1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 55 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 56 #else 57 #define USE_MBEDTLS_FOR_ECDH 58 #endif 59 #endif 60 61 62 // Software ECDH implementation provided by mbedtls 63 #ifdef USE_MBEDTLS_FOR_ECDH 64 #include "mbedtls/config.h" 65 #include "mbedtls/platform.h" 66 #include "mbedtls/ecp.h" 67 #ifndef HAVE_MALLOC 68 #include "mbedtls/memory_buffer_alloc.h" 69 #endif 70 #endif 71 72 #if 0 73 static size_t mbed_memory_allocated_current = 0; 74 static size_t mbed_memory_allocated_max = 0; 75 static size_t mbed_memory_smallest_buffer = 0xfffffff; 76 static int mbed_memory_num_allocations = 0; 77 void * btstack_calloc(size_t count, size_t size){ 78 size_t total = count * size; 79 mbed_memory_allocated_current += total; 80 mbed_memory_allocated_max = btstack_max(mbed_memory_allocated_max, mbed_memory_allocated_current); 81 mbed_memory_smallest_buffer = btstack_min(mbed_memory_smallest_buffer, total); 82 mbed_memory_num_allocations++; 83 void * result = calloc(4 + total, 1); 84 *(uint32_t*) result = total; 85 printf("btstack_calloc(%zu, %zu) -> res %p. Total %lu, Max %lu, Smallest %lu, Count %u\n", count, size, result, mbed_memory_allocated_current, mbed_memory_allocated_max, mbed_memory_smallest_buffer, mbed_memory_num_allocations); 86 return ((uint8_t *) result) + 4; 87 } 88 89 void btstack_free(void * data){ 90 void * orig = ((uint8_t *) data) - 4; 91 size_t total = *(uint32_t *)orig; 92 mbed_memory_allocated_current -= total; 93 mbed_memory_num_allocations--; 94 printf("btstack_free(%p) - %zu bytes. Total %lu, Count %u\n", data, total, mbed_memory_allocated_current, mbed_memory_num_allocations); 95 free(orig); 96 } 97 #endif 98 99 // 100 // SM internal types and globals 101 // 102 103 typedef enum { 104 DKG_W4_WORKING, 105 DKG_CALC_IRK, 106 DKG_W4_IRK, 107 DKG_CALC_DHK, 108 DKG_W4_DHK, 109 DKG_READY 110 } derived_key_generation_t; 111 112 typedef enum { 113 RAU_W4_WORKING, 114 RAU_IDLE, 115 RAU_GET_RANDOM, 116 RAU_W4_RANDOM, 117 RAU_GET_ENC, 118 RAU_W4_ENC, 119 RAU_SET_ADDRESS, 120 } random_address_update_t; 121 122 typedef enum { 123 CMAC_IDLE, 124 CMAC_CALC_SUBKEYS, 125 CMAC_W4_SUBKEYS, 126 CMAC_CALC_MI, 127 CMAC_W4_MI, 128 CMAC_CALC_MLAST, 129 CMAC_W4_MLAST 130 } cmac_state_t; 131 132 typedef enum { 133 JUST_WORKS, 134 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 135 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 136 OK_BOTH_INPUT, // Only input on both, both input PK 137 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 138 OOB // OOB available on both sides 139 } stk_generation_method_t; 140 141 typedef enum { 142 SM_USER_RESPONSE_IDLE, 143 SM_USER_RESPONSE_PENDING, 144 SM_USER_RESPONSE_CONFIRM, 145 SM_USER_RESPONSE_PASSKEY, 146 SM_USER_RESPONSE_DECLINE 147 } sm_user_response_t; 148 149 typedef enum { 150 SM_AES128_IDLE, 151 SM_AES128_ACTIVE 152 } sm_aes128_state_t; 153 154 typedef enum { 155 ADDRESS_RESOLUTION_IDLE, 156 ADDRESS_RESOLUTION_GENERAL, 157 ADDRESS_RESOLUTION_FOR_CONNECTION, 158 } address_resolution_mode_t; 159 160 typedef enum { 161 ADDRESS_RESOLUTION_SUCEEDED, 162 ADDRESS_RESOLUTION_FAILED, 163 } address_resolution_event_t; 164 165 typedef enum { 166 EC_KEY_GENERATION_IDLE, 167 EC_KEY_GENERATION_ACTIVE, 168 EC_KEY_GENERATION_DONE, 169 } ec_key_generation_state_t; 170 171 typedef enum { 172 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 173 } sm_state_var_t; 174 175 // 176 // GLOBAL DATA 177 // 178 179 static uint8_t test_use_fixed_local_csrk; 180 static uint8_t test_use_fixed_ec_keypair; 181 182 // configuration 183 static uint8_t sm_accepted_stk_generation_methods; 184 static uint8_t sm_max_encryption_key_size; 185 static uint8_t sm_min_encryption_key_size; 186 static uint8_t sm_auth_req = 0; 187 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 188 static uint8_t sm_slave_request_security; 189 190 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 191 static sm_key_t sm_persistent_er; 192 static sm_key_t sm_persistent_ir; 193 194 // derived from sm_persistent_ir 195 static sm_key_t sm_persistent_dhk; 196 static sm_key_t sm_persistent_irk; 197 static uint8_t sm_persistent_irk_ready = 0; // used for testing 198 static derived_key_generation_t dkg_state; 199 200 // derived from sm_persistent_er 201 // .. 202 203 // random address update 204 static random_address_update_t rau_state; 205 static bd_addr_t sm_random_address; 206 207 // CMAC Calculation: General 208 static cmac_state_t sm_cmac_state; 209 static uint16_t sm_cmac_message_len; 210 static sm_key_t sm_cmac_k; 211 static sm_key_t sm_cmac_x; 212 static sm_key_t sm_cmac_m_last; 213 static uint8_t sm_cmac_block_current; 214 static uint8_t sm_cmac_block_count; 215 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 216 static void (*sm_cmac_done_handler)(uint8_t * hash); 217 218 // CMAC for ATT Signed Writes 219 static uint8_t sm_cmac_header[3]; 220 static const uint8_t * sm_cmac_message; 221 static uint8_t sm_cmac_sign_counter[4]; 222 223 // CMAC for Secure Connection functions 224 #ifdef ENABLE_LE_SECURE_CONNECTIONS 225 static sm_connection_t * sm_cmac_connection; 226 static uint8_t sm_cmac_sc_buffer[80]; 227 #endif 228 229 // resolvable private address lookup / CSRK calculation 230 static int sm_address_resolution_test; 231 static int sm_address_resolution_ah_calculation_active; 232 static uint8_t sm_address_resolution_addr_type; 233 static bd_addr_t sm_address_resolution_address; 234 static void * sm_address_resolution_context; 235 static address_resolution_mode_t sm_address_resolution_mode; 236 static btstack_linked_list_t sm_address_resolution_general_queue; 237 238 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 239 static sm_aes128_state_t sm_aes128_state; 240 static void * sm_aes128_context; 241 242 // random engine. store context (ususally sm_connection_t) 243 static void * sm_random_context; 244 245 // to receive hci events 246 static btstack_packet_callback_registration_t hci_event_callback_registration; 247 248 /* to dispatch sm event */ 249 static btstack_linked_list_t sm_event_handlers; 250 251 // Software ECDH implementation provided by mbedtls 252 #ifdef USE_MBEDTLS_FOR_ECDH 253 static mbedtls_ecp_keypair le_keypair; 254 static ec_key_generation_state_t ec_key_generation_state; 255 #ifndef HAVE_MALLOC 256 static uint8_t mbedtls_memory_buffer[5000]; // experimental value on 64-bit system 257 #endif 258 #endif 259 260 // 261 // Volume 3, Part H, Chapter 24 262 // "Security shall be initiated by the Security Manager in the device in the master role. 263 // The device in the slave role shall be the responding device." 264 // -> master := initiator, slave := responder 265 // 266 267 // data needed for security setup 268 typedef struct sm_setup_context { 269 270 btstack_timer_source_t sm_timeout; 271 272 // used in all phases 273 uint8_t sm_pairing_failed_reason; 274 275 // user response, (Phase 1 and/or 2) 276 uint8_t sm_user_response; 277 278 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 279 int sm_key_distribution_send_set; 280 int sm_key_distribution_received_set; 281 282 // Phase 2 (Pairing over SMP) 283 stk_generation_method_t sm_stk_generation_method; 284 sm_key_t sm_tk; 285 uint8_t sm_use_secure_connections; 286 287 sm_key_t sm_c1_t3_value; // c1 calculation 288 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 289 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 290 sm_key_t sm_local_random; 291 sm_key_t sm_local_confirm; 292 sm_key_t sm_peer_random; 293 sm_key_t sm_peer_confirm; 294 uint8_t sm_m_addr_type; // address and type can be removed 295 uint8_t sm_s_addr_type; // '' 296 bd_addr_t sm_m_address; // '' 297 bd_addr_t sm_s_address; // '' 298 sm_key_t sm_ltk; 299 300 #ifdef ENABLE_LE_SECURE_CONNECTIONS 301 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 302 uint8_t sm_peer_qy[32]; // '' 303 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 304 sm_key_t sm_local_nonce; // might be combined with sm_local_random 305 sm_key_t sm_peer_dhkey_check; 306 sm_key_t sm_local_dhkey_check; 307 sm_key_t sm_ra; 308 sm_key_t sm_rb; 309 sm_key_t sm_t; // used for f5 310 sm_key_t sm_mackey; 311 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 312 uint8_t sm_state_vars; 313 #endif 314 315 // Phase 3 316 317 // key distribution, we generate 318 uint16_t sm_local_y; 319 uint16_t sm_local_div; 320 uint16_t sm_local_ediv; 321 uint8_t sm_local_rand[8]; 322 sm_key_t sm_local_ltk; 323 sm_key_t sm_local_csrk; 324 sm_key_t sm_local_irk; 325 // sm_local_address/addr_type not needed 326 327 // key distribution, received from peer 328 uint16_t sm_peer_y; 329 uint16_t sm_peer_div; 330 uint16_t sm_peer_ediv; 331 uint8_t sm_peer_rand[8]; 332 sm_key_t sm_peer_ltk; 333 sm_key_t sm_peer_irk; 334 sm_key_t sm_peer_csrk; 335 uint8_t sm_peer_addr_type; 336 bd_addr_t sm_peer_address; 337 338 } sm_setup_context_t; 339 340 // 341 static sm_setup_context_t the_setup; 342 static sm_setup_context_t * setup = &the_setup; 343 344 // active connection - the one for which the_setup is used for 345 static uint16_t sm_active_connection = 0; 346 347 // @returns 1 if oob data is available 348 // stores oob data in provided 16 byte buffer if not null 349 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 350 351 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 352 static btstack_packet_handler_t sm_client_packet_handler = NULL; 353 354 // horizontal: initiator capabilities 355 // vertial: responder capabilities 356 static const stk_generation_method_t stk_generation_method [5] [5] = { 357 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 358 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 359 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 360 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 361 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 362 }; 363 364 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 365 #ifdef ENABLE_LE_SECURE_CONNECTIONS 366 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 367 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 368 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 369 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 370 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 371 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 372 }; 373 #endif 374 375 static void sm_run(void); 376 static void sm_done_for_handle(hci_con_handle_t con_handle); 377 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 378 static inline int sm_calc_actual_encryption_key_size(int other); 379 static int sm_validate_stk_generation_method(void); 380 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 381 382 static void log_info_hex16(const char * name, uint16_t value){ 383 log_info("%-6s 0x%04x", name, value); 384 } 385 386 // @returns 1 if all bytes are 0 387 static int sm_is_null(uint8_t * data, int size){ 388 int i; 389 for (i=0; i < size ; i++){ 390 if (data[i]) return 0; 391 } 392 return 1; 393 } 394 395 static int sm_is_null_random(uint8_t random[8]){ 396 return sm_is_null(random, 8); 397 } 398 399 static int sm_is_null_key(uint8_t * key){ 400 return sm_is_null(key, 16); 401 } 402 403 // Key utils 404 static void sm_reset_tk(void){ 405 int i; 406 for (i=0;i<16;i++){ 407 setup->sm_tk[i] = 0; 408 } 409 } 410 411 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 412 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 413 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 414 int i; 415 for (i = max_encryption_size ; i < 16 ; i++){ 416 key[15-i] = 0; 417 } 418 } 419 420 // SMP Timeout implementation 421 422 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 423 // the Security Manager Timer shall be reset and started. 424 // 425 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 426 // 427 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 428 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 429 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 430 // established. 431 432 static void sm_timeout_handler(btstack_timer_source_t * timer){ 433 log_info("SM timeout"); 434 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 435 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 436 sm_done_for_handle(sm_conn->sm_handle); 437 438 // trigger handling of next ready connection 439 sm_run(); 440 } 441 static void sm_timeout_start(sm_connection_t * sm_conn){ 442 btstack_run_loop_remove_timer(&setup->sm_timeout); 443 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 444 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 445 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 446 btstack_run_loop_add_timer(&setup->sm_timeout); 447 } 448 static void sm_timeout_stop(void){ 449 btstack_run_loop_remove_timer(&setup->sm_timeout); 450 } 451 static void sm_timeout_reset(sm_connection_t * sm_conn){ 452 sm_timeout_stop(); 453 sm_timeout_start(sm_conn); 454 } 455 456 // end of sm timeout 457 458 // GAP Random Address updates 459 static gap_random_address_type_t gap_random_adress_type; 460 static btstack_timer_source_t gap_random_address_update_timer; 461 static uint32_t gap_random_adress_update_period; 462 463 static void gap_random_address_trigger(void){ 464 if (rau_state != RAU_IDLE) return; 465 log_info("gap_random_address_trigger"); 466 rau_state = RAU_GET_RANDOM; 467 sm_run(); 468 } 469 470 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 471 log_info("GAP Random Address Update due"); 472 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 473 btstack_run_loop_add_timer(&gap_random_address_update_timer); 474 gap_random_address_trigger(); 475 } 476 477 static void gap_random_address_update_start(void){ 478 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 479 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 480 btstack_run_loop_add_timer(&gap_random_address_update_timer); 481 } 482 483 static void gap_random_address_update_stop(void){ 484 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 485 } 486 487 488 static void sm_random_start(void * context){ 489 sm_random_context = context; 490 hci_send_cmd(&hci_le_rand); 491 } 492 493 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 494 // context is made availabe to aes128 result handler by this 495 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 496 sm_aes128_state = SM_AES128_ACTIVE; 497 sm_key_t key_flipped, plaintext_flipped; 498 reverse_128(key, key_flipped); 499 reverse_128(plaintext, plaintext_flipped); 500 sm_aes128_context = context; 501 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 502 } 503 504 // ah(k,r) helper 505 // r = padding || r 506 // r - 24 bit value 507 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 508 // r'= padding || r 509 memset(r_prime, 0, 16); 510 memcpy(&r_prime[13], r, 3); 511 } 512 513 // d1 helper 514 // d' = padding || r || d 515 // d,r - 16 bit values 516 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 517 // d'= padding || r || d 518 memset(d1_prime, 0, 16); 519 big_endian_store_16(d1_prime, 12, r); 520 big_endian_store_16(d1_prime, 14, d); 521 } 522 523 // dm helper 524 // r’ = padding || r 525 // r - 64 bit value 526 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 527 memset(r_prime, 0, 16); 528 memcpy(&r_prime[8], r, 8); 529 } 530 531 // calculate arguments for first AES128 operation in C1 function 532 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){ 533 534 // p1 = pres || preq || rat’ || iat’ 535 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 536 // cant octet of pres becomes the most significant octet of p1. 537 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 538 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 539 // p1 is 0x05000800000302070710000001010001." 540 541 sm_key_t p1; 542 reverse_56(pres, &p1[0]); 543 reverse_56(preq, &p1[7]); 544 p1[14] = rat; 545 p1[15] = iat; 546 log_info_key("p1", p1); 547 log_info_key("r", r); 548 549 // t1 = r xor p1 550 int i; 551 for (i=0;i<16;i++){ 552 t1[i] = r[i] ^ p1[i]; 553 } 554 log_info_key("t1", t1); 555 } 556 557 // calculate arguments for second AES128 operation in C1 function 558 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 559 // p2 = padding || ia || ra 560 // "The least significant octet of ra becomes the least significant octet of p2 and 561 // the most significant octet of padding becomes the most significant octet of p2. 562 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 563 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 564 565 sm_key_t p2; 566 memset(p2, 0, 16); 567 memcpy(&p2[4], ia, 6); 568 memcpy(&p2[10], ra, 6); 569 log_info_key("p2", p2); 570 571 // c1 = e(k, t2_xor_p2) 572 int i; 573 for (i=0;i<16;i++){ 574 t3[i] = t2[i] ^ p2[i]; 575 } 576 log_info_key("t3", t3); 577 } 578 579 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 580 log_info_key("r1", r1); 581 log_info_key("r2", r2); 582 memcpy(&r_prime[8], &r2[8], 8); 583 memcpy(&r_prime[0], &r1[8], 8); 584 } 585 586 #ifdef ENABLE_LE_SECURE_CONNECTIONS 587 // Software implementations of crypto toolbox for LE Secure Connection 588 // TODO: replace with code to use AES Engine of HCI Controller 589 typedef uint8_t sm_key24_t[3]; 590 typedef uint8_t sm_key56_t[7]; 591 typedef uint8_t sm_key256_t[32]; 592 593 #if 0 594 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 595 uint32_t rk[RKLENGTH(KEYBITS)]; 596 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 597 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 598 } 599 600 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 601 memcpy(k1, k0, 16); 602 sm_shift_left_by_one_bit_inplace(16, k1); 603 if (k0[0] & 0x80){ 604 k1[15] ^= 0x87; 605 } 606 memcpy(k2, k1, 16); 607 sm_shift_left_by_one_bit_inplace(16, k2); 608 if (k1[0] & 0x80){ 609 k2[15] ^= 0x87; 610 } 611 } 612 613 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 614 sm_key_t k0, k1, k2, zero; 615 memset(zero, 0, 16); 616 617 aes128_calc_cyphertext(key, zero, k0); 618 calc_subkeys(k0, k1, k2); 619 620 int cmac_block_count = (cmac_message_len + 15) / 16; 621 622 // step 3: .. 623 if (cmac_block_count==0){ 624 cmac_block_count = 1; 625 } 626 627 // step 4: set m_last 628 sm_key_t cmac_m_last; 629 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 630 int i; 631 if (sm_cmac_last_block_complete){ 632 for (i=0;i<16;i++){ 633 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 634 } 635 } else { 636 int valid_octets_in_last_block = cmac_message_len & 0x0f; 637 for (i=0;i<16;i++){ 638 if (i < valid_octets_in_last_block){ 639 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 640 continue; 641 } 642 if (i == valid_octets_in_last_block){ 643 cmac_m_last[i] = 0x80 ^ k2[i]; 644 continue; 645 } 646 cmac_m_last[i] = k2[i]; 647 } 648 } 649 650 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 651 // LOG_KEY(cmac_m_last); 652 653 // Step 5 654 sm_key_t cmac_x; 655 memset(cmac_x, 0, 16); 656 657 // Step 6 658 sm_key_t sm_cmac_y; 659 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 660 for (i=0;i<16;i++){ 661 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 662 } 663 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 664 } 665 for (i=0;i<16;i++){ 666 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 667 } 668 669 // Step 7 670 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 671 } 672 #endif 673 674 #if 0 675 // 676 // Link Key Conversion Function h6 677 // 678 // h6(W, keyID) = AES-CMACW(keyID) 679 // - W is 128 bits 680 // - keyID is 32 bits 681 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 682 uint8_t key_id_buffer[4]; 683 big_endian_store_32(key_id_buffer, 0, key_id); 684 aes_cmac(res, w, key_id_buffer, 4); 685 } 686 #endif 687 #endif 688 689 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){ 690 event[0] = type; 691 event[1] = event_size - 2; 692 little_endian_store_16(event, 2, con_handle); 693 event[4] = addr_type; 694 reverse_bd_addr(address, &event[5]); 695 } 696 697 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 698 if (sm_client_packet_handler) { 699 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 700 } 701 // dispatch to all event handlers 702 btstack_linked_list_iterator_t it; 703 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 704 while (btstack_linked_list_iterator_has_next(&it)){ 705 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 706 entry->callback(packet_type, 0, packet, size); 707 } 708 } 709 710 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 711 uint8_t event[11]; 712 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 713 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 714 } 715 716 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){ 717 uint8_t event[15]; 718 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 719 little_endian_store_32(event, 11, passkey); 720 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 721 } 722 723 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){ 724 uint8_t event[13]; 725 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 726 little_endian_store_16(event, 11, index); 727 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 728 } 729 730 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){ 731 732 uint8_t event[18]; 733 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 734 event[11] = result; 735 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 736 } 737 738 // decide on stk generation based on 739 // - pairing request 740 // - io capabilities 741 // - OOB data availability 742 static void sm_setup_tk(void){ 743 744 // default: just works 745 setup->sm_stk_generation_method = JUST_WORKS; 746 747 #ifdef ENABLE_LE_SECURE_CONNECTIONS 748 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 749 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 750 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 751 memset(setup->sm_ra, 0, 16); 752 memset(setup->sm_rb, 0, 16); 753 #else 754 setup->sm_use_secure_connections = 0; 755 #endif 756 757 // If both devices have not set the MITM option in the Authentication Requirements 758 // Flags, then the IO capabilities shall be ignored and the Just Works association 759 // model shall be used. 760 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 761 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 762 log_info("SM: MITM not required by both -> JUST WORKS"); 763 return; 764 } 765 766 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 767 768 // If both devices have out of band authentication data, then the Authentication 769 // Requirements Flags shall be ignored when selecting the pairing method and the 770 // Out of Band pairing method shall be used. 771 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 772 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 773 log_info("SM: have OOB data"); 774 log_info_key("OOB", setup->sm_tk); 775 setup->sm_stk_generation_method = OOB; 776 return; 777 } 778 779 // Reset TK as it has been setup in sm_init_setup 780 sm_reset_tk(); 781 782 // Also use just works if unknown io capabilites 783 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)){ 784 return; 785 } 786 787 // Otherwise the IO capabilities of the devices shall be used to determine the 788 // pairing method as defined in Table 2.4. 789 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 790 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 791 792 #ifdef ENABLE_LE_SECURE_CONNECTIONS 793 // table not define by default 794 if (setup->sm_use_secure_connections){ 795 generation_method = stk_generation_method_with_secure_connection; 796 } 797 #endif 798 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)]; 799 800 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 801 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); 802 } 803 804 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 805 int flags = 0; 806 if (key_set & SM_KEYDIST_ENC_KEY){ 807 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 808 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 809 } 810 if (key_set & SM_KEYDIST_ID_KEY){ 811 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 812 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 813 } 814 if (key_set & SM_KEYDIST_SIGN){ 815 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 816 } 817 return flags; 818 } 819 820 static void sm_setup_key_distribution(uint8_t key_set){ 821 setup->sm_key_distribution_received_set = 0; 822 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 823 } 824 825 // CSRK Key Lookup 826 827 828 static int sm_address_resolution_idle(void){ 829 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 830 } 831 832 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){ 833 memcpy(sm_address_resolution_address, addr, 6); 834 sm_address_resolution_addr_type = addr_type; 835 sm_address_resolution_test = 0; 836 sm_address_resolution_mode = mode; 837 sm_address_resolution_context = context; 838 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 839 } 840 841 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 842 // check if already in list 843 btstack_linked_list_iterator_t it; 844 sm_lookup_entry_t * entry; 845 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 846 while(btstack_linked_list_iterator_has_next(&it)){ 847 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 848 if (entry->address_type != address_type) continue; 849 if (memcmp(entry->address, address, 6)) continue; 850 // already in list 851 return BTSTACK_BUSY; 852 } 853 entry = btstack_memory_sm_lookup_entry_get(); 854 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 855 entry->address_type = (bd_addr_type_t) address_type; 856 memcpy(entry->address, address, 6); 857 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 858 sm_run(); 859 return 0; 860 } 861 862 // CMAC Implementation using AES128 engine 863 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 864 int i; 865 int carry = 0; 866 for (i=len-1; i >= 0 ; i--){ 867 int new_carry = data[i] >> 7; 868 data[i] = data[i] << 1 | carry; 869 carry = new_carry; 870 } 871 } 872 873 // 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 874 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 875 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 876 } 877 static inline void dkg_next_state(void){ 878 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 879 } 880 static inline void rau_next_state(void){ 881 rau_state = (random_address_update_t) (((int)rau_state) + 1); 882 } 883 884 // CMAC calculation using AES Engine 885 886 static inline void sm_cmac_next_state(void){ 887 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 888 } 889 890 static int sm_cmac_last_block_complete(void){ 891 if (sm_cmac_message_len == 0) return 0; 892 return (sm_cmac_message_len & 0x0f) == 0; 893 } 894 895 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 896 if (offset >= sm_cmac_message_len) { 897 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 898 return 0; 899 } 900 901 offset = sm_cmac_message_len - 1 - offset; 902 903 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 904 if (offset < 3){ 905 return sm_cmac_header[offset]; 906 } 907 int actual_message_len_incl_header = sm_cmac_message_len - 4; 908 if (offset < actual_message_len_incl_header){ 909 return sm_cmac_message[offset - 3]; 910 } 911 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 912 } 913 914 // generic cmac calculation 915 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])){ 916 // Generalized CMAC 917 memcpy(sm_cmac_k, key, 16); 918 memset(sm_cmac_x, 0, 16); 919 sm_cmac_block_current = 0; 920 sm_cmac_message_len = message_len; 921 sm_cmac_done_handler = done_callback; 922 sm_cmac_get_byte = get_byte_callback; 923 924 // step 2: n := ceil(len/const_Bsize); 925 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 926 927 // step 3: .. 928 if (sm_cmac_block_count==0){ 929 sm_cmac_block_count = 1; 930 } 931 log_info("sm_cmac_connection %p", sm_cmac_connection); 932 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 933 934 // first, we need to compute l for k1, k2, and m_last 935 sm_cmac_state = CMAC_CALC_SUBKEYS; 936 937 // let's go 938 sm_run(); 939 } 940 941 // cmac for ATT Message signing 942 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)){ 943 // ATT Message Signing 944 sm_cmac_header[0] = opcode; 945 little_endian_store_16(sm_cmac_header, 1, con_handle); 946 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 947 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 948 sm_cmac_message = message; 949 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 950 } 951 952 int sm_cmac_ready(void){ 953 return sm_cmac_state == CMAC_IDLE; 954 } 955 956 static void sm_cmac_handle_aes_engine_ready(void){ 957 switch (sm_cmac_state){ 958 case CMAC_CALC_SUBKEYS: { 959 sm_key_t const_zero; 960 memset(const_zero, 0, 16); 961 sm_cmac_next_state(); 962 sm_aes128_start(sm_cmac_k, const_zero, NULL); 963 break; 964 } 965 case CMAC_CALC_MI: { 966 int j; 967 sm_key_t y; 968 for (j=0;j<16;j++){ 969 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 970 } 971 sm_cmac_block_current++; 972 sm_cmac_next_state(); 973 sm_aes128_start(sm_cmac_k, y, NULL); 974 break; 975 } 976 case CMAC_CALC_MLAST: { 977 int i; 978 sm_key_t y; 979 for (i=0;i<16;i++){ 980 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 981 } 982 log_info_key("Y", y); 983 sm_cmac_block_current++; 984 sm_cmac_next_state(); 985 sm_aes128_start(sm_cmac_k, y, NULL); 986 break; 987 } 988 default: 989 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 990 break; 991 } 992 } 993 994 static void sm_cmac_handle_encryption_result(sm_key_t data){ 995 switch (sm_cmac_state){ 996 case CMAC_W4_SUBKEYS: { 997 sm_key_t k1; 998 memcpy(k1, data, 16); 999 sm_shift_left_by_one_bit_inplace(16, k1); 1000 if (data[0] & 0x80){ 1001 k1[15] ^= 0x87; 1002 } 1003 sm_key_t k2; 1004 memcpy(k2, k1, 16); 1005 sm_shift_left_by_one_bit_inplace(16, k2); 1006 if (k1[0] & 0x80){ 1007 k2[15] ^= 0x87; 1008 } 1009 1010 log_info_key("k", sm_cmac_k); 1011 log_info_key("k1", k1); 1012 log_info_key("k2", k2); 1013 1014 // step 4: set m_last 1015 int i; 1016 if (sm_cmac_last_block_complete()){ 1017 for (i=0;i<16;i++){ 1018 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 1019 } 1020 } else { 1021 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 1022 for (i=0;i<16;i++){ 1023 if (i < valid_octets_in_last_block){ 1024 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1025 continue; 1026 } 1027 if (i == valid_octets_in_last_block){ 1028 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1029 continue; 1030 } 1031 sm_cmac_m_last[i] = k2[i]; 1032 } 1033 } 1034 1035 // next 1036 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1037 break; 1038 } 1039 case CMAC_W4_MI: 1040 memcpy(sm_cmac_x, data, 16); 1041 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1042 break; 1043 case CMAC_W4_MLAST: 1044 // done 1045 log_info("Setting CMAC Engine to IDLE"); 1046 sm_cmac_state = CMAC_IDLE; 1047 log_info_key("CMAC", data); 1048 sm_cmac_done_handler(data); 1049 break; 1050 default: 1051 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1052 break; 1053 } 1054 } 1055 1056 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1057 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1058 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1059 switch (setup->sm_stk_generation_method){ 1060 case PK_RESP_INPUT: 1061 if (sm_conn->sm_role){ 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1064 } else { 1065 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)); 1066 } 1067 break; 1068 case PK_INIT_INPUT: 1069 if (sm_conn->sm_role){ 1070 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)); 1071 } else { 1072 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1073 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1074 } 1075 break; 1076 case OK_BOTH_INPUT: 1077 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1078 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1079 break; 1080 case NK_BOTH_INPUT: 1081 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1082 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)); 1083 break; 1084 case JUST_WORKS: 1085 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1086 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1087 break; 1088 case OOB: 1089 // client already provided OOB data, let's skip notification. 1090 break; 1091 } 1092 } 1093 1094 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1095 int recv_flags; 1096 if (sm_conn->sm_role){ 1097 // slave / responder 1098 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1099 } else { 1100 // master / initiator 1101 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1102 } 1103 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1104 return recv_flags == setup->sm_key_distribution_received_set; 1105 } 1106 1107 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1108 if (sm_active_connection == con_handle){ 1109 sm_timeout_stop(); 1110 sm_active_connection = 0; 1111 log_info("sm: connection 0x%x released setup context", con_handle); 1112 } 1113 } 1114 1115 static int sm_key_distribution_flags_for_auth_req(void){ 1116 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1117 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1118 // encryption information only if bonding requested 1119 flags |= SM_KEYDIST_ENC_KEY; 1120 } 1121 return flags; 1122 } 1123 1124 static void sm_init_setup(sm_connection_t * sm_conn){ 1125 1126 // fill in sm setup 1127 setup->sm_state_vars = 0; 1128 sm_reset_tk(); 1129 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1130 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1131 1132 // query client for OOB data 1133 int have_oob_data = 0; 1134 if (sm_get_oob_data) { 1135 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1136 } 1137 1138 sm_pairing_packet_t * local_packet; 1139 if (sm_conn->sm_role){ 1140 // slave 1141 local_packet = &setup->sm_s_pres; 1142 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1143 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1144 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1145 } else { 1146 // master 1147 local_packet = &setup->sm_m_preq; 1148 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1149 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1150 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1151 1152 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1153 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1154 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1155 } 1156 1157 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1158 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1159 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1160 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1161 } 1162 1163 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1164 1165 sm_pairing_packet_t * remote_packet; 1166 int remote_key_request; 1167 if (sm_conn->sm_role){ 1168 // slave / responder 1169 remote_packet = &setup->sm_m_preq; 1170 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1171 } else { 1172 // master / initiator 1173 remote_packet = &setup->sm_s_pres; 1174 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1175 } 1176 1177 // check key size 1178 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1179 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1180 1181 // decide on STK generation method 1182 sm_setup_tk(); 1183 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1184 1185 // check if STK generation method is acceptable by client 1186 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1187 1188 // identical to responder 1189 sm_setup_key_distribution(remote_key_request); 1190 1191 // JUST WORKS doens't provide authentication 1192 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1193 1194 return 0; 1195 } 1196 1197 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1198 1199 // cache and reset context 1200 int matched_device_id = sm_address_resolution_test; 1201 address_resolution_mode_t mode = sm_address_resolution_mode; 1202 void * context = sm_address_resolution_context; 1203 1204 // reset context 1205 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1206 sm_address_resolution_context = NULL; 1207 sm_address_resolution_test = -1; 1208 hci_con_handle_t con_handle = 0; 1209 1210 sm_connection_t * sm_connection; 1211 uint16_t ediv; 1212 switch (mode){ 1213 case ADDRESS_RESOLUTION_GENERAL: 1214 break; 1215 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1216 sm_connection = (sm_connection_t *) context; 1217 con_handle = sm_connection->sm_handle; 1218 switch (event){ 1219 case ADDRESS_RESOLUTION_SUCEEDED: 1220 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1221 sm_connection->sm_le_db_index = matched_device_id; 1222 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1223 if (sm_connection->sm_role) break; 1224 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1225 sm_connection->sm_security_request_received = 0; 1226 sm_connection->sm_bonding_requested = 0; 1227 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1228 if (ediv){ 1229 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1230 } else { 1231 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1232 } 1233 break; 1234 case ADDRESS_RESOLUTION_FAILED: 1235 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1236 if (sm_connection->sm_role) break; 1237 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1238 sm_connection->sm_security_request_received = 0; 1239 sm_connection->sm_bonding_requested = 0; 1240 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1241 break; 1242 } 1243 break; 1244 default: 1245 break; 1246 } 1247 1248 switch (event){ 1249 case ADDRESS_RESOLUTION_SUCEEDED: 1250 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1251 break; 1252 case ADDRESS_RESOLUTION_FAILED: 1253 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1254 break; 1255 } 1256 } 1257 1258 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1259 1260 int le_db_index = -1; 1261 1262 // lookup device based on IRK 1263 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1264 int i; 1265 for (i=0; i < le_device_db_count(); i++){ 1266 sm_key_t irk; 1267 bd_addr_t address; 1268 int address_type; 1269 le_device_db_info(i, &address_type, address, irk); 1270 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1271 log_info("sm: device found for IRK, updating"); 1272 le_db_index = i; 1273 break; 1274 } 1275 } 1276 } 1277 1278 // if not found, lookup via public address if possible 1279 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1280 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1281 int i; 1282 for (i=0; i < le_device_db_count(); i++){ 1283 bd_addr_t address; 1284 int address_type; 1285 le_device_db_info(i, &address_type, address, NULL); 1286 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1287 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1288 log_info("sm: device found for public address, updating"); 1289 le_db_index = i; 1290 break; 1291 } 1292 } 1293 } 1294 1295 // if not found, add to db 1296 if (le_db_index < 0) { 1297 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1298 } 1299 1300 if (le_db_index >= 0){ 1301 le_device_db_local_counter_set(le_db_index, 0); 1302 1303 // store local CSRK 1304 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1305 log_info("sm: store local CSRK"); 1306 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1307 le_device_db_local_counter_set(le_db_index, 0); 1308 } 1309 1310 // store remote CSRK 1311 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1312 log_info("sm: store remote CSRK"); 1313 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1314 le_device_db_remote_counter_set(le_db_index, 0); 1315 } 1316 1317 // store encryption information 1318 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1319 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1320 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1321 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1322 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1323 } 1324 } 1325 1326 // keep le_db_index 1327 sm_conn->sm_le_db_index = le_db_index; 1328 } 1329 1330 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1331 setup->sm_pairing_failed_reason = reason; 1332 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1333 } 1334 1335 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1336 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1337 } 1338 1339 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1340 1341 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1342 static int sm_passkey_used(stk_generation_method_t method); 1343 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1344 1345 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1346 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1347 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1348 } else { 1349 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1350 } 1351 } 1352 1353 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1354 if (sm_conn->sm_role){ 1355 // Responder 1356 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1357 } else { 1358 // Initiator role 1359 switch (setup->sm_stk_generation_method){ 1360 case JUST_WORKS: 1361 sm_sc_prepare_dhkey_check(sm_conn); 1362 break; 1363 1364 case NK_BOTH_INPUT: 1365 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1366 break; 1367 case PK_INIT_INPUT: 1368 case PK_RESP_INPUT: 1369 case OK_BOTH_INPUT: 1370 if (setup->sm_passkey_bit < 20) { 1371 sm_sc_start_calculating_local_confirm(sm_conn); 1372 } else { 1373 sm_sc_prepare_dhkey_check(sm_conn); 1374 } 1375 break; 1376 case OOB: 1377 // TODO: implement SC OOB 1378 break; 1379 } 1380 } 1381 } 1382 1383 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1384 return sm_cmac_sc_buffer[offset]; 1385 } 1386 1387 static void sm_sc_cmac_done(uint8_t * hash){ 1388 log_info("sm_sc_cmac_done: "); 1389 log_info_hexdump(hash, 16); 1390 1391 sm_connection_t * sm_conn = sm_cmac_connection; 1392 sm_cmac_connection = NULL; 1393 1394 switch (sm_conn->sm_engine_state){ 1395 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1396 memcpy(setup->sm_local_confirm, hash, 16); 1397 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1398 break; 1399 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1400 // check 1401 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1402 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1403 break; 1404 } 1405 sm_sc_state_after_receiving_random(sm_conn); 1406 break; 1407 case SM_SC_W4_CALCULATE_G2: { 1408 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1409 big_endian_store_32(setup->sm_tk, 12, vab); 1410 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1411 sm_trigger_user_response(sm_conn); 1412 break; 1413 } 1414 case SM_SC_W4_CALCULATE_F5_SALT: 1415 memcpy(setup->sm_t, hash, 16); 1416 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1417 break; 1418 case SM_SC_W4_CALCULATE_F5_MACKEY: 1419 memcpy(setup->sm_mackey, hash, 16); 1420 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1421 break; 1422 case SM_SC_W4_CALCULATE_F5_LTK: 1423 memcpy(setup->sm_ltk, hash, 16); 1424 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1425 break; 1426 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1427 memcpy(setup->sm_local_dhkey_check, hash, 16); 1428 if (sm_conn->sm_role){ 1429 // responder 1430 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1431 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1432 } else { 1433 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1434 } 1435 } else { 1436 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1437 } 1438 break; 1439 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1440 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1441 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1442 break; 1443 } 1444 if (sm_conn->sm_role){ 1445 // responder 1446 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1447 } else { 1448 // initiator 1449 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1450 } 1451 break; 1452 default: 1453 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1454 break; 1455 } 1456 sm_run(); 1457 } 1458 1459 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){ 1460 const uint16_t message_len = 65; 1461 sm_cmac_connection = sm_conn; 1462 memcpy(sm_cmac_sc_buffer, u, 32); 1463 memcpy(sm_cmac_sc_buffer+32, v, 32); 1464 sm_cmac_sc_buffer[64] = z; 1465 log_info("f4 key"); 1466 log_info_hexdump(x, 16); 1467 log_info("f4 message"); 1468 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1469 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1470 } 1471 1472 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1473 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1474 static const uint8_t f5_length[] = { 0x01, 0x00}; 1475 1476 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1477 #ifdef USE_MBEDTLS_FOR_ECDH 1478 // da * Pb 1479 mbedtls_ecp_group grp; 1480 mbedtls_ecp_group_init(&grp ); 1481 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1482 mbedtls_ecp_point Q; 1483 mbedtls_ecp_point_init( &Q ); 1484 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1485 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1486 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1487 mbedtls_ecp_point DH; 1488 mbedtls_ecp_point_init(&DH); 1489 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1490 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1491 1492 #ifdef MBEDTLS_MEMORY_DEBUG 1493 mbedtls_memory_buffer_alloc_status(); 1494 #endif 1495 1496 mbedtls_ecp_point_free(&DH); 1497 mbedtls_ecp_point_free(&Q); 1498 mbedtls_ecp_group_free(&grp); 1499 #endif 1500 log_info("dhkey"); 1501 log_info_hexdump(dhkey, 32); 1502 } 1503 1504 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1505 // calculate DHKEY 1506 sm_key256_t dhkey; 1507 sm_sc_calculate_dhkey(dhkey); 1508 1509 // calculate salt for f5 1510 const uint16_t message_len = 32; 1511 sm_cmac_connection = sm_conn; 1512 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1513 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1514 } 1515 1516 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){ 1517 const uint16_t message_len = 53; 1518 sm_cmac_connection = sm_conn; 1519 1520 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1521 sm_cmac_sc_buffer[0] = 0; 1522 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1523 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1524 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1525 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1526 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1527 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1528 log_info("f5 key"); 1529 log_info_hexdump(t, 16); 1530 log_info("f5 message for MacKey"); 1531 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1532 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1533 } 1534 1535 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1536 sm_key56_t bd_addr_master, bd_addr_slave; 1537 bd_addr_master[0] = setup->sm_m_addr_type; 1538 bd_addr_slave[0] = setup->sm_s_addr_type; 1539 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1540 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1541 if (sm_conn->sm_role){ 1542 // responder 1543 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1544 } else { 1545 // initiator 1546 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1547 } 1548 } 1549 1550 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1551 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1552 const uint16_t message_len = 53; 1553 sm_cmac_connection = sm_conn; 1554 sm_cmac_sc_buffer[0] = 1; 1555 // 1..52 setup before 1556 log_info("f5 key"); 1557 log_info_hexdump(t, 16); 1558 log_info("f5 message for LTK"); 1559 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1560 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1561 } 1562 1563 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1564 f5_ltk(sm_conn, setup->sm_t); 1565 } 1566 1567 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){ 1568 const uint16_t message_len = 65; 1569 sm_cmac_connection = sm_conn; 1570 memcpy(sm_cmac_sc_buffer, n1, 16); 1571 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1572 memcpy(sm_cmac_sc_buffer+32, r, 16); 1573 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1574 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1575 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1576 log_info("f6 key"); 1577 log_info_hexdump(w, 16); 1578 log_info("f6 message"); 1579 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1580 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1581 } 1582 1583 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1584 // - U is 256 bits 1585 // - V is 256 bits 1586 // - X is 128 bits 1587 // - Y is 128 bits 1588 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){ 1589 const uint16_t message_len = 80; 1590 sm_cmac_connection = sm_conn; 1591 memcpy(sm_cmac_sc_buffer, u, 32); 1592 memcpy(sm_cmac_sc_buffer+32, v, 32); 1593 memcpy(sm_cmac_sc_buffer+64, y, 16); 1594 log_info("g2 key"); 1595 log_info_hexdump(x, 16); 1596 log_info("g2 message"); 1597 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1598 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1599 } 1600 1601 static void g2_calculate(sm_connection_t * sm_conn) { 1602 // calc Va if numeric comparison 1603 uint8_t value[32]; 1604 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1605 if (sm_conn->sm_role){ 1606 // responder 1607 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1608 } else { 1609 // initiator 1610 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1611 } 1612 } 1613 1614 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1615 uint8_t z = 0; 1616 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1617 // some form of passkey 1618 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1619 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1620 setup->sm_passkey_bit++; 1621 } 1622 #ifdef USE_MBEDTLS_FOR_ECDH 1623 uint8_t local_qx[32]; 1624 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1625 #endif 1626 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1627 } 1628 1629 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1630 uint8_t z = 0; 1631 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1632 // some form of passkey 1633 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1634 // sm_passkey_bit was increased before sending confirm value 1635 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1636 } 1637 #ifdef USE_MBEDTLS_FOR_ECDH 1638 uint8_t local_qx[32]; 1639 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1640 #endif 1641 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1642 } 1643 1644 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1645 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1646 } 1647 1648 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1649 // calculate DHKCheck 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 uint8_t iocap_a[3]; 1656 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1657 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1658 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1659 uint8_t iocap_b[3]; 1660 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1661 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1662 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1663 if (sm_conn->sm_role){ 1664 // responder 1665 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); 1666 } else { 1667 // initiator 1668 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); 1669 } 1670 } 1671 1672 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1673 // validate E = f6() 1674 sm_key56_t bd_addr_master, bd_addr_slave; 1675 bd_addr_master[0] = setup->sm_m_addr_type; 1676 bd_addr_slave[0] = setup->sm_s_addr_type; 1677 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1678 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1679 1680 uint8_t iocap_a[3]; 1681 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1682 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1683 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1684 uint8_t iocap_b[3]; 1685 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1686 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1687 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1688 if (sm_conn->sm_role){ 1689 // responder 1690 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); 1691 } else { 1692 // initiator 1693 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); 1694 } 1695 } 1696 #endif 1697 1698 static void sm_load_security_info(sm_connection_t * sm_connection){ 1699 int encryption_key_size; 1700 int authenticated; 1701 int authorized; 1702 1703 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1704 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1705 &encryption_key_size, &authenticated, &authorized); 1706 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1707 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1708 sm_connection->sm_connection_authenticated = authenticated; 1709 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1710 } 1711 1712 static void sm_run(void){ 1713 1714 btstack_linked_list_iterator_t it; 1715 1716 // assert that we can send at least commands 1717 if (!hci_can_send_command_packet_now()) return; 1718 1719 // 1720 // non-connection related behaviour 1721 // 1722 1723 // distributed key generation 1724 switch (dkg_state){ 1725 case DKG_CALC_IRK: 1726 // already busy? 1727 if (sm_aes128_state == SM_AES128_IDLE) { 1728 // IRK = d1(IR, 1, 0) 1729 sm_key_t d1_prime; 1730 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1731 dkg_next_state(); 1732 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1733 return; 1734 } 1735 break; 1736 case DKG_CALC_DHK: 1737 // already busy? 1738 if (sm_aes128_state == SM_AES128_IDLE) { 1739 // DHK = d1(IR, 3, 0) 1740 sm_key_t d1_prime; 1741 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1742 dkg_next_state(); 1743 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1744 return; 1745 } 1746 break; 1747 default: 1748 break; 1749 } 1750 1751 #ifdef USE_MBEDTLS_FOR_ECDH 1752 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1753 sm_random_start(NULL); 1754 return; 1755 } 1756 #endif 1757 1758 // random address updates 1759 switch (rau_state){ 1760 case RAU_GET_RANDOM: 1761 rau_next_state(); 1762 sm_random_start(NULL); 1763 return; 1764 case RAU_GET_ENC: 1765 // already busy? 1766 if (sm_aes128_state == SM_AES128_IDLE) { 1767 sm_key_t r_prime; 1768 sm_ah_r_prime(sm_random_address, r_prime); 1769 rau_next_state(); 1770 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1771 return; 1772 } 1773 break; 1774 case RAU_SET_ADDRESS: 1775 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1776 rau_state = RAU_IDLE; 1777 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1778 return; 1779 default: 1780 break; 1781 } 1782 1783 // CMAC 1784 switch (sm_cmac_state){ 1785 case CMAC_CALC_SUBKEYS: 1786 case CMAC_CALC_MI: 1787 case CMAC_CALC_MLAST: 1788 // already busy? 1789 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1790 sm_cmac_handle_aes_engine_ready(); 1791 return; 1792 default: 1793 break; 1794 } 1795 1796 // CSRK Lookup 1797 // -- if csrk lookup ready, find connection that require csrk lookup 1798 if (sm_address_resolution_idle()){ 1799 hci_connections_get_iterator(&it); 1800 while(btstack_linked_list_iterator_has_next(&it)){ 1801 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1802 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1803 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1804 // and start lookup 1805 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); 1806 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1807 break; 1808 } 1809 } 1810 } 1811 1812 // -- if csrk lookup ready, resolved addresses for received addresses 1813 if (sm_address_resolution_idle()) { 1814 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1815 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1816 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1817 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1818 btstack_memory_sm_lookup_entry_free(entry); 1819 } 1820 } 1821 1822 // -- Continue with CSRK device lookup by public or resolvable private address 1823 if (!sm_address_resolution_idle()){ 1824 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1825 while (sm_address_resolution_test < le_device_db_count()){ 1826 int addr_type; 1827 bd_addr_t addr; 1828 sm_key_t irk; 1829 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1830 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1831 1832 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1833 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1834 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1835 break; 1836 } 1837 1838 if (sm_address_resolution_addr_type == 0){ 1839 sm_address_resolution_test++; 1840 continue; 1841 } 1842 1843 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1844 1845 log_info("LE Device Lookup: calculate AH"); 1846 log_info_key("IRK", irk); 1847 1848 sm_key_t r_prime; 1849 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1850 sm_address_resolution_ah_calculation_active = 1; 1851 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1852 return; 1853 } 1854 1855 if (sm_address_resolution_test >= le_device_db_count()){ 1856 log_info("LE Device Lookup: not found"); 1857 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1858 } 1859 } 1860 1861 1862 // 1863 // active connection handling 1864 // -- use loop to handle next connection if lock on setup context is released 1865 1866 while (1) { 1867 1868 // Find connections that requires setup context and make active if no other is locked 1869 hci_connections_get_iterator(&it); 1870 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1871 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1872 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1873 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1874 int done = 1; 1875 int err; 1876 switch (sm_connection->sm_engine_state) { 1877 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1878 // send packet if possible, 1879 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1880 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1881 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1882 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1883 } else { 1884 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1885 } 1886 // don't lock sxetup context yet 1887 done = 0; 1888 break; 1889 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1890 sm_init_setup(sm_connection); 1891 // recover pairing request 1892 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1893 err = sm_stk_generation_init(sm_connection); 1894 if (err){ 1895 setup->sm_pairing_failed_reason = err; 1896 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1897 break; 1898 } 1899 sm_timeout_start(sm_connection); 1900 // generate random number first, if we need to show passkey 1901 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1902 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1903 break; 1904 } 1905 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1906 break; 1907 case SM_INITIATOR_PH0_HAS_LTK: 1908 sm_load_security_info(sm_connection); 1909 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1910 break; 1911 case SM_RESPONDER_PH0_RECEIVED_LTK: 1912 switch (sm_connection->sm_irk_lookup_state){ 1913 case IRK_LOOKUP_SUCCEEDED:{ 1914 sm_load_security_info(sm_connection); 1915 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1916 break; 1917 } 1918 case IRK_LOOKUP_FAILED: 1919 // assume that we don't have a LTK for ediv == 0 and random == null 1920 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1921 log_info("LTK Request: ediv & random are empty"); 1922 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1923 // TODO: no need to lock context yet -> done = 0; 1924 break; 1925 } 1926 // re-establish previously used LTK using Rand and EDIV 1927 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1928 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1929 // re-establish used key encryption size 1930 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1931 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1932 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1933 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1934 log_info("sm: received ltk request with key size %u, authenticated %u", 1935 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1936 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1937 break; 1938 default: 1939 // just wait until IRK lookup is completed 1940 // don't lock sxetup context yet 1941 done = 0; 1942 break; 1943 } 1944 break; 1945 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1946 sm_init_setup(sm_connection); 1947 sm_timeout_start(sm_connection); 1948 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1949 break; 1950 default: 1951 done = 0; 1952 break; 1953 } 1954 if (done){ 1955 sm_active_connection = sm_connection->sm_handle; 1956 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1957 } 1958 } 1959 1960 // 1961 // active connection handling 1962 // 1963 1964 if (sm_active_connection == 0) return; 1965 1966 // assert that we could send a SM PDU - not needed for all of the following 1967 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1968 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1969 return; 1970 } 1971 1972 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1973 if (!connection) return; 1974 1975 sm_key_t plaintext; 1976 int key_distribution_flags; 1977 1978 log_info("sm_run: state %u", connection->sm_engine_state); 1979 1980 // responding state 1981 switch (connection->sm_engine_state){ 1982 1983 // general 1984 case SM_GENERAL_SEND_PAIRING_FAILED: { 1985 uint8_t buffer[2]; 1986 buffer[0] = SM_CODE_PAIRING_FAILED; 1987 buffer[1] = setup->sm_pairing_failed_reason; 1988 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1989 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1990 sm_done_for_handle(connection->sm_handle); 1991 break; 1992 } 1993 1994 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1995 case SM_SC_W2_GET_RANDOM_A: 1996 sm_random_start(connection); 1997 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1998 break; 1999 case SM_SC_W2_GET_RANDOM_B: 2000 sm_random_start(connection); 2001 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 2002 break; 2003 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 2004 if (!sm_cmac_ready()) break; 2005 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 2006 sm_sc_calculate_local_confirm(connection); 2007 break; 2008 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 2009 if (!sm_cmac_ready()) break; 2010 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 2011 sm_sc_calculate_remote_confirm(connection); 2012 break; 2013 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 2014 if (!sm_cmac_ready()) break; 2015 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 2016 sm_sc_calculate_f6_for_dhkey_check(connection); 2017 break; 2018 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 2019 if (!sm_cmac_ready()) break; 2020 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 2021 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 2022 break; 2023 case SM_SC_W2_CALCULATE_F5_SALT: 2024 if (!sm_cmac_ready()) break; 2025 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 2026 f5_calculate_salt(connection); 2027 break; 2028 case SM_SC_W2_CALCULATE_F5_MACKEY: 2029 if (!sm_cmac_ready()) break; 2030 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2031 f5_calculate_mackey(connection); 2032 break; 2033 case SM_SC_W2_CALCULATE_F5_LTK: 2034 if (!sm_cmac_ready()) break; 2035 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2036 f5_calculate_ltk(connection); 2037 break; 2038 case SM_SC_W2_CALCULATE_G2: 2039 if (!sm_cmac_ready()) break; 2040 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2041 g2_calculate(connection); 2042 break; 2043 2044 #endif 2045 // initiator side 2046 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2047 sm_key_t peer_ltk_flipped; 2048 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2049 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2050 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2051 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2052 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2053 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2054 return; 2055 } 2056 2057 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2058 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2059 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2060 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2061 sm_timeout_reset(connection); 2062 break; 2063 2064 // responder side 2065 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2066 connection->sm_engine_state = SM_RESPONDER_IDLE; 2067 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2068 sm_done_for_handle(connection->sm_handle); 2069 return; 2070 2071 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2072 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2073 uint8_t buffer[65]; 2074 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2075 // 2076 #ifdef USE_MBEDTLS_FOR_ECDH 2077 uint8_t value[32]; 2078 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2079 reverse_256(value, &buffer[1]); 2080 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2081 reverse_256(value, &buffer[33]); 2082 #endif 2083 2084 // stk generation method 2085 // passkey entry: notify app to show passkey or to request passkey 2086 switch (setup->sm_stk_generation_method){ 2087 case JUST_WORKS: 2088 case NK_BOTH_INPUT: 2089 if (connection->sm_role){ 2090 // responder 2091 sm_sc_start_calculating_local_confirm(connection); 2092 } else { 2093 // initiator 2094 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2095 } 2096 break; 2097 case PK_INIT_INPUT: 2098 case PK_RESP_INPUT: 2099 case OK_BOTH_INPUT: 2100 // use random TK for display 2101 memcpy(setup->sm_ra, setup->sm_tk, 16); 2102 memcpy(setup->sm_rb, setup->sm_tk, 16); 2103 setup->sm_passkey_bit = 0; 2104 2105 if (connection->sm_role){ 2106 // responder 2107 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2108 } else { 2109 // initiator 2110 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2111 } 2112 sm_trigger_user_response(connection); 2113 break; 2114 case OOB: 2115 // TODO: implement SC OOB 2116 break; 2117 } 2118 2119 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2120 sm_timeout_reset(connection); 2121 break; 2122 } 2123 case SM_SC_SEND_CONFIRMATION: { 2124 uint8_t buffer[17]; 2125 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2126 reverse_128(setup->sm_local_confirm, &buffer[1]); 2127 if (connection->sm_role){ 2128 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2129 } else { 2130 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2131 } 2132 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2133 sm_timeout_reset(connection); 2134 break; 2135 } 2136 case SM_SC_SEND_PAIRING_RANDOM: { 2137 uint8_t buffer[17]; 2138 buffer[0] = SM_CODE_PAIRING_RANDOM; 2139 reverse_128(setup->sm_local_nonce, &buffer[1]); 2140 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2141 if (connection->sm_role){ 2142 // responder 2143 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2144 } else { 2145 // initiator 2146 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2147 } 2148 } else { 2149 if (connection->sm_role){ 2150 // responder 2151 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2152 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2153 } else { 2154 sm_sc_prepare_dhkey_check(connection); 2155 } 2156 } else { 2157 // initiator 2158 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2159 } 2160 } 2161 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2162 sm_timeout_reset(connection); 2163 break; 2164 } 2165 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2166 uint8_t buffer[17]; 2167 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2168 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2169 2170 if (connection->sm_role){ 2171 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2172 } else { 2173 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2174 } 2175 2176 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2177 sm_timeout_reset(connection); 2178 break; 2179 } 2180 2181 #endif 2182 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2183 // echo initiator for now 2184 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2185 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2186 2187 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2188 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2189 if (setup->sm_use_secure_connections){ 2190 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2191 // skip LTK/EDIV for SC 2192 log_info("sm: dropping encryption information flag"); 2193 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2194 } 2195 #endif 2196 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); 2197 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); 2198 // update key distribution after ENC was dropped 2199 sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 2200 2201 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2202 sm_timeout_reset(connection); 2203 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2204 if (setup->sm_stk_generation_method == JUST_WORKS){ 2205 sm_trigger_user_response(connection); 2206 } 2207 return; 2208 2209 case SM_PH2_SEND_PAIRING_RANDOM: { 2210 uint8_t buffer[17]; 2211 buffer[0] = SM_CODE_PAIRING_RANDOM; 2212 reverse_128(setup->sm_local_random, &buffer[1]); 2213 if (connection->sm_role){ 2214 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2215 } else { 2216 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2217 } 2218 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2219 sm_timeout_reset(connection); 2220 break; 2221 } 2222 2223 case SM_PH2_GET_RANDOM_TK: 2224 case SM_PH2_C1_GET_RANDOM_A: 2225 case SM_PH2_C1_GET_RANDOM_B: 2226 case SM_PH3_GET_RANDOM: 2227 case SM_PH3_GET_DIV: 2228 sm_next_responding_state(connection); 2229 sm_random_start(connection); 2230 return; 2231 2232 case SM_PH2_C1_GET_ENC_B: 2233 case SM_PH2_C1_GET_ENC_D: 2234 // already busy? 2235 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2236 sm_next_responding_state(connection); 2237 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2238 return; 2239 2240 case SM_PH3_LTK_GET_ENC: 2241 case SM_RESPONDER_PH4_LTK_GET_ENC: 2242 // already busy? 2243 if (sm_aes128_state == SM_AES128_IDLE) { 2244 sm_key_t d_prime; 2245 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2246 sm_next_responding_state(connection); 2247 sm_aes128_start(sm_persistent_er, d_prime, connection); 2248 return; 2249 } 2250 break; 2251 2252 case SM_PH3_CSRK_GET_ENC: 2253 // already busy? 2254 if (sm_aes128_state == SM_AES128_IDLE) { 2255 sm_key_t d_prime; 2256 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2257 sm_next_responding_state(connection); 2258 sm_aes128_start(sm_persistent_er, d_prime, connection); 2259 return; 2260 } 2261 break; 2262 2263 case SM_PH2_C1_GET_ENC_C: 2264 // already busy? 2265 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2266 // calculate m_confirm using aes128 engine - step 1 2267 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); 2268 sm_next_responding_state(connection); 2269 sm_aes128_start(setup->sm_tk, plaintext, connection); 2270 break; 2271 case SM_PH2_C1_GET_ENC_A: 2272 // already busy? 2273 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2274 // calculate confirm using aes128 engine - step 1 2275 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); 2276 sm_next_responding_state(connection); 2277 sm_aes128_start(setup->sm_tk, plaintext, connection); 2278 break; 2279 case SM_PH2_CALC_STK: 2280 // already busy? 2281 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2282 // calculate STK 2283 if (connection->sm_role){ 2284 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2285 } else { 2286 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2287 } 2288 sm_next_responding_state(connection); 2289 sm_aes128_start(setup->sm_tk, plaintext, connection); 2290 break; 2291 case SM_PH3_Y_GET_ENC: 2292 // already busy? 2293 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2294 // PH3B2 - calculate Y from - enc 2295 // Y = dm(DHK, Rand) 2296 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2297 sm_next_responding_state(connection); 2298 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2299 return; 2300 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2301 uint8_t buffer[17]; 2302 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2303 reverse_128(setup->sm_local_confirm, &buffer[1]); 2304 if (connection->sm_role){ 2305 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2306 } else { 2307 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2308 } 2309 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2310 sm_timeout_reset(connection); 2311 return; 2312 } 2313 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2314 sm_key_t stk_flipped; 2315 reverse_128(setup->sm_ltk, stk_flipped); 2316 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2317 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2318 return; 2319 } 2320 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2321 sm_key_t stk_flipped; 2322 reverse_128(setup->sm_ltk, stk_flipped); 2323 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2324 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2325 return; 2326 } 2327 case SM_RESPONDER_PH4_SEND_LTK: { 2328 sm_key_t ltk_flipped; 2329 reverse_128(setup->sm_ltk, ltk_flipped); 2330 connection->sm_engine_state = SM_RESPONDER_IDLE; 2331 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2332 return; 2333 } 2334 case SM_RESPONDER_PH4_Y_GET_ENC: 2335 // already busy? 2336 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2337 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2338 // Y = dm(DHK, Rand) 2339 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2340 sm_next_responding_state(connection); 2341 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2342 return; 2343 2344 case SM_PH3_DISTRIBUTE_KEYS: 2345 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2346 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2347 uint8_t buffer[17]; 2348 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2349 reverse_128(setup->sm_ltk, &buffer[1]); 2350 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2351 sm_timeout_reset(connection); 2352 return; 2353 } 2354 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2355 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2356 uint8_t buffer[11]; 2357 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2358 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2359 reverse_64(setup->sm_local_rand, &buffer[3]); 2360 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2361 sm_timeout_reset(connection); 2362 return; 2363 } 2364 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2365 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2366 uint8_t buffer[17]; 2367 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2368 reverse_128(sm_persistent_irk, &buffer[1]); 2369 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2370 sm_timeout_reset(connection); 2371 return; 2372 } 2373 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2374 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2375 bd_addr_t local_address; 2376 uint8_t buffer[8]; 2377 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2378 gap_advertisements_get_address(&buffer[1], local_address); 2379 reverse_bd_addr(local_address, &buffer[2]); 2380 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2381 sm_timeout_reset(connection); 2382 return; 2383 } 2384 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2385 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2386 2387 // hack to reproduce test runs 2388 if (test_use_fixed_local_csrk){ 2389 memset(setup->sm_local_csrk, 0xcc, 16); 2390 } 2391 2392 uint8_t buffer[17]; 2393 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2394 reverse_128(setup->sm_local_csrk, &buffer[1]); 2395 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2396 sm_timeout_reset(connection); 2397 return; 2398 } 2399 2400 // keys are sent 2401 if (connection->sm_role){ 2402 // slave -> receive master keys if any 2403 if (sm_key_distribution_all_received(connection)){ 2404 sm_key_distribution_handle_all_received(connection); 2405 connection->sm_engine_state = SM_RESPONDER_IDLE; 2406 sm_done_for_handle(connection->sm_handle); 2407 } else { 2408 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2409 } 2410 } else { 2411 // master -> all done 2412 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2413 sm_done_for_handle(connection->sm_handle); 2414 } 2415 break; 2416 2417 default: 2418 break; 2419 } 2420 2421 // check again if active connection was released 2422 if (sm_active_connection) break; 2423 } 2424 } 2425 2426 // note: aes engine is ready as we just got the aes result 2427 static void sm_handle_encryption_result(uint8_t * data){ 2428 2429 sm_aes128_state = SM_AES128_IDLE; 2430 2431 if (sm_address_resolution_ah_calculation_active){ 2432 sm_address_resolution_ah_calculation_active = 0; 2433 // compare calulated address against connecting device 2434 uint8_t hash[3]; 2435 reverse_24(data, hash); 2436 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2437 log_info("LE Device Lookup: matched resolvable private address"); 2438 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2439 return; 2440 } 2441 // no match, try next 2442 sm_address_resolution_test++; 2443 return; 2444 } 2445 2446 switch (dkg_state){ 2447 case DKG_W4_IRK: 2448 reverse_128(data, sm_persistent_irk); 2449 log_info_key("irk", sm_persistent_irk); 2450 dkg_next_state(); 2451 return; 2452 case DKG_W4_DHK: 2453 reverse_128(data, sm_persistent_dhk); 2454 log_info_key("dhk", sm_persistent_dhk); 2455 dkg_next_state(); 2456 // SM Init Finished 2457 return; 2458 default: 2459 break; 2460 } 2461 2462 switch (rau_state){ 2463 case RAU_W4_ENC: 2464 reverse_24(data, &sm_random_address[3]); 2465 rau_next_state(); 2466 return; 2467 default: 2468 break; 2469 } 2470 2471 switch (sm_cmac_state){ 2472 case CMAC_W4_SUBKEYS: 2473 case CMAC_W4_MI: 2474 case CMAC_W4_MLAST: 2475 { 2476 sm_key_t t; 2477 reverse_128(data, t); 2478 sm_cmac_handle_encryption_result(t); 2479 } 2480 return; 2481 default: 2482 break; 2483 } 2484 2485 // retrieve sm_connection provided to sm_aes128_start_encryption 2486 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2487 if (!connection) return; 2488 switch (connection->sm_engine_state){ 2489 case SM_PH2_C1_W4_ENC_A: 2490 case SM_PH2_C1_W4_ENC_C: 2491 { 2492 sm_key_t t2; 2493 reverse_128(data, t2); 2494 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2495 } 2496 sm_next_responding_state(connection); 2497 return; 2498 case SM_PH2_C1_W4_ENC_B: 2499 reverse_128(data, setup->sm_local_confirm); 2500 log_info_key("c1!", setup->sm_local_confirm); 2501 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2502 return; 2503 case SM_PH2_C1_W4_ENC_D: 2504 { 2505 sm_key_t peer_confirm_test; 2506 reverse_128(data, peer_confirm_test); 2507 log_info_key("c1!", peer_confirm_test); 2508 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2509 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2510 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2511 return; 2512 } 2513 if (connection->sm_role){ 2514 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2515 } else { 2516 connection->sm_engine_state = SM_PH2_CALC_STK; 2517 } 2518 } 2519 return; 2520 case SM_PH2_W4_STK: 2521 reverse_128(data, setup->sm_ltk); 2522 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2523 log_info_key("stk", setup->sm_ltk); 2524 if (connection->sm_role){ 2525 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2526 } else { 2527 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2528 } 2529 return; 2530 case SM_PH3_Y_W4_ENC:{ 2531 sm_key_t y128; 2532 reverse_128(data, y128); 2533 setup->sm_local_y = big_endian_read_16(y128, 14); 2534 log_info_hex16("y", setup->sm_local_y); 2535 // PH3B3 - calculate EDIV 2536 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2537 log_info_hex16("ediv", setup->sm_local_ediv); 2538 // PH3B4 - calculate LTK - enc 2539 // LTK = d1(ER, DIV, 0)) 2540 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2541 return; 2542 } 2543 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2544 sm_key_t y128; 2545 reverse_128(data, y128); 2546 setup->sm_local_y = big_endian_read_16(y128, 14); 2547 log_info_hex16("y", setup->sm_local_y); 2548 2549 // PH3B3 - calculate DIV 2550 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2551 log_info_hex16("ediv", setup->sm_local_ediv); 2552 // PH3B4 - calculate LTK - enc 2553 // LTK = d1(ER, DIV, 0)) 2554 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2555 return; 2556 } 2557 case SM_PH3_LTK_W4_ENC: 2558 reverse_128(data, setup->sm_ltk); 2559 log_info_key("ltk", setup->sm_ltk); 2560 // calc CSRK next 2561 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2562 return; 2563 case SM_PH3_CSRK_W4_ENC: 2564 reverse_128(data, setup->sm_local_csrk); 2565 log_info_key("csrk", setup->sm_local_csrk); 2566 if (setup->sm_key_distribution_send_set){ 2567 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2568 } else { 2569 // no keys to send, just continue 2570 if (connection->sm_role){ 2571 // slave -> receive master keys 2572 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2573 } else { 2574 // master -> all done 2575 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2576 sm_done_for_handle(connection->sm_handle); 2577 } 2578 } 2579 return; 2580 case SM_RESPONDER_PH4_LTK_W4_ENC: 2581 reverse_128(data, setup->sm_ltk); 2582 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2583 log_info_key("ltk", setup->sm_ltk); 2584 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2585 return; 2586 default: 2587 break; 2588 } 2589 } 2590 2591 #ifdef USE_MBEDTLS_FOR_ECDH 2592 2593 static void sm_log_ec_keypair(void){ 2594 // print keypair 2595 char buffer[100]; 2596 size_t len; 2597 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2598 log_info("d: %s", buffer); 2599 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2600 log_info("X: %s", buffer); 2601 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2602 log_info("Y: %s", buffer); 2603 } 2604 2605 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2606 int offset = setup->sm_passkey_bit; 2607 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2608 while (size) { 2609 if (offset < 32){ 2610 *buffer++ = setup->sm_peer_qx[offset++]; 2611 } else { 2612 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2613 } 2614 size--; 2615 } 2616 setup->sm_passkey_bit = offset; 2617 return 0; 2618 } 2619 #endif 2620 2621 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2622 static void sm_handle_random_result(uint8_t * data){ 2623 2624 #ifdef USE_MBEDTLS_FOR_ECDH 2625 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2626 int num_bytes = setup->sm_passkey_bit; 2627 if (num_bytes < 32){ 2628 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2629 } else { 2630 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2631 } 2632 num_bytes += 8; 2633 setup->sm_passkey_bit = num_bytes; 2634 2635 if (num_bytes >= 64){ 2636 // generate EC key 2637 setup->sm_passkey_bit = 0; 2638 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2639 sm_log_ec_keypair(); 2640 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2641 } 2642 } 2643 #endif 2644 2645 switch (rau_state){ 2646 case RAU_W4_RANDOM: 2647 // non-resolvable vs. resolvable 2648 switch (gap_random_adress_type){ 2649 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2650 // resolvable: use random as prand and calc address hash 2651 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2652 memcpy(sm_random_address, data, 3); 2653 sm_random_address[0] &= 0x3f; 2654 sm_random_address[0] |= 0x40; 2655 rau_state = RAU_GET_ENC; 2656 break; 2657 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2658 default: 2659 // "The two most significant bits of the address shall be equal to ‘0’"" 2660 memcpy(sm_random_address, data, 6); 2661 sm_random_address[0] &= 0x3f; 2662 rau_state = RAU_SET_ADDRESS; 2663 break; 2664 } 2665 return; 2666 default: 2667 break; 2668 } 2669 2670 // retrieve sm_connection provided to sm_random_start 2671 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2672 if (!connection) return; 2673 switch (connection->sm_engine_state){ 2674 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2675 case SM_SC_W4_GET_RANDOM_A: 2676 memcpy(&setup->sm_local_nonce[0], data, 8); 2677 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2678 break; 2679 case SM_SC_W4_GET_RANDOM_B: 2680 memcpy(&setup->sm_local_nonce[8], data, 8); 2681 // initiator & jw/nc -> send pairing random 2682 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2683 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2684 break; 2685 } else { 2686 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2687 } 2688 break; 2689 #endif 2690 2691 case SM_PH2_W4_RANDOM_TK: 2692 { 2693 // map random to 0-999999 without speding much cycles on a modulus operation 2694 uint32_t tk = little_endian_read_32(data,0); 2695 tk = tk & 0xfffff; // 1048575 2696 if (tk >= 999999){ 2697 tk = tk - 999999; 2698 } 2699 sm_reset_tk(); 2700 big_endian_store_32(setup->sm_tk, 12, tk); 2701 if (connection->sm_role){ 2702 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2703 } else { 2704 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2705 sm_trigger_user_response(connection); 2706 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2707 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2708 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2709 } 2710 } 2711 return; 2712 } 2713 case SM_PH2_C1_W4_RANDOM_A: 2714 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2715 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2716 return; 2717 case SM_PH2_C1_W4_RANDOM_B: 2718 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2719 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2720 return; 2721 case SM_PH3_W4_RANDOM: 2722 reverse_64(data, setup->sm_local_rand); 2723 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2724 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2725 // no db for authenticated flag hack: store flag in bit 4 of LSB 2726 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2727 connection->sm_engine_state = SM_PH3_GET_DIV; 2728 return; 2729 case SM_PH3_W4_DIV: 2730 // use 16 bit from random value as div 2731 setup->sm_local_div = big_endian_read_16(data, 0); 2732 log_info_hex16("div", setup->sm_local_div); 2733 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2734 return; 2735 default: 2736 break; 2737 } 2738 } 2739 2740 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2741 2742 sm_connection_t * sm_conn; 2743 hci_con_handle_t con_handle; 2744 2745 switch (packet_type) { 2746 2747 case HCI_EVENT_PACKET: 2748 switch (hci_event_packet_get_type(packet)) { 2749 2750 case BTSTACK_EVENT_STATE: 2751 // bt stack activated, get started 2752 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2753 log_info("HCI Working!"); 2754 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2755 rau_state = RAU_IDLE; 2756 #ifdef USE_MBEDTLS_FOR_ECDH 2757 if (!test_use_fixed_ec_keypair){ 2758 setup->sm_passkey_bit = 0; 2759 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2760 } 2761 #endif 2762 sm_run(); 2763 } 2764 break; 2765 2766 case HCI_EVENT_LE_META: 2767 switch (packet[2]) { 2768 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2769 2770 log_info("sm: connected"); 2771 2772 if (packet[3]) return; // connection failed 2773 2774 con_handle = little_endian_read_16(packet, 4); 2775 sm_conn = sm_get_connection_for_handle(con_handle); 2776 if (!sm_conn) break; 2777 2778 sm_conn->sm_handle = con_handle; 2779 sm_conn->sm_role = packet[6]; 2780 sm_conn->sm_peer_addr_type = packet[7]; 2781 reverse_bd_addr(&packet[8], 2782 sm_conn->sm_peer_address); 2783 2784 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2785 2786 // reset security properties 2787 sm_conn->sm_connection_encrypted = 0; 2788 sm_conn->sm_connection_authenticated = 0; 2789 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2790 sm_conn->sm_le_db_index = -1; 2791 2792 // prepare CSRK lookup (does not involve setup) 2793 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2794 2795 // just connected -> everything else happens in sm_run() 2796 if (sm_conn->sm_role){ 2797 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2798 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2799 if (sm_slave_request_security) { 2800 // request security if requested by app 2801 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2802 } else { 2803 // otherwise, wait for pairing request 2804 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2805 } 2806 } 2807 break; 2808 } else { 2809 // master 2810 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2811 } 2812 break; 2813 2814 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2815 con_handle = little_endian_read_16(packet, 3); 2816 sm_conn = sm_get_connection_for_handle(con_handle); 2817 if (!sm_conn) break; 2818 2819 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2820 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2821 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2822 break; 2823 } 2824 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2825 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2826 break; 2827 } 2828 2829 // store rand and ediv 2830 reverse_64(&packet[5], sm_conn->sm_local_rand); 2831 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2832 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2833 break; 2834 2835 default: 2836 break; 2837 } 2838 break; 2839 2840 case HCI_EVENT_ENCRYPTION_CHANGE: 2841 con_handle = little_endian_read_16(packet, 3); 2842 sm_conn = sm_get_connection_for_handle(con_handle); 2843 if (!sm_conn) break; 2844 2845 sm_conn->sm_connection_encrypted = packet[5]; 2846 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2847 sm_conn->sm_actual_encryption_key_size); 2848 log_info("event handler, state %u", sm_conn->sm_engine_state); 2849 if (!sm_conn->sm_connection_encrypted) break; 2850 // continue if part of initial pairing 2851 switch (sm_conn->sm_engine_state){ 2852 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2853 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2854 sm_done_for_handle(sm_conn->sm_handle); 2855 break; 2856 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2857 if (sm_conn->sm_role){ 2858 // slave 2859 if (setup->sm_use_secure_connections){ 2860 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2861 } else { 2862 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2863 } 2864 } else { 2865 // master 2866 if (sm_key_distribution_all_received(sm_conn)){ 2867 // skip receiving keys as there are none 2868 sm_key_distribution_handle_all_received(sm_conn); 2869 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2870 } else { 2871 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2872 } 2873 } 2874 break; 2875 default: 2876 break; 2877 } 2878 break; 2879 2880 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2881 con_handle = little_endian_read_16(packet, 3); 2882 sm_conn = sm_get_connection_for_handle(con_handle); 2883 if (!sm_conn) break; 2884 2885 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2886 log_info("event handler, state %u", sm_conn->sm_engine_state); 2887 // continue if part of initial pairing 2888 switch (sm_conn->sm_engine_state){ 2889 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2890 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2891 sm_done_for_handle(sm_conn->sm_handle); 2892 break; 2893 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2894 if (sm_conn->sm_role){ 2895 // slave 2896 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2897 } else { 2898 // master 2899 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2900 } 2901 break; 2902 default: 2903 break; 2904 } 2905 break; 2906 2907 2908 case HCI_EVENT_DISCONNECTION_COMPLETE: 2909 con_handle = little_endian_read_16(packet, 3); 2910 sm_done_for_handle(con_handle); 2911 sm_conn = sm_get_connection_for_handle(con_handle); 2912 if (!sm_conn) break; 2913 2914 // delete stored bonding on disconnect with authentication failure in ph0 2915 if (sm_conn->sm_role == 0 2916 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2917 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2918 le_device_db_remove(sm_conn->sm_le_db_index); 2919 } 2920 2921 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2922 sm_conn->sm_handle = 0; 2923 break; 2924 2925 case HCI_EVENT_COMMAND_COMPLETE: 2926 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2927 sm_handle_encryption_result(&packet[6]); 2928 break; 2929 } 2930 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2931 sm_handle_random_result(&packet[6]); 2932 break; 2933 } 2934 break; 2935 default: 2936 break; 2937 } 2938 break; 2939 default: 2940 break; 2941 } 2942 2943 sm_run(); 2944 } 2945 2946 static inline int sm_calc_actual_encryption_key_size(int other){ 2947 if (other < sm_min_encryption_key_size) return 0; 2948 if (other < sm_max_encryption_key_size) return other; 2949 return sm_max_encryption_key_size; 2950 } 2951 2952 2953 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2954 switch (method){ 2955 case JUST_WORKS: 2956 case NK_BOTH_INPUT: 2957 return 1; 2958 default: 2959 return 0; 2960 } 2961 } 2962 // responder 2963 2964 static int sm_passkey_used(stk_generation_method_t method){ 2965 switch (method){ 2966 case PK_RESP_INPUT: 2967 return 1; 2968 default: 2969 return 0; 2970 } 2971 } 2972 2973 /** 2974 * @return ok 2975 */ 2976 static int sm_validate_stk_generation_method(void){ 2977 // check if STK generation method is acceptable by client 2978 switch (setup->sm_stk_generation_method){ 2979 case JUST_WORKS: 2980 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2981 case PK_RESP_INPUT: 2982 case PK_INIT_INPUT: 2983 case OK_BOTH_INPUT: 2984 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2985 case OOB: 2986 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2987 case NK_BOTH_INPUT: 2988 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2989 return 1; 2990 default: 2991 return 0; 2992 } 2993 } 2994 2995 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2996 2997 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2998 sm_run(); 2999 } 3000 3001 if (packet_type != SM_DATA_PACKET) return; 3002 3003 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3004 if (!sm_conn) return; 3005 3006 if (packet[0] == SM_CODE_PAIRING_FAILED){ 3007 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 3008 return; 3009 } 3010 3011 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 3012 3013 int err; 3014 3015 switch (sm_conn->sm_engine_state){ 3016 3017 // a sm timeout requries a new physical connection 3018 case SM_GENERAL_TIMEOUT: 3019 return; 3020 3021 // Initiator 3022 case SM_INITIATOR_CONNECTED: 3023 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 3024 sm_pdu_received_in_wrong_state(sm_conn); 3025 break; 3026 } 3027 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 3028 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3029 break; 3030 } 3031 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 3032 uint16_t ediv; 3033 sm_key_t ltk; 3034 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3035 if (!sm_is_null_key(ltk) || ediv){ 3036 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3037 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3038 } else { 3039 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3040 } 3041 break; 3042 } 3043 // otherwise, store security request 3044 sm_conn->sm_security_request_received = 1; 3045 break; 3046 3047 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3048 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3049 sm_pdu_received_in_wrong_state(sm_conn); 3050 break; 3051 } 3052 // store pairing request 3053 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3054 err = sm_stk_generation_init(sm_conn); 3055 if (err){ 3056 setup->sm_pairing_failed_reason = err; 3057 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3058 break; 3059 } 3060 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3061 if (setup->sm_use_secure_connections){ 3062 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3063 if (setup->sm_stk_generation_method == JUST_WORKS){ 3064 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3065 sm_trigger_user_response(sm_conn); 3066 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3067 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3068 } 3069 } else { 3070 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3071 } 3072 break; 3073 } 3074 #endif 3075 // generate random number first, if we need to show passkey 3076 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3077 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3078 break; 3079 } 3080 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3081 sm_trigger_user_response(sm_conn); 3082 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3083 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3084 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3085 } 3086 break; 3087 3088 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3089 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3090 sm_pdu_received_in_wrong_state(sm_conn); 3091 break; 3092 } 3093 3094 // store s_confirm 3095 reverse_128(&packet[1], setup->sm_peer_confirm); 3096 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3097 break; 3098 3099 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3100 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3101 sm_pdu_received_in_wrong_state(sm_conn); 3102 break;; 3103 } 3104 3105 // received random value 3106 reverse_128(&packet[1], setup->sm_peer_random); 3107 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3108 break; 3109 3110 // Responder 3111 case SM_RESPONDER_IDLE: 3112 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3113 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3114 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3115 sm_pdu_received_in_wrong_state(sm_conn); 3116 break;; 3117 } 3118 3119 // store pairing request 3120 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3121 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3122 break; 3123 3124 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3125 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3126 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3127 sm_pdu_received_in_wrong_state(sm_conn); 3128 break; 3129 } 3130 3131 // store public key for DH Key calculation 3132 reverse_256(&packet[01], setup->sm_peer_qx); 3133 reverse_256(&packet[33], setup->sm_peer_qy); 3134 3135 #ifdef USE_MBEDTLS_FOR_ECDH 3136 // validate public key 3137 mbedtls_ecp_group grp; 3138 mbedtls_ecp_group_init( &grp ); 3139 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3140 3141 mbedtls_ecp_point Q; 3142 mbedtls_ecp_point_init( &Q ); 3143 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3144 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3145 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3146 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3147 mbedtls_ecp_point_free( & Q); 3148 mbedtls_ecp_group_free( &grp); 3149 if (err){ 3150 log_error("sm: peer public key invalid %x", err); 3151 // uses "unspecified reason", there is no "public key invalid" error code 3152 sm_pdu_received_in_wrong_state(sm_conn); 3153 break; 3154 } 3155 3156 #endif 3157 if (sm_conn->sm_role){ 3158 // responder 3159 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3160 } else { 3161 // initiator 3162 // stk generation method 3163 // passkey entry: notify app to show passkey or to request passkey 3164 switch (setup->sm_stk_generation_method){ 3165 case JUST_WORKS: 3166 case NK_BOTH_INPUT: 3167 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3168 break; 3169 case PK_RESP_INPUT: 3170 sm_sc_start_calculating_local_confirm(sm_conn); 3171 break; 3172 case PK_INIT_INPUT: 3173 case OK_BOTH_INPUT: 3174 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3175 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3176 break; 3177 } 3178 sm_sc_start_calculating_local_confirm(sm_conn); 3179 break; 3180 case OOB: 3181 // TODO: implement SC OOB 3182 break; 3183 } 3184 } 3185 break; 3186 3187 case SM_SC_W4_CONFIRMATION: 3188 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3189 sm_pdu_received_in_wrong_state(sm_conn); 3190 break; 3191 } 3192 // received confirm value 3193 reverse_128(&packet[1], setup->sm_peer_confirm); 3194 3195 if (sm_conn->sm_role){ 3196 // responder 3197 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3198 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3199 // still waiting for passkey 3200 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3201 break; 3202 } 3203 } 3204 sm_sc_start_calculating_local_confirm(sm_conn); 3205 } else { 3206 // initiator 3207 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3208 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3209 } else { 3210 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3211 } 3212 } 3213 break; 3214 3215 case SM_SC_W4_PAIRING_RANDOM: 3216 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3217 sm_pdu_received_in_wrong_state(sm_conn); 3218 break; 3219 } 3220 3221 // received random value 3222 reverse_128(&packet[1], setup->sm_peer_nonce); 3223 3224 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3225 // only check for JUST WORK/NC in initiator role AND passkey entry 3226 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3227 if (sm_conn->sm_role || passkey_entry) { 3228 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3229 } 3230 3231 sm_sc_state_after_receiving_random(sm_conn); 3232 break; 3233 3234 case SM_SC_W2_CALCULATE_G2: 3235 case SM_SC_W4_CALCULATE_G2: 3236 case SM_SC_W2_CALCULATE_F5_SALT: 3237 case SM_SC_W4_CALCULATE_F5_SALT: 3238 case SM_SC_W2_CALCULATE_F5_MACKEY: 3239 case SM_SC_W4_CALCULATE_F5_MACKEY: 3240 case SM_SC_W2_CALCULATE_F5_LTK: 3241 case SM_SC_W4_CALCULATE_F5_LTK: 3242 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3243 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3244 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3245 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3246 sm_pdu_received_in_wrong_state(sm_conn); 3247 break; 3248 } 3249 // store DHKey Check 3250 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3251 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3252 3253 // have we been only waiting for dhkey check command? 3254 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3255 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3256 } 3257 break; 3258 #endif 3259 3260 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3261 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3262 sm_pdu_received_in_wrong_state(sm_conn); 3263 break; 3264 } 3265 3266 // received confirm value 3267 reverse_128(&packet[1], setup->sm_peer_confirm); 3268 3269 // notify client to hide shown passkey 3270 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3271 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3272 } 3273 3274 // handle user cancel pairing? 3275 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3276 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3277 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3278 break; 3279 } 3280 3281 // wait for user action? 3282 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3283 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3284 break; 3285 } 3286 3287 // calculate and send local_confirm 3288 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3289 break; 3290 3291 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3292 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3293 sm_pdu_received_in_wrong_state(sm_conn); 3294 break;; 3295 } 3296 3297 // received random value 3298 reverse_128(&packet[1], setup->sm_peer_random); 3299 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3300 break; 3301 3302 case SM_PH3_RECEIVE_KEYS: 3303 switch(packet[0]){ 3304 case SM_CODE_ENCRYPTION_INFORMATION: 3305 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3306 reverse_128(&packet[1], setup->sm_peer_ltk); 3307 break; 3308 3309 case SM_CODE_MASTER_IDENTIFICATION: 3310 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3311 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3312 reverse_64(&packet[3], setup->sm_peer_rand); 3313 break; 3314 3315 case SM_CODE_IDENTITY_INFORMATION: 3316 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3317 reverse_128(&packet[1], setup->sm_peer_irk); 3318 break; 3319 3320 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3321 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3322 setup->sm_peer_addr_type = packet[1]; 3323 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3324 break; 3325 3326 case SM_CODE_SIGNING_INFORMATION: 3327 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3328 reverse_128(&packet[1], setup->sm_peer_csrk); 3329 break; 3330 default: 3331 // Unexpected PDU 3332 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3333 break; 3334 } 3335 // done with key distribution? 3336 if (sm_key_distribution_all_received(sm_conn)){ 3337 3338 sm_key_distribution_handle_all_received(sm_conn); 3339 3340 if (sm_conn->sm_role){ 3341 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3342 sm_done_for_handle(sm_conn->sm_handle); 3343 } else { 3344 if (setup->sm_use_secure_connections){ 3345 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3346 } else { 3347 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3348 } 3349 } 3350 } 3351 break; 3352 default: 3353 // Unexpected PDU 3354 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3355 break; 3356 } 3357 3358 // try to send preparared packet 3359 sm_run(); 3360 } 3361 3362 // Security Manager Client API 3363 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3364 sm_get_oob_data = get_oob_data_callback; 3365 } 3366 3367 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3368 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3369 } 3370 3371 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3372 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3373 } 3374 3375 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3376 sm_min_encryption_key_size = min_size; 3377 sm_max_encryption_key_size = max_size; 3378 } 3379 3380 void sm_set_authentication_requirements(uint8_t auth_req){ 3381 sm_auth_req = auth_req; 3382 } 3383 3384 void sm_set_io_capabilities(io_capability_t io_capability){ 3385 sm_io_capabilities = io_capability; 3386 } 3387 3388 void sm_set_request_security(int enable){ 3389 sm_slave_request_security = enable; 3390 } 3391 3392 void sm_set_er(sm_key_t er){ 3393 memcpy(sm_persistent_er, er, 16); 3394 } 3395 3396 void sm_set_ir(sm_key_t ir){ 3397 memcpy(sm_persistent_ir, ir, 16); 3398 } 3399 3400 // Testing support only 3401 void sm_test_set_irk(sm_key_t irk){ 3402 memcpy(sm_persistent_irk, irk, 16); 3403 sm_persistent_irk_ready = 1; 3404 } 3405 3406 void sm_test_use_fixed_local_csrk(void){ 3407 test_use_fixed_local_csrk = 1; 3408 } 3409 3410 void sm_init(void){ 3411 // set some (BTstack default) ER and IR 3412 int i; 3413 sm_key_t er; 3414 sm_key_t ir; 3415 for (i=0;i<16;i++){ 3416 er[i] = 0x30 + i; 3417 ir[i] = 0x90 + i; 3418 } 3419 sm_set_er(er); 3420 sm_set_ir(ir); 3421 // defaults 3422 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3423 | SM_STK_GENERATION_METHOD_OOB 3424 | SM_STK_GENERATION_METHOD_PASSKEY 3425 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3426 3427 sm_max_encryption_key_size = 16; 3428 sm_min_encryption_key_size = 7; 3429 3430 sm_cmac_state = CMAC_IDLE; 3431 dkg_state = DKG_W4_WORKING; 3432 rau_state = RAU_W4_WORKING; 3433 sm_aes128_state = SM_AES128_IDLE; 3434 sm_address_resolution_test = -1; // no private address to resolve yet 3435 sm_address_resolution_ah_calculation_active = 0; 3436 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3437 sm_address_resolution_general_queue = NULL; 3438 3439 gap_random_adress_update_period = 15 * 60 * 1000L; 3440 3441 sm_active_connection = 0; 3442 3443 test_use_fixed_local_csrk = 0; 3444 3445 // register for HCI Events from HCI 3446 hci_event_callback_registration.callback = &sm_event_packet_handler; 3447 hci_add_event_handler(&hci_event_callback_registration); 3448 3449 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3450 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3451 3452 #ifdef USE_MBEDTLS_FOR_ECDH 3453 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3454 #ifndef HAVE_MALLOC 3455 mbedtls_memory_buffer_alloc_init(mbedtls_memory_buffer, sizeof(mbedtls_memory_buffer)); 3456 #endif 3457 #endif 3458 } 3459 3460 void sm_test_use_fixed_ec_keypair(void){ 3461 test_use_fixed_ec_keypair = 1; 3462 #ifdef USE_MBEDTLS_FOR_ECDH 3463 // use test keypair from spec 3464 mbedtls_ecp_keypair_init(&le_keypair); 3465 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3466 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3467 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3468 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3469 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3470 #endif 3471 } 3472 3473 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3474 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3475 if (!hci_con) return NULL; 3476 return &hci_con->sm_connection; 3477 } 3478 3479 // @returns 0 if not encrypted, 7-16 otherwise 3480 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3481 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3482 if (!sm_conn) return 0; // wrong connection 3483 if (!sm_conn->sm_connection_encrypted) return 0; 3484 return sm_conn->sm_actual_encryption_key_size; 3485 } 3486 3487 int sm_authenticated(hci_con_handle_t con_handle){ 3488 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3489 if (!sm_conn) return 0; // wrong connection 3490 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3491 return sm_conn->sm_connection_authenticated; 3492 } 3493 3494 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3495 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3496 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3497 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3498 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3499 return sm_conn->sm_connection_authorization_state; 3500 } 3501 3502 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3503 switch (sm_conn->sm_engine_state){ 3504 case SM_GENERAL_IDLE: 3505 case SM_RESPONDER_IDLE: 3506 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3507 sm_run(); 3508 break; 3509 default: 3510 break; 3511 } 3512 } 3513 3514 /** 3515 * @brief Trigger Security Request 3516 */ 3517 void sm_send_security_request(hci_con_handle_t con_handle){ 3518 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3519 if (!sm_conn) return; 3520 sm_send_security_request_for_connection(sm_conn); 3521 } 3522 3523 // request pairing 3524 void sm_request_pairing(hci_con_handle_t con_handle){ 3525 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3526 if (!sm_conn) return; // wrong connection 3527 3528 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3529 if (sm_conn->sm_role){ 3530 sm_send_security_request_for_connection(sm_conn); 3531 } else { 3532 // used as a trigger to start central/master/initiator security procedures 3533 uint16_t ediv; 3534 sm_key_t ltk; 3535 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3536 switch (sm_conn->sm_irk_lookup_state){ 3537 case IRK_LOOKUP_FAILED: 3538 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3539 break; 3540 case IRK_LOOKUP_SUCCEEDED: 3541 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, ltk, NULL, NULL, NULL); 3542 if (!sm_is_null_key(ltk) || ediv){ 3543 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3544 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3545 } else { 3546 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3547 } 3548 break; 3549 default: 3550 sm_conn->sm_bonding_requested = 1; 3551 break; 3552 } 3553 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3554 sm_conn->sm_bonding_requested = 1; 3555 } 3556 } 3557 sm_run(); 3558 } 3559 3560 // called by client app on authorization request 3561 void sm_authorization_decline(hci_con_handle_t con_handle){ 3562 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3563 if (!sm_conn) return; // wrong connection 3564 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3565 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3566 } 3567 3568 void sm_authorization_grant(hci_con_handle_t con_handle){ 3569 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3570 if (!sm_conn) return; // wrong connection 3571 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3572 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3573 } 3574 3575 // GAP Bonding API 3576 3577 void sm_bonding_decline(hci_con_handle_t con_handle){ 3578 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3579 if (!sm_conn) return; // wrong connection 3580 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3581 3582 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3583 switch (setup->sm_stk_generation_method){ 3584 case PK_RESP_INPUT: 3585 case PK_INIT_INPUT: 3586 case OK_BOTH_INPUT: 3587 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3588 break; 3589 case NK_BOTH_INPUT: 3590 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3591 break; 3592 case JUST_WORKS: 3593 case OOB: 3594 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3595 break; 3596 } 3597 } 3598 sm_run(); 3599 } 3600 3601 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3602 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3603 if (!sm_conn) return; // wrong connection 3604 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3605 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3606 if (setup->sm_use_secure_connections){ 3607 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3608 } else { 3609 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3610 } 3611 } 3612 3613 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3614 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3615 sm_sc_prepare_dhkey_check(sm_conn); 3616 } 3617 #endif 3618 3619 sm_run(); 3620 } 3621 3622 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3623 // for now, it's the same 3624 sm_just_works_confirm(con_handle); 3625 } 3626 3627 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3628 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3629 if (!sm_conn) return; // wrong connection 3630 sm_reset_tk(); 3631 big_endian_store_32(setup->sm_tk, 12, passkey); 3632 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3633 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3634 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3635 } 3636 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3637 memcpy(setup->sm_ra, setup->sm_tk, 16); 3638 memcpy(setup->sm_rb, setup->sm_tk, 16); 3639 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3640 sm_sc_start_calculating_local_confirm(sm_conn); 3641 } 3642 #endif 3643 sm_run(); 3644 } 3645 3646 /** 3647 * @brief Identify device in LE Device DB 3648 * @param handle 3649 * @returns index from le_device_db or -1 if not found/identified 3650 */ 3651 int sm_le_device_index(hci_con_handle_t con_handle ){ 3652 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3653 if (!sm_conn) return -1; 3654 return sm_conn->sm_le_db_index; 3655 } 3656 3657 // GAP LE API 3658 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3659 gap_random_address_update_stop(); 3660 gap_random_adress_type = random_address_type; 3661 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3662 gap_random_address_update_start(); 3663 gap_random_address_trigger(); 3664 } 3665 3666 gap_random_address_type_t gap_random_address_get_mode(void){ 3667 return gap_random_adress_type; 3668 } 3669 3670 void gap_random_address_set_update_period(int period_ms){ 3671 gap_random_adress_update_period = period_ms; 3672 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3673 gap_random_address_update_stop(); 3674 gap_random_address_update_start(); 3675 } 3676 3677 void gap_random_address_set(bd_addr_t addr){ 3678 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3679 memcpy(sm_random_address, addr, 6); 3680 rau_state = RAU_SET_ADDRESS; 3681 sm_run(); 3682 } 3683 3684 /* 3685 * @brief Set Advertisement Paramters 3686 * @param adv_int_min 3687 * @param adv_int_max 3688 * @param adv_type 3689 * @param direct_address_type 3690 * @param direct_address 3691 * @param channel_map 3692 * @param filter_policy 3693 * 3694 * @note own_address_type is used from gap_random_address_set_mode 3695 */ 3696 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3697 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3698 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3699 direct_address_typ, direct_address, channel_map, filter_policy); 3700 } 3701 3702