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_state_after_receiving_random(sm_connection_t * sm_conn){ 1323 if (sm_conn->sm_role){ 1324 // Responder 1325 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1326 } else { 1327 // Initiator role 1328 switch (setup->sm_stk_generation_method){ 1329 case JUST_WORKS: 1330 sm_sc_prepare_dhkey_check(sm_conn); 1331 break; 1332 1333 case NK_BOTH_INPUT: 1334 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1335 break; 1336 case PK_INIT_INPUT: 1337 case PK_RESP_INPUT: 1338 case OK_BOTH_INPUT: 1339 if (setup->sm_passkey_bit < 20) { 1340 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1341 } else { 1342 sm_sc_prepare_dhkey_check(sm_conn); 1343 } 1344 break; 1345 case OOB: 1346 // TODO: implement SC OOB 1347 break; 1348 } 1349 } 1350 } 1351 1352 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1353 return sm_cmac_sc_buffer[offset]; 1354 } 1355 1356 static void sm_sc_cmac_done(uint8_t * hash){ 1357 log_info("sm_sc_cmac_done: "); 1358 log_info_hexdump(hash, 16); 1359 1360 sm_connection_t * sm_conn = sm_cmac_connection; 1361 sm_cmac_connection = NULL; 1362 1363 switch (sm_conn->sm_engine_state){ 1364 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1365 memcpy(setup->sm_local_confirm, hash, 16); 1366 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1367 break; 1368 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1369 // check 1370 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1371 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1372 break; 1373 } 1374 sm_sc_state_after_receiving_random(sm_conn); 1375 break; 1376 case SM_SC_W4_CALCULATE_G2: { 1377 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1378 big_endian_store_32(setup->sm_tk, 12, vab); 1379 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1380 sm_trigger_user_response(sm_conn); 1381 break; 1382 } 1383 case SM_SC_W4_CALCULATE_F5_SALT: 1384 memcpy(setup->sm_t, hash, 16); 1385 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1386 break; 1387 case SM_SC_W4_CALCULATE_F5_MACKEY: 1388 memcpy(setup->sm_mackey, hash, 16); 1389 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1390 break; 1391 case SM_SC_W4_CALCULATE_F5_LTK: 1392 memcpy(setup->sm_ltk, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1394 break; 1395 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1396 memcpy(setup->sm_local_dhkey_check, hash, 16); 1397 if (sm_conn->sm_role){ 1398 // responder 1399 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1400 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1401 } else { 1402 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1403 } 1404 } else { 1405 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1406 } 1407 break; 1408 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1409 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1410 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1411 break; 1412 } 1413 if (sm_conn->sm_role){ 1414 // responder 1415 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1416 } else { 1417 // initiator 1418 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1419 } 1420 break; 1421 default: 1422 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1423 break; 1424 } 1425 sm_run(); 1426 } 1427 1428 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){ 1429 const uint16_t message_len = 65; 1430 sm_cmac_connection = sm_conn; 1431 memcpy(sm_cmac_sc_buffer, u, 32); 1432 memcpy(sm_cmac_sc_buffer+32, v, 32); 1433 sm_cmac_sc_buffer[64] = z; 1434 log_info("f4 key"); 1435 log_info_hexdump(x, 16); 1436 log_info("f4 message"); 1437 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1438 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1439 } 1440 1441 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1442 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1443 static const uint8_t f5_length[] = { 0x01, 0x00}; 1444 1445 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1446 #ifdef USE_MBEDTLS_FOR_ECDH 1447 // da * Pb 1448 mbedtls_ecp_group grp; 1449 mbedtls_ecp_group_init( &grp ); 1450 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1451 mbedtls_ecp_point Q; 1452 mbedtls_ecp_point_init( &Q ); 1453 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1454 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1455 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1456 mbedtls_ecp_point DH; 1457 mbedtls_ecp_point_init( &DH ); 1458 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1459 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1460 #endif 1461 log_info("dhkey"); 1462 log_info_hexdump(dhkey, 32); 1463 } 1464 1465 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1466 // calculate DHKEY 1467 sm_key256_t dhkey; 1468 sm_sc_calculate_dhkey(dhkey); 1469 1470 // calculate salt for f5 1471 const uint16_t message_len = 32; 1472 sm_cmac_connection = sm_conn; 1473 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1474 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1475 } 1476 1477 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){ 1478 const uint16_t message_len = 53; 1479 sm_cmac_connection = sm_conn; 1480 1481 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1482 sm_cmac_sc_buffer[0] = 0; 1483 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1484 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1485 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1486 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1487 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1488 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1489 log_info("f5 key"); 1490 log_info_hexdump(t, 16); 1491 log_info("f5 message for MacKey"); 1492 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1493 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1494 } 1495 1496 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1497 sm_key56_t bd_addr_master, bd_addr_slave; 1498 bd_addr_master[0] = setup->sm_m_addr_type; 1499 bd_addr_slave[0] = setup->sm_s_addr_type; 1500 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1501 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1502 if (sm_conn->sm_role){ 1503 // responder 1504 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1505 } else { 1506 // initiator 1507 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1508 } 1509 } 1510 1511 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1512 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1513 const uint16_t message_len = 53; 1514 sm_cmac_connection = sm_conn; 1515 sm_cmac_sc_buffer[0] = 1; 1516 // 1..52 setup before 1517 log_info("f5 key"); 1518 log_info_hexdump(t, 16); 1519 log_info("f5 message for LTK"); 1520 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1521 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1522 } 1523 1524 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1525 f5_ltk(sm_conn, setup->sm_t); 1526 } 1527 1528 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){ 1529 const uint16_t message_len = 65; 1530 sm_cmac_connection = sm_conn; 1531 memcpy(sm_cmac_sc_buffer, n1, 16); 1532 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1533 memcpy(sm_cmac_sc_buffer+32, r, 16); 1534 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1535 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1536 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1537 log_info("f6 key"); 1538 log_info_hexdump(w, 16); 1539 log_info("f6 message"); 1540 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1541 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1542 } 1543 1544 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1545 // - U is 256 bits 1546 // - V is 256 bits 1547 // - X is 128 bits 1548 // - Y is 128 bits 1549 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){ 1550 const uint16_t message_len = 80; 1551 sm_cmac_connection = sm_conn; 1552 memcpy(sm_cmac_sc_buffer, u, 32); 1553 memcpy(sm_cmac_sc_buffer+32, v, 32); 1554 memcpy(sm_cmac_sc_buffer+64, y, 16); 1555 log_info("g2 key"); 1556 log_info_hexdump(x, 16); 1557 log_info("g2 message"); 1558 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1559 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1560 } 1561 1562 static void g2_calculate_engine(sm_connection_t * sm_conn) { 1563 // calc Va if numeric comparison 1564 uint8_t value[32]; 1565 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1566 if (sm_conn->sm_role){ 1567 // responder 1568 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1569 } else { 1570 // initiator 1571 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1572 } 1573 } 1574 1575 static void sm_sc_generate_local_nonce(sm_connection_t * sm_conn){ 1576 // TODO: use random generator to generate nonce 1577 log_info("SM: generate local nonce"); 1578 // generate 128-bit nonce 1579 int i; 1580 for (i=0;i<16;i++){ 1581 setup->sm_local_nonce[i] = rand() & 0xff; 1582 } 1583 } 1584 1585 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1586 uint8_t z = 0; 1587 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1588 // some form of passkey 1589 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1590 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1591 setup->sm_passkey_bit++; 1592 } 1593 #ifdef USE_MBEDTLS_FOR_ECDH 1594 uint8_t local_qx[32]; 1595 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1596 #endif 1597 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1598 } 1599 1600 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1601 uint8_t z = 0; 1602 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1603 // some form of passkey 1604 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1605 // sm_passkey_bit was increased before sending confirm value 1606 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1607 } 1608 #ifdef USE_MBEDTLS_FOR_ECDH 1609 uint8_t local_qx[32]; 1610 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1611 #endif 1612 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1613 } 1614 1615 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1616 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1617 } 1618 1619 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1620 // calculate DHKCheck 1621 sm_key56_t bd_addr_master, bd_addr_slave; 1622 bd_addr_master[0] = setup->sm_m_addr_type; 1623 bd_addr_slave[0] = setup->sm_s_addr_type; 1624 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1625 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1626 uint8_t iocap_a[3]; 1627 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1628 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1629 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1630 uint8_t iocap_b[3]; 1631 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1632 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1633 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1634 if (sm_conn->sm_role){ 1635 // responder 1636 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); 1637 } else { 1638 // initiator 1639 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); 1640 } 1641 } 1642 1643 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1644 // validate E = f6() 1645 sm_key56_t bd_addr_master, bd_addr_slave; 1646 bd_addr_master[0] = setup->sm_m_addr_type; 1647 bd_addr_slave[0] = setup->sm_s_addr_type; 1648 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1649 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1650 1651 uint8_t iocap_a[3]; 1652 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1653 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1654 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1655 uint8_t iocap_b[3]; 1656 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1657 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1658 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1659 if (sm_conn->sm_role){ 1660 // responder 1661 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); 1662 } else { 1663 // initiator 1664 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); 1665 } 1666 } 1667 #endif 1668 1669 1670 static void sm_run(void){ 1671 1672 btstack_linked_list_iterator_t it; 1673 1674 // assert that we can send at least commands 1675 if (!hci_can_send_command_packet_now()) return; 1676 1677 // 1678 // non-connection related behaviour 1679 // 1680 1681 // distributed key generation 1682 switch (dkg_state){ 1683 case DKG_CALC_IRK: 1684 // already busy? 1685 if (sm_aes128_state == SM_AES128_IDLE) { 1686 // IRK = d1(IR, 1, 0) 1687 sm_key_t d1_prime; 1688 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1689 dkg_next_state(); 1690 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1691 return; 1692 } 1693 break; 1694 case DKG_CALC_DHK: 1695 // already busy? 1696 if (sm_aes128_state == SM_AES128_IDLE) { 1697 // DHK = d1(IR, 3, 0) 1698 sm_key_t d1_prime; 1699 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1700 dkg_next_state(); 1701 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1702 return; 1703 } 1704 break; 1705 default: 1706 break; 1707 } 1708 1709 #ifdef USE_MBEDTLS_FOR_ECDH 1710 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1711 sm_random_start(NULL); 1712 return; 1713 } 1714 #endif 1715 1716 // random address updates 1717 switch (rau_state){ 1718 case RAU_GET_RANDOM: 1719 rau_next_state(); 1720 sm_random_start(NULL); 1721 return; 1722 case RAU_GET_ENC: 1723 // already busy? 1724 if (sm_aes128_state == SM_AES128_IDLE) { 1725 sm_key_t r_prime; 1726 sm_ah_r_prime(sm_random_address, r_prime); 1727 rau_next_state(); 1728 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1729 return; 1730 } 1731 break; 1732 case RAU_SET_ADDRESS: 1733 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1734 rau_state = RAU_IDLE; 1735 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1736 return; 1737 default: 1738 break; 1739 } 1740 1741 // CMAC 1742 switch (sm_cmac_state){ 1743 case CMAC_CALC_SUBKEYS: 1744 case CMAC_CALC_MI: 1745 case CMAC_CALC_MLAST: 1746 // already busy? 1747 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1748 sm_cmac_handle_aes_engine_ready(); 1749 return; 1750 default: 1751 break; 1752 } 1753 1754 // CSRK Lookup 1755 // -- if csrk lookup ready, find connection that require csrk lookup 1756 if (sm_address_resolution_idle()){ 1757 hci_connections_get_iterator(&it); 1758 while(btstack_linked_list_iterator_has_next(&it)){ 1759 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1760 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1761 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1762 // and start lookup 1763 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); 1764 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1765 break; 1766 } 1767 } 1768 } 1769 1770 // -- if csrk lookup ready, resolved addresses for received addresses 1771 if (sm_address_resolution_idle()) { 1772 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1773 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1774 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1775 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1776 btstack_memory_sm_lookup_entry_free(entry); 1777 } 1778 } 1779 1780 // -- Continue with CSRK device lookup by public or resolvable private address 1781 if (!sm_address_resolution_idle()){ 1782 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1783 while (sm_address_resolution_test < le_device_db_count()){ 1784 int addr_type; 1785 bd_addr_t addr; 1786 sm_key_t irk; 1787 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1788 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1789 1790 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1791 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1792 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1793 break; 1794 } 1795 1796 if (sm_address_resolution_addr_type == 0){ 1797 sm_address_resolution_test++; 1798 continue; 1799 } 1800 1801 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1802 1803 log_info("LE Device Lookup: calculate AH"); 1804 log_info_key("IRK", irk); 1805 1806 sm_key_t r_prime; 1807 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1808 sm_address_resolution_ah_calculation_active = 1; 1809 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1810 return; 1811 } 1812 1813 if (sm_address_resolution_test >= le_device_db_count()){ 1814 log_info("LE Device Lookup: not found"); 1815 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1816 } 1817 } 1818 1819 1820 // 1821 // active connection handling 1822 // -- use loop to handle next connection if lock on setup context is released 1823 1824 while (1) { 1825 1826 // Find connections that requires setup context and make active if no other is locked 1827 hci_connections_get_iterator(&it); 1828 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1829 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1830 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1831 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1832 int done = 1; 1833 int err; 1834 int encryption_key_size; 1835 int authenticated; 1836 int authorized; 1837 switch (sm_connection->sm_engine_state) { 1838 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1839 // send packet if possible, 1840 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1841 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1842 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1843 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1844 } else { 1845 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1846 } 1847 // don't lock setup context yet 1848 done = 0; 1849 break; 1850 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1851 sm_init_setup(sm_connection); 1852 // recover pairing request 1853 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1854 err = sm_stk_generation_init(sm_connection); 1855 if (err){ 1856 setup->sm_pairing_failed_reason = err; 1857 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1858 break; 1859 } 1860 sm_timeout_start(sm_connection); 1861 // generate random number first, if we need to show passkey 1862 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1863 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1864 break; 1865 } 1866 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1867 break; 1868 case SM_INITIATOR_PH0_HAS_LTK: 1869 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1870 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1871 &encryption_key_size, &authenticated, &authorized); 1872 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1873 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1874 sm_connection->sm_connection_authenticated = authenticated; 1875 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1876 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1877 break; 1878 case SM_RESPONDER_PH0_RECEIVED_LTK: 1879 // re-establish previously used LTK using Rand and EDIV 1880 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1881 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1882 // re-establish used key encryption size 1883 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1884 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1885 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1886 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1887 log_info("sm: received ltk request with key size %u, authenticated %u", 1888 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1889 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1890 break; 1891 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1892 sm_init_setup(sm_connection); 1893 sm_timeout_start(sm_connection); 1894 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1895 break; 1896 default: 1897 done = 0; 1898 break; 1899 } 1900 if (done){ 1901 sm_active_connection = sm_connection->sm_handle; 1902 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1903 } 1904 } 1905 1906 // 1907 // active connection handling 1908 // 1909 1910 if (sm_active_connection == 0) return; 1911 1912 // assert that we could send a SM PDU - not needed for all of the following 1913 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1914 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1915 return; 1916 } 1917 1918 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1919 if (!connection) return; 1920 1921 sm_key_t plaintext; 1922 int key_distribution_flags; 1923 1924 log_info("sm_run: state %u", connection->sm_engine_state); 1925 1926 // responding state 1927 switch (connection->sm_engine_state){ 1928 1929 // general 1930 case SM_GENERAL_SEND_PAIRING_FAILED: { 1931 uint8_t buffer[2]; 1932 buffer[0] = SM_CODE_PAIRING_FAILED; 1933 buffer[1] = setup->sm_pairing_failed_reason; 1934 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1935 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1936 sm_done_for_handle(connection->sm_handle); 1937 break; 1938 } 1939 1940 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1941 case SM_SC_W2_GET_RANDOM_A: 1942 sm_random_start(connection); 1943 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1944 break; 1945 1946 case SM_SC_W2_GET_RANDOM_B: 1947 sm_random_start(connection); 1948 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1949 break; 1950 1951 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1952 if (!sm_cmac_ready()) break; 1953 1954 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1955 sm_sc_generate_local_nonce(connection); 1956 } 1957 1958 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1959 sm_sc_calculate_local_confirm(connection); 1960 break; 1961 1962 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1963 if (!sm_cmac_ready()) break; 1964 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1965 sm_sc_calculate_remote_confirm(connection); 1966 break; 1967 1968 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1969 if (!sm_cmac_ready()) break; 1970 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1971 sm_sc_calculate_f6_for_dhkey_check(connection); 1972 break; 1973 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1974 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1975 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1976 break; 1977 case SM_SC_W2_CALCULATE_F5_SALT: 1978 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1979 f5_calculate_salt(connection); 1980 break; 1981 case SM_SC_W2_CALCULATE_F5_MACKEY: 1982 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 1983 f5_calculate_mackey(connection); 1984 break; 1985 case SM_SC_W2_CALCULATE_F5_LTK: 1986 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 1987 f5_calculate_ltk(connection); 1988 break; 1989 case SM_SC_W2_CALCULATE_G2: 1990 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 1991 g2_calculate_engine(connection); 1992 break; 1993 1994 #endif 1995 // initiator side 1996 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 1997 sm_key_t peer_ltk_flipped; 1998 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 1999 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2000 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2001 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2002 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2003 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2004 return; 2005 } 2006 2007 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2008 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2009 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2010 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2011 sm_timeout_reset(connection); 2012 break; 2013 2014 // responder side 2015 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2016 connection->sm_engine_state = SM_RESPONDER_IDLE; 2017 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2018 return; 2019 2020 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2021 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2022 uint8_t buffer[65]; 2023 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2024 // 2025 #ifdef USE_MBEDTLS_FOR_ECDH 2026 uint8_t value[32]; 2027 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2028 reverse_256(value, &buffer[1]); 2029 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2030 reverse_256(value, &buffer[33]); 2031 #endif 2032 2033 // stk generation method 2034 // passkey entry: notify app to show passkey or to request passkey 2035 switch (setup->sm_stk_generation_method){ 2036 case JUST_WORKS: 2037 case NK_BOTH_INPUT: 2038 if (connection->sm_role){ 2039 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2040 } else { 2041 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2042 } 2043 break; 2044 case PK_INIT_INPUT: 2045 case PK_RESP_INPUT: 2046 case OK_BOTH_INPUT: 2047 // hack for testing: assume user entered '000000' 2048 // memset(setup->sm_tk, 0, 16); 2049 memcpy(setup->sm_ra, setup->sm_tk, 16); 2050 memcpy(setup->sm_rb, setup->sm_tk, 16); 2051 setup->sm_passkey_bit = 0; 2052 if (connection->sm_role){ 2053 // responder 2054 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2055 } else { 2056 // initiator 2057 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2058 } 2059 sm_trigger_user_response(connection); 2060 break; 2061 case OOB: 2062 // TODO: implement SC OOB 2063 break; 2064 } 2065 2066 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2067 sm_timeout_reset(connection); 2068 break; 2069 } 2070 case SM_SC_SEND_CONFIRMATION: { 2071 uint8_t buffer[17]; 2072 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2073 reverse_128(setup->sm_local_confirm, &buffer[1]); 2074 if (connection->sm_role){ 2075 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2076 } else { 2077 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2078 } 2079 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2080 sm_timeout_reset(connection); 2081 break; 2082 } 2083 case SM_SC_SEND_PAIRING_RANDOM: { 2084 uint8_t buffer[17]; 2085 buffer[0] = SM_CODE_PAIRING_RANDOM; 2086 reverse_128(setup->sm_local_nonce, &buffer[1]); 2087 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2088 if (connection->sm_role){ 2089 // responder 2090 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2091 } else { 2092 // initiator 2093 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2094 } 2095 } else { 2096 if (connection->sm_role){ 2097 // responder 2098 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2099 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2100 } else { 2101 sm_sc_prepare_dhkey_check(connection); 2102 } 2103 } else { 2104 // initiator 2105 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2106 } 2107 } 2108 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2109 sm_timeout_reset(connection); 2110 break; 2111 } 2112 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2113 uint8_t buffer[17]; 2114 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2115 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2116 2117 if (connection->sm_role){ 2118 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2119 } else { 2120 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2121 } 2122 2123 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2124 sm_timeout_reset(connection); 2125 break; 2126 } 2127 2128 #endif 2129 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2130 // echo initiator for now 2131 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2132 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2133 2134 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2135 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2136 if (setup->sm_use_secure_connections){ 2137 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2138 // skip LTK/EDIV for SC 2139 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2140 } 2141 #endif 2142 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); 2143 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); 2144 2145 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2146 sm_timeout_reset(connection); 2147 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2148 if (setup->sm_stk_generation_method == JUST_WORKS){ 2149 sm_trigger_user_response(connection); 2150 } 2151 return; 2152 2153 case SM_PH2_SEND_PAIRING_RANDOM: { 2154 uint8_t buffer[17]; 2155 buffer[0] = SM_CODE_PAIRING_RANDOM; 2156 reverse_128(setup->sm_local_random, &buffer[1]); 2157 if (connection->sm_role){ 2158 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2159 } else { 2160 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2161 } 2162 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2163 sm_timeout_reset(connection); 2164 break; 2165 } 2166 2167 case SM_PH2_GET_RANDOM_TK: 2168 case SM_PH2_C1_GET_RANDOM_A: 2169 case SM_PH2_C1_GET_RANDOM_B: 2170 case SM_PH3_GET_RANDOM: 2171 case SM_PH3_GET_DIV: 2172 sm_next_responding_state(connection); 2173 sm_random_start(connection); 2174 return; 2175 2176 case SM_PH2_C1_GET_ENC_B: 2177 case SM_PH2_C1_GET_ENC_D: 2178 // already busy? 2179 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2180 sm_next_responding_state(connection); 2181 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2182 return; 2183 2184 case SM_PH3_LTK_GET_ENC: 2185 case SM_RESPONDER_PH4_LTK_GET_ENC: 2186 // already busy? 2187 if (sm_aes128_state == SM_AES128_IDLE) { 2188 sm_key_t d_prime; 2189 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2190 sm_next_responding_state(connection); 2191 sm_aes128_start(sm_persistent_er, d_prime, connection); 2192 return; 2193 } 2194 break; 2195 2196 case SM_PH3_CSRK_GET_ENC: 2197 // already busy? 2198 if (sm_aes128_state == SM_AES128_IDLE) { 2199 sm_key_t d_prime; 2200 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2201 sm_next_responding_state(connection); 2202 sm_aes128_start(sm_persistent_er, d_prime, connection); 2203 return; 2204 } 2205 break; 2206 2207 case SM_PH2_C1_GET_ENC_C: 2208 // already busy? 2209 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2210 // calculate m_confirm using aes128 engine - step 1 2211 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); 2212 sm_next_responding_state(connection); 2213 sm_aes128_start(setup->sm_tk, plaintext, connection); 2214 break; 2215 case SM_PH2_C1_GET_ENC_A: 2216 // already busy? 2217 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2218 // calculate confirm using aes128 engine - step 1 2219 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); 2220 sm_next_responding_state(connection); 2221 sm_aes128_start(setup->sm_tk, plaintext, connection); 2222 break; 2223 case SM_PH2_CALC_STK: 2224 // already busy? 2225 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2226 // calculate STK 2227 if (connection->sm_role){ 2228 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2229 } else { 2230 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2231 } 2232 sm_next_responding_state(connection); 2233 sm_aes128_start(setup->sm_tk, plaintext, connection); 2234 break; 2235 case SM_PH3_Y_GET_ENC: 2236 // already busy? 2237 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2238 // PH3B2 - calculate Y from - enc 2239 // Y = dm(DHK, Rand) 2240 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2241 sm_next_responding_state(connection); 2242 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2243 return; 2244 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2245 uint8_t buffer[17]; 2246 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2247 reverse_128(setup->sm_local_confirm, &buffer[1]); 2248 if (connection->sm_role){ 2249 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2250 } else { 2251 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2252 } 2253 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2254 sm_timeout_reset(connection); 2255 return; 2256 } 2257 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2258 sm_key_t stk_flipped; 2259 reverse_128(setup->sm_ltk, stk_flipped); 2260 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2261 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2262 return; 2263 } 2264 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2265 sm_key_t stk_flipped; 2266 reverse_128(setup->sm_ltk, stk_flipped); 2267 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2268 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2269 return; 2270 } 2271 case SM_RESPONDER_PH4_SEND_LTK: { 2272 sm_key_t ltk_flipped; 2273 reverse_128(setup->sm_ltk, ltk_flipped); 2274 connection->sm_engine_state = SM_RESPONDER_IDLE; 2275 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2276 return; 2277 } 2278 case SM_RESPONDER_PH4_Y_GET_ENC: 2279 // already busy? 2280 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2281 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2282 // Y = dm(DHK, Rand) 2283 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2284 sm_next_responding_state(connection); 2285 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2286 return; 2287 2288 case SM_PH3_DISTRIBUTE_KEYS: 2289 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2290 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2291 uint8_t buffer[17]; 2292 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2293 reverse_128(setup->sm_ltk, &buffer[1]); 2294 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2295 sm_timeout_reset(connection); 2296 return; 2297 } 2298 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2299 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2300 uint8_t buffer[11]; 2301 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2302 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2303 reverse_64(setup->sm_local_rand, &buffer[3]); 2304 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2305 sm_timeout_reset(connection); 2306 return; 2307 } 2308 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2309 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2310 uint8_t buffer[17]; 2311 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2312 reverse_128(sm_persistent_irk, &buffer[1]); 2313 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2314 sm_timeout_reset(connection); 2315 return; 2316 } 2317 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2318 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2319 bd_addr_t local_address; 2320 uint8_t buffer[8]; 2321 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2322 gap_advertisements_get_address(&buffer[1], local_address); 2323 reverse_bd_addr(local_address, &buffer[2]); 2324 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2325 sm_timeout_reset(connection); 2326 return; 2327 } 2328 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2329 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2330 2331 // hack to reproduce test runs 2332 if (test_use_fixed_local_csrk){ 2333 memset(setup->sm_local_csrk, 0xcc, 16); 2334 } 2335 2336 uint8_t buffer[17]; 2337 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2338 reverse_128(setup->sm_local_csrk, &buffer[1]); 2339 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2340 sm_timeout_reset(connection); 2341 return; 2342 } 2343 2344 // keys are sent 2345 if (connection->sm_role){ 2346 // slave -> receive master keys if any 2347 if (sm_key_distribution_all_received(connection)){ 2348 sm_key_distribution_handle_all_received(connection); 2349 connection->sm_engine_state = SM_RESPONDER_IDLE; 2350 sm_done_for_handle(connection->sm_handle); 2351 } else { 2352 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2353 } 2354 } else { 2355 // master -> all done 2356 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2357 sm_done_for_handle(connection->sm_handle); 2358 } 2359 break; 2360 2361 default: 2362 break; 2363 } 2364 2365 // check again if active connection was released 2366 if (sm_active_connection) break; 2367 } 2368 } 2369 2370 // note: aes engine is ready as we just got the aes result 2371 static void sm_handle_encryption_result(uint8_t * data){ 2372 2373 sm_aes128_state = SM_AES128_IDLE; 2374 2375 if (sm_address_resolution_ah_calculation_active){ 2376 sm_address_resolution_ah_calculation_active = 0; 2377 // compare calulated address against connecting device 2378 uint8_t hash[3]; 2379 reverse_24(data, hash); 2380 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2381 log_info("LE Device Lookup: matched resolvable private address"); 2382 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2383 return; 2384 } 2385 // no match, try next 2386 sm_address_resolution_test++; 2387 return; 2388 } 2389 2390 switch (dkg_state){ 2391 case DKG_W4_IRK: 2392 reverse_128(data, sm_persistent_irk); 2393 log_info_key("irk", sm_persistent_irk); 2394 dkg_next_state(); 2395 return; 2396 case DKG_W4_DHK: 2397 reverse_128(data, sm_persistent_dhk); 2398 log_info_key("dhk", sm_persistent_dhk); 2399 dkg_next_state(); 2400 // SM Init Finished 2401 return; 2402 default: 2403 break; 2404 } 2405 2406 switch (rau_state){ 2407 case RAU_W4_ENC: 2408 reverse_24(data, &sm_random_address[3]); 2409 rau_next_state(); 2410 return; 2411 default: 2412 break; 2413 } 2414 2415 switch (sm_cmac_state){ 2416 case CMAC_W4_SUBKEYS: 2417 case CMAC_W4_MI: 2418 case CMAC_W4_MLAST: 2419 { 2420 sm_key_t t; 2421 reverse_128(data, t); 2422 sm_cmac_handle_encryption_result(t); 2423 } 2424 return; 2425 default: 2426 break; 2427 } 2428 2429 // retrieve sm_connection provided to sm_aes128_start_encryption 2430 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2431 if (!connection) return; 2432 switch (connection->sm_engine_state){ 2433 case SM_PH2_C1_W4_ENC_A: 2434 case SM_PH2_C1_W4_ENC_C: 2435 { 2436 sm_key_t t2; 2437 reverse_128(data, t2); 2438 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2439 } 2440 sm_next_responding_state(connection); 2441 return; 2442 case SM_PH2_C1_W4_ENC_B: 2443 reverse_128(data, setup->sm_local_confirm); 2444 log_info_key("c1!", setup->sm_local_confirm); 2445 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2446 return; 2447 case SM_PH2_C1_W4_ENC_D: 2448 { 2449 sm_key_t peer_confirm_test; 2450 reverse_128(data, peer_confirm_test); 2451 log_info_key("c1!", peer_confirm_test); 2452 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2453 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2454 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2455 return; 2456 } 2457 if (connection->sm_role){ 2458 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2459 } else { 2460 connection->sm_engine_state = SM_PH2_CALC_STK; 2461 } 2462 } 2463 return; 2464 case SM_PH2_W4_STK: 2465 reverse_128(data, setup->sm_ltk); 2466 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2467 log_info_key("stk", setup->sm_ltk); 2468 if (connection->sm_role){ 2469 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2470 } else { 2471 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2472 } 2473 return; 2474 case SM_PH3_Y_W4_ENC:{ 2475 sm_key_t y128; 2476 reverse_128(data, y128); 2477 setup->sm_local_y = big_endian_read_16(y128, 14); 2478 log_info_hex16("y", setup->sm_local_y); 2479 // PH3B3 - calculate EDIV 2480 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2481 log_info_hex16("ediv", setup->sm_local_ediv); 2482 // PH3B4 - calculate LTK - enc 2483 // LTK = d1(ER, DIV, 0)) 2484 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2485 return; 2486 } 2487 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2488 sm_key_t y128; 2489 reverse_128(data, y128); 2490 setup->sm_local_y = big_endian_read_16(y128, 14); 2491 log_info_hex16("y", setup->sm_local_y); 2492 2493 // PH3B3 - calculate DIV 2494 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2495 log_info_hex16("ediv", setup->sm_local_ediv); 2496 // PH3B4 - calculate LTK - enc 2497 // LTK = d1(ER, DIV, 0)) 2498 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2499 return; 2500 } 2501 case SM_PH3_LTK_W4_ENC: 2502 reverse_128(data, setup->sm_ltk); 2503 log_info_key("ltk", setup->sm_ltk); 2504 // calc CSRK next 2505 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2506 return; 2507 case SM_PH3_CSRK_W4_ENC: 2508 reverse_128(data, setup->sm_local_csrk); 2509 log_info_key("csrk", setup->sm_local_csrk); 2510 if (setup->sm_key_distribution_send_set){ 2511 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2512 } else { 2513 // no keys to send, just continue 2514 if (connection->sm_role){ 2515 // slave -> receive master keys 2516 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2517 } else { 2518 // master -> all done 2519 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2520 sm_done_for_handle(connection->sm_handle); 2521 } 2522 } 2523 return; 2524 case SM_RESPONDER_PH4_LTK_W4_ENC: 2525 reverse_128(data, setup->sm_ltk); 2526 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2527 log_info_key("ltk", setup->sm_ltk); 2528 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2529 return; 2530 default: 2531 break; 2532 } 2533 } 2534 2535 #ifdef USE_MBEDTLS_FOR_ECDH 2536 2537 static void sm_log_ec_keypair(void){ 2538 // print keypair 2539 char buffer[100]; 2540 size_t len; 2541 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2542 log_info("d: %s", buffer); 2543 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2544 log_info("X: %s", buffer); 2545 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2546 log_info("Y: %s", buffer); 2547 } 2548 2549 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2550 int offset = setup->sm_passkey_bit; 2551 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2552 while (size) { 2553 if (offset < 32){ 2554 *buffer++ = setup->sm_peer_qx[offset++]; 2555 } else { 2556 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2557 } 2558 size--; 2559 } 2560 setup->sm_passkey_bit = offset; 2561 return 0; 2562 } 2563 #endif 2564 2565 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2566 static void sm_handle_random_result(uint8_t * data){ 2567 2568 #ifdef USE_MBEDTLS_FOR_ECDH 2569 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2570 int num_bytes = setup->sm_passkey_bit; 2571 if (num_bytes < 32){ 2572 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2573 } else { 2574 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2575 } 2576 num_bytes += 8; 2577 setup->sm_passkey_bit = num_bytes; 2578 2579 if (num_bytes >= 64){ 2580 // generate EC key 2581 setup->sm_passkey_bit = 0; 2582 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2583 sm_log_ec_keypair(); 2584 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2585 } 2586 } 2587 #endif 2588 2589 switch (rau_state){ 2590 case RAU_W4_RANDOM: 2591 // non-resolvable vs. resolvable 2592 switch (gap_random_adress_type){ 2593 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2594 // resolvable: use random as prand and calc address hash 2595 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2596 memcpy(sm_random_address, data, 3); 2597 sm_random_address[0] &= 0x3f; 2598 sm_random_address[0] |= 0x40; 2599 rau_state = RAU_GET_ENC; 2600 break; 2601 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2602 default: 2603 // "The two most significant bits of the address shall be equal to ‘0’"" 2604 memcpy(sm_random_address, data, 6); 2605 sm_random_address[0] &= 0x3f; 2606 rau_state = RAU_SET_ADDRESS; 2607 break; 2608 } 2609 return; 2610 default: 2611 break; 2612 } 2613 2614 // retrieve sm_connection provided to sm_random_start 2615 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2616 if (!connection) return; 2617 switch (connection->sm_engine_state){ 2618 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2619 case SM_SC_W4_GET_RANDOM_A: 2620 memcpy(&setup->sm_local_nonce[0], data, 8); 2621 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2622 break; 2623 case SM_SC_W4_GET_RANDOM_B: 2624 memcpy(&setup->sm_local_nonce[8], data, 8); 2625 // TODO: next state 2626 2627 // initiator & jw/nc -> send pairing random 2628 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2629 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2630 break; 2631 } 2632 log_error("SM_SC_W4_GET_RANDOM_B: next state not defined"); 2633 break; 2634 #endif 2635 2636 case SM_PH2_W4_RANDOM_TK: 2637 { 2638 // map random to 0-999999 without speding much cycles on a modulus operation 2639 uint32_t tk = little_endian_read_32(data,0); 2640 tk = tk & 0xfffff; // 1048575 2641 if (tk >= 999999){ 2642 tk = tk - 999999; 2643 } 2644 sm_reset_tk(); 2645 big_endian_store_32(setup->sm_tk, 12, tk); 2646 if (connection->sm_role){ 2647 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2648 } else { 2649 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2650 sm_trigger_user_response(connection); 2651 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2652 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2653 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2654 } 2655 } 2656 return; 2657 } 2658 case SM_PH2_C1_W4_RANDOM_A: 2659 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2660 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2661 return; 2662 case SM_PH2_C1_W4_RANDOM_B: 2663 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2664 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2665 return; 2666 case SM_PH3_W4_RANDOM: 2667 reverse_64(data, setup->sm_local_rand); 2668 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2669 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2670 // no db for authenticated flag hack: store flag in bit 4 of LSB 2671 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2672 connection->sm_engine_state = SM_PH3_GET_DIV; 2673 return; 2674 case SM_PH3_W4_DIV: 2675 // use 16 bit from random value as div 2676 setup->sm_local_div = big_endian_read_16(data, 0); 2677 log_info_hex16("div", setup->sm_local_div); 2678 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2679 return; 2680 default: 2681 break; 2682 } 2683 } 2684 2685 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2686 2687 sm_connection_t * sm_conn; 2688 hci_con_handle_t con_handle; 2689 2690 switch (packet_type) { 2691 2692 case HCI_EVENT_PACKET: 2693 switch (hci_event_packet_get_type(packet)) { 2694 2695 case BTSTACK_EVENT_STATE: 2696 // bt stack activated, get started 2697 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2698 log_info("HCI Working!"); 2699 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2700 rau_state = RAU_IDLE; 2701 #ifdef USE_MBEDTLS_FOR_ECDH 2702 if (!test_use_fixed_ec_keypair){ 2703 setup->sm_passkey_bit = 0; 2704 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2705 } 2706 #endif 2707 sm_run(); 2708 } 2709 break; 2710 2711 case HCI_EVENT_LE_META: 2712 switch (packet[2]) { 2713 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2714 2715 log_info("sm: connected"); 2716 2717 if (packet[3]) return; // connection failed 2718 2719 con_handle = little_endian_read_16(packet, 4); 2720 sm_conn = sm_get_connection_for_handle(con_handle); 2721 if (!sm_conn) break; 2722 2723 sm_conn->sm_handle = con_handle; 2724 sm_conn->sm_role = packet[6]; 2725 sm_conn->sm_peer_addr_type = packet[7]; 2726 reverse_bd_addr(&packet[8], 2727 sm_conn->sm_peer_address); 2728 2729 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2730 2731 // reset security properties 2732 sm_conn->sm_connection_encrypted = 0; 2733 sm_conn->sm_connection_authenticated = 0; 2734 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2735 sm_conn->sm_le_db_index = -1; 2736 2737 // prepare CSRK lookup (does not involve setup) 2738 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2739 2740 // just connected -> everything else happens in sm_run() 2741 if (sm_conn->sm_role){ 2742 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2743 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2744 if (sm_slave_request_security) { 2745 // request security if requested by app 2746 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2747 } else { 2748 // otherwise, wait for pairing request 2749 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2750 } 2751 } 2752 break; 2753 } else { 2754 // master 2755 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2756 } 2757 break; 2758 2759 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2760 con_handle = little_endian_read_16(packet, 3); 2761 sm_conn = sm_get_connection_for_handle(con_handle); 2762 if (!sm_conn) break; 2763 2764 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2765 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2766 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2767 break; 2768 } 2769 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2770 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2771 break; 2772 } 2773 2774 // assume that we don't have a LTK for ediv == 0 and random == null 2775 if (little_endian_read_16(packet, 13) == 0 && sm_is_null_random(&packet[5])){ 2776 log_info("LTK Request: ediv & random are empty"); 2777 sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 2778 break; 2779 } 2780 2781 // store rand and ediv 2782 reverse_64(&packet[5], sm_conn->sm_local_rand); 2783 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2784 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2785 break; 2786 2787 default: 2788 break; 2789 } 2790 break; 2791 2792 case HCI_EVENT_ENCRYPTION_CHANGE: 2793 con_handle = little_endian_read_16(packet, 3); 2794 sm_conn = sm_get_connection_for_handle(con_handle); 2795 if (!sm_conn) break; 2796 2797 sm_conn->sm_connection_encrypted = packet[5]; 2798 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2799 sm_conn->sm_actual_encryption_key_size); 2800 log_info("event handler, state %u", sm_conn->sm_engine_state); 2801 if (!sm_conn->sm_connection_encrypted) break; 2802 // continue if part of initial pairing 2803 switch (sm_conn->sm_engine_state){ 2804 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2805 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2806 sm_done_for_handle(sm_conn->sm_handle); 2807 break; 2808 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2809 if (sm_conn->sm_role){ 2810 // slave 2811 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2812 } else { 2813 // master 2814 if (sm_key_distribution_all_received(sm_conn)){ 2815 // skip receiving keys as there are none 2816 sm_key_distribution_handle_all_received(sm_conn); 2817 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2818 } else { 2819 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2820 } 2821 } 2822 break; 2823 default: 2824 break; 2825 } 2826 break; 2827 2828 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2829 con_handle = little_endian_read_16(packet, 3); 2830 sm_conn = sm_get_connection_for_handle(con_handle); 2831 if (!sm_conn) break; 2832 2833 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2834 log_info("event handler, state %u", sm_conn->sm_engine_state); 2835 // continue if part of initial pairing 2836 switch (sm_conn->sm_engine_state){ 2837 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2838 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2839 sm_done_for_handle(sm_conn->sm_handle); 2840 break; 2841 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2842 if (sm_conn->sm_role){ 2843 // slave 2844 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2845 } else { 2846 // master 2847 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2848 } 2849 break; 2850 default: 2851 break; 2852 } 2853 break; 2854 2855 2856 case HCI_EVENT_DISCONNECTION_COMPLETE: 2857 con_handle = little_endian_read_16(packet, 3); 2858 sm_done_for_handle(con_handle); 2859 sm_conn = sm_get_connection_for_handle(con_handle); 2860 if (!sm_conn) break; 2861 2862 // delete stored bonding on disconnect with authentication failure in ph0 2863 if (sm_conn->sm_role == 0 2864 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2865 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2866 le_device_db_remove(sm_conn->sm_le_db_index); 2867 } 2868 2869 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2870 sm_conn->sm_handle = 0; 2871 break; 2872 2873 case HCI_EVENT_COMMAND_COMPLETE: 2874 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2875 sm_handle_encryption_result(&packet[6]); 2876 break; 2877 } 2878 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2879 sm_handle_random_result(&packet[6]); 2880 break; 2881 } 2882 break; 2883 default: 2884 break; 2885 } 2886 break; 2887 default: 2888 break; 2889 } 2890 2891 sm_run(); 2892 } 2893 2894 static inline int sm_calc_actual_encryption_key_size(int other){ 2895 if (other < sm_min_encryption_key_size) return 0; 2896 if (other < sm_max_encryption_key_size) return other; 2897 return sm_max_encryption_key_size; 2898 } 2899 2900 2901 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2902 switch (method){ 2903 case JUST_WORKS: 2904 case NK_BOTH_INPUT: 2905 return 1; 2906 default: 2907 return 0; 2908 } 2909 } 2910 2911 static int sm_passkey_used(stk_generation_method_t method){ 2912 switch (method){ 2913 case PK_RESP_INPUT: 2914 case PK_INIT_INPUT: 2915 case OK_BOTH_INPUT: 2916 return 1; 2917 default: 2918 return 0; 2919 } 2920 } 2921 2922 /** 2923 * @return ok 2924 */ 2925 static int sm_validate_stk_generation_method(void){ 2926 // check if STK generation method is acceptable by client 2927 switch (setup->sm_stk_generation_method){ 2928 case JUST_WORKS: 2929 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2930 case PK_RESP_INPUT: 2931 case PK_INIT_INPUT: 2932 case OK_BOTH_INPUT: 2933 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2934 case OOB: 2935 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2936 case NK_BOTH_INPUT: 2937 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2938 return 1; 2939 default: 2940 return 0; 2941 } 2942 } 2943 2944 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2945 2946 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2947 sm_run(); 2948 } 2949 2950 if (packet_type != SM_DATA_PACKET) return; 2951 2952 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2953 if (!sm_conn) return; 2954 2955 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2956 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2957 return; 2958 } 2959 2960 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2961 2962 int err; 2963 2964 switch (sm_conn->sm_engine_state){ 2965 2966 // a sm timeout requries a new physical connection 2967 case SM_GENERAL_TIMEOUT: 2968 return; 2969 2970 // Initiator 2971 case SM_INITIATOR_CONNECTED: 2972 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2973 sm_pdu_received_in_wrong_state(sm_conn); 2974 break; 2975 } 2976 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2977 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2978 break; 2979 } 2980 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2981 uint16_t ediv; 2982 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 2983 if (ediv){ 2984 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2985 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2986 } else { 2987 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2988 } 2989 break; 2990 } 2991 // otherwise, store security request 2992 sm_conn->sm_security_request_received = 1; 2993 break; 2994 2995 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 2996 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 2997 sm_pdu_received_in_wrong_state(sm_conn); 2998 break; 2999 } 3000 // store pairing request 3001 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3002 err = sm_stk_generation_init(sm_conn); 3003 if (err){ 3004 setup->sm_pairing_failed_reason = err; 3005 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3006 break; 3007 } 3008 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3009 if (setup->sm_use_secure_connections){ 3010 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3011 if (setup->sm_stk_generation_method == JUST_WORKS){ 3012 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3013 sm_trigger_user_response(sm_conn); 3014 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3015 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3016 } 3017 } else { 3018 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3019 } 3020 break; 3021 } 3022 #endif 3023 // generate random number first, if we need to show passkey 3024 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3025 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3026 break; 3027 } 3028 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3029 sm_trigger_user_response(sm_conn); 3030 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3031 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3032 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3033 } 3034 break; 3035 3036 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3037 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3038 sm_pdu_received_in_wrong_state(sm_conn); 3039 break; 3040 } 3041 3042 // store s_confirm 3043 reverse_128(&packet[1], setup->sm_peer_confirm); 3044 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3045 break; 3046 3047 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3048 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3049 sm_pdu_received_in_wrong_state(sm_conn); 3050 break;; 3051 } 3052 3053 // received random value 3054 reverse_128(&packet[1], setup->sm_peer_random); 3055 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3056 break; 3057 3058 // Responder 3059 case SM_RESPONDER_IDLE: 3060 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3061 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3062 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3063 sm_pdu_received_in_wrong_state(sm_conn); 3064 break;; 3065 } 3066 3067 // store pairing request 3068 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3069 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3070 break; 3071 3072 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3073 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3074 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3075 sm_pdu_received_in_wrong_state(sm_conn); 3076 break; 3077 } 3078 3079 // store public key for DH Key calculation 3080 reverse_256(&packet[01], setup->sm_peer_qx); 3081 reverse_256(&packet[33], setup->sm_peer_qy); 3082 3083 #ifdef USE_MBEDTLS_FOR_ECDH 3084 // validate public key 3085 mbedtls_ecp_group grp; 3086 mbedtls_ecp_group_init( &grp ); 3087 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3088 3089 mbedtls_ecp_point Q; 3090 mbedtls_ecp_point_init( &Q ); 3091 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3092 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3093 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3094 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3095 if (err){ 3096 log_error("sm: peer public key invalid %x", err); 3097 // uses "unspecified reason", there is no "public key invalid" error code 3098 sm_pdu_received_in_wrong_state(sm_conn); 3099 break; 3100 } 3101 #endif 3102 if (sm_conn->sm_role){ 3103 // responder 3104 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3105 } else { 3106 // initiator 3107 // stk generation method 3108 // passkey entry: notify app to show passkey or to request passkey 3109 switch (setup->sm_stk_generation_method){ 3110 case JUST_WORKS: 3111 case NK_BOTH_INPUT: 3112 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3113 break; 3114 case PK_INIT_INPUT: 3115 case PK_RESP_INPUT: 3116 case OK_BOTH_INPUT: 3117 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3118 break; 3119 case OOB: 3120 // TODO: implement SC OOB 3121 break; 3122 } 3123 } 3124 break; 3125 3126 case SM_SC_W4_CONFIRMATION: 3127 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3128 sm_pdu_received_in_wrong_state(sm_conn); 3129 break; 3130 } 3131 // received confirm value 3132 reverse_128(&packet[1], setup->sm_peer_confirm); 3133 3134 if (sm_conn->sm_role){ 3135 // responder 3136 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 3137 } else { 3138 // initiator 3139 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3140 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3141 } else { 3142 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3143 } 3144 } 3145 break; 3146 3147 case SM_SC_W4_PAIRING_RANDOM: 3148 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3149 sm_pdu_received_in_wrong_state(sm_conn); 3150 break; 3151 } 3152 3153 // received random value 3154 reverse_128(&packet[1], setup->sm_peer_nonce); 3155 3156 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3157 // only check for JUST WORK/NC in initiator role AND passkey entry 3158 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3159 if (sm_conn->sm_role || passkey_entry) { 3160 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3161 } 3162 3163 sm_sc_state_after_receiving_random(sm_conn); 3164 break; 3165 3166 case SM_SC_W2_CALCULATE_G2: 3167 case SM_SC_W4_CALCULATE_G2: 3168 case SM_SC_W2_CALCULATE_F5_SALT: 3169 case SM_SC_W4_CALCULATE_F5_SALT: 3170 case SM_SC_W2_CALCULATE_F5_MACKEY: 3171 case SM_SC_W4_CALCULATE_F5_MACKEY: 3172 case SM_SC_W2_CALCULATE_F5_LTK: 3173 case SM_SC_W4_CALCULATE_F5_LTK: 3174 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3175 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3176 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3177 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3178 sm_pdu_received_in_wrong_state(sm_conn); 3179 break; 3180 } 3181 // store DHKey Check 3182 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3183 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3184 3185 // have we been only waiting for dhkey check command? 3186 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3187 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3188 } 3189 break; 3190 #endif 3191 3192 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3193 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3194 sm_pdu_received_in_wrong_state(sm_conn); 3195 break; 3196 } 3197 3198 // received confirm value 3199 reverse_128(&packet[1], setup->sm_peer_confirm); 3200 3201 // notify client to hide shown passkey 3202 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3203 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3204 } 3205 3206 // handle user cancel pairing? 3207 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3208 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3209 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3210 break; 3211 } 3212 3213 // wait for user action? 3214 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3215 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3216 break; 3217 } 3218 3219 // calculate and send local_confirm 3220 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3221 break; 3222 3223 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3224 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3225 sm_pdu_received_in_wrong_state(sm_conn); 3226 break;; 3227 } 3228 3229 // received random value 3230 reverse_128(&packet[1], setup->sm_peer_random); 3231 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3232 break; 3233 3234 case SM_PH3_RECEIVE_KEYS: 3235 switch(packet[0]){ 3236 case SM_CODE_ENCRYPTION_INFORMATION: 3237 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3238 reverse_128(&packet[1], setup->sm_peer_ltk); 3239 break; 3240 3241 case SM_CODE_MASTER_IDENTIFICATION: 3242 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3243 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3244 reverse_64(&packet[3], setup->sm_peer_rand); 3245 break; 3246 3247 case SM_CODE_IDENTITY_INFORMATION: 3248 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3249 reverse_128(&packet[1], setup->sm_peer_irk); 3250 break; 3251 3252 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3253 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3254 setup->sm_peer_addr_type = packet[1]; 3255 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3256 break; 3257 3258 case SM_CODE_SIGNING_INFORMATION: 3259 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3260 reverse_128(&packet[1], setup->sm_peer_csrk); 3261 break; 3262 default: 3263 // Unexpected PDU 3264 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3265 break; 3266 } 3267 // done with key distribution? 3268 if (sm_key_distribution_all_received(sm_conn)){ 3269 3270 sm_key_distribution_handle_all_received(sm_conn); 3271 3272 if (sm_conn->sm_role){ 3273 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3274 sm_done_for_handle(sm_conn->sm_handle); 3275 } else { 3276 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3277 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3278 if (setup->sm_use_secure_connections){ 3279 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3280 } 3281 #endif 3282 } 3283 } 3284 break; 3285 default: 3286 // Unexpected PDU 3287 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3288 break; 3289 } 3290 3291 // try to send preparared packet 3292 sm_run(); 3293 } 3294 3295 // Security Manager Client API 3296 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3297 sm_get_oob_data = get_oob_data_callback; 3298 } 3299 3300 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3301 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3302 } 3303 3304 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3305 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3306 } 3307 3308 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3309 sm_min_encryption_key_size = min_size; 3310 sm_max_encryption_key_size = max_size; 3311 } 3312 3313 void sm_set_authentication_requirements(uint8_t auth_req){ 3314 sm_auth_req = auth_req; 3315 } 3316 3317 void sm_set_io_capabilities(io_capability_t io_capability){ 3318 sm_io_capabilities = io_capability; 3319 } 3320 3321 void sm_set_request_security(int enable){ 3322 sm_slave_request_security = enable; 3323 } 3324 3325 void sm_set_er(sm_key_t er){ 3326 memcpy(sm_persistent_er, er, 16); 3327 } 3328 3329 void sm_set_ir(sm_key_t ir){ 3330 memcpy(sm_persistent_ir, ir, 16); 3331 } 3332 3333 // Testing support only 3334 void sm_test_set_irk(sm_key_t irk){ 3335 memcpy(sm_persistent_irk, irk, 16); 3336 sm_persistent_irk_ready = 1; 3337 } 3338 3339 void sm_test_use_fixed_local_csrk(void){ 3340 test_use_fixed_local_csrk = 1; 3341 } 3342 3343 void sm_init(void){ 3344 // set some (BTstack default) ER and IR 3345 int i; 3346 sm_key_t er; 3347 sm_key_t ir; 3348 for (i=0;i<16;i++){ 3349 er[i] = 0x30 + i; 3350 ir[i] = 0x90 + i; 3351 } 3352 sm_set_er(er); 3353 sm_set_ir(ir); 3354 // defaults 3355 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3356 | SM_STK_GENERATION_METHOD_OOB 3357 | SM_STK_GENERATION_METHOD_PASSKEY 3358 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3359 3360 sm_max_encryption_key_size = 16; 3361 sm_min_encryption_key_size = 7; 3362 3363 sm_cmac_state = CMAC_IDLE; 3364 dkg_state = DKG_W4_WORKING; 3365 rau_state = RAU_W4_WORKING; 3366 sm_aes128_state = SM_AES128_IDLE; 3367 sm_address_resolution_test = -1; // no private address to resolve yet 3368 sm_address_resolution_ah_calculation_active = 0; 3369 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3370 sm_address_resolution_general_queue = NULL; 3371 3372 gap_random_adress_update_period = 15 * 60 * 1000L; 3373 3374 sm_active_connection = 0; 3375 3376 test_use_fixed_local_csrk = 0; 3377 3378 // register for HCI Events from HCI 3379 hci_event_callback_registration.callback = &sm_event_packet_handler; 3380 hci_add_event_handler(&hci_event_callback_registration); 3381 3382 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3383 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3384 3385 #ifdef USE_MBEDTLS_FOR_ECDH 3386 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3387 #endif 3388 } 3389 3390 void sm_test_use_fixed_ec_keypair(void){ 3391 test_use_fixed_ec_keypair = 1; 3392 #ifdef USE_MBEDTLS_FOR_ECDH 3393 // use test keypair from spec 3394 mbedtls_ecp_keypair_init(&le_keypair); 3395 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3396 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3397 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3398 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3399 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3400 #endif 3401 } 3402 3403 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3404 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3405 if (!hci_con) return NULL; 3406 return &hci_con->sm_connection; 3407 } 3408 3409 // @returns 0 if not encrypted, 7-16 otherwise 3410 int sm_encryption_key_size(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; 3414 return sm_conn->sm_actual_encryption_key_size; 3415 } 3416 3417 int sm_authenticated(hci_con_handle_t con_handle){ 3418 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3419 if (!sm_conn) return 0; // wrong connection 3420 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3421 return sm_conn->sm_connection_authenticated; 3422 } 3423 3424 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3425 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3426 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3427 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3428 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3429 return sm_conn->sm_connection_authorization_state; 3430 } 3431 3432 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3433 switch (sm_conn->sm_engine_state){ 3434 case SM_GENERAL_IDLE: 3435 case SM_RESPONDER_IDLE: 3436 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3437 sm_run(); 3438 break; 3439 default: 3440 break; 3441 } 3442 } 3443 3444 /** 3445 * @brief Trigger Security Request 3446 */ 3447 void sm_send_security_request(hci_con_handle_t con_handle){ 3448 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3449 if (!sm_conn) return; 3450 sm_send_security_request_for_connection(sm_conn); 3451 } 3452 3453 // request pairing 3454 void sm_request_pairing(hci_con_handle_t con_handle){ 3455 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3456 if (!sm_conn) return; // wrong connection 3457 3458 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3459 if (sm_conn->sm_role){ 3460 sm_send_security_request_for_connection(sm_conn); 3461 } else { 3462 // used as a trigger to start central/master/initiator security procedures 3463 uint16_t ediv; 3464 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3465 switch (sm_conn->sm_irk_lookup_state){ 3466 case IRK_LOOKUP_FAILED: 3467 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3468 break; 3469 case IRK_LOOKUP_SUCCEEDED: 3470 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3471 if (ediv){ 3472 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3473 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3474 } else { 3475 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3476 } 3477 break; 3478 default: 3479 sm_conn->sm_bonding_requested = 1; 3480 break; 3481 } 3482 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3483 sm_conn->sm_bonding_requested = 1; 3484 } 3485 } 3486 sm_run(); 3487 } 3488 3489 // called by client app on authorization request 3490 void sm_authorization_decline(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_DECLINED; 3494 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3495 } 3496 3497 void sm_authorization_grant(hci_con_handle_t con_handle){ 3498 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3499 if (!sm_conn) return; // wrong connection 3500 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3501 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3502 } 3503 3504 // GAP Bonding API 3505 3506 void sm_bonding_decline(hci_con_handle_t con_handle){ 3507 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3508 if (!sm_conn) return; // wrong connection 3509 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3510 3511 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3512 switch (setup->sm_stk_generation_method){ 3513 case PK_RESP_INPUT: 3514 case PK_INIT_INPUT: 3515 case OK_BOTH_INPUT: 3516 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3517 break; 3518 case NK_BOTH_INPUT: 3519 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3520 break; 3521 case JUST_WORKS: 3522 case OOB: 3523 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3524 break; 3525 } 3526 } 3527 sm_run(); 3528 } 3529 3530 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3531 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3532 if (!sm_conn) return; // wrong connection 3533 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3534 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3535 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3536 3537 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3538 if (setup->sm_use_secure_connections){ 3539 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3540 } 3541 #endif 3542 } 3543 3544 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3545 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3546 sm_sc_prepare_dhkey_check(sm_conn); 3547 } 3548 #endif 3549 3550 sm_run(); 3551 } 3552 3553 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3554 // for now, it's the same 3555 sm_just_works_confirm(con_handle); 3556 } 3557 3558 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3559 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3560 if (!sm_conn) return; // wrong connection 3561 sm_reset_tk(); 3562 big_endian_store_32(setup->sm_tk, 12, passkey); 3563 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3564 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3565 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3566 } 3567 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3568 // if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3569 // sm_sc_prepare_dhkey_check(sm_conn); 3570 // } 3571 #endif 3572 sm_run(); 3573 } 3574 3575 /** 3576 * @brief Identify device in LE Device DB 3577 * @param handle 3578 * @returns index from le_device_db or -1 if not found/identified 3579 */ 3580 int sm_le_device_index(hci_con_handle_t con_handle ){ 3581 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3582 if (!sm_conn) return -1; 3583 return sm_conn->sm_le_db_index; 3584 } 3585 3586 // GAP LE API 3587 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3588 gap_random_address_update_stop(); 3589 gap_random_adress_type = random_address_type; 3590 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3591 gap_random_address_update_start(); 3592 gap_random_address_trigger(); 3593 } 3594 3595 gap_random_address_type_t gap_random_address_get_mode(void){ 3596 return gap_random_adress_type; 3597 } 3598 3599 void gap_random_address_set_update_period(int period_ms){ 3600 gap_random_adress_update_period = period_ms; 3601 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3602 gap_random_address_update_stop(); 3603 gap_random_address_update_start(); 3604 } 3605 3606 void gap_random_address_set(bd_addr_t addr){ 3607 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3608 memcpy(sm_random_address, addr, 6); 3609 rau_state = RAU_SET_ADDRESS; 3610 sm_run(); 3611 } 3612 3613 /* 3614 * @brief Set Advertisement Paramters 3615 * @param adv_int_min 3616 * @param adv_int_max 3617 * @param adv_type 3618 * @param direct_address_type 3619 * @param direct_address 3620 * @param channel_map 3621 * @param filter_policy 3622 * 3623 * @note own_address_type is used from gap_random_address_set_mode 3624 */ 3625 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3626 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3627 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3628 direct_address_typ, direct_address, channel_map, filter_policy); 3629 } 3630 3631