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 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #if defined(MBEDTLS_PLATFORM_C) 66 #include "mbedtls/platform.h" 67 #else 68 #include <stdio.h> 69 #define mbedtls_printf printf 70 #endif 71 #include "mbedtls/ecp.h" 72 #endif 73 74 // 75 // SM internal types and globals 76 // 77 78 typedef enum { 79 DKG_W4_WORKING, 80 DKG_CALC_IRK, 81 DKG_W4_IRK, 82 DKG_CALC_DHK, 83 DKG_W4_DHK, 84 DKG_READY 85 } derived_key_generation_t; 86 87 typedef enum { 88 RAU_W4_WORKING, 89 RAU_IDLE, 90 RAU_GET_RANDOM, 91 RAU_W4_RANDOM, 92 RAU_GET_ENC, 93 RAU_W4_ENC, 94 RAU_SET_ADDRESS, 95 } random_address_update_t; 96 97 typedef enum { 98 CMAC_IDLE, 99 CMAC_CALC_SUBKEYS, 100 CMAC_W4_SUBKEYS, 101 CMAC_CALC_MI, 102 CMAC_W4_MI, 103 CMAC_CALC_MLAST, 104 CMAC_W4_MLAST 105 } cmac_state_t; 106 107 typedef enum { 108 JUST_WORKS, 109 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 110 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 111 OK_BOTH_INPUT, // Only input on both, both input PK 112 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 113 OOB // OOB available on both sides 114 } stk_generation_method_t; 115 116 typedef enum { 117 SM_USER_RESPONSE_IDLE, 118 SM_USER_RESPONSE_PENDING, 119 SM_USER_RESPONSE_CONFIRM, 120 SM_USER_RESPONSE_PASSKEY, 121 SM_USER_RESPONSE_DECLINE 122 } sm_user_response_t; 123 124 typedef enum { 125 SM_AES128_IDLE, 126 SM_AES128_ACTIVE 127 } sm_aes128_state_t; 128 129 typedef enum { 130 ADDRESS_RESOLUTION_IDLE, 131 ADDRESS_RESOLUTION_GENERAL, 132 ADDRESS_RESOLUTION_FOR_CONNECTION, 133 } address_resolution_mode_t; 134 135 typedef enum { 136 ADDRESS_RESOLUTION_SUCEEDED, 137 ADDRESS_RESOLUTION_FAILED, 138 } address_resolution_event_t; 139 140 typedef enum { 141 EC_KEY_GENERATION_IDLE, 142 EC_KEY_GENERATION_ACTIVE, 143 EC_KEY_GENERATION_DONE, 144 } ec_key_generation_state_t; 145 146 typedef enum { 147 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 148 } sm_state_var_t; 149 150 // 151 // GLOBAL DATA 152 // 153 154 static uint8_t test_use_fixed_local_csrk; 155 static uint8_t test_use_fixed_ec_keypair; 156 157 // configuration 158 static uint8_t sm_accepted_stk_generation_methods; 159 static uint8_t sm_max_encryption_key_size; 160 static uint8_t sm_min_encryption_key_size; 161 static uint8_t sm_auth_req = 0; 162 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 163 static uint8_t sm_slave_request_security; 164 165 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 166 static sm_key_t sm_persistent_er; 167 static sm_key_t sm_persistent_ir; 168 169 // derived from sm_persistent_ir 170 static sm_key_t sm_persistent_dhk; 171 static sm_key_t sm_persistent_irk; 172 static uint8_t sm_persistent_irk_ready = 0; // used for testing 173 static derived_key_generation_t dkg_state; 174 175 // derived from sm_persistent_er 176 // .. 177 178 // random address update 179 static random_address_update_t rau_state; 180 static bd_addr_t sm_random_address; 181 182 // CMAC Calculation: General 183 static cmac_state_t sm_cmac_state; 184 static uint16_t sm_cmac_message_len; 185 static sm_key_t sm_cmac_k; 186 static sm_key_t sm_cmac_x; 187 static sm_key_t sm_cmac_m_last; 188 static uint8_t sm_cmac_block_current; 189 static uint8_t sm_cmac_block_count; 190 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 191 static void (*sm_cmac_done_handler)(uint8_t * hash); 192 193 // CMAC for ATT Signed Writes 194 static uint8_t sm_cmac_header[3]; 195 static const uint8_t * sm_cmac_message; 196 static uint8_t sm_cmac_sign_counter[4]; 197 198 // CMAC for Secure Connection functions 199 #ifdef ENABLE_LE_SECURE_CONNECTIONS 200 static sm_connection_t * sm_cmac_connection; 201 static uint8_t sm_cmac_sc_buffer[80]; 202 #endif 203 204 // resolvable private address lookup / CSRK calculation 205 static int sm_address_resolution_test; 206 static int sm_address_resolution_ah_calculation_active; 207 static uint8_t sm_address_resolution_addr_type; 208 static bd_addr_t sm_address_resolution_address; 209 static void * sm_address_resolution_context; 210 static address_resolution_mode_t sm_address_resolution_mode; 211 static btstack_linked_list_t sm_address_resolution_general_queue; 212 213 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 214 static sm_aes128_state_t sm_aes128_state; 215 static void * sm_aes128_context; 216 217 // random engine. store context (ususally sm_connection_t) 218 static void * sm_random_context; 219 220 // to receive hci events 221 static btstack_packet_callback_registration_t hci_event_callback_registration; 222 223 /* to dispatch sm event */ 224 static btstack_linked_list_t sm_event_handlers; 225 226 // Software ECDH implementation provided by mbedtls 227 #ifdef USE_MBEDTLS_FOR_ECDH 228 static mbedtls_ecp_keypair le_keypair; 229 static ec_key_generation_state_t ec_key_generation_state; 230 #endif 231 232 // 233 // Volume 3, Part H, Chapter 24 234 // "Security shall be initiated by the Security Manager in the device in the master role. 235 // The device in the slave role shall be the responding device." 236 // -> master := initiator, slave := responder 237 // 238 239 // data needed for security setup 240 typedef struct sm_setup_context { 241 242 btstack_timer_source_t sm_timeout; 243 244 // used in all phases 245 uint8_t sm_pairing_failed_reason; 246 247 // user response, (Phase 1 and/or 2) 248 uint8_t sm_user_response; 249 250 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 251 int sm_key_distribution_send_set; 252 int sm_key_distribution_received_set; 253 254 // Phase 2 (Pairing over SMP) 255 stk_generation_method_t sm_stk_generation_method; 256 sm_key_t sm_tk; 257 uint8_t sm_use_secure_connections; 258 259 sm_key_t sm_c1_t3_value; // c1 calculation 260 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 261 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 262 sm_key_t sm_local_random; 263 sm_key_t sm_local_confirm; 264 sm_key_t sm_peer_random; 265 sm_key_t sm_peer_confirm; 266 uint8_t sm_m_addr_type; // address and type can be removed 267 uint8_t sm_s_addr_type; // '' 268 bd_addr_t sm_m_address; // '' 269 bd_addr_t sm_s_address; // '' 270 sm_key_t sm_ltk; 271 272 #ifdef ENABLE_LE_SECURE_CONNECTIONS 273 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 274 uint8_t sm_peer_qy[32]; // '' 275 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 276 sm_key_t sm_local_nonce; // might be combined with sm_local_random 277 sm_key_t sm_peer_dhkey_check; 278 sm_key_t sm_local_dhkey_check; 279 sm_key_t sm_ra; 280 sm_key_t sm_rb; 281 sm_key_t sm_t; // used for f5 282 sm_key_t sm_mackey; 283 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 284 uint8_t sm_state_vars; 285 #endif 286 287 // Phase 3 288 289 // key distribution, we generate 290 uint16_t sm_local_y; 291 uint16_t sm_local_div; 292 uint16_t sm_local_ediv; 293 uint8_t sm_local_rand[8]; 294 sm_key_t sm_local_ltk; 295 sm_key_t sm_local_csrk; 296 sm_key_t sm_local_irk; 297 // sm_local_address/addr_type not needed 298 299 // key distribution, received from peer 300 uint16_t sm_peer_y; 301 uint16_t sm_peer_div; 302 uint16_t sm_peer_ediv; 303 uint8_t sm_peer_rand[8]; 304 sm_key_t sm_peer_ltk; 305 sm_key_t sm_peer_irk; 306 sm_key_t sm_peer_csrk; 307 uint8_t sm_peer_addr_type; 308 bd_addr_t sm_peer_address; 309 310 } sm_setup_context_t; 311 312 // 313 static sm_setup_context_t the_setup; 314 static sm_setup_context_t * setup = &the_setup; 315 316 // active connection - the one for which the_setup is used for 317 static uint16_t sm_active_connection = 0; 318 319 // @returns 1 if oob data is available 320 // stores oob data in provided 16 byte buffer if not null 321 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 322 323 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 324 static btstack_packet_handler_t sm_client_packet_handler = NULL; 325 326 // horizontal: initiator capabilities 327 // vertial: responder capabilities 328 static const stk_generation_method_t stk_generation_method [5] [5] = { 329 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 330 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 331 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 332 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 333 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 334 }; 335 336 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 337 #ifdef ENABLE_LE_SECURE_CONNECTIONS 338 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 339 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 340 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 341 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 342 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 343 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 344 }; 345 #endif 346 347 static void sm_run(void); 348 static void sm_done_for_handle(hci_con_handle_t con_handle); 349 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 350 static inline int sm_calc_actual_encryption_key_size(int other); 351 static int sm_validate_stk_generation_method(void); 352 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 353 354 static void log_info_hex16(const char * name, uint16_t value){ 355 log_info("%-6s 0x%04x", name, value); 356 } 357 358 // @returns 1 if all bytes are 0 359 static int sm_is_null(uint8_t * data, int size){ 360 int i; 361 for (i=0; i < size ; i++){ 362 if (data[i]) return 0; 363 } 364 return 1; 365 } 366 367 static int sm_is_null_random(uint8_t random[8]){ 368 return sm_is_null(random, 8); 369 } 370 371 static int sm_is_null_key(uint8_t * key){ 372 return sm_is_null(key, 16); 373 } 374 375 // Key utils 376 static void sm_reset_tk(void){ 377 int i; 378 for (i=0;i<16;i++){ 379 setup->sm_tk[i] = 0; 380 } 381 } 382 383 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 384 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 385 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 386 int i; 387 for (i = max_encryption_size ; i < 16 ; i++){ 388 key[15-i] = 0; 389 } 390 } 391 392 // SMP Timeout implementation 393 394 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 395 // the Security Manager Timer shall be reset and started. 396 // 397 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 398 // 399 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 400 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 401 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 402 // established. 403 404 static void sm_timeout_handler(btstack_timer_source_t * timer){ 405 log_info("SM timeout"); 406 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 407 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 408 sm_done_for_handle(sm_conn->sm_handle); 409 410 // trigger handling of next ready connection 411 sm_run(); 412 } 413 static void sm_timeout_start(sm_connection_t * sm_conn){ 414 btstack_run_loop_remove_timer(&setup->sm_timeout); 415 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 416 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 417 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 418 btstack_run_loop_add_timer(&setup->sm_timeout); 419 } 420 static void sm_timeout_stop(void){ 421 btstack_run_loop_remove_timer(&setup->sm_timeout); 422 } 423 static void sm_timeout_reset(sm_connection_t * sm_conn){ 424 sm_timeout_stop(); 425 sm_timeout_start(sm_conn); 426 } 427 428 // end of sm timeout 429 430 // GAP Random Address updates 431 static gap_random_address_type_t gap_random_adress_type; 432 static btstack_timer_source_t gap_random_address_update_timer; 433 static uint32_t gap_random_adress_update_period; 434 435 static void gap_random_address_trigger(void){ 436 if (rau_state != RAU_IDLE) return; 437 log_info("gap_random_address_trigger"); 438 rau_state = RAU_GET_RANDOM; 439 sm_run(); 440 } 441 442 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 443 log_info("GAP Random Address Update due"); 444 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 445 btstack_run_loop_add_timer(&gap_random_address_update_timer); 446 gap_random_address_trigger(); 447 } 448 449 static void gap_random_address_update_start(void){ 450 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 451 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 452 btstack_run_loop_add_timer(&gap_random_address_update_timer); 453 } 454 455 static void gap_random_address_update_stop(void){ 456 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 457 } 458 459 460 static void sm_random_start(void * context){ 461 sm_random_context = context; 462 hci_send_cmd(&hci_le_rand); 463 } 464 465 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 466 // context is made availabe to aes128 result handler by this 467 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 468 sm_aes128_state = SM_AES128_ACTIVE; 469 sm_key_t key_flipped, plaintext_flipped; 470 reverse_128(key, key_flipped); 471 reverse_128(plaintext, plaintext_flipped); 472 sm_aes128_context = context; 473 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 474 } 475 476 // ah(k,r) helper 477 // r = padding || r 478 // r - 24 bit value 479 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 480 // r'= padding || r 481 memset(r_prime, 0, 16); 482 memcpy(&r_prime[13], r, 3); 483 } 484 485 // d1 helper 486 // d' = padding || r || d 487 // d,r - 16 bit values 488 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 489 // d'= padding || r || d 490 memset(d1_prime, 0, 16); 491 big_endian_store_16(d1_prime, 12, r); 492 big_endian_store_16(d1_prime, 14, d); 493 } 494 495 // dm helper 496 // r’ = padding || r 497 // r - 64 bit value 498 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 499 memset(r_prime, 0, 16); 500 memcpy(&r_prime[8], r, 8); 501 } 502 503 // calculate arguments for first AES128 operation in C1 function 504 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){ 505 506 // p1 = pres || preq || rat’ || iat’ 507 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 508 // cant octet of pres becomes the most significant octet of p1. 509 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 510 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 511 // p1 is 0x05000800000302070710000001010001." 512 513 sm_key_t p1; 514 reverse_56(pres, &p1[0]); 515 reverse_56(preq, &p1[7]); 516 p1[14] = rat; 517 p1[15] = iat; 518 log_info_key("p1", p1); 519 log_info_key("r", r); 520 521 // t1 = r xor p1 522 int i; 523 for (i=0;i<16;i++){ 524 t1[i] = r[i] ^ p1[i]; 525 } 526 log_info_key("t1", t1); 527 } 528 529 // calculate arguments for second AES128 operation in C1 function 530 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 531 // p2 = padding || ia || ra 532 // "The least significant octet of ra becomes the least significant octet of p2 and 533 // the most significant octet of padding becomes the most significant octet of p2. 534 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 535 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 536 537 sm_key_t p2; 538 memset(p2, 0, 16); 539 memcpy(&p2[4], ia, 6); 540 memcpy(&p2[10], ra, 6); 541 log_info_key("p2", p2); 542 543 // c1 = e(k, t2_xor_p2) 544 int i; 545 for (i=0;i<16;i++){ 546 t3[i] = t2[i] ^ p2[i]; 547 } 548 log_info_key("t3", t3); 549 } 550 551 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 552 log_info_key("r1", r1); 553 log_info_key("r2", r2); 554 memcpy(&r_prime[8], &r2[8], 8); 555 memcpy(&r_prime[0], &r1[8], 8); 556 } 557 558 #ifdef ENABLE_LE_SECURE_CONNECTIONS 559 // Software implementations of crypto toolbox for LE Secure Connection 560 // TODO: replace with code to use AES Engine of HCI Controller 561 typedef uint8_t sm_key24_t[3]; 562 typedef uint8_t sm_key56_t[7]; 563 typedef uint8_t sm_key256_t[32]; 564 565 #if 0 566 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 567 uint32_t rk[RKLENGTH(KEYBITS)]; 568 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 569 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 570 } 571 572 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 573 memcpy(k1, k0, 16); 574 sm_shift_left_by_one_bit_inplace(16, k1); 575 if (k0[0] & 0x80){ 576 k1[15] ^= 0x87; 577 } 578 memcpy(k2, k1, 16); 579 sm_shift_left_by_one_bit_inplace(16, k2); 580 if (k1[0] & 0x80){ 581 k2[15] ^= 0x87; 582 } 583 } 584 585 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 586 sm_key_t k0, k1, k2, zero; 587 memset(zero, 0, 16); 588 589 aes128_calc_cyphertext(key, zero, k0); 590 calc_subkeys(k0, k1, k2); 591 592 int cmac_block_count = (cmac_message_len + 15) / 16; 593 594 // step 3: .. 595 if (cmac_block_count==0){ 596 cmac_block_count = 1; 597 } 598 599 // step 4: set m_last 600 sm_key_t cmac_m_last; 601 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 602 int i; 603 if (sm_cmac_last_block_complete){ 604 for (i=0;i<16;i++){ 605 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 606 } 607 } else { 608 int valid_octets_in_last_block = cmac_message_len & 0x0f; 609 for (i=0;i<16;i++){ 610 if (i < valid_octets_in_last_block){ 611 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 612 continue; 613 } 614 if (i == valid_octets_in_last_block){ 615 cmac_m_last[i] = 0x80 ^ k2[i]; 616 continue; 617 } 618 cmac_m_last[i] = k2[i]; 619 } 620 } 621 622 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 623 // LOG_KEY(cmac_m_last); 624 625 // Step 5 626 sm_key_t cmac_x; 627 memset(cmac_x, 0, 16); 628 629 // Step 6 630 sm_key_t sm_cmac_y; 631 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 632 for (i=0;i<16;i++){ 633 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 634 } 635 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 636 } 637 for (i=0;i<16;i++){ 638 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 639 } 640 641 // Step 7 642 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 643 } 644 #endif 645 646 #if 0 647 // 648 // Link Key Conversion Function h6 649 // 650 // h6(W, keyID) = AES-CMACW(keyID) 651 // - W is 128 bits 652 // - keyID is 32 bits 653 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 654 uint8_t key_id_buffer[4]; 655 big_endian_store_32(key_id_buffer, 0, key_id); 656 aes_cmac(res, w, key_id_buffer, 4); 657 } 658 #endif 659 #endif 660 661 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){ 662 event[0] = type; 663 event[1] = event_size - 2; 664 little_endian_store_16(event, 2, con_handle); 665 event[4] = addr_type; 666 reverse_bd_addr(address, &event[5]); 667 } 668 669 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 670 if (sm_client_packet_handler) { 671 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 672 } 673 // dispatch to all event handlers 674 btstack_linked_list_iterator_t it; 675 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 676 while (btstack_linked_list_iterator_has_next(&it)){ 677 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 678 entry->callback(packet_type, 0, packet, size); 679 } 680 } 681 682 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 683 uint8_t event[11]; 684 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 685 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 686 } 687 688 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){ 689 uint8_t event[15]; 690 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 691 little_endian_store_32(event, 11, passkey); 692 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 693 } 694 695 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){ 696 uint8_t event[13]; 697 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 698 little_endian_store_16(event, 11, index); 699 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 700 } 701 702 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){ 703 704 uint8_t event[18]; 705 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 706 event[11] = result; 707 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 708 } 709 710 // decide on stk generation based on 711 // - pairing request 712 // - io capabilities 713 // - OOB data availability 714 static void sm_setup_tk(void){ 715 716 // default: just works 717 setup->sm_stk_generation_method = JUST_WORKS; 718 719 #ifdef ENABLE_LE_SECURE_CONNECTIONS 720 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 721 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 722 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 723 memset(setup->sm_ra, 0, 16); 724 memset(setup->sm_rb, 0, 16); 725 #else 726 setup->sm_use_secure_connections = 0; 727 #endif 728 729 // If both devices have not set the MITM option in the Authentication Requirements 730 // Flags, then the IO capabilities shall be ignored and the Just Works association 731 // model shall be used. 732 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 733 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 734 log_info("SM: MITM not required by both -> JUST WORKS"); 735 return; 736 } 737 738 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 739 740 // If both devices have out of band authentication data, then the Authentication 741 // Requirements Flags shall be ignored when selecting the pairing method and the 742 // Out of Band pairing method shall be used. 743 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 744 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 745 log_info("SM: have OOB data"); 746 log_info_key("OOB", setup->sm_tk); 747 setup->sm_stk_generation_method = OOB; 748 return; 749 } 750 751 // Reset TK as it has been setup in sm_init_setup 752 sm_reset_tk(); 753 754 // Also use just works if unknown io capabilites 755 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)){ 756 return; 757 } 758 759 // Otherwise the IO capabilities of the devices shall be used to determine the 760 // pairing method as defined in Table 2.4. 761 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 762 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 763 764 #ifdef ENABLE_LE_SECURE_CONNECTIONS 765 // table not define by default 766 if (setup->sm_use_secure_connections){ 767 generation_method = stk_generation_method_with_secure_connection; 768 } 769 #endif 770 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)]; 771 772 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 773 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); 774 } 775 776 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 777 int flags = 0; 778 if (key_set & SM_KEYDIST_ENC_KEY){ 779 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 780 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 781 } 782 if (key_set & SM_KEYDIST_ID_KEY){ 783 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 784 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 785 } 786 if (key_set & SM_KEYDIST_SIGN){ 787 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 788 } 789 return flags; 790 } 791 792 static void sm_setup_key_distribution(uint8_t key_set){ 793 setup->sm_key_distribution_received_set = 0; 794 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 795 } 796 797 // CSRK Key Lookup 798 799 800 static int sm_address_resolution_idle(void){ 801 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 802 } 803 804 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){ 805 memcpy(sm_address_resolution_address, addr, 6); 806 sm_address_resolution_addr_type = addr_type; 807 sm_address_resolution_test = 0; 808 sm_address_resolution_mode = mode; 809 sm_address_resolution_context = context; 810 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 811 } 812 813 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 814 // check if already in list 815 btstack_linked_list_iterator_t it; 816 sm_lookup_entry_t * entry; 817 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 818 while(btstack_linked_list_iterator_has_next(&it)){ 819 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 820 if (entry->address_type != address_type) continue; 821 if (memcmp(entry->address, address, 6)) continue; 822 // already in list 823 return BTSTACK_BUSY; 824 } 825 entry = btstack_memory_sm_lookup_entry_get(); 826 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 827 entry->address_type = (bd_addr_type_t) address_type; 828 memcpy(entry->address, address, 6); 829 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 830 sm_run(); 831 return 0; 832 } 833 834 // CMAC Implementation using AES128 engine 835 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 836 int i; 837 int carry = 0; 838 for (i=len-1; i >= 0 ; i--){ 839 int new_carry = data[i] >> 7; 840 data[i] = data[i] << 1 | carry; 841 carry = new_carry; 842 } 843 } 844 845 // 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 846 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 847 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 848 } 849 static inline void dkg_next_state(void){ 850 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 851 } 852 static inline void rau_next_state(void){ 853 rau_state = (random_address_update_t) (((int)rau_state) + 1); 854 } 855 856 // CMAC calculation using AES Engine 857 858 static inline void sm_cmac_next_state(void){ 859 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 860 } 861 862 static int sm_cmac_last_block_complete(void){ 863 if (sm_cmac_message_len == 0) return 0; 864 return (sm_cmac_message_len & 0x0f) == 0; 865 } 866 867 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 868 if (offset >= sm_cmac_message_len) { 869 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 870 return 0; 871 } 872 873 offset = sm_cmac_message_len - 1 - offset; 874 875 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 876 if (offset < 3){ 877 return sm_cmac_header[offset]; 878 } 879 int actual_message_len_incl_header = sm_cmac_message_len - 4; 880 if (offset < actual_message_len_incl_header){ 881 return sm_cmac_message[offset - 3]; 882 } 883 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 884 } 885 886 // generic cmac calculation 887 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])){ 888 // Generalized CMAC 889 memcpy(sm_cmac_k, key, 16); 890 memset(sm_cmac_x, 0, 16); 891 sm_cmac_block_current = 0; 892 sm_cmac_message_len = message_len; 893 sm_cmac_done_handler = done_callback; 894 sm_cmac_get_byte = get_byte_callback; 895 896 // step 2: n := ceil(len/const_Bsize); 897 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 898 899 // step 3: .. 900 if (sm_cmac_block_count==0){ 901 sm_cmac_block_count = 1; 902 } 903 log_info("sm_cmac_connection %p", sm_cmac_connection); 904 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 905 906 // first, we need to compute l for k1, k2, and m_last 907 sm_cmac_state = CMAC_CALC_SUBKEYS; 908 909 // let's go 910 sm_run(); 911 } 912 913 // cmac for ATT Message signing 914 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)){ 915 // ATT Message Signing 916 sm_cmac_header[0] = opcode; 917 little_endian_store_16(sm_cmac_header, 1, con_handle); 918 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 919 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 920 sm_cmac_message = message; 921 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 922 } 923 924 int sm_cmac_ready(void){ 925 return sm_cmac_state == CMAC_IDLE; 926 } 927 928 static void sm_cmac_handle_aes_engine_ready(void){ 929 switch (sm_cmac_state){ 930 case CMAC_CALC_SUBKEYS: { 931 sm_key_t const_zero; 932 memset(const_zero, 0, 16); 933 sm_cmac_next_state(); 934 sm_aes128_start(sm_cmac_k, const_zero, NULL); 935 break; 936 } 937 case CMAC_CALC_MI: { 938 int j; 939 sm_key_t y; 940 for (j=0;j<16;j++){ 941 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 942 } 943 sm_cmac_block_current++; 944 sm_cmac_next_state(); 945 sm_aes128_start(sm_cmac_k, y, NULL); 946 break; 947 } 948 case CMAC_CALC_MLAST: { 949 int i; 950 sm_key_t y; 951 for (i=0;i<16;i++){ 952 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 953 } 954 log_info_key("Y", y); 955 sm_cmac_block_current++; 956 sm_cmac_next_state(); 957 sm_aes128_start(sm_cmac_k, y, NULL); 958 break; 959 } 960 default: 961 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 962 break; 963 } 964 } 965 966 static void sm_cmac_handle_encryption_result(sm_key_t data){ 967 switch (sm_cmac_state){ 968 case CMAC_W4_SUBKEYS: { 969 sm_key_t k1; 970 memcpy(k1, data, 16); 971 sm_shift_left_by_one_bit_inplace(16, k1); 972 if (data[0] & 0x80){ 973 k1[15] ^= 0x87; 974 } 975 sm_key_t k2; 976 memcpy(k2, k1, 16); 977 sm_shift_left_by_one_bit_inplace(16, k2); 978 if (k1[0] & 0x80){ 979 k2[15] ^= 0x87; 980 } 981 982 log_info_key("k", sm_cmac_k); 983 log_info_key("k1", k1); 984 log_info_key("k2", k2); 985 986 // step 4: set m_last 987 int i; 988 if (sm_cmac_last_block_complete()){ 989 for (i=0;i<16;i++){ 990 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 991 } 992 } else { 993 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 994 for (i=0;i<16;i++){ 995 if (i < valid_octets_in_last_block){ 996 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 997 continue; 998 } 999 if (i == valid_octets_in_last_block){ 1000 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1001 continue; 1002 } 1003 sm_cmac_m_last[i] = k2[i]; 1004 } 1005 } 1006 1007 // next 1008 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1009 break; 1010 } 1011 case CMAC_W4_MI: 1012 memcpy(sm_cmac_x, data, 16); 1013 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1014 break; 1015 case CMAC_W4_MLAST: 1016 // done 1017 log_info("Setting CMAC Engine to IDLE"); 1018 sm_cmac_state = CMAC_IDLE; 1019 log_info_key("CMAC", data); 1020 sm_cmac_done_handler(data); 1021 break; 1022 default: 1023 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1024 break; 1025 } 1026 } 1027 1028 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1029 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1030 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1031 switch (setup->sm_stk_generation_method){ 1032 case PK_RESP_INPUT: 1033 if (sm_conn->sm_role){ 1034 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1035 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1036 } else { 1037 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)); 1038 } 1039 break; 1040 case PK_INIT_INPUT: 1041 if (sm_conn->sm_role){ 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 } else { 1044 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1045 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1046 } 1047 break; 1048 case OK_BOTH_INPUT: 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 break; 1052 case NK_BOTH_INPUT: 1053 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1054 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)); 1055 break; 1056 case JUST_WORKS: 1057 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1058 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1059 break; 1060 case OOB: 1061 // client already provided OOB data, let's skip notification. 1062 break; 1063 } 1064 } 1065 1066 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1067 int recv_flags; 1068 if (sm_conn->sm_role){ 1069 // slave / responder 1070 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1071 } else { 1072 // master / initiator 1073 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1074 } 1075 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1076 return recv_flags == setup->sm_key_distribution_received_set; 1077 } 1078 1079 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1080 if (sm_active_connection == con_handle){ 1081 sm_timeout_stop(); 1082 sm_active_connection = 0; 1083 log_info("sm: connection 0x%x released setup context", con_handle); 1084 } 1085 } 1086 1087 static int sm_key_distribution_flags_for_auth_req(void){ 1088 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1089 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1090 // encryption information only if bonding requested 1091 flags |= SM_KEYDIST_ENC_KEY; 1092 } 1093 return flags; 1094 } 1095 1096 static void sm_init_setup(sm_connection_t * sm_conn){ 1097 1098 // fill in sm setup 1099 setup->sm_state_vars = 0; 1100 sm_reset_tk(); 1101 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1102 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1103 1104 // query client for OOB data 1105 int have_oob_data = 0; 1106 if (sm_get_oob_data) { 1107 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1108 } 1109 1110 sm_pairing_packet_t * local_packet; 1111 if (sm_conn->sm_role){ 1112 // slave 1113 local_packet = &setup->sm_s_pres; 1114 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1115 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1116 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1117 } else { 1118 // master 1119 local_packet = &setup->sm_m_preq; 1120 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1121 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1122 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1123 1124 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1125 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1126 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1127 } 1128 1129 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1130 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1131 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1132 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1133 } 1134 1135 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1136 1137 sm_pairing_packet_t * remote_packet; 1138 int remote_key_request; 1139 if (sm_conn->sm_role){ 1140 // slave / responder 1141 remote_packet = &setup->sm_m_preq; 1142 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1143 } else { 1144 // master / initiator 1145 remote_packet = &setup->sm_s_pres; 1146 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1147 } 1148 1149 // check key size 1150 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1151 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1152 1153 // decide on STK generation method 1154 sm_setup_tk(); 1155 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1156 1157 // check if STK generation method is acceptable by client 1158 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1159 1160 // identical to responder 1161 sm_setup_key_distribution(remote_key_request); 1162 1163 // JUST WORKS doens't provide authentication 1164 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1165 1166 return 0; 1167 } 1168 1169 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1170 1171 // cache and reset context 1172 int matched_device_id = sm_address_resolution_test; 1173 address_resolution_mode_t mode = sm_address_resolution_mode; 1174 void * context = sm_address_resolution_context; 1175 1176 // reset context 1177 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1178 sm_address_resolution_context = NULL; 1179 sm_address_resolution_test = -1; 1180 hci_con_handle_t con_handle = 0; 1181 1182 sm_connection_t * sm_connection; 1183 uint16_t ediv; 1184 switch (mode){ 1185 case ADDRESS_RESOLUTION_GENERAL: 1186 break; 1187 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1188 sm_connection = (sm_connection_t *) context; 1189 con_handle = sm_connection->sm_handle; 1190 switch (event){ 1191 case ADDRESS_RESOLUTION_SUCEEDED: 1192 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1193 sm_connection->sm_le_db_index = matched_device_id; 1194 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1195 if (sm_connection->sm_role) break; 1196 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1197 sm_connection->sm_security_request_received = 0; 1198 sm_connection->sm_bonding_requested = 0; 1199 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1200 if (ediv){ 1201 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1202 } else { 1203 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1204 } 1205 break; 1206 case ADDRESS_RESOLUTION_FAILED: 1207 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1208 if (sm_connection->sm_role) break; 1209 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1210 sm_connection->sm_security_request_received = 0; 1211 sm_connection->sm_bonding_requested = 0; 1212 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1213 break; 1214 } 1215 break; 1216 default: 1217 break; 1218 } 1219 1220 switch (event){ 1221 case ADDRESS_RESOLUTION_SUCEEDED: 1222 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1223 break; 1224 case ADDRESS_RESOLUTION_FAILED: 1225 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1226 break; 1227 } 1228 } 1229 1230 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1231 1232 int le_db_index = -1; 1233 1234 // lookup device based on IRK 1235 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1236 int i; 1237 for (i=0; i < le_device_db_count(); i++){ 1238 sm_key_t irk; 1239 bd_addr_t address; 1240 int address_type; 1241 le_device_db_info(i, &address_type, address, irk); 1242 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1243 log_info("sm: device found for IRK, updating"); 1244 le_db_index = i; 1245 break; 1246 } 1247 } 1248 } 1249 1250 // if not found, lookup via public address if possible 1251 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1252 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1253 int i; 1254 for (i=0; i < le_device_db_count(); i++){ 1255 bd_addr_t address; 1256 int address_type; 1257 le_device_db_info(i, &address_type, address, NULL); 1258 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1259 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1260 log_info("sm: device found for public address, updating"); 1261 le_db_index = i; 1262 break; 1263 } 1264 } 1265 } 1266 1267 // if not found, add to db 1268 if (le_db_index < 0) { 1269 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1270 } 1271 1272 if (le_db_index >= 0){ 1273 le_device_db_local_counter_set(le_db_index, 0); 1274 1275 // store local CSRK 1276 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1277 log_info("sm: store local CSRK"); 1278 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1279 le_device_db_local_counter_set(le_db_index, 0); 1280 } 1281 1282 // store remote CSRK 1283 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1284 log_info("sm: store remote CSRK"); 1285 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1286 le_device_db_remote_counter_set(le_db_index, 0); 1287 } 1288 1289 // store encryption information 1290 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1291 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1292 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1293 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1294 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1295 } 1296 } 1297 1298 // keep le_db_index 1299 sm_conn->sm_le_db_index = le_db_index; 1300 } 1301 1302 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1303 setup->sm_pairing_failed_reason = reason; 1304 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1305 } 1306 1307 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1308 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1309 } 1310 1311 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1312 1313 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1314 static int sm_passkey_used(stk_generation_method_t method); 1315 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1316 1317 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1318 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1319 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1320 } else { 1321 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1322 } 1323 } 1324 1325 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1326 if (sm_conn->sm_role){ 1327 // Responder 1328 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1329 } else { 1330 // Initiator role 1331 switch (setup->sm_stk_generation_method){ 1332 case JUST_WORKS: 1333 sm_sc_prepare_dhkey_check(sm_conn); 1334 break; 1335 1336 case NK_BOTH_INPUT: 1337 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1338 break; 1339 case PK_INIT_INPUT: 1340 case PK_RESP_INPUT: 1341 case OK_BOTH_INPUT: 1342 if (setup->sm_passkey_bit < 20) { 1343 sm_sc_start_calculating_local_confirm(sm_conn); 1344 } else { 1345 sm_sc_prepare_dhkey_check(sm_conn); 1346 } 1347 break; 1348 case OOB: 1349 // TODO: implement SC OOB 1350 break; 1351 } 1352 } 1353 } 1354 1355 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1356 return sm_cmac_sc_buffer[offset]; 1357 } 1358 1359 static void sm_sc_cmac_done(uint8_t * hash){ 1360 log_info("sm_sc_cmac_done: "); 1361 log_info_hexdump(hash, 16); 1362 1363 sm_connection_t * sm_conn = sm_cmac_connection; 1364 sm_cmac_connection = NULL; 1365 1366 switch (sm_conn->sm_engine_state){ 1367 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1368 memcpy(setup->sm_local_confirm, hash, 16); 1369 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1370 break; 1371 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1372 // check 1373 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1374 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1375 break; 1376 } 1377 sm_sc_state_after_receiving_random(sm_conn); 1378 break; 1379 case SM_SC_W4_CALCULATE_G2: { 1380 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1381 big_endian_store_32(setup->sm_tk, 12, vab); 1382 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1383 sm_trigger_user_response(sm_conn); 1384 break; 1385 } 1386 case SM_SC_W4_CALCULATE_F5_SALT: 1387 memcpy(setup->sm_t, hash, 16); 1388 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1389 break; 1390 case SM_SC_W4_CALCULATE_F5_MACKEY: 1391 memcpy(setup->sm_mackey, hash, 16); 1392 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1393 break; 1394 case SM_SC_W4_CALCULATE_F5_LTK: 1395 memcpy(setup->sm_ltk, hash, 16); 1396 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1397 break; 1398 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1399 memcpy(setup->sm_local_dhkey_check, hash, 16); 1400 if (sm_conn->sm_role){ 1401 // responder 1402 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1403 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1404 } else { 1405 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1406 } 1407 } else { 1408 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1409 } 1410 break; 1411 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1412 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1413 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1414 break; 1415 } 1416 if (sm_conn->sm_role){ 1417 // responder 1418 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1419 } else { 1420 // initiator 1421 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1422 } 1423 break; 1424 default: 1425 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1426 break; 1427 } 1428 sm_run(); 1429 } 1430 1431 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){ 1432 const uint16_t message_len = 65; 1433 sm_cmac_connection = sm_conn; 1434 memcpy(sm_cmac_sc_buffer, u, 32); 1435 memcpy(sm_cmac_sc_buffer+32, v, 32); 1436 sm_cmac_sc_buffer[64] = z; 1437 log_info("f4 key"); 1438 log_info_hexdump(x, 16); 1439 log_info("f4 message"); 1440 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1441 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1442 } 1443 1444 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1445 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1446 static const uint8_t f5_length[] = { 0x01, 0x00}; 1447 1448 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1449 #ifdef USE_MBEDTLS_FOR_ECDH 1450 // da * Pb 1451 mbedtls_ecp_group grp; 1452 mbedtls_ecp_group_init(&grp ); 1453 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1454 mbedtls_ecp_point Q; 1455 mbedtls_ecp_point_init( &Q ); 1456 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1457 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1458 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1459 mbedtls_ecp_point DH; 1460 mbedtls_ecp_point_init(&DH); 1461 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1462 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1463 mbedtls_ecp_point_free(&DH); 1464 mbedtls_ecp_point_free(&Q); 1465 mbedtls_ecp_group_free(&grp); 1466 #endif 1467 log_info("dhkey"); 1468 log_info_hexdump(dhkey, 32); 1469 } 1470 1471 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1472 // calculate DHKEY 1473 sm_key256_t dhkey; 1474 sm_sc_calculate_dhkey(dhkey); 1475 1476 // calculate salt for f5 1477 const uint16_t message_len = 32; 1478 sm_cmac_connection = sm_conn; 1479 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1480 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1481 } 1482 1483 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){ 1484 const uint16_t message_len = 53; 1485 sm_cmac_connection = sm_conn; 1486 1487 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1488 sm_cmac_sc_buffer[0] = 0; 1489 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1490 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1491 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1492 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1493 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1494 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1495 log_info("f5 key"); 1496 log_info_hexdump(t, 16); 1497 log_info("f5 message for MacKey"); 1498 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1499 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1500 } 1501 1502 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1503 sm_key56_t bd_addr_master, bd_addr_slave; 1504 bd_addr_master[0] = setup->sm_m_addr_type; 1505 bd_addr_slave[0] = setup->sm_s_addr_type; 1506 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1507 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1508 if (sm_conn->sm_role){ 1509 // responder 1510 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1511 } else { 1512 // initiator 1513 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1514 } 1515 } 1516 1517 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1518 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1519 const uint16_t message_len = 53; 1520 sm_cmac_connection = sm_conn; 1521 sm_cmac_sc_buffer[0] = 1; 1522 // 1..52 setup before 1523 log_info("f5 key"); 1524 log_info_hexdump(t, 16); 1525 log_info("f5 message for LTK"); 1526 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1527 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1528 } 1529 1530 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1531 f5_ltk(sm_conn, setup->sm_t); 1532 } 1533 1534 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){ 1535 const uint16_t message_len = 65; 1536 sm_cmac_connection = sm_conn; 1537 memcpy(sm_cmac_sc_buffer, n1, 16); 1538 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1539 memcpy(sm_cmac_sc_buffer+32, r, 16); 1540 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1541 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1542 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1543 log_info("f6 key"); 1544 log_info_hexdump(w, 16); 1545 log_info("f6 message"); 1546 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1547 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1548 } 1549 1550 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1551 // - U is 256 bits 1552 // - V is 256 bits 1553 // - X is 128 bits 1554 // - Y is 128 bits 1555 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){ 1556 const uint16_t message_len = 80; 1557 sm_cmac_connection = sm_conn; 1558 memcpy(sm_cmac_sc_buffer, u, 32); 1559 memcpy(sm_cmac_sc_buffer+32, v, 32); 1560 memcpy(sm_cmac_sc_buffer+64, y, 16); 1561 log_info("g2 key"); 1562 log_info_hexdump(x, 16); 1563 log_info("g2 message"); 1564 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1565 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1566 } 1567 1568 static void g2_calculate(sm_connection_t * sm_conn) { 1569 // calc Va if numeric comparison 1570 uint8_t value[32]; 1571 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1572 if (sm_conn->sm_role){ 1573 // responder 1574 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1575 } else { 1576 // initiator 1577 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1578 } 1579 } 1580 1581 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1582 uint8_t z = 0; 1583 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1584 // some form of passkey 1585 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1586 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1587 setup->sm_passkey_bit++; 1588 } 1589 #ifdef USE_MBEDTLS_FOR_ECDH 1590 uint8_t local_qx[32]; 1591 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1592 #endif 1593 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1594 } 1595 1596 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1597 uint8_t z = 0; 1598 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1599 // some form of passkey 1600 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1601 // sm_passkey_bit was increased before sending confirm value 1602 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1603 } 1604 #ifdef USE_MBEDTLS_FOR_ECDH 1605 uint8_t local_qx[32]; 1606 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1607 #endif 1608 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1609 } 1610 1611 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1612 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1613 } 1614 1615 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1616 // calculate DHKCheck 1617 sm_key56_t bd_addr_master, bd_addr_slave; 1618 bd_addr_master[0] = setup->sm_m_addr_type; 1619 bd_addr_slave[0] = setup->sm_s_addr_type; 1620 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1621 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1622 uint8_t iocap_a[3]; 1623 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1624 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1625 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1626 uint8_t iocap_b[3]; 1627 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1628 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1629 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1630 if (sm_conn->sm_role){ 1631 // responder 1632 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); 1633 } else { 1634 // initiator 1635 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); 1636 } 1637 } 1638 1639 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1640 // validate E = f6() 1641 sm_key56_t bd_addr_master, bd_addr_slave; 1642 bd_addr_master[0] = setup->sm_m_addr_type; 1643 bd_addr_slave[0] = setup->sm_s_addr_type; 1644 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1645 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1646 1647 uint8_t iocap_a[3]; 1648 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1649 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1650 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1651 uint8_t iocap_b[3]; 1652 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1653 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1654 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1655 if (sm_conn->sm_role){ 1656 // responder 1657 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); 1658 } else { 1659 // initiator 1660 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); 1661 } 1662 } 1663 #endif 1664 1665 static void sm_load_security_info(sm_connection_t * sm_connection){ 1666 int encryption_key_size; 1667 int authenticated; 1668 int authorized; 1669 1670 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1671 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1672 &encryption_key_size, &authenticated, &authorized); 1673 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1674 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1675 sm_connection->sm_connection_authenticated = authenticated; 1676 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1677 } 1678 1679 static void sm_run(void){ 1680 1681 btstack_linked_list_iterator_t it; 1682 1683 // assert that we can send at least commands 1684 if (!hci_can_send_command_packet_now()) return; 1685 1686 // 1687 // non-connection related behaviour 1688 // 1689 1690 // distributed key generation 1691 switch (dkg_state){ 1692 case DKG_CALC_IRK: 1693 // already busy? 1694 if (sm_aes128_state == SM_AES128_IDLE) { 1695 // IRK = d1(IR, 1, 0) 1696 sm_key_t d1_prime; 1697 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1698 dkg_next_state(); 1699 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1700 return; 1701 } 1702 break; 1703 case DKG_CALC_DHK: 1704 // already busy? 1705 if (sm_aes128_state == SM_AES128_IDLE) { 1706 // DHK = d1(IR, 3, 0) 1707 sm_key_t d1_prime; 1708 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1709 dkg_next_state(); 1710 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1711 return; 1712 } 1713 break; 1714 default: 1715 break; 1716 } 1717 1718 #ifdef USE_MBEDTLS_FOR_ECDH 1719 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1720 sm_random_start(NULL); 1721 return; 1722 } 1723 #endif 1724 1725 // random address updates 1726 switch (rau_state){ 1727 case RAU_GET_RANDOM: 1728 rau_next_state(); 1729 sm_random_start(NULL); 1730 return; 1731 case RAU_GET_ENC: 1732 // already busy? 1733 if (sm_aes128_state == SM_AES128_IDLE) { 1734 sm_key_t r_prime; 1735 sm_ah_r_prime(sm_random_address, r_prime); 1736 rau_next_state(); 1737 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1738 return; 1739 } 1740 break; 1741 case RAU_SET_ADDRESS: 1742 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1743 rau_state = RAU_IDLE; 1744 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1745 return; 1746 default: 1747 break; 1748 } 1749 1750 // CMAC 1751 switch (sm_cmac_state){ 1752 case CMAC_CALC_SUBKEYS: 1753 case CMAC_CALC_MI: 1754 case CMAC_CALC_MLAST: 1755 // already busy? 1756 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1757 sm_cmac_handle_aes_engine_ready(); 1758 return; 1759 default: 1760 break; 1761 } 1762 1763 // CSRK Lookup 1764 // -- if csrk lookup ready, find connection that require csrk lookup 1765 if (sm_address_resolution_idle()){ 1766 hci_connections_get_iterator(&it); 1767 while(btstack_linked_list_iterator_has_next(&it)){ 1768 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1769 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1770 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1771 // and start lookup 1772 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); 1773 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1774 break; 1775 } 1776 } 1777 } 1778 1779 // -- if csrk lookup ready, resolved addresses for received addresses 1780 if (sm_address_resolution_idle()) { 1781 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1782 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1783 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1784 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1785 btstack_memory_sm_lookup_entry_free(entry); 1786 } 1787 } 1788 1789 // -- Continue with CSRK device lookup by public or resolvable private address 1790 if (!sm_address_resolution_idle()){ 1791 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1792 while (sm_address_resolution_test < le_device_db_count()){ 1793 int addr_type; 1794 bd_addr_t addr; 1795 sm_key_t irk; 1796 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1797 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1798 1799 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1800 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1801 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1802 break; 1803 } 1804 1805 if (sm_address_resolution_addr_type == 0){ 1806 sm_address_resolution_test++; 1807 continue; 1808 } 1809 1810 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1811 1812 log_info("LE Device Lookup: calculate AH"); 1813 log_info_key("IRK", irk); 1814 1815 sm_key_t r_prime; 1816 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1817 sm_address_resolution_ah_calculation_active = 1; 1818 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1819 return; 1820 } 1821 1822 if (sm_address_resolution_test >= le_device_db_count()){ 1823 log_info("LE Device Lookup: not found"); 1824 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1825 } 1826 } 1827 1828 1829 // 1830 // active connection handling 1831 // -- use loop to handle next connection if lock on setup context is released 1832 1833 while (1) { 1834 1835 // Find connections that requires setup context and make active if no other is locked 1836 hci_connections_get_iterator(&it); 1837 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1838 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1839 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1840 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1841 int done = 1; 1842 int err; 1843 switch (sm_connection->sm_engine_state) { 1844 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1845 // send packet if possible, 1846 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1847 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1848 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1849 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1850 } else { 1851 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1852 } 1853 // don't lock sxetup context yet 1854 done = 0; 1855 break; 1856 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1857 sm_init_setup(sm_connection); 1858 // recover pairing request 1859 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1860 err = sm_stk_generation_init(sm_connection); 1861 if (err){ 1862 setup->sm_pairing_failed_reason = err; 1863 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1864 break; 1865 } 1866 sm_timeout_start(sm_connection); 1867 // generate random number first, if we need to show passkey 1868 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1869 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1870 break; 1871 } 1872 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1873 break; 1874 case SM_INITIATOR_PH0_HAS_LTK: 1875 sm_load_security_info(sm_connection); 1876 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1877 break; 1878 case SM_RESPONDER_PH0_RECEIVED_LTK: 1879 switch (sm_connection->sm_irk_lookup_state){ 1880 case IRK_LOOKUP_SUCCEEDED:{ 1881 sm_load_security_info(sm_connection); 1882 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1883 break; 1884 } 1885 case IRK_LOOKUP_FAILED: 1886 // assume that we don't have a LTK for ediv == 0 and random == null 1887 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1888 log_info("LTK Request: ediv & random are empty"); 1889 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1890 // TODO: no need to lock context yet -> done = 0; 1891 break; 1892 } 1893 // re-establish previously used LTK using Rand and EDIV 1894 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1895 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1896 // re-establish used key encryption size 1897 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1898 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1899 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1900 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1901 log_info("sm: received ltk request with key size %u, authenticated %u", 1902 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1903 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1904 break; 1905 default: 1906 // just wait until IRK lookup is completed 1907 // don't lock sxetup context yet 1908 done = 0; 1909 break; 1910 } 1911 break; 1912 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1913 sm_init_setup(sm_connection); 1914 sm_timeout_start(sm_connection); 1915 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1916 break; 1917 default: 1918 done = 0; 1919 break; 1920 } 1921 if (done){ 1922 sm_active_connection = sm_connection->sm_handle; 1923 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1924 } 1925 } 1926 1927 // 1928 // active connection handling 1929 // 1930 1931 if (sm_active_connection == 0) return; 1932 1933 // assert that we could send a SM PDU - not needed for all of the following 1934 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1935 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1936 return; 1937 } 1938 1939 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1940 if (!connection) return; 1941 1942 sm_key_t plaintext; 1943 int key_distribution_flags; 1944 1945 log_info("sm_run: state %u", connection->sm_engine_state); 1946 1947 // responding state 1948 switch (connection->sm_engine_state){ 1949 1950 // general 1951 case SM_GENERAL_SEND_PAIRING_FAILED: { 1952 uint8_t buffer[2]; 1953 buffer[0] = SM_CODE_PAIRING_FAILED; 1954 buffer[1] = setup->sm_pairing_failed_reason; 1955 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1956 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1957 sm_done_for_handle(connection->sm_handle); 1958 break; 1959 } 1960 1961 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1962 case SM_SC_W2_GET_RANDOM_A: 1963 sm_random_start(connection); 1964 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1965 break; 1966 case SM_SC_W2_GET_RANDOM_B: 1967 sm_random_start(connection); 1968 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1969 break; 1970 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1971 if (!sm_cmac_ready()) break; 1972 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1973 sm_sc_calculate_local_confirm(connection); 1974 break; 1975 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1976 if (!sm_cmac_ready()) break; 1977 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1978 sm_sc_calculate_remote_confirm(connection); 1979 break; 1980 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1981 if (!sm_cmac_ready()) break; 1982 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1983 sm_sc_calculate_f6_for_dhkey_check(connection); 1984 break; 1985 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1986 if (!sm_cmac_ready()) break; 1987 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1988 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1989 break; 1990 case SM_SC_W2_CALCULATE_F5_SALT: 1991 if (!sm_cmac_ready()) break; 1992 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1993 f5_calculate_salt(connection); 1994 break; 1995 case SM_SC_W2_CALCULATE_F5_MACKEY: 1996 if (!sm_cmac_ready()) break; 1997 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 1998 f5_calculate_mackey(connection); 1999 break; 2000 case SM_SC_W2_CALCULATE_F5_LTK: 2001 if (!sm_cmac_ready()) break; 2002 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2003 f5_calculate_ltk(connection); 2004 break; 2005 case SM_SC_W2_CALCULATE_G2: 2006 if (!sm_cmac_ready()) break; 2007 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2008 g2_calculate(connection); 2009 break; 2010 2011 #endif 2012 // initiator side 2013 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2014 sm_key_t peer_ltk_flipped; 2015 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2016 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2017 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2018 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2019 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2020 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2021 return; 2022 } 2023 2024 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2025 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2026 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2027 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2028 sm_timeout_reset(connection); 2029 break; 2030 2031 // responder side 2032 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2033 connection->sm_engine_state = SM_RESPONDER_IDLE; 2034 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2035 sm_done_for_handle(connection->sm_handle); 2036 return; 2037 2038 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2039 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2040 uint8_t buffer[65]; 2041 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2042 // 2043 #ifdef USE_MBEDTLS_FOR_ECDH 2044 uint8_t value[32]; 2045 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2046 reverse_256(value, &buffer[1]); 2047 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2048 reverse_256(value, &buffer[33]); 2049 #endif 2050 2051 // stk generation method 2052 // passkey entry: notify app to show passkey or to request passkey 2053 switch (setup->sm_stk_generation_method){ 2054 case JUST_WORKS: 2055 case NK_BOTH_INPUT: 2056 if (connection->sm_role){ 2057 // responder 2058 sm_sc_start_calculating_local_confirm(connection); 2059 } else { 2060 // initiator 2061 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2062 } 2063 break; 2064 case PK_INIT_INPUT: 2065 case PK_RESP_INPUT: 2066 case OK_BOTH_INPUT: 2067 // use random TK for display 2068 memcpy(setup->sm_ra, setup->sm_tk, 16); 2069 memcpy(setup->sm_rb, setup->sm_tk, 16); 2070 setup->sm_passkey_bit = 0; 2071 2072 if (connection->sm_role){ 2073 // responder 2074 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2075 } else { 2076 // initiator 2077 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2078 } 2079 sm_trigger_user_response(connection); 2080 break; 2081 case OOB: 2082 // TODO: implement SC OOB 2083 break; 2084 } 2085 2086 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2087 sm_timeout_reset(connection); 2088 break; 2089 } 2090 case SM_SC_SEND_CONFIRMATION: { 2091 uint8_t buffer[17]; 2092 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2093 reverse_128(setup->sm_local_confirm, &buffer[1]); 2094 if (connection->sm_role){ 2095 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2096 } else { 2097 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2098 } 2099 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2100 sm_timeout_reset(connection); 2101 break; 2102 } 2103 case SM_SC_SEND_PAIRING_RANDOM: { 2104 uint8_t buffer[17]; 2105 buffer[0] = SM_CODE_PAIRING_RANDOM; 2106 reverse_128(setup->sm_local_nonce, &buffer[1]); 2107 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2108 if (connection->sm_role){ 2109 // responder 2110 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2111 } else { 2112 // initiator 2113 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2114 } 2115 } else { 2116 if (connection->sm_role){ 2117 // responder 2118 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2119 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2120 } else { 2121 sm_sc_prepare_dhkey_check(connection); 2122 } 2123 } else { 2124 // initiator 2125 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2126 } 2127 } 2128 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2129 sm_timeout_reset(connection); 2130 break; 2131 } 2132 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2133 uint8_t buffer[17]; 2134 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2135 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2136 2137 if (connection->sm_role){ 2138 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2139 } else { 2140 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2141 } 2142 2143 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2144 sm_timeout_reset(connection); 2145 break; 2146 } 2147 2148 #endif 2149 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2150 // echo initiator for now 2151 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2152 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2153 2154 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2155 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2156 if (setup->sm_use_secure_connections){ 2157 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2158 // skip LTK/EDIV for SC 2159 log_info("sm: dropping encryption information flag"); 2160 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2161 } 2162 #endif 2163 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); 2164 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); 2165 // update key distribution after ENC was dropped 2166 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2167 2168 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2169 sm_timeout_reset(connection); 2170 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2171 if (setup->sm_stk_generation_method == JUST_WORKS){ 2172 sm_trigger_user_response(connection); 2173 } 2174 return; 2175 2176 case SM_PH2_SEND_PAIRING_RANDOM: { 2177 uint8_t buffer[17]; 2178 buffer[0] = SM_CODE_PAIRING_RANDOM; 2179 reverse_128(setup->sm_local_random, &buffer[1]); 2180 if (connection->sm_role){ 2181 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2182 } else { 2183 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2184 } 2185 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2186 sm_timeout_reset(connection); 2187 break; 2188 } 2189 2190 case SM_PH2_GET_RANDOM_TK: 2191 case SM_PH2_C1_GET_RANDOM_A: 2192 case SM_PH2_C1_GET_RANDOM_B: 2193 case SM_PH3_GET_RANDOM: 2194 case SM_PH3_GET_DIV: 2195 sm_next_responding_state(connection); 2196 sm_random_start(connection); 2197 return; 2198 2199 case SM_PH2_C1_GET_ENC_B: 2200 case SM_PH2_C1_GET_ENC_D: 2201 // already busy? 2202 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2203 sm_next_responding_state(connection); 2204 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2205 return; 2206 2207 case SM_PH3_LTK_GET_ENC: 2208 case SM_RESPONDER_PH4_LTK_GET_ENC: 2209 // already busy? 2210 if (sm_aes128_state == SM_AES128_IDLE) { 2211 sm_key_t d_prime; 2212 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2213 sm_next_responding_state(connection); 2214 sm_aes128_start(sm_persistent_er, d_prime, connection); 2215 return; 2216 } 2217 break; 2218 2219 case SM_PH3_CSRK_GET_ENC: 2220 // already busy? 2221 if (sm_aes128_state == SM_AES128_IDLE) { 2222 sm_key_t d_prime; 2223 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2224 sm_next_responding_state(connection); 2225 sm_aes128_start(sm_persistent_er, d_prime, connection); 2226 return; 2227 } 2228 break; 2229 2230 case SM_PH2_C1_GET_ENC_C: 2231 // already busy? 2232 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2233 // calculate m_confirm using aes128 engine - step 1 2234 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); 2235 sm_next_responding_state(connection); 2236 sm_aes128_start(setup->sm_tk, plaintext, connection); 2237 break; 2238 case SM_PH2_C1_GET_ENC_A: 2239 // already busy? 2240 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2241 // calculate confirm using aes128 engine - step 1 2242 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); 2243 sm_next_responding_state(connection); 2244 sm_aes128_start(setup->sm_tk, plaintext, connection); 2245 break; 2246 case SM_PH2_CALC_STK: 2247 // already busy? 2248 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2249 // calculate STK 2250 if (connection->sm_role){ 2251 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2252 } else { 2253 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2254 } 2255 sm_next_responding_state(connection); 2256 sm_aes128_start(setup->sm_tk, plaintext, connection); 2257 break; 2258 case SM_PH3_Y_GET_ENC: 2259 // already busy? 2260 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2261 // PH3B2 - calculate Y from - enc 2262 // Y = dm(DHK, Rand) 2263 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2264 sm_next_responding_state(connection); 2265 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2266 return; 2267 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2268 uint8_t buffer[17]; 2269 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2270 reverse_128(setup->sm_local_confirm, &buffer[1]); 2271 if (connection->sm_role){ 2272 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2273 } else { 2274 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2275 } 2276 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2277 sm_timeout_reset(connection); 2278 return; 2279 } 2280 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2281 sm_key_t stk_flipped; 2282 reverse_128(setup->sm_ltk, stk_flipped); 2283 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2284 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2285 return; 2286 } 2287 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2288 sm_key_t stk_flipped; 2289 reverse_128(setup->sm_ltk, stk_flipped); 2290 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2291 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2292 return; 2293 } 2294 case SM_RESPONDER_PH4_SEND_LTK: { 2295 sm_key_t ltk_flipped; 2296 reverse_128(setup->sm_ltk, ltk_flipped); 2297 connection->sm_engine_state = SM_RESPONDER_IDLE; 2298 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2299 return; 2300 } 2301 case SM_RESPONDER_PH4_Y_GET_ENC: 2302 // already busy? 2303 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2304 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2305 // Y = dm(DHK, Rand) 2306 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2307 sm_next_responding_state(connection); 2308 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2309 return; 2310 2311 case SM_PH3_DISTRIBUTE_KEYS: 2312 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2313 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2314 uint8_t buffer[17]; 2315 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2316 reverse_128(setup->sm_ltk, &buffer[1]); 2317 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2318 sm_timeout_reset(connection); 2319 return; 2320 } 2321 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2322 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2323 uint8_t buffer[11]; 2324 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2325 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2326 reverse_64(setup->sm_local_rand, &buffer[3]); 2327 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2328 sm_timeout_reset(connection); 2329 return; 2330 } 2331 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2332 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2333 uint8_t buffer[17]; 2334 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2335 reverse_128(sm_persistent_irk, &buffer[1]); 2336 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2337 sm_timeout_reset(connection); 2338 return; 2339 } 2340 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2341 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2342 bd_addr_t local_address; 2343 uint8_t buffer[8]; 2344 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2345 gap_advertisements_get_address(&buffer[1], local_address); 2346 reverse_bd_addr(local_address, &buffer[2]); 2347 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2348 sm_timeout_reset(connection); 2349 return; 2350 } 2351 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2352 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2353 2354 // hack to reproduce test runs 2355 if (test_use_fixed_local_csrk){ 2356 memset(setup->sm_local_csrk, 0xcc, 16); 2357 } 2358 2359 uint8_t buffer[17]; 2360 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2361 reverse_128(setup->sm_local_csrk, &buffer[1]); 2362 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2363 sm_timeout_reset(connection); 2364 return; 2365 } 2366 2367 // keys are sent 2368 if (connection->sm_role){ 2369 // slave -> receive master keys if any 2370 if (sm_key_distribution_all_received(connection)){ 2371 sm_key_distribution_handle_all_received(connection); 2372 connection->sm_engine_state = SM_RESPONDER_IDLE; 2373 sm_done_for_handle(connection->sm_handle); 2374 } else { 2375 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2376 } 2377 } else { 2378 // master -> all done 2379 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2380 sm_done_for_handle(connection->sm_handle); 2381 } 2382 break; 2383 2384 default: 2385 break; 2386 } 2387 2388 // check again if active connection was released 2389 if (sm_active_connection) break; 2390 } 2391 } 2392 2393 // note: aes engine is ready as we just got the aes result 2394 static void sm_handle_encryption_result(uint8_t * data){ 2395 2396 sm_aes128_state = SM_AES128_IDLE; 2397 2398 if (sm_address_resolution_ah_calculation_active){ 2399 sm_address_resolution_ah_calculation_active = 0; 2400 // compare calulated address against connecting device 2401 uint8_t hash[3]; 2402 reverse_24(data, hash); 2403 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2404 log_info("LE Device Lookup: matched resolvable private address"); 2405 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2406 return; 2407 } 2408 // no match, try next 2409 sm_address_resolution_test++; 2410 return; 2411 } 2412 2413 switch (dkg_state){ 2414 case DKG_W4_IRK: 2415 reverse_128(data, sm_persistent_irk); 2416 log_info_key("irk", sm_persistent_irk); 2417 dkg_next_state(); 2418 return; 2419 case DKG_W4_DHK: 2420 reverse_128(data, sm_persistent_dhk); 2421 log_info_key("dhk", sm_persistent_dhk); 2422 dkg_next_state(); 2423 // SM Init Finished 2424 return; 2425 default: 2426 break; 2427 } 2428 2429 switch (rau_state){ 2430 case RAU_W4_ENC: 2431 reverse_24(data, &sm_random_address[3]); 2432 rau_next_state(); 2433 return; 2434 default: 2435 break; 2436 } 2437 2438 switch (sm_cmac_state){ 2439 case CMAC_W4_SUBKEYS: 2440 case CMAC_W4_MI: 2441 case CMAC_W4_MLAST: 2442 { 2443 sm_key_t t; 2444 reverse_128(data, t); 2445 sm_cmac_handle_encryption_result(t); 2446 } 2447 return; 2448 default: 2449 break; 2450 } 2451 2452 // retrieve sm_connection provided to sm_aes128_start_encryption 2453 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2454 if (!connection) return; 2455 switch (connection->sm_engine_state){ 2456 case SM_PH2_C1_W4_ENC_A: 2457 case SM_PH2_C1_W4_ENC_C: 2458 { 2459 sm_key_t t2; 2460 reverse_128(data, t2); 2461 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2462 } 2463 sm_next_responding_state(connection); 2464 return; 2465 case SM_PH2_C1_W4_ENC_B: 2466 reverse_128(data, setup->sm_local_confirm); 2467 log_info_key("c1!", setup->sm_local_confirm); 2468 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2469 return; 2470 case SM_PH2_C1_W4_ENC_D: 2471 { 2472 sm_key_t peer_confirm_test; 2473 reverse_128(data, peer_confirm_test); 2474 log_info_key("c1!", peer_confirm_test); 2475 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2476 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2477 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2478 return; 2479 } 2480 if (connection->sm_role){ 2481 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2482 } else { 2483 connection->sm_engine_state = SM_PH2_CALC_STK; 2484 } 2485 } 2486 return; 2487 case SM_PH2_W4_STK: 2488 reverse_128(data, setup->sm_ltk); 2489 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2490 log_info_key("stk", setup->sm_ltk); 2491 if (connection->sm_role){ 2492 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2493 } else { 2494 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2495 } 2496 return; 2497 case SM_PH3_Y_W4_ENC:{ 2498 sm_key_t y128; 2499 reverse_128(data, y128); 2500 setup->sm_local_y = big_endian_read_16(y128, 14); 2501 log_info_hex16("y", setup->sm_local_y); 2502 // PH3B3 - calculate EDIV 2503 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2504 log_info_hex16("ediv", setup->sm_local_ediv); 2505 // PH3B4 - calculate LTK - enc 2506 // LTK = d1(ER, DIV, 0)) 2507 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2508 return; 2509 } 2510 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2511 sm_key_t y128; 2512 reverse_128(data, y128); 2513 setup->sm_local_y = big_endian_read_16(y128, 14); 2514 log_info_hex16("y", setup->sm_local_y); 2515 2516 // PH3B3 - calculate DIV 2517 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2518 log_info_hex16("ediv", setup->sm_local_ediv); 2519 // PH3B4 - calculate LTK - enc 2520 // LTK = d1(ER, DIV, 0)) 2521 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2522 return; 2523 } 2524 case SM_PH3_LTK_W4_ENC: 2525 reverse_128(data, setup->sm_ltk); 2526 log_info_key("ltk", setup->sm_ltk); 2527 // calc CSRK next 2528 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2529 return; 2530 case SM_PH3_CSRK_W4_ENC: 2531 reverse_128(data, setup->sm_local_csrk); 2532 log_info_key("csrk", setup->sm_local_csrk); 2533 if (setup->sm_key_distribution_send_set){ 2534 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2535 } else { 2536 // no keys to send, just continue 2537 if (connection->sm_role){ 2538 // slave -> receive master keys 2539 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2540 } else { 2541 // master -> all done 2542 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2543 sm_done_for_handle(connection->sm_handle); 2544 } 2545 } 2546 return; 2547 case SM_RESPONDER_PH4_LTK_W4_ENC: 2548 reverse_128(data, setup->sm_ltk); 2549 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2550 log_info_key("ltk", setup->sm_ltk); 2551 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2552 return; 2553 default: 2554 break; 2555 } 2556 } 2557 2558 #ifdef USE_MBEDTLS_FOR_ECDH 2559 2560 static void sm_log_ec_keypair(void){ 2561 // print keypair 2562 char buffer[100]; 2563 size_t len; 2564 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2565 log_info("d: %s", buffer); 2566 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2567 log_info("X: %s", buffer); 2568 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2569 log_info("Y: %s", buffer); 2570 } 2571 2572 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2573 int offset = setup->sm_passkey_bit; 2574 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2575 while (size) { 2576 if (offset < 32){ 2577 *buffer++ = setup->sm_peer_qx[offset++]; 2578 } else { 2579 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2580 } 2581 size--; 2582 } 2583 setup->sm_passkey_bit = offset; 2584 return 0; 2585 } 2586 #endif 2587 2588 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2589 static void sm_handle_random_result(uint8_t * data){ 2590 2591 #ifdef USE_MBEDTLS_FOR_ECDH 2592 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2593 int num_bytes = setup->sm_passkey_bit; 2594 if (num_bytes < 32){ 2595 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2596 } else { 2597 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2598 } 2599 num_bytes += 8; 2600 setup->sm_passkey_bit = num_bytes; 2601 2602 if (num_bytes >= 64){ 2603 // generate EC key 2604 setup->sm_passkey_bit = 0; 2605 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2606 sm_log_ec_keypair(); 2607 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2608 } 2609 } 2610 #endif 2611 2612 switch (rau_state){ 2613 case RAU_W4_RANDOM: 2614 // non-resolvable vs. resolvable 2615 switch (gap_random_adress_type){ 2616 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2617 // resolvable: use random as prand and calc address hash 2618 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2619 memcpy(sm_random_address, data, 3); 2620 sm_random_address[0] &= 0x3f; 2621 sm_random_address[0] |= 0x40; 2622 rau_state = RAU_GET_ENC; 2623 break; 2624 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2625 default: 2626 // "The two most significant bits of the address shall be equal to ‘0’"" 2627 memcpy(sm_random_address, data, 6); 2628 sm_random_address[0] &= 0x3f; 2629 rau_state = RAU_SET_ADDRESS; 2630 break; 2631 } 2632 return; 2633 default: 2634 break; 2635 } 2636 2637 // retrieve sm_connection provided to sm_random_start 2638 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2639 if (!connection) return; 2640 switch (connection->sm_engine_state){ 2641 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2642 case SM_SC_W4_GET_RANDOM_A: 2643 memcpy(&setup->sm_local_nonce[0], data, 8); 2644 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2645 break; 2646 case SM_SC_W4_GET_RANDOM_B: 2647 memcpy(&setup->sm_local_nonce[8], data, 8); 2648 // initiator & jw/nc -> send pairing random 2649 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2650 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2651 break; 2652 } else { 2653 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2654 } 2655 break; 2656 #endif 2657 2658 case SM_PH2_W4_RANDOM_TK: 2659 { 2660 // map random to 0-999999 without speding much cycles on a modulus operation 2661 uint32_t tk = little_endian_read_32(data,0); 2662 tk = tk & 0xfffff; // 1048575 2663 if (tk >= 999999){ 2664 tk = tk - 999999; 2665 } 2666 sm_reset_tk(); 2667 big_endian_store_32(setup->sm_tk, 12, tk); 2668 if (connection->sm_role){ 2669 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2670 } else { 2671 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2672 sm_trigger_user_response(connection); 2673 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2674 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2675 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2676 } 2677 } 2678 return; 2679 } 2680 case SM_PH2_C1_W4_RANDOM_A: 2681 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2682 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2683 return; 2684 case SM_PH2_C1_W4_RANDOM_B: 2685 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2686 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2687 return; 2688 case SM_PH3_W4_RANDOM: 2689 reverse_64(data, setup->sm_local_rand); 2690 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2691 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2692 // no db for authenticated flag hack: store flag in bit 4 of LSB 2693 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2694 connection->sm_engine_state = SM_PH3_GET_DIV; 2695 return; 2696 case SM_PH3_W4_DIV: 2697 // use 16 bit from random value as div 2698 setup->sm_local_div = big_endian_read_16(data, 0); 2699 log_info_hex16("div", setup->sm_local_div); 2700 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2701 return; 2702 default: 2703 break; 2704 } 2705 } 2706 2707 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2708 2709 sm_connection_t * sm_conn; 2710 hci_con_handle_t con_handle; 2711 2712 switch (packet_type) { 2713 2714 case HCI_EVENT_PACKET: 2715 switch (hci_event_packet_get_type(packet)) { 2716 2717 case BTSTACK_EVENT_STATE: 2718 // bt stack activated, get started 2719 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2720 log_info("HCI Working!"); 2721 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2722 rau_state = RAU_IDLE; 2723 #ifdef USE_MBEDTLS_FOR_ECDH 2724 if (!test_use_fixed_ec_keypair){ 2725 setup->sm_passkey_bit = 0; 2726 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2727 } 2728 #endif 2729 sm_run(); 2730 } 2731 break; 2732 2733 case HCI_EVENT_LE_META: 2734 switch (packet[2]) { 2735 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2736 2737 log_info("sm: connected"); 2738 2739 if (packet[3]) return; // connection failed 2740 2741 con_handle = little_endian_read_16(packet, 4); 2742 sm_conn = sm_get_connection_for_handle(con_handle); 2743 if (!sm_conn) break; 2744 2745 sm_conn->sm_handle = con_handle; 2746 sm_conn->sm_role = packet[6]; 2747 sm_conn->sm_peer_addr_type = packet[7]; 2748 reverse_bd_addr(&packet[8], 2749 sm_conn->sm_peer_address); 2750 2751 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2752 2753 // reset security properties 2754 sm_conn->sm_connection_encrypted = 0; 2755 sm_conn->sm_connection_authenticated = 0; 2756 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2757 sm_conn->sm_le_db_index = -1; 2758 2759 // prepare CSRK lookup (does not involve setup) 2760 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2761 2762 // just connected -> everything else happens in sm_run() 2763 if (sm_conn->sm_role){ 2764 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2765 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2766 if (sm_slave_request_security) { 2767 // request security if requested by app 2768 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2769 } else { 2770 // otherwise, wait for pairing request 2771 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2772 } 2773 } 2774 break; 2775 } else { 2776 // master 2777 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2778 } 2779 break; 2780 2781 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2782 con_handle = little_endian_read_16(packet, 3); 2783 sm_conn = sm_get_connection_for_handle(con_handle); 2784 if (!sm_conn) break; 2785 2786 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2787 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2788 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2789 break; 2790 } 2791 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2792 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2793 break; 2794 } 2795 2796 // store rand and ediv 2797 reverse_64(&packet[5], sm_conn->sm_local_rand); 2798 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2799 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2800 break; 2801 2802 default: 2803 break; 2804 } 2805 break; 2806 2807 case HCI_EVENT_ENCRYPTION_CHANGE: 2808 con_handle = little_endian_read_16(packet, 3); 2809 sm_conn = sm_get_connection_for_handle(con_handle); 2810 if (!sm_conn) break; 2811 2812 sm_conn->sm_connection_encrypted = packet[5]; 2813 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2814 sm_conn->sm_actual_encryption_key_size); 2815 log_info("event handler, state %u", sm_conn->sm_engine_state); 2816 if (!sm_conn->sm_connection_encrypted) break; 2817 // continue if part of initial pairing 2818 switch (sm_conn->sm_engine_state){ 2819 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2820 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2821 sm_done_for_handle(sm_conn->sm_handle); 2822 break; 2823 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2824 if (sm_conn->sm_role){ 2825 // slave 2826 if (setup->sm_use_secure_connections){ 2827 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2828 } else { 2829 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2830 } 2831 } else { 2832 // master 2833 if (sm_key_distribution_all_received(sm_conn)){ 2834 // skip receiving keys as there are none 2835 sm_key_distribution_handle_all_received(sm_conn); 2836 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2837 } else { 2838 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2839 } 2840 } 2841 break; 2842 default: 2843 break; 2844 } 2845 break; 2846 2847 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2848 con_handle = little_endian_read_16(packet, 3); 2849 sm_conn = sm_get_connection_for_handle(con_handle); 2850 if (!sm_conn) break; 2851 2852 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2853 log_info("event handler, state %u", sm_conn->sm_engine_state); 2854 // continue if part of initial pairing 2855 switch (sm_conn->sm_engine_state){ 2856 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2857 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2858 sm_done_for_handle(sm_conn->sm_handle); 2859 break; 2860 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2861 if (sm_conn->sm_role){ 2862 // slave 2863 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2864 } else { 2865 // master 2866 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2867 } 2868 break; 2869 default: 2870 break; 2871 } 2872 break; 2873 2874 2875 case HCI_EVENT_DISCONNECTION_COMPLETE: 2876 con_handle = little_endian_read_16(packet, 3); 2877 sm_done_for_handle(con_handle); 2878 sm_conn = sm_get_connection_for_handle(con_handle); 2879 if (!sm_conn) break; 2880 2881 // delete stored bonding on disconnect with authentication failure in ph0 2882 if (sm_conn->sm_role == 0 2883 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2884 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2885 le_device_db_remove(sm_conn->sm_le_db_index); 2886 } 2887 2888 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2889 sm_conn->sm_handle = 0; 2890 break; 2891 2892 case HCI_EVENT_COMMAND_COMPLETE: 2893 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2894 sm_handle_encryption_result(&packet[6]); 2895 break; 2896 } 2897 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2898 sm_handle_random_result(&packet[6]); 2899 break; 2900 } 2901 break; 2902 default: 2903 break; 2904 } 2905 break; 2906 default: 2907 break; 2908 } 2909 2910 sm_run(); 2911 } 2912 2913 static inline int sm_calc_actual_encryption_key_size(int other){ 2914 if (other < sm_min_encryption_key_size) return 0; 2915 if (other < sm_max_encryption_key_size) return other; 2916 return sm_max_encryption_key_size; 2917 } 2918 2919 2920 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2921 switch (method){ 2922 case JUST_WORKS: 2923 case NK_BOTH_INPUT: 2924 return 1; 2925 default: 2926 return 0; 2927 } 2928 } 2929 // responder 2930 2931 static int sm_passkey_used(stk_generation_method_t method){ 2932 switch (method){ 2933 case PK_RESP_INPUT: 2934 return 1; 2935 default: 2936 return 0; 2937 } 2938 } 2939 2940 /** 2941 * @return ok 2942 */ 2943 static int sm_validate_stk_generation_method(void){ 2944 // check if STK generation method is acceptable by client 2945 switch (setup->sm_stk_generation_method){ 2946 case JUST_WORKS: 2947 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2948 case PK_RESP_INPUT: 2949 case PK_INIT_INPUT: 2950 case OK_BOTH_INPUT: 2951 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2952 case OOB: 2953 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2954 case NK_BOTH_INPUT: 2955 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2956 return 1; 2957 default: 2958 return 0; 2959 } 2960 } 2961 2962 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2963 2964 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2965 sm_run(); 2966 } 2967 2968 if (packet_type != SM_DATA_PACKET) return; 2969 2970 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2971 if (!sm_conn) return; 2972 2973 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2974 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2975 return; 2976 } 2977 2978 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2979 2980 int err; 2981 2982 switch (sm_conn->sm_engine_state){ 2983 2984 // a sm timeout requries a new physical connection 2985 case SM_GENERAL_TIMEOUT: 2986 return; 2987 2988 // Initiator 2989 case SM_INITIATOR_CONNECTED: 2990 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2991 sm_pdu_received_in_wrong_state(sm_conn); 2992 break; 2993 } 2994 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2995 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2996 break; 2997 } 2998 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2999 uint16_t ediv; 3000 sm_key_t ltk; 3001 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3002 if (!sm_is_null_key(ltk) || ediv){ 3003 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3004 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3005 } else { 3006 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3007 } 3008 break; 3009 } 3010 // otherwise, store security request 3011 sm_conn->sm_security_request_received = 1; 3012 break; 3013 3014 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3015 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3016 sm_pdu_received_in_wrong_state(sm_conn); 3017 break; 3018 } 3019 // store pairing request 3020 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3021 err = sm_stk_generation_init(sm_conn); 3022 if (err){ 3023 setup->sm_pairing_failed_reason = err; 3024 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3025 break; 3026 } 3027 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3028 if (setup->sm_use_secure_connections){ 3029 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3030 if (setup->sm_stk_generation_method == JUST_WORKS){ 3031 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3032 sm_trigger_user_response(sm_conn); 3033 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3034 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3035 } 3036 } else { 3037 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3038 } 3039 break; 3040 } 3041 #endif 3042 // generate random number first, if we need to show passkey 3043 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3044 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3045 break; 3046 } 3047 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3048 sm_trigger_user_response(sm_conn); 3049 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3050 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3051 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3052 } 3053 break; 3054 3055 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3056 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3057 sm_pdu_received_in_wrong_state(sm_conn); 3058 break; 3059 } 3060 3061 // store s_confirm 3062 reverse_128(&packet[1], setup->sm_peer_confirm); 3063 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3064 break; 3065 3066 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3067 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3068 sm_pdu_received_in_wrong_state(sm_conn); 3069 break;; 3070 } 3071 3072 // received random value 3073 reverse_128(&packet[1], setup->sm_peer_random); 3074 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3075 break; 3076 3077 // Responder 3078 case SM_RESPONDER_IDLE: 3079 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3080 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3081 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3082 sm_pdu_received_in_wrong_state(sm_conn); 3083 break;; 3084 } 3085 3086 // store pairing request 3087 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3088 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3089 break; 3090 3091 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3092 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3093 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3094 sm_pdu_received_in_wrong_state(sm_conn); 3095 break; 3096 } 3097 3098 // store public key for DH Key calculation 3099 reverse_256(&packet[01], setup->sm_peer_qx); 3100 reverse_256(&packet[33], setup->sm_peer_qy); 3101 3102 #ifdef USE_MBEDTLS_FOR_ECDH 3103 // validate public key 3104 mbedtls_ecp_group grp; 3105 mbedtls_ecp_group_init( &grp ); 3106 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3107 3108 mbedtls_ecp_point Q; 3109 mbedtls_ecp_point_init( &Q ); 3110 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3111 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3112 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3113 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3114 mbedtls_ecp_point_free( & Q); 3115 mbedtls_ecp_group_free( &grp); 3116 if (err){ 3117 log_error("sm: peer public key invalid %x", err); 3118 // uses "unspecified reason", there is no "public key invalid" error code 3119 sm_pdu_received_in_wrong_state(sm_conn); 3120 break; 3121 } 3122 3123 #endif 3124 if (sm_conn->sm_role){ 3125 // responder 3126 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3127 } else { 3128 // initiator 3129 // stk generation method 3130 // passkey entry: notify app to show passkey or to request passkey 3131 switch (setup->sm_stk_generation_method){ 3132 case JUST_WORKS: 3133 case NK_BOTH_INPUT: 3134 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3135 break; 3136 case PK_RESP_INPUT: 3137 sm_sc_start_calculating_local_confirm(sm_conn); 3138 break; 3139 case PK_INIT_INPUT: 3140 case OK_BOTH_INPUT: 3141 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3142 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3143 break; 3144 } 3145 sm_sc_start_calculating_local_confirm(sm_conn); 3146 break; 3147 case OOB: 3148 // TODO: implement SC OOB 3149 break; 3150 } 3151 } 3152 break; 3153 3154 case SM_SC_W4_CONFIRMATION: 3155 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3156 sm_pdu_received_in_wrong_state(sm_conn); 3157 break; 3158 } 3159 // received confirm value 3160 reverse_128(&packet[1], setup->sm_peer_confirm); 3161 3162 if (sm_conn->sm_role){ 3163 // responder 3164 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3165 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3166 // still waiting for passkey 3167 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3168 break; 3169 } 3170 } 3171 sm_sc_start_calculating_local_confirm(sm_conn); 3172 } else { 3173 // initiator 3174 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3175 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3176 } else { 3177 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3178 } 3179 } 3180 break; 3181 3182 case SM_SC_W4_PAIRING_RANDOM: 3183 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3184 sm_pdu_received_in_wrong_state(sm_conn); 3185 break; 3186 } 3187 3188 // received random value 3189 reverse_128(&packet[1], setup->sm_peer_nonce); 3190 3191 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3192 // only check for JUST WORK/NC in initiator role AND passkey entry 3193 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3194 if (sm_conn->sm_role || passkey_entry) { 3195 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3196 } 3197 3198 sm_sc_state_after_receiving_random(sm_conn); 3199 break; 3200 3201 case SM_SC_W2_CALCULATE_G2: 3202 case SM_SC_W4_CALCULATE_G2: 3203 case SM_SC_W2_CALCULATE_F5_SALT: 3204 case SM_SC_W4_CALCULATE_F5_SALT: 3205 case SM_SC_W2_CALCULATE_F5_MACKEY: 3206 case SM_SC_W4_CALCULATE_F5_MACKEY: 3207 case SM_SC_W2_CALCULATE_F5_LTK: 3208 case SM_SC_W4_CALCULATE_F5_LTK: 3209 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3210 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3211 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3212 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3213 sm_pdu_received_in_wrong_state(sm_conn); 3214 break; 3215 } 3216 // store DHKey Check 3217 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3218 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3219 3220 // have we been only waiting for dhkey check command? 3221 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3222 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3223 } 3224 break; 3225 #endif 3226 3227 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3228 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3229 sm_pdu_received_in_wrong_state(sm_conn); 3230 break; 3231 } 3232 3233 // received confirm value 3234 reverse_128(&packet[1], setup->sm_peer_confirm); 3235 3236 // notify client to hide shown passkey 3237 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3238 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3239 } 3240 3241 // handle user cancel pairing? 3242 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3243 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3244 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3245 break; 3246 } 3247 3248 // wait for user action? 3249 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3250 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3251 break; 3252 } 3253 3254 // calculate and send local_confirm 3255 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3256 break; 3257 3258 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3259 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3260 sm_pdu_received_in_wrong_state(sm_conn); 3261 break;; 3262 } 3263 3264 // received random value 3265 reverse_128(&packet[1], setup->sm_peer_random); 3266 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3267 break; 3268 3269 case SM_PH3_RECEIVE_KEYS: 3270 switch(packet[0]){ 3271 case SM_CODE_ENCRYPTION_INFORMATION: 3272 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3273 reverse_128(&packet[1], setup->sm_peer_ltk); 3274 break; 3275 3276 case SM_CODE_MASTER_IDENTIFICATION: 3277 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3278 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3279 reverse_64(&packet[3], setup->sm_peer_rand); 3280 break; 3281 3282 case SM_CODE_IDENTITY_INFORMATION: 3283 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3284 reverse_128(&packet[1], setup->sm_peer_irk); 3285 break; 3286 3287 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3288 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3289 setup->sm_peer_addr_type = packet[1]; 3290 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3291 break; 3292 3293 case SM_CODE_SIGNING_INFORMATION: 3294 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3295 reverse_128(&packet[1], setup->sm_peer_csrk); 3296 break; 3297 default: 3298 // Unexpected PDU 3299 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3300 break; 3301 } 3302 // done with key distribution? 3303 if (sm_key_distribution_all_received(sm_conn)){ 3304 3305 sm_key_distribution_handle_all_received(sm_conn); 3306 3307 if (sm_conn->sm_role){ 3308 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3309 sm_done_for_handle(sm_conn->sm_handle); 3310 } else { 3311 if (setup->sm_use_secure_connections){ 3312 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3313 } else { 3314 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3315 } 3316 } 3317 } 3318 break; 3319 default: 3320 // Unexpected PDU 3321 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3322 break; 3323 } 3324 3325 // try to send preparared packet 3326 sm_run(); 3327 } 3328 3329 // Security Manager Client API 3330 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3331 sm_get_oob_data = get_oob_data_callback; 3332 } 3333 3334 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3335 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3336 } 3337 3338 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3339 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3340 } 3341 3342 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3343 sm_min_encryption_key_size = min_size; 3344 sm_max_encryption_key_size = max_size; 3345 } 3346 3347 void sm_set_authentication_requirements(uint8_t auth_req){ 3348 sm_auth_req = auth_req; 3349 } 3350 3351 void sm_set_io_capabilities(io_capability_t io_capability){ 3352 sm_io_capabilities = io_capability; 3353 } 3354 3355 void sm_set_request_security(int enable){ 3356 sm_slave_request_security = enable; 3357 } 3358 3359 void sm_set_er(sm_key_t er){ 3360 memcpy(sm_persistent_er, er, 16); 3361 } 3362 3363 void sm_set_ir(sm_key_t ir){ 3364 memcpy(sm_persistent_ir, ir, 16); 3365 } 3366 3367 // Testing support only 3368 void sm_test_set_irk(sm_key_t irk){ 3369 memcpy(sm_persistent_irk, irk, 16); 3370 sm_persistent_irk_ready = 1; 3371 } 3372 3373 void sm_test_use_fixed_local_csrk(void){ 3374 test_use_fixed_local_csrk = 1; 3375 } 3376 3377 void sm_init(void){ 3378 // set some (BTstack default) ER and IR 3379 int i; 3380 sm_key_t er; 3381 sm_key_t ir; 3382 for (i=0;i<16;i++){ 3383 er[i] = 0x30 + i; 3384 ir[i] = 0x90 + i; 3385 } 3386 sm_set_er(er); 3387 sm_set_ir(ir); 3388 // defaults 3389 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3390 | SM_STK_GENERATION_METHOD_OOB 3391 | SM_STK_GENERATION_METHOD_PASSKEY 3392 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3393 3394 sm_max_encryption_key_size = 16; 3395 sm_min_encryption_key_size = 7; 3396 3397 sm_cmac_state = CMAC_IDLE; 3398 dkg_state = DKG_W4_WORKING; 3399 rau_state = RAU_W4_WORKING; 3400 sm_aes128_state = SM_AES128_IDLE; 3401 sm_address_resolution_test = -1; // no private address to resolve yet 3402 sm_address_resolution_ah_calculation_active = 0; 3403 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3404 sm_address_resolution_general_queue = NULL; 3405 3406 gap_random_adress_update_period = 15 * 60 * 1000L; 3407 3408 sm_active_connection = 0; 3409 3410 test_use_fixed_local_csrk = 0; 3411 3412 // register for HCI Events from HCI 3413 hci_event_callback_registration.callback = &sm_event_packet_handler; 3414 hci_add_event_handler(&hci_event_callback_registration); 3415 3416 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3417 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3418 3419 #ifdef USE_MBEDTLS_FOR_ECDH 3420 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3421 #endif 3422 } 3423 3424 void sm_test_use_fixed_ec_keypair(void){ 3425 test_use_fixed_ec_keypair = 1; 3426 #ifdef USE_MBEDTLS_FOR_ECDH 3427 // use test keypair from spec 3428 mbedtls_ecp_keypair_init(&le_keypair); 3429 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3430 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3431 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3432 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3433 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3434 #endif 3435 } 3436 3437 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3438 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3439 if (!hci_con) return NULL; 3440 return &hci_con->sm_connection; 3441 } 3442 3443 // @returns 0 if not encrypted, 7-16 otherwise 3444 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3445 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3446 if (!sm_conn) return 0; // wrong connection 3447 if (!sm_conn->sm_connection_encrypted) return 0; 3448 return sm_conn->sm_actual_encryption_key_size; 3449 } 3450 3451 int sm_authenticated(hci_con_handle_t con_handle){ 3452 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3453 if (!sm_conn) return 0; // wrong connection 3454 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3455 return sm_conn->sm_connection_authenticated; 3456 } 3457 3458 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3459 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3460 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3461 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3462 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3463 return sm_conn->sm_connection_authorization_state; 3464 } 3465 3466 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3467 switch (sm_conn->sm_engine_state){ 3468 case SM_GENERAL_IDLE: 3469 case SM_RESPONDER_IDLE: 3470 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3471 sm_run(); 3472 break; 3473 default: 3474 break; 3475 } 3476 } 3477 3478 /** 3479 * @brief Trigger Security Request 3480 */ 3481 void sm_send_security_request(hci_con_handle_t con_handle){ 3482 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3483 if (!sm_conn) return; 3484 sm_send_security_request_for_connection(sm_conn); 3485 } 3486 3487 // request pairing 3488 void sm_request_pairing(hci_con_handle_t con_handle){ 3489 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3490 if (!sm_conn) return; // wrong connection 3491 3492 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3493 if (sm_conn->sm_role){ 3494 sm_send_security_request_for_connection(sm_conn); 3495 } else { 3496 // used as a trigger to start central/master/initiator security procedures 3497 uint16_t ediv; 3498 sm_key_t ltk; 3499 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3500 switch (sm_conn->sm_irk_lookup_state){ 3501 case IRK_LOOKUP_FAILED: 3502 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3503 break; 3504 case IRK_LOOKUP_SUCCEEDED: 3505 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3506 if (!sm_is_null_key(ltk) || ediv){ 3507 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3508 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3509 } else { 3510 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3511 } 3512 break; 3513 default: 3514 sm_conn->sm_bonding_requested = 1; 3515 break; 3516 } 3517 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3518 sm_conn->sm_bonding_requested = 1; 3519 } 3520 } 3521 sm_run(); 3522 } 3523 3524 // called by client app on authorization request 3525 void sm_authorization_decline(hci_con_handle_t con_handle){ 3526 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3527 if (!sm_conn) return; // wrong connection 3528 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3529 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3530 } 3531 3532 void sm_authorization_grant(hci_con_handle_t con_handle){ 3533 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3534 if (!sm_conn) return; // wrong connection 3535 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3536 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3537 } 3538 3539 // GAP Bonding API 3540 3541 void sm_bonding_decline(hci_con_handle_t con_handle){ 3542 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3543 if (!sm_conn) return; // wrong connection 3544 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3545 3546 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3547 switch (setup->sm_stk_generation_method){ 3548 case PK_RESP_INPUT: 3549 case PK_INIT_INPUT: 3550 case OK_BOTH_INPUT: 3551 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3552 break; 3553 case NK_BOTH_INPUT: 3554 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3555 break; 3556 case JUST_WORKS: 3557 case OOB: 3558 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3559 break; 3560 } 3561 } 3562 sm_run(); 3563 } 3564 3565 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3566 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3567 if (!sm_conn) return; // wrong connection 3568 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3569 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3570 if (setup->sm_use_secure_connections){ 3571 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3572 } else { 3573 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3574 } 3575 } 3576 3577 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3578 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3579 sm_sc_prepare_dhkey_check(sm_conn); 3580 } 3581 #endif 3582 3583 sm_run(); 3584 } 3585 3586 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3587 // for now, it's the same 3588 sm_just_works_confirm(con_handle); 3589 } 3590 3591 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3592 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3593 if (!sm_conn) return; // wrong connection 3594 sm_reset_tk(); 3595 big_endian_store_32(setup->sm_tk, 12, passkey); 3596 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3597 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3598 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3599 } 3600 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3601 memcpy(setup->sm_ra, setup->sm_tk, 16); 3602 memcpy(setup->sm_rb, setup->sm_tk, 16); 3603 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3604 sm_sc_start_calculating_local_confirm(sm_conn); 3605 } 3606 #endif 3607 sm_run(); 3608 } 3609 3610 /** 3611 * @brief Identify device in LE Device DB 3612 * @param handle 3613 * @returns index from le_device_db or -1 if not found/identified 3614 */ 3615 int sm_le_device_index(hci_con_handle_t con_handle ){ 3616 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3617 if (!sm_conn) return -1; 3618 return sm_conn->sm_le_db_index; 3619 } 3620 3621 // GAP LE API 3622 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3623 gap_random_address_update_stop(); 3624 gap_random_adress_type = random_address_type; 3625 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3626 gap_random_address_update_start(); 3627 gap_random_address_trigger(); 3628 } 3629 3630 gap_random_address_type_t gap_random_address_get_mode(void){ 3631 return gap_random_adress_type; 3632 } 3633 3634 void gap_random_address_set_update_period(int period_ms){ 3635 gap_random_adress_update_period = period_ms; 3636 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3637 gap_random_address_update_stop(); 3638 gap_random_address_update_start(); 3639 } 3640 3641 void gap_random_address_set(bd_addr_t addr){ 3642 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3643 memcpy(sm_random_address, addr, 6); 3644 rau_state = RAU_SET_ADDRESS; 3645 sm_run(); 3646 } 3647 3648 /* 3649 * @brief Set Advertisement Paramters 3650 * @param adv_int_min 3651 * @param adv_int_max 3652 * @param adv_type 3653 * @param direct_address_type 3654 * @param direct_address 3655 * @param channel_map 3656 * @param filter_policy 3657 * 3658 * @note own_address_type is used from gap_random_address_set_mode 3659 */ 3660 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3661 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3662 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3663 direct_address_typ, direct_address, channel_map, filter_policy); 3664 } 3665 3666