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; 1208 le_device_db_info(i, &address_type, address, irk); 1209 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1210 log_info("sm: device found for IRK, updating"); 1211 le_db_index = i; 1212 break; 1213 } 1214 } 1215 } 1216 1217 // if not found, lookup via public address if possible 1218 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1219 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1220 int i; 1221 for (i=0; i < le_device_db_max_count(); i++){ 1222 bd_addr_t address; 1223 int address_type; 1224 le_device_db_info(i, &address_type, address, NULL); 1225 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1226 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1227 log_info("sm: device found for public address, updating"); 1228 le_db_index = i; 1229 break; 1230 } 1231 } 1232 } 1233 1234 // if not found, add to db 1235 if (le_db_index < 0) { 1236 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1237 } 1238 1239 if (le_db_index >= 0){ 1240 1241 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1242 1243 #ifdef ENABLE_LE_SIGNED_WRITE 1244 // store local CSRK 1245 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1246 log_info("sm: store local CSRK"); 1247 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1248 le_device_db_local_counter_set(le_db_index, 0); 1249 } 1250 1251 // store remote CSRK 1252 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1253 log_info("sm: store remote CSRK"); 1254 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1255 le_device_db_remote_counter_set(le_db_index, 0); 1256 } 1257 #endif 1258 // store encryption information for secure connections: LTK generated by ECDH 1259 if (setup->sm_use_secure_connections){ 1260 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1261 uint8_t zero_rand[8]; 1262 memset(zero_rand, 0, 8); 1263 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1264 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1265 } 1266 1267 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1268 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1269 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1270 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1271 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1272 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1273 1274 } 1275 } 1276 } else { 1277 log_info("Ignoring received keys, bonding not enabled"); 1278 } 1279 1280 // keep le_db_index 1281 sm_conn->sm_le_db_index = le_db_index; 1282 } 1283 1284 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1285 setup->sm_pairing_failed_reason = reason; 1286 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1287 } 1288 1289 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1290 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1291 } 1292 1293 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1294 1295 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1296 static int sm_passkey_used(stk_generation_method_t method); 1297 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1298 1299 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1300 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1301 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1302 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1303 } else { 1304 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1305 } 1306 } 1307 1308 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1309 if (IS_RESPONDER(sm_conn->sm_role)){ 1310 // Responder 1311 if (setup->sm_stk_generation_method == OOB){ 1312 // generate Nb 1313 log_info("Generate Nb"); 1314 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1315 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1316 } else { 1317 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1318 } 1319 } else { 1320 // Initiator role 1321 switch (setup->sm_stk_generation_method){ 1322 case JUST_WORKS: 1323 sm_sc_prepare_dhkey_check(sm_conn); 1324 break; 1325 1326 case NUMERIC_COMPARISON: 1327 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1328 break; 1329 case PK_INIT_INPUT: 1330 case PK_RESP_INPUT: 1331 case PK_BOTH_INPUT: 1332 if (setup->sm_passkey_bit < 20) { 1333 sm_sc_start_calculating_local_confirm(sm_conn); 1334 } else { 1335 sm_sc_prepare_dhkey_check(sm_conn); 1336 } 1337 break; 1338 case OOB: 1339 sm_sc_prepare_dhkey_check(sm_conn); 1340 break; 1341 } 1342 } 1343 } 1344 1345 static void sm_sc_cmac_done(uint8_t * hash){ 1346 log_info("sm_sc_cmac_done: "); 1347 log_info_hexdump(hash, 16); 1348 1349 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1350 sm_sc_oob_state = SM_SC_OOB_IDLE; 1351 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1352 return; 1353 } 1354 1355 sm_connection_t * sm_conn = sm_cmac_connection; 1356 sm_cmac_connection = NULL; 1357 #ifdef ENABLE_CLASSIC 1358 link_key_type_t link_key_type; 1359 #endif 1360 1361 switch (sm_conn->sm_engine_state){ 1362 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1363 memcpy(setup->sm_local_confirm, hash, 16); 1364 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1365 break; 1366 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1367 // check 1368 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1369 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1370 break; 1371 } 1372 sm_sc_state_after_receiving_random(sm_conn); 1373 break; 1374 case SM_SC_W4_CALCULATE_G2: { 1375 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1376 big_endian_store_32(setup->sm_tk, 12, vab); 1377 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1378 sm_trigger_user_response(sm_conn); 1379 break; 1380 } 1381 case SM_SC_W4_CALCULATE_F5_SALT: 1382 memcpy(setup->sm_t, hash, 16); 1383 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1384 break; 1385 case SM_SC_W4_CALCULATE_F5_MACKEY: 1386 memcpy(setup->sm_mackey, hash, 16); 1387 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1388 break; 1389 case SM_SC_W4_CALCULATE_F5_LTK: 1390 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1391 // Errata Service Release to the Bluetooth Specification: ESR09 1392 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1393 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1394 memcpy(setup->sm_ltk, hash, 16); 1395 memcpy(setup->sm_local_ltk, hash, 16); 1396 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1397 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1398 break; 1399 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1400 memcpy(setup->sm_local_dhkey_check, hash, 16); 1401 if (IS_RESPONDER(sm_conn->sm_role)){ 1402 // responder 1403 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1404 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1405 } else { 1406 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1407 } 1408 } else { 1409 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1410 } 1411 break; 1412 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1413 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1414 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1415 break; 1416 } 1417 if (IS_RESPONDER(sm_conn->sm_role)){ 1418 // responder 1419 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1420 } else { 1421 // initiator 1422 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1423 } 1424 break; 1425 case SM_SC_W4_CALCULATE_H6_ILK: 1426 memcpy(setup->sm_t, hash, 16); 1427 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1428 break; 1429 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1430 #ifdef ENABLE_CLASSIC 1431 reverse_128(hash, setup->sm_t); 1432 link_key_type = sm_conn->sm_connection_authenticated ? 1433 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1434 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1435 if (IS_RESPONDER(sm_conn->sm_role)){ 1436 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1437 } else { 1438 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1439 } 1440 #endif 1441 if (IS_RESPONDER(sm_conn->sm_role)){ 1442 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1443 } else { 1444 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1445 } 1446 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1447 sm_done_for_handle(sm_conn->sm_handle); 1448 break; 1449 default: 1450 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1451 break; 1452 } 1453 sm_run(); 1454 } 1455 1456 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){ 1457 const uint16_t message_len = 65; 1458 sm_cmac_connection = sm_conn; 1459 memcpy(sm_cmac_sc_buffer, u, 32); 1460 memcpy(sm_cmac_sc_buffer+32, v, 32); 1461 sm_cmac_sc_buffer[64] = z; 1462 log_info("f4 key"); 1463 log_info_hexdump(x, 16); 1464 log_info("f4 message"); 1465 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1466 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1467 } 1468 1469 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1470 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1471 static const uint8_t f5_length[] = { 0x01, 0x00}; 1472 1473 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1474 log_info("f5_calculate_salt"); 1475 // calculate salt for f5 1476 const uint16_t message_len = 32; 1477 sm_cmac_connection = sm_conn; 1478 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1479 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1480 } 1481 1482 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){ 1483 const uint16_t message_len = 53; 1484 sm_cmac_connection = sm_conn; 1485 1486 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1487 sm_cmac_sc_buffer[0] = 0; 1488 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1489 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1490 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1491 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1492 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1493 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1494 log_info("f5 key"); 1495 log_info_hexdump(t, 16); 1496 log_info("f5 message for MacKey"); 1497 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1498 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1499 } 1500 1501 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1502 sm_key56_t bd_addr_master, bd_addr_slave; 1503 bd_addr_master[0] = setup->sm_m_addr_type; 1504 bd_addr_slave[0] = setup->sm_s_addr_type; 1505 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1506 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1507 if (IS_RESPONDER(sm_conn->sm_role)){ 1508 // responder 1509 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1510 } else { 1511 // initiator 1512 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1513 } 1514 } 1515 1516 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1517 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1518 const uint16_t message_len = 53; 1519 sm_cmac_connection = sm_conn; 1520 sm_cmac_sc_buffer[0] = 1; 1521 // 1..52 setup before 1522 log_info("f5 key"); 1523 log_info_hexdump(t, 16); 1524 log_info("f5 message for LTK"); 1525 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1526 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1527 } 1528 1529 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1530 f5_ltk(sm_conn, setup->sm_t); 1531 } 1532 1533 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){ 1534 const uint16_t message_len = 65; 1535 sm_cmac_connection = sm_conn; 1536 memcpy(sm_cmac_sc_buffer, n1, 16); 1537 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1538 memcpy(sm_cmac_sc_buffer+32, r, 16); 1539 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1540 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1541 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1542 log_info("f6 key"); 1543 log_info_hexdump(w, 16); 1544 log_info("f6 message"); 1545 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1546 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1547 } 1548 1549 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1550 // - U is 256 bits 1551 // - V is 256 bits 1552 // - X is 128 bits 1553 // - Y is 128 bits 1554 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){ 1555 const uint16_t message_len = 80; 1556 sm_cmac_connection = sm_conn; 1557 memcpy(sm_cmac_sc_buffer, u, 32); 1558 memcpy(sm_cmac_sc_buffer+32, v, 32); 1559 memcpy(sm_cmac_sc_buffer+64, y, 16); 1560 log_info("g2 key"); 1561 log_info_hexdump(x, 16); 1562 log_info("g2 message"); 1563 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1564 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1565 } 1566 1567 static void g2_calculate(sm_connection_t * sm_conn) { 1568 // calc Va if numeric comparison 1569 if (IS_RESPONDER(sm_conn->sm_role)){ 1570 // responder 1571 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1572 } else { 1573 // initiator 1574 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1575 } 1576 } 1577 1578 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1579 uint8_t z = 0; 1580 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1581 // some form of passkey 1582 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1583 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1584 setup->sm_passkey_bit++; 1585 } 1586 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1587 } 1588 1589 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1590 // OOB 1591 if (setup->sm_stk_generation_method == OOB){ 1592 if (IS_RESPONDER(sm_conn->sm_role)){ 1593 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1594 } else { 1595 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1596 } 1597 return; 1598 } 1599 1600 uint8_t z = 0; 1601 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1602 // some form of passkey 1603 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1604 // sm_passkey_bit was increased before sending confirm value 1605 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1606 } 1607 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1608 } 1609 1610 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1611 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1612 1613 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1614 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1615 return; 1616 } else { 1617 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1618 } 1619 } 1620 1621 static void sm_sc_dhkey_calculated(void * arg){ 1622 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1623 log_info("dhkey"); 1624 log_info_hexdump(&setup->sm_dhkey[0], 32); 1625 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1626 // trigger next step 1627 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1628 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1629 } 1630 sm_run(); 1631 } 1632 1633 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1634 // calculate DHKCheck 1635 sm_key56_t bd_addr_master, bd_addr_slave; 1636 bd_addr_master[0] = setup->sm_m_addr_type; 1637 bd_addr_slave[0] = setup->sm_s_addr_type; 1638 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1639 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1640 uint8_t iocap_a[3]; 1641 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1642 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1643 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1644 uint8_t iocap_b[3]; 1645 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1646 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1647 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1648 if (IS_RESPONDER(sm_conn->sm_role)){ 1649 // responder 1650 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1651 } else { 1652 // initiator 1653 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); 1654 } 1655 } 1656 1657 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1658 // validate E = f6() 1659 sm_key56_t bd_addr_master, bd_addr_slave; 1660 bd_addr_master[0] = setup->sm_m_addr_type; 1661 bd_addr_slave[0] = setup->sm_s_addr_type; 1662 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1663 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1664 1665 uint8_t iocap_a[3]; 1666 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1667 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1668 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1669 uint8_t iocap_b[3]; 1670 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1671 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1672 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1673 if (IS_RESPONDER(sm_conn->sm_role)){ 1674 // responder 1675 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); 1676 } else { 1677 // initiator 1678 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); 1679 } 1680 } 1681 1682 1683 // 1684 // Link Key Conversion Function h6 1685 // 1686 // h6(W, keyID) = AES-CMACW(keyID) 1687 // - W is 128 bits 1688 // - keyID is 32 bits 1689 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1690 const uint16_t message_len = 4; 1691 sm_cmac_connection = sm_conn; 1692 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1693 log_info("h6 key"); 1694 log_info_hexdump(w, 16); 1695 log_info("h6 message"); 1696 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1697 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1698 } 1699 1700 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1701 // Errata Service Release to the Bluetooth Specification: ESR09 1702 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1703 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1704 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1705 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1706 } 1707 1708 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1709 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1710 } 1711 1712 #endif 1713 1714 // key management legacy connections: 1715 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1716 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1717 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1718 // - responder reconnects: responder uses LTK receveived from master 1719 1720 // key management secure connections: 1721 // - both devices store same LTK from ECDH key exchange. 1722 1723 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1724 static void sm_load_security_info(sm_connection_t * sm_connection){ 1725 int encryption_key_size; 1726 int authenticated; 1727 int authorized; 1728 1729 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1730 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1731 &encryption_key_size, &authenticated, &authorized); 1732 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1733 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1734 sm_connection->sm_connection_authenticated = authenticated; 1735 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1736 } 1737 #endif 1738 1739 #ifdef ENABLE_LE_PERIPHERAL 1740 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1741 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1742 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1743 // re-establish used key encryption size 1744 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1745 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1746 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1747 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1748 log_info("sm: received ltk request with key size %u, authenticated %u", 1749 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1750 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1751 sm_run(); 1752 } 1753 #endif 1754 1755 static void sm_run(void){ 1756 1757 btstack_linked_list_iterator_t it; 1758 1759 // assert that stack has already bootet 1760 if (hci_get_state() != HCI_STATE_WORKING) return; 1761 1762 // assert that we can send at least commands 1763 if (!hci_can_send_command_packet_now()) return; 1764 1765 // 1766 // non-connection related behaviour 1767 // 1768 1769 // distributed key generation 1770 switch (dkg_state){ 1771 case DKG_CALC_IRK: 1772 // already busy? 1773 if (sm_aes128_state == SM_AES128_IDLE) { 1774 log_info("DKG_CALC_IRK started"); 1775 // IRK = d1(IR, 1, 0) 1776 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1777 sm_aes128_state = SM_AES128_ACTIVE; 1778 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1779 return; 1780 } 1781 break; 1782 case DKG_CALC_DHK: 1783 // already busy? 1784 if (sm_aes128_state == SM_AES128_IDLE) { 1785 log_info("DKG_CALC_DHK started"); 1786 // DHK = d1(IR, 3, 0) 1787 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1788 sm_aes128_state = SM_AES128_ACTIVE; 1789 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1790 return; 1791 } 1792 break; 1793 default: 1794 break; 1795 } 1796 1797 // random address updates 1798 switch (rau_state){ 1799 case RAU_GET_ENC: 1800 // already busy? 1801 if (sm_aes128_state == SM_AES128_IDLE) { 1802 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1803 sm_aes128_state = SM_AES128_ACTIVE; 1804 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1805 return; 1806 } 1807 break; 1808 case RAU_SET_ADDRESS: 1809 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1810 rau_state = RAU_IDLE; 1811 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1812 return; 1813 default: 1814 break; 1815 } 1816 1817 // CSRK Lookup 1818 // -- if csrk lookup ready, find connection that require csrk lookup 1819 if (sm_address_resolution_idle()){ 1820 hci_connections_get_iterator(&it); 1821 while(btstack_linked_list_iterator_has_next(&it)){ 1822 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1823 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1824 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1825 // and start lookup 1826 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); 1827 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1828 break; 1829 } 1830 } 1831 } 1832 1833 // -- if csrk lookup ready, resolved addresses for received addresses 1834 if (sm_address_resolution_idle()) { 1835 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1836 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1837 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1838 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1839 btstack_memory_sm_lookup_entry_free(entry); 1840 } 1841 } 1842 1843 // -- Continue with CSRK device lookup by public or resolvable private address 1844 if (!sm_address_resolution_idle()){ 1845 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1846 while (sm_address_resolution_test < le_device_db_max_count()){ 1847 int addr_type; 1848 bd_addr_t addr; 1849 sm_key_t irk; 1850 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1851 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1852 1853 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1854 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1855 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1856 break; 1857 } 1858 1859 if (sm_address_resolution_addr_type == 0){ 1860 sm_address_resolution_test++; 1861 continue; 1862 } 1863 1864 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1865 1866 log_info("LE Device Lookup: calculate AH"); 1867 log_info_key("IRK", irk); 1868 1869 memcpy(sm_aes128_key, irk, 16); 1870 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1871 sm_address_resolution_ah_calculation_active = 1; 1872 sm_aes128_state = SM_AES128_ACTIVE; 1873 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1874 return; 1875 } 1876 1877 if (sm_address_resolution_test >= le_device_db_max_count()){ 1878 log_info("LE Device Lookup: not found"); 1879 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1880 } 1881 } 1882 1883 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1884 switch (sm_sc_oob_state){ 1885 case SM_SC_OOB_W2_CALC_CONFIRM: 1886 if (!sm_cmac_ready()) break; 1887 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1888 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1889 return; 1890 default: 1891 break; 1892 } 1893 #endif 1894 1895 // assert that we can send at least commands - cmd might have been sent by crypto engine 1896 if (!hci_can_send_command_packet_now()) return; 1897 1898 // handle basic actions that don't requires the full context 1899 hci_connections_get_iterator(&it); 1900 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1901 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1902 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1903 switch(sm_connection->sm_engine_state){ 1904 // responder side 1905 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1906 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1907 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1908 return; 1909 1910 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1911 case SM_SC_RECEIVED_LTK_REQUEST: 1912 switch (sm_connection->sm_irk_lookup_state){ 1913 case IRK_LOOKUP_FAILED: 1914 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1915 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1916 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1917 return; 1918 default: 1919 break; 1920 } 1921 break; 1922 #endif 1923 default: 1924 break; 1925 } 1926 } 1927 1928 // 1929 // active connection handling 1930 // -- use loop to handle next connection if lock on setup context is released 1931 1932 while (1) { 1933 1934 // Find connections that requires setup context and make active if no other is locked 1935 hci_connections_get_iterator(&it); 1936 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1937 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1938 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1939 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1940 int done = 1; 1941 int err; 1942 UNUSED(err); 1943 switch (sm_connection->sm_engine_state) { 1944 #ifdef ENABLE_LE_PERIPHERAL 1945 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1946 // send packet if possible, 1947 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1948 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1949 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1950 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1951 } else { 1952 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1953 } 1954 // don't lock sxetup context yet 1955 done = 0; 1956 break; 1957 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1958 sm_reset_setup(); 1959 sm_init_setup(sm_connection); 1960 // recover pairing request 1961 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1962 err = sm_stk_generation_init(sm_connection); 1963 1964 #ifdef ENABLE_TESTING_SUPPORT 1965 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1966 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1967 err = test_pairing_failure; 1968 } 1969 #endif 1970 if (err){ 1971 setup->sm_pairing_failed_reason = err; 1972 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1973 break; 1974 } 1975 sm_timeout_start(sm_connection); 1976 // generate random number first, if we need to show passkey 1977 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1978 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1979 break; 1980 } 1981 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1982 break; 1983 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1984 sm_reset_setup(); 1985 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1986 break; 1987 #endif 1988 #ifdef ENABLE_LE_CENTRAL 1989 case SM_INITIATOR_PH0_HAS_LTK: 1990 sm_reset_setup(); 1991 sm_load_security_info(sm_connection); 1992 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1993 break; 1994 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1995 sm_reset_setup(); 1996 sm_init_setup(sm_connection); 1997 sm_timeout_start(sm_connection); 1998 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1999 break; 2000 #endif 2001 2002 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2003 case SM_SC_RECEIVED_LTK_REQUEST: 2004 switch (sm_connection->sm_irk_lookup_state){ 2005 case IRK_LOOKUP_SUCCEEDED: 2006 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2007 // start using context by loading security info 2008 sm_reset_setup(); 2009 sm_load_security_info(sm_connection); 2010 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2011 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2012 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2013 break; 2014 } 2015 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2016 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2017 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2018 // don't lock setup context yet 2019 return; 2020 default: 2021 // just wait until IRK lookup is completed 2022 // don't lock setup context yet 2023 done = 0; 2024 break; 2025 } 2026 break; 2027 #endif 2028 default: 2029 done = 0; 2030 break; 2031 } 2032 if (done){ 2033 sm_active_connection_handle = sm_connection->sm_handle; 2034 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); 2035 } 2036 } 2037 2038 // 2039 // active connection handling 2040 // 2041 2042 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2043 2044 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2045 if (!connection) { 2046 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2047 return; 2048 } 2049 2050 // assert that we could send a SM PDU - not needed for all of the following 2051 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2052 log_info("cannot send now, requesting can send now event"); 2053 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2054 return; 2055 } 2056 2057 // send keypress notifications 2058 if (setup->sm_keypress_notification){ 2059 int i; 2060 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2061 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2062 uint8_t action = 0; 2063 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2064 if (flags & (1<<i)){ 2065 int clear_flag = 1; 2066 switch (i){ 2067 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2068 case SM_KEYPRESS_PASSKEY_CLEARED: 2069 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2070 default: 2071 break; 2072 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2073 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2074 num_actions--; 2075 clear_flag = num_actions == 0; 2076 break; 2077 } 2078 if (clear_flag){ 2079 flags &= ~(1<<i); 2080 } 2081 action = i; 2082 break; 2083 } 2084 } 2085 setup->sm_keypress_notification = (num_actions << 5) | flags; 2086 2087 // send keypress notification 2088 uint8_t buffer[2]; 2089 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2090 buffer[1] = action; 2091 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2092 2093 // try 2094 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2095 return; 2096 } 2097 2098 int key_distribution_flags; 2099 UNUSED(key_distribution_flags); 2100 2101 log_info("sm_run: state %u", connection->sm_engine_state); 2102 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2103 log_info("sm_run // cannot send"); 2104 } 2105 switch (connection->sm_engine_state){ 2106 2107 // general 2108 case SM_GENERAL_SEND_PAIRING_FAILED: { 2109 uint8_t buffer[2]; 2110 buffer[0] = SM_CODE_PAIRING_FAILED; 2111 buffer[1] = setup->sm_pairing_failed_reason; 2112 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2113 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2114 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2115 sm_done_for_handle(connection->sm_handle); 2116 break; 2117 } 2118 2119 // responding state 2120 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2121 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2122 if (!sm_cmac_ready()) break; 2123 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2124 sm_sc_calculate_local_confirm(connection); 2125 break; 2126 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2127 if (!sm_cmac_ready()) break; 2128 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2129 sm_sc_calculate_remote_confirm(connection); 2130 break; 2131 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2132 if (!sm_cmac_ready()) break; 2133 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2134 sm_sc_calculate_f6_for_dhkey_check(connection); 2135 break; 2136 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2137 if (!sm_cmac_ready()) break; 2138 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2139 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2140 break; 2141 case SM_SC_W2_CALCULATE_F5_SALT: 2142 if (!sm_cmac_ready()) break; 2143 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2144 f5_calculate_salt(connection); 2145 break; 2146 case SM_SC_W2_CALCULATE_F5_MACKEY: 2147 if (!sm_cmac_ready()) break; 2148 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2149 f5_calculate_mackey(connection); 2150 break; 2151 case SM_SC_W2_CALCULATE_F5_LTK: 2152 if (!sm_cmac_ready()) break; 2153 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2154 f5_calculate_ltk(connection); 2155 break; 2156 case SM_SC_W2_CALCULATE_G2: 2157 if (!sm_cmac_ready()) break; 2158 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2159 g2_calculate(connection); 2160 break; 2161 case SM_SC_W2_CALCULATE_H6_ILK: 2162 if (!sm_cmac_ready()) break; 2163 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2164 h6_calculate_ilk(connection); 2165 break; 2166 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2167 if (!sm_cmac_ready()) break; 2168 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2169 h6_calculate_br_edr_link_key(connection); 2170 break; 2171 #endif 2172 2173 #ifdef ENABLE_LE_CENTRAL 2174 // initiator side 2175 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2176 sm_key_t peer_ltk_flipped; 2177 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2178 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2179 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2180 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2181 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2182 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2183 return; 2184 } 2185 2186 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2187 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2188 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2189 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2190 sm_timeout_reset(connection); 2191 break; 2192 #endif 2193 2194 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2195 2196 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2197 int trigger_user_response = 0; 2198 2199 uint8_t buffer[65]; 2200 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2201 // 2202 reverse_256(&ec_q[0], &buffer[1]); 2203 reverse_256(&ec_q[32], &buffer[33]); 2204 2205 // stk generation method 2206 // passkey entry: notify app to show passkey or to request passkey 2207 switch (setup->sm_stk_generation_method){ 2208 case JUST_WORKS: 2209 case NUMERIC_COMPARISON: 2210 if (IS_RESPONDER(connection->sm_role)){ 2211 // responder 2212 sm_sc_start_calculating_local_confirm(connection); 2213 } else { 2214 // initiator 2215 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2216 } 2217 break; 2218 case PK_INIT_INPUT: 2219 case PK_RESP_INPUT: 2220 case PK_BOTH_INPUT: 2221 // use random TK for display 2222 memcpy(setup->sm_ra, setup->sm_tk, 16); 2223 memcpy(setup->sm_rb, setup->sm_tk, 16); 2224 setup->sm_passkey_bit = 0; 2225 2226 if (IS_RESPONDER(connection->sm_role)){ 2227 // responder 2228 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2229 } else { 2230 // initiator 2231 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2232 } 2233 trigger_user_response = 1; 2234 break; 2235 case OOB: 2236 if (IS_RESPONDER(connection->sm_role)){ 2237 // responder 2238 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2239 } else { 2240 // initiator 2241 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2242 } 2243 break; 2244 } 2245 2246 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2247 sm_timeout_reset(connection); 2248 2249 // trigger user response after sending pdu 2250 if (trigger_user_response){ 2251 sm_trigger_user_response(connection); 2252 } 2253 break; 2254 } 2255 case SM_SC_SEND_CONFIRMATION: { 2256 uint8_t buffer[17]; 2257 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2258 reverse_128(setup->sm_local_confirm, &buffer[1]); 2259 if (IS_RESPONDER(connection->sm_role)){ 2260 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2261 } else { 2262 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2263 } 2264 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2265 sm_timeout_reset(connection); 2266 break; 2267 } 2268 case SM_SC_SEND_PAIRING_RANDOM: { 2269 uint8_t buffer[17]; 2270 buffer[0] = SM_CODE_PAIRING_RANDOM; 2271 reverse_128(setup->sm_local_nonce, &buffer[1]); 2272 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2273 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2274 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2275 if (IS_RESPONDER(connection->sm_role)){ 2276 // responder 2277 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2278 } else { 2279 // initiator 2280 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2281 } 2282 } else { 2283 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2284 if (IS_RESPONDER(connection->sm_role)){ 2285 // responder 2286 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2287 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2288 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2289 } else { 2290 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2291 sm_sc_prepare_dhkey_check(connection); 2292 } 2293 } else { 2294 // initiator 2295 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2296 } 2297 } 2298 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2299 sm_timeout_reset(connection); 2300 break; 2301 } 2302 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2303 uint8_t buffer[17]; 2304 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2305 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2306 2307 if (IS_RESPONDER(connection->sm_role)){ 2308 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2309 } else { 2310 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2311 } 2312 2313 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2314 sm_timeout_reset(connection); 2315 break; 2316 } 2317 2318 #endif 2319 2320 #ifdef ENABLE_LE_PERIPHERAL 2321 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2322 // echo initiator for now 2323 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2324 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2325 2326 if (setup->sm_use_secure_connections){ 2327 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2328 } else { 2329 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2330 } 2331 2332 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); 2333 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); 2334 // update key distribution after ENC was dropped 2335 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2336 2337 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2338 sm_timeout_reset(connection); 2339 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2340 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2341 sm_trigger_user_response(connection); 2342 } 2343 return; 2344 #endif 2345 2346 case SM_PH2_SEND_PAIRING_RANDOM: { 2347 uint8_t buffer[17]; 2348 buffer[0] = SM_CODE_PAIRING_RANDOM; 2349 reverse_128(setup->sm_local_random, &buffer[1]); 2350 if (IS_RESPONDER(connection->sm_role)){ 2351 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2352 } else { 2353 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2354 } 2355 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2356 sm_timeout_reset(connection); 2357 break; 2358 } 2359 2360 case SM_PH2_C1_GET_ENC_A: 2361 // already busy? 2362 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2363 // calculate confirm using aes128 engine - step 1 2364 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); 2365 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2366 sm_aes128_state = SM_AES128_ACTIVE; 2367 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2368 break; 2369 2370 case SM_PH2_C1_GET_ENC_C: 2371 // already busy? 2372 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2373 // calculate m_confirm using aes128 engine - step 1 2374 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); 2375 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2376 sm_aes128_state = SM_AES128_ACTIVE; 2377 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2378 break; 2379 2380 case SM_PH2_CALC_STK: 2381 // already busy? 2382 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2383 // calculate STK 2384 if (IS_RESPONDER(connection->sm_role)){ 2385 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2386 } else { 2387 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2388 } 2389 connection->sm_engine_state = SM_PH2_W4_STK; 2390 sm_aes128_state = SM_AES128_ACTIVE; 2391 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2392 break; 2393 2394 case SM_PH3_Y_GET_ENC: 2395 // already busy? 2396 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2397 // PH3B2 - calculate Y from - enc 2398 // Y = dm(DHK, Rand) 2399 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2400 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2401 sm_aes128_state = SM_AES128_ACTIVE; 2402 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); 2403 break; 2404 2405 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2406 uint8_t buffer[17]; 2407 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2408 reverse_128(setup->sm_local_confirm, &buffer[1]); 2409 if (IS_RESPONDER(connection->sm_role)){ 2410 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2411 } else { 2412 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2413 } 2414 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2415 sm_timeout_reset(connection); 2416 return; 2417 } 2418 #ifdef ENABLE_LE_PERIPHERAL 2419 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2420 sm_key_t stk_flipped; 2421 reverse_128(setup->sm_ltk, stk_flipped); 2422 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2423 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2424 return; 2425 } 2426 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2427 sm_key_t ltk_flipped; 2428 reverse_128(setup->sm_ltk, ltk_flipped); 2429 connection->sm_engine_state = SM_RESPONDER_IDLE; 2430 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2431 sm_done_for_handle(connection->sm_handle); 2432 return; 2433 } 2434 case SM_RESPONDER_PH4_Y_GET_ENC: 2435 // already busy? 2436 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2437 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2438 // Y = dm(DHK, Rand) 2439 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2440 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2441 sm_aes128_state = SM_AES128_ACTIVE; 2442 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); 2443 return; 2444 #endif 2445 #ifdef ENABLE_LE_CENTRAL 2446 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2447 sm_key_t stk_flipped; 2448 reverse_128(setup->sm_ltk, stk_flipped); 2449 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2450 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2451 return; 2452 } 2453 #endif 2454 2455 case SM_PH3_DISTRIBUTE_KEYS: 2456 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2457 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2458 uint8_t buffer[17]; 2459 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2460 reverse_128(setup->sm_ltk, &buffer[1]); 2461 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2462 sm_timeout_reset(connection); 2463 return; 2464 } 2465 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2466 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2467 uint8_t buffer[11]; 2468 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2469 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2470 reverse_64(setup->sm_local_rand, &buffer[3]); 2471 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2472 sm_timeout_reset(connection); 2473 return; 2474 } 2475 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2476 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2477 uint8_t buffer[17]; 2478 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2479 reverse_128(sm_persistent_irk, &buffer[1]); 2480 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2481 sm_timeout_reset(connection); 2482 return; 2483 } 2484 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2485 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2486 bd_addr_t local_address; 2487 uint8_t buffer[8]; 2488 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2489 switch (gap_random_address_get_mode()){ 2490 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2491 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2492 // public or static random 2493 gap_le_get_own_address(&buffer[1], local_address); 2494 break; 2495 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2496 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2497 // fallback to public 2498 gap_local_bd_addr(local_address); 2499 buffer[1] = 0; 2500 break; 2501 } 2502 reverse_bd_addr(local_address, &buffer[2]); 2503 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2504 sm_timeout_reset(connection); 2505 return; 2506 } 2507 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2508 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2509 2510 // hack to reproduce test runs 2511 if (test_use_fixed_local_csrk){ 2512 memset(setup->sm_local_csrk, 0xcc, 16); 2513 } 2514 2515 uint8_t buffer[17]; 2516 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2517 reverse_128(setup->sm_local_csrk, &buffer[1]); 2518 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2519 sm_timeout_reset(connection); 2520 return; 2521 } 2522 2523 // keys are sent 2524 if (IS_RESPONDER(connection->sm_role)){ 2525 // slave -> receive master keys if any 2526 if (sm_key_distribution_all_received(connection)){ 2527 sm_key_distribution_handle_all_received(connection); 2528 connection->sm_engine_state = SM_RESPONDER_IDLE; 2529 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2530 sm_done_for_handle(connection->sm_handle); 2531 } else { 2532 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2533 } 2534 } else { 2535 // master -> all done 2536 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2537 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2538 sm_done_for_handle(connection->sm_handle); 2539 } 2540 break; 2541 2542 default: 2543 break; 2544 } 2545 2546 // check again if active connection was released 2547 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2548 } 2549 } 2550 2551 // sm_aes128_state stays active 2552 static void sm_handle_encryption_result_enc_a(void *arg){ 2553 sm_connection_t * connection = (sm_connection_t*) arg; 2554 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2555 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); 2556 } 2557 2558 static void sm_handle_encryption_result_enc_b(void *arg){ 2559 sm_connection_t * connection = (sm_connection_t*) arg; 2560 sm_aes128_state = SM_AES128_IDLE; 2561 log_info_key("c1!", setup->sm_local_confirm); 2562 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2563 sm_run(); 2564 } 2565 2566 // sm_aes128_state stays active 2567 static void sm_handle_encryption_result_enc_c(void *arg){ 2568 sm_connection_t * connection = (sm_connection_t*) arg; 2569 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2570 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); 2571 } 2572 2573 static void sm_handle_encryption_result_enc_d(void * arg){ 2574 sm_connection_t * connection = (sm_connection_t*) arg; 2575 sm_aes128_state = SM_AES128_IDLE; 2576 log_info_key("c1!", sm_aes128_ciphertext); 2577 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2578 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2579 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2580 sm_run(); 2581 return; 2582 } 2583 if (IS_RESPONDER(connection->sm_role)){ 2584 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2585 sm_run(); 2586 } else { 2587 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2588 sm_aes128_state = SM_AES128_ACTIVE; 2589 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2590 } 2591 } 2592 2593 static void sm_handle_encryption_result_enc_stk(void *arg){ 2594 sm_connection_t * connection = (sm_connection_t*) arg; 2595 sm_aes128_state = SM_AES128_IDLE; 2596 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2597 log_info_key("stk", setup->sm_ltk); 2598 if (IS_RESPONDER(connection->sm_role)){ 2599 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2600 } else { 2601 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2602 } 2603 sm_run(); 2604 } 2605 2606 // sm_aes128_state stays active 2607 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2608 sm_connection_t * connection = (sm_connection_t*) arg; 2609 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2610 log_info_hex16("y", setup->sm_local_y); 2611 // PH3B3 - calculate EDIV 2612 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2613 log_info_hex16("ediv", setup->sm_local_ediv); 2614 // PH3B4 - calculate LTK - enc 2615 // LTK = d1(ER, DIV, 0)) 2616 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2617 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); 2618 } 2619 2620 #ifdef ENABLE_LE_PERIPHERAL 2621 // sm_aes128_state stays active 2622 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2623 sm_connection_t * connection = (sm_connection_t*) arg; 2624 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2625 log_info_hex16("y", setup->sm_local_y); 2626 2627 // PH3B3 - calculate DIV 2628 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2629 log_info_hex16("ediv", setup->sm_local_ediv); 2630 // PH3B4 - calculate LTK - enc 2631 // LTK = d1(ER, DIV, 0)) 2632 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2633 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); 2634 } 2635 #endif 2636 2637 // sm_aes128_state stays active 2638 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2639 sm_connection_t * connection = (sm_connection_t*) arg; 2640 log_info_key("ltk", setup->sm_ltk); 2641 // calc CSRK next 2642 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2643 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); 2644 } 2645 2646 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2647 sm_connection_t * connection = (sm_connection_t*) arg; 2648 sm_aes128_state = SM_AES128_IDLE; 2649 log_info_key("csrk", setup->sm_local_csrk); 2650 if (setup->sm_key_distribution_send_set){ 2651 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2652 } else { 2653 // no keys to send, just continue 2654 if (IS_RESPONDER(connection->sm_role)){ 2655 // slave -> receive master keys 2656 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2657 } else { 2658 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2659 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2660 } else { 2661 // master -> all done 2662 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2663 sm_done_for_handle(connection->sm_handle); 2664 } 2665 } 2666 } 2667 sm_run(); 2668 } 2669 2670 #ifdef ENABLE_LE_PERIPHERAL 2671 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2672 sm_connection_t * connection = (sm_connection_t*) arg; 2673 sm_aes128_state = SM_AES128_IDLE; 2674 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2675 log_info_key("ltk", setup->sm_ltk); 2676 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2677 sm_run(); 2678 } 2679 #endif 2680 2681 static void sm_handle_encryption_result_address_resolution(void *arg){ 2682 UNUSED(arg); 2683 sm_aes128_state = SM_AES128_IDLE; 2684 sm_address_resolution_ah_calculation_active = 0; 2685 // compare calulated address against connecting device 2686 uint8_t * hash = &sm_aes128_ciphertext[13]; 2687 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2688 log_info("LE Device Lookup: matched resolvable private address"); 2689 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2690 sm_run(); 2691 return; 2692 } 2693 // no match, try next 2694 sm_address_resolution_test++; 2695 sm_run(); 2696 } 2697 2698 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2699 UNUSED(arg); 2700 sm_aes128_state = SM_AES128_IDLE; 2701 log_info_key("irk", sm_persistent_irk); 2702 dkg_state = DKG_CALC_DHK; 2703 sm_run(); 2704 } 2705 2706 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2707 UNUSED(arg); 2708 sm_aes128_state = SM_AES128_IDLE; 2709 log_info_key("dhk", sm_persistent_dhk); 2710 dkg_state = DKG_READY; 2711 // DKG calculation complete => SM Init Finished 2712 sm_run(); 2713 } 2714 2715 static void sm_handle_encryption_result_rau(void *arg){ 2716 UNUSED(arg); 2717 sm_aes128_state = SM_AES128_IDLE; 2718 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2719 rau_state = RAU_SET_ADDRESS; 2720 sm_run(); 2721 } 2722 2723 static void sm_handle_random_result_rau(void * arg){ 2724 UNUSED(arg); 2725 // non-resolvable vs. resolvable 2726 switch (gap_random_adress_type){ 2727 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2728 // resolvable: use random as prand and calc address hash 2729 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2730 sm_random_address[0] &= 0x3f; 2731 sm_random_address[0] |= 0x40; 2732 rau_state = RAU_GET_ENC; 2733 break; 2734 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2735 default: 2736 // "The two most significant bits of the address shall be equal to ‘0’"" 2737 sm_random_address[0] &= 0x3f; 2738 rau_state = RAU_SET_ADDRESS; 2739 break; 2740 } 2741 sm_run(); 2742 } 2743 2744 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2745 static void sm_handle_random_result_sc_get_random(void * arg){ 2746 sm_connection_t * connection = (sm_connection_t*) arg; 2747 2748 // OOB 2749 if (setup->sm_stk_generation_method == OOB){ 2750 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2751 sm_run(); 2752 return; 2753 } 2754 2755 // initiator & jw/nc -> send pairing random 2756 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2757 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2758 } else { 2759 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2760 } 2761 sm_run(); 2762 } 2763 #endif 2764 2765 static void sm_handle_random_result_ph2_random(void * arg){ 2766 sm_connection_t * connection = (sm_connection_t*) arg; 2767 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2768 sm_run(); 2769 } 2770 2771 static void sm_handle_random_result_ph2_tk(void * arg){ 2772 sm_connection_t * connection = (sm_connection_t*) arg; 2773 sm_reset_tk(); 2774 uint32_t tk; 2775 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2776 // map random to 0-999999 without speding much cycles on a modulus operation 2777 tk = little_endian_read_32(sm_random_data,0); 2778 tk = tk & 0xfffff; // 1048575 2779 if (tk >= 999999){ 2780 tk = tk - 999999; 2781 } 2782 } else { 2783 // override with pre-defined passkey 2784 tk = sm_fixed_passkey_in_display_role; 2785 } 2786 big_endian_store_32(setup->sm_tk, 12, tk); 2787 if (IS_RESPONDER(connection->sm_role)){ 2788 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2789 } else { 2790 if (setup->sm_use_secure_connections){ 2791 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2792 } else { 2793 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2794 sm_trigger_user_response(connection); 2795 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2796 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2797 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2798 } 2799 } 2800 } 2801 sm_run(); 2802 } 2803 2804 static void sm_handle_random_result_ph3_div(void * arg){ 2805 sm_connection_t * connection = (sm_connection_t*) arg; 2806 // use 16 bit from random value as div 2807 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2808 log_info_hex16("div", setup->sm_local_div); 2809 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2810 sm_run(); 2811 } 2812 2813 static void sm_handle_random_result_ph3_random(void * arg){ 2814 sm_connection_t * connection = (sm_connection_t*) arg; 2815 reverse_64(sm_random_data, setup->sm_local_rand); 2816 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2817 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2818 // no db for authenticated flag hack: store flag in bit 4 of LSB 2819 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2820 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2821 } 2822 2823 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2824 2825 UNUSED(channel); // ok: there is no channel 2826 UNUSED(size); // ok: fixed format HCI events 2827 2828 sm_connection_t * sm_conn; 2829 hci_con_handle_t con_handle; 2830 2831 switch (packet_type) { 2832 2833 case HCI_EVENT_PACKET: 2834 switch (hci_event_packet_get_type(packet)) { 2835 2836 case BTSTACK_EVENT_STATE: 2837 // bt stack activated, get started 2838 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2839 log_info("HCI Working!"); 2840 2841 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2842 2843 // trigger Random Address generation if requested before 2844 switch (gap_random_adress_type){ 2845 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2846 rau_state = RAU_IDLE; 2847 break; 2848 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2849 rau_state = RAU_SET_ADDRESS; 2850 break; 2851 default: 2852 rau_state = RAU_W4_RANDOM; 2853 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2854 break; 2855 } 2856 sm_run(); 2857 } 2858 break; 2859 2860 case HCI_EVENT_LE_META: 2861 switch (packet[2]) { 2862 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2863 2864 log_info("sm: connected"); 2865 2866 if (packet[3]) return; // connection failed 2867 2868 con_handle = little_endian_read_16(packet, 4); 2869 sm_conn = sm_get_connection_for_handle(con_handle); 2870 if (!sm_conn) break; 2871 2872 sm_conn->sm_handle = con_handle; 2873 sm_conn->sm_role = packet[6]; 2874 sm_conn->sm_peer_addr_type = packet[7]; 2875 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2876 2877 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2878 2879 // reset security properties 2880 sm_conn->sm_connection_encrypted = 0; 2881 sm_conn->sm_connection_authenticated = 0; 2882 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2883 sm_conn->sm_le_db_index = -1; 2884 2885 // prepare CSRK lookup (does not involve setup) 2886 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2887 2888 // just connected -> everything else happens in sm_run() 2889 if (IS_RESPONDER(sm_conn->sm_role)){ 2890 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2891 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2892 if (sm_slave_request_security) { 2893 // request security if requested by app 2894 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2895 } else { 2896 // otherwise, wait for pairing request 2897 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2898 } 2899 } 2900 break; 2901 } else { 2902 // master 2903 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2904 } 2905 break; 2906 2907 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2908 con_handle = little_endian_read_16(packet, 3); 2909 sm_conn = sm_get_connection_for_handle(con_handle); 2910 if (!sm_conn) break; 2911 2912 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2913 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2914 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2915 break; 2916 } 2917 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2918 // PH2 SEND LTK as we need to exchange keys in PH3 2919 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2920 break; 2921 } 2922 2923 // store rand and ediv 2924 reverse_64(&packet[5], sm_conn->sm_local_rand); 2925 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2926 2927 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2928 // potentially stored LTK is from the master 2929 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2930 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2931 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2932 break; 2933 } 2934 // additionally check if remote is in LE Device DB if requested 2935 switch(sm_conn->sm_irk_lookup_state){ 2936 case IRK_LOOKUP_FAILED: 2937 log_info("LTK Request: device not in device db"); 2938 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2939 break; 2940 case IRK_LOOKUP_SUCCEEDED: 2941 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2942 break; 2943 default: 2944 // wait for irk look doen 2945 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2946 break; 2947 } 2948 break; 2949 } 2950 2951 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2952 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2953 #else 2954 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2955 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2956 #endif 2957 break; 2958 2959 default: 2960 break; 2961 } 2962 break; 2963 2964 case HCI_EVENT_ENCRYPTION_CHANGE: 2965 con_handle = little_endian_read_16(packet, 3); 2966 sm_conn = sm_get_connection_for_handle(con_handle); 2967 if (!sm_conn) break; 2968 2969 sm_conn->sm_connection_encrypted = packet[5]; 2970 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2971 sm_conn->sm_actual_encryption_key_size); 2972 log_info("event handler, state %u", sm_conn->sm_engine_state); 2973 if (!sm_conn->sm_connection_encrypted) break; 2974 // continue if part of initial pairing 2975 switch (sm_conn->sm_engine_state){ 2976 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2977 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2978 sm_done_for_handle(sm_conn->sm_handle); 2979 break; 2980 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2981 if (IS_RESPONDER(sm_conn->sm_role)){ 2982 // slave 2983 if (setup->sm_use_secure_connections){ 2984 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2985 } else { 2986 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2987 } 2988 } else { 2989 // master 2990 if (sm_key_distribution_all_received(sm_conn)){ 2991 // skip receiving keys as there are none 2992 sm_key_distribution_handle_all_received(sm_conn); 2993 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2994 } else { 2995 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2996 } 2997 } 2998 break; 2999 default: 3000 break; 3001 } 3002 break; 3003 3004 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3005 con_handle = little_endian_read_16(packet, 3); 3006 sm_conn = sm_get_connection_for_handle(con_handle); 3007 if (!sm_conn) break; 3008 3009 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3010 log_info("event handler, state %u", sm_conn->sm_engine_state); 3011 // continue if part of initial pairing 3012 switch (sm_conn->sm_engine_state){ 3013 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3014 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3015 sm_done_for_handle(sm_conn->sm_handle); 3016 break; 3017 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3018 if (IS_RESPONDER(sm_conn->sm_role)){ 3019 // slave 3020 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3021 } else { 3022 // master 3023 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3024 } 3025 break; 3026 default: 3027 break; 3028 } 3029 break; 3030 3031 3032 case HCI_EVENT_DISCONNECTION_COMPLETE: 3033 con_handle = little_endian_read_16(packet, 3); 3034 sm_done_for_handle(con_handle); 3035 sm_conn = sm_get_connection_for_handle(con_handle); 3036 if (!sm_conn) break; 3037 3038 // delete stored bonding on disconnect with authentication failure in ph0 3039 if (sm_conn->sm_role == 0 3040 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3041 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3042 le_device_db_remove(sm_conn->sm_le_db_index); 3043 } 3044 3045 // pairing failed, if it was ongoing 3046 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3047 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3048 } 3049 3050 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3051 sm_conn->sm_handle = 0; 3052 break; 3053 3054 case HCI_EVENT_COMMAND_COMPLETE: 3055 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3056 // set local addr for le device db 3057 bd_addr_t addr; 3058 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3059 le_device_db_set_local_bd_addr(addr); 3060 } 3061 break; 3062 default: 3063 break; 3064 } 3065 break; 3066 default: 3067 break; 3068 } 3069 3070 sm_run(); 3071 } 3072 3073 static inline int sm_calc_actual_encryption_key_size(int other){ 3074 if (other < sm_min_encryption_key_size) return 0; 3075 if (other < sm_max_encryption_key_size) return other; 3076 return sm_max_encryption_key_size; 3077 } 3078 3079 3080 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3081 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3082 switch (method){ 3083 case JUST_WORKS: 3084 case NUMERIC_COMPARISON: 3085 return 1; 3086 default: 3087 return 0; 3088 } 3089 } 3090 // responder 3091 3092 static int sm_passkey_used(stk_generation_method_t method){ 3093 switch (method){ 3094 case PK_RESP_INPUT: 3095 return 1; 3096 default: 3097 return 0; 3098 } 3099 } 3100 3101 static int sm_passkey_entry(stk_generation_method_t method){ 3102 switch (method){ 3103 case PK_RESP_INPUT: 3104 case PK_INIT_INPUT: 3105 case PK_BOTH_INPUT: 3106 return 1; 3107 default: 3108 return 0; 3109 } 3110 } 3111 3112 #endif 3113 3114 /** 3115 * @return ok 3116 */ 3117 static int sm_validate_stk_generation_method(void){ 3118 // check if STK generation method is acceptable by client 3119 switch (setup->sm_stk_generation_method){ 3120 case JUST_WORKS: 3121 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3122 case PK_RESP_INPUT: 3123 case PK_INIT_INPUT: 3124 case PK_BOTH_INPUT: 3125 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3126 case OOB: 3127 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3128 case NUMERIC_COMPARISON: 3129 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3130 return 1; 3131 default: 3132 return 0; 3133 } 3134 } 3135 3136 // size of complete sm_pdu used to validate input 3137 static const uint8_t sm_pdu_size[] = { 3138 0, // 0x00 invalid opcode 3139 7, // 0x01 pairing request 3140 7, // 0x02 pairing response 3141 17, // 0x03 pairing confirm 3142 17, // 0x04 pairing random 3143 2, // 0x05 pairing failed 3144 17, // 0x06 encryption information 3145 11, // 0x07 master identification 3146 17, // 0x08 identification information 3147 8, // 0x09 identify address information 3148 17, // 0x0a signing information 3149 2, // 0x0b security request 3150 65, // 0x0c pairing public key 3151 17, // 0x0d pairing dhk check 3152 2, // 0x0e keypress notification 3153 }; 3154 3155 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3156 3157 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3158 sm_run(); 3159 } 3160 3161 if (packet_type != SM_DATA_PACKET) return; 3162 if (size == 0) return; 3163 3164 uint8_t sm_pdu_code = packet[0]; 3165 3166 // validate pdu size 3167 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3168 if (sm_pdu_size[sm_pdu_code] != size) return; 3169 3170 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3171 if (!sm_conn) return; 3172 3173 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3174 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3175 sm_done_for_handle(con_handle); 3176 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3177 return; 3178 } 3179 3180 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3181 3182 int err; 3183 UNUSED(err); 3184 3185 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3186 uint8_t buffer[5]; 3187 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3188 buffer[1] = 3; 3189 little_endian_store_16(buffer, 2, con_handle); 3190 buffer[4] = packet[1]; 3191 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3192 return; 3193 } 3194 3195 switch (sm_conn->sm_engine_state){ 3196 3197 // a sm timeout requries a new physical connection 3198 case SM_GENERAL_TIMEOUT: 3199 return; 3200 3201 #ifdef ENABLE_LE_CENTRAL 3202 3203 // Initiator 3204 case SM_INITIATOR_CONNECTED: 3205 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3206 sm_pdu_received_in_wrong_state(sm_conn); 3207 break; 3208 } 3209 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3210 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3211 break; 3212 } 3213 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3214 sm_key_t ltk; 3215 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3216 if (!sm_is_null_key(ltk)){ 3217 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3218 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3219 } else { 3220 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3221 } 3222 break; 3223 } 3224 // otherwise, store security request 3225 sm_conn->sm_security_request_received = 1; 3226 break; 3227 3228 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3229 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3230 sm_pdu_received_in_wrong_state(sm_conn); 3231 break; 3232 } 3233 3234 // store pairing request 3235 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3236 err = sm_stk_generation_init(sm_conn); 3237 3238 #ifdef ENABLE_TESTING_SUPPORT 3239 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3240 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3241 err = test_pairing_failure; 3242 } 3243 #endif 3244 3245 if (err){ 3246 setup->sm_pairing_failed_reason = err; 3247 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3248 break; 3249 } 3250 3251 // generate random number first, if we need to show passkey 3252 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3253 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3254 break; 3255 } 3256 3257 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3258 if (setup->sm_use_secure_connections){ 3259 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3260 if (setup->sm_stk_generation_method == JUST_WORKS){ 3261 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3262 sm_trigger_user_response(sm_conn); 3263 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3264 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3265 } 3266 } else { 3267 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3268 } 3269 break; 3270 } 3271 #endif 3272 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3273 sm_trigger_user_response(sm_conn); 3274 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3275 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3276 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3277 } 3278 break; 3279 3280 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3281 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3282 sm_pdu_received_in_wrong_state(sm_conn); 3283 break; 3284 } 3285 3286 // store s_confirm 3287 reverse_128(&packet[1], setup->sm_peer_confirm); 3288 3289 #ifdef ENABLE_TESTING_SUPPORT 3290 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3291 log_info("testing_support: reset confirm value"); 3292 memset(setup->sm_peer_confirm, 0, 16); 3293 } 3294 #endif 3295 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3296 break; 3297 3298 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3299 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3300 sm_pdu_received_in_wrong_state(sm_conn); 3301 break;; 3302 } 3303 3304 // received random value 3305 reverse_128(&packet[1], setup->sm_peer_random); 3306 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3307 break; 3308 #endif 3309 3310 #ifdef ENABLE_LE_PERIPHERAL 3311 // Responder 3312 case SM_RESPONDER_IDLE: 3313 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3314 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3315 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3316 sm_pdu_received_in_wrong_state(sm_conn); 3317 break;; 3318 } 3319 3320 // store pairing request 3321 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3322 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3323 break; 3324 #endif 3325 3326 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3327 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3328 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3329 sm_pdu_received_in_wrong_state(sm_conn); 3330 break; 3331 } 3332 3333 // store public key for DH Key calculation 3334 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3335 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3336 3337 // validate public key 3338 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3339 if (err){ 3340 log_error("sm: peer public key invalid %x", err); 3341 // uses "unspecified reason", there is no "public key invalid" error code 3342 sm_pdu_received_in_wrong_state(sm_conn); 3343 break; 3344 } 3345 3346 // start calculating dhkey 3347 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3348 3349 3350 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3351 if (IS_RESPONDER(sm_conn->sm_role)){ 3352 // responder 3353 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3354 } else { 3355 // initiator 3356 // stk generation method 3357 // passkey entry: notify app to show passkey or to request passkey 3358 switch (setup->sm_stk_generation_method){ 3359 case JUST_WORKS: 3360 case NUMERIC_COMPARISON: 3361 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3362 break; 3363 case PK_RESP_INPUT: 3364 sm_sc_start_calculating_local_confirm(sm_conn); 3365 break; 3366 case PK_INIT_INPUT: 3367 case PK_BOTH_INPUT: 3368 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3369 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3370 break; 3371 } 3372 sm_sc_start_calculating_local_confirm(sm_conn); 3373 break; 3374 case OOB: 3375 // generate Nx 3376 log_info("Generate Na"); 3377 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3378 break; 3379 } 3380 } 3381 break; 3382 3383 case SM_SC_W4_CONFIRMATION: 3384 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3385 sm_pdu_received_in_wrong_state(sm_conn); 3386 break; 3387 } 3388 // received confirm value 3389 reverse_128(&packet[1], setup->sm_peer_confirm); 3390 3391 #ifdef ENABLE_TESTING_SUPPORT 3392 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3393 log_info("testing_support: reset confirm value"); 3394 memset(setup->sm_peer_confirm, 0, 16); 3395 } 3396 #endif 3397 if (IS_RESPONDER(sm_conn->sm_role)){ 3398 // responder 3399 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3400 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3401 // still waiting for passkey 3402 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3403 break; 3404 } 3405 } 3406 sm_sc_start_calculating_local_confirm(sm_conn); 3407 } else { 3408 // initiator 3409 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3410 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3411 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3412 } else { 3413 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3414 } 3415 } 3416 break; 3417 3418 case SM_SC_W4_PAIRING_RANDOM: 3419 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3420 sm_pdu_received_in_wrong_state(sm_conn); 3421 break; 3422 } 3423 3424 // received random value 3425 reverse_128(&packet[1], setup->sm_peer_nonce); 3426 3427 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3428 // only check for JUST WORK/NC in initiator role OR passkey entry 3429 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3430 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3431 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3432 break; 3433 } 3434 3435 // OOB 3436 if (setup->sm_stk_generation_method == OOB){ 3437 3438 // setup local random, set to zero if remote did not receive our data 3439 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3440 if (IS_RESPONDER(sm_conn->sm_role)){ 3441 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3442 log_info("Reset rb as A does not have OOB data"); 3443 memset(setup->sm_rb, 0, 16); 3444 } else { 3445 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3446 log_info("Use stored rb"); 3447 log_info_hexdump(setup->sm_rb, 16); 3448 } 3449 } else { 3450 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3451 log_info("Reset ra as B does not have OOB data"); 3452 memset(setup->sm_ra, 0, 16); 3453 } else { 3454 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3455 log_info("Use stored ra"); 3456 log_info_hexdump(setup->sm_ra, 16); 3457 } 3458 } 3459 3460 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3461 if (setup->sm_have_oob_data){ 3462 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3463 break; 3464 } 3465 } 3466 3467 // TODO: we only get here for Responder role with JW/NC 3468 sm_sc_state_after_receiving_random(sm_conn); 3469 break; 3470 3471 case SM_SC_W2_CALCULATE_G2: 3472 case SM_SC_W4_CALCULATE_G2: 3473 case SM_SC_W4_CALCULATE_DHKEY: 3474 case SM_SC_W2_CALCULATE_F5_SALT: 3475 case SM_SC_W4_CALCULATE_F5_SALT: 3476 case SM_SC_W2_CALCULATE_F5_MACKEY: 3477 case SM_SC_W4_CALCULATE_F5_MACKEY: 3478 case SM_SC_W2_CALCULATE_F5_LTK: 3479 case SM_SC_W4_CALCULATE_F5_LTK: 3480 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3481 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3482 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3483 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3484 sm_pdu_received_in_wrong_state(sm_conn); 3485 break; 3486 } 3487 // store DHKey Check 3488 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3489 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3490 3491 // have we been only waiting for dhkey check command? 3492 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3493 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3494 } 3495 break; 3496 #endif 3497 3498 #ifdef ENABLE_LE_PERIPHERAL 3499 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3500 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3501 sm_pdu_received_in_wrong_state(sm_conn); 3502 break; 3503 } 3504 3505 // received confirm value 3506 reverse_128(&packet[1], setup->sm_peer_confirm); 3507 3508 #ifdef ENABLE_TESTING_SUPPORT 3509 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3510 log_info("testing_support: reset confirm value"); 3511 memset(setup->sm_peer_confirm, 0, 16); 3512 } 3513 #endif 3514 // notify client to hide shown passkey 3515 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3516 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3517 } 3518 3519 // handle user cancel pairing? 3520 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3521 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3522 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3523 break; 3524 } 3525 3526 // wait for user action? 3527 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3528 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3529 break; 3530 } 3531 3532 // calculate and send local_confirm 3533 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3534 break; 3535 3536 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3537 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3538 sm_pdu_received_in_wrong_state(sm_conn); 3539 break;; 3540 } 3541 3542 // received random value 3543 reverse_128(&packet[1], setup->sm_peer_random); 3544 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3545 break; 3546 #endif 3547 3548 case SM_PH3_RECEIVE_KEYS: 3549 switch(sm_pdu_code){ 3550 case SM_CODE_ENCRYPTION_INFORMATION: 3551 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3552 reverse_128(&packet[1], setup->sm_peer_ltk); 3553 break; 3554 3555 case SM_CODE_MASTER_IDENTIFICATION: 3556 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3557 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3558 reverse_64(&packet[3], setup->sm_peer_rand); 3559 break; 3560 3561 case SM_CODE_IDENTITY_INFORMATION: 3562 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3563 reverse_128(&packet[1], setup->sm_peer_irk); 3564 break; 3565 3566 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3567 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3568 setup->sm_peer_addr_type = packet[1]; 3569 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3570 break; 3571 3572 case SM_CODE_SIGNING_INFORMATION: 3573 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3574 reverse_128(&packet[1], setup->sm_peer_csrk); 3575 break; 3576 default: 3577 // Unexpected PDU 3578 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3579 break; 3580 } 3581 // done with key distribution? 3582 if (sm_key_distribution_all_received(sm_conn)){ 3583 3584 sm_key_distribution_handle_all_received(sm_conn); 3585 3586 if (IS_RESPONDER(sm_conn->sm_role)){ 3587 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3588 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3589 } else { 3590 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3591 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3592 sm_done_for_handle(sm_conn->sm_handle); 3593 } 3594 } else { 3595 if (setup->sm_use_secure_connections){ 3596 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3597 } else { 3598 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3599 } 3600 } 3601 } 3602 break; 3603 default: 3604 // Unexpected PDU 3605 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3606 break; 3607 } 3608 3609 // try to send preparared packet 3610 sm_run(); 3611 } 3612 3613 // Security Manager Client API 3614 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3615 sm_get_oob_data = get_oob_data_callback; 3616 } 3617 3618 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)){ 3619 sm_get_sc_oob_data = get_sc_oob_data_callback; 3620 } 3621 3622 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3623 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3624 } 3625 3626 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3627 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3628 } 3629 3630 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3631 sm_min_encryption_key_size = min_size; 3632 sm_max_encryption_key_size = max_size; 3633 } 3634 3635 void sm_set_authentication_requirements(uint8_t auth_req){ 3636 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3637 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3638 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3639 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3640 } 3641 #endif 3642 sm_auth_req = auth_req; 3643 } 3644 3645 void sm_set_io_capabilities(io_capability_t io_capability){ 3646 sm_io_capabilities = io_capability; 3647 } 3648 3649 #ifdef ENABLE_LE_PERIPHERAL 3650 void sm_set_request_security(int enable){ 3651 sm_slave_request_security = enable; 3652 } 3653 #endif 3654 3655 void sm_set_er(sm_key_t er){ 3656 memcpy(sm_persistent_er, er, 16); 3657 } 3658 3659 void sm_set_ir(sm_key_t ir){ 3660 memcpy(sm_persistent_ir, ir, 16); 3661 } 3662 3663 // Testing support only 3664 void sm_test_set_irk(sm_key_t irk){ 3665 memcpy(sm_persistent_irk, irk, 16); 3666 sm_persistent_irk_ready = 1; 3667 } 3668 3669 void sm_test_use_fixed_local_csrk(void){ 3670 test_use_fixed_local_csrk = 1; 3671 } 3672 3673 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3674 static void sm_ec_generated(void * arg){ 3675 UNUSED(arg); 3676 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3677 } 3678 #endif 3679 3680 #ifdef ENABLE_TESTING_SUPPORT 3681 void sm_test_set_pairing_failure(int reason){ 3682 test_pairing_failure = reason; 3683 } 3684 #endif 3685 3686 void sm_init(void){ 3687 // set some (BTstack default) ER and IR 3688 int i; 3689 sm_key_t er; 3690 sm_key_t ir; 3691 for (i=0;i<16;i++){ 3692 er[i] = 0x30 + i; 3693 ir[i] = 0x90 + i; 3694 } 3695 sm_set_er(er); 3696 sm_set_ir(ir); 3697 // defaults 3698 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3699 | SM_STK_GENERATION_METHOD_OOB 3700 | SM_STK_GENERATION_METHOD_PASSKEY 3701 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3702 3703 sm_max_encryption_key_size = 16; 3704 sm_min_encryption_key_size = 7; 3705 3706 sm_fixed_passkey_in_display_role = 0xffffffff; 3707 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3708 3709 #ifdef USE_CMAC_ENGINE 3710 sm_cmac_active = 0; 3711 #endif 3712 dkg_state = DKG_W4_WORKING; 3713 rau_state = RAU_W4_WORKING; 3714 sm_aes128_state = SM_AES128_IDLE; 3715 sm_address_resolution_test = -1; // no private address to resolve yet 3716 sm_address_resolution_ah_calculation_active = 0; 3717 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3718 sm_address_resolution_general_queue = NULL; 3719 3720 gap_random_adress_update_period = 15 * 60 * 1000L; 3721 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3722 3723 test_use_fixed_local_csrk = 0; 3724 3725 // register for HCI Events from HCI 3726 hci_event_callback_registration.callback = &sm_event_packet_handler; 3727 hci_add_event_handler(&hci_event_callback_registration); 3728 3729 // 3730 btstack_crypto_init(); 3731 3732 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3733 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3734 3735 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3736 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3737 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3738 #endif 3739 } 3740 3741 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3742 sm_fixed_passkey_in_display_role = passkey; 3743 } 3744 3745 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3746 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3747 } 3748 3749 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3750 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3751 if (!hci_con) return NULL; 3752 return &hci_con->sm_connection; 3753 } 3754 3755 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3756 switch (sm_conn->sm_engine_state){ 3757 case SM_GENERAL_IDLE: 3758 case SM_RESPONDER_IDLE: 3759 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3760 sm_run(); 3761 break; 3762 default: 3763 break; 3764 } 3765 } 3766 3767 /** 3768 * @brief Trigger Security Request 3769 */ 3770 void sm_send_security_request(hci_con_handle_t con_handle){ 3771 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3772 if (!sm_conn) return; 3773 sm_send_security_request_for_connection(sm_conn); 3774 } 3775 3776 // request pairing 3777 void sm_request_pairing(hci_con_handle_t con_handle){ 3778 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3779 if (!sm_conn) return; // wrong connection 3780 3781 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3782 if (IS_RESPONDER(sm_conn->sm_role)){ 3783 sm_send_security_request_for_connection(sm_conn); 3784 } else { 3785 // used as a trigger to start central/master/initiator security procedures 3786 uint16_t ediv; 3787 sm_key_t ltk; 3788 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3789 switch (sm_conn->sm_irk_lookup_state){ 3790 case IRK_LOOKUP_FAILED: 3791 log_info("irk lookup failed, send pairing request"); 3792 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3793 break; 3794 case IRK_LOOKUP_SUCCEEDED: 3795 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3796 if (!sm_is_null_key(ltk) || ediv){ 3797 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3798 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3799 } else { 3800 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3801 } 3802 break; 3803 default: 3804 log_info("irk lookup pending"); 3805 sm_conn->sm_pairing_requested = 1; 3806 break; 3807 } 3808 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3809 sm_conn->sm_pairing_requested = 1; 3810 } 3811 } 3812 sm_run(); 3813 } 3814 3815 // called by client app on authorization request 3816 void sm_authorization_decline(hci_con_handle_t con_handle){ 3817 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3818 if (!sm_conn) return; // wrong connection 3819 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3820 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3821 } 3822 3823 void sm_authorization_grant(hci_con_handle_t con_handle){ 3824 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3825 if (!sm_conn) return; // wrong connection 3826 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3827 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3828 } 3829 3830 // GAP Bonding API 3831 3832 void sm_bonding_decline(hci_con_handle_t con_handle){ 3833 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3834 if (!sm_conn) return; // wrong connection 3835 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3836 log_info("decline, state %u", sm_conn->sm_engine_state); 3837 switch(sm_conn->sm_engine_state){ 3838 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3839 case SM_SC_W4_USER_RESPONSE: 3840 case SM_SC_W4_CONFIRMATION: 3841 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3842 #endif 3843 case SM_PH1_W4_USER_RESPONSE: 3844 switch (setup->sm_stk_generation_method){ 3845 case PK_RESP_INPUT: 3846 case PK_INIT_INPUT: 3847 case PK_BOTH_INPUT: 3848 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3849 break; 3850 case NUMERIC_COMPARISON: 3851 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3852 break; 3853 case JUST_WORKS: 3854 case OOB: 3855 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3856 break; 3857 } 3858 break; 3859 default: 3860 break; 3861 } 3862 sm_run(); 3863 } 3864 3865 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3866 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3867 if (!sm_conn) return; // wrong connection 3868 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3869 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3870 if (setup->sm_use_secure_connections){ 3871 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3872 } else { 3873 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3874 } 3875 } 3876 3877 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3878 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3879 sm_sc_prepare_dhkey_check(sm_conn); 3880 } 3881 #endif 3882 3883 sm_run(); 3884 } 3885 3886 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3887 // for now, it's the same 3888 sm_just_works_confirm(con_handle); 3889 } 3890 3891 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3892 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3893 if (!sm_conn) return; // wrong connection 3894 sm_reset_tk(); 3895 big_endian_store_32(setup->sm_tk, 12, passkey); 3896 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3897 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3898 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3899 } 3900 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3901 memcpy(setup->sm_ra, setup->sm_tk, 16); 3902 memcpy(setup->sm_rb, setup->sm_tk, 16); 3903 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3904 sm_sc_start_calculating_local_confirm(sm_conn); 3905 } 3906 #endif 3907 sm_run(); 3908 } 3909 3910 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3911 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3912 if (!sm_conn) return; // wrong connection 3913 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3914 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3915 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3916 switch (action){ 3917 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3918 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3919 flags |= (1 << action); 3920 break; 3921 case SM_KEYPRESS_PASSKEY_CLEARED: 3922 // clear counter, keypress & erased flags + set passkey cleared 3923 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3924 break; 3925 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3926 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3927 // erase actions queued 3928 num_actions--; 3929 if (num_actions == 0){ 3930 // clear counter, keypress & erased flags 3931 flags &= 0x19; 3932 } 3933 break; 3934 } 3935 num_actions++; 3936 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3937 break; 3938 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3939 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3940 // enter actions queued 3941 num_actions--; 3942 if (num_actions == 0){ 3943 // clear counter, keypress & erased flags 3944 flags &= 0x19; 3945 } 3946 break; 3947 } 3948 num_actions++; 3949 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3950 break; 3951 default: 3952 break; 3953 } 3954 setup->sm_keypress_notification = (num_actions << 5) | flags; 3955 sm_run(); 3956 } 3957 3958 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3959 static void sm_handle_random_result_oob(void * arg){ 3960 UNUSED(arg); 3961 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3962 sm_run(); 3963 } 3964 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3965 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3966 sm_sc_oob_callback = callback; 3967 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3968 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3969 return 0; 3970 } 3971 #endif 3972 3973 /** 3974 * @brief Identify device in LE Device DB 3975 * @param handle 3976 * @returns index from le_device_db or -1 if not found/identified 3977 */ 3978 int sm_le_device_index(hci_con_handle_t con_handle ){ 3979 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3980 if (!sm_conn) return -1; 3981 return sm_conn->sm_le_db_index; 3982 } 3983 3984 static int gap_random_address_type_requires_updates(void){ 3985 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3986 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3987 return 1; 3988 } 3989 3990 static uint8_t own_address_type(void){ 3991 switch (gap_random_adress_type){ 3992 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3993 return BD_ADDR_TYPE_LE_PUBLIC; 3994 default: 3995 return BD_ADDR_TYPE_LE_RANDOM; 3996 } 3997 } 3998 3999 // GAP LE API 4000 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4001 gap_random_address_update_stop(); 4002 gap_random_adress_type = random_address_type; 4003 hci_le_set_own_address_type(own_address_type()); 4004 if (!gap_random_address_type_requires_updates()) return; 4005 gap_random_address_update_start(); 4006 gap_random_address_trigger(); 4007 } 4008 4009 gap_random_address_type_t gap_random_address_get_mode(void){ 4010 return gap_random_adress_type; 4011 } 4012 4013 void gap_random_address_set_update_period(int period_ms){ 4014 gap_random_adress_update_period = period_ms; 4015 if (!gap_random_address_type_requires_updates()) return; 4016 gap_random_address_update_stop(); 4017 gap_random_address_update_start(); 4018 } 4019 4020 void gap_random_address_set(bd_addr_t addr){ 4021 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4022 memcpy(sm_random_address, addr, 6); 4023 if (rau_state == RAU_W4_WORKING) return; 4024 rau_state = RAU_SET_ADDRESS; 4025 sm_run(); 4026 } 4027 4028 #ifdef ENABLE_LE_PERIPHERAL 4029 /* 4030 * @brief Set Advertisement Paramters 4031 * @param adv_int_min 4032 * @param adv_int_max 4033 * @param adv_type 4034 * @param direct_address_type 4035 * @param direct_address 4036 * @param channel_map 4037 * @param filter_policy 4038 * 4039 * @note own_address_type is used from gap_random_address_set_mode 4040 */ 4041 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4042 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4043 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4044 direct_address_typ, direct_address, channel_map, filter_policy); 4045 } 4046 #endif 4047 4048 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4049 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4050 // wrong connection 4051 if (!sm_conn) return 0; 4052 // already encrypted 4053 if (sm_conn->sm_connection_encrypted) return 0; 4054 // only central can re-encrypt 4055 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4056 // irk status? 4057 switch(sm_conn->sm_irk_lookup_state){ 4058 case IRK_LOOKUP_FAILED: 4059 // done, cannot setup encryption 4060 return 0; 4061 case IRK_LOOKUP_SUCCEEDED: 4062 break; 4063 default: 4064 // IR Lookup pending 4065 return 1; 4066 } 4067 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4068 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4069 } 4070