126 * @note own_address_type is used from gap_random_address_set_mode 4127 */ 4128 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4129 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4130 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4131 direct_address_typ, direct_address, channel_map, filter_policy); 4132 } 4133 #endif 4134 4135 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4136 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4137 // wrong connection 4138 if (!sm_conn) return 0; 4139 // already encrypted 4140 if (sm_conn->sm_connection_encrypted) return 0; 4141 // only central can re-encrypt 4142 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4143 // irk status? 4144 switch(sm_conn->sm_irk_lookup_state){ 4145 case IRK_LOOKUP_FAILED: 4146 // done, cannot setup encryption 4147 return 0; 4148 case IRK_LOOKUP_SUCCEEDED: 4149 break; 4150 default: 4151 // IR Lookup pending 4152 return 1; 4153 } 4154 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4155 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4156 } 4157