1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 // TODO: remove software AES 55 #include "rijndael.h" 56 #endif 57 58 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(HAVE_HCI_CONTROLLER_DHKEY_SUPPORT) 59 #define USE_MBEDTLS_FOR_ECDH 60 #endif 61 62 #ifdef ENABLE_LE_SECURE_CONNECTIONS 63 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 64 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 65 #else 66 #define USE_MBEDTLS_FOR_ECDH 67 #endif 68 #endif 69 70 71 // Software ECDH implementation provided by mbedtls 72 #ifdef USE_MBEDTLS_FOR_ECDH 73 #if !defined(MBEDTLS_CONFIG_FILE) 74 #include "mbedtls/config.h" 75 #else 76 #include MBEDTLS_CONFIG_FILE 77 #endif 78 #if defined(MBEDTLS_PLATFORM_C) 79 #include "mbedtls/platform.h" 80 #else 81 #include <stdio.h> 82 #define mbedtls_printf printf 83 #endif 84 #include "mbedtls/ecp.h" 85 #endif 86 87 // 88 // SM internal types and globals 89 // 90 91 typedef enum { 92 DKG_W4_WORKING, 93 DKG_CALC_IRK, 94 DKG_W4_IRK, 95 DKG_CALC_DHK, 96 DKG_W4_DHK, 97 DKG_READY 98 } derived_key_generation_t; 99 100 typedef enum { 101 RAU_W4_WORKING, 102 RAU_IDLE, 103 RAU_GET_RANDOM, 104 RAU_W4_RANDOM, 105 RAU_GET_ENC, 106 RAU_W4_ENC, 107 RAU_SET_ADDRESS, 108 } random_address_update_t; 109 110 typedef enum { 111 CMAC_IDLE, 112 CMAC_CALC_SUBKEYS, 113 CMAC_W4_SUBKEYS, 114 CMAC_CALC_MI, 115 CMAC_W4_MI, 116 CMAC_CALC_MLAST, 117 CMAC_W4_MLAST 118 } cmac_state_t; 119 120 typedef enum { 121 JUST_WORKS, 122 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 123 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 124 OK_BOTH_INPUT, // Only input on both, both input PK 125 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 126 OOB // OOB available on both sides 127 } stk_generation_method_t; 128 129 typedef enum { 130 SM_USER_RESPONSE_IDLE, 131 SM_USER_RESPONSE_PENDING, 132 SM_USER_RESPONSE_CONFIRM, 133 SM_USER_RESPONSE_PASSKEY, 134 SM_USER_RESPONSE_DECLINE 135 } sm_user_response_t; 136 137 typedef enum { 138 SM_AES128_IDLE, 139 SM_AES128_ACTIVE 140 } sm_aes128_state_t; 141 142 typedef enum { 143 ADDRESS_RESOLUTION_IDLE, 144 ADDRESS_RESOLUTION_GENERAL, 145 ADDRESS_RESOLUTION_FOR_CONNECTION, 146 } address_resolution_mode_t; 147 148 typedef enum { 149 ADDRESS_RESOLUTION_SUCEEDED, 150 ADDRESS_RESOLUTION_FAILED, 151 } address_resolution_event_t; 152 153 typedef enum { 154 EC_KEY_GENERATION_IDLE, 155 EC_KEY_GENERATION_ACTIVE, 156 EC_KEY_GENERATION_DONE, 157 } ec_key_generation_state_t; 158 159 typedef enum { 160 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 161 } sm_state_var_t; 162 163 // 164 // GLOBAL DATA 165 // 166 167 static uint8_t test_use_fixed_local_csrk; 168 static uint8_t test_use_fixed_ec_keypair; 169 170 // configuration 171 static uint8_t sm_accepted_stk_generation_methods; 172 static uint8_t sm_max_encryption_key_size; 173 static uint8_t sm_min_encryption_key_size; 174 static uint8_t sm_auth_req = 0; 175 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 176 static uint8_t sm_slave_request_security; 177 178 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 179 static sm_key_t sm_persistent_er; 180 static sm_key_t sm_persistent_ir; 181 182 // derived from sm_persistent_ir 183 static sm_key_t sm_persistent_dhk; 184 static sm_key_t sm_persistent_irk; 185 static uint8_t sm_persistent_irk_ready = 0; // used for testing 186 static derived_key_generation_t dkg_state; 187 188 // derived from sm_persistent_er 189 // .. 190 191 // random address update 192 static random_address_update_t rau_state; 193 static bd_addr_t sm_random_address; 194 195 // CMAC Calculation: General 196 static cmac_state_t sm_cmac_state; 197 static uint16_t sm_cmac_message_len; 198 static sm_key_t sm_cmac_k; 199 static sm_key_t sm_cmac_x; 200 static sm_key_t sm_cmac_m_last; 201 static uint8_t sm_cmac_block_current; 202 static uint8_t sm_cmac_block_count; 203 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 204 static void (*sm_cmac_done_handler)(uint8_t * hash); 205 206 // CMAC for ATT Signed Writes 207 static uint8_t sm_cmac_header[3]; 208 static const uint8_t * sm_cmac_message; 209 static uint8_t sm_cmac_sign_counter[4]; 210 211 // CMAC for Secure Connection functions 212 #ifdef ENABLE_LE_SECURE_CONNECTIONS 213 static sm_connection_t * sm_cmac_connection; 214 static uint8_t sm_cmac_sc_buffer[80]; 215 #endif 216 217 // resolvable private address lookup / CSRK calculation 218 static int sm_address_resolution_test; 219 static int sm_address_resolution_ah_calculation_active; 220 static uint8_t sm_address_resolution_addr_type; 221 static bd_addr_t sm_address_resolution_address; 222 static void * sm_address_resolution_context; 223 static address_resolution_mode_t sm_address_resolution_mode; 224 static btstack_linked_list_t sm_address_resolution_general_queue; 225 226 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 227 static sm_aes128_state_t sm_aes128_state; 228 static void * sm_aes128_context; 229 230 // random engine. store context (ususally sm_connection_t) 231 static void * sm_random_context; 232 233 // to receive hci events 234 static btstack_packet_callback_registration_t hci_event_callback_registration; 235 236 /* to dispatch sm event */ 237 static btstack_linked_list_t sm_event_handlers; 238 239 // Software ECDH implementation provided by mbedtls 240 #ifdef USE_MBEDTLS_FOR_ECDH 241 static mbedtls_ecp_keypair le_keypair; 242 static ec_key_generation_state_t ec_key_generation_state; 243 #endif 244 245 // 246 // Volume 3, Part H, Chapter 24 247 // "Security shall be initiated by the Security Manager in the device in the master role. 248 // The device in the slave role shall be the responding device." 249 // -> master := initiator, slave := responder 250 // 251 252 // data needed for security setup 253 typedef struct sm_setup_context { 254 255 btstack_timer_source_t sm_timeout; 256 257 // used in all phases 258 uint8_t sm_pairing_failed_reason; 259 260 // user response, (Phase 1 and/or 2) 261 uint8_t sm_user_response; 262 263 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 264 int sm_key_distribution_send_set; 265 int sm_key_distribution_received_set; 266 267 // Phase 2 (Pairing over SMP) 268 stk_generation_method_t sm_stk_generation_method; 269 sm_key_t sm_tk; 270 uint8_t sm_use_secure_connections; 271 272 sm_key_t sm_c1_t3_value; // c1 calculation 273 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 274 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 275 sm_key_t sm_local_random; 276 sm_key_t sm_local_confirm; 277 sm_key_t sm_peer_random; 278 sm_key_t sm_peer_confirm; 279 uint8_t sm_m_addr_type; // address and type can be removed 280 uint8_t sm_s_addr_type; // '' 281 bd_addr_t sm_m_address; // '' 282 bd_addr_t sm_s_address; // '' 283 sm_key_t sm_ltk; 284 285 #ifdef ENABLE_LE_SECURE_CONNECTIONS 286 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 287 uint8_t sm_peer_qy[32]; // '' 288 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 289 sm_key_t sm_local_nonce; // might be combined with sm_local_random 290 sm_key_t sm_peer_dhkey_check; 291 sm_key_t sm_local_dhkey_check; 292 sm_key_t sm_ra; 293 sm_key_t sm_rb; 294 sm_key_t sm_t; // used for f5 295 sm_key_t sm_mackey; 296 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 297 uint8_t sm_state_vars; 298 #endif 299 300 // Phase 3 301 302 // key distribution, we generate 303 uint16_t sm_local_y; 304 uint16_t sm_local_div; 305 uint16_t sm_local_ediv; 306 uint8_t sm_local_rand[8]; 307 sm_key_t sm_local_ltk; 308 sm_key_t sm_local_csrk; 309 sm_key_t sm_local_irk; 310 // sm_local_address/addr_type not needed 311 312 // key distribution, received from peer 313 uint16_t sm_peer_y; 314 uint16_t sm_peer_div; 315 uint16_t sm_peer_ediv; 316 uint8_t sm_peer_rand[8]; 317 sm_key_t sm_peer_ltk; 318 sm_key_t sm_peer_irk; 319 sm_key_t sm_peer_csrk; 320 uint8_t sm_peer_addr_type; 321 bd_addr_t sm_peer_address; 322 323 } sm_setup_context_t; 324 325 // 326 static sm_setup_context_t the_setup; 327 static sm_setup_context_t * setup = &the_setup; 328 329 // active connection - the one for which the_setup is used for 330 static uint16_t sm_active_connection = 0; 331 332 // @returns 1 if oob data is available 333 // stores oob data in provided 16 byte buffer if not null 334 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 335 336 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 337 static btstack_packet_handler_t sm_client_packet_handler = NULL; 338 339 // horizontal: initiator capabilities 340 // vertial: responder capabilities 341 static const stk_generation_method_t stk_generation_method [5] [5] = { 342 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 343 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 344 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 345 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 346 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 347 }; 348 349 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 350 #ifdef ENABLE_LE_SECURE_CONNECTIONS 351 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 352 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 353 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 354 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 355 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 356 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 357 }; 358 #endif 359 360 static void sm_run(void); 361 static void sm_done_for_handle(hci_con_handle_t con_handle); 362 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 363 static inline int sm_calc_actual_encryption_key_size(int other); 364 static int sm_validate_stk_generation_method(void); 365 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 366 367 static void log_info_hex16(const char * name, uint16_t value){ 368 log_info("%-6s 0x%04x", name, value); 369 } 370 371 // @returns 1 if all bytes are 0 372 static int sm_is_null_random(uint8_t random[8]){ 373 int i; 374 for (i=0; i < 8 ; i++){ 375 if (random[i]) return 0; 376 } 377 return 1; 378 } 379 380 // Key utils 381 static void sm_reset_tk(void){ 382 int i; 383 for (i=0;i<16;i++){ 384 setup->sm_tk[i] = 0; 385 } 386 } 387 388 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 389 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 390 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 391 int i; 392 for (i = max_encryption_size ; i < 16 ; i++){ 393 key[15-i] = 0; 394 } 395 } 396 397 // SMP Timeout implementation 398 399 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 400 // the Security Manager Timer shall be reset and started. 401 // 402 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 403 // 404 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 405 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 406 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 407 // established. 408 409 static void sm_timeout_handler(btstack_timer_source_t * timer){ 410 log_info("SM timeout"); 411 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 412 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 413 sm_done_for_handle(sm_conn->sm_handle); 414 415 // trigger handling of next ready connection 416 sm_run(); 417 } 418 static void sm_timeout_start(sm_connection_t * sm_conn){ 419 btstack_run_loop_remove_timer(&setup->sm_timeout); 420 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 421 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 422 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 423 btstack_run_loop_add_timer(&setup->sm_timeout); 424 } 425 static void sm_timeout_stop(void){ 426 btstack_run_loop_remove_timer(&setup->sm_timeout); 427 } 428 static void sm_timeout_reset(sm_connection_t * sm_conn){ 429 sm_timeout_stop(); 430 sm_timeout_start(sm_conn); 431 } 432 433 // end of sm timeout 434 435 // GAP Random Address updates 436 static gap_random_address_type_t gap_random_adress_type; 437 static btstack_timer_source_t gap_random_address_update_timer; 438 static uint32_t gap_random_adress_update_period; 439 440 static void gap_random_address_trigger(void){ 441 if (rau_state != RAU_IDLE) return; 442 log_info("gap_random_address_trigger"); 443 rau_state = RAU_GET_RANDOM; 444 sm_run(); 445 } 446 447 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 448 log_info("GAP Random Address Update due"); 449 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 450 btstack_run_loop_add_timer(&gap_random_address_update_timer); 451 gap_random_address_trigger(); 452 } 453 454 static void gap_random_address_update_start(void){ 455 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 456 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 457 btstack_run_loop_add_timer(&gap_random_address_update_timer); 458 } 459 460 static void gap_random_address_update_stop(void){ 461 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 462 } 463 464 465 static void sm_random_start(void * context){ 466 sm_random_context = context; 467 hci_send_cmd(&hci_le_rand); 468 } 469 470 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 471 // context is made availabe to aes128 result handler by this 472 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 473 sm_aes128_state = SM_AES128_ACTIVE; 474 sm_key_t key_flipped, plaintext_flipped; 475 reverse_128(key, key_flipped); 476 reverse_128(plaintext, plaintext_flipped); 477 sm_aes128_context = context; 478 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 479 } 480 481 // ah(k,r) helper 482 // r = padding || r 483 // r - 24 bit value 484 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 485 // r'= padding || r 486 memset(r_prime, 0, 16); 487 memcpy(&r_prime[13], r, 3); 488 } 489 490 // d1 helper 491 // d' = padding || r || d 492 // d,r - 16 bit values 493 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 494 // d'= padding || r || d 495 memset(d1_prime, 0, 16); 496 big_endian_store_16(d1_prime, 12, r); 497 big_endian_store_16(d1_prime, 14, d); 498 } 499 500 // dm helper 501 // r’ = padding || r 502 // r - 64 bit value 503 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 504 memset(r_prime, 0, 16); 505 memcpy(&r_prime[8], r, 8); 506 } 507 508 // calculate arguments for first AES128 operation in C1 function 509 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, sm_key_t t1){ 510 511 // p1 = pres || preq || rat’ || iat’ 512 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 513 // cant octet of pres becomes the most significant octet of p1. 514 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 515 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 516 // p1 is 0x05000800000302070710000001010001." 517 518 sm_key_t p1; 519 reverse_56(pres, &p1[0]); 520 reverse_56(preq, &p1[7]); 521 p1[14] = rat; 522 p1[15] = iat; 523 log_info_key("p1", p1); 524 log_info_key("r", r); 525 526 // t1 = r xor p1 527 int i; 528 for (i=0;i<16;i++){ 529 t1[i] = r[i] ^ p1[i]; 530 } 531 log_info_key("t1", t1); 532 } 533 534 // calculate arguments for second AES128 operation in C1 function 535 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 536 // p2 = padding || ia || ra 537 // "The least significant octet of ra becomes the least significant octet of p2 and 538 // the most significant octet of padding becomes the most significant octet of p2. 539 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 540 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 541 542 sm_key_t p2; 543 memset(p2, 0, 16); 544 memcpy(&p2[4], ia, 6); 545 memcpy(&p2[10], ra, 6); 546 log_info_key("p2", p2); 547 548 // c1 = e(k, t2_xor_p2) 549 int i; 550 for (i=0;i<16;i++){ 551 t3[i] = t2[i] ^ p2[i]; 552 } 553 log_info_key("t3", t3); 554 } 555 556 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 557 log_info_key("r1", r1); 558 log_info_key("r2", r2); 559 memcpy(&r_prime[8], &r2[8], 8); 560 memcpy(&r_prime[0], &r1[8], 8); 561 } 562 563 #ifdef ENABLE_LE_SECURE_CONNECTIONS 564 // Software implementations of crypto toolbox for LE Secure Connection 565 // TODO: replace with code to use AES Engine of HCI Controller 566 typedef uint8_t sm_key24_t[3]; 567 typedef uint8_t sm_key56_t[7]; 568 typedef uint8_t sm_key256_t[32]; 569 570 #if 0 571 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 572 uint32_t rk[RKLENGTH(KEYBITS)]; 573 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 574 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 575 } 576 577 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 578 memcpy(k1, k0, 16); 579 sm_shift_left_by_one_bit_inplace(16, k1); 580 if (k0[0] & 0x80){ 581 k1[15] ^= 0x87; 582 } 583 memcpy(k2, k1, 16); 584 sm_shift_left_by_one_bit_inplace(16, k2); 585 if (k1[0] & 0x80){ 586 k2[15] ^= 0x87; 587 } 588 } 589 590 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 591 sm_key_t k0, k1, k2, zero; 592 memset(zero, 0, 16); 593 594 aes128_calc_cyphertext(key, zero, k0); 595 calc_subkeys(k0, k1, k2); 596 597 int cmac_block_count = (cmac_message_len + 15) / 16; 598 599 // step 3: .. 600 if (cmac_block_count==0){ 601 cmac_block_count = 1; 602 } 603 604 // step 4: set m_last 605 sm_key_t cmac_m_last; 606 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 607 int i; 608 if (sm_cmac_last_block_complete){ 609 for (i=0;i<16;i++){ 610 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 611 } 612 } else { 613 int valid_octets_in_last_block = cmac_message_len & 0x0f; 614 for (i=0;i<16;i++){ 615 if (i < valid_octets_in_last_block){ 616 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 617 continue; 618 } 619 if (i == valid_octets_in_last_block){ 620 cmac_m_last[i] = 0x80 ^ k2[i]; 621 continue; 622 } 623 cmac_m_last[i] = k2[i]; 624 } 625 } 626 627 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 628 // LOG_KEY(cmac_m_last); 629 630 // Step 5 631 sm_key_t cmac_x; 632 memset(cmac_x, 0, 16); 633 634 // Step 6 635 sm_key_t sm_cmac_y; 636 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 637 for (i=0;i<16;i++){ 638 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 639 } 640 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 641 } 642 for (i=0;i<16;i++){ 643 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 644 } 645 646 // Step 7 647 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 648 } 649 #endif 650 651 #if 0 652 // 653 // Link Key Conversion Function h6 654 // 655 // h6(W, keyID) = AES-CMACW(keyID) 656 // - W is 128 bits 657 // - keyID is 32 bits 658 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 659 uint8_t key_id_buffer[4]; 660 big_endian_store_32(key_id_buffer, 0, key_id); 661 aes_cmac(res, w, key_id_buffer, 4); 662 } 663 #endif 664 #endif 665 666 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 667 event[0] = type; 668 event[1] = event_size - 2; 669 little_endian_store_16(event, 2, con_handle); 670 event[4] = addr_type; 671 reverse_bd_addr(address, &event[5]); 672 } 673 674 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 675 if (sm_client_packet_handler) { 676 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 677 } 678 // dispatch to all event handlers 679 btstack_linked_list_iterator_t it; 680 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 681 while (btstack_linked_list_iterator_has_next(&it)){ 682 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 683 entry->callback(packet_type, 0, packet, size); 684 } 685 } 686 687 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 688 uint8_t event[11]; 689 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 690 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 691 } 692 693 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 694 uint8_t event[15]; 695 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 696 little_endian_store_32(event, 11, passkey); 697 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 698 } 699 700 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 701 uint8_t event[13]; 702 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 703 little_endian_store_16(event, 11, index); 704 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 705 } 706 707 static void sm_notify_client_authorization(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 708 709 uint8_t event[18]; 710 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 711 event[11] = result; 712 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 713 } 714 715 // decide on stk generation based on 716 // - pairing request 717 // - io capabilities 718 // - OOB data availability 719 static void sm_setup_tk(void){ 720 721 // default: just works 722 setup->sm_stk_generation_method = JUST_WORKS; 723 724 #ifdef ENABLE_LE_SECURE_CONNECTIONS 725 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 726 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 727 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 728 memset(setup->sm_ra, 0, 16); 729 memset(setup->sm_rb, 0, 16); 730 #else 731 setup->sm_use_secure_connections = 0; 732 #endif 733 734 // If both devices have not set the MITM option in the Authentication Requirements 735 // Flags, then the IO capabilities shall be ignored and the Just Works association 736 // model shall be used. 737 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 738 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 739 log_info("SM: MITM not required by both -> JUST WORKS"); 740 return; 741 } 742 743 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 744 745 // If both devices have out of band authentication data, then the Authentication 746 // Requirements Flags shall be ignored when selecting the pairing method and the 747 // Out of Band pairing method shall be used. 748 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 749 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 750 log_info("SM: have OOB data"); 751 log_info_key("OOB", setup->sm_tk); 752 setup->sm_stk_generation_method = OOB; 753 return; 754 } 755 756 // Reset TK as it has been setup in sm_init_setup 757 sm_reset_tk(); 758 759 // Also use just works if unknown io capabilites 760 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 761 return; 762 } 763 764 // Otherwise the IO capabilities of the devices shall be used to determine the 765 // pairing method as defined in Table 2.4. 766 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 767 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 768 769 #ifdef ENABLE_LE_SECURE_CONNECTIONS 770 // table not define by default 771 if (setup->sm_use_secure_connections){ 772 generation_method = stk_generation_method_with_secure_connection; 773 } 774 #endif 775 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 776 777 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 778 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 779 } 780 781 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 782 int flags = 0; 783 if (key_set & SM_KEYDIST_ENC_KEY){ 784 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 785 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 786 } 787 if (key_set & SM_KEYDIST_ID_KEY){ 788 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 789 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 790 } 791 if (key_set & SM_KEYDIST_SIGN){ 792 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 793 } 794 return flags; 795 } 796 797 static void sm_setup_key_distribution(uint8_t key_set){ 798 setup->sm_key_distribution_received_set = 0; 799 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 800 } 801 802 // CSRK Key Lookup 803 804 805 static int sm_address_resolution_idle(void){ 806 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 807 } 808 809 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 810 memcpy(sm_address_resolution_address, addr, 6); 811 sm_address_resolution_addr_type = addr_type; 812 sm_address_resolution_test = 0; 813 sm_address_resolution_mode = mode; 814 sm_address_resolution_context = context; 815 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 816 } 817 818 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 819 // check if already in list 820 btstack_linked_list_iterator_t it; 821 sm_lookup_entry_t * entry; 822 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 823 while(btstack_linked_list_iterator_has_next(&it)){ 824 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 825 if (entry->address_type != address_type) continue; 826 if (memcmp(entry->address, address, 6)) continue; 827 // already in list 828 return BTSTACK_BUSY; 829 } 830 entry = btstack_memory_sm_lookup_entry_get(); 831 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 832 entry->address_type = (bd_addr_type_t) address_type; 833 memcpy(entry->address, address, 6); 834 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 835 sm_run(); 836 return 0; 837 } 838 839 // CMAC Implementation using AES128 engine 840 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 841 int i; 842 int carry = 0; 843 for (i=len-1; i >= 0 ; i--){ 844 int new_carry = data[i] >> 7; 845 data[i] = data[i] << 1 | carry; 846 carry = new_carry; 847 } 848 } 849 850 // while x_state++ for an enum is possible in C, it isn't in C++. we use this helpers to avoid compile errors for now 851 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 852 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 853 } 854 static inline void dkg_next_state(void){ 855 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 856 } 857 static inline void rau_next_state(void){ 858 rau_state = (random_address_update_t) (((int)rau_state) + 1); 859 } 860 861 // CMAC calculation using AES Engine 862 863 static inline void sm_cmac_next_state(void){ 864 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 865 } 866 867 static int sm_cmac_last_block_complete(void){ 868 if (sm_cmac_message_len == 0) return 0; 869 return (sm_cmac_message_len & 0x0f) == 0; 870 } 871 872 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 873 if (offset >= sm_cmac_message_len) { 874 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 875 return 0; 876 } 877 878 offset = sm_cmac_message_len - 1 - offset; 879 880 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 881 if (offset < 3){ 882 return sm_cmac_header[offset]; 883 } 884 int actual_message_len_incl_header = sm_cmac_message_len - 4; 885 if (offset < actual_message_len_incl_header){ 886 return sm_cmac_message[offset - 3]; 887 } 888 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 889 } 890 891 // generic cmac calculation 892 void sm_cmac_general_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t hash[8])){ 893 // Generalized CMAC 894 memcpy(sm_cmac_k, key, 16); 895 memset(sm_cmac_x, 0, 16); 896 sm_cmac_block_current = 0; 897 sm_cmac_message_len = message_len; 898 sm_cmac_done_handler = done_callback; 899 sm_cmac_get_byte = get_byte_callback; 900 901 // step 2: n := ceil(len/const_Bsize); 902 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 903 904 // step 3: .. 905 if (sm_cmac_block_count==0){ 906 sm_cmac_block_count = 1; 907 } 908 log_info("sm_cmac_connection %p", sm_cmac_connection); 909 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 910 911 // first, we need to compute l for k1, k2, and m_last 912 sm_cmac_state = CMAC_CALC_SUBKEYS; 913 914 // let's go 915 sm_run(); 916 } 917 918 // cmac for ATT Message signing 919 void sm_cmac_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 920 // ATT Message Signing 921 sm_cmac_header[0] = opcode; 922 little_endian_store_16(sm_cmac_header, 1, con_handle); 923 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 924 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 925 sm_cmac_message = message; 926 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 927 } 928 929 int sm_cmac_ready(void){ 930 return sm_cmac_state == CMAC_IDLE; 931 } 932 933 static void sm_cmac_handle_aes_engine_ready(void){ 934 switch (sm_cmac_state){ 935 case CMAC_CALC_SUBKEYS: { 936 sm_key_t const_zero; 937 memset(const_zero, 0, 16); 938 sm_cmac_next_state(); 939 sm_aes128_start(sm_cmac_k, const_zero, NULL); 940 break; 941 } 942 case CMAC_CALC_MI: { 943 int j; 944 sm_key_t y; 945 for (j=0;j<16;j++){ 946 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 947 } 948 sm_cmac_block_current++; 949 sm_cmac_next_state(); 950 sm_aes128_start(sm_cmac_k, y, NULL); 951 break; 952 } 953 case CMAC_CALC_MLAST: { 954 int i; 955 sm_key_t y; 956 for (i=0;i<16;i++){ 957 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 958 } 959 log_info_key("Y", y); 960 sm_cmac_block_current++; 961 sm_cmac_next_state(); 962 sm_aes128_start(sm_cmac_k, y, NULL); 963 break; 964 } 965 default: 966 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 967 break; 968 } 969 } 970 971 static void sm_cmac_handle_encryption_result(sm_key_t data){ 972 switch (sm_cmac_state){ 973 case CMAC_W4_SUBKEYS: { 974 sm_key_t k1; 975 memcpy(k1, data, 16); 976 sm_shift_left_by_one_bit_inplace(16, k1); 977 if (data[0] & 0x80){ 978 k1[15] ^= 0x87; 979 } 980 sm_key_t k2; 981 memcpy(k2, k1, 16); 982 sm_shift_left_by_one_bit_inplace(16, k2); 983 if (k1[0] & 0x80){ 984 k2[15] ^= 0x87; 985 } 986 987 log_info_key("k", sm_cmac_k); 988 log_info_key("k1", k1); 989 log_info_key("k2", k2); 990 991 // step 4: set m_last 992 int i; 993 if (sm_cmac_last_block_complete()){ 994 for (i=0;i<16;i++){ 995 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 996 } 997 } else { 998 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 999 for (i=0;i<16;i++){ 1000 if (i < valid_octets_in_last_block){ 1001 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1002 continue; 1003 } 1004 if (i == valid_octets_in_last_block){ 1005 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1006 continue; 1007 } 1008 sm_cmac_m_last[i] = k2[i]; 1009 } 1010 } 1011 1012 // next 1013 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1014 break; 1015 } 1016 case CMAC_W4_MI: 1017 memcpy(sm_cmac_x, data, 16); 1018 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1019 break; 1020 case CMAC_W4_MLAST: 1021 // done 1022 log_info("Setting CMAC Engine to IDLE"); 1023 sm_cmac_state = CMAC_IDLE; 1024 log_info_key("CMAC", data); 1025 sm_cmac_done_handler(data); 1026 break; 1027 default: 1028 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1029 break; 1030 } 1031 } 1032 1033 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1034 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1035 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1036 switch (setup->sm_stk_generation_method){ 1037 case PK_RESP_INPUT: 1038 if (sm_conn->sm_role){ 1039 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1040 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1041 } else { 1042 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1043 } 1044 break; 1045 case PK_INIT_INPUT: 1046 if (sm_conn->sm_role){ 1047 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1048 } else { 1049 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1050 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1051 } 1052 break; 1053 case OK_BOTH_INPUT: 1054 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1055 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1056 break; 1057 case NK_BOTH_INPUT: 1058 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1059 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1060 break; 1061 case JUST_WORKS: 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1064 break; 1065 case OOB: 1066 // client already provided OOB data, let's skip notification. 1067 break; 1068 } 1069 } 1070 1071 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1072 int recv_flags; 1073 if (sm_conn->sm_role){ 1074 // slave / responder 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1076 } else { 1077 // master / initiator 1078 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1079 } 1080 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1081 return recv_flags == setup->sm_key_distribution_received_set; 1082 } 1083 1084 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1085 if (sm_active_connection == con_handle){ 1086 sm_timeout_stop(); 1087 sm_active_connection = 0; 1088 log_info("sm: connection 0x%x released setup context", con_handle); 1089 } 1090 } 1091 1092 static int sm_key_distribution_flags_for_auth_req(void){ 1093 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1094 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1095 // encryption information only if bonding requested 1096 flags |= SM_KEYDIST_ENC_KEY; 1097 } 1098 return flags; 1099 } 1100 1101 static void sm_init_setup(sm_connection_t * sm_conn){ 1102 1103 // fill in sm setup 1104 setup->sm_state_vars = 0; 1105 sm_reset_tk(); 1106 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1107 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1108 1109 // query client for OOB data 1110 int have_oob_data = 0; 1111 if (sm_get_oob_data) { 1112 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1113 } 1114 1115 sm_pairing_packet_t * local_packet; 1116 if (sm_conn->sm_role){ 1117 // slave 1118 local_packet = &setup->sm_s_pres; 1119 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1120 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1121 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1122 } else { 1123 // master 1124 local_packet = &setup->sm_m_preq; 1125 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1126 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1127 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1128 1129 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1130 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1131 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1132 } 1133 1134 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1135 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1136 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1137 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1138 } 1139 1140 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1141 1142 sm_pairing_packet_t * remote_packet; 1143 int remote_key_request; 1144 if (sm_conn->sm_role){ 1145 // slave / responder 1146 remote_packet = &setup->sm_m_preq; 1147 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1148 } else { 1149 // master / initiator 1150 remote_packet = &setup->sm_s_pres; 1151 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1152 } 1153 1154 // check key size 1155 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1156 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1157 1158 // decide on STK generation method 1159 sm_setup_tk(); 1160 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1161 1162 // check if STK generation method is acceptable by client 1163 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1164 1165 // identical to responder 1166 sm_setup_key_distribution(remote_key_request); 1167 1168 // JUST WORKS doens't provide authentication 1169 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1170 1171 return 0; 1172 } 1173 1174 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1175 1176 // cache and reset context 1177 int matched_device_id = sm_address_resolution_test; 1178 address_resolution_mode_t mode = sm_address_resolution_mode; 1179 void * context = sm_address_resolution_context; 1180 1181 // reset context 1182 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1183 sm_address_resolution_context = NULL; 1184 sm_address_resolution_test = -1; 1185 hci_con_handle_t con_handle = 0; 1186 1187 sm_connection_t * sm_connection; 1188 uint16_t ediv; 1189 switch (mode){ 1190 case ADDRESS_RESOLUTION_GENERAL: 1191 break; 1192 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1193 sm_connection = (sm_connection_t *) context; 1194 con_handle = sm_connection->sm_handle; 1195 switch (event){ 1196 case ADDRESS_RESOLUTION_SUCEEDED: 1197 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1198 sm_connection->sm_le_db_index = matched_device_id; 1199 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1200 if (sm_connection->sm_role) break; 1201 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1202 sm_connection->sm_security_request_received = 0; 1203 sm_connection->sm_bonding_requested = 0; 1204 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1205 if (ediv){ 1206 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1207 } else { 1208 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1209 } 1210 break; 1211 case ADDRESS_RESOLUTION_FAILED: 1212 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1213 if (sm_connection->sm_role) break; 1214 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1215 sm_connection->sm_security_request_received = 0; 1216 sm_connection->sm_bonding_requested = 0; 1217 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1218 break; 1219 } 1220 break; 1221 default: 1222 break; 1223 } 1224 1225 switch (event){ 1226 case ADDRESS_RESOLUTION_SUCEEDED: 1227 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1228 break; 1229 case ADDRESS_RESOLUTION_FAILED: 1230 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1231 break; 1232 } 1233 } 1234 1235 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1236 1237 int le_db_index = -1; 1238 1239 // lookup device based on IRK 1240 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1241 int i; 1242 for (i=0; i < le_device_db_count(); i++){ 1243 sm_key_t irk; 1244 bd_addr_t address; 1245 int address_type; 1246 le_device_db_info(i, &address_type, address, irk); 1247 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1248 log_info("sm: device found for IRK, updating"); 1249 le_db_index = i; 1250 break; 1251 } 1252 } 1253 } 1254 1255 // if not found, lookup via public address if possible 1256 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1257 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1258 int i; 1259 for (i=0; i < le_device_db_count(); i++){ 1260 bd_addr_t address; 1261 int address_type; 1262 le_device_db_info(i, &address_type, address, NULL); 1263 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1264 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1265 log_info("sm: device found for public address, updating"); 1266 le_db_index = i; 1267 break; 1268 } 1269 } 1270 } 1271 1272 // if not found, add to db 1273 if (le_db_index < 0) { 1274 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1275 } 1276 1277 if (le_db_index >= 0){ 1278 le_device_db_local_counter_set(le_db_index, 0); 1279 1280 // store local CSRK 1281 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1282 log_info("sm: store local CSRK"); 1283 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1284 le_device_db_local_counter_set(le_db_index, 0); 1285 } 1286 1287 // store remote CSRK 1288 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1289 log_info("sm: store remote CSRK"); 1290 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1291 le_device_db_remote_counter_set(le_db_index, 0); 1292 } 1293 1294 // store encryption information 1295 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1296 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1297 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1298 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1299 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1300 } 1301 } 1302 1303 // keep le_db_index 1304 sm_conn->sm_le_db_index = le_db_index; 1305 } 1306 1307 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1308 setup->sm_pairing_failed_reason = reason; 1309 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1310 } 1311 1312 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1313 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1314 } 1315 1316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1317 1318 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1319 static int sm_passkey_used(stk_generation_method_t method); 1320 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1321 1322 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1323 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1324 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1325 } else { 1326 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1327 } 1328 } 1329 1330 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1331 if (sm_conn->sm_role){ 1332 // Responder 1333 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1334 } else { 1335 // Initiator role 1336 switch (setup->sm_stk_generation_method){ 1337 case JUST_WORKS: 1338 sm_sc_prepare_dhkey_check(sm_conn); 1339 break; 1340 1341 case NK_BOTH_INPUT: 1342 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1343 break; 1344 case PK_INIT_INPUT: 1345 case PK_RESP_INPUT: 1346 case OK_BOTH_INPUT: 1347 if (setup->sm_passkey_bit < 20) { 1348 sm_sc_start_calculating_local_confirm(sm_conn); 1349 } else { 1350 sm_sc_prepare_dhkey_check(sm_conn); 1351 } 1352 break; 1353 case OOB: 1354 // TODO: implement SC OOB 1355 break; 1356 } 1357 } 1358 } 1359 1360 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1361 return sm_cmac_sc_buffer[offset]; 1362 } 1363 1364 static void sm_sc_cmac_done(uint8_t * hash){ 1365 log_info("sm_sc_cmac_done: "); 1366 log_info_hexdump(hash, 16); 1367 1368 sm_connection_t * sm_conn = sm_cmac_connection; 1369 sm_cmac_connection = NULL; 1370 1371 switch (sm_conn->sm_engine_state){ 1372 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1373 memcpy(setup->sm_local_confirm, hash, 16); 1374 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1375 break; 1376 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1377 // check 1378 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1379 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1380 break; 1381 } 1382 sm_sc_state_after_receiving_random(sm_conn); 1383 break; 1384 case SM_SC_W4_CALCULATE_G2: { 1385 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1386 big_endian_store_32(setup->sm_tk, 12, vab); 1387 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1388 sm_trigger_user_response(sm_conn); 1389 break; 1390 } 1391 case SM_SC_W4_CALCULATE_F5_SALT: 1392 memcpy(setup->sm_t, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1394 break; 1395 case SM_SC_W4_CALCULATE_F5_MACKEY: 1396 memcpy(setup->sm_mackey, hash, 16); 1397 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1398 break; 1399 case SM_SC_W4_CALCULATE_F5_LTK: 1400 memcpy(setup->sm_ltk, hash, 16); 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1402 break; 1403 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1404 memcpy(setup->sm_local_dhkey_check, hash, 16); 1405 if (sm_conn->sm_role){ 1406 // responder 1407 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1408 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1409 } else { 1410 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1411 } 1412 } else { 1413 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1414 } 1415 break; 1416 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1417 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1418 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1419 break; 1420 } 1421 if (sm_conn->sm_role){ 1422 // responder 1423 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1424 } else { 1425 // initiator 1426 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1427 } 1428 break; 1429 default: 1430 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1431 break; 1432 } 1433 sm_run(); 1434 } 1435 1436 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1437 const uint16_t message_len = 65; 1438 sm_cmac_connection = sm_conn; 1439 memcpy(sm_cmac_sc_buffer, u, 32); 1440 memcpy(sm_cmac_sc_buffer+32, v, 32); 1441 sm_cmac_sc_buffer[64] = z; 1442 log_info("f4 key"); 1443 log_info_hexdump(x, 16); 1444 log_info("f4 message"); 1445 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1446 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1447 } 1448 1449 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1450 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1451 static const uint8_t f5_length[] = { 0x01, 0x00}; 1452 1453 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1454 #ifdef USE_MBEDTLS_FOR_ECDH 1455 // da * Pb 1456 mbedtls_ecp_group grp; 1457 mbedtls_ecp_group_init( &grp ); 1458 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1459 mbedtls_ecp_point Q; 1460 mbedtls_ecp_point_init( &Q ); 1461 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1462 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1463 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1464 mbedtls_ecp_point DH; 1465 mbedtls_ecp_point_init( &DH ); 1466 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1467 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1468 #endif 1469 log_info("dhkey"); 1470 log_info_hexdump(dhkey, 32); 1471 } 1472 1473 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1474 // calculate DHKEY 1475 sm_key256_t dhkey; 1476 sm_sc_calculate_dhkey(dhkey); 1477 1478 // calculate salt for f5 1479 const uint16_t message_len = 32; 1480 sm_cmac_connection = sm_conn; 1481 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1482 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1483 } 1484 1485 static inline void f5_mackkey(sm_connection_t * sm_conn, sm_key_t t, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ 1486 const uint16_t message_len = 53; 1487 sm_cmac_connection = sm_conn; 1488 1489 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1490 sm_cmac_sc_buffer[0] = 0; 1491 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1492 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1493 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1494 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1495 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1496 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1497 log_info("f5 key"); 1498 log_info_hexdump(t, 16); 1499 log_info("f5 message for MacKey"); 1500 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1501 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1502 } 1503 1504 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1505 sm_key56_t bd_addr_master, bd_addr_slave; 1506 bd_addr_master[0] = setup->sm_m_addr_type; 1507 bd_addr_slave[0] = setup->sm_s_addr_type; 1508 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1509 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1510 if (sm_conn->sm_role){ 1511 // responder 1512 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1513 } else { 1514 // initiator 1515 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1516 } 1517 } 1518 1519 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1520 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1521 const uint16_t message_len = 53; 1522 sm_cmac_connection = sm_conn; 1523 sm_cmac_sc_buffer[0] = 1; 1524 // 1..52 setup before 1525 log_info("f5 key"); 1526 log_info_hexdump(t, 16); 1527 log_info("f5 message for LTK"); 1528 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1529 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1530 } 1531 1532 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1533 f5_ltk(sm_conn, setup->sm_t); 1534 } 1535 1536 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w, const sm_key_t n1, const sm_key_t n2, const sm_key_t r, const sm_key24_t io_cap, const sm_key56_t a1, const sm_key56_t a2){ 1537 const uint16_t message_len = 65; 1538 sm_cmac_connection = sm_conn; 1539 memcpy(sm_cmac_sc_buffer, n1, 16); 1540 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1541 memcpy(sm_cmac_sc_buffer+32, r, 16); 1542 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1543 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1544 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1545 log_info("f6 key"); 1546 log_info_hexdump(w, 16); 1547 log_info("f6 message"); 1548 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1549 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1550 } 1551 1552 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1553 // - U is 256 bits 1554 // - V is 256 bits 1555 // - X is 128 bits 1556 // - Y is 128 bits 1557 static void g2_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ 1558 const uint16_t message_len = 80; 1559 sm_cmac_connection = sm_conn; 1560 memcpy(sm_cmac_sc_buffer, u, 32); 1561 memcpy(sm_cmac_sc_buffer+32, v, 32); 1562 memcpy(sm_cmac_sc_buffer+64, y, 16); 1563 log_info("g2 key"); 1564 log_info_hexdump(x, 16); 1565 log_info("g2 message"); 1566 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1567 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1568 } 1569 1570 static void g2_calculate(sm_connection_t * sm_conn) { 1571 // calc Va if numeric comparison 1572 uint8_t value[32]; 1573 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1574 if (sm_conn->sm_role){ 1575 // responder 1576 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1577 } else { 1578 // initiator 1579 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1580 } 1581 } 1582 1583 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1584 uint8_t z = 0; 1585 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1586 // some form of passkey 1587 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1588 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1589 setup->sm_passkey_bit++; 1590 } 1591 #ifdef USE_MBEDTLS_FOR_ECDH 1592 uint8_t local_qx[32]; 1593 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1594 #endif 1595 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1596 } 1597 1598 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1599 uint8_t z = 0; 1600 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1601 // some form of passkey 1602 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1603 // sm_passkey_bit was increased before sending confirm value 1604 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1605 } 1606 #ifdef USE_MBEDTLS_FOR_ECDH 1607 uint8_t local_qx[32]; 1608 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1609 #endif 1610 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1611 } 1612 1613 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1614 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1615 } 1616 1617 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1618 // calculate DHKCheck 1619 sm_key56_t bd_addr_master, bd_addr_slave; 1620 bd_addr_master[0] = setup->sm_m_addr_type; 1621 bd_addr_slave[0] = setup->sm_s_addr_type; 1622 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1623 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1624 uint8_t iocap_a[3]; 1625 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1626 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1627 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1628 uint8_t iocap_b[3]; 1629 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1630 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1631 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1632 if (sm_conn->sm_role){ 1633 // responder 1634 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1635 } else { 1636 // initiator 1637 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1638 } 1639 } 1640 1641 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1642 // validate E = f6() 1643 sm_key56_t bd_addr_master, bd_addr_slave; 1644 bd_addr_master[0] = setup->sm_m_addr_type; 1645 bd_addr_slave[0] = setup->sm_s_addr_type; 1646 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1647 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1648 1649 uint8_t iocap_a[3]; 1650 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1651 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1652 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1653 uint8_t iocap_b[3]; 1654 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1655 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1656 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1657 if (sm_conn->sm_role){ 1658 // responder 1659 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1660 } else { 1661 // initiator 1662 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1663 } 1664 } 1665 #endif 1666 1667 static void sm_load_security_info(sm_connection_t * sm_connection){ 1668 int encryption_key_size; 1669 int authenticated; 1670 int authorized; 1671 1672 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1673 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1674 &encryption_key_size, &authenticated, &authorized); 1675 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1676 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1677 sm_connection->sm_connection_authenticated = authenticated; 1678 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1679 } 1680 1681 static void sm_run(void){ 1682 1683 btstack_linked_list_iterator_t it; 1684 1685 // assert that we can send at least commands 1686 if (!hci_can_send_command_packet_now()) return; 1687 1688 // 1689 // non-connection related behaviour 1690 // 1691 1692 // distributed key generation 1693 switch (dkg_state){ 1694 case DKG_CALC_IRK: 1695 // already busy? 1696 if (sm_aes128_state == SM_AES128_IDLE) { 1697 // IRK = d1(IR, 1, 0) 1698 sm_key_t d1_prime; 1699 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1700 dkg_next_state(); 1701 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1702 return; 1703 } 1704 break; 1705 case DKG_CALC_DHK: 1706 // already busy? 1707 if (sm_aes128_state == SM_AES128_IDLE) { 1708 // DHK = d1(IR, 3, 0) 1709 sm_key_t d1_prime; 1710 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1711 dkg_next_state(); 1712 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1713 return; 1714 } 1715 break; 1716 default: 1717 break; 1718 } 1719 1720 #ifdef USE_MBEDTLS_FOR_ECDH 1721 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1722 sm_random_start(NULL); 1723 return; 1724 } 1725 #endif 1726 1727 // random address updates 1728 switch (rau_state){ 1729 case RAU_GET_RANDOM: 1730 rau_next_state(); 1731 sm_random_start(NULL); 1732 return; 1733 case RAU_GET_ENC: 1734 // already busy? 1735 if (sm_aes128_state == SM_AES128_IDLE) { 1736 sm_key_t r_prime; 1737 sm_ah_r_prime(sm_random_address, r_prime); 1738 rau_next_state(); 1739 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1740 return; 1741 } 1742 break; 1743 case RAU_SET_ADDRESS: 1744 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1745 rau_state = RAU_IDLE; 1746 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1747 return; 1748 default: 1749 break; 1750 } 1751 1752 // CMAC 1753 switch (sm_cmac_state){ 1754 case CMAC_CALC_SUBKEYS: 1755 case CMAC_CALC_MI: 1756 case CMAC_CALC_MLAST: 1757 // already busy? 1758 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1759 sm_cmac_handle_aes_engine_ready(); 1760 return; 1761 default: 1762 break; 1763 } 1764 1765 // CSRK Lookup 1766 // -- if csrk lookup ready, find connection that require csrk lookup 1767 if (sm_address_resolution_idle()){ 1768 hci_connections_get_iterator(&it); 1769 while(btstack_linked_list_iterator_has_next(&it)){ 1770 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1771 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1772 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1773 // and start lookup 1774 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); 1775 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1776 break; 1777 } 1778 } 1779 } 1780 1781 // -- if csrk lookup ready, resolved addresses for received addresses 1782 if (sm_address_resolution_idle()) { 1783 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1784 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1785 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1786 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1787 btstack_memory_sm_lookup_entry_free(entry); 1788 } 1789 } 1790 1791 // -- Continue with CSRK device lookup by public or resolvable private address 1792 if (!sm_address_resolution_idle()){ 1793 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1794 while (sm_address_resolution_test < le_device_db_count()){ 1795 int addr_type; 1796 bd_addr_t addr; 1797 sm_key_t irk; 1798 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1799 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1800 1801 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1802 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1803 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1804 break; 1805 } 1806 1807 if (sm_address_resolution_addr_type == 0){ 1808 sm_address_resolution_test++; 1809 continue; 1810 } 1811 1812 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1813 1814 log_info("LE Device Lookup: calculate AH"); 1815 log_info_key("IRK", irk); 1816 1817 sm_key_t r_prime; 1818 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1819 sm_address_resolution_ah_calculation_active = 1; 1820 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1821 return; 1822 } 1823 1824 if (sm_address_resolution_test >= le_device_db_count()){ 1825 log_info("LE Device Lookup: not found"); 1826 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1827 } 1828 } 1829 1830 1831 // 1832 // active connection handling 1833 // -- use loop to handle next connection if lock on setup context is released 1834 1835 while (1) { 1836 1837 // Find connections that requires setup context and make active if no other is locked 1838 hci_connections_get_iterator(&it); 1839 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1840 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1841 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1842 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1843 int done = 1; 1844 int err; 1845 switch (sm_connection->sm_engine_state) { 1846 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1847 // send packet if possible, 1848 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1849 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1850 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1851 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1852 } else { 1853 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1854 } 1855 // don't lock sxetup context yet 1856 done = 0; 1857 break; 1858 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1859 sm_init_setup(sm_connection); 1860 // recover pairing request 1861 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1862 err = sm_stk_generation_init(sm_connection); 1863 if (err){ 1864 setup->sm_pairing_failed_reason = err; 1865 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1866 break; 1867 } 1868 sm_timeout_start(sm_connection); 1869 // generate random number first, if we need to show passkey 1870 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1871 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1872 break; 1873 } 1874 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1875 break; 1876 case SM_INITIATOR_PH0_HAS_LTK: 1877 sm_load_security_info(sm_connection); 1878 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1879 break; 1880 case SM_RESPONDER_PH0_RECEIVED_LTK: 1881 switch (sm_connection->sm_irk_lookup_state){ 1882 case IRK_LOOKUP_SUCCEEDED:{ 1883 sm_load_security_info(sm_connection); 1884 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1885 break; 1886 } 1887 case IRK_LOOKUP_FAILED: 1888 // assume that we don't have a LTK for ediv == 0 and random == null 1889 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1890 log_info("LTK Request: ediv & random are empty"); 1891 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1892 // TODO: no need to lock context yet -> done = 0; 1893 break; 1894 } 1895 // re-establish previously used LTK using Rand and EDIV 1896 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1897 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1898 // re-establish used key encryption size 1899 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1900 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1901 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1902 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1903 log_info("sm: received ltk request with key size %u, authenticated %u", 1904 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1905 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1906 break; 1907 default: 1908 // just wait until IRK lookup is completed 1909 // don't lock sxetup context yet 1910 done = 0; 1911 break; 1912 } 1913 break; 1914 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1915 sm_init_setup(sm_connection); 1916 sm_timeout_start(sm_connection); 1917 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1918 break; 1919 default: 1920 done = 0; 1921 break; 1922 } 1923 if (done){ 1924 sm_active_connection = sm_connection->sm_handle; 1925 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1926 } 1927 } 1928 1929 // 1930 // active connection handling 1931 // 1932 1933 if (sm_active_connection == 0) return; 1934 1935 // assert that we could send a SM PDU - not needed for all of the following 1936 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1937 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1938 return; 1939 } 1940 1941 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1942 if (!connection) return; 1943 1944 sm_key_t plaintext; 1945 int key_distribution_flags; 1946 1947 log_info("sm_run: state %u", connection->sm_engine_state); 1948 1949 // responding state 1950 switch (connection->sm_engine_state){ 1951 1952 // general 1953 case SM_GENERAL_SEND_PAIRING_FAILED: { 1954 uint8_t buffer[2]; 1955 buffer[0] = SM_CODE_PAIRING_FAILED; 1956 buffer[1] = setup->sm_pairing_failed_reason; 1957 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1958 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1959 sm_done_for_handle(connection->sm_handle); 1960 break; 1961 } 1962 1963 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1964 case SM_SC_W2_GET_RANDOM_A: 1965 sm_random_start(connection); 1966 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1967 break; 1968 case SM_SC_W2_GET_RANDOM_B: 1969 sm_random_start(connection); 1970 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1971 break; 1972 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1973 if (!sm_cmac_ready()) break; 1974 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1975 sm_sc_calculate_local_confirm(connection); 1976 break; 1977 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1980 sm_sc_calculate_remote_confirm(connection); 1981 break; 1982 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1985 sm_sc_calculate_f6_for_dhkey_check(connection); 1986 break; 1987 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1990 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F5_SALT: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1995 f5_calculate_salt(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F5_MACKEY: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2000 f5_calculate_mackey(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_F5_LTK: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2005 f5_calculate_ltk(connection); 2006 break; 2007 case SM_SC_W2_CALCULATE_G2: 2008 if (!sm_cmac_ready()) break; 2009 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2010 g2_calculate(connection); 2011 break; 2012 2013 #endif 2014 // initiator side 2015 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2016 sm_key_t peer_ltk_flipped; 2017 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2018 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2019 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2020 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2021 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2022 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2023 return; 2024 } 2025 2026 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2027 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2028 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2029 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2030 sm_timeout_reset(connection); 2031 break; 2032 2033 // responder side 2034 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2035 connection->sm_engine_state = SM_RESPONDER_IDLE; 2036 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2037 sm_done_for_handle(connection->sm_handle); 2038 return; 2039 2040 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2041 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2042 uint8_t buffer[65]; 2043 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2044 // 2045 #ifdef USE_MBEDTLS_FOR_ECDH 2046 uint8_t value[32]; 2047 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2048 reverse_256(value, &buffer[1]); 2049 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2050 reverse_256(value, &buffer[33]); 2051 #endif 2052 2053 // stk generation method 2054 // passkey entry: notify app to show passkey or to request passkey 2055 switch (setup->sm_stk_generation_method){ 2056 case JUST_WORKS: 2057 case NK_BOTH_INPUT: 2058 if (connection->sm_role){ 2059 // responder 2060 sm_sc_start_calculating_local_confirm(connection); 2061 } else { 2062 // initiator 2063 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2064 } 2065 break; 2066 case PK_INIT_INPUT: 2067 case PK_RESP_INPUT: 2068 case OK_BOTH_INPUT: 2069 // use random TK for display 2070 memcpy(setup->sm_ra, setup->sm_tk, 16); 2071 memcpy(setup->sm_rb, setup->sm_tk, 16); 2072 setup->sm_passkey_bit = 0; 2073 2074 if (connection->sm_role){ 2075 // responder 2076 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2077 } else { 2078 // initiator 2079 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2080 } 2081 sm_trigger_user_response(connection); 2082 break; 2083 case OOB: 2084 // TODO: implement SC OOB 2085 break; 2086 } 2087 2088 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2089 sm_timeout_reset(connection); 2090 break; 2091 } 2092 case SM_SC_SEND_CONFIRMATION: { 2093 uint8_t buffer[17]; 2094 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2095 reverse_128(setup->sm_local_confirm, &buffer[1]); 2096 if (connection->sm_role){ 2097 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2098 } else { 2099 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2100 } 2101 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2102 sm_timeout_reset(connection); 2103 break; 2104 } 2105 case SM_SC_SEND_PAIRING_RANDOM: { 2106 uint8_t buffer[17]; 2107 buffer[0] = SM_CODE_PAIRING_RANDOM; 2108 reverse_128(setup->sm_local_nonce, &buffer[1]); 2109 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2110 if (connection->sm_role){ 2111 // responder 2112 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2113 } else { 2114 // initiator 2115 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2116 } 2117 } else { 2118 if (connection->sm_role){ 2119 // responder 2120 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2121 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2122 } else { 2123 sm_sc_prepare_dhkey_check(connection); 2124 } 2125 } else { 2126 // initiator 2127 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2128 } 2129 } 2130 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2131 sm_timeout_reset(connection); 2132 break; 2133 } 2134 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2135 uint8_t buffer[17]; 2136 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2137 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2138 2139 if (connection->sm_role){ 2140 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2141 } else { 2142 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2143 } 2144 2145 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2146 sm_timeout_reset(connection); 2147 break; 2148 } 2149 2150 #endif 2151 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2152 // echo initiator for now 2153 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2154 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2155 2156 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2157 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2158 if (setup->sm_use_secure_connections){ 2159 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2160 // skip LTK/EDIV for SC 2161 log_info("sm: dropping encryption information flag"); 2162 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2163 } 2164 #endif 2165 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); 2166 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); 2167 // update key distribution after ENC was dropped 2168 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2169 2170 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2171 sm_timeout_reset(connection); 2172 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2173 if (setup->sm_stk_generation_method == JUST_WORKS){ 2174 sm_trigger_user_response(connection); 2175 } 2176 return; 2177 2178 case SM_PH2_SEND_PAIRING_RANDOM: { 2179 uint8_t buffer[17]; 2180 buffer[0] = SM_CODE_PAIRING_RANDOM; 2181 reverse_128(setup->sm_local_random, &buffer[1]); 2182 if (connection->sm_role){ 2183 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2184 } else { 2185 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2186 } 2187 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2188 sm_timeout_reset(connection); 2189 break; 2190 } 2191 2192 case SM_PH2_GET_RANDOM_TK: 2193 case SM_PH2_C1_GET_RANDOM_A: 2194 case SM_PH2_C1_GET_RANDOM_B: 2195 case SM_PH3_GET_RANDOM: 2196 case SM_PH3_GET_DIV: 2197 sm_next_responding_state(connection); 2198 sm_random_start(connection); 2199 return; 2200 2201 case SM_PH2_C1_GET_ENC_B: 2202 case SM_PH2_C1_GET_ENC_D: 2203 // already busy? 2204 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2205 sm_next_responding_state(connection); 2206 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2207 return; 2208 2209 case SM_PH3_LTK_GET_ENC: 2210 case SM_RESPONDER_PH4_LTK_GET_ENC: 2211 // already busy? 2212 if (sm_aes128_state == SM_AES128_IDLE) { 2213 sm_key_t d_prime; 2214 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2215 sm_next_responding_state(connection); 2216 sm_aes128_start(sm_persistent_er, d_prime, connection); 2217 return; 2218 } 2219 break; 2220 2221 case SM_PH3_CSRK_GET_ENC: 2222 // already busy? 2223 if (sm_aes128_state == SM_AES128_IDLE) { 2224 sm_key_t d_prime; 2225 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2226 sm_next_responding_state(connection); 2227 sm_aes128_start(sm_persistent_er, d_prime, connection); 2228 return; 2229 } 2230 break; 2231 2232 case SM_PH2_C1_GET_ENC_C: 2233 // already busy? 2234 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2235 // calculate m_confirm using aes128 engine - step 1 2236 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); 2237 sm_next_responding_state(connection); 2238 sm_aes128_start(setup->sm_tk, plaintext, connection); 2239 break; 2240 case SM_PH2_C1_GET_ENC_A: 2241 // already busy? 2242 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2243 // calculate confirm using aes128 engine - step 1 2244 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); 2245 sm_next_responding_state(connection); 2246 sm_aes128_start(setup->sm_tk, plaintext, connection); 2247 break; 2248 case SM_PH2_CALC_STK: 2249 // already busy? 2250 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2251 // calculate STK 2252 if (connection->sm_role){ 2253 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2254 } else { 2255 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2256 } 2257 sm_next_responding_state(connection); 2258 sm_aes128_start(setup->sm_tk, plaintext, connection); 2259 break; 2260 case SM_PH3_Y_GET_ENC: 2261 // already busy? 2262 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2263 // PH3B2 - calculate Y from - enc 2264 // Y = dm(DHK, Rand) 2265 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2266 sm_next_responding_state(connection); 2267 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2268 return; 2269 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2270 uint8_t buffer[17]; 2271 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2272 reverse_128(setup->sm_local_confirm, &buffer[1]); 2273 if (connection->sm_role){ 2274 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2275 } else { 2276 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2277 } 2278 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2279 sm_timeout_reset(connection); 2280 return; 2281 } 2282 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2283 sm_key_t stk_flipped; 2284 reverse_128(setup->sm_ltk, stk_flipped); 2285 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2286 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2287 return; 2288 } 2289 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2290 sm_key_t stk_flipped; 2291 reverse_128(setup->sm_ltk, stk_flipped); 2292 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2293 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2294 return; 2295 } 2296 case SM_RESPONDER_PH4_SEND_LTK: { 2297 sm_key_t ltk_flipped; 2298 reverse_128(setup->sm_ltk, ltk_flipped); 2299 connection->sm_engine_state = SM_RESPONDER_IDLE; 2300 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2301 return; 2302 } 2303 case SM_RESPONDER_PH4_Y_GET_ENC: 2304 // already busy? 2305 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2306 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2307 // Y = dm(DHK, Rand) 2308 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2309 sm_next_responding_state(connection); 2310 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2311 return; 2312 2313 case SM_PH3_DISTRIBUTE_KEYS: 2314 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2315 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2316 uint8_t buffer[17]; 2317 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2318 reverse_128(setup->sm_ltk, &buffer[1]); 2319 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2320 sm_timeout_reset(connection); 2321 return; 2322 } 2323 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2324 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2325 uint8_t buffer[11]; 2326 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2327 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2328 reverse_64(setup->sm_local_rand, &buffer[3]); 2329 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2330 sm_timeout_reset(connection); 2331 return; 2332 } 2333 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2334 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2335 uint8_t buffer[17]; 2336 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2337 reverse_128(sm_persistent_irk, &buffer[1]); 2338 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2339 sm_timeout_reset(connection); 2340 return; 2341 } 2342 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2343 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2344 bd_addr_t local_address; 2345 uint8_t buffer[8]; 2346 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2347 gap_advertisements_get_address(&buffer[1], local_address); 2348 reverse_bd_addr(local_address, &buffer[2]); 2349 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2350 sm_timeout_reset(connection); 2351 return; 2352 } 2353 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2354 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2355 2356 // hack to reproduce test runs 2357 if (test_use_fixed_local_csrk){ 2358 memset(setup->sm_local_csrk, 0xcc, 16); 2359 } 2360 2361 uint8_t buffer[17]; 2362 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2363 reverse_128(setup->sm_local_csrk, &buffer[1]); 2364 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2365 sm_timeout_reset(connection); 2366 return; 2367 } 2368 2369 // keys are sent 2370 if (connection->sm_role){ 2371 // slave -> receive master keys if any 2372 if (sm_key_distribution_all_received(connection)){ 2373 sm_key_distribution_handle_all_received(connection); 2374 connection->sm_engine_state = SM_RESPONDER_IDLE; 2375 sm_done_for_handle(connection->sm_handle); 2376 } else { 2377 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2378 } 2379 } else { 2380 // master -> all done 2381 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2382 sm_done_for_handle(connection->sm_handle); 2383 } 2384 break; 2385 2386 default: 2387 break; 2388 } 2389 2390 // check again if active connection was released 2391 if (sm_active_connection) break; 2392 } 2393 } 2394 2395 // note: aes engine is ready as we just got the aes result 2396 static void sm_handle_encryption_result(uint8_t * data){ 2397 2398 sm_aes128_state = SM_AES128_IDLE; 2399 2400 if (sm_address_resolution_ah_calculation_active){ 2401 sm_address_resolution_ah_calculation_active = 0; 2402 // compare calulated address against connecting device 2403 uint8_t hash[3]; 2404 reverse_24(data, hash); 2405 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2406 log_info("LE Device Lookup: matched resolvable private address"); 2407 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2408 return; 2409 } 2410 // no match, try next 2411 sm_address_resolution_test++; 2412 return; 2413 } 2414 2415 switch (dkg_state){ 2416 case DKG_W4_IRK: 2417 reverse_128(data, sm_persistent_irk); 2418 log_info_key("irk", sm_persistent_irk); 2419 dkg_next_state(); 2420 return; 2421 case DKG_W4_DHK: 2422 reverse_128(data, sm_persistent_dhk); 2423 log_info_key("dhk", sm_persistent_dhk); 2424 dkg_next_state(); 2425 // SM Init Finished 2426 return; 2427 default: 2428 break; 2429 } 2430 2431 switch (rau_state){ 2432 case RAU_W4_ENC: 2433 reverse_24(data, &sm_random_address[3]); 2434 rau_next_state(); 2435 return; 2436 default: 2437 break; 2438 } 2439 2440 switch (sm_cmac_state){ 2441 case CMAC_W4_SUBKEYS: 2442 case CMAC_W4_MI: 2443 case CMAC_W4_MLAST: 2444 { 2445 sm_key_t t; 2446 reverse_128(data, t); 2447 sm_cmac_handle_encryption_result(t); 2448 } 2449 return; 2450 default: 2451 break; 2452 } 2453 2454 // retrieve sm_connection provided to sm_aes128_start_encryption 2455 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2456 if (!connection) return; 2457 switch (connection->sm_engine_state){ 2458 case SM_PH2_C1_W4_ENC_A: 2459 case SM_PH2_C1_W4_ENC_C: 2460 { 2461 sm_key_t t2; 2462 reverse_128(data, t2); 2463 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2464 } 2465 sm_next_responding_state(connection); 2466 return; 2467 case SM_PH2_C1_W4_ENC_B: 2468 reverse_128(data, setup->sm_local_confirm); 2469 log_info_key("c1!", setup->sm_local_confirm); 2470 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2471 return; 2472 case SM_PH2_C1_W4_ENC_D: 2473 { 2474 sm_key_t peer_confirm_test; 2475 reverse_128(data, peer_confirm_test); 2476 log_info_key("c1!", peer_confirm_test); 2477 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2478 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2479 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2480 return; 2481 } 2482 if (connection->sm_role){ 2483 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2484 } else { 2485 connection->sm_engine_state = SM_PH2_CALC_STK; 2486 } 2487 } 2488 return; 2489 case SM_PH2_W4_STK: 2490 reverse_128(data, setup->sm_ltk); 2491 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2492 log_info_key("stk", setup->sm_ltk); 2493 if (connection->sm_role){ 2494 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2495 } else { 2496 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2497 } 2498 return; 2499 case SM_PH3_Y_W4_ENC:{ 2500 sm_key_t y128; 2501 reverse_128(data, y128); 2502 setup->sm_local_y = big_endian_read_16(y128, 14); 2503 log_info_hex16("y", setup->sm_local_y); 2504 // PH3B3 - calculate EDIV 2505 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2506 log_info_hex16("ediv", setup->sm_local_ediv); 2507 // PH3B4 - calculate LTK - enc 2508 // LTK = d1(ER, DIV, 0)) 2509 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2510 return; 2511 } 2512 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2513 sm_key_t y128; 2514 reverse_128(data, y128); 2515 setup->sm_local_y = big_endian_read_16(y128, 14); 2516 log_info_hex16("y", setup->sm_local_y); 2517 2518 // PH3B3 - calculate DIV 2519 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2520 log_info_hex16("ediv", setup->sm_local_ediv); 2521 // PH3B4 - calculate LTK - enc 2522 // LTK = d1(ER, DIV, 0)) 2523 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2524 return; 2525 } 2526 case SM_PH3_LTK_W4_ENC: 2527 reverse_128(data, setup->sm_ltk); 2528 log_info_key("ltk", setup->sm_ltk); 2529 // calc CSRK next 2530 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2531 return; 2532 case SM_PH3_CSRK_W4_ENC: 2533 reverse_128(data, setup->sm_local_csrk); 2534 log_info_key("csrk", setup->sm_local_csrk); 2535 if (setup->sm_key_distribution_send_set){ 2536 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2537 } else { 2538 // no keys to send, just continue 2539 if (connection->sm_role){ 2540 // slave -> receive master keys 2541 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2542 } else { 2543 // master -> all done 2544 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2545 sm_done_for_handle(connection->sm_handle); 2546 } 2547 } 2548 return; 2549 case SM_RESPONDER_PH4_LTK_W4_ENC: 2550 reverse_128(data, setup->sm_ltk); 2551 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2552 log_info_key("ltk", setup->sm_ltk); 2553 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2554 return; 2555 default: 2556 break; 2557 } 2558 } 2559 2560 #ifdef USE_MBEDTLS_FOR_ECDH 2561 2562 static void sm_log_ec_keypair(void){ 2563 // print keypair 2564 char buffer[100]; 2565 size_t len; 2566 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2567 log_info("d: %s", buffer); 2568 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2569 log_info("X: %s", buffer); 2570 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2571 log_info("Y: %s", buffer); 2572 } 2573 2574 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2575 int offset = setup->sm_passkey_bit; 2576 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2577 while (size) { 2578 if (offset < 32){ 2579 *buffer++ = setup->sm_peer_qx[offset++]; 2580 } else { 2581 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2582 } 2583 size--; 2584 } 2585 setup->sm_passkey_bit = offset; 2586 return 0; 2587 } 2588 #endif 2589 2590 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2591 static void sm_handle_random_result(uint8_t * data){ 2592 2593 #ifdef USE_MBEDTLS_FOR_ECDH 2594 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2595 int num_bytes = setup->sm_passkey_bit; 2596 if (num_bytes < 32){ 2597 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2598 } else { 2599 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2600 } 2601 num_bytes += 8; 2602 setup->sm_passkey_bit = num_bytes; 2603 2604 if (num_bytes >= 64){ 2605 // generate EC key 2606 setup->sm_passkey_bit = 0; 2607 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2608 sm_log_ec_keypair(); 2609 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2610 } 2611 } 2612 #endif 2613 2614 switch (rau_state){ 2615 case RAU_W4_RANDOM: 2616 // non-resolvable vs. resolvable 2617 switch (gap_random_adress_type){ 2618 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2619 // resolvable: use random as prand and calc address hash 2620 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2621 memcpy(sm_random_address, data, 3); 2622 sm_random_address[0] &= 0x3f; 2623 sm_random_address[0] |= 0x40; 2624 rau_state = RAU_GET_ENC; 2625 break; 2626 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2627 default: 2628 // "The two most significant bits of the address shall be equal to ‘0’"" 2629 memcpy(sm_random_address, data, 6); 2630 sm_random_address[0] &= 0x3f; 2631 rau_state = RAU_SET_ADDRESS; 2632 break; 2633 } 2634 return; 2635 default: 2636 break; 2637 } 2638 2639 // retrieve sm_connection provided to sm_random_start 2640 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2641 if (!connection) return; 2642 switch (connection->sm_engine_state){ 2643 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2644 case SM_SC_W4_GET_RANDOM_A: 2645 memcpy(&setup->sm_local_nonce[0], data, 8); 2646 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2647 break; 2648 case SM_SC_W4_GET_RANDOM_B: 2649 memcpy(&setup->sm_local_nonce[8], data, 8); 2650 // initiator & jw/nc -> send pairing random 2651 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2652 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2653 break; 2654 } else { 2655 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2656 } 2657 break; 2658 #endif 2659 2660 case SM_PH2_W4_RANDOM_TK: 2661 { 2662 // map random to 0-999999 without speding much cycles on a modulus operation 2663 uint32_t tk = little_endian_read_32(data,0); 2664 tk = tk & 0xfffff; // 1048575 2665 if (tk >= 999999){ 2666 tk = tk - 999999; 2667 } 2668 sm_reset_tk(); 2669 big_endian_store_32(setup->sm_tk, 12, tk); 2670 if (connection->sm_role){ 2671 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2672 } else { 2673 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2674 sm_trigger_user_response(connection); 2675 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2676 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2677 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2678 } 2679 } 2680 return; 2681 } 2682 case SM_PH2_C1_W4_RANDOM_A: 2683 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2684 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2685 return; 2686 case SM_PH2_C1_W4_RANDOM_B: 2687 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2688 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2689 return; 2690 case SM_PH3_W4_RANDOM: 2691 reverse_64(data, setup->sm_local_rand); 2692 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2693 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2694 // no db for authenticated flag hack: store flag in bit 4 of LSB 2695 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2696 connection->sm_engine_state = SM_PH3_GET_DIV; 2697 return; 2698 case SM_PH3_W4_DIV: 2699 // use 16 bit from random value as div 2700 setup->sm_local_div = big_endian_read_16(data, 0); 2701 log_info_hex16("div", setup->sm_local_div); 2702 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2703 return; 2704 default: 2705 break; 2706 } 2707 } 2708 2709 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2710 2711 sm_connection_t * sm_conn; 2712 hci_con_handle_t con_handle; 2713 2714 switch (packet_type) { 2715 2716 case HCI_EVENT_PACKET: 2717 switch (hci_event_packet_get_type(packet)) { 2718 2719 case BTSTACK_EVENT_STATE: 2720 // bt stack activated, get started 2721 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2722 log_info("HCI Working!"); 2723 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2724 rau_state = RAU_IDLE; 2725 #ifdef USE_MBEDTLS_FOR_ECDH 2726 if (!test_use_fixed_ec_keypair){ 2727 setup->sm_passkey_bit = 0; 2728 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2729 } 2730 #endif 2731 sm_run(); 2732 } 2733 break; 2734 2735 case HCI_EVENT_LE_META: 2736 switch (packet[2]) { 2737 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2738 2739 log_info("sm: connected"); 2740 2741 if (packet[3]) return; // connection failed 2742 2743 con_handle = little_endian_read_16(packet, 4); 2744 sm_conn = sm_get_connection_for_handle(con_handle); 2745 if (!sm_conn) break; 2746 2747 sm_conn->sm_handle = con_handle; 2748 sm_conn->sm_role = packet[6]; 2749 sm_conn->sm_peer_addr_type = packet[7]; 2750 reverse_bd_addr(&packet[8], 2751 sm_conn->sm_peer_address); 2752 2753 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2754 2755 // reset security properties 2756 sm_conn->sm_connection_encrypted = 0; 2757 sm_conn->sm_connection_authenticated = 0; 2758 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2759 sm_conn->sm_le_db_index = -1; 2760 2761 // prepare CSRK lookup (does not involve setup) 2762 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2763 2764 // just connected -> everything else happens in sm_run() 2765 if (sm_conn->sm_role){ 2766 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2767 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2768 if (sm_slave_request_security) { 2769 // request security if requested by app 2770 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2771 } else { 2772 // otherwise, wait for pairing request 2773 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2774 } 2775 } 2776 break; 2777 } else { 2778 // master 2779 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2780 } 2781 break; 2782 2783 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2784 con_handle = little_endian_read_16(packet, 3); 2785 sm_conn = sm_get_connection_for_handle(con_handle); 2786 if (!sm_conn) break; 2787 2788 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2789 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2790 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2791 break; 2792 } 2793 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2794 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2795 break; 2796 } 2797 2798 // store rand and ediv 2799 reverse_64(&packet[5], sm_conn->sm_local_rand); 2800 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2801 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2802 break; 2803 2804 default: 2805 break; 2806 } 2807 break; 2808 2809 case HCI_EVENT_ENCRYPTION_CHANGE: 2810 con_handle = little_endian_read_16(packet, 3); 2811 sm_conn = sm_get_connection_for_handle(con_handle); 2812 if (!sm_conn) break; 2813 2814 sm_conn->sm_connection_encrypted = packet[5]; 2815 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2816 sm_conn->sm_actual_encryption_key_size); 2817 log_info("event handler, state %u", sm_conn->sm_engine_state); 2818 if (!sm_conn->sm_connection_encrypted) break; 2819 // continue if part of initial pairing 2820 switch (sm_conn->sm_engine_state){ 2821 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2822 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2823 sm_done_for_handle(sm_conn->sm_handle); 2824 break; 2825 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2826 if (sm_conn->sm_role){ 2827 // slave 2828 if (setup->sm_use_secure_connections){ 2829 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2830 } else { 2831 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2832 } 2833 } else { 2834 // master 2835 if (sm_key_distribution_all_received(sm_conn)){ 2836 // skip receiving keys as there are none 2837 sm_key_distribution_handle_all_received(sm_conn); 2838 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2839 } else { 2840 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2841 } 2842 } 2843 break; 2844 default: 2845 break; 2846 } 2847 break; 2848 2849 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2850 con_handle = little_endian_read_16(packet, 3); 2851 sm_conn = sm_get_connection_for_handle(con_handle); 2852 if (!sm_conn) break; 2853 2854 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2855 log_info("event handler, state %u", sm_conn->sm_engine_state); 2856 // continue if part of initial pairing 2857 switch (sm_conn->sm_engine_state){ 2858 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2859 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2860 sm_done_for_handle(sm_conn->sm_handle); 2861 break; 2862 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2863 if (sm_conn->sm_role){ 2864 // slave 2865 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2866 } else { 2867 // master 2868 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2869 } 2870 break; 2871 default: 2872 break; 2873 } 2874 break; 2875 2876 2877 case HCI_EVENT_DISCONNECTION_COMPLETE: 2878 con_handle = little_endian_read_16(packet, 3); 2879 sm_done_for_handle(con_handle); 2880 sm_conn = sm_get_connection_for_handle(con_handle); 2881 if (!sm_conn) break; 2882 2883 // delete stored bonding on disconnect with authentication failure in ph0 2884 if (sm_conn->sm_role == 0 2885 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2886 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2887 le_device_db_remove(sm_conn->sm_le_db_index); 2888 } 2889 2890 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2891 sm_conn->sm_handle = 0; 2892 break; 2893 2894 case HCI_EVENT_COMMAND_COMPLETE: 2895 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2896 sm_handle_encryption_result(&packet[6]); 2897 break; 2898 } 2899 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2900 sm_handle_random_result(&packet[6]); 2901 break; 2902 } 2903 break; 2904 default: 2905 break; 2906 } 2907 break; 2908 default: 2909 break; 2910 } 2911 2912 sm_run(); 2913 } 2914 2915 static inline int sm_calc_actual_encryption_key_size(int other){ 2916 if (other < sm_min_encryption_key_size) return 0; 2917 if (other < sm_max_encryption_key_size) return other; 2918 return sm_max_encryption_key_size; 2919 } 2920 2921 2922 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2923 switch (method){ 2924 case JUST_WORKS: 2925 case NK_BOTH_INPUT: 2926 return 1; 2927 default: 2928 return 0; 2929 } 2930 } 2931 // responder 2932 2933 static int sm_passkey_used(stk_generation_method_t method){ 2934 switch (method){ 2935 case PK_RESP_INPUT: 2936 return 1; 2937 default: 2938 return 0; 2939 } 2940 } 2941 2942 /** 2943 * @return ok 2944 */ 2945 static int sm_validate_stk_generation_method(void){ 2946 // check if STK generation method is acceptable by client 2947 switch (setup->sm_stk_generation_method){ 2948 case JUST_WORKS: 2949 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2950 case PK_RESP_INPUT: 2951 case PK_INIT_INPUT: 2952 case OK_BOTH_INPUT: 2953 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2954 case OOB: 2955 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2956 case NK_BOTH_INPUT: 2957 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2958 return 1; 2959 default: 2960 return 0; 2961 } 2962 } 2963 2964 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2965 2966 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2967 sm_run(); 2968 } 2969 2970 if (packet_type != SM_DATA_PACKET) return; 2971 2972 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2973 if (!sm_conn) return; 2974 2975 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2976 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2977 return; 2978 } 2979 2980 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2981 2982 int err; 2983 2984 switch (sm_conn->sm_engine_state){ 2985 2986 // a sm timeout requries a new physical connection 2987 case SM_GENERAL_TIMEOUT: 2988 return; 2989 2990 // Initiator 2991 case SM_INITIATOR_CONNECTED: 2992 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2993 sm_pdu_received_in_wrong_state(sm_conn); 2994 break; 2995 } 2996 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2997 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2998 break; 2999 } 3000 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3001 uint16_t ediv; 3002 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3003 if (ediv){ 3004 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3005 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3006 } else { 3007 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3008 } 3009 break; 3010 } 3011 // otherwise, store security request 3012 sm_conn->sm_security_request_received = 1; 3013 break; 3014 3015 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3016 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3017 sm_pdu_received_in_wrong_state(sm_conn); 3018 break; 3019 } 3020 // store pairing request 3021 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3022 err = sm_stk_generation_init(sm_conn); 3023 if (err){ 3024 setup->sm_pairing_failed_reason = err; 3025 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3026 break; 3027 } 3028 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3029 if (setup->sm_use_secure_connections){ 3030 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3031 if (setup->sm_stk_generation_method == JUST_WORKS){ 3032 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3033 sm_trigger_user_response(sm_conn); 3034 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3035 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3036 } 3037 } else { 3038 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3039 } 3040 break; 3041 } 3042 #endif 3043 // generate random number first, if we need to show passkey 3044 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3045 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3046 break; 3047 } 3048 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3049 sm_trigger_user_response(sm_conn); 3050 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3051 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3052 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3053 } 3054 break; 3055 3056 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3057 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3058 sm_pdu_received_in_wrong_state(sm_conn); 3059 break; 3060 } 3061 3062 // store s_confirm 3063 reverse_128(&packet[1], setup->sm_peer_confirm); 3064 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3065 break; 3066 3067 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3068 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3069 sm_pdu_received_in_wrong_state(sm_conn); 3070 break;; 3071 } 3072 3073 // received random value 3074 reverse_128(&packet[1], setup->sm_peer_random); 3075 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3076 break; 3077 3078 // Responder 3079 case SM_RESPONDER_IDLE: 3080 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3081 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3082 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3083 sm_pdu_received_in_wrong_state(sm_conn); 3084 break;; 3085 } 3086 3087 // store pairing request 3088 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3089 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3090 break; 3091 3092 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3093 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3094 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3095 sm_pdu_received_in_wrong_state(sm_conn); 3096 break; 3097 } 3098 3099 // store public key for DH Key calculation 3100 reverse_256(&packet[01], setup->sm_peer_qx); 3101 reverse_256(&packet[33], setup->sm_peer_qy); 3102 3103 #ifdef USE_MBEDTLS_FOR_ECDH 3104 // validate public key 3105 mbedtls_ecp_group grp; 3106 mbedtls_ecp_group_init( &grp ); 3107 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3108 3109 mbedtls_ecp_point Q; 3110 mbedtls_ecp_point_init( &Q ); 3111 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3112 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3113 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3114 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3115 if (err){ 3116 log_error("sm: peer public key invalid %x", err); 3117 // uses "unspecified reason", there is no "public key invalid" error code 3118 sm_pdu_received_in_wrong_state(sm_conn); 3119 break; 3120 } 3121 #endif 3122 if (sm_conn->sm_role){ 3123 // responder 3124 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3125 } else { 3126 // initiator 3127 // stk generation method 3128 // passkey entry: notify app to show passkey or to request passkey 3129 switch (setup->sm_stk_generation_method){ 3130 case JUST_WORKS: 3131 case NK_BOTH_INPUT: 3132 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3133 break; 3134 case PK_RESP_INPUT: 3135 sm_sc_start_calculating_local_confirm(sm_conn); 3136 break; 3137 case PK_INIT_INPUT: 3138 case OK_BOTH_INPUT: 3139 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3140 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3141 break; 3142 } 3143 sm_sc_start_calculating_local_confirm(sm_conn); 3144 break; 3145 case OOB: 3146 // TODO: implement SC OOB 3147 break; 3148 } 3149 } 3150 break; 3151 3152 case SM_SC_W4_CONFIRMATION: 3153 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3154 sm_pdu_received_in_wrong_state(sm_conn); 3155 break; 3156 } 3157 // received confirm value 3158 reverse_128(&packet[1], setup->sm_peer_confirm); 3159 3160 if (sm_conn->sm_role){ 3161 // responder 3162 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3163 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3164 // still waiting for passkey 3165 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3166 break; 3167 } 3168 } 3169 sm_sc_start_calculating_local_confirm(sm_conn); 3170 } else { 3171 // initiator 3172 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3173 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3174 } else { 3175 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3176 } 3177 } 3178 break; 3179 3180 case SM_SC_W4_PAIRING_RANDOM: 3181 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3182 sm_pdu_received_in_wrong_state(sm_conn); 3183 break; 3184 } 3185 3186 // received random value 3187 reverse_128(&packet[1], setup->sm_peer_nonce); 3188 3189 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3190 // only check for JUST WORK/NC in initiator role AND passkey entry 3191 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3192 if (sm_conn->sm_role || passkey_entry) { 3193 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3194 } 3195 3196 sm_sc_state_after_receiving_random(sm_conn); 3197 break; 3198 3199 case SM_SC_W2_CALCULATE_G2: 3200 case SM_SC_W4_CALCULATE_G2: 3201 case SM_SC_W2_CALCULATE_F5_SALT: 3202 case SM_SC_W4_CALCULATE_F5_SALT: 3203 case SM_SC_W2_CALCULATE_F5_MACKEY: 3204 case SM_SC_W4_CALCULATE_F5_MACKEY: 3205 case SM_SC_W2_CALCULATE_F5_LTK: 3206 case SM_SC_W4_CALCULATE_F5_LTK: 3207 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3208 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3209 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3210 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3211 sm_pdu_received_in_wrong_state(sm_conn); 3212 break; 3213 } 3214 // store DHKey Check 3215 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3216 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3217 3218 // have we been only waiting for dhkey check command? 3219 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3220 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3221 } 3222 break; 3223 #endif 3224 3225 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3226 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3227 sm_pdu_received_in_wrong_state(sm_conn); 3228 break; 3229 } 3230 3231 // received confirm value 3232 reverse_128(&packet[1], setup->sm_peer_confirm); 3233 3234 // notify client to hide shown passkey 3235 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3236 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3237 } 3238 3239 // handle user cancel pairing? 3240 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3241 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3242 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3243 break; 3244 } 3245 3246 // wait for user action? 3247 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3248 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3249 break; 3250 } 3251 3252 // calculate and send local_confirm 3253 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3254 break; 3255 3256 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3257 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3258 sm_pdu_received_in_wrong_state(sm_conn); 3259 break;; 3260 } 3261 3262 // received random value 3263 reverse_128(&packet[1], setup->sm_peer_random); 3264 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3265 break; 3266 3267 case SM_PH3_RECEIVE_KEYS: 3268 switch(packet[0]){ 3269 case SM_CODE_ENCRYPTION_INFORMATION: 3270 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3271 reverse_128(&packet[1], setup->sm_peer_ltk); 3272 break; 3273 3274 case SM_CODE_MASTER_IDENTIFICATION: 3275 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3276 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3277 reverse_64(&packet[3], setup->sm_peer_rand); 3278 break; 3279 3280 case SM_CODE_IDENTITY_INFORMATION: 3281 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3282 reverse_128(&packet[1], setup->sm_peer_irk); 3283 break; 3284 3285 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3286 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3287 setup->sm_peer_addr_type = packet[1]; 3288 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3289 break; 3290 3291 case SM_CODE_SIGNING_INFORMATION: 3292 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3293 reverse_128(&packet[1], setup->sm_peer_csrk); 3294 break; 3295 default: 3296 // Unexpected PDU 3297 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3298 break; 3299 } 3300 // done with key distribution? 3301 if (sm_key_distribution_all_received(sm_conn)){ 3302 3303 sm_key_distribution_handle_all_received(sm_conn); 3304 3305 if (sm_conn->sm_role){ 3306 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3307 sm_done_for_handle(sm_conn->sm_handle); 3308 } else { 3309 if (setup->sm_use_secure_connections){ 3310 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3311 } else { 3312 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3313 } 3314 } 3315 } 3316 break; 3317 default: 3318 // Unexpected PDU 3319 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3320 break; 3321 } 3322 3323 // try to send preparared packet 3324 sm_run(); 3325 } 3326 3327 // Security Manager Client API 3328 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3329 sm_get_oob_data = get_oob_data_callback; 3330 } 3331 3332 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3333 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3334 } 3335 3336 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3337 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3338 } 3339 3340 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3341 sm_min_encryption_key_size = min_size; 3342 sm_max_encryption_key_size = max_size; 3343 } 3344 3345 void sm_set_authentication_requirements(uint8_t auth_req){ 3346 sm_auth_req = auth_req; 3347 } 3348 3349 void sm_set_io_capabilities(io_capability_t io_capability){ 3350 sm_io_capabilities = io_capability; 3351 } 3352 3353 void sm_set_request_security(int enable){ 3354 sm_slave_request_security = enable; 3355 } 3356 3357 void sm_set_er(sm_key_t er){ 3358 memcpy(sm_persistent_er, er, 16); 3359 } 3360 3361 void sm_set_ir(sm_key_t ir){ 3362 memcpy(sm_persistent_ir, ir, 16); 3363 } 3364 3365 // Testing support only 3366 void sm_test_set_irk(sm_key_t irk){ 3367 memcpy(sm_persistent_irk, irk, 16); 3368 sm_persistent_irk_ready = 1; 3369 } 3370 3371 void sm_test_use_fixed_local_csrk(void){ 3372 test_use_fixed_local_csrk = 1; 3373 } 3374 3375 void sm_init(void){ 3376 // set some (BTstack default) ER and IR 3377 int i; 3378 sm_key_t er; 3379 sm_key_t ir; 3380 for (i=0;i<16;i++){ 3381 er[i] = 0x30 + i; 3382 ir[i] = 0x90 + i; 3383 } 3384 sm_set_er(er); 3385 sm_set_ir(ir); 3386 // defaults 3387 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3388 | SM_STK_GENERATION_METHOD_OOB 3389 | SM_STK_GENERATION_METHOD_PASSKEY 3390 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3391 3392 sm_max_encryption_key_size = 16; 3393 sm_min_encryption_key_size = 7; 3394 3395 sm_cmac_state = CMAC_IDLE; 3396 dkg_state = DKG_W4_WORKING; 3397 rau_state = RAU_W4_WORKING; 3398 sm_aes128_state = SM_AES128_IDLE; 3399 sm_address_resolution_test = -1; // no private address to resolve yet 3400 sm_address_resolution_ah_calculation_active = 0; 3401 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3402 sm_address_resolution_general_queue = NULL; 3403 3404 gap_random_adress_update_period = 15 * 60 * 1000L; 3405 3406 sm_active_connection = 0; 3407 3408 test_use_fixed_local_csrk = 0; 3409 3410 // register for HCI Events from HCI 3411 hci_event_callback_registration.callback = &sm_event_packet_handler; 3412 hci_add_event_handler(&hci_event_callback_registration); 3413 3414 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3415 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3416 3417 #ifdef USE_MBEDTLS_FOR_ECDH 3418 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3419 #endif 3420 } 3421 3422 void sm_test_use_fixed_ec_keypair(void){ 3423 test_use_fixed_ec_keypair = 1; 3424 #ifdef USE_MBEDTLS_FOR_ECDH 3425 // use test keypair from spec 3426 mbedtls_ecp_keypair_init(&le_keypair); 3427 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3428 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3429 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3430 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3431 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3432 #endif 3433 } 3434 3435 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3436 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3437 if (!hci_con) return NULL; 3438 return &hci_con->sm_connection; 3439 } 3440 3441 // @returns 0 if not encrypted, 7-16 otherwise 3442 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3443 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3444 if (!sm_conn) return 0; // wrong connection 3445 if (!sm_conn->sm_connection_encrypted) return 0; 3446 return sm_conn->sm_actual_encryption_key_size; 3447 } 3448 3449 int sm_authenticated(hci_con_handle_t con_handle){ 3450 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3451 if (!sm_conn) return 0; // wrong connection 3452 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3453 return sm_conn->sm_connection_authenticated; 3454 } 3455 3456 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3457 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3458 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3459 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3460 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3461 return sm_conn->sm_connection_authorization_state; 3462 } 3463 3464 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3465 switch (sm_conn->sm_engine_state){ 3466 case SM_GENERAL_IDLE: 3467 case SM_RESPONDER_IDLE: 3468 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3469 sm_run(); 3470 break; 3471 default: 3472 break; 3473 } 3474 } 3475 3476 /** 3477 * @brief Trigger Security Request 3478 */ 3479 void sm_send_security_request(hci_con_handle_t con_handle){ 3480 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3481 if (!sm_conn) return; 3482 sm_send_security_request_for_connection(sm_conn); 3483 } 3484 3485 // request pairing 3486 void sm_request_pairing(hci_con_handle_t con_handle){ 3487 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3488 if (!sm_conn) return; // wrong connection 3489 3490 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3491 if (sm_conn->sm_role){ 3492 sm_send_security_request_for_connection(sm_conn); 3493 } else { 3494 // used as a trigger to start central/master/initiator security procedures 3495 uint16_t ediv; 3496 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3497 switch (sm_conn->sm_irk_lookup_state){ 3498 case IRK_LOOKUP_FAILED: 3499 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3500 break; 3501 case IRK_LOOKUP_SUCCEEDED: 3502 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3503 if (ediv){ 3504 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3505 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3506 } else { 3507 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3508 } 3509 break; 3510 default: 3511 sm_conn->sm_bonding_requested = 1; 3512 break; 3513 } 3514 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3515 sm_conn->sm_bonding_requested = 1; 3516 } 3517 } 3518 sm_run(); 3519 } 3520 3521 // called by client app on authorization request 3522 void sm_authorization_decline(hci_con_handle_t con_handle){ 3523 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3524 if (!sm_conn) return; // wrong connection 3525 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3526 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3527 } 3528 3529 void sm_authorization_grant(hci_con_handle_t con_handle){ 3530 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3531 if (!sm_conn) return; // wrong connection 3532 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3533 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3534 } 3535 3536 // GAP Bonding API 3537 3538 void sm_bonding_decline(hci_con_handle_t con_handle){ 3539 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3540 if (!sm_conn) return; // wrong connection 3541 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3542 3543 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3544 switch (setup->sm_stk_generation_method){ 3545 case PK_RESP_INPUT: 3546 case PK_INIT_INPUT: 3547 case OK_BOTH_INPUT: 3548 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3549 break; 3550 case NK_BOTH_INPUT: 3551 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3552 break; 3553 case JUST_WORKS: 3554 case OOB: 3555 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3556 break; 3557 } 3558 } 3559 sm_run(); 3560 } 3561 3562 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3563 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3564 if (!sm_conn) return; // wrong connection 3565 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3566 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3567 if (setup->sm_use_secure_connections){ 3568 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3569 } else { 3570 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3571 } 3572 } 3573 3574 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3575 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3576 sm_sc_prepare_dhkey_check(sm_conn); 3577 } 3578 #endif 3579 3580 sm_run(); 3581 } 3582 3583 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3584 // for now, it's the same 3585 sm_just_works_confirm(con_handle); 3586 } 3587 3588 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3589 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3590 if (!sm_conn) return; // wrong connection 3591 sm_reset_tk(); 3592 big_endian_store_32(setup->sm_tk, 12, passkey); 3593 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3594 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3595 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3596 } 3597 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3598 memcpy(setup->sm_ra, setup->sm_tk, 16); 3599 memcpy(setup->sm_rb, setup->sm_tk, 16); 3600 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3601 sm_sc_start_calculating_local_confirm(sm_conn); 3602 } 3603 #endif 3604 sm_run(); 3605 } 3606 3607 /** 3608 * @brief Identify device in LE Device DB 3609 * @param handle 3610 * @returns index from le_device_db or -1 if not found/identified 3611 */ 3612 int sm_le_device_index(hci_con_handle_t con_handle ){ 3613 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3614 if (!sm_conn) return -1; 3615 return sm_conn->sm_le_db_index; 3616 } 3617 3618 // GAP LE API 3619 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3620 gap_random_address_update_stop(); 3621 gap_random_adress_type = random_address_type; 3622 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3623 gap_random_address_update_start(); 3624 gap_random_address_trigger(); 3625 } 3626 3627 gap_random_address_type_t gap_random_address_get_mode(void){ 3628 return gap_random_adress_type; 3629 } 3630 3631 void gap_random_address_set_update_period(int period_ms){ 3632 gap_random_adress_update_period = period_ms; 3633 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3634 gap_random_address_update_stop(); 3635 gap_random_address_update_start(); 3636 } 3637 3638 void gap_random_address_set(bd_addr_t addr){ 3639 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3640 memcpy(sm_random_address, addr, 6); 3641 rau_state = RAU_SET_ADDRESS; 3642 sm_run(); 3643 } 3644 3645 /* 3646 * @brief Set Advertisement Paramters 3647 * @param adv_int_min 3648 * @param adv_int_max 3649 * @param adv_type 3650 * @param direct_address_type 3651 * @param direct_address 3652 * @param channel_map 3653 * @param filter_policy 3654 * 3655 * @note own_address_type is used from gap_random_address_set_mode 3656 */ 3657 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3658 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3659 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3660 direct_address_typ, direct_address, channel_map, filter_policy); 3661 } 3662 3663