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