1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "sm.c" 39 40 #include <stdio.h> 41 #include <string.h> 42 #include <inttypes.h> 43 44 #include "ble/le_device_db.h" 45 #include "ble/core.h" 46 #include "ble/sm.h" 47 #include "bluetooth_company_id.h" 48 #include "btstack_crypto.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_linked_list.h" 52 #include "btstack_memory.h" 53 #include "gap.h" 54 #include "hci.h" 55 #include "hci_dump.h" 56 #include "l2cap.h" 57 58 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 59 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 60 #endif 61 62 // assert SM Public Key can be sent/received 63 #ifdef ENABLE_LE_SECURE_CONNECTIONS 64 #if HCI_ACL_PAYLOAD_SIZE < 69 65 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" 66 #endif 67 #endif 68 69 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 70 #define IS_RESPONDER(role) (role) 71 #else 72 #ifdef ENABLE_LE_CENTRAL 73 // only central - never responder (avoid 'unused variable' warnings) 74 #define IS_RESPONDER(role) (0 && role) 75 #else 76 // only peripheral - always responder (avoid 'unused variable' warnings) 77 #define IS_RESPONDER(role) (1 || role) 78 #endif 79 #endif 80 81 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 82 #define USE_CMAC_ENGINE 83 #endif 84 85 // 86 // SM internal types and globals 87 // 88 89 typedef enum { 90 DKG_W4_WORKING, 91 DKG_CALC_IRK, 92 DKG_CALC_DHK, 93 DKG_READY 94 } derived_key_generation_t; 95 96 typedef enum { 97 RAU_W4_WORKING, 98 RAU_IDLE, 99 RAU_W4_RANDOM, 100 RAU_GET_ENC, 101 RAU_W4_ENC, 102 RAU_SET_ADDRESS, 103 } random_address_update_t; 104 105 typedef enum { 106 CMAC_IDLE, 107 CMAC_CALC_SUBKEYS, 108 CMAC_W4_SUBKEYS, 109 CMAC_CALC_MI, 110 CMAC_W4_MI, 111 CMAC_CALC_MLAST, 112 CMAC_W4_MLAST 113 } cmac_state_t; 114 115 typedef enum { 116 JUST_WORKS, 117 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 118 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 119 PK_BOTH_INPUT, // Only input on both, both input PK 120 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 121 OOB // OOB available on one (SC) or both sides (legacy) 122 } stk_generation_method_t; 123 124 typedef enum { 125 SM_USER_RESPONSE_IDLE, 126 SM_USER_RESPONSE_PENDING, 127 SM_USER_RESPONSE_CONFIRM, 128 SM_USER_RESPONSE_PASSKEY, 129 SM_USER_RESPONSE_DECLINE 130 } sm_user_response_t; 131 132 typedef enum { 133 SM_AES128_IDLE, 134 SM_AES128_ACTIVE 135 } sm_aes128_state_t; 136 137 typedef enum { 138 ADDRESS_RESOLUTION_IDLE, 139 ADDRESS_RESOLUTION_GENERAL, 140 ADDRESS_RESOLUTION_FOR_CONNECTION, 141 } address_resolution_mode_t; 142 143 typedef enum { 144 ADDRESS_RESOLUTION_SUCEEDED, 145 ADDRESS_RESOLUTION_FAILED, 146 } address_resolution_event_t; 147 148 typedef enum { 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static uint8_t sm_persistent_irk_ready = 0; // used for testing 204 static derived_key_generation_t dkg_state; 205 206 // derived from sm_persistent_er 207 // .. 208 209 // random address update 210 static random_address_update_t rau_state; 211 static bd_addr_t sm_random_address; 212 213 #ifdef USE_CMAC_ENGINE 214 // CMAC Calculation: General 215 static btstack_crypto_aes128_cmac_t sm_cmac_request; 216 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 217 static uint8_t sm_cmac_active; 218 static uint8_t sm_cmac_hash[16]; 219 #endif 220 221 // CMAC for ATT Signed Writes 222 #ifdef ENABLE_LE_SIGNED_WRITE 223 static uint16_t sm_cmac_signed_write_message_len; 224 static uint8_t sm_cmac_signed_write_header[3]; 225 static const uint8_t * sm_cmac_signed_write_message; 226 static uint8_t sm_cmac_signed_write_sign_counter[4]; 227 #endif 228 229 // CMAC for Secure Connection functions 230 #ifdef ENABLE_LE_SECURE_CONNECTIONS 231 static sm_connection_t * sm_cmac_connection; 232 static uint8_t sm_cmac_sc_buffer[80]; 233 #endif 234 235 // resolvable private address lookup / CSRK calculation 236 static int sm_address_resolution_test; 237 static int sm_address_resolution_ah_calculation_active; 238 static uint8_t sm_address_resolution_addr_type; 239 static bd_addr_t sm_address_resolution_address; 240 static void * sm_address_resolution_context; 241 static address_resolution_mode_t sm_address_resolution_mode; 242 static btstack_linked_list_t sm_address_resolution_general_queue; 243 244 // aes128 crypto engine. 245 static sm_aes128_state_t sm_aes128_state; 246 247 // crypto 248 static btstack_crypto_random_t sm_crypto_random_request; 249 static btstack_crypto_aes128_t sm_crypto_aes128_request; 250 #ifdef ENABLE_LE_SECURE_CONNECTIONS 251 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 252 static btstack_crypto_random_t sm_crypto_random_oob_request; 253 #endif 254 255 // temp storage for random data 256 static uint8_t sm_random_data[8]; 257 static uint8_t sm_aes128_key[16]; 258 static uint8_t sm_aes128_plaintext[16]; 259 static uint8_t sm_aes128_ciphertext[16]; 260 261 // to receive hci events 262 static btstack_packet_callback_registration_t hci_event_callback_registration; 263 264 /* to dispatch sm event */ 265 static btstack_linked_list_t sm_event_handlers; 266 267 // LE Secure Connections 268 #ifdef ENABLE_LE_SECURE_CONNECTIONS 269 static ec_key_generation_state_t ec_key_generation_state; 270 static uint8_t ec_q[64]; 271 #endif 272 273 // 274 // Volume 3, Part H, Chapter 24 275 // "Security shall be initiated by the Security Manager in the device in the master role. 276 // The device in the slave role shall be the responding device." 277 // -> master := initiator, slave := responder 278 // 279 280 // data needed for security setup 281 typedef struct sm_setup_context { 282 283 btstack_timer_source_t sm_timeout; 284 285 // used in all phases 286 uint8_t sm_pairing_failed_reason; 287 288 // user response, (Phase 1 and/or 2) 289 uint8_t sm_user_response; 290 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 291 292 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 293 int sm_key_distribution_send_set; 294 int sm_key_distribution_received_set; 295 296 // Phase 2 (Pairing over SMP) 297 stk_generation_method_t sm_stk_generation_method; 298 sm_key_t sm_tk; 299 uint8_t sm_have_oob_data; 300 uint8_t sm_use_secure_connections; 301 302 sm_key_t sm_c1_t3_value; // c1 calculation 303 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 304 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 305 sm_key_t sm_local_random; 306 sm_key_t sm_local_confirm; 307 sm_key_t sm_peer_random; 308 sm_key_t sm_peer_confirm; 309 uint8_t sm_m_addr_type; // address and type can be removed 310 uint8_t sm_s_addr_type; // '' 311 bd_addr_t sm_m_address; // '' 312 bd_addr_t sm_s_address; // '' 313 sm_key_t sm_ltk; 314 315 uint8_t sm_state_vars; 316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 317 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 318 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 319 sm_key_t sm_local_nonce; // might be combined with sm_local_random 320 sm_key_t sm_dhkey; 321 sm_key_t sm_peer_dhkey_check; 322 sm_key_t sm_local_dhkey_check; 323 sm_key_t sm_ra; 324 sm_key_t sm_rb; 325 sm_key_t sm_t; // used for f5 and h6 326 sm_key_t sm_mackey; 327 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 328 #endif 329 330 // Phase 3 331 332 // key distribution, we generate 333 uint16_t sm_local_y; 334 uint16_t sm_local_div; 335 uint16_t sm_local_ediv; 336 uint8_t sm_local_rand[8]; 337 sm_key_t sm_local_ltk; 338 sm_key_t sm_local_csrk; 339 sm_key_t sm_local_irk; 340 // sm_local_address/addr_type not needed 341 342 // key distribution, received from peer 343 uint16_t sm_peer_y; 344 uint16_t sm_peer_div; 345 uint16_t sm_peer_ediv; 346 uint8_t sm_peer_rand[8]; 347 sm_key_t sm_peer_ltk; 348 sm_key_t sm_peer_irk; 349 sm_key_t sm_peer_csrk; 350 uint8_t sm_peer_addr_type; 351 bd_addr_t sm_peer_address; 352 353 } sm_setup_context_t; 354 355 // 356 static sm_setup_context_t the_setup; 357 static sm_setup_context_t * setup = &the_setup; 358 359 // active connection - the one for which the_setup is used for 360 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 361 362 // @returns 1 if oob data is available 363 // stores oob data in provided 16 byte buffer if not null 364 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 365 static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); 366 367 // horizontal: initiator capabilities 368 // vertial: responder capabilities 369 static const stk_generation_method_t stk_generation_method [5] [5] = { 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 372 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 373 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 374 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 375 }; 376 377 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 378 #ifdef ENABLE_LE_SECURE_CONNECTIONS 379 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 380 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 381 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 382 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 383 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 384 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 385 }; 386 #endif 387 388 static void sm_run(void); 389 #ifdef USE_CMAC_ENGINE 390 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); 391 #endif 392 static void sm_done_for_handle(hci_con_handle_t con_handle); 393 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 394 static inline int sm_calc_actual_encryption_key_size(int other); 395 static int sm_validate_stk_generation_method(void); 396 static void sm_handle_encryption_result_address_resolution(void *arg); 397 static void sm_handle_encryption_result_dkg_dhk(void *arg); 398 static void sm_handle_encryption_result_dkg_irk(void *arg); 399 static void sm_handle_encryption_result_enc_a(void *arg); 400 static void sm_handle_encryption_result_enc_b(void *arg); 401 static void sm_handle_encryption_result_enc_c(void *arg); 402 static void sm_handle_encryption_result_enc_csrk(void *arg); 403 static void sm_handle_encryption_result_enc_d(void * arg); 404 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 405 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 406 #ifdef ENABLE_LE_PERIPHERAL 407 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 408 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 409 #endif 410 static void sm_handle_encryption_result_enc_stk(void *arg); 411 static void sm_handle_encryption_result_rau(void *arg); 412 static void sm_handle_random_result_ph2_tk(void * arg); 413 static void sm_handle_random_result_rau(void * arg); 414 #ifdef ENABLE_LE_SECURE_CONNECTIONS 415 static void sm_handle_random_result_sc_get_random(void * arg); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 #endif 418 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 419 420 static void log_info_hex16(const char * name, uint16_t value){ 421 log_info("%-6s 0x%04x", name, value); 422 } 423 424 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 425 // return packet[0]; 426 // } 427 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 428 return packet[1]; 429 } 430 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 431 return packet[2]; 432 } 433 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 434 return packet[3]; 435 } 436 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 437 return packet[4]; 438 } 439 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 440 return packet[5]; 441 } 442 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 443 return packet[6]; 444 } 445 446 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 447 packet[0] = code; 448 } 449 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 450 packet[1] = io_capability; 451 } 452 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 453 packet[2] = oob_data_flag; 454 } 455 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 456 packet[3] = auth_req; 457 } 458 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 459 packet[4] = max_encryption_key_size; 460 } 461 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 462 packet[5] = initiator_key_distribution; 463 } 464 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 465 packet[6] = responder_key_distribution; 466 } 467 468 // @returns 1 if all bytes are 0 469 static int sm_is_null(uint8_t * data, int size){ 470 int i; 471 for (i=0; i < size ; i++){ 472 if (data[i]) return 0; 473 } 474 return 1; 475 } 476 477 static int sm_is_null_random(uint8_t random[8]){ 478 return sm_is_null(random, 8); 479 } 480 481 static int sm_is_null_key(uint8_t * key){ 482 return sm_is_null(key, 16); 483 } 484 485 // Key utils 486 static void sm_reset_tk(void){ 487 int i; 488 for (i=0;i<16;i++){ 489 setup->sm_tk[i] = 0; 490 } 491 } 492 493 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 494 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 495 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 496 int i; 497 for (i = max_encryption_size ; i < 16 ; i++){ 498 key[15-i] = 0; 499 } 500 } 501 502 // SMP Timeout implementation 503 504 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 505 // the Security Manager Timer shall be reset and started. 506 // 507 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 508 // 509 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 510 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 511 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 512 // established. 513 514 static void sm_timeout_handler(btstack_timer_source_t * timer){ 515 log_info("SM timeout"); 516 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 517 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 518 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 519 sm_done_for_handle(sm_conn->sm_handle); 520 521 // trigger handling of next ready connection 522 sm_run(); 523 } 524 static void sm_timeout_start(sm_connection_t * sm_conn){ 525 btstack_run_loop_remove_timer(&setup->sm_timeout); 526 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 527 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 528 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 529 btstack_run_loop_add_timer(&setup->sm_timeout); 530 } 531 static void sm_timeout_stop(void){ 532 btstack_run_loop_remove_timer(&setup->sm_timeout); 533 } 534 static void sm_timeout_reset(sm_connection_t * sm_conn){ 535 sm_timeout_stop(); 536 sm_timeout_start(sm_conn); 537 } 538 539 // end of sm timeout 540 541 // GAP Random Address updates 542 static gap_random_address_type_t gap_random_adress_type; 543 static btstack_timer_source_t gap_random_address_update_timer; 544 static uint32_t gap_random_adress_update_period; 545 546 static void gap_random_address_trigger(void){ 547 log_info("gap_random_address_trigger"); 548 if (rau_state != RAU_IDLE) return; 549 rau_state = RAU_W4_RANDOM; 550 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 551 } 552 553 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 554 UNUSED(timer); 555 556 log_info("GAP Random Address Update due"); 557 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 558 btstack_run_loop_add_timer(&gap_random_address_update_timer); 559 gap_random_address_trigger(); 560 } 561 562 static void gap_random_address_update_start(void){ 563 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 564 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 565 btstack_run_loop_add_timer(&gap_random_address_update_timer); 566 } 567 568 static void gap_random_address_update_stop(void){ 569 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 570 } 571 572 // ah(k,r) helper 573 // r = padding || r 574 // r - 24 bit value 575 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 576 // r'= padding || r 577 memset(r_prime, 0, 16); 578 memcpy(&r_prime[13], r, 3); 579 } 580 581 // d1 helper 582 // d' = padding || r || d 583 // d,r - 16 bit values 584 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 585 // d'= padding || r || d 586 memset(d1_prime, 0, 16); 587 big_endian_store_16(d1_prime, 12, r); 588 big_endian_store_16(d1_prime, 14, d); 589 } 590 591 // dm helper 592 // r’ = padding || r 593 // r - 64 bit value 594 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 595 memset(r_prime, 0, 16); 596 memcpy(&r_prime[8], r, 8); 597 } 598 599 // calculate arguments for first AES128 operation in C1 function 600 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 601 602 // p1 = pres || preq || rat’ || iat’ 603 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 604 // cant octet of pres becomes the most significant octet of p1. 605 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 606 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 607 // p1 is 0x05000800000302070710000001010001." 608 609 sm_key_t p1; 610 reverse_56(pres, &p1[0]); 611 reverse_56(preq, &p1[7]); 612 p1[14] = rat; 613 p1[15] = iat; 614 log_info_key("p1", p1); 615 log_info_key("r", r); 616 617 // t1 = r xor p1 618 int i; 619 for (i=0;i<16;i++){ 620 t1[i] = r[i] ^ p1[i]; 621 } 622 log_info_key("t1", t1); 623 } 624 625 // calculate arguments for second AES128 operation in C1 function 626 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 627 // p2 = padding || ia || ra 628 // "The least significant octet of ra becomes the least significant octet of p2 and 629 // the most significant octet of padding becomes the most significant octet of p2. 630 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 631 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 632 633 sm_key_t p2; 634 memset(p2, 0, 16); 635 memcpy(&p2[4], ia, 6); 636 memcpy(&p2[10], ra, 6); 637 log_info_key("p2", p2); 638 639 // c1 = e(k, t2_xor_p2) 640 int i; 641 for (i=0;i<16;i++){ 642 t3[i] = t2[i] ^ p2[i]; 643 } 644 log_info_key("t3", t3); 645 } 646 647 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 648 log_info_key("r1", r1); 649 log_info_key("r2", r2); 650 memcpy(&r_prime[8], &r2[8], 8); 651 memcpy(&r_prime[0], &r1[8], 8); 652 } 653 654 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 655 UNUSED(channel); 656 657 // log event 658 hci_dump_packet(packet_type, 1, packet, size); 659 // dispatch to all event handlers 660 btstack_linked_list_iterator_t it; 661 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 662 while (btstack_linked_list_iterator_has_next(&it)){ 663 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 664 entry->callback(packet_type, 0, packet, size); 665 } 666 } 667 668 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 669 event[0] = type; 670 event[1] = event_size - 2; 671 little_endian_store_16(event, 2, con_handle); 672 event[4] = addr_type; 673 reverse_bd_addr(address, &event[5]); 674 } 675 676 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 677 uint8_t event[11]; 678 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 679 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 680 } 681 682 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 683 uint8_t event[15]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 little_endian_store_32(event, 11, passkey); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 690 // fetch addr and addr type from db 691 bd_addr_t identity_address; 692 int identity_address_type; 693 le_device_db_info(index, &identity_address_type, identity_address, NULL); 694 695 uint8_t event[19]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 event[11] = identity_address_type; 698 reverse_bd_addr(identity_address, &event[12]); 699 event[18] = index; 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 704 uint8_t event[12]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = status; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 711 uint8_t event[13]; 712 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 713 event[11] = status; 714 event[12] = reason; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 735 736 737 // decide if OOB will be used based on SC vs. Legacy and oob flags 738 int use_oob = 0; 739 if (setup->sm_use_secure_connections){ 740 // In LE Secure Connections pairing, the out of band method is used if at least 741 // one device has the peer device's out of band authentication data available. 742 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 743 } else { 744 // In LE legacy pairing, the out of band method is used if both the devices have 745 // the other device's out of band authentication data available. 746 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 747 } 748 if (use_oob){ 749 log_info("SM: have OOB data"); 750 log_info_key("OOB", setup->sm_tk); 751 setup->sm_stk_generation_method = OOB; 752 return; 753 } 754 755 // If both devices have not set the MITM option in the Authentication Requirements 756 // Flags, then the IO capabilities shall be ignored and the Just Works association 757 // model shall be used. 758 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 759 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 760 log_info("SM: MITM not required by both -> JUST WORKS"); 761 return; 762 } 763 764 // Reset TK as it has been setup in sm_init_setup 765 sm_reset_tk(); 766 767 // Also use just works if unknown io capabilites 768 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 769 return; 770 } 771 772 // Otherwise the IO capabilities of the devices shall be used to determine the 773 // pairing method as defined in Table 2.4. 774 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 775 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 776 777 #ifdef ENABLE_LE_SECURE_CONNECTIONS 778 // table not define by default 779 if (setup->sm_use_secure_connections){ 780 generation_method = stk_generation_method_with_secure_connection; 781 } 782 #endif 783 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 784 785 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 786 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 787 } 788 789 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 790 int flags = 0; 791 if (key_set & SM_KEYDIST_ENC_KEY){ 792 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 794 } 795 if (key_set & SM_KEYDIST_ID_KEY){ 796 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 797 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 798 } 799 if (key_set & SM_KEYDIST_SIGN){ 800 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 801 } 802 return flags; 803 } 804 805 static void sm_setup_key_distribution(uint8_t key_set){ 806 setup->sm_key_distribution_received_set = 0; 807 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 808 } 809 810 // CSRK Key Lookup 811 812 813 static int sm_address_resolution_idle(void){ 814 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 815 } 816 817 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 818 memcpy(sm_address_resolution_address, addr, 6); 819 sm_address_resolution_addr_type = addr_type; 820 sm_address_resolution_test = 0; 821 sm_address_resolution_mode = mode; 822 sm_address_resolution_context = context; 823 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 824 } 825 826 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 827 // check if already in list 828 btstack_linked_list_iterator_t it; 829 sm_lookup_entry_t * entry; 830 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 831 while(btstack_linked_list_iterator_has_next(&it)){ 832 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 833 if (entry->address_type != address_type) continue; 834 if (memcmp(entry->address, address, 6)) continue; 835 // already in list 836 return BTSTACK_BUSY; 837 } 838 entry = btstack_memory_sm_lookup_entry_get(); 839 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 840 entry->address_type = (bd_addr_type_t) address_type; 841 memcpy(entry->address, address, 6); 842 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 843 sm_run(); 844 return 0; 845 } 846 847 // CMAC calculation using AES Engineq 848 #ifdef USE_CMAC_ENGINE 849 850 static void sm_cmac_done_trampoline(void * arg){ 851 UNUSED(arg); 852 sm_cmac_active = 0; 853 (*sm_cmac_done_callback)(sm_cmac_hash); 854 sm_run(); 855 } 856 857 int sm_cmac_ready(void){ 858 return sm_cmac_active == 0; 859 } 860 861 // generic cmac calculation 862 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 863 sm_cmac_active = 1; 864 sm_cmac_done_callback = done_callback; 865 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 866 } 867 #endif 868 869 // cmac for ATT Message signing 870 #ifdef ENABLE_LE_SIGNED_WRITE 871 872 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 873 sm_cmac_active = 1; 874 sm_cmac_done_callback = done_callback; 875 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 876 } 877 878 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_signed_write_message_len) { 880 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_signed_write_message_len - 1 - offset; 885 886 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_signed_write_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_signed_write_message[offset - 3]; 893 } 894 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 898 // ATT Message Signing 899 sm_cmac_signed_write_header[0] = opcode; 900 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 901 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 902 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 903 sm_cmac_signed_write_message = message; 904 sm_cmac_signed_write_message_len = total_message_len; 905 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 906 } 907 #endif 908 909 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 910 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 911 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 912 switch (setup->sm_stk_generation_method){ 913 case PK_RESP_INPUT: 914 if (IS_RESPONDER(sm_conn->sm_role)){ 915 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 916 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 917 } else { 918 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 919 } 920 break; 921 case PK_INIT_INPUT: 922 if (IS_RESPONDER(sm_conn->sm_role)){ 923 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 924 } else { 925 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 926 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 927 } 928 break; 929 case PK_BOTH_INPUT: 930 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 931 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 932 break; 933 case NUMERIC_COMPARISON: 934 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 935 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 936 break; 937 case JUST_WORKS: 938 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 939 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 940 break; 941 case OOB: 942 // client already provided OOB data, let's skip notification. 943 break; 944 } 945 } 946 947 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 948 int recv_flags; 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 // slave / responder 951 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 952 } else { 953 // master / initiator 954 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 955 } 956 957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 958 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 959 if (setup->sm_use_secure_connections){ 960 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 961 } 962 #endif 963 964 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 965 return recv_flags == setup->sm_key_distribution_received_set; 966 } 967 968 static void sm_done_for_handle(hci_con_handle_t con_handle){ 969 if (sm_active_connection_handle == con_handle){ 970 sm_timeout_stop(); 971 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 972 log_info("sm: connection 0x%x released setup context", con_handle); 973 } 974 } 975 976 static int sm_key_distribution_flags_for_auth_req(void){ 977 978 int flags = SM_KEYDIST_ID_KEY; 979 if (sm_auth_req & SM_AUTHREQ_BONDING){ 980 // encryption and signing information only if bonding requested 981 flags |= SM_KEYDIST_ENC_KEY; 982 #ifdef ENABLE_LE_SIGNED_WRITE 983 flags |= SM_KEYDIST_SIGN; 984 #endif 985 } 986 return flags; 987 } 988 989 static void sm_reset_setup(void){ 990 // fill in sm setup 991 setup->sm_state_vars = 0; 992 setup->sm_keypress_notification = 0; 993 sm_reset_tk(); 994 } 995 996 static void sm_init_setup(sm_connection_t * sm_conn){ 997 998 // fill in sm setup 999 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1000 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1001 1002 // query client for Legacy Pairing OOB data 1003 setup->sm_have_oob_data = 0; 1004 if (sm_get_oob_data) { 1005 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1006 } 1007 1008 // if available and SC supported, also ask for SC OOB Data 1009 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1010 memset(setup->sm_ra, 0, 16); 1011 memset(setup->sm_rb, 0, 16); 1012 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1013 if (sm_get_sc_oob_data){ 1014 if (IS_RESPONDER(sm_conn->sm_role)){ 1015 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1016 sm_conn->sm_peer_addr_type, 1017 sm_conn->sm_peer_address, 1018 setup->sm_peer_confirm, 1019 setup->sm_ra); 1020 } else { 1021 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1022 sm_conn->sm_peer_addr_type, 1023 sm_conn->sm_peer_address, 1024 setup->sm_peer_confirm, 1025 setup->sm_rb); 1026 } 1027 } else { 1028 setup->sm_have_oob_data = 0; 1029 } 1030 } 1031 #endif 1032 1033 sm_pairing_packet_t * local_packet; 1034 if (IS_RESPONDER(sm_conn->sm_role)){ 1035 // slave 1036 local_packet = &setup->sm_s_pres; 1037 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1038 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1039 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1040 } else { 1041 // master 1042 local_packet = &setup->sm_m_preq; 1043 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1044 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1045 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1046 1047 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1048 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1049 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1050 } 1051 1052 uint8_t auth_req = sm_auth_req; 1053 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1054 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1055 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1056 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1057 } 1058 1059 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1060 1061 sm_pairing_packet_t * remote_packet; 1062 int remote_key_request; 1063 if (IS_RESPONDER(sm_conn->sm_role)){ 1064 // slave / responder 1065 remote_packet = &setup->sm_m_preq; 1066 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1067 } else { 1068 // master / initiator 1069 remote_packet = &setup->sm_s_pres; 1070 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1071 } 1072 1073 // check key size 1074 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1075 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1076 1077 // decide on STK generation method / SC 1078 sm_setup_tk(); 1079 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1080 1081 // check if STK generation method is acceptable by client 1082 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1083 1084 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1085 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1086 if (setup->sm_use_secure_connections){ 1087 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1088 } 1089 #endif 1090 1091 // identical to responder 1092 sm_setup_key_distribution(remote_key_request); 1093 1094 // JUST WORKS doens't provide authentication 1095 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1096 1097 return 0; 1098 } 1099 1100 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1101 1102 // cache and reset context 1103 int matched_device_id = sm_address_resolution_test; 1104 address_resolution_mode_t mode = sm_address_resolution_mode; 1105 void * context = sm_address_resolution_context; 1106 1107 // reset context 1108 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1109 sm_address_resolution_context = NULL; 1110 sm_address_resolution_test = -1; 1111 hci_con_handle_t con_handle = 0; 1112 1113 sm_connection_t * sm_connection; 1114 #ifdef ENABLE_LE_CENTRAL 1115 sm_key_t ltk; 1116 int have_ltk; 1117 int pairing_need; 1118 #endif 1119 switch (mode){ 1120 case ADDRESS_RESOLUTION_GENERAL: 1121 break; 1122 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1123 sm_connection = (sm_connection_t *) context; 1124 con_handle = sm_connection->sm_handle; 1125 switch (event){ 1126 case ADDRESS_RESOLUTION_SUCEEDED: 1127 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1128 sm_connection->sm_le_db_index = matched_device_id; 1129 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1130 if (sm_connection->sm_role) { 1131 // LTK request received before, IRK required -> start LTK calculation 1132 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1133 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1134 } 1135 break; 1136 } 1137 #ifdef ENABLE_LE_CENTRAL 1138 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1139 have_ltk = !sm_is_null_key(ltk); 1140 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1141 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1142 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1143 // reset requests 1144 sm_connection->sm_security_request_received = 0; 1145 sm_connection->sm_pairing_requested = 0; 1146 // have ltk -> start encryption 1147 if (have_ltk){ 1148 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1149 break; 1150 } 1151 // pairint_request -> send pairing request 1152 if (pairing_need){ 1153 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1154 break; 1155 } 1156 #endif 1157 break; 1158 case ADDRESS_RESOLUTION_FAILED: 1159 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1160 if (sm_connection->sm_role) { 1161 // LTK request received before, IRK required -> negative LTK reply 1162 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1163 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1164 } 1165 break; 1166 } 1167 #ifdef ENABLE_LE_CENTRAL 1168 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1169 sm_connection->sm_security_request_received = 0; 1170 sm_connection->sm_pairing_requested = 0; 1171 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1172 #endif 1173 break; 1174 } 1175 break; 1176 default: 1177 break; 1178 } 1179 1180 switch (event){ 1181 case ADDRESS_RESOLUTION_SUCEEDED: 1182 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1183 break; 1184 case ADDRESS_RESOLUTION_FAILED: 1185 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1186 break; 1187 } 1188 } 1189 1190 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1191 1192 int le_db_index = -1; 1193 1194 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1195 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1196 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1197 & SM_AUTHREQ_BONDING ) != 0; 1198 1199 if (bonding_enabed){ 1200 1201 // lookup device based on IRK 1202 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1203 int i; 1204 for (i=0; i < le_device_db_max_count(); i++){ 1205 sm_key_t irk; 1206 bd_addr_t address; 1207 int address_type = BD_ADDR_TYPE_UNKNOWN; 1208 le_device_db_info(i, &address_type, address, irk); 1209 // check if valid entry retrieved 1210 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1211 // compare IRK 1212 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1213 1214 log_info("sm: device found for IRK, updating"); 1215 le_db_index = i; 1216 break; 1217 } 1218 } else { 1219 // assert IRK is set to zero 1220 memset(setup->sm_peer_irk, 0, 16); 1221 } 1222 1223 // if not found, lookup via public address if possible 1224 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1225 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1226 int i; 1227 for (i=0; i < le_device_db_max_count(); i++){ 1228 bd_addr_t address; 1229 int address_type; 1230 le_device_db_info(i, &address_type, address, NULL); 1231 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1232 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1233 log_info("sm: device found for public address, updating"); 1234 le_db_index = i; 1235 break; 1236 } 1237 } 1238 } 1239 1240 // if not found, add to db 1241 if (le_db_index < 0) { 1242 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1243 } 1244 1245 if (le_db_index >= 0){ 1246 1247 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1248 1249 #ifdef ENABLE_LE_SIGNED_WRITE 1250 // store local CSRK 1251 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1252 log_info("sm: store local CSRK"); 1253 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1254 le_device_db_local_counter_set(le_db_index, 0); 1255 } 1256 1257 // store remote CSRK 1258 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1259 log_info("sm: store remote CSRK"); 1260 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1261 le_device_db_remote_counter_set(le_db_index, 0); 1262 } 1263 #endif 1264 // store encryption information for secure connections: LTK generated by ECDH 1265 if (setup->sm_use_secure_connections){ 1266 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1267 uint8_t zero_rand[8]; 1268 memset(zero_rand, 0, 8); 1269 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1270 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1271 } 1272 1273 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1274 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1275 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1276 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1277 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1278 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1279 1280 } 1281 } 1282 } else { 1283 log_info("Ignoring received keys, bonding not enabled"); 1284 } 1285 1286 // keep le_db_index 1287 sm_conn->sm_le_db_index = le_db_index; 1288 } 1289 1290 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1291 setup->sm_pairing_failed_reason = reason; 1292 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1293 } 1294 1295 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1296 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1297 } 1298 1299 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1300 1301 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1302 static int sm_passkey_used(stk_generation_method_t method); 1303 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1304 1305 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1306 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1307 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1308 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1309 } else { 1310 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1311 } 1312 } 1313 1314 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1315 if (IS_RESPONDER(sm_conn->sm_role)){ 1316 // Responder 1317 if (setup->sm_stk_generation_method == OOB){ 1318 // generate Nb 1319 log_info("Generate Nb"); 1320 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1321 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1322 } else { 1323 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1324 } 1325 } else { 1326 // Initiator role 1327 switch (setup->sm_stk_generation_method){ 1328 case JUST_WORKS: 1329 sm_sc_prepare_dhkey_check(sm_conn); 1330 break; 1331 1332 case NUMERIC_COMPARISON: 1333 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1334 break; 1335 case PK_INIT_INPUT: 1336 case PK_RESP_INPUT: 1337 case PK_BOTH_INPUT: 1338 if (setup->sm_passkey_bit < 20) { 1339 sm_sc_start_calculating_local_confirm(sm_conn); 1340 } else { 1341 sm_sc_prepare_dhkey_check(sm_conn); 1342 } 1343 break; 1344 case OOB: 1345 sm_sc_prepare_dhkey_check(sm_conn); 1346 break; 1347 } 1348 } 1349 } 1350 1351 static void sm_sc_cmac_done(uint8_t * hash){ 1352 log_info("sm_sc_cmac_done: "); 1353 log_info_hexdump(hash, 16); 1354 1355 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1356 sm_sc_oob_state = SM_SC_OOB_IDLE; 1357 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1358 return; 1359 } 1360 1361 sm_connection_t * sm_conn = sm_cmac_connection; 1362 sm_cmac_connection = NULL; 1363 #ifdef ENABLE_CLASSIC 1364 link_key_type_t link_key_type; 1365 #endif 1366 1367 switch (sm_conn->sm_engine_state){ 1368 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1369 memcpy(setup->sm_local_confirm, hash, 16); 1370 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1371 break; 1372 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1373 // check 1374 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1375 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1376 break; 1377 } 1378 sm_sc_state_after_receiving_random(sm_conn); 1379 break; 1380 case SM_SC_W4_CALCULATE_G2: { 1381 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1382 big_endian_store_32(setup->sm_tk, 12, vab); 1383 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1384 sm_trigger_user_response(sm_conn); 1385 break; 1386 } 1387 case SM_SC_W4_CALCULATE_F5_SALT: 1388 memcpy(setup->sm_t, hash, 16); 1389 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1390 break; 1391 case SM_SC_W4_CALCULATE_F5_MACKEY: 1392 memcpy(setup->sm_mackey, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1394 break; 1395 case SM_SC_W4_CALCULATE_F5_LTK: 1396 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1397 // Errata Service Release to the Bluetooth Specification: ESR09 1398 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1399 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1400 memcpy(setup->sm_ltk, hash, 16); 1401 memcpy(setup->sm_local_ltk, hash, 16); 1402 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1403 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1404 break; 1405 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1406 memcpy(setup->sm_local_dhkey_check, hash, 16); 1407 if (IS_RESPONDER(sm_conn->sm_role)){ 1408 // responder 1409 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1410 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1411 } else { 1412 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1413 } 1414 } else { 1415 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1416 } 1417 break; 1418 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1419 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1420 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1421 break; 1422 } 1423 if (IS_RESPONDER(sm_conn->sm_role)){ 1424 // responder 1425 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1426 } else { 1427 // initiator 1428 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1429 } 1430 break; 1431 case SM_SC_W4_CALCULATE_H6_ILK: 1432 memcpy(setup->sm_t, hash, 16); 1433 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1434 break; 1435 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1436 #ifdef ENABLE_CLASSIC 1437 reverse_128(hash, setup->sm_t); 1438 link_key_type = sm_conn->sm_connection_authenticated ? 1439 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1440 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1441 if (IS_RESPONDER(sm_conn->sm_role)){ 1442 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1443 } else { 1444 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1445 } 1446 #endif 1447 if (IS_RESPONDER(sm_conn->sm_role)){ 1448 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1449 } else { 1450 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1451 } 1452 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1453 sm_done_for_handle(sm_conn->sm_handle); 1454 break; 1455 default: 1456 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1457 break; 1458 } 1459 sm_run(); 1460 } 1461 1462 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1463 const uint16_t message_len = 65; 1464 sm_cmac_connection = sm_conn; 1465 memcpy(sm_cmac_sc_buffer, u, 32); 1466 memcpy(sm_cmac_sc_buffer+32, v, 32); 1467 sm_cmac_sc_buffer[64] = z; 1468 log_info("f4 key"); 1469 log_info_hexdump(x, 16); 1470 log_info("f4 message"); 1471 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1472 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1473 } 1474 1475 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1476 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1477 static const uint8_t f5_length[] = { 0x01, 0x00}; 1478 1479 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1480 log_info("f5_calculate_salt"); 1481 // calculate salt for f5 1482 const uint16_t message_len = 32; 1483 sm_cmac_connection = sm_conn; 1484 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1485 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1486 } 1487 1488 static inline void f5_mackkey(sm_connection_t * sm_conn, sm_key_t t, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ 1489 const uint16_t message_len = 53; 1490 sm_cmac_connection = sm_conn; 1491 1492 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1493 sm_cmac_sc_buffer[0] = 0; 1494 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1495 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1496 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1497 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1498 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1499 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1500 log_info("f5 key"); 1501 log_info_hexdump(t, 16); 1502 log_info("f5 message for MacKey"); 1503 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1504 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1505 } 1506 1507 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1508 sm_key56_t bd_addr_master, bd_addr_slave; 1509 bd_addr_master[0] = setup->sm_m_addr_type; 1510 bd_addr_slave[0] = setup->sm_s_addr_type; 1511 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1512 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1513 if (IS_RESPONDER(sm_conn->sm_role)){ 1514 // responder 1515 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1516 } else { 1517 // initiator 1518 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1519 } 1520 } 1521 1522 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1523 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1524 const uint16_t message_len = 53; 1525 sm_cmac_connection = sm_conn; 1526 sm_cmac_sc_buffer[0] = 1; 1527 // 1..52 setup before 1528 log_info("f5 key"); 1529 log_info_hexdump(t, 16); 1530 log_info("f5 message for LTK"); 1531 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1532 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1533 } 1534 1535 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1536 f5_ltk(sm_conn, setup->sm_t); 1537 } 1538 1539 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w, const sm_key_t n1, const sm_key_t n2, const sm_key_t r, const sm_key24_t io_cap, const sm_key56_t a1, const sm_key56_t a2){ 1540 const uint16_t message_len = 65; 1541 sm_cmac_connection = sm_conn; 1542 memcpy(sm_cmac_sc_buffer, n1, 16); 1543 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1544 memcpy(sm_cmac_sc_buffer+32, r, 16); 1545 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1546 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1547 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1548 log_info("f6 key"); 1549 log_info_hexdump(w, 16); 1550 log_info("f6 message"); 1551 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1552 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1553 } 1554 1555 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1556 // - U is 256 bits 1557 // - V is 256 bits 1558 // - X is 128 bits 1559 // - Y is 128 bits 1560 static void g2_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ 1561 const uint16_t message_len = 80; 1562 sm_cmac_connection = sm_conn; 1563 memcpy(sm_cmac_sc_buffer, u, 32); 1564 memcpy(sm_cmac_sc_buffer+32, v, 32); 1565 memcpy(sm_cmac_sc_buffer+64, y, 16); 1566 log_info("g2 key"); 1567 log_info_hexdump(x, 16); 1568 log_info("g2 message"); 1569 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1570 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1571 } 1572 1573 static void g2_calculate(sm_connection_t * sm_conn) { 1574 // calc Va if numeric comparison 1575 if (IS_RESPONDER(sm_conn->sm_role)){ 1576 // responder 1577 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1578 } else { 1579 // initiator 1580 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1581 } 1582 } 1583 1584 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1585 uint8_t z = 0; 1586 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1587 // some form of passkey 1588 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1589 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1590 setup->sm_passkey_bit++; 1591 } 1592 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1593 } 1594 1595 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1596 // OOB 1597 if (setup->sm_stk_generation_method == OOB){ 1598 if (IS_RESPONDER(sm_conn->sm_role)){ 1599 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1600 } else { 1601 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1602 } 1603 return; 1604 } 1605 1606 uint8_t z = 0; 1607 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1608 // some form of passkey 1609 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1610 // sm_passkey_bit was increased before sending confirm value 1611 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1612 } 1613 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1614 } 1615 1616 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1617 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1618 1619 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1620 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1621 return; 1622 } else { 1623 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1624 } 1625 } 1626 1627 static void sm_sc_dhkey_calculated(void * arg){ 1628 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1629 log_info("dhkey"); 1630 log_info_hexdump(&setup->sm_dhkey[0], 32); 1631 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1632 // trigger next step 1633 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1634 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1635 } 1636 sm_run(); 1637 } 1638 1639 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1640 // calculate DHKCheck 1641 sm_key56_t bd_addr_master, bd_addr_slave; 1642 bd_addr_master[0] = setup->sm_m_addr_type; 1643 bd_addr_slave[0] = setup->sm_s_addr_type; 1644 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1645 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1646 uint8_t iocap_a[3]; 1647 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1648 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1649 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1650 uint8_t iocap_b[3]; 1651 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1652 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1653 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1654 if (IS_RESPONDER(sm_conn->sm_role)){ 1655 // responder 1656 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1657 } else { 1658 // initiator 1659 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1660 } 1661 } 1662 1663 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1664 // validate E = f6() 1665 sm_key56_t bd_addr_master, bd_addr_slave; 1666 bd_addr_master[0] = setup->sm_m_addr_type; 1667 bd_addr_slave[0] = setup->sm_s_addr_type; 1668 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1669 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1670 1671 uint8_t iocap_a[3]; 1672 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1673 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1674 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1675 uint8_t iocap_b[3]; 1676 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1677 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1678 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1679 if (IS_RESPONDER(sm_conn->sm_role)){ 1680 // responder 1681 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1682 } else { 1683 // initiator 1684 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1685 } 1686 } 1687 1688 1689 // 1690 // Link Key Conversion Function h6 1691 // 1692 // h6(W, keyID) = AES-CMACW(keyID) 1693 // - W is 128 bits 1694 // - keyID is 32 bits 1695 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1696 const uint16_t message_len = 4; 1697 sm_cmac_connection = sm_conn; 1698 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1699 log_info("h6 key"); 1700 log_info_hexdump(w, 16); 1701 log_info("h6 message"); 1702 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1703 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1704 } 1705 1706 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1707 // Errata Service Release to the Bluetooth Specification: ESR09 1708 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1709 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1710 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1711 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1712 } 1713 1714 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1715 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1716 } 1717 1718 #endif 1719 1720 // key management legacy connections: 1721 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1722 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1723 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1724 // - responder reconnects: responder uses LTK receveived from master 1725 1726 // key management secure connections: 1727 // - both devices store same LTK from ECDH key exchange. 1728 1729 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1730 static void sm_load_security_info(sm_connection_t * sm_connection){ 1731 int encryption_key_size; 1732 int authenticated; 1733 int authorized; 1734 1735 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1736 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1737 &encryption_key_size, &authenticated, &authorized); 1738 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1739 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1740 sm_connection->sm_connection_authenticated = authenticated; 1741 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1742 } 1743 #endif 1744 1745 #ifdef ENABLE_LE_PERIPHERAL 1746 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1747 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1748 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1749 // re-establish used key encryption size 1750 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1751 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1752 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1753 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1754 log_info("sm: received ltk request with key size %u, authenticated %u", 1755 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1756 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1757 sm_run(); 1758 } 1759 #endif 1760 1761 static void sm_run(void){ 1762 1763 btstack_linked_list_iterator_t it; 1764 1765 // assert that stack has already bootet 1766 if (hci_get_state() != HCI_STATE_WORKING) return; 1767 1768 // assert that we can send at least commands 1769 if (!hci_can_send_command_packet_now()) return; 1770 1771 // 1772 // non-connection related behaviour 1773 // 1774 1775 // distributed key generation 1776 switch (dkg_state){ 1777 case DKG_CALC_IRK: 1778 // already busy? 1779 if (sm_aes128_state == SM_AES128_IDLE) { 1780 log_info("DKG_CALC_IRK started"); 1781 // IRK = d1(IR, 1, 0) 1782 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1783 sm_aes128_state = SM_AES128_ACTIVE; 1784 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1785 return; 1786 } 1787 break; 1788 case DKG_CALC_DHK: 1789 // already busy? 1790 if (sm_aes128_state == SM_AES128_IDLE) { 1791 log_info("DKG_CALC_DHK started"); 1792 // DHK = d1(IR, 3, 0) 1793 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1794 sm_aes128_state = SM_AES128_ACTIVE; 1795 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1796 return; 1797 } 1798 break; 1799 default: 1800 break; 1801 } 1802 1803 // random address updates 1804 switch (rau_state){ 1805 case RAU_GET_ENC: 1806 // already busy? 1807 if (sm_aes128_state == SM_AES128_IDLE) { 1808 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1809 sm_aes128_state = SM_AES128_ACTIVE; 1810 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1811 return; 1812 } 1813 break; 1814 case RAU_SET_ADDRESS: 1815 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1816 rau_state = RAU_IDLE; 1817 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1818 return; 1819 default: 1820 break; 1821 } 1822 1823 // CSRK Lookup 1824 // -- if csrk lookup ready, find connection that require csrk lookup 1825 if (sm_address_resolution_idle()){ 1826 hci_connections_get_iterator(&it); 1827 while(btstack_linked_list_iterator_has_next(&it)){ 1828 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1829 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1830 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1831 // and start lookup 1832 sm_address_resolution_start_lookup(sm_connection->sm_peer_addr_type, sm_connection->sm_handle, sm_connection->sm_peer_address, ADDRESS_RESOLUTION_FOR_CONNECTION, sm_connection); 1833 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1834 break; 1835 } 1836 } 1837 } 1838 1839 // -- if csrk lookup ready, resolved addresses for received addresses 1840 if (sm_address_resolution_idle()) { 1841 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1842 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1843 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1844 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1845 btstack_memory_sm_lookup_entry_free(entry); 1846 } 1847 } 1848 1849 // -- Continue with CSRK device lookup by public or resolvable private address 1850 if (!sm_address_resolution_idle()){ 1851 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1852 while (sm_address_resolution_test < le_device_db_max_count()){ 1853 int addr_type; 1854 bd_addr_t addr; 1855 sm_key_t irk; 1856 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1857 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1858 1859 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1860 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1861 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1862 break; 1863 } 1864 1865 if (sm_address_resolution_addr_type == 0){ 1866 sm_address_resolution_test++; 1867 continue; 1868 } 1869 1870 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1871 1872 log_info("LE Device Lookup: calculate AH"); 1873 log_info_key("IRK", irk); 1874 1875 memcpy(sm_aes128_key, irk, 16); 1876 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1877 sm_address_resolution_ah_calculation_active = 1; 1878 sm_aes128_state = SM_AES128_ACTIVE; 1879 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1880 return; 1881 } 1882 1883 if (sm_address_resolution_test >= le_device_db_max_count()){ 1884 log_info("LE Device Lookup: not found"); 1885 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1886 } 1887 } 1888 1889 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1890 switch (sm_sc_oob_state){ 1891 case SM_SC_OOB_W2_CALC_CONFIRM: 1892 if (!sm_cmac_ready()) break; 1893 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1894 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1895 return; 1896 default: 1897 break; 1898 } 1899 #endif 1900 1901 // assert that we can send at least commands - cmd might have been sent by crypto engine 1902 if (!hci_can_send_command_packet_now()) return; 1903 1904 // handle basic actions that don't requires the full context 1905 hci_connections_get_iterator(&it); 1906 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1907 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1908 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1909 switch(sm_connection->sm_engine_state){ 1910 // responder side 1911 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1912 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1913 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1914 return; 1915 1916 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1917 case SM_SC_RECEIVED_LTK_REQUEST: 1918 switch (sm_connection->sm_irk_lookup_state){ 1919 case IRK_LOOKUP_FAILED: 1920 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1921 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1922 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1923 return; 1924 default: 1925 break; 1926 } 1927 break; 1928 #endif 1929 default: 1930 break; 1931 } 1932 } 1933 1934 // 1935 // active connection handling 1936 // -- use loop to handle next connection if lock on setup context is released 1937 1938 while (1) { 1939 1940 // Find connections that requires setup context and make active if no other is locked 1941 hci_connections_get_iterator(&it); 1942 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1943 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1944 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1945 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1946 int done = 1; 1947 int err; 1948 UNUSED(err); 1949 switch (sm_connection->sm_engine_state) { 1950 #ifdef ENABLE_LE_PERIPHERAL 1951 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1952 // send packet if possible, 1953 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1954 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1955 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1956 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1957 } else { 1958 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1959 } 1960 // don't lock sxetup context yet 1961 done = 0; 1962 break; 1963 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1964 sm_reset_setup(); 1965 sm_init_setup(sm_connection); 1966 // recover pairing request 1967 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1968 err = sm_stk_generation_init(sm_connection); 1969 1970 #ifdef ENABLE_TESTING_SUPPORT 1971 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 1972 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 1973 err = test_pairing_failure; 1974 } 1975 #endif 1976 if (err){ 1977 setup->sm_pairing_failed_reason = err; 1978 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1979 break; 1980 } 1981 sm_timeout_start(sm_connection); 1982 // generate random number first, if we need to show passkey 1983 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1984 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 1985 break; 1986 } 1987 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1988 break; 1989 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 1990 sm_reset_setup(); 1991 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 1992 break; 1993 #endif 1994 #ifdef ENABLE_LE_CENTRAL 1995 case SM_INITIATOR_PH0_HAS_LTK: 1996 sm_reset_setup(); 1997 sm_load_security_info(sm_connection); 1998 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1999 break; 2000 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2001 sm_reset_setup(); 2002 sm_init_setup(sm_connection); 2003 sm_timeout_start(sm_connection); 2004 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2005 break; 2006 #endif 2007 2008 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2009 case SM_SC_RECEIVED_LTK_REQUEST: 2010 switch (sm_connection->sm_irk_lookup_state){ 2011 case IRK_LOOKUP_SUCCEEDED: 2012 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2013 // start using context by loading security info 2014 sm_reset_setup(); 2015 sm_load_security_info(sm_connection); 2016 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2017 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2018 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2019 break; 2020 } 2021 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2022 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2023 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2024 // don't lock setup context yet 2025 return; 2026 default: 2027 // just wait until IRK lookup is completed 2028 // don't lock setup context yet 2029 done = 0; 2030 break; 2031 } 2032 break; 2033 #endif 2034 default: 2035 done = 0; 2036 break; 2037 } 2038 if (done){ 2039 sm_active_connection_handle = sm_connection->sm_handle; 2040 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); 2041 } 2042 } 2043 2044 // 2045 // active connection handling 2046 // 2047 2048 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2049 2050 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2051 if (!connection) { 2052 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2053 return; 2054 } 2055 2056 // assert that we could send a SM PDU - not needed for all of the following 2057 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2058 log_info("cannot send now, requesting can send now event"); 2059 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2060 return; 2061 } 2062 2063 // send keypress notifications 2064 if (setup->sm_keypress_notification){ 2065 int i; 2066 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2067 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2068 uint8_t action = 0; 2069 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2070 if (flags & (1<<i)){ 2071 int clear_flag = 1; 2072 switch (i){ 2073 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2074 case SM_KEYPRESS_PASSKEY_CLEARED: 2075 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2076 default: 2077 break; 2078 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2079 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2080 num_actions--; 2081 clear_flag = num_actions == 0; 2082 break; 2083 } 2084 if (clear_flag){ 2085 flags &= ~(1<<i); 2086 } 2087 action = i; 2088 break; 2089 } 2090 } 2091 setup->sm_keypress_notification = (num_actions << 5) | flags; 2092 2093 // send keypress notification 2094 uint8_t buffer[2]; 2095 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2096 buffer[1] = action; 2097 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2098 2099 // try 2100 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2101 return; 2102 } 2103 2104 int key_distribution_flags; 2105 UNUSED(key_distribution_flags); 2106 2107 log_info("sm_run: state %u", connection->sm_engine_state); 2108 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2109 log_info("sm_run // cannot send"); 2110 } 2111 switch (connection->sm_engine_state){ 2112 2113 // general 2114 case SM_GENERAL_SEND_PAIRING_FAILED: { 2115 uint8_t buffer[2]; 2116 buffer[0] = SM_CODE_PAIRING_FAILED; 2117 buffer[1] = setup->sm_pairing_failed_reason; 2118 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2119 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2120 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2121 sm_done_for_handle(connection->sm_handle); 2122 break; 2123 } 2124 2125 // responding state 2126 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2127 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2128 if (!sm_cmac_ready()) break; 2129 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2130 sm_sc_calculate_local_confirm(connection); 2131 break; 2132 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2133 if (!sm_cmac_ready()) break; 2134 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2135 sm_sc_calculate_remote_confirm(connection); 2136 break; 2137 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2138 if (!sm_cmac_ready()) break; 2139 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2140 sm_sc_calculate_f6_for_dhkey_check(connection); 2141 break; 2142 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2143 if (!sm_cmac_ready()) break; 2144 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2145 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2146 break; 2147 case SM_SC_W2_CALCULATE_F5_SALT: 2148 if (!sm_cmac_ready()) break; 2149 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2150 f5_calculate_salt(connection); 2151 break; 2152 case SM_SC_W2_CALCULATE_F5_MACKEY: 2153 if (!sm_cmac_ready()) break; 2154 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2155 f5_calculate_mackey(connection); 2156 break; 2157 case SM_SC_W2_CALCULATE_F5_LTK: 2158 if (!sm_cmac_ready()) break; 2159 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2160 f5_calculate_ltk(connection); 2161 break; 2162 case SM_SC_W2_CALCULATE_G2: 2163 if (!sm_cmac_ready()) break; 2164 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2165 g2_calculate(connection); 2166 break; 2167 case SM_SC_W2_CALCULATE_H6_ILK: 2168 if (!sm_cmac_ready()) break; 2169 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2170 h6_calculate_ilk(connection); 2171 break; 2172 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2173 if (!sm_cmac_ready()) break; 2174 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2175 h6_calculate_br_edr_link_key(connection); 2176 break; 2177 #endif 2178 2179 #ifdef ENABLE_LE_CENTRAL 2180 // initiator side 2181 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2182 sm_key_t peer_ltk_flipped; 2183 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2184 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2185 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2186 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2187 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2188 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2189 return; 2190 } 2191 2192 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2193 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2194 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2195 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2196 sm_timeout_reset(connection); 2197 break; 2198 #endif 2199 2200 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2201 2202 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2203 int trigger_user_response = 0; 2204 2205 uint8_t buffer[65]; 2206 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2207 // 2208 reverse_256(&ec_q[0], &buffer[1]); 2209 reverse_256(&ec_q[32], &buffer[33]); 2210 2211 // stk generation method 2212 // passkey entry: notify app to show passkey or to request passkey 2213 switch (setup->sm_stk_generation_method){ 2214 case JUST_WORKS: 2215 case NUMERIC_COMPARISON: 2216 if (IS_RESPONDER(connection->sm_role)){ 2217 // responder 2218 sm_sc_start_calculating_local_confirm(connection); 2219 } else { 2220 // initiator 2221 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2222 } 2223 break; 2224 case PK_INIT_INPUT: 2225 case PK_RESP_INPUT: 2226 case PK_BOTH_INPUT: 2227 // use random TK for display 2228 memcpy(setup->sm_ra, setup->sm_tk, 16); 2229 memcpy(setup->sm_rb, setup->sm_tk, 16); 2230 setup->sm_passkey_bit = 0; 2231 2232 if (IS_RESPONDER(connection->sm_role)){ 2233 // responder 2234 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2235 } else { 2236 // initiator 2237 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2238 } 2239 trigger_user_response = 1; 2240 break; 2241 case OOB: 2242 if (IS_RESPONDER(connection->sm_role)){ 2243 // responder 2244 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2245 } else { 2246 // initiator 2247 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2248 } 2249 break; 2250 } 2251 2252 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2253 sm_timeout_reset(connection); 2254 2255 // trigger user response after sending pdu 2256 if (trigger_user_response){ 2257 sm_trigger_user_response(connection); 2258 } 2259 break; 2260 } 2261 case SM_SC_SEND_CONFIRMATION: { 2262 uint8_t buffer[17]; 2263 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2264 reverse_128(setup->sm_local_confirm, &buffer[1]); 2265 if (IS_RESPONDER(connection->sm_role)){ 2266 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2267 } else { 2268 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2269 } 2270 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2271 sm_timeout_reset(connection); 2272 break; 2273 } 2274 case SM_SC_SEND_PAIRING_RANDOM: { 2275 uint8_t buffer[17]; 2276 buffer[0] = SM_CODE_PAIRING_RANDOM; 2277 reverse_128(setup->sm_local_nonce, &buffer[1]); 2278 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2279 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2280 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2281 if (IS_RESPONDER(connection->sm_role)){ 2282 // responder 2283 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2284 } else { 2285 // initiator 2286 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2287 } 2288 } else { 2289 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2290 if (IS_RESPONDER(connection->sm_role)){ 2291 // responder 2292 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2293 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2294 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2295 } else { 2296 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2297 sm_sc_prepare_dhkey_check(connection); 2298 } 2299 } else { 2300 // initiator 2301 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2302 } 2303 } 2304 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2305 sm_timeout_reset(connection); 2306 break; 2307 } 2308 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2309 uint8_t buffer[17]; 2310 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2311 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2312 2313 if (IS_RESPONDER(connection->sm_role)){ 2314 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2315 } else { 2316 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2317 } 2318 2319 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2320 sm_timeout_reset(connection); 2321 break; 2322 } 2323 2324 #endif 2325 2326 #ifdef ENABLE_LE_PERIPHERAL 2327 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2328 // echo initiator for now 2329 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2330 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2331 2332 if (setup->sm_use_secure_connections){ 2333 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2334 } else { 2335 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2336 } 2337 2338 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); 2339 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); 2340 // update key distribution after ENC was dropped 2341 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2342 2343 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2344 sm_timeout_reset(connection); 2345 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2346 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2347 sm_trigger_user_response(connection); 2348 } 2349 return; 2350 #endif 2351 2352 case SM_PH2_SEND_PAIRING_RANDOM: { 2353 uint8_t buffer[17]; 2354 buffer[0] = SM_CODE_PAIRING_RANDOM; 2355 reverse_128(setup->sm_local_random, &buffer[1]); 2356 if (IS_RESPONDER(connection->sm_role)){ 2357 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2358 } else { 2359 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2360 } 2361 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2362 sm_timeout_reset(connection); 2363 break; 2364 } 2365 2366 case SM_PH2_C1_GET_ENC_A: 2367 // already busy? 2368 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2369 // calculate confirm using aes128 engine - step 1 2370 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); 2371 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 2372 sm_aes128_state = SM_AES128_ACTIVE; 2373 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, connection); 2374 break; 2375 2376 case SM_PH2_C1_GET_ENC_C: 2377 // already busy? 2378 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2379 // calculate m_confirm using aes128 engine - step 1 2380 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); 2381 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2382 sm_aes128_state = SM_AES128_ACTIVE; 2383 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2384 break; 2385 2386 case SM_PH2_CALC_STK: 2387 // already busy? 2388 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2389 // calculate STK 2390 if (IS_RESPONDER(connection->sm_role)){ 2391 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2392 } else { 2393 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2394 } 2395 connection->sm_engine_state = SM_PH2_W4_STK; 2396 sm_aes128_state = SM_AES128_ACTIVE; 2397 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2398 break; 2399 2400 case SM_PH3_Y_GET_ENC: 2401 // already busy? 2402 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2403 // PH3B2 - calculate Y from - enc 2404 // Y = dm(DHK, Rand) 2405 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2406 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2407 sm_aes128_state = SM_AES128_ACTIVE; 2408 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); 2409 break; 2410 2411 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2412 uint8_t buffer[17]; 2413 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2414 reverse_128(setup->sm_local_confirm, &buffer[1]); 2415 if (IS_RESPONDER(connection->sm_role)){ 2416 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2417 } else { 2418 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2419 } 2420 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2421 sm_timeout_reset(connection); 2422 return; 2423 } 2424 #ifdef ENABLE_LE_PERIPHERAL 2425 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2426 sm_key_t stk_flipped; 2427 reverse_128(setup->sm_ltk, stk_flipped); 2428 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2429 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2430 return; 2431 } 2432 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2433 sm_key_t ltk_flipped; 2434 reverse_128(setup->sm_ltk, ltk_flipped); 2435 connection->sm_engine_state = SM_RESPONDER_IDLE; 2436 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2437 sm_done_for_handle(connection->sm_handle); 2438 return; 2439 } 2440 case SM_RESPONDER_PH4_Y_GET_ENC: 2441 // already busy? 2442 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2443 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2444 // Y = dm(DHK, Rand) 2445 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2446 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2447 sm_aes128_state = SM_AES128_ACTIVE; 2448 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); 2449 return; 2450 #endif 2451 #ifdef ENABLE_LE_CENTRAL 2452 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2453 sm_key_t stk_flipped; 2454 reverse_128(setup->sm_ltk, stk_flipped); 2455 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2456 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2457 return; 2458 } 2459 #endif 2460 2461 case SM_PH3_DISTRIBUTE_KEYS: 2462 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2463 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2464 uint8_t buffer[17]; 2465 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2466 reverse_128(setup->sm_ltk, &buffer[1]); 2467 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2468 sm_timeout_reset(connection); 2469 return; 2470 } 2471 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2472 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2473 uint8_t buffer[11]; 2474 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2475 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2476 reverse_64(setup->sm_local_rand, &buffer[3]); 2477 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2478 sm_timeout_reset(connection); 2479 return; 2480 } 2481 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2482 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2483 uint8_t buffer[17]; 2484 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2485 reverse_128(sm_persistent_irk, &buffer[1]); 2486 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2487 sm_timeout_reset(connection); 2488 return; 2489 } 2490 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2491 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2492 bd_addr_t local_address; 2493 uint8_t buffer[8]; 2494 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2495 switch (gap_random_address_get_mode()){ 2496 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2497 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2498 // public or static random 2499 gap_le_get_own_address(&buffer[1], local_address); 2500 break; 2501 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2502 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2503 // fallback to public 2504 gap_local_bd_addr(local_address); 2505 buffer[1] = 0; 2506 break; 2507 } 2508 reverse_bd_addr(local_address, &buffer[2]); 2509 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2510 sm_timeout_reset(connection); 2511 return; 2512 } 2513 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2514 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2515 2516 // hack to reproduce test runs 2517 if (test_use_fixed_local_csrk){ 2518 memset(setup->sm_local_csrk, 0xcc, 16); 2519 } 2520 2521 uint8_t buffer[17]; 2522 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2523 reverse_128(setup->sm_local_csrk, &buffer[1]); 2524 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2525 sm_timeout_reset(connection); 2526 return; 2527 } 2528 2529 // keys are sent 2530 if (IS_RESPONDER(connection->sm_role)){ 2531 // slave -> receive master keys if any 2532 if (sm_key_distribution_all_received(connection)){ 2533 sm_key_distribution_handle_all_received(connection); 2534 connection->sm_engine_state = SM_RESPONDER_IDLE; 2535 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2536 sm_done_for_handle(connection->sm_handle); 2537 } else { 2538 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2539 } 2540 } else { 2541 // master -> all done 2542 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2543 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2544 sm_done_for_handle(connection->sm_handle); 2545 } 2546 break; 2547 2548 default: 2549 break; 2550 } 2551 2552 // check again if active connection was released 2553 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2554 } 2555 } 2556 2557 // sm_aes128_state stays active 2558 static void sm_handle_encryption_result_enc_a(void *arg){ 2559 sm_connection_t * connection = (sm_connection_t*) arg; 2560 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2561 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); 2562 } 2563 2564 static void sm_handle_encryption_result_enc_b(void *arg){ 2565 sm_connection_t * connection = (sm_connection_t*) arg; 2566 sm_aes128_state = SM_AES128_IDLE; 2567 log_info_key("c1!", setup->sm_local_confirm); 2568 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2569 sm_run(); 2570 } 2571 2572 // sm_aes128_state stays active 2573 static void sm_handle_encryption_result_enc_c(void *arg){ 2574 sm_connection_t * connection = (sm_connection_t*) arg; 2575 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2576 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); 2577 } 2578 2579 static void sm_handle_encryption_result_enc_d(void * arg){ 2580 sm_connection_t * connection = (sm_connection_t*) arg; 2581 sm_aes128_state = SM_AES128_IDLE; 2582 log_info_key("c1!", sm_aes128_ciphertext); 2583 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2584 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2585 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2586 sm_run(); 2587 return; 2588 } 2589 if (IS_RESPONDER(connection->sm_role)){ 2590 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2591 sm_run(); 2592 } else { 2593 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2594 sm_aes128_state = SM_AES128_ACTIVE; 2595 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2596 } 2597 } 2598 2599 static void sm_handle_encryption_result_enc_stk(void *arg){ 2600 sm_connection_t * connection = (sm_connection_t*) arg; 2601 sm_aes128_state = SM_AES128_IDLE; 2602 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2603 log_info_key("stk", setup->sm_ltk); 2604 if (IS_RESPONDER(connection->sm_role)){ 2605 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2606 } else { 2607 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2608 } 2609 sm_run(); 2610 } 2611 2612 // sm_aes128_state stays active 2613 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2614 sm_connection_t * connection = (sm_connection_t*) arg; 2615 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2616 log_info_hex16("y", setup->sm_local_y); 2617 // PH3B3 - calculate EDIV 2618 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2619 log_info_hex16("ediv", setup->sm_local_ediv); 2620 // PH3B4 - calculate LTK - enc 2621 // LTK = d1(ER, DIV, 0)) 2622 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2623 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); 2624 } 2625 2626 #ifdef ENABLE_LE_PERIPHERAL 2627 // sm_aes128_state stays active 2628 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2629 sm_connection_t * connection = (sm_connection_t*) arg; 2630 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2631 log_info_hex16("y", setup->sm_local_y); 2632 2633 // PH3B3 - calculate DIV 2634 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2635 log_info_hex16("ediv", setup->sm_local_ediv); 2636 // PH3B4 - calculate LTK - enc 2637 // LTK = d1(ER, DIV, 0)) 2638 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2639 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); 2640 } 2641 #endif 2642 2643 // sm_aes128_state stays active 2644 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2645 sm_connection_t * connection = (sm_connection_t*) arg; 2646 log_info_key("ltk", setup->sm_ltk); 2647 // calc CSRK next 2648 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2649 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); 2650 } 2651 2652 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2653 sm_connection_t * connection = (sm_connection_t*) arg; 2654 sm_aes128_state = SM_AES128_IDLE; 2655 log_info_key("csrk", setup->sm_local_csrk); 2656 if (setup->sm_key_distribution_send_set){ 2657 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2658 } else { 2659 // no keys to send, just continue 2660 if (IS_RESPONDER(connection->sm_role)){ 2661 // slave -> receive master keys 2662 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2663 } else { 2664 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2665 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2666 } else { 2667 // master -> all done 2668 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2669 sm_done_for_handle(connection->sm_handle); 2670 } 2671 } 2672 } 2673 sm_run(); 2674 } 2675 2676 #ifdef ENABLE_LE_PERIPHERAL 2677 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2678 sm_connection_t * connection = (sm_connection_t*) arg; 2679 sm_aes128_state = SM_AES128_IDLE; 2680 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2681 log_info_key("ltk", setup->sm_ltk); 2682 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2683 sm_run(); 2684 } 2685 #endif 2686 2687 static void sm_handle_encryption_result_address_resolution(void *arg){ 2688 UNUSED(arg); 2689 sm_aes128_state = SM_AES128_IDLE; 2690 sm_address_resolution_ah_calculation_active = 0; 2691 // compare calulated address against connecting device 2692 uint8_t * hash = &sm_aes128_ciphertext[13]; 2693 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2694 log_info("LE Device Lookup: matched resolvable private address"); 2695 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2696 sm_run(); 2697 return; 2698 } 2699 // no match, try next 2700 sm_address_resolution_test++; 2701 sm_run(); 2702 } 2703 2704 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2705 UNUSED(arg); 2706 sm_aes128_state = SM_AES128_IDLE; 2707 log_info_key("irk", sm_persistent_irk); 2708 dkg_state = DKG_CALC_DHK; 2709 sm_run(); 2710 } 2711 2712 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2713 UNUSED(arg); 2714 sm_aes128_state = SM_AES128_IDLE; 2715 log_info_key("dhk", sm_persistent_dhk); 2716 dkg_state = DKG_READY; 2717 // DKG calculation complete => SM Init Finished 2718 sm_run(); 2719 } 2720 2721 static void sm_handle_encryption_result_rau(void *arg){ 2722 UNUSED(arg); 2723 sm_aes128_state = SM_AES128_IDLE; 2724 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2725 rau_state = RAU_SET_ADDRESS; 2726 sm_run(); 2727 } 2728 2729 static void sm_handle_random_result_rau(void * arg){ 2730 UNUSED(arg); 2731 // non-resolvable vs. resolvable 2732 switch (gap_random_adress_type){ 2733 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2734 // resolvable: use random as prand and calc address hash 2735 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2736 sm_random_address[0] &= 0x3f; 2737 sm_random_address[0] |= 0x40; 2738 rau_state = RAU_GET_ENC; 2739 break; 2740 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2741 default: 2742 // "The two most significant bits of the address shall be equal to ‘0’"" 2743 sm_random_address[0] &= 0x3f; 2744 rau_state = RAU_SET_ADDRESS; 2745 break; 2746 } 2747 sm_run(); 2748 } 2749 2750 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2751 static void sm_handle_random_result_sc_get_random(void * arg){ 2752 sm_connection_t * connection = (sm_connection_t*) arg; 2753 2754 // OOB 2755 if (setup->sm_stk_generation_method == OOB){ 2756 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2757 sm_run(); 2758 return; 2759 } 2760 2761 // initiator & jw/nc -> send pairing random 2762 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2763 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2764 } else { 2765 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2766 } 2767 sm_run(); 2768 } 2769 #endif 2770 2771 static void sm_handle_random_result_ph2_random(void * arg){ 2772 sm_connection_t * connection = (sm_connection_t*) arg; 2773 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2774 sm_run(); 2775 } 2776 2777 static void sm_handle_random_result_ph2_tk(void * arg){ 2778 sm_connection_t * connection = (sm_connection_t*) arg; 2779 sm_reset_tk(); 2780 uint32_t tk; 2781 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2782 // map random to 0-999999 without speding much cycles on a modulus operation 2783 tk = little_endian_read_32(sm_random_data,0); 2784 tk = tk & 0xfffff; // 1048575 2785 if (tk >= 999999){ 2786 tk = tk - 999999; 2787 } 2788 } else { 2789 // override with pre-defined passkey 2790 tk = sm_fixed_passkey_in_display_role; 2791 } 2792 big_endian_store_32(setup->sm_tk, 12, tk); 2793 if (IS_RESPONDER(connection->sm_role)){ 2794 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2795 } else { 2796 if (setup->sm_use_secure_connections){ 2797 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2798 } else { 2799 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2800 sm_trigger_user_response(connection); 2801 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2802 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2803 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2804 } 2805 } 2806 } 2807 sm_run(); 2808 } 2809 2810 static void sm_handle_random_result_ph3_div(void * arg){ 2811 sm_connection_t * connection = (sm_connection_t*) arg; 2812 // use 16 bit from random value as div 2813 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2814 log_info_hex16("div", setup->sm_local_div); 2815 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2816 sm_run(); 2817 } 2818 2819 static void sm_handle_random_result_ph3_random(void * arg){ 2820 sm_connection_t * connection = (sm_connection_t*) arg; 2821 reverse_64(sm_random_data, setup->sm_local_rand); 2822 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2823 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2824 // no db for authenticated flag hack: store flag in bit 4 of LSB 2825 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2826 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2827 } 2828 2829 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2830 2831 UNUSED(channel); // ok: there is no channel 2832 UNUSED(size); // ok: fixed format HCI events 2833 2834 sm_connection_t * sm_conn; 2835 hci_con_handle_t con_handle; 2836 2837 switch (packet_type) { 2838 2839 case HCI_EVENT_PACKET: 2840 switch (hci_event_packet_get_type(packet)) { 2841 2842 case BTSTACK_EVENT_STATE: 2843 // bt stack activated, get started 2844 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2845 log_info("HCI Working!"); 2846 2847 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2848 2849 // trigger Random Address generation if requested before 2850 switch (gap_random_adress_type){ 2851 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2852 rau_state = RAU_IDLE; 2853 break; 2854 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2855 rau_state = RAU_SET_ADDRESS; 2856 break; 2857 default: 2858 rau_state = RAU_W4_RANDOM; 2859 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 2860 break; 2861 } 2862 sm_run(); 2863 } 2864 break; 2865 2866 case HCI_EVENT_LE_META: 2867 switch (packet[2]) { 2868 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2869 2870 log_info("sm: connected"); 2871 2872 if (packet[3]) return; // connection failed 2873 2874 con_handle = little_endian_read_16(packet, 4); 2875 sm_conn = sm_get_connection_for_handle(con_handle); 2876 if (!sm_conn) break; 2877 2878 sm_conn->sm_handle = con_handle; 2879 sm_conn->sm_role = packet[6]; 2880 sm_conn->sm_peer_addr_type = packet[7]; 2881 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2882 2883 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2884 2885 // reset security properties 2886 sm_conn->sm_connection_encrypted = 0; 2887 sm_conn->sm_connection_authenticated = 0; 2888 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2889 sm_conn->sm_le_db_index = -1; 2890 2891 // prepare CSRK lookup (does not involve setup) 2892 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2893 2894 // just connected -> everything else happens in sm_run() 2895 if (IS_RESPONDER(sm_conn->sm_role)){ 2896 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2897 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2898 if (sm_slave_request_security) { 2899 // request security if requested by app 2900 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2901 } else { 2902 // otherwise, wait for pairing request 2903 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2904 } 2905 } 2906 break; 2907 } else { 2908 // master 2909 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2910 } 2911 break; 2912 2913 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2914 con_handle = little_endian_read_16(packet, 3); 2915 sm_conn = sm_get_connection_for_handle(con_handle); 2916 if (!sm_conn) break; 2917 2918 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2919 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2920 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2921 break; 2922 } 2923 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2924 // PH2 SEND LTK as we need to exchange keys in PH3 2925 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2926 break; 2927 } 2928 2929 // store rand and ediv 2930 reverse_64(&packet[5], sm_conn->sm_local_rand); 2931 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2932 2933 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2934 // potentially stored LTK is from the master 2935 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2936 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2937 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2938 break; 2939 } 2940 // additionally check if remote is in LE Device DB if requested 2941 switch(sm_conn->sm_irk_lookup_state){ 2942 case IRK_LOOKUP_FAILED: 2943 log_info("LTK Request: device not in device db"); 2944 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2945 break; 2946 case IRK_LOOKUP_SUCCEEDED: 2947 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2948 break; 2949 default: 2950 // wait for irk look doen 2951 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2952 break; 2953 } 2954 break; 2955 } 2956 2957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2958 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2959 #else 2960 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2961 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2962 #endif 2963 break; 2964 2965 default: 2966 break; 2967 } 2968 break; 2969 2970 case HCI_EVENT_ENCRYPTION_CHANGE: 2971 con_handle = little_endian_read_16(packet, 3); 2972 sm_conn = sm_get_connection_for_handle(con_handle); 2973 if (!sm_conn) break; 2974 2975 sm_conn->sm_connection_encrypted = packet[5]; 2976 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2977 sm_conn->sm_actual_encryption_key_size); 2978 log_info("event handler, state %u", sm_conn->sm_engine_state); 2979 if (!sm_conn->sm_connection_encrypted) break; 2980 // continue if part of initial pairing 2981 switch (sm_conn->sm_engine_state){ 2982 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2983 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2984 sm_done_for_handle(sm_conn->sm_handle); 2985 break; 2986 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2987 if (IS_RESPONDER(sm_conn->sm_role)){ 2988 // slave 2989 if (setup->sm_use_secure_connections){ 2990 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2991 } else { 2992 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 2993 } 2994 } else { 2995 // master 2996 if (sm_key_distribution_all_received(sm_conn)){ 2997 // skip receiving keys as there are none 2998 sm_key_distribution_handle_all_received(sm_conn); 2999 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3000 } else { 3001 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3002 } 3003 } 3004 break; 3005 default: 3006 break; 3007 } 3008 break; 3009 3010 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3011 con_handle = little_endian_read_16(packet, 3); 3012 sm_conn = sm_get_connection_for_handle(con_handle); 3013 if (!sm_conn) break; 3014 3015 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3016 log_info("event handler, state %u", sm_conn->sm_engine_state); 3017 // continue if part of initial pairing 3018 switch (sm_conn->sm_engine_state){ 3019 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3020 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3021 sm_done_for_handle(sm_conn->sm_handle); 3022 break; 3023 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3024 if (IS_RESPONDER(sm_conn->sm_role)){ 3025 // slave 3026 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3027 } else { 3028 // master 3029 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3030 } 3031 break; 3032 default: 3033 break; 3034 } 3035 break; 3036 3037 3038 case HCI_EVENT_DISCONNECTION_COMPLETE: 3039 con_handle = little_endian_read_16(packet, 3); 3040 sm_done_for_handle(con_handle); 3041 sm_conn = sm_get_connection_for_handle(con_handle); 3042 if (!sm_conn) break; 3043 3044 // delete stored bonding on disconnect with authentication failure in ph0 3045 if (sm_conn->sm_role == 0 3046 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3047 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3048 le_device_db_remove(sm_conn->sm_le_db_index); 3049 } 3050 3051 // pairing failed, if it was ongoing 3052 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3053 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3054 } 3055 3056 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3057 sm_conn->sm_handle = 0; 3058 break; 3059 3060 case HCI_EVENT_COMMAND_COMPLETE: 3061 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3062 // set local addr for le device db 3063 bd_addr_t addr; 3064 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3065 le_device_db_set_local_bd_addr(addr); 3066 } 3067 break; 3068 default: 3069 break; 3070 } 3071 break; 3072 default: 3073 break; 3074 } 3075 3076 sm_run(); 3077 } 3078 3079 static inline int sm_calc_actual_encryption_key_size(int other){ 3080 if (other < sm_min_encryption_key_size) return 0; 3081 if (other < sm_max_encryption_key_size) return other; 3082 return sm_max_encryption_key_size; 3083 } 3084 3085 3086 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3087 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3088 switch (method){ 3089 case JUST_WORKS: 3090 case NUMERIC_COMPARISON: 3091 return 1; 3092 default: 3093 return 0; 3094 } 3095 } 3096 // responder 3097 3098 static int sm_passkey_used(stk_generation_method_t method){ 3099 switch (method){ 3100 case PK_RESP_INPUT: 3101 return 1; 3102 default: 3103 return 0; 3104 } 3105 } 3106 3107 static int sm_passkey_entry(stk_generation_method_t method){ 3108 switch (method){ 3109 case PK_RESP_INPUT: 3110 case PK_INIT_INPUT: 3111 case PK_BOTH_INPUT: 3112 return 1; 3113 default: 3114 return 0; 3115 } 3116 } 3117 3118 #endif 3119 3120 /** 3121 * @return ok 3122 */ 3123 static int sm_validate_stk_generation_method(void){ 3124 // check if STK generation method is acceptable by client 3125 switch (setup->sm_stk_generation_method){ 3126 case JUST_WORKS: 3127 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3128 case PK_RESP_INPUT: 3129 case PK_INIT_INPUT: 3130 case PK_BOTH_INPUT: 3131 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3132 case OOB: 3133 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3134 case NUMERIC_COMPARISON: 3135 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3136 return 1; 3137 default: 3138 return 0; 3139 } 3140 } 3141 3142 // size of complete sm_pdu used to validate input 3143 static const uint8_t sm_pdu_size[] = { 3144 0, // 0x00 invalid opcode 3145 7, // 0x01 pairing request 3146 7, // 0x02 pairing response 3147 17, // 0x03 pairing confirm 3148 17, // 0x04 pairing random 3149 2, // 0x05 pairing failed 3150 17, // 0x06 encryption information 3151 11, // 0x07 master identification 3152 17, // 0x08 identification information 3153 8, // 0x09 identify address information 3154 17, // 0x0a signing information 3155 2, // 0x0b security request 3156 65, // 0x0c pairing public key 3157 17, // 0x0d pairing dhk check 3158 2, // 0x0e keypress notification 3159 }; 3160 3161 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3162 3163 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3164 sm_run(); 3165 } 3166 3167 if (packet_type != SM_DATA_PACKET) return; 3168 if (size == 0) return; 3169 3170 uint8_t sm_pdu_code = packet[0]; 3171 3172 // validate pdu size 3173 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3174 if (sm_pdu_size[sm_pdu_code] != size) return; 3175 3176 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3177 if (!sm_conn) return; 3178 3179 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3180 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3181 sm_done_for_handle(con_handle); 3182 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3183 return; 3184 } 3185 3186 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3187 3188 int err; 3189 UNUSED(err); 3190 3191 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3192 uint8_t buffer[5]; 3193 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3194 buffer[1] = 3; 3195 little_endian_store_16(buffer, 2, con_handle); 3196 buffer[4] = packet[1]; 3197 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3198 return; 3199 } 3200 3201 switch (sm_conn->sm_engine_state){ 3202 3203 // a sm timeout requries a new physical connection 3204 case SM_GENERAL_TIMEOUT: 3205 return; 3206 3207 #ifdef ENABLE_LE_CENTRAL 3208 3209 // Initiator 3210 case SM_INITIATOR_CONNECTED: 3211 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3212 sm_pdu_received_in_wrong_state(sm_conn); 3213 break; 3214 } 3215 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3216 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3217 break; 3218 } 3219 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3220 sm_key_t ltk; 3221 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3222 if (!sm_is_null_key(ltk)){ 3223 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3224 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3225 } else { 3226 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3227 } 3228 break; 3229 } 3230 // otherwise, store security request 3231 sm_conn->sm_security_request_received = 1; 3232 break; 3233 3234 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3235 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3236 sm_pdu_received_in_wrong_state(sm_conn); 3237 break; 3238 } 3239 3240 // store pairing request 3241 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3242 err = sm_stk_generation_init(sm_conn); 3243 3244 #ifdef ENABLE_TESTING_SUPPORT 3245 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3246 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3247 err = test_pairing_failure; 3248 } 3249 #endif 3250 3251 if (err){ 3252 setup->sm_pairing_failed_reason = err; 3253 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3254 break; 3255 } 3256 3257 // generate random number first, if we need to show passkey 3258 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3259 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3260 break; 3261 } 3262 3263 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3264 if (setup->sm_use_secure_connections){ 3265 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3266 if (setup->sm_stk_generation_method == JUST_WORKS){ 3267 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3268 sm_trigger_user_response(sm_conn); 3269 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3270 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3271 } 3272 } else { 3273 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3274 } 3275 break; 3276 } 3277 #endif 3278 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3279 sm_trigger_user_response(sm_conn); 3280 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3281 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3282 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3283 } 3284 break; 3285 3286 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3287 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3288 sm_pdu_received_in_wrong_state(sm_conn); 3289 break; 3290 } 3291 3292 // store s_confirm 3293 reverse_128(&packet[1], setup->sm_peer_confirm); 3294 3295 #ifdef ENABLE_TESTING_SUPPORT 3296 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3297 log_info("testing_support: reset confirm value"); 3298 memset(setup->sm_peer_confirm, 0, 16); 3299 } 3300 #endif 3301 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3302 break; 3303 3304 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3305 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3306 sm_pdu_received_in_wrong_state(sm_conn); 3307 break;; 3308 } 3309 3310 // received random value 3311 reverse_128(&packet[1], setup->sm_peer_random); 3312 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3313 break; 3314 #endif 3315 3316 #ifdef ENABLE_LE_PERIPHERAL 3317 // Responder 3318 case SM_RESPONDER_IDLE: 3319 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3320 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3321 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3322 sm_pdu_received_in_wrong_state(sm_conn); 3323 break;; 3324 } 3325 3326 // store pairing request 3327 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3328 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3329 break; 3330 #endif 3331 3332 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3333 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3334 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3335 sm_pdu_received_in_wrong_state(sm_conn); 3336 break; 3337 } 3338 3339 // store public key for DH Key calculation 3340 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3341 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3342 3343 // validate public key 3344 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3345 if (err){ 3346 log_error("sm: peer public key invalid %x", err); 3347 // uses "unspecified reason", there is no "public key invalid" error code 3348 sm_pdu_received_in_wrong_state(sm_conn); 3349 break; 3350 } 3351 3352 // start calculating dhkey 3353 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3354 3355 3356 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3357 if (IS_RESPONDER(sm_conn->sm_role)){ 3358 // responder 3359 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3360 } else { 3361 // initiator 3362 // stk generation method 3363 // passkey entry: notify app to show passkey or to request passkey 3364 switch (setup->sm_stk_generation_method){ 3365 case JUST_WORKS: 3366 case NUMERIC_COMPARISON: 3367 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3368 break; 3369 case PK_RESP_INPUT: 3370 sm_sc_start_calculating_local_confirm(sm_conn); 3371 break; 3372 case PK_INIT_INPUT: 3373 case PK_BOTH_INPUT: 3374 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3375 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3376 break; 3377 } 3378 sm_sc_start_calculating_local_confirm(sm_conn); 3379 break; 3380 case OOB: 3381 // generate Nx 3382 log_info("Generate Na"); 3383 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3384 break; 3385 } 3386 } 3387 break; 3388 3389 case SM_SC_W4_CONFIRMATION: 3390 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3391 sm_pdu_received_in_wrong_state(sm_conn); 3392 break; 3393 } 3394 // received confirm value 3395 reverse_128(&packet[1], setup->sm_peer_confirm); 3396 3397 #ifdef ENABLE_TESTING_SUPPORT 3398 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3399 log_info("testing_support: reset confirm value"); 3400 memset(setup->sm_peer_confirm, 0, 16); 3401 } 3402 #endif 3403 if (IS_RESPONDER(sm_conn->sm_role)){ 3404 // responder 3405 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3406 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3407 // still waiting for passkey 3408 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3409 break; 3410 } 3411 } 3412 sm_sc_start_calculating_local_confirm(sm_conn); 3413 } else { 3414 // initiator 3415 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3416 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3417 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3418 } else { 3419 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3420 } 3421 } 3422 break; 3423 3424 case SM_SC_W4_PAIRING_RANDOM: 3425 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3426 sm_pdu_received_in_wrong_state(sm_conn); 3427 break; 3428 } 3429 3430 // received random value 3431 reverse_128(&packet[1], setup->sm_peer_nonce); 3432 3433 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3434 // only check for JUST WORK/NC in initiator role OR passkey entry 3435 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3436 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3437 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3438 break; 3439 } 3440 3441 // OOB 3442 if (setup->sm_stk_generation_method == OOB){ 3443 3444 // setup local random, set to zero if remote did not receive our data 3445 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3446 if (IS_RESPONDER(sm_conn->sm_role)){ 3447 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3448 log_info("Reset rb as A does not have OOB data"); 3449 memset(setup->sm_rb, 0, 16); 3450 } else { 3451 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3452 log_info("Use stored rb"); 3453 log_info_hexdump(setup->sm_rb, 16); 3454 } 3455 } else { 3456 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3457 log_info("Reset ra as B does not have OOB data"); 3458 memset(setup->sm_ra, 0, 16); 3459 } else { 3460 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3461 log_info("Use stored ra"); 3462 log_info_hexdump(setup->sm_ra, 16); 3463 } 3464 } 3465 3466 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3467 if (setup->sm_have_oob_data){ 3468 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3469 break; 3470 } 3471 } 3472 3473 // TODO: we only get here for Responder role with JW/NC 3474 sm_sc_state_after_receiving_random(sm_conn); 3475 break; 3476 3477 case SM_SC_W2_CALCULATE_G2: 3478 case SM_SC_W4_CALCULATE_G2: 3479 case SM_SC_W4_CALCULATE_DHKEY: 3480 case SM_SC_W2_CALCULATE_F5_SALT: 3481 case SM_SC_W4_CALCULATE_F5_SALT: 3482 case SM_SC_W2_CALCULATE_F5_MACKEY: 3483 case SM_SC_W4_CALCULATE_F5_MACKEY: 3484 case SM_SC_W2_CALCULATE_F5_LTK: 3485 case SM_SC_W4_CALCULATE_F5_LTK: 3486 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3487 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3488 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3489 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3490 sm_pdu_received_in_wrong_state(sm_conn); 3491 break; 3492 } 3493 // store DHKey Check 3494 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3495 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3496 3497 // have we been only waiting for dhkey check command? 3498 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3499 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3500 } 3501 break; 3502 #endif 3503 3504 #ifdef ENABLE_LE_PERIPHERAL 3505 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3506 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3507 sm_pdu_received_in_wrong_state(sm_conn); 3508 break; 3509 } 3510 3511 // received confirm value 3512 reverse_128(&packet[1], setup->sm_peer_confirm); 3513 3514 #ifdef ENABLE_TESTING_SUPPORT 3515 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3516 log_info("testing_support: reset confirm value"); 3517 memset(setup->sm_peer_confirm, 0, 16); 3518 } 3519 #endif 3520 // notify client to hide shown passkey 3521 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3522 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3523 } 3524 3525 // handle user cancel pairing? 3526 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3527 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3528 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3529 break; 3530 } 3531 3532 // wait for user action? 3533 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3534 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3535 break; 3536 } 3537 3538 // calculate and send local_confirm 3539 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3540 break; 3541 3542 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3543 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3544 sm_pdu_received_in_wrong_state(sm_conn); 3545 break;; 3546 } 3547 3548 // received random value 3549 reverse_128(&packet[1], setup->sm_peer_random); 3550 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3551 break; 3552 #endif 3553 3554 case SM_PH3_RECEIVE_KEYS: 3555 switch(sm_pdu_code){ 3556 case SM_CODE_ENCRYPTION_INFORMATION: 3557 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3558 reverse_128(&packet[1], setup->sm_peer_ltk); 3559 break; 3560 3561 case SM_CODE_MASTER_IDENTIFICATION: 3562 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3563 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3564 reverse_64(&packet[3], setup->sm_peer_rand); 3565 break; 3566 3567 case SM_CODE_IDENTITY_INFORMATION: 3568 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3569 reverse_128(&packet[1], setup->sm_peer_irk); 3570 break; 3571 3572 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3573 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3574 setup->sm_peer_addr_type = packet[1]; 3575 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3576 break; 3577 3578 case SM_CODE_SIGNING_INFORMATION: 3579 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3580 reverse_128(&packet[1], setup->sm_peer_csrk); 3581 break; 3582 default: 3583 // Unexpected PDU 3584 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3585 break; 3586 } 3587 // done with key distribution? 3588 if (sm_key_distribution_all_received(sm_conn)){ 3589 3590 sm_key_distribution_handle_all_received(sm_conn); 3591 3592 if (IS_RESPONDER(sm_conn->sm_role)){ 3593 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3594 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3595 } else { 3596 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3597 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3598 sm_done_for_handle(sm_conn->sm_handle); 3599 } 3600 } else { 3601 if (setup->sm_use_secure_connections){ 3602 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3603 } else { 3604 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3605 } 3606 } 3607 } 3608 break; 3609 default: 3610 // Unexpected PDU 3611 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3612 break; 3613 } 3614 3615 // try to send preparared packet 3616 sm_run(); 3617 } 3618 3619 // Security Manager Client API 3620 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3621 sm_get_oob_data = get_oob_data_callback; 3622 } 3623 3624 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)){ 3625 sm_get_sc_oob_data = get_sc_oob_data_callback; 3626 } 3627 3628 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3629 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3630 } 3631 3632 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3633 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3634 } 3635 3636 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3637 sm_min_encryption_key_size = min_size; 3638 sm_max_encryption_key_size = max_size; 3639 } 3640 3641 void sm_set_authentication_requirements(uint8_t auth_req){ 3642 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3643 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3644 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3645 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3646 } 3647 #endif 3648 sm_auth_req = auth_req; 3649 } 3650 3651 void sm_set_io_capabilities(io_capability_t io_capability){ 3652 sm_io_capabilities = io_capability; 3653 } 3654 3655 #ifdef ENABLE_LE_PERIPHERAL 3656 void sm_set_request_security(int enable){ 3657 sm_slave_request_security = enable; 3658 } 3659 #endif 3660 3661 void sm_set_er(sm_key_t er){ 3662 memcpy(sm_persistent_er, er, 16); 3663 } 3664 3665 void sm_set_ir(sm_key_t ir){ 3666 memcpy(sm_persistent_ir, ir, 16); 3667 } 3668 3669 // Testing support only 3670 void sm_test_set_irk(sm_key_t irk){ 3671 memcpy(sm_persistent_irk, irk, 16); 3672 sm_persistent_irk_ready = 1; 3673 } 3674 3675 void sm_test_use_fixed_local_csrk(void){ 3676 test_use_fixed_local_csrk = 1; 3677 } 3678 3679 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3680 static void sm_ec_generated(void * arg){ 3681 UNUSED(arg); 3682 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3683 } 3684 #endif 3685 3686 #ifdef ENABLE_TESTING_SUPPORT 3687 void sm_test_set_pairing_failure(int reason){ 3688 test_pairing_failure = reason; 3689 } 3690 #endif 3691 3692 void sm_init(void){ 3693 // set some (BTstack default) ER and IR 3694 int i; 3695 sm_key_t er; 3696 sm_key_t ir; 3697 for (i=0;i<16;i++){ 3698 er[i] = 0x30 + i; 3699 ir[i] = 0x90 + i; 3700 } 3701 sm_set_er(er); 3702 sm_set_ir(ir); 3703 // defaults 3704 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3705 | SM_STK_GENERATION_METHOD_OOB 3706 | SM_STK_GENERATION_METHOD_PASSKEY 3707 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3708 3709 sm_max_encryption_key_size = 16; 3710 sm_min_encryption_key_size = 7; 3711 3712 sm_fixed_passkey_in_display_role = 0xffffffff; 3713 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3714 3715 #ifdef USE_CMAC_ENGINE 3716 sm_cmac_active = 0; 3717 #endif 3718 dkg_state = DKG_W4_WORKING; 3719 rau_state = RAU_W4_WORKING; 3720 sm_aes128_state = SM_AES128_IDLE; 3721 sm_address_resolution_test = -1; // no private address to resolve yet 3722 sm_address_resolution_ah_calculation_active = 0; 3723 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3724 sm_address_resolution_general_queue = NULL; 3725 3726 gap_random_adress_update_period = 15 * 60 * 1000L; 3727 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3728 3729 test_use_fixed_local_csrk = 0; 3730 3731 // register for HCI Events from HCI 3732 hci_event_callback_registration.callback = &sm_event_packet_handler; 3733 hci_add_event_handler(&hci_event_callback_registration); 3734 3735 // 3736 btstack_crypto_init(); 3737 3738 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3739 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3740 3741 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3742 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3743 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3744 #endif 3745 } 3746 3747 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3748 sm_fixed_passkey_in_display_role = passkey; 3749 } 3750 3751 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3752 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3753 } 3754 3755 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3756 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3757 if (!hci_con) return NULL; 3758 return &hci_con->sm_connection; 3759 } 3760 3761 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3762 switch (sm_conn->sm_engine_state){ 3763 case SM_GENERAL_IDLE: 3764 case SM_RESPONDER_IDLE: 3765 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3766 sm_run(); 3767 break; 3768 default: 3769 break; 3770 } 3771 } 3772 3773 /** 3774 * @brief Trigger Security Request 3775 */ 3776 void sm_send_security_request(hci_con_handle_t con_handle){ 3777 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3778 if (!sm_conn) return; 3779 sm_send_security_request_for_connection(sm_conn); 3780 } 3781 3782 // request pairing 3783 void sm_request_pairing(hci_con_handle_t con_handle){ 3784 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3785 if (!sm_conn) return; // wrong connection 3786 3787 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3788 if (IS_RESPONDER(sm_conn->sm_role)){ 3789 sm_send_security_request_for_connection(sm_conn); 3790 } else { 3791 // used as a trigger to start central/master/initiator security procedures 3792 uint16_t ediv; 3793 sm_key_t ltk; 3794 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3795 switch (sm_conn->sm_irk_lookup_state){ 3796 case IRK_LOOKUP_FAILED: 3797 log_info("irk lookup failed, send pairing request"); 3798 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3799 break; 3800 case IRK_LOOKUP_SUCCEEDED: 3801 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3802 if (!sm_is_null_key(ltk) || ediv){ 3803 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3804 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3805 } else { 3806 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3807 } 3808 break; 3809 default: 3810 log_info("irk lookup pending"); 3811 sm_conn->sm_pairing_requested = 1; 3812 break; 3813 } 3814 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3815 sm_conn->sm_pairing_requested = 1; 3816 } 3817 } 3818 sm_run(); 3819 } 3820 3821 // called by client app on authorization request 3822 void sm_authorization_decline(hci_con_handle_t con_handle){ 3823 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3824 if (!sm_conn) return; // wrong connection 3825 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3826 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3827 } 3828 3829 void sm_authorization_grant(hci_con_handle_t con_handle){ 3830 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3831 if (!sm_conn) return; // wrong connection 3832 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3833 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3834 } 3835 3836 // GAP Bonding API 3837 3838 void sm_bonding_decline(hci_con_handle_t con_handle){ 3839 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3840 if (!sm_conn) return; // wrong connection 3841 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3842 log_info("decline, state %u", sm_conn->sm_engine_state); 3843 switch(sm_conn->sm_engine_state){ 3844 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3845 case SM_SC_W4_USER_RESPONSE: 3846 case SM_SC_W4_CONFIRMATION: 3847 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3848 #endif 3849 case SM_PH1_W4_USER_RESPONSE: 3850 switch (setup->sm_stk_generation_method){ 3851 case PK_RESP_INPUT: 3852 case PK_INIT_INPUT: 3853 case PK_BOTH_INPUT: 3854 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3855 break; 3856 case NUMERIC_COMPARISON: 3857 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3858 break; 3859 case JUST_WORKS: 3860 case OOB: 3861 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3862 break; 3863 } 3864 break; 3865 default: 3866 break; 3867 } 3868 sm_run(); 3869 } 3870 3871 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3872 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3873 if (!sm_conn) return; // wrong connection 3874 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3875 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3876 if (setup->sm_use_secure_connections){ 3877 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3878 } else { 3879 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3880 } 3881 } 3882 3883 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3884 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3885 sm_sc_prepare_dhkey_check(sm_conn); 3886 } 3887 #endif 3888 3889 sm_run(); 3890 } 3891 3892 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3893 // for now, it's the same 3894 sm_just_works_confirm(con_handle); 3895 } 3896 3897 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3898 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3899 if (!sm_conn) return; // wrong connection 3900 sm_reset_tk(); 3901 big_endian_store_32(setup->sm_tk, 12, passkey); 3902 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3903 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3904 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3905 } 3906 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3907 memcpy(setup->sm_ra, setup->sm_tk, 16); 3908 memcpy(setup->sm_rb, setup->sm_tk, 16); 3909 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3910 sm_sc_start_calculating_local_confirm(sm_conn); 3911 } 3912 #endif 3913 sm_run(); 3914 } 3915 3916 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3917 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3918 if (!sm_conn) return; // wrong connection 3919 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3920 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3921 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3922 switch (action){ 3923 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3924 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3925 flags |= (1 << action); 3926 break; 3927 case SM_KEYPRESS_PASSKEY_CLEARED: 3928 // clear counter, keypress & erased flags + set passkey cleared 3929 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3930 break; 3931 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3932 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3933 // erase actions queued 3934 num_actions--; 3935 if (num_actions == 0){ 3936 // clear counter, keypress & erased flags 3937 flags &= 0x19; 3938 } 3939 break; 3940 } 3941 num_actions++; 3942 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 3943 break; 3944 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 3945 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 3946 // enter actions queued 3947 num_actions--; 3948 if (num_actions == 0){ 3949 // clear counter, keypress & erased flags 3950 flags &= 0x19; 3951 } 3952 break; 3953 } 3954 num_actions++; 3955 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 3956 break; 3957 default: 3958 break; 3959 } 3960 setup->sm_keypress_notification = (num_actions << 5) | flags; 3961 sm_run(); 3962 } 3963 3964 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3965 static void sm_handle_random_result_oob(void * arg){ 3966 UNUSED(arg); 3967 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 3968 sm_run(); 3969 } 3970 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 3971 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 3972 sm_sc_oob_callback = callback; 3973 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 3974 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 3975 return 0; 3976 } 3977 #endif 3978 3979 /** 3980 * @brief Identify device in LE Device DB 3981 * @param handle 3982 * @returns index from le_device_db or -1 if not found/identified 3983 */ 3984 int sm_le_device_index(hci_con_handle_t con_handle ){ 3985 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3986 if (!sm_conn) return -1; 3987 return sm_conn->sm_le_db_index; 3988 } 3989 3990 static int gap_random_address_type_requires_updates(void){ 3991 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3992 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return 0; 3993 return 1; 3994 } 3995 3996 static uint8_t own_address_type(void){ 3997 switch (gap_random_adress_type){ 3998 case GAP_RANDOM_ADDRESS_TYPE_OFF: 3999 return BD_ADDR_TYPE_LE_PUBLIC; 4000 default: 4001 return BD_ADDR_TYPE_LE_RANDOM; 4002 } 4003 } 4004 4005 // GAP LE API 4006 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4007 gap_random_address_update_stop(); 4008 gap_random_adress_type = random_address_type; 4009 hci_le_set_own_address_type(own_address_type()); 4010 if (!gap_random_address_type_requires_updates()) return; 4011 gap_random_address_update_start(); 4012 gap_random_address_trigger(); 4013 } 4014 4015 gap_random_address_type_t gap_random_address_get_mode(void){ 4016 return gap_random_adress_type; 4017 } 4018 4019 void gap_random_address_set_update_period(int period_ms){ 4020 gap_random_adress_update_period = period_ms; 4021 if (!gap_random_address_type_requires_updates()) return; 4022 gap_random_address_update_stop(); 4023 gap_random_address_update_start(); 4024 } 4025 4026 void gap_random_address_set(bd_addr_t addr){ 4027 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4028 memcpy(sm_random_address, addr, 6); 4029 if (rau_state == RAU_W4_WORKING) return; 4030 rau_state = RAU_SET_ADDRESS; 4031 sm_run(); 4032 } 4033 4034 #ifdef ENABLE_LE_PERIPHERAL 4035 /* 4036 * @brief Set Advertisement Paramters 4037 * @param adv_int_min 4038 * @param adv_int_max 4039 * @param adv_type 4040 * @param direct_address_type 4041 * @param direct_address 4042 * @param channel_map 4043 * @param filter_policy 4044 * 4045 * @note own_address_type is used from gap_random_address_set_mode 4046 */ 4047 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4048 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4049 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4050 direct_address_typ, direct_address, channel_map, filter_policy); 4051 } 4052 #endif 4053 4054 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4055 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4056 // wrong connection 4057 if (!sm_conn) return 0; 4058 // already encrypted 4059 if (sm_conn->sm_connection_encrypted) return 0; 4060 // only central can re-encrypt 4061 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4062 // irk status? 4063 switch(sm_conn->sm_irk_lookup_state){ 4064 case IRK_LOOKUP_FAILED: 4065 // done, cannot setup encryption 4066 return 0; 4067 case IRK_LOOKUP_SUCCEEDED: 4068 break; 4069 default: 4070 // IR Lookup pending 4071 return 1; 4072 } 4073 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4074 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4075 } 4076