1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #if defined(MBEDTLS_PLATFORM_C) 66 #include "mbedtls/platform.h" 67 #else 68 #include <stdio.h> 69 #define mbedtls_printf printf 70 #endif 71 #include "mbedtls/ecp.h" 72 #endif 73 74 void * btstack_calloc(size_t count, size_t size){ 75 void * result = calloc(count, size); 76 printf("btstack_calloc(%zu, %zu) -> res %p\n", count, size, result); 77 return result; 78 } 79 80 void btstack_free(void * data){ 81 printf("btstack_free(%p)\n", data); 82 } 83 // 84 // SM internal types and globals 85 // 86 87 typedef enum { 88 DKG_W4_WORKING, 89 DKG_CALC_IRK, 90 DKG_W4_IRK, 91 DKG_CALC_DHK, 92 DKG_W4_DHK, 93 DKG_READY 94 } derived_key_generation_t; 95 96 typedef enum { 97 RAU_W4_WORKING, 98 RAU_IDLE, 99 RAU_GET_RANDOM, 100 RAU_W4_RANDOM, 101 RAU_GET_ENC, 102 RAU_W4_ENC, 103 RAU_SET_ADDRESS, 104 } random_address_update_t; 105 106 typedef enum { 107 CMAC_IDLE, 108 CMAC_CALC_SUBKEYS, 109 CMAC_W4_SUBKEYS, 110 CMAC_CALC_MI, 111 CMAC_W4_MI, 112 CMAC_CALC_MLAST, 113 CMAC_W4_MLAST 114 } cmac_state_t; 115 116 typedef enum { 117 JUST_WORKS, 118 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 119 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 120 OK_BOTH_INPUT, // Only input on both, both input PK 121 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 122 OOB // OOB available on both sides 123 } stk_generation_method_t; 124 125 typedef enum { 126 SM_USER_RESPONSE_IDLE, 127 SM_USER_RESPONSE_PENDING, 128 SM_USER_RESPONSE_CONFIRM, 129 SM_USER_RESPONSE_PASSKEY, 130 SM_USER_RESPONSE_DECLINE 131 } sm_user_response_t; 132 133 typedef enum { 134 SM_AES128_IDLE, 135 SM_AES128_ACTIVE 136 } sm_aes128_state_t; 137 138 typedef enum { 139 ADDRESS_RESOLUTION_IDLE, 140 ADDRESS_RESOLUTION_GENERAL, 141 ADDRESS_RESOLUTION_FOR_CONNECTION, 142 } address_resolution_mode_t; 143 144 typedef enum { 145 ADDRESS_RESOLUTION_SUCEEDED, 146 ADDRESS_RESOLUTION_FAILED, 147 } address_resolution_event_t; 148 149 typedef enum { 150 EC_KEY_GENERATION_IDLE, 151 EC_KEY_GENERATION_ACTIVE, 152 EC_KEY_GENERATION_DONE, 153 } ec_key_generation_state_t; 154 155 typedef enum { 156 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 157 } sm_state_var_t; 158 159 // 160 // GLOBAL DATA 161 // 162 163 static uint8_t test_use_fixed_local_csrk; 164 static uint8_t test_use_fixed_ec_keypair; 165 166 // configuration 167 static uint8_t sm_accepted_stk_generation_methods; 168 static uint8_t sm_max_encryption_key_size; 169 static uint8_t sm_min_encryption_key_size; 170 static uint8_t sm_auth_req = 0; 171 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 172 static uint8_t sm_slave_request_security; 173 174 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 175 static sm_key_t sm_persistent_er; 176 static sm_key_t sm_persistent_ir; 177 178 // derived from sm_persistent_ir 179 static sm_key_t sm_persistent_dhk; 180 static sm_key_t sm_persistent_irk; 181 static uint8_t sm_persistent_irk_ready = 0; // used for testing 182 static derived_key_generation_t dkg_state; 183 184 // derived from sm_persistent_er 185 // .. 186 187 // random address update 188 static random_address_update_t rau_state; 189 static bd_addr_t sm_random_address; 190 191 // CMAC Calculation: General 192 static cmac_state_t sm_cmac_state; 193 static uint16_t sm_cmac_message_len; 194 static sm_key_t sm_cmac_k; 195 static sm_key_t sm_cmac_x; 196 static sm_key_t sm_cmac_m_last; 197 static uint8_t sm_cmac_block_current; 198 static uint8_t sm_cmac_block_count; 199 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 200 static void (*sm_cmac_done_handler)(uint8_t * hash); 201 202 // CMAC for ATT Signed Writes 203 static uint8_t sm_cmac_header[3]; 204 static const uint8_t * sm_cmac_message; 205 static uint8_t sm_cmac_sign_counter[4]; 206 207 // CMAC for Secure Connection functions 208 #ifdef ENABLE_LE_SECURE_CONNECTIONS 209 static sm_connection_t * sm_cmac_connection; 210 static uint8_t sm_cmac_sc_buffer[80]; 211 #endif 212 213 // resolvable private address lookup / CSRK calculation 214 static int sm_address_resolution_test; 215 static int sm_address_resolution_ah_calculation_active; 216 static uint8_t sm_address_resolution_addr_type; 217 static bd_addr_t sm_address_resolution_address; 218 static void * sm_address_resolution_context; 219 static address_resolution_mode_t sm_address_resolution_mode; 220 static btstack_linked_list_t sm_address_resolution_general_queue; 221 222 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 223 static sm_aes128_state_t sm_aes128_state; 224 static void * sm_aes128_context; 225 226 // random engine. store context (ususally sm_connection_t) 227 static void * sm_random_context; 228 229 // to receive hci events 230 static btstack_packet_callback_registration_t hci_event_callback_registration; 231 232 /* to dispatch sm event */ 233 static btstack_linked_list_t sm_event_handlers; 234 235 // Software ECDH implementation provided by mbedtls 236 #ifdef USE_MBEDTLS_FOR_ECDH 237 static mbedtls_ecp_keypair le_keypair; 238 static ec_key_generation_state_t ec_key_generation_state; 239 #endif 240 241 // 242 // Volume 3, Part H, Chapter 24 243 // "Security shall be initiated by the Security Manager in the device in the master role. 244 // The device in the slave role shall be the responding device." 245 // -> master := initiator, slave := responder 246 // 247 248 // data needed for security setup 249 typedef struct sm_setup_context { 250 251 btstack_timer_source_t sm_timeout; 252 253 // used in all phases 254 uint8_t sm_pairing_failed_reason; 255 256 // user response, (Phase 1 and/or 2) 257 uint8_t sm_user_response; 258 259 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 260 int sm_key_distribution_send_set; 261 int sm_key_distribution_received_set; 262 263 // Phase 2 (Pairing over SMP) 264 stk_generation_method_t sm_stk_generation_method; 265 sm_key_t sm_tk; 266 uint8_t sm_use_secure_connections; 267 268 sm_key_t sm_c1_t3_value; // c1 calculation 269 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 270 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 271 sm_key_t sm_local_random; 272 sm_key_t sm_local_confirm; 273 sm_key_t sm_peer_random; 274 sm_key_t sm_peer_confirm; 275 uint8_t sm_m_addr_type; // address and type can be removed 276 uint8_t sm_s_addr_type; // '' 277 bd_addr_t sm_m_address; // '' 278 bd_addr_t sm_s_address; // '' 279 sm_key_t sm_ltk; 280 281 #ifdef ENABLE_LE_SECURE_CONNECTIONS 282 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 283 uint8_t sm_peer_qy[32]; // '' 284 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 285 sm_key_t sm_local_nonce; // might be combined with sm_local_random 286 sm_key_t sm_peer_dhkey_check; 287 sm_key_t sm_local_dhkey_check; 288 sm_key_t sm_ra; 289 sm_key_t sm_rb; 290 sm_key_t sm_t; // used for f5 291 sm_key_t sm_mackey; 292 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 293 uint8_t sm_state_vars; 294 #endif 295 296 // Phase 3 297 298 // key distribution, we generate 299 uint16_t sm_local_y; 300 uint16_t sm_local_div; 301 uint16_t sm_local_ediv; 302 uint8_t sm_local_rand[8]; 303 sm_key_t sm_local_ltk; 304 sm_key_t sm_local_csrk; 305 sm_key_t sm_local_irk; 306 // sm_local_address/addr_type not needed 307 308 // key distribution, received from peer 309 uint16_t sm_peer_y; 310 uint16_t sm_peer_div; 311 uint16_t sm_peer_ediv; 312 uint8_t sm_peer_rand[8]; 313 sm_key_t sm_peer_ltk; 314 sm_key_t sm_peer_irk; 315 sm_key_t sm_peer_csrk; 316 uint8_t sm_peer_addr_type; 317 bd_addr_t sm_peer_address; 318 319 } sm_setup_context_t; 320 321 // 322 static sm_setup_context_t the_setup; 323 static sm_setup_context_t * setup = &the_setup; 324 325 // active connection - the one for which the_setup is used for 326 static uint16_t sm_active_connection = 0; 327 328 // @returns 1 if oob data is available 329 // stores oob data in provided 16 byte buffer if not null 330 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 331 332 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 333 static btstack_packet_handler_t sm_client_packet_handler = NULL; 334 335 // horizontal: initiator capabilities 336 // vertial: responder capabilities 337 static const stk_generation_method_t stk_generation_method [5] [5] = { 338 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 339 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 340 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 341 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 342 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 343 }; 344 345 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 346 #ifdef ENABLE_LE_SECURE_CONNECTIONS 347 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 348 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 349 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 350 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 351 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 352 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 353 }; 354 #endif 355 356 static void sm_run(void); 357 static void sm_done_for_handle(hci_con_handle_t con_handle); 358 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 359 static inline int sm_calc_actual_encryption_key_size(int other); 360 static int sm_validate_stk_generation_method(void); 361 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 362 363 static void log_info_hex16(const char * name, uint16_t value){ 364 log_info("%-6s 0x%04x", name, value); 365 } 366 367 // @returns 1 if all bytes are 0 368 static int sm_is_null(uint8_t * data, int size){ 369 int i; 370 for (i=0; i < size ; i++){ 371 if (data[i]) return 0; 372 } 373 return 1; 374 } 375 376 static int sm_is_null_random(uint8_t random[8]){ 377 return sm_is_null(random, 8); 378 } 379 380 static int sm_is_null_key(uint8_t * key){ 381 return sm_is_null(key, 16); 382 } 383 384 // Key utils 385 static void sm_reset_tk(void){ 386 int i; 387 for (i=0;i<16;i++){ 388 setup->sm_tk[i] = 0; 389 } 390 } 391 392 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 393 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 394 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 395 int i; 396 for (i = max_encryption_size ; i < 16 ; i++){ 397 key[15-i] = 0; 398 } 399 } 400 401 // SMP Timeout implementation 402 403 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 404 // the Security Manager Timer shall be reset and started. 405 // 406 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 407 // 408 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 409 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 410 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 411 // established. 412 413 static void sm_timeout_handler(btstack_timer_source_t * timer){ 414 log_info("SM timeout"); 415 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 416 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 417 sm_done_for_handle(sm_conn->sm_handle); 418 419 // trigger handling of next ready connection 420 sm_run(); 421 } 422 static void sm_timeout_start(sm_connection_t * sm_conn){ 423 btstack_run_loop_remove_timer(&setup->sm_timeout); 424 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 425 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 426 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 427 btstack_run_loop_add_timer(&setup->sm_timeout); 428 } 429 static void sm_timeout_stop(void){ 430 btstack_run_loop_remove_timer(&setup->sm_timeout); 431 } 432 static void sm_timeout_reset(sm_connection_t * sm_conn){ 433 sm_timeout_stop(); 434 sm_timeout_start(sm_conn); 435 } 436 437 // end of sm timeout 438 439 // GAP Random Address updates 440 static gap_random_address_type_t gap_random_adress_type; 441 static btstack_timer_source_t gap_random_address_update_timer; 442 static uint32_t gap_random_adress_update_period; 443 444 static void gap_random_address_trigger(void){ 445 if (rau_state != RAU_IDLE) return; 446 log_info("gap_random_address_trigger"); 447 rau_state = RAU_GET_RANDOM; 448 sm_run(); 449 } 450 451 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 452 log_info("GAP Random Address Update due"); 453 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 454 btstack_run_loop_add_timer(&gap_random_address_update_timer); 455 gap_random_address_trigger(); 456 } 457 458 static void gap_random_address_update_start(void){ 459 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 460 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 461 btstack_run_loop_add_timer(&gap_random_address_update_timer); 462 } 463 464 static void gap_random_address_update_stop(void){ 465 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 466 } 467 468 469 static void sm_random_start(void * context){ 470 sm_random_context = context; 471 hci_send_cmd(&hci_le_rand); 472 } 473 474 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 475 // context is made availabe to aes128 result handler by this 476 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 477 sm_aes128_state = SM_AES128_ACTIVE; 478 sm_key_t key_flipped, plaintext_flipped; 479 reverse_128(key, key_flipped); 480 reverse_128(plaintext, plaintext_flipped); 481 sm_aes128_context = context; 482 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 483 } 484 485 // ah(k,r) helper 486 // r = padding || r 487 // r - 24 bit value 488 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 489 // r'= padding || r 490 memset(r_prime, 0, 16); 491 memcpy(&r_prime[13], r, 3); 492 } 493 494 // d1 helper 495 // d' = padding || r || d 496 // d,r - 16 bit values 497 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 498 // d'= padding || r || d 499 memset(d1_prime, 0, 16); 500 big_endian_store_16(d1_prime, 12, r); 501 big_endian_store_16(d1_prime, 14, d); 502 } 503 504 // dm helper 505 // r’ = padding || r 506 // r - 64 bit value 507 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 508 memset(r_prime, 0, 16); 509 memcpy(&r_prime[8], r, 8); 510 } 511 512 // calculate arguments for first AES128 operation in C1 function 513 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){ 514 515 // p1 = pres || preq || rat’ || iat’ 516 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 517 // cant octet of pres becomes the most significant octet of p1. 518 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 519 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 520 // p1 is 0x05000800000302070710000001010001." 521 522 sm_key_t p1; 523 reverse_56(pres, &p1[0]); 524 reverse_56(preq, &p1[7]); 525 p1[14] = rat; 526 p1[15] = iat; 527 log_info_key("p1", p1); 528 log_info_key("r", r); 529 530 // t1 = r xor p1 531 int i; 532 for (i=0;i<16;i++){ 533 t1[i] = r[i] ^ p1[i]; 534 } 535 log_info_key("t1", t1); 536 } 537 538 // calculate arguments for second AES128 operation in C1 function 539 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 540 // p2 = padding || ia || ra 541 // "The least significant octet of ra becomes the least significant octet of p2 and 542 // the most significant octet of padding becomes the most significant octet of p2. 543 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 544 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 545 546 sm_key_t p2; 547 memset(p2, 0, 16); 548 memcpy(&p2[4], ia, 6); 549 memcpy(&p2[10], ra, 6); 550 log_info_key("p2", p2); 551 552 // c1 = e(k, t2_xor_p2) 553 int i; 554 for (i=0;i<16;i++){ 555 t3[i] = t2[i] ^ p2[i]; 556 } 557 log_info_key("t3", t3); 558 } 559 560 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 561 log_info_key("r1", r1); 562 log_info_key("r2", r2); 563 memcpy(&r_prime[8], &r2[8], 8); 564 memcpy(&r_prime[0], &r1[8], 8); 565 } 566 567 #ifdef ENABLE_LE_SECURE_CONNECTIONS 568 // Software implementations of crypto toolbox for LE Secure Connection 569 // TODO: replace with code to use AES Engine of HCI Controller 570 typedef uint8_t sm_key24_t[3]; 571 typedef uint8_t sm_key56_t[7]; 572 typedef uint8_t sm_key256_t[32]; 573 574 #if 0 575 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 576 uint32_t rk[RKLENGTH(KEYBITS)]; 577 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 578 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 579 } 580 581 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 582 memcpy(k1, k0, 16); 583 sm_shift_left_by_one_bit_inplace(16, k1); 584 if (k0[0] & 0x80){ 585 k1[15] ^= 0x87; 586 } 587 memcpy(k2, k1, 16); 588 sm_shift_left_by_one_bit_inplace(16, k2); 589 if (k1[0] & 0x80){ 590 k2[15] ^= 0x87; 591 } 592 } 593 594 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 595 sm_key_t k0, k1, k2, zero; 596 memset(zero, 0, 16); 597 598 aes128_calc_cyphertext(key, zero, k0); 599 calc_subkeys(k0, k1, k2); 600 601 int cmac_block_count = (cmac_message_len + 15) / 16; 602 603 // step 3: .. 604 if (cmac_block_count==0){ 605 cmac_block_count = 1; 606 } 607 608 // step 4: set m_last 609 sm_key_t cmac_m_last; 610 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 611 int i; 612 if (sm_cmac_last_block_complete){ 613 for (i=0;i<16;i++){ 614 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 615 } 616 } else { 617 int valid_octets_in_last_block = cmac_message_len & 0x0f; 618 for (i=0;i<16;i++){ 619 if (i < valid_octets_in_last_block){ 620 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 621 continue; 622 } 623 if (i == valid_octets_in_last_block){ 624 cmac_m_last[i] = 0x80 ^ k2[i]; 625 continue; 626 } 627 cmac_m_last[i] = k2[i]; 628 } 629 } 630 631 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 632 // LOG_KEY(cmac_m_last); 633 634 // Step 5 635 sm_key_t cmac_x; 636 memset(cmac_x, 0, 16); 637 638 // Step 6 639 sm_key_t sm_cmac_y; 640 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 641 for (i=0;i<16;i++){ 642 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 643 } 644 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 645 } 646 for (i=0;i<16;i++){ 647 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 648 } 649 650 // Step 7 651 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 652 } 653 #endif 654 655 #if 0 656 // 657 // Link Key Conversion Function h6 658 // 659 // h6(W, keyID) = AES-CMACW(keyID) 660 // - W is 128 bits 661 // - keyID is 32 bits 662 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 663 uint8_t key_id_buffer[4]; 664 big_endian_store_32(key_id_buffer, 0, key_id); 665 aes_cmac(res, w, key_id_buffer, 4); 666 } 667 #endif 668 #endif 669 670 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){ 671 event[0] = type; 672 event[1] = event_size - 2; 673 little_endian_store_16(event, 2, con_handle); 674 event[4] = addr_type; 675 reverse_bd_addr(address, &event[5]); 676 } 677 678 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 679 if (sm_client_packet_handler) { 680 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 681 } 682 // dispatch to all event handlers 683 btstack_linked_list_iterator_t it; 684 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 685 while (btstack_linked_list_iterator_has_next(&it)){ 686 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 687 entry->callback(packet_type, 0, packet, size); 688 } 689 } 690 691 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 692 uint8_t event[11]; 693 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 694 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 695 } 696 697 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){ 698 uint8_t event[15]; 699 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 700 little_endian_store_32(event, 11, passkey); 701 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 702 } 703 704 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){ 705 uint8_t event[13]; 706 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 707 little_endian_store_16(event, 11, index); 708 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 709 } 710 711 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){ 712 713 uint8_t event[18]; 714 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 715 event[11] = result; 716 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 717 } 718 719 // decide on stk generation based on 720 // - pairing request 721 // - io capabilities 722 // - OOB data availability 723 static void sm_setup_tk(void){ 724 725 // default: just works 726 setup->sm_stk_generation_method = JUST_WORKS; 727 728 #ifdef ENABLE_LE_SECURE_CONNECTIONS 729 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 730 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 731 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 732 memset(setup->sm_ra, 0, 16); 733 memset(setup->sm_rb, 0, 16); 734 #else 735 setup->sm_use_secure_connections = 0; 736 #endif 737 738 // If both devices have not set the MITM option in the Authentication Requirements 739 // Flags, then the IO capabilities shall be ignored and the Just Works association 740 // model shall be used. 741 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 742 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 743 log_info("SM: MITM not required by both -> JUST WORKS"); 744 return; 745 } 746 747 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 748 749 // If both devices have out of band authentication data, then the Authentication 750 // Requirements Flags shall be ignored when selecting the pairing method and the 751 // Out of Band pairing method shall be used. 752 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 753 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 754 log_info("SM: have OOB data"); 755 log_info_key("OOB", setup->sm_tk); 756 setup->sm_stk_generation_method = OOB; 757 return; 758 } 759 760 // Reset TK as it has been setup in sm_init_setup 761 sm_reset_tk(); 762 763 // Also use just works if unknown io capabilites 764 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)){ 765 return; 766 } 767 768 // Otherwise the IO capabilities of the devices shall be used to determine the 769 // pairing method as defined in Table 2.4. 770 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 771 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 772 773 #ifdef ENABLE_LE_SECURE_CONNECTIONS 774 // table not define by default 775 if (setup->sm_use_secure_connections){ 776 generation_method = stk_generation_method_with_secure_connection; 777 } 778 #endif 779 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)]; 780 781 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 782 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); 783 } 784 785 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 786 int flags = 0; 787 if (key_set & SM_KEYDIST_ENC_KEY){ 788 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 789 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 790 } 791 if (key_set & SM_KEYDIST_ID_KEY){ 792 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 793 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 794 } 795 if (key_set & SM_KEYDIST_SIGN){ 796 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 797 } 798 return flags; 799 } 800 801 static void sm_setup_key_distribution(uint8_t key_set){ 802 setup->sm_key_distribution_received_set = 0; 803 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 804 } 805 806 // CSRK Key Lookup 807 808 809 static int sm_address_resolution_idle(void){ 810 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 811 } 812 813 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){ 814 memcpy(sm_address_resolution_address, addr, 6); 815 sm_address_resolution_addr_type = addr_type; 816 sm_address_resolution_test = 0; 817 sm_address_resolution_mode = mode; 818 sm_address_resolution_context = context; 819 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 820 } 821 822 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 823 // check if already in list 824 btstack_linked_list_iterator_t it; 825 sm_lookup_entry_t * entry; 826 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 827 while(btstack_linked_list_iterator_has_next(&it)){ 828 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 829 if (entry->address_type != address_type) continue; 830 if (memcmp(entry->address, address, 6)) continue; 831 // already in list 832 return BTSTACK_BUSY; 833 } 834 entry = btstack_memory_sm_lookup_entry_get(); 835 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 836 entry->address_type = (bd_addr_type_t) address_type; 837 memcpy(entry->address, address, 6); 838 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 839 sm_run(); 840 return 0; 841 } 842 843 // CMAC Implementation using AES128 engine 844 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 845 int i; 846 int carry = 0; 847 for (i=len-1; i >= 0 ; i--){ 848 int new_carry = data[i] >> 7; 849 data[i] = data[i] << 1 | carry; 850 carry = new_carry; 851 } 852 } 853 854 // 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 855 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 856 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 857 } 858 static inline void dkg_next_state(void){ 859 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 860 } 861 static inline void rau_next_state(void){ 862 rau_state = (random_address_update_t) (((int)rau_state) + 1); 863 } 864 865 // CMAC calculation using AES Engine 866 867 static inline void sm_cmac_next_state(void){ 868 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 869 } 870 871 static int sm_cmac_last_block_complete(void){ 872 if (sm_cmac_message_len == 0) return 0; 873 return (sm_cmac_message_len & 0x0f) == 0; 874 } 875 876 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 877 if (offset >= sm_cmac_message_len) { 878 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 879 return 0; 880 } 881 882 offset = sm_cmac_message_len - 1 - offset; 883 884 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 885 if (offset < 3){ 886 return sm_cmac_header[offset]; 887 } 888 int actual_message_len_incl_header = sm_cmac_message_len - 4; 889 if (offset < actual_message_len_incl_header){ 890 return sm_cmac_message[offset - 3]; 891 } 892 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 893 } 894 895 // generic cmac calculation 896 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])){ 897 // Generalized CMAC 898 memcpy(sm_cmac_k, key, 16); 899 memset(sm_cmac_x, 0, 16); 900 sm_cmac_block_current = 0; 901 sm_cmac_message_len = message_len; 902 sm_cmac_done_handler = done_callback; 903 sm_cmac_get_byte = get_byte_callback; 904 905 // step 2: n := ceil(len/const_Bsize); 906 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 907 908 // step 3: .. 909 if (sm_cmac_block_count==0){ 910 sm_cmac_block_count = 1; 911 } 912 log_info("sm_cmac_connection %p", sm_cmac_connection); 913 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 914 915 // first, we need to compute l for k1, k2, and m_last 916 sm_cmac_state = CMAC_CALC_SUBKEYS; 917 918 // let's go 919 sm_run(); 920 } 921 922 // cmac for ATT Message signing 923 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)){ 924 // ATT Message Signing 925 sm_cmac_header[0] = opcode; 926 little_endian_store_16(sm_cmac_header, 1, con_handle); 927 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 928 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 929 sm_cmac_message = message; 930 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 931 } 932 933 int sm_cmac_ready(void){ 934 return sm_cmac_state == CMAC_IDLE; 935 } 936 937 static void sm_cmac_handle_aes_engine_ready(void){ 938 switch (sm_cmac_state){ 939 case CMAC_CALC_SUBKEYS: { 940 sm_key_t const_zero; 941 memset(const_zero, 0, 16); 942 sm_cmac_next_state(); 943 sm_aes128_start(sm_cmac_k, const_zero, NULL); 944 break; 945 } 946 case CMAC_CALC_MI: { 947 int j; 948 sm_key_t y; 949 for (j=0;j<16;j++){ 950 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 951 } 952 sm_cmac_block_current++; 953 sm_cmac_next_state(); 954 sm_aes128_start(sm_cmac_k, y, NULL); 955 break; 956 } 957 case CMAC_CALC_MLAST: { 958 int i; 959 sm_key_t y; 960 for (i=0;i<16;i++){ 961 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 962 } 963 log_info_key("Y", y); 964 sm_cmac_block_current++; 965 sm_cmac_next_state(); 966 sm_aes128_start(sm_cmac_k, y, NULL); 967 break; 968 } 969 default: 970 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 971 break; 972 } 973 } 974 975 static void sm_cmac_handle_encryption_result(sm_key_t data){ 976 switch (sm_cmac_state){ 977 case CMAC_W4_SUBKEYS: { 978 sm_key_t k1; 979 memcpy(k1, data, 16); 980 sm_shift_left_by_one_bit_inplace(16, k1); 981 if (data[0] & 0x80){ 982 k1[15] ^= 0x87; 983 } 984 sm_key_t k2; 985 memcpy(k2, k1, 16); 986 sm_shift_left_by_one_bit_inplace(16, k2); 987 if (k1[0] & 0x80){ 988 k2[15] ^= 0x87; 989 } 990 991 log_info_key("k", sm_cmac_k); 992 log_info_key("k1", k1); 993 log_info_key("k2", k2); 994 995 // step 4: set m_last 996 int i; 997 if (sm_cmac_last_block_complete()){ 998 for (i=0;i<16;i++){ 999 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1000 } 1001 } else { 1002 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1003 for (i=0;i<16;i++){ 1004 if (i < valid_octets_in_last_block){ 1005 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1006 continue; 1007 } 1008 if (i == valid_octets_in_last_block){ 1009 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1010 continue; 1011 } 1012 sm_cmac_m_last[i] = k2[i]; 1013 } 1014 } 1015 1016 // next 1017 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1018 break; 1019 } 1020 case CMAC_W4_MI: 1021 memcpy(sm_cmac_x, data, 16); 1022 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1023 break; 1024 case CMAC_W4_MLAST: 1025 // done 1026 log_info("Setting CMAC Engine to IDLE"); 1027 sm_cmac_state = CMAC_IDLE; 1028 log_info_key("CMAC", data); 1029 sm_cmac_done_handler(data); 1030 break; 1031 default: 1032 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1033 break; 1034 } 1035 } 1036 1037 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1038 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1039 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1040 switch (setup->sm_stk_generation_method){ 1041 case PK_RESP_INPUT: 1042 if (sm_conn->sm_role){ 1043 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1044 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1045 } else { 1046 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)); 1047 } 1048 break; 1049 case PK_INIT_INPUT: 1050 if (sm_conn->sm_role){ 1051 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)); 1052 } else { 1053 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1054 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1055 } 1056 break; 1057 case OK_BOTH_INPUT: 1058 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1059 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1060 break; 1061 case NK_BOTH_INPUT: 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 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)); 1064 break; 1065 case JUST_WORKS: 1066 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1067 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1068 break; 1069 case OOB: 1070 // client already provided OOB data, let's skip notification. 1071 break; 1072 } 1073 } 1074 1075 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1076 int recv_flags; 1077 if (sm_conn->sm_role){ 1078 // slave / responder 1079 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1080 } else { 1081 // master / initiator 1082 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1083 } 1084 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1085 return recv_flags == setup->sm_key_distribution_received_set; 1086 } 1087 1088 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1089 if (sm_active_connection == con_handle){ 1090 sm_timeout_stop(); 1091 sm_active_connection = 0; 1092 log_info("sm: connection 0x%x released setup context", con_handle); 1093 } 1094 } 1095 1096 static int sm_key_distribution_flags_for_auth_req(void){ 1097 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1098 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1099 // encryption information only if bonding requested 1100 flags |= SM_KEYDIST_ENC_KEY; 1101 } 1102 return flags; 1103 } 1104 1105 static void sm_init_setup(sm_connection_t * sm_conn){ 1106 1107 // fill in sm setup 1108 setup->sm_state_vars = 0; 1109 sm_reset_tk(); 1110 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1111 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1112 1113 // query client for OOB data 1114 int have_oob_data = 0; 1115 if (sm_get_oob_data) { 1116 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1117 } 1118 1119 sm_pairing_packet_t * local_packet; 1120 if (sm_conn->sm_role){ 1121 // slave 1122 local_packet = &setup->sm_s_pres; 1123 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1124 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1125 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1126 } else { 1127 // master 1128 local_packet = &setup->sm_m_preq; 1129 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1130 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1131 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1132 1133 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1134 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1135 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1136 } 1137 1138 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1139 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1140 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1141 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1142 } 1143 1144 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1145 1146 sm_pairing_packet_t * remote_packet; 1147 int remote_key_request; 1148 if (sm_conn->sm_role){ 1149 // slave / responder 1150 remote_packet = &setup->sm_m_preq; 1151 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1152 } else { 1153 // master / initiator 1154 remote_packet = &setup->sm_s_pres; 1155 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1156 } 1157 1158 // check key size 1159 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1160 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1161 1162 // decide on STK generation method 1163 sm_setup_tk(); 1164 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1165 1166 // check if STK generation method is acceptable by client 1167 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1168 1169 // identical to responder 1170 sm_setup_key_distribution(remote_key_request); 1171 1172 // JUST WORKS doens't provide authentication 1173 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1174 1175 return 0; 1176 } 1177 1178 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1179 1180 // cache and reset context 1181 int matched_device_id = sm_address_resolution_test; 1182 address_resolution_mode_t mode = sm_address_resolution_mode; 1183 void * context = sm_address_resolution_context; 1184 1185 // reset context 1186 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1187 sm_address_resolution_context = NULL; 1188 sm_address_resolution_test = -1; 1189 hci_con_handle_t con_handle = 0; 1190 1191 sm_connection_t * sm_connection; 1192 uint16_t ediv; 1193 switch (mode){ 1194 case ADDRESS_RESOLUTION_GENERAL: 1195 break; 1196 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1197 sm_connection = (sm_connection_t *) context; 1198 con_handle = sm_connection->sm_handle; 1199 switch (event){ 1200 case ADDRESS_RESOLUTION_SUCEEDED: 1201 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1202 sm_connection->sm_le_db_index = matched_device_id; 1203 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1204 if (sm_connection->sm_role) break; 1205 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1206 sm_connection->sm_security_request_received = 0; 1207 sm_connection->sm_bonding_requested = 0; 1208 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1209 if (ediv){ 1210 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1211 } else { 1212 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1213 } 1214 break; 1215 case ADDRESS_RESOLUTION_FAILED: 1216 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1217 if (sm_connection->sm_role) break; 1218 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1219 sm_connection->sm_security_request_received = 0; 1220 sm_connection->sm_bonding_requested = 0; 1221 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1222 break; 1223 } 1224 break; 1225 default: 1226 break; 1227 } 1228 1229 switch (event){ 1230 case ADDRESS_RESOLUTION_SUCEEDED: 1231 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1232 break; 1233 case ADDRESS_RESOLUTION_FAILED: 1234 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1235 break; 1236 } 1237 } 1238 1239 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1240 1241 int le_db_index = -1; 1242 1243 // lookup device based on IRK 1244 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1245 int i; 1246 for (i=0; i < le_device_db_count(); i++){ 1247 sm_key_t irk; 1248 bd_addr_t address; 1249 int address_type; 1250 le_device_db_info(i, &address_type, address, irk); 1251 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1252 log_info("sm: device found for IRK, updating"); 1253 le_db_index = i; 1254 break; 1255 } 1256 } 1257 } 1258 1259 // if not found, lookup via public address if possible 1260 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1261 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1262 int i; 1263 for (i=0; i < le_device_db_count(); i++){ 1264 bd_addr_t address; 1265 int address_type; 1266 le_device_db_info(i, &address_type, address, NULL); 1267 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1268 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1269 log_info("sm: device found for public address, updating"); 1270 le_db_index = i; 1271 break; 1272 } 1273 } 1274 } 1275 1276 // if not found, add to db 1277 if (le_db_index < 0) { 1278 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1279 } 1280 1281 if (le_db_index >= 0){ 1282 le_device_db_local_counter_set(le_db_index, 0); 1283 1284 // store local CSRK 1285 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1286 log_info("sm: store local CSRK"); 1287 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1288 le_device_db_local_counter_set(le_db_index, 0); 1289 } 1290 1291 // store remote CSRK 1292 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1293 log_info("sm: store remote CSRK"); 1294 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1295 le_device_db_remote_counter_set(le_db_index, 0); 1296 } 1297 1298 // store encryption information 1299 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1300 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1301 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1302 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1303 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1304 } 1305 } 1306 1307 // keep le_db_index 1308 sm_conn->sm_le_db_index = le_db_index; 1309 } 1310 1311 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1312 setup->sm_pairing_failed_reason = reason; 1313 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1314 } 1315 1316 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1317 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1318 } 1319 1320 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1321 1322 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1323 static int sm_passkey_used(stk_generation_method_t method); 1324 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1325 1326 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1327 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1328 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1329 } else { 1330 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1331 } 1332 } 1333 1334 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1335 if (sm_conn->sm_role){ 1336 // Responder 1337 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1338 } else { 1339 // Initiator role 1340 switch (setup->sm_stk_generation_method){ 1341 case JUST_WORKS: 1342 sm_sc_prepare_dhkey_check(sm_conn); 1343 break; 1344 1345 case NK_BOTH_INPUT: 1346 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1347 break; 1348 case PK_INIT_INPUT: 1349 case PK_RESP_INPUT: 1350 case OK_BOTH_INPUT: 1351 if (setup->sm_passkey_bit < 20) { 1352 sm_sc_start_calculating_local_confirm(sm_conn); 1353 } else { 1354 sm_sc_prepare_dhkey_check(sm_conn); 1355 } 1356 break; 1357 case OOB: 1358 // TODO: implement SC OOB 1359 break; 1360 } 1361 } 1362 } 1363 1364 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1365 return sm_cmac_sc_buffer[offset]; 1366 } 1367 1368 static void sm_sc_cmac_done(uint8_t * hash){ 1369 log_info("sm_sc_cmac_done: "); 1370 log_info_hexdump(hash, 16); 1371 1372 sm_connection_t * sm_conn = sm_cmac_connection; 1373 sm_cmac_connection = NULL; 1374 1375 switch (sm_conn->sm_engine_state){ 1376 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1377 memcpy(setup->sm_local_confirm, hash, 16); 1378 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1379 break; 1380 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1381 // check 1382 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1383 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1384 break; 1385 } 1386 sm_sc_state_after_receiving_random(sm_conn); 1387 break; 1388 case SM_SC_W4_CALCULATE_G2: { 1389 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1390 big_endian_store_32(setup->sm_tk, 12, vab); 1391 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1392 sm_trigger_user_response(sm_conn); 1393 break; 1394 } 1395 case SM_SC_W4_CALCULATE_F5_SALT: 1396 memcpy(setup->sm_t, hash, 16); 1397 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1398 break; 1399 case SM_SC_W4_CALCULATE_F5_MACKEY: 1400 memcpy(setup->sm_mackey, hash, 16); 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1402 break; 1403 case SM_SC_W4_CALCULATE_F5_LTK: 1404 memcpy(setup->sm_ltk, hash, 16); 1405 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1406 break; 1407 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1408 memcpy(setup->sm_local_dhkey_check, hash, 16); 1409 if (sm_conn->sm_role){ 1410 // responder 1411 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1412 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1413 } else { 1414 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1415 } 1416 } else { 1417 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1418 } 1419 break; 1420 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1421 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1422 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1423 break; 1424 } 1425 if (sm_conn->sm_role){ 1426 // responder 1427 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1428 } else { 1429 // initiator 1430 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1431 } 1432 break; 1433 default: 1434 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1435 break; 1436 } 1437 sm_run(); 1438 } 1439 1440 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){ 1441 const uint16_t message_len = 65; 1442 sm_cmac_connection = sm_conn; 1443 memcpy(sm_cmac_sc_buffer, u, 32); 1444 memcpy(sm_cmac_sc_buffer+32, v, 32); 1445 sm_cmac_sc_buffer[64] = z; 1446 log_info("f4 key"); 1447 log_info_hexdump(x, 16); 1448 log_info("f4 message"); 1449 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1450 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1451 } 1452 1453 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1454 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1455 static const uint8_t f5_length[] = { 0x01, 0x00}; 1456 1457 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1458 #ifdef USE_MBEDTLS_FOR_ECDH 1459 // da * Pb 1460 mbedtls_ecp_group grp; 1461 mbedtls_ecp_group_init(&grp ); 1462 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1463 mbedtls_ecp_point Q; 1464 mbedtls_ecp_point_init( &Q ); 1465 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1466 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1467 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1468 mbedtls_ecp_point DH; 1469 mbedtls_ecp_point_init(&DH); 1470 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1471 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1472 mbedtls_ecp_point_free(&DH); 1473 mbedtls_ecp_point_free(&Q); 1474 mbedtls_ecp_group_free(&grp); 1475 #endif 1476 log_info("dhkey"); 1477 log_info_hexdump(dhkey, 32); 1478 } 1479 1480 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1481 // calculate DHKEY 1482 sm_key256_t dhkey; 1483 sm_sc_calculate_dhkey(dhkey); 1484 1485 // calculate salt for f5 1486 const uint16_t message_len = 32; 1487 sm_cmac_connection = sm_conn; 1488 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1489 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1490 } 1491 1492 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){ 1493 const uint16_t message_len = 53; 1494 sm_cmac_connection = sm_conn; 1495 1496 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1497 sm_cmac_sc_buffer[0] = 0; 1498 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1499 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1500 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1501 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1502 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1503 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1504 log_info("f5 key"); 1505 log_info_hexdump(t, 16); 1506 log_info("f5 message for MacKey"); 1507 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1508 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1509 } 1510 1511 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1512 sm_key56_t bd_addr_master, bd_addr_slave; 1513 bd_addr_master[0] = setup->sm_m_addr_type; 1514 bd_addr_slave[0] = setup->sm_s_addr_type; 1515 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1516 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1517 if (sm_conn->sm_role){ 1518 // responder 1519 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1520 } else { 1521 // initiator 1522 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1523 } 1524 } 1525 1526 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1527 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1528 const uint16_t message_len = 53; 1529 sm_cmac_connection = sm_conn; 1530 sm_cmac_sc_buffer[0] = 1; 1531 // 1..52 setup before 1532 log_info("f5 key"); 1533 log_info_hexdump(t, 16); 1534 log_info("f5 message for LTK"); 1535 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1536 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1537 } 1538 1539 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1540 f5_ltk(sm_conn, setup->sm_t); 1541 } 1542 1543 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){ 1544 const uint16_t message_len = 65; 1545 sm_cmac_connection = sm_conn; 1546 memcpy(sm_cmac_sc_buffer, n1, 16); 1547 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1548 memcpy(sm_cmac_sc_buffer+32, r, 16); 1549 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1550 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1551 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1552 log_info("f6 key"); 1553 log_info_hexdump(w, 16); 1554 log_info("f6 message"); 1555 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1556 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1557 } 1558 1559 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1560 // - U is 256 bits 1561 // - V is 256 bits 1562 // - X is 128 bits 1563 // - Y is 128 bits 1564 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){ 1565 const uint16_t message_len = 80; 1566 sm_cmac_connection = sm_conn; 1567 memcpy(sm_cmac_sc_buffer, u, 32); 1568 memcpy(sm_cmac_sc_buffer+32, v, 32); 1569 memcpy(sm_cmac_sc_buffer+64, y, 16); 1570 log_info("g2 key"); 1571 log_info_hexdump(x, 16); 1572 log_info("g2 message"); 1573 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1574 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1575 } 1576 1577 static void g2_calculate(sm_connection_t * sm_conn) { 1578 // calc Va if numeric comparison 1579 uint8_t value[32]; 1580 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1581 if (sm_conn->sm_role){ 1582 // responder 1583 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1584 } else { 1585 // initiator 1586 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1587 } 1588 } 1589 1590 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1591 uint8_t z = 0; 1592 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1593 // some form of passkey 1594 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1595 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1596 setup->sm_passkey_bit++; 1597 } 1598 #ifdef USE_MBEDTLS_FOR_ECDH 1599 uint8_t local_qx[32]; 1600 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1601 #endif 1602 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1603 } 1604 1605 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1606 uint8_t z = 0; 1607 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1608 // some form of passkey 1609 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1610 // sm_passkey_bit was increased before sending confirm value 1611 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1612 } 1613 #ifdef USE_MBEDTLS_FOR_ECDH 1614 uint8_t local_qx[32]; 1615 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1616 #endif 1617 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1618 } 1619 1620 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1621 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1622 } 1623 1624 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1625 // calculate DHKCheck 1626 sm_key56_t bd_addr_master, bd_addr_slave; 1627 bd_addr_master[0] = setup->sm_m_addr_type; 1628 bd_addr_slave[0] = setup->sm_s_addr_type; 1629 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1630 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1631 uint8_t iocap_a[3]; 1632 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1633 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1634 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1635 uint8_t iocap_b[3]; 1636 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1637 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1638 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1639 if (sm_conn->sm_role){ 1640 // responder 1641 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); 1642 } else { 1643 // initiator 1644 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); 1645 } 1646 } 1647 1648 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1649 // validate E = f6() 1650 sm_key56_t bd_addr_master, bd_addr_slave; 1651 bd_addr_master[0] = setup->sm_m_addr_type; 1652 bd_addr_slave[0] = setup->sm_s_addr_type; 1653 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1654 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1655 1656 uint8_t iocap_a[3]; 1657 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1658 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1659 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1660 uint8_t iocap_b[3]; 1661 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1662 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1663 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1664 if (sm_conn->sm_role){ 1665 // responder 1666 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); 1667 } else { 1668 // initiator 1669 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); 1670 } 1671 } 1672 #endif 1673 1674 static void sm_load_security_info(sm_connection_t * sm_connection){ 1675 int encryption_key_size; 1676 int authenticated; 1677 int authorized; 1678 1679 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1680 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1681 &encryption_key_size, &authenticated, &authorized); 1682 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1683 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1684 sm_connection->sm_connection_authenticated = authenticated; 1685 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1686 } 1687 1688 static void sm_run(void){ 1689 1690 btstack_linked_list_iterator_t it; 1691 1692 // assert that we can send at least commands 1693 if (!hci_can_send_command_packet_now()) return; 1694 1695 // 1696 // non-connection related behaviour 1697 // 1698 1699 // distributed key generation 1700 switch (dkg_state){ 1701 case DKG_CALC_IRK: 1702 // already busy? 1703 if (sm_aes128_state == SM_AES128_IDLE) { 1704 // IRK = d1(IR, 1, 0) 1705 sm_key_t d1_prime; 1706 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1707 dkg_next_state(); 1708 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1709 return; 1710 } 1711 break; 1712 case DKG_CALC_DHK: 1713 // already busy? 1714 if (sm_aes128_state == SM_AES128_IDLE) { 1715 // DHK = d1(IR, 3, 0) 1716 sm_key_t d1_prime; 1717 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1718 dkg_next_state(); 1719 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1720 return; 1721 } 1722 break; 1723 default: 1724 break; 1725 } 1726 1727 #ifdef USE_MBEDTLS_FOR_ECDH 1728 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1729 sm_random_start(NULL); 1730 return; 1731 } 1732 #endif 1733 1734 // random address updates 1735 switch (rau_state){ 1736 case RAU_GET_RANDOM: 1737 rau_next_state(); 1738 sm_random_start(NULL); 1739 return; 1740 case RAU_GET_ENC: 1741 // already busy? 1742 if (sm_aes128_state == SM_AES128_IDLE) { 1743 sm_key_t r_prime; 1744 sm_ah_r_prime(sm_random_address, r_prime); 1745 rau_next_state(); 1746 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1747 return; 1748 } 1749 break; 1750 case RAU_SET_ADDRESS: 1751 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1752 rau_state = RAU_IDLE; 1753 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1754 return; 1755 default: 1756 break; 1757 } 1758 1759 // CMAC 1760 switch (sm_cmac_state){ 1761 case CMAC_CALC_SUBKEYS: 1762 case CMAC_CALC_MI: 1763 case CMAC_CALC_MLAST: 1764 // already busy? 1765 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1766 sm_cmac_handle_aes_engine_ready(); 1767 return; 1768 default: 1769 break; 1770 } 1771 1772 // CSRK Lookup 1773 // -- if csrk lookup ready, find connection that require csrk lookup 1774 if (sm_address_resolution_idle()){ 1775 hci_connections_get_iterator(&it); 1776 while(btstack_linked_list_iterator_has_next(&it)){ 1777 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1778 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1779 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1780 // and start lookup 1781 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); 1782 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1783 break; 1784 } 1785 } 1786 } 1787 1788 // -- if csrk lookup ready, resolved addresses for received addresses 1789 if (sm_address_resolution_idle()) { 1790 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1791 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1792 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1793 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1794 btstack_memory_sm_lookup_entry_free(entry); 1795 } 1796 } 1797 1798 // -- Continue with CSRK device lookup by public or resolvable private address 1799 if (!sm_address_resolution_idle()){ 1800 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1801 while (sm_address_resolution_test < le_device_db_count()){ 1802 int addr_type; 1803 bd_addr_t addr; 1804 sm_key_t irk; 1805 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1806 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1807 1808 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1809 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1810 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1811 break; 1812 } 1813 1814 if (sm_address_resolution_addr_type == 0){ 1815 sm_address_resolution_test++; 1816 continue; 1817 } 1818 1819 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1820 1821 log_info("LE Device Lookup: calculate AH"); 1822 log_info_key("IRK", irk); 1823 1824 sm_key_t r_prime; 1825 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1826 sm_address_resolution_ah_calculation_active = 1; 1827 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1828 return; 1829 } 1830 1831 if (sm_address_resolution_test >= le_device_db_count()){ 1832 log_info("LE Device Lookup: not found"); 1833 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1834 } 1835 } 1836 1837 1838 // 1839 // active connection handling 1840 // -- use loop to handle next connection if lock on setup context is released 1841 1842 while (1) { 1843 1844 // Find connections that requires setup context and make active if no other is locked 1845 hci_connections_get_iterator(&it); 1846 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1847 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1848 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1849 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1850 int done = 1; 1851 int err; 1852 switch (sm_connection->sm_engine_state) { 1853 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1854 // send packet if possible, 1855 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1856 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1857 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1858 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1859 } else { 1860 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1861 } 1862 // don't lock sxetup context yet 1863 done = 0; 1864 break; 1865 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1866 sm_init_setup(sm_connection); 1867 // recover pairing request 1868 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1869 err = sm_stk_generation_init(sm_connection); 1870 if (err){ 1871 setup->sm_pairing_failed_reason = err; 1872 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1873 break; 1874 } 1875 sm_timeout_start(sm_connection); 1876 // generate random number first, if we need to show passkey 1877 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1878 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1879 break; 1880 } 1881 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1882 break; 1883 case SM_INITIATOR_PH0_HAS_LTK: 1884 sm_load_security_info(sm_connection); 1885 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1886 break; 1887 case SM_RESPONDER_PH0_RECEIVED_LTK: 1888 switch (sm_connection->sm_irk_lookup_state){ 1889 case IRK_LOOKUP_SUCCEEDED:{ 1890 sm_load_security_info(sm_connection); 1891 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1892 break; 1893 } 1894 case IRK_LOOKUP_FAILED: 1895 // assume that we don't have a LTK for ediv == 0 and random == null 1896 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1897 log_info("LTK Request: ediv & random are empty"); 1898 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1899 // TODO: no need to lock context yet -> done = 0; 1900 break; 1901 } 1902 // re-establish previously used LTK using Rand and EDIV 1903 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1904 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1905 // re-establish used key encryption size 1906 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1907 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1908 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1909 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1910 log_info("sm: received ltk request with key size %u, authenticated %u", 1911 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1912 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1913 break; 1914 default: 1915 // just wait until IRK lookup is completed 1916 // don't lock sxetup context yet 1917 done = 0; 1918 break; 1919 } 1920 break; 1921 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1922 sm_init_setup(sm_connection); 1923 sm_timeout_start(sm_connection); 1924 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1925 break; 1926 default: 1927 done = 0; 1928 break; 1929 } 1930 if (done){ 1931 sm_active_connection = sm_connection->sm_handle; 1932 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1933 } 1934 } 1935 1936 // 1937 // active connection handling 1938 // 1939 1940 if (sm_active_connection == 0) return; 1941 1942 // assert that we could send a SM PDU - not needed for all of the following 1943 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1944 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1945 return; 1946 } 1947 1948 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1949 if (!connection) return; 1950 1951 sm_key_t plaintext; 1952 int key_distribution_flags; 1953 1954 log_info("sm_run: state %u", connection->sm_engine_state); 1955 1956 // responding state 1957 switch (connection->sm_engine_state){ 1958 1959 // general 1960 case SM_GENERAL_SEND_PAIRING_FAILED: { 1961 uint8_t buffer[2]; 1962 buffer[0] = SM_CODE_PAIRING_FAILED; 1963 buffer[1] = setup->sm_pairing_failed_reason; 1964 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1965 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1966 sm_done_for_handle(connection->sm_handle); 1967 break; 1968 } 1969 1970 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1971 case SM_SC_W2_GET_RANDOM_A: 1972 sm_random_start(connection); 1973 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1974 break; 1975 case SM_SC_W2_GET_RANDOM_B: 1976 sm_random_start(connection); 1977 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1978 break; 1979 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1980 if (!sm_cmac_ready()) break; 1981 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1982 sm_sc_calculate_local_confirm(connection); 1983 break; 1984 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1985 if (!sm_cmac_ready()) break; 1986 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1987 sm_sc_calculate_remote_confirm(connection); 1988 break; 1989 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1990 if (!sm_cmac_ready()) break; 1991 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1992 sm_sc_calculate_f6_for_dhkey_check(connection); 1993 break; 1994 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1995 if (!sm_cmac_ready()) break; 1996 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1997 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1998 break; 1999 case SM_SC_W2_CALCULATE_F5_SALT: 2000 if (!sm_cmac_ready()) break; 2001 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2002 f5_calculate_salt(connection); 2003 break; 2004 case SM_SC_W2_CALCULATE_F5_MACKEY: 2005 if (!sm_cmac_ready()) break; 2006 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2007 f5_calculate_mackey(connection); 2008 break; 2009 case SM_SC_W2_CALCULATE_F5_LTK: 2010 if (!sm_cmac_ready()) break; 2011 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2012 f5_calculate_ltk(connection); 2013 break; 2014 case SM_SC_W2_CALCULATE_G2: 2015 if (!sm_cmac_ready()) break; 2016 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2017 g2_calculate(connection); 2018 break; 2019 2020 #endif 2021 // initiator side 2022 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2023 sm_key_t peer_ltk_flipped; 2024 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2025 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2026 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2027 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2028 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2029 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2030 return; 2031 } 2032 2033 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2034 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2035 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2036 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2037 sm_timeout_reset(connection); 2038 break; 2039 2040 // responder side 2041 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2042 connection->sm_engine_state = SM_RESPONDER_IDLE; 2043 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2044 sm_done_for_handle(connection->sm_handle); 2045 return; 2046 2047 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2048 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2049 uint8_t buffer[65]; 2050 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2051 // 2052 #ifdef USE_MBEDTLS_FOR_ECDH 2053 uint8_t value[32]; 2054 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2055 reverse_256(value, &buffer[1]); 2056 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2057 reverse_256(value, &buffer[33]); 2058 #endif 2059 2060 // stk generation method 2061 // passkey entry: notify app to show passkey or to request passkey 2062 switch (setup->sm_stk_generation_method){ 2063 case JUST_WORKS: 2064 case NK_BOTH_INPUT: 2065 if (connection->sm_role){ 2066 // responder 2067 sm_sc_start_calculating_local_confirm(connection); 2068 } else { 2069 // initiator 2070 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2071 } 2072 break; 2073 case PK_INIT_INPUT: 2074 case PK_RESP_INPUT: 2075 case OK_BOTH_INPUT: 2076 // use random TK for display 2077 memcpy(setup->sm_ra, setup->sm_tk, 16); 2078 memcpy(setup->sm_rb, setup->sm_tk, 16); 2079 setup->sm_passkey_bit = 0; 2080 2081 if (connection->sm_role){ 2082 // responder 2083 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2084 } else { 2085 // initiator 2086 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2087 } 2088 sm_trigger_user_response(connection); 2089 break; 2090 case OOB: 2091 // TODO: implement SC OOB 2092 break; 2093 } 2094 2095 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2096 sm_timeout_reset(connection); 2097 break; 2098 } 2099 case SM_SC_SEND_CONFIRMATION: { 2100 uint8_t buffer[17]; 2101 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2102 reverse_128(setup->sm_local_confirm, &buffer[1]); 2103 if (connection->sm_role){ 2104 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2105 } else { 2106 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2107 } 2108 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2109 sm_timeout_reset(connection); 2110 break; 2111 } 2112 case SM_SC_SEND_PAIRING_RANDOM: { 2113 uint8_t buffer[17]; 2114 buffer[0] = SM_CODE_PAIRING_RANDOM; 2115 reverse_128(setup->sm_local_nonce, &buffer[1]); 2116 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2117 if (connection->sm_role){ 2118 // responder 2119 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2120 } else { 2121 // initiator 2122 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2123 } 2124 } else { 2125 if (connection->sm_role){ 2126 // responder 2127 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2128 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2129 } else { 2130 sm_sc_prepare_dhkey_check(connection); 2131 } 2132 } else { 2133 // initiator 2134 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2135 } 2136 } 2137 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2138 sm_timeout_reset(connection); 2139 break; 2140 } 2141 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2142 uint8_t buffer[17]; 2143 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2144 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2145 2146 if (connection->sm_role){ 2147 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2148 } else { 2149 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2150 } 2151 2152 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2153 sm_timeout_reset(connection); 2154 break; 2155 } 2156 2157 #endif 2158 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2159 // echo initiator for now 2160 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2161 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2162 2163 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2164 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2165 if (setup->sm_use_secure_connections){ 2166 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2167 // skip LTK/EDIV for SC 2168 log_info("sm: dropping encryption information flag"); 2169 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2170 } 2171 #endif 2172 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); 2173 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); 2174 // update key distribution after ENC was dropped 2175 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2176 2177 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2178 sm_timeout_reset(connection); 2179 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2180 if (setup->sm_stk_generation_method == JUST_WORKS){ 2181 sm_trigger_user_response(connection); 2182 } 2183 return; 2184 2185 case SM_PH2_SEND_PAIRING_RANDOM: { 2186 uint8_t buffer[17]; 2187 buffer[0] = SM_CODE_PAIRING_RANDOM; 2188 reverse_128(setup->sm_local_random, &buffer[1]); 2189 if (connection->sm_role){ 2190 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2191 } else { 2192 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2193 } 2194 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2195 sm_timeout_reset(connection); 2196 break; 2197 } 2198 2199 case SM_PH2_GET_RANDOM_TK: 2200 case SM_PH2_C1_GET_RANDOM_A: 2201 case SM_PH2_C1_GET_RANDOM_B: 2202 case SM_PH3_GET_RANDOM: 2203 case SM_PH3_GET_DIV: 2204 sm_next_responding_state(connection); 2205 sm_random_start(connection); 2206 return; 2207 2208 case SM_PH2_C1_GET_ENC_B: 2209 case SM_PH2_C1_GET_ENC_D: 2210 // already busy? 2211 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2212 sm_next_responding_state(connection); 2213 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2214 return; 2215 2216 case SM_PH3_LTK_GET_ENC: 2217 case SM_RESPONDER_PH4_LTK_GET_ENC: 2218 // already busy? 2219 if (sm_aes128_state == SM_AES128_IDLE) { 2220 sm_key_t d_prime; 2221 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2222 sm_next_responding_state(connection); 2223 sm_aes128_start(sm_persistent_er, d_prime, connection); 2224 return; 2225 } 2226 break; 2227 2228 case SM_PH3_CSRK_GET_ENC: 2229 // already busy? 2230 if (sm_aes128_state == SM_AES128_IDLE) { 2231 sm_key_t d_prime; 2232 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2233 sm_next_responding_state(connection); 2234 sm_aes128_start(sm_persistent_er, d_prime, connection); 2235 return; 2236 } 2237 break; 2238 2239 case SM_PH2_C1_GET_ENC_C: 2240 // already busy? 2241 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2242 // calculate m_confirm using aes128 engine - step 1 2243 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); 2244 sm_next_responding_state(connection); 2245 sm_aes128_start(setup->sm_tk, plaintext, connection); 2246 break; 2247 case SM_PH2_C1_GET_ENC_A: 2248 // already busy? 2249 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2250 // calculate confirm using aes128 engine - step 1 2251 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); 2252 sm_next_responding_state(connection); 2253 sm_aes128_start(setup->sm_tk, plaintext, connection); 2254 break; 2255 case SM_PH2_CALC_STK: 2256 // already busy? 2257 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2258 // calculate STK 2259 if (connection->sm_role){ 2260 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2261 } else { 2262 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2263 } 2264 sm_next_responding_state(connection); 2265 sm_aes128_start(setup->sm_tk, plaintext, connection); 2266 break; 2267 case SM_PH3_Y_GET_ENC: 2268 // already busy? 2269 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2270 // PH3B2 - calculate Y from - enc 2271 // Y = dm(DHK, Rand) 2272 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2273 sm_next_responding_state(connection); 2274 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2275 return; 2276 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2277 uint8_t buffer[17]; 2278 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2279 reverse_128(setup->sm_local_confirm, &buffer[1]); 2280 if (connection->sm_role){ 2281 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2282 } else { 2283 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2284 } 2285 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2286 sm_timeout_reset(connection); 2287 return; 2288 } 2289 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2290 sm_key_t stk_flipped; 2291 reverse_128(setup->sm_ltk, stk_flipped); 2292 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2293 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2294 return; 2295 } 2296 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2297 sm_key_t stk_flipped; 2298 reverse_128(setup->sm_ltk, stk_flipped); 2299 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2300 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2301 return; 2302 } 2303 case SM_RESPONDER_PH4_SEND_LTK: { 2304 sm_key_t ltk_flipped; 2305 reverse_128(setup->sm_ltk, ltk_flipped); 2306 connection->sm_engine_state = SM_RESPONDER_IDLE; 2307 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2308 return; 2309 } 2310 case SM_RESPONDER_PH4_Y_GET_ENC: 2311 // already busy? 2312 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2313 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2314 // Y = dm(DHK, Rand) 2315 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2316 sm_next_responding_state(connection); 2317 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2318 return; 2319 2320 case SM_PH3_DISTRIBUTE_KEYS: 2321 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2322 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2323 uint8_t buffer[17]; 2324 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2325 reverse_128(setup->sm_ltk, &buffer[1]); 2326 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2327 sm_timeout_reset(connection); 2328 return; 2329 } 2330 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2331 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2332 uint8_t buffer[11]; 2333 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2334 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2335 reverse_64(setup->sm_local_rand, &buffer[3]); 2336 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2337 sm_timeout_reset(connection); 2338 return; 2339 } 2340 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2341 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2342 uint8_t buffer[17]; 2343 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2344 reverse_128(sm_persistent_irk, &buffer[1]); 2345 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2346 sm_timeout_reset(connection); 2347 return; 2348 } 2349 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2350 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2351 bd_addr_t local_address; 2352 uint8_t buffer[8]; 2353 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2354 gap_advertisements_get_address(&buffer[1], local_address); 2355 reverse_bd_addr(local_address, &buffer[2]); 2356 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2357 sm_timeout_reset(connection); 2358 return; 2359 } 2360 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2361 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2362 2363 // hack to reproduce test runs 2364 if (test_use_fixed_local_csrk){ 2365 memset(setup->sm_local_csrk, 0xcc, 16); 2366 } 2367 2368 uint8_t buffer[17]; 2369 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2370 reverse_128(setup->sm_local_csrk, &buffer[1]); 2371 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2372 sm_timeout_reset(connection); 2373 return; 2374 } 2375 2376 // keys are sent 2377 if (connection->sm_role){ 2378 // slave -> receive master keys if any 2379 if (sm_key_distribution_all_received(connection)){ 2380 sm_key_distribution_handle_all_received(connection); 2381 connection->sm_engine_state = SM_RESPONDER_IDLE; 2382 sm_done_for_handle(connection->sm_handle); 2383 } else { 2384 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2385 } 2386 } else { 2387 // master -> all done 2388 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2389 sm_done_for_handle(connection->sm_handle); 2390 } 2391 break; 2392 2393 default: 2394 break; 2395 } 2396 2397 // check again if active connection was released 2398 if (sm_active_connection) break; 2399 } 2400 } 2401 2402 // note: aes engine is ready as we just got the aes result 2403 static void sm_handle_encryption_result(uint8_t * data){ 2404 2405 sm_aes128_state = SM_AES128_IDLE; 2406 2407 if (sm_address_resolution_ah_calculation_active){ 2408 sm_address_resolution_ah_calculation_active = 0; 2409 // compare calulated address against connecting device 2410 uint8_t hash[3]; 2411 reverse_24(data, hash); 2412 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2413 log_info("LE Device Lookup: matched resolvable private address"); 2414 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2415 return; 2416 } 2417 // no match, try next 2418 sm_address_resolution_test++; 2419 return; 2420 } 2421 2422 switch (dkg_state){ 2423 case DKG_W4_IRK: 2424 reverse_128(data, sm_persistent_irk); 2425 log_info_key("irk", sm_persistent_irk); 2426 dkg_next_state(); 2427 return; 2428 case DKG_W4_DHK: 2429 reverse_128(data, sm_persistent_dhk); 2430 log_info_key("dhk", sm_persistent_dhk); 2431 dkg_next_state(); 2432 // SM Init Finished 2433 return; 2434 default: 2435 break; 2436 } 2437 2438 switch (rau_state){ 2439 case RAU_W4_ENC: 2440 reverse_24(data, &sm_random_address[3]); 2441 rau_next_state(); 2442 return; 2443 default: 2444 break; 2445 } 2446 2447 switch (sm_cmac_state){ 2448 case CMAC_W4_SUBKEYS: 2449 case CMAC_W4_MI: 2450 case CMAC_W4_MLAST: 2451 { 2452 sm_key_t t; 2453 reverse_128(data, t); 2454 sm_cmac_handle_encryption_result(t); 2455 } 2456 return; 2457 default: 2458 break; 2459 } 2460 2461 // retrieve sm_connection provided to sm_aes128_start_encryption 2462 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2463 if (!connection) return; 2464 switch (connection->sm_engine_state){ 2465 case SM_PH2_C1_W4_ENC_A: 2466 case SM_PH2_C1_W4_ENC_C: 2467 { 2468 sm_key_t t2; 2469 reverse_128(data, t2); 2470 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2471 } 2472 sm_next_responding_state(connection); 2473 return; 2474 case SM_PH2_C1_W4_ENC_B: 2475 reverse_128(data, setup->sm_local_confirm); 2476 log_info_key("c1!", setup->sm_local_confirm); 2477 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2478 return; 2479 case SM_PH2_C1_W4_ENC_D: 2480 { 2481 sm_key_t peer_confirm_test; 2482 reverse_128(data, peer_confirm_test); 2483 log_info_key("c1!", peer_confirm_test); 2484 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2485 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2486 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2487 return; 2488 } 2489 if (connection->sm_role){ 2490 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2491 } else { 2492 connection->sm_engine_state = SM_PH2_CALC_STK; 2493 } 2494 } 2495 return; 2496 case SM_PH2_W4_STK: 2497 reverse_128(data, setup->sm_ltk); 2498 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2499 log_info_key("stk", setup->sm_ltk); 2500 if (connection->sm_role){ 2501 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2502 } else { 2503 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2504 } 2505 return; 2506 case SM_PH3_Y_W4_ENC:{ 2507 sm_key_t y128; 2508 reverse_128(data, y128); 2509 setup->sm_local_y = big_endian_read_16(y128, 14); 2510 log_info_hex16("y", setup->sm_local_y); 2511 // PH3B3 - calculate EDIV 2512 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2513 log_info_hex16("ediv", setup->sm_local_ediv); 2514 // PH3B4 - calculate LTK - enc 2515 // LTK = d1(ER, DIV, 0)) 2516 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2517 return; 2518 } 2519 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2520 sm_key_t y128; 2521 reverse_128(data, y128); 2522 setup->sm_local_y = big_endian_read_16(y128, 14); 2523 log_info_hex16("y", setup->sm_local_y); 2524 2525 // PH3B3 - calculate DIV 2526 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2527 log_info_hex16("ediv", setup->sm_local_ediv); 2528 // PH3B4 - calculate LTK - enc 2529 // LTK = d1(ER, DIV, 0)) 2530 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2531 return; 2532 } 2533 case SM_PH3_LTK_W4_ENC: 2534 reverse_128(data, setup->sm_ltk); 2535 log_info_key("ltk", setup->sm_ltk); 2536 // calc CSRK next 2537 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2538 return; 2539 case SM_PH3_CSRK_W4_ENC: 2540 reverse_128(data, setup->sm_local_csrk); 2541 log_info_key("csrk", setup->sm_local_csrk); 2542 if (setup->sm_key_distribution_send_set){ 2543 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2544 } else { 2545 // no keys to send, just continue 2546 if (connection->sm_role){ 2547 // slave -> receive master keys 2548 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2549 } else { 2550 // master -> all done 2551 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2552 sm_done_for_handle(connection->sm_handle); 2553 } 2554 } 2555 return; 2556 case SM_RESPONDER_PH4_LTK_W4_ENC: 2557 reverse_128(data, setup->sm_ltk); 2558 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2559 log_info_key("ltk", setup->sm_ltk); 2560 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2561 return; 2562 default: 2563 break; 2564 } 2565 } 2566 2567 #ifdef USE_MBEDTLS_FOR_ECDH 2568 2569 static void sm_log_ec_keypair(void){ 2570 // print keypair 2571 char buffer[100]; 2572 size_t len; 2573 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2574 log_info("d: %s", buffer); 2575 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2576 log_info("X: %s", buffer); 2577 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2578 log_info("Y: %s", buffer); 2579 } 2580 2581 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2582 int offset = setup->sm_passkey_bit; 2583 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2584 while (size) { 2585 if (offset < 32){ 2586 *buffer++ = setup->sm_peer_qx[offset++]; 2587 } else { 2588 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2589 } 2590 size--; 2591 } 2592 setup->sm_passkey_bit = offset; 2593 return 0; 2594 } 2595 #endif 2596 2597 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2598 static void sm_handle_random_result(uint8_t * data){ 2599 2600 #ifdef USE_MBEDTLS_FOR_ECDH 2601 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2602 int num_bytes = setup->sm_passkey_bit; 2603 if (num_bytes < 32){ 2604 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2605 } else { 2606 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2607 } 2608 num_bytes += 8; 2609 setup->sm_passkey_bit = num_bytes; 2610 2611 if (num_bytes >= 64){ 2612 // generate EC key 2613 setup->sm_passkey_bit = 0; 2614 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2615 sm_log_ec_keypair(); 2616 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2617 } 2618 } 2619 #endif 2620 2621 switch (rau_state){ 2622 case RAU_W4_RANDOM: 2623 // non-resolvable vs. resolvable 2624 switch (gap_random_adress_type){ 2625 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2626 // resolvable: use random as prand and calc address hash 2627 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2628 memcpy(sm_random_address, data, 3); 2629 sm_random_address[0] &= 0x3f; 2630 sm_random_address[0] |= 0x40; 2631 rau_state = RAU_GET_ENC; 2632 break; 2633 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2634 default: 2635 // "The two most significant bits of the address shall be equal to ‘0’"" 2636 memcpy(sm_random_address, data, 6); 2637 sm_random_address[0] &= 0x3f; 2638 rau_state = RAU_SET_ADDRESS; 2639 break; 2640 } 2641 return; 2642 default: 2643 break; 2644 } 2645 2646 // retrieve sm_connection provided to sm_random_start 2647 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2648 if (!connection) return; 2649 switch (connection->sm_engine_state){ 2650 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2651 case SM_SC_W4_GET_RANDOM_A: 2652 memcpy(&setup->sm_local_nonce[0], data, 8); 2653 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2654 break; 2655 case SM_SC_W4_GET_RANDOM_B: 2656 memcpy(&setup->sm_local_nonce[8], data, 8); 2657 // initiator & jw/nc -> send pairing random 2658 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2659 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2660 break; 2661 } else { 2662 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2663 } 2664 break; 2665 #endif 2666 2667 case SM_PH2_W4_RANDOM_TK: 2668 { 2669 // map random to 0-999999 without speding much cycles on a modulus operation 2670 uint32_t tk = little_endian_read_32(data,0); 2671 tk = tk & 0xfffff; // 1048575 2672 if (tk >= 999999){ 2673 tk = tk - 999999; 2674 } 2675 sm_reset_tk(); 2676 big_endian_store_32(setup->sm_tk, 12, tk); 2677 if (connection->sm_role){ 2678 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2679 } else { 2680 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2681 sm_trigger_user_response(connection); 2682 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2683 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2684 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2685 } 2686 } 2687 return; 2688 } 2689 case SM_PH2_C1_W4_RANDOM_A: 2690 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2691 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2692 return; 2693 case SM_PH2_C1_W4_RANDOM_B: 2694 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2695 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2696 return; 2697 case SM_PH3_W4_RANDOM: 2698 reverse_64(data, setup->sm_local_rand); 2699 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2700 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2701 // no db for authenticated flag hack: store flag in bit 4 of LSB 2702 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2703 connection->sm_engine_state = SM_PH3_GET_DIV; 2704 return; 2705 case SM_PH3_W4_DIV: 2706 // use 16 bit from random value as div 2707 setup->sm_local_div = big_endian_read_16(data, 0); 2708 log_info_hex16("div", setup->sm_local_div); 2709 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2710 return; 2711 default: 2712 break; 2713 } 2714 } 2715 2716 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2717 2718 sm_connection_t * sm_conn; 2719 hci_con_handle_t con_handle; 2720 2721 switch (packet_type) { 2722 2723 case HCI_EVENT_PACKET: 2724 switch (hci_event_packet_get_type(packet)) { 2725 2726 case BTSTACK_EVENT_STATE: 2727 // bt stack activated, get started 2728 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2729 log_info("HCI Working!"); 2730 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2731 rau_state = RAU_IDLE; 2732 #ifdef USE_MBEDTLS_FOR_ECDH 2733 if (!test_use_fixed_ec_keypair){ 2734 setup->sm_passkey_bit = 0; 2735 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2736 } 2737 #endif 2738 sm_run(); 2739 } 2740 break; 2741 2742 case HCI_EVENT_LE_META: 2743 switch (packet[2]) { 2744 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2745 2746 log_info("sm: connected"); 2747 2748 if (packet[3]) return; // connection failed 2749 2750 con_handle = little_endian_read_16(packet, 4); 2751 sm_conn = sm_get_connection_for_handle(con_handle); 2752 if (!sm_conn) break; 2753 2754 sm_conn->sm_handle = con_handle; 2755 sm_conn->sm_role = packet[6]; 2756 sm_conn->sm_peer_addr_type = packet[7]; 2757 reverse_bd_addr(&packet[8], 2758 sm_conn->sm_peer_address); 2759 2760 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2761 2762 // reset security properties 2763 sm_conn->sm_connection_encrypted = 0; 2764 sm_conn->sm_connection_authenticated = 0; 2765 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2766 sm_conn->sm_le_db_index = -1; 2767 2768 // prepare CSRK lookup (does not involve setup) 2769 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2770 2771 // just connected -> everything else happens in sm_run() 2772 if (sm_conn->sm_role){ 2773 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2774 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2775 if (sm_slave_request_security) { 2776 // request security if requested by app 2777 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2778 } else { 2779 // otherwise, wait for pairing request 2780 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2781 } 2782 } 2783 break; 2784 } else { 2785 // master 2786 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2787 } 2788 break; 2789 2790 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2791 con_handle = little_endian_read_16(packet, 3); 2792 sm_conn = sm_get_connection_for_handle(con_handle); 2793 if (!sm_conn) break; 2794 2795 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2796 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2797 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2798 break; 2799 } 2800 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2801 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2802 break; 2803 } 2804 2805 // store rand and ediv 2806 reverse_64(&packet[5], sm_conn->sm_local_rand); 2807 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2808 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2809 break; 2810 2811 default: 2812 break; 2813 } 2814 break; 2815 2816 case HCI_EVENT_ENCRYPTION_CHANGE: 2817 con_handle = little_endian_read_16(packet, 3); 2818 sm_conn = sm_get_connection_for_handle(con_handle); 2819 if (!sm_conn) break; 2820 2821 sm_conn->sm_connection_encrypted = packet[5]; 2822 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2823 sm_conn->sm_actual_encryption_key_size); 2824 log_info("event handler, state %u", sm_conn->sm_engine_state); 2825 if (!sm_conn->sm_connection_encrypted) break; 2826 // continue if part of initial pairing 2827 switch (sm_conn->sm_engine_state){ 2828 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2829 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2830 sm_done_for_handle(sm_conn->sm_handle); 2831 break; 2832 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2833 if (sm_conn->sm_role){ 2834 // slave 2835 if (setup->sm_use_secure_connections){ 2836 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2837 } else { 2838 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2839 } 2840 } else { 2841 // master 2842 if (sm_key_distribution_all_received(sm_conn)){ 2843 // skip receiving keys as there are none 2844 sm_key_distribution_handle_all_received(sm_conn); 2845 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2846 } else { 2847 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2848 } 2849 } 2850 break; 2851 default: 2852 break; 2853 } 2854 break; 2855 2856 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2857 con_handle = little_endian_read_16(packet, 3); 2858 sm_conn = sm_get_connection_for_handle(con_handle); 2859 if (!sm_conn) break; 2860 2861 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2862 log_info("event handler, state %u", sm_conn->sm_engine_state); 2863 // continue if part of initial pairing 2864 switch (sm_conn->sm_engine_state){ 2865 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2866 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2867 sm_done_for_handle(sm_conn->sm_handle); 2868 break; 2869 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2870 if (sm_conn->sm_role){ 2871 // slave 2872 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2873 } else { 2874 // master 2875 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2876 } 2877 break; 2878 default: 2879 break; 2880 } 2881 break; 2882 2883 2884 case HCI_EVENT_DISCONNECTION_COMPLETE: 2885 con_handle = little_endian_read_16(packet, 3); 2886 sm_done_for_handle(con_handle); 2887 sm_conn = sm_get_connection_for_handle(con_handle); 2888 if (!sm_conn) break; 2889 2890 // delete stored bonding on disconnect with authentication failure in ph0 2891 if (sm_conn->sm_role == 0 2892 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2893 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2894 le_device_db_remove(sm_conn->sm_le_db_index); 2895 } 2896 2897 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2898 sm_conn->sm_handle = 0; 2899 break; 2900 2901 case HCI_EVENT_COMMAND_COMPLETE: 2902 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2903 sm_handle_encryption_result(&packet[6]); 2904 break; 2905 } 2906 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2907 sm_handle_random_result(&packet[6]); 2908 break; 2909 } 2910 break; 2911 default: 2912 break; 2913 } 2914 break; 2915 default: 2916 break; 2917 } 2918 2919 sm_run(); 2920 } 2921 2922 static inline int sm_calc_actual_encryption_key_size(int other){ 2923 if (other < sm_min_encryption_key_size) return 0; 2924 if (other < sm_max_encryption_key_size) return other; 2925 return sm_max_encryption_key_size; 2926 } 2927 2928 2929 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2930 switch (method){ 2931 case JUST_WORKS: 2932 case NK_BOTH_INPUT: 2933 return 1; 2934 default: 2935 return 0; 2936 } 2937 } 2938 // responder 2939 2940 static int sm_passkey_used(stk_generation_method_t method){ 2941 switch (method){ 2942 case PK_RESP_INPUT: 2943 return 1; 2944 default: 2945 return 0; 2946 } 2947 } 2948 2949 /** 2950 * @return ok 2951 */ 2952 static int sm_validate_stk_generation_method(void){ 2953 // check if STK generation method is acceptable by client 2954 switch (setup->sm_stk_generation_method){ 2955 case JUST_WORKS: 2956 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2957 case PK_RESP_INPUT: 2958 case PK_INIT_INPUT: 2959 case OK_BOTH_INPUT: 2960 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2961 case OOB: 2962 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2963 case NK_BOTH_INPUT: 2964 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2965 return 1; 2966 default: 2967 return 0; 2968 } 2969 } 2970 2971 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2972 2973 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2974 sm_run(); 2975 } 2976 2977 if (packet_type != SM_DATA_PACKET) return; 2978 2979 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2980 if (!sm_conn) return; 2981 2982 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2983 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2984 return; 2985 } 2986 2987 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2988 2989 int err; 2990 2991 switch (sm_conn->sm_engine_state){ 2992 2993 // a sm timeout requries a new physical connection 2994 case SM_GENERAL_TIMEOUT: 2995 return; 2996 2997 // Initiator 2998 case SM_INITIATOR_CONNECTED: 2999 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3000 sm_pdu_received_in_wrong_state(sm_conn); 3001 break; 3002 } 3003 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3004 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3005 break; 3006 } 3007 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3008 uint16_t ediv; 3009 sm_key_t ltk; 3010 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3011 if (!sm_is_null_key(ltk) || ediv){ 3012 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3013 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3014 } else { 3015 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3016 } 3017 break; 3018 } 3019 // otherwise, store security request 3020 sm_conn->sm_security_request_received = 1; 3021 break; 3022 3023 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3024 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3025 sm_pdu_received_in_wrong_state(sm_conn); 3026 break; 3027 } 3028 // store pairing request 3029 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3030 err = sm_stk_generation_init(sm_conn); 3031 if (err){ 3032 setup->sm_pairing_failed_reason = err; 3033 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3034 break; 3035 } 3036 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3037 if (setup->sm_use_secure_connections){ 3038 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3039 if (setup->sm_stk_generation_method == JUST_WORKS){ 3040 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3041 sm_trigger_user_response(sm_conn); 3042 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3043 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3044 } 3045 } else { 3046 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3047 } 3048 break; 3049 } 3050 #endif 3051 // generate random number first, if we need to show passkey 3052 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3053 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3054 break; 3055 } 3056 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3057 sm_trigger_user_response(sm_conn); 3058 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3059 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3060 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3061 } 3062 break; 3063 3064 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3065 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3066 sm_pdu_received_in_wrong_state(sm_conn); 3067 break; 3068 } 3069 3070 // store s_confirm 3071 reverse_128(&packet[1], setup->sm_peer_confirm); 3072 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3073 break; 3074 3075 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3076 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3077 sm_pdu_received_in_wrong_state(sm_conn); 3078 break;; 3079 } 3080 3081 // received random value 3082 reverse_128(&packet[1], setup->sm_peer_random); 3083 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3084 break; 3085 3086 // Responder 3087 case SM_RESPONDER_IDLE: 3088 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3089 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3090 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3091 sm_pdu_received_in_wrong_state(sm_conn); 3092 break;; 3093 } 3094 3095 // store pairing request 3096 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3097 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3098 break; 3099 3100 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3101 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3102 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3103 sm_pdu_received_in_wrong_state(sm_conn); 3104 break; 3105 } 3106 3107 // store public key for DH Key calculation 3108 reverse_256(&packet[01], setup->sm_peer_qx); 3109 reverse_256(&packet[33], setup->sm_peer_qy); 3110 3111 #ifdef USE_MBEDTLS_FOR_ECDH 3112 // validate public key 3113 mbedtls_ecp_group grp; 3114 mbedtls_ecp_group_init( &grp ); 3115 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3116 3117 mbedtls_ecp_point Q; 3118 mbedtls_ecp_point_init( &Q ); 3119 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3120 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3121 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3122 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3123 mbedtls_ecp_point_free( & Q); 3124 mbedtls_ecp_group_free( &grp); 3125 if (err){ 3126 log_error("sm: peer public key invalid %x", err); 3127 // uses "unspecified reason", there is no "public key invalid" error code 3128 sm_pdu_received_in_wrong_state(sm_conn); 3129 break; 3130 } 3131 3132 #endif 3133 if (sm_conn->sm_role){ 3134 // responder 3135 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3136 } else { 3137 // initiator 3138 // stk generation method 3139 // passkey entry: notify app to show passkey or to request passkey 3140 switch (setup->sm_stk_generation_method){ 3141 case JUST_WORKS: 3142 case NK_BOTH_INPUT: 3143 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3144 break; 3145 case PK_RESP_INPUT: 3146 sm_sc_start_calculating_local_confirm(sm_conn); 3147 break; 3148 case PK_INIT_INPUT: 3149 case OK_BOTH_INPUT: 3150 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3151 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3152 break; 3153 } 3154 sm_sc_start_calculating_local_confirm(sm_conn); 3155 break; 3156 case OOB: 3157 // TODO: implement SC OOB 3158 break; 3159 } 3160 } 3161 break; 3162 3163 case SM_SC_W4_CONFIRMATION: 3164 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3165 sm_pdu_received_in_wrong_state(sm_conn); 3166 break; 3167 } 3168 // received confirm value 3169 reverse_128(&packet[1], setup->sm_peer_confirm); 3170 3171 if (sm_conn->sm_role){ 3172 // responder 3173 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3174 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3175 // still waiting for passkey 3176 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3177 break; 3178 } 3179 } 3180 sm_sc_start_calculating_local_confirm(sm_conn); 3181 } else { 3182 // initiator 3183 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3184 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3185 } else { 3186 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3187 } 3188 } 3189 break; 3190 3191 case SM_SC_W4_PAIRING_RANDOM: 3192 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3193 sm_pdu_received_in_wrong_state(sm_conn); 3194 break; 3195 } 3196 3197 // received random value 3198 reverse_128(&packet[1], setup->sm_peer_nonce); 3199 3200 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3201 // only check for JUST WORK/NC in initiator role AND passkey entry 3202 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3203 if (sm_conn->sm_role || passkey_entry) { 3204 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3205 } 3206 3207 sm_sc_state_after_receiving_random(sm_conn); 3208 break; 3209 3210 case SM_SC_W2_CALCULATE_G2: 3211 case SM_SC_W4_CALCULATE_G2: 3212 case SM_SC_W2_CALCULATE_F5_SALT: 3213 case SM_SC_W4_CALCULATE_F5_SALT: 3214 case SM_SC_W2_CALCULATE_F5_MACKEY: 3215 case SM_SC_W4_CALCULATE_F5_MACKEY: 3216 case SM_SC_W2_CALCULATE_F5_LTK: 3217 case SM_SC_W4_CALCULATE_F5_LTK: 3218 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3219 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3220 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3221 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3222 sm_pdu_received_in_wrong_state(sm_conn); 3223 break; 3224 } 3225 // store DHKey Check 3226 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3227 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3228 3229 // have we been only waiting for dhkey check command? 3230 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3231 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3232 } 3233 break; 3234 #endif 3235 3236 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3237 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3238 sm_pdu_received_in_wrong_state(sm_conn); 3239 break; 3240 } 3241 3242 // received confirm value 3243 reverse_128(&packet[1], setup->sm_peer_confirm); 3244 3245 // notify client to hide shown passkey 3246 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3247 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3248 } 3249 3250 // handle user cancel pairing? 3251 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3252 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3253 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3254 break; 3255 } 3256 3257 // wait for user action? 3258 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3259 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3260 break; 3261 } 3262 3263 // calculate and send local_confirm 3264 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3265 break; 3266 3267 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3268 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3269 sm_pdu_received_in_wrong_state(sm_conn); 3270 break;; 3271 } 3272 3273 // received random value 3274 reverse_128(&packet[1], setup->sm_peer_random); 3275 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3276 break; 3277 3278 case SM_PH3_RECEIVE_KEYS: 3279 switch(packet[0]){ 3280 case SM_CODE_ENCRYPTION_INFORMATION: 3281 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3282 reverse_128(&packet[1], setup->sm_peer_ltk); 3283 break; 3284 3285 case SM_CODE_MASTER_IDENTIFICATION: 3286 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3287 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3288 reverse_64(&packet[3], setup->sm_peer_rand); 3289 break; 3290 3291 case SM_CODE_IDENTITY_INFORMATION: 3292 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3293 reverse_128(&packet[1], setup->sm_peer_irk); 3294 break; 3295 3296 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3297 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3298 setup->sm_peer_addr_type = packet[1]; 3299 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3300 break; 3301 3302 case SM_CODE_SIGNING_INFORMATION: 3303 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3304 reverse_128(&packet[1], setup->sm_peer_csrk); 3305 break; 3306 default: 3307 // Unexpected PDU 3308 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3309 break; 3310 } 3311 // done with key distribution? 3312 if (sm_key_distribution_all_received(sm_conn)){ 3313 3314 sm_key_distribution_handle_all_received(sm_conn); 3315 3316 if (sm_conn->sm_role){ 3317 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3318 sm_done_for_handle(sm_conn->sm_handle); 3319 } else { 3320 if (setup->sm_use_secure_connections){ 3321 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3322 } else { 3323 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3324 } 3325 } 3326 } 3327 break; 3328 default: 3329 // Unexpected PDU 3330 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3331 break; 3332 } 3333 3334 // try to send preparared packet 3335 sm_run(); 3336 } 3337 3338 // Security Manager Client API 3339 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3340 sm_get_oob_data = get_oob_data_callback; 3341 } 3342 3343 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3344 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3345 } 3346 3347 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3348 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3349 } 3350 3351 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3352 sm_min_encryption_key_size = min_size; 3353 sm_max_encryption_key_size = max_size; 3354 } 3355 3356 void sm_set_authentication_requirements(uint8_t auth_req){ 3357 sm_auth_req = auth_req; 3358 } 3359 3360 void sm_set_io_capabilities(io_capability_t io_capability){ 3361 sm_io_capabilities = io_capability; 3362 } 3363 3364 void sm_set_request_security(int enable){ 3365 sm_slave_request_security = enable; 3366 } 3367 3368 void sm_set_er(sm_key_t er){ 3369 memcpy(sm_persistent_er, er, 16); 3370 } 3371 3372 void sm_set_ir(sm_key_t ir){ 3373 memcpy(sm_persistent_ir, ir, 16); 3374 } 3375 3376 // Testing support only 3377 void sm_test_set_irk(sm_key_t irk){ 3378 memcpy(sm_persistent_irk, irk, 16); 3379 sm_persistent_irk_ready = 1; 3380 } 3381 3382 void sm_test_use_fixed_local_csrk(void){ 3383 test_use_fixed_local_csrk = 1; 3384 } 3385 3386 void sm_init(void){ 3387 // set some (BTstack default) ER and IR 3388 int i; 3389 sm_key_t er; 3390 sm_key_t ir; 3391 for (i=0;i<16;i++){ 3392 er[i] = 0x30 + i; 3393 ir[i] = 0x90 + i; 3394 } 3395 sm_set_er(er); 3396 sm_set_ir(ir); 3397 // defaults 3398 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3399 | SM_STK_GENERATION_METHOD_OOB 3400 | SM_STK_GENERATION_METHOD_PASSKEY 3401 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3402 3403 sm_max_encryption_key_size = 16; 3404 sm_min_encryption_key_size = 7; 3405 3406 sm_cmac_state = CMAC_IDLE; 3407 dkg_state = DKG_W4_WORKING; 3408 rau_state = RAU_W4_WORKING; 3409 sm_aes128_state = SM_AES128_IDLE; 3410 sm_address_resolution_test = -1; // no private address to resolve yet 3411 sm_address_resolution_ah_calculation_active = 0; 3412 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3413 sm_address_resolution_general_queue = NULL; 3414 3415 gap_random_adress_update_period = 15 * 60 * 1000L; 3416 3417 sm_active_connection = 0; 3418 3419 test_use_fixed_local_csrk = 0; 3420 3421 // register for HCI Events from HCI 3422 hci_event_callback_registration.callback = &sm_event_packet_handler; 3423 hci_add_event_handler(&hci_event_callback_registration); 3424 3425 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3426 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3427 3428 #ifdef USE_MBEDTLS_FOR_ECDH 3429 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3430 #endif 3431 } 3432 3433 void sm_test_use_fixed_ec_keypair(void){ 3434 test_use_fixed_ec_keypair = 1; 3435 #ifdef USE_MBEDTLS_FOR_ECDH 3436 // use test keypair from spec 3437 mbedtls_ecp_keypair_init(&le_keypair); 3438 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3439 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3440 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3441 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3442 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3443 #endif 3444 } 3445 3446 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3447 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3448 if (!hci_con) return NULL; 3449 return &hci_con->sm_connection; 3450 } 3451 3452 // @returns 0 if not encrypted, 7-16 otherwise 3453 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3454 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3455 if (!sm_conn) return 0; // wrong connection 3456 if (!sm_conn->sm_connection_encrypted) return 0; 3457 return sm_conn->sm_actual_encryption_key_size; 3458 } 3459 3460 int sm_authenticated(hci_con_handle_t con_handle){ 3461 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3462 if (!sm_conn) return 0; // wrong connection 3463 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3464 return sm_conn->sm_connection_authenticated; 3465 } 3466 3467 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3468 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3469 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3470 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3471 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3472 return sm_conn->sm_connection_authorization_state; 3473 } 3474 3475 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3476 switch (sm_conn->sm_engine_state){ 3477 case SM_GENERAL_IDLE: 3478 case SM_RESPONDER_IDLE: 3479 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3480 sm_run(); 3481 break; 3482 default: 3483 break; 3484 } 3485 } 3486 3487 /** 3488 * @brief Trigger Security Request 3489 */ 3490 void sm_send_security_request(hci_con_handle_t con_handle){ 3491 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3492 if (!sm_conn) return; 3493 sm_send_security_request_for_connection(sm_conn); 3494 } 3495 3496 // request pairing 3497 void sm_request_pairing(hci_con_handle_t con_handle){ 3498 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3499 if (!sm_conn) return; // wrong connection 3500 3501 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3502 if (sm_conn->sm_role){ 3503 sm_send_security_request_for_connection(sm_conn); 3504 } else { 3505 // used as a trigger to start central/master/initiator security procedures 3506 uint16_t ediv; 3507 sm_key_t ltk; 3508 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3509 switch (sm_conn->sm_irk_lookup_state){ 3510 case IRK_LOOKUP_FAILED: 3511 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3512 break; 3513 case IRK_LOOKUP_SUCCEEDED: 3514 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3515 if (!sm_is_null_key(ltk) || ediv){ 3516 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3517 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3518 } else { 3519 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3520 } 3521 break; 3522 default: 3523 sm_conn->sm_bonding_requested = 1; 3524 break; 3525 } 3526 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3527 sm_conn->sm_bonding_requested = 1; 3528 } 3529 } 3530 sm_run(); 3531 } 3532 3533 // called by client app on authorization request 3534 void sm_authorization_decline(hci_con_handle_t con_handle){ 3535 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3536 if (!sm_conn) return; // wrong connection 3537 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3538 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3539 } 3540 3541 void sm_authorization_grant(hci_con_handle_t con_handle){ 3542 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3543 if (!sm_conn) return; // wrong connection 3544 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3545 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3546 } 3547 3548 // GAP Bonding API 3549 3550 void sm_bonding_decline(hci_con_handle_t con_handle){ 3551 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3552 if (!sm_conn) return; // wrong connection 3553 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3554 3555 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3556 switch (setup->sm_stk_generation_method){ 3557 case PK_RESP_INPUT: 3558 case PK_INIT_INPUT: 3559 case OK_BOTH_INPUT: 3560 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3561 break; 3562 case NK_BOTH_INPUT: 3563 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3564 break; 3565 case JUST_WORKS: 3566 case OOB: 3567 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3568 break; 3569 } 3570 } 3571 sm_run(); 3572 } 3573 3574 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3575 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3576 if (!sm_conn) return; // wrong connection 3577 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3578 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3579 if (setup->sm_use_secure_connections){ 3580 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3581 } else { 3582 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3583 } 3584 } 3585 3586 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3587 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3588 sm_sc_prepare_dhkey_check(sm_conn); 3589 } 3590 #endif 3591 3592 sm_run(); 3593 } 3594 3595 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3596 // for now, it's the same 3597 sm_just_works_confirm(con_handle); 3598 } 3599 3600 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3601 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3602 if (!sm_conn) return; // wrong connection 3603 sm_reset_tk(); 3604 big_endian_store_32(setup->sm_tk, 12, passkey); 3605 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3606 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3607 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3608 } 3609 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3610 memcpy(setup->sm_ra, setup->sm_tk, 16); 3611 memcpy(setup->sm_rb, setup->sm_tk, 16); 3612 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3613 sm_sc_start_calculating_local_confirm(sm_conn); 3614 } 3615 #endif 3616 sm_run(); 3617 } 3618 3619 /** 3620 * @brief Identify device in LE Device DB 3621 * @param handle 3622 * @returns index from le_device_db or -1 if not found/identified 3623 */ 3624 int sm_le_device_index(hci_con_handle_t con_handle ){ 3625 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3626 if (!sm_conn) return -1; 3627 return sm_conn->sm_le_db_index; 3628 } 3629 3630 // GAP LE API 3631 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3632 gap_random_address_update_stop(); 3633 gap_random_adress_type = random_address_type; 3634 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3635 gap_random_address_update_start(); 3636 gap_random_address_trigger(); 3637 } 3638 3639 gap_random_address_type_t gap_random_address_get_mode(void){ 3640 return gap_random_adress_type; 3641 } 3642 3643 void gap_random_address_set_update_period(int period_ms){ 3644 gap_random_adress_update_period = period_ms; 3645 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3646 gap_random_address_update_stop(); 3647 gap_random_address_update_start(); 3648 } 3649 3650 void gap_random_address_set(bd_addr_t addr){ 3651 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3652 memcpy(sm_random_address, addr, 6); 3653 rau_state = RAU_SET_ADDRESS; 3654 sm_run(); 3655 } 3656 3657 /* 3658 * @brief Set Advertisement Paramters 3659 * @param adv_int_min 3660 * @param adv_int_max 3661 * @param adv_type 3662 * @param direct_address_type 3663 * @param direct_address 3664 * @param channel_map 3665 * @param filter_policy 3666 * 3667 * @note own_address_type is used from gap_random_address_set_mode 3668 */ 3669 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3670 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3671 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3672 direct_address_typ, direct_address, channel_map, filter_policy); 3673 } 3674 3675