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 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 // TODO: remove software AES 55 #include "rijndael.h" 56 #endif 57 58 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(HAVE_HCI_CONTROLLER_DHKEY_SUPPORT) 59 #define USE_MBEDTLS_FOR_ECDH 60 #endif 61 62 #ifdef ENABLE_LE_SECURE_CONNECTIONS 63 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 64 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 65 #else 66 #define USE_MBEDTLS_FOR_ECDH 67 #endif 68 #endif 69 70 71 // Software ECDH implementation provided by mbedtls 72 #ifdef USE_MBEDTLS_FOR_ECDH 73 #if !defined(MBEDTLS_CONFIG_FILE) 74 #include "mbedtls/config.h" 75 #else 76 #include MBEDTLS_CONFIG_FILE 77 #endif 78 #if defined(MBEDTLS_PLATFORM_C) 79 #include "mbedtls/platform.h" 80 #else 81 #include <stdio.h> 82 #define mbedtls_printf printf 83 #endif 84 #include "mbedtls/ecp.h" 85 #endif 86 87 // 88 // SM internal types and globals 89 // 90 91 typedef enum { 92 DKG_W4_WORKING, 93 DKG_CALC_IRK, 94 DKG_W4_IRK, 95 DKG_CALC_DHK, 96 DKG_W4_DHK, 97 DKG_READY 98 } derived_key_generation_t; 99 100 typedef enum { 101 RAU_W4_WORKING, 102 RAU_IDLE, 103 RAU_GET_RANDOM, 104 RAU_W4_RANDOM, 105 RAU_GET_ENC, 106 RAU_W4_ENC, 107 RAU_SET_ADDRESS, 108 } random_address_update_t; 109 110 typedef enum { 111 CMAC_IDLE, 112 CMAC_CALC_SUBKEYS, 113 CMAC_W4_SUBKEYS, 114 CMAC_CALC_MI, 115 CMAC_W4_MI, 116 CMAC_CALC_MLAST, 117 CMAC_W4_MLAST 118 } cmac_state_t; 119 120 typedef enum { 121 JUST_WORKS, 122 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 123 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 124 OK_BOTH_INPUT, // Only input on both, both input PK 125 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 126 OOB // OOB available on both sides 127 } stk_generation_method_t; 128 129 typedef enum { 130 SM_USER_RESPONSE_IDLE, 131 SM_USER_RESPONSE_PENDING, 132 SM_USER_RESPONSE_CONFIRM, 133 SM_USER_RESPONSE_PASSKEY, 134 SM_USER_RESPONSE_DECLINE 135 } sm_user_response_t; 136 137 typedef enum { 138 SM_AES128_IDLE, 139 SM_AES128_ACTIVE 140 } sm_aes128_state_t; 141 142 typedef enum { 143 ADDRESS_RESOLUTION_IDLE, 144 ADDRESS_RESOLUTION_GENERAL, 145 ADDRESS_RESOLUTION_FOR_CONNECTION, 146 } address_resolution_mode_t; 147 148 typedef enum { 149 ADDRESS_RESOLUTION_SUCEEDED, 150 ADDRESS_RESOLUTION_FAILED, 151 } address_resolution_event_t; 152 153 typedef enum { 154 EC_KEY_GENERATION_IDLE, 155 EC_KEY_GENERATION_ACTIVE, 156 EC_KEY_GENERATION_DONE, 157 } ec_key_generation_state_t; 158 159 typedef enum { 160 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 161 } sm_state_var_t; 162 163 // 164 // GLOBAL DATA 165 // 166 167 static uint8_t test_use_fixed_local_csrk; 168 static uint8_t test_use_fixed_ec_keypair; 169 170 // configuration 171 static uint8_t sm_accepted_stk_generation_methods; 172 static uint8_t sm_max_encryption_key_size; 173 static uint8_t sm_min_encryption_key_size; 174 static uint8_t sm_auth_req = 0; 175 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 176 static uint8_t sm_slave_request_security; 177 178 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 179 static sm_key_t sm_persistent_er; 180 static sm_key_t sm_persistent_ir; 181 182 // derived from sm_persistent_ir 183 static sm_key_t sm_persistent_dhk; 184 static sm_key_t sm_persistent_irk; 185 static uint8_t sm_persistent_irk_ready = 0; // used for testing 186 static derived_key_generation_t dkg_state; 187 188 // derived from sm_persistent_er 189 // .. 190 191 // random address update 192 static random_address_update_t rau_state; 193 static bd_addr_t sm_random_address; 194 195 // CMAC Calculation: General 196 static cmac_state_t sm_cmac_state; 197 static uint16_t sm_cmac_message_len; 198 static sm_key_t sm_cmac_k; 199 static sm_key_t sm_cmac_x; 200 static sm_key_t sm_cmac_m_last; 201 static uint8_t sm_cmac_block_current; 202 static uint8_t sm_cmac_block_count; 203 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 204 static void (*sm_cmac_done_handler)(uint8_t * hash); 205 206 // CMAC for ATT Signed Writes 207 static uint8_t sm_cmac_header[3]; 208 static const uint8_t * sm_cmac_message; 209 static uint8_t sm_cmac_sign_counter[4]; 210 211 // CMAC for Secure Connection functions 212 #ifdef ENABLE_LE_SECURE_CONNECTIONS 213 static sm_connection_t * sm_cmac_connection; 214 static uint8_t sm_cmac_sc_buffer[80]; 215 #endif 216 217 // resolvable private address lookup / CSRK calculation 218 static int sm_address_resolution_test; 219 static int sm_address_resolution_ah_calculation_active; 220 static uint8_t sm_address_resolution_addr_type; 221 static bd_addr_t sm_address_resolution_address; 222 static void * sm_address_resolution_context; 223 static address_resolution_mode_t sm_address_resolution_mode; 224 static btstack_linked_list_t sm_address_resolution_general_queue; 225 226 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 227 static sm_aes128_state_t sm_aes128_state; 228 static void * sm_aes128_context; 229 230 // random engine. store context (ususally sm_connection_t) 231 static void * sm_random_context; 232 233 // to receive hci events 234 static btstack_packet_callback_registration_t hci_event_callback_registration; 235 236 /* to dispatch sm event */ 237 static btstack_linked_list_t sm_event_handlers; 238 239 // Software ECDH implementation provided by mbedtls 240 #ifdef USE_MBEDTLS_FOR_ECDH 241 static mbedtls_ecp_keypair le_keypair; 242 static ec_key_generation_state_t ec_key_generation_state; 243 #endif 244 245 // 246 // Volume 3, Part H, Chapter 24 247 // "Security shall be initiated by the Security Manager in the device in the master role. 248 // The device in the slave role shall be the responding device." 249 // -> master := initiator, slave := responder 250 // 251 252 // data needed for security setup 253 typedef struct sm_setup_context { 254 255 btstack_timer_source_t sm_timeout; 256 257 // used in all phases 258 uint8_t sm_pairing_failed_reason; 259 260 // user response, (Phase 1 and/or 2) 261 uint8_t sm_user_response; 262 263 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 264 int sm_key_distribution_send_set; 265 int sm_key_distribution_received_set; 266 267 // Phase 2 (Pairing over SMP) 268 stk_generation_method_t sm_stk_generation_method; 269 sm_key_t sm_tk; 270 uint8_t sm_use_secure_connections; 271 272 sm_key_t sm_c1_t3_value; // c1 calculation 273 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 274 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 275 sm_key_t sm_local_random; 276 sm_key_t sm_local_confirm; 277 sm_key_t sm_peer_random; 278 sm_key_t sm_peer_confirm; 279 uint8_t sm_m_addr_type; // address and type can be removed 280 uint8_t sm_s_addr_type; // '' 281 bd_addr_t sm_m_address; // '' 282 bd_addr_t sm_s_address; // '' 283 sm_key_t sm_ltk; 284 285 #ifdef ENABLE_LE_SECURE_CONNECTIONS 286 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 287 uint8_t sm_peer_qy[32]; // '' 288 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 289 sm_key_t sm_local_nonce; // might be combined with sm_local_random 290 sm_key_t sm_peer_dhkey_check; 291 sm_key_t sm_local_dhkey_check; 292 sm_key_t sm_ra; 293 sm_key_t sm_rb; 294 sm_key_t sm_t; // used for f5 295 sm_key_t sm_mackey; 296 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 297 uint8_t sm_state_vars; 298 #endif 299 300 // Phase 3 301 302 // key distribution, we generate 303 uint16_t sm_local_y; 304 uint16_t sm_local_div; 305 uint16_t sm_local_ediv; 306 uint8_t sm_local_rand[8]; 307 sm_key_t sm_local_ltk; 308 sm_key_t sm_local_csrk; 309 sm_key_t sm_local_irk; 310 // sm_local_address/addr_type not needed 311 312 // key distribution, received from peer 313 uint16_t sm_peer_y; 314 uint16_t sm_peer_div; 315 uint16_t sm_peer_ediv; 316 uint8_t sm_peer_rand[8]; 317 sm_key_t sm_peer_ltk; 318 sm_key_t sm_peer_irk; 319 sm_key_t sm_peer_csrk; 320 uint8_t sm_peer_addr_type; 321 bd_addr_t sm_peer_address; 322 323 } sm_setup_context_t; 324 325 // 326 static sm_setup_context_t the_setup; 327 static sm_setup_context_t * setup = &the_setup; 328 329 // active connection - the one for which the_setup is used for 330 static uint16_t sm_active_connection = 0; 331 332 // @returns 1 if oob data is available 333 // stores oob data in provided 16 byte buffer if not null 334 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 335 336 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 337 static btstack_packet_handler_t sm_client_packet_handler = NULL; 338 339 // horizontal: initiator capabilities 340 // vertial: responder capabilities 341 static const stk_generation_method_t stk_generation_method [5] [5] = { 342 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 343 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 344 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 345 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 346 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 347 }; 348 349 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 350 #ifdef ENABLE_LE_SECURE_CONNECTIONS 351 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 352 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 353 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 354 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 355 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 356 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 357 }; 358 #endif 359 360 static void sm_run(void); 361 static void sm_done_for_handle(hci_con_handle_t con_handle); 362 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 363 static inline int sm_calc_actual_encryption_key_size(int other); 364 static int sm_validate_stk_generation_method(void); 365 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 366 367 static void log_info_hex16(const char * name, uint16_t value){ 368 log_info("%-6s 0x%04x", name, value); 369 } 370 371 // @returns 1 if all bytes are 0 372 static int sm_is_null_random(uint8_t random[8]){ 373 int i; 374 for (i=0; i < 8 ; i++){ 375 if (random[i]) return 0; 376 } 377 return 1; 378 } 379 380 // Key utils 381 static void sm_reset_tk(void){ 382 int i; 383 for (i=0;i<16;i++){ 384 setup->sm_tk[i] = 0; 385 } 386 } 387 388 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 389 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 390 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 391 int i; 392 for (i = max_encryption_size ; i < 16 ; i++){ 393 key[15-i] = 0; 394 } 395 } 396 397 // SMP Timeout implementation 398 399 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 400 // the Security Manager Timer shall be reset and started. 401 // 402 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 403 // 404 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 405 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 406 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 407 // established. 408 409 static void sm_timeout_handler(btstack_timer_source_t * timer){ 410 log_info("SM timeout"); 411 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 412 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 413 sm_done_for_handle(sm_conn->sm_handle); 414 415 // trigger handling of next ready connection 416 sm_run(); 417 } 418 static void sm_timeout_start(sm_connection_t * sm_conn){ 419 btstack_run_loop_remove_timer(&setup->sm_timeout); 420 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 421 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 422 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 423 btstack_run_loop_add_timer(&setup->sm_timeout); 424 } 425 static void sm_timeout_stop(void){ 426 btstack_run_loop_remove_timer(&setup->sm_timeout); 427 } 428 static void sm_timeout_reset(sm_connection_t * sm_conn){ 429 sm_timeout_stop(); 430 sm_timeout_start(sm_conn); 431 } 432 433 // end of sm timeout 434 435 // GAP Random Address updates 436 static gap_random_address_type_t gap_random_adress_type; 437 static btstack_timer_source_t gap_random_address_update_timer; 438 static uint32_t gap_random_adress_update_period; 439 440 static void gap_random_address_trigger(void){ 441 if (rau_state != RAU_IDLE) return; 442 log_info("gap_random_address_trigger"); 443 rau_state = RAU_GET_RANDOM; 444 sm_run(); 445 } 446 447 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 448 log_info("GAP Random Address Update due"); 449 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 450 btstack_run_loop_add_timer(&gap_random_address_update_timer); 451 gap_random_address_trigger(); 452 } 453 454 static void gap_random_address_update_start(void){ 455 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 456 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 457 btstack_run_loop_add_timer(&gap_random_address_update_timer); 458 } 459 460 static void gap_random_address_update_stop(void){ 461 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 462 } 463 464 465 static void sm_random_start(void * context){ 466 sm_random_context = context; 467 hci_send_cmd(&hci_le_rand); 468 } 469 470 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 471 // context is made availabe to aes128 result handler by this 472 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 473 sm_aes128_state = SM_AES128_ACTIVE; 474 sm_key_t key_flipped, plaintext_flipped; 475 reverse_128(key, key_flipped); 476 reverse_128(plaintext, plaintext_flipped); 477 sm_aes128_context = context; 478 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 479 } 480 481 // ah(k,r) helper 482 // r = padding || r 483 // r - 24 bit value 484 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 485 // r'= padding || r 486 memset(r_prime, 0, 16); 487 memcpy(&r_prime[13], r, 3); 488 } 489 490 // d1 helper 491 // d' = padding || r || d 492 // d,r - 16 bit values 493 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 494 // d'= padding || r || d 495 memset(d1_prime, 0, 16); 496 big_endian_store_16(d1_prime, 12, r); 497 big_endian_store_16(d1_prime, 14, d); 498 } 499 500 // dm helper 501 // r’ = padding || r 502 // r - 64 bit value 503 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 504 memset(r_prime, 0, 16); 505 memcpy(&r_prime[8], r, 8); 506 } 507 508 // calculate arguments for first AES128 operation in C1 function 509 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, sm_key_t t1){ 510 511 // p1 = pres || preq || rat’ || iat’ 512 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 513 // cant octet of pres becomes the most significant octet of p1. 514 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 515 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 516 // p1 is 0x05000800000302070710000001010001." 517 518 sm_key_t p1; 519 reverse_56(pres, &p1[0]); 520 reverse_56(preq, &p1[7]); 521 p1[14] = rat; 522 p1[15] = iat; 523 log_info_key("p1", p1); 524 log_info_key("r", r); 525 526 // t1 = r xor p1 527 int i; 528 for (i=0;i<16;i++){ 529 t1[i] = r[i] ^ p1[i]; 530 } 531 log_info_key("t1", t1); 532 } 533 534 // calculate arguments for second AES128 operation in C1 function 535 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 536 // p2 = padding || ia || ra 537 // "The least significant octet of ra becomes the least significant octet of p2 and 538 // the most significant octet of padding becomes the most significant octet of p2. 539 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 540 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 541 542 sm_key_t p2; 543 memset(p2, 0, 16); 544 memcpy(&p2[4], ia, 6); 545 memcpy(&p2[10], ra, 6); 546 log_info_key("p2", p2); 547 548 // c1 = e(k, t2_xor_p2) 549 int i; 550 for (i=0;i<16;i++){ 551 t3[i] = t2[i] ^ p2[i]; 552 } 553 log_info_key("t3", t3); 554 } 555 556 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 557 log_info_key("r1", r1); 558 log_info_key("r2", r2); 559 memcpy(&r_prime[8], &r2[8], 8); 560 memcpy(&r_prime[0], &r1[8], 8); 561 } 562 563 #ifdef ENABLE_LE_SECURE_CONNECTIONS 564 // Software implementations of crypto toolbox for LE Secure Connection 565 // TODO: replace with code to use AES Engine of HCI Controller 566 typedef uint8_t sm_key24_t[3]; 567 typedef uint8_t sm_key56_t[7]; 568 typedef uint8_t sm_key256_t[32]; 569 570 #if 0 571 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 572 uint32_t rk[RKLENGTH(KEYBITS)]; 573 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 574 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 575 } 576 577 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 578 memcpy(k1, k0, 16); 579 sm_shift_left_by_one_bit_inplace(16, k1); 580 if (k0[0] & 0x80){ 581 k1[15] ^= 0x87; 582 } 583 memcpy(k2, k1, 16); 584 sm_shift_left_by_one_bit_inplace(16, k2); 585 if (k1[0] & 0x80){ 586 k2[15] ^= 0x87; 587 } 588 } 589 590 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 591 sm_key_t k0, k1, k2, zero; 592 memset(zero, 0, 16); 593 594 aes128_calc_cyphertext(key, zero, k0); 595 calc_subkeys(k0, k1, k2); 596 597 int cmac_block_count = (cmac_message_len + 15) / 16; 598 599 // step 3: .. 600 if (cmac_block_count==0){ 601 cmac_block_count = 1; 602 } 603 604 // step 4: set m_last 605 sm_key_t cmac_m_last; 606 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 607 int i; 608 if (sm_cmac_last_block_complete){ 609 for (i=0;i<16;i++){ 610 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 611 } 612 } else { 613 int valid_octets_in_last_block = cmac_message_len & 0x0f; 614 for (i=0;i<16;i++){ 615 if (i < valid_octets_in_last_block){ 616 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 617 continue; 618 } 619 if (i == valid_octets_in_last_block){ 620 cmac_m_last[i] = 0x80 ^ k2[i]; 621 continue; 622 } 623 cmac_m_last[i] = k2[i]; 624 } 625 } 626 627 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 628 // LOG_KEY(cmac_m_last); 629 630 // Step 5 631 sm_key_t cmac_x; 632 memset(cmac_x, 0, 16); 633 634 // Step 6 635 sm_key_t sm_cmac_y; 636 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 637 for (i=0;i<16;i++){ 638 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 639 } 640 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 641 } 642 for (i=0;i<16;i++){ 643 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 644 } 645 646 // Step 7 647 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 648 } 649 #endif 650 651 #if 0 652 // 653 // Link Key Conversion Function h6 654 // 655 // h6(W, keyID) = AES-CMACW(keyID) 656 // - W is 128 bits 657 // - keyID is 32 bits 658 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 659 uint8_t key_id_buffer[4]; 660 big_endian_store_32(key_id_buffer, 0, key_id); 661 aes_cmac(res, w, key_id_buffer, 4); 662 } 663 #endif 664 #endif 665 666 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){ 667 event[0] = type; 668 event[1] = event_size - 2; 669 little_endian_store_16(event, 2, con_handle); 670 event[4] = addr_type; 671 reverse_bd_addr(address, &event[5]); 672 } 673 674 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 675 if (sm_client_packet_handler) { 676 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 677 } 678 // dispatch to all event handlers 679 btstack_linked_list_iterator_t it; 680 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 681 while (btstack_linked_list_iterator_has_next(&it)){ 682 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 683 entry->callback(packet_type, 0, packet, size); 684 } 685 } 686 687 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 688 uint8_t event[11]; 689 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 690 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 691 } 692 693 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){ 694 uint8_t event[15]; 695 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 696 little_endian_store_32(event, 11, passkey); 697 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 698 } 699 700 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){ 701 uint8_t event[13]; 702 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 703 little_endian_store_16(event, 11, index); 704 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 705 } 706 707 static void sm_notify_client_authorization(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 708 709 uint8_t event[18]; 710 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 711 event[11] = result; 712 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 713 } 714 715 // decide on stk generation based on 716 // - pairing request 717 // - io capabilities 718 // - OOB data availability 719 static void sm_setup_tk(void){ 720 721 // default: just works 722 setup->sm_stk_generation_method = JUST_WORKS; 723 724 #ifdef ENABLE_LE_SECURE_CONNECTIONS 725 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 726 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 727 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 728 memset(setup->sm_ra, 0, 16); 729 memset(setup->sm_rb, 0, 16); 730 #else 731 setup->sm_use_secure_connections = 0; 732 #endif 733 734 // If both devices have not set the MITM option in the Authentication Requirements 735 // Flags, then the IO capabilities shall be ignored and the Just Works association 736 // model shall be used. 737 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 738 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 739 log_info("SM: MITM not required by both -> JUST WORKS"); 740 return; 741 } 742 743 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 744 745 // If both devices have out of band authentication data, then the Authentication 746 // Requirements Flags shall be ignored when selecting the pairing method and the 747 // Out of Band pairing method shall be used. 748 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 749 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 750 log_info("SM: have OOB data"); 751 log_info_key("OOB", setup->sm_tk); 752 setup->sm_stk_generation_method = OOB; 753 return; 754 } 755 756 // Reset TK as it has been setup in sm_init_setup 757 sm_reset_tk(); 758 759 // Also use just works if unknown io capabilites 760 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)){ 761 return; 762 } 763 764 // Otherwise the IO capabilities of the devices shall be used to determine the 765 // pairing method as defined in Table 2.4. 766 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 767 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 768 769 #ifdef ENABLE_LE_SECURE_CONNECTIONS 770 // table not define by default 771 if (setup->sm_use_secure_connections){ 772 generation_method = stk_generation_method_with_secure_connection; 773 } 774 #endif 775 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)]; 776 777 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 778 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); 779 } 780 781 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 782 int flags = 0; 783 if (key_set & SM_KEYDIST_ENC_KEY){ 784 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 785 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 786 } 787 if (key_set & SM_KEYDIST_ID_KEY){ 788 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 789 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 790 } 791 if (key_set & SM_KEYDIST_SIGN){ 792 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 793 } 794 return flags; 795 } 796 797 static void sm_setup_key_distribution(uint8_t key_set){ 798 setup->sm_key_distribution_received_set = 0; 799 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 800 } 801 802 // CSRK Key Lookup 803 804 805 static int sm_address_resolution_idle(void){ 806 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 807 } 808 809 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){ 810 memcpy(sm_address_resolution_address, addr, 6); 811 sm_address_resolution_addr_type = addr_type; 812 sm_address_resolution_test = 0; 813 sm_address_resolution_mode = mode; 814 sm_address_resolution_context = context; 815 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 816 } 817 818 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 819 // check if already in list 820 btstack_linked_list_iterator_t it; 821 sm_lookup_entry_t * entry; 822 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 823 while(btstack_linked_list_iterator_has_next(&it)){ 824 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 825 if (entry->address_type != address_type) continue; 826 if (memcmp(entry->address, address, 6)) continue; 827 // already in list 828 return BTSTACK_BUSY; 829 } 830 entry = btstack_memory_sm_lookup_entry_get(); 831 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 832 entry->address_type = (bd_addr_type_t) address_type; 833 memcpy(entry->address, address, 6); 834 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 835 sm_run(); 836 return 0; 837 } 838 839 // CMAC Implementation using AES128 engine 840 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 841 int i; 842 int carry = 0; 843 for (i=len-1; i >= 0 ; i--){ 844 int new_carry = data[i] >> 7; 845 data[i] = data[i] << 1 | carry; 846 carry = new_carry; 847 } 848 } 849 850 // while x_state++ for an enum is possible in C, it isn't in C++. we use this helpers to avoid compile errors for now 851 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 852 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 853 } 854 static inline void dkg_next_state(void){ 855 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 856 } 857 static inline void rau_next_state(void){ 858 rau_state = (random_address_update_t) (((int)rau_state) + 1); 859 } 860 861 // CMAC calculation using AES Engine 862 863 static inline void sm_cmac_next_state(void){ 864 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 865 } 866 867 static int sm_cmac_last_block_complete(void){ 868 if (sm_cmac_message_len == 0) return 0; 869 return (sm_cmac_message_len & 0x0f) == 0; 870 } 871 872 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 873 if (offset >= sm_cmac_message_len) { 874 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 875 return 0; 876 } 877 878 offset = sm_cmac_message_len - 1 - offset; 879 880 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 881 if (offset < 3){ 882 return sm_cmac_header[offset]; 883 } 884 int actual_message_len_incl_header = sm_cmac_message_len - 4; 885 if (offset < actual_message_len_incl_header){ 886 return sm_cmac_message[offset - 3]; 887 } 888 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 889 } 890 891 // generic cmac calculation 892 void sm_cmac_general_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t hash[8])){ 893 // Generalized CMAC 894 memcpy(sm_cmac_k, key, 16); 895 memset(sm_cmac_x, 0, 16); 896 sm_cmac_block_current = 0; 897 sm_cmac_message_len = message_len; 898 sm_cmac_done_handler = done_callback; 899 sm_cmac_get_byte = get_byte_callback; 900 901 // step 2: n := ceil(len/const_Bsize); 902 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 903 904 // step 3: .. 905 if (sm_cmac_block_count==0){ 906 sm_cmac_block_count = 1; 907 } 908 log_info("sm_cmac_connection %p", sm_cmac_connection); 909 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 910 911 // first, we need to compute l for k1, k2, and m_last 912 sm_cmac_state = CMAC_CALC_SUBKEYS; 913 914 // let's go 915 sm_run(); 916 } 917 918 // cmac for ATT Message signing 919 void sm_cmac_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)){ 920 // ATT Message Signing 921 sm_cmac_header[0] = opcode; 922 little_endian_store_16(sm_cmac_header, 1, con_handle); 923 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 924 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 925 sm_cmac_message = message; 926 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 927 } 928 929 int sm_cmac_ready(void){ 930 return sm_cmac_state == CMAC_IDLE; 931 } 932 933 static void sm_cmac_handle_aes_engine_ready(void){ 934 switch (sm_cmac_state){ 935 case CMAC_CALC_SUBKEYS: { 936 sm_key_t const_zero; 937 memset(const_zero, 0, 16); 938 sm_cmac_next_state(); 939 sm_aes128_start(sm_cmac_k, const_zero, NULL); 940 break; 941 } 942 case CMAC_CALC_MI: { 943 int j; 944 sm_key_t y; 945 for (j=0;j<16;j++){ 946 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 947 } 948 sm_cmac_block_current++; 949 sm_cmac_next_state(); 950 sm_aes128_start(sm_cmac_k, y, NULL); 951 break; 952 } 953 case CMAC_CALC_MLAST: { 954 int i; 955 sm_key_t y; 956 for (i=0;i<16;i++){ 957 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 958 } 959 log_info_key("Y", y); 960 sm_cmac_block_current++; 961 sm_cmac_next_state(); 962 sm_aes128_start(sm_cmac_k, y, NULL); 963 break; 964 } 965 default: 966 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 967 break; 968 } 969 } 970 971 static void sm_cmac_handle_encryption_result(sm_key_t data){ 972 switch (sm_cmac_state){ 973 case CMAC_W4_SUBKEYS: { 974 sm_key_t k1; 975 memcpy(k1, data, 16); 976 sm_shift_left_by_one_bit_inplace(16, k1); 977 if (data[0] & 0x80){ 978 k1[15] ^= 0x87; 979 } 980 sm_key_t k2; 981 memcpy(k2, k1, 16); 982 sm_shift_left_by_one_bit_inplace(16, k2); 983 if (k1[0] & 0x80){ 984 k2[15] ^= 0x87; 985 } 986 987 log_info_key("k", sm_cmac_k); 988 log_info_key("k1", k1); 989 log_info_key("k2", k2); 990 991 // step 4: set m_last 992 int i; 993 if (sm_cmac_last_block_complete()){ 994 for (i=0;i<16;i++){ 995 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 996 } 997 } else { 998 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 999 for (i=0;i<16;i++){ 1000 if (i < valid_octets_in_last_block){ 1001 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1002 continue; 1003 } 1004 if (i == valid_octets_in_last_block){ 1005 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1006 continue; 1007 } 1008 sm_cmac_m_last[i] = k2[i]; 1009 } 1010 } 1011 1012 // next 1013 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1014 break; 1015 } 1016 case CMAC_W4_MI: 1017 memcpy(sm_cmac_x, data, 16); 1018 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1019 break; 1020 case CMAC_W4_MLAST: 1021 // done 1022 log_info("Setting CMAC Engine to IDLE"); 1023 sm_cmac_state = CMAC_IDLE; 1024 log_info_key("CMAC", data); 1025 sm_cmac_done_handler(data); 1026 break; 1027 default: 1028 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1029 break; 1030 } 1031 } 1032 1033 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1034 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1035 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1036 switch (setup->sm_stk_generation_method){ 1037 case PK_RESP_INPUT: 1038 if (sm_conn->sm_role){ 1039 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1040 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1041 } else { 1042 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)); 1043 } 1044 break; 1045 case PK_INIT_INPUT: 1046 if (sm_conn->sm_role){ 1047 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)); 1048 } else { 1049 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1050 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1051 } 1052 break; 1053 case OK_BOTH_INPUT: 1054 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1055 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1056 break; 1057 case NK_BOTH_INPUT: 1058 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1059 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)); 1060 break; 1061 case JUST_WORKS: 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1064 break; 1065 case OOB: 1066 // client already provided OOB data, let's skip notification. 1067 break; 1068 } 1069 } 1070 1071 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1072 int recv_flags; 1073 if (sm_conn->sm_role){ 1074 // slave / responder 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1076 } else { 1077 // master / initiator 1078 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1079 } 1080 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1081 return recv_flags == setup->sm_key_distribution_received_set; 1082 } 1083 1084 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1085 if (sm_active_connection == con_handle){ 1086 sm_timeout_stop(); 1087 sm_active_connection = 0; 1088 log_info("sm: connection 0x%x released setup context", con_handle); 1089 } 1090 } 1091 1092 static int sm_key_distribution_flags_for_auth_req(void){ 1093 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1094 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1095 // encryption information only if bonding requested 1096 flags |= SM_KEYDIST_ENC_KEY; 1097 } 1098 return flags; 1099 } 1100 1101 static void sm_init_setup(sm_connection_t * sm_conn){ 1102 1103 // fill in sm setup 1104 setup->sm_state_vars = 0; 1105 sm_reset_tk(); 1106 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1107 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1108 1109 // query client for OOB data 1110 int have_oob_data = 0; 1111 if (sm_get_oob_data) { 1112 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1113 } 1114 1115 sm_pairing_packet_t * local_packet; 1116 if (sm_conn->sm_role){ 1117 // slave 1118 local_packet = &setup->sm_s_pres; 1119 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1120 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1121 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1122 } else { 1123 // master 1124 local_packet = &setup->sm_m_preq; 1125 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1126 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1127 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1128 1129 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1130 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1131 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1132 } 1133 1134 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1135 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1136 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1137 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1138 } 1139 1140 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1141 1142 sm_pairing_packet_t * remote_packet; 1143 int remote_key_request; 1144 if (sm_conn->sm_role){ 1145 // slave / responder 1146 remote_packet = &setup->sm_m_preq; 1147 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1148 } else { 1149 // master / initiator 1150 remote_packet = &setup->sm_s_pres; 1151 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1152 } 1153 1154 // check key size 1155 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1156 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1157 1158 // decide on STK generation method 1159 sm_setup_tk(); 1160 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1161 1162 // check if STK generation method is acceptable by client 1163 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1164 1165 // identical to responder 1166 sm_setup_key_distribution(remote_key_request); 1167 1168 // JUST WORKS doens't provide authentication 1169 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1170 1171 return 0; 1172 } 1173 1174 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1175 1176 // cache and reset context 1177 int matched_device_id = sm_address_resolution_test; 1178 address_resolution_mode_t mode = sm_address_resolution_mode; 1179 void * context = sm_address_resolution_context; 1180 1181 // reset context 1182 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1183 sm_address_resolution_context = NULL; 1184 sm_address_resolution_test = -1; 1185 hci_con_handle_t con_handle = 0; 1186 1187 sm_connection_t * sm_connection; 1188 uint16_t ediv; 1189 switch (mode){ 1190 case ADDRESS_RESOLUTION_GENERAL: 1191 break; 1192 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1193 sm_connection = (sm_connection_t *) context; 1194 con_handle = sm_connection->sm_handle; 1195 switch (event){ 1196 case ADDRESS_RESOLUTION_SUCEEDED: 1197 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1198 sm_connection->sm_le_db_index = matched_device_id; 1199 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1200 if (sm_connection->sm_role) break; 1201 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1202 sm_connection->sm_security_request_received = 0; 1203 sm_connection->sm_bonding_requested = 0; 1204 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1205 if (ediv){ 1206 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1207 } else { 1208 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1209 } 1210 break; 1211 case ADDRESS_RESOLUTION_FAILED: 1212 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1213 if (sm_connection->sm_role) break; 1214 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1215 sm_connection->sm_security_request_received = 0; 1216 sm_connection->sm_bonding_requested = 0; 1217 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1218 break; 1219 } 1220 break; 1221 default: 1222 break; 1223 } 1224 1225 switch (event){ 1226 case ADDRESS_RESOLUTION_SUCEEDED: 1227 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1228 break; 1229 case ADDRESS_RESOLUTION_FAILED: 1230 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1231 break; 1232 } 1233 } 1234 1235 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1236 1237 int le_db_index = -1; 1238 1239 // lookup device based on IRK 1240 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1241 int i; 1242 for (i=0; i < le_device_db_count(); i++){ 1243 sm_key_t irk; 1244 bd_addr_t address; 1245 int address_type; 1246 le_device_db_info(i, &address_type, address, irk); 1247 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1248 log_info("sm: device found for IRK, updating"); 1249 le_db_index = i; 1250 break; 1251 } 1252 } 1253 } 1254 1255 // if not found, lookup via public address if possible 1256 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1257 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1258 int i; 1259 for (i=0; i < le_device_db_count(); i++){ 1260 bd_addr_t address; 1261 int address_type; 1262 le_device_db_info(i, &address_type, address, NULL); 1263 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1264 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1265 log_info("sm: device found for public address, updating"); 1266 le_db_index = i; 1267 break; 1268 } 1269 } 1270 } 1271 1272 // if not found, add to db 1273 if (le_db_index < 0) { 1274 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1275 } 1276 1277 if (le_db_index >= 0){ 1278 le_device_db_local_counter_set(le_db_index, 0); 1279 1280 // store local CSRK 1281 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1282 log_info("sm: store local CSRK"); 1283 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1284 le_device_db_local_counter_set(le_db_index, 0); 1285 } 1286 1287 // store remote CSRK 1288 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1289 log_info("sm: store remote CSRK"); 1290 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1291 le_device_db_remote_counter_set(le_db_index, 0); 1292 } 1293 1294 // store encryption information 1295 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1296 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1297 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1298 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1299 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1300 } 1301 } 1302 1303 // keep le_db_index 1304 sm_conn->sm_le_db_index = le_db_index; 1305 } 1306 1307 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1308 setup->sm_pairing_failed_reason = reason; 1309 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1310 } 1311 1312 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1313 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1314 } 1315 1316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1317 1318 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1319 static int sm_passkey_used(stk_generation_method_t method); 1320 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1321 1322 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1323 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1324 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1325 } else { 1326 sm_conn->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1327 } 1328 } 1329 1330 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1331 if (sm_conn->sm_role){ 1332 // Responder 1333 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1334 } else { 1335 // Initiator role 1336 switch (setup->sm_stk_generation_method){ 1337 case JUST_WORKS: 1338 sm_sc_prepare_dhkey_check(sm_conn); 1339 break; 1340 1341 case NK_BOTH_INPUT: 1342 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1343 break; 1344 case PK_INIT_INPUT: 1345 case PK_RESP_INPUT: 1346 case OK_BOTH_INPUT: 1347 if (setup->sm_passkey_bit < 20) { 1348 sm_sc_start_calculating_local_confirm(sm_conn); 1349 } else { 1350 sm_sc_prepare_dhkey_check(sm_conn); 1351 } 1352 break; 1353 case OOB: 1354 // TODO: implement SC OOB 1355 break; 1356 } 1357 } 1358 } 1359 1360 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1361 return sm_cmac_sc_buffer[offset]; 1362 } 1363 1364 static void sm_sc_cmac_done(uint8_t * hash){ 1365 log_info("sm_sc_cmac_done: "); 1366 log_info_hexdump(hash, 16); 1367 1368 sm_connection_t * sm_conn = sm_cmac_connection; 1369 sm_cmac_connection = NULL; 1370 1371 switch (sm_conn->sm_engine_state){ 1372 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1373 memcpy(setup->sm_local_confirm, hash, 16); 1374 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1375 break; 1376 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1377 // check 1378 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1379 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1380 break; 1381 } 1382 sm_sc_state_after_receiving_random(sm_conn); 1383 break; 1384 case SM_SC_W4_CALCULATE_G2: { 1385 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1386 big_endian_store_32(setup->sm_tk, 12, vab); 1387 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1388 sm_trigger_user_response(sm_conn); 1389 break; 1390 } 1391 case SM_SC_W4_CALCULATE_F5_SALT: 1392 memcpy(setup->sm_t, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1394 break; 1395 case SM_SC_W4_CALCULATE_F5_MACKEY: 1396 memcpy(setup->sm_mackey, hash, 16); 1397 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1398 break; 1399 case SM_SC_W4_CALCULATE_F5_LTK: 1400 memcpy(setup->sm_ltk, hash, 16); 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1402 break; 1403 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1404 memcpy(setup->sm_local_dhkey_check, hash, 16); 1405 if (sm_conn->sm_role){ 1406 // responder 1407 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1408 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1409 } else { 1410 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1411 } 1412 } else { 1413 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1414 } 1415 break; 1416 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1417 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1418 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1419 break; 1420 } 1421 if (sm_conn->sm_role){ 1422 // responder 1423 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1424 } else { 1425 // initiator 1426 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1427 } 1428 break; 1429 default: 1430 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1431 break; 1432 } 1433 sm_run(); 1434 } 1435 1436 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){ 1437 const uint16_t message_len = 65; 1438 sm_cmac_connection = sm_conn; 1439 memcpy(sm_cmac_sc_buffer, u, 32); 1440 memcpy(sm_cmac_sc_buffer+32, v, 32); 1441 sm_cmac_sc_buffer[64] = z; 1442 log_info("f4 key"); 1443 log_info_hexdump(x, 16); 1444 log_info("f4 message"); 1445 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1446 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1447 } 1448 1449 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1450 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1451 static const uint8_t f5_length[] = { 0x01, 0x00}; 1452 1453 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1454 #ifdef USE_MBEDTLS_FOR_ECDH 1455 // da * Pb 1456 mbedtls_ecp_group grp; 1457 mbedtls_ecp_group_init( &grp ); 1458 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1459 mbedtls_ecp_point Q; 1460 mbedtls_ecp_point_init( &Q ); 1461 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1462 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1463 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1464 mbedtls_ecp_point DH; 1465 mbedtls_ecp_point_init( &DH ); 1466 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1467 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1468 #endif 1469 log_info("dhkey"); 1470 log_info_hexdump(dhkey, 32); 1471 } 1472 1473 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1474 // calculate DHKEY 1475 sm_key256_t dhkey; 1476 sm_sc_calculate_dhkey(dhkey); 1477 1478 // calculate salt for f5 1479 const uint16_t message_len = 32; 1480 sm_cmac_connection = sm_conn; 1481 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1482 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1483 } 1484 1485 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){ 1486 const uint16_t message_len = 53; 1487 sm_cmac_connection = sm_conn; 1488 1489 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1490 sm_cmac_sc_buffer[0] = 0; 1491 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1492 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1493 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1494 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1495 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1496 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1497 log_info("f5 key"); 1498 log_info_hexdump(t, 16); 1499 log_info("f5 message for MacKey"); 1500 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1501 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1502 } 1503 1504 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1505 sm_key56_t bd_addr_master, bd_addr_slave; 1506 bd_addr_master[0] = setup->sm_m_addr_type; 1507 bd_addr_slave[0] = setup->sm_s_addr_type; 1508 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1509 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1510 if (sm_conn->sm_role){ 1511 // responder 1512 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1513 } else { 1514 // initiator 1515 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1516 } 1517 } 1518 1519 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1520 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1521 const uint16_t message_len = 53; 1522 sm_cmac_connection = sm_conn; 1523 sm_cmac_sc_buffer[0] = 1; 1524 // 1..52 setup before 1525 log_info("f5 key"); 1526 log_info_hexdump(t, 16); 1527 log_info("f5 message for LTK"); 1528 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1529 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1530 } 1531 1532 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1533 f5_ltk(sm_conn, setup->sm_t); 1534 } 1535 1536 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){ 1537 const uint16_t message_len = 65; 1538 sm_cmac_connection = sm_conn; 1539 memcpy(sm_cmac_sc_buffer, n1, 16); 1540 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1541 memcpy(sm_cmac_sc_buffer+32, r, 16); 1542 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1543 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1544 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1545 log_info("f6 key"); 1546 log_info_hexdump(w, 16); 1547 log_info("f6 message"); 1548 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1549 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1550 } 1551 1552 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1553 // - U is 256 bits 1554 // - V is 256 bits 1555 // - X is 128 bits 1556 // - Y is 128 bits 1557 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){ 1558 const uint16_t message_len = 80; 1559 sm_cmac_connection = sm_conn; 1560 memcpy(sm_cmac_sc_buffer, u, 32); 1561 memcpy(sm_cmac_sc_buffer+32, v, 32); 1562 memcpy(sm_cmac_sc_buffer+64, y, 16); 1563 log_info("g2 key"); 1564 log_info_hexdump(x, 16); 1565 log_info("g2 message"); 1566 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1567 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1568 } 1569 1570 static void g2_calculate(sm_connection_t * sm_conn) { 1571 // calc Va if numeric comparison 1572 uint8_t value[32]; 1573 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1574 if (sm_conn->sm_role){ 1575 // responder 1576 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1577 } else { 1578 // initiator 1579 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1580 } 1581 } 1582 1583 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1584 uint8_t z = 0; 1585 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1586 // some form of passkey 1587 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1588 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1589 setup->sm_passkey_bit++; 1590 } 1591 #ifdef USE_MBEDTLS_FOR_ECDH 1592 uint8_t local_qx[32]; 1593 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1594 #endif 1595 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1596 } 1597 1598 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1599 uint8_t z = 0; 1600 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1601 // some form of passkey 1602 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1603 // sm_passkey_bit was increased before sending confirm value 1604 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1605 } 1606 #ifdef USE_MBEDTLS_FOR_ECDH 1607 uint8_t local_qx[32]; 1608 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1609 #endif 1610 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1611 } 1612 1613 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1614 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1615 } 1616 1617 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1618 // calculate DHKCheck 1619 sm_key56_t bd_addr_master, bd_addr_slave; 1620 bd_addr_master[0] = setup->sm_m_addr_type; 1621 bd_addr_slave[0] = setup->sm_s_addr_type; 1622 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1623 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1624 uint8_t iocap_a[3]; 1625 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1626 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1627 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1628 uint8_t iocap_b[3]; 1629 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1630 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1631 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1632 if (sm_conn->sm_role){ 1633 // responder 1634 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); 1635 } else { 1636 // initiator 1637 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); 1638 } 1639 } 1640 1641 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1642 // validate E = f6() 1643 sm_key56_t bd_addr_master, bd_addr_slave; 1644 bd_addr_master[0] = setup->sm_m_addr_type; 1645 bd_addr_slave[0] = setup->sm_s_addr_type; 1646 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1647 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1648 1649 uint8_t iocap_a[3]; 1650 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1651 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1652 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1653 uint8_t iocap_b[3]; 1654 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1655 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1656 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1657 if (sm_conn->sm_role){ 1658 // responder 1659 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); 1660 } else { 1661 // initiator 1662 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); 1663 } 1664 } 1665 #endif 1666 1667 1668 static void sm_run(void){ 1669 1670 btstack_linked_list_iterator_t it; 1671 1672 // assert that we can send at least commands 1673 if (!hci_can_send_command_packet_now()) return; 1674 1675 // 1676 // non-connection related behaviour 1677 // 1678 1679 // distributed key generation 1680 switch (dkg_state){ 1681 case DKG_CALC_IRK: 1682 // already busy? 1683 if (sm_aes128_state == SM_AES128_IDLE) { 1684 // IRK = d1(IR, 1, 0) 1685 sm_key_t d1_prime; 1686 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1687 dkg_next_state(); 1688 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1689 return; 1690 } 1691 break; 1692 case DKG_CALC_DHK: 1693 // already busy? 1694 if (sm_aes128_state == SM_AES128_IDLE) { 1695 // DHK = d1(IR, 3, 0) 1696 sm_key_t d1_prime; 1697 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1698 dkg_next_state(); 1699 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1700 return; 1701 } 1702 break; 1703 default: 1704 break; 1705 } 1706 1707 #ifdef USE_MBEDTLS_FOR_ECDH 1708 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1709 sm_random_start(NULL); 1710 return; 1711 } 1712 #endif 1713 1714 // random address updates 1715 switch (rau_state){ 1716 case RAU_GET_RANDOM: 1717 rau_next_state(); 1718 sm_random_start(NULL); 1719 return; 1720 case RAU_GET_ENC: 1721 // already busy? 1722 if (sm_aes128_state == SM_AES128_IDLE) { 1723 sm_key_t r_prime; 1724 sm_ah_r_prime(sm_random_address, r_prime); 1725 rau_next_state(); 1726 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1727 return; 1728 } 1729 break; 1730 case RAU_SET_ADDRESS: 1731 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1732 rau_state = RAU_IDLE; 1733 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1734 return; 1735 default: 1736 break; 1737 } 1738 1739 // CMAC 1740 switch (sm_cmac_state){ 1741 case CMAC_CALC_SUBKEYS: 1742 case CMAC_CALC_MI: 1743 case CMAC_CALC_MLAST: 1744 // already busy? 1745 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1746 sm_cmac_handle_aes_engine_ready(); 1747 return; 1748 default: 1749 break; 1750 } 1751 1752 // CSRK Lookup 1753 // -- if csrk lookup ready, find connection that require csrk lookup 1754 if (sm_address_resolution_idle()){ 1755 hci_connections_get_iterator(&it); 1756 while(btstack_linked_list_iterator_has_next(&it)){ 1757 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1758 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1759 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1760 // and start lookup 1761 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); 1762 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1763 break; 1764 } 1765 } 1766 } 1767 1768 // -- if csrk lookup ready, resolved addresses for received addresses 1769 if (sm_address_resolution_idle()) { 1770 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1771 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1772 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1773 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1774 btstack_memory_sm_lookup_entry_free(entry); 1775 } 1776 } 1777 1778 // -- Continue with CSRK device lookup by public or resolvable private address 1779 if (!sm_address_resolution_idle()){ 1780 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1781 while (sm_address_resolution_test < le_device_db_count()){ 1782 int addr_type; 1783 bd_addr_t addr; 1784 sm_key_t irk; 1785 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1786 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1787 1788 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1789 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1790 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1791 break; 1792 } 1793 1794 if (sm_address_resolution_addr_type == 0){ 1795 sm_address_resolution_test++; 1796 continue; 1797 } 1798 1799 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1800 1801 log_info("LE Device Lookup: calculate AH"); 1802 log_info_key("IRK", irk); 1803 1804 sm_key_t r_prime; 1805 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1806 sm_address_resolution_ah_calculation_active = 1; 1807 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1808 return; 1809 } 1810 1811 if (sm_address_resolution_test >= le_device_db_count()){ 1812 log_info("LE Device Lookup: not found"); 1813 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1814 } 1815 } 1816 1817 1818 // 1819 // active connection handling 1820 // -- use loop to handle next connection if lock on setup context is released 1821 1822 while (1) { 1823 1824 // Find connections that requires setup context and make active if no other is locked 1825 hci_connections_get_iterator(&it); 1826 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1827 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1828 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1829 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1830 int done = 1; 1831 int err; 1832 int encryption_key_size; 1833 int authenticated; 1834 int authorized; 1835 switch (sm_connection->sm_engine_state) { 1836 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1837 // send packet if possible, 1838 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1839 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1840 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1841 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1842 } else { 1843 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1844 } 1845 // don't lock setup context yet 1846 done = 0; 1847 break; 1848 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1849 sm_init_setup(sm_connection); 1850 // recover pairing request 1851 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1852 err = sm_stk_generation_init(sm_connection); 1853 if (err){ 1854 setup->sm_pairing_failed_reason = err; 1855 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1856 break; 1857 } 1858 sm_timeout_start(sm_connection); 1859 // generate random number first, if we need to show passkey 1860 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1861 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1862 break; 1863 } 1864 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1865 break; 1866 case SM_INITIATOR_PH0_HAS_LTK: 1867 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1868 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1869 &encryption_key_size, &authenticated, &authorized); 1870 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1871 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1872 sm_connection->sm_connection_authenticated = authenticated; 1873 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1874 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1875 break; 1876 case SM_RESPONDER_PH0_RECEIVED_LTK: 1877 // re-establish previously used LTK using Rand and EDIV 1878 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1879 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1880 // re-establish used key encryption size 1881 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1882 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1883 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1884 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1885 log_info("sm: received ltk request with key size %u, authenticated %u", 1886 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1887 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1888 break; 1889 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1890 sm_init_setup(sm_connection); 1891 sm_timeout_start(sm_connection); 1892 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1893 break; 1894 default: 1895 done = 0; 1896 break; 1897 } 1898 if (done){ 1899 sm_active_connection = sm_connection->sm_handle; 1900 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1901 } 1902 } 1903 1904 // 1905 // active connection handling 1906 // 1907 1908 if (sm_active_connection == 0) return; 1909 1910 // assert that we could send a SM PDU - not needed for all of the following 1911 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1912 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1913 return; 1914 } 1915 1916 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1917 if (!connection) return; 1918 1919 sm_key_t plaintext; 1920 int key_distribution_flags; 1921 1922 log_info("sm_run: state %u", connection->sm_engine_state); 1923 1924 // responding state 1925 switch (connection->sm_engine_state){ 1926 1927 // general 1928 case SM_GENERAL_SEND_PAIRING_FAILED: { 1929 uint8_t buffer[2]; 1930 buffer[0] = SM_CODE_PAIRING_FAILED; 1931 buffer[1] = setup->sm_pairing_failed_reason; 1932 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1933 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1934 sm_done_for_handle(connection->sm_handle); 1935 break; 1936 } 1937 1938 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1939 case SM_SC_W2_GET_RANDOM_A: 1940 sm_random_start(connection); 1941 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1942 break; 1943 case SM_SC_W2_GET_RANDOM_B: 1944 sm_random_start(connection); 1945 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1946 break; 1947 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1948 if (!sm_cmac_ready()) break; 1949 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1950 sm_sc_calculate_local_confirm(connection); 1951 break; 1952 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1953 if (!sm_cmac_ready()) break; 1954 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1955 sm_sc_calculate_remote_confirm(connection); 1956 break; 1957 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1958 if (!sm_cmac_ready()) break; 1959 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1960 sm_sc_calculate_f6_for_dhkey_check(connection); 1961 break; 1962 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1963 if (!sm_cmac_ready()) break; 1964 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1965 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1966 break; 1967 case SM_SC_W2_CALCULATE_F5_SALT: 1968 if (!sm_cmac_ready()) break; 1969 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1970 f5_calculate_salt(connection); 1971 break; 1972 case SM_SC_W2_CALCULATE_F5_MACKEY: 1973 if (!sm_cmac_ready()) break; 1974 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 1975 f5_calculate_mackey(connection); 1976 break; 1977 case SM_SC_W2_CALCULATE_F5_LTK: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 1980 f5_calculate_ltk(connection); 1981 break; 1982 case SM_SC_W2_CALCULATE_G2: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 1985 g2_calculate(connection); 1986 break; 1987 1988 #endif 1989 // initiator side 1990 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 1991 sm_key_t peer_ltk_flipped; 1992 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 1993 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 1994 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 1995 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 1996 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 1997 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 1998 return; 1999 } 2000 2001 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2002 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2003 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2004 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2005 sm_timeout_reset(connection); 2006 break; 2007 2008 // responder side 2009 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2010 connection->sm_engine_state = SM_RESPONDER_IDLE; 2011 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2012 return; 2013 2014 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2015 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2016 uint8_t buffer[65]; 2017 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2018 // 2019 #ifdef USE_MBEDTLS_FOR_ECDH 2020 uint8_t value[32]; 2021 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2022 reverse_256(value, &buffer[1]); 2023 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2024 reverse_256(value, &buffer[33]); 2025 #endif 2026 2027 // stk generation method 2028 // passkey entry: notify app to show passkey or to request passkey 2029 switch (setup->sm_stk_generation_method){ 2030 case JUST_WORKS: 2031 case NK_BOTH_INPUT: 2032 if (connection->sm_role){ 2033 sm_sc_start_calculating_local_confirm(connection); 2034 } else { 2035 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2036 } 2037 break; 2038 case PK_INIT_INPUT: 2039 case PK_RESP_INPUT: 2040 case OK_BOTH_INPUT: 2041 // hack for testing: assume user entered '000000' 2042 // memset(setup->sm_tk, 0, 16); 2043 memcpy(setup->sm_ra, setup->sm_tk, 16); 2044 memcpy(setup->sm_rb, setup->sm_tk, 16); 2045 setup->sm_passkey_bit = 0; 2046 if (connection->sm_role){ 2047 // responder 2048 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2049 } else { 2050 // initiator 2051 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2052 } 2053 sm_trigger_user_response(connection); 2054 break; 2055 case OOB: 2056 // TODO: implement SC OOB 2057 break; 2058 } 2059 2060 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2061 sm_timeout_reset(connection); 2062 break; 2063 } 2064 case SM_SC_SEND_CONFIRMATION: { 2065 uint8_t buffer[17]; 2066 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2067 reverse_128(setup->sm_local_confirm, &buffer[1]); 2068 if (connection->sm_role){ 2069 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2070 } else { 2071 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2072 } 2073 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2074 sm_timeout_reset(connection); 2075 break; 2076 } 2077 case SM_SC_SEND_PAIRING_RANDOM: { 2078 uint8_t buffer[17]; 2079 buffer[0] = SM_CODE_PAIRING_RANDOM; 2080 reverse_128(setup->sm_local_nonce, &buffer[1]); 2081 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2082 if (connection->sm_role){ 2083 // responder 2084 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2085 } else { 2086 // initiator 2087 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2088 } 2089 } else { 2090 if (connection->sm_role){ 2091 // responder 2092 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2093 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2094 } else { 2095 sm_sc_prepare_dhkey_check(connection); 2096 } 2097 } else { 2098 // initiator 2099 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2100 } 2101 } 2102 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2103 sm_timeout_reset(connection); 2104 break; 2105 } 2106 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2107 uint8_t buffer[17]; 2108 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2109 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2110 2111 if (connection->sm_role){ 2112 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2113 } else { 2114 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2115 } 2116 2117 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2118 sm_timeout_reset(connection); 2119 break; 2120 } 2121 2122 #endif 2123 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2124 // echo initiator for now 2125 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2126 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2127 2128 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2129 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2130 if (setup->sm_use_secure_connections){ 2131 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2132 // skip LTK/EDIV for SC 2133 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2134 } 2135 #endif 2136 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); 2137 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); 2138 2139 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2140 sm_timeout_reset(connection); 2141 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2142 if (setup->sm_stk_generation_method == JUST_WORKS){ 2143 sm_trigger_user_response(connection); 2144 } 2145 return; 2146 2147 case SM_PH2_SEND_PAIRING_RANDOM: { 2148 uint8_t buffer[17]; 2149 buffer[0] = SM_CODE_PAIRING_RANDOM; 2150 reverse_128(setup->sm_local_random, &buffer[1]); 2151 if (connection->sm_role){ 2152 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2153 } else { 2154 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2155 } 2156 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2157 sm_timeout_reset(connection); 2158 break; 2159 } 2160 2161 case SM_PH2_GET_RANDOM_TK: 2162 case SM_PH2_C1_GET_RANDOM_A: 2163 case SM_PH2_C1_GET_RANDOM_B: 2164 case SM_PH3_GET_RANDOM: 2165 case SM_PH3_GET_DIV: 2166 sm_next_responding_state(connection); 2167 sm_random_start(connection); 2168 return; 2169 2170 case SM_PH2_C1_GET_ENC_B: 2171 case SM_PH2_C1_GET_ENC_D: 2172 // already busy? 2173 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2174 sm_next_responding_state(connection); 2175 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2176 return; 2177 2178 case SM_PH3_LTK_GET_ENC: 2179 case SM_RESPONDER_PH4_LTK_GET_ENC: 2180 // already busy? 2181 if (sm_aes128_state == SM_AES128_IDLE) { 2182 sm_key_t d_prime; 2183 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2184 sm_next_responding_state(connection); 2185 sm_aes128_start(sm_persistent_er, d_prime, connection); 2186 return; 2187 } 2188 break; 2189 2190 case SM_PH3_CSRK_GET_ENC: 2191 // already busy? 2192 if (sm_aes128_state == SM_AES128_IDLE) { 2193 sm_key_t d_prime; 2194 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2195 sm_next_responding_state(connection); 2196 sm_aes128_start(sm_persistent_er, d_prime, connection); 2197 return; 2198 } 2199 break; 2200 2201 case SM_PH2_C1_GET_ENC_C: 2202 // already busy? 2203 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2204 // calculate m_confirm using aes128 engine - step 1 2205 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, plaintext); 2206 sm_next_responding_state(connection); 2207 sm_aes128_start(setup->sm_tk, plaintext, connection); 2208 break; 2209 case SM_PH2_C1_GET_ENC_A: 2210 // already busy? 2211 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2212 // calculate confirm using aes128 engine - step 1 2213 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, plaintext); 2214 sm_next_responding_state(connection); 2215 sm_aes128_start(setup->sm_tk, plaintext, connection); 2216 break; 2217 case SM_PH2_CALC_STK: 2218 // already busy? 2219 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2220 // calculate STK 2221 if (connection->sm_role){ 2222 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2223 } else { 2224 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2225 } 2226 sm_next_responding_state(connection); 2227 sm_aes128_start(setup->sm_tk, plaintext, connection); 2228 break; 2229 case SM_PH3_Y_GET_ENC: 2230 // already busy? 2231 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2232 // PH3B2 - calculate Y from - enc 2233 // Y = dm(DHK, Rand) 2234 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2235 sm_next_responding_state(connection); 2236 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2237 return; 2238 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2239 uint8_t buffer[17]; 2240 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2241 reverse_128(setup->sm_local_confirm, &buffer[1]); 2242 if (connection->sm_role){ 2243 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2244 } else { 2245 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2246 } 2247 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2248 sm_timeout_reset(connection); 2249 return; 2250 } 2251 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2252 sm_key_t stk_flipped; 2253 reverse_128(setup->sm_ltk, stk_flipped); 2254 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2255 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2256 return; 2257 } 2258 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2259 sm_key_t stk_flipped; 2260 reverse_128(setup->sm_ltk, stk_flipped); 2261 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2262 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2263 return; 2264 } 2265 case SM_RESPONDER_PH4_SEND_LTK: { 2266 sm_key_t ltk_flipped; 2267 reverse_128(setup->sm_ltk, ltk_flipped); 2268 connection->sm_engine_state = SM_RESPONDER_IDLE; 2269 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2270 return; 2271 } 2272 case SM_RESPONDER_PH4_Y_GET_ENC: 2273 // already busy? 2274 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2275 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2276 // Y = dm(DHK, Rand) 2277 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2278 sm_next_responding_state(connection); 2279 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2280 return; 2281 2282 case SM_PH3_DISTRIBUTE_KEYS: 2283 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2284 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2285 uint8_t buffer[17]; 2286 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2287 reverse_128(setup->sm_ltk, &buffer[1]); 2288 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2289 sm_timeout_reset(connection); 2290 return; 2291 } 2292 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2293 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2294 uint8_t buffer[11]; 2295 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2296 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2297 reverse_64(setup->sm_local_rand, &buffer[3]); 2298 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2299 sm_timeout_reset(connection); 2300 return; 2301 } 2302 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2303 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2304 uint8_t buffer[17]; 2305 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2306 reverse_128(sm_persistent_irk, &buffer[1]); 2307 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2308 sm_timeout_reset(connection); 2309 return; 2310 } 2311 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2312 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2313 bd_addr_t local_address; 2314 uint8_t buffer[8]; 2315 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2316 gap_advertisements_get_address(&buffer[1], local_address); 2317 reverse_bd_addr(local_address, &buffer[2]); 2318 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2319 sm_timeout_reset(connection); 2320 return; 2321 } 2322 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2323 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2324 2325 // hack to reproduce test runs 2326 if (test_use_fixed_local_csrk){ 2327 memset(setup->sm_local_csrk, 0xcc, 16); 2328 } 2329 2330 uint8_t buffer[17]; 2331 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2332 reverse_128(setup->sm_local_csrk, &buffer[1]); 2333 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2334 sm_timeout_reset(connection); 2335 return; 2336 } 2337 2338 // keys are sent 2339 if (connection->sm_role){ 2340 // slave -> receive master keys if any 2341 if (sm_key_distribution_all_received(connection)){ 2342 sm_key_distribution_handle_all_received(connection); 2343 connection->sm_engine_state = SM_RESPONDER_IDLE; 2344 sm_done_for_handle(connection->sm_handle); 2345 } else { 2346 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2347 } 2348 } else { 2349 // master -> all done 2350 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2351 sm_done_for_handle(connection->sm_handle); 2352 } 2353 break; 2354 2355 default: 2356 break; 2357 } 2358 2359 // check again if active connection was released 2360 if (sm_active_connection) break; 2361 } 2362 } 2363 2364 // note: aes engine is ready as we just got the aes result 2365 static void sm_handle_encryption_result(uint8_t * data){ 2366 2367 sm_aes128_state = SM_AES128_IDLE; 2368 2369 if (sm_address_resolution_ah_calculation_active){ 2370 sm_address_resolution_ah_calculation_active = 0; 2371 // compare calulated address against connecting device 2372 uint8_t hash[3]; 2373 reverse_24(data, hash); 2374 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2375 log_info("LE Device Lookup: matched resolvable private address"); 2376 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2377 return; 2378 } 2379 // no match, try next 2380 sm_address_resolution_test++; 2381 return; 2382 } 2383 2384 switch (dkg_state){ 2385 case DKG_W4_IRK: 2386 reverse_128(data, sm_persistent_irk); 2387 log_info_key("irk", sm_persistent_irk); 2388 dkg_next_state(); 2389 return; 2390 case DKG_W4_DHK: 2391 reverse_128(data, sm_persistent_dhk); 2392 log_info_key("dhk", sm_persistent_dhk); 2393 dkg_next_state(); 2394 // SM Init Finished 2395 return; 2396 default: 2397 break; 2398 } 2399 2400 switch (rau_state){ 2401 case RAU_W4_ENC: 2402 reverse_24(data, &sm_random_address[3]); 2403 rau_next_state(); 2404 return; 2405 default: 2406 break; 2407 } 2408 2409 switch (sm_cmac_state){ 2410 case CMAC_W4_SUBKEYS: 2411 case CMAC_W4_MI: 2412 case CMAC_W4_MLAST: 2413 { 2414 sm_key_t t; 2415 reverse_128(data, t); 2416 sm_cmac_handle_encryption_result(t); 2417 } 2418 return; 2419 default: 2420 break; 2421 } 2422 2423 // retrieve sm_connection provided to sm_aes128_start_encryption 2424 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2425 if (!connection) return; 2426 switch (connection->sm_engine_state){ 2427 case SM_PH2_C1_W4_ENC_A: 2428 case SM_PH2_C1_W4_ENC_C: 2429 { 2430 sm_key_t t2; 2431 reverse_128(data, t2); 2432 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2433 } 2434 sm_next_responding_state(connection); 2435 return; 2436 case SM_PH2_C1_W4_ENC_B: 2437 reverse_128(data, setup->sm_local_confirm); 2438 log_info_key("c1!", setup->sm_local_confirm); 2439 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2440 return; 2441 case SM_PH2_C1_W4_ENC_D: 2442 { 2443 sm_key_t peer_confirm_test; 2444 reverse_128(data, peer_confirm_test); 2445 log_info_key("c1!", peer_confirm_test); 2446 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2447 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2448 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2449 return; 2450 } 2451 if (connection->sm_role){ 2452 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2453 } else { 2454 connection->sm_engine_state = SM_PH2_CALC_STK; 2455 } 2456 } 2457 return; 2458 case SM_PH2_W4_STK: 2459 reverse_128(data, setup->sm_ltk); 2460 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2461 log_info_key("stk", setup->sm_ltk); 2462 if (connection->sm_role){ 2463 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2464 } else { 2465 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2466 } 2467 return; 2468 case SM_PH3_Y_W4_ENC:{ 2469 sm_key_t y128; 2470 reverse_128(data, y128); 2471 setup->sm_local_y = big_endian_read_16(y128, 14); 2472 log_info_hex16("y", setup->sm_local_y); 2473 // PH3B3 - calculate EDIV 2474 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2475 log_info_hex16("ediv", setup->sm_local_ediv); 2476 // PH3B4 - calculate LTK - enc 2477 // LTK = d1(ER, DIV, 0)) 2478 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2479 return; 2480 } 2481 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2482 sm_key_t y128; 2483 reverse_128(data, y128); 2484 setup->sm_local_y = big_endian_read_16(y128, 14); 2485 log_info_hex16("y", setup->sm_local_y); 2486 2487 // PH3B3 - calculate DIV 2488 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2489 log_info_hex16("ediv", setup->sm_local_ediv); 2490 // PH3B4 - calculate LTK - enc 2491 // LTK = d1(ER, DIV, 0)) 2492 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2493 return; 2494 } 2495 case SM_PH3_LTK_W4_ENC: 2496 reverse_128(data, setup->sm_ltk); 2497 log_info_key("ltk", setup->sm_ltk); 2498 // calc CSRK next 2499 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2500 return; 2501 case SM_PH3_CSRK_W4_ENC: 2502 reverse_128(data, setup->sm_local_csrk); 2503 log_info_key("csrk", setup->sm_local_csrk); 2504 if (setup->sm_key_distribution_send_set){ 2505 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2506 } else { 2507 // no keys to send, just continue 2508 if (connection->sm_role){ 2509 // slave -> receive master keys 2510 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2511 } else { 2512 // master -> all done 2513 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2514 sm_done_for_handle(connection->sm_handle); 2515 } 2516 } 2517 return; 2518 case SM_RESPONDER_PH4_LTK_W4_ENC: 2519 reverse_128(data, setup->sm_ltk); 2520 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2521 log_info_key("ltk", setup->sm_ltk); 2522 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2523 return; 2524 default: 2525 break; 2526 } 2527 } 2528 2529 #ifdef USE_MBEDTLS_FOR_ECDH 2530 2531 static void sm_log_ec_keypair(void){ 2532 // print keypair 2533 char buffer[100]; 2534 size_t len; 2535 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2536 log_info("d: %s", buffer); 2537 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2538 log_info("X: %s", buffer); 2539 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2540 log_info("Y: %s", buffer); 2541 } 2542 2543 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2544 int offset = setup->sm_passkey_bit; 2545 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2546 while (size) { 2547 if (offset < 32){ 2548 *buffer++ = setup->sm_peer_qx[offset++]; 2549 } else { 2550 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2551 } 2552 size--; 2553 } 2554 setup->sm_passkey_bit = offset; 2555 return 0; 2556 } 2557 #endif 2558 2559 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2560 static void sm_handle_random_result(uint8_t * data){ 2561 2562 #ifdef USE_MBEDTLS_FOR_ECDH 2563 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2564 int num_bytes = setup->sm_passkey_bit; 2565 if (num_bytes < 32){ 2566 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2567 } else { 2568 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2569 } 2570 num_bytes += 8; 2571 setup->sm_passkey_bit = num_bytes; 2572 2573 if (num_bytes >= 64){ 2574 // generate EC key 2575 setup->sm_passkey_bit = 0; 2576 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2577 sm_log_ec_keypair(); 2578 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2579 } 2580 } 2581 #endif 2582 2583 switch (rau_state){ 2584 case RAU_W4_RANDOM: 2585 // non-resolvable vs. resolvable 2586 switch (gap_random_adress_type){ 2587 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2588 // resolvable: use random as prand and calc address hash 2589 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2590 memcpy(sm_random_address, data, 3); 2591 sm_random_address[0] &= 0x3f; 2592 sm_random_address[0] |= 0x40; 2593 rau_state = RAU_GET_ENC; 2594 break; 2595 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2596 default: 2597 // "The two most significant bits of the address shall be equal to ‘0’"" 2598 memcpy(sm_random_address, data, 6); 2599 sm_random_address[0] &= 0x3f; 2600 rau_state = RAU_SET_ADDRESS; 2601 break; 2602 } 2603 return; 2604 default: 2605 break; 2606 } 2607 2608 // retrieve sm_connection provided to sm_random_start 2609 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2610 if (!connection) return; 2611 switch (connection->sm_engine_state){ 2612 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2613 case SM_SC_W4_GET_RANDOM_A: 2614 memcpy(&setup->sm_local_nonce[0], data, 8); 2615 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2616 break; 2617 case SM_SC_W4_GET_RANDOM_B: 2618 memcpy(&setup->sm_local_nonce[8], data, 8); 2619 // initiator & jw/nc -> send pairing random 2620 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2621 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2622 break; 2623 } else { 2624 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2625 } 2626 break; 2627 #endif 2628 2629 case SM_PH2_W4_RANDOM_TK: 2630 { 2631 // map random to 0-999999 without speding much cycles on a modulus operation 2632 uint32_t tk = little_endian_read_32(data,0); 2633 tk = tk & 0xfffff; // 1048575 2634 if (tk >= 999999){ 2635 tk = tk - 999999; 2636 } 2637 sm_reset_tk(); 2638 big_endian_store_32(setup->sm_tk, 12, tk); 2639 if (connection->sm_role){ 2640 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2641 } else { 2642 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2643 sm_trigger_user_response(connection); 2644 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2645 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2646 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2647 } 2648 } 2649 return; 2650 } 2651 case SM_PH2_C1_W4_RANDOM_A: 2652 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2653 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2654 return; 2655 case SM_PH2_C1_W4_RANDOM_B: 2656 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2657 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2658 return; 2659 case SM_PH3_W4_RANDOM: 2660 reverse_64(data, setup->sm_local_rand); 2661 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2662 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2663 // no db for authenticated flag hack: store flag in bit 4 of LSB 2664 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2665 connection->sm_engine_state = SM_PH3_GET_DIV; 2666 return; 2667 case SM_PH3_W4_DIV: 2668 // use 16 bit from random value as div 2669 setup->sm_local_div = big_endian_read_16(data, 0); 2670 log_info_hex16("div", setup->sm_local_div); 2671 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2672 return; 2673 default: 2674 break; 2675 } 2676 } 2677 2678 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2679 2680 sm_connection_t * sm_conn; 2681 hci_con_handle_t con_handle; 2682 2683 switch (packet_type) { 2684 2685 case HCI_EVENT_PACKET: 2686 switch (hci_event_packet_get_type(packet)) { 2687 2688 case BTSTACK_EVENT_STATE: 2689 // bt stack activated, get started 2690 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2691 log_info("HCI Working!"); 2692 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2693 rau_state = RAU_IDLE; 2694 #ifdef USE_MBEDTLS_FOR_ECDH 2695 if (!test_use_fixed_ec_keypair){ 2696 setup->sm_passkey_bit = 0; 2697 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2698 } 2699 #endif 2700 sm_run(); 2701 } 2702 break; 2703 2704 case HCI_EVENT_LE_META: 2705 switch (packet[2]) { 2706 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2707 2708 log_info("sm: connected"); 2709 2710 if (packet[3]) return; // connection failed 2711 2712 con_handle = little_endian_read_16(packet, 4); 2713 sm_conn = sm_get_connection_for_handle(con_handle); 2714 if (!sm_conn) break; 2715 2716 sm_conn->sm_handle = con_handle; 2717 sm_conn->sm_role = packet[6]; 2718 sm_conn->sm_peer_addr_type = packet[7]; 2719 reverse_bd_addr(&packet[8], 2720 sm_conn->sm_peer_address); 2721 2722 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2723 2724 // reset security properties 2725 sm_conn->sm_connection_encrypted = 0; 2726 sm_conn->sm_connection_authenticated = 0; 2727 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2728 sm_conn->sm_le_db_index = -1; 2729 2730 // prepare CSRK lookup (does not involve setup) 2731 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2732 2733 // just connected -> everything else happens in sm_run() 2734 if (sm_conn->sm_role){ 2735 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2736 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2737 if (sm_slave_request_security) { 2738 // request security if requested by app 2739 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2740 } else { 2741 // otherwise, wait for pairing request 2742 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2743 } 2744 } 2745 break; 2746 } else { 2747 // master 2748 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2749 } 2750 break; 2751 2752 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2753 con_handle = little_endian_read_16(packet, 3); 2754 sm_conn = sm_get_connection_for_handle(con_handle); 2755 if (!sm_conn) break; 2756 2757 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2758 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2759 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2760 break; 2761 } 2762 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2763 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2764 break; 2765 } 2766 2767 // assume that we don't have a LTK for ediv == 0 and random == null 2768 if (little_endian_read_16(packet, 13) == 0 && sm_is_null_random(&packet[5])){ 2769 log_info("LTK Request: ediv & random are empty"); 2770 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2771 break; 2772 } 2773 2774 // store rand and ediv 2775 reverse_64(&packet[5], sm_conn->sm_local_rand); 2776 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2777 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2778 break; 2779 2780 default: 2781 break; 2782 } 2783 break; 2784 2785 case HCI_EVENT_ENCRYPTION_CHANGE: 2786 con_handle = little_endian_read_16(packet, 3); 2787 sm_conn = sm_get_connection_for_handle(con_handle); 2788 if (!sm_conn) break; 2789 2790 sm_conn->sm_connection_encrypted = packet[5]; 2791 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2792 sm_conn->sm_actual_encryption_key_size); 2793 log_info("event handler, state %u", sm_conn->sm_engine_state); 2794 if (!sm_conn->sm_connection_encrypted) break; 2795 // continue if part of initial pairing 2796 switch (sm_conn->sm_engine_state){ 2797 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2798 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2799 sm_done_for_handle(sm_conn->sm_handle); 2800 break; 2801 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2802 if (sm_conn->sm_role){ 2803 // slave 2804 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2805 } else { 2806 // master 2807 if (sm_key_distribution_all_received(sm_conn)){ 2808 // skip receiving keys as there are none 2809 sm_key_distribution_handle_all_received(sm_conn); 2810 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2811 } else { 2812 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2813 } 2814 } 2815 break; 2816 default: 2817 break; 2818 } 2819 break; 2820 2821 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2822 con_handle = little_endian_read_16(packet, 3); 2823 sm_conn = sm_get_connection_for_handle(con_handle); 2824 if (!sm_conn) break; 2825 2826 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2827 log_info("event handler, state %u", sm_conn->sm_engine_state); 2828 // continue if part of initial pairing 2829 switch (sm_conn->sm_engine_state){ 2830 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2831 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2832 sm_done_for_handle(sm_conn->sm_handle); 2833 break; 2834 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2835 if (sm_conn->sm_role){ 2836 // slave 2837 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2838 } else { 2839 // master 2840 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2841 } 2842 break; 2843 default: 2844 break; 2845 } 2846 break; 2847 2848 2849 case HCI_EVENT_DISCONNECTION_COMPLETE: 2850 con_handle = little_endian_read_16(packet, 3); 2851 sm_done_for_handle(con_handle); 2852 sm_conn = sm_get_connection_for_handle(con_handle); 2853 if (!sm_conn) break; 2854 2855 // delete stored bonding on disconnect with authentication failure in ph0 2856 if (sm_conn->sm_role == 0 2857 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2858 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2859 le_device_db_remove(sm_conn->sm_le_db_index); 2860 } 2861 2862 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2863 sm_conn->sm_handle = 0; 2864 break; 2865 2866 case HCI_EVENT_COMMAND_COMPLETE: 2867 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2868 sm_handle_encryption_result(&packet[6]); 2869 break; 2870 } 2871 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2872 sm_handle_random_result(&packet[6]); 2873 break; 2874 } 2875 break; 2876 default: 2877 break; 2878 } 2879 break; 2880 default: 2881 break; 2882 } 2883 2884 sm_run(); 2885 } 2886 2887 static inline int sm_calc_actual_encryption_key_size(int other){ 2888 if (other < sm_min_encryption_key_size) return 0; 2889 if (other < sm_max_encryption_key_size) return other; 2890 return sm_max_encryption_key_size; 2891 } 2892 2893 2894 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2895 switch (method){ 2896 case JUST_WORKS: 2897 case NK_BOTH_INPUT: 2898 return 1; 2899 default: 2900 return 0; 2901 } 2902 } 2903 2904 static int sm_passkey_used(stk_generation_method_t method){ 2905 switch (method){ 2906 case PK_RESP_INPUT: 2907 case PK_INIT_INPUT: 2908 case OK_BOTH_INPUT: 2909 return 1; 2910 default: 2911 return 0; 2912 } 2913 } 2914 2915 /** 2916 * @return ok 2917 */ 2918 static int sm_validate_stk_generation_method(void){ 2919 // check if STK generation method is acceptable by client 2920 switch (setup->sm_stk_generation_method){ 2921 case JUST_WORKS: 2922 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2923 case PK_RESP_INPUT: 2924 case PK_INIT_INPUT: 2925 case OK_BOTH_INPUT: 2926 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2927 case OOB: 2928 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2929 case NK_BOTH_INPUT: 2930 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2931 return 1; 2932 default: 2933 return 0; 2934 } 2935 } 2936 2937 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2938 2939 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2940 sm_run(); 2941 } 2942 2943 if (packet_type != SM_DATA_PACKET) return; 2944 2945 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2946 if (!sm_conn) return; 2947 2948 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2949 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2950 return; 2951 } 2952 2953 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2954 2955 int err; 2956 2957 switch (sm_conn->sm_engine_state){ 2958 2959 // a sm timeout requries a new physical connection 2960 case SM_GENERAL_TIMEOUT: 2961 return; 2962 2963 // Initiator 2964 case SM_INITIATOR_CONNECTED: 2965 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2966 sm_pdu_received_in_wrong_state(sm_conn); 2967 break; 2968 } 2969 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2970 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2971 break; 2972 } 2973 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2974 uint16_t ediv; 2975 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 2976 if (ediv){ 2977 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2978 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2979 } else { 2980 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2981 } 2982 break; 2983 } 2984 // otherwise, store security request 2985 sm_conn->sm_security_request_received = 1; 2986 break; 2987 2988 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 2989 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 2990 sm_pdu_received_in_wrong_state(sm_conn); 2991 break; 2992 } 2993 // store pairing request 2994 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 2995 err = sm_stk_generation_init(sm_conn); 2996 if (err){ 2997 setup->sm_pairing_failed_reason = err; 2998 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2999 break; 3000 } 3001 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3002 if (setup->sm_use_secure_connections){ 3003 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3004 if (setup->sm_stk_generation_method == JUST_WORKS){ 3005 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3006 sm_trigger_user_response(sm_conn); 3007 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3008 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3009 } 3010 } else { 3011 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3012 } 3013 break; 3014 } 3015 #endif 3016 // generate random number first, if we need to show passkey 3017 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3018 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3019 break; 3020 } 3021 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3022 sm_trigger_user_response(sm_conn); 3023 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3024 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3025 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3026 } 3027 break; 3028 3029 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3030 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3031 sm_pdu_received_in_wrong_state(sm_conn); 3032 break; 3033 } 3034 3035 // store s_confirm 3036 reverse_128(&packet[1], setup->sm_peer_confirm); 3037 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3038 break; 3039 3040 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3041 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3042 sm_pdu_received_in_wrong_state(sm_conn); 3043 break;; 3044 } 3045 3046 // received random value 3047 reverse_128(&packet[1], setup->sm_peer_random); 3048 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3049 break; 3050 3051 // Responder 3052 case SM_RESPONDER_IDLE: 3053 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3054 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3055 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3056 sm_pdu_received_in_wrong_state(sm_conn); 3057 break;; 3058 } 3059 3060 // store pairing request 3061 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3062 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3063 break; 3064 3065 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3066 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3067 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3068 sm_pdu_received_in_wrong_state(sm_conn); 3069 break; 3070 } 3071 3072 // store public key for DH Key calculation 3073 reverse_256(&packet[01], setup->sm_peer_qx); 3074 reverse_256(&packet[33], setup->sm_peer_qy); 3075 3076 #ifdef USE_MBEDTLS_FOR_ECDH 3077 // validate public key 3078 mbedtls_ecp_group grp; 3079 mbedtls_ecp_group_init( &grp ); 3080 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3081 3082 mbedtls_ecp_point Q; 3083 mbedtls_ecp_point_init( &Q ); 3084 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3085 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3086 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3087 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3088 if (err){ 3089 log_error("sm: peer public key invalid %x", err); 3090 // uses "unspecified reason", there is no "public key invalid" error code 3091 sm_pdu_received_in_wrong_state(sm_conn); 3092 break; 3093 } 3094 #endif 3095 if (sm_conn->sm_role){ 3096 // responder 3097 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3098 } else { 3099 // initiator 3100 // stk generation method 3101 // passkey entry: notify app to show passkey or to request passkey 3102 switch (setup->sm_stk_generation_method){ 3103 case JUST_WORKS: 3104 case NK_BOTH_INPUT: 3105 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3106 break; 3107 case PK_INIT_INPUT: 3108 case PK_RESP_INPUT: 3109 case OK_BOTH_INPUT: 3110 sm_sc_start_calculating_local_confirm(sm_conn); 3111 break; 3112 case OOB: 3113 // TODO: implement SC OOB 3114 break; 3115 } 3116 } 3117 break; 3118 3119 case SM_SC_W4_CONFIRMATION: 3120 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3121 sm_pdu_received_in_wrong_state(sm_conn); 3122 break; 3123 } 3124 // received confirm value 3125 reverse_128(&packet[1], setup->sm_peer_confirm); 3126 3127 if (sm_conn->sm_role){ 3128 // responder 3129 sm_sc_start_calculating_local_confirm(sm_conn); 3130 } else { 3131 // initiator 3132 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3133 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3134 } else { 3135 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3136 } 3137 } 3138 break; 3139 3140 case SM_SC_W4_PAIRING_RANDOM: 3141 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3142 sm_pdu_received_in_wrong_state(sm_conn); 3143 break; 3144 } 3145 3146 // received random value 3147 reverse_128(&packet[1], setup->sm_peer_nonce); 3148 3149 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3150 // only check for JUST WORK/NC in initiator role AND passkey entry 3151 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3152 if (sm_conn->sm_role || passkey_entry) { 3153 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3154 } 3155 3156 sm_sc_state_after_receiving_random(sm_conn); 3157 break; 3158 3159 case SM_SC_W2_CALCULATE_G2: 3160 case SM_SC_W4_CALCULATE_G2: 3161 case SM_SC_W2_CALCULATE_F5_SALT: 3162 case SM_SC_W4_CALCULATE_F5_SALT: 3163 case SM_SC_W2_CALCULATE_F5_MACKEY: 3164 case SM_SC_W4_CALCULATE_F5_MACKEY: 3165 case SM_SC_W2_CALCULATE_F5_LTK: 3166 case SM_SC_W4_CALCULATE_F5_LTK: 3167 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3168 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3169 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3170 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3171 sm_pdu_received_in_wrong_state(sm_conn); 3172 break; 3173 } 3174 // store DHKey Check 3175 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3176 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3177 3178 // have we been only waiting for dhkey check command? 3179 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3180 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3181 } 3182 break; 3183 #endif 3184 3185 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3186 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3187 sm_pdu_received_in_wrong_state(sm_conn); 3188 break; 3189 } 3190 3191 // received confirm value 3192 reverse_128(&packet[1], setup->sm_peer_confirm); 3193 3194 // notify client to hide shown passkey 3195 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3196 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3197 } 3198 3199 // handle user cancel pairing? 3200 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3201 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3202 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3203 break; 3204 } 3205 3206 // wait for user action? 3207 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3208 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3209 break; 3210 } 3211 3212 // calculate and send local_confirm 3213 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3214 break; 3215 3216 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3217 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3218 sm_pdu_received_in_wrong_state(sm_conn); 3219 break;; 3220 } 3221 3222 // received random value 3223 reverse_128(&packet[1], setup->sm_peer_random); 3224 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3225 break; 3226 3227 case SM_PH3_RECEIVE_KEYS: 3228 switch(packet[0]){ 3229 case SM_CODE_ENCRYPTION_INFORMATION: 3230 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3231 reverse_128(&packet[1], setup->sm_peer_ltk); 3232 break; 3233 3234 case SM_CODE_MASTER_IDENTIFICATION: 3235 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3236 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3237 reverse_64(&packet[3], setup->sm_peer_rand); 3238 break; 3239 3240 case SM_CODE_IDENTITY_INFORMATION: 3241 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3242 reverse_128(&packet[1], setup->sm_peer_irk); 3243 break; 3244 3245 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3246 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3247 setup->sm_peer_addr_type = packet[1]; 3248 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3249 break; 3250 3251 case SM_CODE_SIGNING_INFORMATION: 3252 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3253 reverse_128(&packet[1], setup->sm_peer_csrk); 3254 break; 3255 default: 3256 // Unexpected PDU 3257 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3258 break; 3259 } 3260 // done with key distribution? 3261 if (sm_key_distribution_all_received(sm_conn)){ 3262 3263 sm_key_distribution_handle_all_received(sm_conn); 3264 3265 if (sm_conn->sm_role){ 3266 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3267 sm_done_for_handle(sm_conn->sm_handle); 3268 } else { 3269 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3270 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3271 if (setup->sm_use_secure_connections){ 3272 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3273 } 3274 #endif 3275 } 3276 } 3277 break; 3278 default: 3279 // Unexpected PDU 3280 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3281 break; 3282 } 3283 3284 // try to send preparared packet 3285 sm_run(); 3286 } 3287 3288 // Security Manager Client API 3289 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3290 sm_get_oob_data = get_oob_data_callback; 3291 } 3292 3293 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3294 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3295 } 3296 3297 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3298 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3299 } 3300 3301 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3302 sm_min_encryption_key_size = min_size; 3303 sm_max_encryption_key_size = max_size; 3304 } 3305 3306 void sm_set_authentication_requirements(uint8_t auth_req){ 3307 sm_auth_req = auth_req; 3308 } 3309 3310 void sm_set_io_capabilities(io_capability_t io_capability){ 3311 sm_io_capabilities = io_capability; 3312 } 3313 3314 void sm_set_request_security(int enable){ 3315 sm_slave_request_security = enable; 3316 } 3317 3318 void sm_set_er(sm_key_t er){ 3319 memcpy(sm_persistent_er, er, 16); 3320 } 3321 3322 void sm_set_ir(sm_key_t ir){ 3323 memcpy(sm_persistent_ir, ir, 16); 3324 } 3325 3326 // Testing support only 3327 void sm_test_set_irk(sm_key_t irk){ 3328 memcpy(sm_persistent_irk, irk, 16); 3329 sm_persistent_irk_ready = 1; 3330 } 3331 3332 void sm_test_use_fixed_local_csrk(void){ 3333 test_use_fixed_local_csrk = 1; 3334 } 3335 3336 void sm_init(void){ 3337 // set some (BTstack default) ER and IR 3338 int i; 3339 sm_key_t er; 3340 sm_key_t ir; 3341 for (i=0;i<16;i++){ 3342 er[i] = 0x30 + i; 3343 ir[i] = 0x90 + i; 3344 } 3345 sm_set_er(er); 3346 sm_set_ir(ir); 3347 // defaults 3348 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3349 | SM_STK_GENERATION_METHOD_OOB 3350 | SM_STK_GENERATION_METHOD_PASSKEY 3351 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3352 3353 sm_max_encryption_key_size = 16; 3354 sm_min_encryption_key_size = 7; 3355 3356 sm_cmac_state = CMAC_IDLE; 3357 dkg_state = DKG_W4_WORKING; 3358 rau_state = RAU_W4_WORKING; 3359 sm_aes128_state = SM_AES128_IDLE; 3360 sm_address_resolution_test = -1; // no private address to resolve yet 3361 sm_address_resolution_ah_calculation_active = 0; 3362 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3363 sm_address_resolution_general_queue = NULL; 3364 3365 gap_random_adress_update_period = 15 * 60 * 1000L; 3366 3367 sm_active_connection = 0; 3368 3369 test_use_fixed_local_csrk = 0; 3370 3371 // register for HCI Events from HCI 3372 hci_event_callback_registration.callback = &sm_event_packet_handler; 3373 hci_add_event_handler(&hci_event_callback_registration); 3374 3375 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3376 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3377 3378 #ifdef USE_MBEDTLS_FOR_ECDH 3379 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3380 #endif 3381 } 3382 3383 void sm_test_use_fixed_ec_keypair(void){ 3384 test_use_fixed_ec_keypair = 1; 3385 #ifdef USE_MBEDTLS_FOR_ECDH 3386 // use test keypair from spec 3387 mbedtls_ecp_keypair_init(&le_keypair); 3388 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3389 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3390 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3391 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3392 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3393 #endif 3394 } 3395 3396 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3397 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3398 if (!hci_con) return NULL; 3399 return &hci_con->sm_connection; 3400 } 3401 3402 // @returns 0 if not encrypted, 7-16 otherwise 3403 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3404 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3405 if (!sm_conn) return 0; // wrong connection 3406 if (!sm_conn->sm_connection_encrypted) return 0; 3407 return sm_conn->sm_actual_encryption_key_size; 3408 } 3409 3410 int sm_authenticated(hci_con_handle_t con_handle){ 3411 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3412 if (!sm_conn) return 0; // wrong connection 3413 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3414 return sm_conn->sm_connection_authenticated; 3415 } 3416 3417 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3418 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3419 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3420 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3421 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3422 return sm_conn->sm_connection_authorization_state; 3423 } 3424 3425 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3426 switch (sm_conn->sm_engine_state){ 3427 case SM_GENERAL_IDLE: 3428 case SM_RESPONDER_IDLE: 3429 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3430 sm_run(); 3431 break; 3432 default: 3433 break; 3434 } 3435 } 3436 3437 /** 3438 * @brief Trigger Security Request 3439 */ 3440 void sm_send_security_request(hci_con_handle_t con_handle){ 3441 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3442 if (!sm_conn) return; 3443 sm_send_security_request_for_connection(sm_conn); 3444 } 3445 3446 // request pairing 3447 void sm_request_pairing(hci_con_handle_t con_handle){ 3448 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3449 if (!sm_conn) return; // wrong connection 3450 3451 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3452 if (sm_conn->sm_role){ 3453 sm_send_security_request_for_connection(sm_conn); 3454 } else { 3455 // used as a trigger to start central/master/initiator security procedures 3456 uint16_t ediv; 3457 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3458 switch (sm_conn->sm_irk_lookup_state){ 3459 case IRK_LOOKUP_FAILED: 3460 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3461 break; 3462 case IRK_LOOKUP_SUCCEEDED: 3463 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3464 if (ediv){ 3465 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3466 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3467 } else { 3468 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3469 } 3470 break; 3471 default: 3472 sm_conn->sm_bonding_requested = 1; 3473 break; 3474 } 3475 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3476 sm_conn->sm_bonding_requested = 1; 3477 } 3478 } 3479 sm_run(); 3480 } 3481 3482 // called by client app on authorization request 3483 void sm_authorization_decline(hci_con_handle_t con_handle){ 3484 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3485 if (!sm_conn) return; // wrong connection 3486 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3487 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3488 } 3489 3490 void sm_authorization_grant(hci_con_handle_t con_handle){ 3491 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3492 if (!sm_conn) return; // wrong connection 3493 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3494 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3495 } 3496 3497 // GAP Bonding API 3498 3499 void sm_bonding_decline(hci_con_handle_t con_handle){ 3500 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3501 if (!sm_conn) return; // wrong connection 3502 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3503 3504 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3505 switch (setup->sm_stk_generation_method){ 3506 case PK_RESP_INPUT: 3507 case PK_INIT_INPUT: 3508 case OK_BOTH_INPUT: 3509 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3510 break; 3511 case NK_BOTH_INPUT: 3512 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3513 break; 3514 case JUST_WORKS: 3515 case OOB: 3516 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3517 break; 3518 } 3519 } 3520 sm_run(); 3521 } 3522 3523 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3524 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3525 if (!sm_conn) return; // wrong connection 3526 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3527 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3528 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3529 3530 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3531 if (setup->sm_use_secure_connections){ 3532 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3533 } 3534 #endif 3535 } 3536 3537 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3538 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3539 sm_sc_prepare_dhkey_check(sm_conn); 3540 } 3541 #endif 3542 3543 sm_run(); 3544 } 3545 3546 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3547 // for now, it's the same 3548 sm_just_works_confirm(con_handle); 3549 } 3550 3551 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3552 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3553 if (!sm_conn) return; // wrong connection 3554 sm_reset_tk(); 3555 big_endian_store_32(setup->sm_tk, 12, passkey); 3556 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3557 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3558 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3559 } 3560 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3561 // if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3562 // sm_sc_prepare_dhkey_check(sm_conn); 3563 // } 3564 #endif 3565 sm_run(); 3566 } 3567 3568 /** 3569 * @brief Identify device in LE Device DB 3570 * @param handle 3571 * @returns index from le_device_db or -1 if not found/identified 3572 */ 3573 int sm_le_device_index(hci_con_handle_t con_handle ){ 3574 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3575 if (!sm_conn) return -1; 3576 return sm_conn->sm_le_db_index; 3577 } 3578 3579 // GAP LE API 3580 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3581 gap_random_address_update_stop(); 3582 gap_random_adress_type = random_address_type; 3583 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3584 gap_random_address_update_start(); 3585 gap_random_address_trigger(); 3586 } 3587 3588 gap_random_address_type_t gap_random_address_get_mode(void){ 3589 return gap_random_adress_type; 3590 } 3591 3592 void gap_random_address_set_update_period(int period_ms){ 3593 gap_random_adress_update_period = period_ms; 3594 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3595 gap_random_address_update_stop(); 3596 gap_random_address_update_start(); 3597 } 3598 3599 void gap_random_address_set(bd_addr_t addr){ 3600 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3601 memcpy(sm_random_address, addr, 6); 3602 rau_state = RAU_SET_ADDRESS; 3603 sm_run(); 3604 } 3605 3606 /* 3607 * @brief Set Advertisement Paramters 3608 * @param adv_int_min 3609 * @param adv_int_max 3610 * @param adv_type 3611 * @param direct_address_type 3612 * @param direct_address 3613 * @param channel_map 3614 * @param filter_policy 3615 * 3616 * @note own_address_type is used from gap_random_address_set_mode 3617 */ 3618 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3619 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3620 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3621 direct_address_typ, direct_address, channel_map, filter_policy); 3622 } 3623 3624