1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "sm.c" 39 40 #include <stdio.h> 41 #include <string.h> 42 #include <inttypes.h> 43 44 #include "ble/le_device_db.h" 45 #include "ble/core.h" 46 #include "ble/sm.h" 47 #include "bluetooth_company_id.h" 48 #include "btstack_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "gap.h" 54 #include "hci.h" 55 #include "hci_dump.h" 56 #include "l2cap.h" 57 58 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 59 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 60 #endif 61 62 // assert SM Public Key can be sent/received 63 #ifdef ENABLE_LE_SECURE_CONNECTIONS 64 #if HCI_ACL_PAYLOAD_SIZE < 69 65 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 66 #endif 67 #endif 68 69 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 70 #define IS_RESPONDER(role) (role) 71 #else 72 #ifdef ENABLE_LE_CENTRAL 73 // only central - never responder (avoid 'unused variable' warnings) 74 #define IS_RESPONDER(role) (0 && role) 75 #else 76 // only peripheral - always responder (avoid 'unused variable' warnings) 77 #define IS_RESPONDER(role) (1 || role) 78 #endif 79 #endif 80 81 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 82 #define USE_CMAC_ENGINE 83 #endif 84 85 // 86 // SM internal types and globals 87 // 88 89 typedef enum { 90 DKG_W4_WORKING, 91 DKG_CALC_IRK, 92 DKG_CALC_DHK, 93 DKG_READY 94 } derived_key_generation_t; 95 96 typedef enum { 97 RAU_W4_WORKING, 98 RAU_IDLE, 99 RAU_W4_RANDOM, 100 RAU_GET_ENC, 101 RAU_W4_ENC, 102 RAU_SET_ADDRESS, 103 } random_address_update_t; 104 105 typedef enum { 106 CMAC_IDLE, 107 CMAC_CALC_SUBKEYS, 108 CMAC_W4_SUBKEYS, 109 CMAC_CALC_MI, 110 CMAC_W4_MI, 111 CMAC_CALC_MLAST, 112 CMAC_W4_MLAST 113 } cmac_state_t; 114 115 typedef enum { 116 JUST_WORKS, 117 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 118 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 119 PK_BOTH_INPUT, // Only input on both, both input PK 120 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 121 OOB // OOB available on one (SC) or both sides (legacy) 122 } stk_generation_method_t; 123 124 typedef enum { 125 SM_USER_RESPONSE_IDLE, 126 SM_USER_RESPONSE_PENDING, 127 SM_USER_RESPONSE_CONFIRM, 128 SM_USER_RESPONSE_PASSKEY, 129 SM_USER_RESPONSE_DECLINE 130 } sm_user_response_t; 131 132 typedef enum { 133 SM_AES128_IDLE, 134 SM_AES128_ACTIVE 135 } sm_aes128_state_t; 136 137 typedef enum { 138 ADDRESS_RESOLUTION_IDLE, 139 ADDRESS_RESOLUTION_GENERAL, 140 ADDRESS_RESOLUTION_FOR_CONNECTION, 141 } address_resolution_mode_t; 142 143 typedef enum { 144 ADDRESS_RESOLUTION_SUCEEDED, 145 ADDRESS_RESOLUTION_FAILED, 146 } address_resolution_event_t; 147 148 typedef enum { 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static uint8_t sm_persistent_irk_ready = 0; // used for testing 204 static derived_key_generation_t dkg_state; 205 206 // derived from sm_persistent_er 207 // .. 208 209 // random address update 210 static random_address_update_t rau_state; 211 static bd_addr_t sm_random_address; 212 213 #ifdef USE_CMAC_ENGINE 214 // CMAC Calculation: General 215 static btstack_crypto_aes128_cmac_t sm_cmac_request; 216 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 217 static uint8_t sm_cmac_active; 218 static uint8_t sm_cmac_hash[16]; 219 #endif 220 221 // CMAC for ATT Signed Writes 222 #ifdef ENABLE_LE_SIGNED_WRITE 223 static uint16_t sm_cmac_signed_write_message_len; 224 static uint8_t sm_cmac_signed_write_header[3]; 225 static const uint8_t * sm_cmac_signed_write_message; 226 static uint8_t sm_cmac_signed_write_sign_counter[4]; 227 #endif 228 229 // CMAC for Secure Connection functions 230 #ifdef ENABLE_LE_SECURE_CONNECTIONS 231 static sm_connection_t * sm_cmac_connection; 232 static uint8_t sm_cmac_sc_buffer[80]; 233 #endif 234 235 // resolvable private address lookup / CSRK calculation 236 static int sm_address_resolution_test; 237 static int sm_address_resolution_ah_calculation_active; 238 static uint8_t sm_address_resolution_addr_type; 239 static bd_addr_t sm_address_resolution_address; 240 static void * sm_address_resolution_context; 241 static address_resolution_mode_t sm_address_resolution_mode; 242 static btstack_linked_list_t sm_address_resolution_general_queue; 243 244 // aes128 crypto engine. 245 static sm_aes128_state_t sm_aes128_state; 246 247 // crypto 248 static btstack_crypto_random_t sm_crypto_random_request; 249 static btstack_crypto_aes128_t sm_crypto_aes128_request; 250 #ifdef ENABLE_LE_SECURE_CONNECTIONS 251 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 252 static btstack_crypto_random_t sm_crypto_random_oob_request; 253 #endif 254 255 // temp storage for random data 256 static uint8_t sm_random_data[8]; 257 static uint8_t sm_aes128_key[16]; 258 static uint8_t sm_aes128_plaintext[16]; 259 static uint8_t sm_aes128_ciphertext[16]; 260 261 // to receive hci events 262 static btstack_packet_callback_registration_t hci_event_callback_registration; 263 264 /* to dispatch sm event */ 265 static btstack_linked_list_t sm_event_handlers; 266 267 // LE Secure Connections 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static ec_key_generation_state_t ec_key_generation_state; 270 static uint8_t ec_q[64]; 271 #endif 272 273 // 274 // Volume 3, Part H, Chapter 24 275 // "Security shall be initiated by the Security Manager in the device in the master role. 276 // The device in the slave role shall be the responding device." 277 // -> master := initiator, slave := responder 278 // 279 280 // data needed for security setup 281 typedef struct sm_setup_context { 282 283 btstack_timer_source_t sm_timeout; 284 285 // used in all phases 286 uint8_t sm_pairing_failed_reason; 287 288 // user response, (Phase 1 and/or 2) 289 uint8_t sm_user_response; 290 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 291 292 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 293 int sm_key_distribution_send_set; 294 int sm_key_distribution_received_set; 295 296 // Phase 2 (Pairing over SMP) 297 stk_generation_method_t sm_stk_generation_method; 298 sm_key_t sm_tk; 299 uint8_t sm_have_oob_data; 300 uint8_t sm_use_secure_connections; 301 302 sm_key_t sm_c1_t3_value; // c1 calculation 303 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 304 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 305 sm_key_t sm_local_random; 306 sm_key_t sm_local_confirm; 307 sm_key_t sm_peer_random; 308 sm_key_t sm_peer_confirm; 309 uint8_t sm_m_addr_type; // address and type can be removed 310 uint8_t sm_s_addr_type; // '' 311 bd_addr_t sm_m_address; // '' 312 bd_addr_t sm_s_address; // '' 313 sm_key_t sm_ltk; 314 315 uint8_t sm_state_vars; 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 318 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 319 sm_key_t sm_local_nonce; // might be combined with sm_local_random 320 sm_key_t sm_dhkey; 321 sm_key_t sm_peer_dhkey_check; 322 sm_key_t sm_local_dhkey_check; 323 sm_key_t sm_ra; 324 sm_key_t sm_rb; 325 sm_key_t sm_t; // used for f5 and h6 326 sm_key_t sm_mackey; 327 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 328 #endif 329 330 // Phase 3 331 332 // key distribution, we generate 333 uint16_t sm_local_y; 334 uint16_t sm_local_div; 335 uint16_t sm_local_ediv; 336 uint8_t sm_local_rand[8]; 337 sm_key_t sm_local_ltk; 338 sm_key_t sm_local_csrk; 339 sm_key_t sm_local_irk; 340 // sm_local_address/addr_type not needed 341 342 // key distribution, received from peer 343 uint16_t sm_peer_y; 344 uint16_t sm_peer_div; 345 uint16_t sm_peer_ediv; 346 uint8_t sm_peer_rand[8]; 347 sm_key_t sm_peer_ltk; 348 sm_key_t sm_peer_irk; 349 sm_key_t sm_peer_csrk; 350 uint8_t sm_peer_addr_type; 351 bd_addr_t sm_peer_address; 352 353 } sm_setup_context_t; 354 355 // 356 static sm_setup_context_t the_setup; 357 static sm_setup_context_t * setup = &the_setup; 358 359 // active connection - the one for which the_setup is used for 360 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 361 362 // @returns 1 if oob data is available 363 // stores oob data in provided 16 byte buffer if not null 364 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 365 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 366 367 // horizontal: initiator capabilities 368 // vertial: responder capabilities 369 static const stk_generation_method_t stk_generation_method [5] [5] = { 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 373 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 374 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 375 }; 376 377 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 378 #ifdef ENABLE_LE_SECURE_CONNECTIONS 379 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 380 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 381 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 382 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 383 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 384 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 385 }; 386 #endif 387 388 static void sm_run(void); 389 #ifdef USE_CMAC_ENGINE 390 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 391 #endif 392 static void sm_done_for_handle(hci_con_handle_t con_handle); 393 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 394 static inline int sm_calc_actual_encryption_key_size(int other); 395 static int sm_validate_stk_generation_method(void); 396 static void sm_handle_encryption_result_address_resolution(void *arg); 397 static void sm_handle_encryption_result_dkg_dhk(void *arg); 398 static void sm_handle_encryption_result_dkg_irk(void *arg); 399 static void sm_handle_encryption_result_enc_a(void *arg); 400 static void sm_handle_encryption_result_enc_b(void *arg); 401 static void sm_handle_encryption_result_enc_c(void *arg); 402 static void sm_handle_encryption_result_enc_csrk(void *arg); 403 static void sm_handle_encryption_result_enc_d(void * arg); 404 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 405 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 406 #ifdef ENABLE_LE_PERIPHERAL 407 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 408 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 409 #endif 410 static void sm_handle_encryption_result_enc_stk(void *arg); 411 static void sm_handle_encryption_result_rau(void *arg); 412 static void sm_handle_random_result_ph2_tk(void * arg); 413 static void sm_handle_random_result_rau(void * arg); 414 #ifdef ENABLE_LE_SECURE_CONNECTIONS 415 static void sm_handle_random_result_sc_get_random(void * arg); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 #endif 418 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 419 420 static void log_info_hex16(const char * name, uint16_t value){ 421 log_info("%-6s 0x%04x", name, value); 422 } 423 424 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 425 // return packet[0]; 426 // } 427 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 428 return packet[1]; 429 } 430 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 431 return packet[2]; 432 } 433 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 434 return packet[3]; 435 } 436 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 437 return packet[4]; 438 } 439 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 440 return packet[5]; 441 } 442 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 443 return packet[6]; 444 } 445 446 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 447 packet[0] = code; 448 } 449 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 450 packet[1] = io_capability; 451 } 452 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 453 packet[2] = oob_data_flag; 454 } 455 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 456 packet[3] = auth_req; 457 } 458 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 459 packet[4] = max_encryption_key_size; 460 } 461 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 462 packet[5] = initiator_key_distribution; 463 } 464 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 465 packet[6] = responder_key_distribution; 466 } 467 468 // @returns 1 if all bytes are 0 469 static int sm_is_null(uint8_t * data, int size){ 470 int i; 471 for (i=0; i < size ; i++){ 472 if (data[i]) return 0; 473 } 474 return 1; 475 } 476 477 static int sm_is_null_random(uint8_t random[8]){ 478 return sm_is_null(random, 8); 479 } 480 481 static int sm_is_null_key(uint8_t * key){ 482 return sm_is_null(key, 16); 483 } 484 485 // Key utils 486 static void sm_reset_tk(void){ 487 int i; 488 for (i=0;i<16;i++){ 489 setup->sm_tk[i] = 0; 490 } 491 } 492 493 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 494 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 495 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 496 int i; 497 for (i = max_encryption_size ; i < 16 ; i++){ 498 key[15-i] = 0; 499 } 500 } 501 502 // SMP Timeout implementation 503 504 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 505 // the Security Manager Timer shall be reset and started. 506 // 507 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 508 // 509 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 510 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 511 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 512 // established. 513 514 static void sm_timeout_handler(btstack_timer_source_t * timer){ 515 log_info("SM timeout"); 516 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 517 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 518 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 519 sm_done_for_handle(sm_conn->sm_handle); 520 521 // trigger handling of next ready connection 522 sm_run(); 523 } 524 static void sm_timeout_start(sm_connection_t * sm_conn){ 525 btstack_run_loop_remove_timer(&setup->sm_timeout); 526 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 527 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 528 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 529 btstack_run_loop_add_timer(&setup->sm_timeout); 530 } 531 static void sm_timeout_stop(void){ 532 btstack_run_loop_remove_timer(&setup->sm_timeout); 533 } 534 static void sm_timeout_reset(sm_connection_t * sm_conn){ 535 sm_timeout_stop(); 536 sm_timeout_start(sm_conn); 537 } 538 539 // end of sm timeout 540 541 // GAP Random Address updates 542 static gap_random_address_type_t gap_random_adress_type; 543 static btstack_timer_source_t gap_random_address_update_timer; 544 static uint32_t gap_random_adress_update_period; 545 546 static void gap_random_address_trigger(void){ 547 log_info("gap_random_address_trigger"); 548 if (rau_state != RAU_IDLE) return; 549 rau_state = RAU_W4_RANDOM; 550 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 551 } 552 553 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 554 UNUSED(timer); 555 556 log_info("GAP Random Address Update due"); 557 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 558 btstack_run_loop_add_timer(&gap_random_address_update_timer); 559 gap_random_address_trigger(); 560 } 561 562 static void gap_random_address_update_start(void){ 563 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 564 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 565 btstack_run_loop_add_timer(&gap_random_address_update_timer); 566 } 567 568 static void gap_random_address_update_stop(void){ 569 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 570 } 571 572 // ah(k,r) helper 573 // r = padding || r 574 // r - 24 bit value 575 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 576 // r'= padding || r 577 memset(r_prime, 0, 16); 578 memcpy(&r_prime[13], r, 3); 579 } 580 581 // d1 helper 582 // d' = padding || r || d 583 // d,r - 16 bit values 584 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 585 // d'= padding || r || d 586 memset(d1_prime, 0, 16); 587 big_endian_store_16(d1_prime, 12, r); 588 big_endian_store_16(d1_prime, 14, d); 589 } 590 591 // dm helper 592 // r’ = padding || r 593 // r - 64 bit value 594 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 595 memset(r_prime, 0, 16); 596 memcpy(&r_prime[8], r, 8); 597 } 598 599 // calculate arguments for first AES128 operation in C1 function 600 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 601 602 // p1 = pres || preq || rat’ || iat’ 603 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 604 // cant octet of pres becomes the most significant octet of p1. 605 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 606 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 607 // p1 is 0x05000800000302070710000001010001." 608 609 sm_key_t p1; 610 reverse_56(pres, &p1[0]); 611 reverse_56(preq, &p1[7]); 612 p1[14] = rat; 613 p1[15] = iat; 614 log_info_key("p1", p1); 615 log_info_key("r", r); 616 617 // t1 = r xor p1 618 int i; 619 for (i=0;i<16;i++){ 620 t1[i] = r[i] ^ p1[i]; 621 } 622 log_info_key("t1", t1); 623 } 624 625 // calculate arguments for second AES128 operation in C1 function 626 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 627 // p2 = padding || ia || ra 628 // "The least significant octet of ra becomes the least significant octet of p2 and 629 // the most significant octet of padding becomes the most significant octet of p2. 630 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 631 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 632 633 sm_key_t p2; 634 memset(p2, 0, 16); 635 memcpy(&p2[4], ia, 6); 636 memcpy(&p2[10], ra, 6); 637 log_info_key("p2", p2); 638 639 // c1 = e(k, t2_xor_p2) 640 int i; 641 for (i=0;i<16;i++){ 642 t3[i] = t2[i] ^ p2[i]; 643 } 644 log_info_key("t3", t3); 645 } 646 647 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 648 log_info_key("r1", r1); 649 log_info_key("r2", r2); 650 memcpy(&r_prime[8], &r2[8], 8); 651 memcpy(&r_prime[0], &r1[8], 8); 652 } 653 654 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 655 UNUSED(channel); 656 657 // log event 658 hci_dump_packet(packet_type, 1, packet, size); 659 // dispatch to all event handlers 660 btstack_linked_list_iterator_t it; 661 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 662 while (btstack_linked_list_iterator_has_next(&it)){ 663 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 664 entry->callback(packet_type, 0, packet, size); 665 } 666 } 667 668 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 669 event[0] = type; 670 event[1] = event_size - 2; 671 little_endian_store_16(event, 2, con_handle); 672 event[4] = addr_type; 673 reverse_bd_addr(address, &event[5]); 674 } 675 676 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 677 uint8_t event[11]; 678 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 679 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 680 } 681 682 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 683 uint8_t event[15]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 little_endian_store_32(event, 11, passkey); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 690 // fetch addr and addr type from db 691 bd_addr_t identity_address; 692 int identity_address_type; 693 le_device_db_info(index, &identity_address_type, identity_address, NULL); 694 695 uint8_t event[19]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 event[11] = identity_address_type; 698 reverse_bd_addr(identity_address, &event[12]); 699 event[18] = index; 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 704 uint8_t event[12]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = status; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 711 uint8_t event[13]; 712 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 713 event[11] = status; 714 event[12] = reason; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 735 736 737 // decide if OOB will be used based on SC vs. Legacy and oob flags 738 int use_oob = 0; 739 if (setup->sm_use_secure_connections){ 740 // In LE Secure Connections pairing, the out of band method is used if at least 741 // one device has the peer device's out of band authentication data available. 742 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 743 } else { 744 // In LE legacy pairing, the out of band method is used if both the devices have 745 // the other device's out of band authentication data available. 746 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 747 } 748 if (use_oob){ 749 log_info("SM: have OOB data"); 750 log_info_key("OOB", setup->sm_tk); 751 setup->sm_stk_generation_method = OOB; 752 return; 753 } 754 755 // If both devices have not set the MITM option in the Authentication Requirements 756 // Flags, then the IO capabilities shall be ignored and the Just Works association 757 // model shall be used. 758 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 759 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 760 log_info("SM: MITM not required by both -> JUST WORKS"); 761 return; 762 } 763 764 // Reset TK as it has been setup in sm_init_setup 765 sm_reset_tk(); 766 767 // Also use just works if unknown io capabilites 768 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 769 return; 770 } 771 772 // Otherwise the IO capabilities of the devices shall be used to determine the 773 // pairing method as defined in Table 2.4. 774 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 775 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 776 777 #ifdef ENABLE_LE_SECURE_CONNECTIONS 778 // table not define by default 779 if (setup->sm_use_secure_connections){ 780 generation_method = stk_generation_method_with_secure_connection; 781 } 782 #endif 783 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 784 785 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 786 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 787 } 788 789 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 790 int flags = 0; 791 if (key_set & SM_KEYDIST_ENC_KEY){ 792 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 794 } 795 if (key_set & SM_KEYDIST_ID_KEY){ 796 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 797 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 798 } 799 if (key_set & SM_KEYDIST_SIGN){ 800 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 801 } 802 return flags; 803 } 804 805 static void sm_setup_key_distribution(uint8_t key_set){ 806 setup->sm_key_distribution_received_set = 0; 807 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 808 } 809 810 // CSRK Key Lookup 811 812 813 static int sm_address_resolution_idle(void){ 814 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 815 } 816 817 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 818 memcpy(sm_address_resolution_address, addr, 6); 819 sm_address_resolution_addr_type = addr_type; 820 sm_address_resolution_test = 0; 821 sm_address_resolution_mode = mode; 822 sm_address_resolution_context = context; 823 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 824 } 825 826 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 827 // check if already in list 828 btstack_linked_list_iterator_t it; 829 sm_lookup_entry_t * entry; 830 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 831 while(btstack_linked_list_iterator_has_next(&it)){ 832 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 833 if (entry->address_type != address_type) continue; 834 if (memcmp(entry->address, address, 6)) continue; 835 // already in list 836 return BTSTACK_BUSY; 837 } 838 entry = btstack_memory_sm_lookup_entry_get(); 839 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 840 entry->address_type = (bd_addr_type_t) address_type; 841 memcpy(entry->address, address, 6); 842 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 843 sm_run(); 844 return 0; 845 } 846 847 // CMAC calculation using AES Engineq 848 #ifdef USE_CMAC_ENGINE 849 850 static void sm_cmac_done_trampoline(void * arg){ 851 UNUSED(arg); 852 sm_cmac_active = 0; 853 (*sm_cmac_done_callback)(sm_cmac_hash); 854 sm_run(); 855 } 856 857 int sm_cmac_ready(void){ 858 return sm_cmac_active == 0; 859 } 860 861 // generic cmac calculation 862 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 863 sm_cmac_active = 1; 864 sm_cmac_done_callback = done_callback; 865 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 866 } 867 #endif 868 869 // cmac for ATT Message signing 870 #ifdef ENABLE_LE_SIGNED_WRITE 871 872 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 873 sm_cmac_active = 1; 874 sm_cmac_done_callback = done_callback; 875 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 876 } 877 878 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_signed_write_message_len) { 880 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_signed_write_message_len - 1 - offset; 885 886 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_signed_write_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_signed_write_message[offset - 3]; 893 } 894 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 898 // ATT Message Signing 899 sm_cmac_signed_write_header[0] = opcode; 900 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 901 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 902 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 903 sm_cmac_signed_write_message = message; 904 sm_cmac_signed_write_message_len = total_message_len; 905 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 906 } 907 #endif 908 909 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 910 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 911 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 912 switch (setup->sm_stk_generation_method){ 913 case PK_RESP_INPUT: 914 if (IS_RESPONDER(sm_conn->sm_role)){ 915 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 916 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 917 } else { 918 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 919 } 920 break; 921 case PK_INIT_INPUT: 922 if (IS_RESPONDER(sm_conn->sm_role)){ 923 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 924 } else { 925 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 926 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 927 } 928 break; 929 case PK_BOTH_INPUT: 930 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 931 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 932 break; 933 case NUMERIC_COMPARISON: 934 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 935 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 936 break; 937 case JUST_WORKS: 938 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 939 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 940 break; 941 case OOB: 942 // client already provided OOB data, let's skip notification. 943 break; 944 } 945 } 946 947 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 948 int recv_flags; 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 // slave / responder 951 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 952 } else { 953 // master / initiator 954 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 955 } 956 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 957 return recv_flags == setup->sm_key_distribution_received_set; 958 } 959 960 static void sm_done_for_handle(hci_con_handle_t con_handle){ 961 if (sm_active_connection_handle == con_handle){ 962 sm_timeout_stop(); 963 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 964 log_info("sm: connection 0x%x released setup context", con_handle); 965 } 966 } 967 968 static int sm_key_distribution_flags_for_auth_req(void){ 969 970 int flags = SM_KEYDIST_ID_KEY; 971 if (sm_auth_req & SM_AUTHREQ_BONDING){ 972 // encryption and signing information only if bonding requested 973 flags |= SM_KEYDIST_ENC_KEY; 974 #ifdef ENABLE_LE_SIGNED_WRITE 975 flags |= SM_KEYDIST_SIGN; 976 #endif 977 } 978 return flags; 979 } 980 981 static void sm_reset_setup(void){ 982 // fill in sm setup 983 setup->sm_state_vars = 0; 984 setup->sm_keypress_notification = 0; 985 sm_reset_tk(); 986 } 987 988 static void sm_init_setup(sm_connection_t * sm_conn){ 989 990 // fill in sm setup 991 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 992 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 993 994 // query client for Legacy Pairing OOB data 995 setup->sm_have_oob_data = 0; 996 if (sm_get_oob_data) { 997 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 998 } 999 1000 // if available and SC supported, also ask for SC OOB Data 1001 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1002 memset(setup->sm_ra, 0, 16); 1003 memset(setup->sm_rb, 0, 16); 1004 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1005 if (sm_get_sc_oob_data){ 1006 if (IS_RESPONDER(sm_conn->sm_role)){ 1007 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1008 sm_conn->sm_peer_addr_type, 1009 sm_conn->sm_peer_address, 1010 setup->sm_peer_confirm, 1011 setup->sm_ra); 1012 } else { 1013 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1014 sm_conn->sm_peer_addr_type, 1015 sm_conn->sm_peer_address, 1016 setup->sm_peer_confirm, 1017 setup->sm_rb); 1018 } 1019 } else { 1020 setup->sm_have_oob_data = 0; 1021 } 1022 } 1023 #endif 1024 1025 sm_pairing_packet_t * local_packet; 1026 if (IS_RESPONDER(sm_conn->sm_role)){ 1027 // slave 1028 local_packet = &setup->sm_s_pres; 1029 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1030 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1031 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1032 } else { 1033 // master 1034 local_packet = &setup->sm_m_preq; 1035 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1036 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1037 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1038 1039 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1040 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1041 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1042 } 1043 1044 uint8_t auth_req = sm_auth_req; 1045 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1046 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1047 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1048 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1049 } 1050 1051 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1052 1053 sm_pairing_packet_t * remote_packet; 1054 int remote_key_request; 1055 if (IS_RESPONDER(sm_conn->sm_role)){ 1056 // slave / responder 1057 remote_packet = &setup->sm_m_preq; 1058 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1059 } else { 1060 // master / initiator 1061 remote_packet = &setup->sm_s_pres; 1062 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1063 } 1064 1065 // check key size 1066 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1067 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1068 1069 // decide on STK generation method 1070 sm_setup_tk(); 1071 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1072 1073 // check if STK generation method is acceptable by client 1074 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1075 1076 // identical to responder 1077 sm_setup_key_distribution(remote_key_request); 1078 1079 // JUST WORKS doens't provide authentication 1080 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1081 1082 return 0; 1083 } 1084 1085 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1086 1087 // cache and reset context 1088 int matched_device_id = sm_address_resolution_test; 1089 address_resolution_mode_t mode = sm_address_resolution_mode; 1090 void * context = sm_address_resolution_context; 1091 1092 // reset context 1093 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1094 sm_address_resolution_context = NULL; 1095 sm_address_resolution_test = -1; 1096 hci_con_handle_t con_handle = 0; 1097 1098 sm_connection_t * sm_connection; 1099 #ifdef ENABLE_LE_CENTRAL 1100 sm_key_t ltk; 1101 #endif 1102 switch (mode){ 1103 case ADDRESS_RESOLUTION_GENERAL: 1104 break; 1105 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1106 sm_connection = (sm_connection_t *) context; 1107 con_handle = sm_connection->sm_handle; 1108 switch (event){ 1109 case ADDRESS_RESOLUTION_SUCEEDED: 1110 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1111 sm_connection->sm_le_db_index = matched_device_id; 1112 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1113 if (sm_connection->sm_role) { 1114 // LTK request received before, IRK required -> start LTK calculation 1115 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1116 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1117 } 1118 break; 1119 } 1120 #ifdef ENABLE_LE_CENTRAL 1121 log_info("central: bonding requested %u, prev security request %u", sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received); 1122 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1123 sm_connection->sm_security_request_received = 0; 1124 sm_connection->sm_pairing_requested = 0; 1125 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1126 if (!sm_is_null_key(ltk)){ 1127 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1128 } else { 1129 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1130 } 1131 #endif 1132 break; 1133 case ADDRESS_RESOLUTION_FAILED: 1134 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1135 if (sm_connection->sm_role) { 1136 // LTK request received before, IRK required -> negative LTK reply 1137 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1138 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1139 } 1140 break; 1141 } 1142 #ifdef ENABLE_LE_CENTRAL 1143 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1144 sm_connection->sm_security_request_received = 0; 1145 sm_connection->sm_pairing_requested = 0; 1146 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1147 #endif 1148 break; 1149 } 1150 break; 1151 default: 1152 break; 1153 } 1154 1155 switch (event){ 1156 case ADDRESS_RESOLUTION_SUCEEDED: 1157 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1158 break; 1159 case ADDRESS_RESOLUTION_FAILED: 1160 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1161 break; 1162 } 1163 } 1164 1165 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1166 1167 int le_db_index = -1; 1168 1169 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1170 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1171 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1172 & SM_AUTHREQ_BONDING ) != 0; 1173 1174 if (bonding_enabed){ 1175 1176 // lookup device based on IRK 1177 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1178 int i; 1179 for (i=0; i < le_device_db_max_count(); i++){ 1180 sm_key_t irk; 1181 bd_addr_t address; 1182 int address_type; 1183 le_device_db_info(i, &address_type, address, irk); 1184 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1185 log_info("sm: device found for IRK, updating"); 1186 le_db_index = i; 1187 break; 1188 } 1189 } 1190 } 1191 1192 // if not found, lookup via public address if possible 1193 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1194 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1195 int i; 1196 for (i=0; i < le_device_db_max_count(); i++){ 1197 bd_addr_t address; 1198 int address_type; 1199 le_device_db_info(i, &address_type, address, NULL); 1200 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1201 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1202 log_info("sm: device found for public address, updating"); 1203 le_db_index = i; 1204 break; 1205 } 1206 } 1207 } 1208 1209 // if not found, add to db 1210 if (le_db_index < 0) { 1211 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1212 } 1213 1214 if (le_db_index >= 0){ 1215 1216 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1217 1218 #ifdef ENABLE_LE_SIGNED_WRITE 1219 // store local CSRK 1220 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1221 log_info("sm: store local CSRK"); 1222 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1223 le_device_db_local_counter_set(le_db_index, 0); 1224 } 1225 1226 // store remote CSRK 1227 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1228 log_info("sm: store remote CSRK"); 1229 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1230 le_device_db_remote_counter_set(le_db_index, 0); 1231 } 1232 #endif 1233 // store encryption information for secure connections: LTK generated by ECDH 1234 if (setup->sm_use_secure_connections){ 1235 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1236 uint8_t zero_rand[8]; 1237 memset(zero_rand, 0, 8); 1238 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1239 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1240 } 1241 1242 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1243 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1244 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1245 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1246 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1247 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1248 1249 } 1250 } 1251 } else { 1252 log_info("Ignoring received keys, bonding not enabled"); 1253 } 1254 1255 // keep le_db_index 1256 sm_conn->sm_le_db_index = le_db_index; 1257 } 1258 1259 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1260 setup->sm_pairing_failed_reason = reason; 1261 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1262 } 1263 1264 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1265 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1266 } 1267 1268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1269 1270 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1271 static int sm_passkey_used(stk_generation_method_t method); 1272 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1273 1274 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1275 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1276 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1277 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1278 } else { 1279 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1280 } 1281 } 1282 1283 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1284 if (IS_RESPONDER(sm_conn->sm_role)){ 1285 // Responder 1286 if (setup->sm_stk_generation_method == OOB){ 1287 // generate Nb 1288 log_info("Generate Nb"); 1289 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1290 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1291 } else { 1292 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1293 } 1294 } else { 1295 // Initiator role 1296 switch (setup->sm_stk_generation_method){ 1297 case JUST_WORKS: 1298 sm_sc_prepare_dhkey_check(sm_conn); 1299 break; 1300 1301 case NUMERIC_COMPARISON: 1302 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1303 break; 1304 case PK_INIT_INPUT: 1305 case PK_RESP_INPUT: 1306 case PK_BOTH_INPUT: 1307 if (setup->sm_passkey_bit < 20) { 1308 sm_sc_start_calculating_local_confirm(sm_conn); 1309 } else { 1310 sm_sc_prepare_dhkey_check(sm_conn); 1311 } 1312 break; 1313 case OOB: 1314 sm_sc_prepare_dhkey_check(sm_conn); 1315 break; 1316 } 1317 } 1318 } 1319 1320 static void sm_sc_cmac_done(uint8_t * hash){ 1321 log_info("sm_sc_cmac_done: "); 1322 log_info_hexdump(hash, 16); 1323 1324 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1325 sm_sc_oob_state = SM_SC_OOB_IDLE; 1326 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1327 return; 1328 } 1329 1330 sm_connection_t * sm_conn = sm_cmac_connection; 1331 sm_cmac_connection = NULL; 1332 #ifdef ENABLE_CLASSIC 1333 link_key_type_t link_key_type; 1334 #endif 1335 1336 switch (sm_conn->sm_engine_state){ 1337 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1338 memcpy(setup->sm_local_confirm, hash, 16); 1339 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1340 break; 1341 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1342 // check 1343 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1344 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1345 break; 1346 } 1347 sm_sc_state_after_receiving_random(sm_conn); 1348 break; 1349 case SM_SC_W4_CALCULATE_G2: { 1350 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1351 big_endian_store_32(setup->sm_tk, 12, vab); 1352 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1353 sm_trigger_user_response(sm_conn); 1354 break; 1355 } 1356 case SM_SC_W4_CALCULATE_F5_SALT: 1357 memcpy(setup->sm_t, hash, 16); 1358 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1359 break; 1360 case SM_SC_W4_CALCULATE_F5_MACKEY: 1361 memcpy(setup->sm_mackey, hash, 16); 1362 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1363 break; 1364 case SM_SC_W4_CALCULATE_F5_LTK: 1365 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1366 // Errata Service Release to the Bluetooth Specification: ESR09 1367 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1368 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1369 memcpy(setup->sm_ltk, hash, 16); 1370 memcpy(setup->sm_local_ltk, hash, 16); 1371 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1372 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1373 break; 1374 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1375 memcpy(setup->sm_local_dhkey_check, hash, 16); 1376 if (IS_RESPONDER(sm_conn->sm_role)){ 1377 // responder 1378 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1379 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1380 } else { 1381 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1382 } 1383 } else { 1384 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1385 } 1386 break; 1387 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1388 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1389 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1390 break; 1391 } 1392 if (IS_RESPONDER(sm_conn->sm_role)){ 1393 // responder 1394 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1395 } else { 1396 // initiator 1397 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1398 } 1399 break; 1400 case SM_SC_W4_CALCULATE_H6_ILK: 1401 memcpy(setup->sm_t, hash, 16); 1402 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1403 break; 1404 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1405 #ifdef ENABLE_CLASSIC 1406 reverse_128(hash, setup->sm_t); 1407 link_key_type = sm_conn->sm_connection_authenticated ? 1408 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1409 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1410 if (IS_RESPONDER(sm_conn->sm_role)){ 1411 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1412 } else { 1413 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1414 } 1415 #endif 1416 if (IS_RESPONDER(sm_conn->sm_role)){ 1417 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1418 } else { 1419 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1420 } 1421 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1422 sm_done_for_handle(sm_conn->sm_handle); 1423 break; 1424 default: 1425 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1426 break; 1427 } 1428 sm_run(); 1429 } 1430 1431 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){ 1432 const uint16_t message_len = 65; 1433 sm_cmac_connection = sm_conn; 1434 memcpy(sm_cmac_sc_buffer, u, 32); 1435 memcpy(sm_cmac_sc_buffer+32, v, 32); 1436 sm_cmac_sc_buffer[64] = z; 1437 log_info("f4 key"); 1438 log_info_hexdump(x, 16); 1439 log_info("f4 message"); 1440 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1441 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1442 } 1443 1444 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1445 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1446 static const uint8_t f5_length[] = { 0x01, 0x00}; 1447 1448 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1449 log_info("f5_calculate_salt"); 1450 // calculate salt for f5 1451 const uint16_t message_len = 32; 1452 sm_cmac_connection = sm_conn; 1453 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1454 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1455 } 1456 1457 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){ 1458 const uint16_t message_len = 53; 1459 sm_cmac_connection = sm_conn; 1460 1461 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1462 sm_cmac_sc_buffer[0] = 0; 1463 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1464 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1465 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1466 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1467 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1468 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1469 log_info("f5 key"); 1470 log_info_hexdump(t, 16); 1471 log_info("f5 message for MacKey"); 1472 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1473 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1474 } 1475 1476 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1477 sm_key56_t bd_addr_master, bd_addr_slave; 1478 bd_addr_master[0] = setup->sm_m_addr_type; 1479 bd_addr_slave[0] = setup->sm_s_addr_type; 1480 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1481 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1482 if (IS_RESPONDER(sm_conn->sm_role)){ 1483 // responder 1484 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1485 } else { 1486 // initiator 1487 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1488 } 1489 } 1490 1491 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1492 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1493 const uint16_t message_len = 53; 1494 sm_cmac_connection = sm_conn; 1495 sm_cmac_sc_buffer[0] = 1; 1496 // 1..52 setup before 1497 log_info("f5 key"); 1498 log_info_hexdump(t, 16); 1499 log_info("f5 message for LTK"); 1500 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1501 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1502 } 1503 1504 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1505 f5_ltk(sm_conn, setup->sm_t); 1506 } 1507 1508 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){ 1509 const uint16_t message_len = 65; 1510 sm_cmac_connection = sm_conn; 1511 memcpy(sm_cmac_sc_buffer, n1, 16); 1512 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1513 memcpy(sm_cmac_sc_buffer+32, r, 16); 1514 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1515 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1516 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1517 log_info("f6 key"); 1518 log_info_hexdump(w, 16); 1519 log_info("f6 message"); 1520 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1521 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1522 } 1523 1524 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1525 // - U is 256 bits 1526 // - V is 256 bits 1527 // - X is 128 bits 1528 // - Y is 128 bits 1529 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){ 1530 const uint16_t message_len = 80; 1531 sm_cmac_connection = sm_conn; 1532 memcpy(sm_cmac_sc_buffer, u, 32); 1533 memcpy(sm_cmac_sc_buffer+32, v, 32); 1534 memcpy(sm_cmac_sc_buffer+64, y, 16); 1535 log_info("g2 key"); 1536 log_info_hexdump(x, 16); 1537 log_info("g2 message"); 1538 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1539 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1540 } 1541 1542 static void g2_calculate(sm_connection_t * sm_conn) { 1543 // calc Va if numeric comparison 1544 if (IS_RESPONDER(sm_conn->sm_role)){ 1545 // responder 1546 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1547 } else { 1548 // initiator 1549 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1550 } 1551 } 1552 1553 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1554 uint8_t z = 0; 1555 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1556 // some form of passkey 1557 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1558 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1559 setup->sm_passkey_bit++; 1560 } 1561 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1562 } 1563 1564 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1565 // OOB 1566 if (setup->sm_stk_generation_method == OOB){ 1567 if (IS_RESPONDER(sm_conn->sm_role)){ 1568 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1569 } else { 1570 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1571 } 1572 return; 1573 } 1574 1575 uint8_t z = 0; 1576 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1577 // some form of passkey 1578 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1579 // sm_passkey_bit was increased before sending confirm value 1580 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1581 } 1582 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1583 } 1584 1585 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1586 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1587 1588 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1589 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1590 return; 1591 } else { 1592 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1593 } 1594 } 1595 1596 static void sm_sc_dhkey_calculated(void * arg){ 1597 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1598 log_info("dhkey"); 1599 log_info_hexdump(&setup->sm_dhkey[0], 32); 1600 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1601 // trigger next step 1602 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1603 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1604 } 1605 sm_run(); 1606 } 1607 1608 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1609 // calculate DHKCheck 1610 sm_key56_t bd_addr_master, bd_addr_slave; 1611 bd_addr_master[0] = setup->sm_m_addr_type; 1612 bd_addr_slave[0] = setup->sm_s_addr_type; 1613 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1614 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1615 uint8_t iocap_a[3]; 1616 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1617 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1618 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1619 uint8_t iocap_b[3]; 1620 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1621 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1622 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1623 if (IS_RESPONDER(sm_conn->sm_role)){ 1624 // responder 1625 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); 1626 } else { 1627 // initiator 1628 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); 1629 } 1630 } 1631 1632 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1633 // validate E = f6() 1634 sm_key56_t bd_addr_master, bd_addr_slave; 1635 bd_addr_master[0] = setup->sm_m_addr_type; 1636 bd_addr_slave[0] = setup->sm_s_addr_type; 1637 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1638 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1639 1640 uint8_t iocap_a[3]; 1641 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1642 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1643 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1644 uint8_t iocap_b[3]; 1645 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1646 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1647 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1648 if (IS_RESPONDER(sm_conn->sm_role)){ 1649 // responder 1650 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); 1651 } else { 1652 // initiator 1653 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); 1654 } 1655 } 1656 1657 1658 // 1659 // Link Key Conversion Function h6 1660 // 1661 // h6(W, keyID) = AES-CMACW(keyID) 1662 // - W is 128 bits 1663 // - keyID is 32 bits 1664 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1665 const uint16_t message_len = 4; 1666 sm_cmac_connection = sm_conn; 1667 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1668 log_info("h6 key"); 1669 log_info_hexdump(w, 16); 1670 log_info("h6 message"); 1671 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1672 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1673 } 1674 1675 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1676 // Errata Service Release to the Bluetooth Specification: ESR09 1677 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1678 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1679 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1680 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1681 } 1682 1683 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1684 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1685 } 1686 1687 #endif 1688 1689 // key management legacy connections: 1690 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1691 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1692 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1693 // - responder reconnects: responder uses LTK receveived from master 1694 1695 // key management secure connections: 1696 // - both devices store same LTK from ECDH key exchange. 1697 1698 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1699 static void sm_load_security_info(sm_connection_t * sm_connection){ 1700 int encryption_key_size; 1701 int authenticated; 1702 int authorized; 1703 1704 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1705 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1706 &encryption_key_size, &authenticated, &authorized); 1707 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1708 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1709 sm_connection->sm_connection_authenticated = authenticated; 1710 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1711 } 1712 #endif 1713 1714 #ifdef ENABLE_LE_PERIPHERAL 1715 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1716 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1717 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1718 // re-establish used key encryption size 1719 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1720 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1721 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1722 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1723 log_info("sm: received ltk request with key size %u, authenticated %u", 1724 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1725 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1726 sm_run(); 1727 } 1728 #endif 1729 1730 static void sm_run(void){ 1731 1732 btstack_linked_list_iterator_t it; 1733 1734 // assert that stack has already bootet 1735 if (hci_get_state() != HCI_STATE_WORKING) return; 1736 1737 // assert that we can send at least commands 1738 if (!hci_can_send_command_packet_now()) return; 1739 1740 // 1741 // non-connection related behaviour 1742 // 1743 1744 // distributed key generation 1745 switch (dkg_state){ 1746 case DKG_CALC_IRK: 1747 // already busy? 1748 if (sm_aes128_state == SM_AES128_IDLE) { 1749 log_info("DKG_CALC_IRK started"); 1750 // IRK = d1(IR, 1, 0) 1751 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1752 sm_aes128_state = SM_AES128_ACTIVE; 1753 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1754 return; 1755 } 1756 break; 1757 case DKG_CALC_DHK: 1758 // already busy? 1759 if (sm_aes128_state == SM_AES128_IDLE) { 1760 log_info("DKG_CALC_DHK started"); 1761 // DHK = d1(IR, 3, 0) 1762 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1763 sm_aes128_state = SM_AES128_ACTIVE; 1764 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1765 return; 1766 } 1767 break; 1768 default: 1769 break; 1770 } 1771 1772 // random address updates 1773 switch (rau_state){ 1774 case RAU_GET_ENC: 1775 // already busy? 1776 if (sm_aes128_state == SM_AES128_IDLE) { 1777 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1778 sm_aes128_state = SM_AES128_ACTIVE; 1779 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1780 return; 1781 } 1782 break; 1783 case RAU_SET_ADDRESS: 1784 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1785 rau_state = RAU_IDLE; 1786 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1787 return; 1788 default: 1789 break; 1790 } 1791 1792 // CSRK Lookup 1793 // -- if csrk lookup ready, find connection that require csrk lookup 1794 if (sm_address_resolution_idle()){ 1795 hci_connections_get_iterator(&it); 1796 while(btstack_linked_list_iterator_has_next(&it)){ 1797 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1798 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1799 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1800 // and start lookup 1801 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); 1802 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1803 break; 1804 } 1805 } 1806 } 1807 1808 // -- if csrk lookup ready, resolved addresses for received addresses 1809 if (sm_address_resolution_idle()) { 1810 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1811 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1812 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1813 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1814 btstack_memory_sm_lookup_entry_free(entry); 1815 } 1816 } 1817 1818 // -- Continue with CSRK device lookup by public or resolvable private address 1819 if (!sm_address_resolution_idle()){ 1820 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1821 while (sm_address_resolution_test < le_device_db_max_count()){ 1822 int addr_type; 1823 bd_addr_t addr; 1824 sm_key_t irk; 1825 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1826 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1827 1828 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1829 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1830 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1831 break; 1832 } 1833 1834 if (sm_address_resolution_addr_type == 0){ 1835 sm_address_resolution_test++; 1836 continue; 1837 } 1838 1839 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1840 1841 log_info("LE Device Lookup: calculate AH"); 1842 log_info_key("IRK", irk); 1843 1844 memcpy(sm_aes128_key, irk, 16); 1845 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1846 sm_address_resolution_ah_calculation_active = 1; 1847 sm_aes128_state = SM_AES128_ACTIVE; 1848 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1849 return; 1850 } 1851 1852 if (sm_address_resolution_test >= le_device_db_max_count()){ 1853 log_info("LE Device Lookup: not found"); 1854 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1855 } 1856 } 1857 1858 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1859 switch (sm_sc_oob_state){ 1860 case SM_SC_OOB_W2_CALC_CONFIRM: 1861 if (!sm_cmac_ready()) break; 1862 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1863 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1864 return; 1865 default: 1866 break; 1867 } 1868 #endif 1869 1870 // handle basic actions that don't requires the full context 1871 hci_connections_get_iterator(&it); 1872 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1873 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1874 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1875 switch(sm_connection->sm_engine_state){ 1876 // responder side 1877 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1878 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1879 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1880 return; 1881 1882 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1883 case SM_SC_RECEIVED_LTK_REQUEST: 1884 switch (sm_connection->sm_irk_lookup_state){ 1885 case IRK_LOOKUP_FAILED: 1886 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1887 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1888 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1889 return; 1890 default: 1891 break; 1892 } 1893 break; 1894 #endif 1895 default: 1896 break; 1897 } 1898 } 1899 1900 // 1901 // active connection handling 1902 // -- use loop to handle next connection if lock on setup context is released 1903 1904 while (1) { 1905 1906 // Find connections that requires setup context and make active if no other is locked 1907 hci_connections_get_iterator(&it); 1908 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1909 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1910 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1911 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1912 int done = 1; 1913 int err; 1914 UNUSED(err); 1915 switch (sm_connection->sm_engine_state) { 1916 #ifdef ENABLE_LE_PERIPHERAL 1917 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1918 // send packet if possible, 1919 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1920 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1921 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1922 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1923 } else { 1924 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1925 } 1926 // don't lock sxetup context yet 1927 done = 0; 1928 break; 1929 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1930 sm_reset_setup(); 1931 sm_init_setup(sm_connection); 1932 // recover pairing request 1933 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1934 err = sm_stk_generation_init(sm_connection); 1935 1936 #ifdef ENABLE_TESTING_SUPPORT 1937 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1938 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1939 err = test_pairing_failure; 1940 } 1941 #endif 1942 if (err){ 1943 setup->sm_pairing_failed_reason = err; 1944 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1945 break; 1946 } 1947 sm_timeout_start(sm_connection); 1948 // generate random number first, if we need to show passkey 1949 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1950 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1951 break; 1952 } 1953 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1954 break; 1955 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1956 sm_reset_setup(); 1957 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1958 break; 1959 #endif 1960 #ifdef ENABLE_LE_CENTRAL 1961 case SM_INITIATOR_PH0_HAS_LTK: 1962 sm_reset_setup(); 1963 sm_load_security_info(sm_connection); 1964 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1965 break; 1966 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1967 sm_reset_setup(); 1968 sm_init_setup(sm_connection); 1969 sm_timeout_start(sm_connection); 1970 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1971 break; 1972 #endif 1973 1974 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1975 case SM_SC_RECEIVED_LTK_REQUEST: 1976 switch (sm_connection->sm_irk_lookup_state){ 1977 case IRK_LOOKUP_SUCCEEDED: 1978 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 1979 // start using context by loading security info 1980 sm_reset_setup(); 1981 sm_load_security_info(sm_connection); 1982 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 1983 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 1984 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 1985 break; 1986 } 1987 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 1988 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1989 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1990 // don't lock setup context yet 1991 return; 1992 default: 1993 // just wait until IRK lookup is completed 1994 // don't lock setup context yet 1995 done = 0; 1996 break; 1997 } 1998 break; 1999 #endif 2000 default: 2001 done = 0; 2002 break; 2003 } 2004 if (done){ 2005 sm_active_connection_handle = sm_connection->sm_handle; 2006 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); 2007 } 2008 } 2009 2010 // 2011 // active connection handling 2012 // 2013 2014 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2015 2016 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2017 if (!connection) { 2018 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2019 return; 2020 } 2021 2022 // assert that we could send a SM PDU - not needed for all of the following 2023 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2024 log_info("cannot send now, requesting can send now event"); 2025 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2026 return; 2027 } 2028 2029 // send keypress notifications 2030 if (setup->sm_keypress_notification){ 2031 int i; 2032 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2033 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2034 uint8_t action = 0; 2035 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2036 if (flags & (1<<i)){ 2037 int clear_flag = 1; 2038 switch (i){ 2039 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2040 case SM_KEYPRESS_PASSKEY_CLEARED: 2041 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2042 default: 2043 break; 2044 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2045 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2046 num_actions--; 2047 clear_flag = num_actions == 0; 2048 break; 2049 } 2050 if (clear_flag){ 2051 flags &= ~(1<<i); 2052 } 2053 action = i; 2054 break; 2055 } 2056 } 2057 setup->sm_keypress_notification = (num_actions << 5) | flags; 2058 2059 // send keypress notification 2060 uint8_t buffer[2]; 2061 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2062 buffer[1] = action; 2063 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2064 2065 // try 2066 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2067 return; 2068 } 2069 2070 int key_distribution_flags; 2071 UNUSED(key_distribution_flags); 2072 2073 log_info("sm_run: state %u", connection->sm_engine_state); 2074 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2075 log_info("sm_run // cannot send"); 2076 } 2077 switch (connection->sm_engine_state){ 2078 2079 // general 2080 case SM_GENERAL_SEND_PAIRING_FAILED: { 2081 uint8_t buffer[2]; 2082 buffer[0] = SM_CODE_PAIRING_FAILED; 2083 buffer[1] = setup->sm_pairing_failed_reason; 2084 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2085 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2086 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2087 sm_done_for_handle(connection->sm_handle); 2088 break; 2089 } 2090 2091 // responding state 2092 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2093 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2094 if (!sm_cmac_ready()) break; 2095 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2096 sm_sc_calculate_local_confirm(connection); 2097 break; 2098 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2099 if (!sm_cmac_ready()) break; 2100 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2101 sm_sc_calculate_remote_confirm(connection); 2102 break; 2103 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2104 if (!sm_cmac_ready()) break; 2105 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2106 sm_sc_calculate_f6_for_dhkey_check(connection); 2107 break; 2108 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2109 if (!sm_cmac_ready()) break; 2110 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2111 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2112 break; 2113 case SM_SC_W2_CALCULATE_F5_SALT: 2114 if (!sm_cmac_ready()) break; 2115 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2116 f5_calculate_salt(connection); 2117 break; 2118 case SM_SC_W2_CALCULATE_F5_MACKEY: 2119 if (!sm_cmac_ready()) break; 2120 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2121 f5_calculate_mackey(connection); 2122 break; 2123 case SM_SC_W2_CALCULATE_F5_LTK: 2124 if (!sm_cmac_ready()) break; 2125 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2126 f5_calculate_ltk(connection); 2127 break; 2128 case SM_SC_W2_CALCULATE_G2: 2129 if (!sm_cmac_ready()) break; 2130 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2131 g2_calculate(connection); 2132 break; 2133 case SM_SC_W2_CALCULATE_H6_ILK: 2134 if (!sm_cmac_ready()) break; 2135 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2136 h6_calculate_ilk(connection); 2137 break; 2138 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2139 if (!sm_cmac_ready()) break; 2140 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2141 h6_calculate_br_edr_link_key(connection); 2142 break; 2143 #endif 2144 2145 #ifdef ENABLE_LE_CENTRAL 2146 // initiator side 2147 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2148 sm_key_t peer_ltk_flipped; 2149 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2150 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2151 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2152 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2153 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2154 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2155 return; 2156 } 2157 2158 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2159 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2160 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2161 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2162 sm_timeout_reset(connection); 2163 break; 2164 #endif 2165 2166 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2167 2168 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2169 int trigger_user_response = 0; 2170 2171 uint8_t buffer[65]; 2172 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2173 // 2174 reverse_256(&ec_q[0], &buffer[1]); 2175 reverse_256(&ec_q[32], &buffer[33]); 2176 2177 // stk generation method 2178 // passkey entry: notify app to show passkey or to request passkey 2179 switch (setup->sm_stk_generation_method){ 2180 case JUST_WORKS: 2181 case NUMERIC_COMPARISON: 2182 if (IS_RESPONDER(connection->sm_role)){ 2183 // responder 2184 sm_sc_start_calculating_local_confirm(connection); 2185 } else { 2186 // initiator 2187 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2188 } 2189 break; 2190 case PK_INIT_INPUT: 2191 case PK_RESP_INPUT: 2192 case PK_BOTH_INPUT: 2193 // use random TK for display 2194 memcpy(setup->sm_ra, setup->sm_tk, 16); 2195 memcpy(setup->sm_rb, setup->sm_tk, 16); 2196 setup->sm_passkey_bit = 0; 2197 2198 if (IS_RESPONDER(connection->sm_role)){ 2199 // responder 2200 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2201 } else { 2202 // initiator 2203 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2204 } 2205 trigger_user_response = 1; 2206 break; 2207 case OOB: 2208 if (IS_RESPONDER(connection->sm_role)){ 2209 // responder 2210 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2211 } else { 2212 // initiator 2213 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2214 } 2215 break; 2216 } 2217 2218 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2219 sm_timeout_reset(connection); 2220 2221 // trigger user response after sending pdu 2222 if (trigger_user_response){ 2223 sm_trigger_user_response(connection); 2224 } 2225 break; 2226 } 2227 case SM_SC_SEND_CONFIRMATION: { 2228 uint8_t buffer[17]; 2229 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2230 reverse_128(setup->sm_local_confirm, &buffer[1]); 2231 if (IS_RESPONDER(connection->sm_role)){ 2232 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2233 } else { 2234 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2235 } 2236 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2237 sm_timeout_reset(connection); 2238 break; 2239 } 2240 case SM_SC_SEND_PAIRING_RANDOM: { 2241 uint8_t buffer[17]; 2242 buffer[0] = SM_CODE_PAIRING_RANDOM; 2243 reverse_128(setup->sm_local_nonce, &buffer[1]); 2244 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2245 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2246 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2247 if (IS_RESPONDER(connection->sm_role)){ 2248 // responder 2249 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2250 } else { 2251 // initiator 2252 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2253 } 2254 } else { 2255 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2256 if (IS_RESPONDER(connection->sm_role)){ 2257 // responder 2258 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2259 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2260 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2261 } else { 2262 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2263 sm_sc_prepare_dhkey_check(connection); 2264 } 2265 } else { 2266 // initiator 2267 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2268 } 2269 } 2270 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2271 sm_timeout_reset(connection); 2272 break; 2273 } 2274 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2275 uint8_t buffer[17]; 2276 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2277 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2278 2279 if (IS_RESPONDER(connection->sm_role)){ 2280 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2281 } else { 2282 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2283 } 2284 2285 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2286 sm_timeout_reset(connection); 2287 break; 2288 } 2289 2290 #endif 2291 2292 #ifdef ENABLE_LE_PERIPHERAL 2293 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2294 // echo initiator for now 2295 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2296 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2297 2298 if (setup->sm_use_secure_connections){ 2299 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2300 // skip LTK/EDIV for SC 2301 log_info("sm: dropping encryption information flag"); 2302 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2303 } else { 2304 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2305 } 2306 2307 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); 2308 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); 2309 // update key distribution after ENC was dropped 2310 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2311 2312 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2313 sm_timeout_reset(connection); 2314 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2315 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2316 sm_trigger_user_response(connection); 2317 } 2318 return; 2319 #endif 2320 2321 case SM_PH2_SEND_PAIRING_RANDOM: { 2322 uint8_t buffer[17]; 2323 buffer[0] = SM_CODE_PAIRING_RANDOM; 2324 reverse_128(setup->sm_local_random, &buffer[1]); 2325 if (IS_RESPONDER(connection->sm_role)){ 2326 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2327 } else { 2328 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2329 } 2330 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2331 sm_timeout_reset(connection); 2332 break; 2333 } 2334 2335 case SM_PH2_C1_GET_ENC_A: 2336 // already busy? 2337 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2338 // calculate confirm using aes128 engine - step 1 2339 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); 2340 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2341 sm_aes128_state = SM_AES128_ACTIVE; 2342 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2343 break; 2344 2345 case SM_PH2_C1_GET_ENC_C: 2346 // already busy? 2347 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2348 // calculate m_confirm using aes128 engine - step 1 2349 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); 2350 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2351 sm_aes128_state = SM_AES128_ACTIVE; 2352 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2353 break; 2354 2355 case SM_PH2_CALC_STK: 2356 // already busy? 2357 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2358 // calculate STK 2359 if (IS_RESPONDER(connection->sm_role)){ 2360 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2361 } else { 2362 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2363 } 2364 connection->sm_engine_state = SM_PH2_W4_STK; 2365 sm_aes128_state = SM_AES128_ACTIVE; 2366 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2367 break; 2368 2369 case SM_PH3_Y_GET_ENC: 2370 // already busy? 2371 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2372 // PH3B2 - calculate Y from - enc 2373 // Y = dm(DHK, Rand) 2374 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2375 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2376 sm_aes128_state = SM_AES128_ACTIVE; 2377 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); 2378 break; 2379 2380 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2381 uint8_t buffer[17]; 2382 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2383 reverse_128(setup->sm_local_confirm, &buffer[1]); 2384 if (IS_RESPONDER(connection->sm_role)){ 2385 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2386 } else { 2387 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2388 } 2389 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2390 sm_timeout_reset(connection); 2391 return; 2392 } 2393 #ifdef ENABLE_LE_PERIPHERAL 2394 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2395 sm_key_t stk_flipped; 2396 reverse_128(setup->sm_ltk, stk_flipped); 2397 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2398 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2399 return; 2400 } 2401 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2402 sm_key_t ltk_flipped; 2403 reverse_128(setup->sm_ltk, ltk_flipped); 2404 connection->sm_engine_state = SM_RESPONDER_IDLE; 2405 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2406 sm_done_for_handle(connection->sm_handle); 2407 return; 2408 } 2409 case SM_RESPONDER_PH4_Y_GET_ENC: 2410 // already busy? 2411 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2412 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2413 // Y = dm(DHK, Rand) 2414 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2415 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2416 sm_aes128_state = SM_AES128_ACTIVE; 2417 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); 2418 return; 2419 #endif 2420 #ifdef ENABLE_LE_CENTRAL 2421 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2422 sm_key_t stk_flipped; 2423 reverse_128(setup->sm_ltk, stk_flipped); 2424 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2425 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2426 return; 2427 } 2428 #endif 2429 2430 case SM_PH3_DISTRIBUTE_KEYS: 2431 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2432 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2433 uint8_t buffer[17]; 2434 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2435 reverse_128(setup->sm_ltk, &buffer[1]); 2436 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2437 sm_timeout_reset(connection); 2438 return; 2439 } 2440 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2441 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2442 uint8_t buffer[11]; 2443 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2444 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2445 reverse_64(setup->sm_local_rand, &buffer[3]); 2446 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2447 sm_timeout_reset(connection); 2448 return; 2449 } 2450 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2451 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2452 uint8_t buffer[17]; 2453 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2454 reverse_128(sm_persistent_irk, &buffer[1]); 2455 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2456 sm_timeout_reset(connection); 2457 return; 2458 } 2459 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2460 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2461 bd_addr_t local_address; 2462 uint8_t buffer[8]; 2463 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2464 switch (gap_random_address_get_mode()){ 2465 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2466 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2467 // public or static random 2468 gap_le_get_own_address(&buffer[1], local_address); 2469 break; 2470 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2471 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2472 // fallback to public 2473 gap_local_bd_addr(local_address); 2474 buffer[1] = 0; 2475 break; 2476 } 2477 reverse_bd_addr(local_address, &buffer[2]); 2478 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2479 sm_timeout_reset(connection); 2480 return; 2481 } 2482 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2483 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2484 2485 // hack to reproduce test runs 2486 if (test_use_fixed_local_csrk){ 2487 memset(setup->sm_local_csrk, 0xcc, 16); 2488 } 2489 2490 uint8_t buffer[17]; 2491 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2492 reverse_128(setup->sm_local_csrk, &buffer[1]); 2493 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2494 sm_timeout_reset(connection); 2495 return; 2496 } 2497 2498 // keys are sent 2499 if (IS_RESPONDER(connection->sm_role)){ 2500 // slave -> receive master keys if any 2501 if (sm_key_distribution_all_received(connection)){ 2502 sm_key_distribution_handle_all_received(connection); 2503 connection->sm_engine_state = SM_RESPONDER_IDLE; 2504 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2505 sm_done_for_handle(connection->sm_handle); 2506 } else { 2507 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2508 } 2509 } else { 2510 // master -> all done 2511 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2512 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2513 sm_done_for_handle(connection->sm_handle); 2514 } 2515 break; 2516 2517 default: 2518 break; 2519 } 2520 2521 // check again if active connection was released 2522 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2523 } 2524 } 2525 2526 // sm_aes128_state stays active 2527 static void sm_handle_encryption_result_enc_a(void *arg){ 2528 sm_connection_t * connection = (sm_connection_t*) arg; 2529 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2530 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); 2531 } 2532 2533 static void sm_handle_encryption_result_enc_b(void *arg){ 2534 sm_connection_t * connection = (sm_connection_t*) arg; 2535 sm_aes128_state = SM_AES128_IDLE; 2536 log_info_key("c1!", setup->sm_local_confirm); 2537 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2538 sm_run(); 2539 } 2540 2541 // sm_aes128_state stays active 2542 static void sm_handle_encryption_result_enc_c(void *arg){ 2543 sm_connection_t * connection = (sm_connection_t*) arg; 2544 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2545 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); 2546 } 2547 2548 static void sm_handle_encryption_result_enc_d(void * arg){ 2549 sm_connection_t * connection = (sm_connection_t*) arg; 2550 sm_aes128_state = SM_AES128_IDLE; 2551 log_info_key("c1!", sm_aes128_ciphertext); 2552 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2553 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2554 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2555 sm_run(); 2556 return; 2557 } 2558 if (IS_RESPONDER(connection->sm_role)){ 2559 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2560 sm_run(); 2561 } else { 2562 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2563 sm_aes128_state = SM_AES128_ACTIVE; 2564 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2565 } 2566 } 2567 2568 static void sm_handle_encryption_result_enc_stk(void *arg){ 2569 sm_connection_t * connection = (sm_connection_t*) arg; 2570 sm_aes128_state = SM_AES128_IDLE; 2571 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2572 log_info_key("stk", setup->sm_ltk); 2573 if (IS_RESPONDER(connection->sm_role)){ 2574 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2575 } else { 2576 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2577 } 2578 sm_run(); 2579 } 2580 2581 // sm_aes128_state stays active 2582 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2583 sm_connection_t * connection = (sm_connection_t*) arg; 2584 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2585 log_info_hex16("y", setup->sm_local_y); 2586 // PH3B3 - calculate EDIV 2587 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2588 log_info_hex16("ediv", setup->sm_local_ediv); 2589 // PH3B4 - calculate LTK - enc 2590 // LTK = d1(ER, DIV, 0)) 2591 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2592 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); 2593 } 2594 2595 #ifdef ENABLE_LE_PERIPHERAL 2596 // sm_aes128_state stays active 2597 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2598 sm_connection_t * connection = (sm_connection_t*) arg; 2599 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2600 log_info_hex16("y", setup->sm_local_y); 2601 2602 // PH3B3 - calculate DIV 2603 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2604 log_info_hex16("ediv", setup->sm_local_ediv); 2605 // PH3B4 - calculate LTK - enc 2606 // LTK = d1(ER, DIV, 0)) 2607 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2608 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); 2609 } 2610 #endif 2611 2612 // sm_aes128_state stays active 2613 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2614 sm_connection_t * connection = (sm_connection_t*) arg; 2615 log_info_key("ltk", setup->sm_ltk); 2616 // calc CSRK next 2617 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2618 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); 2619 } 2620 2621 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2622 sm_connection_t * connection = (sm_connection_t*) arg; 2623 sm_aes128_state = SM_AES128_IDLE; 2624 log_info_key("csrk", setup->sm_local_csrk); 2625 if (setup->sm_key_distribution_send_set){ 2626 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2627 } else { 2628 // no keys to send, just continue 2629 if (IS_RESPONDER(connection->sm_role)){ 2630 // slave -> receive master keys 2631 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2632 } else { 2633 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2634 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2635 } else { 2636 // master -> all done 2637 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2638 sm_done_for_handle(connection->sm_handle); 2639 } 2640 } 2641 } 2642 sm_run(); 2643 } 2644 2645 #ifdef ENABLE_LE_PERIPHERAL 2646 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2647 sm_connection_t * connection = (sm_connection_t*) arg; 2648 sm_aes128_state = SM_AES128_IDLE; 2649 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2650 log_info_key("ltk", setup->sm_ltk); 2651 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2652 sm_run(); 2653 } 2654 #endif 2655 2656 static void sm_handle_encryption_result_address_resolution(void *arg){ 2657 UNUSED(arg); 2658 sm_aes128_state = SM_AES128_IDLE; 2659 sm_address_resolution_ah_calculation_active = 0; 2660 // compare calulated address against connecting device 2661 uint8_t * hash = &sm_aes128_ciphertext[13]; 2662 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2663 log_info("LE Device Lookup: matched resolvable private address"); 2664 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2665 sm_run(); 2666 return; 2667 } 2668 // no match, try next 2669 sm_address_resolution_test++; 2670 sm_run(); 2671 } 2672 2673 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2674 UNUSED(arg); 2675 sm_aes128_state = SM_AES128_IDLE; 2676 log_info_key("irk", sm_persistent_irk); 2677 dkg_state = DKG_CALC_DHK; 2678 sm_run(); 2679 } 2680 2681 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2682 UNUSED(arg); 2683 sm_aes128_state = SM_AES128_IDLE; 2684 log_info_key("dhk", sm_persistent_dhk); 2685 dkg_state = DKG_READY; 2686 // DKG calculation complete => SM Init Finished 2687 sm_run(); 2688 } 2689 2690 static void sm_handle_encryption_result_rau(void *arg){ 2691 UNUSED(arg); 2692 sm_aes128_state = SM_AES128_IDLE; 2693 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2694 rau_state = RAU_SET_ADDRESS; 2695 sm_run(); 2696 } 2697 2698 static void sm_handle_random_result_rau(void * arg){ 2699 UNUSED(arg); 2700 // non-resolvable vs. resolvable 2701 switch (gap_random_adress_type){ 2702 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2703 // resolvable: use random as prand and calc address hash 2704 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2705 sm_random_address[0] &= 0x3f; 2706 sm_random_address[0] |= 0x40; 2707 rau_state = RAU_GET_ENC; 2708 break; 2709 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2710 default: 2711 // "The two most significant bits of the address shall be equal to ‘0’"" 2712 sm_random_address[0] &= 0x3f; 2713 rau_state = RAU_SET_ADDRESS; 2714 break; 2715 } 2716 sm_run(); 2717 } 2718 2719 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2720 static void sm_handle_random_result_sc_get_random(void * arg){ 2721 sm_connection_t * connection = (sm_connection_t*) arg; 2722 2723 // OOB 2724 if (setup->sm_stk_generation_method == OOB){ 2725 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2726 sm_run(); 2727 return; 2728 } 2729 2730 // initiator & jw/nc -> send pairing random 2731 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2732 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2733 } else { 2734 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2735 } 2736 sm_run(); 2737 } 2738 #endif 2739 2740 static void sm_handle_random_result_ph2_random(void * arg){ 2741 sm_connection_t * connection = (sm_connection_t*) arg; 2742 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2743 sm_run(); 2744 } 2745 2746 static void sm_handle_random_result_ph2_tk(void * arg){ 2747 sm_connection_t * connection = (sm_connection_t*) arg; 2748 sm_reset_tk(); 2749 uint32_t tk; 2750 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2751 // map random to 0-999999 without speding much cycles on a modulus operation 2752 tk = little_endian_read_32(sm_random_data,0); 2753 tk = tk & 0xfffff; // 1048575 2754 if (tk >= 999999){ 2755 tk = tk - 999999; 2756 } 2757 } else { 2758 // override with pre-defined passkey 2759 tk = sm_fixed_passkey_in_display_role; 2760 } 2761 big_endian_store_32(setup->sm_tk, 12, tk); 2762 if (IS_RESPONDER(connection->sm_role)){ 2763 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2764 } else { 2765 if (setup->sm_use_secure_connections){ 2766 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2767 } else { 2768 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2769 sm_trigger_user_response(connection); 2770 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2771 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2772 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2773 } 2774 } 2775 } 2776 sm_run(); 2777 } 2778 2779 static void sm_handle_random_result_ph3_div(void * arg){ 2780 sm_connection_t * connection = (sm_connection_t*) arg; 2781 // use 16 bit from random value as div 2782 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2783 log_info_hex16("div", setup->sm_local_div); 2784 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2785 sm_run(); 2786 } 2787 2788 static void sm_handle_random_result_ph3_random(void * arg){ 2789 sm_connection_t * connection = (sm_connection_t*) arg; 2790 reverse_64(sm_random_data, setup->sm_local_rand); 2791 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2792 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2793 // no db for authenticated flag hack: store flag in bit 4 of LSB 2794 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2795 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2796 } 2797 2798 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2799 2800 UNUSED(channel); // ok: there is no channel 2801 UNUSED(size); // ok: fixed format HCI events 2802 2803 sm_connection_t * sm_conn; 2804 hci_con_handle_t con_handle; 2805 2806 switch (packet_type) { 2807 2808 case HCI_EVENT_PACKET: 2809 switch (hci_event_packet_get_type(packet)) { 2810 2811 case BTSTACK_EVENT_STATE: 2812 // bt stack activated, get started 2813 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2814 log_info("HCI Working!"); 2815 2816 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2817 2818 // trigger Random Address generation if requested before 2819 switch (gap_random_adress_type){ 2820 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2821 rau_state = RAU_IDLE; 2822 break; 2823 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2824 rau_state = RAU_SET_ADDRESS; 2825 break; 2826 default: 2827 rau_state = RAU_W4_RANDOM; 2828 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2829 break; 2830 } 2831 sm_run(); 2832 } 2833 break; 2834 2835 case HCI_EVENT_LE_META: 2836 switch (packet[2]) { 2837 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2838 2839 log_info("sm: connected"); 2840 2841 if (packet[3]) return; // connection failed 2842 2843 con_handle = little_endian_read_16(packet, 4); 2844 sm_conn = sm_get_connection_for_handle(con_handle); 2845 if (!sm_conn) break; 2846 2847 sm_conn->sm_handle = con_handle; 2848 sm_conn->sm_role = packet[6]; 2849 sm_conn->sm_peer_addr_type = packet[7]; 2850 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2851 2852 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2853 2854 // reset security properties 2855 sm_conn->sm_connection_encrypted = 0; 2856 sm_conn->sm_connection_authenticated = 0; 2857 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2858 sm_conn->sm_le_db_index = -1; 2859 2860 // prepare CSRK lookup (does not involve setup) 2861 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2862 2863 // just connected -> everything else happens in sm_run() 2864 if (IS_RESPONDER(sm_conn->sm_role)){ 2865 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2866 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2867 if (sm_slave_request_security) { 2868 // request security if requested by app 2869 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2870 } else { 2871 // otherwise, wait for pairing request 2872 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2873 } 2874 } 2875 break; 2876 } else { 2877 // master 2878 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2879 } 2880 break; 2881 2882 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2883 con_handle = little_endian_read_16(packet, 3); 2884 sm_conn = sm_get_connection_for_handle(con_handle); 2885 if (!sm_conn) break; 2886 2887 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2888 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2889 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2890 break; 2891 } 2892 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2893 // PH2 SEND LTK as we need to exchange keys in PH3 2894 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2895 break; 2896 } 2897 2898 // store rand and ediv 2899 reverse_64(&packet[5], sm_conn->sm_local_rand); 2900 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2901 2902 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2903 // potentially stored LTK is from the master 2904 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2905 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2906 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2907 break; 2908 } 2909 // additionally check if remote is in LE Device DB if requested 2910 switch(sm_conn->sm_irk_lookup_state){ 2911 case IRK_LOOKUP_FAILED: 2912 log_info("LTK Request: device not in device db"); 2913 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2914 break; 2915 case IRK_LOOKUP_SUCCEEDED: 2916 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2917 break; 2918 default: 2919 // wait for irk look doen 2920 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2921 break; 2922 } 2923 break; 2924 } 2925 2926 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2927 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2928 #else 2929 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2930 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2931 #endif 2932 break; 2933 2934 default: 2935 break; 2936 } 2937 break; 2938 2939 case HCI_EVENT_ENCRYPTION_CHANGE: 2940 con_handle = little_endian_read_16(packet, 3); 2941 sm_conn = sm_get_connection_for_handle(con_handle); 2942 if (!sm_conn) break; 2943 2944 sm_conn->sm_connection_encrypted = packet[5]; 2945 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2946 sm_conn->sm_actual_encryption_key_size); 2947 log_info("event handler, state %u", sm_conn->sm_engine_state); 2948 if (!sm_conn->sm_connection_encrypted) break; 2949 // continue if part of initial pairing 2950 switch (sm_conn->sm_engine_state){ 2951 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2952 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2953 sm_done_for_handle(sm_conn->sm_handle); 2954 break; 2955 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2956 if (IS_RESPONDER(sm_conn->sm_role)){ 2957 // slave 2958 if (setup->sm_use_secure_connections){ 2959 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2960 } else { 2961 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2962 } 2963 } else { 2964 // master 2965 if (sm_key_distribution_all_received(sm_conn)){ 2966 // skip receiving keys as there are none 2967 sm_key_distribution_handle_all_received(sm_conn); 2968 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2969 } else { 2970 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2971 } 2972 } 2973 break; 2974 default: 2975 break; 2976 } 2977 break; 2978 2979 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2980 con_handle = little_endian_read_16(packet, 3); 2981 sm_conn = sm_get_connection_for_handle(con_handle); 2982 if (!sm_conn) break; 2983 2984 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2985 log_info("event handler, state %u", sm_conn->sm_engine_state); 2986 // continue if part of initial pairing 2987 switch (sm_conn->sm_engine_state){ 2988 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2989 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2990 sm_done_for_handle(sm_conn->sm_handle); 2991 break; 2992 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2993 if (IS_RESPONDER(sm_conn->sm_role)){ 2994 // slave 2995 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2996 } else { 2997 // master 2998 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2999 } 3000 break; 3001 default: 3002 break; 3003 } 3004 break; 3005 3006 3007 case HCI_EVENT_DISCONNECTION_COMPLETE: 3008 con_handle = little_endian_read_16(packet, 3); 3009 sm_done_for_handle(con_handle); 3010 sm_conn = sm_get_connection_for_handle(con_handle); 3011 if (!sm_conn) break; 3012 3013 // delete stored bonding on disconnect with authentication failure in ph0 3014 if (sm_conn->sm_role == 0 3015 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3016 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3017 le_device_db_remove(sm_conn->sm_le_db_index); 3018 } 3019 3020 // pairing failed, if it was ongoing 3021 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3022 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3023 } 3024 3025 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3026 sm_conn->sm_handle = 0; 3027 break; 3028 3029 case HCI_EVENT_COMMAND_COMPLETE: 3030 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3031 // set local addr for le device db 3032 bd_addr_t addr; 3033 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3034 le_device_db_set_local_bd_addr(addr); 3035 } 3036 break; 3037 default: 3038 break; 3039 } 3040 break; 3041 default: 3042 break; 3043 } 3044 3045 sm_run(); 3046 } 3047 3048 static inline int sm_calc_actual_encryption_key_size(int other){ 3049 if (other < sm_min_encryption_key_size) return 0; 3050 if (other < sm_max_encryption_key_size) return other; 3051 return sm_max_encryption_key_size; 3052 } 3053 3054 3055 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3056 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3057 switch (method){ 3058 case JUST_WORKS: 3059 case NUMERIC_COMPARISON: 3060 return 1; 3061 default: 3062 return 0; 3063 } 3064 } 3065 // responder 3066 3067 static int sm_passkey_used(stk_generation_method_t method){ 3068 switch (method){ 3069 case PK_RESP_INPUT: 3070 return 1; 3071 default: 3072 return 0; 3073 } 3074 } 3075 3076 static int sm_passkey_entry(stk_generation_method_t method){ 3077 switch (method){ 3078 case PK_RESP_INPUT: 3079 case PK_INIT_INPUT: 3080 case PK_BOTH_INPUT: 3081 return 1; 3082 default: 3083 return 0; 3084 } 3085 } 3086 3087 #endif 3088 3089 /** 3090 * @return ok 3091 */ 3092 static int sm_validate_stk_generation_method(void){ 3093 // check if STK generation method is acceptable by client 3094 switch (setup->sm_stk_generation_method){ 3095 case JUST_WORKS: 3096 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3097 case PK_RESP_INPUT: 3098 case PK_INIT_INPUT: 3099 case PK_BOTH_INPUT: 3100 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3101 case OOB: 3102 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3103 case NUMERIC_COMPARISON: 3104 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3105 return 1; 3106 default: 3107 return 0; 3108 } 3109 } 3110 3111 // size of complete sm_pdu used to validate input 3112 static const uint8_t sm_pdu_size[] = { 3113 0, // 0x00 invalid opcode 3114 7, // 0x01 pairing request 3115 7, // 0x02 pairing response 3116 17, // 0x03 pairing confirm 3117 17, // 0x04 pairing random 3118 2, // 0x05 pairing failed 3119 17, // 0x06 encryption information 3120 11, // 0x07 master identification 3121 17, // 0x08 identification information 3122 8, // 0x09 identify address information 3123 17, // 0x0a signing information 3124 2, // 0x0b security request 3125 65, // 0x0c pairing public key 3126 17, // 0x0d pairing dhk check 3127 2, // 0x0e keypress notification 3128 }; 3129 3130 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3131 3132 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3133 sm_run(); 3134 } 3135 3136 if (packet_type != SM_DATA_PACKET) return; 3137 if (size == 0) return; 3138 3139 uint8_t sm_pdu_code = packet[0]; 3140 3141 // validate pdu size 3142 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3143 if (sm_pdu_size[sm_pdu_code] != size) return; 3144 3145 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3146 if (!sm_conn) return; 3147 3148 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3149 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3150 sm_done_for_handle(con_handle); 3151 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3152 return; 3153 } 3154 3155 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3156 3157 int err; 3158 UNUSED(err); 3159 3160 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3161 uint8_t buffer[5]; 3162 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3163 buffer[1] = 3; 3164 little_endian_store_16(buffer, 2, con_handle); 3165 buffer[4] = packet[1]; 3166 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3167 return; 3168 } 3169 3170 switch (sm_conn->sm_engine_state){ 3171 3172 // a sm timeout requries a new physical connection 3173 case SM_GENERAL_TIMEOUT: 3174 return; 3175 3176 #ifdef ENABLE_LE_CENTRAL 3177 3178 // Initiator 3179 case SM_INITIATOR_CONNECTED: 3180 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3181 sm_pdu_received_in_wrong_state(sm_conn); 3182 break; 3183 } 3184 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3185 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3186 break; 3187 } 3188 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3189 sm_key_t ltk; 3190 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3191 if (!sm_is_null_key(ltk)){ 3192 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3193 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3194 } else { 3195 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3196 } 3197 break; 3198 } 3199 // otherwise, store security request 3200 sm_conn->sm_security_request_received = 1; 3201 break; 3202 3203 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3204 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3205 sm_pdu_received_in_wrong_state(sm_conn); 3206 break; 3207 } 3208 3209 // store pairing request 3210 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3211 err = sm_stk_generation_init(sm_conn); 3212 3213 #ifdef ENABLE_TESTING_SUPPORT 3214 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3215 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3216 err = test_pairing_failure; 3217 } 3218 #endif 3219 3220 if (err){ 3221 setup->sm_pairing_failed_reason = err; 3222 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3223 break; 3224 } 3225 3226 // generate random number first, if we need to show passkey 3227 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3228 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3229 break; 3230 } 3231 3232 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3233 if (setup->sm_use_secure_connections){ 3234 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3235 if (setup->sm_stk_generation_method == JUST_WORKS){ 3236 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3237 sm_trigger_user_response(sm_conn); 3238 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3239 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3240 } 3241 } else { 3242 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3243 } 3244 break; 3245 } 3246 #endif 3247 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3248 sm_trigger_user_response(sm_conn); 3249 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3250 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3251 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3252 } 3253 break; 3254 3255 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3256 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3257 sm_pdu_received_in_wrong_state(sm_conn); 3258 break; 3259 } 3260 3261 // store s_confirm 3262 reverse_128(&packet[1], setup->sm_peer_confirm); 3263 3264 #ifdef ENABLE_TESTING_SUPPORT 3265 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3266 log_info("testing_support: reset confirm value"); 3267 memset(setup->sm_peer_confirm, 0, 16); 3268 } 3269 #endif 3270 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3271 break; 3272 3273 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3274 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3275 sm_pdu_received_in_wrong_state(sm_conn); 3276 break;; 3277 } 3278 3279 // received random value 3280 reverse_128(&packet[1], setup->sm_peer_random); 3281 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3282 break; 3283 #endif 3284 3285 #ifdef ENABLE_LE_PERIPHERAL 3286 // Responder 3287 case SM_RESPONDER_IDLE: 3288 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3289 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3290 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3291 sm_pdu_received_in_wrong_state(sm_conn); 3292 break;; 3293 } 3294 3295 // store pairing request 3296 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3297 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3298 break; 3299 #endif 3300 3301 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3302 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3303 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3304 sm_pdu_received_in_wrong_state(sm_conn); 3305 break; 3306 } 3307 3308 // store public key for DH Key calculation 3309 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3310 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3311 3312 // validate public key 3313 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3314 if (err){ 3315 log_error("sm: peer public key invalid %x", err); 3316 // uses "unspecified reason", there is no "public key invalid" error code 3317 sm_pdu_received_in_wrong_state(sm_conn); 3318 break; 3319 } 3320 3321 // start calculating dhkey 3322 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3323 3324 3325 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3326 if (IS_RESPONDER(sm_conn->sm_role)){ 3327 // responder 3328 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3329 } else { 3330 // initiator 3331 // stk generation method 3332 // passkey entry: notify app to show passkey or to request passkey 3333 switch (setup->sm_stk_generation_method){ 3334 case JUST_WORKS: 3335 case NUMERIC_COMPARISON: 3336 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3337 break; 3338 case PK_RESP_INPUT: 3339 sm_sc_start_calculating_local_confirm(sm_conn); 3340 break; 3341 case PK_INIT_INPUT: 3342 case PK_BOTH_INPUT: 3343 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3344 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3345 break; 3346 } 3347 sm_sc_start_calculating_local_confirm(sm_conn); 3348 break; 3349 case OOB: 3350 // generate Nx 3351 log_info("Generate Na"); 3352 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3353 break; 3354 } 3355 } 3356 break; 3357 3358 case SM_SC_W4_CONFIRMATION: 3359 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3360 sm_pdu_received_in_wrong_state(sm_conn); 3361 break; 3362 } 3363 // received confirm value 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 if (IS_RESPONDER(sm_conn->sm_role)){ 3373 // responder 3374 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3375 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3376 // still waiting for passkey 3377 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3378 break; 3379 } 3380 } 3381 sm_sc_start_calculating_local_confirm(sm_conn); 3382 } else { 3383 // initiator 3384 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3385 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3386 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3387 } else { 3388 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3389 } 3390 } 3391 break; 3392 3393 case SM_SC_W4_PAIRING_RANDOM: 3394 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3395 sm_pdu_received_in_wrong_state(sm_conn); 3396 break; 3397 } 3398 3399 // received random value 3400 reverse_128(&packet[1], setup->sm_peer_nonce); 3401 3402 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3403 // only check for JUST WORK/NC in initiator role OR passkey entry 3404 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3405 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3406 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3407 break; 3408 } 3409 3410 // OOB 3411 if (setup->sm_stk_generation_method == OOB){ 3412 3413 // setup local random, set to zero if remote did not receive our data 3414 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3415 if (IS_RESPONDER(sm_conn->sm_role)){ 3416 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3417 log_info("Reset rb as A does not have OOB data"); 3418 memset(setup->sm_rb, 0, 16); 3419 } else { 3420 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3421 log_info("Use stored rb"); 3422 log_info_hexdump(setup->sm_rb, 16); 3423 } 3424 } else { 3425 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3426 log_info("Reset ra as B does not have OOB data"); 3427 memset(setup->sm_ra, 0, 16); 3428 } else { 3429 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3430 log_info("Use stored ra"); 3431 log_info_hexdump(setup->sm_ra, 16); 3432 } 3433 } 3434 3435 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3436 if (setup->sm_have_oob_data){ 3437 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3438 break; 3439 } 3440 } 3441 3442 // TODO: we only get here for Responder role with JW/NC 3443 sm_sc_state_after_receiving_random(sm_conn); 3444 break; 3445 3446 case SM_SC_W2_CALCULATE_G2: 3447 case SM_SC_W4_CALCULATE_G2: 3448 case SM_SC_W4_CALCULATE_DHKEY: 3449 case SM_SC_W2_CALCULATE_F5_SALT: 3450 case SM_SC_W4_CALCULATE_F5_SALT: 3451 case SM_SC_W2_CALCULATE_F5_MACKEY: 3452 case SM_SC_W4_CALCULATE_F5_MACKEY: 3453 case SM_SC_W2_CALCULATE_F5_LTK: 3454 case SM_SC_W4_CALCULATE_F5_LTK: 3455 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3456 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3457 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3458 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3459 sm_pdu_received_in_wrong_state(sm_conn); 3460 break; 3461 } 3462 // store DHKey Check 3463 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3464 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3465 3466 // have we been only waiting for dhkey check command? 3467 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3468 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3469 } 3470 break; 3471 #endif 3472 3473 #ifdef ENABLE_LE_PERIPHERAL 3474 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3475 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3476 sm_pdu_received_in_wrong_state(sm_conn); 3477 break; 3478 } 3479 3480 // received confirm value 3481 reverse_128(&packet[1], setup->sm_peer_confirm); 3482 3483 #ifdef ENABLE_TESTING_SUPPORT 3484 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3485 log_info("testing_support: reset confirm value"); 3486 memset(setup->sm_peer_confirm, 0, 16); 3487 } 3488 #endif 3489 // notify client to hide shown passkey 3490 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3491 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3492 } 3493 3494 // handle user cancel pairing? 3495 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3496 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3497 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3498 break; 3499 } 3500 3501 // wait for user action? 3502 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3503 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3504 break; 3505 } 3506 3507 // calculate and send local_confirm 3508 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3509 break; 3510 3511 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3512 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3513 sm_pdu_received_in_wrong_state(sm_conn); 3514 break;; 3515 } 3516 3517 // received random value 3518 reverse_128(&packet[1], setup->sm_peer_random); 3519 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3520 break; 3521 #endif 3522 3523 case SM_PH3_RECEIVE_KEYS: 3524 switch(sm_pdu_code){ 3525 case SM_CODE_ENCRYPTION_INFORMATION: 3526 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3527 reverse_128(&packet[1], setup->sm_peer_ltk); 3528 break; 3529 3530 case SM_CODE_MASTER_IDENTIFICATION: 3531 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3532 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3533 reverse_64(&packet[3], setup->sm_peer_rand); 3534 break; 3535 3536 case SM_CODE_IDENTITY_INFORMATION: 3537 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3538 reverse_128(&packet[1], setup->sm_peer_irk); 3539 break; 3540 3541 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3542 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3543 setup->sm_peer_addr_type = packet[1]; 3544 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3545 break; 3546 3547 case SM_CODE_SIGNING_INFORMATION: 3548 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3549 reverse_128(&packet[1], setup->sm_peer_csrk); 3550 break; 3551 default: 3552 // Unexpected PDU 3553 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3554 break; 3555 } 3556 // done with key distribution? 3557 if (sm_key_distribution_all_received(sm_conn)){ 3558 3559 sm_key_distribution_handle_all_received(sm_conn); 3560 3561 if (IS_RESPONDER(sm_conn->sm_role)){ 3562 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3563 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3564 } else { 3565 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3566 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3567 sm_done_for_handle(sm_conn->sm_handle); 3568 } 3569 } else { 3570 if (setup->sm_use_secure_connections){ 3571 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3572 } else { 3573 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3574 } 3575 } 3576 } 3577 break; 3578 default: 3579 // Unexpected PDU 3580 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3581 break; 3582 } 3583 3584 // try to send preparared packet 3585 sm_run(); 3586 } 3587 3588 // Security Manager Client API 3589 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3590 sm_get_oob_data = get_oob_data_callback; 3591 } 3592 3593 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)){ 3594 sm_get_sc_oob_data = get_sc_oob_data_callback; 3595 } 3596 3597 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3598 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3599 } 3600 3601 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3602 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3603 } 3604 3605 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3606 sm_min_encryption_key_size = min_size; 3607 sm_max_encryption_key_size = max_size; 3608 } 3609 3610 void sm_set_authentication_requirements(uint8_t auth_req){ 3611 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3612 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3613 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3614 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3615 } 3616 #endif 3617 sm_auth_req = auth_req; 3618 } 3619 3620 void sm_set_io_capabilities(io_capability_t io_capability){ 3621 sm_io_capabilities = io_capability; 3622 } 3623 3624 #ifdef ENABLE_LE_PERIPHERAL 3625 void sm_set_request_security(int enable){ 3626 sm_slave_request_security = enable; 3627 } 3628 #endif 3629 3630 void sm_set_er(sm_key_t er){ 3631 memcpy(sm_persistent_er, er, 16); 3632 } 3633 3634 void sm_set_ir(sm_key_t ir){ 3635 memcpy(sm_persistent_ir, ir, 16); 3636 } 3637 3638 // Testing support only 3639 void sm_test_set_irk(sm_key_t irk){ 3640 memcpy(sm_persistent_irk, irk, 16); 3641 sm_persistent_irk_ready = 1; 3642 } 3643 3644 void sm_test_use_fixed_local_csrk(void){ 3645 test_use_fixed_local_csrk = 1; 3646 } 3647 3648 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3649 static void sm_ec_generated(void * arg){ 3650 UNUSED(arg); 3651 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3652 } 3653 #endif 3654 3655 #ifdef ENABLE_TESTING_SUPPORT 3656 void sm_test_set_pairing_failure(int reason){ 3657 test_pairing_failure = reason; 3658 } 3659 #endif 3660 3661 void sm_init(void){ 3662 // set some (BTstack default) ER and IR 3663 int i; 3664 sm_key_t er; 3665 sm_key_t ir; 3666 for (i=0;i<16;i++){ 3667 er[i] = 0x30 + i; 3668 ir[i] = 0x90 + i; 3669 } 3670 sm_set_er(er); 3671 sm_set_ir(ir); 3672 // defaults 3673 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3674 | SM_STK_GENERATION_METHOD_OOB 3675 | SM_STK_GENERATION_METHOD_PASSKEY 3676 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3677 3678 sm_max_encryption_key_size = 16; 3679 sm_min_encryption_key_size = 7; 3680 3681 sm_fixed_passkey_in_display_role = 0xffffffff; 3682 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3683 3684 #ifdef USE_CMAC_ENGINE 3685 sm_cmac_active = 0; 3686 #endif 3687 dkg_state = DKG_W4_WORKING; 3688 rau_state = RAU_W4_WORKING; 3689 sm_aes128_state = SM_AES128_IDLE; 3690 sm_address_resolution_test = -1; // no private address to resolve yet 3691 sm_address_resolution_ah_calculation_active = 0; 3692 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3693 sm_address_resolution_general_queue = NULL; 3694 3695 gap_random_adress_update_period = 15 * 60 * 1000L; 3696 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3697 3698 test_use_fixed_local_csrk = 0; 3699 3700 // register for HCI Events from HCI 3701 hci_event_callback_registration.callback = &sm_event_packet_handler; 3702 hci_add_event_handler(&hci_event_callback_registration); 3703 3704 // 3705 btstack_crypto_init(); 3706 3707 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3708 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3709 3710 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3711 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3712 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3713 #endif 3714 } 3715 3716 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3717 sm_fixed_passkey_in_display_role = passkey; 3718 } 3719 3720 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3721 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3722 } 3723 3724 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3725 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3726 if (!hci_con) return NULL; 3727 return &hci_con->sm_connection; 3728 } 3729 3730 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3731 switch (sm_conn->sm_engine_state){ 3732 case SM_GENERAL_IDLE: 3733 case SM_RESPONDER_IDLE: 3734 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3735 sm_run(); 3736 break; 3737 default: 3738 break; 3739 } 3740 } 3741 3742 /** 3743 * @brief Trigger Security Request 3744 */ 3745 void sm_send_security_request(hci_con_handle_t con_handle){ 3746 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3747 if (!sm_conn) return; 3748 sm_send_security_request_for_connection(sm_conn); 3749 } 3750 3751 // request pairing 3752 void sm_request_pairing(hci_con_handle_t con_handle){ 3753 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3754 if (!sm_conn) return; // wrong connection 3755 3756 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3757 if (IS_RESPONDER(sm_conn->sm_role)){ 3758 sm_send_security_request_for_connection(sm_conn); 3759 } else { 3760 // used as a trigger to start central/master/initiator security procedures 3761 uint16_t ediv; 3762 sm_key_t ltk; 3763 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3764 switch (sm_conn->sm_irk_lookup_state){ 3765 case IRK_LOOKUP_FAILED: 3766 log_info("irk lookup failed, send pairing request"); 3767 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3768 break; 3769 case IRK_LOOKUP_SUCCEEDED: 3770 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3771 if (!sm_is_null_key(ltk) || ediv){ 3772 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3773 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3774 } else { 3775 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3776 } 3777 break; 3778 default: 3779 log_info("irk lookup pending"); 3780 sm_conn->sm_pairing_requested = 1; 3781 break; 3782 } 3783 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3784 sm_conn->sm_pairing_requested = 1; 3785 } 3786 } 3787 sm_run(); 3788 } 3789 3790 // called by client app on authorization request 3791 void sm_authorization_decline(hci_con_handle_t con_handle){ 3792 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3793 if (!sm_conn) return; // wrong connection 3794 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3795 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3796 } 3797 3798 void sm_authorization_grant(hci_con_handle_t con_handle){ 3799 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3800 if (!sm_conn) return; // wrong connection 3801 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3802 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3803 } 3804 3805 // GAP Bonding API 3806 3807 void sm_bonding_decline(hci_con_handle_t con_handle){ 3808 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3809 if (!sm_conn) return; // wrong connection 3810 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3811 log_info("decline, state %u", sm_conn->sm_engine_state); 3812 switch(sm_conn->sm_engine_state){ 3813 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3814 case SM_SC_W4_USER_RESPONSE: 3815 case SM_SC_W4_CONFIRMATION: 3816 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3817 #endif 3818 case SM_PH1_W4_USER_RESPONSE: 3819 switch (setup->sm_stk_generation_method){ 3820 case PK_RESP_INPUT: 3821 case PK_INIT_INPUT: 3822 case PK_BOTH_INPUT: 3823 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3824 break; 3825 case NUMERIC_COMPARISON: 3826 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3827 break; 3828 case JUST_WORKS: 3829 case OOB: 3830 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3831 break; 3832 } 3833 break; 3834 default: 3835 break; 3836 } 3837 sm_run(); 3838 } 3839 3840 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3841 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3842 if (!sm_conn) return; // wrong connection 3843 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3844 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3845 if (setup->sm_use_secure_connections){ 3846 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3847 } else { 3848 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3849 } 3850 } 3851 3852 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3853 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3854 sm_sc_prepare_dhkey_check(sm_conn); 3855 } 3856 #endif 3857 3858 sm_run(); 3859 } 3860 3861 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3862 // for now, it's the same 3863 sm_just_works_confirm(con_handle); 3864 } 3865 3866 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3867 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3868 if (!sm_conn) return; // wrong connection 3869 sm_reset_tk(); 3870 big_endian_store_32(setup->sm_tk, 12, passkey); 3871 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3872 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3873 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3874 } 3875 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3876 memcpy(setup->sm_ra, setup->sm_tk, 16); 3877 memcpy(setup->sm_rb, setup->sm_tk, 16); 3878 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3879 sm_sc_start_calculating_local_confirm(sm_conn); 3880 } 3881 #endif 3882 sm_run(); 3883 } 3884 3885 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3886 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3887 if (!sm_conn) return; // wrong connection 3888 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3889 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3890 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3891 switch (action){ 3892 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3893 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3894 flags |= (1 << action); 3895 break; 3896 case SM_KEYPRESS_PASSKEY_CLEARED: 3897 // clear counter, keypress & erased flags + set passkey cleared 3898 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3899 break; 3900 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3901 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3902 // erase actions queued 3903 num_actions--; 3904 if (num_actions == 0){ 3905 // clear counter, keypress & erased flags 3906 flags &= 0x19; 3907 } 3908 break; 3909 } 3910 num_actions++; 3911 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3912 break; 3913 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3914 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3915 // enter actions queued 3916 num_actions--; 3917 if (num_actions == 0){ 3918 // clear counter, keypress & erased flags 3919 flags &= 0x19; 3920 } 3921 break; 3922 } 3923 num_actions++; 3924 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3925 break; 3926 default: 3927 break; 3928 } 3929 setup->sm_keypress_notification = (num_actions << 5) | flags; 3930 sm_run(); 3931 } 3932 3933 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3934 static void sm_handle_random_result_oob(void * arg){ 3935 UNUSED(arg); 3936 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3937 sm_run(); 3938 } 3939 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3940 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3941 sm_sc_oob_callback = callback; 3942 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3943 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3944 return 0; 3945 } 3946 #endif 3947 3948 /** 3949 * @brief Identify device in LE Device DB 3950 * @param handle 3951 * @returns index from le_device_db or -1 if not found/identified 3952 */ 3953 int sm_le_device_index(hci_con_handle_t con_handle ){ 3954 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3955 if (!sm_conn) return -1; 3956 return sm_conn->sm_le_db_index; 3957 } 3958 3959 static int gap_random_address_type_requires_updates(void){ 3960 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3961 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3962 return 1; 3963 } 3964 3965 static uint8_t own_address_type(void){ 3966 switch (gap_random_adress_type){ 3967 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3968 return BD_ADDR_TYPE_LE_PUBLIC; 3969 default: 3970 return BD_ADDR_TYPE_LE_RANDOM; 3971 } 3972 } 3973 3974 // GAP LE API 3975 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3976 gap_random_address_update_stop(); 3977 gap_random_adress_type = random_address_type; 3978 hci_le_set_own_address_type(own_address_type()); 3979 if (!gap_random_address_type_requires_updates()) return; 3980 gap_random_address_update_start(); 3981 gap_random_address_trigger(); 3982 } 3983 3984 gap_random_address_type_t gap_random_address_get_mode(void){ 3985 return gap_random_adress_type; 3986 } 3987 3988 void gap_random_address_set_update_period(int period_ms){ 3989 gap_random_adress_update_period = period_ms; 3990 if (!gap_random_address_type_requires_updates()) return; 3991 gap_random_address_update_stop(); 3992 gap_random_address_update_start(); 3993 } 3994 3995 void gap_random_address_set(bd_addr_t addr){ 3996 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 3997 memcpy(sm_random_address, addr, 6); 3998 if (rau_state == RAU_W4_WORKING) return; 3999 rau_state = RAU_SET_ADDRESS; 4000 sm_run(); 4001 } 4002 4003 #ifdef ENABLE_LE_PERIPHERAL 4004 /* 4005 * @brief Set Advertisement Paramters 4006 * @param adv_int_min 4007 * @param adv_int_max 4008 * @param adv_type 4009 * @param direct_address_type 4010 * @param direct_address 4011 * @param channel_map 4012 * @param filter_policy 4013 * 4014 * @note own_address_type is used from gap_random_address_set_mode 4015 */ 4016 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4017 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4018 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4019 direct_address_typ, direct_address, channel_map, filter_policy); 4020 } 4021 #endif 4022