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