1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "sm.c" 39 40 #include <stdio.h> 41 #include <string.h> 42 #include <inttypes.h> 43 44 #include "ble/le_device_db.h" 45 #include "ble/core.h" 46 #include "ble/sm.h" 47 #include "bluetooth_company_id.h" 48 #include "btstack_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "gap.h" 54 #include "hci.h" 55 #include "hci_dump.h" 56 #include "l2cap.h" 57 58 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 59 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 60 #endif 61 62 // assert SM Public Key can be sent/received 63 #ifdef ENABLE_LE_SECURE_CONNECTIONS 64 #if HCI_ACL_PAYLOAD_SIZE < 69 65 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 66 #endif 67 #endif 68 69 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 70 #define IS_RESPONDER(role) (role) 71 #else 72 #ifdef ENABLE_LE_CENTRAL 73 // only central - never responder (avoid 'unused variable' warnings) 74 #define IS_RESPONDER(role) (0 && role) 75 #else 76 // only peripheral - always responder (avoid 'unused variable' warnings) 77 #define IS_RESPONDER(role) (1 || role) 78 #endif 79 #endif 80 81 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 82 #define USE_CMAC_ENGINE 83 #endif 84 85 // 86 // SM internal types and globals 87 // 88 89 typedef enum { 90 DKG_W4_WORKING, 91 DKG_CALC_IRK, 92 DKG_CALC_DHK, 93 DKG_READY 94 } derived_key_generation_t; 95 96 typedef enum { 97 RAU_W4_WORKING, 98 RAU_IDLE, 99 RAU_W4_RANDOM, 100 RAU_GET_ENC, 101 RAU_W4_ENC, 102 RAU_SET_ADDRESS, 103 } random_address_update_t; 104 105 typedef enum { 106 CMAC_IDLE, 107 CMAC_CALC_SUBKEYS, 108 CMAC_W4_SUBKEYS, 109 CMAC_CALC_MI, 110 CMAC_W4_MI, 111 CMAC_CALC_MLAST, 112 CMAC_W4_MLAST 113 } cmac_state_t; 114 115 typedef enum { 116 JUST_WORKS, 117 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 118 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 119 PK_BOTH_INPUT, // Only input on both, both input PK 120 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 121 OOB // OOB available on one (SC) or both sides (legacy) 122 } stk_generation_method_t; 123 124 typedef enum { 125 SM_USER_RESPONSE_IDLE, 126 SM_USER_RESPONSE_PENDING, 127 SM_USER_RESPONSE_CONFIRM, 128 SM_USER_RESPONSE_PASSKEY, 129 SM_USER_RESPONSE_DECLINE 130 } sm_user_response_t; 131 132 typedef enum { 133 SM_AES128_IDLE, 134 SM_AES128_ACTIVE 135 } sm_aes128_state_t; 136 137 typedef enum { 138 ADDRESS_RESOLUTION_IDLE, 139 ADDRESS_RESOLUTION_GENERAL, 140 ADDRESS_RESOLUTION_FOR_CONNECTION, 141 } address_resolution_mode_t; 142 143 typedef enum { 144 ADDRESS_RESOLUTION_SUCEEDED, 145 ADDRESS_RESOLUTION_FAILED, 146 } address_resolution_event_t; 147 148 typedef enum { 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static uint8_t sm_persistent_irk_ready = 0; // used for testing 204 static derived_key_generation_t dkg_state; 205 206 // derived from sm_persistent_er 207 // .. 208 209 // random address update 210 static random_address_update_t rau_state; 211 static bd_addr_t sm_random_address; 212 213 #ifdef USE_CMAC_ENGINE 214 // CMAC Calculation: General 215 static btstack_crypto_aes128_cmac_t sm_cmac_request; 216 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 217 static uint8_t sm_cmac_active; 218 static uint8_t sm_cmac_hash[16]; 219 #endif 220 221 // CMAC for ATT Signed Writes 222 #ifdef ENABLE_LE_SIGNED_WRITE 223 static uint16_t sm_cmac_signed_write_message_len; 224 static uint8_t sm_cmac_signed_write_header[3]; 225 static const uint8_t * sm_cmac_signed_write_message; 226 static uint8_t sm_cmac_signed_write_sign_counter[4]; 227 #endif 228 229 // CMAC for Secure Connection functions 230 #ifdef ENABLE_LE_SECURE_CONNECTIONS 231 static sm_connection_t * sm_cmac_connection; 232 static uint8_t sm_cmac_sc_buffer[80]; 233 #endif 234 235 // resolvable private address lookup / CSRK calculation 236 static int sm_address_resolution_test; 237 static int sm_address_resolution_ah_calculation_active; 238 static uint8_t sm_address_resolution_addr_type; 239 static bd_addr_t sm_address_resolution_address; 240 static void * sm_address_resolution_context; 241 static address_resolution_mode_t sm_address_resolution_mode; 242 static btstack_linked_list_t sm_address_resolution_general_queue; 243 244 // aes128 crypto engine. 245 static sm_aes128_state_t sm_aes128_state; 246 247 // crypto 248 static btstack_crypto_random_t sm_crypto_random_request; 249 static btstack_crypto_aes128_t sm_crypto_aes128_request; 250 #ifdef ENABLE_LE_SECURE_CONNECTIONS 251 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 252 static btstack_crypto_random_t sm_crypto_random_oob_request; 253 #endif 254 255 // temp storage for random data 256 static uint8_t sm_random_data[8]; 257 static uint8_t sm_aes128_key[16]; 258 static uint8_t sm_aes128_plaintext[16]; 259 static uint8_t sm_aes128_ciphertext[16]; 260 261 // to receive hci events 262 static btstack_packet_callback_registration_t hci_event_callback_registration; 263 264 /* to dispatch sm event */ 265 static btstack_linked_list_t sm_event_handlers; 266 267 // LE Secure Connections 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static ec_key_generation_state_t ec_key_generation_state; 270 static uint8_t ec_q[64]; 271 #endif 272 273 // 274 // Volume 3, Part H, Chapter 24 275 // "Security shall be initiated by the Security Manager in the device in the master role. 276 // The device in the slave role shall be the responding device." 277 // -> master := initiator, slave := responder 278 // 279 280 // data needed for security setup 281 typedef struct sm_setup_context { 282 283 btstack_timer_source_t sm_timeout; 284 285 // used in all phases 286 uint8_t sm_pairing_failed_reason; 287 288 // user response, (Phase 1 and/or 2) 289 uint8_t sm_user_response; 290 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 291 292 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 293 int sm_key_distribution_send_set; 294 int sm_key_distribution_received_set; 295 296 // Phase 2 (Pairing over SMP) 297 stk_generation_method_t sm_stk_generation_method; 298 sm_key_t sm_tk; 299 uint8_t sm_have_oob_data; 300 uint8_t sm_use_secure_connections; 301 302 sm_key_t sm_c1_t3_value; // c1 calculation 303 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 304 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 305 sm_key_t sm_local_random; 306 sm_key_t sm_local_confirm; 307 sm_key_t sm_peer_random; 308 sm_key_t sm_peer_confirm; 309 uint8_t sm_m_addr_type; // address and type can be removed 310 uint8_t sm_s_addr_type; // '' 311 bd_addr_t sm_m_address; // '' 312 bd_addr_t sm_s_address; // '' 313 sm_key_t sm_ltk; 314 315 uint8_t sm_state_vars; 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 318 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 319 sm_key_t sm_local_nonce; // might be combined with sm_local_random 320 sm_key_t sm_dhkey; 321 sm_key_t sm_peer_dhkey_check; 322 sm_key_t sm_local_dhkey_check; 323 sm_key_t sm_ra; 324 sm_key_t sm_rb; 325 sm_key_t sm_t; // used for f5 and h6 326 sm_key_t sm_mackey; 327 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 328 #endif 329 330 // Phase 3 331 332 // key distribution, we generate 333 uint16_t sm_local_y; 334 uint16_t sm_local_div; 335 uint16_t sm_local_ediv; 336 uint8_t sm_local_rand[8]; 337 sm_key_t sm_local_ltk; 338 sm_key_t sm_local_csrk; 339 sm_key_t sm_local_irk; 340 // sm_local_address/addr_type not needed 341 342 // key distribution, received from peer 343 uint16_t sm_peer_y; 344 uint16_t sm_peer_div; 345 uint16_t sm_peer_ediv; 346 uint8_t sm_peer_rand[8]; 347 sm_key_t sm_peer_ltk; 348 sm_key_t sm_peer_irk; 349 sm_key_t sm_peer_csrk; 350 uint8_t sm_peer_addr_type; 351 bd_addr_t sm_peer_address; 352 353 } sm_setup_context_t; 354 355 // 356 static sm_setup_context_t the_setup; 357 static sm_setup_context_t * setup = &the_setup; 358 359 // active connection - the one for which the_setup is used for 360 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 361 362 // @returns 1 if oob data is available 363 // stores oob data in provided 16 byte buffer if not null 364 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 365 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 366 367 // horizontal: initiator capabilities 368 // vertial: responder capabilities 369 static const stk_generation_method_t stk_generation_method [5] [5] = { 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 373 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 374 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 375 }; 376 377 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 378 #ifdef ENABLE_LE_SECURE_CONNECTIONS 379 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 380 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 381 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 382 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 383 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 384 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 385 }; 386 #endif 387 388 static void sm_run(void); 389 #ifdef USE_CMAC_ENGINE 390 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 391 #endif 392 static void sm_done_for_handle(hci_con_handle_t con_handle); 393 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 394 static inline int sm_calc_actual_encryption_key_size(int other); 395 static int sm_validate_stk_generation_method(void); 396 static void sm_handle_encryption_result_address_resolution(void *arg); 397 static void sm_handle_encryption_result_dkg_dhk(void *arg); 398 static void sm_handle_encryption_result_dkg_irk(void *arg); 399 static void sm_handle_encryption_result_enc_a(void *arg); 400 static void sm_handle_encryption_result_enc_b(void *arg); 401 static void sm_handle_encryption_result_enc_c(void *arg); 402 static void sm_handle_encryption_result_enc_csrk(void *arg); 403 static void sm_handle_encryption_result_enc_d(void * arg); 404 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 405 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 406 #ifdef ENABLE_LE_PERIPHERAL 407 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 408 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 409 #endif 410 static void sm_handle_encryption_result_enc_stk(void *arg); 411 static void sm_handle_encryption_result_rau(void *arg); 412 static void sm_handle_random_result_ph2_tk(void * arg); 413 static void sm_handle_random_result_rau(void * arg); 414 #ifdef ENABLE_LE_SECURE_CONNECTIONS 415 static void sm_handle_random_result_sc_get_random(void * arg); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 #endif 418 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 419 420 static void log_info_hex16(const char * name, uint16_t value){ 421 log_info("%-6s 0x%04x", name, value); 422 } 423 424 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 425 // return packet[0]; 426 // } 427 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 428 return packet[1]; 429 } 430 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 431 return packet[2]; 432 } 433 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 434 return packet[3]; 435 } 436 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 437 return packet[4]; 438 } 439 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 440 return packet[5]; 441 } 442 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 443 return packet[6]; 444 } 445 446 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 447 packet[0] = code; 448 } 449 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 450 packet[1] = io_capability; 451 } 452 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 453 packet[2] = oob_data_flag; 454 } 455 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 456 packet[3] = auth_req; 457 } 458 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 459 packet[4] = max_encryption_key_size; 460 } 461 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 462 packet[5] = initiator_key_distribution; 463 } 464 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 465 packet[6] = responder_key_distribution; 466 } 467 468 // @returns 1 if all bytes are 0 469 static int sm_is_null(uint8_t * data, int size){ 470 int i; 471 for (i=0; i < size ; i++){ 472 if (data[i]) return 0; 473 } 474 return 1; 475 } 476 477 static int sm_is_null_random(uint8_t random[8]){ 478 return sm_is_null(random, 8); 479 } 480 481 static int sm_is_null_key(uint8_t * key){ 482 return sm_is_null(key, 16); 483 } 484 485 // Key utils 486 static void sm_reset_tk(void){ 487 int i; 488 for (i=0;i<16;i++){ 489 setup->sm_tk[i] = 0; 490 } 491 } 492 493 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 494 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 495 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 496 int i; 497 for (i = max_encryption_size ; i < 16 ; i++){ 498 key[15-i] = 0; 499 } 500 } 501 502 // SMP Timeout implementation 503 504 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 505 // the Security Manager Timer shall be reset and started. 506 // 507 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 508 // 509 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 510 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 511 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 512 // established. 513 514 static void sm_timeout_handler(btstack_timer_source_t * timer){ 515 log_info("SM timeout"); 516 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 517 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 518 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 519 sm_done_for_handle(sm_conn->sm_handle); 520 521 // trigger handling of next ready connection 522 sm_run(); 523 } 524 static void sm_timeout_start(sm_connection_t * sm_conn){ 525 btstack_run_loop_remove_timer(&setup->sm_timeout); 526 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 527 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 528 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 529 btstack_run_loop_add_timer(&setup->sm_timeout); 530 } 531 static void sm_timeout_stop(void){ 532 btstack_run_loop_remove_timer(&setup->sm_timeout); 533 } 534 static void sm_timeout_reset(sm_connection_t * sm_conn){ 535 sm_timeout_stop(); 536 sm_timeout_start(sm_conn); 537 } 538 539 // end of sm timeout 540 541 // GAP Random Address updates 542 static gap_random_address_type_t gap_random_adress_type; 543 static btstack_timer_source_t gap_random_address_update_timer; 544 static uint32_t gap_random_adress_update_period; 545 546 static void gap_random_address_trigger(void){ 547 log_info("gap_random_address_trigger"); 548 if (rau_state != RAU_IDLE) return; 549 rau_state = RAU_W4_RANDOM; 550 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 551 } 552 553 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 554 UNUSED(timer); 555 556 log_info("GAP Random Address Update due"); 557 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 558 btstack_run_loop_add_timer(&gap_random_address_update_timer); 559 gap_random_address_trigger(); 560 } 561 562 static void gap_random_address_update_start(void){ 563 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 564 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 565 btstack_run_loop_add_timer(&gap_random_address_update_timer); 566 } 567 568 static void gap_random_address_update_stop(void){ 569 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 570 } 571 572 // ah(k,r) helper 573 // r = padding || r 574 // r - 24 bit value 575 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 576 // r'= padding || r 577 memset(r_prime, 0, 16); 578 memcpy(&r_prime[13], r, 3); 579 } 580 581 // d1 helper 582 // d' = padding || r || d 583 // d,r - 16 bit values 584 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 585 // d'= padding || r || d 586 memset(d1_prime, 0, 16); 587 big_endian_store_16(d1_prime, 12, r); 588 big_endian_store_16(d1_prime, 14, d); 589 } 590 591 // dm helper 592 // r’ = padding || r 593 // r - 64 bit value 594 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 595 memset(r_prime, 0, 16); 596 memcpy(&r_prime[8], r, 8); 597 } 598 599 // calculate arguments for first AES128 operation in C1 function 600 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 601 602 // p1 = pres || preq || rat’ || iat’ 603 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 604 // cant octet of pres becomes the most significant octet of p1. 605 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 606 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 607 // p1 is 0x05000800000302070710000001010001." 608 609 sm_key_t p1; 610 reverse_56(pres, &p1[0]); 611 reverse_56(preq, &p1[7]); 612 p1[14] = rat; 613 p1[15] = iat; 614 log_info_key("p1", p1); 615 log_info_key("r", r); 616 617 // t1 = r xor p1 618 int i; 619 for (i=0;i<16;i++){ 620 t1[i] = r[i] ^ p1[i]; 621 } 622 log_info_key("t1", t1); 623 } 624 625 // calculate arguments for second AES128 operation in C1 function 626 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 627 // p2 = padding || ia || ra 628 // "The least significant octet of ra becomes the least significant octet of p2 and 629 // the most significant octet of padding becomes the most significant octet of p2. 630 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 631 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 632 633 sm_key_t p2; 634 memset(p2, 0, 16); 635 memcpy(&p2[4], ia, 6); 636 memcpy(&p2[10], ra, 6); 637 log_info_key("p2", p2); 638 639 // c1 = e(k, t2_xor_p2) 640 int i; 641 for (i=0;i<16;i++){ 642 t3[i] = t2[i] ^ p2[i]; 643 } 644 log_info_key("t3", t3); 645 } 646 647 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 648 log_info_key("r1", r1); 649 log_info_key("r2", r2); 650 memcpy(&r_prime[8], &r2[8], 8); 651 memcpy(&r_prime[0], &r1[8], 8); 652 } 653 654 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 655 UNUSED(channel); 656 657 // log event 658 hci_dump_packet(packet_type, 1, packet, size); 659 // dispatch to all event handlers 660 btstack_linked_list_iterator_t it; 661 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 662 while (btstack_linked_list_iterator_has_next(&it)){ 663 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 664 entry->callback(packet_type, 0, packet, size); 665 } 666 } 667 668 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 669 event[0] = type; 670 event[1] = event_size - 2; 671 little_endian_store_16(event, 2, con_handle); 672 event[4] = addr_type; 673 reverse_bd_addr(address, &event[5]); 674 } 675 676 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 677 uint8_t event[11]; 678 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 679 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 680 } 681 682 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 683 uint8_t event[15]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 little_endian_store_32(event, 11, passkey); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 690 // fetch addr and addr type from db 691 bd_addr_t identity_address; 692 int identity_address_type; 693 le_device_db_info(index, &identity_address_type, identity_address, NULL); 694 695 uint8_t event[19]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 event[11] = identity_address_type; 698 reverse_bd_addr(identity_address, &event[12]); 699 event[18] = index; 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 704 uint8_t event[12]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = status; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 711 uint8_t event[13]; 712 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 713 event[11] = status; 714 event[12] = reason; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 735 736 737 // decide if OOB will be used based on SC vs. Legacy and oob flags 738 int use_oob = 0; 739 if (setup->sm_use_secure_connections){ 740 // In LE Secure Connections pairing, the out of band method is used if at least 741 // one device has the peer device's out of band authentication data available. 742 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 743 } else { 744 // In LE legacy pairing, the out of band method is used if both the devices have 745 // the other device's out of band authentication data available. 746 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 747 } 748 if (use_oob){ 749 log_info("SM: have OOB data"); 750 log_info_key("OOB", setup->sm_tk); 751 setup->sm_stk_generation_method = OOB; 752 return; 753 } 754 755 // If both devices have not set the MITM option in the Authentication Requirements 756 // Flags, then the IO capabilities shall be ignored and the Just Works association 757 // model shall be used. 758 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 759 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 760 log_info("SM: MITM not required by both -> JUST WORKS"); 761 return; 762 } 763 764 // Reset TK as it has been setup in sm_init_setup 765 sm_reset_tk(); 766 767 // Also use just works if unknown io capabilites 768 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 769 return; 770 } 771 772 // Otherwise the IO capabilities of the devices shall be used to determine the 773 // pairing method as defined in Table 2.4. 774 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 775 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 776 777 #ifdef ENABLE_LE_SECURE_CONNECTIONS 778 // table not define by default 779 if (setup->sm_use_secure_connections){ 780 generation_method = stk_generation_method_with_secure_connection; 781 } 782 #endif 783 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 784 785 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 786 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 787 } 788 789 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 790 int flags = 0; 791 if (key_set & SM_KEYDIST_ENC_KEY){ 792 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 794 } 795 if (key_set & SM_KEYDIST_ID_KEY){ 796 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 797 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 798 } 799 if (key_set & SM_KEYDIST_SIGN){ 800 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 801 } 802 return flags; 803 } 804 805 static void sm_setup_key_distribution(uint8_t key_set){ 806 setup->sm_key_distribution_received_set = 0; 807 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 808 } 809 810 // CSRK Key Lookup 811 812 813 static int sm_address_resolution_idle(void){ 814 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 815 } 816 817 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 818 memcpy(sm_address_resolution_address, addr, 6); 819 sm_address_resolution_addr_type = addr_type; 820 sm_address_resolution_test = 0; 821 sm_address_resolution_mode = mode; 822 sm_address_resolution_context = context; 823 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 824 } 825 826 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 827 // check if already in list 828 btstack_linked_list_iterator_t it; 829 sm_lookup_entry_t * entry; 830 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 831 while(btstack_linked_list_iterator_has_next(&it)){ 832 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 833 if (entry->address_type != address_type) continue; 834 if (memcmp(entry->address, address, 6)) continue; 835 // already in list 836 return BTSTACK_BUSY; 837 } 838 entry = btstack_memory_sm_lookup_entry_get(); 839 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 840 entry->address_type = (bd_addr_type_t) address_type; 841 memcpy(entry->address, address, 6); 842 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 843 sm_run(); 844 return 0; 845 } 846 847 // CMAC calculation using AES Engineq 848 #ifdef USE_CMAC_ENGINE 849 850 static void sm_cmac_done_trampoline(void * arg){ 851 UNUSED(arg); 852 sm_cmac_active = 0; 853 (*sm_cmac_done_callback)(sm_cmac_hash); 854 sm_run(); 855 } 856 857 int sm_cmac_ready(void){ 858 return sm_cmac_active == 0; 859 } 860 861 // generic cmac calculation 862 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 863 sm_cmac_active = 1; 864 sm_cmac_done_callback = done_callback; 865 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 866 } 867 #endif 868 869 // cmac for ATT Message signing 870 #ifdef ENABLE_LE_SIGNED_WRITE 871 872 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 873 sm_cmac_active = 1; 874 sm_cmac_done_callback = done_callback; 875 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 876 } 877 878 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_signed_write_message_len) { 880 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_signed_write_message_len - 1 - offset; 885 886 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_signed_write_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_signed_write_message[offset - 3]; 893 } 894 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 898 // ATT Message Signing 899 sm_cmac_signed_write_header[0] = opcode; 900 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 901 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 902 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 903 sm_cmac_signed_write_message = message; 904 sm_cmac_signed_write_message_len = total_message_len; 905 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 906 } 907 #endif 908 909 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 910 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 911 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 912 switch (setup->sm_stk_generation_method){ 913 case PK_RESP_INPUT: 914 if (IS_RESPONDER(sm_conn->sm_role)){ 915 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 916 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 917 } else { 918 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 919 } 920 break; 921 case PK_INIT_INPUT: 922 if (IS_RESPONDER(sm_conn->sm_role)){ 923 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 924 } else { 925 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 926 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 927 } 928 break; 929 case PK_BOTH_INPUT: 930 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 931 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 932 break; 933 case NUMERIC_COMPARISON: 934 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 935 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 936 break; 937 case JUST_WORKS: 938 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 939 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 940 break; 941 case OOB: 942 // client already provided OOB data, let's skip notification. 943 break; 944 } 945 } 946 947 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 948 int recv_flags; 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 // slave / responder 951 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 952 } else { 953 // master / initiator 954 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 955 } 956 957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 958 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 959 if (setup->sm_use_secure_connections){ 960 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 961 } 962 #endif 963 964 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 965 return recv_flags == setup->sm_key_distribution_received_set; 966 } 967 968 static void sm_done_for_handle(hci_con_handle_t con_handle){ 969 if (sm_active_connection_handle == con_handle){ 970 sm_timeout_stop(); 971 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 972 log_info("sm: connection 0x%x released setup context", con_handle); 973 } 974 } 975 976 static int sm_key_distribution_flags_for_auth_req(void){ 977 978 int flags = SM_KEYDIST_ID_KEY; 979 if (sm_auth_req & SM_AUTHREQ_BONDING){ 980 // encryption and signing information only if bonding requested 981 flags |= SM_KEYDIST_ENC_KEY; 982 #ifdef ENABLE_LE_SIGNED_WRITE 983 flags |= SM_KEYDIST_SIGN; 984 #endif 985 } 986 return flags; 987 } 988 989 static void sm_reset_setup(void){ 990 // fill in sm setup 991 setup->sm_state_vars = 0; 992 setup->sm_keypress_notification = 0; 993 sm_reset_tk(); 994 } 995 996 static void sm_init_setup(sm_connection_t * sm_conn){ 997 998 // fill in sm setup 999 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1000 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1001 1002 // query client for Legacy Pairing OOB data 1003 setup->sm_have_oob_data = 0; 1004 if (sm_get_oob_data) { 1005 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1006 } 1007 1008 // if available and SC supported, also ask for SC OOB Data 1009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1010 memset(setup->sm_ra, 0, 16); 1011 memset(setup->sm_rb, 0, 16); 1012 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1013 if (sm_get_sc_oob_data){ 1014 if (IS_RESPONDER(sm_conn->sm_role)){ 1015 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1016 sm_conn->sm_peer_addr_type, 1017 sm_conn->sm_peer_address, 1018 setup->sm_peer_confirm, 1019 setup->sm_ra); 1020 } else { 1021 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1022 sm_conn->sm_peer_addr_type, 1023 sm_conn->sm_peer_address, 1024 setup->sm_peer_confirm, 1025 setup->sm_rb); 1026 } 1027 } else { 1028 setup->sm_have_oob_data = 0; 1029 } 1030 } 1031 #endif 1032 1033 sm_pairing_packet_t * local_packet; 1034 if (IS_RESPONDER(sm_conn->sm_role)){ 1035 // slave 1036 local_packet = &setup->sm_s_pres; 1037 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1038 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1039 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1040 } else { 1041 // master 1042 local_packet = &setup->sm_m_preq; 1043 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1044 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1045 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1046 1047 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1048 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1049 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1050 } 1051 1052 uint8_t auth_req = sm_auth_req; 1053 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1054 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1055 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1056 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1057 } 1058 1059 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1060 1061 sm_pairing_packet_t * remote_packet; 1062 int remote_key_request; 1063 if (IS_RESPONDER(sm_conn->sm_role)){ 1064 // slave / responder 1065 remote_packet = &setup->sm_m_preq; 1066 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1067 } else { 1068 // master / initiator 1069 remote_packet = &setup->sm_s_pres; 1070 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1071 } 1072 1073 // check key size 1074 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1075 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1076 1077 // decide on STK generation method / SC 1078 sm_setup_tk(); 1079 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1080 1081 // check if STK generation method is acceptable by client 1082 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1083 1084 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1085 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1086 if (setup->sm_use_secure_connections){ 1087 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1088 } 1089 #endif 1090 1091 // identical to responder 1092 sm_setup_key_distribution(remote_key_request); 1093 1094 // JUST WORKS doens't provide authentication 1095 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1096 1097 return 0; 1098 } 1099 1100 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1101 1102 // cache and reset context 1103 int matched_device_id = sm_address_resolution_test; 1104 address_resolution_mode_t mode = sm_address_resolution_mode; 1105 void * context = sm_address_resolution_context; 1106 1107 // reset context 1108 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1109 sm_address_resolution_context = NULL; 1110 sm_address_resolution_test = -1; 1111 hci_con_handle_t con_handle = 0; 1112 1113 sm_connection_t * sm_connection; 1114 #ifdef ENABLE_LE_CENTRAL 1115 sm_key_t ltk; 1116 int have_ltk; 1117 int pairing_need; 1118 #endif 1119 switch (mode){ 1120 case ADDRESS_RESOLUTION_GENERAL: 1121 break; 1122 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1123 sm_connection = (sm_connection_t *) context; 1124 con_handle = sm_connection->sm_handle; 1125 switch (event){ 1126 case ADDRESS_RESOLUTION_SUCEEDED: 1127 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1128 sm_connection->sm_le_db_index = matched_device_id; 1129 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1130 if (sm_connection->sm_role) { 1131 // LTK request received before, IRK required -> start LTK calculation 1132 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1133 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1134 } 1135 break; 1136 } 1137 #ifdef ENABLE_LE_CENTRAL 1138 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1139 have_ltk = !sm_is_null_key(ltk); 1140 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1141 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1142 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1143 // reset requests 1144 sm_connection->sm_security_request_received = 0; 1145 sm_connection->sm_pairing_requested = 0; 1146 // have ltk -> start encryption 1147 if (have_ltk){ 1148 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1149 break; 1150 } 1151 // pairint_request -> send pairing request 1152 if (pairing_need){ 1153 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1154 break; 1155 } 1156 #endif 1157 break; 1158 case ADDRESS_RESOLUTION_FAILED: 1159 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1160 if (sm_connection->sm_role) { 1161 // LTK request received before, IRK required -> negative LTK reply 1162 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1163 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1164 } 1165 break; 1166 } 1167 #ifdef ENABLE_LE_CENTRAL 1168 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1169 sm_connection->sm_security_request_received = 0; 1170 sm_connection->sm_pairing_requested = 0; 1171 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1172 #endif 1173 break; 1174 } 1175 break; 1176 default: 1177 break; 1178 } 1179 1180 switch (event){ 1181 case ADDRESS_RESOLUTION_SUCEEDED: 1182 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1183 break; 1184 case ADDRESS_RESOLUTION_FAILED: 1185 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1186 break; 1187 } 1188 } 1189 1190 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1191 1192 int le_db_index = -1; 1193 1194 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1195 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1196 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1197 & SM_AUTHREQ_BONDING ) != 0; 1198 1199 if (bonding_enabed){ 1200 1201 // lookup device based on IRK 1202 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1203 int i; 1204 for (i=0; i < le_device_db_max_count(); i++){ 1205 sm_key_t irk; 1206 bd_addr_t address; 1207 int address_type = BD_ADDR_TYPE_UNKNOWN; 1208 le_device_db_info(i, &address_type, address, irk); 1209 // check if valid entry retrieved 1210 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1211 // compare IRK 1212 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1213 1214 log_info("sm: device found for IRK, updating"); 1215 le_db_index = i; 1216 break; 1217 } 1218 } else { 1219 // assert IRK is set to zero 1220 memset(setup->sm_peer_irk, 0, 16); 1221 } 1222 1223 // if not found, lookup via public address if possible 1224 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1225 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1226 int i; 1227 for (i=0; i < le_device_db_max_count(); i++){ 1228 bd_addr_t address; 1229 int address_type; 1230 le_device_db_info(i, &address_type, address, NULL); 1231 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1232 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1233 log_info("sm: device found for public address, updating"); 1234 le_db_index = i; 1235 break; 1236 } 1237 } 1238 } 1239 1240 // if not found, add to db 1241 if (le_db_index < 0) { 1242 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1243 } 1244 1245 if (le_db_index >= 0){ 1246 1247 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1248 1249 #ifdef ENABLE_LE_SIGNED_WRITE 1250 // store local CSRK 1251 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1252 log_info("sm: store local CSRK"); 1253 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1254 le_device_db_local_counter_set(le_db_index, 0); 1255 } 1256 1257 // store remote CSRK 1258 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1259 log_info("sm: store remote CSRK"); 1260 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1261 le_device_db_remote_counter_set(le_db_index, 0); 1262 } 1263 #endif 1264 // store encryption information for secure connections: LTK generated by ECDH 1265 if (setup->sm_use_secure_connections){ 1266 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1267 uint8_t zero_rand[8]; 1268 memset(zero_rand, 0, 8); 1269 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1270 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1271 } 1272 1273 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1274 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1275 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1276 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1277 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1278 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1279 1280 } 1281 } 1282 } else { 1283 log_info("Ignoring received keys, bonding not enabled"); 1284 } 1285 1286 // keep le_db_index 1287 sm_conn->sm_le_db_index = le_db_index; 1288 } 1289 1290 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1291 setup->sm_pairing_failed_reason = reason; 1292 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1293 } 1294 1295 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1296 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1297 } 1298 1299 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1300 1301 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1302 static int sm_passkey_used(stk_generation_method_t method); 1303 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1304 1305 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1306 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1307 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1308 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1309 } else { 1310 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1311 } 1312 } 1313 1314 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1315 if (IS_RESPONDER(sm_conn->sm_role)){ 1316 // Responder 1317 if (setup->sm_stk_generation_method == OOB){ 1318 // generate Nb 1319 log_info("Generate Nb"); 1320 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1321 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1322 } else { 1323 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1324 } 1325 } else { 1326 // Initiator role 1327 switch (setup->sm_stk_generation_method){ 1328 case JUST_WORKS: 1329 sm_sc_prepare_dhkey_check(sm_conn); 1330 break; 1331 1332 case NUMERIC_COMPARISON: 1333 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1334 break; 1335 case PK_INIT_INPUT: 1336 case PK_RESP_INPUT: 1337 case PK_BOTH_INPUT: 1338 if (setup->sm_passkey_bit < 20) { 1339 sm_sc_start_calculating_local_confirm(sm_conn); 1340 } else { 1341 sm_sc_prepare_dhkey_check(sm_conn); 1342 } 1343 break; 1344 case OOB: 1345 sm_sc_prepare_dhkey_check(sm_conn); 1346 break; 1347 } 1348 } 1349 } 1350 1351 static void sm_sc_cmac_done(uint8_t * hash){ 1352 log_info("sm_sc_cmac_done: "); 1353 log_info_hexdump(hash, 16); 1354 1355 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1356 sm_sc_oob_state = SM_SC_OOB_IDLE; 1357 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1358 return; 1359 } 1360 1361 sm_connection_t * sm_conn = sm_cmac_connection; 1362 sm_cmac_connection = NULL; 1363 #ifdef ENABLE_CLASSIC 1364 link_key_type_t link_key_type; 1365 #endif 1366 1367 switch (sm_conn->sm_engine_state){ 1368 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1369 memcpy(setup->sm_local_confirm, hash, 16); 1370 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1371 break; 1372 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1373 // check 1374 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1375 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1376 break; 1377 } 1378 sm_sc_state_after_receiving_random(sm_conn); 1379 break; 1380 case SM_SC_W4_CALCULATE_G2: { 1381 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1382 big_endian_store_32(setup->sm_tk, 12, vab); 1383 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1384 sm_trigger_user_response(sm_conn); 1385 break; 1386 } 1387 case SM_SC_W4_CALCULATE_F5_SALT: 1388 memcpy(setup->sm_t, hash, 16); 1389 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1390 break; 1391 case SM_SC_W4_CALCULATE_F5_MACKEY: 1392 memcpy(setup->sm_mackey, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1394 break; 1395 case SM_SC_W4_CALCULATE_F5_LTK: 1396 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1397 // Errata Service Release to the Bluetooth Specification: ESR09 1398 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1399 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1400 memcpy(setup->sm_ltk, hash, 16); 1401 memcpy(setup->sm_local_ltk, hash, 16); 1402 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1403 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1404 break; 1405 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1406 memcpy(setup->sm_local_dhkey_check, hash, 16); 1407 if (IS_RESPONDER(sm_conn->sm_role)){ 1408 // responder 1409 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1410 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1411 } else { 1412 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1413 } 1414 } else { 1415 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1416 } 1417 break; 1418 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1419 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1420 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1421 break; 1422 } 1423 if (IS_RESPONDER(sm_conn->sm_role)){ 1424 // responder 1425 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1426 } else { 1427 // initiator 1428 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1429 } 1430 break; 1431 case SM_SC_W4_CALCULATE_H6_ILK: 1432 memcpy(setup->sm_t, hash, 16); 1433 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1434 break; 1435 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1436 #ifdef ENABLE_CLASSIC 1437 reverse_128(hash, setup->sm_t); 1438 link_key_type = sm_conn->sm_connection_authenticated ? 1439 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1440 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1441 if (IS_RESPONDER(sm_conn->sm_role)){ 1442 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1443 } else { 1444 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1445 } 1446 #endif 1447 if (IS_RESPONDER(sm_conn->sm_role)){ 1448 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1449 } else { 1450 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1451 } 1452 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1453 sm_done_for_handle(sm_conn->sm_handle); 1454 break; 1455 default: 1456 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1457 break; 1458 } 1459 sm_run(); 1460 } 1461 1462 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){ 1463 const uint16_t message_len = 65; 1464 sm_cmac_connection = sm_conn; 1465 memcpy(sm_cmac_sc_buffer, u, 32); 1466 memcpy(sm_cmac_sc_buffer+32, v, 32); 1467 sm_cmac_sc_buffer[64] = z; 1468 log_info("f4 key"); 1469 log_info_hexdump(x, 16); 1470 log_info("f4 message"); 1471 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1472 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1473 } 1474 1475 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1476 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1477 static const uint8_t f5_length[] = { 0x01, 0x00}; 1478 1479 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1480 log_info("f5_calculate_salt"); 1481 // calculate salt for f5 1482 const uint16_t message_len = 32; 1483 sm_cmac_connection = sm_conn; 1484 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1485 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1486 } 1487 1488 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){ 1489 const uint16_t message_len = 53; 1490 sm_cmac_connection = sm_conn; 1491 1492 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1493 sm_cmac_sc_buffer[0] = 0; 1494 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1495 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1496 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1497 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1498 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1499 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1500 log_info("f5 key"); 1501 log_info_hexdump(t, 16); 1502 log_info("f5 message for MacKey"); 1503 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1504 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1505 } 1506 1507 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1508 sm_key56_t bd_addr_master, bd_addr_slave; 1509 bd_addr_master[0] = setup->sm_m_addr_type; 1510 bd_addr_slave[0] = setup->sm_s_addr_type; 1511 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1512 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1513 if (IS_RESPONDER(sm_conn->sm_role)){ 1514 // responder 1515 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1516 } else { 1517 // initiator 1518 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1519 } 1520 } 1521 1522 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1523 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1524 const uint16_t message_len = 53; 1525 sm_cmac_connection = sm_conn; 1526 sm_cmac_sc_buffer[0] = 1; 1527 // 1..52 setup before 1528 log_info("f5 key"); 1529 log_info_hexdump(t, 16); 1530 log_info("f5 message for LTK"); 1531 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1532 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1533 } 1534 1535 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1536 f5_ltk(sm_conn, setup->sm_t); 1537 } 1538 1539 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){ 1540 const uint16_t message_len = 65; 1541 sm_cmac_connection = sm_conn; 1542 memcpy(sm_cmac_sc_buffer, n1, 16); 1543 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1544 memcpy(sm_cmac_sc_buffer+32, r, 16); 1545 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1546 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1547 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1548 log_info("f6 key"); 1549 log_info_hexdump(w, 16); 1550 log_info("f6 message"); 1551 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1552 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1553 } 1554 1555 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1556 // - U is 256 bits 1557 // - V is 256 bits 1558 // - X is 128 bits 1559 // - Y is 128 bits 1560 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){ 1561 const uint16_t message_len = 80; 1562 sm_cmac_connection = sm_conn; 1563 memcpy(sm_cmac_sc_buffer, u, 32); 1564 memcpy(sm_cmac_sc_buffer+32, v, 32); 1565 memcpy(sm_cmac_sc_buffer+64, y, 16); 1566 log_info("g2 key"); 1567 log_info_hexdump(x, 16); 1568 log_info("g2 message"); 1569 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1570 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1571 } 1572 1573 static void g2_calculate(sm_connection_t * sm_conn) { 1574 // calc Va if numeric comparison 1575 if (IS_RESPONDER(sm_conn->sm_role)){ 1576 // responder 1577 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1578 } else { 1579 // initiator 1580 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1581 } 1582 } 1583 1584 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1585 uint8_t z = 0; 1586 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1587 // some form of passkey 1588 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1589 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1590 setup->sm_passkey_bit++; 1591 } 1592 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1593 } 1594 1595 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1596 // OOB 1597 if (setup->sm_stk_generation_method == OOB){ 1598 if (IS_RESPONDER(sm_conn->sm_role)){ 1599 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1600 } else { 1601 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1602 } 1603 return; 1604 } 1605 1606 uint8_t z = 0; 1607 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1608 // some form of passkey 1609 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1610 // sm_passkey_bit was increased before sending confirm value 1611 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1612 } 1613 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1614 } 1615 1616 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1617 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1618 1619 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1620 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1621 return; 1622 } else { 1623 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1624 } 1625 } 1626 1627 static void sm_sc_dhkey_calculated(void * arg){ 1628 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1629 log_info("dhkey"); 1630 log_info_hexdump(&setup->sm_dhkey[0], 32); 1631 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1632 // trigger next step 1633 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1634 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1635 } 1636 sm_run(); 1637 } 1638 1639 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1640 // calculate DHKCheck 1641 sm_key56_t bd_addr_master, bd_addr_slave; 1642 bd_addr_master[0] = setup->sm_m_addr_type; 1643 bd_addr_slave[0] = setup->sm_s_addr_type; 1644 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1645 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1646 uint8_t iocap_a[3]; 1647 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1648 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1649 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1650 uint8_t iocap_b[3]; 1651 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1652 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1653 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1654 if (IS_RESPONDER(sm_conn->sm_role)){ 1655 // responder 1656 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); 1657 } else { 1658 // initiator 1659 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); 1660 } 1661 } 1662 1663 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1664 // validate E = f6() 1665 sm_key56_t bd_addr_master, bd_addr_slave; 1666 bd_addr_master[0] = setup->sm_m_addr_type; 1667 bd_addr_slave[0] = setup->sm_s_addr_type; 1668 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1669 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1670 1671 uint8_t iocap_a[3]; 1672 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1673 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1674 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1675 uint8_t iocap_b[3]; 1676 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1677 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1678 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1679 if (IS_RESPONDER(sm_conn->sm_role)){ 1680 // responder 1681 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); 1682 } else { 1683 // initiator 1684 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); 1685 } 1686 } 1687 1688 1689 // 1690 // Link Key Conversion Function h6 1691 // 1692 // h6(W, keyID) = AES-CMACW(keyID) 1693 // - W is 128 bits 1694 // - keyID is 32 bits 1695 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1696 const uint16_t message_len = 4; 1697 sm_cmac_connection = sm_conn; 1698 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1699 log_info("h6 key"); 1700 log_info_hexdump(w, 16); 1701 log_info("h6 message"); 1702 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1703 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1704 } 1705 1706 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1707 // Errata Service Release to the Bluetooth Specification: ESR09 1708 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1709 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1710 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1711 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1712 } 1713 1714 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1715 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1716 } 1717 1718 #endif 1719 1720 // key management legacy connections: 1721 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1722 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1723 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1724 // - responder reconnects: responder uses LTK receveived from master 1725 1726 // key management secure connections: 1727 // - both devices store same LTK from ECDH key exchange. 1728 1729 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1730 static void sm_load_security_info(sm_connection_t * sm_connection){ 1731 int encryption_key_size; 1732 int authenticated; 1733 int authorized; 1734 1735 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1736 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1737 &encryption_key_size, &authenticated, &authorized); 1738 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1739 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1740 sm_connection->sm_connection_authenticated = authenticated; 1741 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1742 } 1743 #endif 1744 1745 #ifdef ENABLE_LE_PERIPHERAL 1746 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1747 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1748 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1749 // re-establish used key encryption size 1750 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1751 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1752 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1753 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1754 log_info("sm: received ltk request with key size %u, authenticated %u", 1755 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1756 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1757 sm_run(); 1758 } 1759 #endif 1760 1761 static void sm_run(void){ 1762 1763 btstack_linked_list_iterator_t it; 1764 1765 // assert that stack has already bootet 1766 if (hci_get_state() != HCI_STATE_WORKING) return; 1767 1768 // assert that we can send at least commands 1769 if (!hci_can_send_command_packet_now()) return; 1770 1771 // 1772 // non-connection related behaviour 1773 // 1774 1775 // distributed key generation 1776 switch (dkg_state){ 1777 case DKG_CALC_IRK: 1778 // already busy? 1779 if (sm_aes128_state == SM_AES128_IDLE) { 1780 log_info("DKG_CALC_IRK started"); 1781 // IRK = d1(IR, 1, 0) 1782 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1783 sm_aes128_state = SM_AES128_ACTIVE; 1784 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1785 return; 1786 } 1787 break; 1788 case DKG_CALC_DHK: 1789 // already busy? 1790 if (sm_aes128_state == SM_AES128_IDLE) { 1791 log_info("DKG_CALC_DHK started"); 1792 // DHK = d1(IR, 3, 0) 1793 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1794 sm_aes128_state = SM_AES128_ACTIVE; 1795 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1796 return; 1797 } 1798 break; 1799 default: 1800 break; 1801 } 1802 1803 // random address updates 1804 switch (rau_state){ 1805 case RAU_GET_ENC: 1806 // already busy? 1807 if (sm_aes128_state == SM_AES128_IDLE) { 1808 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1809 sm_aes128_state = SM_AES128_ACTIVE; 1810 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1811 return; 1812 } 1813 break; 1814 case RAU_SET_ADDRESS: 1815 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1816 rau_state = RAU_IDLE; 1817 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1818 return; 1819 default: 1820 break; 1821 } 1822 1823 // CSRK Lookup 1824 // -- if csrk lookup ready, find connection that require csrk lookup 1825 if (sm_address_resolution_idle()){ 1826 hci_connections_get_iterator(&it); 1827 while(btstack_linked_list_iterator_has_next(&it)){ 1828 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1829 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1830 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1831 // and start lookup 1832 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); 1833 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1834 break; 1835 } 1836 } 1837 } 1838 1839 // -- if csrk lookup ready, resolved addresses for received addresses 1840 if (sm_address_resolution_idle()) { 1841 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1842 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1843 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1844 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1845 btstack_memory_sm_lookup_entry_free(entry); 1846 } 1847 } 1848 1849 // -- Continue with CSRK device lookup by public or resolvable private address 1850 if (!sm_address_resolution_idle()){ 1851 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1852 while (sm_address_resolution_test < le_device_db_max_count()){ 1853 int addr_type; 1854 bd_addr_t addr; 1855 sm_key_t irk; 1856 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1857 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1858 1859 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1860 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1861 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1862 break; 1863 } 1864 1865 if (sm_address_resolution_addr_type == 0){ 1866 sm_address_resolution_test++; 1867 continue; 1868 } 1869 1870 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1871 1872 log_info("LE Device Lookup: calculate AH"); 1873 log_info_key("IRK", irk); 1874 1875 memcpy(sm_aes128_key, irk, 16); 1876 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1877 sm_address_resolution_ah_calculation_active = 1; 1878 sm_aes128_state = SM_AES128_ACTIVE; 1879 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1880 return; 1881 } 1882 1883 if (sm_address_resolution_test >= le_device_db_max_count()){ 1884 log_info("LE Device Lookup: not found"); 1885 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1886 } 1887 } 1888 1889 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1890 switch (sm_sc_oob_state){ 1891 case SM_SC_OOB_W2_CALC_CONFIRM: 1892 if (!sm_cmac_ready()) break; 1893 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1894 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1895 return; 1896 default: 1897 break; 1898 } 1899 #endif 1900 1901 // assert that we can send at least commands - cmd might have been sent by crypto engine 1902 if (!hci_can_send_command_packet_now()) return; 1903 1904 // handle basic actions that don't requires the full context 1905 hci_connections_get_iterator(&it); 1906 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1907 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1908 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1909 switch(sm_connection->sm_engine_state){ 1910 // responder side 1911 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1912 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1913 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1914 return; 1915 1916 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1917 case SM_SC_RECEIVED_LTK_REQUEST: 1918 switch (sm_connection->sm_irk_lookup_state){ 1919 case IRK_LOOKUP_FAILED: 1920 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1921 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1922 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1923 return; 1924 default: 1925 break; 1926 } 1927 break; 1928 #endif 1929 default: 1930 break; 1931 } 1932 } 1933 1934 // 1935 // active connection handling 1936 // -- use loop to handle next connection if lock on setup context is released 1937 1938 while (1) { 1939 1940 // Find connections that requires setup context and make active if no other is locked 1941 hci_connections_get_iterator(&it); 1942 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1943 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1944 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1945 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1946 int done = 1; 1947 int err; 1948 UNUSED(err); 1949 switch (sm_connection->sm_engine_state) { 1950 #ifdef ENABLE_LE_PERIPHERAL 1951 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1952 // send packet if possible, 1953 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1954 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1955 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1956 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1957 } else { 1958 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1959 } 1960 // don't lock sxetup context yet 1961 done = 0; 1962 break; 1963 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1964 sm_reset_setup(); 1965 sm_init_setup(sm_connection); 1966 // recover pairing request 1967 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1968 err = sm_stk_generation_init(sm_connection); 1969 1970 #ifdef ENABLE_TESTING_SUPPORT 1971 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1972 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1973 err = test_pairing_failure; 1974 } 1975 #endif 1976 if (err){ 1977 setup->sm_pairing_failed_reason = err; 1978 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1979 break; 1980 } 1981 sm_timeout_start(sm_connection); 1982 // generate random number first, if we need to show passkey 1983 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1984 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1985 break; 1986 } 1987 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1988 break; 1989 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1990 sm_reset_setup(); 1991 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1992 break; 1993 1994 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1995 case SM_SC_RECEIVED_LTK_REQUEST: 1996 switch (sm_connection->sm_irk_lookup_state){ 1997 case IRK_LOOKUP_SUCCEEDED: 1998 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 1999 // start using context by loading security info 2000 sm_reset_setup(); 2001 sm_load_security_info(sm_connection); 2002 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2003 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2004 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2005 break; 2006 } 2007 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2008 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2009 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2010 // don't lock setup context yet 2011 return; 2012 default: 2013 // just wait until IRK lookup is completed 2014 // don't lock setup context yet 2015 done = 0; 2016 break; 2017 } 2018 break; 2019 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2020 #endif /* ENABLE_LE_PERIPHERAL */ 2021 2022 #ifdef ENABLE_LE_CENTRAL 2023 case SM_INITIATOR_PH0_HAS_LTK: 2024 sm_reset_setup(); 2025 sm_load_security_info(sm_connection); 2026 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2027 break; 2028 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2029 sm_reset_setup(); 2030 sm_init_setup(sm_connection); 2031 sm_timeout_start(sm_connection); 2032 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2033 break; 2034 #endif 2035 2036 default: 2037 done = 0; 2038 break; 2039 } 2040 if (done){ 2041 sm_active_connection_handle = sm_connection->sm_handle; 2042 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); 2043 } 2044 } 2045 2046 // 2047 // active connection handling 2048 // 2049 2050 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2051 2052 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2053 if (!connection) { 2054 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2055 return; 2056 } 2057 2058 // assert that we could send a SM PDU - not needed for all of the following 2059 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2060 log_info("cannot send now, requesting can send now event"); 2061 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2062 return; 2063 } 2064 2065 // send keypress notifications 2066 if (setup->sm_keypress_notification){ 2067 int i; 2068 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2069 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2070 uint8_t action = 0; 2071 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2072 if (flags & (1<<i)){ 2073 int clear_flag = 1; 2074 switch (i){ 2075 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2076 case SM_KEYPRESS_PASSKEY_CLEARED: 2077 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2078 default: 2079 break; 2080 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2081 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2082 num_actions--; 2083 clear_flag = num_actions == 0; 2084 break; 2085 } 2086 if (clear_flag){ 2087 flags &= ~(1<<i); 2088 } 2089 action = i; 2090 break; 2091 } 2092 } 2093 setup->sm_keypress_notification = (num_actions << 5) | flags; 2094 2095 // send keypress notification 2096 uint8_t buffer[2]; 2097 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2098 buffer[1] = action; 2099 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2100 2101 // try 2102 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2103 return; 2104 } 2105 2106 int key_distribution_flags; 2107 UNUSED(key_distribution_flags); 2108 2109 log_info("sm_run: state %u", connection->sm_engine_state); 2110 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2111 log_info("sm_run // cannot send"); 2112 } 2113 switch (connection->sm_engine_state){ 2114 2115 // general 2116 case SM_GENERAL_SEND_PAIRING_FAILED: { 2117 uint8_t buffer[2]; 2118 buffer[0] = SM_CODE_PAIRING_FAILED; 2119 buffer[1] = setup->sm_pairing_failed_reason; 2120 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2121 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2122 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2123 sm_done_for_handle(connection->sm_handle); 2124 break; 2125 } 2126 2127 // responding state 2128 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2129 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2130 if (!sm_cmac_ready()) break; 2131 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2132 sm_sc_calculate_local_confirm(connection); 2133 break; 2134 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2135 if (!sm_cmac_ready()) break; 2136 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2137 sm_sc_calculate_remote_confirm(connection); 2138 break; 2139 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2140 if (!sm_cmac_ready()) break; 2141 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2142 sm_sc_calculate_f6_for_dhkey_check(connection); 2143 break; 2144 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2145 if (!sm_cmac_ready()) break; 2146 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2147 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2148 break; 2149 case SM_SC_W2_CALCULATE_F5_SALT: 2150 if (!sm_cmac_ready()) break; 2151 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2152 f5_calculate_salt(connection); 2153 break; 2154 case SM_SC_W2_CALCULATE_F5_MACKEY: 2155 if (!sm_cmac_ready()) break; 2156 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2157 f5_calculate_mackey(connection); 2158 break; 2159 case SM_SC_W2_CALCULATE_F5_LTK: 2160 if (!sm_cmac_ready()) break; 2161 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2162 f5_calculate_ltk(connection); 2163 break; 2164 case SM_SC_W2_CALCULATE_G2: 2165 if (!sm_cmac_ready()) break; 2166 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2167 g2_calculate(connection); 2168 break; 2169 case SM_SC_W2_CALCULATE_H6_ILK: 2170 if (!sm_cmac_ready()) break; 2171 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2172 h6_calculate_ilk(connection); 2173 break; 2174 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2175 if (!sm_cmac_ready()) break; 2176 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2177 h6_calculate_br_edr_link_key(connection); 2178 break; 2179 #endif 2180 2181 #ifdef ENABLE_LE_CENTRAL 2182 // initiator side 2183 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2184 sm_key_t peer_ltk_flipped; 2185 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2186 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2187 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2188 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2189 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2190 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2191 return; 2192 } 2193 2194 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2195 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2196 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2197 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2198 sm_timeout_reset(connection); 2199 break; 2200 #endif 2201 2202 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2203 2204 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2205 int trigger_user_response = 0; 2206 2207 uint8_t buffer[65]; 2208 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2209 // 2210 reverse_256(&ec_q[0], &buffer[1]); 2211 reverse_256(&ec_q[32], &buffer[33]); 2212 2213 // stk generation method 2214 // passkey entry: notify app to show passkey or to request passkey 2215 switch (setup->sm_stk_generation_method){ 2216 case JUST_WORKS: 2217 case NUMERIC_COMPARISON: 2218 if (IS_RESPONDER(connection->sm_role)){ 2219 // responder 2220 sm_sc_start_calculating_local_confirm(connection); 2221 } else { 2222 // initiator 2223 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2224 } 2225 break; 2226 case PK_INIT_INPUT: 2227 case PK_RESP_INPUT: 2228 case PK_BOTH_INPUT: 2229 // use random TK for display 2230 memcpy(setup->sm_ra, setup->sm_tk, 16); 2231 memcpy(setup->sm_rb, setup->sm_tk, 16); 2232 setup->sm_passkey_bit = 0; 2233 2234 if (IS_RESPONDER(connection->sm_role)){ 2235 // responder 2236 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2237 } else { 2238 // initiator 2239 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2240 } 2241 trigger_user_response = 1; 2242 break; 2243 case OOB: 2244 if (IS_RESPONDER(connection->sm_role)){ 2245 // responder 2246 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2247 } else { 2248 // initiator 2249 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2250 } 2251 break; 2252 } 2253 2254 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2255 sm_timeout_reset(connection); 2256 2257 // trigger user response after sending pdu 2258 if (trigger_user_response){ 2259 sm_trigger_user_response(connection); 2260 } 2261 break; 2262 } 2263 case SM_SC_SEND_CONFIRMATION: { 2264 uint8_t buffer[17]; 2265 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2266 reverse_128(setup->sm_local_confirm, &buffer[1]); 2267 if (IS_RESPONDER(connection->sm_role)){ 2268 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2269 } else { 2270 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2271 } 2272 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2273 sm_timeout_reset(connection); 2274 break; 2275 } 2276 case SM_SC_SEND_PAIRING_RANDOM: { 2277 uint8_t buffer[17]; 2278 buffer[0] = SM_CODE_PAIRING_RANDOM; 2279 reverse_128(setup->sm_local_nonce, &buffer[1]); 2280 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2281 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2282 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2283 if (IS_RESPONDER(connection->sm_role)){ 2284 // responder 2285 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2286 } else { 2287 // initiator 2288 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2289 } 2290 } else { 2291 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2292 if (IS_RESPONDER(connection->sm_role)){ 2293 // responder 2294 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2295 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2296 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2297 } else { 2298 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2299 sm_sc_prepare_dhkey_check(connection); 2300 } 2301 } else { 2302 // initiator 2303 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2304 } 2305 } 2306 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2307 sm_timeout_reset(connection); 2308 break; 2309 } 2310 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2311 uint8_t buffer[17]; 2312 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2313 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2314 2315 if (IS_RESPONDER(connection->sm_role)){ 2316 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2317 } else { 2318 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2319 } 2320 2321 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2322 sm_timeout_reset(connection); 2323 break; 2324 } 2325 2326 #endif 2327 2328 #ifdef ENABLE_LE_PERIPHERAL 2329 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2330 // echo initiator for now 2331 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2332 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2333 2334 if (setup->sm_use_secure_connections){ 2335 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2336 } else { 2337 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2338 } 2339 2340 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); 2341 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); 2342 // update key distribution after ENC was dropped 2343 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2344 2345 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2346 sm_timeout_reset(connection); 2347 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2348 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2349 sm_trigger_user_response(connection); 2350 } 2351 return; 2352 #endif 2353 2354 case SM_PH2_SEND_PAIRING_RANDOM: { 2355 uint8_t buffer[17]; 2356 buffer[0] = SM_CODE_PAIRING_RANDOM; 2357 reverse_128(setup->sm_local_random, &buffer[1]); 2358 if (IS_RESPONDER(connection->sm_role)){ 2359 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2360 } else { 2361 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2362 } 2363 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2364 sm_timeout_reset(connection); 2365 break; 2366 } 2367 2368 case SM_PH2_C1_GET_ENC_A: 2369 // already busy? 2370 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2371 // calculate confirm using aes128 engine - step 1 2372 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); 2373 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2374 sm_aes128_state = SM_AES128_ACTIVE; 2375 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2376 break; 2377 2378 case SM_PH2_C1_GET_ENC_C: 2379 // already busy? 2380 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2381 // calculate m_confirm using aes128 engine - step 1 2382 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); 2383 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2384 sm_aes128_state = SM_AES128_ACTIVE; 2385 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2386 break; 2387 2388 case SM_PH2_CALC_STK: 2389 // already busy? 2390 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2391 // calculate STK 2392 if (IS_RESPONDER(connection->sm_role)){ 2393 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2394 } else { 2395 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2396 } 2397 connection->sm_engine_state = SM_PH2_W4_STK; 2398 sm_aes128_state = SM_AES128_ACTIVE; 2399 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2400 break; 2401 2402 case SM_PH3_Y_GET_ENC: 2403 // already busy? 2404 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2405 // PH3B2 - calculate Y from - enc 2406 // Y = dm(DHK, Rand) 2407 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2408 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2409 sm_aes128_state = SM_AES128_ACTIVE; 2410 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); 2411 break; 2412 2413 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2414 uint8_t buffer[17]; 2415 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2416 reverse_128(setup->sm_local_confirm, &buffer[1]); 2417 if (IS_RESPONDER(connection->sm_role)){ 2418 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2419 } else { 2420 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2421 } 2422 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2423 sm_timeout_reset(connection); 2424 return; 2425 } 2426 #ifdef ENABLE_LE_PERIPHERAL 2427 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2428 sm_key_t stk_flipped; 2429 reverse_128(setup->sm_ltk, stk_flipped); 2430 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2431 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2432 return; 2433 } 2434 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2435 sm_key_t ltk_flipped; 2436 reverse_128(setup->sm_ltk, ltk_flipped); 2437 connection->sm_engine_state = SM_RESPONDER_IDLE; 2438 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2439 sm_done_for_handle(connection->sm_handle); 2440 return; 2441 } 2442 case SM_RESPONDER_PH4_Y_GET_ENC: 2443 // already busy? 2444 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2445 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2446 // Y = dm(DHK, Rand) 2447 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2448 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2449 sm_aes128_state = SM_AES128_ACTIVE; 2450 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); 2451 return; 2452 #endif 2453 #ifdef ENABLE_LE_CENTRAL 2454 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2455 sm_key_t stk_flipped; 2456 reverse_128(setup->sm_ltk, stk_flipped); 2457 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2458 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2459 return; 2460 } 2461 #endif 2462 2463 case SM_PH3_DISTRIBUTE_KEYS: 2464 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2465 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2466 uint8_t buffer[17]; 2467 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2468 reverse_128(setup->sm_ltk, &buffer[1]); 2469 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2470 sm_timeout_reset(connection); 2471 return; 2472 } 2473 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2474 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2475 uint8_t buffer[11]; 2476 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2477 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2478 reverse_64(setup->sm_local_rand, &buffer[3]); 2479 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2480 sm_timeout_reset(connection); 2481 return; 2482 } 2483 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2484 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2485 uint8_t buffer[17]; 2486 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2487 reverse_128(sm_persistent_irk, &buffer[1]); 2488 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2489 sm_timeout_reset(connection); 2490 return; 2491 } 2492 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2493 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2494 bd_addr_t local_address; 2495 uint8_t buffer[8]; 2496 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2497 switch (gap_random_address_get_mode()){ 2498 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2499 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2500 // public or static random 2501 gap_le_get_own_address(&buffer[1], local_address); 2502 break; 2503 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2504 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2505 // fallback to public 2506 gap_local_bd_addr(local_address); 2507 buffer[1] = 0; 2508 break; 2509 } 2510 reverse_bd_addr(local_address, &buffer[2]); 2511 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2512 sm_timeout_reset(connection); 2513 return; 2514 } 2515 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2516 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2517 2518 // hack to reproduce test runs 2519 if (test_use_fixed_local_csrk){ 2520 memset(setup->sm_local_csrk, 0xcc, 16); 2521 } 2522 2523 uint8_t buffer[17]; 2524 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2525 reverse_128(setup->sm_local_csrk, &buffer[1]); 2526 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2527 sm_timeout_reset(connection); 2528 return; 2529 } 2530 2531 // keys are sent 2532 if (IS_RESPONDER(connection->sm_role)){ 2533 // slave -> receive master keys if any 2534 if (sm_key_distribution_all_received(connection)){ 2535 sm_key_distribution_handle_all_received(connection); 2536 connection->sm_engine_state = SM_RESPONDER_IDLE; 2537 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2538 sm_done_for_handle(connection->sm_handle); 2539 } else { 2540 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2541 } 2542 } else { 2543 // master -> all done 2544 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2545 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2546 sm_done_for_handle(connection->sm_handle); 2547 } 2548 break; 2549 2550 default: 2551 break; 2552 } 2553 2554 // check again if active connection was released 2555 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2556 } 2557 } 2558 2559 // sm_aes128_state stays active 2560 static void sm_handle_encryption_result_enc_a(void *arg){ 2561 sm_connection_t * connection = (sm_connection_t*) arg; 2562 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2563 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); 2564 } 2565 2566 static void sm_handle_encryption_result_enc_b(void *arg){ 2567 sm_connection_t * connection = (sm_connection_t*) arg; 2568 sm_aes128_state = SM_AES128_IDLE; 2569 log_info_key("c1!", setup->sm_local_confirm); 2570 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2571 sm_run(); 2572 } 2573 2574 // sm_aes128_state stays active 2575 static void sm_handle_encryption_result_enc_c(void *arg){ 2576 sm_connection_t * connection = (sm_connection_t*) arg; 2577 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2578 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); 2579 } 2580 2581 static void sm_handle_encryption_result_enc_d(void * arg){ 2582 sm_connection_t * connection = (sm_connection_t*) arg; 2583 sm_aes128_state = SM_AES128_IDLE; 2584 log_info_key("c1!", sm_aes128_ciphertext); 2585 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2586 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2587 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2588 sm_run(); 2589 return; 2590 } 2591 if (IS_RESPONDER(connection->sm_role)){ 2592 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2593 sm_run(); 2594 } else { 2595 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2596 sm_aes128_state = SM_AES128_ACTIVE; 2597 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2598 } 2599 } 2600 2601 static void sm_handle_encryption_result_enc_stk(void *arg){ 2602 sm_connection_t * connection = (sm_connection_t*) arg; 2603 sm_aes128_state = SM_AES128_IDLE; 2604 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2605 log_info_key("stk", setup->sm_ltk); 2606 if (IS_RESPONDER(connection->sm_role)){ 2607 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2608 } else { 2609 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2610 } 2611 sm_run(); 2612 } 2613 2614 // sm_aes128_state stays active 2615 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2616 sm_connection_t * connection = (sm_connection_t*) arg; 2617 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2618 log_info_hex16("y", setup->sm_local_y); 2619 // PH3B3 - calculate EDIV 2620 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2621 log_info_hex16("ediv", setup->sm_local_ediv); 2622 // PH3B4 - calculate LTK - enc 2623 // LTK = d1(ER, DIV, 0)) 2624 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2625 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); 2626 } 2627 2628 #ifdef ENABLE_LE_PERIPHERAL 2629 // sm_aes128_state stays active 2630 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2631 sm_connection_t * connection = (sm_connection_t*) arg; 2632 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2633 log_info_hex16("y", setup->sm_local_y); 2634 2635 // PH3B3 - calculate DIV 2636 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2637 log_info_hex16("ediv", setup->sm_local_ediv); 2638 // PH3B4 - calculate LTK - enc 2639 // LTK = d1(ER, DIV, 0)) 2640 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2641 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); 2642 } 2643 #endif 2644 2645 // sm_aes128_state stays active 2646 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2647 sm_connection_t * connection = (sm_connection_t*) arg; 2648 log_info_key("ltk", setup->sm_ltk); 2649 // calc CSRK next 2650 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2651 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); 2652 } 2653 2654 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2655 sm_connection_t * connection = (sm_connection_t*) arg; 2656 sm_aes128_state = SM_AES128_IDLE; 2657 log_info_key("csrk", setup->sm_local_csrk); 2658 if (setup->sm_key_distribution_send_set){ 2659 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2660 } else { 2661 // no keys to send, just continue 2662 if (IS_RESPONDER(connection->sm_role)){ 2663 // slave -> receive master keys 2664 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2665 } else { 2666 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2667 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2668 } else { 2669 // master -> all done 2670 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2671 sm_done_for_handle(connection->sm_handle); 2672 } 2673 } 2674 } 2675 sm_run(); 2676 } 2677 2678 #ifdef ENABLE_LE_PERIPHERAL 2679 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2680 sm_connection_t * connection = (sm_connection_t*) arg; 2681 sm_aes128_state = SM_AES128_IDLE; 2682 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2683 log_info_key("ltk", setup->sm_ltk); 2684 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2685 sm_run(); 2686 } 2687 #endif 2688 2689 static void sm_handle_encryption_result_address_resolution(void *arg){ 2690 UNUSED(arg); 2691 sm_aes128_state = SM_AES128_IDLE; 2692 sm_address_resolution_ah_calculation_active = 0; 2693 // compare calulated address against connecting device 2694 uint8_t * hash = &sm_aes128_ciphertext[13]; 2695 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2696 log_info("LE Device Lookup: matched resolvable private address"); 2697 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2698 sm_run(); 2699 return; 2700 } 2701 // no match, try next 2702 sm_address_resolution_test++; 2703 sm_run(); 2704 } 2705 2706 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2707 UNUSED(arg); 2708 sm_aes128_state = SM_AES128_IDLE; 2709 log_info_key("irk", sm_persistent_irk); 2710 dkg_state = DKG_CALC_DHK; 2711 sm_run(); 2712 } 2713 2714 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2715 UNUSED(arg); 2716 sm_aes128_state = SM_AES128_IDLE; 2717 log_info_key("dhk", sm_persistent_dhk); 2718 dkg_state = DKG_READY; 2719 // DKG calculation complete => SM Init Finished 2720 sm_run(); 2721 } 2722 2723 static void sm_handle_encryption_result_rau(void *arg){ 2724 UNUSED(arg); 2725 sm_aes128_state = SM_AES128_IDLE; 2726 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2727 rau_state = RAU_SET_ADDRESS; 2728 sm_run(); 2729 } 2730 2731 static void sm_handle_random_result_rau(void * arg){ 2732 UNUSED(arg); 2733 // non-resolvable vs. resolvable 2734 switch (gap_random_adress_type){ 2735 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2736 // resolvable: use random as prand and calc address hash 2737 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2738 sm_random_address[0] &= 0x3f; 2739 sm_random_address[0] |= 0x40; 2740 rau_state = RAU_GET_ENC; 2741 break; 2742 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2743 default: 2744 // "The two most significant bits of the address shall be equal to ‘0’"" 2745 sm_random_address[0] &= 0x3f; 2746 rau_state = RAU_SET_ADDRESS; 2747 break; 2748 } 2749 sm_run(); 2750 } 2751 2752 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2753 static void sm_handle_random_result_sc_get_random(void * arg){ 2754 sm_connection_t * connection = (sm_connection_t*) arg; 2755 2756 // OOB 2757 if (setup->sm_stk_generation_method == OOB){ 2758 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2759 sm_run(); 2760 return; 2761 } 2762 2763 // initiator & jw/nc -> send pairing random 2764 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2765 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2766 } else { 2767 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2768 } 2769 sm_run(); 2770 } 2771 #endif 2772 2773 static void sm_handle_random_result_ph2_random(void * arg){ 2774 sm_connection_t * connection = (sm_connection_t*) arg; 2775 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2776 sm_run(); 2777 } 2778 2779 static void sm_handle_random_result_ph2_tk(void * arg){ 2780 sm_connection_t * connection = (sm_connection_t*) arg; 2781 sm_reset_tk(); 2782 uint32_t tk; 2783 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2784 // map random to 0-999999 without speding much cycles on a modulus operation 2785 tk = little_endian_read_32(sm_random_data,0); 2786 tk = tk & 0xfffff; // 1048575 2787 if (tk >= 999999){ 2788 tk = tk - 999999; 2789 } 2790 } else { 2791 // override with pre-defined passkey 2792 tk = sm_fixed_passkey_in_display_role; 2793 } 2794 big_endian_store_32(setup->sm_tk, 12, tk); 2795 if (IS_RESPONDER(connection->sm_role)){ 2796 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2797 } else { 2798 if (setup->sm_use_secure_connections){ 2799 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2800 } else { 2801 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2802 sm_trigger_user_response(connection); 2803 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2804 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2805 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2806 } 2807 } 2808 } 2809 sm_run(); 2810 } 2811 2812 static void sm_handle_random_result_ph3_div(void * arg){ 2813 sm_connection_t * connection = (sm_connection_t*) arg; 2814 // use 16 bit from random value as div 2815 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2816 log_info_hex16("div", setup->sm_local_div); 2817 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2818 sm_run(); 2819 } 2820 2821 static void sm_handle_random_result_ph3_random(void * arg){ 2822 sm_connection_t * connection = (sm_connection_t*) arg; 2823 reverse_64(sm_random_data, setup->sm_local_rand); 2824 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2825 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2826 // no db for authenticated flag hack: store flag in bit 4 of LSB 2827 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2828 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2829 } 2830 2831 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2832 2833 UNUSED(channel); // ok: there is no channel 2834 UNUSED(size); // ok: fixed format HCI events 2835 2836 sm_connection_t * sm_conn; 2837 hci_con_handle_t con_handle; 2838 2839 switch (packet_type) { 2840 2841 case HCI_EVENT_PACKET: 2842 switch (hci_event_packet_get_type(packet)) { 2843 2844 case BTSTACK_EVENT_STATE: 2845 // bt stack activated, get started 2846 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2847 log_info("HCI Working!"); 2848 2849 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2850 2851 // trigger Random Address generation if requested before 2852 switch (gap_random_adress_type){ 2853 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2854 rau_state = RAU_IDLE; 2855 break; 2856 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2857 rau_state = RAU_SET_ADDRESS; 2858 break; 2859 default: 2860 rau_state = RAU_W4_RANDOM; 2861 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2862 break; 2863 } 2864 sm_run(); 2865 } 2866 break; 2867 2868 case HCI_EVENT_LE_META: 2869 switch (packet[2]) { 2870 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2871 2872 log_info("sm: connected"); 2873 2874 if (packet[3]) return; // connection failed 2875 2876 con_handle = little_endian_read_16(packet, 4); 2877 sm_conn = sm_get_connection_for_handle(con_handle); 2878 if (!sm_conn) break; 2879 2880 sm_conn->sm_handle = con_handle; 2881 sm_conn->sm_role = packet[6]; 2882 sm_conn->sm_peer_addr_type = packet[7]; 2883 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2884 2885 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2886 2887 // reset security properties 2888 sm_conn->sm_connection_encrypted = 0; 2889 sm_conn->sm_connection_authenticated = 0; 2890 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2891 sm_conn->sm_le_db_index = -1; 2892 2893 // prepare CSRK lookup (does not involve setup) 2894 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2895 2896 // just connected -> everything else happens in sm_run() 2897 if (IS_RESPONDER(sm_conn->sm_role)){ 2898 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2899 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2900 if (sm_slave_request_security) { 2901 // request security if requested by app 2902 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2903 } else { 2904 // otherwise, wait for pairing request 2905 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2906 } 2907 } 2908 break; 2909 } else { 2910 // master 2911 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2912 } 2913 break; 2914 2915 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2916 con_handle = little_endian_read_16(packet, 3); 2917 sm_conn = sm_get_connection_for_handle(con_handle); 2918 if (!sm_conn) break; 2919 2920 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2921 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2922 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2923 break; 2924 } 2925 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2926 // PH2 SEND LTK as we need to exchange keys in PH3 2927 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2928 break; 2929 } 2930 2931 // store rand and ediv 2932 reverse_64(&packet[5], sm_conn->sm_local_rand); 2933 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2934 2935 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2936 // potentially stored LTK is from the master 2937 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2938 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2939 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2940 break; 2941 } 2942 // additionally check if remote is in LE Device DB if requested 2943 switch(sm_conn->sm_irk_lookup_state){ 2944 case IRK_LOOKUP_FAILED: 2945 log_info("LTK Request: device not in device db"); 2946 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2947 break; 2948 case IRK_LOOKUP_SUCCEEDED: 2949 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2950 break; 2951 default: 2952 // wait for irk look doen 2953 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2954 break; 2955 } 2956 break; 2957 } 2958 2959 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2960 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2961 #else 2962 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2963 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2964 #endif 2965 break; 2966 2967 default: 2968 break; 2969 } 2970 break; 2971 2972 case HCI_EVENT_ENCRYPTION_CHANGE: 2973 con_handle = little_endian_read_16(packet, 3); 2974 sm_conn = sm_get_connection_for_handle(con_handle); 2975 if (!sm_conn) break; 2976 2977 sm_conn->sm_connection_encrypted = packet[5]; 2978 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2979 sm_conn->sm_actual_encryption_key_size); 2980 log_info("event handler, state %u", sm_conn->sm_engine_state); 2981 2982 // encryption change event concludes re-encryption for bonded devices (even if it fails) 2983 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 2984 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2985 sm_done_for_handle(sm_conn->sm_handle); 2986 break; 2987 } 2988 2989 if (!sm_conn->sm_connection_encrypted) break; 2990 2991 // continue pairing 2992 switch (sm_conn->sm_engine_state){ 2993 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2994 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2995 sm_done_for_handle(sm_conn->sm_handle); 2996 break; 2997 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2998 if (IS_RESPONDER(sm_conn->sm_role)){ 2999 // slave 3000 if (setup->sm_use_secure_connections){ 3001 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3002 } else { 3003 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3004 } 3005 } else { 3006 // master 3007 if (sm_key_distribution_all_received(sm_conn)){ 3008 // skip receiving keys as there are none 3009 sm_key_distribution_handle_all_received(sm_conn); 3010 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3011 } else { 3012 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3013 } 3014 } 3015 break; 3016 default: 3017 break; 3018 } 3019 break; 3020 3021 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3022 con_handle = little_endian_read_16(packet, 3); 3023 sm_conn = sm_get_connection_for_handle(con_handle); 3024 if (!sm_conn) break; 3025 3026 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3027 log_info("event handler, state %u", sm_conn->sm_engine_state); 3028 // continue if part of initial pairing 3029 switch (sm_conn->sm_engine_state){ 3030 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3031 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3032 sm_done_for_handle(sm_conn->sm_handle); 3033 break; 3034 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3035 if (IS_RESPONDER(sm_conn->sm_role)){ 3036 // slave 3037 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3038 } else { 3039 // master 3040 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3041 } 3042 break; 3043 default: 3044 break; 3045 } 3046 break; 3047 3048 3049 case HCI_EVENT_DISCONNECTION_COMPLETE: 3050 con_handle = little_endian_read_16(packet, 3); 3051 sm_done_for_handle(con_handle); 3052 sm_conn = sm_get_connection_for_handle(con_handle); 3053 if (!sm_conn) break; 3054 3055 // delete stored bonding on disconnect with authentication failure in ph0 3056 if (sm_conn->sm_role == 0 3057 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3058 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3059 le_device_db_remove(sm_conn->sm_le_db_index); 3060 } 3061 3062 // pairing failed, if it was ongoing 3063 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3064 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3065 } 3066 3067 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3068 sm_conn->sm_handle = 0; 3069 break; 3070 3071 case HCI_EVENT_COMMAND_COMPLETE: 3072 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3073 // set local addr for le device db 3074 bd_addr_t addr; 3075 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3076 le_device_db_set_local_bd_addr(addr); 3077 } 3078 break; 3079 default: 3080 break; 3081 } 3082 break; 3083 default: 3084 break; 3085 } 3086 3087 sm_run(); 3088 } 3089 3090 static inline int sm_calc_actual_encryption_key_size(int other){ 3091 if (other < sm_min_encryption_key_size) return 0; 3092 if (other < sm_max_encryption_key_size) return other; 3093 return sm_max_encryption_key_size; 3094 } 3095 3096 3097 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3098 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3099 switch (method){ 3100 case JUST_WORKS: 3101 case NUMERIC_COMPARISON: 3102 return 1; 3103 default: 3104 return 0; 3105 } 3106 } 3107 // responder 3108 3109 static int sm_passkey_used(stk_generation_method_t method){ 3110 switch (method){ 3111 case PK_RESP_INPUT: 3112 return 1; 3113 default: 3114 return 0; 3115 } 3116 } 3117 3118 static int sm_passkey_entry(stk_generation_method_t method){ 3119 switch (method){ 3120 case PK_RESP_INPUT: 3121 case PK_INIT_INPUT: 3122 case PK_BOTH_INPUT: 3123 return 1; 3124 default: 3125 return 0; 3126 } 3127 } 3128 3129 #endif 3130 3131 /** 3132 * @return ok 3133 */ 3134 static int sm_validate_stk_generation_method(void){ 3135 // check if STK generation method is acceptable by client 3136 switch (setup->sm_stk_generation_method){ 3137 case JUST_WORKS: 3138 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3139 case PK_RESP_INPUT: 3140 case PK_INIT_INPUT: 3141 case PK_BOTH_INPUT: 3142 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3143 case OOB: 3144 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3145 case NUMERIC_COMPARISON: 3146 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3147 return 1; 3148 default: 3149 return 0; 3150 } 3151 } 3152 3153 // size of complete sm_pdu used to validate input 3154 static const uint8_t sm_pdu_size[] = { 3155 0, // 0x00 invalid opcode 3156 7, // 0x01 pairing request 3157 7, // 0x02 pairing response 3158 17, // 0x03 pairing confirm 3159 17, // 0x04 pairing random 3160 2, // 0x05 pairing failed 3161 17, // 0x06 encryption information 3162 11, // 0x07 master identification 3163 17, // 0x08 identification information 3164 8, // 0x09 identify address information 3165 17, // 0x0a signing information 3166 2, // 0x0b security request 3167 65, // 0x0c pairing public key 3168 17, // 0x0d pairing dhk check 3169 2, // 0x0e keypress notification 3170 }; 3171 3172 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3173 3174 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3175 sm_run(); 3176 } 3177 3178 if (packet_type != SM_DATA_PACKET) return; 3179 if (size == 0) return; 3180 3181 uint8_t sm_pdu_code = packet[0]; 3182 3183 // validate pdu size 3184 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3185 if (sm_pdu_size[sm_pdu_code] != size) return; 3186 3187 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3188 if (!sm_conn) return; 3189 3190 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3191 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3192 sm_done_for_handle(con_handle); 3193 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3194 return; 3195 } 3196 3197 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3198 3199 int err; 3200 UNUSED(err); 3201 3202 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3203 uint8_t buffer[5]; 3204 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3205 buffer[1] = 3; 3206 little_endian_store_16(buffer, 2, con_handle); 3207 buffer[4] = packet[1]; 3208 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3209 return; 3210 } 3211 3212 switch (sm_conn->sm_engine_state){ 3213 3214 // a sm timeout requries a new physical connection 3215 case SM_GENERAL_TIMEOUT: 3216 return; 3217 3218 #ifdef ENABLE_LE_CENTRAL 3219 3220 // Initiator 3221 case SM_INITIATOR_CONNECTED: 3222 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3223 sm_pdu_received_in_wrong_state(sm_conn); 3224 break; 3225 } 3226 3227 // IRK complete? 3228 switch (sm_conn->sm_irk_lookup_state){ 3229 case IRK_LOOKUP_FAILED: 3230 case IRK_LOOKUP_SUCCEEDED: 3231 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3232 break; 3233 default: 3234 break; 3235 } 3236 3237 // otherwise, store security request 3238 sm_conn->sm_security_request_received = 1; 3239 break; 3240 3241 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3242 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3243 sm_pdu_received_in_wrong_state(sm_conn); 3244 break; 3245 } 3246 3247 // store pairing request 3248 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3249 err = sm_stk_generation_init(sm_conn); 3250 3251 #ifdef ENABLE_TESTING_SUPPORT 3252 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3253 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3254 err = test_pairing_failure; 3255 } 3256 #endif 3257 3258 if (err){ 3259 setup->sm_pairing_failed_reason = err; 3260 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3261 break; 3262 } 3263 3264 // generate random number first, if we need to show passkey 3265 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3266 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3267 break; 3268 } 3269 3270 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3271 if (setup->sm_use_secure_connections){ 3272 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3273 if (setup->sm_stk_generation_method == JUST_WORKS){ 3274 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3275 sm_trigger_user_response(sm_conn); 3276 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3277 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3278 } 3279 } else { 3280 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3281 } 3282 break; 3283 } 3284 #endif 3285 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3286 sm_trigger_user_response(sm_conn); 3287 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3288 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3289 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3290 } 3291 break; 3292 3293 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3294 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3295 sm_pdu_received_in_wrong_state(sm_conn); 3296 break; 3297 } 3298 3299 // store s_confirm 3300 reverse_128(&packet[1], setup->sm_peer_confirm); 3301 3302 #ifdef ENABLE_TESTING_SUPPORT 3303 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3304 log_info("testing_support: reset confirm value"); 3305 memset(setup->sm_peer_confirm, 0, 16); 3306 } 3307 #endif 3308 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3309 break; 3310 3311 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3312 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3313 sm_pdu_received_in_wrong_state(sm_conn); 3314 break;; 3315 } 3316 3317 // received random value 3318 reverse_128(&packet[1], setup->sm_peer_random); 3319 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3320 break; 3321 #endif 3322 3323 #ifdef ENABLE_LE_PERIPHERAL 3324 // Responder 3325 case SM_RESPONDER_IDLE: 3326 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3327 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3328 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3329 sm_pdu_received_in_wrong_state(sm_conn); 3330 break;; 3331 } 3332 3333 // store pairing request 3334 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3335 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3336 break; 3337 #endif 3338 3339 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3340 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3341 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3342 sm_pdu_received_in_wrong_state(sm_conn); 3343 break; 3344 } 3345 3346 // store public key for DH Key calculation 3347 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3348 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3349 3350 // validate public key 3351 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3352 if (err){ 3353 log_error("sm: peer public key invalid %x", err); 3354 // uses "unspecified reason", there is no "public key invalid" error code 3355 sm_pdu_received_in_wrong_state(sm_conn); 3356 break; 3357 } 3358 3359 // start calculating dhkey 3360 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3361 3362 3363 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3364 if (IS_RESPONDER(sm_conn->sm_role)){ 3365 // responder 3366 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3367 } else { 3368 // initiator 3369 // stk generation method 3370 // passkey entry: notify app to show passkey or to request passkey 3371 switch (setup->sm_stk_generation_method){ 3372 case JUST_WORKS: 3373 case NUMERIC_COMPARISON: 3374 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3375 break; 3376 case PK_RESP_INPUT: 3377 sm_sc_start_calculating_local_confirm(sm_conn); 3378 break; 3379 case PK_INIT_INPUT: 3380 case PK_BOTH_INPUT: 3381 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3382 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3383 break; 3384 } 3385 sm_sc_start_calculating_local_confirm(sm_conn); 3386 break; 3387 case OOB: 3388 // generate Nx 3389 log_info("Generate Na"); 3390 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3391 break; 3392 } 3393 } 3394 break; 3395 3396 case SM_SC_W4_CONFIRMATION: 3397 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3398 sm_pdu_received_in_wrong_state(sm_conn); 3399 break; 3400 } 3401 // received confirm value 3402 reverse_128(&packet[1], setup->sm_peer_confirm); 3403 3404 #ifdef ENABLE_TESTING_SUPPORT 3405 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3406 log_info("testing_support: reset confirm value"); 3407 memset(setup->sm_peer_confirm, 0, 16); 3408 } 3409 #endif 3410 if (IS_RESPONDER(sm_conn->sm_role)){ 3411 // responder 3412 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3413 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3414 // still waiting for passkey 3415 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3416 break; 3417 } 3418 } 3419 sm_sc_start_calculating_local_confirm(sm_conn); 3420 } else { 3421 // initiator 3422 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3423 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3424 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3425 } else { 3426 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3427 } 3428 } 3429 break; 3430 3431 case SM_SC_W4_PAIRING_RANDOM: 3432 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3433 sm_pdu_received_in_wrong_state(sm_conn); 3434 break; 3435 } 3436 3437 // received random value 3438 reverse_128(&packet[1], setup->sm_peer_nonce); 3439 3440 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3441 // only check for JUST WORK/NC in initiator role OR passkey entry 3442 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3443 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3444 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3445 break; 3446 } 3447 3448 // OOB 3449 if (setup->sm_stk_generation_method == OOB){ 3450 3451 // setup local random, set to zero if remote did not receive our data 3452 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3453 if (IS_RESPONDER(sm_conn->sm_role)){ 3454 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3455 log_info("Reset rb as A does not have OOB data"); 3456 memset(setup->sm_rb, 0, 16); 3457 } else { 3458 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3459 log_info("Use stored rb"); 3460 log_info_hexdump(setup->sm_rb, 16); 3461 } 3462 } else { 3463 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3464 log_info("Reset ra as B does not have OOB data"); 3465 memset(setup->sm_ra, 0, 16); 3466 } else { 3467 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3468 log_info("Use stored ra"); 3469 log_info_hexdump(setup->sm_ra, 16); 3470 } 3471 } 3472 3473 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3474 if (setup->sm_have_oob_data){ 3475 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3476 break; 3477 } 3478 } 3479 3480 // TODO: we only get here for Responder role with JW/NC 3481 sm_sc_state_after_receiving_random(sm_conn); 3482 break; 3483 3484 case SM_SC_W2_CALCULATE_G2: 3485 case SM_SC_W4_CALCULATE_G2: 3486 case SM_SC_W4_CALCULATE_DHKEY: 3487 case SM_SC_W2_CALCULATE_F5_SALT: 3488 case SM_SC_W4_CALCULATE_F5_SALT: 3489 case SM_SC_W2_CALCULATE_F5_MACKEY: 3490 case SM_SC_W4_CALCULATE_F5_MACKEY: 3491 case SM_SC_W2_CALCULATE_F5_LTK: 3492 case SM_SC_W4_CALCULATE_F5_LTK: 3493 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3494 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3495 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3496 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3497 sm_pdu_received_in_wrong_state(sm_conn); 3498 break; 3499 } 3500 // store DHKey Check 3501 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3502 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3503 3504 // have we been only waiting for dhkey check command? 3505 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3506 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3507 } 3508 break; 3509 #endif 3510 3511 #ifdef ENABLE_LE_PERIPHERAL 3512 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3513 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3514 sm_pdu_received_in_wrong_state(sm_conn); 3515 break; 3516 } 3517 3518 // received confirm value 3519 reverse_128(&packet[1], setup->sm_peer_confirm); 3520 3521 #ifdef ENABLE_TESTING_SUPPORT 3522 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3523 log_info("testing_support: reset confirm value"); 3524 memset(setup->sm_peer_confirm, 0, 16); 3525 } 3526 #endif 3527 // notify client to hide shown passkey 3528 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3529 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3530 } 3531 3532 // handle user cancel pairing? 3533 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3534 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3535 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3536 break; 3537 } 3538 3539 // wait for user action? 3540 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3541 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3542 break; 3543 } 3544 3545 // calculate and send local_confirm 3546 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3547 break; 3548 3549 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3550 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3551 sm_pdu_received_in_wrong_state(sm_conn); 3552 break;; 3553 } 3554 3555 // received random value 3556 reverse_128(&packet[1], setup->sm_peer_random); 3557 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3558 break; 3559 #endif 3560 3561 case SM_PH3_RECEIVE_KEYS: 3562 switch(sm_pdu_code){ 3563 case SM_CODE_ENCRYPTION_INFORMATION: 3564 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3565 reverse_128(&packet[1], setup->sm_peer_ltk); 3566 break; 3567 3568 case SM_CODE_MASTER_IDENTIFICATION: 3569 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3570 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3571 reverse_64(&packet[3], setup->sm_peer_rand); 3572 break; 3573 3574 case SM_CODE_IDENTITY_INFORMATION: 3575 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3576 reverse_128(&packet[1], setup->sm_peer_irk); 3577 break; 3578 3579 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3580 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3581 setup->sm_peer_addr_type = packet[1]; 3582 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3583 break; 3584 3585 case SM_CODE_SIGNING_INFORMATION: 3586 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3587 reverse_128(&packet[1], setup->sm_peer_csrk); 3588 break; 3589 default: 3590 // Unexpected PDU 3591 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3592 break; 3593 } 3594 // done with key distribution? 3595 if (sm_key_distribution_all_received(sm_conn)){ 3596 3597 sm_key_distribution_handle_all_received(sm_conn); 3598 3599 if (IS_RESPONDER(sm_conn->sm_role)){ 3600 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3601 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3602 } else { 3603 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3604 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3605 sm_done_for_handle(sm_conn->sm_handle); 3606 } 3607 } else { 3608 if (setup->sm_use_secure_connections){ 3609 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3610 } else { 3611 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3612 } 3613 } 3614 } 3615 break; 3616 default: 3617 // Unexpected PDU 3618 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3619 break; 3620 } 3621 3622 // try to send preparared packet 3623 sm_run(); 3624 } 3625 3626 // Security Manager Client API 3627 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3628 sm_get_oob_data = get_oob_data_callback; 3629 } 3630 3631 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)){ 3632 sm_get_sc_oob_data = get_sc_oob_data_callback; 3633 } 3634 3635 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3636 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3637 } 3638 3639 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3640 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3641 } 3642 3643 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3644 sm_min_encryption_key_size = min_size; 3645 sm_max_encryption_key_size = max_size; 3646 } 3647 3648 void sm_set_authentication_requirements(uint8_t auth_req){ 3649 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3650 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3651 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3652 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3653 } 3654 #endif 3655 sm_auth_req = auth_req; 3656 } 3657 3658 void sm_set_io_capabilities(io_capability_t io_capability){ 3659 sm_io_capabilities = io_capability; 3660 } 3661 3662 #ifdef ENABLE_LE_PERIPHERAL 3663 void sm_set_request_security(int enable){ 3664 sm_slave_request_security = enable; 3665 } 3666 #endif 3667 3668 void sm_set_er(sm_key_t er){ 3669 memcpy(sm_persistent_er, er, 16); 3670 } 3671 3672 void sm_set_ir(sm_key_t ir){ 3673 memcpy(sm_persistent_ir, ir, 16); 3674 } 3675 3676 // Testing support only 3677 void sm_test_set_irk(sm_key_t irk){ 3678 memcpy(sm_persistent_irk, irk, 16); 3679 sm_persistent_irk_ready = 1; 3680 } 3681 3682 void sm_test_use_fixed_local_csrk(void){ 3683 test_use_fixed_local_csrk = 1; 3684 } 3685 3686 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3687 static void sm_ec_generated(void * arg){ 3688 UNUSED(arg); 3689 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3690 } 3691 #endif 3692 3693 #ifdef ENABLE_TESTING_SUPPORT 3694 void sm_test_set_pairing_failure(int reason){ 3695 test_pairing_failure = reason; 3696 } 3697 #endif 3698 3699 void sm_init(void){ 3700 // set some (BTstack default) ER and IR 3701 int i; 3702 sm_key_t er; 3703 sm_key_t ir; 3704 for (i=0;i<16;i++){ 3705 er[i] = 0x30 + i; 3706 ir[i] = 0x90 + i; 3707 } 3708 sm_set_er(er); 3709 sm_set_ir(ir); 3710 // defaults 3711 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3712 | SM_STK_GENERATION_METHOD_OOB 3713 | SM_STK_GENERATION_METHOD_PASSKEY 3714 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3715 3716 sm_max_encryption_key_size = 16; 3717 sm_min_encryption_key_size = 7; 3718 3719 sm_fixed_passkey_in_display_role = 0xffffffff; 3720 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3721 3722 #ifdef USE_CMAC_ENGINE 3723 sm_cmac_active = 0; 3724 #endif 3725 dkg_state = DKG_W4_WORKING; 3726 rau_state = RAU_W4_WORKING; 3727 sm_aes128_state = SM_AES128_IDLE; 3728 sm_address_resolution_test = -1; // no private address to resolve yet 3729 sm_address_resolution_ah_calculation_active = 0; 3730 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3731 sm_address_resolution_general_queue = NULL; 3732 3733 gap_random_adress_update_period = 15 * 60 * 1000L; 3734 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3735 3736 test_use_fixed_local_csrk = 0; 3737 3738 // register for HCI Events from HCI 3739 hci_event_callback_registration.callback = &sm_event_packet_handler; 3740 hci_add_event_handler(&hci_event_callback_registration); 3741 3742 // 3743 btstack_crypto_init(); 3744 3745 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3746 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3747 3748 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3749 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3750 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3751 #endif 3752 } 3753 3754 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3755 sm_fixed_passkey_in_display_role = passkey; 3756 } 3757 3758 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3759 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3760 } 3761 3762 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3763 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3764 if (!hci_con) return NULL; 3765 return &hci_con->sm_connection; 3766 } 3767 3768 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3769 switch (sm_conn->sm_engine_state){ 3770 case SM_GENERAL_IDLE: 3771 case SM_RESPONDER_IDLE: 3772 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3773 sm_run(); 3774 break; 3775 default: 3776 break; 3777 } 3778 } 3779 3780 /** 3781 * @brief Trigger Security Request 3782 */ 3783 void sm_send_security_request(hci_con_handle_t con_handle){ 3784 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3785 if (!sm_conn) return; 3786 sm_send_security_request_for_connection(sm_conn); 3787 } 3788 3789 // request pairing 3790 void sm_request_pairing(hci_con_handle_t con_handle){ 3791 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3792 if (!sm_conn) return; // wrong connection 3793 3794 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3795 if (IS_RESPONDER(sm_conn->sm_role)){ 3796 sm_send_security_request_for_connection(sm_conn); 3797 } else { 3798 // used as a trigger to start central/master/initiator security procedures 3799 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3800 switch (sm_conn->sm_irk_lookup_state){ 3801 case IRK_LOOKUP_SUCCEEDED: 3802 case IRK_LOOKUP_FAILED: 3803 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3804 break; 3805 default: 3806 log_info("irk lookup pending"); 3807 sm_conn->sm_pairing_requested = 1; 3808 break; 3809 } 3810 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3811 sm_conn->sm_pairing_requested = 1; 3812 } 3813 } 3814 sm_run(); 3815 } 3816 3817 // called by client app on authorization request 3818 void sm_authorization_decline(hci_con_handle_t con_handle){ 3819 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3820 if (!sm_conn) return; // wrong connection 3821 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3822 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3823 } 3824 3825 void sm_authorization_grant(hci_con_handle_t con_handle){ 3826 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3827 if (!sm_conn) return; // wrong connection 3828 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3829 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3830 } 3831 3832 // GAP Bonding API 3833 3834 void sm_bonding_decline(hci_con_handle_t con_handle){ 3835 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3836 if (!sm_conn) return; // wrong connection 3837 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3838 log_info("decline, state %u", sm_conn->sm_engine_state); 3839 switch(sm_conn->sm_engine_state){ 3840 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3841 case SM_SC_W4_USER_RESPONSE: 3842 case SM_SC_W4_CONFIRMATION: 3843 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3844 #endif 3845 case SM_PH1_W4_USER_RESPONSE: 3846 switch (setup->sm_stk_generation_method){ 3847 case PK_RESP_INPUT: 3848 case PK_INIT_INPUT: 3849 case PK_BOTH_INPUT: 3850 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3851 break; 3852 case NUMERIC_COMPARISON: 3853 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3854 break; 3855 case JUST_WORKS: 3856 case OOB: 3857 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3858 break; 3859 } 3860 break; 3861 default: 3862 break; 3863 } 3864 sm_run(); 3865 } 3866 3867 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3868 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3869 if (!sm_conn) return; // wrong connection 3870 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3871 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3872 if (setup->sm_use_secure_connections){ 3873 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3874 } else { 3875 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3876 } 3877 } 3878 3879 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3880 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3881 sm_sc_prepare_dhkey_check(sm_conn); 3882 } 3883 #endif 3884 3885 sm_run(); 3886 } 3887 3888 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3889 // for now, it's the same 3890 sm_just_works_confirm(con_handle); 3891 } 3892 3893 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3894 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3895 if (!sm_conn) return; // wrong connection 3896 sm_reset_tk(); 3897 big_endian_store_32(setup->sm_tk, 12, passkey); 3898 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3899 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3900 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3901 } 3902 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3903 memcpy(setup->sm_ra, setup->sm_tk, 16); 3904 memcpy(setup->sm_rb, setup->sm_tk, 16); 3905 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3906 sm_sc_start_calculating_local_confirm(sm_conn); 3907 } 3908 #endif 3909 sm_run(); 3910 } 3911 3912 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3913 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3914 if (!sm_conn) return; // wrong connection 3915 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3916 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3917 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3918 switch (action){ 3919 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3920 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3921 flags |= (1 << action); 3922 break; 3923 case SM_KEYPRESS_PASSKEY_CLEARED: 3924 // clear counter, keypress & erased flags + set passkey cleared 3925 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3926 break; 3927 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3928 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3929 // erase actions queued 3930 num_actions--; 3931 if (num_actions == 0){ 3932 // clear counter, keypress & erased flags 3933 flags &= 0x19; 3934 } 3935 break; 3936 } 3937 num_actions++; 3938 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3939 break; 3940 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3941 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3942 // enter actions queued 3943 num_actions--; 3944 if (num_actions == 0){ 3945 // clear counter, keypress & erased flags 3946 flags &= 0x19; 3947 } 3948 break; 3949 } 3950 num_actions++; 3951 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3952 break; 3953 default: 3954 break; 3955 } 3956 setup->sm_keypress_notification = (num_actions << 5) | flags; 3957 sm_run(); 3958 } 3959 3960 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3961 static void sm_handle_random_result_oob(void * arg){ 3962 UNUSED(arg); 3963 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3964 sm_run(); 3965 } 3966 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3967 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3968 sm_sc_oob_callback = callback; 3969 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3970 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3971 return 0; 3972 } 3973 #endif 3974 3975 /** 3976 * @brief Identify device in LE Device DB 3977 * @param handle 3978 * @returns index from le_device_db or -1 if not found/identified 3979 */ 3980 int sm_le_device_index(hci_con_handle_t con_handle ){ 3981 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3982 if (!sm_conn) return -1; 3983 return sm_conn->sm_le_db_index; 3984 } 3985 3986 static int gap_random_address_type_requires_updates(void){ 3987 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3988 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3989 return 1; 3990 } 3991 3992 static uint8_t own_address_type(void){ 3993 switch (gap_random_adress_type){ 3994 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3995 return BD_ADDR_TYPE_LE_PUBLIC; 3996 default: 3997 return BD_ADDR_TYPE_LE_RANDOM; 3998 } 3999 } 4000 4001 // GAP LE API 4002 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4003 gap_random_address_update_stop(); 4004 gap_random_adress_type = random_address_type; 4005 hci_le_set_own_address_type(own_address_type()); 4006 if (!gap_random_address_type_requires_updates()) return; 4007 gap_random_address_update_start(); 4008 gap_random_address_trigger(); 4009 } 4010 4011 gap_random_address_type_t gap_random_address_get_mode(void){ 4012 return gap_random_adress_type; 4013 } 4014 4015 void gap_random_address_set_update_period(int period_ms){ 4016 gap_random_adress_update_period = period_ms; 4017 if (!gap_random_address_type_requires_updates()) return; 4018 gap_random_address_update_stop(); 4019 gap_random_address_update_start(); 4020 } 4021 4022 void gap_random_address_set(bd_addr_t addr){ 4023 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4024 memcpy(sm_random_address, addr, 6); 4025 if (rau_state == RAU_W4_WORKING) return; 4026 rau_state = RAU_SET_ADDRESS; 4027 sm_run(); 4028 } 4029 4030 #ifdef ENABLE_LE_PERIPHERAL 4031 /* 4032 * @brief Set Advertisement Paramters 4033 * @param adv_int_min 4034 * @param adv_int_max 4035 * @param adv_type 4036 * @param direct_address_type 4037 * @param direct_address 4038 * @param channel_map 4039 * @param filter_policy 4040 * 4041 * @note own_address_type is used from gap_random_address_set_mode 4042 */ 4043 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4044 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4045 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4046 direct_address_typ, direct_address, channel_map, filter_policy); 4047 } 4048 #endif 4049 4050 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4051 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4052 // wrong connection 4053 if (!sm_conn) return 0; 4054 // already encrypted 4055 if (sm_conn->sm_connection_encrypted) return 0; 4056 // only central can re-encrypt 4057 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4058 // irk status? 4059 switch(sm_conn->sm_irk_lookup_state){ 4060 case IRK_LOOKUP_FAILED: 4061 // done, cannot setup encryption 4062 return 0; 4063 case IRK_LOOKUP_SUCCEEDED: 4064 break; 4065 default: 4066 // IR Lookup pending 4067 return 1; 4068 } 4069 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4070 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4071 } 4072