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 #include "mbedtls/platform.h" 66 #include "mbedtls/ecp.h" 67 #include "sm_mbedtls_allocator.h" 68 #endif 69 70 // 71 // SM internal types and globals 72 // 73 74 typedef enum { 75 DKG_W4_WORKING, 76 DKG_CALC_IRK, 77 DKG_W4_IRK, 78 DKG_CALC_DHK, 79 DKG_W4_DHK, 80 DKG_READY 81 } derived_key_generation_t; 82 83 typedef enum { 84 RAU_W4_WORKING, 85 RAU_IDLE, 86 RAU_GET_RANDOM, 87 RAU_W4_RANDOM, 88 RAU_GET_ENC, 89 RAU_W4_ENC, 90 RAU_SET_ADDRESS, 91 } random_address_update_t; 92 93 typedef enum { 94 CMAC_IDLE, 95 CMAC_CALC_SUBKEYS, 96 CMAC_W4_SUBKEYS, 97 CMAC_CALC_MI, 98 CMAC_W4_MI, 99 CMAC_CALC_MLAST, 100 CMAC_W4_MLAST 101 } cmac_state_t; 102 103 typedef enum { 104 JUST_WORKS, 105 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 106 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 107 OK_BOTH_INPUT, // Only input on both, both input PK 108 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 109 OOB // OOB available on both sides 110 } stk_generation_method_t; 111 112 typedef enum { 113 SM_USER_RESPONSE_IDLE, 114 SM_USER_RESPONSE_PENDING, 115 SM_USER_RESPONSE_CONFIRM, 116 SM_USER_RESPONSE_PASSKEY, 117 SM_USER_RESPONSE_DECLINE 118 } sm_user_response_t; 119 120 typedef enum { 121 SM_AES128_IDLE, 122 SM_AES128_ACTIVE 123 } sm_aes128_state_t; 124 125 typedef enum { 126 ADDRESS_RESOLUTION_IDLE, 127 ADDRESS_RESOLUTION_GENERAL, 128 ADDRESS_RESOLUTION_FOR_CONNECTION, 129 } address_resolution_mode_t; 130 131 typedef enum { 132 ADDRESS_RESOLUTION_SUCEEDED, 133 ADDRESS_RESOLUTION_FAILED, 134 } address_resolution_event_t; 135 136 typedef enum { 137 EC_KEY_GENERATION_IDLE, 138 EC_KEY_GENERATION_ACTIVE, 139 EC_KEY_GENERATION_DONE, 140 } ec_key_generation_state_t; 141 142 typedef enum { 143 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 144 } sm_state_var_t; 145 146 // 147 // GLOBAL DATA 148 // 149 150 static uint8_t test_use_fixed_local_csrk; 151 static uint8_t test_use_fixed_ec_keypair; 152 153 // configuration 154 static uint8_t sm_accepted_stk_generation_methods; 155 static uint8_t sm_max_encryption_key_size; 156 static uint8_t sm_min_encryption_key_size; 157 static uint8_t sm_auth_req = 0; 158 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 159 static uint8_t sm_slave_request_security; 160 161 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 162 static sm_key_t sm_persistent_er; 163 static sm_key_t sm_persistent_ir; 164 165 // derived from sm_persistent_ir 166 static sm_key_t sm_persistent_dhk; 167 static sm_key_t sm_persistent_irk; 168 static uint8_t sm_persistent_irk_ready = 0; // used for testing 169 static derived_key_generation_t dkg_state; 170 171 // derived from sm_persistent_er 172 // .. 173 174 // random address update 175 static random_address_update_t rau_state; 176 static bd_addr_t sm_random_address; 177 178 // CMAC Calculation: General 179 static cmac_state_t sm_cmac_state; 180 static uint16_t sm_cmac_message_len; 181 static sm_key_t sm_cmac_k; 182 static sm_key_t sm_cmac_x; 183 static sm_key_t sm_cmac_m_last; 184 static uint8_t sm_cmac_block_current; 185 static uint8_t sm_cmac_block_count; 186 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 187 static void (*sm_cmac_done_handler)(uint8_t * hash); 188 189 // CMAC for ATT Signed Writes 190 static uint8_t sm_cmac_header[3]; 191 static const uint8_t * sm_cmac_message; 192 static uint8_t sm_cmac_sign_counter[4]; 193 194 // CMAC for Secure Connection functions 195 #ifdef ENABLE_LE_SECURE_CONNECTIONS 196 static sm_connection_t * sm_cmac_connection; 197 static uint8_t sm_cmac_sc_buffer[80]; 198 #endif 199 200 // resolvable private address lookup / CSRK calculation 201 static int sm_address_resolution_test; 202 static int sm_address_resolution_ah_calculation_active; 203 static uint8_t sm_address_resolution_addr_type; 204 static bd_addr_t sm_address_resolution_address; 205 static void * sm_address_resolution_context; 206 static address_resolution_mode_t sm_address_resolution_mode; 207 static btstack_linked_list_t sm_address_resolution_general_queue; 208 209 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 210 static sm_aes128_state_t sm_aes128_state; 211 static void * sm_aes128_context; 212 213 // random engine. store context (ususally sm_connection_t) 214 static void * sm_random_context; 215 216 // to receive hci events 217 static btstack_packet_callback_registration_t hci_event_callback_registration; 218 219 /* to dispatch sm event */ 220 static btstack_linked_list_t sm_event_handlers; 221 222 // Software ECDH implementation provided by mbedtls 223 #ifdef USE_MBEDTLS_FOR_ECDH 224 // group is always valid 225 static mbedtls_ecp_group mbedtls_ec_group; 226 static ec_key_generation_state_t ec_key_generation_state; 227 static uint8_t ec_qx[32]; 228 static uint8_t ec_qy[32]; 229 static uint8_t ec_d[32]; 230 #ifndef HAVE_MALLOC 231 static uint8_t mbedtls_memory_buffer[4500+70*sizeof(void *)]; // experimental value on 64-bit system 232 #endif 233 #endif 234 235 // 236 // Volume 3, Part H, Chapter 24 237 // "Security shall be initiated by the Security Manager in the device in the master role. 238 // The device in the slave role shall be the responding device." 239 // -> master := initiator, slave := responder 240 // 241 242 // data needed for security setup 243 typedef struct sm_setup_context { 244 245 btstack_timer_source_t sm_timeout; 246 247 // used in all phases 248 uint8_t sm_pairing_failed_reason; 249 250 // user response, (Phase 1 and/or 2) 251 uint8_t sm_user_response; 252 253 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 254 int sm_key_distribution_send_set; 255 int sm_key_distribution_received_set; 256 257 // Phase 2 (Pairing over SMP) 258 stk_generation_method_t sm_stk_generation_method; 259 sm_key_t sm_tk; 260 uint8_t sm_use_secure_connections; 261 262 sm_key_t sm_c1_t3_value; // c1 calculation 263 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 264 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 265 sm_key_t sm_local_random; 266 sm_key_t sm_local_confirm; 267 sm_key_t sm_peer_random; 268 sm_key_t sm_peer_confirm; 269 uint8_t sm_m_addr_type; // address and type can be removed 270 uint8_t sm_s_addr_type; // '' 271 bd_addr_t sm_m_address; // '' 272 bd_addr_t sm_s_address; // '' 273 sm_key_t sm_ltk; 274 275 uint8_t sm_state_vars; 276 #ifdef ENABLE_LE_SECURE_CONNECTIONS 277 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 278 uint8_t sm_peer_qy[32]; // '' 279 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 280 sm_key_t sm_local_nonce; // might be combined with sm_local_random 281 sm_key_t sm_peer_dhkey_check; 282 sm_key_t sm_local_dhkey_check; 283 sm_key_t sm_ra; 284 sm_key_t sm_rb; 285 sm_key_t sm_t; // used for f5 286 sm_key_t sm_mackey; 287 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 288 #endif 289 290 // Phase 3 291 292 // key distribution, we generate 293 uint16_t sm_local_y; 294 uint16_t sm_local_div; 295 uint16_t sm_local_ediv; 296 uint8_t sm_local_rand[8]; 297 sm_key_t sm_local_ltk; 298 sm_key_t sm_local_csrk; 299 sm_key_t sm_local_irk; 300 // sm_local_address/addr_type not needed 301 302 // key distribution, received from peer 303 uint16_t sm_peer_y; 304 uint16_t sm_peer_div; 305 uint16_t sm_peer_ediv; 306 uint8_t sm_peer_rand[8]; 307 sm_key_t sm_peer_ltk; 308 sm_key_t sm_peer_irk; 309 sm_key_t sm_peer_csrk; 310 uint8_t sm_peer_addr_type; 311 bd_addr_t sm_peer_address; 312 313 } sm_setup_context_t; 314 315 // 316 static sm_setup_context_t the_setup; 317 static sm_setup_context_t * setup = &the_setup; 318 319 // active connection - the one for which the_setup is used for 320 static uint16_t sm_active_connection = 0; 321 322 // @returns 1 if oob data is available 323 // stores oob data in provided 16 byte buffer if not null 324 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 325 326 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 327 static btstack_packet_handler_t sm_client_packet_handler = NULL; 328 329 // horizontal: initiator capabilities 330 // vertial: responder capabilities 331 static const stk_generation_method_t stk_generation_method [5] [5] = { 332 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 333 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 334 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 335 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 336 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 337 }; 338 339 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 340 #ifdef ENABLE_LE_SECURE_CONNECTIONS 341 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 342 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 343 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 344 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 345 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 346 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 347 }; 348 #endif 349 350 static void sm_run(void); 351 static void sm_done_for_handle(hci_con_handle_t con_handle); 352 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 353 static inline int sm_calc_actual_encryption_key_size(int other); 354 static int sm_validate_stk_generation_method(void); 355 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 356 357 static void log_info_hex16(const char * name, uint16_t value){ 358 log_info("%-6s 0x%04x", name, value); 359 } 360 361 // @returns 1 if all bytes are 0 362 static int sm_is_null(uint8_t * data, int size){ 363 int i; 364 for (i=0; i < size ; i++){ 365 if (data[i]) return 0; 366 } 367 return 1; 368 } 369 370 static int sm_is_null_random(uint8_t random[8]){ 371 return sm_is_null(random, 8); 372 } 373 374 static int sm_is_null_key(uint8_t * key){ 375 return sm_is_null(key, 16); 376 } 377 378 // Key utils 379 static void sm_reset_tk(void){ 380 int i; 381 for (i=0;i<16;i++){ 382 setup->sm_tk[i] = 0; 383 } 384 } 385 386 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 387 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 388 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 389 int i; 390 for (i = max_encryption_size ; i < 16 ; i++){ 391 key[15-i] = 0; 392 } 393 } 394 395 // SMP Timeout implementation 396 397 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 398 // the Security Manager Timer shall be reset and started. 399 // 400 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 401 // 402 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 403 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 404 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 405 // established. 406 407 static void sm_timeout_handler(btstack_timer_source_t * timer){ 408 log_info("SM timeout"); 409 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 410 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 411 sm_done_for_handle(sm_conn->sm_handle); 412 413 // trigger handling of next ready connection 414 sm_run(); 415 } 416 static void sm_timeout_start(sm_connection_t * sm_conn){ 417 btstack_run_loop_remove_timer(&setup->sm_timeout); 418 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 419 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 420 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 421 btstack_run_loop_add_timer(&setup->sm_timeout); 422 } 423 static void sm_timeout_stop(void){ 424 btstack_run_loop_remove_timer(&setup->sm_timeout); 425 } 426 static void sm_timeout_reset(sm_connection_t * sm_conn){ 427 sm_timeout_stop(); 428 sm_timeout_start(sm_conn); 429 } 430 431 // end of sm timeout 432 433 // GAP Random Address updates 434 static gap_random_address_type_t gap_random_adress_type; 435 static btstack_timer_source_t gap_random_address_update_timer; 436 static uint32_t gap_random_adress_update_period; 437 438 static void gap_random_address_trigger(void){ 439 if (rau_state != RAU_IDLE) return; 440 log_info("gap_random_address_trigger"); 441 rau_state = RAU_GET_RANDOM; 442 sm_run(); 443 } 444 445 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 446 log_info("GAP Random Address Update due"); 447 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 448 btstack_run_loop_add_timer(&gap_random_address_update_timer); 449 gap_random_address_trigger(); 450 } 451 452 static void gap_random_address_update_start(void){ 453 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 454 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 455 btstack_run_loop_add_timer(&gap_random_address_update_timer); 456 } 457 458 static void gap_random_address_update_stop(void){ 459 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 460 } 461 462 463 static void sm_random_start(void * context){ 464 sm_random_context = context; 465 hci_send_cmd(&hci_le_rand); 466 } 467 468 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 469 // context is made availabe to aes128 result handler by this 470 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 471 sm_aes128_state = SM_AES128_ACTIVE; 472 sm_key_t key_flipped, plaintext_flipped; 473 reverse_128(key, key_flipped); 474 reverse_128(plaintext, plaintext_flipped); 475 sm_aes128_context = context; 476 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 477 } 478 479 // ah(k,r) helper 480 // r = padding || r 481 // r - 24 bit value 482 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 483 // r'= padding || r 484 memset(r_prime, 0, 16); 485 memcpy(&r_prime[13], r, 3); 486 } 487 488 // d1 helper 489 // d' = padding || r || d 490 // d,r - 16 bit values 491 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 492 // d'= padding || r || d 493 memset(d1_prime, 0, 16); 494 big_endian_store_16(d1_prime, 12, r); 495 big_endian_store_16(d1_prime, 14, d); 496 } 497 498 // dm helper 499 // r’ = padding || r 500 // r - 64 bit value 501 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 502 memset(r_prime, 0, 16); 503 memcpy(&r_prime[8], r, 8); 504 } 505 506 // calculate arguments for first AES128 operation in C1 function 507 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){ 508 509 // p1 = pres || preq || rat’ || iat’ 510 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 511 // cant octet of pres becomes the most significant octet of p1. 512 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 513 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 514 // p1 is 0x05000800000302070710000001010001." 515 516 sm_key_t p1; 517 reverse_56(pres, &p1[0]); 518 reverse_56(preq, &p1[7]); 519 p1[14] = rat; 520 p1[15] = iat; 521 log_info_key("p1", p1); 522 log_info_key("r", r); 523 524 // t1 = r xor p1 525 int i; 526 for (i=0;i<16;i++){ 527 t1[i] = r[i] ^ p1[i]; 528 } 529 log_info_key("t1", t1); 530 } 531 532 // calculate arguments for second AES128 operation in C1 function 533 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 534 // p2 = padding || ia || ra 535 // "The least significant octet of ra becomes the least significant octet of p2 and 536 // the most significant octet of padding becomes the most significant octet of p2. 537 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 538 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 539 540 sm_key_t p2; 541 memset(p2, 0, 16); 542 memcpy(&p2[4], ia, 6); 543 memcpy(&p2[10], ra, 6); 544 log_info_key("p2", p2); 545 546 // c1 = e(k, t2_xor_p2) 547 int i; 548 for (i=0;i<16;i++){ 549 t3[i] = t2[i] ^ p2[i]; 550 } 551 log_info_key("t3", t3); 552 } 553 554 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 555 log_info_key("r1", r1); 556 log_info_key("r2", r2); 557 memcpy(&r_prime[8], &r2[8], 8); 558 memcpy(&r_prime[0], &r1[8], 8); 559 } 560 561 #ifdef ENABLE_LE_SECURE_CONNECTIONS 562 // Software implementations of crypto toolbox for LE Secure Connection 563 // TODO: replace with code to use AES Engine of HCI Controller 564 typedef uint8_t sm_key24_t[3]; 565 typedef uint8_t sm_key56_t[7]; 566 typedef uint8_t sm_key256_t[32]; 567 568 #if 0 569 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 570 uint32_t rk[RKLENGTH(KEYBITS)]; 571 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 572 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 573 } 574 575 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 576 memcpy(k1, k0, 16); 577 sm_shift_left_by_one_bit_inplace(16, k1); 578 if (k0[0] & 0x80){ 579 k1[15] ^= 0x87; 580 } 581 memcpy(k2, k1, 16); 582 sm_shift_left_by_one_bit_inplace(16, k2); 583 if (k1[0] & 0x80){ 584 k2[15] ^= 0x87; 585 } 586 } 587 588 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 589 sm_key_t k0, k1, k2, zero; 590 memset(zero, 0, 16); 591 592 aes128_calc_cyphertext(key, zero, k0); 593 calc_subkeys(k0, k1, k2); 594 595 int cmac_block_count = (cmac_message_len + 15) / 16; 596 597 // step 3: .. 598 if (cmac_block_count==0){ 599 cmac_block_count = 1; 600 } 601 602 // step 4: set m_last 603 sm_key_t cmac_m_last; 604 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 605 int i; 606 if (sm_cmac_last_block_complete){ 607 for (i=0;i<16;i++){ 608 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 609 } 610 } else { 611 int valid_octets_in_last_block = cmac_message_len & 0x0f; 612 for (i=0;i<16;i++){ 613 if (i < valid_octets_in_last_block){ 614 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 615 continue; 616 } 617 if (i == valid_octets_in_last_block){ 618 cmac_m_last[i] = 0x80 ^ k2[i]; 619 continue; 620 } 621 cmac_m_last[i] = k2[i]; 622 } 623 } 624 625 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 626 // LOG_KEY(cmac_m_last); 627 628 // Step 5 629 sm_key_t cmac_x; 630 memset(cmac_x, 0, 16); 631 632 // Step 6 633 sm_key_t sm_cmac_y; 634 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 635 for (i=0;i<16;i++){ 636 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 637 } 638 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 639 } 640 for (i=0;i<16;i++){ 641 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 642 } 643 644 // Step 7 645 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 646 } 647 #endif 648 649 #if 0 650 // 651 // Link Key Conversion Function h6 652 // 653 // h6(W, keyID) = AES-CMACW(keyID) 654 // - W is 128 bits 655 // - keyID is 32 bits 656 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 657 uint8_t key_id_buffer[4]; 658 big_endian_store_32(key_id_buffer, 0, key_id); 659 aes_cmac(res, w, key_id_buffer, 4); 660 } 661 #endif 662 #endif 663 664 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){ 665 event[0] = type; 666 event[1] = event_size - 2; 667 little_endian_store_16(event, 2, con_handle); 668 event[4] = addr_type; 669 reverse_bd_addr(address, &event[5]); 670 } 671 672 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 673 if (sm_client_packet_handler) { 674 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 675 } 676 // dispatch to all event handlers 677 btstack_linked_list_iterator_t it; 678 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 679 while (btstack_linked_list_iterator_has_next(&it)){ 680 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 681 entry->callback(packet_type, 0, packet, size); 682 } 683 } 684 685 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 686 uint8_t event[11]; 687 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 688 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 689 } 690 691 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){ 692 uint8_t event[15]; 693 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 694 little_endian_store_32(event, 11, passkey); 695 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 696 } 697 698 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){ 699 uint8_t event[13]; 700 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 701 little_endian_store_16(event, 11, index); 702 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 703 } 704 705 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){ 706 707 uint8_t event[18]; 708 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 709 event[11] = result; 710 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 711 } 712 713 // decide on stk generation based on 714 // - pairing request 715 // - io capabilities 716 // - OOB data availability 717 static void sm_setup_tk(void){ 718 719 // default: just works 720 setup->sm_stk_generation_method = JUST_WORKS; 721 722 #ifdef ENABLE_LE_SECURE_CONNECTIONS 723 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 724 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 725 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 726 memset(setup->sm_ra, 0, 16); 727 memset(setup->sm_rb, 0, 16); 728 #else 729 setup->sm_use_secure_connections = 0; 730 #endif 731 732 // If both devices have not set the MITM option in the Authentication Requirements 733 // Flags, then the IO capabilities shall be ignored and the Just Works association 734 // model shall be used. 735 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 736 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 737 log_info("SM: MITM not required by both -> JUST WORKS"); 738 return; 739 } 740 741 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 742 743 // If both devices have out of band authentication data, then the Authentication 744 // Requirements Flags shall be ignored when selecting the pairing method and the 745 // Out of Band pairing method shall be used. 746 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 747 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 748 log_info("SM: have OOB data"); 749 log_info_key("OOB", setup->sm_tk); 750 setup->sm_stk_generation_method = OOB; 751 return; 752 } 753 754 // Reset TK as it has been setup in sm_init_setup 755 sm_reset_tk(); 756 757 // Also use just works if unknown io capabilites 758 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)){ 759 return; 760 } 761 762 // Otherwise the IO capabilities of the devices shall be used to determine the 763 // pairing method as defined in Table 2.4. 764 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 765 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 766 767 #ifdef ENABLE_LE_SECURE_CONNECTIONS 768 // table not define by default 769 if (setup->sm_use_secure_connections){ 770 generation_method = stk_generation_method_with_secure_connection; 771 } 772 #endif 773 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)]; 774 775 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 776 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); 777 } 778 779 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 780 int flags = 0; 781 if (key_set & SM_KEYDIST_ENC_KEY){ 782 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 783 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 784 } 785 if (key_set & SM_KEYDIST_ID_KEY){ 786 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 787 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 788 } 789 if (key_set & SM_KEYDIST_SIGN){ 790 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 791 } 792 return flags; 793 } 794 795 static void sm_setup_key_distribution(uint8_t key_set){ 796 setup->sm_key_distribution_received_set = 0; 797 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 798 } 799 800 // CSRK Key Lookup 801 802 803 static int sm_address_resolution_idle(void){ 804 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 805 } 806 807 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){ 808 memcpy(sm_address_resolution_address, addr, 6); 809 sm_address_resolution_addr_type = addr_type; 810 sm_address_resolution_test = 0; 811 sm_address_resolution_mode = mode; 812 sm_address_resolution_context = context; 813 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 814 } 815 816 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 817 // check if already in list 818 btstack_linked_list_iterator_t it; 819 sm_lookup_entry_t * entry; 820 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 821 while(btstack_linked_list_iterator_has_next(&it)){ 822 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 823 if (entry->address_type != address_type) continue; 824 if (memcmp(entry->address, address, 6)) continue; 825 // already in list 826 return BTSTACK_BUSY; 827 } 828 entry = btstack_memory_sm_lookup_entry_get(); 829 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 830 entry->address_type = (bd_addr_type_t) address_type; 831 memcpy(entry->address, address, 6); 832 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 833 sm_run(); 834 return 0; 835 } 836 837 // CMAC Implementation using AES128 engine 838 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 839 int i; 840 int carry = 0; 841 for (i=len-1; i >= 0 ; i--){ 842 int new_carry = data[i] >> 7; 843 data[i] = data[i] << 1 | carry; 844 carry = new_carry; 845 } 846 } 847 848 // 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 849 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 850 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 851 } 852 static inline void dkg_next_state(void){ 853 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 854 } 855 static inline void rau_next_state(void){ 856 rau_state = (random_address_update_t) (((int)rau_state) + 1); 857 } 858 859 // CMAC calculation using AES Engine 860 861 static inline void sm_cmac_next_state(void){ 862 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 863 } 864 865 static int sm_cmac_last_block_complete(void){ 866 if (sm_cmac_message_len == 0) return 0; 867 return (sm_cmac_message_len & 0x0f) == 0; 868 } 869 870 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 871 if (offset >= sm_cmac_message_len) { 872 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 873 return 0; 874 } 875 876 offset = sm_cmac_message_len - 1 - offset; 877 878 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 879 if (offset < 3){ 880 return sm_cmac_header[offset]; 881 } 882 int actual_message_len_incl_header = sm_cmac_message_len - 4; 883 if (offset < actual_message_len_incl_header){ 884 return sm_cmac_message[offset - 3]; 885 } 886 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 887 } 888 889 // generic cmac calculation 890 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])){ 891 // Generalized CMAC 892 memcpy(sm_cmac_k, key, 16); 893 memset(sm_cmac_x, 0, 16); 894 sm_cmac_block_current = 0; 895 sm_cmac_message_len = message_len; 896 sm_cmac_done_handler = done_callback; 897 sm_cmac_get_byte = get_byte_callback; 898 899 // step 2: n := ceil(len/const_Bsize); 900 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 901 902 // step 3: .. 903 if (sm_cmac_block_count==0){ 904 sm_cmac_block_count = 1; 905 } 906 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 907 908 // first, we need to compute l for k1, k2, and m_last 909 sm_cmac_state = CMAC_CALC_SUBKEYS; 910 911 // let's go 912 sm_run(); 913 } 914 915 // cmac for ATT Message signing 916 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)){ 917 // ATT Message Signing 918 sm_cmac_header[0] = opcode; 919 little_endian_store_16(sm_cmac_header, 1, con_handle); 920 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 921 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 922 sm_cmac_message = message; 923 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 924 } 925 926 int sm_cmac_ready(void){ 927 return sm_cmac_state == CMAC_IDLE; 928 } 929 930 static void sm_cmac_handle_aes_engine_ready(void){ 931 switch (sm_cmac_state){ 932 case CMAC_CALC_SUBKEYS: { 933 sm_key_t const_zero; 934 memset(const_zero, 0, 16); 935 sm_cmac_next_state(); 936 sm_aes128_start(sm_cmac_k, const_zero, NULL); 937 break; 938 } 939 case CMAC_CALC_MI: { 940 int j; 941 sm_key_t y; 942 for (j=0;j<16;j++){ 943 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 944 } 945 sm_cmac_block_current++; 946 sm_cmac_next_state(); 947 sm_aes128_start(sm_cmac_k, y, NULL); 948 break; 949 } 950 case CMAC_CALC_MLAST: { 951 int i; 952 sm_key_t y; 953 for (i=0;i<16;i++){ 954 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 955 } 956 log_info_key("Y", y); 957 sm_cmac_block_current++; 958 sm_cmac_next_state(); 959 sm_aes128_start(sm_cmac_k, y, NULL); 960 break; 961 } 962 default: 963 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 964 break; 965 } 966 } 967 968 static void sm_cmac_handle_encryption_result(sm_key_t data){ 969 switch (sm_cmac_state){ 970 case CMAC_W4_SUBKEYS: { 971 sm_key_t k1; 972 memcpy(k1, data, 16); 973 sm_shift_left_by_one_bit_inplace(16, k1); 974 if (data[0] & 0x80){ 975 k1[15] ^= 0x87; 976 } 977 sm_key_t k2; 978 memcpy(k2, k1, 16); 979 sm_shift_left_by_one_bit_inplace(16, k2); 980 if (k1[0] & 0x80){ 981 k2[15] ^= 0x87; 982 } 983 984 log_info_key("k", sm_cmac_k); 985 log_info_key("k1", k1); 986 log_info_key("k2", k2); 987 988 // step 4: set m_last 989 int i; 990 if (sm_cmac_last_block_complete()){ 991 for (i=0;i<16;i++){ 992 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 993 } 994 } else { 995 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 996 for (i=0;i<16;i++){ 997 if (i < valid_octets_in_last_block){ 998 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 999 continue; 1000 } 1001 if (i == valid_octets_in_last_block){ 1002 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1003 continue; 1004 } 1005 sm_cmac_m_last[i] = k2[i]; 1006 } 1007 } 1008 1009 // next 1010 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1011 break; 1012 } 1013 case CMAC_W4_MI: 1014 memcpy(sm_cmac_x, data, 16); 1015 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1016 break; 1017 case CMAC_W4_MLAST: 1018 // done 1019 log_info("Setting CMAC Engine to IDLE"); 1020 sm_cmac_state = CMAC_IDLE; 1021 log_info_key("CMAC", data); 1022 sm_cmac_done_handler(data); 1023 break; 1024 default: 1025 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1026 break; 1027 } 1028 } 1029 1030 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1031 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1032 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1033 switch (setup->sm_stk_generation_method){ 1034 case PK_RESP_INPUT: 1035 if (sm_conn->sm_role){ 1036 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1037 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1038 } else { 1039 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)); 1040 } 1041 break; 1042 case PK_INIT_INPUT: 1043 if (sm_conn->sm_role){ 1044 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)); 1045 } else { 1046 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1047 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1048 } 1049 break; 1050 case OK_BOTH_INPUT: 1051 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1052 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1053 break; 1054 case NK_BOTH_INPUT: 1055 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1056 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)); 1057 break; 1058 case JUST_WORKS: 1059 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1060 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1061 break; 1062 case OOB: 1063 // client already provided OOB data, let's skip notification. 1064 break; 1065 } 1066 } 1067 1068 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1069 int recv_flags; 1070 if (sm_conn->sm_role){ 1071 // slave / responder 1072 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1073 } else { 1074 // master / initiator 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1076 } 1077 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1078 return recv_flags == setup->sm_key_distribution_received_set; 1079 } 1080 1081 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1082 if (sm_active_connection == con_handle){ 1083 sm_timeout_stop(); 1084 sm_active_connection = 0; 1085 log_info("sm: connection 0x%x released setup context", con_handle); 1086 } 1087 } 1088 1089 static int sm_key_distribution_flags_for_auth_req(void){ 1090 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1091 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1092 // encryption information only if bonding requested 1093 flags |= SM_KEYDIST_ENC_KEY; 1094 } 1095 return flags; 1096 } 1097 1098 static void sm_init_setup(sm_connection_t * sm_conn){ 1099 1100 // fill in sm setup 1101 setup->sm_state_vars = 0; 1102 sm_reset_tk(); 1103 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1104 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1105 1106 // query client for OOB data 1107 int have_oob_data = 0; 1108 if (sm_get_oob_data) { 1109 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1110 } 1111 1112 sm_pairing_packet_t * local_packet; 1113 if (sm_conn->sm_role){ 1114 // slave 1115 local_packet = &setup->sm_s_pres; 1116 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1117 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1118 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1119 } else { 1120 // master 1121 local_packet = &setup->sm_m_preq; 1122 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1123 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1124 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1125 1126 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1127 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1128 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1129 } 1130 1131 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1132 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1133 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1134 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1135 } 1136 1137 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1138 1139 sm_pairing_packet_t * remote_packet; 1140 int remote_key_request; 1141 if (sm_conn->sm_role){ 1142 // slave / responder 1143 remote_packet = &setup->sm_m_preq; 1144 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1145 } else { 1146 // master / initiator 1147 remote_packet = &setup->sm_s_pres; 1148 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1149 } 1150 1151 // check key size 1152 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1153 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1154 1155 // decide on STK generation method 1156 sm_setup_tk(); 1157 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1158 1159 // check if STK generation method is acceptable by client 1160 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1161 1162 // identical to responder 1163 sm_setup_key_distribution(remote_key_request); 1164 1165 // JUST WORKS doens't provide authentication 1166 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1167 1168 return 0; 1169 } 1170 1171 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1172 1173 // cache and reset context 1174 int matched_device_id = sm_address_resolution_test; 1175 address_resolution_mode_t mode = sm_address_resolution_mode; 1176 void * context = sm_address_resolution_context; 1177 1178 // reset context 1179 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1180 sm_address_resolution_context = NULL; 1181 sm_address_resolution_test = -1; 1182 hci_con_handle_t con_handle = 0; 1183 1184 sm_connection_t * sm_connection; 1185 uint16_t ediv; 1186 switch (mode){ 1187 case ADDRESS_RESOLUTION_GENERAL: 1188 break; 1189 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1190 sm_connection = (sm_connection_t *) context; 1191 con_handle = sm_connection->sm_handle; 1192 switch (event){ 1193 case ADDRESS_RESOLUTION_SUCEEDED: 1194 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1195 sm_connection->sm_le_db_index = matched_device_id; 1196 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1197 if (sm_connection->sm_role) break; 1198 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1199 sm_connection->sm_security_request_received = 0; 1200 sm_connection->sm_bonding_requested = 0; 1201 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1202 if (ediv){ 1203 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1204 } else { 1205 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1206 } 1207 break; 1208 case ADDRESS_RESOLUTION_FAILED: 1209 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1210 if (sm_connection->sm_role) break; 1211 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1212 sm_connection->sm_security_request_received = 0; 1213 sm_connection->sm_bonding_requested = 0; 1214 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1215 break; 1216 } 1217 break; 1218 default: 1219 break; 1220 } 1221 1222 switch (event){ 1223 case ADDRESS_RESOLUTION_SUCEEDED: 1224 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1225 break; 1226 case ADDRESS_RESOLUTION_FAILED: 1227 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1228 break; 1229 } 1230 } 1231 1232 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1233 1234 int le_db_index = -1; 1235 1236 // lookup device based on IRK 1237 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1238 int i; 1239 for (i=0; i < le_device_db_count(); i++){ 1240 sm_key_t irk; 1241 bd_addr_t address; 1242 int address_type; 1243 le_device_db_info(i, &address_type, address, irk); 1244 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1245 log_info("sm: device found for IRK, updating"); 1246 le_db_index = i; 1247 break; 1248 } 1249 } 1250 } 1251 1252 // if not found, lookup via public address if possible 1253 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1254 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1255 int i; 1256 for (i=0; i < le_device_db_count(); i++){ 1257 bd_addr_t address; 1258 int address_type; 1259 le_device_db_info(i, &address_type, address, NULL); 1260 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1261 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1262 log_info("sm: device found for public address, updating"); 1263 le_db_index = i; 1264 break; 1265 } 1266 } 1267 } 1268 1269 // if not found, add to db 1270 if (le_db_index < 0) { 1271 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1272 } 1273 1274 if (le_db_index >= 0){ 1275 le_device_db_local_counter_set(le_db_index, 0); 1276 1277 // store local CSRK 1278 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1279 log_info("sm: store local CSRK"); 1280 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1281 le_device_db_local_counter_set(le_db_index, 0); 1282 } 1283 1284 // store remote CSRK 1285 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1286 log_info("sm: store remote CSRK"); 1287 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1288 le_device_db_remote_counter_set(le_db_index, 0); 1289 } 1290 1291 // store encryption information 1292 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1293 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1294 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1295 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1296 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1297 } 1298 } 1299 1300 // keep le_db_index 1301 sm_conn->sm_le_db_index = le_db_index; 1302 } 1303 1304 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1305 setup->sm_pairing_failed_reason = reason; 1306 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1307 } 1308 1309 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1310 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1311 } 1312 1313 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1314 1315 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1316 static int sm_passkey_used(stk_generation_method_t method); 1317 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1318 1319 static void sm_log_ec_keypair(void){ 1320 log_info("d: %s", ec_d); 1321 log_info("X: %s", ec_qx); 1322 log_info("Y: %s", ec_qy); 1323 } 1324 1325 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1326 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1327 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1328 } else { 1329 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1330 } 1331 } 1332 1333 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1334 if (sm_conn->sm_role){ 1335 // Responder 1336 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1337 } else { 1338 // Initiator role 1339 switch (setup->sm_stk_generation_method){ 1340 case JUST_WORKS: 1341 sm_sc_prepare_dhkey_check(sm_conn); 1342 break; 1343 1344 case NK_BOTH_INPUT: 1345 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1346 break; 1347 case PK_INIT_INPUT: 1348 case PK_RESP_INPUT: 1349 case OK_BOTH_INPUT: 1350 if (setup->sm_passkey_bit < 20) { 1351 sm_sc_start_calculating_local_confirm(sm_conn); 1352 } else { 1353 sm_sc_prepare_dhkey_check(sm_conn); 1354 } 1355 break; 1356 case OOB: 1357 // TODO: implement SC OOB 1358 break; 1359 } 1360 } 1361 } 1362 1363 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1364 return sm_cmac_sc_buffer[offset]; 1365 } 1366 1367 static void sm_sc_cmac_done(uint8_t * hash){ 1368 log_info("sm_sc_cmac_done: "); 1369 log_info_hexdump(hash, 16); 1370 1371 sm_connection_t * sm_conn = sm_cmac_connection; 1372 sm_cmac_connection = NULL; 1373 1374 switch (sm_conn->sm_engine_state){ 1375 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1376 memcpy(setup->sm_local_confirm, hash, 16); 1377 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1378 break; 1379 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1380 // check 1381 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1382 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1383 break; 1384 } 1385 sm_sc_state_after_receiving_random(sm_conn); 1386 break; 1387 case SM_SC_W4_CALCULATE_G2: { 1388 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1389 big_endian_store_32(setup->sm_tk, 12, vab); 1390 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1391 sm_trigger_user_response(sm_conn); 1392 break; 1393 } 1394 case SM_SC_W4_CALCULATE_F5_SALT: 1395 memcpy(setup->sm_t, hash, 16); 1396 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1397 break; 1398 case SM_SC_W4_CALCULATE_F5_MACKEY: 1399 memcpy(setup->sm_mackey, hash, 16); 1400 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1401 break; 1402 case SM_SC_W4_CALCULATE_F5_LTK: 1403 memcpy(setup->sm_ltk, hash, 16); 1404 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1405 break; 1406 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1407 memcpy(setup->sm_local_dhkey_check, hash, 16); 1408 if (sm_conn->sm_role){ 1409 // responder 1410 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1411 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1412 } else { 1413 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1414 } 1415 } else { 1416 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1417 } 1418 break; 1419 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1420 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1421 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1422 break; 1423 } 1424 if (sm_conn->sm_role){ 1425 // responder 1426 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1427 } else { 1428 // initiator 1429 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1430 } 1431 break; 1432 default: 1433 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1434 break; 1435 } 1436 sm_run(); 1437 } 1438 1439 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){ 1440 const uint16_t message_len = 65; 1441 sm_cmac_connection = sm_conn; 1442 memcpy(sm_cmac_sc_buffer, u, 32); 1443 memcpy(sm_cmac_sc_buffer+32, v, 32); 1444 sm_cmac_sc_buffer[64] = z; 1445 log_info("f4 key"); 1446 log_info_hexdump(x, 16); 1447 log_info("f4 message"); 1448 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1449 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1450 } 1451 1452 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1453 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1454 static const uint8_t f5_length[] = { 0x01, 0x00}; 1455 1456 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1457 #ifdef USE_MBEDTLS_FOR_ECDH 1458 // da * Pb 1459 mbedtls_mpi d; 1460 mbedtls_ecp_point Q; 1461 mbedtls_mpi_init(&d); 1462 mbedtls_ecp_point_init(&Q); 1463 mbedtls_mpi_read_binary(&d, ec_d, 32); 1464 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1465 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1466 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1467 mbedtls_ecp_point DH; 1468 mbedtls_ecp_point_init(&DH); 1469 mbedtls_ecp_mul(&mbedtls_ec_group, &DH, &d, &Q, NULL, NULL); 1470 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1471 mbedtls_ecp_point_free(&DH); 1472 mbedtls_ecp_point_free(&Q); 1473 #endif 1474 log_info("dhkey"); 1475 log_info_hexdump(dhkey, 32); 1476 } 1477 1478 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1479 // calculate DHKEY 1480 sm_key256_t dhkey; 1481 sm_sc_calculate_dhkey(dhkey); 1482 1483 // calculate salt for f5 1484 const uint16_t message_len = 32; 1485 sm_cmac_connection = sm_conn; 1486 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1487 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1488 } 1489 1490 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){ 1491 const uint16_t message_len = 53; 1492 sm_cmac_connection = sm_conn; 1493 1494 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1495 sm_cmac_sc_buffer[0] = 0; 1496 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1497 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1498 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1499 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1500 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1501 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1502 log_info("f5 key"); 1503 log_info_hexdump(t, 16); 1504 log_info("f5 message for MacKey"); 1505 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1506 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1507 } 1508 1509 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1510 sm_key56_t bd_addr_master, bd_addr_slave; 1511 bd_addr_master[0] = setup->sm_m_addr_type; 1512 bd_addr_slave[0] = setup->sm_s_addr_type; 1513 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1514 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1515 if (sm_conn->sm_role){ 1516 // responder 1517 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1518 } else { 1519 // initiator 1520 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1521 } 1522 } 1523 1524 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1525 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1526 const uint16_t message_len = 53; 1527 sm_cmac_connection = sm_conn; 1528 sm_cmac_sc_buffer[0] = 1; 1529 // 1..52 setup before 1530 log_info("f5 key"); 1531 log_info_hexdump(t, 16); 1532 log_info("f5 message for LTK"); 1533 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1534 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1535 } 1536 1537 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1538 f5_ltk(sm_conn, setup->sm_t); 1539 } 1540 1541 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){ 1542 const uint16_t message_len = 65; 1543 sm_cmac_connection = sm_conn; 1544 memcpy(sm_cmac_sc_buffer, n1, 16); 1545 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1546 memcpy(sm_cmac_sc_buffer+32, r, 16); 1547 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1548 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1549 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1550 log_info("f6 key"); 1551 log_info_hexdump(w, 16); 1552 log_info("f6 message"); 1553 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1554 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1555 } 1556 1557 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1558 // - U is 256 bits 1559 // - V is 256 bits 1560 // - X is 128 bits 1561 // - Y is 128 bits 1562 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){ 1563 const uint16_t message_len = 80; 1564 sm_cmac_connection = sm_conn; 1565 memcpy(sm_cmac_sc_buffer, u, 32); 1566 memcpy(sm_cmac_sc_buffer+32, v, 32); 1567 memcpy(sm_cmac_sc_buffer+64, y, 16); 1568 log_info("g2 key"); 1569 log_info_hexdump(x, 16); 1570 log_info("g2 message"); 1571 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1572 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1573 } 1574 1575 static void g2_calculate(sm_connection_t * sm_conn) { 1576 // calc Va if numeric comparison 1577 if (sm_conn->sm_role){ 1578 // responder 1579 g2_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, setup->sm_local_nonce);; 1580 } else { 1581 // initiator 1582 g2_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1583 } 1584 } 1585 1586 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1587 uint8_t z = 0; 1588 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1589 // some form of passkey 1590 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1591 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1592 setup->sm_passkey_bit++; 1593 } 1594 f4_engine(sm_conn, ec_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1595 } 1596 1597 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1598 uint8_t z = 0; 1599 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1600 // some form of passkey 1601 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1602 // sm_passkey_bit was increased before sending confirm value 1603 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1604 } 1605 f4_engine(sm_conn, setup->sm_peer_qx, ec_qx, setup->sm_peer_nonce, z); 1606 } 1607 1608 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1609 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1610 } 1611 1612 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1613 // calculate DHKCheck 1614 sm_key56_t bd_addr_master, bd_addr_slave; 1615 bd_addr_master[0] = setup->sm_m_addr_type; 1616 bd_addr_slave[0] = setup->sm_s_addr_type; 1617 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1618 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1619 uint8_t iocap_a[3]; 1620 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1621 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1622 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1623 uint8_t iocap_b[3]; 1624 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1625 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1626 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1627 if (sm_conn->sm_role){ 1628 // responder 1629 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); 1630 } else { 1631 // initiator 1632 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); 1633 } 1634 } 1635 1636 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1637 // validate E = f6() 1638 sm_key56_t bd_addr_master, bd_addr_slave; 1639 bd_addr_master[0] = setup->sm_m_addr_type; 1640 bd_addr_slave[0] = setup->sm_s_addr_type; 1641 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1642 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1643 1644 uint8_t iocap_a[3]; 1645 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1646 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1647 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1648 uint8_t iocap_b[3]; 1649 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1650 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1651 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1652 if (sm_conn->sm_role){ 1653 // responder 1654 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); 1655 } else { 1656 // initiator 1657 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); 1658 } 1659 } 1660 #endif 1661 1662 static void sm_load_security_info(sm_connection_t * sm_connection){ 1663 int encryption_key_size; 1664 int authenticated; 1665 int authorized; 1666 1667 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1668 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1669 &encryption_key_size, &authenticated, &authorized); 1670 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1671 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1672 sm_connection->sm_connection_authenticated = authenticated; 1673 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1674 } 1675 1676 static void sm_run(void){ 1677 1678 btstack_linked_list_iterator_t it; 1679 1680 // assert that we can send at least commands 1681 if (!hci_can_send_command_packet_now()) return; 1682 1683 // 1684 // non-connection related behaviour 1685 // 1686 1687 // distributed key generation 1688 switch (dkg_state){ 1689 case DKG_CALC_IRK: 1690 // already busy? 1691 if (sm_aes128_state == SM_AES128_IDLE) { 1692 // IRK = d1(IR, 1, 0) 1693 sm_key_t d1_prime; 1694 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1695 dkg_next_state(); 1696 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1697 return; 1698 } 1699 break; 1700 case DKG_CALC_DHK: 1701 // already busy? 1702 if (sm_aes128_state == SM_AES128_IDLE) { 1703 // DHK = d1(IR, 3, 0) 1704 sm_key_t d1_prime; 1705 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1706 dkg_next_state(); 1707 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1708 return; 1709 } 1710 break; 1711 default: 1712 break; 1713 } 1714 1715 #ifdef USE_MBEDTLS_FOR_ECDH 1716 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1717 sm_random_start(NULL); 1718 return; 1719 } 1720 #endif 1721 1722 // random address updates 1723 switch (rau_state){ 1724 case RAU_GET_RANDOM: 1725 rau_next_state(); 1726 sm_random_start(NULL); 1727 return; 1728 case RAU_GET_ENC: 1729 // already busy? 1730 if (sm_aes128_state == SM_AES128_IDLE) { 1731 sm_key_t r_prime; 1732 sm_ah_r_prime(sm_random_address, r_prime); 1733 rau_next_state(); 1734 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1735 return; 1736 } 1737 break; 1738 case RAU_SET_ADDRESS: 1739 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1740 rau_state = RAU_IDLE; 1741 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1742 return; 1743 default: 1744 break; 1745 } 1746 1747 // CMAC 1748 switch (sm_cmac_state){ 1749 case CMAC_CALC_SUBKEYS: 1750 case CMAC_CALC_MI: 1751 case CMAC_CALC_MLAST: 1752 // already busy? 1753 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1754 sm_cmac_handle_aes_engine_ready(); 1755 return; 1756 default: 1757 break; 1758 } 1759 1760 // CSRK Lookup 1761 // -- if csrk lookup ready, find connection that require csrk lookup 1762 if (sm_address_resolution_idle()){ 1763 hci_connections_get_iterator(&it); 1764 while(btstack_linked_list_iterator_has_next(&it)){ 1765 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1766 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1767 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1768 // and start lookup 1769 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); 1770 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1771 break; 1772 } 1773 } 1774 } 1775 1776 // -- if csrk lookup ready, resolved addresses for received addresses 1777 if (sm_address_resolution_idle()) { 1778 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1779 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1780 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1781 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1782 btstack_memory_sm_lookup_entry_free(entry); 1783 } 1784 } 1785 1786 // -- Continue with CSRK device lookup by public or resolvable private address 1787 if (!sm_address_resolution_idle()){ 1788 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1789 while (sm_address_resolution_test < le_device_db_count()){ 1790 int addr_type; 1791 bd_addr_t addr; 1792 sm_key_t irk; 1793 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1794 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1795 1796 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1797 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1798 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1799 break; 1800 } 1801 1802 if (sm_address_resolution_addr_type == 0){ 1803 sm_address_resolution_test++; 1804 continue; 1805 } 1806 1807 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1808 1809 log_info("LE Device Lookup: calculate AH"); 1810 log_info_key("IRK", irk); 1811 1812 sm_key_t r_prime; 1813 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1814 sm_address_resolution_ah_calculation_active = 1; 1815 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1816 return; 1817 } 1818 1819 if (sm_address_resolution_test >= le_device_db_count()){ 1820 log_info("LE Device Lookup: not found"); 1821 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1822 } 1823 } 1824 1825 1826 // 1827 // active connection handling 1828 // -- use loop to handle next connection if lock on setup context is released 1829 1830 while (1) { 1831 1832 // Find connections that requires setup context and make active if no other is locked 1833 hci_connections_get_iterator(&it); 1834 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1835 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1836 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1837 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1838 int done = 1; 1839 int err; 1840 switch (sm_connection->sm_engine_state) { 1841 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1842 // send packet if possible, 1843 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1844 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1845 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1846 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1847 } else { 1848 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1849 } 1850 // don't lock sxetup context yet 1851 done = 0; 1852 break; 1853 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1854 sm_init_setup(sm_connection); 1855 // recover pairing request 1856 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1857 err = sm_stk_generation_init(sm_connection); 1858 if (err){ 1859 setup->sm_pairing_failed_reason = err; 1860 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1861 break; 1862 } 1863 sm_timeout_start(sm_connection); 1864 // generate random number first, if we need to show passkey 1865 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1866 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1867 break; 1868 } 1869 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1870 break; 1871 case SM_INITIATOR_PH0_HAS_LTK: 1872 sm_load_security_info(sm_connection); 1873 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1874 break; 1875 case SM_RESPONDER_PH0_RECEIVED_LTK: 1876 switch (sm_connection->sm_irk_lookup_state){ 1877 case IRK_LOOKUP_SUCCEEDED:{ 1878 sm_load_security_info(sm_connection); 1879 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1880 break; 1881 } 1882 case IRK_LOOKUP_FAILED: 1883 // assume that we don't have a LTK for ediv == 0 and random == null 1884 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1885 log_info("LTK Request: ediv & random are empty"); 1886 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1887 // TODO: no need to lock context yet -> done = 0; 1888 break; 1889 } 1890 // re-establish previously used LTK using Rand and EDIV 1891 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1892 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1893 // re-establish used key encryption size 1894 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1895 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1896 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1897 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1898 log_info("sm: received ltk request with key size %u, authenticated %u", 1899 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1900 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1901 break; 1902 default: 1903 // just wait until IRK lookup is completed 1904 // don't lock sxetup context yet 1905 done = 0; 1906 break; 1907 } 1908 break; 1909 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1910 sm_init_setup(sm_connection); 1911 sm_timeout_start(sm_connection); 1912 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1913 break; 1914 default: 1915 done = 0; 1916 break; 1917 } 1918 if (done){ 1919 sm_active_connection = sm_connection->sm_handle; 1920 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1921 } 1922 } 1923 1924 // 1925 // active connection handling 1926 // 1927 1928 if (sm_active_connection == 0) return; 1929 1930 // assert that we could send a SM PDU - not needed for all of the following 1931 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1932 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1933 return; 1934 } 1935 1936 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1937 if (!connection) return; 1938 1939 sm_key_t plaintext; 1940 int key_distribution_flags; 1941 1942 log_info("sm_run: state %u", connection->sm_engine_state); 1943 1944 // responding state 1945 switch (connection->sm_engine_state){ 1946 1947 // general 1948 case SM_GENERAL_SEND_PAIRING_FAILED: { 1949 uint8_t buffer[2]; 1950 buffer[0] = SM_CODE_PAIRING_FAILED; 1951 buffer[1] = setup->sm_pairing_failed_reason; 1952 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1953 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1954 sm_done_for_handle(connection->sm_handle); 1955 break; 1956 } 1957 1958 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1959 case SM_SC_W2_GET_RANDOM_A: 1960 sm_random_start(connection); 1961 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1962 break; 1963 case SM_SC_W2_GET_RANDOM_B: 1964 sm_random_start(connection); 1965 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1966 break; 1967 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1968 if (!sm_cmac_ready()) break; 1969 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1970 sm_sc_calculate_local_confirm(connection); 1971 break; 1972 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1973 if (!sm_cmac_ready()) break; 1974 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1975 sm_sc_calculate_remote_confirm(connection); 1976 break; 1977 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1980 sm_sc_calculate_f6_for_dhkey_check(connection); 1981 break; 1982 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1985 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1986 break; 1987 case SM_SC_W2_CALCULATE_F5_SALT: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1990 f5_calculate_salt(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F5_MACKEY: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 1995 f5_calculate_mackey(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F5_LTK: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2000 f5_calculate_ltk(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_G2: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2005 g2_calculate(connection); 2006 break; 2007 2008 #endif 2009 // initiator side 2010 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2011 sm_key_t peer_ltk_flipped; 2012 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2013 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2014 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2015 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2016 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2017 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2018 return; 2019 } 2020 2021 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2022 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2023 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2024 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2025 sm_timeout_reset(connection); 2026 break; 2027 2028 // responder side 2029 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2030 connection->sm_engine_state = SM_RESPONDER_IDLE; 2031 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2032 sm_done_for_handle(connection->sm_handle); 2033 return; 2034 2035 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2036 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2037 uint8_t buffer[65]; 2038 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2039 // 2040 reverse_256(ec_qx, &buffer[1]); 2041 reverse_256(ec_qy, &buffer[33]); 2042 2043 // stk generation method 2044 // passkey entry: notify app to show passkey or to request passkey 2045 switch (setup->sm_stk_generation_method){ 2046 case JUST_WORKS: 2047 case NK_BOTH_INPUT: 2048 if (connection->sm_role){ 2049 // responder 2050 sm_sc_start_calculating_local_confirm(connection); 2051 } else { 2052 // initiator 2053 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2054 } 2055 break; 2056 case PK_INIT_INPUT: 2057 case PK_RESP_INPUT: 2058 case OK_BOTH_INPUT: 2059 // use random TK for display 2060 memcpy(setup->sm_ra, setup->sm_tk, 16); 2061 memcpy(setup->sm_rb, setup->sm_tk, 16); 2062 setup->sm_passkey_bit = 0; 2063 2064 if (connection->sm_role){ 2065 // responder 2066 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2067 } else { 2068 // initiator 2069 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2070 } 2071 sm_trigger_user_response(connection); 2072 break; 2073 case OOB: 2074 // TODO: implement SC OOB 2075 break; 2076 } 2077 2078 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2079 sm_timeout_reset(connection); 2080 break; 2081 } 2082 case SM_SC_SEND_CONFIRMATION: { 2083 uint8_t buffer[17]; 2084 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2085 reverse_128(setup->sm_local_confirm, &buffer[1]); 2086 if (connection->sm_role){ 2087 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2088 } else { 2089 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2090 } 2091 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2092 sm_timeout_reset(connection); 2093 break; 2094 } 2095 case SM_SC_SEND_PAIRING_RANDOM: { 2096 uint8_t buffer[17]; 2097 buffer[0] = SM_CODE_PAIRING_RANDOM; 2098 reverse_128(setup->sm_local_nonce, &buffer[1]); 2099 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2100 if (connection->sm_role){ 2101 // responder 2102 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2103 } else { 2104 // initiator 2105 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2106 } 2107 } else { 2108 if (connection->sm_role){ 2109 // responder 2110 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2111 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2112 } else { 2113 sm_sc_prepare_dhkey_check(connection); 2114 } 2115 } else { 2116 // initiator 2117 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2118 } 2119 } 2120 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2121 sm_timeout_reset(connection); 2122 break; 2123 } 2124 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2125 uint8_t buffer[17]; 2126 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2127 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2128 2129 if (connection->sm_role){ 2130 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2131 } else { 2132 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2133 } 2134 2135 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2136 sm_timeout_reset(connection); 2137 break; 2138 } 2139 2140 #endif 2141 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2142 // echo initiator for now 2143 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2144 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2145 2146 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2147 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2148 if (setup->sm_use_secure_connections){ 2149 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2150 // skip LTK/EDIV for SC 2151 log_info("sm: dropping encryption information flag"); 2152 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2153 } 2154 #endif 2155 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); 2156 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); 2157 // update key distribution after ENC was dropped 2158 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2159 2160 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2161 sm_timeout_reset(connection); 2162 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2163 if (setup->sm_stk_generation_method == JUST_WORKS){ 2164 sm_trigger_user_response(connection); 2165 } 2166 return; 2167 2168 case SM_PH2_SEND_PAIRING_RANDOM: { 2169 uint8_t buffer[17]; 2170 buffer[0] = SM_CODE_PAIRING_RANDOM; 2171 reverse_128(setup->sm_local_random, &buffer[1]); 2172 if (connection->sm_role){ 2173 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2174 } else { 2175 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2176 } 2177 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2178 sm_timeout_reset(connection); 2179 break; 2180 } 2181 2182 case SM_PH2_GET_RANDOM_TK: 2183 case SM_PH2_C1_GET_RANDOM_A: 2184 case SM_PH2_C1_GET_RANDOM_B: 2185 case SM_PH3_GET_RANDOM: 2186 case SM_PH3_GET_DIV: 2187 sm_next_responding_state(connection); 2188 sm_random_start(connection); 2189 return; 2190 2191 case SM_PH2_C1_GET_ENC_B: 2192 case SM_PH2_C1_GET_ENC_D: 2193 // already busy? 2194 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2195 sm_next_responding_state(connection); 2196 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2197 return; 2198 2199 case SM_PH3_LTK_GET_ENC: 2200 case SM_RESPONDER_PH4_LTK_GET_ENC: 2201 // already busy? 2202 if (sm_aes128_state == SM_AES128_IDLE) { 2203 sm_key_t d_prime; 2204 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2205 sm_next_responding_state(connection); 2206 sm_aes128_start(sm_persistent_er, d_prime, connection); 2207 return; 2208 } 2209 break; 2210 2211 case SM_PH3_CSRK_GET_ENC: 2212 // already busy? 2213 if (sm_aes128_state == SM_AES128_IDLE) { 2214 sm_key_t d_prime; 2215 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2216 sm_next_responding_state(connection); 2217 sm_aes128_start(sm_persistent_er, d_prime, connection); 2218 return; 2219 } 2220 break; 2221 2222 case SM_PH2_C1_GET_ENC_C: 2223 // already busy? 2224 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2225 // calculate m_confirm using aes128 engine - step 1 2226 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); 2227 sm_next_responding_state(connection); 2228 sm_aes128_start(setup->sm_tk, plaintext, connection); 2229 break; 2230 case SM_PH2_C1_GET_ENC_A: 2231 // already busy? 2232 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2233 // calculate confirm using aes128 engine - step 1 2234 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); 2235 sm_next_responding_state(connection); 2236 sm_aes128_start(setup->sm_tk, plaintext, connection); 2237 break; 2238 case SM_PH2_CALC_STK: 2239 // already busy? 2240 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2241 // calculate STK 2242 if (connection->sm_role){ 2243 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2244 } else { 2245 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2246 } 2247 sm_next_responding_state(connection); 2248 sm_aes128_start(setup->sm_tk, plaintext, connection); 2249 break; 2250 case SM_PH3_Y_GET_ENC: 2251 // already busy? 2252 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2253 // PH3B2 - calculate Y from - enc 2254 // Y = dm(DHK, Rand) 2255 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2256 sm_next_responding_state(connection); 2257 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2258 return; 2259 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2260 uint8_t buffer[17]; 2261 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2262 reverse_128(setup->sm_local_confirm, &buffer[1]); 2263 if (connection->sm_role){ 2264 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2265 } else { 2266 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2267 } 2268 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2269 sm_timeout_reset(connection); 2270 return; 2271 } 2272 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2273 sm_key_t stk_flipped; 2274 reverse_128(setup->sm_ltk, stk_flipped); 2275 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2276 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2277 return; 2278 } 2279 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2280 sm_key_t stk_flipped; 2281 reverse_128(setup->sm_ltk, stk_flipped); 2282 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2283 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2284 return; 2285 } 2286 case SM_RESPONDER_PH4_SEND_LTK: { 2287 sm_key_t ltk_flipped; 2288 reverse_128(setup->sm_ltk, ltk_flipped); 2289 connection->sm_engine_state = SM_RESPONDER_IDLE; 2290 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2291 return; 2292 } 2293 case SM_RESPONDER_PH4_Y_GET_ENC: 2294 // already busy? 2295 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2296 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2297 // Y = dm(DHK, Rand) 2298 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2299 sm_next_responding_state(connection); 2300 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2301 return; 2302 2303 case SM_PH3_DISTRIBUTE_KEYS: 2304 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2305 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2306 uint8_t buffer[17]; 2307 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2308 reverse_128(setup->sm_ltk, &buffer[1]); 2309 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2310 sm_timeout_reset(connection); 2311 return; 2312 } 2313 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2314 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2315 uint8_t buffer[11]; 2316 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2317 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2318 reverse_64(setup->sm_local_rand, &buffer[3]); 2319 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2320 sm_timeout_reset(connection); 2321 return; 2322 } 2323 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2324 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2325 uint8_t buffer[17]; 2326 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2327 reverse_128(sm_persistent_irk, &buffer[1]); 2328 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2329 sm_timeout_reset(connection); 2330 return; 2331 } 2332 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2333 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2334 bd_addr_t local_address; 2335 uint8_t buffer[8]; 2336 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2337 gap_advertisements_get_address(&buffer[1], local_address); 2338 reverse_bd_addr(local_address, &buffer[2]); 2339 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2340 sm_timeout_reset(connection); 2341 return; 2342 } 2343 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2344 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2345 2346 // hack to reproduce test runs 2347 if (test_use_fixed_local_csrk){ 2348 memset(setup->sm_local_csrk, 0xcc, 16); 2349 } 2350 2351 uint8_t buffer[17]; 2352 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2353 reverse_128(setup->sm_local_csrk, &buffer[1]); 2354 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2355 sm_timeout_reset(connection); 2356 return; 2357 } 2358 2359 // keys are sent 2360 if (connection->sm_role){ 2361 // slave -> receive master keys if any 2362 if (sm_key_distribution_all_received(connection)){ 2363 sm_key_distribution_handle_all_received(connection); 2364 connection->sm_engine_state = SM_RESPONDER_IDLE; 2365 sm_done_for_handle(connection->sm_handle); 2366 } else { 2367 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2368 } 2369 } else { 2370 // master -> all done 2371 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2372 sm_done_for_handle(connection->sm_handle); 2373 } 2374 break; 2375 2376 default: 2377 break; 2378 } 2379 2380 // check again if active connection was released 2381 if (sm_active_connection) break; 2382 } 2383 } 2384 2385 // note: aes engine is ready as we just got the aes result 2386 static void sm_handle_encryption_result(uint8_t * data){ 2387 2388 sm_aes128_state = SM_AES128_IDLE; 2389 2390 if (sm_address_resolution_ah_calculation_active){ 2391 sm_address_resolution_ah_calculation_active = 0; 2392 // compare calulated address against connecting device 2393 uint8_t hash[3]; 2394 reverse_24(data, hash); 2395 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2396 log_info("LE Device Lookup: matched resolvable private address"); 2397 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2398 return; 2399 } 2400 // no match, try next 2401 sm_address_resolution_test++; 2402 return; 2403 } 2404 2405 switch (dkg_state){ 2406 case DKG_W4_IRK: 2407 reverse_128(data, sm_persistent_irk); 2408 log_info_key("irk", sm_persistent_irk); 2409 dkg_next_state(); 2410 return; 2411 case DKG_W4_DHK: 2412 reverse_128(data, sm_persistent_dhk); 2413 log_info_key("dhk", sm_persistent_dhk); 2414 dkg_next_state(); 2415 // SM Init Finished 2416 return; 2417 default: 2418 break; 2419 } 2420 2421 switch (rau_state){ 2422 case RAU_W4_ENC: 2423 reverse_24(data, &sm_random_address[3]); 2424 rau_next_state(); 2425 return; 2426 default: 2427 break; 2428 } 2429 2430 switch (sm_cmac_state){ 2431 case CMAC_W4_SUBKEYS: 2432 case CMAC_W4_MI: 2433 case CMAC_W4_MLAST: 2434 { 2435 sm_key_t t; 2436 reverse_128(data, t); 2437 sm_cmac_handle_encryption_result(t); 2438 } 2439 return; 2440 default: 2441 break; 2442 } 2443 2444 // retrieve sm_connection provided to sm_aes128_start_encryption 2445 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2446 if (!connection) return; 2447 switch (connection->sm_engine_state){ 2448 case SM_PH2_C1_W4_ENC_A: 2449 case SM_PH2_C1_W4_ENC_C: 2450 { 2451 sm_key_t t2; 2452 reverse_128(data, t2); 2453 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2454 } 2455 sm_next_responding_state(connection); 2456 return; 2457 case SM_PH2_C1_W4_ENC_B: 2458 reverse_128(data, setup->sm_local_confirm); 2459 log_info_key("c1!", setup->sm_local_confirm); 2460 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2461 return; 2462 case SM_PH2_C1_W4_ENC_D: 2463 { 2464 sm_key_t peer_confirm_test; 2465 reverse_128(data, peer_confirm_test); 2466 log_info_key("c1!", peer_confirm_test); 2467 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2468 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2469 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2470 return; 2471 } 2472 if (connection->sm_role){ 2473 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2474 } else { 2475 connection->sm_engine_state = SM_PH2_CALC_STK; 2476 } 2477 } 2478 return; 2479 case SM_PH2_W4_STK: 2480 reverse_128(data, setup->sm_ltk); 2481 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2482 log_info_key("stk", setup->sm_ltk); 2483 if (connection->sm_role){ 2484 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2485 } else { 2486 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2487 } 2488 return; 2489 case SM_PH3_Y_W4_ENC:{ 2490 sm_key_t y128; 2491 reverse_128(data, y128); 2492 setup->sm_local_y = big_endian_read_16(y128, 14); 2493 log_info_hex16("y", setup->sm_local_y); 2494 // PH3B3 - calculate EDIV 2495 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2496 log_info_hex16("ediv", setup->sm_local_ediv); 2497 // PH3B4 - calculate LTK - enc 2498 // LTK = d1(ER, DIV, 0)) 2499 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2500 return; 2501 } 2502 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2503 sm_key_t y128; 2504 reverse_128(data, y128); 2505 setup->sm_local_y = big_endian_read_16(y128, 14); 2506 log_info_hex16("y", setup->sm_local_y); 2507 2508 // PH3B3 - calculate DIV 2509 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2510 log_info_hex16("ediv", setup->sm_local_ediv); 2511 // PH3B4 - calculate LTK - enc 2512 // LTK = d1(ER, DIV, 0)) 2513 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2514 return; 2515 } 2516 case SM_PH3_LTK_W4_ENC: 2517 reverse_128(data, setup->sm_ltk); 2518 log_info_key("ltk", setup->sm_ltk); 2519 // calc CSRK next 2520 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2521 return; 2522 case SM_PH3_CSRK_W4_ENC: 2523 reverse_128(data, setup->sm_local_csrk); 2524 log_info_key("csrk", setup->sm_local_csrk); 2525 if (setup->sm_key_distribution_send_set){ 2526 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2527 } else { 2528 // no keys to send, just continue 2529 if (connection->sm_role){ 2530 // slave -> receive master keys 2531 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2532 } else { 2533 // master -> all done 2534 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2535 sm_done_for_handle(connection->sm_handle); 2536 } 2537 } 2538 return; 2539 case SM_RESPONDER_PH4_LTK_W4_ENC: 2540 reverse_128(data, setup->sm_ltk); 2541 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2542 log_info_key("ltk", setup->sm_ltk); 2543 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2544 return; 2545 default: 2546 break; 2547 } 2548 } 2549 2550 #ifdef USE_MBEDTLS_FOR_ECDH 2551 2552 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2553 int offset = setup->sm_passkey_bit; 2554 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2555 while (size) { 2556 if (offset < 32){ 2557 *buffer++ = setup->sm_peer_qx[offset++]; 2558 } else { 2559 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2560 } 2561 size--; 2562 } 2563 setup->sm_passkey_bit = offset; 2564 return 0; 2565 } 2566 #endif 2567 2568 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2569 static void sm_handle_random_result(uint8_t * data){ 2570 2571 #ifdef USE_MBEDTLS_FOR_ECDH 2572 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2573 int num_bytes = setup->sm_passkey_bit; 2574 if (num_bytes < 32){ 2575 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2576 } else { 2577 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2578 } 2579 num_bytes += 8; 2580 setup->sm_passkey_bit = num_bytes; 2581 2582 if (num_bytes >= 64){ 2583 // generate EC key 2584 setup->sm_passkey_bit = 0; 2585 mbedtls_mpi d; 2586 mbedtls_ecp_point P; 2587 mbedtls_mpi_init(&d); 2588 mbedtls_ecp_point_init(&P); 2589 mbedtls_ecp_gen_keypair(&mbedtls_ec_group, &d, &P, &sm_generate_f_rng, NULL); 2590 mbedtls_mpi_write_binary(&P.X, ec_qx, 16); 2591 mbedtls_mpi_write_binary(&P.Y, ec_qy, 16); 2592 mbedtls_mpi_write_binary(&d, ec_d, 16); 2593 sm_log_ec_keypair(); 2594 mbedtls_ecp_point_free(&P); 2595 mbedtls_mpi_free(&d); 2596 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2597 } 2598 } 2599 #endif 2600 2601 switch (rau_state){ 2602 case RAU_W4_RANDOM: 2603 // non-resolvable vs. resolvable 2604 switch (gap_random_adress_type){ 2605 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2606 // resolvable: use random as prand and calc address hash 2607 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2608 memcpy(sm_random_address, data, 3); 2609 sm_random_address[0] &= 0x3f; 2610 sm_random_address[0] |= 0x40; 2611 rau_state = RAU_GET_ENC; 2612 break; 2613 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2614 default: 2615 // "The two most significant bits of the address shall be equal to ‘0’"" 2616 memcpy(sm_random_address, data, 6); 2617 sm_random_address[0] &= 0x3f; 2618 rau_state = RAU_SET_ADDRESS; 2619 break; 2620 } 2621 return; 2622 default: 2623 break; 2624 } 2625 2626 // retrieve sm_connection provided to sm_random_start 2627 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2628 if (!connection) return; 2629 switch (connection->sm_engine_state){ 2630 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2631 case SM_SC_W4_GET_RANDOM_A: 2632 memcpy(&setup->sm_local_nonce[0], data, 8); 2633 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2634 break; 2635 case SM_SC_W4_GET_RANDOM_B: 2636 memcpy(&setup->sm_local_nonce[8], data, 8); 2637 // initiator & jw/nc -> send pairing random 2638 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2639 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2640 break; 2641 } else { 2642 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2643 } 2644 break; 2645 #endif 2646 2647 case SM_PH2_W4_RANDOM_TK: 2648 { 2649 // map random to 0-999999 without speding much cycles on a modulus operation 2650 uint32_t tk = little_endian_read_32(data,0); 2651 tk = tk & 0xfffff; // 1048575 2652 if (tk >= 999999){ 2653 tk = tk - 999999; 2654 } 2655 sm_reset_tk(); 2656 big_endian_store_32(setup->sm_tk, 12, tk); 2657 if (connection->sm_role){ 2658 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2659 } else { 2660 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2661 sm_trigger_user_response(connection); 2662 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2663 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2664 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2665 } 2666 } 2667 return; 2668 } 2669 case SM_PH2_C1_W4_RANDOM_A: 2670 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2671 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2672 return; 2673 case SM_PH2_C1_W4_RANDOM_B: 2674 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2675 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2676 return; 2677 case SM_PH3_W4_RANDOM: 2678 reverse_64(data, setup->sm_local_rand); 2679 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2680 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2681 // no db for authenticated flag hack: store flag in bit 4 of LSB 2682 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2683 connection->sm_engine_state = SM_PH3_GET_DIV; 2684 return; 2685 case SM_PH3_W4_DIV: 2686 // use 16 bit from random value as div 2687 setup->sm_local_div = big_endian_read_16(data, 0); 2688 log_info_hex16("div", setup->sm_local_div); 2689 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2690 return; 2691 default: 2692 break; 2693 } 2694 } 2695 2696 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2697 2698 sm_connection_t * sm_conn; 2699 hci_con_handle_t con_handle; 2700 2701 switch (packet_type) { 2702 2703 case HCI_EVENT_PACKET: 2704 switch (hci_event_packet_get_type(packet)) { 2705 2706 case BTSTACK_EVENT_STATE: 2707 // bt stack activated, get started 2708 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2709 log_info("HCI Working!"); 2710 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2711 rau_state = RAU_IDLE; 2712 #ifdef USE_MBEDTLS_FOR_ECDH 2713 if (!test_use_fixed_ec_keypair){ 2714 setup->sm_passkey_bit = 0; 2715 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2716 } 2717 #endif 2718 sm_run(); 2719 } 2720 break; 2721 2722 case HCI_EVENT_LE_META: 2723 switch (packet[2]) { 2724 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2725 2726 log_info("sm: connected"); 2727 2728 if (packet[3]) return; // connection failed 2729 2730 con_handle = little_endian_read_16(packet, 4); 2731 sm_conn = sm_get_connection_for_handle(con_handle); 2732 if (!sm_conn) break; 2733 2734 sm_conn->sm_handle = con_handle; 2735 sm_conn->sm_role = packet[6]; 2736 sm_conn->sm_peer_addr_type = packet[7]; 2737 reverse_bd_addr(&packet[8], 2738 sm_conn->sm_peer_address); 2739 2740 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2741 2742 // reset security properties 2743 sm_conn->sm_connection_encrypted = 0; 2744 sm_conn->sm_connection_authenticated = 0; 2745 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2746 sm_conn->sm_le_db_index = -1; 2747 2748 // prepare CSRK lookup (does not involve setup) 2749 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2750 2751 // just connected -> everything else happens in sm_run() 2752 if (sm_conn->sm_role){ 2753 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2754 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2755 if (sm_slave_request_security) { 2756 // request security if requested by app 2757 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2758 } else { 2759 // otherwise, wait for pairing request 2760 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2761 } 2762 } 2763 break; 2764 } else { 2765 // master 2766 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2767 } 2768 break; 2769 2770 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2771 con_handle = little_endian_read_16(packet, 3); 2772 sm_conn = sm_get_connection_for_handle(con_handle); 2773 if (!sm_conn) break; 2774 2775 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2776 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2777 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2778 break; 2779 } 2780 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2781 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2782 break; 2783 } 2784 2785 // store rand and ediv 2786 reverse_64(&packet[5], sm_conn->sm_local_rand); 2787 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2788 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2789 break; 2790 2791 default: 2792 break; 2793 } 2794 break; 2795 2796 case HCI_EVENT_ENCRYPTION_CHANGE: 2797 con_handle = little_endian_read_16(packet, 3); 2798 sm_conn = sm_get_connection_for_handle(con_handle); 2799 if (!sm_conn) break; 2800 2801 sm_conn->sm_connection_encrypted = packet[5]; 2802 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2803 sm_conn->sm_actual_encryption_key_size); 2804 log_info("event handler, state %u", sm_conn->sm_engine_state); 2805 if (!sm_conn->sm_connection_encrypted) break; 2806 // continue if part of initial pairing 2807 switch (sm_conn->sm_engine_state){ 2808 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2809 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2810 sm_done_for_handle(sm_conn->sm_handle); 2811 break; 2812 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2813 if (sm_conn->sm_role){ 2814 // slave 2815 if (setup->sm_use_secure_connections){ 2816 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2817 } else { 2818 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2819 } 2820 } else { 2821 // master 2822 if (sm_key_distribution_all_received(sm_conn)){ 2823 // skip receiving keys as there are none 2824 sm_key_distribution_handle_all_received(sm_conn); 2825 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2826 } else { 2827 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2828 } 2829 } 2830 break; 2831 default: 2832 break; 2833 } 2834 break; 2835 2836 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2837 con_handle = little_endian_read_16(packet, 3); 2838 sm_conn = sm_get_connection_for_handle(con_handle); 2839 if (!sm_conn) break; 2840 2841 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2842 log_info("event handler, state %u", sm_conn->sm_engine_state); 2843 // continue if part of initial pairing 2844 switch (sm_conn->sm_engine_state){ 2845 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2846 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2847 sm_done_for_handle(sm_conn->sm_handle); 2848 break; 2849 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2850 if (sm_conn->sm_role){ 2851 // slave 2852 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2853 } else { 2854 // master 2855 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2856 } 2857 break; 2858 default: 2859 break; 2860 } 2861 break; 2862 2863 2864 case HCI_EVENT_DISCONNECTION_COMPLETE: 2865 con_handle = little_endian_read_16(packet, 3); 2866 sm_done_for_handle(con_handle); 2867 sm_conn = sm_get_connection_for_handle(con_handle); 2868 if (!sm_conn) break; 2869 2870 // delete stored bonding on disconnect with authentication failure in ph0 2871 if (sm_conn->sm_role == 0 2872 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2873 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2874 le_device_db_remove(sm_conn->sm_le_db_index); 2875 } 2876 2877 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2878 sm_conn->sm_handle = 0; 2879 break; 2880 2881 case HCI_EVENT_COMMAND_COMPLETE: 2882 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2883 sm_handle_encryption_result(&packet[6]); 2884 break; 2885 } 2886 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2887 sm_handle_random_result(&packet[6]); 2888 break; 2889 } 2890 break; 2891 default: 2892 break; 2893 } 2894 break; 2895 default: 2896 break; 2897 } 2898 2899 sm_run(); 2900 } 2901 2902 static inline int sm_calc_actual_encryption_key_size(int other){ 2903 if (other < sm_min_encryption_key_size) return 0; 2904 if (other < sm_max_encryption_key_size) return other; 2905 return sm_max_encryption_key_size; 2906 } 2907 2908 2909 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2910 switch (method){ 2911 case JUST_WORKS: 2912 case NK_BOTH_INPUT: 2913 return 1; 2914 default: 2915 return 0; 2916 } 2917 } 2918 // responder 2919 2920 static int sm_passkey_used(stk_generation_method_t method){ 2921 switch (method){ 2922 case PK_RESP_INPUT: 2923 return 1; 2924 default: 2925 return 0; 2926 } 2927 } 2928 2929 /** 2930 * @return ok 2931 */ 2932 static int sm_validate_stk_generation_method(void){ 2933 // check if STK generation method is acceptable by client 2934 switch (setup->sm_stk_generation_method){ 2935 case JUST_WORKS: 2936 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2937 case PK_RESP_INPUT: 2938 case PK_INIT_INPUT: 2939 case OK_BOTH_INPUT: 2940 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2941 case OOB: 2942 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2943 case NK_BOTH_INPUT: 2944 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2945 return 1; 2946 default: 2947 return 0; 2948 } 2949 } 2950 2951 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2952 2953 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2954 sm_run(); 2955 } 2956 2957 if (packet_type != SM_DATA_PACKET) return; 2958 2959 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2960 if (!sm_conn) return; 2961 2962 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2963 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2964 return; 2965 } 2966 2967 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2968 2969 int err; 2970 2971 switch (sm_conn->sm_engine_state){ 2972 2973 // a sm timeout requries a new physical connection 2974 case SM_GENERAL_TIMEOUT: 2975 return; 2976 2977 // Initiator 2978 case SM_INITIATOR_CONNECTED: 2979 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2980 sm_pdu_received_in_wrong_state(sm_conn); 2981 break; 2982 } 2983 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2984 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2985 break; 2986 } 2987 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2988 uint16_t ediv; 2989 sm_key_t ltk; 2990 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 2991 if (!sm_is_null_key(ltk) || ediv){ 2992 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2993 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2994 } else { 2995 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2996 } 2997 break; 2998 } 2999 // otherwise, store security request 3000 sm_conn->sm_security_request_received = 1; 3001 break; 3002 3003 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3004 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3005 sm_pdu_received_in_wrong_state(sm_conn); 3006 break; 3007 } 3008 // store pairing request 3009 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3010 err = sm_stk_generation_init(sm_conn); 3011 if (err){ 3012 setup->sm_pairing_failed_reason = err; 3013 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3014 break; 3015 } 3016 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3017 if (setup->sm_use_secure_connections){ 3018 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3019 if (setup->sm_stk_generation_method == JUST_WORKS){ 3020 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3021 sm_trigger_user_response(sm_conn); 3022 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3023 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3024 } 3025 } else { 3026 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3027 } 3028 break; 3029 } 3030 #endif 3031 // generate random number first, if we need to show passkey 3032 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3033 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3034 break; 3035 } 3036 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3037 sm_trigger_user_response(sm_conn); 3038 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3039 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3040 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3041 } 3042 break; 3043 3044 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3045 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3046 sm_pdu_received_in_wrong_state(sm_conn); 3047 break; 3048 } 3049 3050 // store s_confirm 3051 reverse_128(&packet[1], setup->sm_peer_confirm); 3052 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3053 break; 3054 3055 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3056 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3057 sm_pdu_received_in_wrong_state(sm_conn); 3058 break;; 3059 } 3060 3061 // received random value 3062 reverse_128(&packet[1], setup->sm_peer_random); 3063 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3064 break; 3065 3066 // Responder 3067 case SM_RESPONDER_IDLE: 3068 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3069 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3070 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3071 sm_pdu_received_in_wrong_state(sm_conn); 3072 break;; 3073 } 3074 3075 // store pairing request 3076 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3077 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3078 break; 3079 3080 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3081 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3082 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3083 sm_pdu_received_in_wrong_state(sm_conn); 3084 break; 3085 } 3086 3087 // store public key for DH Key calculation 3088 reverse_256(&packet[01], setup->sm_peer_qx); 3089 reverse_256(&packet[33], setup->sm_peer_qy); 3090 3091 #ifdef USE_MBEDTLS_FOR_ECDH 3092 // validate public key 3093 mbedtls_ecp_point Q; 3094 mbedtls_ecp_point_init( &Q ); 3095 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3096 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3097 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3098 err = mbedtls_ecp_check_pubkey(&mbedtls_ec_group, &Q); 3099 mbedtls_ecp_point_free( & Q); 3100 if (err){ 3101 log_error("sm: peer public key invalid %x", err); 3102 // uses "unspecified reason", there is no "public key invalid" error code 3103 sm_pdu_received_in_wrong_state(sm_conn); 3104 break; 3105 } 3106 3107 #endif 3108 if (sm_conn->sm_role){ 3109 // responder 3110 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3111 } else { 3112 // initiator 3113 // stk generation method 3114 // passkey entry: notify app to show passkey or to request passkey 3115 switch (setup->sm_stk_generation_method){ 3116 case JUST_WORKS: 3117 case NK_BOTH_INPUT: 3118 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3119 break; 3120 case PK_RESP_INPUT: 3121 sm_sc_start_calculating_local_confirm(sm_conn); 3122 break; 3123 case PK_INIT_INPUT: 3124 case OK_BOTH_INPUT: 3125 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3126 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3127 break; 3128 } 3129 sm_sc_start_calculating_local_confirm(sm_conn); 3130 break; 3131 case OOB: 3132 // TODO: implement SC OOB 3133 break; 3134 } 3135 } 3136 break; 3137 3138 case SM_SC_W4_CONFIRMATION: 3139 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3140 sm_pdu_received_in_wrong_state(sm_conn); 3141 break; 3142 } 3143 // received confirm value 3144 reverse_128(&packet[1], setup->sm_peer_confirm); 3145 3146 if (sm_conn->sm_role){ 3147 // responder 3148 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3149 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3150 // still waiting for passkey 3151 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3152 break; 3153 } 3154 } 3155 sm_sc_start_calculating_local_confirm(sm_conn); 3156 } else { 3157 // initiator 3158 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3159 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3160 } else { 3161 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3162 } 3163 } 3164 break; 3165 3166 case SM_SC_W4_PAIRING_RANDOM: 3167 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3168 sm_pdu_received_in_wrong_state(sm_conn); 3169 break; 3170 } 3171 3172 // received random value 3173 reverse_128(&packet[1], setup->sm_peer_nonce); 3174 3175 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3176 // only check for JUST WORK/NC in initiator role AND passkey entry 3177 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3178 if (sm_conn->sm_role || passkey_entry) { 3179 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3180 } 3181 3182 sm_sc_state_after_receiving_random(sm_conn); 3183 break; 3184 3185 case SM_SC_W2_CALCULATE_G2: 3186 case SM_SC_W4_CALCULATE_G2: 3187 case SM_SC_W2_CALCULATE_F5_SALT: 3188 case SM_SC_W4_CALCULATE_F5_SALT: 3189 case SM_SC_W2_CALCULATE_F5_MACKEY: 3190 case SM_SC_W4_CALCULATE_F5_MACKEY: 3191 case SM_SC_W2_CALCULATE_F5_LTK: 3192 case SM_SC_W4_CALCULATE_F5_LTK: 3193 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3194 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3195 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3196 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3197 sm_pdu_received_in_wrong_state(sm_conn); 3198 break; 3199 } 3200 // store DHKey Check 3201 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3202 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3203 3204 // have we been only waiting for dhkey check command? 3205 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3206 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3207 } 3208 break; 3209 #endif 3210 3211 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3212 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3213 sm_pdu_received_in_wrong_state(sm_conn); 3214 break; 3215 } 3216 3217 // received confirm value 3218 reverse_128(&packet[1], setup->sm_peer_confirm); 3219 3220 // notify client to hide shown passkey 3221 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3222 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3223 } 3224 3225 // handle user cancel pairing? 3226 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3227 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3228 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3229 break; 3230 } 3231 3232 // wait for user action? 3233 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3234 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3235 break; 3236 } 3237 3238 // calculate and send local_confirm 3239 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3240 break; 3241 3242 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3243 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3244 sm_pdu_received_in_wrong_state(sm_conn); 3245 break;; 3246 } 3247 3248 // received random value 3249 reverse_128(&packet[1], setup->sm_peer_random); 3250 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3251 break; 3252 3253 case SM_PH3_RECEIVE_KEYS: 3254 switch(packet[0]){ 3255 case SM_CODE_ENCRYPTION_INFORMATION: 3256 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3257 reverse_128(&packet[1], setup->sm_peer_ltk); 3258 break; 3259 3260 case SM_CODE_MASTER_IDENTIFICATION: 3261 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3262 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3263 reverse_64(&packet[3], setup->sm_peer_rand); 3264 break; 3265 3266 case SM_CODE_IDENTITY_INFORMATION: 3267 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3268 reverse_128(&packet[1], setup->sm_peer_irk); 3269 break; 3270 3271 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3272 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3273 setup->sm_peer_addr_type = packet[1]; 3274 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3275 break; 3276 3277 case SM_CODE_SIGNING_INFORMATION: 3278 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3279 reverse_128(&packet[1], setup->sm_peer_csrk); 3280 break; 3281 default: 3282 // Unexpected PDU 3283 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3284 break; 3285 } 3286 // done with key distribution? 3287 if (sm_key_distribution_all_received(sm_conn)){ 3288 3289 sm_key_distribution_handle_all_received(sm_conn); 3290 3291 if (sm_conn->sm_role){ 3292 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3293 sm_done_for_handle(sm_conn->sm_handle); 3294 } else { 3295 if (setup->sm_use_secure_connections){ 3296 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3297 } else { 3298 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3299 } 3300 } 3301 } 3302 break; 3303 default: 3304 // Unexpected PDU 3305 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3306 break; 3307 } 3308 3309 // try to send preparared packet 3310 sm_run(); 3311 } 3312 3313 // Security Manager Client API 3314 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3315 sm_get_oob_data = get_oob_data_callback; 3316 } 3317 3318 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3319 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3320 } 3321 3322 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3323 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3324 } 3325 3326 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3327 sm_min_encryption_key_size = min_size; 3328 sm_max_encryption_key_size = max_size; 3329 } 3330 3331 void sm_set_authentication_requirements(uint8_t auth_req){ 3332 sm_auth_req = auth_req; 3333 } 3334 3335 void sm_set_io_capabilities(io_capability_t io_capability){ 3336 sm_io_capabilities = io_capability; 3337 } 3338 3339 void sm_set_request_security(int enable){ 3340 sm_slave_request_security = enable; 3341 } 3342 3343 void sm_set_er(sm_key_t er){ 3344 memcpy(sm_persistent_er, er, 16); 3345 } 3346 3347 void sm_set_ir(sm_key_t ir){ 3348 memcpy(sm_persistent_ir, ir, 16); 3349 } 3350 3351 // Testing support only 3352 void sm_test_set_irk(sm_key_t irk){ 3353 memcpy(sm_persistent_irk, irk, 16); 3354 sm_persistent_irk_ready = 1; 3355 } 3356 3357 void sm_test_use_fixed_local_csrk(void){ 3358 test_use_fixed_local_csrk = 1; 3359 } 3360 3361 void sm_init(void){ 3362 // set some (BTstack default) ER and IR 3363 int i; 3364 sm_key_t er; 3365 sm_key_t ir; 3366 for (i=0;i<16;i++){ 3367 er[i] = 0x30 + i; 3368 ir[i] = 0x90 + i; 3369 } 3370 sm_set_er(er); 3371 sm_set_ir(ir); 3372 // defaults 3373 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3374 | SM_STK_GENERATION_METHOD_OOB 3375 | SM_STK_GENERATION_METHOD_PASSKEY 3376 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3377 3378 sm_max_encryption_key_size = 16; 3379 sm_min_encryption_key_size = 7; 3380 3381 sm_cmac_state = CMAC_IDLE; 3382 dkg_state = DKG_W4_WORKING; 3383 rau_state = RAU_W4_WORKING; 3384 sm_aes128_state = SM_AES128_IDLE; 3385 sm_address_resolution_test = -1; // no private address to resolve yet 3386 sm_address_resolution_ah_calculation_active = 0; 3387 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3388 sm_address_resolution_general_queue = NULL; 3389 3390 gap_random_adress_update_period = 15 * 60 * 1000L; 3391 3392 sm_active_connection = 0; 3393 3394 test_use_fixed_local_csrk = 0; 3395 3396 // register for HCI Events from HCI 3397 hci_event_callback_registration.callback = &sm_event_packet_handler; 3398 hci_add_event_handler(&hci_event_callback_registration); 3399 3400 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3401 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3402 3403 #ifdef USE_MBEDTLS_FOR_ECDH 3404 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3405 mbedtls_ecp_group_init(&mbedtls_ec_group); 3406 mbedtls_ecp_group_load(&mbedtls_ec_group, MBEDTLS_ECP_DP_SECP256R1); 3407 #ifndef HAVE_MALLOC 3408 sm_mbedtls_allocator_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3409 #endif 3410 3411 #if 0 3412 // test 3413 printf("test dhkey check\n"); 3414 sm_key256_t dhkey; 3415 memcpy(setup->sm_peer_qx, ec_qx, 32); 3416 memcpy(setup->sm_peer_qy, ec_qy, 32); 3417 sm_sc_calculate_dhkey(dhkey); 3418 #endif 3419 #endif 3420 } 3421 3422 void sm_test_use_fixed_ec_keypair(void){ 3423 test_use_fixed_ec_keypair = 1; 3424 #ifdef USE_MBEDTLS_FOR_ECDH 3425 // use test keypair from spec 3426 mbedtls_mpi x; 3427 mbedtls_mpi_read_string( &x, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3428 mbedtls_mpi_write_binary(&x, ec_qx, 16); 3429 mbedtls_mpi_read_string( &x, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3430 mbedtls_mpi_write_binary(&x, ec_qy, 16); 3431 mbedtls_mpi_read_string( &x, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3432 mbedtls_mpi_write_binary(&x, ec_d, 16); 3433 #endif 3434 } 3435 3436 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3437 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3438 if (!hci_con) return NULL; 3439 return &hci_con->sm_connection; 3440 } 3441 3442 // @returns 0 if not encrypted, 7-16 otherwise 3443 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3444 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3445 if (!sm_conn) return 0; // wrong connection 3446 if (!sm_conn->sm_connection_encrypted) return 0; 3447 return sm_conn->sm_actual_encryption_key_size; 3448 } 3449 3450 int sm_authenticated(hci_con_handle_t con_handle){ 3451 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3452 if (!sm_conn) return 0; // wrong connection 3453 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3454 return sm_conn->sm_connection_authenticated; 3455 } 3456 3457 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3458 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3459 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3460 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3461 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3462 return sm_conn->sm_connection_authorization_state; 3463 } 3464 3465 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3466 switch (sm_conn->sm_engine_state){ 3467 case SM_GENERAL_IDLE: 3468 case SM_RESPONDER_IDLE: 3469 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3470 sm_run(); 3471 break; 3472 default: 3473 break; 3474 } 3475 } 3476 3477 /** 3478 * @brief Trigger Security Request 3479 */ 3480 void sm_send_security_request(hci_con_handle_t con_handle){ 3481 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3482 if (!sm_conn) return; 3483 sm_send_security_request_for_connection(sm_conn); 3484 } 3485 3486 // request pairing 3487 void sm_request_pairing(hci_con_handle_t con_handle){ 3488 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3489 if (!sm_conn) return; // wrong connection 3490 3491 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3492 if (sm_conn->sm_role){ 3493 sm_send_security_request_for_connection(sm_conn); 3494 } else { 3495 // used as a trigger to start central/master/initiator security procedures 3496 uint16_t ediv; 3497 sm_key_t ltk; 3498 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3499 switch (sm_conn->sm_irk_lookup_state){ 3500 case IRK_LOOKUP_FAILED: 3501 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3502 break; 3503 case IRK_LOOKUP_SUCCEEDED: 3504 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3505 if (!sm_is_null_key(ltk) || ediv){ 3506 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3507 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3508 } else { 3509 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3510 } 3511 break; 3512 default: 3513 sm_conn->sm_bonding_requested = 1; 3514 break; 3515 } 3516 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3517 sm_conn->sm_bonding_requested = 1; 3518 } 3519 } 3520 sm_run(); 3521 } 3522 3523 // called by client app on authorization request 3524 void sm_authorization_decline(hci_con_handle_t con_handle){ 3525 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3526 if (!sm_conn) return; // wrong connection 3527 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3528 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3529 } 3530 3531 void sm_authorization_grant(hci_con_handle_t con_handle){ 3532 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3533 if (!sm_conn) return; // wrong connection 3534 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3535 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3536 } 3537 3538 // GAP Bonding API 3539 3540 void sm_bonding_decline(hci_con_handle_t con_handle){ 3541 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3542 if (!sm_conn) return; // wrong connection 3543 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3544 3545 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3546 switch (setup->sm_stk_generation_method){ 3547 case PK_RESP_INPUT: 3548 case PK_INIT_INPUT: 3549 case OK_BOTH_INPUT: 3550 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3551 break; 3552 case NK_BOTH_INPUT: 3553 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3554 break; 3555 case JUST_WORKS: 3556 case OOB: 3557 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3558 break; 3559 } 3560 } 3561 sm_run(); 3562 } 3563 3564 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3565 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3566 if (!sm_conn) return; // wrong connection 3567 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3568 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3569 if (setup->sm_use_secure_connections){ 3570 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3571 } else { 3572 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3573 } 3574 } 3575 3576 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3577 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3578 sm_sc_prepare_dhkey_check(sm_conn); 3579 } 3580 #endif 3581 3582 sm_run(); 3583 } 3584 3585 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3586 // for now, it's the same 3587 sm_just_works_confirm(con_handle); 3588 } 3589 3590 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3591 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3592 if (!sm_conn) return; // wrong connection 3593 sm_reset_tk(); 3594 big_endian_store_32(setup->sm_tk, 12, passkey); 3595 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3596 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3597 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3598 } 3599 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3600 memcpy(setup->sm_ra, setup->sm_tk, 16); 3601 memcpy(setup->sm_rb, setup->sm_tk, 16); 3602 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3603 sm_sc_start_calculating_local_confirm(sm_conn); 3604 } 3605 #endif 3606 sm_run(); 3607 } 3608 3609 /** 3610 * @brief Identify device in LE Device DB 3611 * @param handle 3612 * @returns index from le_device_db or -1 if not found/identified 3613 */ 3614 int sm_le_device_index(hci_con_handle_t con_handle ){ 3615 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3616 if (!sm_conn) return -1; 3617 return sm_conn->sm_le_db_index; 3618 } 3619 3620 // GAP LE API 3621 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3622 gap_random_address_update_stop(); 3623 gap_random_adress_type = random_address_type; 3624 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3625 gap_random_address_update_start(); 3626 gap_random_address_trigger(); 3627 } 3628 3629 gap_random_address_type_t gap_random_address_get_mode(void){ 3630 return gap_random_adress_type; 3631 } 3632 3633 void gap_random_address_set_update_period(int period_ms){ 3634 gap_random_adress_update_period = period_ms; 3635 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3636 gap_random_address_update_stop(); 3637 gap_random_address_update_start(); 3638 } 3639 3640 void gap_random_address_set(bd_addr_t addr){ 3641 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3642 memcpy(sm_random_address, addr, 6); 3643 rau_state = RAU_SET_ADDRESS; 3644 sm_run(); 3645 } 3646 3647 /* 3648 * @brief Set Advertisement Paramters 3649 * @param adv_int_min 3650 * @param adv_int_max 3651 * @param adv_type 3652 * @param direct_address_type 3653 * @param direct_address 3654 * @param channel_map 3655 * @param filter_policy 3656 * 3657 * @note own_address_type is used from gap_random_address_set_mode 3658 */ 3659 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3660 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3661 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3662 direct_address_typ, direct_address, channel_map, filter_policy); 3663 } 3664 3665