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 <string.h> 41 #include <inttypes.h> 42 43 #include "ble/le_device_db.h" 44 #include "ble/core.h" 45 #include "ble/sm.h" 46 #include "bluetooth_company_id.h" 47 #include "btstack_crypto.h" 48 #include "btstack_debug.h" 49 #include "btstack_event.h" 50 #include "btstack_linked_list.h" 51 #include "btstack_memory.h" 52 #include "gap.h" 53 #include "hci.h" 54 #include "hci_dump.h" 55 #include "l2cap.h" 56 57 #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) 58 #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." 59 #endif 60 61 // assert SM Public Key can be sent/received 62 #ifdef ENABLE_LE_SECURE_CONNECTIONS 63 #if HCI_ACL_PAYLOAD_SIZE < 69 64 #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" 65 #endif 66 #endif 67 68 #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) 69 #define IS_RESPONDER(role) (role) 70 #else 71 #ifdef ENABLE_LE_CENTRAL 72 // only central - never responder (avoid 'unused variable' warnings) 73 #define IS_RESPONDER(role) (0 && role) 74 #else 75 // only peripheral - always responder (avoid 'unused variable' warnings) 76 #define IS_RESPONDER(role) (1 || role) 77 #endif 78 #endif 79 80 #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) 81 #define USE_CMAC_ENGINE 82 #endif 83 84 // 85 // SM internal types and globals 86 // 87 88 typedef enum { 89 DKG_W4_WORKING, 90 DKG_CALC_IRK, 91 DKG_CALC_DHK, 92 DKG_READY 93 } derived_key_generation_t; 94 95 typedef enum { 96 RAU_IDLE, 97 RAU_GET_RANDOM, 98 RAU_W4_RANDOM, 99 RAU_GET_ENC, 100 RAU_W4_ENC, 101 RAU_SET_ADDRESS, 102 } random_address_update_t; 103 104 typedef enum { 105 CMAC_IDLE, 106 CMAC_CALC_SUBKEYS, 107 CMAC_W4_SUBKEYS, 108 CMAC_CALC_MI, 109 CMAC_W4_MI, 110 CMAC_CALC_MLAST, 111 CMAC_W4_MLAST 112 } cmac_state_t; 113 114 typedef enum { 115 JUST_WORKS, 116 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 117 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 118 PK_BOTH_INPUT, // Only input on both, both input PK 119 NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides 120 OOB // OOB available on one (SC) or both sides (legacy) 121 } stk_generation_method_t; 122 123 typedef enum { 124 SM_USER_RESPONSE_IDLE, 125 SM_USER_RESPONSE_PENDING, 126 SM_USER_RESPONSE_CONFIRM, 127 SM_USER_RESPONSE_PASSKEY, 128 SM_USER_RESPONSE_DECLINE 129 } sm_user_response_t; 130 131 typedef enum { 132 SM_AES128_IDLE, 133 SM_AES128_ACTIVE 134 } sm_aes128_state_t; 135 136 typedef enum { 137 ADDRESS_RESOLUTION_IDLE, 138 ADDRESS_RESOLUTION_GENERAL, 139 ADDRESS_RESOLUTION_FOR_CONNECTION, 140 } address_resolution_mode_t; 141 142 typedef enum { 143 ADDRESS_RESOLUTION_SUCEEDED, 144 ADDRESS_RESOLUTION_FAILED, 145 } address_resolution_event_t; 146 147 typedef enum { 148 EC_KEY_GENERATION_IDLE, 149 EC_KEY_GENERATION_ACTIVE, 150 EC_KEY_GENERATION_DONE, 151 } ec_key_generation_state_t; 152 153 typedef enum { 154 SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, 155 SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, 157 } sm_state_var_t; 158 159 typedef enum { 160 SM_SC_OOB_IDLE, 161 SM_SC_OOB_W4_RANDOM, 162 SM_SC_OOB_W2_CALC_CONFIRM, 163 SM_SC_OOB_W4_CONFIRM, 164 } sm_sc_oob_state_t; 165 166 typedef uint8_t sm_key24_t[3]; 167 typedef uint8_t sm_key56_t[7]; 168 typedef uint8_t sm_key256_t[32]; 169 170 // 171 // GLOBAL DATA 172 // 173 174 static uint8_t test_use_fixed_local_csrk; 175 176 #ifdef ENABLE_TESTING_SUPPORT 177 static uint8_t test_pairing_failure; 178 #endif 179 180 // configuration 181 static uint8_t sm_accepted_stk_generation_methods; 182 static uint8_t sm_max_encryption_key_size; 183 static uint8_t sm_min_encryption_key_size; 184 static uint8_t sm_auth_req = 0; 185 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 186 static uint8_t sm_slave_request_security; 187 static uint32_t sm_fixed_passkey_in_display_role; 188 static uint8_t sm_reconstruct_ltk_without_le_device_db_entry; 189 190 #ifdef ENABLE_LE_SECURE_CONNECTIONS 191 static uint8_t sm_sc_oob_random[16]; 192 static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); 193 static sm_sc_oob_state_t sm_sc_oob_state; 194 #endif 195 196 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 197 static sm_key_t sm_persistent_er; 198 static sm_key_t sm_persistent_ir; 199 200 // derived from sm_persistent_ir 201 static sm_key_t sm_persistent_dhk; 202 static sm_key_t sm_persistent_irk; 203 static derived_key_generation_t dkg_state; 204 205 // derived from sm_persistent_er 206 // .. 207 208 // random address update 209 static random_address_update_t rau_state; 210 static bd_addr_t sm_random_address; 211 212 #ifdef USE_CMAC_ENGINE 213 // CMAC Calculation: General 214 static btstack_crypto_aes128_cmac_t sm_cmac_request; 215 static void (*sm_cmac_done_callback)(uint8_t hash[8]); 216 static uint8_t sm_cmac_active; 217 static uint8_t sm_cmac_hash[16]; 218 #endif 219 220 // CMAC for ATT Signed Writes 221 #ifdef ENABLE_LE_SIGNED_WRITE 222 static uint16_t sm_cmac_signed_write_message_len; 223 static uint8_t sm_cmac_signed_write_header[3]; 224 static const uint8_t * sm_cmac_signed_write_message; 225 static uint8_t sm_cmac_signed_write_sign_counter[4]; 226 #endif 227 228 // CMAC for Secure Connection functions 229 #ifdef ENABLE_LE_SECURE_CONNECTIONS 230 static sm_connection_t * sm_cmac_connection; 231 static uint8_t sm_cmac_sc_buffer[80]; 232 #endif 233 234 // resolvable private address lookup / CSRK calculation 235 static int sm_address_resolution_test; 236 static int sm_address_resolution_ah_calculation_active; 237 static uint8_t sm_address_resolution_addr_type; 238 static bd_addr_t sm_address_resolution_address; 239 static void * sm_address_resolution_context; 240 static address_resolution_mode_t sm_address_resolution_mode; 241 static btstack_linked_list_t sm_address_resolution_general_queue; 242 243 // aes128 crypto engine. 244 static sm_aes128_state_t sm_aes128_state; 245 246 // crypto 247 static btstack_crypto_random_t sm_crypto_random_request; 248 static btstack_crypto_aes128_t sm_crypto_aes128_request; 249 #ifdef ENABLE_LE_SECURE_CONNECTIONS 250 static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; 251 static btstack_crypto_random_t sm_crypto_random_oob_request; 252 #endif 253 254 // temp storage for random data 255 static uint8_t sm_random_data[8]; 256 static uint8_t sm_aes128_key[16]; 257 static uint8_t sm_aes128_plaintext[16]; 258 static uint8_t sm_aes128_ciphertext[16]; 259 260 // to receive hci events 261 static btstack_packet_callback_registration_t hci_event_callback_registration; 262 263 /* to dispatch sm event */ 264 static btstack_linked_list_t sm_event_handlers; 265 266 // LE Secure Connections 267 #ifdef ENABLE_LE_SECURE_CONNECTIONS 268 static ec_key_generation_state_t ec_key_generation_state; 269 static uint8_t ec_q[64]; 270 #endif 271 272 // 273 // Volume 3, Part H, Chapter 24 274 // "Security shall be initiated by the Security Manager in the device in the master role. 275 // The device in the slave role shall be the responding device." 276 // -> master := initiator, slave := responder 277 // 278 279 // data needed for security setup 280 typedef struct sm_setup_context { 281 282 btstack_timer_source_t sm_timeout; 283 284 // used in all phases 285 uint8_t sm_pairing_failed_reason; 286 287 // user response, (Phase 1 and/or 2) 288 uint8_t sm_user_response; 289 uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count 290 291 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 292 int sm_key_distribution_send_set; 293 int sm_key_distribution_received_set; 294 295 // Phase 2 (Pairing over SMP) 296 stk_generation_method_t sm_stk_generation_method; 297 sm_key_t sm_tk; 298 uint8_t sm_have_oob_data; 299 uint8_t sm_use_secure_connections; 300 301 sm_key_t sm_c1_t3_value; // c1 calculation 302 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 303 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 304 sm_key_t sm_local_random; 305 sm_key_t sm_local_confirm; 306 sm_key_t sm_peer_random; 307 sm_key_t sm_peer_confirm; 308 uint8_t sm_m_addr_type; // address and type can be removed 309 uint8_t sm_s_addr_type; // '' 310 bd_addr_t sm_m_address; // '' 311 bd_addr_t sm_s_address; // '' 312 sm_key_t sm_ltk; 313 314 uint8_t sm_state_vars; 315 #ifdef ENABLE_LE_SECURE_CONNECTIONS 316 uint8_t sm_peer_q[64]; // also stores random for EC key generation during init 317 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 318 sm_key_t sm_local_nonce; // might be combined with sm_local_random 319 sm_key_t sm_dhkey; 320 sm_key_t sm_peer_dhkey_check; 321 sm_key_t sm_local_dhkey_check; 322 sm_key_t sm_ra; 323 sm_key_t sm_rb; 324 sm_key_t sm_t; // used for f5 and h6 325 sm_key_t sm_mackey; 326 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 327 #endif 328 329 // Phase 3 330 331 // key distribution, we generate 332 uint16_t sm_local_y; 333 uint16_t sm_local_div; 334 uint16_t sm_local_ediv; 335 uint8_t sm_local_rand[8]; 336 sm_key_t sm_local_ltk; 337 sm_key_t sm_local_csrk; 338 sm_key_t sm_local_irk; 339 // sm_local_address/addr_type not needed 340 341 // key distribution, received from peer 342 uint16_t sm_peer_y; 343 uint16_t sm_peer_div; 344 uint16_t sm_peer_ediv; 345 uint8_t sm_peer_rand[8]; 346 sm_key_t sm_peer_ltk; 347 sm_key_t sm_peer_irk; 348 sm_key_t sm_peer_csrk; 349 uint8_t sm_peer_addr_type; 350 bd_addr_t sm_peer_address; 351 352 } sm_setup_context_t; 353 354 // 355 static sm_setup_context_t the_setup; 356 static sm_setup_context_t * setup = &the_setup; 357 358 // active connection - the one for which the_setup is used for 359 static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 360 361 // @returns 1 if oob data is available 362 // stores oob data in provided 16 byte buffer if not null 363 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 364 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); 365 366 // horizontal: initiator capabilities 367 // vertial: responder capabilities 368 static const stk_generation_method_t stk_generation_method [5] [5] = { 369 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 370 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 371 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 372 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 373 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 374 }; 375 376 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 377 #ifdef ENABLE_LE_SECURE_CONNECTIONS 378 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 379 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 380 { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 381 { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 382 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 383 { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, 384 }; 385 #endif 386 387 static void sm_run(void); 388 #ifdef USE_CMAC_ENGINE 389 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)); 390 #endif 391 static void sm_done_for_handle(hci_con_handle_t con_handle); 392 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 393 static inline int sm_calc_actual_encryption_key_size(int other); 394 static int sm_validate_stk_generation_method(void); 395 static void sm_handle_encryption_result_address_resolution(void *arg); 396 static void sm_handle_encryption_result_dkg_dhk(void *arg); 397 static void sm_handle_encryption_result_dkg_irk(void *arg); 398 static void sm_handle_encryption_result_enc_a(void *arg); 399 static void sm_handle_encryption_result_enc_b(void *arg); 400 static void sm_handle_encryption_result_enc_c(void *arg); 401 static void sm_handle_encryption_result_enc_csrk(void *arg); 402 static void sm_handle_encryption_result_enc_d(void * arg); 403 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); 404 static void sm_handle_encryption_result_enc_ph3_y(void *arg); 405 #ifdef ENABLE_LE_PERIPHERAL 406 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); 407 static void sm_handle_encryption_result_enc_ph4_y(void *arg); 408 #endif 409 static void sm_handle_encryption_result_enc_stk(void *arg); 410 static void sm_handle_encryption_result_rau(void *arg); 411 static void sm_handle_random_result_ph2_tk(void * arg); 412 static void sm_handle_random_result_rau(void * arg); 413 #ifdef ENABLE_LE_SECURE_CONNECTIONS 414 static void sm_ec_generate_new_key(void); 415 static void sm_handle_random_result_sc_get_random(void * arg); 416 static int sm_passkey_entry(stk_generation_method_t method); 417 #endif 418 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); 419 420 static void log_info_hex16(const char * name, uint16_t value){ 421 log_info("%-6s 0x%04x", name, value); 422 } 423 424 // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ 425 // return packet[0]; 426 // } 427 static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ 428 return packet[1]; 429 } 430 static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ 431 return packet[2]; 432 } 433 static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ 434 return packet[3]; 435 } 436 static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ 437 return packet[4]; 438 } 439 static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ 440 return packet[5]; 441 } 442 static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ 443 return packet[6]; 444 } 445 446 static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ 447 packet[0] = code; 448 } 449 static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ 450 packet[1] = io_capability; 451 } 452 static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ 453 packet[2] = oob_data_flag; 454 } 455 static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ 456 packet[3] = auth_req; 457 } 458 static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ 459 packet[4] = max_encryption_key_size; 460 } 461 static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ 462 packet[5] = initiator_key_distribution; 463 } 464 static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ 465 packet[6] = responder_key_distribution; 466 } 467 468 // @returns 1 if all bytes are 0 469 static int sm_is_null(uint8_t * data, int size){ 470 int i; 471 for (i=0; i < size ; i++){ 472 if (data[i]) return 0; 473 } 474 return 1; 475 } 476 477 static int sm_is_null_random(uint8_t random[8]){ 478 return sm_is_null(random, 8); 479 } 480 481 static int sm_is_null_key(uint8_t * key){ 482 return sm_is_null(key, 16); 483 } 484 485 // Key utils 486 static void sm_reset_tk(void){ 487 int i; 488 for (i=0;i<16;i++){ 489 setup->sm_tk[i] = 0; 490 } 491 } 492 493 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 494 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 495 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 496 int i; 497 for (i = max_encryption_size ; i < 16 ; i++){ 498 key[15-i] = 0; 499 } 500 } 501 502 // SMP Timeout implementation 503 504 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 505 // the Security Manager Timer shall be reset and started. 506 // 507 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 508 // 509 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 510 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 511 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 512 // established. 513 514 static void sm_timeout_handler(btstack_timer_source_t * timer){ 515 log_info("SM timeout"); 516 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 517 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 518 sm_notify_client_status_reason(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); 519 sm_done_for_handle(sm_conn->sm_handle); 520 521 // trigger handling of next ready connection 522 sm_run(); 523 } 524 static void sm_timeout_start(sm_connection_t * sm_conn){ 525 btstack_run_loop_remove_timer(&setup->sm_timeout); 526 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 527 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 528 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 529 btstack_run_loop_add_timer(&setup->sm_timeout); 530 } 531 static void sm_timeout_stop(void){ 532 btstack_run_loop_remove_timer(&setup->sm_timeout); 533 } 534 static void sm_timeout_reset(sm_connection_t * sm_conn){ 535 sm_timeout_stop(); 536 sm_timeout_start(sm_conn); 537 } 538 539 // end of sm timeout 540 541 // GAP Random Address updates 542 static gap_random_address_type_t gap_random_adress_type; 543 static btstack_timer_source_t gap_random_address_update_timer; 544 static uint32_t gap_random_adress_update_period; 545 546 static void gap_random_address_trigger(void){ 547 log_info("gap_random_address_trigger"); 548 if (rau_state != RAU_IDLE) return; 549 rau_state = RAU_GET_RANDOM; 550 sm_run(); 551 } 552 553 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 554 UNUSED(timer); 555 556 log_info("GAP Random Address Update due"); 557 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 558 btstack_run_loop_add_timer(&gap_random_address_update_timer); 559 gap_random_address_trigger(); 560 } 561 562 static void gap_random_address_update_start(void){ 563 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 564 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 565 btstack_run_loop_add_timer(&gap_random_address_update_timer); 566 } 567 568 static void gap_random_address_update_stop(void){ 569 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 570 } 571 572 // ah(k,r) helper 573 // r = padding || r 574 // r - 24 bit value 575 static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ 576 // r'= padding || r 577 memset(r_prime, 0, 16); 578 memcpy(&r_prime[13], r, 3); 579 } 580 581 // d1 helper 582 // d' = padding || r || d 583 // d,r - 16 bit values 584 static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ 585 // d'= padding || r || d 586 memset(d1_prime, 0, 16); 587 big_endian_store_16(d1_prime, 12, r); 588 big_endian_store_16(d1_prime, 14, d); 589 } 590 591 // dm helper 592 // r’ = padding || r 593 // r - 64 bit value 594 static void sm_dm_r_prime(uint8_t r[8], uint8_t * r_prime){ 595 memset(r_prime, 0, 16); 596 memcpy(&r_prime[8], r, 8); 597 } 598 599 // calculate arguments for first AES128 operation in C1 function 600 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ 601 602 // p1 = pres || preq || rat’ || iat’ 603 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 604 // cant octet of pres becomes the most significant octet of p1. 605 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 606 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 607 // p1 is 0x05000800000302070710000001010001." 608 609 sm_key_t p1; 610 reverse_56(pres, &p1[0]); 611 reverse_56(preq, &p1[7]); 612 p1[14] = rat; 613 p1[15] = iat; 614 log_info_key("p1", p1); 615 log_info_key("r", r); 616 617 // t1 = r xor p1 618 int i; 619 for (i=0;i<16;i++){ 620 t1[i] = r[i] ^ p1[i]; 621 } 622 log_info_key("t1", t1); 623 } 624 625 // calculate arguments for second AES128 operation in C1 function 626 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ 627 // p2 = padding || ia || ra 628 // "The least significant octet of ra becomes the least significant octet of p2 and 629 // the most significant octet of padding becomes the most significant octet of p2. 630 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 631 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 632 633 sm_key_t p2; 634 memset(p2, 0, 16); 635 memcpy(&p2[4], ia, 6); 636 memcpy(&p2[10], ra, 6); 637 log_info_key("p2", p2); 638 639 // c1 = e(k, t2_xor_p2) 640 int i; 641 for (i=0;i<16;i++){ 642 t3[i] = t2[i] ^ p2[i]; 643 } 644 log_info_key("t3", t3); 645 } 646 647 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ 648 log_info_key("r1", r1); 649 log_info_key("r2", r2); 650 memcpy(&r_prime[8], &r2[8], 8); 651 memcpy(&r_prime[0], &r1[8], 8); 652 } 653 654 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 655 UNUSED(channel); 656 657 // log event 658 hci_dump_packet(packet_type, 1, packet, size); 659 // dispatch to all event handlers 660 btstack_linked_list_iterator_t it; 661 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 662 while (btstack_linked_list_iterator_has_next(&it)){ 663 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 664 entry->callback(packet_type, 0, packet, size); 665 } 666 } 667 668 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 669 event[0] = type; 670 event[1] = event_size - 2; 671 little_endian_store_16(event, 2, con_handle); 672 event[4] = addr_type; 673 reverse_bd_addr(address, &event[5]); 674 } 675 676 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 677 uint8_t event[11]; 678 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 679 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 680 } 681 682 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 683 uint8_t event[15]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 little_endian_store_32(event, 11, passkey); 686 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 687 } 688 689 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 690 // fetch addr and addr type from db 691 bd_addr_t identity_address; 692 int identity_address_type; 693 le_device_db_info(index, &identity_address_type, identity_address, NULL); 694 695 uint8_t event[20]; 696 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 697 event[11] = identity_address_type; 698 reverse_bd_addr(identity_address, &event[12]); 699 little_endian_store_16(event, 18, index); 700 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 701 } 702 703 static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ 704 uint8_t event[12]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = status; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 static void sm_notify_client_status_reason(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ 711 uint8_t event[13]; 712 sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); 713 event[11] = status; 714 event[12] = reason; 715 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 716 } 717 718 // decide on stk generation based on 719 // - pairing request 720 // - io capabilities 721 // - OOB data availability 722 static void sm_setup_tk(void){ 723 724 // default: just works 725 setup->sm_stk_generation_method = JUST_WORKS; 726 727 #ifdef ENABLE_LE_SECURE_CONNECTIONS 728 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 729 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 730 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 731 #else 732 setup->sm_use_secure_connections = 0; 733 #endif 734 log_info("Secure pairing: %u", setup->sm_use_secure_connections); 735 736 737 // decide if OOB will be used based on SC vs. Legacy and oob flags 738 int use_oob = 0; 739 if (setup->sm_use_secure_connections){ 740 // In LE Secure Connections pairing, the out of band method is used if at least 741 // one device has the peer device's out of band authentication data available. 742 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 743 } else { 744 // In LE legacy pairing, the out of band method is used if both the devices have 745 // the other device's out of band authentication data available. 746 use_oob = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 747 } 748 if (use_oob){ 749 log_info("SM: have OOB data"); 750 log_info_key("OOB", setup->sm_tk); 751 setup->sm_stk_generation_method = OOB; 752 return; 753 } 754 755 // If both devices have not set the MITM option in the Authentication Requirements 756 // Flags, then the IO capabilities shall be ignored and the Just Works association 757 // model shall be used. 758 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 759 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 760 log_info("SM: MITM not required by both -> JUST WORKS"); 761 return; 762 } 763 764 // Reset TK as it has been setup in sm_init_setup 765 sm_reset_tk(); 766 767 // Also use just works if unknown io capabilites 768 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 769 return; 770 } 771 772 // Otherwise the IO capabilities of the devices shall be used to determine the 773 // pairing method as defined in Table 2.4. 774 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 775 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 776 777 #ifdef ENABLE_LE_SECURE_CONNECTIONS 778 // table not define by default 779 if (setup->sm_use_secure_connections){ 780 generation_method = stk_generation_method_with_secure_connection; 781 } 782 #endif 783 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 784 785 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 786 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 787 } 788 789 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 790 int flags = 0; 791 if (key_set & SM_KEYDIST_ENC_KEY){ 792 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 794 } 795 if (key_set & SM_KEYDIST_ID_KEY){ 796 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 797 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 798 } 799 if (key_set & SM_KEYDIST_SIGN){ 800 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 801 } 802 return flags; 803 } 804 805 static void sm_setup_key_distribution(uint8_t key_set){ 806 setup->sm_key_distribution_received_set = 0; 807 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 808 } 809 810 // CSRK Key Lookup 811 812 813 static int sm_address_resolution_idle(void){ 814 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 815 } 816 817 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 818 memcpy(sm_address_resolution_address, addr, 6); 819 sm_address_resolution_addr_type = addr_type; 820 sm_address_resolution_test = 0; 821 sm_address_resolution_mode = mode; 822 sm_address_resolution_context = context; 823 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 824 } 825 826 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 827 // check if already in list 828 btstack_linked_list_iterator_t it; 829 sm_lookup_entry_t * entry; 830 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 831 while(btstack_linked_list_iterator_has_next(&it)){ 832 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 833 if (entry->address_type != address_type) continue; 834 if (memcmp(entry->address, address, 6)) continue; 835 // already in list 836 return BTSTACK_BUSY; 837 } 838 entry = btstack_memory_sm_lookup_entry_get(); 839 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 840 entry->address_type = (bd_addr_type_t) address_type; 841 memcpy(entry->address, address, 6); 842 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 843 sm_run(); 844 return 0; 845 } 846 847 // CMAC calculation using AES Engineq 848 #ifdef USE_CMAC_ENGINE 849 850 static void sm_cmac_done_trampoline(void * arg){ 851 UNUSED(arg); 852 sm_cmac_active = 0; 853 (*sm_cmac_done_callback)(sm_cmac_hash); 854 sm_run(); 855 } 856 857 int sm_cmac_ready(void){ 858 return sm_cmac_active == 0; 859 } 860 861 // generic cmac calculation 862 static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ 863 sm_cmac_active = 1; 864 sm_cmac_done_callback = done_callback; 865 btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 866 } 867 #endif 868 869 // cmac for ATT Message signing 870 #ifdef ENABLE_LE_SIGNED_WRITE 871 872 static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ 873 sm_cmac_active = 1; 874 sm_cmac_done_callback = done_callback; 875 btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); 876 } 877 878 static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ 879 if (offset >= sm_cmac_signed_write_message_len) { 880 log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); 881 return 0; 882 } 883 884 offset = sm_cmac_signed_write_message_len - 1 - offset; 885 886 // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] 887 if (offset < 3){ 888 return sm_cmac_signed_write_header[offset]; 889 } 890 int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; 891 if (offset < actual_message_len_incl_header){ 892 return sm_cmac_signed_write_message[offset - 3]; 893 } 894 return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; 895 } 896 897 void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 898 // ATT Message Signing 899 sm_cmac_signed_write_header[0] = opcode; 900 little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); 901 little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); 902 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 903 sm_cmac_signed_write_message = message; 904 sm_cmac_signed_write_message_len = total_message_len; 905 sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); 906 } 907 #endif 908 909 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 910 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 911 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 912 switch (setup->sm_stk_generation_method){ 913 case PK_RESP_INPUT: 914 if (IS_RESPONDER(sm_conn->sm_role)){ 915 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 916 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 917 } else { 918 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 919 } 920 break; 921 case PK_INIT_INPUT: 922 if (IS_RESPONDER(sm_conn->sm_role)){ 923 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 924 } else { 925 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 926 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 927 } 928 break; 929 case PK_BOTH_INPUT: 930 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 931 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 932 break; 933 case NUMERIC_COMPARISON: 934 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 935 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 936 break; 937 case JUST_WORKS: 938 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 939 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 940 break; 941 case OOB: 942 // client already provided OOB data, let's skip notification. 943 break; 944 } 945 } 946 947 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 948 int recv_flags; 949 if (IS_RESPONDER(sm_conn->sm_role)){ 950 // slave / responder 951 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 952 } else { 953 // master / initiator 954 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 955 } 956 957 #ifdef ENABLE_LE_SECURE_CONNECTIONS 958 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 959 if (setup->sm_use_secure_connections){ 960 recv_flags &= ~(SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION | SM_KEYDIST_FLAG_MASTER_IDENTIFICATION); 961 } 962 #endif 963 964 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 965 return (setup->sm_key_distribution_received_set & recv_flags) == recv_flags; 966 } 967 968 static void sm_done_for_handle(hci_con_handle_t con_handle){ 969 if (sm_active_connection_handle == con_handle){ 970 sm_timeout_stop(); 971 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 972 log_info("sm: connection 0x%x released setup context", con_handle); 973 974 #ifdef ENABLE_LE_SECURE_CONNECTIONS 975 // generate new ec key after each pairing (that used it) 976 if (setup->sm_use_secure_connections){ 977 sm_ec_generate_new_key(); 978 } 979 #endif 980 } 981 } 982 983 static int sm_key_distribution_flags_for_auth_req(void){ 984 985 int flags = SM_KEYDIST_ID_KEY; 986 if (sm_auth_req & SM_AUTHREQ_BONDING){ 987 // encryption and signing information only if bonding requested 988 flags |= SM_KEYDIST_ENC_KEY; 989 #ifdef ENABLE_LE_SIGNED_WRITE 990 flags |= SM_KEYDIST_SIGN; 991 #endif 992 } 993 return flags; 994 } 995 996 static void sm_reset_setup(void){ 997 // fill in sm setup 998 setup->sm_state_vars = 0; 999 setup->sm_keypress_notification = 0; 1000 sm_reset_tk(); 1001 } 1002 1003 static void sm_init_setup(sm_connection_t * sm_conn){ 1004 1005 // fill in sm setup 1006 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1007 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1008 1009 // query client for Legacy Pairing OOB data 1010 setup->sm_have_oob_data = 0; 1011 if (sm_get_oob_data) { 1012 setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1013 } 1014 1015 // if available and SC supported, also ask for SC OOB Data 1016 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1017 memset(setup->sm_ra, 0, 16); 1018 memset(setup->sm_rb, 0, 16); 1019 if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ 1020 if (sm_get_sc_oob_data){ 1021 if (IS_RESPONDER(sm_conn->sm_role)){ 1022 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1023 sm_conn->sm_peer_addr_type, 1024 sm_conn->sm_peer_address, 1025 setup->sm_peer_confirm, 1026 setup->sm_ra); 1027 } else { 1028 setup->sm_have_oob_data = (*sm_get_sc_oob_data)( 1029 sm_conn->sm_peer_addr_type, 1030 sm_conn->sm_peer_address, 1031 setup->sm_peer_confirm, 1032 setup->sm_rb); 1033 } 1034 } else { 1035 setup->sm_have_oob_data = 0; 1036 } 1037 } 1038 #endif 1039 1040 sm_pairing_packet_t * local_packet; 1041 if (IS_RESPONDER(sm_conn->sm_role)){ 1042 // slave 1043 local_packet = &setup->sm_s_pres; 1044 gap_le_get_own_address(&setup->sm_s_addr_type, setup->sm_s_address); 1045 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1046 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1047 } else { 1048 // master 1049 local_packet = &setup->sm_m_preq; 1050 gap_le_get_own_address(&setup->sm_m_addr_type, setup->sm_m_address); 1051 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1052 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1053 1054 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1055 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1056 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1057 } 1058 1059 uint8_t auth_req = sm_auth_req; 1060 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1061 sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); 1062 sm_pairing_packet_set_auth_req(*local_packet, auth_req); 1063 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1064 } 1065 1066 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1067 1068 sm_pairing_packet_t * remote_packet; 1069 int remote_key_request; 1070 if (IS_RESPONDER(sm_conn->sm_role)){ 1071 // slave / responder 1072 remote_packet = &setup->sm_m_preq; 1073 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1074 } else { 1075 // master / initiator 1076 remote_packet = &setup->sm_s_pres; 1077 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1078 } 1079 1080 // check key size 1081 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1082 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1083 1084 // decide on STK generation method / SC 1085 sm_setup_tk(); 1086 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1087 1088 // check if STK generation method is acceptable by client 1089 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1090 1091 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1092 // LTK (= encyrption information & master identification) only used exchanged for LE Legacy Connection 1093 if (setup->sm_use_secure_connections){ 1094 remote_key_request &= ~SM_KEYDIST_ENC_KEY; 1095 } 1096 #endif 1097 1098 // identical to responder 1099 sm_setup_key_distribution(remote_key_request); 1100 1101 // JUST WORKS doens't provide authentication 1102 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1103 1104 return 0; 1105 } 1106 1107 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1108 1109 // cache and reset context 1110 int matched_device_id = sm_address_resolution_test; 1111 address_resolution_mode_t mode = sm_address_resolution_mode; 1112 void * context = sm_address_resolution_context; 1113 1114 // reset context 1115 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1116 sm_address_resolution_context = NULL; 1117 sm_address_resolution_test = -1; 1118 hci_con_handle_t con_handle = 0; 1119 1120 sm_connection_t * sm_connection; 1121 #ifdef ENABLE_LE_CENTRAL 1122 sm_key_t ltk; 1123 int have_ltk; 1124 int pairing_need; 1125 #endif 1126 switch (mode){ 1127 case ADDRESS_RESOLUTION_GENERAL: 1128 break; 1129 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1130 sm_connection = (sm_connection_t *) context; 1131 con_handle = sm_connection->sm_handle; 1132 switch (event){ 1133 case ADDRESS_RESOLUTION_SUCEEDED: 1134 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1135 sm_connection->sm_le_db_index = matched_device_id; 1136 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1137 if (sm_connection->sm_role) { 1138 // LTK request received before, IRK required -> start LTK calculation 1139 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1140 sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 1141 } 1142 break; 1143 } 1144 #ifdef ENABLE_LE_CENTRAL 1145 le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 1146 have_ltk = !sm_is_null_key(ltk); 1147 pairing_need = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; 1148 log_info("central: pairing request local %u, remote %u => action %u. have_ltk %u", 1149 sm_connection->sm_pairing_requested, sm_connection->sm_security_request_received, pairing_need, have_ltk); 1150 // reset requests 1151 sm_connection->sm_security_request_received = 0; 1152 sm_connection->sm_pairing_requested = 0; 1153 1154 // have ltk -> start encryption 1155 // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request 1156 // "When a bond has been created between two devices, any reconnection should result in the local device 1157 // enabling or requesting encryption with the remote device before initiating any service request." 1158 if (have_ltk){ 1159 #ifdef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 1160 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1161 break; 1162 #else 1163 log_info("central: defer enabling encryption for bonded device"); 1164 #endif 1165 } 1166 // pairint_request -> send pairing request 1167 if (pairing_need){ 1168 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1169 break; 1170 } 1171 #endif 1172 break; 1173 case ADDRESS_RESOLUTION_FAILED: 1174 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1175 if (sm_connection->sm_role) { 1176 // LTK request received before, IRK required -> negative LTK reply 1177 if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ 1178 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1179 } 1180 break; 1181 } 1182 #ifdef ENABLE_LE_CENTRAL 1183 if (!sm_connection->sm_pairing_requested && !sm_connection->sm_security_request_received) break; 1184 sm_connection->sm_security_request_received = 0; 1185 sm_connection->sm_pairing_requested = 0; 1186 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1187 #endif 1188 break; 1189 } 1190 break; 1191 default: 1192 break; 1193 } 1194 1195 switch (event){ 1196 case ADDRESS_RESOLUTION_SUCEEDED: 1197 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1198 break; 1199 case ADDRESS_RESOLUTION_FAILED: 1200 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1201 break; 1202 } 1203 } 1204 1205 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1206 1207 int le_db_index = -1; 1208 1209 // only store pairing information if both sides are bondable, i.e., the bonadble flag is set 1210 int bonding_enabed = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 1211 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 1212 & SM_AUTHREQ_BONDING ) != 0; 1213 1214 if (bonding_enabed){ 1215 1216 // lookup device based on IRK 1217 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1218 int i; 1219 for (i=0; i < le_device_db_max_count(); i++){ 1220 sm_key_t irk; 1221 bd_addr_t address; 1222 int address_type = BD_ADDR_TYPE_UNKNOWN; 1223 le_device_db_info(i, &address_type, address, irk); 1224 // check if valid entry retrieved 1225 if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; 1226 // compare IRK 1227 if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; 1228 1229 log_info("sm: device found for IRK, updating"); 1230 le_db_index = i; 1231 break; 1232 } 1233 } else { 1234 // assert IRK is set to zero 1235 memset(setup->sm_peer_irk, 0, 16); 1236 } 1237 1238 // if not found, lookup via public address if possible 1239 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1240 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1241 int i; 1242 for (i=0; i < le_device_db_max_count(); i++){ 1243 bd_addr_t address; 1244 int address_type; 1245 le_device_db_info(i, &address_type, address, NULL); 1246 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1247 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1248 log_info("sm: device found for public address, updating"); 1249 le_db_index = i; 1250 break; 1251 } 1252 } 1253 } 1254 1255 // if not found, add to db 1256 if (le_db_index < 0) { 1257 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1258 } 1259 1260 if (le_db_index >= 0){ 1261 1262 sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); 1263 1264 #ifdef ENABLE_LE_SIGNED_WRITE 1265 // store local CSRK 1266 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1267 log_info("sm: store local CSRK"); 1268 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1269 le_device_db_local_counter_set(le_db_index, 0); 1270 } 1271 1272 // store remote CSRK 1273 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1274 log_info("sm: store remote CSRK"); 1275 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1276 le_device_db_remote_counter_set(le_db_index, 0); 1277 } 1278 #endif 1279 // store encryption information for secure connections: LTK generated by ECDH 1280 if (setup->sm_use_secure_connections){ 1281 log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1282 uint8_t zero_rand[8]; 1283 memset(zero_rand, 0, 8); 1284 le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, 1285 sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1286 } 1287 1288 // store encryption information for legacy pairing: peer LTK, EDIV, RAND 1289 else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) 1290 && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ 1291 log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1292 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1293 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1294 1295 } 1296 } 1297 } else { 1298 log_info("Ignoring received keys, bonding not enabled"); 1299 } 1300 1301 // keep le_db_index 1302 sm_conn->sm_le_db_index = le_db_index; 1303 } 1304 1305 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1306 setup->sm_pairing_failed_reason = reason; 1307 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1308 } 1309 1310 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1311 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1312 } 1313 1314 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1315 1316 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1317 static int sm_passkey_used(stk_generation_method_t method); 1318 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1319 1320 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1321 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1322 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1323 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1324 } else { 1325 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1326 } 1327 } 1328 1329 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1330 if (IS_RESPONDER(sm_conn->sm_role)){ 1331 // Responder 1332 if (setup->sm_stk_generation_method == OOB){ 1333 // generate Nb 1334 log_info("Generate Nb"); 1335 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1336 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 1337 } else { 1338 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1339 } 1340 } else { 1341 // Initiator role 1342 switch (setup->sm_stk_generation_method){ 1343 case JUST_WORKS: 1344 sm_sc_prepare_dhkey_check(sm_conn); 1345 break; 1346 1347 case NUMERIC_COMPARISON: 1348 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1349 break; 1350 case PK_INIT_INPUT: 1351 case PK_RESP_INPUT: 1352 case PK_BOTH_INPUT: 1353 if (setup->sm_passkey_bit < 20) { 1354 sm_sc_start_calculating_local_confirm(sm_conn); 1355 } else { 1356 sm_sc_prepare_dhkey_check(sm_conn); 1357 } 1358 break; 1359 case OOB: 1360 sm_sc_prepare_dhkey_check(sm_conn); 1361 break; 1362 } 1363 } 1364 } 1365 1366 static void sm_sc_cmac_done(uint8_t * hash){ 1367 log_info("sm_sc_cmac_done: "); 1368 log_info_hexdump(hash, 16); 1369 1370 if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ 1371 sm_sc_oob_state = SM_SC_OOB_IDLE; 1372 (*sm_sc_oob_callback)(hash, sm_sc_oob_random); 1373 return; 1374 } 1375 1376 sm_connection_t * sm_conn = sm_cmac_connection; 1377 sm_cmac_connection = NULL; 1378 #ifdef ENABLE_CLASSIC 1379 link_key_type_t link_key_type; 1380 #endif 1381 1382 switch (sm_conn->sm_engine_state){ 1383 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1384 memcpy(setup->sm_local_confirm, hash, 16); 1385 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1386 break; 1387 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1388 // check 1389 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1390 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1391 break; 1392 } 1393 sm_sc_state_after_receiving_random(sm_conn); 1394 break; 1395 case SM_SC_W4_CALCULATE_G2: { 1396 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1397 big_endian_store_32(setup->sm_tk, 12, vab); 1398 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1399 sm_trigger_user_response(sm_conn); 1400 break; 1401 } 1402 case SM_SC_W4_CALCULATE_F5_SALT: 1403 memcpy(setup->sm_t, hash, 16); 1404 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1405 break; 1406 case SM_SC_W4_CALCULATE_F5_MACKEY: 1407 memcpy(setup->sm_mackey, hash, 16); 1408 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1409 break; 1410 case SM_SC_W4_CALCULATE_F5_LTK: 1411 // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk 1412 // Errata Service Release to the Bluetooth Specification: ESR09 1413 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1414 // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1415 memcpy(setup->sm_ltk, hash, 16); 1416 memcpy(setup->sm_local_ltk, hash, 16); 1417 sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); 1418 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1419 break; 1420 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1421 memcpy(setup->sm_local_dhkey_check, hash, 16); 1422 if (IS_RESPONDER(sm_conn->sm_role)){ 1423 // responder 1424 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1425 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1426 } else { 1427 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1428 } 1429 } else { 1430 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1431 } 1432 break; 1433 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1434 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1435 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1436 break; 1437 } 1438 if (IS_RESPONDER(sm_conn->sm_role)){ 1439 // responder 1440 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1441 } else { 1442 // initiator 1443 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1444 } 1445 break; 1446 case SM_SC_W4_CALCULATE_H6_ILK: 1447 memcpy(setup->sm_t, hash, 16); 1448 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY; 1449 break; 1450 case SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY: 1451 #ifdef ENABLE_CLASSIC 1452 reverse_128(hash, setup->sm_t); 1453 link_key_type = sm_conn->sm_connection_authenticated ? 1454 AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; 1455 log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); 1456 if (IS_RESPONDER(sm_conn->sm_role)){ 1457 gap_store_link_key_for_bd_addr(setup->sm_m_address, setup->sm_t, link_key_type); 1458 } else { 1459 gap_store_link_key_for_bd_addr(setup->sm_s_address, setup->sm_t, link_key_type); 1460 } 1461 #endif 1462 if (IS_RESPONDER(sm_conn->sm_role)){ 1463 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 1464 } else { 1465 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 1466 } 1467 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 1468 sm_done_for_handle(sm_conn->sm_handle); 1469 break; 1470 default: 1471 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1472 break; 1473 } 1474 sm_run(); 1475 } 1476 1477 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){ 1478 const uint16_t message_len = 65; 1479 sm_cmac_connection = sm_conn; 1480 memcpy(sm_cmac_sc_buffer, u, 32); 1481 memcpy(sm_cmac_sc_buffer+32, v, 32); 1482 sm_cmac_sc_buffer[64] = z; 1483 log_info("f4 key"); 1484 log_info_hexdump(x, 16); 1485 log_info("f4 message"); 1486 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1487 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1488 } 1489 1490 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1491 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1492 static const uint8_t f5_length[] = { 0x01, 0x00}; 1493 1494 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1495 log_info("f5_calculate_salt"); 1496 // calculate salt for f5 1497 const uint16_t message_len = 32; 1498 sm_cmac_connection = sm_conn; 1499 memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); 1500 sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1501 } 1502 1503 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){ 1504 const uint16_t message_len = 53; 1505 sm_cmac_connection = sm_conn; 1506 1507 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1508 sm_cmac_sc_buffer[0] = 0; 1509 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1510 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1511 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1512 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1513 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1514 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1515 log_info("f5 key"); 1516 log_info_hexdump(t, 16); 1517 log_info("f5 message for MacKey"); 1518 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1519 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1520 } 1521 1522 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1523 sm_key56_t bd_addr_master, bd_addr_slave; 1524 bd_addr_master[0] = setup->sm_m_addr_type; 1525 bd_addr_slave[0] = setup->sm_s_addr_type; 1526 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1527 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1528 if (IS_RESPONDER(sm_conn->sm_role)){ 1529 // responder 1530 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1531 } else { 1532 // initiator 1533 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1534 } 1535 } 1536 1537 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1538 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1539 const uint16_t message_len = 53; 1540 sm_cmac_connection = sm_conn; 1541 sm_cmac_sc_buffer[0] = 1; 1542 // 1..52 setup before 1543 log_info("f5 key"); 1544 log_info_hexdump(t, 16); 1545 log_info("f5 message for LTK"); 1546 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1547 sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1548 } 1549 1550 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1551 f5_ltk(sm_conn, setup->sm_t); 1552 } 1553 1554 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){ 1555 const uint16_t message_len = 65; 1556 sm_cmac_connection = sm_conn; 1557 memcpy(sm_cmac_sc_buffer, n1, 16); 1558 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1559 memcpy(sm_cmac_sc_buffer+32, r, 16); 1560 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1561 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1562 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1563 log_info("f6 key"); 1564 log_info_hexdump(w, 16); 1565 log_info("f6 message"); 1566 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1567 sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1568 } 1569 1570 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1571 // - U is 256 bits 1572 // - V is 256 bits 1573 // - X is 128 bits 1574 // - Y is 128 bits 1575 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){ 1576 const uint16_t message_len = 80; 1577 sm_cmac_connection = sm_conn; 1578 memcpy(sm_cmac_sc_buffer, u, 32); 1579 memcpy(sm_cmac_sc_buffer+32, v, 32); 1580 memcpy(sm_cmac_sc_buffer+64, y, 16); 1581 log_info("g2 key"); 1582 log_info_hexdump(x, 16); 1583 log_info("g2 message"); 1584 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1585 sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1586 } 1587 1588 static void g2_calculate(sm_connection_t * sm_conn) { 1589 // calc Va if numeric comparison 1590 if (IS_RESPONDER(sm_conn->sm_role)){ 1591 // responder 1592 g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; 1593 } else { 1594 // initiator 1595 g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); 1596 } 1597 } 1598 1599 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1600 uint8_t z = 0; 1601 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1602 // some form of passkey 1603 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1604 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1605 setup->sm_passkey_bit++; 1606 } 1607 f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); 1608 } 1609 1610 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1611 // OOB 1612 if (setup->sm_stk_generation_method == OOB){ 1613 if (IS_RESPONDER(sm_conn->sm_role)){ 1614 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); 1615 } else { 1616 f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); 1617 } 1618 return; 1619 } 1620 1621 uint8_t z = 0; 1622 if (sm_passkey_entry(setup->sm_stk_generation_method)){ 1623 // some form of passkey 1624 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1625 // sm_passkey_bit was increased before sending confirm value 1626 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1627 } 1628 f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); 1629 } 1630 1631 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1632 log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED ? 1 : 0); 1633 1634 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED){ 1635 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1636 return; 1637 } else { 1638 sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; 1639 } 1640 } 1641 1642 static void sm_sc_dhkey_calculated(void * arg){ 1643 sm_connection_t * sm_conn = (sm_connection_t *) arg; 1644 log_info("dhkey"); 1645 log_info_hexdump(&setup->sm_dhkey[0], 32); 1646 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; 1647 // trigger next step 1648 if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ 1649 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1650 } 1651 sm_run(); 1652 } 1653 1654 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1655 // calculate DHKCheck 1656 sm_key56_t bd_addr_master, bd_addr_slave; 1657 bd_addr_master[0] = setup->sm_m_addr_type; 1658 bd_addr_slave[0] = setup->sm_s_addr_type; 1659 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1660 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1661 uint8_t iocap_a[3]; 1662 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1663 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1664 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1665 uint8_t iocap_b[3]; 1666 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1667 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1668 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1669 if (IS_RESPONDER(sm_conn->sm_role)){ 1670 // responder 1671 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); 1672 } else { 1673 // initiator 1674 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); 1675 } 1676 } 1677 1678 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1679 // validate E = f6() 1680 sm_key56_t bd_addr_master, bd_addr_slave; 1681 bd_addr_master[0] = setup->sm_m_addr_type; 1682 bd_addr_slave[0] = setup->sm_s_addr_type; 1683 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1684 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1685 1686 uint8_t iocap_a[3]; 1687 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1688 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1689 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1690 uint8_t iocap_b[3]; 1691 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1692 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1693 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1694 if (IS_RESPONDER(sm_conn->sm_role)){ 1695 // responder 1696 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); 1697 } else { 1698 // initiator 1699 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); 1700 } 1701 } 1702 1703 1704 // 1705 // Link Key Conversion Function h6 1706 // 1707 // h6(W, keyID) = AES-CMACW(keyID) 1708 // - W is 128 bits 1709 // - keyID is 32 bits 1710 static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ 1711 const uint16_t message_len = 4; 1712 sm_cmac_connection = sm_conn; 1713 big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); 1714 log_info("h6 key"); 1715 log_info_hexdump(w, 16); 1716 log_info("h6 message"); 1717 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1718 sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); 1719 } 1720 1721 // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) 1722 // Errata Service Release to the Bluetooth Specification: ESR09 1723 // E6405 – Cross transport key derivation from a key of size less than 128 bits 1724 // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." 1725 static void h6_calculate_ilk(sm_connection_t * sm_conn){ 1726 h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" 1727 } 1728 1729 static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ 1730 h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" 1731 } 1732 1733 #endif 1734 1735 // key management legacy connections: 1736 // - potentially two different LTKs based on direction. each device stores LTK provided by peer 1737 // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) 1738 // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder 1739 // - responder reconnects: responder uses LTK receveived from master 1740 1741 // key management secure connections: 1742 // - both devices store same LTK from ECDH key exchange. 1743 1744 #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) 1745 static void sm_load_security_info(sm_connection_t * sm_connection){ 1746 int encryption_key_size; 1747 int authenticated; 1748 int authorized; 1749 1750 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1751 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1752 &encryption_key_size, &authenticated, &authorized); 1753 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1754 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1755 sm_connection->sm_connection_authenticated = authenticated; 1756 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1757 } 1758 #endif 1759 1760 #ifdef ENABLE_LE_PERIPHERAL 1761 static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ 1762 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1763 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1764 // re-establish used key encryption size 1765 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1766 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1767 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1768 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1769 log_info("sm: received ltk request with key size %u, authenticated %u", 1770 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1771 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1772 sm_run(); 1773 } 1774 #endif 1775 1776 static void sm_run(void){ 1777 1778 btstack_linked_list_iterator_t it; 1779 1780 // assert that stack has already bootet 1781 if (hci_get_state() != HCI_STATE_WORKING) return; 1782 1783 // assert that we can send at least commands 1784 if (!hci_can_send_command_packet_now()) return; 1785 1786 // 1787 // non-connection related behaviour 1788 // 1789 1790 // distributed key generation 1791 switch (dkg_state){ 1792 case DKG_CALC_IRK: 1793 // already busy? 1794 if (sm_aes128_state == SM_AES128_IDLE) { 1795 log_info("DKG_CALC_IRK started"); 1796 // IRK = d1(IR, 1, 0) 1797 sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime 1798 sm_aes128_state = SM_AES128_ACTIVE; 1799 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); 1800 return; 1801 } 1802 break; 1803 case DKG_CALC_DHK: 1804 // already busy? 1805 if (sm_aes128_state == SM_AES128_IDLE) { 1806 log_info("DKG_CALC_DHK started"); 1807 // DHK = d1(IR, 3, 0) 1808 sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime 1809 sm_aes128_state = SM_AES128_ACTIVE; 1810 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); 1811 return; 1812 } 1813 break; 1814 default: 1815 break; 1816 } 1817 1818 // random address updates 1819 switch (rau_state){ 1820 case RAU_GET_RANDOM: 1821 rau_state = RAU_W4_RANDOM; 1822 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 8, &sm_handle_random_result_rau, NULL); 1823 return; 1824 case RAU_GET_ENC: 1825 // already busy? 1826 if (sm_aes128_state == SM_AES128_IDLE) { 1827 sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); 1828 sm_aes128_state = SM_AES128_ACTIVE; 1829 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); 1830 return; 1831 } 1832 break; 1833 case RAU_SET_ADDRESS: 1834 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1835 rau_state = RAU_IDLE; 1836 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1837 return; 1838 default: 1839 break; 1840 } 1841 1842 // CSRK Lookup 1843 // -- if csrk lookup ready, find connection that require csrk lookup 1844 if (sm_address_resolution_idle()){ 1845 hci_connections_get_iterator(&it); 1846 while(btstack_linked_list_iterator_has_next(&it)){ 1847 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1848 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1849 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1850 // and start lookup 1851 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); 1852 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1853 break; 1854 } 1855 } 1856 } 1857 1858 // -- if csrk lookup ready, resolved addresses for received addresses 1859 if (sm_address_resolution_idle()) { 1860 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1861 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1862 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1863 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1864 btstack_memory_sm_lookup_entry_free(entry); 1865 } 1866 } 1867 1868 // -- Continue with CSRK device lookup by public or resolvable private address 1869 if (!sm_address_resolution_idle()){ 1870 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_max_count()); 1871 while (sm_address_resolution_test < le_device_db_max_count()){ 1872 int addr_type; 1873 bd_addr_t addr; 1874 sm_key_t irk; 1875 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1876 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1877 1878 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1879 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1880 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1881 break; 1882 } 1883 1884 if (sm_address_resolution_addr_type == 0){ 1885 sm_address_resolution_test++; 1886 continue; 1887 } 1888 1889 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1890 1891 log_info("LE Device Lookup: calculate AH"); 1892 log_info_key("IRK", irk); 1893 1894 memcpy(sm_aes128_key, irk, 16); 1895 sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); 1896 sm_address_resolution_ah_calculation_active = 1; 1897 sm_aes128_state = SM_AES128_ACTIVE; 1898 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); 1899 return; 1900 } 1901 1902 if (sm_address_resolution_test >= le_device_db_max_count()){ 1903 log_info("LE Device Lookup: not found"); 1904 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1905 } 1906 } 1907 1908 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1909 switch (sm_sc_oob_state){ 1910 case SM_SC_OOB_W2_CALC_CONFIRM: 1911 if (!sm_cmac_ready()) break; 1912 sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; 1913 f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); 1914 return; 1915 default: 1916 break; 1917 } 1918 #endif 1919 1920 // assert that we can send at least commands - cmd might have been sent by crypto engine 1921 if (!hci_can_send_command_packet_now()) return; 1922 1923 // handle basic actions that don't requires the full context 1924 hci_connections_get_iterator(&it); 1925 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1926 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1927 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1928 switch(sm_connection->sm_engine_state){ 1929 // responder side 1930 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 1931 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1932 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1933 return; 1934 1935 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1936 case SM_SC_RECEIVED_LTK_REQUEST: 1937 switch (sm_connection->sm_irk_lookup_state){ 1938 case IRK_LOOKUP_FAILED: 1939 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Failed)"); 1940 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 1941 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 1942 return; 1943 default: 1944 break; 1945 } 1946 break; 1947 #endif 1948 default: 1949 break; 1950 } 1951 } 1952 1953 // 1954 // active connection handling 1955 // -- use loop to handle next connection if lock on setup context is released 1956 1957 while (1) { 1958 1959 // Find connections that requires setup context and make active if no other is locked 1960 hci_connections_get_iterator(&it); 1961 while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ 1962 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1963 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1964 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1965 int done = 1; 1966 int err; 1967 UNUSED(err); 1968 1969 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1970 // assert ec key is ready 1971 if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED 1972 || sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST){ 1973 if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ 1974 sm_ec_generate_new_key(); 1975 } 1976 if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ 1977 continue; 1978 } 1979 } 1980 #endif 1981 1982 switch (sm_connection->sm_engine_state) { 1983 #ifdef ENABLE_LE_PERIPHERAL 1984 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1985 // send packet if possible, 1986 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1987 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1988 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1989 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1990 } else { 1991 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1992 } 1993 // don't lock sxetup context yet 1994 done = 0; 1995 break; 1996 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1997 sm_reset_setup(); 1998 sm_init_setup(sm_connection); 1999 // recover pairing request 2000 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 2001 err = sm_stk_generation_init(sm_connection); 2002 2003 #ifdef ENABLE_TESTING_SUPPORT 2004 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 2005 log_info("testing_support: respond with pairing failure %u", test_pairing_failure); 2006 err = test_pairing_failure; 2007 } 2008 #endif 2009 if (err){ 2010 setup->sm_pairing_failed_reason = err; 2011 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2012 break; 2013 } 2014 sm_timeout_start(sm_connection); 2015 // generate random number first, if we need to show passkey 2016 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 2017 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_connection); 2018 break; 2019 } 2020 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2021 break; 2022 case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: 2023 sm_reset_setup(); 2024 sm_start_calculating_ltk_from_ediv_and_rand(sm_connection); 2025 break; 2026 2027 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2028 case SM_SC_RECEIVED_LTK_REQUEST: 2029 switch (sm_connection->sm_irk_lookup_state){ 2030 case IRK_LOOKUP_SUCCEEDED: 2031 // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null 2032 // start using context by loading security info 2033 sm_reset_setup(); 2034 sm_load_security_info(sm_connection); 2035 if (setup->sm_peer_ediv == 0 && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ 2036 memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); 2037 sm_connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2038 break; 2039 } 2040 log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); 2041 sm_connection->sm_engine_state = SM_RESPONDER_IDLE; 2042 hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); 2043 // don't lock setup context yet 2044 return; 2045 default: 2046 // just wait until IRK lookup is completed 2047 // don't lock setup context yet 2048 done = 0; 2049 break; 2050 } 2051 break; 2052 #endif /* ENABLE_LE_SECURE_CONNECTIONS */ 2053 #endif /* ENABLE_LE_PERIPHERAL */ 2054 2055 #ifdef ENABLE_LE_CENTRAL 2056 case SM_INITIATOR_PH0_HAS_LTK: 2057 sm_reset_setup(); 2058 sm_load_security_info(sm_connection); 2059 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 2060 break; 2061 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 2062 sm_reset_setup(); 2063 sm_init_setup(sm_connection); 2064 sm_timeout_start(sm_connection); 2065 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 2066 break; 2067 #endif 2068 2069 default: 2070 done = 0; 2071 break; 2072 } 2073 if (done){ 2074 sm_active_connection_handle = sm_connection->sm_handle; 2075 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); 2076 } 2077 } 2078 2079 // 2080 // active connection handling 2081 // 2082 2083 if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; 2084 2085 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); 2086 if (!connection) { 2087 log_info("no connection for handle 0x%04x", sm_active_connection_handle); 2088 return; 2089 } 2090 2091 // assert that we could send a SM PDU - not needed for all of the following 2092 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2093 log_info("cannot send now, requesting can send now event"); 2094 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2095 return; 2096 } 2097 2098 // send keypress notifications 2099 if (setup->sm_keypress_notification){ 2100 int i; 2101 uint8_t flags = setup->sm_keypress_notification & 0x1f; 2102 uint8_t num_actions = setup->sm_keypress_notification >> 5; 2103 uint8_t action = 0; 2104 for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ 2105 if (flags & (1<<i)){ 2106 int clear_flag = 1; 2107 switch (i){ 2108 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 2109 case SM_KEYPRESS_PASSKEY_CLEARED: 2110 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 2111 default: 2112 break; 2113 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 2114 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 2115 num_actions--; 2116 clear_flag = num_actions == 0; 2117 break; 2118 } 2119 if (clear_flag){ 2120 flags &= ~(1<<i); 2121 } 2122 action = i; 2123 break; 2124 } 2125 } 2126 setup->sm_keypress_notification = (num_actions << 5) | flags; 2127 2128 // send keypress notification 2129 uint8_t buffer[2]; 2130 buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; 2131 buffer[1] = action; 2132 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2133 2134 // try 2135 l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 2136 return; 2137 } 2138 2139 int key_distribution_flags; 2140 UNUSED(key_distribution_flags); 2141 2142 log_info("sm_run: state %u", connection->sm_engine_state); 2143 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 2144 log_info("sm_run // cannot send"); 2145 } 2146 switch (connection->sm_engine_state){ 2147 2148 // general 2149 case SM_GENERAL_SEND_PAIRING_FAILED: { 2150 uint8_t buffer[2]; 2151 buffer[0] = SM_CODE_PAIRING_FAILED; 2152 buffer[1] = setup->sm_pairing_failed_reason; 2153 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2154 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2155 sm_notify_client_status_reason(connection, ERROR_CODE_AUTHENTICATION_FAILURE, setup->sm_pairing_failed_reason); 2156 sm_done_for_handle(connection->sm_handle); 2157 break; 2158 } 2159 2160 // responding state 2161 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2162 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2163 if (!sm_cmac_ready()) break; 2164 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2165 sm_sc_calculate_local_confirm(connection); 2166 break; 2167 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2168 if (!sm_cmac_ready()) break; 2169 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2170 sm_sc_calculate_remote_confirm(connection); 2171 break; 2172 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2173 if (!sm_cmac_ready()) break; 2174 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2175 sm_sc_calculate_f6_for_dhkey_check(connection); 2176 break; 2177 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2178 if (!sm_cmac_ready()) break; 2179 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2180 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2181 break; 2182 case SM_SC_W2_CALCULATE_F5_SALT: 2183 if (!sm_cmac_ready()) break; 2184 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2185 f5_calculate_salt(connection); 2186 break; 2187 case SM_SC_W2_CALCULATE_F5_MACKEY: 2188 if (!sm_cmac_ready()) break; 2189 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2190 f5_calculate_mackey(connection); 2191 break; 2192 case SM_SC_W2_CALCULATE_F5_LTK: 2193 if (!sm_cmac_ready()) break; 2194 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2195 f5_calculate_ltk(connection); 2196 break; 2197 case SM_SC_W2_CALCULATE_G2: 2198 if (!sm_cmac_ready()) break; 2199 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2200 g2_calculate(connection); 2201 break; 2202 case SM_SC_W2_CALCULATE_H6_ILK: 2203 if (!sm_cmac_ready()) break; 2204 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_ILK; 2205 h6_calculate_ilk(connection); 2206 break; 2207 case SM_SC_W2_CALCULATE_H6_BR_EDR_LINK_KEY: 2208 if (!sm_cmac_ready()) break; 2209 connection->sm_engine_state = SM_SC_W4_CALCULATE_H6_BR_EDR_LINK_KEY; 2210 h6_calculate_br_edr_link_key(connection); 2211 break; 2212 #endif 2213 2214 #ifdef ENABLE_LE_CENTRAL 2215 // initiator side 2216 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2217 sm_key_t peer_ltk_flipped; 2218 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2219 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2220 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2221 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2222 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2223 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2224 return; 2225 } 2226 2227 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2228 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2229 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2230 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2231 sm_timeout_reset(connection); 2232 break; 2233 #endif 2234 2235 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2236 2237 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2238 int trigger_user_response = 0; 2239 2240 uint8_t buffer[65]; 2241 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2242 // 2243 reverse_256(&ec_q[0], &buffer[1]); 2244 reverse_256(&ec_q[32], &buffer[33]); 2245 2246 #ifdef ENABLE_TESTING_SUPPORT 2247 if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ 2248 log_info("testing_support: invalidating public key"); 2249 // flip single bit of public key coordinate 2250 buffer[1] ^= 1; 2251 } 2252 #endif 2253 2254 // stk generation method 2255 // passkey entry: notify app to show passkey or to request passkey 2256 switch (setup->sm_stk_generation_method){ 2257 case JUST_WORKS: 2258 case NUMERIC_COMPARISON: 2259 if (IS_RESPONDER(connection->sm_role)){ 2260 // responder 2261 sm_sc_start_calculating_local_confirm(connection); 2262 } else { 2263 // initiator 2264 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2265 } 2266 break; 2267 case PK_INIT_INPUT: 2268 case PK_RESP_INPUT: 2269 case PK_BOTH_INPUT: 2270 // use random TK for display 2271 memcpy(setup->sm_ra, setup->sm_tk, 16); 2272 memcpy(setup->sm_rb, setup->sm_tk, 16); 2273 setup->sm_passkey_bit = 0; 2274 2275 if (IS_RESPONDER(connection->sm_role)){ 2276 // responder 2277 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2278 } else { 2279 // initiator 2280 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2281 } 2282 trigger_user_response = 1; 2283 break; 2284 case OOB: 2285 if (IS_RESPONDER(connection->sm_role)){ 2286 // responder 2287 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2288 } else { 2289 // initiator 2290 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2291 } 2292 break; 2293 } 2294 2295 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2296 sm_timeout_reset(connection); 2297 2298 // trigger user response after sending pdu 2299 if (trigger_user_response){ 2300 sm_trigger_user_response(connection); 2301 } 2302 break; 2303 } 2304 case SM_SC_SEND_CONFIRMATION: { 2305 uint8_t buffer[17]; 2306 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2307 reverse_128(setup->sm_local_confirm, &buffer[1]); 2308 if (IS_RESPONDER(connection->sm_role)){ 2309 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2310 } else { 2311 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2312 } 2313 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2314 sm_timeout_reset(connection); 2315 break; 2316 } 2317 case SM_SC_SEND_PAIRING_RANDOM: { 2318 uint8_t buffer[17]; 2319 buffer[0] = SM_CODE_PAIRING_RANDOM; 2320 reverse_128(setup->sm_local_nonce, &buffer[1]); 2321 log_info("stk method %u, num bits %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); 2322 if (sm_passkey_entry(setup->sm_stk_generation_method) && setup->sm_passkey_bit < 20){ 2323 log_info("SM_SC_SEND_PAIRING_RANDOM A"); 2324 if (IS_RESPONDER(connection->sm_role)){ 2325 // responder 2326 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2327 } else { 2328 // initiator 2329 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2330 } 2331 } else { 2332 log_info("SM_SC_SEND_PAIRING_RANDOM B"); 2333 if (IS_RESPONDER(connection->sm_role)){ 2334 // responder 2335 if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ 2336 log_info("SM_SC_SEND_PAIRING_RANDOM B1"); 2337 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2338 } else { 2339 log_info("SM_SC_SEND_PAIRING_RANDOM B2"); 2340 sm_sc_prepare_dhkey_check(connection); 2341 } 2342 } else { 2343 // initiator 2344 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2345 } 2346 } 2347 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2348 sm_timeout_reset(connection); 2349 break; 2350 } 2351 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2352 uint8_t buffer[17]; 2353 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2354 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2355 2356 if (IS_RESPONDER(connection->sm_role)){ 2357 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2358 } else { 2359 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2360 } 2361 2362 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2363 sm_timeout_reset(connection); 2364 break; 2365 } 2366 2367 #endif 2368 2369 #ifdef ENABLE_LE_PERIPHERAL 2370 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2371 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2372 2373 // start with initiator key dist flags 2374 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2375 2376 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2377 // LTK (= encyrption information & master identification) only exchanged for LE Legacy Connection 2378 if (setup->sm_use_secure_connections){ 2379 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2380 } 2381 #endif 2382 // setup in response 2383 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); 2384 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); 2385 2386 // update key distribution after ENC was dropped 2387 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2388 2389 if (setup->sm_use_secure_connections){ 2390 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2391 } else { 2392 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2393 } 2394 2395 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2396 sm_timeout_reset(connection); 2397 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2398 if (!setup->sm_use_secure_connections || setup->sm_stk_generation_method == JUST_WORKS){ 2399 sm_trigger_user_response(connection); 2400 } 2401 return; 2402 #endif 2403 2404 case SM_PH2_SEND_PAIRING_RANDOM: { 2405 uint8_t buffer[17]; 2406 buffer[0] = SM_CODE_PAIRING_RANDOM; 2407 reverse_128(setup->sm_local_random, &buffer[1]); 2408 if (IS_RESPONDER(connection->sm_role)){ 2409 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2410 } else { 2411 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2412 } 2413 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2414 sm_timeout_reset(connection); 2415 break; 2416 } 2417 2418 case SM_PH2_C1_GET_ENC_A: 2419 // already busy? 2420 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2421 // calculate confirm using aes128 engine - step 1 2422 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); 2423 connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; 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_a, connection); 2426 break; 2427 2428 case SM_PH2_C1_GET_ENC_C: 2429 // already busy? 2430 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2431 // calculate m_confirm using aes128 engine - step 1 2432 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); 2433 connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; 2434 sm_aes128_state = SM_AES128_ACTIVE; 2435 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, connection); 2436 break; 2437 2438 case SM_PH2_CALC_STK: 2439 // already busy? 2440 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2441 // calculate STK 2442 if (IS_RESPONDER(connection->sm_role)){ 2443 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); 2444 } else { 2445 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2446 } 2447 connection->sm_engine_state = SM_PH2_W4_STK; 2448 sm_aes128_state = SM_AES128_ACTIVE; 2449 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2450 break; 2451 2452 case SM_PH3_Y_GET_ENC: 2453 // already busy? 2454 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2455 // PH3B2 - calculate Y from - enc 2456 // Y = dm(DHK, Rand) 2457 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2458 connection->sm_engine_state = SM_PH3_Y_W4_ENC; 2459 sm_aes128_state = SM_AES128_ACTIVE; 2460 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); 2461 break; 2462 2463 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2464 uint8_t buffer[17]; 2465 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2466 reverse_128(setup->sm_local_confirm, &buffer[1]); 2467 if (IS_RESPONDER(connection->sm_role)){ 2468 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2469 } else { 2470 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2471 } 2472 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2473 sm_timeout_reset(connection); 2474 return; 2475 } 2476 #ifdef ENABLE_LE_PERIPHERAL 2477 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2478 sm_key_t stk_flipped; 2479 reverse_128(setup->sm_ltk, stk_flipped); 2480 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2481 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2482 return; 2483 } 2484 case SM_RESPONDER_PH4_SEND_LTK_REPLY: { 2485 sm_key_t ltk_flipped; 2486 reverse_128(setup->sm_ltk, ltk_flipped); 2487 connection->sm_engine_state = SM_RESPONDER_IDLE; 2488 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2489 sm_done_for_handle(connection->sm_handle); 2490 return; 2491 } 2492 case SM_RESPONDER_PH4_Y_GET_ENC: 2493 // already busy? 2494 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2495 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2496 // Y = dm(DHK, Rand) 2497 sm_dm_r_prime(setup->sm_local_rand, sm_aes128_plaintext); 2498 connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; 2499 sm_aes128_state = SM_AES128_ACTIVE; 2500 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); 2501 return; 2502 #endif 2503 #ifdef ENABLE_LE_CENTRAL 2504 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2505 sm_key_t stk_flipped; 2506 reverse_128(setup->sm_ltk, stk_flipped); 2507 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2508 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2509 return; 2510 } 2511 #endif 2512 2513 case SM_PH3_DISTRIBUTE_KEYS: 2514 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2515 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2516 uint8_t buffer[17]; 2517 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2518 reverse_128(setup->sm_ltk, &buffer[1]); 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_MASTER_IDENTIFICATION){ 2524 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2525 uint8_t buffer[11]; 2526 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2527 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2528 reverse_64(setup->sm_local_rand, &buffer[3]); 2529 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2530 sm_timeout_reset(connection); 2531 return; 2532 } 2533 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2534 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2535 uint8_t buffer[17]; 2536 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2537 reverse_128(sm_persistent_irk, &buffer[1]); 2538 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2539 sm_timeout_reset(connection); 2540 return; 2541 } 2542 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2543 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2544 bd_addr_t local_address; 2545 uint8_t buffer[8]; 2546 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2547 switch (gap_random_address_get_mode()){ 2548 case GAP_RANDOM_ADDRESS_TYPE_OFF: 2549 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 2550 // public or static random 2551 gap_le_get_own_address(&buffer[1], local_address); 2552 break; 2553 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2554 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2555 // fallback to public 2556 gap_local_bd_addr(local_address); 2557 buffer[1] = 0; 2558 break; 2559 } 2560 reverse_bd_addr(local_address, &buffer[2]); 2561 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2562 sm_timeout_reset(connection); 2563 return; 2564 } 2565 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2566 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2567 2568 // hack to reproduce test runs 2569 if (test_use_fixed_local_csrk){ 2570 memset(setup->sm_local_csrk, 0xcc, 16); 2571 } 2572 2573 uint8_t buffer[17]; 2574 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2575 reverse_128(setup->sm_local_csrk, &buffer[1]); 2576 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2577 sm_timeout_reset(connection); 2578 return; 2579 } 2580 2581 // keys are sent 2582 if (IS_RESPONDER(connection->sm_role)){ 2583 // slave -> receive master keys if any 2584 if (sm_key_distribution_all_received(connection)){ 2585 sm_key_distribution_handle_all_received(connection); 2586 connection->sm_engine_state = SM_RESPONDER_IDLE; 2587 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2588 sm_done_for_handle(connection->sm_handle); 2589 } else { 2590 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2591 } 2592 } else { 2593 // master -> all done 2594 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2595 sm_notify_client_status_reason(connection, ERROR_CODE_SUCCESS, 0); 2596 sm_done_for_handle(connection->sm_handle); 2597 } 2598 break; 2599 2600 default: 2601 break; 2602 } 2603 2604 // check again if active connection was released 2605 if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; 2606 } 2607 } 2608 2609 // sm_aes128_state stays active 2610 static void sm_handle_encryption_result_enc_a(void *arg){ 2611 sm_connection_t * connection = (sm_connection_t*) arg; 2612 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2613 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); 2614 } 2615 2616 static void sm_handle_encryption_result_enc_b(void *arg){ 2617 sm_connection_t * connection = (sm_connection_t*) arg; 2618 sm_aes128_state = SM_AES128_IDLE; 2619 log_info_key("c1!", setup->sm_local_confirm); 2620 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2621 sm_run(); 2622 } 2623 2624 // sm_aes128_state stays active 2625 static void sm_handle_encryption_result_enc_c(void *arg){ 2626 sm_connection_t * connection = (sm_connection_t*) arg; 2627 sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2628 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); 2629 } 2630 2631 static void sm_handle_encryption_result_enc_d(void * arg){ 2632 sm_connection_t * connection = (sm_connection_t*) arg; 2633 sm_aes128_state = SM_AES128_IDLE; 2634 log_info_key("c1!", sm_aes128_ciphertext); 2635 if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ 2636 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2637 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2638 sm_run(); 2639 return; 2640 } 2641 if (IS_RESPONDER(connection->sm_role)){ 2642 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2643 sm_run(); 2644 } else { 2645 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); 2646 sm_aes128_state = SM_AES128_ACTIVE; 2647 btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, connection); 2648 } 2649 } 2650 2651 static void sm_handle_encryption_result_enc_stk(void *arg){ 2652 sm_connection_t * connection = (sm_connection_t*) arg; 2653 sm_aes128_state = SM_AES128_IDLE; 2654 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2655 log_info_key("stk", setup->sm_ltk); 2656 if (IS_RESPONDER(connection->sm_role)){ 2657 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2658 } else { 2659 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2660 } 2661 sm_run(); 2662 } 2663 2664 // sm_aes128_state stays active 2665 static void sm_handle_encryption_result_enc_ph3_y(void *arg){ 2666 sm_connection_t * connection = (sm_connection_t*) arg; 2667 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2668 log_info_hex16("y", setup->sm_local_y); 2669 // PH3B3 - calculate EDIV 2670 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2671 log_info_hex16("ediv", setup->sm_local_ediv); 2672 // PH3B4 - calculate LTK - enc 2673 // LTK = d1(ER, DIV, 0)) 2674 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2675 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); 2676 } 2677 2678 #ifdef ENABLE_LE_PERIPHERAL 2679 // sm_aes128_state stays active 2680 static void sm_handle_encryption_result_enc_ph4_y(void *arg){ 2681 sm_connection_t * connection = (sm_connection_t*) arg; 2682 setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); 2683 log_info_hex16("y", setup->sm_local_y); 2684 2685 // PH3B3 - calculate DIV 2686 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2687 log_info_hex16("ediv", setup->sm_local_ediv); 2688 // PH3B4 - calculate LTK - enc 2689 // LTK = d1(ER, DIV, 0)) 2690 sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); 2691 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); 2692 } 2693 #endif 2694 2695 // sm_aes128_state stays active 2696 static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ 2697 sm_connection_t * connection = (sm_connection_t*) arg; 2698 log_info_key("ltk", setup->sm_ltk); 2699 // calc CSRK next 2700 sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); 2701 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); 2702 } 2703 2704 static void sm_handle_encryption_result_enc_csrk(void *arg){ 2705 sm_connection_t * connection = (sm_connection_t*) arg; 2706 sm_aes128_state = SM_AES128_IDLE; 2707 log_info_key("csrk", setup->sm_local_csrk); 2708 if (setup->sm_key_distribution_send_set){ 2709 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2710 } else { 2711 // no keys to send, just continue 2712 if (IS_RESPONDER(connection->sm_role)){ 2713 // slave -> receive master keys 2714 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2715 } else { 2716 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 2717 connection->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 2718 } else { 2719 // master -> all done 2720 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2721 sm_done_for_handle(connection->sm_handle); 2722 } 2723 } 2724 } 2725 sm_run(); 2726 } 2727 2728 #ifdef ENABLE_LE_PERIPHERAL 2729 static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ 2730 sm_connection_t * connection = (sm_connection_t*) arg; 2731 sm_aes128_state = SM_AES128_IDLE; 2732 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2733 log_info_key("ltk", setup->sm_ltk); 2734 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; 2735 sm_run(); 2736 } 2737 #endif 2738 2739 static void sm_handle_encryption_result_address_resolution(void *arg){ 2740 UNUSED(arg); 2741 sm_aes128_state = SM_AES128_IDLE; 2742 sm_address_resolution_ah_calculation_active = 0; 2743 // compare calulated address against connecting device 2744 uint8_t * hash = &sm_aes128_ciphertext[13]; 2745 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2746 log_info("LE Device Lookup: matched resolvable private address"); 2747 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2748 sm_run(); 2749 return; 2750 } 2751 // no match, try next 2752 sm_address_resolution_test++; 2753 sm_run(); 2754 } 2755 2756 static void sm_handle_encryption_result_dkg_irk(void *arg){ 2757 UNUSED(arg); 2758 sm_aes128_state = SM_AES128_IDLE; 2759 log_info_key("irk", sm_persistent_irk); 2760 dkg_state = DKG_CALC_DHK; 2761 sm_run(); 2762 } 2763 2764 static void sm_handle_encryption_result_dkg_dhk(void *arg){ 2765 UNUSED(arg); 2766 sm_aes128_state = SM_AES128_IDLE; 2767 log_info_key("dhk", sm_persistent_dhk); 2768 dkg_state = DKG_READY; 2769 // DKG calculation complete => SM Init Finished 2770 sm_run(); 2771 } 2772 2773 static void sm_handle_encryption_result_rau(void *arg){ 2774 UNUSED(arg); 2775 sm_aes128_state = SM_AES128_IDLE; 2776 memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); 2777 rau_state = RAU_SET_ADDRESS; 2778 sm_run(); 2779 } 2780 2781 static void sm_handle_random_result_rau(void * arg){ 2782 UNUSED(arg); 2783 // non-resolvable vs. resolvable 2784 switch (gap_random_adress_type){ 2785 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2786 // resolvable: use random as prand and calc address hash 2787 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2788 sm_random_address[0] &= 0x3f; 2789 sm_random_address[0] |= 0x40; 2790 rau_state = RAU_GET_ENC; 2791 break; 2792 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2793 default: 2794 // "The two most significant bits of the address shall be equal to ‘0’"" 2795 sm_random_address[0] &= 0x3f; 2796 rau_state = RAU_SET_ADDRESS; 2797 break; 2798 } 2799 sm_run(); 2800 } 2801 2802 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2803 static void sm_handle_random_result_sc_get_random(void * arg){ 2804 sm_connection_t * connection = (sm_connection_t*) arg; 2805 2806 // OOB 2807 if (setup->sm_stk_generation_method == OOB){ 2808 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2809 sm_run(); 2810 return; 2811 } 2812 2813 // initiator & jw/nc -> send pairing random 2814 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2815 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2816 } else { 2817 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2818 } 2819 sm_run(); 2820 } 2821 #endif 2822 2823 static void sm_handle_random_result_ph2_random(void * arg){ 2824 sm_connection_t * connection = (sm_connection_t*) arg; 2825 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2826 sm_run(); 2827 } 2828 2829 static void sm_handle_random_result_ph2_tk(void * arg){ 2830 sm_connection_t * connection = (sm_connection_t*) arg; 2831 sm_reset_tk(); 2832 uint32_t tk; 2833 if (sm_fixed_passkey_in_display_role == 0xffffffff){ 2834 // map random to 0-999999 without speding much cycles on a modulus operation 2835 tk = little_endian_read_32(sm_random_data,0); 2836 tk = tk & 0xfffff; // 1048575 2837 if (tk >= 999999){ 2838 tk = tk - 999999; 2839 } 2840 } else { 2841 // override with pre-defined passkey 2842 tk = sm_fixed_passkey_in_display_role; 2843 } 2844 big_endian_store_32(setup->sm_tk, 12, tk); 2845 if (IS_RESPONDER(connection->sm_role)){ 2846 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2847 } else { 2848 if (setup->sm_use_secure_connections){ 2849 connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 2850 } else { 2851 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2852 sm_trigger_user_response(connection); 2853 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2854 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2855 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, connection); 2856 } 2857 } 2858 } 2859 sm_run(); 2860 } 2861 2862 static void sm_handle_random_result_ph3_div(void * arg){ 2863 sm_connection_t * connection = (sm_connection_t*) arg; 2864 // use 16 bit from random value as div 2865 setup->sm_local_div = big_endian_read_16(sm_random_data, 0); 2866 log_info_hex16("div", setup->sm_local_div); 2867 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2868 sm_run(); 2869 } 2870 2871 static void sm_handle_random_result_ph3_random(void * arg){ 2872 sm_connection_t * connection = (sm_connection_t*) arg; 2873 reverse_64(sm_random_data, setup->sm_local_rand); 2874 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2875 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2876 // no db for authenticated flag hack: store flag in bit 4 of LSB 2877 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2878 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, connection); 2879 } 2880 2881 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2882 2883 UNUSED(channel); // ok: there is no channel 2884 UNUSED(size); // ok: fixed format HCI events 2885 2886 sm_connection_t * sm_conn; 2887 hci_con_handle_t con_handle; 2888 2889 switch (packet_type) { 2890 2891 case HCI_EVENT_PACKET: 2892 switch (hci_event_packet_get_type(packet)) { 2893 2894 case BTSTACK_EVENT_STATE: 2895 // bt stack activated, get started 2896 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2897 log_info("HCI Working!"); 2898 } 2899 break; 2900 2901 case HCI_EVENT_LE_META: 2902 switch (packet[2]) { 2903 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2904 2905 log_info("sm: connected"); 2906 2907 if (packet[3]) return; // connection failed 2908 2909 con_handle = little_endian_read_16(packet, 4); 2910 sm_conn = sm_get_connection_for_handle(con_handle); 2911 if (!sm_conn) break; 2912 2913 sm_conn->sm_handle = con_handle; 2914 sm_conn->sm_role = packet[6]; 2915 sm_conn->sm_peer_addr_type = packet[7]; 2916 reverse_bd_addr(&packet[8], sm_conn->sm_peer_address); 2917 2918 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2919 2920 // reset security properties 2921 sm_conn->sm_connection_encrypted = 0; 2922 sm_conn->sm_connection_authenticated = 0; 2923 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2924 sm_conn->sm_le_db_index = -1; 2925 2926 // prepare CSRK lookup (does not involve setup) 2927 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2928 2929 // just connected -> everything else happens in sm_run() 2930 if (IS_RESPONDER(sm_conn->sm_role)){ 2931 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2932 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2933 if (sm_slave_request_security) { 2934 // request security if requested by app 2935 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2936 } else { 2937 // otherwise, wait for pairing request 2938 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2939 } 2940 } 2941 break; 2942 } else { 2943 // master 2944 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2945 } 2946 break; 2947 2948 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2949 con_handle = little_endian_read_16(packet, 3); 2950 sm_conn = sm_get_connection_for_handle(con_handle); 2951 if (!sm_conn) break; 2952 2953 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2954 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2955 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2956 break; 2957 } 2958 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2959 // PH2 SEND LTK as we need to exchange keys in PH3 2960 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2961 break; 2962 } 2963 2964 // store rand and ediv 2965 reverse_64(&packet[5], sm_conn->sm_local_rand); 2966 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2967 2968 // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a 2969 // potentially stored LTK is from the master 2970 if (sm_conn->sm_local_ediv != 0 || !sm_is_null_random(sm_conn->sm_local_rand)){ 2971 if (sm_reconstruct_ltk_without_le_device_db_entry){ 2972 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2973 break; 2974 } 2975 // additionally check if remote is in LE Device DB if requested 2976 switch(sm_conn->sm_irk_lookup_state){ 2977 case IRK_LOOKUP_FAILED: 2978 log_info("LTK Request: device not in device db"); 2979 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2980 break; 2981 case IRK_LOOKUP_SUCCEEDED: 2982 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; 2983 break; 2984 default: 2985 // wait for irk look doen 2986 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; 2987 break; 2988 } 2989 break; 2990 } 2991 2992 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2993 sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; 2994 #else 2995 log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); 2996 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2997 #endif 2998 break; 2999 3000 default: 3001 break; 3002 } 3003 break; 3004 3005 case HCI_EVENT_ENCRYPTION_CHANGE: 3006 con_handle = little_endian_read_16(packet, 3); 3007 sm_conn = sm_get_connection_for_handle(con_handle); 3008 if (!sm_conn) break; 3009 3010 sm_conn->sm_connection_encrypted = packet[5]; 3011 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 3012 sm_conn->sm_actual_encryption_key_size); 3013 log_info("event handler, state %u", sm_conn->sm_engine_state); 3014 3015 // encryption change event concludes re-encryption for bonded devices (even if it fails) 3016 if (sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED){ 3017 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3018 // notify client, if pairing was requested before 3019 if (sm_conn->sm_pairing_requested){ 3020 sm_conn->sm_pairing_requested = 0; 3021 if (sm_conn->sm_connection_encrypted){ 3022 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3023 } else { 3024 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, 0); 3025 } 3026 } 3027 sm_done_for_handle(sm_conn->sm_handle); 3028 break; 3029 } 3030 3031 if (!sm_conn->sm_connection_encrypted) break; 3032 3033 // continue pairing 3034 switch (sm_conn->sm_engine_state){ 3035 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3036 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3037 sm_done_for_handle(sm_conn->sm_handle); 3038 break; 3039 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3040 if (IS_RESPONDER(sm_conn->sm_role)){ 3041 // slave 3042 if (setup->sm_use_secure_connections){ 3043 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3044 } else { 3045 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3046 } 3047 } else { 3048 // master 3049 if (sm_key_distribution_all_received(sm_conn)){ 3050 // skip receiving keys as there are none 3051 sm_key_distribution_handle_all_received(sm_conn); 3052 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3053 } else { 3054 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3055 } 3056 } 3057 break; 3058 default: 3059 break; 3060 } 3061 break; 3062 3063 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 3064 con_handle = little_endian_read_16(packet, 3); 3065 sm_conn = sm_get_connection_for_handle(con_handle); 3066 if (!sm_conn) break; 3067 3068 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 3069 log_info("event handler, state %u", sm_conn->sm_engine_state); 3070 // continue if part of initial pairing 3071 switch (sm_conn->sm_engine_state){ 3072 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 3073 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 3074 sm_done_for_handle(sm_conn->sm_handle); 3075 break; 3076 case SM_PH2_W4_CONNECTION_ENCRYPTED: 3077 if (IS_RESPONDER(sm_conn->sm_role)){ 3078 // slave 3079 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3080 } else { 3081 // master 3082 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 3083 } 3084 break; 3085 default: 3086 break; 3087 } 3088 break; 3089 3090 3091 case HCI_EVENT_DISCONNECTION_COMPLETE: 3092 con_handle = little_endian_read_16(packet, 3); 3093 sm_done_for_handle(con_handle); 3094 sm_conn = sm_get_connection_for_handle(con_handle); 3095 if (!sm_conn) break; 3096 3097 // delete stored bonding on disconnect with authentication failure in ph0 3098 if (sm_conn->sm_role == 0 3099 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 3100 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 3101 le_device_db_remove(sm_conn->sm_le_db_index); 3102 } 3103 3104 // pairing failed, if it was ongoing 3105 if (sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED && sm_conn->sm_engine_state != SM_GENERAL_IDLE){ 3106 sm_notify_client_status_reason(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); 3107 } 3108 3109 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 3110 sm_conn->sm_handle = 0; 3111 break; 3112 3113 case HCI_EVENT_COMMAND_COMPLETE: 3114 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_read_bd_addr)){ 3115 // set local addr for le device db 3116 bd_addr_t addr; 3117 reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); 3118 le_device_db_set_local_bd_addr(addr); 3119 } 3120 break; 3121 default: 3122 break; 3123 } 3124 break; 3125 default: 3126 break; 3127 } 3128 3129 sm_run(); 3130 } 3131 3132 static inline int sm_calc_actual_encryption_key_size(int other){ 3133 if (other < sm_min_encryption_key_size) return 0; 3134 if (other < sm_max_encryption_key_size) return other; 3135 return sm_max_encryption_key_size; 3136 } 3137 3138 3139 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3140 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 3141 switch (method){ 3142 case JUST_WORKS: 3143 case NUMERIC_COMPARISON: 3144 return 1; 3145 default: 3146 return 0; 3147 } 3148 } 3149 // responder 3150 3151 static int sm_passkey_used(stk_generation_method_t method){ 3152 switch (method){ 3153 case PK_RESP_INPUT: 3154 return 1; 3155 default: 3156 return 0; 3157 } 3158 } 3159 3160 static int sm_passkey_entry(stk_generation_method_t method){ 3161 switch (method){ 3162 case PK_RESP_INPUT: 3163 case PK_INIT_INPUT: 3164 case PK_BOTH_INPUT: 3165 return 1; 3166 default: 3167 return 0; 3168 } 3169 } 3170 3171 #endif 3172 3173 /** 3174 * @return ok 3175 */ 3176 static int sm_validate_stk_generation_method(void){ 3177 // check if STK generation method is acceptable by client 3178 switch (setup->sm_stk_generation_method){ 3179 case JUST_WORKS: 3180 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 3181 case PK_RESP_INPUT: 3182 case PK_INIT_INPUT: 3183 case PK_BOTH_INPUT: 3184 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 3185 case OOB: 3186 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 3187 case NUMERIC_COMPARISON: 3188 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 3189 default: 3190 return 0; 3191 } 3192 } 3193 3194 // size of complete sm_pdu used to validate input 3195 static const uint8_t sm_pdu_size[] = { 3196 0, // 0x00 invalid opcode 3197 7, // 0x01 pairing request 3198 7, // 0x02 pairing response 3199 17, // 0x03 pairing confirm 3200 17, // 0x04 pairing random 3201 2, // 0x05 pairing failed 3202 17, // 0x06 encryption information 3203 11, // 0x07 master identification 3204 17, // 0x08 identification information 3205 8, // 0x09 identify address information 3206 17, // 0x0a signing information 3207 2, // 0x0b security request 3208 65, // 0x0c pairing public key 3209 17, // 0x0d pairing dhk check 3210 2, // 0x0e keypress notification 3211 }; 3212 3213 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 3214 3215 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 3216 sm_run(); 3217 } 3218 3219 if (packet_type != SM_DATA_PACKET) return; 3220 if (size == 0) return; 3221 3222 uint8_t sm_pdu_code = packet[0]; 3223 3224 // validate pdu size 3225 if (sm_pdu_code >= sizeof(sm_pdu_size)) return; 3226 if (sm_pdu_size[sm_pdu_code] != size) return; 3227 3228 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3229 if (!sm_conn) return; 3230 3231 if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ 3232 sm_notify_client_status_reason(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); 3233 sm_done_for_handle(con_handle); 3234 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3235 return; 3236 } 3237 3238 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); 3239 3240 int err; 3241 UNUSED(err); 3242 3243 if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ 3244 uint8_t buffer[5]; 3245 buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; 3246 buffer[1] = 3; 3247 little_endian_store_16(buffer, 2, con_handle); 3248 buffer[4] = packet[1]; 3249 sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); 3250 return; 3251 } 3252 3253 switch (sm_conn->sm_engine_state){ 3254 3255 // a sm timeout requries a new physical connection 3256 case SM_GENERAL_TIMEOUT: 3257 return; 3258 3259 #ifdef ENABLE_LE_CENTRAL 3260 3261 // Initiator 3262 case SM_INITIATOR_CONNECTED: 3263 if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3264 sm_pdu_received_in_wrong_state(sm_conn); 3265 break; 3266 } 3267 3268 // IRK complete? 3269 switch (sm_conn->sm_irk_lookup_state){ 3270 case IRK_LOOKUP_FAILED: 3271 case IRK_LOOKUP_SUCCEEDED: 3272 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3273 break; 3274 default: 3275 break; 3276 } 3277 3278 // otherwise, store security request 3279 sm_conn->sm_security_request_received = 1; 3280 break; 3281 3282 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3283 // Core 5, Vol 3, Part H, 2.4.6: 3284 // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request 3285 // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." 3286 if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ 3287 log_info("Ignoring Security Request"); 3288 break; 3289 } 3290 3291 // all other pdus are incorrect 3292 if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ 3293 sm_pdu_received_in_wrong_state(sm_conn); 3294 break; 3295 } 3296 3297 // store pairing request 3298 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3299 err = sm_stk_generation_init(sm_conn); 3300 3301 #ifdef ENABLE_TESTING_SUPPORT 3302 if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ 3303 log_info("testing_support: abort with pairing failure %u", test_pairing_failure); 3304 err = test_pairing_failure; 3305 } 3306 #endif 3307 3308 if (err){ 3309 setup->sm_pairing_failed_reason = err; 3310 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3311 break; 3312 } 3313 3314 // generate random number first, if we need to show passkey 3315 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3316 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, sm_conn); 3317 break; 3318 } 3319 3320 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3321 if (setup->sm_use_secure_connections){ 3322 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3323 if (setup->sm_stk_generation_method == JUST_WORKS){ 3324 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3325 sm_trigger_user_response(sm_conn); 3326 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3327 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3328 } 3329 } else { 3330 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3331 } 3332 break; 3333 } 3334 #endif 3335 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3336 sm_trigger_user_response(sm_conn); 3337 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3338 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3339 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3340 } 3341 break; 3342 3343 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3344 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3345 sm_pdu_received_in_wrong_state(sm_conn); 3346 break; 3347 } 3348 3349 // store s_confirm 3350 reverse_128(&packet[1], setup->sm_peer_confirm); 3351 3352 #ifdef ENABLE_TESTING_SUPPORT 3353 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3354 log_info("testing_support: reset confirm value"); 3355 memset(setup->sm_peer_confirm, 0, 16); 3356 } 3357 #endif 3358 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3359 break; 3360 3361 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3362 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3363 sm_pdu_received_in_wrong_state(sm_conn); 3364 break;; 3365 } 3366 3367 // received random value 3368 reverse_128(&packet[1], setup->sm_peer_random); 3369 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3370 break; 3371 #endif 3372 3373 #ifdef ENABLE_LE_PERIPHERAL 3374 // Responder 3375 case SM_RESPONDER_IDLE: 3376 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3377 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3378 if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ 3379 sm_pdu_received_in_wrong_state(sm_conn); 3380 break;; 3381 } 3382 3383 // store pairing request 3384 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3385 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3386 break; 3387 #endif 3388 3389 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3390 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3391 if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ 3392 sm_pdu_received_in_wrong_state(sm_conn); 3393 break; 3394 } 3395 3396 // store public key for DH Key calculation 3397 reverse_256(&packet[01], &setup->sm_peer_q[0]); 3398 reverse_256(&packet[33], &setup->sm_peer_q[32]); 3399 3400 // validate public key 3401 err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); 3402 if (err){ 3403 log_error("sm: peer public key invalid %x", err); 3404 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 3405 break; 3406 } 3407 3408 // start calculating dhkey 3409 btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, sm_conn); 3410 3411 3412 log_info("public key received, generation method %u", setup->sm_stk_generation_method); 3413 if (IS_RESPONDER(sm_conn->sm_role)){ 3414 // responder 3415 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3416 } else { 3417 // initiator 3418 // stk generation method 3419 // passkey entry: notify app to show passkey or to request passkey 3420 switch (setup->sm_stk_generation_method){ 3421 case JUST_WORKS: 3422 case NUMERIC_COMPARISON: 3423 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3424 break; 3425 case PK_RESP_INPUT: 3426 sm_sc_start_calculating_local_confirm(sm_conn); 3427 break; 3428 case PK_INIT_INPUT: 3429 case PK_BOTH_INPUT: 3430 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3431 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3432 break; 3433 } 3434 sm_sc_start_calculating_local_confirm(sm_conn); 3435 break; 3436 case OOB: 3437 // generate Nx 3438 log_info("Generate Na"); 3439 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3440 break; 3441 } 3442 } 3443 break; 3444 3445 case SM_SC_W4_CONFIRMATION: 3446 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3447 sm_pdu_received_in_wrong_state(sm_conn); 3448 break; 3449 } 3450 // received confirm value 3451 reverse_128(&packet[1], setup->sm_peer_confirm); 3452 3453 #ifdef ENABLE_TESTING_SUPPORT 3454 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3455 log_info("testing_support: reset confirm value"); 3456 memset(setup->sm_peer_confirm, 0, 16); 3457 } 3458 #endif 3459 if (IS_RESPONDER(sm_conn->sm_role)){ 3460 // responder 3461 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3462 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3463 // still waiting for passkey 3464 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3465 break; 3466 } 3467 } 3468 sm_sc_start_calculating_local_confirm(sm_conn); 3469 } else { 3470 // initiator 3471 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3472 // sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3473 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_get_random, sm_conn); 3474 } else { 3475 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3476 } 3477 } 3478 break; 3479 3480 case SM_SC_W4_PAIRING_RANDOM: 3481 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3482 sm_pdu_received_in_wrong_state(sm_conn); 3483 break; 3484 } 3485 3486 // received random value 3487 reverse_128(&packet[1], setup->sm_peer_nonce); 3488 3489 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3490 // only check for JUST WORK/NC in initiator role OR passkey entry 3491 if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) 3492 || (sm_passkey_used(setup->sm_stk_generation_method)) ) { 3493 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3494 break; 3495 } 3496 3497 // OOB 3498 if (setup->sm_stk_generation_method == OOB){ 3499 3500 // setup local random, set to zero if remote did not receive our data 3501 log_info("Received nonce, setup local random ra/rb for dhkey check"); 3502 if (IS_RESPONDER(sm_conn->sm_role)){ 3503 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0){ 3504 log_info("Reset rb as A does not have OOB data"); 3505 memset(setup->sm_rb, 0, 16); 3506 } else { 3507 memcpy(setup->sm_rb, sm_sc_oob_random, 16); 3508 log_info("Use stored rb"); 3509 log_info_hexdump(setup->sm_rb, 16); 3510 } 3511 } else { 3512 if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0){ 3513 log_info("Reset ra as B does not have OOB data"); 3514 memset(setup->sm_ra, 0, 16); 3515 } else { 3516 memcpy(setup->sm_ra, sm_sc_oob_random, 16); 3517 log_info("Use stored ra"); 3518 log_info_hexdump(setup->sm_ra, 16); 3519 } 3520 } 3521 3522 // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received 3523 if (setup->sm_have_oob_data){ 3524 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3525 break; 3526 } 3527 } 3528 3529 // TODO: we only get here for Responder role with JW/NC 3530 sm_sc_state_after_receiving_random(sm_conn); 3531 break; 3532 3533 case SM_SC_W2_CALCULATE_G2: 3534 case SM_SC_W4_CALCULATE_G2: 3535 case SM_SC_W4_CALCULATE_DHKEY: 3536 case SM_SC_W2_CALCULATE_F5_SALT: 3537 case SM_SC_W4_CALCULATE_F5_SALT: 3538 case SM_SC_W2_CALCULATE_F5_MACKEY: 3539 case SM_SC_W4_CALCULATE_F5_MACKEY: 3540 case SM_SC_W2_CALCULATE_F5_LTK: 3541 case SM_SC_W4_CALCULATE_F5_LTK: 3542 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3543 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3544 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3545 if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ 3546 sm_pdu_received_in_wrong_state(sm_conn); 3547 break; 3548 } 3549 // store DHKey Check 3550 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3551 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3552 3553 // have we been only waiting for dhkey check command? 3554 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3555 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3556 } 3557 break; 3558 #endif 3559 3560 #ifdef ENABLE_LE_PERIPHERAL 3561 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3562 if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ 3563 sm_pdu_received_in_wrong_state(sm_conn); 3564 break; 3565 } 3566 3567 // received confirm value 3568 reverse_128(&packet[1], setup->sm_peer_confirm); 3569 3570 #ifdef ENABLE_TESTING_SUPPORT 3571 if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ 3572 log_info("testing_support: reset confirm value"); 3573 memset(setup->sm_peer_confirm, 0, 16); 3574 } 3575 #endif 3576 // notify client to hide shown passkey 3577 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3578 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3579 } 3580 3581 // handle user cancel pairing? 3582 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3583 setup->sm_pairing_failed_reason = SM_REASON_PASSKEY_ENTRY_FAILED; 3584 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3585 break; 3586 } 3587 3588 // wait for user action? 3589 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3590 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3591 break; 3592 } 3593 3594 // calculate and send local_confirm 3595 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3596 break; 3597 3598 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3599 if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ 3600 sm_pdu_received_in_wrong_state(sm_conn); 3601 break;; 3602 } 3603 3604 // received random value 3605 reverse_128(&packet[1], setup->sm_peer_random); 3606 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3607 break; 3608 #endif 3609 3610 case SM_PH3_RECEIVE_KEYS: 3611 switch(sm_pdu_code){ 3612 case SM_CODE_ENCRYPTION_INFORMATION: 3613 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3614 reverse_128(&packet[1], setup->sm_peer_ltk); 3615 break; 3616 3617 case SM_CODE_MASTER_IDENTIFICATION: 3618 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3619 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3620 reverse_64(&packet[3], setup->sm_peer_rand); 3621 break; 3622 3623 case SM_CODE_IDENTITY_INFORMATION: 3624 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3625 reverse_128(&packet[1], setup->sm_peer_irk); 3626 break; 3627 3628 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3629 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3630 setup->sm_peer_addr_type = packet[1]; 3631 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3632 break; 3633 3634 case SM_CODE_SIGNING_INFORMATION: 3635 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3636 reverse_128(&packet[1], setup->sm_peer_csrk); 3637 break; 3638 default: 3639 // Unexpected PDU 3640 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3641 break; 3642 } 3643 // done with key distribution? 3644 if (sm_key_distribution_all_received(sm_conn)){ 3645 3646 sm_key_distribution_handle_all_received(sm_conn); 3647 3648 if (IS_RESPONDER(sm_conn->sm_role)){ 3649 if (setup->sm_use_secure_connections && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION)){ 3650 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_H6_ILK; 3651 } else { 3652 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3653 sm_notify_client_status_reason(sm_conn, ERROR_CODE_SUCCESS, 0); 3654 sm_done_for_handle(sm_conn->sm_handle); 3655 } 3656 } else { 3657 if (setup->sm_use_secure_connections){ 3658 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3659 } else { 3660 btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, sm_conn); 3661 } 3662 } 3663 } 3664 break; 3665 default: 3666 // Unexpected PDU 3667 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3668 break; 3669 } 3670 3671 // try to send preparared packet 3672 sm_run(); 3673 } 3674 3675 // Security Manager Client API 3676 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ 3677 sm_get_oob_data = get_oob_data_callback; 3678 } 3679 3680 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)){ 3681 sm_get_sc_oob_data = get_sc_oob_data_callback; 3682 } 3683 3684 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3685 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3686 } 3687 3688 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3689 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3690 } 3691 3692 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3693 sm_min_encryption_key_size = min_size; 3694 sm_max_encryption_key_size = max_size; 3695 } 3696 3697 void sm_set_authentication_requirements(uint8_t auth_req){ 3698 #ifndef ENABLE_LE_SECURE_CONNECTIONS 3699 if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ 3700 log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); 3701 auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; 3702 } 3703 #endif 3704 sm_auth_req = auth_req; 3705 } 3706 3707 void sm_set_io_capabilities(io_capability_t io_capability){ 3708 sm_io_capabilities = io_capability; 3709 } 3710 3711 #ifdef ENABLE_LE_PERIPHERAL 3712 void sm_set_request_security(int enable){ 3713 sm_slave_request_security = enable; 3714 } 3715 #endif 3716 3717 void sm_set_er(sm_key_t er){ 3718 memcpy(sm_persistent_er, er, 16); 3719 } 3720 3721 void sm_set_ir(sm_key_t ir){ 3722 memcpy(sm_persistent_ir, ir, 16); 3723 } 3724 3725 // Testing support only 3726 void sm_test_set_irk(sm_key_t irk){ 3727 memcpy(sm_persistent_irk, irk, 16); 3728 dkg_state = DKG_CALC_DHK; 3729 } 3730 3731 void sm_test_use_fixed_local_csrk(void){ 3732 test_use_fixed_local_csrk = 1; 3733 } 3734 3735 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3736 static void sm_ec_generated(void * arg){ 3737 UNUSED(arg); 3738 ec_key_generation_state = EC_KEY_GENERATION_DONE; 3739 // trigger pairing if pending for ec key 3740 sm_run(); 3741 } 3742 static void sm_ec_generate_new_key(void){ 3743 log_info("sm: generate new ec key"); 3744 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 3745 btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); 3746 } 3747 #endif 3748 3749 #ifdef ENABLE_TESTING_SUPPORT 3750 void sm_test_set_pairing_failure(int reason){ 3751 test_pairing_failure = reason; 3752 } 3753 #endif 3754 3755 void sm_init(void){ 3756 // set some (BTstack default) ER and IR 3757 int i; 3758 sm_key_t er; 3759 sm_key_t ir; 3760 for (i=0;i<16;i++){ 3761 er[i] = 0x30 + i; 3762 ir[i] = 0x90 + i; 3763 } 3764 sm_set_er(er); 3765 sm_set_ir(ir); 3766 // defaults 3767 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3768 | SM_STK_GENERATION_METHOD_OOB 3769 | SM_STK_GENERATION_METHOD_PASSKEY 3770 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3771 3772 sm_max_encryption_key_size = 16; 3773 sm_min_encryption_key_size = 7; 3774 3775 sm_fixed_passkey_in_display_role = 0xffffffff; 3776 sm_reconstruct_ltk_without_le_device_db_entry = 1; 3777 3778 #ifdef USE_CMAC_ENGINE 3779 sm_cmac_active = 0; 3780 #endif 3781 dkg_state = DKG_CALC_IRK; 3782 rau_state = RAU_IDLE; 3783 sm_aes128_state = SM_AES128_IDLE; 3784 sm_address_resolution_test = -1; // no private address to resolve yet 3785 sm_address_resolution_ah_calculation_active = 0; 3786 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3787 sm_address_resolution_general_queue = NULL; 3788 3789 gap_random_adress_update_period = 15 * 60 * 1000L; 3790 sm_active_connection_handle = HCI_CON_HANDLE_INVALID; 3791 3792 test_use_fixed_local_csrk = 0; 3793 3794 // register for HCI Events from HCI 3795 hci_event_callback_registration.callback = &sm_event_packet_handler; 3796 hci_add_event_handler(&hci_event_callback_registration); 3797 3798 // 3799 btstack_crypto_init(); 3800 3801 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3802 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3803 3804 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3805 sm_ec_generate_new_key(); 3806 #endif 3807 } 3808 3809 void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ 3810 sm_fixed_passkey_in_display_role = passkey; 3811 } 3812 3813 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ 3814 sm_reconstruct_ltk_without_le_device_db_entry = allow; 3815 } 3816 3817 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3818 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3819 if (!hci_con) return NULL; 3820 return &hci_con->sm_connection; 3821 } 3822 3823 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3824 switch (sm_conn->sm_engine_state){ 3825 case SM_GENERAL_IDLE: 3826 case SM_RESPONDER_IDLE: 3827 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3828 sm_run(); 3829 break; 3830 default: 3831 break; 3832 } 3833 } 3834 3835 /** 3836 * @brief Trigger Security Request 3837 */ 3838 void sm_send_security_request(hci_con_handle_t con_handle){ 3839 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3840 if (!sm_conn) return; 3841 sm_send_security_request_for_connection(sm_conn); 3842 } 3843 3844 // request pairing 3845 void sm_request_pairing(hci_con_handle_t con_handle){ 3846 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3847 if (!sm_conn) return; // wrong connection 3848 3849 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3850 if (IS_RESPONDER(sm_conn->sm_role)){ 3851 sm_send_security_request_for_connection(sm_conn); 3852 } else { 3853 // used as a trigger to start central/master/initiator security procedures 3854 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3855 uint8_t ltk[16]; 3856 switch (sm_conn->sm_irk_lookup_state){ 3857 case IRK_LOOKUP_SUCCEEDED: 3858 #ifndef ENABLE_LE_CENTRAL_AUTO_ENCRYPTION 3859 le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL); 3860 int have_ltk = !sm_is_null_key(ltk); 3861 log_info("have ltk %u", have_ltk); 3862 // trigger 'pairing complete' event on encryption change 3863 sm_conn->sm_pairing_requested = 1; 3864 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3865 break; 3866 #endif 3867 /* explicit fall-through */ 3868 3869 case IRK_LOOKUP_FAILED: 3870 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3871 break; 3872 default: 3873 log_info("irk lookup pending"); 3874 sm_conn->sm_pairing_requested = 1; 3875 break; 3876 } 3877 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3878 sm_conn->sm_pairing_requested = 1; 3879 } 3880 } 3881 sm_run(); 3882 } 3883 3884 // called by client app on authorization request 3885 void sm_authorization_decline(hci_con_handle_t con_handle){ 3886 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3887 if (!sm_conn) return; // wrong connection 3888 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3889 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3890 } 3891 3892 void sm_authorization_grant(hci_con_handle_t con_handle){ 3893 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3894 if (!sm_conn) return; // wrong connection 3895 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3896 sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3897 } 3898 3899 // GAP Bonding API 3900 3901 void sm_bonding_decline(hci_con_handle_t con_handle){ 3902 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3903 if (!sm_conn) return; // wrong connection 3904 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3905 log_info("decline, state %u", sm_conn->sm_engine_state); 3906 switch(sm_conn->sm_engine_state){ 3907 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3908 case SM_SC_W4_USER_RESPONSE: 3909 case SM_SC_W4_CONFIRMATION: 3910 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3911 #endif 3912 case SM_PH1_W4_USER_RESPONSE: 3913 switch (setup->sm_stk_generation_method){ 3914 case PK_RESP_INPUT: 3915 case PK_INIT_INPUT: 3916 case PK_BOTH_INPUT: 3917 sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); 3918 break; 3919 case NUMERIC_COMPARISON: 3920 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3921 break; 3922 case JUST_WORKS: 3923 case OOB: 3924 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3925 break; 3926 } 3927 break; 3928 default: 3929 break; 3930 } 3931 sm_run(); 3932 } 3933 3934 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3935 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3936 if (!sm_conn) return; // wrong connection 3937 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3938 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3939 if (setup->sm_use_secure_connections){ 3940 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3941 } else { 3942 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3943 } 3944 } 3945 3946 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3947 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3948 sm_sc_prepare_dhkey_check(sm_conn); 3949 } 3950 #endif 3951 3952 sm_run(); 3953 } 3954 3955 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3956 // for now, it's the same 3957 sm_just_works_confirm(con_handle); 3958 } 3959 3960 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3961 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3962 if (!sm_conn) return; // wrong connection 3963 sm_reset_tk(); 3964 big_endian_store_32(setup->sm_tk, 12, passkey); 3965 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3966 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3967 btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, sm_conn); 3968 } 3969 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3970 memcpy(setup->sm_ra, setup->sm_tk, 16); 3971 memcpy(setup->sm_rb, setup->sm_tk, 16); 3972 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3973 sm_sc_start_calculating_local_confirm(sm_conn); 3974 } 3975 #endif 3976 sm_run(); 3977 } 3978 3979 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ 3980 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3981 if (!sm_conn) return; // wrong connection 3982 if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; 3983 uint8_t num_actions = setup->sm_keypress_notification >> 5; 3984 uint8_t flags = setup->sm_keypress_notification & 0x1f; 3985 switch (action){ 3986 case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: 3987 case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: 3988 flags |= (1 << action); 3989 break; 3990 case SM_KEYPRESS_PASSKEY_CLEARED: 3991 // clear counter, keypress & erased flags + set passkey cleared 3992 flags = (flags & 0x19) | (1 << SM_KEYPRESS_PASSKEY_CLEARED); 3993 break; 3994 case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: 3995 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)){ 3996 // erase actions queued 3997 num_actions--; 3998 if (num_actions == 0){ 3999 // clear counter, keypress & erased flags 4000 flags &= 0x19; 4001 } 4002 break; 4003 } 4004 num_actions++; 4005 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); 4006 break; 4007 case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: 4008 if (flags & (1 << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)){ 4009 // enter actions queued 4010 num_actions--; 4011 if (num_actions == 0){ 4012 // clear counter, keypress & erased flags 4013 flags &= 0x19; 4014 } 4015 break; 4016 } 4017 num_actions++; 4018 flags |= (1 << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); 4019 break; 4020 default: 4021 break; 4022 } 4023 setup->sm_keypress_notification = (num_actions << 5) | flags; 4024 sm_run(); 4025 } 4026 4027 #ifdef ENABLE_LE_SECURE_CONNECTIONS 4028 static void sm_handle_random_result_oob(void * arg){ 4029 UNUSED(arg); 4030 sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; 4031 sm_run(); 4032 } 4033 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ 4034 if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; 4035 sm_sc_oob_callback = callback; 4036 sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; 4037 btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); 4038 return 0; 4039 } 4040 #endif 4041 4042 /** 4043 * @brief Identify device in LE Device DB 4044 * @param handle 4045 * @returns index from le_device_db or -1 if not found/identified 4046 */ 4047 int sm_le_device_index(hci_con_handle_t con_handle ){ 4048 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4049 if (!sm_conn) return -1; 4050 return sm_conn->sm_le_db_index; 4051 } 4052 4053 static int gap_random_address_type_requires_updates(void){ 4054 switch (gap_random_adress_type){ 4055 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4056 case GAP_RANDOM_ADDRESS_TYPE_STATIC: 4057 return 0; 4058 default: 4059 return 1; 4060 } 4061 } 4062 4063 static uint8_t own_address_type(void){ 4064 switch (gap_random_adress_type){ 4065 case GAP_RANDOM_ADDRESS_TYPE_OFF: 4066 return BD_ADDR_TYPE_LE_PUBLIC; 4067 default: 4068 return BD_ADDR_TYPE_LE_RANDOM; 4069 } 4070 } 4071 4072 // GAP LE API 4073 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 4074 gap_random_address_update_stop(); 4075 gap_random_adress_type = random_address_type; 4076 hci_le_set_own_address_type(own_address_type()); 4077 if (!gap_random_address_type_requires_updates()) return; 4078 gap_random_address_update_start(); 4079 gap_random_address_trigger(); 4080 } 4081 4082 gap_random_address_type_t gap_random_address_get_mode(void){ 4083 return gap_random_adress_type; 4084 } 4085 4086 void gap_random_address_set_update_period(int period_ms){ 4087 gap_random_adress_update_period = period_ms; 4088 if (!gap_random_address_type_requires_updates()) return; 4089 gap_random_address_update_stop(); 4090 gap_random_address_update_start(); 4091 } 4092 4093 void gap_random_address_set(bd_addr_t addr){ 4094 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); 4095 memcpy(sm_random_address, addr, 6); 4096 rau_state = RAU_SET_ADDRESS; 4097 sm_run(); 4098 } 4099 4100 #ifdef ENABLE_LE_PERIPHERAL 4101 /* 4102 * @brief Set Advertisement Paramters 4103 * @param adv_int_min 4104 * @param adv_int_max 4105 * @param adv_type 4106 * @param direct_address_type 4107 * @param direct_address 4108 * @param channel_map 4109 * @param filter_policy 4110 * 4111 * @note own_address_type is used from gap_random_address_set_mode 4112 */ 4113 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 4114 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 4115 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 4116 direct_address_typ, direct_address, channel_map, filter_policy); 4117 } 4118 #endif 4119 4120 int gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ 4121 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 4122 // wrong connection 4123 if (!sm_conn) return 0; 4124 // already encrypted 4125 if (sm_conn->sm_connection_encrypted) return 0; 4126 // only central can re-encrypt 4127 if (sm_conn->sm_role == HCI_ROLE_SLAVE) return 0; 4128 // irk status? 4129 switch(sm_conn->sm_irk_lookup_state){ 4130 case IRK_LOOKUP_FAILED: 4131 // done, cannot setup encryption 4132 return 0; 4133 case IRK_LOOKUP_SUCCEEDED: 4134 break; 4135 default: 4136 // IR Lookup pending 4137 return 1; 4138 } 4139 // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset 4140 return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; 4141 } 4142